Универзитет у Крагујевцу Природнo-математички факултет Анка Пејовић Синтеза нових биолошки активних хетероцикличних једињења која садрже фероцен - Докторска дисертација - Крагујевац, 2015. Идентификациона страница докторске дисертације I. Аутор Име и презиме: Анка Пејовић Датум и место рођења: 21.10.1986. год., Ђаковица Садашње запослење: истраживач-сарадник, Природно-математички факултет, Крагујевац II. Докторска дисертација Наслов: Синтеза нових биолошки активних хетероцикличних једињења која садрже фероцен Број страница – 144, број слика – 42, број схема – 15, број табела -11, број библиографских јединица -273. Установа и место где је рад израђен: Природно-математички факултет, Крагујевац Научна област (УКД):Хемија (54), Органска хемија (547) Ментор: др Растко Д. Вукићевић III. Оцена и одбрана Датум пријаве теме: 11.06.2014. год. Комисија за оцену подобности теме и кандидата: 1. Др Растко Д. Вукићевић, редовни професор (ментор) Природно-математички факултет, Крагујевац Ужа научна област: Органска хемија 2. Dr. Matthias D’hooghe, Professor, co-promoter, (Др Матиас Дохе, професор, ко-ментор), Department of Sustainable Organic Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Belgium Ужа научна област: Органска хемија 3. Др Нико Радуловић, ванредни професор Природно-математички факултет, Ниш Ужа научна област: Органска хемија 4. Др Иван Дамљановић, научни сарадник Природно-математички факултет, Крагујевац Ужа научна област: Хемија Број одлуке и датум прихватања докторске дисертације: Комисија за оцену и одбрану докторске дисертације: 1. Др Растко Д. Вукићевић, редовни професор (ментор) Природно-математички факултет, Крагујевац Ужа научна област: Органска хемија 2. Dr. Matthias D’hooghe, Professor, co-promoter, (Др Матиас Дохе, професор, ко-ментор), Department of Sustainable Organic Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Belgium Ужа научна област: Органска хемија 3. Др Нико Радуловић, ванредни професор Природно-математички факултет, Ниш Ужа научна област: Органска хемија 4. Др Зоран Ратковић, доцент Природно-математички факултет, Крагујевац Ужа научна област: Органска хемија 5. Др Иван Дамљановић, научни сарадник Природно-математички факултет, Крагујевац Ужа научна област: Хемија Датим одбране докторске дисертације: Ова докторска дисертација је рађена у Институту за хемију Природно- математичког факултета Универзитета у Крагујевцу. Део истраживања урађен је на Факултету за биоинжењеринг Универзитета у Генту, Белгија (Faculty of Bioscience Engineering, Gent University, Belgium). Тему за рад предложио је др Растко Д. Вукићевић, редовни професор Природно- математичког факултета у Крагујевцу, који је и руководио његовом израдом, а истраживањима спроведеним у Белгији руководио је ко-ментор, Матијас Дохе, професор Факултета за биоинжењеринг Универзитета у Генту, Белгија (Matthias Dˈhooghe, Faculty of Bioscience Engineering, Gent University, Belgium). За указану несебичну помоћ и подршку коју су ми пружили у свим фазама израде ове дисертације изражавам им велику захвалност. Највећи део биолошких испитивања која су урађена са једињењима синтетисаним током израде овог рада (као и тумачење добијених резултата) спроведен је под руководством др Нико Радуловића, ванредног професора Природно-математичког факултета у Нишу, па му на томе и на помоћи пруженој при писању овог рада срдачно захваљујем. Такође се захваљујем др Зорану Ратковићу, доценту и др Ивану Дамљановићу, научном сараднику Природно-математичког факултета у Крагујевцу за корисне савете и сугестије током писања ове дисертације. Захваљујем се др Горану А. Богдановићу, научном саветнику Института за нуклеарне науке „Винча“ на урађеним кристалографским анализама и тумачењу њихових резултата описаним у овом раду. Посебно се захваљујем колегама из лабораторије - др Мирјани Вукићевић, ванредном професору Факултета медицинских наука у Крагујевцу, др Данијели Илић-Коматини, доценту Факултета техничких наука у Косовској Митровици, Драгани Стевановић, асистенту и мр Александри Минић, истраживач-приправнику Природно-математичког факултета у Крагујевцу, као и др Мартини Јатзак (Martyna Jatczak), Факултет за биоинжењеринг у Генту, на изванредној сарадњи и свесрадној помоћи коју су ми указивали током израде овог рада. Истраживања урађена током израде овог рада део су пројекта бр. ОИ 172034, (руководилац проф. др Растко Д. Вукићевић), који се финансира средствима Министарства просвете, науке и технолошког развоја Републике Србије, на чему се Министарству срдачно захваљујем. Посебну захвалност дугујем својој породици која ми је увек пружала безусловну помоћ и подршку и била мој највећи ослонац. i    Садржај 1 Увод 1 Општи део 2 Фероцен и његови деривати у медицини 5 2.1 Деривати фероцена као цитотоксични/антитуморски агенси 9 2.1.1 Фероцифени, фероцифеноли и фероценофани 9 2.1.2 Деривати фероценилралоксифена 14 2.1.3 Полифенолски деривати фероцена 15 2.1.4 Фероценски деривати андрогена и антиандрогена 17 2.1.5 Фероценијум-соли 19 2.1.6 Конјугати фероцена са неким биолошки активним молекулима 20 2.1.7 Фроценски деривати ДНК-интеркалатора 24 2.1.8 Различити антитуморски деривати фероцена 25 2.2 Деривати фероцена као антималаријски агенси 28 2.3 Деривати фероцена као анти-HIV агенси 32 Наши радови 3 Синтеза биолошки активних хетероцикличних једињења која садрже фероцен 35 3.1 2-Фероценил-1,3-тиазолидин-4-они 35 3.1.1 Синтеза и карактеризација 36 3.1.2 Редокс особине 41 3.2 2-Фероценил-2,3-дихидрохинолин-4-(1H)-они 43 3.2.1 Синтеза и карактеризација 43 3.2.2 Редокс особине 49 3.3 6-Фероценил-1,3-оксазинани, 6-фероценил-1,3-оксазинан-2-они и 4-фероценилтетрахидропиримидин-2(1Н)-они 50 3.3.1 3-(Ариламино)-1-фероценилпропан-1-они 52 3.3.1.1 Синтеза и карактеризација 53 3.3.1.2 Редокс особине 59 3.3.2 Синтеза и карактеризација 3-арил-6-фероценил-1,3-оксазинана 62 3.3.3 Синтеза и карактеризација 3-арил-6-фероценил-1,3-оксазинан-2-она 66 3.3.4 Синтеза и карактеризација 1,3-дисупституисаних 4-фероценилтетрахидро- пиримидин-2(1Н)-она 71 3.4 Преглед резултата тестова биолошке и фармаколошке активности синтетисаних једињења 75 Експериментални део 4 Експериментални део 77 4.1 Опште напомене 77 4.2 Синтеза N-супституисаних 2-фероценил-1,3-тиазолидин-4-она 92а-л 78 4.3 Синтеза 2-фероценил-2,3-дихидрохинолин-4(1H)-она 95а-в 85 ii  4.4 Синтеза 6-фероценил-1,3-оксазинана (102а-к), 6-фероценил-1,3-оксазинан- -2-она (104а-г, ђ-к) и 4-фероценилтетрахидропиримидин-2(1Н)-она (106а, в, г, ђ, е, з, ј, к) 88 4.4.1 Синтеза акрилоилфероцена (97) 88 4.4.2 Синтеза 3-(фениламино)-1-фероценилпропан-1-она 99а-о 88 4.4.3 Синтеза 3-(фениламино)-1-фероценилпропан-1-ола 101а-к 95 4.4.4 Синтеза N-супституисаних 6-фероценил-1,3-оксазинана 102а-к 99 4.4.5 Синтеза N-супституисаних 6-фероценил-1,3-оксазин-2-она 104а-г, ђ-к 104 4.4.5.1 Синтеза етил-арил(3-фероценил-3-хидроксипропил)карбамата (103а-к) 104 4.4.5.2 Циклизација хидроксикарбамата 103а-г, ђ-к до 6-фероценил-1,3-оксазин- -2-она 104а-г, ђ-к 108 4.4.6 Синтеза 1,3-дисупституисаних 4-фероценилтетрахидропиримидин-2(H)-она 106а, в, г, ђ, е, ж, и, ј 113 4.4.6.1 Синтеза етил-арил[3-фероценил-3-(изопропиламино)пропил]- карбамата 105а-к 113 4.4.6.2 Циклизација деривата 1,3-пропандиамина 105а, в, г, ђ, е, з, ј, к до 1,3-дисупституисаних 4-фероценилпиримидин-2(1Н)-она 106а, в, г, ђ, е, з, ј, к 118 Извод 123 Summary 127 Литература 131 Биографија 141 Списак радова 143 Прилог 1 Увод Хетeроциклична једињења (хетероцикли) су најбројнија група органских једињења и имају огроман значај у свим важним видовима човекове делатности. Већинa лекова који се користе у хуманој медицини и ветерини, као и биолошки активних препарата који се користе у агрохемији, или су мали хетероцикли или једињења чија структура обухвата неки хетероцикл.1 Такође, бројни адитиви и модификатори који се користе у производњи козметичких препарата, у индустрији информационих материјала, пластике итд., спадају у ову групу једињења. Иако је општепознато да хетероцикли (са једним до три хетероатома) улазе у састав огромног броја једињења од (индустријског) интереса за електронику, оптику, хемију материјала, биологију, фармакологију итд., производњу лекова треба посебно издвојити. Како је објављено, од десет лекова (званично прописаних за лечење одговарајућих болести) који су у периоду јун 2006. – јун 2007. донели фармацеутској индустрији највећу добит – седам су хетероциклична једињења.1 Због тога није чудно да су хетероцикли дуже од једног века најзаступљенија група једињења у истраживањима у области органске хемије. Нађено је да молекули чије структуре обухватају и неки хетероцикл и фероценил-групу такође често показују биолошку активност,2 па се синтезом ових једињења и проценом њихове биолошке активности данас бави велики број истраживачких група широм света. У Институту за хемију Природно-математичког факултета у Крагујевцу дуже од деценије и по одвијају се интензивна истраживања у области хемије фероцена. Почетна испитивања, која су довела до побољшања најстарије методе за дериватизацију овог металоцена - Фридел- Крафтсовог (Friedel-Crafts) ациловања,3-5 проширена су на синтезу деривата фероцена различите структуре,6-8 од којих неки показују запажену биолошку активност. Нарочиту пажњу привлачи синтеза деривата фероцена који садрже пиразолски прстен,9 пошто је нађено да нека од тих једињења показују антимикробну10, 11 и антитуморску активност.12 Тема ове доктoрске дисертације спада у област хемије хетероцикличних једињења која су истовремено и деривати фероцена. Њена реализација у великој мери ослањаће се на искуства стечена током поменутих истраживања3-12 и представља њихов логичан наставак. Основни циљеви дисертације су синтеза пет група једињења за која се претпоставља да би, слично, одговарајућим нефероценским аналозима, могли да 2      показују извесну биолошку активност, а чија је основа један од следећих деривата фероцена: 1. 2-фероценил-1,3-тиазолидин-4-он, 2. 2-фероценил-2,3-дихидрохинолин-4(1H)-он, 3. 6-фероценил-1,3-оксазинан, 4. 6-фероценил-1,3-оксазинан-2-он и 5. 4-фероценилтетрахидропиримидин-2(1H)-он. На основу детаљне претраге доступне литературе направљен је план по коме би се прва група једињења (2-фероценил-1,3-тиазолидин-4-они) синтетисала из трговачки доступних ацикличних супстрата, поступцима који су описани за добијање одговарајућих деривата који уместо фероценил- садрже неку арил-групу. Међутим, на основу те претраге за остале четири групе једињења није било могуће смислити план синтезе из једноставних, трговачки доступних реагенаса, тј. показало се да је неопходна синтеза одговарајућих прекурсора који би, подесно одабраним реакцијама, дали циљне деривате хетероцикла. Из тога произлазе и нови циљеви: (i) синтеза 1-(2-аминофенил)-3-фероценилпроп-2-ен-1-она као прекурсора 2-фероценил-2,3-дихидрохинолин-4(1H)-она и (ii) синтеза серије 1,3-аминоалкохола чији карбинолни угљеников атом носи фероценил-групу, као прекурсора одговарајућих шесточланих хетероцикла - 1,3-оксазинана, 1,3-оксазинан-2-она и тетрахидропиримидинона. И овде се испоставило да је само прву групу једињења могуће добити из трговачки доступних супстрата, а да је синтеза друге групе вишестепена, јер се ти алкохоли могу добити из одговарајућих Манихових (Manich) база које, са своје стране, нису описане у литератури. То је пред нас поставило додатни задатак - испитивање услова за синтезу Манихових база које садрже фероцен. Реализација синтетичких циљева ове дисертације подразумева потврду структура свих познатих и утврђивање структуре свих нових једињења синтетисаних током истраживања, помоћу физичких и спектроскопских података (IR, 1H и 13C NMR, GС-MЅ), а кад је то могуће и рендгеноструктурном анализом. Пошто је фероценско језгро елeктрофора – биће описане електрохемијске особине (цикловолтаметријом) готовo свих група једињења. Коначно, на основу упоређивања структуре једињења чија је синтеза предвиђена овим истраживањима и одговарајућих нефероценских деривата о чијој биолошкој 3      активности постоји обиље литературних података, одлучено је да се сва синтетисана једињења пошаљу одговарајућим лабораторијама да би се обавили следећи биолошки тестови: 1. испитивање анксиолитичких особинa N-супституисаних 2-фероценил-1,3- тиазолидин-4-она и 2. испитивање антимикробне активности (i) 2-фероценил-2,3-дихидрохинолин- 4(1H)-она, (ii) Манихових база које садрже фероцен, (iii) 6-фероценил-1,3- оксазинана, (iv) 6-фероценил-1,3-оксазинан-2-она, (v) и 4-фероценилтетр- ахидропиримидин-2(1H)-она 3. испитивање антиканцерогене активности (i) 6-фероценил-1,3-оксазинана (ii) 6-фероценил-1,3-оксазинан-2-она и (iii) 4-фероценилтетрахидропирими- дин-2(1H)-она. Резултати тих испитивања, међутим, неће бити изложени у овом раду, већ ће о томе на крају поглавља „Наши радови“ бити дат само кратак коментар. Ипак, пошто се ради о синтези једињења за која се претпоставља да ће показивати неку биолошку активност, чинило се прикладним да у Општем делу буде изложен преглед резултата испитивања биолошке активности фероцена и његових деривата, описаних до данас у литератури. Како је о томе објављен огроман број радова (чији приказ би далеко надишао обим овог рада), биће приказана само најважнијa испитивања антиканцерогене, антималаријске и анти-ХИВ активности ове класе једињења.         Општи део 2 Фероцен и његови деривати у медицини Фероцен је органометално једињење молекулске формуле Fe(C5H5)2, које су, независно једна од друге, први пут 1951. године синтетисале две групе истраживача.13, 14 За мање од годину дана након тога структура фероцена (Слика 2.1) скоро потпуно је објашњена,15, 16 а ово откриће представља почетак модерне органометалне хемије: уводе се термини “сендвич једињење” и “металоцени”, који се користе и данас, не само за фероцен и његове деривате, као што је то био случај на почетку, већ за много шири опсег једињења, који укључују и друге метале.   Слика 2.1. Структура фероцена Рендгенструктурном анализом утврђено је да се фероцен у кристалном стању налази у “антипризматичној“ конформацији,17 али се код његових деривата запажа делимично одступање од ове конформације, пре свега код оних чији су прстенови повезани „премошћивањем“. У гасовитом стању постоји равнотежа између призматичне (еклипсне) и антипризматичне (степеничасте) конформације, које раздваја енергетска баријера од око 3,77 kJ/mol (Схема 2.1).18   Схема 2.1. Конформације фероцена: а) антипризматична (степеничаста) и б) призматична (еклипсна) Систематско име бис(η5-циклопентадиенил)гвожђе све мање се користи, пошто је према усвојеној номенклатури дозвољено тривијално име фероцен19 (уобичајене скраћенице: FeCp2, FcH), као и назив фероценил (Fc) за остатак C5H5FeC5H4- и 1,1'-фероценил (fc) за остатак Fe(C5H4-)2. Два прстена нумеришу се у смеру кретања казаљке на сату бројевима 1-5 (за супституисани, или више супституисани прстен), односно 1'-5' (за несупституисани, односно мање супституисани прстен). 6  Физичке особине фероцена указују на типично ковалентно, неполарно једињење, нерастворно у води а растворно у алкохолу, етру, бензену и већини других органских растварача. Три чињенице описују готово све хемијске особине фероцена: (i) лака оксидација до фероценијум-јона, са оксидационим потенцијалом од -0,225 до -0,367 V (зависно од растварача; Схема 2.2),20 (ii) ароматични карактер који се огледа у високој реактивности у реакцијама електрофилне супституције19 (у Фридел-Крафтсовом (Friedel-Crafts) ациловању и меркуровању реагује 106 односно 109 пута брже од бензена21) и (iii) могућност директне металације. Нарочито су важне ове две последње особине, на којима је заснована синтеза великог броја лакше или теже доступних деривата фероцена. Схема 2.2. Оксидација фероцена Оно што фероцен, односно његове деривате, чини веома корисним у органској синтези јесте неочекивано велика стабилност за једно органометално једињење, тако да се могу вршити најразноврсније промене, како у бочном низу тако и на самом фероценском језгру, а да се при том његова основна структура не поремети. Главне методе за синтезу самог фероцена темеље се на реакцији феро-соли (Fe(II)-соли) са циклопентадиенил-анјоном. Најбоља лабораторијска метода за добијање овог металоцена јесте реакција феро-хлорида (FeCl2) са калијум-хидроксидом и циклопентадиеном у смеши диметилсулфоксида и 1,2-диметоксиетана.22 Реакција циклопентадиенил-натријума (добијеног из циклопентадиена и натријума у ксилену) са фери-хлоридом (FeCl3) и гвожђем у тетрахидрофурану23 такође је подесна (могу се достићи приноси и до 90%23). У литератури су описани и следећи поступци: (i) директна реакција циклопентадиена и гвожђа на 300 ºC,14 (ii) реакција циклопентадиенил-магнезијум- бромида са фери-хлоридом у смеси бензена и етра (прва синтеза фероцена)13 и (iii) реакција циклопентадиена са гвожђе-пентакарбонилом.24 Међутим, фероцен је данас трговачки доступно, релативно јефтино једињење, углавном захваљујући 7  чињеници да је нађена ефикасна електрохемијска метода за његову континуирану синтезу,25 која се изводи на два начина. Први поступак представља директну електролизу циклопентадиена у раствору натријум-бромида у диметилформамиду, коришћењем аноде од гвожђа (Схема 2.3):   Схема 2.3. Електрохемијско добијање фероцена Међутим, због неких споредних реакција, као што су делимична димеризација циклопентадиена, његова редукција до циклопентена водоником издвојеним на катоди (која је катализована присутним фероценом и другим врстама гвожђа), Диелс- Алдерова (Diels-Alder) реакција овог једињења на циклопентадиен итд., дисконтинуа- лна синтеза (тј., синтеза у два ступња) много је ефикаснија (Схема 2.4): Схема 2.4. Дисконтинуална синтеза фероцена Захваљујући изванредним физичко-хемијским особинама, фероцен је врло брзо након открића привукао пажњу научне јавности, па је ова област хемије почела нагло да се развија.16, 26 Тако је, захваљујући релативно лакој дериватизацији и специфичним редокс својствима, овај металоцен нашао широку примену у области материјала,27, 28 и молекулског инжењеринга,29 молекулских феромагнетика,30 модификованих електрода за редокс-катализоване реакције,31 полимера32 и дендритских електрохемијских сензора за препознавање молекула.33 С друге стране, стабилност на ваздуху и у воденој средини, као и повољне електрохемијске особине фероцена и његових деривата, допринели су великој популарности ових једињења у биолошким истраживањима.34-40 Како се показало да су неки деривати овог једињења веома активни (у in vivo и in vitro условима) против неколико врста болести, као што су гљивичне и бактеријске инфекције,41, 42 маларија,39, 43-45 вирус хумане имунодефицијенције (HIV),46 као и рак34-40 - не чуди чињеница да се данас веома активно истражује употреба деривата овог металоцена у медицини. 8  Из године у годину бележи се пораст броја људи оболелих од различитих врста рака, па с тога истраживачи из више научних области неуморно раде на проналажењу нових класа једињења која би, за разлику од постојећих, имала што шири спектар деловања уз што мање нежељених ефеката. Антитуморска својства фероцена и његових деривата први пут су испитивана крајем седамдесетих, када је Брајнс (Brynes) са сарадницима објавио чланак о цитотоксичној активности деривата фероцена (који у свом саставу садрже амино- или амидо-групе) у случају ћелијске линије лимфоцитне леукемије P-388.47 Иако се испоставило да је антитуморска активност ових једињења ниска, значај ових истраживања је у томе што су показала да увођење фероценил-групе у неки молекул може да побољша ту активност (Слика 2.2).47 Слика 2.2. Деривати фероцена тестирани против лимфоцитне леукемије P-38847 Захваљујући тим истраживањима нагло је порасло интересовање за ова једињења, што је довело до синтезе великог броја нових деривата фероцена и процене њихове антитуморске активности. Маларија је болест од које се сваке године зарази од 300 до 350 милиона људи, а чак 1,3 милиона умре. Неколико врста крвних паразита рода Plasmodium изазива ову болест, а неке од њих су постале резистентне на конвенционалну терапију чинећи ову болест још озбиљнијом. Данас велики број истраживача интензивно ради на синтези деривата фероцена за које се претпоставља да би могли бити ефикасни у борби против ове болести. Вирус хумане имунодефицијенције, или скраћено HIV, спада у групу ретровируса који изазива синдром стечене имунодефицијенције, познат као AIDS или сида. Данас у свету од ове болести болује око 40 милиона људи, а вакцина још није пронађена. И у овој области врше се интензивна истраживања активности деривата фероцена; нађено је да на неке од њих треба озбиљно гледати као на тзв. „водећа једињења“ („lead compoundѕ“, тј. једињења чија се структура, због одређене 9  фармаколошке или биолошке активности, може узети као основа за синтетичке модификације којима би се добили молекули са побољшаним поменутим особинама). У овом раду биће дат кратак преглед најважнијих истраживања која су спроведена у области примене деривата фероцена у лечењу рака, маларије и HIV-а. 2.1 Деривати фероцена као цитотоксични/антитуморски агенси Рак представља групу болести која укључује абнормални раст ћелија са потенцијалном могућношћу да нападне или се прошири на остале делове тела. За лечења рака користи се хемотерапија, која се заснива на употреби (антитуморских, тј. цитотоксичних) лекова, којима се систематски лече и контролишу злоћудни тумори. Међутим, иако је до данас синтетисан велики број цитотоксика и цитостатика, њихова ефикасност је све мања, односно отпорност туморских ћелија на њихово деловање је све већа. Осим смањене активности, присутан је велики број нежељених ефеката (цитотоксици нису токсични (селективни) само према трансформисаним ћелијама већ и према здравим) које узрокују ова једињења. У циљу превазилажења ових недостатака, синтетисан је велики број деривата фероцена, од којих су се неки показали као добри цитотоксични/антитуморски агенси док су други тренутно на клиничким испитивањима.48 2.1.1 Фероцифени, фероцифеноли и фероценофани Међу једињењима која садрже фероценско језгро, за фероцифен је најдетаљније проучавано његово антитуморско дејство. Ова обимна истраживања дала су резултате који веома обећавају у погледу третмана рака дојке.39, 40 У принципу, тумори дојке могу се поделити у четири групе: (а) Имунохистохемијски позитивни на рецепторе за ендокрине (естроген или прогестерон; ЕR(+)); (б) Имунохистохемијски позитивни на протеин HER2 (human epidermal growth factor receptor 2); (в) Троструко негативна експресија, тј. естроген, прогестерон и HER2 негативани; (г) Тростуко позитивна експресија, тј. естроген, прогестерон и HER2 позитивни. Тумори који су ЕR (+) пролиферишу као одговор на дејство естрогена. Око две трећине свих случајева припада овој групи тумора, а која је осетљива на хормонску 10  терапију селективним модулаторима естрогенског рецептора (SERM). Постоје две подврсте рецептора ЕR(+) – ћелијских линија - код ових врста ћелија тумора јављају се две подврсте рецептора - ЕRα и ЕRβ.49 Примарни лекови који се употребљавају у третирању рака дојке су тамоксифен50 7 и хидрокситамоксифен 8 (Слика 2.3).   Слика 2.3. Примарни лекови у третману рака дојке и њихови фероценски аналози Тамоксифен се понаша у in vivo условима као цитотоксични агенс који организам нарочито добро подноси. Постоје два дијастереомера, Z и E конфигурације, од којих је Z изомер знатно јачи антиестрогени агенс. Антипролиферативно деловање тамоксифена произлази из конкурентског везивања (он је компетитивни антагонист) за рецептор ЕRα, чиме се у туморском ткиву спречава транскрипција ДНК посредством естрадиола.51 Осим позитивних, тамоксифен испољава и неке нежељене ефекте: током дуге терапије може да се развије отпорност на овај лек, повећава ризик од згрушавања крви у плућима, а неефикасан је против хормон-независних тумора.52 Жауен (Jaouen) и сарадници синтетисали су хидроксифероцифене 9 (разликују се по дужини диметиламино-ланца, n = 2-5, 8) -деривате фероцена чија је структура заснована на структури тамоксифена 7 и хидрокситамоксифена 8.53-55 Антипролиферативна активност хидроксифероцифена испитивана је на хормон- зависним MCF-7 ћелијама рака дојке (које се одликују повишеном експресијом ЕRα естрогенског рецептора) и на MDA-MB-231 ћелијама које се сврставају у хормон- независне ћелија рака дојке (пошто их карактерише одсуство ЕRα естрогенског рецептора). Нађено је да је ефекат деловања хидроксифероцифена 9 на MCF-7 ћелије упоредив са ефектом који показује хидрокситамоксифен 8; ефекат његовог деловања је незнатно већи при концентрацији од 0,1 μМ, док је значајно супериорнији при 11  концентрацији од 1 μМ. Док је хидрокситамоксифен потпуно неактиван према хормон- независним ћелијама – хидроксифероцифен испољава јак антипролиферативни ефекат према њима уз изузетно ниску вредност IC50 (концентрација потребна да се постигне 50% инхибиције раста ћелија). Неколико SAR студија (од енгл. structure–activity relationship) указује на повезаност активности хидроксифероцифена и (а) стереохемије једињења, (б) ефекта N,N-диметиламино-ланца, (в) присуства и положаја фенил-групе, (г) улоге и положаја фероценил-групе, (д) конјугације система, и (ђ) „функционализације“ фенил-група.40, 56 (а) Иако је антипролиферативна активност (Z)-хидрокситамоксифена већа од активности његовог (Е)-диастереоизомера, при тестирању активности појединачних изомера фероцифена на канцерогене ћелије није било могуће направити разлику у активности ових молекула због брзе изомеризације хидроксифероцифена у протичним растварачима.56 (б) Са повећањем дужине (ω-N,N-диметиламино)алкил-ланца опада афинитет везивања хидроксифероцифена за естрогенски рецептор. Даља испитивања показала су да дужина ланца има јак утицај и на антиестрогена својства, док је његов утицај на цитотоксичност контроверзан.40, 57 (в) Серија пара- и мета-супституисаних моно- и дихидроксилних фенола, који носе једну или две фероценил-групе употребљена је да се испита утицај положаја хидроксилних група на цитотоксичност према ћелијама рака дојке.58-60 Испоставило се да фероцифени који садрже само једно фероценско језгро и две хидроксилне групе у два пара положаја показују високу токсичност према овим ћелијама.40, 58-60 (г) Активност хидроксифероцифена упоређена је са активношћу деривата код којих је фероценско језгро замењено комплексима титана, ренијума или рутенијума, а показало се да фероцифени показују најбољу цитотоксичну активност од свих аналога тамоксифена чија структура је на неки начин модификована металима.61, 62 (д) Како би се одредило да ли и на који начин конјуговани -електронски систем ових молекула, који повезује фероценил- и фенил-групе, утиче на антитуморску активност, синтетисана је серија једињења која садрже sp3 угљеников атом уместо винил-групе. Показало се да је активност једињења која поседују π-систем значајно већа од активности неконјугованих аналога.63 (ђ) Утицај супституената фенил-група различитих од ОН процењен је испитивањем аналога фероцифена који садрже Cl, Br, CF3, CN, NH2, NHCOMe, 12  OCOMe, OMe, SCOMe и SMe (Слика 2.4).60, 64, 65 Док су фероцифени који садрже Cl (10), Br (11), CF3 (12), OMe (13), SCOMe (14) и SMe (15) супституенте неактивни, једињења са CN (16), NH2 (17), NHCOMe (18) и OCOMe супституентима (19) показала су значајну антипролиферативну активност при концентрацији од 10 μМ (Слика 2.4).   Слика 2.4. Структуре неких деривата фероцифена 13  Занимљиво је да једињења која садрже две ацетокси-групе показују слично понашање као дифенолски фероцифени, што указује на то да се ензимска хидролиза догађа унутар ћелија. Отуда се једињење 19 може сматрати „пролеком“.40 Крути молекули се, уколико имају одговарајућу геометрију за везивање за активно место, обично јаче вежу за естрогенске рецепторе од њихових флексибилних аналога, пошто флексибилни молекули морају прво да успоставе ту геометрију, узрокујући нижу ентропију и слабије везивање.40 Тако су Жауен и сарадници синтетисали низ једињења која садрже циклично [3]фероценофанско језгро и упоредили њихову антитуморску активност са активношћу нецикличних аналога (Слика 2.5).66-68 [3]Фероценофанил-деривати су код свих једињења са супституентима на фенил-групама у пара-положају показали већу цитотоксичност од одговарајућих фероценил-деривата, а једињења са протичним супституентима (Слика 2.5) показала највишу активност.66, 68   Слика 2.5. Формуле деривата фероценофана 20 и 21, структурно сличних тамоксифену.66, 68 Нађено је, такође, да положај двоструке везе у односу на фероценил-групу може значајно да утиче на активност ових молекула. На пример, упоређивањем активности једињења 20, код кога је један Cp прстен фероценског језгра везан директно за угљеник двогубе везе, са активношћу једињења 21, код кога су фероценил-група и двострука веза повезане преко метиленског моста, утврђено је да је цитотоксичност конјугованог једињења 20 већа за један ред величине. Једињење 21 показало је и изузетан антипролиферативни ефекат на хормон-независне MDA-MB-231 и PC-3 ћелијске линије са IC50 = 0,09 μМ.66, 68 Описана истраживања показала су да се везивањем фероценил-групе за скелет тамоксифена и хидрокситамоксифена добијају деривати ових једињења који имају одређене предности, као што су повећана цитотоксичност56 и активност и према 14  хормон-зависним и хормон-независним ћелијама рака дојке.69 Сматра се да је за антитуморску активност ове групе једињења одговорна реакција насталог фероценијум-јона in vivo уз грађење активних кисеоничних радикала (као што су хидроксилни), који изазивају оштећење ћелија рака.70, 71 2.1.2 Деривати фероценилралоксифена Подстакнути добрим резултатима добијеним са фероценил-аналозима тамоксифена, Маркес (Marques) и сарадници испитали су могућност увођења фероценил-групе и код ралоксифена (једињење 22, Слика 2.6), још једног селективног модулатора естрогенског рецептора (SERM).72 Синтетисана је група једињења сродних ралоксифену који садрже једну фероценил-групу и одређена њихова цитотоксична активност према неколико линија туморских ћелија. Сва тестирана једињења показала су значајну цитотоксичну активност према ћелијским линијама рака јајника, грлића материце, плућа, дебелог црева и дојке. Треба издвојити [3-фероценил-6- метоксибензо[b]тиофен-2-ил][4-пиперазин-1-ил)метилфенил]метанон (23, Слика 2.6), HO S OH O N O S OCH3 O N N H 22 23 Fe   Слика 2.6. Структура ралоксифена (22) и његовог фероценил-аналога 23 чије су IC50 вредности веома ниске, чак за више од једног реда ниже од оних за цисплатину. Утврђено је и да једињење 23 активира каспазу-3 у ћелијама јајника, односно да је узрок смрти ћелија тумора највероватније апоптоза, а не некроза.72 На основу резултата добијених из ове студије лако се закључује да би даљи рад у овој области 15  могао бити веома успешан, пошто су нека од синтетисаних једињења показала и антиестрогене и цитотоксичне особине. С обзиром на то да је велики број синтетисаних деривата фероцена показао значајну активност, претпоставило се да би и везивање саме фероценске јединице за језгро неког од ендокриних метаболита, путем измењене интеракције са рецепторима и таквих модификованих биолиганда, могло да доведе до цитотоксичног ефекта.40 Да би се испитала ова хипотеза, фероценил-група је везана за скелет естрадиола, а потом је испитана активност добијеног једињења. Испоставило се да су синтетисана једињења показала нижу антитуморску активност од деривата фероцифена и ралоксифена.69, 73 Ови резултати указују на то да антитуморска активност фероценил-SERM једињења није последица самог присуства фероценил-групе у унутрашњости ћелије.74, 75 2.1.3 Полифенолски деривати фероцена Полифенолска једињења, као што су стилбени, флавоноиди, проантоцијанидини и њихови деривати спадају у групу једињења биљног порекла која су највише изучавана због њиховог антиоксидативног потенцијала.76-78 Жауен и сарадници синтетисали су неколико деривата полифенолских једињења која у својој структури садрже фероценил-групу, а потом су испитали њихову цитотоксичност користећи стандардне ћелијске линије рака дојке.79, 80 Резултати су показали да дифенолско једињење 1,1-бис(4’-хидроксифенил-)-2-фероценил-1-бутен (24) показује добро антипролиферативно дејство и на хормон-зависне (MCF7) и хормон-независне (MDA- MB231) ћелије рака дојке (Слика 2.7). Изненађујуће, 1,2-бис(4'-хидроксифенил-)-2- фероценил-1-бутен (25) (Слика 2.7), региоизомер једињења 24, показује слабије дејство на ове ћелијске линије.   Слика 2.7. Структуре фероценил-деривата дифенолних једињења (24, 25) 16  Једињење 24 показује чак јаче антипролиферативно дејство од 4-хидроситамоксифена. Снажна антипролиферативна активност једињења 24 последица је присуства фероценил-групе, а њен положај у томе игра важну улогу. Треба напоменути и да се повећање активности једињења 24 не може приписати само већем афинитету према рецептору, пошто је, у ствари, релативни афинитет везивања (relative binding affinity, RBA) једињења 24 за ЕRα виши од оног који има 25. Постоје две суштинске разлике у структури ових једињења: (i) у једињењу 24 једна од две фенолске групе оријентисана је увек trans у односу на фероценил-групу, што није случај са једињењем 25; (ii) у једињењу 24 две фенолске групе деле исти угљеников атом, док је у региоизомеру 25 свака фенил-група везана је за различит олефински угљеников атом. Жауен је са сарадницима синтетисао и серију једноставних неконјугованих дифенолских деривата фероцена (орто, пара; мета, пара; пара, пара- 26, 27 и 28, Слика 2.8). Ова једињења имају афинитет за оба типа естрогенских рецептора сличан претходно поменутим дериватима. Она показују значајну цитотоксичност у in vitro условима према хормон-независним ћелијским линијама рака простате (PC3) и дојке (MDA-MB231). Ова активност је израженија са PC3, а по активности издваја се орто, пара дифенолски дериват. Електрохемијска мерења показала су да је цитотоксичност ових једињења у корелацији са лакоћом оксидације фероценил-групе. Ова једињења су знатно мање цитотоксична од фероценских дифенолских деривата бутена. Слика 2.8. Структуре неконјугованих дифенил-деривата фероцена (26, 27, 28) Жауен и сарадници подвргли су фероцен реакцији са метокси-супституисаним бензил- и бензхидрил-алкохолом у присуству трифлуорсирћетне киселине, што је дало метоксибензил- или бензхидрил-фероцене, који су деметиловањем наградили фероценилфеноле, односно бисфеноле.81 Резултати су показали да деривати бисфенол- фероцена 29 (Слика 2.9) испољавају висок афинитет за оба типа естрогенских рецептора (ЕRα и ЕRβ). 17    Слика 2.9. Структура бисфенол-деривата фероцена 2.1.4 Фероценски деривати андрогена и антиандрогена Тестостерон (30) и његов активни метаболит дихидротестостерон (31) (Слика 2.10) могу да изазову малигни раст простате. Отуда се лечење рака простате заснива на употреби антиандрогена, молекула који блокирају хормонално дејство андрогена тако   Слика 2.10. Структуре тестостерона (30) и дихидротестостерона (31) што се везују за рецептор уместо тестостерона. Укључивање фероцена у структуру антиандрогена могло би да доведе до повећања антитуморске активности ових молекула. Слика 2.11. Фероценил-деривати тестостерона (32) и дихидротестостерона (33) 18  Овим проблемом бавиле су се две групе истраживача. Прво је Жауен са сарадницима увео фероценил-групу у C-17 положај стероидног скелета тестостерона и дихидротестостерона са етинил-супституентом (Слика 2.11). Андрогена активност синтетисаних једињења била је прилично ниска, највероватније зато што рецептор не толерише супституент у положају 17. Међутим, молекули 32 и 33 (Слика 2.11) су показали јаку антипролиферативну активност према хормон-независним PC-3 ћелијама рака простате.82 Маносрои (Manosroi) је са сарадницима спровео сличну студију, у којој је синтетисао дериват тестостерона 34 (Слика 2.12), увођењем фероценил-групе у положај C-2 овог хормона. Иако рецепторска активност овог једињења још увек није испитана, оно је показало високу цитотоксичност (у поређењу са доксорубицином) према HeLa ћелијама.83 Слика 2.12. Фероценил-дериват тестостерона (34) Нулитамид (35, Слика 2.13) је нестероидни антиандрогени терапеутски агенс, који се даје пацијентима који болују од рака простате. У покушају да се повећа терапеутска ефикасност овог једињења, синтетисана је серија деривата фероценил- нулитамида.84   Слика 2.13. Структуре нулитамида (35) и фероценил-аналога овог једињења (36) Очекивало се да ће антитуморска активност ових једињења проистећи из њиховог антиандрогеног ефекта, али су она показала необичан ефекат. Једињење 36 показало је 19  значајну цитотоксичну активност према PC-3 хормон-независним ћелијама рака простате (IC50 вредност 5,4 mM), што је директно показало да се његова активност не одвија преко антиандрогенског рецептора. Неочекивано понашање фероценских деривата тестостерона, дихидротестостерона и нулитамида – ниска андрогена активност, а висока цитотоксичност према хормон-независним ћелијама рака простате - још увек није јасно објашњено, али делимичан разлог је можда то што фероценил-група некако спречава везивање ових једињења за одговарајуће рецепторе. 2.1.5 Фероценијум-соли Синтеза деривата фероцена који показују антитуморску активност, а који су растворни у води значајно је привукла пажњу медицинских хемичара.85-87 Неки резултати указују на то да су ова једињења ефикасни антитуморски агенси, у неким случајевима ефикаснији од деривата нерастворних у води.88 Пионири у овој области су Копф-Мајер (Kӧpf-Maier) и сарадници, који су открили антитуморску активност фероценијум-соли.89 У оквиру тих истраживања тестирана је активност фероцена и неких фероценијум-соли на мишевима оболелих од Ehrlich ascites тумора (ЕАТ). Због слабе растворљивости фероцена у води он је животињама убризган као раствор у пропилен-гликолу и примећено је да нема антитуморску активност према ЕАТ. С друге стране, фероценијум-соли су растворне у води, па су животињама убризгане у физиолошком раствору. Ефекат третирања фероценијум-тетрахлорфератима, као што је [Cp2Fe]+[FeCl4]- (37а), био је преживљавање и до 83% животиња, а продужење животног века од 380% у поређењу са негативним (нетретираним тест супстанцама) контролама (Слика 2.14).89   Слика 2.14. Структуре фероценијум-тетрахлорферата 37а и фероценијум-тријодида 37б Попова и сарадници су радили на тестирању активности синтетисаних једињења 37а и 37б према вирусу Rauscher леукемије. Њихови резултати су показали да је фероценијум-тријодид (37б) ефикасан против ове болести, а да [Cp2Fe]+[FeCl4]- (37а) 20  није показао такву активност (Слика 2.14).90 Ово указује на јаку зависност антитуморске активности фероценијум-соли од врсте анјона и рака. Претпоставља се да би фероценска једињења могла да се оксидују у ћелијама преко нормалних метаболичких процеса и да, онда, фероценијум- и неутрални фероценски деривати заједно испољавају антипролиферативну активност.91, 92 Механизам деловања фероценијум-соли могао би да обухвата и генерисање радикала Фентоновим (Fenton) путем што узрокује оштећење ДНК и апоптозу ћелија.71, 93, 94 2.1.6 Конјугати фероцена са неким биолошки активним молекулима Сњегур (Snegur) и сарадници синтетисали су серију деривата триазола који садрже језгро овог металоцена (Слика 2.15) и испитали њихов утицај на раст ћелија тумора и токсичност у in vivo условима.95-97 Испоставило се да животиње добро подносе третман овим једињењима, а која показују нижу токсичност у односу клинички употребљаване лекове. На третираним мишевима није запажена било каква видљива промена, као ни промена на унутрашњим органима.95, 96   Слика 2.15. Два примера из серије фероценилалкилтриазола који су активни према солидним туморима (који не садрже цисте или течне делове) Најбоље резултате показало је једињење 38 против солидних тумора, показујући инхибицију раста тумора и од 100%. Успешно деловање једињења 38 објашњава се следећим чињеницама:95  хидрофилна бензотриазолил-група обезбеђује транспорт у воденој средини, а липофилна фероценил-група омогућава пропустљивост мембране;  фероценил-група је способна да формира јонске везе (након оксидације до фероценијум-јона), док триазолил-група при цепању ДНК може да формира водоничне везе са фосфатним групама;  планарни хетероциклични прстен и гломазна фероценил-група могу да се уметну између равни хетероцикличних азотних база ДНК (интеркалирају); 21  Табела 2.1. Синтеза конјугата фероцена и полиаспартамида Ознака носача R1 R2 Једињење 40-C 40 41-C 41 42-C 42 43-C 43 44-C 44 45-C Директно везивање 45 46-C 46 47-C 47 48-C 48 Нојзе (Neuse) и сарадници98-105 су синтетисали конјугате фероцена са полиаспартамидом користећи различите „линкере“ да повежу хидрофилни (полиаспартамид) и липофилни фрагмент (фероцен) (40-48, Табела 2.1) и испитали њихову цитоксичност према ћелијама рака дебелог црева. Као линкери коришћени су алифатични амидни и естарски фрагменти, подложни хидролизи под физиолошким условима. Ова једињења добијају се реакцијом 4-фероценилбутерне киселине са бочном амидном,98 односно хидроксилном групом полиаспартамида.99 Такође је синтетисано и једињење 49 (Схема 2.5), полазећи од полиамида 49-C. Испитивањем физичких особина ових једињења показало се да су она добро растворна у води, а сматра се да су за то одговорне присутне функционалне групе (терцијарне 22  амино групе у бочном ланцу код једињења 40-45, бочне хидроксилне групе код једињења 46-48 и олиго-сегменти - етилен-оксидни фрагменти унутар ланца код једињења 49).   Схема 2.5. Синтеза конјугата фероцена 49 Процењена је антипролиферативна активност синтетисаних конјугата 40-49 на ћелијској линији Colo и ради поређења на HeLa линији. Утврђено је да већина конјугата инхибира раст обе врсте ћелија, при чему су се конјугати 40-45 и 49 показали активнијим. Недавно је синтетисана серија једињења – деривата фероцена чија структура обухвата три кључне компоненте: (а) фероценил-групу, (б) конјуговани део који се оксидује на нижем потенцијалу од фероценил-групе, и (в) дериват пептида који може да интерагује са биомолекулима преко секундарних интеракција, као што су водоничне везе.106-109 Сви добијени фероценил-пептиди тестирани су у in vitro условима против ћелијске линије H1299 (хумане ћелије рака плућа). Већина од њих показала је значајну   Слика 2.16. Структура фероценил-пептида 50 23  активност, тј. за њих су одређене ниске IC50 вредности. Посебно, етил-естар 6- фероценил-2-нафтамидобутерне киселине (50, Слика 2.16) показао већу активност у in vitro условима (ниска вредност IC50) од цисплатине.106-109 Потенцијалне антитуморске особине деривата нуклеозида и самих нуклеинских база које садрже фероценско језгро биле су предмет изучавања неколико истраживачких група.110, 111 Тако су Сименел (Simenel) и сарадници синтетисали серију фероценил-деривата тимина, аденина, цитозина и јодцитозина.110 Из овог низа издваја се 1-N-фероценилметилтимин (51, Слика 2.17), чија је антитуморска активност према неким врстама тумора код животиња (као што су карцином Ca755, меланом B16 и Lewis-ов карцином плућа) проучавана у in vivo условима. На пример, значајна је његова антитуморска активност према карциному Ca755 (70% инхибиције раста ћелија у поређењу са контролном).   Слика 2.17. Структура фероценил-деривата тимина 51 Примећен је, такође, синергетски ефекат једињења 51 и добро познатог антитуморског лека циклофосфамида на антитуморску активност према карциному Ca755.110 Илудин М (52, Слика 2.18) је цитотоксин који припада групи сесквитерпена пронађених у неким гљивама.112 Мада су илудини јако активни према разним врстама тумора, екстремна токсичност спречава њихову клиничку примену.112 Неки семисинтетски деривати илудина са смањеном токсичношћу тренутно су у фази II клиничких испитивања према неким врстама рака, укључујући рак простате, јајника, панкреаса, бубрега, дојке и плућа.113, 114 У тежњи да повећају терапеутски индекс илуидина М (као и специфичност према одређеним ћелијским линијама), Шоберт (Schobert) и сарадници синтетисали су његове естре са фероцен-1,1'-дикарбоксилном и фероценкарбоксилном киселином.115 Показало се да је токсичност за немалигне фибробласте бис(илуидинил-М)-фероцен-1,1'-дикарбоксилат (53, Слика 2.18) далеко мања, а селективност према туморима и специфичност према трансформисаним ћелијским линијама знатно већа него у случају илудина М. Ово побољшање 24  делимично потиче од заштите енонског система илудина М од напада глутатиона, коју обезбеђује фероценско језгро.115   Слика 2.18. Структура илудина М (52) и фероценил-деривата овог једињења 53 Ретиноиди обухватају активне метаболите витамина А (ретинол) и играју важну улогу у расту и развоју кичмењака, помажући диференцијацију ћелија, развој ембриона, одговор имуног система и репродукцију.116 Неке trans-ретинске киселине тренутно се користе у лечењу дерматолошких поремећаја и као хемотерапеутски агенси против различитих тумора. Њихово деловање заснива се на везивању и активацији рецептора ретинске киселине (RARs) или Х рецептора ретиноида (RXRs).117 У настојању да се побољша антитуморска активност ове групе једињења, припремљени су неки деривати фероцена (једињење 54, Слика 2.19), а њихова антипролиферативна активност изучена је на ћелијским линијама А549 (хумане ћелија рака плућа), BEL7404 (рака јетре) и Tca (рака језика).74 Мада су резултати показали да је антипролиферативна активност фероценил-аналога већа од активности саме 13-cis- ретинске киселине, нађене IC50 вредности су, ипак, скромне (19-40 μМ).74 Слика 2.19. Структура фероценил-деривата ретиноида 54 2.1.7 Фероценски деривати ДНК-интеркалатора Везивање фероценил-групе за ДНК-интеркалаторе представља начин да се ова група приближи ДНК и тако дође у положај подесан да је оштети или да убије ћелију. Онг (Ong) и сарадници синтетисали су једињење 55 (Слика 2.20) везивањем фероцена за молекул акридина (ДНК-интеркалатор), и поредили његову антитуморску активност 25  са активношћу аналога фероцена који не садрже акридинил-групу (једињење 56, Слика 2.20).75 Тестови у in vitro условима показали су да фероценски дериват акридина 55 испољава високу токсичност према четири ћелијске линије канцера, док је једињење 56 неактивно. Главни разлог те неактивности јесте немогућност фенил-деривата 56 да се вежу за ДНК.   Слика 2.20. Структуре фероценил-једињења везаних за акридин (55) и бензил-групу (56) 2.1.8 Различити антитуморски деривати фероцена Топоизомеразе (тип I и II) су ензими који омогућавају расплитање и поновно уплитање ДНК, како би се олакшала њихова репликација и омогућила контрола синтезе протеина. У нормалним ћелијама активност топоизомеразе II је строго контролисана, док је њен ниво при брзој деоби трансформисаних ћелија веома висок.118 Ова разлика у количини/активности топоизомеразе између здравих и трансформисаних ћелија чини ове ензиме потенцијалним метама антитуморских агенаса. Кондапи (Kondapi) и сарадници синтетисали су серију деривата фероцена и испитали њихове инхибиторске особине према топоизомерази II.119, 120 Нађено је да су фероценски азлактон 57 и 2-фероценилметил-1-морфолино-1-етантион (58) активнији од осталих једињења која су синтетисали.120 Резултати указују на то да два једињења реагују са топоизомеразом II и инхибирају њену активност узрокујући бројне генетске промене које на крају воде до умирања малигне ћелије.120   Слика 2.21. Деривати фероцена који инхибирају топоизомеразу II 26  Иста група истраживача нашла је да једињење 59 (Слика 2.22) показује антипролиферативну активност према неколико линија хуманих ћелија рака, посебно према Colo 205 (аденокарцином дебелог црева).119 Механизам деловања ових једињења није баш сасвим јасан, што се нарочито односи на улогу фероценил-групе. Аутори предлажу два суштински другачија механизма инхибиције активности топоизомеразе II једињењима 57 и 58, сматрајући да фероценски азлактон инхибира активност ензима преко формирања разградивог комплекса (ДНК + топо II + дериват фероцена), а да морфолински дериват конкурише грађењу ATП и тако инхибира каталитичке активности ензима. 59 Fe NHO N OH   Слика 2.22. Структура оксима 1,1ˈ-((хидроксиимино)метил)фероценилалдехида Што се тиче деловања једињења 59, претпоставља се да се ензим и једињење 59 везују преко хетероатома алдоксимских група. Постоји значајан број једињења која у свом саставу садрже фероценско језгро и функционалне групе (тј. хетероатоме) са електрон-донорским особинама, па представљају подесне лиганде (често полидентатне) за комплексирање са јонима прелазних метала; за нека од њих испитана је антитуморска активност. Тако су, на пример, Раџпут (Rajput) и сарадници121 припремили серију фероценских деривата пиридина и фенилпиридина и направили њихове комплексе типа [MCl(CO)2(L)], [M(cod)(L)2]ClO4 и [M'Cl2(L)2], где је M = Rh или Ir, cod = 1,5-циклооксадиен, M' = Pt или Pd, а L један од поменутих лиганада.   Слика 2.23. Два примера из серије комплекса који садрже фероцен, а која су показала значајну цитотоксичну активност 27  Неколико синтетисаних комплекса показало је значајну цитотоксичну активност према канцерогеним ћелијама WHCO1, при чему нарочито треба истаћи једињења 60 и 61 (Слика 2.23).121 Крац (Kraatz) и сарадници синтетисали су фероценски дериват пиразола 62,122 које лако може да се координује са јонима различитих прелазних метала. Ова група истраживача направила је и детаљно описала комплексе овог лиганда са јонима гвожђа, кобалта и никла (63, 64 и 65, Слика 2.24). Испитана је њихова цитотоксичност и показало се да су хумане ћелије аденокарцинома (MCF-7) осетљиве на све ове комплексе, и да је најактивнији комплекс кобалта. Занимљив је налаз да цитотоксичност ових комплекса опада са порастом редокс потенцијала (E1/2) метала (низ цитотоксичности: Co > Ni > Fe; низ редокс потенцијала: Co < Ni Br) и природа тешког атома јасно се исказују већим хемијским померањем атома који носе халоген (С6–123,5 и 110,4 за 95б, односно 95в). На основу анализе 1H NMR спектара једињења 95а-в могу се извући корисни закључци о њиховој структури. Велика константа спрезања протона H2 са једним од протона везаних за C3 (12,4 за 95а, 13,5 за 95б, и 13,0 Hz за 95в) једино се може објаснити диаксијалним, антиперипланарним распоредом H2 и H3ax протона, што директно указује на полустоличасту конформацију прстена дихидрохинолинона, са фероценил-групом на С2 у псеудоекваторијалном положају. Пада у очи и додатно фино цепање сигнала протона H3aq ових једињења у њиховим 1H NMR спектрима (1,2 за 95а, 1,5 за 95б, и 1,5 Hz за 95в), које је последица интеракције NH-H3eq (спрезање кроз четири везе, “W“ спрезање). Због познате стереоспецифичности “W“ спрезања ово представља доказ тетраедарске геометрије N, C2 и C3 атома, тј. потврду полустоли- часте конформације прстена. С друге стране, једини резултат очекиваног спрезања кроз три везе између NH и H2 јесте проширење мултиплета протона H2. Сва три једињења су чврсте, кристалне супстанце подесне за рендгеноструктурну анализу, која је недвосмислено потврдила њихове структуре. Она је, такође, показала да су закључци о конформацији дихидрохинолонског прстена изведени на основу анализе 1H NMR спектара исправни. Наиме, разматрањем ових структура (које су међусобно веома сличне) издвајају се следеће главне карактеристике: (i) фероценско језгро има готово идеалну еклипсну конформацију, (ii) циклопентадиенски прстенови фероценског језгра готово идеално су паралелни и (iii) дихидрохинолонски прстен заузима полустоличасту конформацију. 48  На слици 3.5 приказане су структуре сва три једињења, при чему су дате различите пројекције, тако да свака осликава једну од поменутих особености: еклипсну конформацију фероцена (95а), паралелан положај циклопентадиенских прстенова (95б) и полустоличасту конформацију дихидрохинолонског прстена (95в). 95а 95б 95в Слика 3.5. Молекулска структура (ORTEP прикази) дихидрохинолона 95а-в. 49  3.2.2 Редокс особине Редокс особине дихидрохинолона 95а-в испитане су цикличном волтаметријом ових једињења под истим експерименталним условима као тиазолидинони 92а-л. На основу прелиминарних експеримената одабрана је област потенцијала („потенцијалски прозор“) од 0,000 до +1,500 V, а добијени подаци за сва три деривата дати су у Табели 3.4. На Слици 3.6. дати су цикловолтамограми репрезентативног узорка – једињења 95а. Волтамограм (в) на Слици 3.6. добијен је као први скен и на њему се појављују два јасно дефинисана оксидациона (O1, на 0,458 и O2, на 1,340 V) и један редукциони талас (R1, на 0.592 V). Пошто се редукциони талас појављује и кад се не достигне потенцијал О2 (волтамограм (д), Слика 3.6), очигледно је да се ту редукује честица која настаје оксидационим процесом на О1. Како је разлика између њих блиска теоријској – ради се о реверзибилном процесу и приписује се фероценил-групи. Редокс потенцијал тог процеса је само мало позитивнији од редокс потенцијала фероцена (за око 50 mV; Слика 3.6., волтамограм (в)) што се приписује слабим електрон-привлачним особинама угљениковог атома у α-положају у односу на фероценско језгро (за њега је везан атом азота). Слика 3.6. Циклични вотамограми 1 mМ раствора 2-фероценил-2,3-дихидрохинолин- 4-(1H)-она (95а) (0,1 M раствор LiClO4 у ацетонитрилу Pt диск ( = 2 mm), ν = 0,1 Vs-1): (а) електролит, (б) 1 mМ раствор фероцена (в) први скен (скенирање до 1,5 V) и (г) други скен (скенирање до 1,5 V) (д) скенирање до 0,75 V 50  Процеси на О1 и R1 су дифузионо-контролисани, пошто су струје оба пика пропорционалне корену брзине скенирања, а њихов однос не зависи од те брзине. Други оксидациони талас (О2 на 1,340 V) очигледно је одговор радне електроде на неки иреверзибилни оксидациони процес, пошто одговарајући редукциони талас није нађен. Не постоје литературни подаци о цикличној волтаметрији 2,3-дихидрохинолин- 4-(1H)-она или њeгових деривата, али извесна сличност једињења 95а са N-алкиланилинима189-191 свакако постоји (азот везан за ароматично језгро). Пренос електрона са ароматичног језгра (или са атома азота) на радну електроду на том потенцијалу свакако је вероватан и требало би да он даје катјон-радикал, који је веома реактиван и сигурно одмах реагује са неком компонентом из реакционе средине. Код поменутих N-алкиланилина производ те рекције може да се „види“ на другом и наредним скеновима, али се ти таласи налазе у области у којој се појављују оксидациони и редукциони таласи фероценског језгра, па се у случају једињења 95 са њим преклапају. Табела 3.4. Електрохемијски подаци једињења 95а-в (услови као на Слици 3.6.) Једињење Eox1 (V) Eox2 (V) Ered (V) E1/2 (V)а ΔE (V) 95а 0,458 1,340 0,360 0,409 0,098 95б 0,476 1,373 0,378 0,427 0,098 95в 0,473 1,401 0,381 0,427 0,092 аE1/2 = (Eox1+ Ered1)/2 Електрохемијске особине фероценских дихидрохинолона (и дихидрохинолина уопште) су, очигледно, веома занимљиве и заслужују посебна изучавања, која са своје стране, и обимом и природом излазе из oквира овог рада. 3.3 6-Фероценил-1,3-оксазинани, 6-фероценил-1,3-оксазинан-2-они и 4-фероценилтетрахидропиримидин-2(1Н)-они 1,3-Оксазинани, 1,3-оксазин-2-они и тетрахидропиримидин-2-они, шесточлани хетероциклични системи са два хетероатома, често су део сложенијих, фармаколошки важних молекула, па су веома цењени као мали синтетички блокови. У литератури су описани бројни поступци за њихово добијање, као што је реакција примарних нитроалкана, формалдехида и примарних амина (и амонијака), која даје 5-алкил-5- нитро-1,3-оксазинане.192 Отварањем прстена изоксазола под дејством m-хлорпербе- нзоеве киселине и рециклизацијом интермедијерног нитрона добијају се (у високим 51  приносима) 3-хидрокси-1,3-оксазинани.193 Најједноставније опште методе за добијање 1,3-оксазинана су, чини се, реакције 1,3-аминоалкохола са фозгеном и алдехидима.194-196 Чињеница да постоје бројни добро описани поступци за добијање 1,3-амино- алкохола197-199 чини ту методу нарочито привлачном, па је одабрана и за синтезу фероценских 1,3-оксазинана у оквиру ових истраживања. Постоје бројни литературни подаци о синтези 1,3-оксазин-2-она - шесточланих цилкичних уретана –а све описане методе у којима се користе алифатични супстрати могу се сврстати у две основне групе: интермолекулске и интрамолекулске циклизације. Као полазни супстрати код интeрмолекулских циклизација користе се 1,3-бифункционална једињења код којих бар једна функционална група садржи атом кисеоника или атом азота. 1,3-Аминоалкохоли су најчешћи избор, и углавном су подвргавани реакцији са дериватима карбоксилних киселина (етилен-карбонат,200 уреа,201 1,1ˈ-карбонилдиимидазол202 и трифозген203, 204), али је уграђивање карбонилне групе између атома кисеоника и азота код ових супстрата могуће употребом и других донора ове групе (нпр. угљен-моноксида,205, 206 односно угљен-диоксида207). Трихлорацетати,208 трифлуорацетамиди,209 или N-бензилоксикарбонил-деривати 1,3- амино-алкохола,210 као и N-терц-бутоксикарбонил-тозилати211 и N-ароил-нитрати212 такође могу бити преведени у одговарајуће 1,3-оксазин-2-оне. Као алтернатива 1,3-аминоалкохолима у синтези цикличних уретана могу да послуже 3-хлорпро- панол213, 214 и 3-бромпропан-1-амин,215, 216 а недавно је у лабораторијама нашег факултета развијен трокомпонентни поступак за добијање ових хетероцикла полазећи од 1,3-дибромпропана (one-pot реакција овог дихалогенида са примарним аминима и бикарбонатом).217 Хофманово (Hofmann) премештање 4-хидроксиамида,218 Курциусово (Curtius) премештање 4-хидроксихидразида,219 халоциклизација алил-,220 хомоалил-,221, 222 или аленил-карбамата,223 халоциклизација алил-амина у присуству угљен-диоксида,224 као и Шарплесова (Sharpless) асиметрична дихидрокилација хомоалилних карбамата,225 су интрамолекулске циклизационе методе за добијање 1,3-оксазин-2-она. За синтезу фероценских 1,3-оксазин-2-она у оквиру ових истраживања одабран је први приступ (интермолекулске циклизације) и одговарајући 1,3-аминоалкохоли као полазни супстрати. За синтезу деривата хидрогенизованих пиримидинона такође постоје бројни описани поступци, као што је, нпр., Биђинелијева (Biginelli) реакција, која представља 52  трокомпонентну кисело-катализовану синтезу дихидропиримидинона из алдехида, β-кетоестара и карбамида.226-228 С друге стране, полисупституисани деривати тетрахи- дропиримидинонамогу се синтетисати, нпр., one-pot реакцијом метил-естра пропинске киселине, ароматичних амина, ароматичних алдехида и карбамида.229 За синтезу фероценских деривата тетрахидропиримидинона, предвиђену овим истраживањима, одабран је приступ са фероценским моноацилованим 1,3-диаминима, који су добијени из одговарајућих Манихових база, преко 1,3-аминоалкохола. 3.3.1 3-(Ариламино)-1-фероценилпропан-1-они Како су за добијање све три циљне групе фероценских шесточланих хетероцикличних једињења - 1,3-оксазинана, 1,3-оксазинан-2-она и тетрахидропирими- дин-2-она као кључни интермедијери предвиђени одговарајући 3-амино-1-фероце- нилпропан-1-оли, синтеза одговарајућих Манихових база, које би редукцијом дале ове супстрате, наметнула се као први задатак. Манихове (Mannich) базе (β-аминокетони) значајни су синтетички блокови из којих се, поред 1,3-аминоалкохола, могу добити бројни други производи,230 а једна од најважнијих примена ових једињења јесте синтеза фармацеутских препарата.231-233 Најпознатији метод за добијање Манихових база је, свакако, Манихова реакција,234, 235 али она има доста недостатака. Три најважнија су драстични реакциони услови, дуга реакциона времена и немогућност коришћења примарних амина као аминске компоненте. (Не може да се спречи ступање секундарних β-аминокетона, насталих реакцијом примарних амина, у ову реакцију, а то значи да се на овај начин могу синтетисати само терцијарни β-аминокетони.) Одлична и највише коришћена алтернатива Манихове реакције јесте аза-Мајклова реакција, тј. адиција амина на α,β-незасићена карбонилна једињења.236 Аза-Мајклова реакција има неколико предности у односу на Манихову, а најважније су благи реакциони услови и могућност синтезе секундарних β-аминокетона. Развијено је много каталитичких система за извођење ове реакције до данас.237-258 Док се адиција алифатичних амина на Мајклове акцепторе одвија лако, чак и без катализатора,259, 260 ароматични амини, због смањене нуклеофилности аминског азота, не подлежу овој реакцији лако, нарочито под благим реакционим условима и кад се користе катализатори који не угрожавају животну средину.241, 248, 250, 255, 258 53  За синтезу 3-(ариламино)-1-фероценилпропан-1-она у овим истраживањима одабрана је аза-Мајклова реакција акрилоилфероцена (97) као Мајкловог акцептора и ароматичних амина (супституисаних анилина 98а-о) као донора (Схема 3.4). У литератури постоји само једно саопштење о адицији амина на неки α,β-незасићени ацилфероцен,250 у коме аутори описују реакцију неколико фероценских деривата халконског типа са алифатичним аминима, под благим реакционим условима. Одговарајући β-аминокетони добијени су у високим приносима, али под описаним реакционим условима ароматични амини не понашају се као Мајклови донори. И поред тога што су ароматични амини нереактивни у овој реакцији кад се глина користи као катализатор,255 одлучено је да се синтеза циљних фероценских β-аминокетона изведе применом баш једне глине као катализатора - монтморилонита К-10, али уз истовремену примену микроталaсног зрачења. 3.3.1.1 Синтеза и карактеризација Пошто акрилоилфероцен (97) није трговачки доступан, истраживања су започета синтезом овог једињења. За оптимизацију услова синтезе β-аминокетона 99а-о први представник Мајклових донора 98а-о – несупституисани анилин (98а) – одабран је као тест-супстрат. У првом огледу смеша кетона 97 (1 mmol) и амина 98а (1 mmol) изложена је микроталасном зрачењу (500 W, 5 min) без присуства катализатора и без растварача. Након уобичајене обраде реакционе смеше и флеш хроматографије (силикагел/толуен, па хексан/етил-ацетат 9:1) добијен је β-аминокетон 99а у приносу од 37% (Табела 3.5, оглед 1). Продужетак времена зрачења (на 10 min) није дао значајно бољи резултат (Табела 3.5, оглед 2). У следећа два експеримента истој смеши реактаната додато је 100 mg монтморилонита К-10, па је подвргнута микроталасима (500W, 5 и 10 min), што је принос β-аминокетона 99а повисило на 67% (Табела 3.5, огледи 3 и 4). Повећање количине катализатора на 500 mg, у следећем експерименту, дало је само нешто бољи резултат (61%, Табела 3.5, оглед 5). Пошто је у свим експериментима из реакционих смеша издвајано релативно мало заосталог полазног кетона 97 (до 10%), закључено је да се одвија нека споредна реакција, највероватније нека врста полимеризације, пошто је производ (који није ни изолован ни идентификован) врло поларан (практично се не помера са врха колоне 54  Табела 3.5. Реакција акрилоилфероцена (97) са анилином (98а) Број Катализатор (mg) Однос реактаната (97:99a) Дужина излагања (min) Производи 97 (%) 99a (%) 1 Без катализатора 1:1 5 16 37 2 Без катализатора 1:1 10 8 38 3 100 1:1 5 5 53 4 100 1:1 10 67 5 500 1:1 5 1 61 6 100 1:2 5 85 7 100 1:2 10 83 поменутом смешом растварача). Тај производ (или више њих) може бити резултат вишеструке Мајкове адиције добијеног β-аминокетона на више молекула акрилоилфероцена, можда чак, преко терцијарних амина, и до кватeрнерних амонијум- соли, за које се очекује такво хроматографско понашање. Да би се то предупредило (бар статистички) изведен је оглед са двоструко већом количином амина (97/98а = 1:2; 100 mg катализатора). Циљно једињење – β-амино- кетон 99а – добијено је у приносу од 85%, без обзира на то да ли је време зрачења било 5 или 10 min (Табела 3.5, огледи 6 и 7). Реакциони услови нађени на овај начин (1 mmol акрилоилфероцена, 2 mmol ариламина, 100 mg монтморилонита К-10, 500 W, 5 min) примењени су на реакцију преосталих седамнаест амина (98б-о), а циљне Манихове базе 99б-о добијене су углавном у високим приносима (и до 98%; Схема 3.4., Табела 3.6.). Иако се аза-Мајклова реакција под овим условима изводи веома једноставно (видети Експериментални део), одлучено је да се изведе реакција у ултразвучној кади уместо у микроталасној пећи, пошто је недавно објављено да се ароматични амини под дејством ултразвука понашају као добри Мајклови донори.250 Тако је из амина 98а (реакциони услови: 1 mmol акрилоилфероцена, 2 mmol анилина, 100 mg монтморилонита К-10, 60 min у ултразвучној кади) β-аминокетон 99а добијен у сличном приносу као и у реакцији изведеној у микроталасној пећи (80%, Табела 3.6.). Показало се да и остали амини реагују слично, а добијени резултати дати су у Табели 3.6. Као што се из те табеле може видети, остварују се високи приноси 55  Fe ClCH2CH2COCl а) б) H2N Fe в) 1 96 97 99a-o98a-o Fe O Cl Fe O R + O 98 и 99 а 2-CH3 H 3-CH3 4-CH3 2,4,6-triCH3 2-F 3-F 4-F 2-Cl 3-Cl 4-Cl 2-NO2 3-NO2 4-NO2 б в г д ђ е ж и ј к л з љ R H N R 4-C4H9 м н њ o 2-COCH3 3-COCH3 4-COCH3   Схема 3.4. Синтеза 3-(ариламино)-1-фероценилпропан-1-она: а) AlCl3, CH2Cl2, с.т., б) CH3COOK, етанол, рефлукс, 2,5 h, в) без растварача, монтморилонит К-10, 5 min у микроталасној пећи (500 W), 60 min у ултразвучној кади β-аминокетона 99а-о, осим у случају три нитроанилина 98л-м, што се приписује смањеној нуклеофилности аминског азота због присуства изразито електрон-привлачне нитро-групе. Ови резултати, који показују да је аза-Мајклова реакција готово једнако успешна кад се изводи у микроталасној пећии или у ултразвучној кади, на неки начин препоручују синтетичарима ову другу, зато што је ултразвучна када знатно јефтинија, па је има готово свака лабораторија. Структуре свих синтетисаних Манихових база потврђене су 1H, 13C NMR и IR спектроскопијом. У IR спектрима уочавају се интензивне апсорпционе траке за карбонилну (на 1660 cm-1, оштра) и NH групу (на 3340-3390 cm-1, оштра). У 1H NMR спектрима налазе се сигнали карактеристични за моносупституисани фероцен (два псеудотриплета на око 4,76 и 4,50 и синглет на ~ 4,12 ppm) као и два мултиплета који 56  потичу од присуства две метиленске групе O=C-CH2-CH2-N (на 3,25-3,83 и 2,97-3,12 ppm). Табела 3.6. Синтеза Манихових база (99а-99о) Редни број Амин Производ Приноса (%) MW 1 98а 99а 85 80 2 98б 99б 89 90 3 98в 99в 80 80 4 98г 99г 95 85 5 98д 99д 59 82 6 98ђ 99ђ 92 93 7 98е 99е 98 90 8 98ж 99ж 89 91 9 98з 99з 83 95 10 98и 99и 93 93 11 98ј 99ј 87 90 12 98к 99к 93 89 13 98л 99л 64 35 57  Табела3.6. (Наставак) Редни број Амин Производ MW 14 98љ 99љ 87 61 15 98м 99м 64 59 16 98н 99н 71 77 17 98њ 99њ 81 75 18 98о 99о 60 70 аПринос производа је израчунат у односу на акрилоил-фероцен. Занимљиво је запажање да се у спектрима неких једињења спрежу протон везан за атом азота (NH) и протони суседне метиленске групе, при чему су у бројним случајевима сигнали метиленских протона оштри или нешто развученији квартети. Овакав облик тих сигнала последица је чињенице да су вициналне константе спрезања N-H и CH2-CH2 случајно исте (J ca. 6 Hz). N-H протон углавном се јавља у облику широког сигнала на 3,6-4,8 ppm (изузетак је једињење 99л), док протони метиленске групе дају квартет (уместо триплета). Да се заиста ради о том спрезању потврдили су експерименти са додатком D2O када се дотично спрезање изгубило. Подаци из 13C NMR спектара су, такође, у сагласности са приписаним структурама синтетисаних једињења. Тако се сигнали на 78,7, 72,4, 69,8 и 69,2 могу приписати атомима угљеника фероценил-групе док други, карактеристични сигнали који се јављају на око 200 ppm и два на око 38 ppm припадају карбонилној, односно метиленским групама. Већина синтетисаних Манихових база кристалне су супстанце, подесне за рендгено-структурну анализу, која је урађена за неколико од њих. На Слици 3.7 дати су молекулски дијаграми једињења 99в (а), 99ј (б),99к (в), 99л (г), 99љ (д) и 99н (ђ) који недвосмислено потврђују приписану структуру. 58  a) б) в) г) д) ђ) Слика 3.7. Структуре (ORTEP прикази) Манихових база 99в (а), 99ј (б), 99к (в), 99л (г), 99љ (д) и 99н (ђ) 59  Та анализа показала је да је конформација циклопентадиенских-прстенова код свих једињења блиска еклипсној, да се карбонилна група налази у равни са супституисаним циклопентадиенским прстеном и да се вредности за дужине и углове веза слажу са очекиваним. Конформација ариламино-фрагмента код свих молекула слична је, осим у случају β-аминокетона 99л и 99н. Наиме, у свим овим молекулима постоји само један донор протона за грађење водоничне везе – водоник из NH групе - и у кристалним решеткама свих анализираних једињења, осим ова два, постоји интермолекулска водонична веза између тог водоника из једног молекула и карбонилног кисеоника из другог. Ова водонична веза довољно је јака да се награде димери, али у молекулима 99л и 99н постоје и атоми кисеоника (добри акцетори: кисеоникови атоми нитро-групе у првом и кисеоник ацетил-групе у другом) који могу конформационо толико да се прибиже водонику из NH групе - да се награди јака интрамолекулска водонична веза (видети структуре г и ђ, Слика 3.7), а која се задржава и у кристалном стању. Зато је и положај арил-групе у конформацији коју молекули ових једињења имају у чврстом стању другачији од осталих. 3.3.1.2 Редокс особине Циклична волтаметрија коришћена је и за одређивање редокс особина Манихових база (испитане су особине аминокетона 99а-д, е-м, тј. тринаест од укупно осамнаест синтетисаних). На Слици 3.8. дати су волтамограми репрезентативног једињења 99а, а у Табели 3.7 подаци о испитиваним β-аминокетонима (99а-д, е-м) добијени цикловолтаметријским мерењима у 0,1 mol/L раствору литијум-перхлората у ацетонитрилу. Диск од стакластог графита ( = 2 mm) коришћен је као радна, а платинска спирала као помоћна електрода у потенцијалском прозору 0,000-1,500 V (одабраном на основу пробних мерења). Као што се из података са Слике 3.8. и из Табеле 3.7. види, једињења 99а-д, е-м показују два добро дефинисана оксидациона (O1, на 0,650-0,693 V и O2, на 0,693-1,373 V) и један редукциони талас (R1, на 0,592-0,620 V). Како се редукциони талас јавља и кад се мерење одвија у опсегу 0,000-0,750 V (испод потенцијала другог оксидационог таласа), закључено је да таласи О1 и R1 припадају једном реверзибилном редокс пару (разлика између потенцијала на овим таласима блиска је теоријској вредности) који, очигледно, потиче од фероценског језгра. Јачине струја на анодном и катодном таласу 60  пропорционалне су корену брзине промене потенцијала (подаци нису приказани) и независне од те брзине, што указује на процес контролисан дифузијом.   Слика 3.8. Циклични вотамограми 1 mМ раствора 3-(фениламино)-1-фероценилпро- пан-1-она (99а) (0,1 M раствор LiClO4 у ацетонитрилу стакласти графит ( = 2 mm), ν = 0,1 Vs-1): А) 0,000-1,500 V [(а) електролит, (б) први скен, (в) други скен) г) 1 mМ раствор фероцена] и Б) 0,000-0.75 V [(а) први скен, (б) други скен)] Табела 3.7. Електрохемијски подаци једињења 99а-д, е-м(услови као на Слици 3.8.) Једињење Eox1 (V) Eox2 (V) Ered (V) E1/2 (V)a ΔE (V) 99а 0,665 0,851 0,620 0,6425 0,045 99б 0,653 0,803 0,598 0,6255 0,055 99в 0,653 0,784 0,613 0,633 0,040 99г 0,693 0,693 0,604 0,6485 0,089 99д 0,662 0,830 0,604 0,633 0,058 99е 0,647 0,992 0,601 0,624 0,046 99ж 0,644 0,983 0,595 0,6195 0,049 99з 0,638 0,861 0,598 0,618 0,040 99и 0,647 1,031 0,595 0,621 0,052 99ј 0,647 1,007 0,595 0,621 0,052 99к 0,662 0,952 0,610 0,636 0,052 99л 0,659 1,373 0,595 0,627 0,064 99љ 0,650 1,166 0,610 0,630 0,04 99м 0,653 1,361 0,592 0,6225 0,061 аE1/2 = (Eox1+ Ered1)/2 61  Како се редукциони талас који би одговарао другом оксидационом таласу O2 не појављује, очигледно је да он представља одговор радне електроде на неки иреверзибилни пренос електрона са ариламино-групе на њу. Готово иста појава већ је запажена и код једињења 95а-в (одељак 3.2.2) и објашњена на основу поређења резултата са литературним податацима за N-алкиланилине.189-191 Да би се добили релевантни подаци за поређење, синтетисан је 4-(фениламино)бутан-2-он (100), једињење које се од 99а разликује по томе што уместо фероценског језгра садржи метил-групу (Слика 3.9). H N O   Слика 3.9. 4-(фениламино)бутан-2-он (100) Циклична волтаметрија овог једињења под истим условима (Слика 3.9) показује у првом скену један оксидациони талас (на 0,815 V, тј. онај који одговара другом оксидационом таласу једињења 99а; фероценски, разумљиво, недостаје) и чак три редукциона, а у другом још три оксидациона (одговарају оксидацији производа насталих на редукционим таласима првог скена).Кад се овом једињењу дода фероцен – сва три редукциона и сва три оксидациона таласа из другог скена не виде се, јер су преклопљени. Слика 3.10. Циклични вотамограми 3 mМ раствора 4-(фениламино)бутан-2-она (100) (0,1 M раствор LiClO4 у ацетонитрилу, стакласти графит ( = 2 mm), ν = 0,1 Vs-1): А) без ацетилфероцена [(а) први скен, (б) други скен]; Б) са 3 mМ раствором ацетилфероцена (први скен) 62  3.3.2 Синтеза и карактеризација 3-арил-6-фероценил-1,3-оксазинана Најпознатије методе за добијање 1,3-оксазинана обухватају, као што је већ напоменуто, одговарајуће 1,3-аминоалкохоле као супстрате.194-196 Реакцијa карбонилних једињења са овим супстратима представља кондензацију која се одвија лако, а степен супституисаности производа контролише се структуром аминоалкохола. Карбонилно једињење одређује врсту супституента само у положају 2: са формалдехидом добија се оксазинан који је у положају 2 несупституисан, са алдехидима моносупституисан, а са кетонима дисупституисан (Схема 3.5).196   Схема 3.5. Реакција карбонилних једињења и амино-алкохола За синтезу фероценских N-арил-1,3-оксазинана предвиђених овим истраживањима одабрана је реакција одговарајућих N-арил-1,3-аминоалкохола и 1 екв. HCHOTHF, с.т., 12 h Fe N O 102a-к R 99, 101 и 102 а 2-CH3 H 3-CH3 4-CH3 2,4,6-triCH3 2-F 3-F 4-F 2-Cl 3-Cl 4-Cl б в г д ђ е ж и ј з R 4-C4H9 к Fe 101a-к H N OH 5 екв. NaBH4 CH3OH, с.т., 1,5 hFe 99a-к H N O RR   Схема 3.6. Синтеза деривата 3-(ариламино)-1-фероценилпропан-1-ола (101а-к) и 3-арил-6-фероценил-1,3-оксазинана 102а-к 63  Табела 3.8. Синтеза 1,3-аминоалкохола 101а-к и оксазинана 102а-к Број Манихова база Производ 1,3-Аминоалкохол Принос (%)a  Оксазинан Принос (%)б 1 99а   101а 90   102а 90 2 99б 101б 92 102б 92 3 99в 101в 90 102в 90 4 99г 101г 80 102г 80 5 99д 101д 91 102д 91 6 99ђ 101ђ 97 102ђ 97 7 99е 101е 93   102е 93 64  Табела 3.8. (Наставак) Број Манихова база 1,3-Аминоалкохол Принос (%)a Оксазинан Принос (%)б 8 99ж   101ж 91 102ж 91 9 99з   101з 95 Fe N O F 102з 95 10 99и 101и 90   102и 90 11 99ј 101ј 98 102ј 98 12 99к   101к 85   102к 85 aПриноси изолованих једињења хроматографског пречишћавања на Al2O3, бПриноси изолованих једињења хроматографског пречишћавања на силикагелу 65  формалдехида. Серија ових алкохола добијена је редукцијом Манихових база чија је синтеза описана у претходним одељцима. Редукција се изводи третирањем β- аминокетона 99а-к вишком (5 мол-еквивалента) натријум-бор-хидрида у метанолу, на собној температури (Схема 3.6.). Одговарајући 3-(ариламино)-1-фероценилпропан-1- оли 100а-к, добијени су у високим приносима (80-98%), као што показују подаци дати у Табели 3.8. Добијени аминоалкохоли подвргнути су у следећем кораку кондензацији са формалдехидом (Схема 3.6). Реакција се изводи тако што се раствору алкохола 101а-к(1 mmol) у тетрахидрофурану дода водени раствор формалдехида (1 mmol) и смеша меша преко ноћи. Након уобичајене обраде и пречишћавања хроматографијом на стубу (SiO2/хексан-етил-ацетат, 9:1) изоловани су циљни молекули – 3-арил-6- фероценил-1,3-оксазинани 102а-к – углавном у високим приносима (и до 99%), као што показују подаци у Табели 3.8. Изузетак је једињење 102д, које је добијено у приносу од само 36%. Пошто три метил-групе могу само да повећају нуклеофилност азота, разлози за ово нису електронске природе. Супституенти у оба o-положаја свакако отежавају приступ електрофилној честици атому азота на првом ступњу реакције (видети Схему 3.7).   Схема 3.7. Механизам настајања оксазина 102а 66  Описана кондензација у првом кораку веома је слична Маниховој реацији. Као што је приказано на Схеми 3.7., на том првом кораку нуклеофилни амински азот напада карбонилни угљеников атом формалдехида (чија електрофилност значајно може да се повећа траговима минералних киселина, преко интермедијерног јона II), дајући катјон III, који депротоновањем даје интермедијерно једињење IV. Реакција се, даље, наставља протоновањем хидроксилног кисеоника баш на карбиноламинском угљенику, што даје катјон V, који се дехидтатише до катјона VI. Овај катјон, са своје стране, подлеже интрамолекулском нуклеофилном нападу хидроксилног кисеоника, тј., циклизацији чији је производ 1,3-оксазинански прстен (катјон VII). Коначан производ добија се депротоновањем овог катјона. Структуре свих синтетисаних оксазинана су потврђене 1H NMR,13C NMR и IR спектроскопијом. У IR спектрима налазе се апсорпционе траке за метиленске и метинске групе. У 1H NMR спектрима налазе се сигнали карактеристични за моносупституисани фероцен (два псеудо dt (или m) на око 4,20 ppm, односно на око 4,17 ppm и синглет на ~ 4,12 ppm) као и сигнали који потичу од присуства две метиленске O-C-CH2-CH2-N (pseudo ddt (или m) који се јавља на око 3,91, ddd (или m) који се јавља на око 3,49, dddd (или m) који се јавља на око 2,02 као и pseudo ddt (или m) који се јавља на око 1,78), као и једне метинске групе (dd на око 4,48 ppm). Осим ових у 1H NMR спектрима се налазе и сигнали који потичу од метиленске групе која повезује атоме кисеоника и азота О-CH2-N (dd односно d, који се јављају на око 5,30 односно 4,74). Подаци из 13C NMR спектара су такође у сагласности са структурама синтетисаних једињења. Тако се сигнали на око 88,9, 68,6, 68,0, 67,8, 67,3 и 66,0 ppm могу приписати угљеницима фероценил-групе док други карактеристични сигнали који се јављају на око 148,9, 129,1, 120,5 и 118,4 ppm припадају угљеницима из аромата. Сигнали који се јављају на око 81,3, 76,0, 49,9 и 29,2 ppm припадају метинским и метиленским угљеницима оксазинанског прстена. 3.3.3 Синтеза и карактеризација 3-арил-6-фероценил-1,3-оксазинан-2-она 1,3-Оксазин-2-они, или шесточлани циклични уретани, испољавају различите биолошке, односно фармаколошке активности, као што су антибактеријска,261 противупална262 и антитромбоцитна.263 Неки од деривата ових хетероцикала користе 67  се у третману астме, алергија, чирева и дијабетеса,264 а неки се користе за синтезу фармаколошки важних супстанци.265, 266 Иако је примена 1,3-оксазинан-2-она за добијање 1,3-аминоалкохола позната синтетичка реакција,267, 268 „супротна“ синтеза је један од најважнијих начина за добијање цикличних уретана (видети почетак поглавља 3.3). Одговарајући фероценски аминоалкохоли, 3-(ариламино)-1-фероценилпропан-1-оли (101а-к), чија је синтеза детаљно описана у претходним одељцима овога рада, одабрани су као полазни супстрати за синтезу фероценских 1,3-оксазинан-2-она предвиђену овим истраживањима. У том циљу смишљена је „инсертација“ С=О групе између хидроксилног кисеоника и аминског азота ових супстрата у два корака. У првом кораку те синтезе примењена је позната реакција за добијање естара карбаминске киселине - реакција амина са етил-хлорформијатом. Тако су аминоалкохоли 101а-к (1 mmol) третирани раствором натријум-хидроксида (4 екв.) и етил-хлорформијатом (2 екв.), што је дало карбамате 103а-к (Схема 3.8), углавном у високим приносима (Табела 3.9).   Схема 3.8. Синтеза деривата етил-N-арил-N-3-(фероценил-3-хидроксипропил)карба- мата (103а-к) и 3-арил-6-фероценил-1,3-оксазин-2-она (104а-г, ђ-к) 68  У другом кораку успостављени су услови за интрамолекулску нуклеофилну супституцију једне алкокси групе другом, тј. услови за изградњу шесточланог (оксазинанонског) прстена. То је постигнто краткотрајним (15 s) третирањем раствора карбамата 103а-к у тетрахидрофурану четвороструком количином натријум-хидрида, на хладно (5 °C), а добијени резултати дати су у Табели 3.9. Детаљан механизам ове реакције приказан је у следећем одељку (Схема 3.10.). Неки од тих резултата су, у најмању руку, необични, као што је потпуни изостанак синтезе одговарајућег цикличног уретана из алифатичног 103д. То се може приписати стерним факторима, тј. присуству супституената у оба о-положаја, јер и уретани 103б и 103з (са метил-групом, односно хлором у о-положају) дају знатно ниже приносе одговарајућих цикличних уретана (104б, односно 104з) у овој реакцији. То што хидроксиуретан 103ђ даје циклични уретан 104ђ у високом приносу (97%; Табела 3.9., број 7) не оповргава ову тврдњу, пошто је атом флуора знатно мање волуминозан од метил-групе и атома хлора. Структуре свих синтетисаних оксазинона су потврђене 1H NMR,13C NMR и IR спектроскопијом. У IR спектрима налазе се интензивне апсорпционе траке за карбонилну (на 1685 cm-1). У 1H NMR спектрима налазе се сигнали карактеристични за моносупституисани фероцен (два псеудо dt (или m) на око 4,36 ppm односно на око 4,28 ppm и синглет на ~ 4,24 ppm) као и сигнали који потичу од присуства две метиленске групе (ddd (или m) који се јавља на око 3,81 односно 3,70 ppm, као и dddd (или m) који је јавља на око 2,45 односно 2,28 ppm). Сигнали који потичу од присуства метинске групе (dd који се јавља на око 5,31 ppm) се такође јављају у 1H NMR спектрима ових једињења. Подаци из 13C NMR спектара су такође у сагласности са структурама синтетисаних једињења. Тако се сигнали на 86,3, 69,1, 68,5, 68,4, 67,4 и 66,1 ppm могу приписати угљеницима фероценил-групе други карактеристични сигнали који се јављају на око 152,8 ppm и три на око 76,2, 47,9 и 28,9 ppm припадају карбонилној односно метиленским групама. Сигнали који се јављају на око 143,1, 129,4, 126,9 и 126,0 ppm припадају угљеницима ароматичног језгра. Занимљиво је да је код једињења 104б примећено постојање два диастереоизомера. Спречена ротација око CАр-N везе узроковала је настајање два диастереоизомера што се може видети из 1H и 13C NMR спектаралних података овог једињења (Експериментални део). 69  Табела 3.9. Синтеза хидроксиуретана 103а-к и оксазинанона 104а-г, ђ-к Број 1,3-Аминоалкохол Производ Естар карбаминске киселине Принос (%)  Оксазинанон Принос (%) 1 101а   103а 93   104а 64 2 101б 103б 94 104б 47 3 101в 103в 91 Fe N O O 104в 53 4 101г 103г 99 104г 84 5 101д   103д 94   104д 6 101ђ   103ђ 82   104ђ 80 70  Табела 3.9. (Наставак) Број 1,3-Аминоалкохол Естар карбаминске киселине Принос (%)  Оксазинанон Принос (%) 7 101е 103е 49 104е 97 8 101ж   103ж 99   104ж 84 9 101з 103з 92   103з 97 10 101и   103и 36   104и 10 11 101ј   103ј 95 104j 77 12 101к   103к 85   104к 89 71  3.3.4 Синтеза и карактеризација 1,3-дисупституисаних 4-фероценилтетрахи- дропиримидин-2(1Н)-она Од када је Биђинели 1893. године228 објавио чланак о синтези неких деривата пиримидин-2(1H)-она, нагло је порасло интересовање синтетичара за ову групу једињења, пре свега због широког спектра биолошких и фармаколошких особина које неки од њих испољавају.269, 270 За синтезу тетрахидропиримидин-2(1H)-она, који спадају у ову групу једињења, описани су, као што је раније напоменуто (видети почетак поглавља 3.3), бројни поступци.226-229 За синтезу тетрахидропиримидин-2(1H)-она који садрже фероценил-групу, планирану овим истраживањима, као полазни супстрати одабрани су хидроксиуретани 103а-к. Овај избор је логичан, пошто су тетрахидропиримидин-2(1H)-они аза-деривати цикличних уретана 104. Наиме, Схема 3.9. Синтеза диамина 105а-к и тетрахидропиримидина 106а, в, г, ђ, е, з, ј, к α-фероценил-карбокатјони су веома стабилни,271 па је и супституција хидроксилне групе из тог положаја другим нуклеофилима релативно лака.271 Имајући то на уму, направљен је план за оптимизацију услова под којима би хидроксиуретани 103а-к подлегли супституцији под дејством изопропиламина и дали одговарајуће деривате 72  Табела 3.10. Синтеза моноацилованих диамина 105а-к тетрахидропиримидин-2-она 106а, в, г, ђ, е, з, ј, к Број Естар карбаминске киселине Производ Диамино дериват Принос (%)a  Тетрахидропиримидинон Принос (%)б 1 103а 105а 96 106а 61 2 103б 105б 91 106б 3 103в 105в 81 106в 58 4 103г 105г 68 106г 66 5 103д 105д 85   106д 6 103ђ 105ђ 87 106ђ 60 73  Табела 3.10. (Наставак) Број Естар карбаминске киселине Диамино дериват  Принос (%)  Тетрахидропиримидинон  Принос (%) 7 103е 105е 95 106е 57 8 103ж 105ж 95 106ж 9 103з 105з 95 106з 63 10 103и 105и 63 106и 11 103ј   105ј 63 106ј 50 12 103к 105к 76   106к 53 74  1,3-пропандиамине 105а-к, који би, у следећем кораку, интрамолекулском циклизацијом били преведени у циљне молекуле – хетероцикле 106а-к. У првом кораку третирањем хидроксиуретана 103а-к (1 mmol) раствором изопропиламина (4 eq) у тетрахидрофурану, у присуству триетиламина (1,5 eq) и анхидрида трифлуорсирћетне киселине (1,5 eq) добијена су једињења 105а-к (Схема 3.9.), углавном у високим приносима (Табела 3.10). У другом кораку успостављени су услови за интрамолекулску циклизацију, тј. склапање тетрахидропиримидинског прстена, третирањем раствора интермедијера 105а-к (1 mmol) у тетрахидрофурану двоструко већом количином бутил-литијума, на температури од -78 °C (Схема 3.9). Синтеза хетероцикла типа 106 још је осетљивија на стерне сметње које су запажене код синтезе цикличних уреа 104. Наиме, ова реакција се показала неуспешном у случају свих орто-супституисаних диаминских деривата 105, осим деривата флуора (105е).   Схема 3.10. Механизам интрамолекулске циклизације хидроксиуретана 103а и деривата 1,3-пропандиамнина 105а Механизам реакција циклизације хидроксиуретана 103 и деривата 1,3-пропандиамина 105 је идентичан и приказан је на Схеми 3.10. Одговарајућа база (натријум-хидрид у случају синтезе цикличних уреатана 104 и n-бутил-литијум у 75  случају цикличних уреа 106) депротонује протичну групу (ОH у случају 103 и NH у случају 105), дајући анјонски нуклеофил који интрамолекулском супституцијом истискује одлазећу етокси-групу. Структуре свих синтетисаних тетрахидропиримидинона (106а, в, г, ђ, е, з, и, ј) су потврђене 1H NMR,13C NMR и IR спектроскопијом. У IR спектрима налази се интензивна апсорпциона трака за карбонилну групу (на 1636 cm-1). У 1H NMR спектрима налазе се сигнали карактеристични за моносупституисани фероцен (два псеудо dt (или m) на око 4,24 ppm, односно на око 4,11 ppm, синглет на ~ 4,16 ppm), као и два сигнала које потичу од метиленских протона O=C-CH2-CH2-N (ddd (или m) који се јавља на око 3,57, dddd (или m) који се јавља на око 3,52, dddd (или m) који се јавља на око 2,28 као и dddd (или m) који се јавља на око 2,21). У 1H NMR спектрима је, такође, примећен и сигнал који припада метинским протонима (ddd (или m) на око 4,46 ppm) као и сигнали протона изопропил-групе ((d) који се јавља на око 1,38 ppm односно на око 1,29 ppm). Подаци из 13C NMR спектара су такође у сагласности са структурама синтетисаних једињења. Тако се сигнали на 91,2, 69,4, 68,9, 68,4, 66,7 и 66,0 ppm могу приписати угљеницима фероценил-групе, док сигнали који се јављају на око 144,3, 128,8, 126,0 и 125,2 ppm припадају угљениковим атомима фенил-групе. Други карактеристични сигнали који се јављају на око 154,5, 53,0, 45,2 и 31,7 ppm одговарају карбонил-, метин и метиленским угљеницима док сигнали на 50,9, 21,3 и 20,9 ppm одговарају угљеницима изопропил-групе. 3.4 Преглед резултата тестова биолошке и фармаколошке активности синтетисаних једињења Као што је на почетку поглавља Наши радови речено, већина једињења добијених током израде ове дисертације дата је одговарајућим специјализованим лабораторијама на испитивање њихове биолошке активности. У најкраћем, резултати тих испитивања могу се сумирати на следећи начин: - После тестирања у неколико различитих in vivo модела нађено је да сви 2-фероценил-1,3-тиазолидин-4-они (92а-л) показују снажну анксиолитичку активност, која заслужује даља истраживања. - 2-Фероценил-2,3-дихидрохинолин-4-(1H)-они (95а-в) показују изразиту и неселективну антимикробну активност и према Грам позитивним (три соја) и према Грам негативним бактеријама (пет сојева), као и према једној 76  гљивичној врсти у in vitro условима. Због тога ова једињења такође заслужују пажњу медицинских хемичара. - Манихове базе 99, такође, показују извесну антимикробну активност, која је слабије изражена него у случају фероценских дихидрохинолин-4-(1H)-она 95а-в, али није занемарљива. - Коначно, испитана је биолошка активност и шесточланих хетероцикла 102а- к, 104а-г, ђ-к и 106а, в, г, ђ, е, з, ј, к и показало се да већина од њих показује слабу антимикробну активност, док нека испољавају слабу до умерену цитотоксичност.      Експериментални део 4 Експериментални део 4.1 Опште напомене Хемикалије и растварачи коришћени током израде овог рада доступне су трговачки (Sigma-Aldrich, Fluka, Merck, Acros Organics) и употребљаване су без додатног пречишћавања, осим што су растварачи дестиловани и сушени кад је то било неопходно. Tачке топљења одређиване су на апарату MelTemp, модел 1001 као и Kofler bench уређају типа WME Heizbank of Wagner & Munz и нису кориговане. Танкослојна хроматографија (TLC) извођена је на алуминијумским плочама превученим слојем силика-гела дебљине 0,2 mm (Silica gel 60, Merck и Silica gel 40, F254, Merck), уз визуелизацију UV лампом (254 nm) или изазивањем мрља воденим раствором H2SO4 (50% v/v) или етанолским раствором фосфомолибденске киселине (12 g у 250 mL растварача. Препаративна хроматогрфија вршена је на стубу силика- гела (Silica gel 60, 0,063-0,200 mm, Merck). Препаративнa танкослојна хроматографија извођена је на стакленим плочама превученим слојем силика гела (Silica Gel GF 250um)  димензија 10x20cm. Инфрацрвени спектри су снимљени на Perkin-Elmer FTIR 31725-X и Spectrum One FT-IR спектрометрима. NMR спектри (1H, 13C, 1H-1H COSY, NOESY, HSQC и HMBC) су снимани на уређајима Varian Gemini (200 MHz) и Bruker Advance III-400 (400 MHz), користећи CDCl3 као растварач. Хемијска померања дата су у ppm (δ) у односу на тетраметилсилан (TMS), који је употребљен као интерни стандард, а константе купловања у херцима (Hz). 1H NMR и 13C NMR спектри су снимани на 200 и 400 Hz односно 50 и 100 Hz. UV спектри су снимaни на UV-1650 PC Shimadzu спектрометру у ацетонитрилу као растварачу. Микроанализе су изведене на Carlo Erba 1106 микроанализатору; добијени резултати у сагласности су са израчунатим вредностима у граници дозвољене грешке. Масени спектри су снимљени помоћу Agilent 1100 Series (ES, 4000V) уређаја, а масени спектри високе резолуције урађени на апаратима Agilent Technologies 6210 Series Time- of-Flight и JEOL Mstation JMS 700. 78  GC-MS анализе су урађене на Hewlett-Packard 6890N гасном хроматографу који је био опремљен силика капиларном колоном DB-5MS и спојен са 5975B селективним масеним детектором. Циклична волтаметрија извођена је у атмосфери аргона у троелектродној ћелији уз коришћење потенциостата Autolab PGSTAT 302N, холандског произвођача Eco Chemie. Дискови од платина и стакластог графита ( = 2 mm) коришћени су као радна електрода, платинска жица као помоћна а потенцијали су мерени у односу на Ag/AgCl референтну електроду. За реакције у микроталасном реактору коришћен је апарат Microsynth опремљен контролорима температуре и притиска, а реакције под дејством ултразвука Elmasonic S30 (Elma, Немачка) ултразвучно купатило, френквенције 37 kHz, снаге 30 W. Подаци o дифракцији X-зрака на монокристалима одговарајућих једињења прикупљени су на собној температури, користећи апарат Oxford Diffraction Xcalibur Sapphire3 Gemini diffractometer, опремљен извором зрачења Mo Kα ( = 0.71073 Å). За анализу података коришћени су софтвери CrysAlis software272 и SCALE3 ABSPACK,272 за решавање структура SHELXS273 и за утачњавање SHELXL.273 4.2 Синтеза N-супституисаних 2-фероценил-1,3-тиазолидин-4-она 92а-л Раствор одговарајућег примарног амина (91а-л, 1 mmol) и фероценилалдехида (214 mg, 1 mmol, 90) у 2 mL тетрахидрофурана третира се у ултразвуком 5 min на 0 °C, па му се дода тиогиколна киселина (184 mg, 2 mmol) и третман настави још 5 min. Реакционој смеши се, затим, дода N,N'-дициклохексилкарбодиимид (206 mg, 1 mmol) и сонификација настави на 0 °C настави 15 min. Награђена дициклохексилуреа (DCU) одвоји се цеђењем, растварач упари и чврсти остатак екстрахује етил-ацетатом (3×10 mL). Спојени органски слојеви се исперу воденим раствором лимунске киселине (5%), водом, раствором NaHCO3 (5%) и засићеним раствором натријум-хлорида и суше анхидрованим Na2SO4 преко ноћи. Раствор се процеди и растварач упари, а остатак пречишћава стубном хроматографијом (20g SiO2, хексан/етил-ацетат 9 : 1), дајући тиазоидиноне 92а-л. Добијени резултати приказани су у Табели 3.1, а спектрални подаци на основу којих су идентификовани следе. 79  3-Бутил-2-фероценил-1,3-тиазолидин-4-он (92а). Принос 71%. IR (KBr, ν, cm-1): 3095, 2958, 2931, 2871, 1669, 1442, 1410, 1377, 1297, 1106, 820; UV–Vis (CH3CN): λmax (log ε) 422 (2,56), 202 (4,51) nm; 1H NMR (200 MHz, CDCl3): δ 0,83 (t, J = 6,8 Hz, 3H, CH3), 1,11–1,40 (m, 4H, CH2CH2CH3), 2,82 (ddd, J = 13,8, 8,4, 5,4 Hz, 1H, CHAHBN), 3,36 (ddd, J = 13,8, 8,4, 5,4 Hz, 1H, CHAHBN), 3,61 (AA’, 2H, SCH2CO), 4,14–4,31 (преклапање сигнала, 8H, H–C (1’’), H–C (2’’), H–C (3’’), H–C (4’’), H–C (5’’), H–C (2’), H–C (3’), H–C (4’)), 4,41 (m, 1H, H–C (5’)), 5,51 (br. s, 1H, N–CH–S); 13C NMR (50 MHz, CDCl3): δ 13,7 (CH3), 19,9 (CH2CH3), 29,0 (CH2CH2N), 33,4 (SCH2CO), 42,0 (CH2N), 61,3 (N–CH–S), 67,7, 68,0 (C (3’), (C (4’)), 69,0 (C(1’’), C(2’’), C (3’’), C (4’’), C (5’’)), 69,8, 70,0 (C (2’), C (5’)), 85,1 (C (1’)), 170,2 (CO); MS (EI, 70 eV) m/z(%): 343 [M]+ (100), 41 (2,6), 56 (10,1), 77 (2,2), 97 (2,7), 121 (28,4), 148 (7,9), 166 (8,2), 186 (17,3), 199 (5,1), 213 (7,8), 230 (6), 270 (61,7), 310 (2,4); HRMS (ESI): m/z израчунато за C17H21FeNOS + H+ [M + H+]: 344,07715. Нађено: 344,07709; Израчунато за C17H21FeNOS (343,07): C, 59,48, H, 6,17, Fe, 16,27, N, 4,08, S, 9,34%. Нађено: C, 59,14, H, 6,28, N, 3,73, S, 9,54%. 3-Пентил-2-фероценил-1,3-тиазолидин-4-он (92б). Принос 78%. Т.Т. = 90 ºC; IR (KBr, ν, cm-1): 3092, 2953, 2930, 2872, 2856, 1663, 1459, 1402, 1381, 1308, 1104, 1002, 820; UV–Vis (CH3CN): λmax (log ε) 422 (2,40), 315 (2,68), 203 (4,71) nm; 1H NMR (200 MHz, CDCl3): δ 0,84 (t, J = 6,8 Hz, 3H, CH3), 1,10–1,48 (m, 6H, (CH2)3), 2,84 (ddd, J = 13,9, 8,7, 5,2 Hz, 1H, CHAHBN), 3,35 (ddd, J = 13,9, 8,7, 5,2 Hz, 1H, CHAHBN), 3,62 (AA’, 2H, SCH2CO), 4,21–4,32 (преклапање сигнала, 8H, H–C (1’’), H–C (2’’), H–C (3’’), H–C (4’’), H–C (5’’), H–C (2’), H–C (3’), H–C (4’)), 4,43 (m, 1H, H–C (5’)), 5,52 (br. s, 1H, N–CH–S); 13C NMR (50 MHz, CDCl3): δ13,9 (CH3), 22,2, 26,6, 28,8 (CH2CH2CH2CH3), 33,4 (SCH2CO), 42,3 (CH2N), 61,4 (N–CH–S), 67,7, 68,4 (C (3’), (C4’)), 69,0 (C (1’’), C (2’’), C (3’’), C(4’’), C(5’’)), 69,8, 70,0 (C (2’), C (5’)),85,1 (C (1’)), 170,1 (CO); MS (EI, 70 eV) m/z (%): 357 [M]+ (100), 43 (3,3), 56 (7,3), 77 (2,0), 97 (2,5), 121 (26,4), 148 (6,6), 166 (8,0), 186 (18,8), 199 (6,5), 213 (10,4), 230 (6,9), 249 (2,6), 264 (1,6), 284 (67), 324 (2,8); HRMS (ESI): m/z израчунато за C18H23FeNOS + H+ [M + H+]: 358,09280. Нађено: 358,09283; Израчунато за C18H23FeNOS (357,08): C, 60,51, H, 6,49, Fe, 15,63, N, 3,92, S, 8,95%. Нађено: C, 60,83, H, 6,64, N, 3,64, S, 8,80%. Fe S N O H3C(H2C)3 1' Fe S N O 2' 3' 5' 1''3'' 4'' 5'' HBHA 80  2-Фероценил-3-хексил-1,3-тиазолидин-4-он (92в). Принос 72%. Т.Т. = 72 °C; IR (KBr, ν, cm-1): 3095, 2954, 2927, 2857, 1671, 1441, 1409, 1377, 1298, 1226, 1106, 1001, 818; UV-Vis (CH3CN): λmax (log ε) 430 (2,33), 203 (4,89) nm; 1H NMR (200 MHz, CDCl3): δ 0,85 (t, J = 6,5 Hz, 3H, CH3), 1,08–1,46 (m, 8H, (CH2)4CH3), 2,80 (ddd, J = 13,9, 8,6, 5,3 Hz, 1H, CHAHBN), 3,31 (ddd, J = 13,9, 8,6, 5,3 Hz, 1H, CHAHBN), 3,62 (AA’, 2H, SCH2CO), 4,16–4,33 (преклапање сигнала, 8H, H–C (1’’), H–C (2’’), H–C (3’’), H–C (4’’), H–C (5’’), H–C (2’), H–C (3’), H–C (4’)), 4,43 (m, 1H, H–C (5’)), 5,52 (br. s, 1H, N–CH–S); 13C NMR (50 MHz, CDCl3): δ 13,9 (CH3), 22,4 (CH2CH3), 26,4, 26,8, 31,3 (CH2CH2CH2CH2CH3), 33,4 (SCH2CO), 42,4 (CH2N), 61,4 (N–CH–S), 67,7, 68,4 (C (3’), (C (4’)), 69,0 (C (1’’), C (2’’), C (3’’), C (4’’), C (5’’)), 69,8, 70,0 (C (2’), C (5’)), 85,1 (C (1’)), 170,1 (CO); MS (EI, 70 eV) m/z (%): 371 [M]+ (100), 43 (5,5), 56 (8,7), 77 (2,0), 97 (2,6), 121 (28,2), 148 (6,4), 166 (7,8), 186 (18,5), 199 (5,5), 213 (10,6), 240 (2,2), 263 (2,1), 298 (58), 338 (2,4); HRMS (ESI): m/z израчунато за C19H25FeNOS + H+ [M + H+]: 372,10845. Нађено: 372,10840; Израчунато за C19H25FeNOS (371,10): C, 61,46, H, 6,79, Fe, 15,04, N, 3,77, S, 8,64%. Нађено: C, 61,31, H, 6,90, N, 3,65, S, 8,83%.  3-Октил-2-фероценил-1,3-тиазолидин-4-он (92г). Принос 71%. Т.Т. = 62 °C; IR (KBr, ν, cm-1): 3093, 2954, 2924, 2852, 1662, 1441, 1402, 1379, 1307, 1105, 1002, 821; UV-Vis (CH3CN): λmax (log ε) 422 (2,61), 329 (2,82), 203 (4,80) nm; 1H NMR (200 MHz, CDCl3): δ 0,87 (t, J = 6,5 Hz, 3H, CH3), 1,10–1,31 (m, 12H, (CH2)6CH3), 2,84 (ddd, J = 13,9, 8,6, 5,3 Hz, 1H, CHAHBN), 3,33 (ddd, J = 13,9, 8,6, 5,3 Hz, 1H, CHAHBN), 3,62 (AA’, 2H, SCH2CO), 4,19–4,33 (преклапање сигнала, 8H, H–C (1’’), H–C (2’’), H–C (3’’), H–C (4’’), H–C (5’’), H–C (2’), H–C (3’), H–C (4’)), 4,43 (m, 1H, H–C (5’)), 5,52 (br. s, 1H, N–CH–S); 13C NMR (50 MHz, CDCl3): δ 14,0 (CH3), 22,6 (CH2CH3), 26,7, 26,9, 29,0, 29,1, 31,7 (CH2CH2CH2CH2CH2CH2CH3), 33,4 (SCH2CO), 42,4 (CH2N), 61,4 (N–CH–S), 67,7, 68,4, (C (3’), (C4’)), 69,0 (C (1’’), C (2’’), C (3’’), C (4’’), C (5’’)), 69,8, 70,0 (C (2’), C (5’)), 85,1 (C (1’)), 170,1 (CO); MS (EI, 70 eV) m/z (%): 399 [M]+ (100), 41 (6,5), 56 (7,4), 79 (2,0), 97 (2,5), 121 (27,7), 148 (6,0), 166 (8,4), 186 (20,4), 199 (6,6), 213 (10,2), 230 (10,0), 260 (2,4), 291 (1,9), 326 (56,2), 366 (2,3); HRMS (ESI): m/z израчунато за C21H29FeNOS + H+ [M + H+]: 400,13975. Нађено: Fe S N O H3C(H2C)6 Fe S N O H3C(H2C)4 81  400,13968; Израчунато за C21H29FeNOS (399,13): C, 63,16, H,7,32, Fe, 13,98, N, 3,51, S,8,03%. Нађено: C, 63,09, H, 7,15, N, 3,49, S, 8,00%. 3-Додецил-2-фероценил-1,3-тиазолидин-4-он (92д). Принос 90%. Т.Т. = 70 ºC; IR (KBr, ν, cm-1): 2960, 2921, 2852, 1664, 1466, 1402, 1385, 1287, 1123; UV-Vis (CH3CN): λmax (log ε) 430 (2,61), 324 (2,74), 203 (4,71) nm; 1H NMR (200 MHz, CDCl3): δ 0,87 (t, J = 6,5 Hz, 3H, CH3), 1,04–1,41 (m, 20H, (CH2)10), 2,83 (ddd, J = 14,0, 8,6, 5,4 Hz, 1H, CHAHBN), 3,33 (ddd, J = 14,0, 8,6, 5,4 Hz, 1H, CHAHBN), 3,62 (AA’, 2H, SCH2CO), 4,17–4,34 (преклапање сигнала, 8H, H–C (1’’), H–C (2’’), H–C (3’’), H–C (4’’), H–C (5’’), H–C (2’), H–C (3’), H–C (4’)), 4,44 (m, 1H, H–C (5’)), 5,52 (br. s, 1H, N–CH–S); 13C NMR (50 MHz, CDCl3): δ 14,1 (CH3), 22,6 (CH2CH3), 26,7, 26,9, 29,1–29,6, 31,8((CH2)9CH2CH3), 33,4 (SCH2CO), 42,4 (CH2N), 61,4 (N–CH–S), 67,7, 68,4 (C (3’), (C (4’)), 69,0 (C (1’’), C (2’’), C (3’’), C(4’’), C (5’’)), 69,8, 70,0 (C (2’), C (5’)), 85,2 (C (1’)), 170,1 (CO); MS (EI, 70 eV) m/z (%): 455 [M]+ (100), 43 (8,5), 55 (4,3), 69 (1,8), 97 (1,8), 121 (17,4), 148 (4,6), 166 (6,6), 186 (13,9), 199 (6,8), 213 (7,1), 230 (10,1), 288 (3,1), 310 (0,7), 347 (0,8), 382 (32,3), 422 (1,1); HRMS (ESI): m/z израчунато за C25H37FeNOS + H+ [M + H+]: 456,20235. Нађено: 456,20239; Израчунато за C25H37FeNOS (441,18): C, 65,92, H, 8,19, Fe, 12,26, N, 3,08, S 7,04%. Нађено: C, 66,50, H, 7,85, N, 3,54, S, 7,52%. 2-Фероценил-3-хексадецил-1,3-тиазолидин-4-он (92ђ). Принос 62%. Т.Т. = 75ºC; IR (KBr, ν, cm-1): 3091, 2951, 2918, 2871, 2849, 1664, 1465, 1402, 1381, 1308, 1105, 1002, 823; UV-Vis (CH3CN): λmax (log ε) 441 (2,20), 324 (2,25), 203 (4,72) nm; 1H NMR (200 MHz, CDCl3): δ 0,88 (t, J = 6,6 Hz, 3H, CH3), 1,03–1,39 (m, 28H, (CH2)14CH3), 2,82 (ddd, J = 13,8, 8,4, 5,4 Hz, 1H, CHAHBN), 3,33 (ddd, J = 13,8, 8,4, 5,4 Hz, 1H, CHAHBN), 3,62 (AA’, 2H, SCH2CO), 4,18–4,32 (преклапање сигнала, 8H, H–C (1’’), H–C (2’’), H–C (3’’), H–C (4’’), H–C (5’’), H–C (2’), H–C (3’), H–C (4’)), 4,43 (m, 1H, H–C (5’)), 5,52 (br. s, 1H, N–CH–S); 13C NMR (50 MHz, CDCl3): δ 14,1 (CH3), 22,7 (CH2CH3), 26,7, 26,9, 29,2–29,7, 31,9 ((CH2)13CH2CH3), 33,5 (SCH2CO), 42,4 (CH2N), 61,4 (N–CH–S), 67,8, 68,5, (C (3’), (C (4’)), 69,0 (C (1’’), C (2’’), C (3’’), C (4’’), C (5’’)), 69,8, 70,0 (C (2’), C (5’)), 85,2 (C (1’)), 170,1 (CO); MS (EI, 70 eV) m/z (%): 511 [M]+ (100), 43 (12,3), 57 (5,3), 69 (2,4), Fe S N O H3C(H2C)9 Fe S N O H3C(H2C)14 82  97 (1,6), 121 (12,9), 148 (4,2), 166 (6,3), 186 (11,4), 199 (7,1), 213 (6,2), 230 (11,0), 260 (1,4), 287 (1,6), 324 (0,9), 344 (1,4), 366 (0,5), 397 (0,4), 438 (18,7), 478 (0,6); HRMS (ESI): m/z израчунато за C29H45FeNOS + H+ [M + H+]: 512,26495. Нађено: 512,26501. Израчунато за C29H45FeNOS (511,26): C, 68,08, H, 8,87, Fe, 10,92, N, 2,77, S, 6,27%. Нађено: C, 67,83, H, 7,85, N, 2,88, S, 6,26%. 3-(4-Метоксифенетил)-2-фероценил-1,3-тиазолидин-4-он (92е). Принос 82%. Т.Т. = 130 ºC; IR (KBr, ν, cm-1): 3100,2965, 2924, 2838, 1668, 1511, 1458, 1401, 1304, 1241, 1177, 1029, 817; UV-Vis (CH3CN): λmax (log ε) 438 (2,18), 431 (2,18), 197 (5,08) nm; MS (EI, 70 eV) m/z (%):421 [M]+ (100), 39 (1,1), 56 (8,2), 65 (2,0), 77 (6,6), 91 (5,9), 105 (4,3), 121 (36,6), 135 (16,5),148 (2,4), 166 (5,4), 186 (9,5), 199 (7,0), 226 (9,0), 255 (1,8), 287 (14,8), 314 (7,1), 348 (12,5),388 (0,2); HRMS (ESI): m/z израчунато за C22H23FeNOS + H+ [M + H+]: 406,09280. Нађено: 406,09286. Израчунато за C22H23FeNOS (405,08): C, 62,71, H, 5,50, Fe, 13,25, N, 3,32, S, 7,62%. Нађено: C, 62,59, H, 5,31, N, 3,60, S, 7,58%. 3-Бензил-2-фероценил-1,3-тиазолидин-4-он (92ж). Принос 80%. Т.Т. = 105 ºC; IR (KBr, ν, cm-1): 3087, 2924, 1670, 1495, 1435, 1399, 1299, 1106, 817, 746, 698; UV-Vis (CH3CN): λmax (log ε) 430 (2,24), 322 (2,38), 202 (4,78) nm; 1H NMR (200 MHz, CDCl3): δ 3,61 (d, J = 15,1 Hz, 1H, CHACHBN), 3,72 (AA’, 2H, SCH2CO), 4,04 (dt, J = 2,2, 1,1, 1,1 Hz, 1H, H–C (2’)), 4,15–4,23 (преклапање сигнала, 6H, H–C (1’’), H–C (2’’), H–C (3’’), H–C (4’’), H–C (5’’), H–C (3’)), 4,27 (m, 1H, H–C (4’)), 4,41 (m, 1H, H–C (5’)), 4,96 (br. d, J = 15,1 Hz, 1H, CHAHBN), 5,34 (br. s, 1H, N–CH–S), 7,13 (m, 2H, H–C (2’’’), H–C (6’’’)), 7,30 (преклапање сигнала, 3H, H–C (3’’’), H–C (4’’’), H–C (5’’’)); 13C NMR (50 MHz, CDCl3): δ 33,3 (SCH2CO), 45,2 (CH2N), 60,5 (N–CH–S), 67,6, 68,2 (C (3’), C (4’)), 68,9 (C (1’’), C (2’’), C (3’’), C (4’’), C (5’’)), 69,8, 70,5 (C (2’), C (5’)), 84,6 (C (1’)), 127,4 (C (4’’’)), 127,8, 128,5 (C (2’’’), C (3’’’), C (5’’’), C (6’’’)), 135,7 (C (1’’’)), 170,5 (CO); MS (EI, 70 eV) m/z (%): 377 [M]+ (100), 39 (1,3), 56 (10,0), 65 (4,9), 91 (21,2), 121 (25,3), 146 (6,4), 166 (6,0), 186 (7,9), 213 (26,4), 237 (6,5), 269 (6,8), 304 (16,4), 344 (0,8); HRMS (ESI): m/z израчунато за C20H19FeNOS + H+ Fe S N OH3CO 1' Fe S N O 2' 3' 5' 1''3'' 4'' 5'' 1''' 2''' 3''' 4''' 5''' 6''' 83  [M + H+]: 378,06150. Нађено: 378,06143. Израчунато за C20H19FeNOS (377,05): C, 63,67, H, 5,08, Fe, 14,80, N, 3,71, S, 8,50%. Нађено: C, 63,91, H, 4,96, N, 3,89, S, 8,78%. 2-Фероценил-3-фурфурил-1,3-тиазолидин-4-он (92з). Принос 99%. IR (KBr, ν, cm-1): 2924, 1680, 1504, 1400,1301, 1229, 1046, 1009, 821, 739; UV-Vis (CH3CN): λmax (log ε) 431 (2,28), 422 (2,39), 204 (4,82) nm; 1H NMR (200 MHz, CDCl3): δ 3,65 (АА’, 2H, SCH2CO), 3,70 (d, J = 15,6 Hz, 1H, CHACHBN), 4,18–4,34 (преклапање сигнала, 8H, H–C (1’’), H–C (2’’), H–C (3’’), H–C (4’’), H–C (5’’), H–C (2’), H–C (3’), H–C (4’)), 4,43 (dt, J = 2,4, 1,3, 1,3 Hz, 1H, H–C (5’)), 4,81 (br. d, J = 15,6 Hz, 1H, CHAHBN), 5,48 (br. s, 1H, N–CH–S), 6,18 (br. d, J = 3,2 Hz, 1H, H–C (3’’’)), 6,30 (dd, J = 3,2, 1,8 Hz, 1H, H–C (4’’’)), 7,37 (dd, J = 1,8, 0,7 Hz, 1H, H–C (5’’’)); 13C NMR (50 MHz, CDCl3): δ 33,2 (SCH2CO), 38,1 (CH2N), 60,7 (N–CH–S), 67,6, 68,4 (C (3’), C (4’)), 69,0 (C (1’’), C (2’’), C (3’’), C (4’’), C (5’’)), 69,8, 70,7 (C (2’), C (5’)), 84,3 (C (1’)), 108,6, 110,2 (C (3’’’), C (4’’’)), 142,3 (C (5’’’)), 149,5 (C (2’’’)), 170,2 (CO); MS (EI, 70 eV) m/z (%): 367 [M]+ (100), 39 (1,4), 56 (10,1), 81 (21,3), 94 (2,6), 121 (26,4), 129 (6,5), 146 (2,1), 166 (4,5), 186 (7,8), 213 (28,6), 230 (9,6), 244 (5,1), 259 (3,2), 292 (9,0), 320 (0,3), 334 (0,3); HRMS (ESI): m/z израчунато за C18H17FeNO2S + H+ [M + H+]: 368,04077. Нађено: 368,04075. Израчунато за C18H17FeNO2S (367,03): C, 58,87, H, 4,67, Fe, 15,21, N, 3,81, S 8,73%. Нађено: C, 58,59, H, 4,73, N, 3,68, S, 8,53%. 3-Tенил-2-фероценил-1,3-тиазолидин-4-он (92и). Принос 74%. IR (KBr, ν, cm-1): 2924, 1676, 1400, 1301, 1232, 1106, 1039, 823, 703; UV-Vis (CH3CN): λmax (log ε) 430 (2,32), 322 (2,33), 202 (4,89) nm; 1H NMR (200 MHz, CDCl3): δ 3,64 (АА’, 2H, SCH2CO), 3,87 (d, J = 15,3 Hz, 1H, CHACHBN), 4,20–4,32 (преклапање сигнала, 8H, H–C (1’’), H–C (2’’), H–C (3’’), H–C (4’’), H–C (5’’), H–C (2’), H–C (3’), H–C (4’)), 4,43 (dt, J = 2,4, 1,2, 1,2 Hz, 1H, H–C (5’)), 4,95 (br. d, J = 15,3 Hz, 1H, CHAHBN), 5,45 (br. s, 1H, N–CH–S), 6,86 (br. d, J = 3,4 Hz, 1H, H–C (3’’’)), 6,93 (dd, J = 5,0, 3,4 Hz, H–C (4’’’)), 7,21 (dd, J = 5,0, 1,2 Hz, 1H, H–C (5’’’)); 13C NMR (50 MHz, CDCl3): δ 33,2 (SCH2CO), 39,9 (CH2N), 60,2 (N–CH–S), 67,7, 68,4 (C (3’), C (4’)), 69,0 (C (1’’), C (2’’), C (3’’), C (4’’), C (5’’)), 69,9, 70,6 (C (2’), C (5’)), 84,3 (C (1’)), 125,4, 126,6, 126,8 (C (3’’’), C (4’’’), C (5’’’)), 138,1 (C(2’’’)), 170,2 (CO); MS (EI, 70 eV) m/z (%): 383 [M]+ (100), 45 (3,4), 56 (10,4), 97 (32,7), 121 (27,8), 166 (4,7), 1' Fe S N O 2' 3' 5' 1''3'' 4'' 5'' 2''' 3''' 4''' 5''' o 1' Fe S N O 2' 3' 5' 1''3'' 4'' 5'' 2''' 3''' 4''' 5''' s 84  186 (8,3), 213 (26,3), 230 (9,2), 245 (1,6), 275 (6,0), 290 (1,2), 308 (11,4), 334 (0,3); HRMS (ESI): m/z израчунато за C18H17FeNOS2 + H+ [M + H+]: 383,01010. Нађено: 383,01002. Израчунато за C18H17FeNOS2 (383,01): C, 56,40, H, 4,47, Fe, 14,57, N, 3,65, S,16,73%. Нађено: C, 56,12, H, 4,28, N, 3,47, S, 16,94%. 3-Фенил-2-фероценил-1,3-тиазолидин-4-он (92ј). Принос 61%. Т.Т. = 146 ºC. IR (KBr, ν, cm-1): 3099, 2910, 1674, 1592, 1495, 1454, 1402, 1276, 1216, 1026, 811, 692; UV-Vis (CH3CN): λmax (log ε) 439 (2,19), 431 (2,18), 203 (4,92) nm; 1H NMR (200 MHz, CDCl3): δ 3,70 (dt, J = 2,5, 1,3, 1,3 Hz, 1H, H–C (2’)), 3,81 (АА’, 2H, SCH2CO), 3,99 (dt, J = 2,5, 1,3, 1,3 Hz, 1H, H–C (3’)), 4,15 (s, 5H, H–C (1’’), H–C (2’’), H–C (3’’), H–C (4’’), H–C (5’’)), 4,20 (tdd, J = 2,5, 1,3, 0,9 Hz, 1H, H–C (4’)), 4,47 (dt, J = 2,5, 1,3, 1,3 Hz, 1H, H–C (5’)), 5,90 (br. s, 1H, N–CH–S), 6,96 (dd, J = 8,0, 1,7 Hz, 2H, H–C (2’’’), H–C (6’’’)), 7,28 (m, 3H, преклапање сигнала, H–C (3’’’), H–C (4’’’), H–C (5’’’)); 13C NMR (50 MHz, CDCl3): δ 33,6 (SCH2CO), 63,9 (N–CH–S), 67,2, 68,3 (C (3’), C (4’)), 68,8 (C (1’’), C (2’’), C (3’’), C (4’’), C (5’’)), 69,4, 70,4 (C (2’), C (5’)), 85,3 (C (1’)), 127,7 (C (2’’’), C (6’’’)), 127,8 (C (4’’’)), 129,0 (C (3’’’), C (5’’’)), 137,1 (C (1’’’)), 170,3 (CO); MS (EI, 70 eV) m/z (%): 363 [M]+ (100), 39 (1,1), 56 (8,9), 77 (7,8), 104 (3,5), 121 (20,2), 145 (4,0), 186 (10,4), 224 (15,4), 255 (6,0), 269 (3,0), 290 (34,6), 303 (0,1), 321 (2,3), 345 (0,1); HRMS (ESI): m/z израчунато за C19H17FeNOS + H+ [M + H+]: 364,04585. Нађено: 364,04578. Израчунато за C19H17FeNOS (363,04): C, 62,82, H, 4,72, Fe, 15,37, N, 3,86, S 8,83%. Нађено: C, 53,01, H, 4,83, N, 3,55, S, 8,98%. 3-(m-Толил)-2-фероценил-1,3-тиазолидин-4-он (92к). Принос 63%. Т.Т. = 138 ºC, IR (KBr, ν, cm-1): 3079, 2920, 1674, 1587, 1491, 1456, 1365, 1300, 1216, 1106, 1000, 821, 692; UV-Vis (CH3CN): λmax (log ε) 431 (2,23), 204 (4,96) nm; 1H NMR (200 MHz, CDCl3): δ 2,27 (s, 3H, CH3), 3,71 (dt, J = 2,5, 1,3, 1,3 Hz, 1H, H–C (2’)), 3,81 (АА’, 2H, SCH2CO), 4,01 (dt, J = 2,5, 2,5, 1,3 Hz, 1H, H–C (3’)), 4,15 (s, 5H, H–C (1’’), H–C (2’’), H–C (3’’), H–C (4’’), H–C (5’’)), 4,21 (tdd, J = 2,5, 1,3, 0,5 Hz, 1H, H–C (4’)), 4,47 (dt, J = 2,5, 1,3, 1,3 Hz, 1H, H–C (5’)), 5,88 (br. s, 1H, N–CH–S), 6,79 (преклапање сигнала, 2H, H–C (2’’’), H–C (6’’’)), 7,05 (br. d, J = 7,6, 1H,H–C (4’’’)), 7,18 (t, J = 7,6 Hz, 1H‚ H–C (5’’’)); 13C NMR (50 MHz, CDCl3): δ 21,2 (CH3), 33,6 (SCH2CO), 64,0 (N–CH–S), 67,2, 68,3 (C (3’), C (4’)), 68,9 (C (1’’), C (2’’), C (3’’), C (4’’), C (5’’)), 1' Fe S N O 2' 3' 5' 1''3'' 4'' 5'' 1''' 2''' 3''' 4''' 5''' 6''' Fe S N O 85  69,4, 70,5 (C (2’), C (5’)), 85,5 (C (1’)), 124,8, 128,4, 128,7, 128,8 (C (2’’’), C (4’’’), C (5’’’), C (6’’’)), 137,1 (C (3’’’)), 139,0 (C (1’’’)),170,4 (CO); MS (EI, 70 eV) m/z (%): 377 [M]+ (100), 39 (1,9), 56 (10,1), 77 (1,7), 91 (11,1), 121 (25,1), 152 (9,2), 166 (7,9), 182 (12,3), 214 (8,7), 238 (18,8), 269 (6,9), 283 (3,5),304 (41,3), 319 (0,2), 335 (2,6), 359 (0,2); HRMS (ESI): m/z израчунато за C20H19FeNOS + H+ [M + H+]: 378,06150. Нађено: 378,06154; Израчунато за C20H19FeNOS (377,05): C, 63,67, H, 5,08, Fe, 14,80, N, 3,71, S, 8,50%. Нађено: C, 63,51, H, 5,22, N, 3,61, S, 8,64%. 3-(p-Толил)-2-фероценил-1,3-тиазолидин-4-он (92л). Принос 48%. Т.Т. = 154 ºC; IR (KBr, ν, cm-1): 3072, 2923, 1672, 1514, 1457, 1385, 1367, 1304, 1007, 1026; UV-Vis (CH3CN): λmax (log ε) 432 (2,26), 204 (4,85) nm; 1H NMR (200 MHz, CDCl3): δ 2,29 (s, 3H, CH3), 3,73 (br. s, 1H, H–C (2’)), 3,81 (АА’, 2H, SCH2CO), 4,03 (br. s, 1H, H–C (3’)), 4,17 (s, 5H, H–C (1’’), H–C (2’’), H–C (3’’), H–C (4’’), H–C (5’’)), 4,22 (br. s, 1H, H–C (4’)), 4,49 (br. s, 1H, H–C (5’)), 5,85 (br. s, 1H, N–CH–S), 6,82 (AA’BB’, J = 8,2 Hz, 2H, H–C (2’’’), H–C (6’’’)), 7,09 (AA’BB’, J = 8,2 Hz, 2H, H–C (3’’’), H–C (5’’’)); 13C NMR (50 MHz, CDCl3): δ 21,1 (CH3), 33,6 (SCH2CO), 64,0 (N–CH–S), 67,3, 68,4 (C (3’), C (4’)), 68,9 (C (1’’), C (2’’), C (3’’), C (4’’), C (5’’)), 69,4, 70,6 (C (2’), C (5’)), 85,5 (C (1’)), 127,6 (C (2’’’), C (6’’’)), 129,7 (C (3’’’), C (5’’’)), 134,5 (C (4’’’)), 137,8 (C (1’’’)), 170,5 (CO); MS (EI, 70 eV) m/z (%): 377 [M]+ (100), 39 (1,8), 56 (10,9), 77 (1,9), 91 (9,4), 121 (25,9), 152 (10,4), 166 (7,4), 182 (11,9), 214 (9,8), 238 (16,5), 269 (6,5), 283 (2,8), 304 (35), 319 (0,2), 335 (2,4), 359 (0,2); HRMS (ESI): m/z израчунато за C20H19FeNOS + H+ [M + H+]: 378,06150. Нађено: 378,06152. Израчунато за C20H19FeNOS (377,05): C, 63,67, H, 5,08, Fe, 14,80, N, 3,71, S, 8,50%. Нађено:C, 63,38, H, 5,08, N, 3,93, S, 8,62%. 4.3 Синтеза 2-фероценил-2,3-дихидрохинолин-4(1H)-она 95а-в Раствор фероценилалдехида (214 mg, 1 mmol, 90), одговарајућег o-аминоацето- фенона (93а-в, 1 mmol) и 100 mg NaOH (2,5 mmol) у 10 mL етанола меша се на собној температури преко ноћи, па се растварач упари и остатку дода 10 mL воде. Смеса се неутралише раствором 2 M HCl (лакмус папир) и екстрахује дихлорметаном (2×30 mL). Спојени органски слојеви се суше анхидрованим Na2SO4 преко ноћи, раствор процеди и растварач упари. Остатак се пречишћава стубном хроматографијом Fe S N O 86  (20 g SiO2, хексан/етил-ацетат 9 : 1). Добијени халкони 94а-в се даље третирају према јеном од три поступка (методе А, Б и В). Метода А. У авану са тучком добро се хомогенизује смеса одговарајуће количине монтморилонита К-10 (видети Наше радове, Табела 3.3.) и одговарајућег халкона добијеног у претходном експерименту (94а-в, ≈ 1 mmol), пренесе у тефлонску кивету и зрачи без растварача у микроталасном реактору (500 W, 5 min). Након охлађења на собну температуру (око 10 min), смеса се екстрахује етил-ацетатом (320 mL), прикупљени органски слојеви суше изнад анхидрованог Na2SO4 преко ноћи, па се раствор процеди и растварач упари. Остатак се пречишћава стубном хроматографијом (20 g SiO2, хексан/етил-ацетат = 9 : 1), а добијени резултати приказани су у Табели 3.3. Метода Б. Раствор одговарајућег халкона (94а-в, ≈ 1 mmol) у 6 mL смеше глацијалне сирћетне киселине и 90% ортофосфорне (1:1, v/v) меша se 50 min на собној температури и излије у смесу воде и леда. Добијени раствор се екстрахује етил- ацетатом (3×25 mL), спојени органски слојеви исперу раствором NaHCO3 и суше анхидрованим Na2SO4 преко ноћи. Раствор процеди и растварач и упари, а остатак пречишћава стубном хроматографијом (20 g SiO2, хексан/етил-ацетат = 9 : 1). Добијени резултати дати су у Табели 3.3. Метода В. Раствор одговарајућег халкона (94а-в, 1 mmol) у смеси сирћетне и ортофосфорне киселине (6 mL, 1:1 v/v) сипа се у епрувету и третира у ултразвучном купатилу 50 min, а потом обрађује као у претходном експерименту. Резултати су дати у Табели 3.3. Једињења 95а-в  су нова, а физички и спектрални подаци на основу којих су идентификовани следе.  2-Фероценил-2,3-дихидрохинолин-4-(1H)-он (95а). Т.Т. = 150 ºC; IR (KBr, ν, cm-1): 3323, 3078, 2991, 1651, 1608, 1507, 1480, 1321, 769; 1H NMR (200 MHz, CDCl3): δ 2,74 (dd, J = 16,2, 12,4 Hz, 1H, H–C (3ax)), 2,87 (ddd, J = 16,2, 4,6, 1,2 Hz, 1H, H–C (3eq)), 4,19–4,25 (m, 8H, Fc, 5H из несупституисаног Cp и 3H из супституисаног Cp), 4,27–4,31 (m, 1H, Fc), 4,45 (dd, J = 12,4, 4,6 Hz, 1H, H–C (2)), 4,65 (br. s, 1H, NH), 6,72 (br. d, J = 7,7 Hz, 1H, H–C (8)), 6,77 (br. t, J ~ 7,4 Hz, 1H, H–C (6)), 7,33 (ddd, J = 7,7, 6,3, 1,4 Hz, 1H, H–C (7)), 7,86 (dd, J = 7,7, 1,4 Hz, H–C (5)); 13C NMR (200 MHz, CDCl3): δ 45,9 (C (3)), 52,9 (C (2)), 66,1, 66,7 (C (3’), C (4’)), 68,2, 68,3 (C (2’), C (5’)), 68,5 (C (1’’), C (2’’), C (3’’), C (4’’), C (5’’)), 89,3 (C (1’)), 115,7 (C (8)), 118,1 1' 2'' 3' 5' 1'' 3'' 4'' Fe HN O 4' 2' 2 3 4 4a 5 6 78 8a 87  (C (6)), 118,9 (C (4a)), 127,6 (C (5)), 135,3 (C (7)), 151,2 (C (8a)), 193,5 (C (4)); Израчунато за C19H17FeNO (331,07): C, 68,90, H, 5,17, N, 4,23%; Нађено: C, 68,87, H, 5,14, N, 4,25%. 2-Фероценил-6-хлор-2,3-дихидрохинолин-4-(1H)-он (95б). Т.Т. = 144 °C; IR (KBr, ν, cm-1): 3340, 2924, 1657, 1615, 1501, 1480, 1408, 1294, 816; 1H NMR (200 MHz, CDCl3): δ 2,73 (dd, J = 16,5, 13,5 Hz, 1H, H–C (3ax)), 2,87 (ddd, J = 16,5, 4,0, 1,5 Hz, 1H, H–C (3eq)), 4,20–4,24 (m, 8H, Fc, 5H из несупституисаног Cp и 3H из супституисаног Cp), 4,28–4,25 (m, 1H, Fc), 4,45 (dd, J = 13,5, 4,0 Hz, 1H, H–C (2)), 4,66 (br. s, 1H, NH), 6,66 (d, J = 8,5 Hz, 1H, H–C (8)), 7,26 (dd, J = 8,5, 2,5 Hz, 1H, H–C (7)), 7,82 (d, J = 2,5 Hz, 1H, H–C (5)); 13C NMR (200 MHz, CDCl3): δ 45,4 (C (3)), 52,9 (C (2)), 66,1, 66,6 (C (3’), C (4’)), 68,3 (C (1’’), C (2’’), C (3’’), C (4’’), C (5’’)), 68,4, 68,6 (C (2’), C (5’)), 88,9 (C (1’)), 117,3 (C (8)), 119,6 (C (4a)), 123,5 (C (6)), 126,9 (C (5)), 135,2 (C (7)), 149,5 (C (8a)), 192,4 (C (5)); Израчунато за C19H16ClFeNO (365,03): C, 62,41, H, 4,41, N, 3,83%; Нађено: C, 62,37, H, 4,44, N, 3,79%. 6-Бром-2-фероценил-2,3-дихидрохинолин-4-(1H)-он (95в). Т.Т. = 179 °C; IR (KBr, ν, cm- 1): 3327, 2924, 1657, 1600, 1494, 1394, 1284, 820; 1H NMR (200 MHz, CDCl3): δ 2,73 (dd, J = 16,5, 13,0 Hz, 1H, H–C (3ax)), 2,87 (ddd, J = 16,5, 4,0, 1,5 Hz, 1H, H–C (3eq)), 4,20–4,24 (m, 8H, Fc, 5H из несупституисаног Cp и 3H из супституисаног Cp), 4,25–4,27 (m, 1H, Fc), 4,44 (dd, J = 13,0, 3,5 Hz, 1H, H–C (2)), 4,66 (br. s, 1H, NH), 6,61 (d, J = 8,5 Hz, 1H, H–C (8)), 7,38 (dd, J = 8,5, 2,5 Hz, 1H, H–C (7)), 7,96 (d, J = 2,5 Hz, 1H, H–C (5)); 13C NMR (200 MHz, CDCl3): δ 45,3 (C (3)), 52,7 (C (2)), 66,1, 66,6 (C (3’), C (4’)), 68,3 (C (1’’), C (2’’), C (3’’), C (4’’), C (5’’)), 68,4, 68,5 (C (2’), C (5’)), 88,8 (C (1’)), 110,4 (C (6)), 117,6 (C (8)), 120,1 (C (4a)), 130,0 (C (5)), 137,8 (C (7)), 149,9 (C (8a)), 192,2 (C (4)); Израчунато за C19H16BrFeNO (408,9765): C, 55,65, H, 3,93, N, 3,42%; Нађено: C, 55,60, H, 3,97, N, 3,41%. 88  4.4 Синтеза 6-фероценил-1,3-оксазинана (102а-к), 6-фероценил-1,3- оксази-нан-2-она (104а-г, ђ-к) и 4-фероценилтетрахидропирими- дин-2(1Н)-она (106а, в, г, ђ, е, з, ј, к) 4.4.1 Синтеза акрилоилфероцена (97) Раствору 2,8 g (15 mmol) фероцена (1) у сувом дихлорметану (100 mL) дода се 2,0 g (15 mmol) анхидрованог AlCl3 па се охлади у леденом купатилу. Насталој суспензији дода се 1,9 g (15mmol) 3-хлорпропиолнил-хлорид, реакциона смеса меша 5 h, излије у 100 mL воде и процеди кроз Бихнеров (Büchner) левак. Органски слој се одвоји а водени екстрахује дихлорметаном (2×30 mL), па се спојени органски слојеви исперу засићеним раствором NaHCO3 и суше изнад анхидрованог Na2SO4 преко ноћи. Растварач се упари, остатак раствори у толуену и пропусти кроз кратку колону силика- гела. Толуен се уклони дестилацијом под сниженим притиском, чврстом остатку дода 1,5 g калијум-ацетат и 100 mL етанола и настала смеса рефлуктује 2,5 h. Етанол се упари под сниженим притиском, остатку дода 100 mL воде и екстрахује дихлорметаном (3×30 mL). Спојени органски слојеви се суше преко ноћи изнад анхидрованог Na2SO4, растварач упари а остатак пречишћава хроматографијом на стубу (20 g SiO2/толуен). Добија се 2,41 g (~ 10,5 mmol, ~ 67%) чистог акрилоилфероцена. 4.4.2 Синтеза 3-(фениламино)-1-фероценилпропан-1-она 99а-о Синтеза у микроталасном реактору. Смеса акрилоилфероцена (97; 240 mg, 1 mmol), одговарајућег амина (98а-о, 2 mmol) и 100 mg монтморилонита изложи се дејству микроталасног зрачења (5 min, 500 W), па се смеса охлађена на собну температуру екстрахује дихлорметаном (2×30 mL). Сакупљени органски слојеви суше се анхидрованим Na2SO4 преко ноћи, раствор процеди, растварач упари, а остатак пречишћава флеш хроматографијом (20 g SiO2; толуеном се са колоне спира неизреаговани анилин, а остатак смешом хексан/етил-ацетат = 9 : 1). Добијени резултати дати су у Табели 3.6. Синтеза у ултразвучном купатилу. Смеса акрилоилфероцена (97; 240 mg, 1 mmol), одговарајућег амина (2 mmol, 98а-о) и 100 mg монтморилонита К-10 излаже се једночасовном дејству ултразвучних таласа, па се реакциона смеса обради као у претходном експерименту Резултати су дати у Табели 3.6. 89  Све добијене Манихове базе 99а-о су нова једињења, а физички и спектрални подаци на основу којих су идентификована следе. 3-(Фениламино)-1-фероценилпропан-1-он (99а). Т.Т. = 106 ºC; IR (KBr, ν, cm-1): 3358, 3085, 2933, 1655, 1603, 1515, 1498, 1456, 1401, 1274, 1069, 825, 746, 695; 1H NMR (200 MHz, CDCl3): δ 3,01 (t, J = 6,1 Hz, 2H, CO–CH2), 3,57 (t, J = 6,1 Hz, 2H, N–CH2), 4,11 (s, 5H, Fc), 4,21 (br. s, 1H, NH), 4,49 (t, J = 1,9 Hz, 2H, Fc), 4,76 (t, J = 1,9 Hz, 2H, Fc), 6,58–6,78 (m, 3H, Ar), 7,10–7,30 (m, 2H, Ar); 13C NMR (50 MHz, CDCl3): δ 38,0 (C–C), 38,5 (N–C), 69,1 (Fc), 69,7 (Fc), 72,3 (Fc), 78,7 (Fc), 112,9 (Ar), 117,4 (Ar), 129,2 (Ar), 147,6 (Ar), 203,4 (CO); Израчунато за C19H19FeNO (333,08): C, 68,49, H, 5,75, N, 4,20%. Нађено: C, 68,51, H, 5,71, N, 4,23%. 3-(о-Толиламино)-1-фероценилпропан-1-он (99б). Т.Т. = 112 ºC; IR (KBr, ν, cm-1): 3393, 3098, 2918, 1668, 1603, 1503, 1457, 1408, 1260, 1068, 826, 754; 1H NMR (200 MHz, CDCl3): δ 2,13 (s, 3H, CH3), 3,04 (t, J = 6,0 Hz, 2H, CO–CH2), 3,54–3,69 (m, 2H, N–CH2), 4,10 (s, 5H, Fc), 4,14 (br. s, 1H, NH), 4,49 (t, J = 1,9 Hz, 2H, Fc), 4,76 (t, J = 1,9 Hz, 2H, Fc), 6,59–6,76 (m, 2H, Ar), 6,98–7,25 (m, 2H, Ar); 13C NMR (50 MHz, CDCl3): δ 17,4 (CH3), 38,1 (C–C), 38,6 (N–C), 69,1 (Fc), 69,7 (Fc), 72,3 (Fc), 78,7 (Fc), 109,5 (Ar), 117,0 (Ar), 122,4 (Ar), 127,0 (Ar), 130,2 (Ar), 145,6 (Ar), 203,5 (CO); Израчунато за C20H21FeNO (347,10): C, 69,18, H, 6,10, N, 4,03%. Нађено: C, 69,19, H, 6,13, N, 3,99%. 3-(m-Толиламино)-1-фероценилпропан-1-он (99в). Т.Т. = 121 ºC; IR (KBr, ν, cm-1): 3349, 3082, 2934, 1655, 1603, 1457, 1404, 1281, 1265, 1106, 826, 773; 1H NMR (200 MHz, CDCl3): δ 2,27 (s, 3H, CH3), 2,99 (t, J = 6,1 Hz, 2H, CO–CH2), 3,55 (t, J = 6,1 Hz, 2H,N–CH2), 4,11 (s, 5H, Fc), 4,13 (br. s, 1H, NH), 4,48 (t, J = 1,9 Hz, 2H, Fc), 4,75 (t, J = 1,9 Hz, 2H, Fc), 6,48–6,59 (m, 3H, Ar), 6,92–7,18 (m, 1H, Ar); 13C NMR (50 MHz, CDCl3): δ 21,5 (CH3), 38,1 (C–C), 38,6 (N–C), 69,1 (Fc), 69,7 (Fc), 72,2 (Fc), 78,7 (Fc), 110,1 (Ar), 113,8 (Ar), 118,3 (Ar), 129,1 (Ar), 138,9 (Ar), 147,6 (Ar), 203,4 (CO); Израчунато за C20H21FeNO (347,10): C, 69,18, H, 6,10, N, 4,03%; Нађено: C, 69,17, H, 6,07, N, 4,04%. Fe H N O Fe H N O Fe H N O 90  3-(p-Толиламино)-1-фероценилпропан-1-он (99г). Т.Т. = 73 ºC; IR (KBr, ν, cm-1): 3351, 3090, 2918, 1656, 1618, 1521, 1456, 1401, 1273, 1070, 824, 807; 1H NMR (200 MHz, CDCl3): δ 2,22 (s, 3H, CH3), 2,98 (t, J = 6,1 Hz, 2H, CO–CH2), 3,53 (t, J = 6,1 Hz, 2H, N–CH2), 4,06 (br. s, 1H, NH), 4,10 (s, 5H, Fc), 4,47 (t, J = 1,9 Hz, 2H, Fc), 4,74 (t, J = 1,9 Hz, 2H, Fc), 6,57 (d, J = 8,4 Hz, 2H, Ar), 6,99 (d, J = 8,2 Hz, 2H, Ar); 13C NMR (50 MHz, CDCl3): δ 20,2 (CH3), 38,1 (C–C), 38,9 (N–C), 69,0 (Fc), 69,7 (Fc), 72,2 (Fc), 78,7 (Fc), 113,1 (Ar), 126,5 (Ar), 129,7 (Ar), 145,3 (Ar), 203,4 (CO); Израчунато за C20H21FeNO (347,10): C, 69,18, H, 6,10, N, 4,03%; Нађено: C, 69,20, H, 6,10, N, 4,05%. 3-(Меситиламино)-1-фероценилпропан-1-он (99д). Т.Т. = 86 ºC; IR (KBr, ν, cm-1): 3378, 3094, 2940, 1655, 1485, 1456, 1376, 1310, 1243, 1021, 821; 1H NMR (200 MHz, CDCl3): δ 2,22 (s, 3H, p–CH3), 2,31 (s, 6H, o–CH3), 2,97 (t, J = 5,7 Hz, 2H, CO–CH2), 3,25(t, J = 5,7 Hz, 2H, N–CH2), 3,62 (br. s, 1H, NH), 4,18 (s, 5H, Fc), 4,48 (t, J = 1,8 Hz, 2H, Fc), 4,77 (t, J = 1,8 Hz, 2H, Fc), 6,82 (s, 2H, Ar); 13C NMR (50 MHz, CDCl3): δ 18,1 (o-CH3), 20,5(p-CH3), 39,7 (C–C), 43,1 (N–C), 69,1 (Fc), 69,7 (Fc), 72,2 (Fc), 78,7 (Fc), 129,2 (Ar), 130,0 (Ar), 131,2 (Ar), 143,3 (Ar), 203,9 (CO); Израчунато за C22H25FeNO (375,13): C, 70,41, H, 6,71, N, 3,73%; Нађено: C, 70,40, H, 6,70, N, 3,75%. 3-(4-Бутилфениламино)-1-фероценилпропан-1-он (99ђ). 1H NMR (400 MHz, CDCl3) δ 0.89 (t, J = 7.3 Hz, 3H), 1.25–1.38 (m, 2H), 1.47– 1.59 (m, 2H), 2.43–2.54 (m, 2H), 3.01 (t, J = 6.1 Hz, 2H), 3.55 (t, J = 6.1 Hz, 2H), 4.06 (br. s, 1H, OH или NH), 4,12 (s, 5H, Fc), 4.50 (t, J = 1,9 Hz, 2H, Fc), 4.76 (t, J = 1,9 Hz, 2H, Fc), 6.57–6.63 (m, 2H, Ar), 6.97–7.03 (m, 2H, Ar); 13C NMR (100 MHz, CDCl3) δ 14.0, 22.3, 34.0, 34.7, 38.3, 39.1, 69.2, 69.8, 72.4, 78.9, 113.2, 129.2, 132.1, 145.6, 203.5; 1-Фероценил-3-(2-флуорфениламино)пропан-1-он (99е). Т.Т. = 89 ºC; IR (KBr, ν, cm-1): 3383, 3096, 2903, 1665, 1619, 1529, 1402, 1261, 1190, 824, 735; 1H NMR (200 MHz, CDCl3): δ 3,02 (t, J = 6,1 Hz, 2H, CO–CH2), 3,48–3,71(br. q, 2H, N–CH2), 4,12 (s, 5H, Fc), 4,37 (br. s, 1H, NH),4,50 (t, J = 1,8 Hz, 2H, Fc), 4,77 (t, J = 1,8 Hz, 2H, Fc), 6,50–7,13 Fe H N O Bu-n 91  (m, 4H, Ar); 13C NMR (50 MHz, CDCl3): δ 38,1 (C–C), 38,2 (N–C), 69,1 (Fc), 69,7 (Fc), 72,4 (Fc), 78,7 (Fc), 111,9 (JCF = 3,3 Hz, Ar), 114,6 (JC-F = 18,5 Hz, Ar), 116,7 (JC-F = 7,0 Hz, Ar), 124,5 (JC-F = 3,4 Hz, Ar), 136,2 (JC-F = 11,5 Hz, Ar), 151,7 (JC-F = 238,8 Hz, Ar), 202,9 (CO); Израчунато за C19H18FeNO (351,07): C, 64,98, H, 5,17, N, 3,99%; Нађено: C, 64,99, H, 5,20, N, 4,01%. 1-Фероценил-3-(3-флуорфениламино)пропан-1-он (99ж). Т.Т. = 124 ºC; IR (KBr, ν, cm-1): 3362, 3098, 2945, 1654, 1622, 1499, 1457, 1399, 1261, 1154, 1072, 840, 823, 755, 686; 1H NMR (200 MHz, CDCl3): δ 3,01 (t, J = 6,0 Hz, 2H, CO–CH2), 3,46–3,63 (br. q, 2H, N–CH2), 4,12 (s, 5H, Fc), 4,39 (br. s, 1H, NH), 4,51 (t, J = 1,9 Hz, 2H, Fc), 4,77 (t, J = 1,9 Hz, 2H, Fc), 6,28–6,48 (m, 3H, Ar), 7,01–7,20 (m, 1H, Ar); 13C NMR (50 MHz, CDCl3): δ 37,8 (C–C), 38,4 (N–C), 69,1 (Fc), 69,8 (Fc), 72,4 (Fc), 78,6 (Fc), 99,3 (JC-F = 25,3 Hz, Ar), 103,8 (JC-F = 21,6 Hz, Ar), 108,9 (JC-F = 2,3 Hz, Ar), 130,4 (JC-F = 10,2 Hz, Ar), 149,5 (JC-F = 10,6 Hz, Ar), 164,2 (JC-F = 242,8 Hz, Ar), 203,3 (CO); Израчунато за C19H18FFeNO (351,07): C, 64,98, H, 5,17, N, 3,99%; Нађено: C, 64,95, H, 5,17, N, 4,00%. 1-Фероценил-3-(4-флуорфениламино)пропан-1-он (99з). Т.Т.= 127ºC; IR (KBr, ν, cm-1): 3399, 3102, 2911, 1664, 1521, 1461, 1400, 1219, 1050, 818, 785; 1H NMR (200 MHz, CDCl3): δ 3,00 (t, J = 6,0 Hz, 2H, CO–CH2), 3,52 (t, J = 6,0 Hz, 2H, N–CH2), 4,12 (s, 5H, Fc), 4,12 (br. s, 1H, NH), 4,51 (t, J = 1,9 Hz, 2H, Fc), 4,76 (t, J = 1,9 Hz, 2H, Fc), 6,54–6,66 (m, 2H, Ar), 6,82–6,97 (m, 2H, Ar); 13C NMR (50 MHz, CDCl3): δ 37,9 (C–C), 39,3 (N–C), 69,1 (Fc), 69,8 (Fc), 72,4 (Fc), 78,7 (Fc), 99,3 (JC-F = 25,3 Hz, Ar), 103,8 (JC-F = 21,6 Hz, Ar), 113,9 (JC-F = 7,4 Hz, Ar), 115,7 (JC-F = 22,3 Hz, Ar), 144,1 (JC-F = 1,5 Hz, Ar), 155,9 (JC-F = 235,1 Hz, Ar), 203,4 (CO); Израчунато за C19H18FFeNO (351,07): C, 64,98, H, 5,17, N, 3,99%; Нађено: C, 65,00, H, 5,21, N, 3,97%. 1-Фероценил-3-(2-хлорфениламино)пропан-1-он (99и). Т.Т. = 108 ºC; IR (KBr, ν, cm-1): 3418, 3096,2921, 1675, 1599, 1504, 1456, 1410, 1325, 1256, 1025,823, 750; 1H NMR (200 MHz, CDCl3): δ 3,03 (t, J = 6,2 Hz, 2H, CO–CH2), 3,64 (q, J = 6,1 Hz, 2H, N–CH2), 4,12 (s, 5H, Fc), 4,50 (t, J = 1,9 Hz, 2H, Fc), 4,77 (br. s, 1H, NH), 4,77 (t, J = 1,9 Hz, 2H, Fc), 6,55–6,82 (m, 2H, Ar), 7,10–7,33 (m, 2H, Ar); 13C NMR (50 MHz, CDCl3): Fe H N O F Fe H N O F 92  δ 38,1 (C–C), 38,1 (N–C), 69,2 (Fc), 69,8 (Fc), 72,4 (Fc), 78,7 (Fc), 110,9 (Ar), 117,3 (Ar), 119,4 (Ar), 127,8 (Ar), 129,3 (Ar), 143,5 (Ar), 202,7 (CO); Израчунато за C19H18ClFeNO (367,04): C, 62,07, H, 4,93, N, 3,81%; Нађено: C, 62,03, H, 4,94, N, 3,78%. 1-Фероценил-3-(3-хлорфениламино)пропан-1-он (99ј). Т.Т. = 121 ºC; IR (KBr, ν, cm-1): 3353, 3086, 2930, 1654, 1596, 1487, 1456, 1400, 1275, 1248, 1073,822, 758; 1H NMR (200 MHz, CDCl3): δ 3,00 (t, J = 6,0 Hz, 2H, CO–CH2), 3,46–3,61 (br. q, 2H, N–CH2), 4,12 (s, 5H, Fc), 4,36 (br. s, 1H, NH), 4,50 (t, J = 1,9 Hz, 2H, Fc), 4,76 (t, J = 1,9 Hz, 2H, Fc), 6,45–6,72 (m, 3H, Ar), 7,00–7,14 (m, 1H, Ar); 13C NMR (50 MHz, CDCl3): δ 37,8 (C–C), 38,3 (N–C), 69,1 (Fc), 69,7 (Fc), 72,4 (Fc), 78,6 (Fc), 111,4 (Ar), 112,2 (Ar), 117,2 (Ar), 130,2 (Ar), 135,0 (Ar), 148,8 (Ar), 203,2 (CO); Израчунато за C19H18ClFeNO (367,04): C, 62,07, H, 4,93, N, 3,81%; Нађено:C, 62,05, H, 4,96, N, 3,80%. 1-Фероценил-3-(4-хлорфениламино)пропан-1-он (99к). Т.Т. = 51 ºC; IR (KBr, ν, cm-1): 3344, 3092, 2933, 1658, 1596, 1509, 1493, 1456, 1396, 1273, 1088,1066, 824, 799; 1H NMR (200 MHz, CDCl3): δ 2,98 (t, J = 6,0 Hz, 2H, CO–CH2), 3,52 (t, J = 6,0 Hz, 2H, N–CH2), 4,11 (s, 5H, Fc), 4,24 (br. s, 1H, NH), 4,50 (t, J = 1,9 Hz, 2H, Fc), 4,75 (t, J = 1,9 Hz, 2H, Fc), 6,50–6,65 (m, 2H, Ar), 7,01–7,19 (m, 2H, Ar); 13C NMR (50 MHz, CDCl3): δ 37,8 (C–C), 38,7 (N–C), 69,1 (Fc), 69,7 (Fc), 72,4 (Fc), 78,6 (Fc), 113,9 (Ar), 121,8 (Ar), 129,0 (Ar), 146,2 (Ar), 203,3 (CO); Израчунато за C19H18ClFeNO (367,04): C, 62,07, H, 4,93, N, 3,81%; Нађено: C, 62,10, H, 4,94, N, 3,79%. 3-(2-Нитрофениламино)-1-фероценилпропан-1-он (99л). Т.Т. = 96 ºC; IR (KBr, ν, cm-1): 3377, 3116,2935, 1661, 1617, 1568, 1508, 1457, 1399, 1263, 1238,1149, 823, 743; 1H NMR (200 MHz, CDCl3): δ 3,12 (t, J = 6,6 Hz, 2H, CO–CH2), 3,76 (q, J = 6,6 Hz, 2H, N–CH2), 4,17 (s, 5H, Fc), 4,53 (t, J = 1,9 Hz, 2H, Fc), 4,80 (t, J = 1,9 Hz, 2H, Fc), 6,59–6,75 (m, 1H, Ar), 6,96 (d, J = 8,5 Hz, 1H, Ar), 7,40–7,60 (m, 1H, Ar), 8,11–8,42 (m, 2H, NH и Ar); 13C NMR (50 MHz, CDCl3): δ 37,6 (C–C), 38,3 (N–C), 69,1 (Fc), 69,7 (Fc), 72,5 (Fc), 78,3 (Fc), 113,4 (Ar), 115,3 (Ar), 126,9 (Ar), 136,1 (Ar), 145,0 Fe H N O Cl Fe H N O Cl Fe H N O Cl Fe H N O O2N 93  (Ar), 201,5 (CO); Израчунато за C19H18FeN2O3 (378,07): C, 60,34, H, 4,80, N, 7,41%; Нађено: C, 60,30, H, 4,81, N, 7,41%. 3-(3-Нитрофениламино)-1-фероценилпропан-1-он (99љ). Т.Т. = 91 ºC; IR (KBr, ν, cm-1): 3329, 3098, 2956, 1656, 1620, 1526, 1456, 1347, 1265, 1238, 826, 782; 1H NMR (200 MHz, CDCl3): δ 3,05 (t, J = 5,9 Hz, 2H, CO–CH2), 3,70–3,54 (br. q, 2H, N–CH2), 4,13 (s, 5H, Fc), 4,53 (t, J = 1,9 Hz, 2H, Fc), 4,71 (br. s, 1H, NH), 4,78 (t, J = 1,9 Hz, 2H, Fc), 6,85–6,98 (m, 1H, Ar), 7,21–7,36 (m, 1H, Ar), 7,40–7,60 (m, 2H, Ar); 13C NMR (50 MHz, CDCl3): δ 37,7 (C–C), 38,4 (N–C), 69,2 (Fc), 69,8 (Fc), 72,6 (Fc), 78,4 (Fc), 105,9 (Ar), 111,9 (Ar), 119,2 (Ar), 129,8 (Ar), 147,6 (Ar), 148,6 (Ar), 203,3 (CO); Израчунато за C19H18FeN2O3 (378,07): C, 60,34, H, 4,80, N, 7,41%; Нађено: C, 60,32, H, 4,84, N, 7,43%. 3-(4-Нитрофениламино)-1-фероценилпропан-1-он (99м). Т.Т. = 189-190 ºC; IR (KBr, ν, cm-1): 3356, 3107, 2907, 1653, 1604, 1501, 1471, 1319, 1115, 832, 754; 1H NMR (200 MHz, CDCl3): δ 3,07 (t, J = 6,1 Hz, 2H, CO–CH2), 3,66 (t, J = 6,1 Hz, 2H, N–CH2), 3,74 (br. s, 1H, NH), 4,14 (s, 5H, Fc), 4,58 (t, J = 1,9 Hz, 2H, Fc), 4,79 (t, J = 1,9 Hz, 2H, Fc), 6,61 (d, J = 9,2 Hz, 2H, Ar), 8,09 (d, J = 9,2 Hz, 2H, Ar); 13C NMR (50 MHz, CDCl3): δ 38,0 (C–C), 38,0 (N–C), 69,5 (Fc), 70,1 (Fc), 73,2 (Fc), 78,3 (Fc), 111,0 (Ar), 126,8 (Ar), 137,5 (Ar), 153,5 (Ar), 204,0 (CO); Израчунато за C19H18FeN2O3 (378,07): C, 60,34, H, 4,80, N, 7,41%; Нађено: C, 60,33, H, 4,82, N, 7,38%. 3-[(2-Ацетилфенил)амино]-1-фероценилпропан-1-он (99н). Т.Т. = 119 ºC; IR (KBr, ν, cm- 1): 3322, 1667, 1630, 1567, 1515, 1503, 1458, 1250, 1228,1205, 1168, 1146, 1107, 949, 752, 609; 1H NMR (200 MHz, CDCl3): δ 2,57 (s, CH3), 3,08 (br. t, J = 7,0 Hz, CH2 (2)), 3,68 (dt, J = 6,9, 5,8 Hz, CH2 (3)), 4,17 (s, H–C (1’’), H–C (2’’), H–C (3’’), H–C (4’’), H–C (5’’), 4,51 (pseudo t, H–C (3’), H–C (4’)), 4,80 (pseudo t, H–C (2’)), 6,61 (ddd, J = 8,1, 7,1, 1,1 Hz, H–C (4’’’)), 6,83 (br. d, J = 8,6 Hz, H–C (6’’’)), 7,40 (ddd, J = 8,6, 7,1, 1,6 Hz, H–C (5’’’)), 7,75 (dd, J = 8,1, 1,6 Hz, H–C (3’’’)), 9,01 (t, J = 5,8 Hz, NH); 13C NMR (50 MHz, CDCl3): δ 27,9 (CH3), 38,8, 37,4 (C(2), C (3)), 69,3 (C (3’), C (4’)), 69,8 (C (1’’), C (2’’), C (3’’), C (4’’), C (5’’)), 72,4 Fe H N O NO2 94  (C (2’), C (5’)), 78,8 (C (1’)), 114,2, 111,5 (C (4’’’), C (6’’’)), 117,8 (C (2’’’)), 135,1, 132,8 (C (3’’’), C (5’’’)), 150,6 (C (1’’’)), 200,8 (COMe), 202,1 (C (1)); Израчунато за C21H21FeNO2 (375,24): C, 67,22, H, 5,64, N, 3,73%; Нађено: C, 67,30, H, 5,67, N, 3,71%. 3-[(3-Ацетилфенил)амино]-1-фероценилпропан-1-он (99њ). Т.Т. = 106 ºC; IR (KBr, ν, cm-1): 3363, 1677, 1652, 1600, 1519, 1473, 1453, 1283, 1263, 1106, 826, 782, 688; 1H NMR (200 MHz, CDCl3): δ 2,57 (s, CH3), 3,04 (t, J = 5,9 Hz, CH2 (2)), 3,62 (pseudo q, J = 5,9 Hz, CH2 (3)), 4,11 (s, H–C (1’’), H–C (2’’), H–C (3’’), H–C (4’’), H–C (5’’)), 4,43 (br. t, J = 5,9 Hz, NH), 4,51 (pseudo t, J = 2,0 Hz, H–C (3’), H–C (4’)), 4,77 (pseudo t, J = 2,0 Hz, H–C (2’), H–C (5’)), 6,84 (ddd, J = 8,2, 2,6, 1,3 Hz, H–C (6’’’)), 7,22–7,30 (m, преклапање сигнала, H–C (2’’’), H–C (4’’’), H–C (5’’’)); 13C NMR (50 MHz, CDCl3): δ 26,7 (CH3), 38,6, 37,9 (C (2), C (3)), 69,2 (C (3’), C (4’)), 69,8 (C (1’’), C (2’’), C (3’’), C (4’’), C (5’’)), 72,5 (C (2’), C (5’)), 78,7 (C (1’)), 111,1 (C (2’’’)), 118,2, 118,0 (C (4’’’), C (6’’’)), 129,4 (C (5’’’)), 138,2 (C (3’’’)), 147,2 (C (1’’’)), 198,7 (COMe), 203,4 (C (1)); Израчунато за C21H21FeNO2 (375,24): C, 67,22, H, 5,64, N, 3,73%; Нађено: C, 67,23, H, 5,60, N, 3,72%. 3-[(4-Ацетилфенил)амино]-1-фероценилпропан-1-он (99о). Т.Т. = 182 ºC; IR (KBr, ν, cm-1): 3330, 1665, 1647, 1600, 1584, 1456, 1361, 1283, 1263, 1180, 1042, 959, 825, 584; 1H NMR (200 MHz, CDCl3): δ 2,49 (s, CH3), 3,04 (t, J = 5,9 Hz, CH2 (2)), 3,66 (pseudo q, J = 5,9 Hz, CH2 (3)), 4,11 (s, H–C (1’’), H–C (2’’), H–C (3’’), H–C (4’’), H–C (5’’)), 4,53 (pseudo t, J = 2,0 Hz, H–C (3’), H–C (4’)), 4,78 (pseudo t, J = 2,0 Hz, H–C (2’), H–C (5’)), 4,81(br. t, J = 5,9 Hz, NH), 6,61 (AA’XX’, Jo = 8,9 Hz, Jm =2,4 Hz, H–C (2’’’), H–C (6’’’)), 7,84 (AA’XX’, Jo = 8,9 Hz, Jm =2,4 Hz, H–C (3’’’), H–C (5’’’)); 13C NMR (50 MHz, CDCl3): δ 26,0 (Me), 38,0, 37,9 (C (2), C (3)), 69,2 (C (3’), C (4’)), 69,8 (C (1’’), C (2’’), C (3’’), C (4’’), C (5’’)), 72,6 (C (2’), C (5’)), 78,6 (C (1’)), 111,4 (C (2’’’), (C (6’’’)), 126,8 (C (4’’’), 130,9 (C (3’’’), C (5’’’)), 151,6 (C (1’’’)), 196,3 (COMe), 203,0 (C (1)); Израчунато за C21H21FeNO2 (375,24): C, 67,22, H, 5,64, N, 3,73%; Нађено: C, 67,18, H, 5,59, N, 3,70%. 95  4.4.3 Синтеза 3-(фениламино)-1-фероценилпропан-1-ола 101а-к У метанолски раствор (30 mL) одговарајуће Манихове базе (1 mmol, 99а-к) дода се натријумборхидрид у вишку (189 mg, 5 mmol) у порцијама, смеса се меша на собној температури и прати танкослојном хроматографијом. По завршеној реакцији (око 1.5 h) упари се растварач, а остатку дода вода. Смеса се екстрахује дихлорметаном (3×20 mL), спојени органски слојеви исперу водом и засићеним раствором натријум- хлорида и суше анхидрованим Na2SO4 преко ноћи. Раствор се процеди и растварач упари, а остатак пречисти стубном хроматографијом (20 g Al2O3, хексан/етил-ацетат = 9 : 1). 3-(Фениламино)-1-фероценилпропан-1-ол (101а). Принос 90%. Т.Т. = 90 ºC; IR (KBr, ν, cm-1): 3296, 2916, 1601, 1507, 1055, 816, 754, 697; 1H NMR (CDCl3, 400 MHz): δ 1,93 (pseudo ddt, J = 13,9, 8,2, 6,5 Hz, 1H, H–C (2b)), 2,00 (pseudo dtd, J = 13,9, 6,5, 4,2 Hz, 1H, H–C (2a)), 2,19 (br. s, 1H, NH или OH), 3,28 (pseudo t, J = 6,5 Hz, 2H, H–C (3a), H–C (3b)), 3,96 (br. s, 1H, NH или OH), 4,18 (s, 5H, Fc), 4,15–4,20 (преклапање сигнала, m, 3H, Fc), 4,23–4,26 (m, 1H, Fc), 4,52 (dd, J = 8,3, 4,2 Hz, 1H, H–C (1)), 6,57–6,65 (m, 2H, H–C (2’’’), H–C (6’’’), Ar), 6,65–6,72 (m, 1H, H–C (4’’’), Ar), 7,11–7,21 (m, 2H, H–C (3’’’), H–C (5’’’), Ar); 13C NMR (CDCl3, 100 MHz): δ 37,3 (C (2)), 41,6 (C (3)), 65,6, 67,0, 68,1, 68,2, 68,5, 68,8 (C (1’’), C (2’’), C (3’’), C (4’’), C (5’’), Fc), 93,8 (C (1’), Fc), 113,1 (C (2’’’), C (6’’’), Ar), 117,5 (C (4’’’), Ar), 129,3 (C (3’’’), C (5’’’), Ar), 148,5 (C (1’’’), Ar); MS (ES+): m/z = 336,10 (MH+); HRMS (ESI): m/z израчунато за C19H21FeNO + H+ [M + H+]: 336,1051. Нађено: 336,1039.` 3-(o-Толиламино)-1-фероценилпропан-1-ол (101б). Принос 92%. Т.Т. = 86 ºC; IR (KBr, ν, cm-1): 3314, 3250, 2914, 1504, 824, 750; 1H NMR (CDCl3, 400 MHz): δ 1,92–2,11 (m, 2H), 2,12 (s, 3H, CH3), 2,23 (br. s, 1H, OH или NH), 3,31 (pseudo t, J = 6,4 Hz, 2H), 3,94 (br. s, 1H, OH или NH), 4,18 (s, 5H, Fc), 4,14–4,20 (m, 3H, Fc), 4,23–4,27 (m, 1H, Fc), 4,53(dd, J = 8,2, 4,0 Hz, 1H), 6,57–6,68 (m, 2H, Ar), 7,01–7,07 (m, 1H, Ar), 7,07–7,15 (m, 1H, Ar); 13C NMR (CDCl3, 100 MHz): δ 17,5, 37,1, 41,5, 65,4, 66,9, 68,0, 68,1, 68,3, 69,0, 93,6, 109,6, 116,8, 122,0, 127,1, 130,0, 146,3; HRMS (ESI): m/z израчунато за C20H23FeNO + H+ [M + H+]: 350,1207. Нађено: 350,1200. Fe H N OH 1''' 2''' 3''' 4''' 5''' 6''' 2 3 H N OH 1' 2'' 3' 5' 1'' 3'' 4'' Fe 4' 2' 1 96  3-(m-Толиламино)-1-фероценилпропан-1-ол (101в). Принос 90%. Т.Т. = 96 °C; IR (KBr, ν, cm-1): 3303, 2915, 1514, 1278, 1057, 813, 786, 698; 1H NMR (CDCl3, 400 MHz): δ 1,88–2,05 (m, 2H), 2,17 (br. s, 1H, OH или NH), 2,27 (s, 3H, CH3), 3,27 (pseudo t, J = 6,5 Hz, 2H), 3,89 (br. s, 1H, OH или NH), 4,19 (s, 5H, Fc), 4,16-4,21 (m, 3H, Fc), 4,25 (m, 1H, Fc), 4,52 (dd, J = 8,3, 4,2 Hz, 1H), 6,40–6,47 (m, 2H, Ar), 6,49–6,55 (m, 1H, Ar), 7,02–7,09 (m, 1H, Ar); 13C NMR (CDCl3, 100 MHz): δ 21,6, 37,2, 41,5, 65,5, 66,9, 68,0, 68,1, 68,3, 68,7, 93,7, 110,2, 113,8, 118,3, 129,1, 139,0, 148,4; MS (ES+): m/z = 349,10 (M+). HRMS (ESI): m/z израчунато за C20H23FeNO + H+ [M + H+]: 350,1207. Нађено: 350,1206. 3-(p-Толиламино)-1-фероценилпропан-1-ол (101г). Принос 80%. Т.Т. = 122ºC; IR (KBr, ν, cm-1): 3298, 2897, 1506, 1256, 813, 750; 1H NMR (CDCl3, 400 MHz): δ 1,87–2,05 (m, 2H), 2,23 (s, 3H, CH3), 3,68 (br. s, 1H, OH или NH), 3,26 (pseudo t, J = 6,5 Hz, 2H), 4,19 (s, 5H, Fc), 4,15–4,21 (m, 3H, Fc), 4,25 (pseudo dt, J = 2,4, 1,4 Hz, 1H, Fc), 4,53 (dd, J = 8,2, 4,3 Hz, 1H), 6,52–6,58 (m, 2H, Ar), 6,95–7,01 (m, 2H, Ar); 13C NMR (CDCl3, 100 MHz): δ 20,4, 37,3, 41,9, 65,4, 66,9, 68,0, 68,0, 68,3, 68,8, 93,7, 113,2, 126,6, 129,7, 146,1; MS (ES+): m/z = 349,10 (M+); HRMS (ESI): m/z израчунато за C20H23FeNO + H+ [M + H+]: 350,1207. Нађено: 350,1197. 3-(Меситиламино)-1-фероценилпропан-1-ол (101д). Принос 91%. Т.Т. = 74 ºC; IR (KBr, ν, cm-1): 3307, 2910, 1484, 1221, 1026, 993, 827, 809; 1H NMR (CDCl3, 400 MHz): δ 1,87–2,02 (m, 2H), 2,23 (br. s, 3H, CH3), 2,28 (br. s, 6H, 2CH3), 3,00–3,10 (m, 1H), 3,09–3,17 (m, 1H), 3,20 (br. s, 2H, OH и NH), 4,15 (pseudo t, J = 1,8 Hz, 2H, Fc), 4,19 (s, 5H, Fc), 4,18 (pseudo dt, J = 3,1, 1,8 Hz, 1H, Fc), 4,28 (pseudo dt, J = 3,1, 1,8 Hz, 1H, Fc), 4,63 (dd, J = 8,6, 3,9 Hz, 1H), 6,83 (br. s, 2H, Ar); 13C NMR (CDCl3, 100 MHz): δ 18,3, 20,6, 38,5, 47,0, 65,8, 66,5, 67,8, 67,9, 68,4, 69,8, 93,5, 129,5, 130,1, 131,9, 143,1; MS (ES+): m/z = 378,10 (MH+); HRMS (ESI): m/z израчунато за C22H27FeNO + H+ [M + H+]: 378,1520. Нађено: 378,1516. 3-(4-Бутилфениламино)-1-фероценилпропан-1-ол (101ђ). Принос 97%. Т.Т. = 100 °C. IR (KBr, ν, cm-1): 3101, 2922, 1515, 1055, 811; 1H NMR (CDCl3, 400 MHz): δ 0,90 (t, J = 7,3 Hz, 3H), 1,25–1,40 (m, 2H), 1,48–1,59 (m, 2H), 1,85-2,03 (m, 2H), 2,29 (br. s, 1H, OH или Fe H N OH 97  NH), 2,45–2,52 (m, 2H), 3,25 (pseudo t, J = 6,5 Hz, 2H), 3,56 (br. s, 1H, OH или NH), 4,16 (s, 5H, Fc), 4,12–4,18 (m, 3H, Fc), 4,21–4,25 (m, 1H, Fc), 4,51 (dd, J = 8,2, 4,2 Hz, 1H), 6,51–6,57 (m, 2H, Ar), 6,94–6,99 (m, 2H, Ar); 13C NMR (CDCl3, 100 MHz): δ 13,9, 22,3, 33,9, 34,7, 37,6, 41,9, 65,6, 66,9, 67,9, 68,0, 68,4, 68,8, 93,9, 113,3, 129,1, 132,0, 146,4; MS (ES+): m/z = 391,2 (M+); HRMS (ESI): m/z израчунато за C23H29FeNO + H+ [M + H+]: 392,1677. Нађено: 392,1660. 1-Фероценил-3-(2-флуорфениламино)пропан-1-ол (101е). Принос 93%. Т.Т. = 70 ºC; IR (KBr, ν, cm-1): 3358, 3093, 1617, 1515, 816, 742; 1H NMR (CDCl3, 400 MHz): δ 1.90–2,07 (m, 2H), 2,20 (br. s, 1H, OH или NH), 3,24–3.37 (m, 2H), 4,18 (s, 5H, Fc), 4,06–4,30 (преклапање сигнала m, 5H, 4Fc и OH или NH), 4,52 (dd, J = 8,4, 4,2 Hz, 1H), 6.60 (pseudo tdd, J = 8.0, 5.0, 1.4 Hz, 1H), 6,70 (pseudo td, J =8.0, 1.2 Hz, 1H, Ar), 6,95 (ddd, J = 12.0, 8.0, 1.2 Hz, 1H, Ar), 6,98 (br. pseudo t, J ~ 8.0 Hz, 1H, Ar); 13C NMR (CDCl3, 100 MHz): δ 37,2, 40,9, 65,4, 66,9, 68,0, 68,1, 68,3, 68,4, 93,6, 112,1 (d, JC–F = 2,9 Hz), 114,3 (d, JC-F = 18,3 Hz), 116,4 (d, JC-F = 7,3 Hz), 124,6 (d, JC-F = 3,7 Hz), 136,8 (d, 2JC-F = 11,5 Hz), 151,6 (d, 1JC-F = 238,2 Hz); MS (ES+): m/z = 353,1 (M+); HRMS (ESI): m/z израчунато за C19H20FFeNO - OH+ [M - OH+]: 336,0851. Нађено: 336,0845. 1-Фероценил-3-(3-флуорфениламино)пропан-1-ол (101ж). Принос 91%. Т.Т. = 88 ºC; IR (KBr, ν, cm-1): 3102, 1620, 1494, 1148, 820, 760; 1H NMR (CDCl3, 400 MHz): δ 1,87–2,05 (m, 2H), 2,09 (br. s, 1H, OH или NH), 3,25 (pseudo t, J = 6,5 Hz, 2H), 4,20 (s, 5H, Fc), 4,16–4,22 (m, 3H, Fc), 4,24–4,26 (m, 1H, Fc), 4,51 (dd, J = 8,2, 4,1 Hz, 1H), 6,25–6,31 (m, 1H, Ar), 6,33–6,40 (m, 2H, Ar), 7,03–7,12 (m, 1H, Ar); 13C NMR (CDCl3, 100 MHz): δ 37,0, 41,3, 65,3, 66,9, 68,1, 68,2, 68,3, 68,7, 93,6, 99,3 (d, JC-F = 25,3 Hz), 103,5 (d, JC-F = 21,6 Hz), 108,7 (d, JC-F = 2,2 Hz), 130,2 (d, JC-F = 10,3 Hz), 150,2 (d, JC-F = 10,8 Hz), 164,2 (d, JC-F = 242,5 Hz). MS (ES+): m/z = 353,1 (M+). HRMS (ESI): m/z израчунато за C19H20FFeNO - OH+ [M - OH+]: 336,0851. Нађено: 336,0845. 1-Фероценил-3-(4-флуорфениламино)пропан-1-ол (101з). Принос 95%. Т.Т. = 80 ºC; IR (KBr, ν, cm-1): 3261, 2918, 1512, 1213, 812; 1H NMR (CDCl3, 400 MHz): δ 1,87–2,04 (m, 2H), 2,19 (br. s, 1H, OH или NH), 3,24 (pseudo t, J = 6,5 Hz, 2H), 3,87 (br. s, 1H, OH или Fe H N OH F Fe H N OH F Fe H N OH Bu-n 98  NH), 4,20 (s, 5H, Fc), 4,17–4,21 (m, 3H, Fc), 4,24–4,26 (m, 1H, Fc), 4,52 (dd, J = 8,2, 4,2 Hz, 1H), 6,51–6,57 (m, 2H, Ar), 6,84–6,92 (m, 2H, Ar); 13C NMR (CDCl3, 100 MHz): δ 37,1, 42,2, 65,3, 66,9, 68,0, 68,1, 68,3, 68,8, 93,7, 113,8 (d, JC-F = 7,4 Hz), 115,6 (d, JC-F = 22,2 Hz), 144,7 (d, JC-F = 1,8 Hz), 155,8 (d, JC-F = 234,7 Hz); MS (ES+): m/z = 353,1 (M+); HRMS (ESI): m/z израчунато за C19H20FFeNO - OH+ [M - OH+]: 336,0851. Нађено: 336,0848. 1-Фероценил-3-(2-хлорфениламино)пропан-1-ол (101и). Принос 90%. IR (KBr, ν, cm-1): 3308, 2911, 1482, 1221, 1028, 998, 827, 809; 1H NMR (CDCl3, 400 MHz): δ 1,92–2,09 (m, 2H), 2,10 (br. s, 1H, OH или NH), 3,32 (pseudo t, J = 5,9 Hz, 2H), 4,19 (s, 5H, Fc), 4,04–4,22 (m, 3H, Fc), 4,23–4,28 (m, 1H, Fc), 4,53 (dd, J = 7,8, 3,7 Hz, 1H), 4,67 (br. s, 1H, OH или NH), 6,57–6,69 (m, 2H, Ar), 7,09–7,16 (m, 1H, Ar), 7,21–7,27 (m, 1H, Ar); 13C NMR (CDCl3, 100 MHz): δ 37,0, 41,0, 65,4, 66,9, 68,1, 68,1, 68,3, 68,4, 93,6, 111,1, 117,0, 119,1, 127,8, 129,1, 144,2; MS (ES+): m/z = 352,0 (M – OH+); HRMS (ESI): m/z израчунато за C19H20ClFeNO - OH+ [M - OH+]: 352,0555. Нађено: 352,0564. 1-Фероценил-3-(3-хлорфениламино)пропан-1-ол (101ј). Принос 98%. Т.Т. = 94 ºC; IR (KBr, ν, cm-1): 3098, 1596, 1486, 1050, 819, 764; 1H NMR (CDCl3, 400 MHz): δ 1,85–2,06 (m, 2H), 2,10 (br. s, 1H, OH или NH), 3,25 (pseudo t, J = 6,5 Hz, 2H), 4,20 (s, 5H, Fc), 4,17–4,22 (m, 3H, Fc), 4,24–4,26 (m, 1H, Fc), 4,51 (dd, J = 8,3, 4,1 Hz, 1H), 6,44–6,48 (m, 1H, Ar), 6,55–6,58 (m, 1H, Ar), 6,62–6,66 (m, 1H, Ar), 7,02–7,08 (m, 1H, Ar); 13C NMR (CDCl3, 100 MHz): δ 36,9, 41,3, 65,3, 67,0, 68,1, 68,2, 68,3, 68,7, 93,6, 111,2, 112,4, 117,0, 130,1, 135,0, 149,5; MS (ES+): m/z = 369,0 (M+); HRMS (ESI): m/z израчунато за C19H20ClFeNO - OH+ [M - OH+]: 352,0555. Нађено: 352,0553. 1-Фероценил-3-(4-хлорфениламино)-пропан-1-ол (101к). Принос 85%. Т.Т. = 104 ºC; IR (KBr, ν, cm-1): 3253, 2921, 1617, 1513, 815, 742; 1H NMR (CDCl3, 400 MHz): δ 1,87–2,05 (m, 2H), 2,11 (br. s, 1H, OH или NH), 3,24 (pseudo t, J = 6,5 Hz, 2H), 4,04 (br. s, 1H, OH или NH), 4,20 (s, 5H, Fc), 4,13–4,21 (m, 3H, Fc), 4,23–4,25 (m, 1H, Fc), 4,51 (dd, J = 8,2, 4,2 Hz, 1H), 6,49–6,55 (m, 2H, Ar), 7,08–7,13 (m, 2H, Ar); 13C NMR (CDCl3, 100 MHz): δ Fe H N OH Cl Fe H N OH Cl 99  37,0, 41,6, 65,3, 66,9, 68,1, 68,2, 68,3, 68,8, 93,7, 113,9, 121,8, 129,0, 147,0; MS (ES+): m/z = 352,0 (M - OH+); HRMS (ESI): m/z израчунато за C19H20ClFeNO - OH+ [M - OH+]: 352,0555. Нађено: 352,0547. 4.4.4 Синтеза N-супституисаних 6-фероценил-1,3-оксазинана 102а-к У тетрахидрофурански раствор одговарајућег 1,3-аминоалкохола 101а-к (1 mmol) дода се 0,082 mL 37%-ног воденог раствора формалдехида (30 mg, 1 mmol) и смеса меша на собној температури преко ноћи. По завршеној реакцији упари се растварач, остатак разблажи водом и смеса екстрахује дихлорметаном (3×20 mL). Спојени органски слојеви се суше анхидрованим Na2SO4 преко ноћи, раствор процеди, растварач упари, а остатак пречишћава хроматографијом на стубу (20 g SiO2, хексан/етил-ацетат = 8 : 2). Једињења 102а-к су нова, а физички и спектрални подаци на основу којих су идентификована следе. 3-Фенил-6-фероценил-1,3-оксазинан (102a). Принос 78%. Т.Т. = 86 ºC; IR (KBr, ν, cm-1): 2922, 1689, 1507, 1060, 813; 1H NMR (CDCl3, 400 MHz): δ 1,78 (pseudo ddt, J =13,1, 2,9, 2,4 Hz, 1H, H–C (5eq)), 2,02 (dddd, J = 13,1, 12,7, 11,2, 4,3 Hz, 1H, H–C (5ax)), 3,49 (ddd, J = 13,5, 12,7, 2,9 Hz, 1H, H-C (4ax)), 3,91 (pseudo ddt, J = 13,5, 4,3, 2,3 Hz, 1H, H–C (4eq)), 4,12 (s, 5H, H–C (1’’), H–C (2’’), H–C (3’’), H–C (4’’), H–C (5’’), Fc), 4,07–4,15 (m, 2H, H–C (3’’), H–C (4’’), Fc), 4,17 (pseudo dt, J = 2,5, 1,3 Hz, H–C (2’’) или H–C (5’’), Fc), 4,22 (pseudo dt, J = 2,5, 1,3 Hz, H–C (2’’) или H–C (5’’), Fc), 4,48 (dd, J = 11,2, 2,4 Hz, 1H, H–C (6ax)), 4,74 (d, J = 10,7 Hz, H–C (2ax), 1H), 5,30 (dd, J = 10,7, 2,3 Hz, H–C (2eq), 1H), 6,87–6,93 (m, 1H, H–C (4’), Ar), 7,09–7,13 (m, 2H, H–C (2’), H–C (6’), Ar), 7,27–7,34 (m, 2H, H–C (3’), H–C (5’), Ar); 13C NMR (CDCl3, 100 MHz): δ 29,2 (C (5)), 49,9 (C (4)), 66,0 (C (2’’) или C (5’’), Fc), 67,3 (C (2’’) или C (5’’), Fc), 67,8 (C (3’’) или C (4’’), Fc), 68,0 (C (3’’) или C (4’’), Fc), 68,6 (C (1’’’), C (2’’’), C (3’’’), C (4’’’), C (5’’’), Fc), 76,0 (C (6)), 81,3 (C (2)), 88,9 (C (1’’), Fc), 118,4 (C (2’), C (6’), Ar), 120,5 (C (4’), Ar), 129,1 (C (3’), C (5’), Ar), 148,9 (C (1’), Ar); MS (ES+): m/z = 348,1 (MH+); HRMS (ESI): m/z израчунато за C20H21FeNO + H+ [M + H+]: 348,1050. Нађено: 348,1041. Fe H N OH Cl 2 1''3'' 5''4'' 2'' N O 4 5 6 1' 2''' 3' 5'1''' 3''' 4''' Fe 4'2' 6' 100  3-(o-Толил)-6-фероценил-1,3-оксазинан (102б). Принос 99%. Т.Т. = 102 ºC; IR (KBr, ν, cm-1): 2954, 1491, 1067, 763; 1H NMR (CDCl3, 400 MHz): δ 1,71 (pseudo dq, J =13,1, 2,3 Hz, 1H), 2,02 (pseudo dtd, J = 11,7, 4,7 Hz, 1H), 2,30 (br.s, 3H, CH3), 3,37 (pseudo ddt, J = 13,3, 4,7, 2,1 Hz, 1H), 3,45 (ddd, J = 13,3, 12,1, 2,8 Hz, 1H), 4,16 (s, 5H, Fc), 4,12–4,18 (преклапање сигнала, 2H, Fc), 4,20–4,23 (m, 1H, Fc), 4,25–4,28 (m, 1H, Fc), 4,45 (dd, J = 11,3, 2,1 Hz, 1H), 4,76 (d, J = 10,5 Hz, 1H), 4,94 (dd, J = 10,5, 1,9 Hz, 1H), 7,00 (br. pseudo t, J = 7.4 Hz, 1H, Ar), 7.14 (br. pseudo t, J = 7.5 Hz, 1H, Ar), 7,17 (br. d, J = 7.0 Hz, 1H, Ar), 7,55 (br. d, J = 7.9 Hz, 1H, Ar); 13C NMR (CDCl3, 100 MHz): δ 18,1, 28,9, 50,1, 66,0, 67,4, 67,8, 68,0, 68,6, 75,5, 83,4, 89,2, 122,6, 123,4, 126,3, 131,0, 132,4, 148,8; MS (ES+): m/z = 362,10 (MH+); HRMS (ESI): m/z израчунато за C21H23FeNO + H+ [M + H+]: 362,1207. Нађено: 362,1202. 3-(m-Толил)-6-фероценил-1,3-оксазинан (102в). Принос 98%. Т.Т. = 112 ºC; IR (KBr, ν, cm-1): 2921, 1685, 1591, 1483, 1000, 982, 778; 1H NMR (CDCl3, 400 MHz): 1,73–1,80 (m, 1H), 1,96–2,08 (m, 1H), 2,32 (s, 3H, CH3), 3,47 (ddd, J = 13,5, 12,7, 2,8 Hz, 1H), 3,89 (pseudo ddt, J = 13,5, 4,3, 2,3 Hz, 1H), 4,10–4,15 (m, 2H, Fc), 4,12 (s, 5H, Fc), 4,17 (pseudo dt, J = 2,4, 1,3 Hz, 1H, Fc), 4,22 (pseudo dt, J = 2,4, 1,3 Hz, 1H, Fc), 4,47 (dd, J = 11,2, 2,3 Hz, 1H), 4,73 (d, J = 10,7 Hz, 1H), 5,29 (dd, J = 10,7, 2,3 Hz, 1H), 6,70–6,74 (m, 1H, Ar), 6,87–6,97 (m, 2H, Ar), 7,12–7,19 (m, 1H, Ar); 13C NMR (CDCl3, 100 MHz): δ 21,7, 29,2, 50,0, 66,0, 67,3, 67,7, 67,9, 68,6, 75,9, 81,3, 88,9, 115,6, 119,2, 121,4, 128,9, 138,8, 148,9; MS (ES+): m/z = 362,10 (MH+); HRMS (ESI): m/z израчунато за C21H23FeNO + H+ [M + H+]: 362,1207. Нађено: 362,1194. 3-(p-Толил)-6-фероценил-1,3-оксазинан (102г). Принос 99%. Т.Т. = 98 ºC; IR (KBr, ν, cm- 1): 2863, 1513, 999, 979, 808; 1H NMR (CDCl3, 400 MHz): δ 1,71–1,78 (m, 1H), 1,95–2,08 (m, 1H), 2,27 (s, 3H, CH3), 3,46 (ddd, J= 13,4, 12,7, 2,8 Hz, 1H), 3,83 (pseudo ddt, J = 13,4, 4,3, 2,3 Hz, 1H), 4,10–4,15 (m, 2H, Fc), 4,12 (s, 5H, Fc), 4,17 (pseudo dt, J = 2,5, 1,3 Hz, 1H, Fc), 4,22 (pseudo dt, J = 2,5, 1,3 Hz, 1H, Fc), 4,45 (dd, J = 11,2, 2,4 Hz, 1H), 4,72 (d, J = 10,6 Hz, 1H), 5,24 (dd, J = 10,6, 2,3 Hz, 1H), 6,99–7,05 (m, 2H, Ar), 7,05–7,11 (m, 2H, Ar); 13C NMR (CDCl3, 100 MHz): δ 20,5, 101  29,1, 50,3, 66,0, 67,3, 67,7, 67,9, 68,6, 75,9, 81,6, 89,0, 118,8, 129,6, 130,0, 146,6; MS (ES+): m/z = 362,10 (MH+); HRMS (ESI): m/z израчунато за C21H23FeNO + H+ [M + H+]: 362,1207. Нађено: 362,1202. 3-(Меситил)-6-фероценил-1,3-оксазинан (102д). Принос 36%. Т.Т. = 140 ºC; IR (KBr, ν, cm-1): 2923, 1684, 1163, 1058, 999, 815; 1H NMR (CDCl3, 400 MHz): δ 1,91 (pseudo dq, J = 12,6, 2,4 Hz, 1H), 2,11 (pseudo qd, J = 12,0, 4,8 Hz, 1H), 2,24 (br. s, 3H, CH3), 2,25 (br. s, 3H, CH3), 2,38 (br. s, 3H, CH3), 3,16 (pseudo ddt, J = 12,1, 4,8, 1,7 Hz, 1H), 3,56 (pseudo td, J = 12,0, 2,8 Hz, 1H), 4.12–4.17 (m, 2H, Fc), 4,18 (s, 5H, Fc), 4,26 (pseudo dt, J =2,4, 1,3 Hz, 1H, Fc), 4,29 (pseudo dt, J = 2,4, 1,3 Hz, 1H, Fc), 4,34 (dd, J = 11,3, 2,2 Hz, 1H), 4,56 (dd, J = 8,9, 1,7 Hz, 1H), 4,93 (d, J = 8,9 Hz, 1H), 6,79 (br. s, 1H, Ar), 6,89 (br. s, 1H, Ar); 13C NMR (CDCl3, 100 MHz): δ 19,3, 19,8, 20,7, 32,3, 49,0, 66,0, 67,6, 67,7, 68,0, 68,6, 75,5, 82,7, 89,2, 129,3, 129,5, 134,6, 136,3, 137,1, 143,9; MS (ES+): m/z = 390,1 (MH+); HRMS (ESI): m/z израчунато за C23H27FeNO + H+ [M + H+]: 390,1520. Нађено: 390,1507. 3-(4-Бутилфенил)-6-фероценил-1,3-оксазинан (102ђ). Принос 81%. Т.Т. = 70 ºC; IR (KBr, ν, cm-1): 2928, 1684, 1514, 1163, 996, 981, 815; 1H NMR (CDCl3, 400 MHz): δ 0,91 (t, J = 7,3 Hz, 3H), 1,29–1,39 (m, 2H), 1,51–1,61 (m, 2H), 1,69–1,77 (m, 1H), 1,96–2,08 (m, 1H), 2,50–2,56 (m, 2H), 3,43 (ddd, J = 13,4, 12,5, 2,9 Hz, 1H), 3,82 (pseudo ddt, J = 13,4, 4,3, 2,3 Hz, 1H), 4,11 (s, 5H, Fc), 4,08–4,13 (m, 2H, Fc), 4,16 (pseudo dt, J = 2,5, 1,3 Hz, 1H, Fc), 4,21 (pseudo dt, J = 2,5, 1,3 Hz, 1H, Fc), 4,44 (dd, J = 11,2, 2,4 Hz, 1H), 4,70 (d, J = 10,5 Hz, 1H), 5,24 (dd, J = 10,5, 2,3 Hz, 1H), 6,99–7,03 (m, 2H, Ar), 7,04–7,09 (m, 2H, Ar); 13C NMR (CDCl3, 100 MHz): δ 13,9, 22,4, 29,6, 33,7, 34,8, 50,2, 66,1, 67,2, 67,7, 67,8, 68,6, 76,0, 81,8, 89,4, 118,6, 129,0, 135,1, 146,9; MS (ES+): m/z = 404,2 (MH+); HRMS (ESI): m/z израчунато за C24H29FeNO + H+ [M + H+]: 404,1677. Нађено: 404,1671. 6-Фероценил-3-(2-флуорфенил)-1,3-оксазинан (102е). Принос 84%. Т.Т. = 100 ºC; IR (KBr, ν, cm-1): 2921, 1496, 1002, 808, 755; 1H NMR (CDCl3, 400 MHz): δ 1,72–1,80 (m, 1H), 1,93–2,06 (m, 1H), 3,49–3,59 (m, 1H), 3,75 (pseudo ddt, J = 13,8, 4,3, 2,2 Hz, 1H), 4,14 (s, 5H, Fc), 4,12–4,17 (m, 2H, Fc), 4,18 (pseudo dt, J = 2,5, 1,3 Hz, 1H, Fc), 4,24 (pseudo dt, J = 2,5, 1,3 Hz, 1H, Fc), 4,49 (dd, J = 11,2, 2,3 Hz, 1H), 4,80 (d, J = 10,8 Hz, 1H), 5,12 (dd, Fe N O Bu-n 102  J = 10,8, 2,2 Hz, 1H), 6,92–7,10 (m, 3H, Ar), 7,40–7,48 (m, 1H, Ar); 13C NMR (CDCl3, 100 MHz): δ 29,2, 50,0, 65,9, 67,3, 67,8, 68,0, 68,6, 75,8, 82,2, 88,9, 116,1 (d, JC-F = 20,6 Hz), 122,5 (d, JC-F = 2,5 Hz), 123,1 (d, JC-F = 7,9 Hz), 124,3 (d, JC-F = 3,7 Hz), 137,4 (d, JC-F = 8,7 Hz), 155,7 (d, JC-F = 245,3 Hz); MS (ES+): m/z = 366,1 (MH+); HRMS (ESI): m/z израчунато за C20H20FFeNO + H+ [M + H+]: 366,0957. Нађено: 366,0949. 6-Фероценил-3-(3-флуорфенил)-1,3-оксазинан (102ж). Принос 99%. Т.Т. = 111 ºC; IR (KBr, ν, cm-1): 3097, 1596, 1487, 1047, 998, 820, 761; 1H NMR (CDCl3, 400 MHz): δ 1,75–1,82 (m, 1H), 1,94–2,06 (m, 1H), 3,47 (ddd, J = 13,7, 12,6, 2,9 Hz, 1H), 3,88 (pseudo ddt, J = 13,7, 4,3, 2,4 Hz, 1H), 4,11 (s, 5H, Fc), 4,09–4,15 (m, 2H, Fc), 4,16 (pseudo dt, J = 2,4, 1,2 Hz, 1H, Fc), 4,21 (pseudo dt, J = 2,4, 1,2 Hz, 1H, Fc), 4,48 (dd, J = 11,2, 2,4 Hz, 1H), 4,71 (d, J = 10,8 Hz, 1H), 5,28 (dd, J = 10,8, 2,4 Hz, 1H), 6,50–6,63 (m, 1H, Ar), 6,73–6,80 (m, 1H, Ar), 6,80–6,86 (m, 1H, Ar), 7,15–7,23 (m, 1H, Ar); 13C NMR (CDCl3, 100 MHz): δ 29,3, 49,5, 65,9, 67,2, 67,8, 68,0, 68,6, 76,0, 80,8, 88,7, 105,0 (d, JC-F = 24,6 Hz), 106,8 (d, JC-F = 21,3 Hz), 113,4 (d, JC-F = 2,5 Hz), 130,2 (d, JC-F = 9,8 Hz), 150,6 (d, JC-F = 9,8 Hz), 163,8 (d, JC-F = 243,7 Hz); IR (ATR): MS (ES+): m/z = 366,1 (MH+); HRMS (ESI): m/z израчунато за C20H20FFeNO + H+ [M + H+]: 366,0957. Нађено: 366,0950. 6-Фероценил-3-(4-флуорфенил)-1,3-оксазинан (102з). Принос 76 %. Т.Т. = 110 ºC; IR (KBr, ν, cm-1): 2922, 1515, 1055, 943, 811; 1H NMR (CDCl3, 400 MHz): δ 1,71–1,79 (m, 1H), 1,93–2,06 (m, 1H), 3,50 (ddd, J = 13,6, 12,6, 2,8 Hz, 1H), 3,78 (pseudo ddt, J = 13,6, 4,4, 2,3 Hz, 1H), 4,13 (s, 5H, Fc), 4,11–4,16 (m, 2H, Fc), 4,17 (pseudo dt, J =2,5, 1,3 Hz, 1H, Fc), 4,22 (pseudo dt, J = 2,5, 1,3 Hz, 1H, Fc), 4,47 (dd, J = 11,2, 2,4 Hz, 1H), 4,74 (d, J = 10,7 Hz, 1H), 5,18 (dd, J = 10,7, 2,3 Hz, 1H), 6,92–7,00 (m, 2H, Ar), 7,05–7,11 (m, 2H, Ar); 13C NMR (CDCl3, 100 MHz): δ 28,8, 50,9, 65,9, 67,3, 67,8, 68,0, 68,6, 76,0, 81,8, 88,8, 115,5 (d, JC-F = 22,1 Hz), 120,4 (d, JC-F = 7,7 Hz), 145,4 (d, JC-F = 2,4 Hz), 157,6 (d, JC-F = 239,5 Hz); MS (ES+): m/z = 366,10 (MH+); HRMS (ESI): m/z израчунато за C20H20FFeNO + H+ [M + H+]: 366,0957. Нађено: 366,0943. 103  6-Фероценил-3-(2-хлорфенил)-1,3-оксазинан (102и). Принос 77%. IR (KBr, ν, cm-1): 2870, 1479, 1050, 1002, 752; 1H NMR (CDCl3, 400 MHz): δ 1,69–1,77 (m, 1H), 1,90–2,02 (m, 1H), 3,53 (ddd, J = 13,9, 12,7, 2,8 Hz, 1H), 3,77 (pseudo ddt, J = 13,9, 4,3, 2,3 Hz, 1H), 4,16 (s, 5H, Fc), 4,13–4,18 (m, 2H, Fc), 4,20 (pseudo dt, J = 2,4, 1,2 Hz, 1H, Fc), 4,26 (pseudo dt, J = 2,4, 1,2 Hz, 1H, Fc), 4,49 (dd, J = 11,3, 2,2 Hz, 1H), 4,86 (d, J = 10,9 Hz, 1H), 5,06 (dd, J = 10,9, 2,3 Hz, 1H), 6,96–7,02 (m, 1H, Ar), 7,16–7,23 (m, 1H, Ar), 7,33–7,38 (m, 1H, Ar), 7,66–7,71 (m, 1H, Ar); 13C NMR (CDCl3, 100 MHz): δ 28,9, 50,0, 66,0, 67,3, 67,8, 68,1, 68,6, 75,7, 82,9, 89,1, 124,2, 124,3, 127,4, 128,6, 130,5, 146,9; MS (ES+): m/z = 382,0 (MH+); HRMS (ESI): m/z израчунато за C20H20ClFeNO + H+ [M + H+]: 382,0661. Нађено: 382,0647. 6-Фероценил-3-(3-хлорфенил)-1,3-оксазинан (102ј). Принос 85%. Т.Т. = 118 ºC; IR (KBr, ν, cm-1): 2893, 1592, 1481, 1001, 982, 778; 1H NMR (CDCl3, 400 MHz): δ 1,76–1,82 (m, 1H), 1,94–2,06 (m, 1H), 3,49 (ddd, J = 13,7, 12,6, 2,9 Hz, 1H), 3,89 (pseudo ddt, J = 13,7, 4,3, 2,4 Hz, 1H), 4,12 (s, 5H, Fc), 4,10–4,15 (m, 2H, Fc), 4,17 (pseudo dt, J = 2,5, 1,3 Hz, 1H, Fc), 4,21 (pseudo dt, J = 2,5, 1,3 Hz, 1H, Fc), 4,48 (dd, J = 11,2, 2,4 Hz, 1H), 4,72 (d, J = 10,9 Hz, 1H), 5,27 (dd, J = 10,9, 2,4 Hz, 1H), 6,84–6,87 (m, 1H, Ar), 6,94–6,98 (m, 1H, Ar), 7,06–7,09 (m, 1H, Ar), 7,14–7,20 (m, 1H, Ar); 13C NMR (CDCl3, 100 MHz): δ 29,3, 49,7, 65,9, 67,2, 67,8, 68,0, 68,6, 76,0, 80,8, 88,7, 116,2, 118,2, 120,3, 130,1, 134,9, 150,1; MS (ES+): m/z = 382,0 (MH+); HRMS (ESI): m/z израчунато за C20H20ClFeNO + H+ [M + H+]: 382,0661. Нађено: 382,0650. 6-Фероценил-3-(4-хлорфенил)-1,3-оксазинан (102к). Принос 77%. Т.Т. = 162 ºC; IR (KBr, ν, cm-1): 2870, 1479, 999, 813, 752; 1H NMR (CDCl3, 400 MHz): δ 1,72–1,80 (m, 1H), 1,92–2,04 (m, 1H), 3,48 (ddd, J = 13,6, 12,7, 2,8 Hz, 1H), 3,83 (pseudo ddt, J = 13,6, 4,3, 2,3 Hz, 1H), 4,12 (s, 5H, Fc), 4,10–4,18 (m, 2H, Fc), 4,15 (pseudo dt, J = 2,4, 1,3 Hz, 1H, Fc), 4,20 (pseudo dt, J = 2,4, 1,3 Hz, 1H, Fc), 4,47 (dd, J = 11,2, 2,4 Hz, 1H), 4,72 (d, J = 10,8 Hz, 1H), 5,22 (dd, J = 10,8, 2,3 Hz, 1H), 7,00–7,05 (m, 2H, Ar), 7,18–7,23 (m, 2H, Ar); 13C NMR (CDCl3, 100 MHz): δ 29,1, 50,2, 65,9, 67,2, 67,8, 68,0, 68,6, 76,0, 81,1, 88,7, 119,7, 125,4, 129,0, 147,6; MS (ES+): Fe N O Cl 104  m/z = 382,1 (MH+); HRMS (ESI): m/z израчунато за C20H20ClFeNO + H+ [M + H+]: 382,0661. Нађено: 382,0651. 4.4.5 Синтеза N-супституисаних 6-фероценил-1,3-оксазин-2-она 104а-г, ђ-к 4.4.5.1 Синтеза етил-арил(3-фероценил-3-хидроксипропил)карбамата (103а-к) Раствору одговарајућег аминоалкохола 101а-о (1 mmol) у толуену (10 mL) дода се водени раствор натријум-хидроксида [160 mg (4 mmol) у 10 mL воде], а након двочасовног мешања на собној температури и 0,19 mL етил-хлорформијата (217,4 mg, 2 mmol) и настала смеса меша преко ноћи. Растварач се удаљи дестилацијом, остатаку се дода 15 mL воде, а смеса екстрахује три пута са по 30 mL дихлорметана. Органски слојеви се споје и исперу водом. Раствор дихлорметана се даље третира као у огледу 4.4.4. Етил-фенил(3-фероценил-3-хидроксипропил)карбамат (103а). Принос 93%. IR (KBr, ν, cm-1): 3448, 2979, 1677, 1409, 1296, 1277, 1021, 766, 696; 1H NMR (CDCl3, 400 MHz): δ 1,20 (t, J = 7,0 Hz, 3H, CH2CH3), 1,85 (dddd, J = 13,6, 9,2, 7,5, 4,7 Hz, 1H, H–C (2b’)), 1,98 (dtd, J = 13,6, 7,8, 3,8 Hz, 1H, H–C (2a’)), 2,72 (br. s, 1H), 3,72 (ddd, J = 12,9, 7,8, 4,7 Hz, 1H, H–C (1a)), 4,02 (br. ddd, J = 12,9, 7,8, 7,5 Hz, 1H), 4,14 (s, 5H), 4,11–4,19 (преклапање сигнала, 5H, 3×CH, Fc), 4,22 (pseudo q, J = 1,6 Hz, 1H), 4,43 (dd, J = 9,2, 3,8 Hz, 1H, H–C (3’)), 7,17–7,22 (m, 2H, H–C (2’’), H–C (6’’), Ar), 7,22–7,27 (m, 1H, H–C (4’’), Ar), 7,33–7,40 (m, 2H, H–C (3’’), H–C (5’’), Ar); 13C NMR (CDCl3, 100 MHz): δ 14,7 (OCH2CH3), 36,6 (C (2’)), 47,6 (C (1’)), 61,9 (OCH2CH3), 66,8 (C (3’), C (2’’’), C (3’’’), C (4’’’), C (5’’’), Fc), 67,0, 67,9, 68,0, 68,5 (C (1’’’’), C (2’’’’), C (3’’’’), C (4’’’’), C (5’’’’), Fc), 93,2 (C (1’’’), Fc), 126,7 (C (4’’), Ar), 127,3 (C (2’’), C (3’’), C (5’’), C (6’’), Ar), 129,1, 142,0 (C (1’’), Ar), 156,2 (CO); MS (ES+): m/z = 407,10 (M+); HRMS (ESI): m/z израчунато за C22H25FeNO3 + Na+ [M + Na+]: 430,1082. Нађено: 430,1070. Етил-3-фероценил-3-хидроксипропил(o-толил)карбамат (103б). Спектрални подаци дати за смешу диастереоизомера (61:39). Принос 94%. IR (KBr, ν, cm-1): 3437, 2973, 1677, 1410, 1301, 1022, 769; 1H NMR (CDCl3, 400 MHz): δ 1,13 (t, J = 6,9 Hz), 1,72–2,07 (m,преклапање сигнала), 2,22 (s), 2,23 (s), 2,72 (br. s), 3,13–3,23 (m), 3,30-3,41 (m), 3,68– 2' 3' 1'' 3'' 5'' 4'' 2'' N O O OH 1'''3''' 5'''4''' 2''' 2'''' 1'''' 3'''' 4'''' Fe 6'' 1 105  3,96 (m), 4,15 (s, Fc), 4,17 (s, Fc), 4,00–4,27 (m), 4,40–4,52 (m), 7,00–7,15 (m, Ar), 7,16–7,29 (m, преклапање сигнала, Ar); 13C NMR (CDCl3, 100 MHz): δ 14,7, 17,6, 17,8, 36,4, 36,6, 46,8, 47,9, 61,6, 61,7, 65,7, 66,0, 66,5, 66,7, 67,3, 67,7, 67,7, 67,8, 68,3, 68,4, 92,9, 93,3, 126,6, 126,8, 127,4, 127,7, 128,0, 128,5, 130,8, 131,1, 135,7, 135,9, 140,2, 140,6, 156,1, 156,6; MS (ES+): m/z = 421,1 (M+); HRMS (ESI): m/z израчунато за C23H27FeNO3 - OH+ [M - OH+]: 404,1313. Нађено: 404,1335. Етил-3-фероценил-3-хидроксипропил(m-толил)карбамат (103в). Принос 91%. IR (KBr, ν, cm-1): 3450, 2928, 1677, 1407, 1299, 1038, 702; 1H NMR (CDCl3, 400 MHz): δ 1,21 (t, J = 6,7 Hz, 3H, CH3), 1,78–1,91 (m, 1H), 1,92–2,04 (m, 1H), 2,35 (s, 3H, CH3), 2,79 (br. s, 1H, OH), 3,64–3,75 (m, 1H), 3,93–4,11 (m, 1H), 4,14 (s, 5H, Fc), 4,11–4,21 (m, 5H), 4,21–4,26 (m, 1H), 4,38–4,48 (m,1H), 6,94–7,03 (m, 2H, Ar), 7,03–7,09 (m, 1H, Ar), 7,20–7,28 (m, 1H, Ar); 13C NMR (CDCl3, 100 MHz): δ 14,6, 21,4, 36,4, 47,5, 61,8, 66,0, 66,6, 66,8, 67,8, 67,9, 68,4, 93,0, 124,2, 127,5, 127,8, 128,8, 138,9, 141,7, 156,2; MS (ES+): m/z = 421,10 (M+); HRMS (ESI): m/z израчунато за C23H27FeNO3 + Na+ [M + Na+]: 444,1238. Нађено: 444,1225. Етил-3-фероценил-3-хидроксипропил(p-толил)карбамат (103г). Принос 99%. IR (KBr, ν, cm-1): 3439, 2925, 1676, 1415, 1294, 1019, 817; 1H NMR (CDCl3, 400 MHz): δ 1,20 (t, J = 6,7 Hz, 3H, CH3), 1,76–1,89 (m, 1H), 1,91–2,02 (m, 1H), 2,34 (s, 3H, CH3), 2,89 (br. s, 1H, OH), 3,60–3,73 (m, 1H), 3,90–4,11 (m, 1H), 4,15 (s, 5H, Fc), 4,11–4,20 (m, 5H), 4,22 (pseudo q, J = 1,6 Hz, 1H), 4,43 (pseudo dt, J = 9,3, 3,3 Hz, 1H), 7,04–7,10 (m, 2H, Ar), 7,13–7,19 (m, 2H, Ar); 13C NMR (CDCl3, 100 MHz): δ 14,6, 21,0, 36,4, 47,5, 61,8, 66,0, 66,6, 66,8, 67,7, 67,9, 68,4, 93,0, 127,0, 129,7, 136,4, 139,1, 156,3; MS (ES+): m/z = 421,10 (M+); HRMS (ESI): m/z израчунато за C23H27FeNO3 + Na+ [M + Na+]: 444,1238. Нађено: 444,1222. 106  Етил-3-фероценил-3-хидроксипропил(меситил)карбамат (103д). Принос 94%. Т.Т. = 84 ºC; IR (KBr, ν, cm-1): 3457, 2915, 1671, 1409, 1298, 1020, 819; 1H NMR (CDCl3, 400 MHz): δ 1,14 (t, J = 7,0 Hz, 3H, CH3), 1,86 (dddd, J = 13,4, 9,0, 8,5, 4,7 Hz, 1H), 1,98 (dddd, J = 13,4, 9,0, 7,4, 3,7 Hz, 1H), 2,17 (br. s, 3H, CH3), 2,18 (br. s, 3H, CH3), 2,23 (br. s, 3H, CH3), 2,86 (d, J = 4,1 Hz, 1H), 3,47 (ddd, J = 13,9, 9,0, 4,7 Hz, 1H), 3,85 (ddd, J = 13,9, 8,5, 7,4 Hz, 1H), 4,17 (s, 5H, Fc), 4,04–4,26 (m, 6H), 4,44 (pseudo dt, J = 9,0, 3,8 Hz, 1H), 6,89 (br.s, 1H, Ar), 6,90 (br. s, 1H, Ar); 13C NMR (CDCl3, 100 MHz): δ 14,8, 18,1, 18,3, 20,9, 37,0, 47,6, 61,6, 65,7, 66,6, 67,3, 67,7, 67,8, 68,3, 68,4, 93,4, 129,2, 129,4, 135,4, 135,6, 137,0, 137,2, 156,5; MS (ES+): m/z = 450,20 (MH+); HRMS (ESI): m/z израчунато за C25H31FeNO3 + Na+ [M + Na+]: 472,1551. Нађено: 472,1535. Етил-4-бутилфенил(3-фероценил-3-хидроксипропил)карбамат (103ђ). Принос 82%. IR (KBr, ν, cm-1): 3438, 2929, 1677, 1514, 1301, 1284, 815; 1H NMR (CDCl3, 400 MHz): δ 0,92 (t, J = 7,3 Hz, 3H), 1,20 (t, J = 7,1 Hz, 3H), 1,41–1,30 (m, 2H), 1,65–1,55 (m, 2H), 1,80–1,91 (m, 1H), 1,93–2,03 (m, 1H), 2,54 (br. s, 1H, OH), 2,56–2,64 (m, 2H), 3,70 (ddd, J = 12,9, 7,8, 4,9 Hz, 1H), 3,90–4,01 (m, 1H), 4,14 (s, 5H, Fc), 4,09–4,17 (m, 5H), 4,20–4,22 (m, 1H), 4,42 (pseudo dt, J = 9,0, 3,8 Hz, 1H), 7,05–7,10 (m, 2H, Ar), 7,12–7,17 (m, 2H, Ar); 13C NMR (CDCl3, 100 MHz): δ 13,9, 14,6, 22,4, 33,5, 35,2, 36,8, 47,7, 61,7, 66,0, 66,7, 67,1, 67,8, 67,9, 68,4, 93,4, 126,9, 129,0, 139,6, 141,3, 156,3; MS (ES+): m/z = 446,2 (M - OH+); HRMS (ESI): m/z израчунато за C26H33FeNO3 + Na+ [M + Na+]: 486,1708. Нађено: 486,1706. Етил-3-фероценил-3-хидроксипропил(2-флуорфенил)карбамат (103е). Принос 49%. Т.Т. = 68 ºC; IR (KBr, ν, cm-1): 3439, 2931, 1682, 1292, 1023, 768; 1H NMR (CDCl3, 400 MHz): δ 1,05–1,40 (m, 3H), 1,73–1,89 (m, 1H), 1,90–2,01 (m, 1H), 2,80–3,03 (m, 1H), 3,54–3,70 (m, 1H), 4,15 (s, 5H, Fc), 3,95–4,31 (m, 6H), 4,40–4,52 (m, 1H), 7,09–7,19 (m, 2H, Ar), 7,19–7,39 (m, 2H, Ar); 13C NMR (CDCl3, 100 MHz): δ 14,5, 36,4, 47,3, 62,1, 66,0, 66,6, 67,7, 67,9, 68,4, 92,9, 116,4 (d, JC-F = 20,9 Hz), 124,5 (d, JC-F = 3,9 Hz), 128,8 (d, JC-F = 7,9 Hz), 129,4, 156,1, 107  158,4 (d, JC-F = 249,7 Hz); MS (ES+): m/z = 408,10 (M - OH+); HRMS (ESI): m/z израчунато за C22H24FFeNO3 - OH+ [M - OH+]: 408,1062. Нађено: 408,1062. Етил-3-фероценил-3-хидроксипропил(3-флуорфенил)карбамат (103ж). Принос 99%. IR (KBr, ν, cm-1): 3451, 2980, 1682, 1406, 1302, 1171, 769, 696; 1H NMR (CDCl3, 400 MHz): δ 1,22 (t, J = 7,1 Hz, 3H), 1,80–1,92 (m, 1H), 1,92–2,03 (m, 1H), 2,50 (br. s, 1H, OH), 3,75 (ddd, J = 13,4, 7,9, 4,9 Hz, 1H), 3,90–4,01 (m, 1H), 4,15 (s, 5H, Fc), 4,11–4,20 (m, 5H), 4,22 (pseudo q, J = 1,6 Hz, 1H), 4,40 (dt, J = 8,7, 3,7 Hz, 1H), 6,90–6,97 (m, 2H, Ar), 6,98–7,04 (m, 1H, Ar), 7,27–7,34 (m, 1H, Ar); 13C NMR(CDCl3, 100 MHz): δ 14,5, 36,5, 47,4, 62,0, 65,8, 66,7, 67,0, 67,9, 68,0, 68,4, 93,1, 113,4 (d, JC-F = 21,0 Hz), 114,4 (d, JC -F = 22,6 Hz), 122,5, 129,9 (d, JC-F = 9,2 Hz), 143,4 (d, JC-F =9,9 Hz), 155,6, 162,7 (d, JC-F = 246,6 Hz); MS (ES+): m/z =408,10 (M - OH+); HRMS (ESI): m/z израчунато за C22H24FFeNO3 - OH+ [M - OH+]: 408,1062. Нађено: 408,1062. Етил-3-фероценил-3-хидроксипропил(4-флуорфенил)карбамат (103з). Принос 92%. IR (KBr, ν, cm-1): 3439, 2979, 1682, 1592, 1478, 1292, 1023, 768; 1H NMR (CDCl3, 400 MHz): δ 1,13 (t, J = 6,8 Hz, 3H), 1,71–1,94 (m, 2H), 2,63 (br. s, 1H, OH), 3,56–3,69 (m, 1H), 3,79–3,95 (m, 1H), 4,09 (s, 5H, Fc), 4,03–4,18 (m, 6H), 4,28–4,40 (m, 1H), 6,93–6,97 (m, 2H, Ar), 7,04–7,12 (m, 2H, Ar); 13C NMR (CDCl3, 100 MHz): δ 13,5, 35,4, 46,7, 60,8, 64,7, 65,7, 65,9, 66,8, 66,9, 67,3, 92,1, 114,8 (d, JC-F = 22,6 Hz), 127,9(d, JC-F = 8,1 Hz), 136,8, 155,0, 160,0 (d, JC-F = 246,4 Hz); MS (ES+): m/z = 425,1 (MH+). Етил-3-фероценил-3-хидроксипропил(2-хлорфенил)карбамат (103и). Спектрални подаци дати за смешу диастереоизомера (53:47). Принос 36%. IR (KBr, ν, cm-1): 3450, 2978, 1683, 1481, 1408, 1302, 1021, 816, 762; 1H NMR (CDCl3, 400 MHz): δ 1,14 (t, J = 6,8 Hz, 3H), 1,15 (t, J = 6,8 Hz, 3H),1,34 (br. s, 2H), 1,74–2,05 (m, 4H), 2,85 (d, J = 3,7 Hz, 1H), 2,87 (d, J = 3,7 Hz, 1H), 3,46–3,57 (m, 1H), 3,67–3,76 (m, 1H), 3,91–4,02 (m, 1H), 4,02–4,12 (m, 1H), 4,16 (s, 5H, Fc), 4,17 (s, 5H, Fc), 3,90–4,31 (m, 10H), 108  4,41–4,48 (m, 1H), 4,53–4,61 (m, 1H), 7,21–7,34 (m, 6H, Ar), 7,41–7,50 (m, 2H, Ar);13C NMR (CDCl3, 100 MHz): δ 14,5, 36,5, 36,6, 46,9, 47,8, 62,0, 62,0, 65,9, 66,6, 66,7, 66,8, 66,9, 67,7, 67,8, 67,9, 68,4, 93,0, 93,2, 127,4, 127,7, 128,5, 128,7, 129,6, 130,2, 130,3, 133,2, 133,4, 139,1, 139,3, 155,9, 156,1; MS (ES+): m/z = 424,1 (M - OH+); HRMS (ESI): m/z израчунато за C22H24ClFeNO3 - OH+ [M - OH+]: 441,0767. Нађено: 441,0774. Етил-3-фероценил-3-хидроксипропил(3-хлорфенил)карбамат (103ј). Принос 95%. IR (KBr, ν, cm-1): 3437, 2977, 1682, 1592, 1292, 1023, 694; 1H NMR (CDCl3, 400 MHz): δ 1,22 (t, J = 7,1 Hz, 3H), 1,92–1,81 (m, 1H), 1,97 (dddd, J = 13,5, 8,2, 7,4, 4,1 Hz, 1H), 2,33 (d, J = 3,1 Hz, 1H), 3,75 (ddd, J = 13,5, 8,2, 5,1 Hz, 1H), 3,87–3,97 (m, 1H), 4,15 (s, 5H, Fc), 4,12–4,20 (m, 5H), 4,21 (pseudo q, J = 1,6 Hz, 1H), 4,40 (pseudo dt, J = 8,2, 4,0 Hz, 1H), 7,08–7,12 (m, 1H, Ar), 7,19–7,24 (m, 2H, Ar), 7,24–7,29 (m, 1H, Ar); 13C NMR (CDCl3, 100 MHz): δ 14,6, 36,7, 47,6, 62,0, 65,9, 66,9, 67,2, 68,0, 68,1, 68,5, 93,4, 125,2, 126,7, 127,4, 129,9, 134,5, 143,4, 155,7; MS (ES+): m/z = 424,1 (M - OH+); HRMS (ESI): m/z израчунато за C22H24ClFeNO3 - OH+ [M - OH+]: 441,0767. Нађено: 441,0755. Етил-3-фероценил-3-хидроксипропил(4-хлорфенил)карбамат (103к). Принос 85%. IR (KBr, ν, cm-1): 3450, 2977, 1681, 1493, 1287, 1091, 1014, 817, 767; 1H NMR (CDCl3, 400 MHz): δ 1,21 (t, J = 7,0 Hz, 3H), 1,78–1,90 (m, 1H), 1,90–2,01 (m, 1H), 2,53 (br. s, 1H, OH), 3,71 (ddd, J = 13,4, 8,2, 5,0 Hz, 1H), 3,88–3,99 (m, 1H), 4,16 (s, 5H, Fc), 4,12–4,20 (m, 5H), 4,21 (pseudo q, J = 1,6 Hz, 1H), 4,40 (pseudo dt, J = 8,2, 4,0 Hz, 1H), 7,09–7,16 (m, 2H, Ar), 7,29–7,35 (m, 2H, Ar); 13C NMR (CDCl3, 100 MHz): δ 14,6, 36,5, 47,5, 61,9, 65,7, 66,7, 67,0, 67,9, 68,0, 68,4, 93,1, 128,4, 129,2, 132,1, 140,5, 155,8; MS (ES+): m/z = 424,1 (M - OH+); HRMS (ESI): m/z израчунато за C22H24ClFeNO3 - OH+ [M - OH+]: 441,0767. Нађено: 441,0758. 4.4.5.2 Циклизација хидроксикарбамата 103а-г, ђ-к до 6-фероценил-1,3-оксазин-2- она 104а-г, ђ-к Раствору одговарајућег хидроксикарбамата 103а-г, ђ-к (1 mmol) у 10 mL тетрахидрофурана охлађеном се на 5 °C дода се 50 mg NaH (2 mmol), смеса меша 15 s и 109  брзо склони са леденог купатила. Потом се упари растварач и суви остатак обрађује се по пропису 4.4.4. 3-Фенил-6-фероценил-1,3-оксазин-2-он (104а). Принос 64%. Т.Т. = 148 ºC; IR (KBr, ν, cm-1): 2894, 1685, 1592, 1483, 1001, 982, 778; 1H NMR (CDCl3, 400 MHz): δ 2,28 (dddd, J = 13,8, 10,2, 9,5, 5,5 Hz, 1H, H–C (5ax)), 2,45 (dddd, J = 13,8, 4,9, 4,1, 3,0 Hz, 1H, H–C (5eq)), 3,70 (ddd, J = 11,7, 5,5, 4,1 Hz, 1H, H–C (4eq)), 3,81 (ddd, J = 11,7, 10,2, 4,9 Hz, 1H, H–C (4ax)), 4,24 (s, 5H, H–C (1’’’), H–C (2’’’), H–C (3’’’), H–C (4’’’), H–C (5’’’), Fc), 4,19–4,23 (m, 2H, H–C (3’’), H–C (4’’), Fc), 4,28 (pseudo dt, J = 2,5, 1,3 Hz, H–C (2’’) или H–C (5’’), 1H, Fc), 4,36 (pseudo dt, J = 2,5, 1,3 Hz, H–C (2’’) или H–C (5’’), 1H, Fc), 5,31 (dd, J = 9,5, 3,0 Hz, H–C (6ax), 1H), 7,24–7,29 (m, 1H, H–C (4’), Ar), 7,33–7,37 (m, 2H, H–C (2’), H–C (6’), Ar), 7,38–7,43 (m, 2H, H–C (3’), H–C (5’), Ar); 13C NMR (CDCl3, 100 MHz): δ 28,9 (C (5)), 47,9 (C (4)), 66,1 (C (2’’) или C (5’’), Fc), 67,4 (C (2’’) или C (5’’), Fc), 68,4 (C (3’’) или C (4’’), Fc), 68,5 (C (3’’) или C (4’’), Fc), 69,1 (C (1’’’), C (2’’’), C (3’’’), C (4’’’), C (5’’’), Fc), 76,2 (C (6)), 86,3 (C (1’’), Fc), 126,0 (C (4’), Ar), 126,9 (C (2’), C (6’), Ar), 129,4 (C (3’), C (5’), Ar), 143,1 (C (1’), Ar), 152,8 (C (2)); MS (ES+): m/z = 362,1 (MH+); HRMS (ESI): m/z израчунато за C20H19FeNO2 + H+ [M + H+]: 362,0844. Нађено: 362,0834. 3-(o-Толил)-6-фероценил-1,3-оксазин-2-он (104б). Спектрални подаци дати за смешу диастереоизомера (52:48). Принос 47%. Т.Т. = 167 ºC; IR (KBr, ν, cm-1): 2928, 1688, 1506, 1067, 815; 1H NMR (CDCl3, 400 MHz): δ 2,20–2,35 (преклапање сигнала, m), 2,26 (s), 2,32 (s), 2,36–2,51 (преклапање сигнала, m), 3,43 (ddd, J = 11,7, 5,1, 3,4 Hz), 3,53–3,65 (преклапање сигнала, m), 3,70-3,79 (m), 4,19–4,26 (преклапање сигнала, m), 4,23 (s), 4,24 (s), 4,27–4,31 (преклапање сигнала, m), 4,36–4,41 (преклапање сигнала, m), 5,31 (dd, J = 9,3, 2,8 Hz), 5,34 (dd, J = 10,2, 2,6 Hz), 7,15–7,32 (преклапање сигнала, m); 13C NMR (CDCl3, 100 MHz): δ 17,5, 17,6, 28,7, 28,8, 47,6, 47,9, 65,8, 65,9, 67,3, 67,5, 68,3, 68,4, 69,0, 69,0, 76,0, 76,3, 86,2, 86,2, 127,2, 127,4, 127,4, 128,1, 128,1, 131,2, 131,4, 135,5, 135,6, 141,4, 152,2, 152,3; MS (ES+): m/z = 376,1 (MH+); HRMS (ESI): m/z израчунато за C21H21FeNO2 + H+ [M + H+]: 376,1000. Нађено: 376,0995. 3-(m-Толил)-6-фероценил-1,3-оксазин-2-он (104в). Принос 53%. Т.Т. = 128 ºC; IR (KBr, ν, cm-1): 2894, 1685, 1591, 1483, 1052, 1001, 982, 778; 1H NMR (CDCl3, 400 MHz): 1''3'' 5''4'' 2'' N O 4 5 6 1' 2''' 3' 5'1''' 3''' 4''' Fe 4'2' 6' o 110  δ 2,18–2,35 (m, 1H), 2,36 (s, 3H, CH3), 2,39–2,48 (m, 1H), 3,62–3,70 (m, 1H), 3,72–3,82 (m, 1H), 4,23 (s, 5H, Fc), 4,19– 4,26 (m, 2H, Fc), 4,26–4,29 (m, 1H, Fc), 4,34–4,37 (m, 1H, Fc), 5,29 (dd, J = 9,5, 2,9 Hz, 1H), 7,06–7,10 (m, 1H, Ar), 7,10–7,18 (m, 2H, Ar), 7,26–7,31 (m, 1H, Ar); 13C NMR (CDCl3, 100 MHz): δ 21,4, 28,8, 47,9, 66,0, 67,3, 68,3, 68,3, 68,9, 76,1, 86,2, 122,9, 126,7, 127,7, 129,1, 139,2, 142,9, 152,7; MS (ES+): m/z = 376,1 (MH+); HRMS (ESI): m/z израчунато за C21H21FeNO2 + H+ [M + H+]: 376,1000. Нађено: 376,0991. 3-(p-Толил)-6-фероценил-1,3-оксазин-2-он (104г). Принос 84%. Т.Т. = 180 ºC; IR (KBr, ν, cm-1): 2921, 1685, 1403, 1157, 818; 1H NMR (CDCl3, 400 MHz): δ 2,26 (dddd, J = 13,7, 10,2, 9,6, 5,5 Hz, 1H), 2,35 (s, 3H, CH3), 2,43 (dddd, J = 13,7, 5,0, 4,0, 2,9 Hz, 1H), 3,66 (ddd, J = 11,7,5,5, 4,0 Hz, 1H), 3,77 (ddd, J = 11,7, 10,2, 5,0 Hz, 1H), 4,23 (s, 5H, Fc), 4,19–4,25 (m, 2H, Fc), 4,27 (pseudo dt, J = 2,5, 1,3 Hz, 1H, Fc), 4,35 (pseudo dt, J = 2,5, 1,3 Hz, 1H, Fc), 5,29 (dd, J = 9,6, 2,9 Hz, 1H), 7,16–7,28 (m, 4H, Ar); 13C NMR (CDCl3, 100 MHz): δ 21,0, 28,8, 47,9, 66,0, 67,3, 68,3, 68,3, 68,9, 76,0, 86,2, 125,8, 129,9, 136,7, 140,4, 152,8; MS (ES+): m/z = 376,1 (MH+); HRMS (ESI): m/z израчунато за C21H21FeNO2 + H+ [M + H+]: 376,1000. Нађено: 376,0990. 3-(4-Бутилфенил)-6-фероценил-1,3-оксазин-2-он (104ђ). Принос 80%. Т.Т. = 146 ºC; IR (KBr, ν, cm-1): 2925, 1683, 1414, 1161, 815; 1H NMR (CDCl3, 400 MHz): δ 0,93 (t, J = 7,3 Hz, 3H), 1,30–1,43 (m, 2H), 1,53–1,68 (m, 2H), 2,20–2,32 (m, 1H), 2,38–2,48 (m, 1H), 2,56–2,64 (m, 2H), 3,67 (ddd, J = 11,6, 5,5, 4,1 Hz, 1H), 3,77 (ddd, J = 11,6, 10,2, 4,9 Hz, 1H), 4,23 (s, 5H, Fc), 4,19–4,25 (m, 2H, Fc), 4,27 (pseudo dt, J = 2,4, 1,2 Hz, 1H, Fc), 4,36 (pseudo dt, J = 2,4, 1,2 Hz, 1H, Fc), 5,29 (dd, J = 9,5, 2,9 Hz, 1H), 7,17–7,21 (m, 2H, Ar), 7,22–7,26 (m, 2H, Ar); 13C NMR (CDCl3, 100 MHz): δ 13,9, 22,4, 28,8, 33,5, 35,2, 47,9, 66,0, 67,3, 68,3, 68,4, 69,0, 76,0, 86,3, 125,7, 129,2, 140,5, 141,6, 152,8; MS (ES+): m/z = 418,1 (MH+); HRMS (ESI): m/z израчунато за C24H27FeNO2 + H+ [M + H+]: 418,1470. Нађено: 418,1448. 6-Фероценил-3-(2-флуорфенил)-1,3-оксазин-2-он (104е). Принос 97%. Т.Т. = 154 ºC; IR (KBr, ν, cm-1): 2924, 1697, 1502, 1418, 1166, 754; 1H NMR (CDCl3, 400 MHz): δ 2,21–2,34 (m, 1H), 2,39–2,48 (m, 1H), 3,56–3,63 (m, 1H), 3,71–3,79 (m, 1H), 4,23 (s, 5H, Fc), 111  4,19–4,25 (m, 2H, Fc), 4,26–4,30 (m, 1H, Fc), 4,36–4,39 (m, 1H, Fc), 5,32 (dd, J = 9,5, 2,9 Hz, 1H), 7,12–7,21 (m, 2H, Ar), 7,25–7,38 (m, 2H, Ar); 13C NMR (CDCl3, 100 MHz): δ 28,6, 47,6, 66,0, 67,3, 68,3, 68,4, 68,9, 76,4, 86,0, 116,8 (d, JC-F = 19,9 Hz), 124,8 (d, JC-F = 3,8 Hz), 129,2 (d, JC-F = 8,0 Hz), 129,4 (d, JC-F = 1,0 Hz), 130,1 (d, JC-F = 12,4 Hz), 152,3, 158,0 (d, JC-F = 250,2 Hz); MS (ES+): m/z = 380,1 (MH+); HRMS (ESI): m/z израчунато за C20H18FFeNO2 + H+ [M + H+]: 380,0749. Нађено: 380,0741. 6-Фероценил-3-(3-флуорфенил)-1,3-оксазин-2-он (104ж). Принос 84%. Т.Т. = 144 ºC; IR (KBr, ν, cm-1): 2894, 1685, 1591, 1483, 1001, 982, 778; 1H NMR (CDCl3, 400 MHz): δ 2,21–2,32 (m, 1H), 2,41–2,50 (m, 1H), 3,69 (ddd, J = 11,5, 5,4, 4,2 Hz, 1H), 3,80 (ddd, J = 11,5, 10,2, 4,9 Hz, 1H), 4,23 (s, 5H, Fc), 4,20–4,25 (m, 2H, Fc), 4,27 (pseudo dt, J = 2,5, 1,3 Hz, 1H, Fc), 4,34 (pseudo dt, J = 2,5, 1,3 Hz, 1H, Fc), 5,30 (dd, J = 9,6, 3,0 Hz, 1H), 6,93–6,99 (m, 1H, Ar), 7,10–7,18 (m, 2H, Ar), 7,31–7,38 (m, 1H, Ar); 13C NMR (CDCl3, 100 MHz): δ 28,7, 47,6, 66,0, 67,2, 68,4, 68,5, 69,0, 76,3, 85,9, 113,2 (d, JC-F = 23,5 Hz), 113,6 (d, JC-F = 21,0 Hz), 121,1 (d, JC-F = 3,2 Hz), 130,2 (d, JC-F = 9,2 Hz), 144,4 (d, JC-F = 9,9 Hz), 152,2, 162,8 (d, JC-F = 246,6 Hz); MS (ES+): m/z = 380,1 (MH+); HRMS (ESI): m/z израчунато за C20H18FFeNO2 + H+ [M + H+]: 380,0749. Нађено: 380,0739. 6-Фероценил-3-(4-флуорфенил)-1,3-оксазин-2-он (104з). Принос 97%. Т.Т. = 144 ºC; IR (KBr, ν, cm-1): 2921, 1615, 1515, 1055, 943, 811; 1H NMR (CDCl3, 400 MHz): δ 2,12–2,25 (m, 1H), 2,32–2,41 (m, 1H), 3,53–3,61 (m, 1H), 3,65–3,74 (m, 1H), 4,16 (s, 5H, Fc), 4,12–4,17 (m, 2H, Fc), 4,20 (pseudo dt, J = 2,4, 1,2 Hz, 1H, Fc), 4,27 (pseudo dt, J = 2,4, 1,2 Hz, 1H, Fc), 5,23 (dd, J = 9,5, 2,8 Hz, 1H), 6,97–7,04 (m, 2H, Ar), 7,20–7,27 (m, 2H, Ar); 13C NMR (CDCl3, 100 MHz): δ 28,7, 48,1, 66,0, 67,2, 68,4, 68,4, 69,0, 76,2, 86,0, 116,1 (d, JC-F = 22,7 Hz), 127,7 (d, JC-F = 8,5 Hz), 138,9 (d, JC-F = 3,1 Hz), 152,7, 161,0 (d, JC-F = 246,4 Hz); MS (ES+): m/z = 380,1 (MH+); HRMS (ESI): m/z израчунато за C20H18FFeNO2 + H+ [M + H+]: 380,0749. Нађено: 380,0737. 6-Фероценил-3-(2-хлорфенил)-1,3-оксазин-2-он (104и). Принос 10%. Т.Т. = 150 ºC; IR (KBr, ν, cm-1): 2918, 1694, 1484, 1422, 1168, 756; 1H NMR (CDCl3, 400 MHz): 112  δ 2,20–2,55 (m, 2H), 3,44–3,86 (m, 2H), 4,24 (s, 5H, Fc), 4,20– 4,26 (m, 2H, Fc), 4,27–4,33 (m, 1H, Fc), 4,36–4,42 (m, 1H, Fc), 5,34 (pseudo d, J = 9,4 Hz, 1H), 7,26–7,40 (m, 3H, Ar), 7,46– 7,52 (m, 1H, Ar); 13C NMR (CDCl3, 100 MHz): δ 28,6, 47,5, 66,0, 67,4, 68,3, 68,9, 76,2, 86,1, 128,1, 129,3, 129,8, 130,5, 132,6, 139,8, 152,2; MS (ES+): m/z =396,10 (MH+); HRMS (ESI): m/z израчунато за C20H18ClFeNO2 + H+ [M + H+]: 396,0454. Нађено: 396,0448. 6-Фероценил-3-(3-хлорфенил)-1,3-оксазин-2-он (104ј). Принос 77%. Т.Т. = 128 ºC; IR (KBr, ν, cm-1): 2916, 1682, 1045; 1H NMR (CDCl3, 400 MHz): δ 2,19–2,30 (m, 1H), 2,38–2,47 (m, 1H), 3,68 (ddd, J = 11,5, 5,5, 4,4 Hz, 1H), 3,77 (ddd, J = 11,5, 9,9, 4,9 Hz, 1H), 4,23 (s, 5H, Fc), 4,18–4,24 (m, 2H, Fc), 4,26 (pseudo dt, J = 2,5, 1,3 Hz, 1H, Fc), 4,33 (pseudo dt, J = 2,5, 1,3 Hz, 1H, Fc), 5,29 (dd, J = 9,3, 3,1 Hz, 1H), 7,20–7,24 (m, 1H, Ar), 7,25–7,33 (m, 2H, Ar), 7,36–7,39 (m, 1H, Ar); 13C NMR (CDCl3, 100 MHz): δ 29,0, 47,6, 66,1, 67,1, 68,4, 68,5, 69,1, 76,3, 86,3, 124,0, 126,1, 126,8, 130,1, 134,7, 144,3, 152,2; MS (ES+): m/z = 396,1 (MH+); HRMS (ESI): m/z израчунато за C20H18ClFeNO2 + H+ [M + H+]: 396,0454. Нађено: 396,0447. 6-Фероценил-3-(4-хлорфенил)-1,3-оксазин-2-он (104к). Принос 89%. Т.Т. = 170 ºC; IR (KBr, ν, cm-1): 3098, 1596, 1486, 1049, 819, 764; 1H NMR (CDCl3, 400 MHz): δ 2,21–2,33 (m, 1H), 2,41–2,49 (m, 1H), 3,67 (ddd, J = 11,5, 5,4, 4,2 Hz, 1H), 3,79 (ddd, J = 11,5, 10,2, 4,9 Hz, 1H), 4,23 (s, 5H, Fc), 4,20–4,25 (m, 2H, Fc), 4,27 (pseudo dt, J = 2,5, 1,3 Hz, 1H, Fc), 4,34 (pseudo dt, J = 2,5, 1,3 Hz, 1H, Fc), 5,31 (dd, J = 9,5, 3,0 Hz, 1H), 7,28–7,33 (m, 2H, Ar), 7,34–7,39 (m, 2H, Ar); 13C NMR (CDCl3, 100 MHz): δ 28,8, 47,7, 66,0, 67,2, 68,4, 68,4, 69,0, 76,3, 86,0, 127,1, 129,3, 132,2, 141,5, 152,4; MS (ES+): m/z = 396,0 (MH+); HRMS (ESI): m/z израчунато за C20H18ClFeNO2 + H+ [M + H+]: 396,0454. Нађено: 396,0443. 113  4.4.6 Синтеза 1,3-дисупституисаних 4-фероценилтетрахидропиримидин- 2(H)-она 106а, в, г, ђ, е, ж, и, ј 4.4.6.1 Синтеза етил-арил[3-фероценил-3-(изопропиламино)пропил]карбамата 105а-к Раствор хидроксикарбамата 103а-о (1 mmol), 0,21 mL триетиламина (152 mg, 1.5 mmol) и 0,21 mL анхидрида трифлуорсирћетне киселине (315 mg, 1.5 mmol) у тетрахидрофурану (10 mL) меша се у атмосфери азота 16 h на 0 °C. Реакционој смеси дода се 0,327 mL изопропил-амина (236 mg, 4 mmol) и настави са мешањем још 16 h на собној температури. Потом се упари растварач и суви остатак се обрађује по пропису 4.4.4. Етил-фенил[3-фероценил-3-(изопропиламино)пропил]карбамат (105а). Принос 96%. IR (KBr, ν, cm-1): 3093, 2961, 1694, 1276, 729, 696; 1H NMR (CDCl3, 400 MHz): δ 0,97 (d, J = 6,2 Hz, 3H, CH(CHa3)(CHb3)), 1,00 (d, J = 6,2 Hz, 3H, CH(CHa3)(CHb3)), 1,21 (t, J = 7,0 Hz, 3H, CH2CH3), 1,48 (br. s, 1H, NH), 1,84 (dddd, J = 14,0, 9,2, 7,7, 5,5 Hz, 1H, H–C (2b’)), 2,10 (dddd, J = 14,0, 9,5, 6,2, 4,8 Hz, 1H, H–C (2a’)), 2,82 (pseudo septulet, J = 6,2 Hz, 1H, CH(CH3)2), 3,38 (dd, J = 7,7, 4,8 Hz, 1H, H–C (3’)), 3,77 (ddd, J = 14,0, 9,2, 6,2 Hz, 1H, H–C (1a’)), 3,84 (ddd, J = 14,0, 9,5, 5,5 Hz, 1H, H–C (1b’)), 4,01–4,03 (m, 1H, Fc), 4,04 (s, 5H, Fc), 4,06–4,08 (преклапање сигнала, 2H, Fc), 4,09–4,11 (m, 1H, Fc), 4,15 (q, J = 7,0 Hz, 2H, CH2CH3), 7,18–7,24 (m, 3H, H–C (4’’), H–C (5’’), H–C (6’’), Ar), 7,31–7,37 (m, 2H, H–C (3’’), H–C (5’’), Ar); 13C NMR (CDCl3, 100 MHz): δ 14,7 (OCH2CH3), 23,1 (CH(CHa3)(CHb3)), 23,7 (CH(CHa3)(CHb3)), 35,1 (C (2’)), 45,6 (NHCH(CH3)2, C (1’), C (3’)), 48,0, 51,6, 61,5 (OCH2CH3), 66,2 (C (2’’’), C (3’’’), C (4’’’), C (5’’’), Fc), 67,0, 67,1, 67,4, 68,4 (C (1’’’’), C (2’’’’), C (3’’’’), C (4’’’’), C (5’’’’), Fc), 93,2 (C (1’’’), Fc), 126,3 (C (4’’), Ph), 127,0 (C (2’’), C (3’’), C (5’’), C (6’’), Ph), 128,9, 142,2 (C (1’’), Ph), 155,6 (CO); MS (ES+): m/z = 449,3 (MH+); HRMS (ESI): m/z израчунато за C25H32FeN2O2 + H+ [M + H+]: 449,1892. Нађено: 449,1867. Етил-3-фероценил-3-(изопропиламино)пропил(o-толил)карбамат (105б). Спектрални подаци дати за смешу диастереоизомера (54:46). Принос 91%. IR (KBr, ν, cm-1): 3092, 2961, 1697, 1298, 725; 1H NMR (CDCl3, 400 MHz): δ 0,90–1,05 (преклапање сигнала), 2' 3' 1'' 3'' 5'' 4'' 2'' N O O HN 1'''3''' 5'''4''' 2''' 2'''' 1'''' 3'''' 4'''' Fe 6'' 1' 114  0,98 (d, J = 6,2 Hz), 1,01 (d, J = 6,2 Hz), 1,12 (t, J = 6,1 Hz), 1,31 (br. s), 1,79–2,01 (преклапање сигнала, m), 2,04– 2,19 (преклапање сигнала, m), 2,22 (s), 2,23 (s), 2,82 (pseudo septulet, J = 6,2 Hz), 2,82 (pseudo septulet, J = 6,2 Hz), 3,28–3,51 (преклапање сигнала, m), 3,52–3,98 (преклапање сигнала, m), 4,05 (s), 4,06 (s), 3,98–4,27 (преклапање сигнала, m), 7,05–7,27 (m); 13C NMR (CDCl3, 100 MHz): δ 14,7, 17,8, 22,6, 23,0, 23,5, 23,6, 34,6, 34,9, 45,7, 48,1, 51,9, 52,0, 61,4, 61,4, 66,1, 67,0, 67,1, 67,2, 67,3, 67,5, 68,4, 68,4, 93,2, 93,2, 126,6, 127,3, 127,4, 128,0, 128,3, 130,9, 135,8, 136,0, 140,6, 140,7, 155,7, 155,8; MS (ES+): m/z = 463,2 (MH+); HRMS (ESI): m/z израчунато за C26H34FeN2O2 + H+ [M + H+]: 463,2048. Нађено: 463,2062. Етил-3-фероценил-3-(изопропиламино)пропил(m-толил)карбамат (105в). Принос 81%. IR (KBr, ν, cm-1): 3092, 2959, 1697, 1296, 1172, 702; 1H NMR (CDCl3, 400 MHz): δ 0,99 (d, J = 6,2 Hz, 3H), 1,01 (d, J = 6,2 Hz, 3H), 1,22 (t, J = 7,0 Hz, 3H), 1,80–1,94 (m, 1H), 2,06–2,18 (m, 1H), 2,34 (s, 3H), 2,83 (pseudo septulet, J = 6,2 Hz, 1H), 3,40 (dd, J = 7,8, 4,7 Hz, 1H), 3,70–3,87 (m, 2H), 4,01–4,06 (m, 1H), 4,05 (s, 5H, Fc), 4,06–4,10 (m, 2H), 4,10–4,12 (m, 1H), 4,15 (q, J = 7,1 Hz, 2H), 6,98–7,05 (m, 3H, Ar), 7,19–7,25 (m, 1H, Ar); 13C NMR (CDCl3, 100 MHz): δ 14,6, 21,4, 22,9, 23,5, 35,0, 45,7, 47,9, 51,6, 61,5, 66,2, 67,1, 67,1, 67,4, 68,4, 92,8, 124,0, 127,1, 127,6, 128,7, 138,7, 142,0, 155,8; MS (ES+): m/z = 463,2 (MH+); HRMS (ESI): m/z израчунато за C26H34FeN2O2 + H+ [M + H+]: 463,2048. Нађено: 463,2033. Етил-3-фероценил-3-(изопропиламино)пропил(p-толил)карбамат (105г). Принос 68%. IR (KBr, ν, cm-1): 3093, 2959, 1695, 1292, 818; 1H NMR (CDCl3, 400 MHz): δ 0,98 (d, J = 6,2 Hz, 3H), 1,01 (d, J = 6,2 Hz, 3H), 1,21 (t, J = 6,6 Hz, 3H), 1,77–1,92 (m, 1H), 2,03–2,16 (m, 1H), 2,33 (s, 3H, CH3), 2,83 (pseudo septulet, J = 6,2 Hz, 1H), 3,39 (dd, J = 7,6, 4,9 Hz, 1H), 3,69–3,86 (m, 2H), 4,02–4,06 (m, 1H), 4,05 (s, 5H, Fc), 4,07–4,09 (m, 2H), 4,09–4,12 (m, 1H), 4,14 (q, J = 7,0 Hz, 2H), 7,04–7,12 (m, 2H, Ar), 7,12–7,17 (m, 2H, Ar); 13C NMR (CDCl3, 100 MHz): Fe N O O HN 115  δ 14,7, 21,0, 23,0, 23,6, 35,0, 45,7, 48,0, 51,7, 61,5, 66,2, 67,0, 67,1, 67,4, 68,4, 93,1, 126,8, 129,5, 136,0, 139,5, 155,8; MS (ES+): m/z = 463,3 (MH+); HRMS (ESI): m/z израчунато за C26H34FeN2O2 + H+ [M + H+]: 463,2048. Нађено: 463,2040. Етил-3-фероценил-3-(изопропиламино)пропил(меситил)карбамат (105д). Спектрални подаци дати за смешу диастереоизомера (77:23). Принос 85%. IR (KBr, ν, cm-1): 3094, 2958, 1696, 1304, 811; 1H NMR (CDCl3, 400 MHz): δ 0,98 (d, J = 6,2 Hz), 0,99 (d, J = 6,2 Hz), 0,96–1,03 (преклапање сигнала), 1,12 (t, J = 7,0 Hz), 1,20 (t, J = 7,0 Hz), 1,78-1,92 (m, преклапање сигнала), 2,03-2,16 (m, преклапање сигнала), 2,17 (s), 2,17 (s), 2,19 (s), 2,19 (s), 2,24 (s), 2,26 (s), 2,76-2,88 (m, преклапање сигнала), 3,26-3,39 (m, преклапање сигнала), 3,43-3,63 (m, преклапање сигнала), 3,67-3,78 (m), 4,06 (s, 5H), 4,00–4,14 (m, преклапање сигнала), 6,87 (br. s); 13C NMR (CDCl3, 100 MHz): δ 14,8, 14,9, 18,2, 18,3, 20,9, 20,9, 23,2, 23,4, 23,6, 23,7, 34,7, 35,4, 45,8, 48,1, 48,2, 52,3, 61,2, 61,3, 66,0, 66,1, 66,8, 67,0, 67,1, 67,2, 67,3, 68,4, 93,4, 93,5, 129,1, 129,1, 129,3, 129,3, 135,5, 135,6, 135,7, 136,7, 136,7, 137,1, 137,7, 155,2, 155,8; MS (ES+): m/z = 491,3 (MH+); HRMS (ESI): m/z израчунато за C28H38FeN2O2 + H+ [M + H+]: 491,2355. Нађено: 491,2350. Етил-4-бутилфенил[3-фероценил-3-(изопропиламино)пропил]карбамата (105ђ). При- нос 87%. IR (KBr, ν, cm-1): 3094, 2957, 1695, 1280, 816; 1H NMR (CDCl3, 400 MHz): δ 0,90 (t, J = 7,3 Hz, 3H), 0,97 (d, J = 6,2 Hz, 3H),1,01 (d, J = 6,2 Hz, 3H), 1,21 (t, J = 6,3 Hz, 3H), 1,28–1,41 (m, 2H), 1,51–1,62 (m, 2H), 1,77–1,94 (m, 1H), 2,04- 2,20 (m, 1H), 2,49–2,66 (m, 2H), 2,82 (pseudo septulet, J = 6,2 Hz, 1H), 3,40 (dd, J = 7,7, 4,7 Hz, 1H), 3,70–3,88 (m, 2H), 4,04 (s, 5H, Fc), 3,99–4,06 (m, 1H), 4,06–4,09 (m, 2H), 4,09–4,11 (m, 1H), 4,15 (q, J = 7,2 Hz, 2H), 7,06–7,12 (m, 2H, Ar), 7,13–7,17 (m, 2H, Ar); 13C NMR (CDCl3, 100 MHz): δ 13,9, 14,7, 22,3, 22,8, 23,5, 33,5, 35,1, 45,7,48,0, 51,6, 61,5, 66,2, 67,1, 67,1, 67,4, 68,4, 92,7, 126,7, 128,8, 139,6, 141,0, 155,8; MS (ES+): m/z = 505,3 (MH+); HRMS (ESI): m/z израчунато за C29H40FeN2O2 + H+ [M + H+]: 505,2518. Нађено: 505,2510. Fe N O O HN Fe N O O HN Bu-n 116  Етил-3-фероценил-3-(изопропиламино)пропил(2-флуорфенил)карбамат (105е). При- нос 95%. IR (KBr, ν, cm-1): 3084, 2958, 1694, 1503, 1166, 1155, 811; 1H NMR (CDCl3, 400 MHz): δ 0,95 (d, J = 6,2 Hz, 3H), 0,99 (d, J = 6,2 Hz, 3H), 1,05–1,39 (m, 3H), 1,75–1,97 (m, 1H), 2,08–2,20 (m, 1H), 2,81 (pseudo septulet, J = 6,2 Hz, 1H), 3,31–3,47 (m, 1H), 3,67–3,89 (m, 2H), 4,05 (s, 5H, Fc), 3,98–4,06 (m, 1H), 4,06–4,09 (m, 2H), 4,09–4,11 (m, 1H), 4,11–4,20 (m, 2H), 7,08–7,16 (m, 2H, Ar), 7,19–7,27 (m, 2H, Ar); 13C NMR (CDCl3, 100 MHz): δ 14,5, 22,6, 23,5, 34,7, 45,6, 48,0, 51,5, 61,8, 66,1, 67,1, 67,2, 67,5, 68,4, 92,8, 116,3 (d, JC-F = 19,8 Hz), 124,5 (d, JC-F = 3,8 Hz), 128,5 (d, JC-F = 7,9 Hz), 129,3, 129,7, 155,5, 158,3 (d, JC-F = 249,4 Hz); MS (ES+): m/z = 467,2 (MH+); HRMS (ESI): m/z израчунато за C25H31FFeN2O2 + H+ [M + H+]: 467,1797. Нађено: 467,1780. Етил-3-фероценил-3-(изопропиламино)пропил(3-флуорфенил)карбамат (105ж). При- нос 95%. IR (KBr, ν, cm-1): 3084, 2958, 1693, 1168, 1155, 811; 1H NMR (CDCl3, 400 MHz): δ 1,01 (d, J = 6,2 Hz, 3H), 1,04 (d, J = 6,2 Hz, 3H), 1,22 (t, J = 7,1 Hz, 3H), 1,79–1,96 (m, 1H), 2,09–2,22 (m, 1H), 2,85 (pseudo septulet, J = 6,2 Hz, 1H), 3,44 (dd, J = 6,2, 4,5 Hz, 1H), 3,72–3,92 (m, 2H), 4,06 (s, 5H, Fc), 4,02–4,15 (m, 4H), 4,17 (q, J = 7,1 Hz, 2H), 6,89–6,95 (m, 1H, Ar), 6,96–7,05 (m, 2H, Ar), 7,26–7,34 (m, 1H, Ar); 13C NMR (CDCl3, 100 MHz): δ 14,6, 23,3, 34,8, 45,8, 47,7, 51,7, 61,9, 66,3, 67,1, 67,3, 67,7, 68,5, 93,1, 113,2 (d, JC-F = 21,2 Hz), 114,2 (d, JC-F = 22,8 Hz), 122,2, 129,9 (d, JC-F = 9,2 Hz), 143,6 (d, JC-F = 9,5 Hz), 155,5, 162,7 (d, JC-F = 246,4 Hz); MS (ES+): m/z = 467,2 (MH+); HRMS (ESI): m/z израчунато за C25H31FFeN2O2 + H+ [M + H+]: 467,1797. Нађено: 467,1789. Етил-3-фероценил-3-(изопропиламино)пропил(4-флуорфенил)карбамат (105з). При-нос 95%. IR (KBr, ν, cm-1): 3378, 2960, 1693, 1508, 841, 812; 1H NMR (CDCl3, 400 MHz): δ 0,99 (d, J = 6,2 Hz, 3H), 1,02 (d, J = 6,2 Hz, 3H), 1,22 (t, J = 6,8 Hz, 3H), 1,77– 1,92 (m, 1H), 2,02–2,16 (m, 1H), 2,84 (pseudo septulet, J = 6,2 Hz, 1H), 3,41 (dd, J = 7,0, 5,1 Hz, 1H), 3,70–3,81 (m, 2H), 4,06 (s, 5H, Fc), 4,02–4,15 (m, 4H), 4,17 (q, J = 117  7,1 Hz, 2H), 6,89–6,95 (m, 1H, Ar), 6,96–7,05 (m, 2H, Ar), 7,26–7,34 (m, 1H, Ar); 13C NMR (CDCl3, 100 MHz): δ 14,6, 23,0, 23,4, 34,9, 45,8, 48,1, 51,7, 61,7, 66,3, 66,9, 67,2, 67,5, 68,4, 92,7, 115,7 (d, JC-F = 22,6 Hz), 128,7 (d, JC-F = 7,2 Hz), 138,1, 155,7, 160,8 (d, JC-F = 245,7 Hz); MS (ES+): m/z = 467,2 (MH+); HRMS (ESI): m/z израчунато за C25H31FFeN2O2 + H+ [M + H+]: 467,1797. Нађено: 467,1786. Етил-3-фероценил-3-(изопропиламино)пропил(2-хлорфенил)карбамат (105и). Спектра- лни подаци дати за смешу диастереоизомера (55:45). Принос 63%. IR (KBr, ν, cm-1): 3094, 2961, 1698, 1199, 1150, 732; 1H NMR (CDCl3, 400 MHz): δ 0,96 (d, J = 6,2 Hz), 1,00 (t, J = 6,4 Hz), 1,01 (d, J = 6,2 Hz), 1,71–2,13 (m), 2,13–2,27 (m), 2,81 (pseudo septulet, J = 6,2 Hz,), 2,87 (pseudo septulet, J = 6,2 Hz), 3,28–3,59 (m), 4,07 (s), 4,09 (s), 3,96–4,43 (m), 7,17–7,38 (m), 7,41–7,52 (m); 13C NMR (CDCl3, 100 MHz): δ 14,6, 14,6, 23,0, 23,1, 23,7, 23,8, 34,8, 34,9, 45,6, 45,7, 48,0, 48,4, 51,8, 51,8, 61,5, 61,7, 66,0, 67,0, 67,1, 67,1, 67,3, 68,4, 68,4, 93,3, 93,4, 127,4, 127,5, 128,3, 128,4, 128,8, 128,9, 129,7, 130,1, 133,3, 133,5, 139,4, 139,6, 155,3, 155,4; MS (ES+): m/z = 483,2 (MH+); HRMS (ESI): m/z израчунато за C25H31ClFeN2O2 + H+ [M + H+]: 483,1502. Нађено: 483,1481. Етил-3-фероценил-3-(изопропиламино)пропил(3-хлорфенил)карбамат (105ј). Спектра- лни подаци дати за смешу диастереоизомера (90:10). Принос 63%. IR (KBr, ν, cm-1): 3084, 2958, 1691, 1167, 1156, 811; 1H NMR (CDCl3, 400 MHz): δ 1,01 (d, J = 6,2 Hz), 1,05 (d, J = 6,2 Hz), 1,09 (d, J = 6,2 Hz), 1,11 (d, J = 6,2 Hz), 1,23 (t, J = 7,1 Hz), 1,76–2,00 (m, преклапање сигнала), 2,05–2,23 (m), 2,23–2,36 (m), 2,85 (pseudo septulet, J = 6,2 Hz), 2,97 (pseudo septulet, J = 6,2 Hz),3,12–3,27 (m), 3,43 (dd, J = 7,4, 4,5 Hz), 3,62 (dd, J = 7,9, 3,3 Hz), 3,69–3,93 (m), 4,07 (s, Fc), 4,03–4,16 (m), 4,17 (q, J = 7,1 Hz), 6,42–6,47 (m, Ar), 6,52–6,56 (m, Ar), 6,58–6,63 (m, Ar), 7,01–7,08 (m, Ar), 7,11–7,15 (m, Ar), 7,18–7,22 (m, Ar), 7,23–7,31 (m, Ar); 13C NMR (CDCl3, 100 MHz): δ 14,6, 22,7, 23,3, 33,8, 34,8, 44,2, 45,8, 47,8, 51,7,53,6, 61,9, 66,1, 66,4, 67,0, 67,1, 67,3, 67,4, 67,6, 67,8, 68,5, 68,5, 92,2, 111,1, 112,0, 116,5, 124,9, 126,4, 127,1, 129,8, 130,1, 134,3, 134,9, 143,3, 150,0, 155,5; MS (ES+): m/z = 483,2 (MH+); HRMS (ESI): m/z израчунато за C25H31ClFeN2O2 + H+ [M + H+]: 483,1502. Нађено: 483,1481. 118  Етил-3-фероценил-3-(изопропиламино)пропил(4-хлорфенил)карбамат (105к). Принос 76%. IR (KBr, ν, cm-1): 3094, 2964, 1698, 1493, 1284, 1092, 818; 1H NMR (CDCl3, 400 MHz): δ 0,99 (d, J = 6,2 Hz, 3H), 1,02 (d, J = 6,2 Hz, 3H), 1,22 (t, J =7,1 Hz, 3H), 1,74–1,86 (m, 1H), 2,02–2,13 (m, 1H), 2,84 (pseudo septulet, J = 6,2 Hz, 1H), 3,38 (dd, J = 7,4, 4,9 Hz, 1H), 3,68–3,83 (m, 2H), 4,07 (s, 5H, Fc), 4,05–4,10 (m, 3H), 4,10–4,12 (m, 1H), 4,15 (q, J = 7,0 Hz, 2H), 7,11–7,18 (m, 2H, Ar), 7,27–7,33 (m, 2H, Ar); 13C NMR (CDCl3, 100 MHz): δ 14,6, 23,2, 23,5, 35,1, 45,7, 47,9, 51,7, 61,7, 66,2, 66,8, 67,2, 67,4, 68,4, 93,0, 128,1, 129,0, 131,6, 140,8, 155,4; MS (ES+): m/z = 483,2 (MH+); HRMS (ESI): m/z израчунато за C25H31ClFeN2O2 + H+ [M + H+]: 483,1502. Нађено: 483,1480. 4.4.6.2 Циклизација деривата 1,3-пропандиамина 105а, в, г, ђ, е, з, ј, к до 1,3- дисупституисаних 4-фероценилпиримидин-2(1Н)-она 106а, в, г, ђ, е, з, ј, к Раствор одговарајућег етил-арил[3-фероценил-3-(изопропиламино)пропил]кар- бамата 105а, в, г, ђ, е, з, ј, к (1 mmol) и 0,80 mL n-бутил-литијума (128 mg, 2 mmol, 2,5 M раствор у хексану) у сувом тетрахидрофурану (10 mL) меша се 1 h у атмосфери азота на температури од 0 °C, растварач упари, остатку дода вода. Реакциона смеса екстрахује етил-ацетатом (3×10 mL), спојени органски слојеви исперу водом и суше анхидрованим Na2SO4 преко ноћи. Раствор се процеди, растварач упари, а остатак пречишћава препаративном танкослојном хроматографијом (SiO2, хексан/етил-ацетат = 6 : 4). 3-Изопропил-1-фенил-4-фероценилтетрахидропиримидин-2-он (106а). Принос 61%. IR (KBr, ν, cm-1): 2963, 1636, 1482, 1438, 1301, 1195, 747, 694; 1H NMR (CDCl3, 400 MHz): δ 1,29 (d, J = 6,8 Hz, 3H, H–C (3’’), изопропил), 1,38 (d, J = 6,8 Hz, 3H, H–C (1’’), изопропил), 2,21 (dddd, J = 13,0, 6,9, 5,5, 3,7 Hz, 1H, H–C (5eq)), 2,28 (dddd, J = 13,0, 10,5, 5,9, 4,7 Hz, 1H, H–C (5ax)), 3,52 (dddd, J = 12,0, 6,9, 5,9, 0,8 Hz, 1H, H–C (6eq)), 3,57 (ddd, J = 12,0, 10,5, 5,5 Hz, 1H, H–C (6ax)), 4,11 (pseudo dt, J = 2,4, 1,2 Hz, 1H, H–C (3’’’) или H–C (4’’’), Fc), 4,16 (преклапање сигнала, 1H, H–C (2’’), изопропил-, центар је изведен из HSQC), 4,16 (s, преклапање сигнала, 5H, H–C (1’’’’), H–C (2’’’’), H–C (3’’’’), H–C (4’’’’), H–C (5’’’’), Fc), 4,16 (преклапање сигнала, 1H, H–C (2’’’) или H–C (3’’’) или H–C (5’’’), Fc, центар 1'' 3'' 2'' N N 4 5 6 1' 3' 5' 4'2' 6' 1'''3''' 5'''4''' 2''' 2'''' 1'''' 3'''' 4'''' Fe O 119  је изведен из HSQC), 4,17 (преклапање сигнала, 1H, H–C (2’’’) или H–C (3’’’) или H–C (5’’’), Fc, центар је изведен из HSQC), 4,24 (pseudo dt, J = 2,4, 1,2 Hz, 1H, H–C (2’’’) или H–C (5’’’), Fc), 4,46 (ddd, J = 4,7, 3,7, 0,8 Hz, 1H, H–C (4eq)), 7,10–7,16 (m, 1H, H–C (4’), Ar), 7,20–7,25 (m, 2H, H–C (2’), H–C (6’), Ar), 7,27–7,33 (m, 2H, H–C (3’), H–C (5’), Ar); 13C NMR (CDCl3, 100 MHz): δ 20,9 (C (3’’), изопропил), 21,3 (C (1’’), изопропил), 31,7 (C (5)), 45,2 (C (6)), 50,9 (C (2’’), изопропил), 53,0 (C (4)), 66,0 (везан за H на 4,24 ppm, C (2’’’) или C (3’’’) или C (4’’’) или C (5’’’), Fc) 66,7 (везан за H на 4,16 ppm, C (2’’’) или C (3’’’) или C (4’’’) или C (5’’’), Fc), 68,4 (везан за H на 4,17 ppm, C (2’’’) или C (3’’’) или C (4’’’) или C (5’’’), Fc), 68,9 (C (1’’’), C (2’’’), C (3’’’), C (4’’’), C (5’’’), Fc), 69,4 (везан за H на 4,24 ppm, C (2’’’) или C (5’’’), Fc), 91,2 (C (1’’’), Fc), 125,2 (C (4’), Ar), 126,0 (C (2’), C (6’), Ar), 128,8 (C (3’), C (5’), Ar), 144,3 (C (1’), Ar), 154,5 (C (2)); MS (ES+): m/z = 403,2 (MH+); HRMS (ESI): m/z израчунато за C23H26FeN2O + H+ [M + H+]: 403,1473. Нађено: 403,1475. 3-Изопропил-1-(m-толил)-4-фероценилтетрахидропиримидин-2-он (106в). Принос 58%. IR (KBr, ν, cm-1): 2968, 1635, 1484, 1442, 1302, 1196, 697; 1H NMR (CDCl3, 400 MHz): δ 1,28 (dd, J = 6,8 Hz, 3H), 1,37 (dd, J = 6,8 Hz, 3H), 2,17–2,31 (m, 2H), 2,32 (s, 3H, CH3), 3,46–3,60 (m, 2H), 4,12 (pseudo dt, J = 2,4, 1,3 Hz, 1H, Fc), 4,16 (s, 5H, Fc), 4,14–4,20 (m, 3H), 4,24 (pseudo dt, J = 2,4, 1,3 Hz, 1H, Fc), 4,45 (pseudo t, J = 3,9 Hz, 1H), 6,92–6,97 (m, 1H, Ar), 6,99–7,03 (m, 1H, Ar), 7,03–7,09 (m, 1H, Ar), 7,15–7,23 (m, 1H, Ar); 13C NMR (CDCl3, 100 MHz): δ 20,8, 21,2, 21,4, 31,6, 45,2, 50,8, 52,9, 65,9, 66,6, 68,3, 68,8, 69,3, 91,2, 123,0, 126,1, 126,8, 128,5, 138,4, 144,2, 154,5; MS (ES+): m/z = 417,2 (MH+); HRMS (ESI): m/z израчунато за C24H28FeN2O + H+ [M + H+]: 417,1629. Нађено: 417,1622. 3-Изопропил-1-(p-толил)-4-фероценилтетрахидропиримидин-2-он (106г). Принос 66%. IR (KBr, ν, cm-1): 2927, 1635, 1480, 1440, 1300, 1194, 814; 1H NMR (CDCl3, 400 MHz): δ 1,27 (dd, J = 6,8 Hz, 3H), 1,36 (dd, J = 6,8 Hz, 3H), 2,16–2,29 (m, 2H), 2,29 (s, 3H, CH3), 3,45–3,58 (m, 2H), 4,11 (pseudo dt, J = 2,4, 1,3 Hz, 1H), 4,15 (s, 5H, Fc), 4,12–4,20 (m, 3H), 4,23 (pseudo dt, J = 2,4, 1,3 Hz, 1H), 4,44 (pseudo t, J = 3,9 Hz, 1H), 7,10 (br. s, 4H, Ar); 13C NMR (CDCl3, 100 MHz): δ 20,9, 20,9, 21,2, 31,5, 45,2, 50,7, 52,7, 120  65,9, 66,5, 68,3, 68,8, 69,3, 91,2, 125,9, 129,3, 134,8, 141,7, 154,6; MS (ES+): m/z = 417,2 (MH+); HRMS (ESI): m/z израчунато за C24H28FeN2O + H+ [M + H+]: 417,1629. Нађено: 417,1620. 1-(4-Бутилфенил)-3-изопропил-4-фероценилтетрахидропиримидин-2-он (106ђ). При- нос 60%. Т.Т. = 88 ºC; IR (KBr, ν, cm-1): 2927, 1636, 1479, 1446, 1295, 1194, 816; 1H NMR (CDCl3, 400 MHz): δ 0,90 (t, J = 7,3 Hz, 3H), 1,28 (dd, J = 6,8 Hz, 3H), 1,38 (dd, J = 6,8 Hz, 3H), 1,24–1,41 (m, 2H), 1,50–1,60 (m, 2H), 2,16–2,31 (m, 2H), 2,52–2,59 (m, 2H), 3,45–3,60 (m, 2H), 4,10–4,13 (m, 1H), 4,15 (s, 5H, Fc), 4,13–4,19 (m, 3H), 4,24 (pseudo dt, J = 2,4, 1,3 Hz, 1H), 4,45 (pseudo t, J = 3,9 Hz, 1H), 7,11 (br. s, 4H, Ar); 13C NMR (CDCl3, 100 MHz): δ 13,9, 20,8, 21,3, 22,3, 31,6, 33,6, 35,1, 45,2, 50,9, 52,9, 65,9, 66,5, 68,3, 68,8, 69,3, 91,2, 125,8, 128,7, 139,8, 141,8, 154,6; MS (ES+): m/z = 459,2 (MH+); HRMS (ESI): m/z израчунато за C27H34FeN2O + H+ [M + H+]: 459,2099. Нађено: 459,2095. 4-Фероценил-1-(2-флуорфенил)-3-изопропилтетрахидропиримидин-2-он (106е). Принос 57%. IR (KBr, ν, cm-1): 2930, 1636, 1500, 1447, 1313, 1200, 819, 751, 727; 1H NMR (CDCl3, 400 MHz): δ 1,25 (d, J = 6,8 Hz, 3H), 1,39 (d, J = 6,8 Hz, 3H), 2,17–2,36 (m, 2H), 3,55–3,64 (m, 2H), 4,16 (s, 5H, Fc), 4,08–4,22 (m, 4H), 4,25–4,28 (m, 1H), 4,45 (pseudo t, J = 3,6 Hz, 1H), 7,05–7,12 (m, 2H, Ar), 7,15–7,21 (m, 1H, Ar), 7,22–7,27 (m, 1H, Ar); 13C NMR (CDCl3, 100 MHz): δ 20,8, 21,2, 31,5, 45,1, 45,1, 51,1, 53,2, 66,0, 66,5, 68,3, 68,8, 69,3, 91,2, 116,4 (d, JC-F = 20,3 Hz), 124,3 (d, JC-F = 3,7 Hz), 127,8 (d, JC-F = 8,0 Hz), 129,8 (d, JC-F = 1,7 Hz), 131,6 (d, JC-F = 12,4 Hz), 154,0, 158,5 (d, JC-F = 249,0 Hz); MS (ES+): m/z = 421,1 (MH+); HRMS (ESI): m/z израчунато за C23H25FFeN2O + H+ [M + H+]: 421,1378. Нађено: 421,1366. 3-Изопропил-4-фероценил-1-(4-флуорфенил)тетрахидропиримидин-2-он (106з). При- нос 63%. IR (KBr, ν, cm-1): 2929, 1634, 1480, 1441, 1296, 1193, 818; 1H NMR (CDCl3, 400 MHz): δ 1,29 (d, J = 6,8 Hz, 3H), 1,38 (d, J = 6,8 Hz, 3H), 2,16–2,30 (m, 2H), 3,41–3,57 (m, 2H), 4,07–4,11 (m, 1H), 4,16 (s, 5H, Fc), 4,11–4,21 (m, 3H), 4,22–4,25 (m, 1H), 4,47 (pseudo t, J = 3,8Hz, 1H), 6,95–7,09 (m, 2H, Ar), 7,13–7,20 (m, 2H, Ar); 13C NMR (CDCl3, 100 MHz): δ 20,8, 21,3, 31,5, 45,4, 51,0, 53,0, 65,8, 66,6, 68,4, 68,8, 69,2, 91,0, 115,4 (d, JC- Fe N N O F Fe N N O Bu-n 121  F = 22,5 Hz), 127,8 (d, JC-F = 8,3 Hz), 140,2 (d, JC-F = 3,0 Hz), 154,5, 160,2 (d, JC-F = 244,1 Hz); MS (ES+): m/z = 421,1 (MH+); HRMS (ESI): m/z израчунато за C23H25FFeN2O + H+ [M + H]+: 421,1378. Нађено: 421,1370. 3-Изопропил-4-фероценил-1-(3-хлорофенил)тетрахидропиримидин-2-он (106ј). Принос 50%. IR (KBr, ν, cm-1): 2925, 1639, 1475, 1441, 1196, 819, 688; 1H NMR (CDCl3, 400 MHz): δ 1,29 (d, J = 6,8 Hz, 3H), 1,38 (d, J = 6,8 Hz, 3H), 2,19–2,32 (m, 2H), 3,47–3,59 (m, 2H), 4,08–4,10 (m, 1H), 4,16 (s, 5H, Fc), 4,11–4,21 (m, 3H), 4,21–4,23 (m, 1H), 4,46 (pseudo t, J = 4,0 Hz, 1H), 7,07–7,11 (m, 1H, Ar), 7,12–7,16 (m, 1H, Ar), 7,19–7,26 (m, 2H, Ar); 13C NMR (CDCl3, 100 MHz): δ 20,7, 21,2, 31,5, 44,9, 51,1, 53,0, 65,8, 66,7, 68,4, 68,8, 69,2, 90,8, 123,8, 125,0, 125,7, 129,5, 133,9, 145,4, 154,1; MS (ES+): m/z = 437,1 (MH+); HRMS (ESI): m/z израчунато за C23H25ClFeN2O + H+ [M + H+]: 437,1083. Нађено: 437,1083. 3-Изопропил-4-фероценил-1-(4-хлорофенил)тетрахидропиримидин-2-он (106к). При- нос 53%. Т.Т. = 114 ºC; IR (KBr, ν, cm-1): 2964, 1640, 1474, 1447, 1301, 1195, 804; 1H NMR (CDCl3, 400 MHz): δ 1,29 (d, J = 6,8 Hz, 3H), 1,37 (d, J = 6,8 Hz, 3H), 2,18–2,31 (m, 2H), 3,44–3,57 (m, 2H), 4,09 (pseudo dt, J = 2,4, 1,2 Hz, 1H), 4,16 (s, 5H, Fc), 4,08–4,20 (m, 3H), 4,21 (pseudo dt, J = 2,4, 1,2 Hz, 1H), 4,46 (pseudo t, J = 3,9Hz, 1H), 7,14–7,19 (m, 2H, Ar), 7,23–7,28 (m, 2H, Ar); 13C NMR (CDCl3, 100 MHz): δ 20,8, 21,2, 31,5, 45,0, 51,0, 53,0, 65,8, 66,7, 68,4, 68,8, 69,2, 90,8, 126,9, 128,6, 130,3, 142,8, 154,3; MS (ES+): m/z = 437,1 (MH+); HRMS (ESI): m/z израчунато за C23H25ClFeN2O + H+ [M + H+]: 437,1083. Нађено: 437,1077.     Извод У овом раду описанa je синтеза и спектроскопска карактеризација хетероцикличних једињења која садрже фероценил-групу, а представљају деривате једног од следећих пет хетороцикла: - 1,3-тиазолидин-4-он, - 2,3-дихидрохинолин-4(1H)-он, - 1,3-оксазинан, - 1,3-оксазинан-2-он и - тетрахидропиримидин-2(1Н)-он. Синтеза прве групе хетероцикличних једињења - деривата тиазолидинона који у положају 2 садрже фероценил-групу, 92а-л, остварена је полазећи од трговачки доступних супстрата – тиогликолне киселине, фероценалдехида (90) и одговарајућих амина (91а-л). Ова трокомпонентна реакција одвија се у једној фази (one pot реакција), излагањем смесе реактаната ултразвучним таласима у присуству N,N'-дициклохексил- карбодиимида (DCC) као дехидратационог средства. Нађено је да се највиши приноси (48-99%) остварују када је однос реактана 90/91а-л/тиогликолнакиселина = 1:1:2. Сва једињења (која су синтетисана по први пут) изолована су у чистом стању и детаљно окарактерисана физичким и спектроскопским подацима (тачке топљења, микроанализа, IR, 1H и 13C NMR, MS и HRMS), а једно од њих (92ј) било је подесно за рендгеноструктурну кристалну анализу, па му је на тај начин недвосмислено потврђена структура. Редокс особине свих тринаест тиазолидинона испитане су електрохемијски, техником цикличне волтаметрије и нађено је да у опсегу потенцијала 0,000-1,000 V једину електрофору у њиховој структури представља фероценско језгро. Редокс потенцијали ових једињења (E1/2 = 0,487-0,512V) нешто су позитивнији од редокс потенцијала фероцена (0,391 V), што се објашњава чињеницом да је фероценско језгро везано за угљеников атом који носи два хетероатома. Успешна синтеза три дихидрохинолина - 2-фероценил-2,3-дихидрохинолин-4- (1H)-она и његових 6-хлор- и 6-бром-деривата (95а-в) - остварена је у два корака: алдолна кондензација одговарајућег 2-аминоацетoфенона (93а-в) и фероценалдехида (90) у првом даје одговарајуће 2'-аминохалконе 94а-в у приносима 60-90%, а у другом ти халкони под дејством (i) микроталасног зрачења у присуству монтморилонита К-10 124  као катализатора (11-14%), (ii) смеше сирћетне и ортофосфорне киселине на собној температури (36-61%) или (iii) смеше сирћетне и ортофосфорне киселине у ултразвучном купатилу (70-74%) подлежу интрамолекулској циклизацији. Сва три једињења детаљно су описана физичким и спектроскопским подацима (тачке топљења, микроанализа, IR, 1H и 13C NMR), као и рендгеноструктурном анализом, док су њихове редокс особине испитане цикличном волтаметријом. Показало се (у опсегу потенцијала 0,000-1,500 V) да структуре ових једињења садрже две електрофоре – фероценско језгро (реверзибилни редокс процес на E1/2 = 0,409-0.427 V) и амински азот (иреверзибилна оксидација на E = 1,349-1.401 V). Синтеза три последње групе хетероцикличних једињења која садрже фероцен, описаних у овој дисертацији - оксазинана 102а-к, оксазинанона 104а-г, ђ-к и пиримидинона 106а, в, г, ђ, е, з, ј, к, остварена је у неколико корака. На првом ступњу синтетисани су прекурсори ових хетроцикла - одговарајући 1,3-аминоалкохоли 100а-к (3-(ариламино)-1-фероце-нилпропан-1-оли). То је, такође, једна вишестепена синтеза, а испланирана је тако да се алкохоли 100а-к добију редукцијом одговарајућих Манихових база - 3-(ариламино)-1-фероценилпропан-1-она (99а-к). Аминокетони 99а-к синтетисани су аза-Мајкловом адицијом одговарајућих амина 98а-к на акрилоилфероцен (97), који се, са своје стране, добија дехидрохалогеновањем (3- хлорпро-паноил)фероцена (96) - производа Фридел-Крафтсовог ациловања фероцена 3- хлорпропионил-хлоридом. Пошто аза-Мајклова адиција има шири синтетички значај, овoј реакцији посвећена је посебна пажња. Зато је још неколико трговачки доступних амина (98л-о) укључено у ова испитивања, иако производи њихове адиције нису употребљени за синтезу хетероцикла 102, 104 и 106. Из тих истраживања произашла су два оригинална прописа за синтезу фероценских Манихових база. Најпре је, после систематског испитивања, нађено да се излагање смесе енона 97 и ариламини 98а-к (у односу 97/98 = 1:2) микроталасном зрачењу (500 W, 5 min) у присуству монтморилонита К-10 добијају аминокетони 99а-к у приносу 59-98%. Међутим, даља испитивања показала су да је аза-Мајклова адиција амина 98а-к на енон 97 готово једнако успешна и кад се смес реактаната и катализатора подвргну дејству ултразвучних таласа. Разуме се, овај други процес је прихватљивији већем броју органских лабораторија, пошто је за његово извођење потребно обично ултразвучно купатило, које је многоструко јевтиније од микроталасног реактора. 125  Сви добијени кетони су нова једињења и детаљно су описани спектроскопским подацима (тачке топљења, микроанализа, IR, 1H и 13C NMR), а већина од њих су чврсте, кристалне супстанце, подесне за рендгеноструктурну анализу, што је урађено за шест репрезентативних примера. Редокс особине кетона 99а-д, е-м испитане су цикловолтаметријски и добијени су резултати слични онима за једињења 95а-в: и ова једињења садрже две електрофоре – фероценско језгро (реверзибилни редокс процес на E1/2 = 0,618-0,648 V) и азот везан за фенил-групу (иреверзибилна оксидација на 0.693- 1,373 V). Синтеза 6-фероценил-1,3-оксазинана 102а-к остварена је мешањем тетрахид- рофуранских раствора одговарајућих 1,3-аминоалкохола 101а-к и воденог раствора формалдехида преко ноћи, на собној темперартури. Хетероцикли 102а-к добијени су у приносима 80-98%. Сва једињења су нова, па су описана одговарајућим спектроскопским подацима (тачке топљења, IR, 1H и 13C NMR и MS). Серија хетероцикличних једињења – деривата 6-фероценил-1,3-оксазин-2-она (104а-г, ђ-к), синтетисана је у два корака. У првом кораку те синтезе, аминоалкохоли 101а-к подвргнути су реакцији са етил-хлорформијатом, па је добијена серија одговарајућих карбамата (103а-к) у приносима 36-99%. Интрамолекулском циклизацијом тако добијених карбамата 103а-к под дејством натријум-хидрида, у следећој фази, синтетисани су 1,3-оксазин-2-они (104а-г, ђ-к). Интересантно, хидроксиуретан 103д не подлеже овој реакцији, највероватније из стерних разлога. Сва добијена једињења су нова и детаљно су описана физичким и спектроскопским подацима (тачке топљења, IR, 1H и 13C NMR и MS). Последњи део ове тезе посвећен је изучавању реакционих услова синтезе серије 4-фероценилтетрахидропиримидин-2(1Н)-она типа 106. Ова једињења добијена су у тростепеном поступку из аминоалкохола 101а-к, од којих први представља већ описану синтезу хидроксиуретана 103а-к. Хидроксикарбамати 103а-к подвргнути су нуклеофилној супституцији изопропиламином у присуству триетиламина, па су добијени деривати 1,3-пропандиамина 105а-к у приносима 63-96%. У последњем кораку синтезе, дејством n-бутил-литијума, остварује се интрамолекулска супституција етокси-групе уретанског фрагмента аминским азотом, која даје тетрахидропиримидиноне (цикличне карбамиде) 106. Међутим, иако су из свих алкохола 101а-к добијени сви хидроксиуретани 103а-к а из њих сви деривати 1,3- птопандиамина 105а-к, добијени су само тетрахидропиримидинони 126  106а, в, г, ђ, е, з, ј, к, у приносима 53-63%. Ово је објашњено стерном и електронском природом диамина 105б, д, ж, и. Структуре свих осам синтетисаних једињења потврђене су физичким и спектроскопским подацима (тачке топљења, IR, 1H и 13C NMR и MS). Већина синтетисаних једињења дата су одговарајућим специјализованим лабораторијама на испитивање њихове биолошке активности, а резултати се укратко могу сумирати овако: - После тестирања у неколико различитих in vivo модела нађено је да сви 2-фероценил-1,3-тиазолидин-4-они (92а-л) показују снажну анксиолитичку активност, која заслужује даља истраживања. - 2-Фероценил-2,3-дихидрохинолин-4-(1H)-они (95а-в) показују изразиту и неселективну антимикробну активност и према грам позитивним (три соја) и према грам негативним бактеријама (пет сојева), као и према једној гљивичној врсти у in vitro условима. Због тога ова једињења такође заслужују пажњу медицинских хемичара. - Манихове базе 99 такође показују извесну антимикробну активност, која је слабије изражена него у случају фероценских дихидрохинолин-4-(1H)-она 95а-в, али није занемарљива. - Коначно, испитана је биолошка активност и шесточланих хетероцикла 102а-к, 104а-г, ђ-к и 106а, в, г, ђ, е, з, ј, к и показало се да већина од њих показују слабу антимикробну активност, док нека испољавају слабу до умерену цитотоксичност. Summary In this work, the synthesis and spectral characterization of a variety of novel ferrocene derivatives containing one of the following five heterocyclic scaffolds has been described: - 1,3-thiazolidin-4-one, - 2,3-dihydroquinolin-4(1H)-one, - 1,3-oxazinane, - 1,3-oxazinan-2-one, - tetrahydropyrimidin-2-one. The synthesis of the first group of heterocyclic compounds – derivatives of thiazolidinone bearing a ferrocenyl group at position 2, 92а-л, – was performed using the commercially available substrates thioglycolic acid, ferrocenecarboxaldehyde (90) and the appropriate amines 91а-л. This three-component reaction was carried out in one step (one- pot reaction) through ultrasonic irradiation of the mixture of reactants and N,N'-dicyclohexylcarbodiimide (DCC) as the dehydrating agent. It was found that the highest yields (48-99%) were achieved with a 90/91а-л/thioglycolic acid = 1:1:2 ratio. All new products (synthesized for the first time) were isolated in pure form and characterized in detail by means of their physical and spectral data (melting points, microanalysis, IR, 1H and 13C NMR, MS and HRMS). One of them (92j) was found to be suitable for single-crystal X-ray diffraction analysis, thus providing unambiguous confirmation for its molecular structure. Redox properties of all thirteen thiazolidinone derivatives were assessed by an electrochemical technique (cyclic voltammetry), and it was found that the ferrocene unit represents the only electrophore present in these structures in the potential window 0.000-1.000 V. The redox potentials of these compounds (E1/2 = 0.487- 0.512 V) were slightly more positive than that of ferrocene itself (0.391 V), and this is a consequence of the fact that the ferrocene unit is connected to a carbon atom bearing two electronegative heteroatoms. The successful synthesis of three new ferrocene-containing dihydroquinolinones – 2- ferrocenyl-2,3-dihydroquinolin-4(1H)-one and its 6-chloro- and 6-bromoderivatives (95а-в) – was achieved in a two-step manner. The first reaction step yielded 2'-aminochalcones 94а-в by an aldol condensation of the corresponding 2-aminoacetоfenones (93а-в) and ferrocenecarboxaldehyde (90) (60-90%), whereas in a second phase these chalcones were 128  converted into the target dihydroquinolinones 95а-в by subjecting them to one of the following procedures: (i) microwave irradiation of 95а-в in the presence of montmorillonite K-10 as the catalyst (11-14%), (ii) treatment with a mixture of CH3COOH and H3PO4 at room temperature (36-61%), and (iii) sonication in the presence of a CH3COOH/H3PO4 mixture (70-74%). All three new compounds were characterized by physical and spectroscopic data analysis (melting points, microanalysis, IR, 1H and 13C NMR), as well as by single-crystal X- ray diffraction, while their redox properties were evaluated using cyclic voltammetry. It turned out that these compounds comprised two electrophores active within the 0.000-1.500 V potential window: the ferrocene unit (a reversible redox process at E1/2 = 0.409-0.427 V) and the aniline-type nitrogen (an irreversible oxidation at E = 1.349-1.401 V). The last three groups of ferrocene-containing heterocyclic compounds described in this dissertation (oxazinanes 102а-к, oxazinanones 104а-г, ђ-к and tetrahydropyrimidinones 106а, в, г, ђ, е, з, ј, к) were synthesized in several steps. The first step involved the synthesis of 1,3-aminoalcohols 100а-к (3-arylamino-1-ferrocenylpropan-1-ols) as appropriate precursors for all three groups of heterocycles. The preparation of these aminoalcohols was realized via a multistage process: alcohols 100а-к were synthesized by reduction of the corresponding Mannich bases 99а-к (3-arylamino-1-ferrocenylpropan-1-ones) obtained by аza-Michael addition of the corresponding aromatic amines to acryloylferrocene (97). Compound 97 was synthesized by dehydrohalogenation of the Friedel-Crafts acylation product of ferrocene and 3-chloropropanoyl chloride, i.e., 3-chloro-1-ferrocenylpropan-1-one (96). Since the aza-Michael addition represents an important reaction in synthetic organic chemistry, particular attention was devoted to this approach. Thus, several additional commercially available amines 98л-о were included in the above-described investigations, although the products of their addition were not employed in the syntheses of heterocycles 102, 104 and 106. This study resulted in the development of two new procedures for the synthesis of ferrocene-containing Mannich bases. Firstly, after systematic examinations, it was found that microwave irradiation (500 W, 5 min) of the mixture of enone 97 and arylamines 98а-к (97/98 = 1:2) in the presence of montmorillonite K-10 provided Mannich bases 98а-к in 59-98% yield. However, further investigations revealed that the aza-Michael addition of amines 98а-к to enone 97 could also be successfully accomplished by sonication instead of microwave irradiation of the same mixture of reactants and catalyst, affording the corresponding aminoketones in almost the same yields. This second process is, of course, 129  much more appealing to synthetic chemists since it requires an ultrasonic bath – a much simpler and cheaper equipment than a microwave reactor. All the obtained ketones were characterized as new compounds by means of their physical/chemical and spectroscopic data (melting points, microanalysis, IR, 1H and 13C NMR), while the structure of six representatives was also confirmed by single-crystal X- ray diffraction. The redox properties of ketones 99а-д, е-м were evaluated by cyclovoltammetry, and it was found that these compounds, similar to 95а-в, contain two electrophores: the ferrocene unit (a reversible redox process at E1/2 = 0.618-0.648 V) and the nitrogen atom bonded to an aryl group (an irreversible oxidation at E = 0.693-1.373 V). 6-Ferrocenyl-1,3-oxazinanes 102а-к were synthesized in one step from the corresponding aminoalcohols 101а-к by overnight stirring of a tetrahydrofurane solution of these compounds and an aqueous solution of formaldehyde, at room temperature. Heterocycles 102а-к were thus obtained in 80-98% yield. All compounds are new and were fully characterized by physical and spectral data analysis (melting points, IR, 1H and 13C NMR, and MS). 6-Ferrocenyl-1,3-oxazinan-2-ones 104а-г, ђ-к were synthesized in two steps. In the first step of this synthesis, aminoalcohols 101а-к reacted with ethyl chloroformate to yield a series of corresponding carbamates (103а-к) in 36-99% yield. 1,3-Oxazinan-2-ones 104а- г, ђ-к were subsequently obtained by an intramolecular cyclization of compounds 103а-к promoted by means of sodium hydride. Surprisingly, the hydroxyurethane 103д did not undergo this reaction, probably due to steric reasons. All the obtained compounds are new and were characterized in detail by physical and spectral data analysis (melting points, IR, 1H and 13C NMR, and MS). The last part of this dissertation was devoted to the search for the best reaction conditions to provide a synthetic entry into 4-ferrocenyltetrahydropyrimidin-2(1H)-ones 106. These compounds were obtained from aminoalcohols 101а-к in a three-step protocol, including the described synthesis of hydroxyurethanes 103а-к. These products were submitted to nucleophilic substitution with isopropylamine in the presence of triethylamine, furnishing 1,3-propanediamine derivatives 105а-к in 63-96% yield. In the last step of this synthesis, an intramolecular displacement of the ethoxy group (in the urethane fragment) by the amine nitrogen was achieved upon treatment with n-butyllithium, yielding the corresponding tetrahydropyrimidinones (cyclic ureas) 106. However, even though all aminoalcohols 101а-к were successfully converted into the corresponding hydroxyurethanes 103а-к, and the latter into the corresponding 1,3-propanediamines 105, only 130  tetrahydropyrimidinones 106а, в, г, ђ, е, з, ј, к were obtained following this protocol in 53- 63% yield. The failure of the reaction in the case of derivatives 105б, д, ж, и was attributed to steric and electronic reasons. The structures of all eight synthesized compounds were confirmed by analysis of their physical and spectral data (melting points, IR, 1H and 13C NMR, and MS). Most of the synthesized compounds were sent to appropriate collaborating laboratories in order to evaluate their biological activity, and the obtained results may be briefly summarized as follows: - After testing in several different in vivo models, it was found that all 2-ferrocenyl-1,3-thiazolidine-4-ones (92a-л) showed strong anxiolytic activity, which certainly deserves further research. - 2-Ferrocenyl-2,3-dihydroquinoline-4(1H)-ones (95a-в) exhibited significant and non-selective antimicrobial activity against Gram-positive (three strains) and Gram-negative bacteria (five strains), as well as against a single fungal species (in vitro). Therefore, these compounds also deserve the attention of medicinal chemists. - Mannich bases 99 exhibited some degree of antimicrobial activity, which was less than the activity of ferrocene-containing dihydroquinoline-4-(1H)-ones (95a-в). - Finally, the biological activity of the six-membered heterocycles 102а-к, 104а-г, ђ-к and 106a, в, г, ђ, e, з, j, к, was also tested, and it turned out that most of them exhibited no or weak antimicrobial activity, while some of them showed weak to moderate cytotoxicity. Литература 1. J. A. Joule J, K. Mills, Heterocyclic Chemistry, 5th ed., A John Wiley & Sons, Ltd., Publication, 2010. 2. C. Ornelas, New J. Chem. 35 (2011) 1973. 3. R. D. Vukićević, M. Vukićević, Z. Ratković, S. Konstantinović, Synlett 12 (1998) 1329. 4. R. D. Vukićević, Z. R. Ratković, M. D. Vukićević, S. Konstantinović, Tetrahedron Lett. 39 (1998) 5837. 5. M. D. Vukićević, Z. R. Ratković, A. V. Teodorović, G. S. Stojanović, R. D. Vukićević, Tetrahedron 58 (2002) 9001. 6. G. Eminović, M. D. Vukićević, Z. Ratković, D. Ilić, R. D. Vukićević, Synlett 15 (2003) 2416. 7. D. Ilić, I. Damljanović, D. Stevanović, M. Vukićević, N. Radulović, V. Kahlenberg, G. Laus, R. D. Vukićević, Polyhedron 29 (2010) 1863. 8. D. Ilić, I. Damljanović, D. Stevanović, M. Vukićević, P. Blagojević, N. Radulović, R. D. Vukićević, Chem. Biodiversity 9 (2012) 2236. 9. M. Joksović, Z. Ratković, M. Vukićević, R. D. Vukićević, Synlett 16 (2006) 2581. 10. I. Damljanović, M. Vukićević, N. Radulović, R. Palić, E. Ellmerer, Z. Ratković, M. D. Joksović, R. D. Vukićević, Bioorg. Med. Chem. Lett. 19 (2009) 1093. 11. I. Damljanović, M. Čolović, M. Vukićević, D. Manojlović, N. Radulović, K. Wurst, G. Laus, Z. Ratković, M. Joksović, R. D. Vukićević, J. Organomet. Chem. 694 (2009) 1575. 12. Z. Ratković, Z. D. Juranić, T. Stanojković, D. Manojlović, R. D. Vukićević, N. Radulović, M. D. Joksović, Bioorg. Chem. 38 (2010) 26. 13. T. J. Kealy, P. L. Pauson, Nature 168 (1951) 1039. 14. S. A. Miller, J. A. Tebboth, J. F. Tremaine, J. Chem. Soc. (1952) 632. 15. G. Wilkinson, M. Rosenblum, M. C. Whiting, R. B. Woodward, J. Am. Chem. Soc. 74 (1952) 2125. 16. L. E. Orgel, J. D. Dunitz, Nature 171 (1953) 121. 17. J. Dunitz, L. Orgel, A. Rich, Acta. Cryst. 9 (1956) 373. 18. A. Haaland, J. E. Nilson, J. Chem. Soc. Chem. Comm. (1968) 88. 19. R. Woodward, M. Rosenblum, M. Whitig, J. Am. Chem. Soc. 74 (1952) 3458. 20. J. G. Mason, M. Rosenblum, J. Am. Chem. Soc. 82 (1960) 4206. 21. A. Togui, T. Hayashi, Ferrocenes: Homogenous Catalysis, Organic Synthesis, Material Science, VCH, Weinheim, 1995. 22. W. L. Jolly, Inorg. Synth. 11 (1968) 120. 23. G. Wilkinson, Org. Synth. 4 (1963) 473. 24. G. Wilkinson, P. Pauson, F. Cotton, J. Amer. Chem. Soc. 76 (1954) 1970. 25. W. Eisenbach, H. Lehmkuhl, Chem.-Ing.-Teach. 54 (1982) 690. 26. M. Rosenblum, Chemistry of the Iron-Group Metallocenes, Part I, Interscience, New York, (1965). 27. A. Labande, J. Ruiz, D. Astruc, J. Am. Chem. Soc. 124 (2002) 1782. 28. P. Chen, Q. Wu, Y. Ping Ding, Small 3 (2007) 644. 29. D. Braga, M. Polito, M. Bracaccini, D. DˈAddario, E. Tagliavini, L. Sturba, 132  Organometallics 22 (2003) 2142. 30. J. S. Miller, A. J. Epstein, W. M. Reiff, Acc. Chem. Res. 21 (1988) 114. 31. S. J. Higgins, C. L. Jones, S. M. Francis, Synthetic Metals 98 (1999) 211. 32. M. Saleem, H. Yu, L. Wang, Z. Abdin, H. Khalid, M. Akram, N. M. Abbasi, J. Huang, Analytica Chim. Acta (2015) 1. 33. M. Sakakida, K. Nishida, M. Shichiri, Sensors and Actuators B 13-14 (1993) 319. 34. A. I. Mufula, B. A. Aderibigbe, E. W. Neuse, H. E. Mukaya, J. Inorg. Organomet. Polym. 22 (2012) 423. 35. J. C. Swarts, E. W. Neuse, G. J. Lamprecht, J. Inorg. Organomet. Polym. 4 (1994) 143. 36. D. R. van Staveren, N. Metzler-Nolte, Chem. Rev. 104 (2004) 5931. 37. C. S. Allardyce, A. Dorcier, C. Scolaro, P. J. Dyson, Appl. Organomet. Chem., 19 (2005) 1. 38. L. V. Snegur, V. N. Babin, A. A. Simenel, Y. S. Nekrasov, L. A. Ostrovskaya, N. S. Sergeeva, Russ. Chem. Bull., Int. Ed. 59 (2010) 2167. 39. M. F. R. Fouda, M. M. Abd-Elzaher, R. A. Abdelsamaia, A. A. Labib, Appl. Organomet. Chem. 21 (2007) 613. 40. E. A. Hillard, A. Vessieres, G. Jaouen, Top. Organomet. Chem. 32 (2010) 81. 41. C. Biot, N. Francois, L. Maciejewski, J. Brocard, D. Poulain, Bioorg. Med. Chem. Lett. 10 (2000) 839. 42. J. Zhang, Appl. Organomet. Chem. 22 (2008) 6. 43. C. Biot, G. Glorian, L. Maciejewski, J. Brocard, O. Domarle, G. Blampain, P. Millet, A. J. Georges, H. Abessolo, D. Dive, J. Lebibi, J. Med. Chem. 40 (1997) 3715. 44. L. Delhaes, C. Biot, L. Berry, L. Maciejewski, D. Camus, J. Brocard, D. Dive, Bioorg. Med. Chem. 8 (2000) 2739. 45. T. Itoh, S. Shirakami, N. Ishida, Y. Yamashita, T. Yoshida, H. S. Kim, Y. Wataya, Bioorg. Med. Chem Lett. 10 (2000) 1657. 46. A. K. Kondapi, N. Satyanarayana, A. Saikrishna, Arch. Biochem. Byophys. 450 (2006) 123. 47. V. J. Fiorina, R. J. Dubois, S. Brynes, J. Med. Chem. 21 (1978) 393. 48. S. Top, A. Vessieres, C. Cabestaing, I. Laios, G. Leclersq, C. Provot, G. Jaouen, J. Organometal. Chem. 637 (2001) 500. 49. S. C. Nagel, J. L. Hagerbalger, D. P. McDonnell, Endocrinology 142 (2001) 4721. 50. V. Craig Jordan, Curr. Probl. Cancer 16 (1992) 129. 51. H. Huynh, X. Yang, M. Pollak, J. Biol. Chem. 271 (1996) 1016. 52. J. Cuzick, T. Powles, U. Veronesi, J. Forbes, R. Edwards, S. Ashley, P. Boyle, Lancet 361 (2003) 296. 53. S. Top, J. Tang, A. Vessieres, D. Carrez, C. Provot, G. Jaouen, Chem. Commun. (1996) 955. 54. S. Top, B. Dauer, J. Vaissermann, G. Jaouen, J. Organomet. Chem. 541 (1997) 355. 55. S. Top, A. Vessieres, G. Laclercq, J. Quivy, J. Tang, J. Vaissermann, M. Huche, G. Jaouen, Chem. Eur. J. 9 (2003) 5223. 56. A. Nguyen, S. Top, P. Pigeon, A. Vessieres, E. Hillard, M. Plamont, M. Huche, C. Rigamonti, G. Jaouen, Chem. Eur. J. 15 (2009) 684. 57. I. Shiina, Y. Sano, K. Nakata, T. Kikuchi, A. Sasaki, M. Ikekita, Y. Nagahara, 133  Y. Hasome, T. Yamori, K. Yamazaki, Biochem. Pharmacol. 75 (2008) 1014. 58. E. A. Hillard, P. Pigeon, A. Vessieres, C. Amatore, G. Jaouen, Dalton Trans. (2007) 5073. 59. E. A. Hillard, A. Vessieres, S. Top, P. Pigeon, K. Kowalki, M. Huche, G. Jaouen, J. Organomet. Chem. 692 (2007) 1315. 60. J. B. Heilmann, E. A. Hillard, M. Plamont, P. Pigeon, M. Bolte, G. Jaouen, A. Vessieres, J. Organomet. Chem. 693 (2008) 1716. 61. G. Jaouen, S. Top, A. Vessieres, P. Pigeon, G. Leclercq, I. Laois, Chem. Commun. (2001) 383. 62. S. Top, A. Vessieres, P. Pigeon, M. Rager, M. Huche, E. Salomon, C. Cabestaing, J. Vaissermann, G. Jaouen, ChemBioChem 5 (2004) 1104. 63. E. Hillard, A. Vessieres, L. Thouin, G. Jaouen, C. Amatore, Angew. Chem., Int. Ed. 45 (2006) 285. 64. O. Zekri, E. Hillard, S. Top, A. Vessieres, P. Pigeon, M. Plamont, M. Huche, S. Boutamine, M. McGlinchey, H. Muller-Bunz, G. Jaouen, Dalton Trans. (2009) 4318. 65. P. Pigeon, S. Top, O. Zekri, E. Hillard, A. Vessieres, M. Plamont, O. Buriez, E. Labbe, M. Huche, S. Boutamine, C. Amatore, G. Jaouen, J. Organomet. Chem. 694 (2009) 895. 66. D. Plazuk, A. Vessieres, E. Hillard, O. Buriez, E. Labbe, P. Pigeon, M. Plamont, C. Amatore, J. Zakrzewski, G. Jaouen, J. Med. Chem. 52 (2009) 4964. 67. M. Gӧrmen, P. Pigeon, S. Top, E. Hillard, M. Huche, C. Hartinger, F. de Montigny, M. Plamont, A. Vessieres, G. Jaouen, ChemMedChem 5 (2010) 2039. 68. M. Gӧrmen, D. Plazuk, P. Pigeon, E. Hillard, M. Plamont, S. Top, A. Vessieres, G. Jaouen, Tetrahedron Lett. 51 (2010) 118. 69. A. Vessieres, S. Top, W. Beck, E. Hillard, G. Jaouen, Dalton Trans. (2006) 529. 70. D. Osella, H. Mahboobi, D. Colangelo, G. Cavigiolio, A. Vessieres, G. Jaouen, Inorg. Chim. Acta 358 (2005) 1993. 71. H. Tamura, M. Miwa, Chem. Lett. 11 (1997) 1177. 72. A. P. Ferreira, J. L. F. da Silva, M. T. Duarte, M. F. M. da Piedade, M. P. Robalo, S. G. Harjivan, C. Marzano, V. Gandin, M. M. Marques, Organometallics 28 (2009) 5412. 73. A. Vessieres, D. Spera, S. Top, B. Misterkiewicz, J. Heldt, E. Hillard, M. Huche, M. Plamont, E. Napolitano, R. Fiaschi, G. Jaouen, ChemMedChem 1 (2006) 1275. 74. B. Long, S. Liang, D. Xin, Y. Yang, J. Xiang, Eur. J. Med.Chem. 44 (2009) 2572. 75. C.-W. Ong, J.-Y. Jeng, S.-S. Juang, C.-F. Chen, Bioorg. Med. Chem. Lett. 2 (1992) 929. 76. R. Corder, J. Douthwaite, D. Lees, N. Khan, A. Visendos-Santos, E. Wood, M. Carrier, Nature 414 (2001) 863. 77. S. Quideau, ChemBioChem 4 (2004) 427. 78. C. Santos-Buelga, G. Williamson, Methods in Polyphenol Analysis, RSC: Cambridge, (2003). 79. A. Vessieres, S. Top, P.Pigeon, E. Hillard, L. Boubeker, D. Spera, G. Jaouen, J. Med. Chem. 48 (2005) 3937. 80. E. Hillard, A. Vessieres, F. Le Bideau, D. Plazuk, D. Spera, M. Huch, G. Jaouen, ChemMedChem. 1 (2006) 551. 81. D. Plazuk, A. Vessieres, F. Le Bideau, G. Jaouen, J. Zakrzewskib, Tetrahedron Lett. 45 (2004) 5425. 82. S. Top, C. Thibaudeau, A. Vessieres, E. Brule, F. Le Bideaau, J. Joerger, M. Plamont, S. Samreth, A. Edgar, J. Marrot, P. Herson, G. Jaouen, Organometallics 28 (2009) 1414. 134  83. J. Manosroi, K. Rueanto, K. Boonpisuttinant, W. Manosroi, C. Biot, H. Akazawa, T. Akihisa, W. Issarangporn, A. Manosroi, J. Med. Chem. 53 (2010) 3937. 84. O. Payen, S. Top, A. Vessieres, E. Brule, M. Plamont, M. McGlinchey, H. Müller- Bunz, G. Jaouen, J. Med. Chem. 51 (2008) 1791. 85. E. W. Neuse, F. B. D. Khan, M. Meirim, Appl. Organomet. Chem. 2 (1987) 129. 86. E. W. Neuse, M. G. Meirim, N. F. Blom, Organometallics 7 (1988) 2562. 87. L. Weissfloch, M. Wagner, T. Probst, R. Senekowitsch-Schmidtke, K. Tempel, M. Molls, BioMetals 14 (2001) 43. 88. P. Kӧpf-Maier, H. Kӧpf, E. Neuse, Angew. Chem. 23 (1984) 456. 89. P. Kӧpf-Maier, H. Kӧpf, E. Neuse, J. Cancer Res. Clin. Oncol. 108 (1984) 336. 90. L. Popova, V. Babin, Y. Belousov, Y. Nekrasov, A. Snegireva, N. Borodina, G. Shaposhnikova, O. Bychenko, P. Raevskii, N. Morozova, A. Iiyina, K. Shitkov, Appl. Organomet. Chem. 7 (1993) 85. 91. P. Kӧpf-Maier, H. Kӧpf, Bioinorganic Chemistry, Springer Berlin/Heidelberg, 70 (1988) 103. 92. E. Neuse, F. Kanzawa, Appl. Organomet. Chem. 4 (1990) 19. 93. A. Houlton, R. Roberts, J. Silver, J. Organomet. Chem. 418 (1991) 107. 94. D. Osella, M. Ferrali, P. Zanello, F. Laschi, M. Fontani, C. Nervi, G. Cavigiolio, Inorg. Chim. Acta 306 (2000) 42. 95. L. V. Snegur, A. A. Simenel, Y. S. Nekrasov, E. A. Morozova, Z. A. Starikova, S. M. Peregudova, Y. V. Kuzmenko, V. N. Babin, L. A. Ostrovskaya, N. V. Bluchterova, M. M. Fomina, J. Organomet. Chem. 689 (2004) 2473. 96. L. V. Snegur, Y. S. Nekrasov, N. S. Sergeeva, Z. V. Zhilina, V. V. Gumenyuk, Z. A. Starikova, A. A. Simenel, N. B. M. Morozova, I. K. Sviridova, V. N. Babin, Appl. Organomet. Chem. 22 (2008) 139. 97. A. A. Simenel, S. V. Samarina, L. V. Snegur, Z. A. Starikova, L. A. Ostrovskaya, N. V. Bluchterova, M. M. Fomina, Appl. Organomet. Chem. 22 (2008) 276. 98. M. Meirim, E. Neuse, G. Caldwell, J. Inorg. Organomet. Polym. 7 (1997) 71. 99. M. Meirim, E. Neuse, G. Caldwell, J. Inorg. Organomet. Polym. 8 (1998) 225. 100. E. Neuse, M. Meirim, D. D. N”Da, G. Caldwell, J. Inorg. Organomet. Polym. 9 (1999) 221. 101. G. Caldwell, M. Meirim, E. Neuse, K. Beloussow, W. Shen, J. Inorg. Organomet. Polym. 10 (2000) 93. 102. B. Schechter, G. Caldwell, E. Neuse, J. Inorg. Organomet. Polym. 10 (2000) 177. 103. M. Johnson, E. Kreft, D. D. N”Da, E. Neuse, J. van Rensburg, J. Inorg. Organomet. Polym. 13 (2003) 255. 104. E. W. Neuse, Macromol. Symp. 172 (2001) 127. 105. E. W. Neuse, Polym. Adv.Technol. 9 (1998) 786. 106. A. J. Corry, A. Goel, S. R. Alley, P. N. Kelly, D. O'Sullivan, D. Savage, P. T. M. Kenny, J. Organomet. Chem. 692 (2007) 1405. 107. A. Goel, D. Savage, S. R. Alley, P. N. Kelly, D. O'Sullivan, H. Mueller-Bunz, P. T. M. Kenny, J. Organomet. Chem. 692 (2007) 1292. 108. A. Mooney, A. J. Corry, D. O'Sullivan, D. K. Rai, P. T. M. Kenny, J. Organomet. Chem. 694 (2009) 886. 135  109. A. Mooney, A. J. Corry, C. N. Ruairc, T. Mahgoub, D. O'Sullivan, N. O'Donovan, J. Crown, S. Varughese, S. M. Draper, D. K. Rai, P. T. M. Kenny, Dalton Trans. 39 (2010) 8228. 110. A. A. Simenel, E. A. Morozova, L. V. Snegur, S. I. Zykova, V. V. Kachala, L. A. Ostrovskaya, N. V. Bluchterova, M. M. Fomina, Appl. Organomet. Chem. 23 (2009) 219. 111. A. A. Simenel, G. A. Dokuchaeva, L. V. Snegur, A. N. Rodionov, M. M. Ilyin, S. I. Zykova, L. A. Ostrovskaya, N. V. Bluchterova, M. M. Fomina, V. A. Rikova, Appl. Organomet. Chem. 25 (2011) 70. 112. M. J. Kelner, T. C. McMorris, W. T. Beck, J. M. Zamora, R. Taetle, Cancer Res. 47 (1987) 3186. 113. F. R. Kinder, R.-M. Wang, W. E. Bauta, K. W. Bair, Bioorg. Med. Chem. Lett. 6 (1996) 1029. 114. M. J. Kelner, T. C. McMorris, L. Estes, W. Wnag, K. M. Samson, R. Taetle, Invest. New Drugs 14 (1996) 161. 115. S. Knauer, B. Biersack, M. Zoldakova, K. Effenberger, W. Milius, R. Schobert, Anti-Cancer Drugs 20 (2009) 676. 116. J. Paik, S. Vogel, R. Piantedosi, A. Sykes, W.Blaner, K. Swisshelm, Biochemistry 39 (2000) 8073. 117. A. Nudelman, A. Rephaeli, J. Med. Chem. 43 (2000) 2962. 118. J. Roca, Trends Biochem. Sci. 20 (1995) 156. 119. Y. N. Vashisht Gopal, D. Jayaraju, A. K. Kondapi, Arch. Biochem. Biophys. 376 (2000) 229. 120. A. D. S. Krishna, G. Panda, A. K. Kondapi, Arch. Biochem. Biophys. 438 (2005) 206. 121. J. R. Rajput, A. T. Moss, D. T. Hutton, C. E. Hendricks, A. C. Imrie, J. Organomet. Chem. 689 (2004) 1553. 122. W. C. M. Duivenvoorden, Y. Liu, G. Schatte, H. Kraatz, Inorg. Chim. Acta 358 (2005) 3183. 123. V. Zsoldos-Mady, A. Csampai, R. Szabo, E. Meszaros-Alapi, J. Pasztor, F. Hudecz, P. Sohar, ChemMedChem. 1 (2006) 1119. 124. L. Chen, J. Chen, L. Sun, Q. Xie, Appl. Organomet. Chem. 19 (2005) 1038. 125. WHO. Weekly Epidemiol. Rep. 3 (1996) 17. 126. WHO. Weekly Epidemiol. Rep. 4 (1996) 25. 127. WHO. Weekly Epidemiol. Rep. 5 (1996) 37. 128. C. Biot, S. Caron, L. Maciejewski, J. Brocard, J. Labelled Compd Radiopharm. 51 (1998) 911. 129. O. Domarle, G. Blampain, H. Agnaniet, T. Nzadiyabi, J. Lebibi, J. Brocard, L. Maciejewski, C. Biot, A. Georges, P. Millet, Antimicrob. Agents Chemother. 42 (1998) 540. 130. C. Biot, L. Delhaes, H. Abessolo, O. Domarle, L. Maciejewski, M. Mortuaire, P. Delcourt, P. Deloron, D. Camus, D. Dive, J. Brocard, J. Organomet. Chem. 589 (1999) 59. 131. C. Biot, L. Delhaes, C. N'Dyae, L. Maciejewski, D. Camus, D. Dive, J. Brocard, Bioorg. Med. Chem. 7 (1999) 2843. 132. L. Delhaes, H. Abessolo, C. Biot, L. Berry, P. Delcourt, L. Maciejewski, J. Brocard, 136  D. Camus, D. Dive, Parasitol. Res. 87 (2001) 239. 133. C. Biot, L. Delhaes, L. Maciejewski, M. Mortuaire, D. Camus, D. Dive, J. Brocard, Eur. J. Med. Chem. 35 (2000) 707. 134. L. Delhaes, C. Biot, L. Berry, P. Delcourt, L. Maciejewski, D. Camus, J. Brocard, D. Dive, ChemBioChem. 3 (2002) 418. 135. C. Atteke, J. Ndong, A. Aubouy, L. Maciejewski, J. Brocard, J. Lebibi, P. Deloron, J. Antimicrob. Chemother. 51 (2003) 1021. 136. W. Daher, C. Biot, T. Fandeur, H. Jouin, L. Pelinski, E. Viscogliosi, L. Fraisse, B. Pradines, J. Brocard, J. Khalife, D. Dive, Malaria J. 5 (2006) 11. 137. C. Biot, Curr. Med. Chem. Anti-Infective Agents 3 (2004) 135. 138. B. Pradines, A. Tall, C. Rogier, A. Spiegel, J. Mosnier, L. Marrama, T. Fusai, P. Millet, E. Panconi, J. Trape, D. Parzy, Trop. Med. Int. Health 7 (2002) 265. 139. C. Biot, J. Dessolin, I. Ricard, D. Dive, J. Organometal. Chem. 689 (2004) 4678. 140. X. Wu, P. Wilairat, M. Go, Bioorg. Med. Chem. Lett. 12 (2002) 2299. 141. X. Wu, E. R. T. Tiekink, I. Kostetski, N. Kocherginsky, T. L. C. Agnes, S. B. Khoo, P. Wilairat, M. L. Go, Eur. J. Pharm. Sci. 27 (2006) 175. 142. A. Baramee, A. Coppin, M. Mortuaaire, L. Pelinski, S. Tomavoc, J. Brocard, Bioorg. Med. Chem. 14 (2006) 1294. 143. C. Biot, D. Taramelli, I. Forfar-Bares, L. A. Maciejewski, M. Boyce, G. Nowogrocki, J. S. Brocard, N. Basilico, P. Olliaro, T. J. Egan, Mol. Pharm. 2 (2005) 185. 144. M. De Champdore, G. Di Fabio, A. Messere, D. Montesarchio, G. Piccialli, R. Loddo, M. La Colla, P. La Colla, Tetrahedron 60 (2004) 6555. 145. B. Loev, M. Flores, J. Org. Chem. 26 (1961) 3595. 146. A. Verma, S. K. Saraf, Eur. J. Med. Chem. 43 (2008) 897. 147. F. Brown, Chem. Rev. 61 (1961) 463. 148. H. Erlenmeyer, V. Oberlin, Hel. Chim. Acta 30 (1947) 1329. 149. A. Surrey, J. Am. Chem. Soc. 69 (1947) 2911. 150. K. M. Hassan, Z. Naturforsch 33b (1978) 1508. 151. R. Rawal, R. Tripathi, S. Kulkarni, R. Paranjape, S. Katti, C. Pannecouque, E. Clercq, Chem. Biol. Drug. Des. 72 (2008) 147. 152. R. Rawal, T. Srivastava, W. Haq, S. Katti, J. Chem. Res. 5 (2004) 368. 153. T. Srivastava, W. Haq, S. Katti, Tetrahedron 58 (2002) 7619. 154. I. Damljanović, D. Stevanović, A. Pejović, M. Vukićević, S. Novaković, G. Bogdanović, T. Mihajlov-Krstev, N. Radulović, R. Vukićević, J. Org. Chem. 696 (2011) 3703. 155. C. Woolston, J. Lee, F. Swinbourne, Phosphorus Sulfur 78 (1993) 223. 156. C. Woolston, J. Lee, F. Swinbourne, W. Thomas, Mag. Reson. Chem. 30 (1992) 1075. 157. J. Tierney, D. Sheridan, K. Kovalesky, Heterocycl. Commun. 6 (2000) 105. 158. C. Woolston, J. Lee, F. Swinbourne, Magn. Reson. Chem. 31 (1993) 348. 159. C. Woolston, J. Lee, F. Swinbourne, Phosphorus Sulfur 97 (1994) 157. 160. G. Innorta, F. Scagnolari, A. Modelli, S. Torroni, A. Foffani, S. Sorriso, J. Organomet. Chem. 241 (1983) 375. 161. D. Hickel, J. M. Leger, A. Carpy, M. G. Vigorita, A. Chimirri, S. Grasso, Acta Crystallogr. C 39 (1983) 240. 162. A. S. Wagman, M. P. Wentland, in: J. B. Taylor, D. J. Triggle (Eds.), Comprehensive 137  Medicinal Chemistry II, vol. 7, Elsevier, Amsterdam, 2006, pp. 567. 163. M. S. Atwal, L. Bauer, S.N. Dixit, J.E. Gearien, R.W. Morris, J. Med. Chem. 8 (1965) 566. 164. Y. Xia, Z.-Y. Yang, P. Xia, K. F. Bastow, Y. Tachibana, S.-C. Kuo, E. Hamel, T. Hackl, K.- H. Lee, J. Med. Chem. 41 (1998) 1155. 165. S.-X-Zhang, J. Feng, S.-C. Kuo, A. Brossi, E. Hamel, A. Tropsha, K.-H-Lee, J. Med. Chem. 43 (2000) 167. 166. L. N. Bheemanapalli, A. Kaur, R. Arora, Sangeeta, R. R. Akkinepally, N. M. Javali, Med. Chem. Res. 21 (2012) 1741. 167. O. V. Singh, R. S. Kapil, Synth. Commun. 23 (1993) 277. 168. O. Prakash, D. Kumar, R. K. Saini, S. P. Singh, Synth. Commun. 24 (1994) 2167. 169. W. J. Lee, J. M. Chea, Y. Jahng, Bull. Korean Chem. Soc. 30 (2009) 3061. 170. M. Zora, Ö. Velioǧlu, J. Organomet. Chem. 693 (2008) 2159. 171. G. Janzso, E. M. Philbin, Tetrahedron Lett. 12 (1971) 3075. 172. A. L. Tökés, L. Szilágy, Synth. Comm. 17 (1987) 1235. 173. J. A. Donnelly, D. F. Farrell, J. Org. Chem. 55 (1990) 1757. 174. J. S. Mahanty, M. De, P. Das, N. G. Kundu, Tetrahedron 53 (1997) 13397. 175. R.S. Varma, R.K. Saini, Synlett (1997) 857. 176. R. Varma, J. Heterocyclic Chem. 36 (1999) 1565. 177. K. H. Kumar, P. T. Perumal, Can. J. Chem. 84 (2006) 1079. 178. N. Ahmed, J. E. van Lier, Tetrahedron Lett. 47 (2006) 2725. 179. J. Li, L. Jin, C. Yu, W. Su, J. Chem. Res. (2009) 170. 180. N. Ahmed, J. E. van Lier, Tetrahedron Lett. 48 (2007) 13. 181. E. Tang, B. Chen, L. Zhang, W. Li, J. Lin, Synlett (2011) 707. 182. L. Wu, B. Niu, W. Li, F. Yan, Bull. Korean Chem. Soc. 30 (2009) 2777. 183. D. Kumar, G. Patel, B. Mishra, R. Varma, Tetrahedron Lett. 49 (2008) 6974. 184. D. Kumar, G. Patel, A. Kumar, R. Roy, J. Heterocyclic Chem. 46 (2009) 791. 185. R. N. Bhattacharya, P. Kundu, G. Mait, Synth. Commun. 40 (2010) 476. 186. M. Muthukrishnan, M. Mujahid, V. Punitharasu, D. A. Dnyaneshwar, Synth. Commun. 40 (2010) 1391. 187. J. Lee, H. Jung, J. Korean Chem. Soc. 51 (2007) 106. 188. M. J. Mphahlele, P.T. Kaye, Magn. Reson. Chem., 36 (1998) 69 189. Z. Galus, R. Adams, J. Phys. Chem. 67 (1963) 862. 190. J. Bacon, R. Adams, J. Am. Chem. Soc. 90 (1968) 6596. 191. R. Ojani, J. Raoof, B. Norouzi, J. Mater. Sci. 44 (2009) 4095. 192. T. Urbanski, Synthesis (1974) 613. 193. S. M. A. Hashmi, S. A. Ali, M. I. M. Wazeer, Tetrahedron 54 (1998) 12959. 194. J. Barluenga, M. Tomás, Adv. Heterocycl. Chem. 57 (1993) 1. 195. M. I. N. C. Harris, A. C. H. Braga, J. Braz. Chem. Soc. 15 (2004) 971. 196. Z. Eckstein, T. Urbanski, 1,3-Oxazine Derivatives in Advances in Heterocyclic Chemistry, Ed A. R. Katritzky, A. J. Boulton Advances in Heterocyclic Chemistry Vol 23, (1978). Academic Press, New York. 197. C. Z. Yao, Z. F.; Xiao, X. S. Ning, J. Liu, X. W. Zhang, Y. B. Kang, Org. Lett. 16 (2014) 5824. 138  198. J. S. Yadav, Y. Jayasudhan Reddy, P. Adi Narayana Reddy, B. V. Subba Reddy, Org. Lett. 15 (2013) 546. 199. S. Zsolt; G. Timea; O. Sandor Balazs; F. Ferenc, Tetrahedron- Asymmetr. 25 (2014) 1138. 200. E. Dyer, H. Scott, J. Am. Chem. Soc. 79 (1957) 672. 201. J. Y. Kim, R. Varma, Tetrahedron Lett. 45 (2004) 7205. 202. L. Caggiano, D. J. Fox, S. Warren, Chem. Commun. (2002) 2528. 203. N. Zanatta, A. M. C. Squizani, F. Fantinel, F. M. Nachtigall, D. M. Borchhardt, H. G. Bonacorso, M. A. P. Martins, J. Braz. Chem. Soc. 16 (2005) 1255. 204. M. Sainsbury, in Comprehensive Heterocyclic Chemistry, Vol. 3, A. R. Katritzky, C. W. Rees, Eds., Pergamon: Oxford, (1984) 995. 205. P. Giannoccaro, A. Dibenedetto, M. Gargano, E. Quaranta, M. Aresta, Organometallics 27 (2008) 967. 206. N. Sonoda, G. Yamamoto, K. Naysukawa, K. Kondo, S. Murai, Tetrahedron Lett. 16 (1975) 1969. 207. Y. Kubota, M. Kodaka, T. Tomohiro, H. Okano, J. Chem. Soc., Perkin Trans. 1 (1993) 5. 208. G. Y. Lesher, A. R. Surrey, J. Am. Chem. Soc. 77 (1955) 636. 209. J.-R. Ella-Menye, G. Wang, Tetrahedron 63 (2007) 10034. 210. B. B. Lohray, S. Baskaran,; B. Y. Reddy, K. S. Rao, Tetrahedron Lett. 39 (1998) 6555. 211. T. P. Curran, M. P. Pollastri, S. M. Abelleira, R. Messier, T. A. McCollum, C. G. Rowe, Tetrahedron Lett. 35 (1994) 5409. 212. A. G. Korepin, P. V. Galkin, N. M. Glushakova, E. K. Perepelkina, M. V. Loginova, V. P. Lodygina,; Yu. A. Ol’khov, L. T. Eremenko, Russ. Chem. Bull, 52 (2003) 2221. 213. J. Pierce, R. Adams, J. Am. Chem. Soc. 45 (1923) 790. 214. B. L. Phillips, P. A. Argabright, Heterocycl. Chem. 3 (1966) 84. 215. A. Inesi, V. Mucciante, L. Rossi, J. Org. Chem. 63 (1998) 1337. 216. M. A. Casadei, F. M. Moracci, G. Zappia, A. Inesi, L. Rossi, J. Org. Chem. 62 (1997) 6754. 217. S. Trifunovic, D. Dimitrijevic, G. Vasic, N. Radulovic, M. Vukicevic, F. W. Heinemann, R. D. Vukicevic, Synthesis 6 (2010) 943. 218. M.-S. Park, J.-W- Lee, Arch. Pharmacal Res. 16 (1993) 158. 219. J. M. Sullivan, H. F. Efner, J. Org. Chem. 33 (1968) 2134. 220. J. M. Jordá-Gregori, M. E. González-Rosende, J. Sepúlveda-Arques, R. Galeazzi, M. Orena, Tetrahedron- Asymmetr. 10 (1999) 1135. 221. A. Bogini, G. Cardillo, M. Orena, G. Poorzi, S. Sandrini, Chem. Lett. (1988) 87. 222. M. Fujita, O. Kitagawa, T. Suzuki, T. Taguchi, J. Org. Chem. 62 (1997) 7330. 223. S.-K. Kang, T.-G- Baik, Y. Hur, Tetrahedron 55 (1999) 6863. 224. E. Garcia-Egido, I. Fenández, L. Muñoz, Synth. Commun. 36 (2006) 3029. 225. P. J. Walsh, Y. L. Bennani, K. B. Sharpless, Tetrahedron Lett. 34 (1993) 5545. 226. C. O. Kappe, Tetrahedron 32 (1993) 6937. 227. H. E. Zaugg, W. B. Martin, in: Organic Reactions [Russian translation], Vol. 14, I. F. Lutsenko (ed.), Mir, Moscow (1967), p. 98. 228. P. Biginelli, Gazz. Chim. Ital. 23 (1893) 360. 139  229. L.-L. Zhang, J. Sun, C.-G. Yan, Mol. Divers. 18 (2014) 79. 230. M. Tramontini, L. Angiolini, Tetrahedron 46 (1990) 1791. 231. S. Ebel, Synthetische Arzneimittel. VCH, Weinheim, 1979. 232. P. Traxler, U. Trinks, E. Buchdunger, H. Mett, T. Meyer, M. Müller, U. Regenass, J. Rösel, N. Lydon, J. Med. Chem. 38 (1995) 2441. 233. J. R. Dimmock, K. K. Sidhu, M. Chen, R. S. Reid, T. M. Allen, G. Y. Kao, G. A. Truitt, Eur. J. Med. Chem. 28 (1993) 313. 234. M. Tramontini, L. Angiolini, Tetrahedron 46 (1990) 1791. 235. M. Arend, B. Westermann, N. Risch, Angew. Chem., Int. Ed. Engl. 37 (1998) 1044. 236. P. Perlmutter, Conjugated Addition Reactions in Organic Synthesis. Pergamon Press, Oxford, 1992. 237. X. Ai, X. Wang, J. Liu, Z. Ge, T. Cheng, R. Li, Tetrahedron 66 (2010) 5373. 238. A.-G. Ying, L. Liu, G.-F. Wua, G. Chen, X.-Z. Chen, W.-D. Ye, Tetrahedron Lett. 50 (2009) 1653. 239. K. De, J. Legros, B. Crousse, D. Bonnet-Delpon, J. Org. Chem. 74 (2009) 6260. 240. H. Pessoa-Mahana, M. González, M. González, D. Pessoa-Mahana, R. N. Araya- Maturana, N. Ron, C. Saitz, Arkivoc xi (2009) 316. 241. R. Trivedi, P. Lalitha, S. Roy, Synth. Commun. 38 (2008) 3556. 242. B. M. Reddy, M. K. Patil, B. T. Reddy, Catal. Lett. 126 (2008) 413. 243. M. L. Kantam, M. Roy, S. Roy, B. Sreedhar, R. L. De, Catal. Commun. 9 (2008) 2226. 244. M. J. Bhanushali, N. S. Nandurkar, S. R. Jagtap, B. M. Bhanage, Catal. Commun. 9 (2008) 1189. 245. A. V. Narsaiah, Lett. Org. Chem. 4 (2007) 462. 246. J.-M. Xu, Q. Wu, Q.-Y. Zhang, F. Zhang, F. X.-F. Lin, Eur. J. Org. Chem. (2007) 1798. 247. K. Surendra, N.S. Krishnaveni, R. Sridhar, K.R. Rao, Tetrahedron Lett. 47 (2006) 2125. 248. M. M. Hashemi, B. Eftekhari-Sis, A. Abdollahifar, B. Khalili, Tetrahedron 62 (2006) 672. 249. M. Chaudhuri, K.S. Hussain, M.L. Kantam, B. Neelima, Tetrahedron Lett. 46 (2005) 8329. 250. J.-M. Yang, S.-J. Ji, D.-G. Gu, Z.-L. Shen, S.-Y. Wang, J. Organomet. Chem. 690 (2005) 2989. 251. G. Bartoli, M. Bartolacci, A. Giuliani, E. Marcantoni, M. Massaccesi, E. Torregiani, J. Org. Chem. 70 (2005) 169. 252. M. L. Kantam, B. Neelima, C. V. Reddy, J. Mol. Catal. A: Chem. 241 (2005) 147. 253. M. L. Kantam, V. Neeraja, B. Kavita, B. Neelima, M. K. Chaudhuri, S. Hussain, Adv. Synth. Catal. 347 (2005) 763. 254. L. Xu, L.-W. Li, C.-G. Xia, Helv. Chim. Acta 87 (2004) 1522. 255. N. S. Shaikh, V. H. Deshpande, A. V. Bedekar, Tetrahedron 57 (2001) 9045. 256. M. Vijender, P. Kishore, B. Satyanarayana, Synth. Commun. 37 (2007) 589. 257. G. Bartoli, M. Bosco, E. Marcantoni, M. Petrini, L. Sambri, E. Torregiani, J. Org. Chem. 66 (2001) 9052. 258. L.-W. Xu, J.-W. Li, C.-G. Xia, S.-L. Zhou, X.-X. Hu, Synlett (2003) 2425. 259. B. C. Ranu, S. Banerjee, Tetrahedron Lett. 48 (2007) 141. 260. R. Kumar, P. Chaudhary, S. Nimesh, R. Chandra, Green Chem. 8 (2006) 356. 261. G. Wang, Anti-Infect. Agents Med. Chem. 7 (2008) 32. 140  262. T. Ullrich, K. Baumann, K. Welzenbach, S. Schmutz, G. Camenisch, J. G. Meingassner, G. Weitz-Schmidt, Bioorg. Med. Chem. Lett. . 263. F. Jin, 2000 Confalone P N PCT Int. Appl. WO0000481, 119; Chem. Abstr. 132 78560. 264. J. M. Cassady, K. K. Chan, H. G. Floss, E. Leistner, Chem. Pharm. Bull. 52 (2004) 1. 265. Y.-F. Wang, T. Izawa, S. Kobayashi, M. Ohno, J. Am. Chem. Soc. 104 (1982) 6465. 266. R. B. Woodward, E. Logusch, K. P. Nambiar, K. Sakan, D. E. Ward, B.-W. Au-Yeung, P. Balaram, L. J. Browne, P. J. Card, C. H. Chen, R. B. Chenevert, A. Fliri, K. Frobel, et. al. J. Am. Chem. Soc. 103 (1981) 3213. 267. Hirama, T. Shigemoto, Y. Yamazaki, S. Ito, J. Am. Chem. Soc. 107 (1985) 1797. 268. T. R. Abbas, J. I. G. Cadogan, A. A. Doyle, I. Gosney, P. K. G. Hodgson, G. E. Howells, A. N. Hulme, S. Parsons, I. H. Sadler, Tetrahedron Lett. 38 (1997) 4917. 269. C. O. Kappe, Acc. Chem. Res. 33 (2000) 879. 270. C. O. Kappe, Eur. J. Med. Chem. 35 (2000) 1043. 271. I. Damljanovic, D. Stevanovic, A. Pejovic, D. Ilic, M. Zivkovic, J. Jovanovic, M. Vukicevic, G. A. Bogdanovic, N. S. Radulovic, R. D. Vukicevic, RSC Advances 4 (2014) 43792. 272. Oxford Diffraction (2008). CrysAlis CCD and CrysAlis RED. Versions 1.171.32.24. Oxford Diffraction Ltd., Abington, England. 273. G. M. Sheldrick, Acta Crystallogr., Sect. A 64 (2008) 112. Биографија Анка Пејовић je рoђена 21.10.1986. године у Ђаковици. Основну и Прву техничку школу завршила је у Крагујевцу. На Природно-математички факултет у Крагујевцу, група Хемија, уписала се 2005. године и дипломирала јула 2010. са просечном оценом 9,30, чиме је стекла стручни назив – дипломирани хемичар. У току основних студија, школске 2008/09 године, била је стипендиста Фонда за младе таленте Владе Републике Србије. 2011. године уручено јој је специјално признање и годишња награда Српског хемијског друштва намењена најбољим дипломираним студентима. Докторске академске студије на Природно-математичком факултету у Крагујевцу (група Хемија, смер Органска хемија) уписала је шк. 2010/11. Јануара 2011. запослила се као истраживач-приправник, а од децембра 2012. као истраживач- сарадник за ужу научну област Органска хемија на Природно-математичком факултету у Крагујевцу. До сада је водила вежбе из предмета Ораганске синтезе 1 и Ораганска хемија 3 у Институту за хемију Природно-математичког факултета у Крагујевцу. Учествује у изради пројекта Министарства просвете, науке и технолошког развоја Републике Србије – „Нове електрохемијске и хемијске методе у синтези органских једињења од интереса за медицину и хемију материјала”, бр. 172034, 2011-, руководилац проф. др Растко Д. Вукићевић. У оквиру Erasmus Mundus Basileus IV програма, боравила је десет месеци (2013/2014) као стипендиста у Институту за одрживу органску хемију и технологију, Факултета биотехничких наука, Универзитета у Генту, у групи професора Матијаса Доха (Matthias D'hooghe). Анка Пејовић се бави научно-истраживачким радом у области органске и електроорганске хемије. Предмет њеног истраживања је синтеза неких деривата фероцена који у свом саставу садрже различите структурне фрагменте и функционалне групе као и реакције у којима се реактанати и/или катализатори генеришу електрохемијским методама. До сада је објавила тринаест научних радова у познатим часописима међународног значаја, једно саопштење на међународној научној конференији штампано у изводу и шест саопштења на националним научним конференцијама штампаним у изводу.     143  Списак радова и саопштења Анке З. Пејовић Анка Пејовић до сада је објавила тринаест научних радова и седам саопштења на научним скуповима. 1 Списак научних радова Анке Пејовић *Радови под бројем 1.1, 1.2, 1.3, 1.11 и 1.12 су у оквиру теме за докторску дисертацију 1.1 I. Damljanović, D. Stevanović, A. Pejović, M. D. Vukićević, S. B. Novaković, G. A. Bogdanović, T. M. Mihajilov-Krstev, N. S. Radulović, R. D. Vukićević,   J. Organomet. Chem., 696 (2011) 3703.  1.2 A. Pejović, D. Stevanović, I. Damljanović, M. Vukićević,  S. B. Novaković, G. A. Bogdanović, T. Mihajilov-Krstev, N. Radulović, R. D. Vukićević, Helv. Chim. Acta, 95 (2012) 1425 1.3 A. Pejović, I. Damljanović, D. Stevanović, M. D. Vukićević, S. B. Novaković, G. A. Bogdanović, N. S. Radulović, R. D. Vukićević, Polyhedron, 31 (2012) 789. 1.4 D. Stevanović, A. Pejović, I. Damljanović, M. Vukićević, G. A. Bogdanović, R. D. Vukićević, Tetrahedron Lett., 53 (2012) 6257. 1.5 Z. Leka, S. B. Novaković, A. Pejović, G. A. Bogdanović, R. D. Vukićević, Acta Crystallogr E., 68 (2012) m231. 1.6 D. Stevanović, A. Pejović, S. B. Novaković, G. A. Bogdanović, V. Divjaković, R. D. Vukićević, Acta Crystallogr C., 68 (2012) m37. 1.7 Z. Leka, S. B. Novaković, A. Pejović, G. A. Bogdanović, R. D. Vukicević, Acta Crystallogr E., 68 (2012) m995 1.8 A. Pejović, I. Damljanović, D. Stevanović, D. Ilić, M. D. Vukićević, G. A. Bogdanović, R. D. Vukićević, Tetrahedron Lett., 54 (2013) 4776 1.9 D. Stevanović, A. Pejović, I. Damljanović, M. D. Vukićević, G. Dobrikov, V. Dimitrov, M. S. Denić, N. S. Radulović, R. D. Vukićević, Helv. Chim. Acta, 96 (2013) 1103 1.10 I. Damljanović, D. Stevanović, A. Pejović, D. Ilić, M. Živković, J. Jovanović, M. Vukićević, G. A. Bogdanović, N. S. Radulović, R. D. Vukićević, RSC Advances, 4 (2014)43792 1.11 А. Pejović, M. S. Denić, D. Stevanović, I. Damljanović, M. Vukićević, K. Kostova, M. Tavlinova-Kirilova, P. Randjelović, N. M. Stojanović, G. A. Bogdanović, P. Blagojević, M. D'hooghe, N. S. Radulović, R. D. Vukićević, Eur. J. Med. Chem., 83 (2014) 57 1.12 A. Pejović, B. Danneels, T. Desmet, B. T. Cham, T. Nguyen, N. S. Radulović, R. D. Vukićević, M. D’hooghe, Synlett, (2015), doi: 10.1055/s-0034-1380348, in press. 144  1.13 D. Stevanović, A. Pejović, I. Damljanović, A. Minić, G. A. Bogdanović, M. Vukićević, N. S. Radulović, R. D. Vukićević, Carbohyd. Res., 407 (2015) 111.  2 Списак научних саопштења Анке Пејовић 2.1 Списак научних саопштења на међународним научним скуповима Анке Пејовић 2.1.1 Synthesis of N,N-diethyl-1-ferrocenyl-3-thiabutanamine and its application in Suzuki- Miyaura cross coupling, D. D. Stevanović, A. Pejović, I. S. Damljanović, M. D. Vukićević, R. D. Vukićević, 8th International Conference of the Chemical Societies of the South-East European Countries, Belgrade, Serbia, June 27-29, 2013. Book of Abstracts BS-Sy P02 p.16. 2.2 Списак научних саопштења на националним научним скуповима Анке Пејовић 2.2.1 Synthesis of 3-aminoaryl-1-ferrocenyl-propan-1-ones, А. Pejović, I. Damljanović, D. Stevanović, D. S. Ilić-Komatina, R. D. Vukićević, 49th Meeting of the Serbian Chemical Society, Kragujevac, Serbia May 13-14, 2011, Book of Abstracts OH06-O p. 124. 2.2.2 2-Ferrocenylthiazolidin-4-ones: Synthesis and spectral characteristics, I. Damljanović, D. Stevanović, A. Pejović, D. S. Ilić-Komatina, R. D. Vukićević, 49th Meeting of the Serbian Chemical Society, Kragujevac, Serbia May 13-14, 2011, Book of Abstracts OH28-P p. 146. 2.2.3 Michael addition catalyzed by electrochemically generated zirconium compounds, А. Pejović, I. Damljanović, D. Stevanović, D. S. Ilić-Komatina, M. D. Vukićević, R. D. Vukićević, Golden Jubilee 50th Meeting of the Serbian Chemical Society, Belgrade, Serbia, 14-15 june 2012 Book of Abstracts OH P26 p. 169. 2.2.4 Ferrocene containing alcohols and oximes: the synthesis, spectral and electrochemical characterization and antimicrobial activity, I. Damljanović, D. S. Ilić-Komatina, D. D. Stevanović, A. Z. Pejović, М. D. Vukićević, P. Blagojević, N. Radulović, R. D. Vukićević, Golden Jubilee 50th Meeting of the Serbian Chemical Society, Belgrade, Serbia, 14-1515 june 2012, Book of Abstracts OH P23 p. 166. 2.2.5 Електрохемијско генерисање катализатора за Феријеово премештање и тиа- Michael-овуадицију са растворне цирконијумове електроде, Д. Стевановић, A. Пејовић, И. Дамљановић, M. Вукићевић, Г. А Богдановић, Р. Д. Вукићевић, Прва конференција младих хемичара Србије, Београд, Србија, 19-20 октобар 2012, Књига кратких извода, стр. 102. 2.2.6 J. Jovanović, D. Stevanović, A. Pejović, I. Damljanović, M. Vukićević, N. Radulović, R. D. Vukićević, „Synthesis of 1-aryl-4-ferrocenyl-3-phenyltetrahydropyrimidin- 2(1H)-ones“, 51th Meeting of the Serbian Chemical Society, Niš, Serbia, Јune 5-7, 2014. Book of Abstracts OH O 01 p. 87.     Прилог lp riz vic iko 12, 69, att f Nis rads Syntheses of fourteen new 3-(arylamino)-1-ferrocenylpropan-1-ones have been achieved in good to excellent yields by an aza-Michael addition of different arylamines to acryloylferrocene. The reaction was blocks, which can easily be converted into a range of useful deriv- atives, such as 1,3-aminoalcohols and products of the substitution of the amino group with some other nucleophile [11,12]. Among rated carbonyls [17]. There are several advantages of this reaction, such as the mild reaction conditions and the possibility to synthesize secondary Mannich bases. A plethora of catalytic systems have been developed for this reaction up to date [18e39]. While the addition of aliphatic amines to Michael acceptors proceeds readily (even without a catalyst [40,41]), aromatic ones did not undergo this reaction easily because of its lower nucleo- philicity, particularly when mild conditions and environmental friendly catalysts were used [22,29,31,36,39]. * Corresponding author. ** Corresponding author. Fax: þ381 34 33 50 40. E-mail addresses: nikoradulovic@yahoo.com (N. Radulovic), vuk@kg.ac.rs Contents lists available at Journal of Organom journal homepage: www.elsev Journal of Organometallic Chemistry 696 (2011) 3703e3713(R.D. Vukicevic).1. Introduction Derivatives of ferrocene are of widespread interest in many fields of chemistry, such as organic synthesis [1], coordination chemistry [2], material sciences [1,3,4] and, nowadays, medicinal chemistry [5e10]. This is the consequence of several unique features of these compounds, such as the easiness of derivatization, the outstanding stability in both, aqueous and non-aqueous media, very interesting redox properties, etc. Multifunctional derivatives of this metallocene are particularly valuable, and in this regard Mannich bases (Mannich ketones; b-aminoketones) containing a ferrocene unit might be very interesting. In general, Mannich bases are versatile synthetic building many applications of Mannich bases and their derivatives, however, the most important ones are surely those applied in synthesis of pharmaceuticals [11,13e15]. The most famous synthetic approach to Mannich bases is, of course, the Mannich reaction [11,12,16] which, however, has many disadvantages. Drastic reaction condi- tions and long reaction times (causing many side reactions) are the main ones [11,12,16]. Furthermore, the use of primary amines in this reaction is not suitable, since the obtained products are also good substrates of the same reaction that continues up to the substitu- tion of both hydrogen atoms of the amine group giving, thus, tertiary amines containing two 3-oxo-groups. A very good alter- native to the Mannich reaction is the aza-Michael addition e the conjugate addition of amines to the olefinic bond of a,b-unsatu-Article history: Received 22 June 2011 Received in revised form 17 August 2011 Accepted 18 August 2011 Keywords: 3-(Arylamino)-1-ferrocenylpropan-1-ones Mannich bases Acryloylferrocene Montmorillonite K-10 Microwave irradiation Antibacterial activity0022-328X/$ e see front matter  2011 Elsevier B.V. doi:10.1016/j.jorganchem.2011.08.016performed by microwave (MW) irradiation (500 W/5 min) of a mixture of reactants and montmorillonite K-10, without a solvent. The obtained compounds were spectrally and electrochemically (cyclic vol- tammetry) fully characterized, whereas single-crystal X-ray analysis has been performed for three of them. In a microdilution assay, all of the compounds were shown to have a broad-spectrum effect on Gram-negative and -positive bacteria, although the degree of inhibition varied. A notable activity was observed for all compounds in inhibiting the growth of an important human pathogen Staphylococcus aureus.  2011 Elsevier B.V. All rights reserved.a r t i c l e i n f o a b s t r a c tAntibacterial 3-(arylamino)-1-ferroceny electrochemical and structural characte Ivan Damljanovica, Dragana Stevanovica, Anka Pejo Goran A. Bogdanovicc, Tatjana Mihajlov-Krstevd, N aDepartment of Chemistry, Faculty of Science, University of Kragujevac, R. Domanovica bDepartment of Pharmacy, Faculty of Medicine, University of Kragujevac, S. Markovica cVinca Institute of Nuclear Sciences, Laboratory of Theoretical Physics and Condensed M dDepartment of Biology and Ecology, Faculty of Science and Mathematics, University o eDepartment of Chemistry, Faculty of Science and Mathematics, University of Nis, VisegAll rights reserved.ropan-1-ones: Synthesis, spectral, ation a, Mirjana Vukicevicb, Sladjana B. Novakovicc, Radulovice,*, Rastko D. Vukicevica,** 34000 Kragujevac, Serbia 34000 Kragujevac, Serbia er Physics, PO Box 522, 11001 Belgrade, Serbia , Visegradska 33, 18000 Nis, Serbia ka 33, 18000 Nis, Serbia SciVerse ScienceDirect etallic Chemistry ier .com/locate/ jorganchem According to the best of our knowledge, there is only one previous report on the addition of amines to some a,b-unsaturated acylferrocenes [31], where the authors described the reaction of several chalcone-type ferrocenes with aliphatic amines under mild conditions (ultrasound irradiation and water as the solvent). The corresponding b-aminoketones were obtained in high yields. However, the reaction failedwhenaromatic amineswereusedas the Michael-donors. In continuation of our permanent interest in the synthesis of ferrocene derivatives containing more than one heteroatom in the side chain (interesting fromtheboth the synthetic andmedicinal chemistry points of view) [42e48], herewithwewish to report on a suitable synthesis of a series of 3-(arylamino)-1- ferrocenylpropan-1-ones by the addition of various aromatic next two experiments we performed by irradiating the same I. Damljanovic et al. / Journal of Organomet3704Scheme 1. Synthesis of 3-(arylamino)-1-ferrocenylpropan-1-ones: (i) AlCl3, CH2Cl2, r.t.amines to 1-ferrocenylprop-2-en-1-one (acryloylferrocene). 2. Results and discussion 2.1. Synthesis The primary goal of our study was to find and optimize a procedure for the synthesis of 3-(arylamino)-1-ferrocenylpropan- 1-ones with particular attention paid to finding mild enough conditions for the reaction to proceed with an acceptable yield and making use of an environmental friendly catalyst. Knowing that the application of environmentally benign catalysts such as clay [36] and mild reaction conditions [31,39] does not make possible the addition of aromatic amines to Michael acceptors (contrary to aliphatic ones), we expected that the simultaneous use of mont- morillonite K-10 (as a solid acidic catalyst) and microwave irradi- ation would improve the outcome of this approach. It turned out that this idea was quite correct, and that the corresponding Man- nich bases were obtained in good to almost quantitative yields. Our investigations began by the preparation of the intended Michael acceptor e acryloylferrocene (3, Scheme 1). This was achieved by FriedeleCrafts acylation of ferrocene (1) with 3- chloropropanoic acid chloride in the presence of AlCl3 as the Lewis acid catalyst [49], and the subsequent dehydrohalogenation of the obtained (3-chloropropionyl)ferrocene (2) by means of potassium acetate [50]. In order to optimize the synthesis of the title compounds (5aen, Scheme 1), aniline (4a) was used as the test substrate for the addition to the conjugated enone e acryloylferrocene (3). Thus, when ketone 3 (1 mmol) and amine 4a (1 mmol) were irradiated in a microwave oven (500 W, 5 min) without a catalyst or solvent, and after the usual work-up and flash chromatography (silica gel/ toluene, then n-hexaneeethyl acetate 9:1), the pure b-amino- ketone 5a (Scheme 1) was obtained in 37% yield. The same result was achieved by a prolongation of the reaction time to 10 min. The(ii) CH3COOK, ethanol, reflux, 2.5 h. (iii) solvent-free, montmorillonite K-10, MW, 500 W, 5 min.mixture of reagents in the presence of 100 mg of montmorillonite K-10 (500 W, 5 and 10 min), and this resulted in an increase of the yield of 5a up to 55%. Experiments with the increased amount of the catalyst (up to 500 mg) did not affect the yield significantly. Since only small amounts of the starting ketone 3 have been recovered (up to 10%) from the above performed experiments, we concluded that this compound underwent a certain side reaction (most probably some kind of polymerization, because a very polar dark product, which was neither isolated nor identified, formed during the runs). This side product may be the result of multiple Michael additions of the formed b-aminoketones to more mole- cules of acryloylferrocene, perhaps even leading through tertiary amines to quaternary ammonium salts that would be expected to behave in this way. In order to (statistically) suppress this, the following experiments were performed using a double amount of the amine 4a. The target compound e b-aminoketone 5a e was obtained in 85% yield, regardless the reaction time (5 or 10 min). Then the same reaction conditions (1 mmol of acryl- oylferrocene/2 mmol of arylamine/100 mg of montmorillonite K- 10/500 W/5 min) were applied to the reaction of the ketone 3with the another thirteen substrates 4ben. The corresponding Mannich bases 5benwere obtained in good to excellent yields (see Table 1) and were fully spectrally characterized (see below). As it can be seen from the data listed in Table 1, the lowest yields of the corresponding Mannich bases were achieved when amines 4e, 4l and 4n were used. In the case of 4e the steric nature (bulk- iness) of the substrate is the most likely reason for it, whereas the lowered nucleophilicity of the amino group of the two nitroanilines causes the decrease in the yields of 4l and 4n. In order to try to improve the yields in these cases, we performed experiments having a prolonged time of exposure of the reactants and the catalyst to MW irradiation. However, not even doubling the reac- tion time to 10 min did not cause an increase in obtained yields. Again, the unconsumed amines were recovered almost quantita- tively and almost no ketone 3, further strengthening the notion of multiple Michael additions. 2.2. Spectral characterization Intense absorption bands were present in the IR spectra of the obtained 3-(N-arylamino)propanones 5 for the C]O (at around 1660 cm1) and secondary NH groups (3340e3390 cm1, sharp). The 1H NMR spectra contained typical signals for a mono- substituted ferrocene (two triplets at w4.76 and 4.50 ppm, and a singlet atw4.12 ppm) and were also characterized by the presence of two multiplet signals for the protons of the O]CeCH2eCH2eN grouping, which were positioned in the region of 3.25e3.83 and 2.97e3.12 ppm (generally in agreement with a previous report [51]). An interesting feature of the 1H NMR spectra was the occur- rence of coupling of the NH protons with those of the adjacent CH2 group. The NeCH2 signals appeared as either sharp or somewhat broadened quartets in a number of cases (the ortho- and meta- substituted anilines with an electron-withdrawing group) from accidental equivalence of the vicinal HNeCH2 and CH2eCH2 couplings (J ca. 6 Hz). Such a coupling was not observed for the benzene analogs where the CH2 group bonded to amino showed little indication of coupling to the NH protons, so NH exchange must have been rapid on the NMR time scale [52] as also seems to be the case with compounds 5aee,h,n in the current study. The proton of the secondary amino group was a broadened signal at 3.6e4.8 ppm, typical of NH protons of anilines in CDCl3 solution, with the only exception for compound 5l, an o-nitroaniline (ca. d 8) that had, as expected, an NH signal downfield of this range. The broadening has several sources: partially averaged coupling to allic Chemistry 696 (2011) 3703e3713neighboring protons, intermolecular exchange with other NH Table 1 Structures of the newly prepared 3-(arylamino)-1-ferrocenylpropan-1-ones (5aen) and corresponding starting amines (4aen), as well as the yield of the reactions. Run Amine Product Yielda 1 4a 5a 85% 2 4b 5b 89% 3 4c 5c 80% 4 4d 5d 95% 5 4e 5e 59% 6 4f 5f 98% 7 4g 5g 89% 8 4h 5h 83% 9 4i 5i 93% 10 4j 5j 87% 11 4k 5k 93% 12 4l 5l 64% (continued on next page) I. Damljanovic et al. / Journal of Organometallic Chemistry 696 (2011) 3703e3713 3705 signals and in the transformation of the mentioned quartets could be explained by the formation of the N1eH.O2 intra- met(NHeCH2) to the corresponding triplets, thus corroborating the existence of such NHeCH2 coupling. It appears that this slow chemical exchange is more pronounced for the more acidic NH protons and those involved in intramolecular hydrogen bonding (the proximity of the electron-withdrawing groups, halogens and the nitro group, in ortho- and meta-positions). The aromatic protons in the positions ortho to the amino group of the aniline fragment afford diagnostic signals from their high field disposition (at 6.6e6.8 ppm). 13C NMR spectra also corrobo- rate the structure of these ferrocene derivatives. Signals at ca. 78.7, 72.4, 69.8 and 69.2 can be attributed to the ferrocene moiety while the other characteristic signals, one at about 200 ppm and two about 38 ppm, are those corresponding to the carbonyl- and methylene carbons, respectively. 2.3. X-ray crystal structure of 5j, 5l and 5m Most of the synthesized compounds were crystal substances, suitable for X-ray crystal structure analysis. Herein, we present theprotons, and partially coalesced coupling to the quadrupolar 14N nucleus (I¼ 1), which usually has a short T1. The labile NH protons were identified by shaking the CDCl3 solutions of the compounds with a drop of D2O, which resulted in the disappearance of the NH Table 1 (continued ) Run Amine 13 4m 14 4n a Isolated yields based on the starting enone. I. Damljanovic et al. / Journal of Organo3706structures of 5j, 5l and 5m compounds (Fig. 1aec). The cyclopentadienyl rings (Cp) of the title compounds 5j and 5m are close to an eclipsed geometry. The C1eCg1eCg2eC6 torsion angle is 9.5(5) in 5j and 11.3(5) in 5m (Cg1 and Cg2 are centroids of the corresponding Cp rings). In 5l, the Cp rings are more eclipsed and the C1eCg1eCg2eC6 torsion angle is 4.0(4). In all three compounds the Cp rings within the ferrocenyl units are almost parallel with interplanar angles 1.1(4), 2.3(4) and 0.7(5) for 5j, 5m and 5l, respectively. The Cg1eCg2 distance (3.295, 3.309 and 3.301A) and the Cg1eFeeCg2 angle (178.5, 177.4 and 178.5) are also very similar for all crystal structures. The C1]O1 carbonyl group lies approximately in the plane of the substituted Cp ring with the O1eC11eC1eC5 angle 4.5(8), 3.2(8) and 6.9(9) for the three compounds, respectively. Bond lengths and angles show expected values (Table 2). The C1eC11eC12eC13eN1 fragment, although consisted of single bonds, adopts a similar conformation in all three mole- cules (Fig.1aec). The C1eC11eC12eC13 and the C11eC12eC13eN1 torsion angles are 167.5(4)/74.4(6), 164.4(4)/67.4(7) and 179.2(5)/71.8(7) for 5j, 5m and 5l, respectively. However, regardless of this similarity, the directionality of N1eC14 bond andmolecular hydrogen bond (Fig. 1c) which does not exist in 5j and 5m. The only significant H-bond donor in all three crystal structures is the N1eH group. In 5j and 5m, adjacent molecules form centrosymmetric dimers by hydrogen bonding between N1eH and O1. Geometry of these dimers for both crystal structures is very similar (see Fig. A2 in Supplementary material). In 5l, the N1eH does not participate in any intermolecular H-bonding. Geometrical parameters for the selected intra- and intermolecular interactions are given in Table 3. 2.4. Electrochemistry Cyclic voltammetry in acetonitrile containing 0.1 mol/l lithium perchlorate as the supporting electrolyte has been used for the evaluation of electrochemical properties of the compounds 5aen. The voltammogram of compound 5a is presented here (Fig. 2) asthe resulting orientation of the C14-phenyl ring are quite different for compound 5l. The C12eC13eN1eC14 torsion angle describes this difference (74.2(6), 68.7(8) and 175.7(6) for 5j, 5m and 5l, respectively). The orientation of the phenyl ring with respect to the ferrocenyl unit is well illustrated in Supplementary material (Fig. A1). This conformational particularity of the structure 5l Product Yielda 5m 87% 5n 64% allic Chemistry 696 (2011) 3703e3713a representative example, whereas the data of the other compounds are listed in Table 4. As it can be seen from the summarized data, all of the synthesized b-aminoketones exhibited two well defined oxidation waves on the forward potential sweep (O1, at 0.650e0.693 V and O2, at 0.693e1.373 V, respectively) and one reduction wave on the back potential sweep (R1, at 0.592e0.620 V). As depicted in Fig. 2B for 5a, the reduction peak R1 appeared also when the potential was reversed after O1. Since the difference between the values of these two potentials is close to the theoretical one, O1 and R apparently belong to a reversible redox couple, appearing due to the presence of the ferrocene nucleus. Their position lays more than 200 mV higher than that of the unsubstituted ferrocene (see Fig. A3 in the Supplementary material), as expected for ferrocene derivatives possessing an electron-withdrawing group conjugated to the cyclopentadienyl ring(s). Both the anodic (O1) and cathodic (R1) peak currents are proportional to the square root of the scan rate (as depicted for 5a, Fig. A4 in Supplementary material), and their ratio is independent of the scan rate, indicating a diffusion-controlled process. The second oxidation wave (O2) is due to an irreversible oxidation of the aniline unit of these molecules. A study of the cyclovoltammetry of N-alkylanilines [53e55] showed that these compounds undergo irreversible anodic oxidation, producing a single oxidation wave on the first scan. Upon reversal of the scan three cathodic waves are obtained (at the potentials between 0.2 and 0.5 V). In the subsequent anodic scans three anodic waves appeared at the corresponding potentials, making up together with the cathodic ones three reversible couples. It was demonstrated that they belong to the products obtained from the species formed by the anodic oxidation of anilines [53e55]. We assumed that the lack of such type of waves in the cyclovoltammograms of compounds 5aen is a consequence of their accidental overlapping with the waves belonging to the ferrocene unit. In order to confirm it, 4-(phenylamino)butan-2-one (6) was synthesized and its elec- trochemical properties investigated by cyclic voltammetry subject to the same conditions. As depicted in Fig. 3, this compound exhibited only one oxidation wave in the first cycle (Fig. 3A, solid curve), but three in the second one (curve b). However, when presence. Previous workers [56e58] have found that certain Table 2 Selected bond lengths and angles for 5j, 5m and 5l. 5j 5m 5l Bond lengths (A) O1eC11 1.223(6) 1.220(6) 1.218(6) N1eC14 1.380(8) 1.358(7) 1.351(8) N1eC13 1.440(7) 1.454(7) 1.452(8) C1eC11 1.462(7) 1.457(8) 1.459(8) C11eC12 1.497(7) 1.514(8) 1.507(8) C12eC13 1.519(7) 1.523(8) 1.519(8) C16eCl 1.731(6) CeN2 1.470(8) 1.440(9) N2eO2 1.217(7) 1.237(7) N2eO3 1.237(7) 1.223(7) Bond angles () O1eC11eC1 122.3(5) 122.3(6) 121.6(5) O1eC11eC12 120.4(5) 121.4(5) 120.4(6) C1eC11eC12 117.2(5) 116.3(5) 117.9(5) C11eC12eC13 113.7(4) 112.7(5) 113.2(5) N1eC13eC12 113.6(5) 113.8(5) 109.6(5) C14eN1eC13 122.8(5) 123.3(5) 124.6(6) 5j C4eH4.N1i 0.93 3.559(7) 2.69 156 N1eH1N.O1ii 0.91(6) 3.020(7) 2.14(6) 164(4) C7eH7.Cl1iii 0.93 3.625(13) 2.87 139 Symmetry codes: (i) x 1, þyþ 1, þz; (ii) xþ 1, yþ 1, zþ 1; (iii) xþ 1, yþ 1, zþ 2 5m C9eH9.O2i 0.93 3.443(10) 2.66 143 C4eH4.O3i 0.93 3.272(10) 2.65 125 N1eH1N.O1ii 0.73(4) 3.142(7) 2.46(5) 156(5) C19eH19.O1ii 0.93 3.388(7) 2.64 138 Symmetry codes: (i) xþ 1, yþ 1, zþ 1; (ii) xþ 2, yþ 1, z 5l N1eH1N.O1i 0.76(8) 2.984(8) 2.70(8) 105(6) N1eH1N.O2i 0.76(8) 2.625(8) 2.01(7) 139(7) C6eH6.O2i 0.93 3.469(10) 2.63 150 C16eH16.O3i 0.93 2.662(11) 2.34 100 C2eH2.O1ii 0.93 3.352(7) 2.57 142 C9eH9.O3iii 0.93 3.373(9) 2.67 133 C12eH12a.O1iv 0.97 3.130(8) 2.44 128 Symmetry codes: (i) x,y,z; (ii) xþ 1, þy, þz; (iii) xþ 1, þyþ 1/2, z 1/2; (iv) I. Damljanovic et al. / Journal of Organometallic Chemistry 696 (2011) 3703e3713 3707Fig. 1. The molecular structure of 5j (a), 5m (b) and 5l (c; N1eH.O2 is labeled by dashed lines) with the atom numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.Mannich bases possessed in vitro antimicrobial activity. Chatten et al. [59] have shown that besides the difference in aminemoieties, the substituents in phenyl ketones also exert an influence on Table 3 Geometrical parameters (A,) of hydrogen bonds and selected CeH.O interactions for 5j, 5m and 5l. The CeH.O interactions are given if H.O distance is shorter than 2.7A and CeH.O angle is larger than 100 . DeH.A DeH D.A H.A DeH.Aacetylferrocene was added, these waves overlapped with the electrode response of acetylferrocene (curve c), and we find this to be sufficient evidence to back up the above statements. 2.5. Biology Medicinal chemists are open to the inclusion of ferrocene into their drug design strategies because of the novelty introduced by itsxþ 1/2, yþ 1/2þ 2, z 0.1 V (s I. Damljanovic et al. / Journal of Organomet3708activities. These observations together with the fact that ferrocene is widely regarded as a substitute for the aromatic benzene ring prompted the preparation and testing of the antibacterial activity of Mannich products containing a ferrocene system as a part of the ketone moiety. The minimum inhibitory concentration (MIC) of the synthesized compounds 5aenwas measured against growth of six bacteria (three Gram-positive and three Gram-negative) that were chosen to represent the major types of bacteria associated with human disease. The results of these studies and those of minimal bactericidal activity (MBC) are presented in Table 5 as the averages of multiple determinations. The tested bacteria were generally sensitive to these compounds, and as shown in Table 5, the values of MIC for compounds 5aen varied between 0.02 and 12.50 mg/ml. Growth inhibition of the bacteria was observed for all of the compounds early in the incubation period but the test organism overgrew the inhibition zones within 48 h as reflected in the high differences in the obtained MIC and MBC values. The best results (Table 5) were obtained against a Gram-negative bacterium and an important human pathogen, Staphylococcus aureus (MIC values 0.02e0.10 mg/ml), but most of the compounds exhibited activity at least one hundred fold lower than Tetracycline against both Gram- positive and negative bacteria (although the latter seem to be more Fig. 2. Cyclic voltammograms of 5a at the glassy carbon electrode (2 mm diameter) by a the electrolyte, solid curve e first scan, dotted curve e second scan) and B) up to 0.75susceptible to the compounds). Infections caused by Pseudomonas aeruginosa are often difficult to treat chemotherapeutically because of the unusually high resistance of the organism to most antimi- crobial drugs [60,61] and because resistance to other drugs may Table 4 Peak potentials obtained by cyclic voltammetry of the Mannich bases 5aen at the glassy carbon electrode (2 mm diameter) by a 0.1 V s1 scan rate in a 0.1 M aceto- nitrile solution of LiClO4. Compound O1 (mV) O2 (mV) R (mV) 5a 665 851 620 5b 653 803 598 5c 653 784 613 5d 693 693 604 5e 662 830 604 5f 647 992 601 5g 644 983 595 5h 638 861 598 5i 647 1031 595 5j 647 1007 595 5k 662 952 610 5l 659 1373 595 5m 650 1166 610 5n 653 1361 592evolve rapidly [61]. Therefore, it was not surprising that this organism was the most resistant to nearly all of the compounds studied. When comparing the activity of the herein synthesized Mannich bases, in general, compounds having an electron-acceptor functionality (5fen) appeared not to be more or less effective in inhibiting the growth of all bacteria than compounds possessing a electron-donating substituent or no substituent at all (5aee). A similar stands for the sets of three regioisomeric compounds (differing only in the position of the substituent on the benzene ring), e.g. 5bed, since they had amutually very similar antibacterial effect as well. It was tempting to assume that the steric effects could prevent the ortho isomers from interacting with the receptor of the test organisms, however, the differences in potency usually ascribed to substituents at the various positions in the benzene ring have not been found. The other parts of the molecule seem to have a much more important contribution to the activities observed. Some Mannich bases derived from the corresponding acetophe- nones (analogous to the currently prepared ferrocene derivatives) were found to possess significant antimicrobial activity [62] (e.g. in a disk diffusion assay [62], 1-phenyl-3-(phenylamino)propan-1- one, the analog of compound 5a, inhibited the growth of Escher- ichia coliwith a zone of 15 mm in diameter, while at the same dose V s1 scan rate in a 0.1 M acetonitrile solution of LiClO4: A) up to 1.5 V (dashed curve e olid curve e first scan, dotted curve e second scan). allic Chemistry 696 (2011) 3703e3713per disk the antibiotic ofloxacin had a zone of 22 mm). Since ferrocene is electron donating (spara ferrocene 0.18 compared to spara phenyl 0.01) and electron donation to the ketone can occur, one can take this as a possible cause of the decrease in activity in the case of the metallocene containing compounds. 3. Conclusion In conclusion, we described herein an easily performable procedure for the synthesis ofN-aryl-3-amino-1-ferrocenylpropan- 1-ones via an aza-Michael addition of the corresponding aromatic amines to acryloylferrocene in good to excellent yields. We unambiguously showed that both, the catalyst (montmorillonite K-10) and the microwave irradiation play an important role in this synthesis. The procedure requires short reaction times, and employs an environmentally friendly, as well as cheap catalyst. A trait worth noting of the 1H NMR spectra of the synthesized b- aminoketones, possessing electron-withdrawing substituents in the ortho- and meta-positions of the aniline moiety of the mole- cules, was the occurrence of coupling of the NH protons with those of the adjacent CH2 group, indicating a slow NH exchange on the NMR time scale. The NeCH2 signals appeared as quartets from accidental equivalence of the vicinal HNeCH2 and CH2eCH2 couplings. Such coupling that appears to be in connection with the acidity and/or intramolecular hydrogen bonding was not observed of inhibition varied. A notable exception to the generally medium- low activity is shown by the fact that all compounds inhibited best S. aureus. The introduction of either an electron-donating or Fig. 3. Cyclic voltammograms of 3 mM solution of 4-(phenylamino)butan-2-one (6) at the glassy carbon electrode (2 mm diameter) by a 0.1 V s1 scan rate in a 0.1 M acetonitrile solution of LiClO4: A) without acetylferrocene (solid curve e first scan, dotted curve e second scan) and B) with 3 mM acetylferrocene (first scan). thes I. Damljanovic et al. / Journal of Organometallic Chemistry 696 (2011) 3703e3713 3709for the benzene analogs or for the compounds having electron- donating or para-electron-withdrawing substituents. The structure of three compounds was unequivocally corrobo- rated by single-crystal X-ray analysis. Besides some conformational similarity in molecular structure of all three compounds, two of them with NO2 substituent at the phenyl ring show different orientation of the phenyl ring regarding to the rest of molecule. The ferrocene compound with NO2 in the ortho position forms strong NeH.O intramolecular hydrogen bond while other two compounds use the same NeH donor group for formation of geometrically similar centrosymmetric dimers. All of the compounds appeared to have broad-spectrum effect on Gram-negative and Gram-positive bacteria, although the degree Table 5 Minimal inhibitory (MIC) and minimal bactericidal concentrations (MBC) of the synCompound (mg/ml) 5a 5b 5c 5d 5e 5f 5g Gram () bacterial strains Escherichia coli ATCC 25922 MIC 0.78 0.39 0.39 0.39 0.78 0.78 0.78 MBC 25.00 25.00 25.00 25.00 25.00 25.00 25.00 Salmonella enterica ATCC 13076 MIC 0.78 6.25 1.56 1.56 0.78 1.56 12.50 MBC 12.50 50.00 25.00 12.50 12.50 12.50 50.00 Pseudomonas aeruginosa ATCC 27853 MIC 1.56 0.78 1.56 3.12 3.12 3.12 3.12 MBC 25.00 25.00 12.50 25.00 12.50 25.00 25.00 Gram (þ) bacterial strains Staphylococcus aureus ATCC 6538 MIC 0.02 0.02 0.10 0.02 0.02 0.05 0.10 MBC 3.12 3.12 6.25 3.12 3.12 3.12 6.25 Bacillus cereus ATCC 10876 MIC 0.39 1.56 3.12 0.10 1.56 0.39 0.39 MBC 25.00 50.00 50.00 12.50 25.00 12.50 12.50 Clostridium perfringens ATCC 19404 MIC 0.39 0.20 0.20 0.20 0.20 0.20 0.39 MBC 12.50 12.50 12.50 12.50 12.50 25.00 6.25 T, Tetracycline (mg/ml).acceptor group in the ortho position to the phenyl resulted in no alteration in activity. 4. Experimental section 4.1. General remarks All chemicals were commercially available and used as received, except that the solvents were purified by distillation. Chromato- graphic separations were carried out using silica gel 60 (Merck, 230e400 mesh ASTM), whereas silica gel 60 on Al plates, layer thickness 0.2 mm (Merck) was used for TLC. Melting points (uncorrected) were determined on a Mel-Temp capillary melting ized Mannich bases 5aen.5h 5i 5j 5k 5l 5m 5n T 0.20 0.39 0.78 0.39 0.39 1.56 0.39 1.56 25.00 25.00 25.00 25.00 12.50 25.00 25.00 1.56 0.20 0.78 1.56 0.39 0.39 0.78 0.39 3.12 12.50 12.50 12.50 12.50 12.50 12.50 12.50 3.12 3.12 1.56 3.12 3.12 1.56 1.56 0.78 3.12 25.00 25.00 25.00 25.00 25.00 25.00 25.00 3.12 0.02 0.10 0.10 0.05 0.10 0.10 0.02 0.09 3.12 6.25 6.25 3.12 6.25 6.25 3.12 0.09 0.78 0.78 0.78 0.39 0.39 0.39 0.39 1.56 25.00 25.00 25.00 12.50 25.00 12.50 12.50 1.56 0.39 0.20 0.20 0.20 0.39 0.39 0.20 1.56 6.25 12.50 12.50 12.50 12.50 12.50 12.50 1.56 metAcryloylferrocene (3, 1 mmol), the corresponding amine (4aen, 2 mmol) and 100 mg of montmorillonite K-10 were well mixed and irradiated in a microwave oven for 5 min at (500 W). The reaction mixture was extracted with dichloromethane (30 ml), the solvent evaporated and the crude product purified by flash chromatog- raphy (SiO2). Amines were eluted with toluene, whereas ketone 3 and the target Mannich bases 5aen were separated by using of a mixed solvent (n-hexane/ethyl acetate¼ 9:1, v/v) as the eluent. In all cases the complete excess of the amines was recovered. The spectral data of compounds 5aen follow. 4.3.1. 1-Ferrocenyl-3-(phenylamino)propan-1-one (5a) m.p. 106 C; IR: nmax (KBr)/cm1 3358, 3085, 2933, 1655, 1603, 1515, 1498, 1456, 1401, 1274, 1069, 825, 746, 695; 1H NMR (200 MHz, CDCl3) d 7.30e7.10 (m, 2H, Ar), 6.78e6.58 (m, 3H, Ar), 4.76 (t, J¼ 1.9 Hz, 2H, Fc), 4.49 (t, J¼ 1.9 Hz, 2H, Fc), 4.21 (brs, 1H, NH), 4.11 (s, 5H, Fc), 3.57 (t, J¼ 6.1 Hz, 2H, NeCH2), 3.01 (t, J¼ 6.1 Hz, 2H, COeCH2); 13C NMR (50 MHz, CDCl3) d 203.4 (CO), 147.6 (Ar), 129.2 (Ar), 117.4 (Ar), 112.9 (Ar), 78.7 (Fc), 72.3 (Fc), 69.7 (Fc), 69.1 (Fc), 38.5 (NeC), 38.0 (CeC); Anal. Calcd. (C H FeNO): C,Anhydrous AlCl3 (2.0 g, 15 mmol) was suspended in a cooled solution (an ice bath) of 2.8 g (15 mmol) of ferrocene (1) and 1.9 g (15 mmol) of 3-chloropropionyl chloride in 100 ml of dry dichloromethane, and the obtained mixture stirred for 5 h. The mixture was quenched with water (100 ml), filtered off (Buchner funnel), and the organic layer was separated. The water layer was extracted with two additional 30 ml portions of dichloromethane, the combined organic layers were washed with saturated solution of NaHCO3 and the solvent distilled off. The crude product was re- dissolved in toluene, passed through a short column of silica, and the toluene evaporated. The solid residue was placed in a solution of 1.5 g of CH3COOK in 100 ml of ethanol and refluxed for 2.5 h. After that the ethanol was evaporated, the residue extracted with dichloromethane and the obtained solution dried over anhydrous Na2SO4. Flash chromatography (SiO2/toluene) gave 2.41 g (w10.5 mmol;w67% based on ferrocene) of pure acryloylferrocene (3). The spectral data of 3 were in agreement with the literature ones [63]. 4.3. General procedure for the synthesis of Mannich bases 5aenpoints apparatus, model 1001. The 1H and 13C NMR spectra of the samples in CDCl3 were recorded on a Varian Gemini (200 MHz) spectrometer. Chemical shifts are expressed in d (ppm), relative to residual solvent protons as the internal standard (CDCl3: 7.26 ppm for 1H and 77 ppm for 13C). Cyclic voltammetry experiments were performed at room temperature under argon in a three-electrode cell using an Autolab potentiostat (PGSTAT 302N). The working electrode was a glassy carbon disk (2 mm diameter). The counter electrode was a platinum wire, and a silver wire was used as the reference electrode. IR measurements were carried out with a Per- kineElmer FTIR 31725-X spectrophotometer. Microanalysis of carbon, hydrogen and nitrogen was carried out with a Carlo Erba 1106 microanalyser; their results agreed favorably with the calcu- lated values. The reactions (microwave assisted syntheses) were performed by placing the teflon quivet with the reagents without a solvent in a closed reactor equipped with pressure and temper- ature control units and irradiating inside the cavity of a MicroSynth (Milestone) according to the following parameters: power 500W, 5 min. 4.2. Acryloylferrocene (3) I. Damljanovic et al. / Journal of Organo371019 19 68.49; H, 5.75; N, 4.20; Found: C, 68.51; H, 5.71; N, 4.23.4.3.2. 1-Ferrocenyl-3-(o-tolylamino)propan-1-one (5b) m.p. 112 C; IR: nmax (KBr)/cm1 3393, 3098, 2918, 1668, 1603, 1503, 1457, 1408, 1260, 1068, 826, 754; 1H NMR (200 MHz, CDCl3) d 7.25e6.98 (m, 2H, Ar), 6.76e6.59 (m, 2H, Ar), 4.76 (t, J¼ 1.9 Hz, 2H, Fc), 4.49 (t, J¼ 1.9 Hz, 2H, Fc), 4.14 (brs, 1H, NH), 4.10 (s, 5H, Fc), 3.69e3.54 (m, 2H, NeCH2), 3.04 (t, J¼ 6.0 Hz, 2H, COeCH2), 2.13 (s, 3H, CH3); 13C NMR (50 MHz, CDCl3) d 203.5 (CO), 145.6 (Ar), 130.2 (Ar), 127.0 (Ar), 122.4 (Ar), 117.0 (Ar), 109.5 (Ar), 78.7 (Fc), 72.3 (Fc), 69.7 (Fc), 69.1 (Fc), 38.6 (NeC), 38.1 (CeC), 17.4 (CH3); Anal. Calcd. (C20H21FeNO): C, 69.18; H, 6.10; N, 4.03; Found: C, 69.19; H, 6.13; N, 3.99. 4.3.3. 1-Ferrocenyl-3-(m-tolylamino)propan-1-one (5c) m.p. 121 C; IR: nmax (KBr)/cm1 3349, 3082, 2934, 1655, 1603, 1457, 1404, 1281, 1265, 1106, 826, 773; 1H NMR (200 MHz, CDCl3) d 7.18e6.92 (m,1H, Ar), 6.59e6.48 (m, 3H, Ar), 4.75 (t, J¼ 1.9 Hz, 2H, Fc), 4.48 (t, J¼ 1.9 Hz, 2H, Fc), 4.13 (brs, 1H, NH), 4.11 (s, 5H, Fc), 3.55 (t, J¼ 6.1 Hz, 2H, NeCH2), 2.99 (t, J¼ 6.1 Hz, 2H, COeCH2), 2.27 (s, 3H, CH3); 13C NMR (50 MHz, CDCl3) d 2034 (CO), 147.6 (Ar), 138.9 (Ar), 129.1 (Ar), 118.3 (Ar), 113.8 (Ar), 110.1 (Ar), 78.7 (Fc), 72.2 (Fc), 69.7 (Fc), 69.1 (Fc), 38.6 (NeC), 38.1 (CeC), 21.5 (CH3); Anal. Calcd. (C20H21FeNO): C, 69.18; H, 6.10; N, 4.03; Found: C, 69.17; H, 6.07; N, 4.04. 4.3.4. 1-Ferrocenyl-3-(p-tolylamino)propan-1-one (5d) m.p. 73 C; IR: nmax (KBr)/cm1 3351, 3090, 2918, 1656, 1618, 1521, 1456, 1401, 1273, 1070, 824, 807; 1H NMR (200 MHz, CDCl3) d 6.99 (d, J¼ 8.2 Hz, 2H, Ar), 6.57 (d, J¼ 8.4 Hz, 2H, Ar), 4.74 (t, J¼ 1.9 Hz, 2H, Fc), 4.47 (t, J¼ 1.9 Hz, 2H, Fc), 4.10 (s, 5H, Fc), 4.06 (brs, 1H, NH), 3.53 (t, J¼ 6.1 Hz, 2H, NeCH2), 2.98 (t, J¼ 6.1 Hz, 2H, COeCH2), 2.22 (s, 3H, CH3); 13C NMR (50 MHz, CDCl3) d 203.4 (CO), 145.3 (Ar), 129.7 (Ar), 126.5 (Ar), 113.1 (Ar), 78.7 (Fc), 72.2 (Fc), 69.7 (Fc), 69.0 (Fc), 38.9 (NeC), 38.1 (CeC), 20.2 (CH3); Anal. Calcd. (C20H21FeNO): C, 69.18; H, 6.10; N, 4.03; Found: C, 69.20; H, 6.10; N, 4.05. 4.3.5. 1-Ferrocenyl-3-(mesitylamino)propan-1-one (5e) m.p. 86 C; IR: nmax (KBr)/cm1 3378, 3094, 2940, 1655, 1485, 1456, 1376, 1310, 1243, 1021, 821; 1H NMR (200 MHz, CDCl3) d 6.82 (s, 2H, Ar), 4.77 (t, J¼ 1.8 Hz, 2H, Fc), 4.48 (t, J¼ 1.8 Hz, 2H, Fc), 4.18 (s, 5H, Fc), 3.62 (brs, 1H, NH), 3.25 (t, J¼ 5.7 Hz, 2H, NeCH2), 2.97 (t, J¼ 5.7 Hz, 2H, COeCH2), 2.31 (s, 6H, o-CH3), 2.22 (s, 3H, p-CH3); 13C NMR (50 MHz, CDCl3) d 203.9 (CO), 143.3 (Ar), 131.2 (Ar), 130.0 (Ar), 129.2 (Ar), 78.7 (Fc), 72.2 (Fc), 69.7 (Fc), 69.1 (Fc), 43.1 (NeC), 39.7 (CeC), 20.5 (p-CH3), 18.1 (o-CH3); Anal. Calcd. (C22H25FeNO): C, 70.41; H, 6.71; N, 3.73; Found: C, 70.40; H, 6.70; N, 3.75. 4.3.6. 1-Ferrocenyl-3-(2-fluorophenylamino)propan-1-one (5f) m.p. 89 C; IR: nmax (KBr)/cm1 3383, 3096, 2903, 1665, 1619, 1529, 1402, 1261, 1190, 824, 735; 1H NMR (200 MHz, CDCl3) d 7.13e6.50 (m, 4H, Ar), 4.77 (t, J¼ 1.8 Hz, 2H, Fc), 4.50 (t, J¼ 1.8 Hz, 2H, Fc), 4.37 (brs, 1H, NH), 4.12 (s, 5H, Fc), 3.71e3.48 (brq, 2H, NeCH2), 3.02 (t, J¼ 6.1 Hz, 2H, COeCH2); 13C NMR (50 MHz, CDCl3) d 202.9 (CO),151.7 (JCF¼ 238.8 Hz, Ar),136.2 (JCF¼ 11.5 Hz, Ar),124.5 (JCF¼ 3.4 Hz, Ar), 116.7 (JCF¼ 7.0 Hz, Ar), 114.6 (JCF¼ 18.5 Hz, Ar), 111.9 (JCF¼ 3.3 Hz, Ar), 78.7 (Fc), 72.4 (Fc), 69.7 (Fc), 69.1 (Fc), 38.2 (NeC), 38.1 (CeC); Anal. Calcd. (C19H18FFeNO): C, 64.98; H, 5.17; N, 3.99; Found: C, 64.99; H, 5.20; N, 4.01. 4.3.7. 1-Ferrocenyl-3-(3-fluorophenylamino)propan-1-one (5g) m.p. 124 C; IR: nmax (KBr)/cm1 3362, 3098, 2945, 1654, 1622, 1499, 1457, 1399, 1261, 1154, 1072, 840, 823, 755, 686; 1H NMR (200 MHz, CDCl3) d 7.20e7.01 (m, 1H, Ar), 6.48e6.28 (m, 3H, Ar), 4.77 (t, J¼ 1.9 Hz, 2H, Fc), 4.51 (t, J¼ 1.9 Hz, 2H, Fc), 4.39 (brs, 1H, allic Chemistry 696 (2011) 3703e3713NH), 4.12 (s, 5H, Fc), 3.63e3.46 (brq, 2H, NeCH2), 3.01 (t, J¼ 6.0 Hz, 2H, COeCH2); 13C NMR (50 MHz, CDCl3) d 203.3 (CO), 164.2 (JCF¼ 242.8 Hz, Ar), 149.5 (JCF¼ 10.6 Hz, Ar), 130.4 (JCF¼ 10.2 Hz, Ar), 108.9 (JCF¼ 2.3 Hz, Ar), 103.8 (JCF¼ 21.6 Hz, Ar), 99.3 (JCF¼ 25.3 Hz, Ar), 78.6 (Fc), 72.4 (Fc), 69.8 (Fc), 69.1 (Fc), 38.4 (NeC), 37.8 (CeC); Anal. Calcd. (C19H18FFeNO): C, 64.98; H, 5.17; N, 3.99; Found: C, 64.95; H, 5.17; N, 4.00. 4.3.8. 1-Ferrocenyl-3-(4-fluorophenylamino)propan-1-one (5h) m.p. 127 C; IR: nmax (KBr)/cm1 3399, 3102, 2911, 1664, 1521, 1461, 1400, 1219, 1050, 818, 785; 1H NMR (200 MHz, CDCl3) d 6.97e6.82 (m, 2H, Ar), 6.66e6.54 (m, 2H, Ar), 4.76 (t, J¼ 1.9 Hz, 2H, Fc), 4.51 (t, J¼ 1.9 Hz, 2H, Fc), 4.12 (brs, 1H, NH), 4.12 (s, 5H, Fc), 3.52 (t, J¼ 6.0 Hz, 2H, NeCH2), 3.00 (t, J¼ 6.0 Hz, 2H, COeCH2); 13C NMR (50 MHz, CDCl3) d 203.4 (CO), 155.9 (JCF¼ 235.1 Hz, Ar), 144.1 (JCF¼ 1.5 Hz, Ar), 115.7 (JCF¼ 22.3 Hz, Ar), 113.9 (JCF¼ 7.4 Hz, Ar), 103.8 (JCF¼ 21.6 Hz, Ar), 99.3 (JCF¼ 25.3 Hz, Ar), 78.7 (Fc), 72.4 (Fc), 69.8 (Fc), 69.1 (Fc), 39.3 (NeC), 37.9 (CeC); Anal. Calcd. (C19H18FFeNO): C, 64.98; H, 5.17; N, 3.99; Found: C, 65.00; H, 5.21; N, 3.97. 4.3.9. 3-(2-Chlorophenylamino)-1-ferrocenylpropan-1-one (5i) m.p. 108 C; IR: nmax (KBr)/cm1 3418, 3096, 2921, 1675, 1599, 1504, 1456, 1410, 1325, 1256, 1025, 823, 750; 1H NMR (200 MHz, CDCl3) d 7.33e7.10 (m, 2H, Ar), 6.82e6.55 (m, 2H, Ar), 4.77 (t, J¼ 1.9 Hz, 2H, Fc), 4.77 (brs, 1H, NH), 4.50 (t, J¼ 1.9 Hz, 2H, Fc), 4.12 (s, 5H, Fc), 3.64 (q, J¼ 6.1 Hz, 2H, NeCH2), 3.03 (t, J¼ 6.2 Hz, 2H, COeCH2); 13C NMR (50 MHz, CDCl3) d 202.7 (CO), 143.5 (Ar), 129.3 J¼ 1.9 Hz, 2H, Fc), 4.50 (t, J¼ 1.9 Hz, 2H, Fc), 4.36 (brs, 1H, NH), 4.12 (s, 5H, Fc), 3.61e3.46 (brq, 2H, NeCH2), 3.00 (t, J¼ 6.0 Hz, 2H, COeCH2); 13C NMR (50 MHz, CDCl3) d 203.2 (CO), 148.8 (Ar), 135.0 (Ar), 130.2 (Ar), 117.2 (Ar), 112.2 (Ar), 111.4 (Ar), 78.6 (Fc), 72.4 (Fc), 69.7 (Fc), 69.1 (Fc), 38.3 (NeC), 37.8 (CeC); Anal. Calcd. (C19H18ClFeNO): C, 62.07; H, 4.93; N, 3.81; Found: C, 62.05; H, 4.96; N, 3.80. 4.3.11. 3-(4-Chlorophenylamino)-1-ferrocenylpropan-1-one (5k) m.p. 51 C; IR: nmax (KBr)/cm1 3344, 3092, 2933, 1658, 1596, 1509, 1493, 1456, 1396, 1273, 1088, 1066, 824, 799; 1H NMR (200 MHz, CDCl3) d 7.19e7.01 (m, 2H, Ar), 6.65e6.50 (m, 3H, Ar), 4.75 (t, J¼ 1.9 Hz, 2H, Fc), 4.50 (t, J¼ 1.9 Hz, 2H, Fc), 4.24 (brs, 1H, NH), 4.11 (s, 5H, Fc), 3.52 (t, J¼ 6.0 Hz, 2H, NeCH2), 2.98 (t, J¼ 6.0 Hz, 2H, COeCH2); 13C NMR (50 MHz, CDCl3) d 203.3 (CO), 146.2 (Ar), 129.0 (Ar), 121.8 (Ar), 113.9 (Ar), 78.6 (Fc), 72.4 (Fc), 69.7 (Fc), 69.1 (Fc), 38.7 (NeC), 37.8 (CeC); Anal. Calcd. (C19H18ClFeNO): C, 62.07; H, 4.93; N, 3.81; Found: C, 62.10; H, 4.94; N, 3.79. 4.3.12. 1-Ferrocenyl-3-(2-nitrophenylamino)propan-1-one (5l) m.p. 96 C; IR: nmax (KBr)/cm1 3377, 3116, 2935, 1661, 1617, 1568, 1508, 1457, 1399, 1263, 1238, 1149, 823, 743; 1H NMR (200 MHz, CDCl3) d 8.42e8.11 (m, 2H, NH and Ar), 7.60e7.40 (m,1H, Ar), 6.96 (d, J¼ 8.5 Hz, 1H, Ar), 6.75e6.59 (m, 1H, Ar), 4.80 (t, J¼ 1.9 Hz, 2H, Fc), 4.53 (t, J¼ 1.9 Hz, 2H, Fc), 4.17 (s, 5H, Fc), 3.76 (q, J¼ 6.6 Hz, 2H, NeCH2), 3.12 (t, J¼ 6.6 Hz, 2H, COeCH2); 13C NMR (50 MHz, CDCl3) d 201.5 (CO), 145.0 (Ar), 136.1 (Ar), 126.9 (Ar), 115.3 I. Damljanovic et al. / Journal of Organometallic Chemistry 696 (2011) 3703e3713 3711(Ar), 127.8 (Ar), 119.4 (Ar), 117.3 (Ar), 110.9 (Ar), 78.7 (Fc), 72.4 (Fc), 69.8 (Fc), 69.2 (Fc), 38.1 (NeC), 38.1 (CeC); Anal. Calcd. (C19H18ClFeNO): C, 62.07; H, 4.93; N, 3.81; Found: C, 62.03; H, 4.94; N, 3.78. 4.3.10. 3-(3-Chlorophenylamino)-1-ferrocenylpropan-1-one (5j) m.p. 121 C; IR: nmax (KBr)/cm1 3353, 3086, 2930, 1654, 1596, 1487, 1456, 1400, 1275, 1248, 1073, 822, 758; 1H NMR (200 MHz, CDCl3) d 7.14e7.00 (m, 1H, Ar), 6.72e6.45 (m, 3H, Ar), 4.76 (t, Table 6 Crystallographic data for 5j, 5m and 5l. Identification code 5j Empirical formula C19H18ClFeNO Formula weight 367.64 Color, crystal shape Dark-orange, prism Crystal size (mm3) 0.32 30 25 Temperature (K) 293(2) Wavelength (A) 0.71073 Crystal system Triclinic Space group P 1 Unit cell dimensions a (A) 7.5449(7) b (A) 9.7317(8) c (A) 12.5382(11) a () 88.912(7) b () 76.107(8) g () 69.330(12) V (A3) 833.96(13) Z 2 Dcalc (Mg/m3) 1.464 m (mm1) 1.067 q range for data collection () 3.03e28.97 Reflections collected 6698 Independent reflections, Rint 3803, 0.0458 Completeness (%) to q¼ 26.32 99.6 Refinement method Full-matrix least-squares on F2 Data/restraints/parameters 3803/0/212 Goodness-of-fit on F2 1.090 Final R1/wR2 indices [I> 2s(I)] 0.0889/0.1997(Ar), 113.4(Ar), 78.3 (Fc), 72.5 (Fc), 69.7 (Fc), 69.1 (Fc), 38.3 (NeC), 37.6 (CeC); Anal. Calcd. (C19H18FeN2O3): C, 60.34; H, 4.80; N, 7.41; Found: C, 60.30; H, 4.81; N, 7.41. 4.3.13. 1-Ferrocenyl-3-(3-nitrophenylamino)propan-1-one (5m) m.p. 91 C; IR: nmax (KBr)/cm1 3329, 3098, 2956, 1656, 1620, 1526, 1456, 1347, 1265, 1238, 826, 782; 1H NMR (200 MHz, CDCl3) d 7.60e7.40 (m, 2H, Ar), 7.36e7.21 (m,1H, Ar), 7.36e7.21 (m,1H, Ar), 6.98e6.85 (m, 1H, Ar), 4.78 (t, J¼ 1.9 Hz, 2H, Fc), 4.71 (brs, 1H, NH), 5m 5l C19H18FeN2O3 C19H18FeN2O3 378.20 378.20 Dark-orange, plate Dark-orange, prism 0.36 0.31 0.10 028 0.25 0.23 293(2) 293(2) 0.71073 0.71073 Triclinic Orthorhombic P 1 P212121 9.109(3) 5.8295(7) 9.659(2) 13.6390(18) 11.242(3) 21.231(4) 65.53(3) 90 72.79(2) 90 84.94(4) 90 859.3(4) 1688.0(4) 2 4 1.462 1.488 0.898 0.914 2.98e28.92 3.14e29.03 5930 5237 3877, 0.1109 3564, 0.0470 99.7 99.8 Full-matrix least-squares on F2 Full-matrix least-squares on F2 3877/0/230 3564/0/230 0.992 1.052 0.0853/0.1856 0.0683/0.1349 met4.53 (t, J¼ 1.9 Hz, 2H, Fc), 4.13 (s, 5H, Fc), 3.70e3.54 (brq, 2H, NeCH2), 3.05 (t, J¼ 5.9 Hz, 2H, COeCH2); 13C NMR (50 MHz, CDCl3) d 203.3 (CO), 148.6 (Ar), 147.6 (Ar), 129.8 (Ar), 119.2 (Ar), 111.9 (Ar), 105.9 (Ar), 78.4 (Fc), 72.6 (Fc), 69.8 (Fc), 69.2 (Fc), 38.4 (NeC), 37.7 (CeC); Anal. Calcd. (C19H18FeN2O3): C, 60.34; H, 4.80; N, 7.41; Found: C, 60.32; H, 4.84; N, 7.43. 4.3.14. 1-Ferrocenyl-3-(4-nitrophenylamino)propan-1-one (5n) m.p. 189e190 C; IR: nmax (KBr)/cm1 3356, 3107, 2907, 1653, 1604, 1501, 1471, 1319, 1115, 832, 754; 1H NMR (200 MHz, CDCl3) d 8.09 (d, J¼ 9.2 Hz, 2H, Ar), 6.61 (d, J¼ 9.2 Hz, 2H, Ar), 4.79 (t, J¼ 1.9 Hz, 2H, Fc), 4.58 (t, J¼ 1.9 Hz, 2H, Fc), 4.14 (s, 5H, Fc), 3.74 (brs, 1H, NH), 3.66 (t, J¼ 6.1 Hz, 2H, NeCH2), 3.07 (t, J¼ 6.1 Hz, 2H, COeCH2). 13C NMR (50 MHz, CDCl3) d 204.0 (CO), 153.5 (Ar), 137.5 (Ar), 126.8 (Ar), 111.0 (Ar), 78.3 (Fc), 73.2 (Fc), 70.1 (Fc), 69.5 (Fc), 38.0 (NeC), 38.0 (CeC); Anal. Calcd. (C19H18FeN2O3): C, 60.34; H, 4.80; N, 7.41; Found: C, 60.33; H, 4.82; N, 7.38. 4.4. X-ray crystallography Single-crystal diffraction data for 5j, 5l and 5m were collected on a Oxford Diffraction Xcalibur Sapphire3 Gemini diffractometer equipped with Mo Ka radiation (l¼ 0.71073A) at room tempera- ture. Data were processed with CrysAlis software [64] with multi- scan absorption corrections applied using SCALE3 ABSPACK [64]. All three crystal structures were solved with SHELXS [65] and refined using SHELXL [65]. The H1n atom attached to N1 was located by difference Fourier synthesis and refined isotropically. All other H atomswere placed at geometrically calculated positions with the CeH distances fixed to 0.93 from C(sp2); 0.97 and 0.98A from methylene and methine C(sp3), respectively. The corresponding isotropic displacement parameters of the hydrogen atoms were equal to 1.2Ueq and 1.5Ueq of the parent C(sp2) and C(sp3), respectively. A summary of crystallographic data is given in Table 6. Figures were produced using ORTEP-3 [66] and MERCURY, Version 2.4 [67]. The software used for the preparation of the materials for publication: WinGX [68], PLATON [69], PARST [70]. 4.5. Biology 4.5.1. Test microorganisms The synthesized Mannich bases 5aen were tested against a panel of microorganisms (American Type Culture Collection strains), including Gram-positive S. aureus ATCC 6538, Bacillus cereus ATCC 10876, Clostridium perfringens ATCC 19404, Gram- negative Salmonella enterica ATCC 13076, E. coli ATCC 25922 and P. aeruginosa ATCC 27853. Bacterial strains were maintained on Nutrient agar at optimal temperature of 37 C at the Microbiology Laboratory (Department of Biology, Faculty of Science and Mathe- matics, University of Nis). 4.5.2. Screening of antimicrobial activity Antimicrobial activity was evaluated using a brothmicrodilution method according to NCCLS (2003) [71]. Minimum inhibitory concentrations (MIC) determination was performed by a serial dilution method in 96 well microtitre plates. Bacterial species were cultured at 37 C in Mueller Hinton agar. After 18 h of cultivation, bacterial suspensions were made in Mueller Hinton broth and their turbidity was standardized to 0.5 McFarland. Absorbance of every suspension was confirmed on a spectrophotometer (UVeVIS 1650, Shimadzu, Japan). The final density of bacterial inoculi corre- sponded to 5105 CFU (colony forming units). Stock solutions of the compounds 5aen were prepared in 10% I. Damljanovic et al. / Journal of Organo3712(v/v) aqueous dimethyl sulfoxide (DMSO) in the concentrationrange 0.01e50.00 mg/ml (the diluting factor 2). The bacterial inoculum was added to all wells containing the compounds in appropriate concentrations and the plates were incubated at 37 C during 24 h. Tetracycline served as a positive control, while the solvent (10% DMSO(aq)) was used as a negative control. The DMSO solvent controls did not produce any measurable inhibition of the test organisms. Replicate tests performed with a specific dilution of a test compound on any given day were in excellent agreement and results obtained with a specific dilution of any given compound on different days were generally in close agreement. One non- inoculated well, free of the antimicrobial agents, was also included to ensure medium sterility. Bacterial growth was visualized by adding 20 ml of 0.5% (w/w) triphenyltetrazolium chloride (TTC) aqueous solution [72]. Minimal inhibitory concentration (MIC) was defined as the lowest concen- tration of the compounds 5aen that inhibited visible growth (red colored pellet on the bottom of the wells after the addition of TTC), while minimal bactericidal concentration (MBC) was defined as the lowest concentration of the compound that killed 99.9% of bacterial cells. To determine MBC, broth was taken from each well without any visible growth and inoculated inMueller Hinton agar (MHA) for 24 h at 37 C. 4.5.3. Statistical analysis All experiments were done in quantiplicate andmean values are presented. In order to evaluate statistically any significant differ- ences among mean values, a one-way ANOVA test was used. p values less than 0.05 (p< 0.05) were used as the significance level. Acknowledgment This work was supported by the Ministry of Education and Science of the Republic of Serbia (grant 172034). Appendix. Supplementary material Supplementary data associated with this article can be found, in the online version, at doi:10.1016/j.jorganchem.2011.08.016. Appendix A. Supplementary data CCDC 827956, 827957 and 821837 contain the supplementary crystallographic data for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif. References [1] A. Togni, T. Hayashi (Eds.), Ferrocenes: Homogenous Catalysts, Organic Synthesis, Material Science, VCH, Weinheim, 1995. [2] W.R. Cullen, J.D. Woollins, Coord. Chem. Rev. 39 (1981) 1e30. [3] S. Barlow, D.O. Hare, Chem. Rev. 97 (1997) 637e670. [4] K. Kulbaba, I. Manners, Macromol. Rapid Commun. 22 (2001) 711e724. [5] C. Biot, G. Glorian, L.A. Maciejewski, J.S. Brocard, J. Med. Chem. 40 (1997) 3715e3718. [6] D. Osella, M. Ferrali, P. Zanello, F. Laschi, M. Fontani, C. Nervid, G. Cavigiolio, Inorg. Chim. Acta 306 (2000) 42e48. [7] J.S. Top, A. Vessieres, R. Alberto, J. Organomet. Chem. 600 (2000) 23e36. [8] D.R. van Staveren, N. Metzler-Nolte, Chem. Rev. 104 (2004) 5931e5985. [9] E.W. Neuse, J. Inorg. Organomet. Polym. Mater. 15 (2005) 3e32. [10] C.S. Allardyce, A. Dorcier, C. Scolaro, P.J. Dyson, Appl. Organomet. Chem. 19 (2005) 1e10. [11] M. Tramontini, L. Angiolini, Mannich-Bases, Chemistry and Uses. CRC, Boca Raton, FL, 1994. [12] M. Tramontini, L. Angiolini, Tetrahedron 46 (1990) 1791e1831. [13] S. Ebel, Synthetische Arzneimittel. VCH, Weinheim, 1979. [14] P. Traxler, U. Trinks, E. Buchdunger, H. Mett, T. Meyer, M. Müller, U. Regenass, J. Rösel, N. Lydon, J. Med. Chem. 38 (1995) 2441e2448. allic Chemistry 696 (2011) 3703e3713[15] J.R. Dimmock, K.K. Sidhu, M. Chen, R.S. Reid, T.M. Allen, G.Y. Kao, G.A. Truitt, Eur. J. Med. Chem. 28 (1993) 313e322. [16] M. Arend, B. Westermann, N. Risch, Angew. Chem., Int. Ed. Engl. 37 (1998) 1044e1070. [17] P. Perlmutter, Conjugated Addition Reactions in Organic Synthesis. Pergamon Press, Oxford, 1992. [18] X. Ai, X. Wang, J. Liu, Z. Ge, T. Cheng, R. Li, Tetrahedron 66 (2010) 5373e5377. [19] A.-G. Ying, L. Liu, G.-F. Wua, G. Chen, X.-Z. Chen, W.-D. Ye, Tetrahedron Lett. 50 (2009) 1653e1657. [20] K. De, J. Legros, B. Crousse, D. Bonnet-Delpon, J. Organomet. Chem. 74 (2009) 6260e6265. [21] H. Pessoa-Mahana, M. González, M. González, D. Pessoa-Mahana, R.N. Araya- Maturana, N. Ron, C. Saitz, Arkivoc xi (2009) 316e325. [22] R. Trivedi, P. Lalitha, S. Roy, Synth. Commun. 38 (2008) 3556e3566. [23] B.M. Reddy, M.K. Patil, B.T. Reddy, Catal. Lett. 126 (2008) 413e418. [24] M.L. Kantam, M. Roy, S. Roy, B. Sreedhar, R.L. De, Catal. Commun. 9 (2008) 2226e2230. [25] M.J. Bhanushali, N.S. Nandurkar, S.R. Jagtap, B.M. Bhanage, Catal. Commun. 9 (2008) 1189e1195. [26] A.V. Narsaiah, Lett. Org. Chem. 4 (2007) 462e464. [27] J.-M. Xu, Q. Wu, Q.-Y. Zhang, F. Zhang, F.X.-F. Lin, Eur. J. Org. Chem. (2007) 1798e1802. [28] K. Surendra, N.S. Krishnaveni, R. Sridhar, K.R. Rao, Tetrahedron Lett. 47 (2006) 2125e2127. [29] M.M. Hashemi, B. Eftekhari-Sis, A. Abdollahifar, B. Khalili, Tetrahedron 62 (2006) 672e677. [30] M. Chaudhuri, K.S. Hussain, M.L. Kantam, B. Neelima, Tetrahedron Lett. 46 (2005) 8329e8331. [31] J.-M. Yang, S.-J. Ji, D.-G. Gu, Z.-L. Shen, S.-Y. Wang, J. Organomet. Chem. 690 (2005) 2989e2995. [32] G. Bartoli, M. Bartolacci, A. Giuliani, E. Marcantoni, M. Massaccesi, E. Torregiani, J. Org. Chem. 70 (2005) 169e174. [33] M.L. Kantam, B.Neelima, C.V. Reddy, J.Mol. Catal. A: Chem. 241 (2005) 147e150. [34] M.L. Kantam, V. Neeraja, B. Kavita, B. Neelima, M.K. Chaudhuri, S. Hussain, Adv. Synth. Catal. 347 (2005) 763e766. [35] L. Xu, L.-W. Li, C.-G. Xia, Helv. Chim. Acta 87 (2004) 1522e1526. [36] N.S. Shaikh, V.H. Deshpande, A.V. Bedekar, Tetrahedron 57 (2001) 9045e9048. [37] M. Vijender, P. Kishore, B. Satyanarayana, Synth. Commun. 37 (2007) [44] M. Joksovic, V. Markovic, Z.D. Juranic, T. Stanojkovic, L.S. Jovanovic, I.S. Damljanovic, K. Meszaros Szecsenyi, N. Todorovic, S. Trifunovic, R.D. Vukicevic, J. Organomet. Chem. 694 (2009) 3935e3942. [45] I. Damljanovic, M. Vukicevic, N. Radulovic, R. Palic, E. Ellmerrer, Z. Ratkovic, M. Joksovic, R.D. Vukicevic, Bioorg. Med. Chem. Lett. 19 (2009) 1093e1096. [46] D. Razafimahefa, D.A. Ralambomanana, L. Hammouche, L. Pélinski, S. Lauvagie, C. Bebear, J. Brocard, J. Maugein, Bioorg. Med. Chem. Lett. 15 (2005) 2301e2303. [47] D.A. Ralambomanana, D. Razafimahefa-Ramilison, A.C. Rakotohova, J. Maugein, L. Pélinski, Bioorg. Med. Chem. 16 (2008) 9546e9553. [48] M. El Arbi, P. Pigeon, S. Top, A. Rhouma, S. Aifa, A. Rebai, A. Vessières, M.-A. Plamont, G. Jaouen, J. Organomet. Chem. 696 (2011) 1038e1048. [49] L. Schwink, P. Knochel, T. Eberle, J. Okuda, Organometallics 17 (1998) 7e9. [50] A. Bartoszewicz, M. Livendahl, B. Martin-Matute, Chem. Eur. J. 14 (2008) 10547e10550. [51] K.W. Anderson, J.J. Tepe, Tetrahedron 58 (2002) 8475e8481. [52] S.V. Volkov, S.V. Kutyakov, A.N. Levov, E.I. Polyakova, Le Tuan An, S.A. Soldatova, P.B. Terentiev, A.T. Soldatenkov, Chem. Heterocycl. Compd. 43 (2007) 1260e1268. [53] Z. Galus, R.N. Adams, J. Phys. Chem. 67 (1963) 862e866. [54] J. Bacon, R.N. Adams, J. Am. Chem. Soc. 90 (1968) 6596e6599. [55] R. Ojani, J.-B. Raoof, B. Norouzi, J. Mater. Sci. 44 (2009) 4095e4103. [56] S.B. Britton, W.L. Nobles, J. Am. Pharm. Assoc. 44 (1955) 717e718. [57] C.C. Blanton, W.L. Nobles, J. Pharm. Sci. 53 (1964) 1130e1132. [58] E.D. Taylor, W.L. Nobles, J. Am. Pharm. Assoc. 49 (1960) 317e319. [59] L.G. Chatten, G.E. Myers, K.K. Khullar, G.A. Yager, J. Pharm. Sci. 60 (1971) 316e318. [60] S.J. Decourcy Jr., S. Mudd, Antimicrob. Agents Chemother. 1968 (1969) 72e77. [61] M. Sonne, E. Jawetz, Appl. Microbiol. 17 (1969) 893e896. [62] H.S. Chouhan, S.K. Singh, N.S.H.N. Moorthy, Asian J. Chem. 22 (2010) 7903e7908. [63] O. Dogan, V. Senol, S. Zeytinci, H. Koyuncu, A. Bulut, J. Organomet. Chem. 690 (2005) 430. [64] Oxford Diffraction, CrysAlis CCD and CrysAlis RED Versions 1.171.32.24. Oxford Diffraction Ltd., Abington, England, 2008. [65] G.M. Sheldrick, Acta Crystallogr. A 64 (2008) 112e122. I. Damljanovic et al. / Journal of Organometallic Chemistry 696 (2011) 3703e3713 3713591e594. [38] G. Bartoli, M. Bosco, E. Marcantoni, M. Petrini, L. Sambri, E. Torregiani, J. Org. Chem. 66 (2001) 9052e9055. [39] L.-W. Xu, J.-W. Li, C.-G. Xia, S.-L. Zhou, X.-X. Hu, Synlett (2003) 2425e2427. [40] B.C. Ranu, S. Banerjee, Tetrahedron Lett. 48 (2007) 141e143. [41] R. Kumar, P. Chaudhary, S. Nimesh, R. Chandra, Green Chem. 8 (2006) 356e358. [42] M. Joksovic, Z. Ratkovic, M. Vukicevic, R.D. Vukicevic, Synlett 16 (2006) 2581e2584. [43] I. Damljanovic, M. Colovic, M. Vukicevic, D. Manojlovic, N. Radulovic, K. Wurst, G. Laus, Z. Ratkovic, M. Joksovic, R.D. Vukicevic, J. Organomet. Chem. 694 (2009) 1575e1580.[66] L.J. Farrugia, J. Appl. Crystallogr. 30 (1997) 565. [67] C.F. Macrae, P.R. Edgington, P. McCabe, E. Pidcock, G.P. Shields, R. Taylor, M. Towler, J. van de Streek, J. Appl. Crystallogr. 39 (2006) 453e457. [68] L.J. Farrugia, J. Appl. Crystallogr. 32 (1999) 837e838. [69] A.L. Spek, J. Appl. Crystallogr. 36 (2003) 7e13. [70] M. Nardelli, J. Appl. Crystallogr. 28 (1995) 659. [71] NCCLS e National Committee for Clinical Laboratory Standards, Document M100-S11. Performance Standards for Antimicrobial Susceptibility Testing. National Committee for Clinical Laboratory Standard, Wayne, PA, USA, 2003. [72] N. Radulovic, M. Dekic, Z. Stojanovic-Radic, S. Zoranic, Chem. Biodivers. 7 (2010) 2783e2800.     electronic reprint Acta Crystallographica Section C Crystal Structure Communications ISSN 0108-2701 Editor: Anthony Linden A new polymorph of 1-ferrocenyl-3-(3-nitroanilino)propan-1-one Dragana Stevanovic´, Anka Pejovic´, Sladjana B. Novakovic´, Goran A. Bogdanovic´, Vladimir Divjakovic´ and Rastko D. Vukic´evic´ Acta Cryst. (2012). C68, m37–m40 Copyright c© International Union of Crystallography Author(s) of this paper may load this reprint on their own web site or institutional repository provided that this cover page is retained. Republication of this article or its storage in electronic databases other than as specified above is not permitted without prior permission in writing from the IUCr. For further information see http://journals.iucr.org/services/authorrights.html Acta Crystallographica Section C: Crystal Structure Communications specializes in the rapid dissemination of high-quality studies of crystal and molecular structures of interest in fields such as chemistry, biochemistry, mineralogy, pharmacology, physics and mate- rials science. The numerical and text descriptions of each structure are submitted to the journal electronically as a Crystallographic Information File (CIF) and are checked and typeset automatically prior to peer review. The journal is well known for its high stan- dards of structural reliability and presentation. Section C publishes approximately 1000 structures per year; readers have access to an archive that includes high-quality structural data for over 10000 compounds. Crystallography Journals Online is available from journals.iucr.org Acta Cryst. (2012). C68, m37–m40 Stevanovic´ et al. · [Fe(C5H5)(C14H13N2O3)] A new polymorph of 1-ferrocenyl- 3-(3-nitroanilino)propan-1-one Dragana Stevanovic´,a Anka Pejovic´,a Sladjana B. Novakovic´,b* Goran A. Bogdanovic´,b Vladimir Divjakovic´c and Rastko D. Vukic´evic´a aDepartment of Chemistry, Faculty of Science, University of Kragujevac, R. Domanovic´a 12, 34000 Kragujevac, Serbia, b’Vincˇa’ Institute of Nuclear Sciences, Laboratory of Theoretical Physics and Condensed Matter Physics, PO Box 522, 11001 Belgrade, Serbia, and cDepartment of Physics, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovic´a 4, 21000 Novi Sad, Serbia Correspondence e-mail: snovak@vin.bg.ac.rs Received 14 November 2011 Accepted 8 January 2012 Online 14 January 2012 Recrystallization of the title compound, [Fe(C5H5)(C14H13- N2O3)], from a mixture of n-hexane and dichloromethane gave the new polymorph, denoted (I), which crystallizes in the same space group (P1) as the previously reported structure, denoted (II). The Fe—C distances in (I) range from 2.015 (3) to 2.048 (2) A˚ and the average value of the C—C bond lengths in the two cyclopentadienyl (Cp) rings is 1.403 (13) A˚. As indicated by the smallest C—Cg1—Cg2—C torsion angle of 1.4 (Cg1 and Cg2 are the centroids of the two Cp rings), the orientation of the Cp rings in (I) is more eclipsed than in the case of (II), for which the value was 15.3. Despite the pronounced conformational similarity between (I) and (II), the formation of self-complementary N—H  O hydrogen- bonded dimers represents the only structural motif common to the two polymorphs. In the extended structure, molecules of (I) utilize C—H  O hydrogen bonds and, unlike (II), an extensive set of intermolecular C—H   interactions. Finger- print plots based on Hirshfeld surfaces are used to compare the packing of the two polymorphs. Comment Ferrocene, an unnatural compound, has attracted intense attention from chemists since its discovery in 1951 (Kealy & Pauson, 1951; Miller et al., 1952) and particularly after its first functionalization by Friedel–Crafts acylation (Woodward et al., 1952). This interest is a consequence of several unique properties of ferrocene and its derivatives, including nontoxicity, easy handling, outstanding stability in both aqueous and non-aqueous media etc. The most attractive feature of these compounds is their ease of functionalization; following classical organic protocols one can synthesize a ‘double’ of any known compound in which the aromatic unit is substituted by ferrocene. Ferrocene exists in three polymorphic forms, one at room temperature, which is monoclinic (Seiler & Dunitz, 1979a; Takusagawa & Koetzle, 1979), and two at low temperature, viz. triclinic and orthorhombic (Seiler & Dunitz, 1979b, 1982). At the molecular level, the ferrocene molecules within these forms differ only in the relative orientation of the two cyclo- pentadienyl (Cp) rings (Braga et al., 1998). The low rotation barrier of the Cp rings accounts for the considerable flexibility of the ferrocene (Fc) unit, which can be further related to the evident structural polymorphism of Fc-containing compounds. Aliphatic substituents, when present on Fc units, add to the overall structural flexibility which plays an important role in the polymorphism of these compounds. A Cambridge Struc- tural Database (CSD, Version 5.31, August 2010; Allen, 2002) survey of Fc-containing crystal structures, for which the special text string ‘polymorphism’ has been registered, retrieved 78 different compounds. Among these structures there are 16 examples in which the polymorphs crystallize in the same space group. We report here a new polymorph of 1-ferrocenyl-3-(3- nitroanilino)propan-1-one obtained by recrystallization from a mixture of n-hexane and dichloromethane. The novel poly- morph, denoted (I) (Fig. 1), as well as the previously described polymorph, denoted (II) (Damljanovic´ et al., 2011), crystal- lizes in the space group P1, with one molecule in the asym- metal-organic compounds Acta Cryst. (2012). C68, m37–m40 doi:10.1107/S0108270112000765 # 2012 International Union of Crystallography m37 Acta Crystallographica Section C Crystal Structure Communications ISSN 0108-2701 Figure 1 The molecular structure of (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 35% probability level. electronic reprint metric unit. The unit cells of (I) and (II) display similar volumes but differ significantly in axis lengths and angles. The previously reported examples of monosubstituted 3-aryl- amino-1-ferrocenylpropan-1-ones (Damljanovic´ et al., 2011) indicate the existence of two molecular conformations, mostly dependent on the position of the substituent on the arylamino group. Molecules (I) and (II) belong to the same conforma- tional type and exhibit only slight structural dissimilarity, but they display a significant packing polymorphism. For (I), the bond distances (Table 1) within the Fc unit are as expected for monosubstituted derivatives. The C—C bonds in the substi- tuted cyclopentadienyl ring, Cp1, are slightly longer than those in the unsubstituted ring, Cp2. One should, however, take into account that the apparently shorter C—C bonds in the unsubstituted ring may be a result of the strong libration in this ring, as demonstrated by the elongated ellipsoids. Disorder of the Cp rings in ferrocene is a well known phenomenon which was initially described by Seiler & Dunitz (1979a). The longest Cp bonds are C1—C2 [1.437 (3) A˚] and C1—C5 [1.429 (3) A˚] vicinal to the substituent at C1 (Fig. 1). As previously observed in similar monosubstituted Fc-based compounds (Ratkovic´ et al., 2010), the metal atom could be considered as positioned slightly closer to the substituted Cp1 ring (Fe1—Cg1 = 1.64 A˚ and Fe1—Cg2 = 1.65 A˚; Cg1 and Cg2 are the centroids of the Cp1 and Cp2 rings, respectively). The Cp1 and Cp2 rings are almost parallel, with a dihedral angle of 1.3 (2), similar to the value of 2.3 (4) in (II). The most pronounced difference in the Fc units of (I) and (II) concerns the mutual orientation of Cp rings. The C1—Cg1—Cg2—C6 torsion angles of 1.4 in (I) and 15.3 in (II) indicate a more significant deviation from an eclipsed conformation in the case of (II). Bond lengths and angles within the substituents are similar in (I) and (II). Torsion angles (Table 2) indicate small but noticeable differences in the conformation of the C1–C14 chains which are enabled by free rotation around the corre- sponding single bonds. These differences accompany a slight variation in the Cp2/Ph dihedral angle, viz. 85.7 (1) and 82.7 (2) for (I) and (II), respectively. A good gauge of the conformational differences between (I) and (II) is the relative displacement of arylamino atom N1 from the Fe1/Cg2/C6 plane, which bisects Cp2 and contains the Fe1 atom [0.55 A˚ in (I) and 2.05 A˚ in (II), see Fig. S1 in the Supplementary materials]. In the packing of the two polymorphs, the strongest inter- molecular N1—H1n  O1i interactions [symmetry code: (i) x + 1, y + 2, z + 1], formed between their aliphatic moieties, link the centrosymmetrically related molecules into dimers characterized by the same cyclic R22(12) motif (Etter, 1990). The N1—H1n  O1i hydrogen bond in (I) is somewhat shorter [N1  O1i = 3.018 (2) A˚ in (I) and 3.133 (6) A˚ in (II)] and displays better directionality than the analogous inter- action in (II). The N1—H1n  O1 interactions in (II) are additionally supported by a C6—H6  O1i interaction, while in (I) the relative disposition of the neighbouring molecules obviates this interaction (see Fig. S2 in the Supplementary materials). The dimer mediated by N1—H1n  O1i is the only motif common to the two structures. This interaction involves the strongest donor and acceptor, and represents the best initial aggregation mode for this compound. Beyond that, polymorphs (I) and (II) display pronounced differences. In metal-organic compounds m38 Stevanovic´ et al.  [Fe(C5H5)(C14H13N2O3)] Acta Cryst. (2012). C68, m37–m40 Figure 2 The N1—H1  O1 hydrogen-bonded dimers of (I) (top) and (II) (bottom), interconnected by corresponding C—H   and C—H  O interactions, respectively. H atoms not involved in intermolecular interactions have been excluded for the sake of clarity. Figure 3 Fingerprint plots of (I) (top) and (II) (bottom). electronic reprint (II), the strongest remaining acceptors, the nitro O atoms, interact with a pair of C—H donors, one from each Cp ring of the Fc unit. In this manner, the bent configuration of the molecule is utilized to form a macrocyclic motif centred at (12, 1 2, 1 2) (Fig. 2, bottom). This motif is not seen for (I); indeed, in (I), the same pair of C—H donors is involved in a pair of C— H   interactions towards the neighbouring benzene ring, forming an infinite chain parallel to b. Fig. 2 shows the dimers common to (I) and (II) interconnected by C—H   [(I); Fig. 2, top] and C—H  O [(II); Fig. 2, bottom] interactions, respectively. In (I), the nitro O atoms have a completely different role from that observed in (II). Atom O2 in (I) is involved in an acceptor-bifurcated hydrogen bond (both H  O < 2.6 A˚), with the C15—H15 benzene ring and the aliphatic C13—H13a group as donors. The interaction with acceptor atom O3 is weaker and involves the cyclopentadienyl C7—H7 group as donor. This is the only interaction between the Fc moiety and NO2 in (I), in contrast to (II), where there are three. While Fc in (I) play an important role in C—H   interactions, both as a C—H donor and as a  acceptor, in (II) only one intermolecular C—H   interaction is observed (Table 3, see Fig. S3 in the Supplementary materials). The differences in the overall patterns of interactions in the crystal structures of polymorphs (I) and (II) are best illu- strated through Hirshfeld surfaces (see Fig. S4 in the Supplementary materials) and the corresponding fingerprint plots (Fig. 3) (Wolff et al., 2007; Spackman & McKinnon, 2002). This two-dimensional mapping summarizes the inter- molecular interactions present in the crystal structures and reflects the influences of the different crystal environments on the two polymorphs. The values de and di are defined as the distances from a point on the Hirshfeld surface to the nearest atoms external and internal to the surface, respectively. For each (de,di) pair, the fingerprint plot gives its frequency of occurrence in the structure, using colour to represent frequency. As discussed by Spackman & Jayatilaka (2009), various types of interactions in a molecular structure give rise to characteristic patterns in the fingerprint plot. The finger- print plots for (I) and (II) show distinctly different shapes; however, the dominant feature with each of them is a pair of sharp spikes corresponding to the shortest O  H contacts. Taking into account the de and di values, it is clear that poly- morph (I) exhibits shorter hydrogen-bonding interactions. Moreover, a systematic shift of the whole pattern to shorter contacts in (I) suggests a more dense packing in the case of this polymorph. This accords with the densities Dcalc of 1.475 and 1.462 Mg m3 for (I) and (II), respectively. If the density of the different polymorphs is considered as a measure of their relative stabilities (Braga et al., 1998), one can conclude that polymorph (I) is the more stable of the two. An important feature in the fingerprint plot of (I), which is lacking in (II), is the wing-like accumulation at the top left and bottom right of the graph, corresponding to the C—H   interactions. The region between the spikes corresponds to the H  H contacts, which are obviously more numerous for (I). The shortest intermolecular H  H distance (2.42 A˚) is found between atom H1n (attached to N1) and cyclopentadienyl atom H5 (located in the vicinity of the O-atom acceptor interacting with H1n). The percentage contributions of the H  O contacts to the fingerprint plot is 24.8% for (I) and slightly higher in the case of (II) (27.1%). On the other hand, the contribution of H  C contacts is higher for polymorph (I) [19.1% in comparison to 13.1% for (II)], in agreement with the greater number of observed C—H   interactions (see Fig. S3 in the Supplementary materials). In summary, the two polymorphs of 1-ferrocenyl-3-(3- nitroanilino)propan-1-one represent the infrequent case in which polymorphs of Fc compounds crystallize with the same space group. Indeed, the molecules in polymorphs (I) and (II) exhibit almost the same conformation, and form similar centrosymmetric dimers; nevertheless, they display completely different three-dimensional packing which is based entirely on weak noncovalent interactions. Experimental Polymorph (I) was synthesized according to the previously reported procedure of Damljanovic´ et al. (2011). The solid product obtained following column chromatography was dissolved in a small amount of dichloromethane (2–3 ml) and n-hexane was added carefully to this solution until the first appearance of turbidity. One or two drops of dichloromethane were then added to obtain a clear solution, which was allowed to evaporate slowly at room temperature, producing crystals of (I). Crystal data [Fe(C5H5)(C14H13N2O3)] Mr = 378.20 Triclinic, P1 a = 7.6075 (3) A˚ b = 10.1342 (7) A˚ c = 11.9062 (6) A˚  = 73.805 (5)  = 81.350 (4)  = 75.891 (5) V = 851.55 (8) A˚3 Z = 2 Mo K radiation  = 0.91 mm1 T = 293 K 0.22  0.18  0.15 mm Data collection Oxford Diffraction Xcalibur Sapphire3 Gemini diffractometer Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009) Tmin = 0.933, Tmax = 1.000 6735 measured reflections 3884 independent reflections 3147 reflections with I > 2(I) Rint = 0.021 Refinement R[F 2 > 2(F 2)] = 0.042 wR(F 2) = 0.091 S = 1.05 3884 reflections 227 parameters H-atom parameters constrained max = 0.21 e A˚ 3 min = 0.34 e A˚3 metal-organic compounds Acta Cryst. (2012). C68, m37–m40 Stevanovic´ et al.  [Fe(C5H5)(C14H13N2O3)] m39 Table 1 Selected geometric parameters (A˚, ). O1—C11 1.219 (2) O2—N2 1.205 (3) O3—N2 1.209 (2) N1—C13 1.449 (3) N1—C14 1.372 (3) N2—C16 1.470 (3) C1—C11 1.463 (3) C11—C12 1.509 (3) C12—C13 1.512 (3) O1—C11—C1 121.19 (19) O1—C11—C12 120.3 (2) N1—C13—C12 114.00 (18) C14—N1—C13 122.85 (17) C1—C11—C12 118.54 (18) C11—C12—C13 112.79 (17) electronic reprint H atoms bonded to C atoms were placed at calculated positions, with C—H distances fixed at 0.93 A˚ for aromatic Csp2 atoms and at 0.97 A˚ for methylene Csp3 atoms. The corresponding isotropic displacement parameters of the H atoms were set equal to 1.2Ueq and 1.5Ueq of the parent Csp 2 and Csp3 atoms, respectively. The H atom attached to N1 was located by difference Fourier synthesis, then the N—H bond length was idealized to 0.86 A˚ and the H atom constrained to ride on its parent atom with its isotropic displacement parameter freely refined. In order to compare the Hirshfeld fingerprint plots for the two polymorphs on the same grounds, the corresponding N—Hbond in (II) was elongated to the identical value of 0.86 A˚. The refinement of (II) was then continued until convergence in the same manner as for (I). The parameters for (II) given in Table 3 are slightly altered from the original publication (Damljanovic´ et al., 2011) due to this modification. Data collection: CrysAlis PRO (Oxford Diffraction, 2009); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and Mercury (Macrae et al., 2006); software used to prepare material for publication: WinGX (Farrugia, 1999), PLATON (Spek, 2009) and PARST (Nardelli, 1995). This work was supported financially by the Ministry of Education and Science of the Republic of Serbia (project Nos. 172014, 172035 and 172034). Supplementary data for this paper are available from the IUCr electronic archives (Reference: FA3265). Services for accessing these data are described at the back of the journal. References Allen, F. H. (2002). Acta Cryst. B58, 380–388. Braga, D., Grepioni, F. & Desiraju, G. R. (1998). Chem. Rev. 98, 1375–1405. Damljanovic´, I., Stevanovic´, D., Pejovic´, A., Vukic´evic´, M., Novakovic´, S. B., Bogdanovic´, G. A., Mihajlov-Krstev, T., Radulovic´, N. & Vukic´evic´, R. D. (2011). J. Organomet. Chem. 696, 3703–3713. Etter, M. C. (1990). Acc. Chem. Res. 23, 120–126. Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. Kealy, T. J. & Pauson, P. L. (1951). Nature (London), 168, 1039–1040. Macrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst. 39, 453–457. Miller, S. A., Tebboth, J. F. & Tremaine, J. F. (1952). J. Chem. Soc. pp. 632– 635. Nardelli, M. (1995). J. Appl. Cryst. 28, 659. Oxford Diffraction (2009). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, Oxfordshire, England. Ratkovic´, Z., Novakovic´, S. B., Bogdanovic´, G. A., Segan, D. & Vukic´evic´, R. D. (2010). Polyhedron, 29, 2311–2317. Seiler, P. & Dunitz, J. D. (1979a). Acta Cryst. B35, 1068–1074. Seiler, P. & Dunitz, J. D. (1979b). Acta Cryst. B35, 2020–2032. Seiler, P. & Dunitz, J. D. (1982). Acta Cryst. B38, 1741–1745. Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Spackman, M. A. & Jayatilaka, D. (2009). CrystEngComm, 11, 19–32. Spackman, M. A. & McKinnon, J. J. (2002). CrystEngComm, 4, 378–392. Spek, A. L. (2009). Acta Cryst. D65, 148–155. Takusagawa, F. & Koetzle, T. F. (1979). Acta Cryst. B35, 1074–1081. Wolff, S. K., Grimwood, D. J., McKinnon, J. J., Jayatilaka, D. & Spackman, M. A. (2007). CrystalExplorer. University of Western Australia, Crawley, Western Australia (http://hirshfeldsurface.net/CrystlExplorer). Woodward, R. B., Rosenblum, M. &Whiting, M. (1952). J. Am. Chem. Soc. 74, 3458–3459. metal-organic compounds m40 Stevanovic´ et al.  [Fe(C5H5)(C14H13N2O3)] Acta Cryst. (2012). C68, m37–m40 Table 2 Selected torsion angles () for (I) and (II). (I) (II) C1—C11—C12—C13 167.40 (16) 164.4 (4) C5—C1—C11—C12 169.19 (18) 178.8 (5) C11—C12—C13—N1 65.2 (2) 67.4 (7) C12—C13—N1—C14 74.4 (3) 68.7 (8) C13—N1—C14—C15 11.7 (3) 13.0 (9) O1—C11—C12—C13 12.5 (3) 17.6 (7) Table 3 Geometric parameters (A˚, ) for intermolecular interactions. Only contacts with H  C < 3.0 A˚were considered as potential intermolecular C—H   interactions. H  Cg represents the distance between the H atom and the centroid of the aromatic ring. See Refinement text below for further details of the data for (II). D—H  A D—H H  A D  A D—H  A H  Cg (I) N1—H1n  O1i 0.86 2.18 3.018 (2) 165 C19—H19  O1i 0.93 2.64 3.361 (2) 135 C13—H13a  O2ii 0.97 2.55 3.411 (3) 147 C15—H15  O2ii 0.93 2.51 3.422 (3) 168 C7—H7  O3iii 0.93 2.62 3.383 (4) 140 C17—H17  C3iv 0.93 2.90 3.824 (3) 173 2.87 C17—H17  C4iv 0.93 2.73 3.541 (3) 146 2.87 C12—H12A  C7v 0.93 2.90 3.724 (4) 143 3.06 C12—H12A  C8v 0.93 2.91 3.903 (3) 137 3.06 C4—H4  C14vi 0.93 2.94 3.857 (4) 160 3.31 C4—H4  C15vi 0.93 2.74 3.536 (4) 144 3.31 C9—H9  C17vi 0.93 2.87 3.780 (5) 144 3.19 (II) N1—H1n  O1i 0.86 2.34 3.133 (6) 154 C6—H6  O1i 0.93 2.70 3.601 (6) 163 C19—H19  O1i 0.93 2.64 3.388 (7) 138 C9—H9  O2ii 0.93 2.66 3.444 (10) 143 C4—H4  O3ii 0.93 2.65 3.273 (10) 125 C18—H18  C7iii 0.93 2.78 3.577 (15) 145 3.23 Symmetry codes for (I): (i)x + 1,y + 2,z + 1; (ii)x + 1,y + 1,z + 2; (iii)x + 2, y + 1,z + 2; (iv) x + 1, y  1, z; (v) x 1, y, z; (vi) x, y + 1, z. Symmetry codes for (II): (i) x + 2, y + 1, z; (ii) x + 1, y + 1, z + 1; (iii) x + 2, y + 1, z + 1. electronic reprint     electronic reprint Acta Crystallographica Section E Structure Reports Online ISSN 1600-5368 Editors: W.T.A. Harrison, H. Stoeckli-Evans, E. R.T. Tiekink and M. Weil 1-Ferrocenyl-3-(3-fluoroanilino)propan-1-one Zorica Leka, Sladjana B. Novakovic´, Anka Pejovic´, Goran A. Bogdanovic´ and Rastko D. Vukic´evic´ Acta Cryst. (2012). E68, m231 This open-access article is distributed under the terms of the Creative Commons Attribution Licence http://creativecommons.org/licenses/by/2.0/uk/legalcode, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited. Acta Crystallographica Section E Structure Reports Online Editors: W. Clegg and D. G. Watson journals.iucr.org International Union of Crystallography * Chester ISSN 1600-5368 Volume 61 Part 11 November 2005 Inorganic compounds Metal-organic compounds Organic compounds Acta Crystallographica Section E: Structure Reports Online is the IUCr’s highly popu- lar open-access structural journal. It provides a simple and easily accessible publication mechanism for the growing number of inorganic, metal-organic and organic crystal struc- ture determinations. The electronic submission, validation, refereeing and publication facilities of the journal ensure very rapid and high-quality publication, whilst key indica- tors and validation reports provide measures of structural reliability. The journal publishes over 4000 structures per year. The average publication time is less than one month. Crystallography Journals Online is available from journals.iucr.org Acta Cryst. (2012). E68, m231 Leka et al. · [Fe(C5H5)(C14H13FNO)] 1-Ferrocenyl-3-(3-fluoroanilino)propan- 1-one Zorica Leka,a* Sladjana B. Novakovic´,b Anka Pejovic´,c Goran A. Bogdanovic´b and Rastko D. Vukic´evic´c aFaculty of Metallurgy and Technology, University of Montenegro, Cetinjski put bb, 81000 Podgorica, Montenegro, b’Vincˇa’ Institute of Nuclear Sciences, Laboratory of Theoretical Physics and Condensed Matter Physics, PO Box 522, 11001 Belgrade, Serbia, and cDepartment of Chemistry, Faculty of Science, University of Kragujevac, R. Domanovic´a 12, 34000 Kragujevac, Serbia Correspondence e-mail: zorica@ac.me Received 18 January 2012; accepted 26 January 2012 Key indicators: single-crystal X-ray study; T = 293 K; mean (C–C) = 0.005 A˚; R factor = 0.049; wR factor = 0.102; data-to-parameter ratio = 17.2. The title ferrocene derivative, [Fe(C5H5)(C14H13FNO)], crys- tallizes in the same space group with similar unit-cell parameters as the derivatives 3-anilino-1-ferrocenylpropan- 1-one [Leka et al. (2012). Acta Cryst. E68, m229] and 1- ferrocenyl-3-(4-methylanilino)propan-1-one [Leka et al. (2012). Acta Cryst. E68, m230]. The dihedral angle between the best planes of the benzene ring and the substituted cyclopentadienyl ring is 83.4 (1). The presence of the electronegative fluoro substituent in the meta position of the aniline group does not alter the crystal packing compared to the other two derivatives. The molecules are connected into centrosymmetric dimers via N—H  O hydrogen bonds. In addition, C—H  O and C—H  N contacts stabilize the crystal packing. Related literature For the physico-chemical properties of ferrocene-based compounds see: Togni & Hayashi (1995). For related crystal structures and details of the synthesis see: Damljanovic´ et al. (2011); Stevanovic´ et al. (2012); Leka et al. (2012a,b). Experimental Crystal data [Fe(C5H5)(C14H13FNO)] Mr = 351.19 Triclinic, P1 a = 7.6602 (4) A˚ b = 9.6438 (4) A˚ c = 12.0626 (6) A˚  = 86.548 (4)  = 73.590 (4)  = 69.138 (4) V = 797.95 (7) A˚3 Z = 2 Mo K radiation  = 0.96 mm1 T = 293 K 0.30  0.24  0.22 mm Data collection Oxford Diffraction Xcalibur Sapphire3 Gemini diffractometer Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009) Tmin = 0.892, Tmax = 1.000 6470 measured reflections 3637 independent reflections 2733 reflections with I > 2(I) Rint = 0.039 Refinement R[F 2 > 2(F 2)] = 0.049 wR(F 2) = 0.102 S = 1.06 3637 reflections 212 parameters H atoms treated by a mixture of independent and constrained refinement max = 0.32 e A˚ 3 min = 0.42 e A˚3 Table 1 Hydrogen-bond geometry (A˚, ). D—H  A D—H H  A D  A D—H  A N1—H1N  O1i 0.83 (3) 2.24 (3) 3.049 (3) 165 (3) C19—H19  O1i 0.93 2.57 3.342 (3) 141 C4—H4  N1ii 0.93 2.66 3.517 (3) 153 Symmetry codes: (i) xþ 1;yþ 1;zþ 1; (ii) x 1; yþ 1; z. Data collection: CrysAlis PRO (Oxford Diffraction, 2009); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and POV-RAY (Persistence of Vision, 2004); software used to prepare material for publication: WinGX (Farrugia, 1999), PLATON (Spek, 2009) and PARST (Nardelli, 1995). This work was supported by the Ministry of Education and Science of the Republic of Serbia (project Nos. 172014, 172035 and 172034). We thank Dr Vladimir Divjakovic´ for help with the X-ray data collection. Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: BT5792). References Damljanovic´, I., Stevanovic´, D., Pejovic´, A., Vukic´evic´, M., Novakovic´, S. B., Bogdanovic´, G. A., Mihajlov-Krstev, T., Radulovic´, N. & Vukic´evic´, R. D. (2011). J. Organomet. Chem. 696, 3703–3713. Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. Leka, Z., Novakovic´, S. B., Stevanovic´, D., Bogdanovic´, G. A. & Vukic´evic´, R. D. (2012a). Acta Cryst. E68, m229. Leka, Z., Novakovic´, S. B., Stevanovic´, D., Bogdanovic´, G. A. & Vukic´evic´, R. D. (2012b). Acta Cryst. E68, m230. Nardelli, M. (1995). J. Appl. Cryst. 28, 659. Oxford Diffraction (2009). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, Oxfordshire, England. Persistence of Vision (2004). POV-RAY. Persistence of Vision Pty Ltd, Williamstown, Victoria, Australia. URL: http://www.povray.org/. Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Spek, A. L. (2009). Acta Cryst. D65, 148–155. Stevanovic´, D., Pejovic´, A., Novakovic´, S. B., Bogdanovic´, G. A., Divjakovic´, V. & Vukic´evic´, R. D. (2012). Acta Cryst. C68, m37–m40. Togni, A. & Hayashi, T. (1995). Ferrocenes: Homogeneous Catalysis, Organic Synthesis, Materials Science. New York: VCH. metal-organic compounds Acta Cryst. (2012). E68, m231 doi:10.1107/S1600536812003510 Leka et al. m231 Acta Crystallographica Section E Structure Reports Online ISSN 1600-5368 electronic reprint     electronic reprint                         ! "#$ % &'#' $( )*' $+ ( %,' - . /# '    !" #$%$& $'$  ''( )' '&  *"' $ '+ "  #   )  $'$,'  #&  +"$  ,-,-,-,. /0 ' #  # &$'$  ''12  &$$  ''12  ),'  '   "#,' '  0 # &,, 3. 3/4 '+$ (#'+$"+&555, #",'  4#" ) #  *" '' ,-,-,-,-6     '+$'++ ) "#"',''$ 7 . 0 ( # ' +"'$  $   &  & ''$ ) $'$ ,8-9 ' 3:4 !*"  #+$ "+ '$ 12  $ 12  ++    ) '#""$%!' $ $$ ) #' "$ #+!; /; ?+@    9 " , #'  $'    ,-9 #* : :84   $, '+$ )9 +#A   A' ' 9 6 #'$ electronic reprint        &  )  ' # ".B'""$ ' '9  &  ) $'2 #          &,/9/ ,.9&6C  D  D/ :  D3. )  *D .3!  E 9$ "FG !H ID 884 D8 33. 4 ,'  /73 D: 3.7. 4 JD K: 0 D 333 4 LD :3 E HD73 /.7. 0 D:= MD8 /:. 0 G    ND3: 7. 0  O .O  D8:8 :/8 4  C*>P"Q''R    38' SF ! P$Q 8# TU ' !D : >F3 7'*  J *D: 0 J D 0 V "DEW "'F  ,$GSCXC*> : #DEW  D 7:  *D  DE3W3 3.8  electronic reprint      !$% S  G $ F+  1A *F Q$ F& ' !TU D .: 9$ F  "  &! D  9 "$ *'   'D 3 &D<U Y  Y .: #DY < 38 Z 2(I) Rint = 0.029 Refinement R[F 2 > 2(F 2)] = 0.039 wR(F 2) = 0.097 S = 1.04 3694 reflections 213 parameters H atoms treated by a mixture of independent and constrained refinement max = 0.28 e A˚ 3 min = 0.28 e A˚3 Table 1 Hydrogen-bond geometry (A˚, ). Cg is the centroid of the C14–C19 ring. D—H  A D—H H  A D  A D—H  A C12—H12A  O1i 0.97 2.38 3.182 (3) 139 C19—H19  Cg1i 0.93 2.98 3.838 (3) 160 Symmetry code: (i) x;yþ 12; zþ 12. Data collection: CrysAlis PRO (Oxford Diffraction, 2009); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) andMercury (Macrae et al., 2006); software used to prepare material for publication: WinGX (Farrugia, 1999), PLATON (Spek, 2009) and PARST (Nardelli, 1995). This work was supported by the Ministry of Education and Science of the Republic of Serbia (project Nos. 172014, 172035 and 172034). Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: BT5950). References Damljanovic´, I., Stevanovic´, D., Pejovic´, A., Vukic´evic´, M., Novakovic´, S. B., Bogdanovic´, G. A., Mihajlov-Krstev, T., Radulovic´, N. & Vukic´evic´, R. D. (2011). J. Organomet. Chem. 696, 3703–3713. Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. Leka, Z., Novakovic´, S. B., Pejovic´, A., Bogdanovic´, G. A. & Vukic´evic´, R. D. (2012c). Acta Cryst. E68, m231. Leka, Z., Novakovic´, S. B., Stevanovic´, D., Bogdanovic´, G. A. & Vukic´evic´, R. D. (2012a). Acta Cryst. E68, m229. Leka, Z., Novakovic´, S. B., Stevanovic´, D., Bogdanovic´, G. A. & Vukic´evic´, R. D. (2012b). Acta Cryst. E68, m230. Macrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst. 39, 453–457. Nardelli, M. (1995). J. Appl. Cryst. 28, 659. Oxford Diffraction (2009). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, Oxfordshire, England. Pejovic´, A., Stevanovic´, D., Damljanovic´, I., Vukic´evic´, M., Novakovic´, S. B., Bogdanovic´, G. A., Mihajilov-Krstev, T., Radulovic´, N. & Vukic´evic´, R. D. (2012). Helv. Chim. Acta. Accepted. metal-organic compounds Acta Cryst. (2012). E68, m995–m996 doi:10.1107/S1600536812028802 Leka et al. m995 Acta Crystallographica Section E Structure Reports Online ISSN 1600-5368 Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Spek, A. L. (2009). Acta Cryst. D65, 148–155. Stevanovic´, D., Pejovic´, A., Novakovic´, S. B., Bogdanovic´, G. A., Divjakovic´, V. & Vukic´evic´, R. D. (2012). Acta Cryst. C68, m37–m40. Togni, A. & Hayashi, T. (1995). In Ferrocenes: Homogenous Catalysis, Organic Synthesis, Materials Science. New York: VCH. metal-organic compounds m996 Leka et al.  [Fe(C5H5)(C15H16NO)] Acta Cryst. (2012). E68, m995–m996 supplementary materials sup-1Acta Cryst. (2012). E68, m995–m996 supplementary materials Acta Cryst. (2012). E68, m995–m996 [doi:10.1107/S1600536812028802] 1-Ferrocenyl-3-(2-methylanilino)propan-1-one Zorica Leka, Sladjana B. Novaković, Anka Pejović, Goran A. Bogdanović and Rastko D. Vukićević Comment The title compound 1-Ferrocenyl-3-(o-tolylamino)propan-1-one (I), Fig. 1, shows considerable conformational differences in comparison to the crystal structures of two closely related derivatives, 1-Ferrocenyl-4-(m-tolylamino)- propan-1-one (Pejović et al., 2012) and 1-Ferrocenyl-3-(p-tolylamino)propan-1-one (Leka et al., 2012b). The torsion angles C1—C11—C12—C13, C11—C12—C13—N1 and C12—C13—N1—C4 within the aliphatic fragment have the values of -161.7 (2), 78.9 (3) and 168.9 (2)°. The latter torsion angle which defines the final orientation of the phenyl ring significantly differs from the values found in m-tolylamino [69.4 (4)°] and p-tolylamino [70.6 (3)°] derivatives. On the other hand, the conformation of the title compound is closer to the one found in those 3-(arylamino)-1- ferrocenylpropan-1-ones which comprise other ortho substituted arylamino fragments, such as previously reported 1- Ferrocenyl-3-(2-acetylphenylamino)propan-1-one (Stevanović et al., 2012) and 1-Ferrocenyl-3-(2-nitrophenylamino)- propan-1-one (Damljanović et al., 2011), [the torsion angle C12—C13—N1—C4 in these compounds has the value -176.1 (6) and -175.7 (6)° respectively]. In the molecule of (I) the phenyl ring is nearly orthogonally positioned with regard to substituted Cp ring. The dihedral angle between the mean planes of the phenyl ring and the substituted Cp ring is 84.63 (7)°. The Cp rings within the Fc unit display nearly eclipsed conformation with C1—Cg1—Cg2—C6 angle of 9.93° (Cg is centroid of the corresponding Cp ring). The molecules of (I) connect via C12–H12a···O1 interaction into zigzag chain extended along c axis (Fig. 2). The chains are further related by means of extensive C—H···π interactions, C19—H19···Cg1i: H···Cg 2.98 Å, H-Perp 2.87 Å, X—H···Cg 160°, (i = x, -y + 1/2, z - 1/2); C8—H8···Cg1ii: H···Cg 3.02 Å, H-Perp 2.84 Å, X—H···Cg 140° (ii = -x + 1, -y, -z + 1); C13—H13b···Cg1i: H···Cg 3.35 Å, H-Perp 2.87 Å, X—H···Cg 127°; C16—H16···Cg2iii: H···Cg 3.07 Å, H-Perp 2.97 Å, X—H···Cg 168 ° (iii = -x + 1, -y, -z + 1); C20—H20a···Cg2iii: H···Cg 3.38 Å, H-Perp 2.95 Å, X—H···Cg 140° (Cg1 and Cg2 are centroids of phenyl and unsubstituted Cp ring respectively). Experimental The compound was obtained by an aza-Michael addition of the coresponding arylamine to acryloylferrocene. The reaction was performed by microwave (MW) irradiation (500 W/5 min) of a mixture of reactants and montmorillonite K-10, without a solvent as described by Damljanović et al. (2011). Refinement H atoms bonded to C atoms were placed at geometrically calculated positions and refined using a riding model. C—H distances were fixed to 0.93, 0.97 and 0.96 Å from aromatic, methylene and methyl C atoms, respectively. The Uiso(H) values set to 1.2 times Ueq of the corresponding C atoms (1.5 for methyl groups). The H atom attached to the N atom was refined isotropically. supplementary materials sup-2Acta Cryst. (2012). E68, m995–m996 Computing details Data collection: CrysAlis PRO (Oxford Diffraction, 2009); cell refinement: CrysAlis PRO (Oxford Diffraction, 2009); data reduction: CrysAlis PRO (Oxford Diffraction, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and Mercury (Macrae et al., 2006); software used to prepare material for publication: WinGX (Farrugia, 1999), PLATON (Spek, 2009) and PARST (Nardelli, 1995). Figure 1 The molecular structure of (I), with atom labels and 40% probability displacement ellipsoids for non-H atoms. supplementary materials sup-3Acta Cryst. (2012). E68, m995–m996 Figure 2 Segment of the crystal packing. The C12—H···O1 interactions connecting the molecules into chains are indicated by black dotted lines. C—H···π interactions are given in blue doted lines. 1-Ferrocenyl-3-(2-methylanilino)propan-1-one Crystal data [Fe(C5H5)(C15H16NO)] Mr = 347.23 Monoclinic, P21/c Hall symbol: -P 2ybc a = 12.1343 (4) Å b = 17.8010 (7) Å c = 7.5464 (2) Å β = 92.946 (3)° V = 1627.89 (9) Å3 Z = 4 F(000) = 728 Dx = 1.417 Mg m−3 Mo Kα radiation, λ = 0.71073 Å Cell parameters from 3389 reflections θ = 3.3–28.9° µ = 0.93 mm−1 T = 293 K Prismatic, orange 0.22 × 0.18 × 0.12 mm Data collection Oxford Diffraction Xcalibur Sapphire3 Gemini diffractometer Radiation source: Enhance (Mo) X-ray Source Graphite monochromator Detector resolution: 16.3280 pixels mm-1 ω scans Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009)′ Tmin = 0.923, Tmax = 1.000 7605 measured reflections 3694 independent reflections 2843 reflections with I > 2σ(I) Rint = 0.029 θmax = 29.0°, θmin = 3.3° h = −15→16 k = −22→19 l = −10→9 supplementary materials sup-4Acta Cryst. (2012). E68, m995–m996 Refinement Refinement on F2 Least-squares matrix: full R[F2 > 2σ(F2)] = 0.039 wR(F2) = 0.097 S = 1.04 3694 reflections 213 parameters 0 restraints Primary atom site location: structure-invariant direct methods Secondary atom site location: difference Fourier map Hydrogen site location: inferred from neighbouring sites H atoms treated by a mixture of independent and constrained refinement w = 1/[σ2(Fo2) + (0.0396P)2 + 0.2313P] where P = (Fo2 + 2Fc2)/3 (Δ/σ)max < 0.001 Δρmax = 0.28 e Å−3 Δρmin = −0.28 e Å−3 Special details Experimental. Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm. ′CrysAlisPro, (Oxford Diffraction, 2009)′ Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) x y z Uiso*/Ueq Fe 0.80589 (2) 0.094395 (18) 0.51346 (4) 0.03546 (12) O1 0.61741 (15) 0.26845 (11) 0.5452 (2) 0.0615 (5) N1 0.41087 (17) 0.15206 (13) 0.4050 (2) 0.0427 (5) C1 0.73752 (18) 0.17593 (14) 0.6608 (3) 0.0382 (5) C2 0.76352 (19) 0.11125 (15) 0.7678 (3) 0.0445 (6) H2 0.7136 0.0826 0.8284 0.053* C3 0.8779 (2) 0.09863 (17) 0.7649 (3) 0.0541 (7) H3 0.9167 0.0604 0.8244 0.065* C4 0.9240 (2) 0.15390 (17) 0.6566 (3) 0.0538 (7) H4 0.9980 0.1580 0.6319 0.065* C5 0.83831 (19) 0.20199 (14) 0.5919 (3) 0.0452 (6) H5 0.8461 0.2432 0.5179 0.054* C6 0.7064 (2) 0.07479 (17) 0.2926 (3) 0.0570 (7) H6 0.6430 0.1015 0.2583 0.068* C7 0.7122 (2) 0.01088 (18) 0.4021 (3) 0.0616 (8) H7 0.6528 −0.0122 0.4534 0.074* C8 0.8221 (3) −0.01211 (16) 0.4207 (3) 0.0595 (7) H8 0.8489 −0.0531 0.4860 0.071* C9 0.8845 (2) 0.03759 (17) 0.3236 (3) 0.0565 (7) H9 0.9605 0.0354 0.3135 0.068* C10 0.8143 (2) 0.09090 (16) 0.2445 (3) 0.0551 (7) H10 0.8351 0.1303 0.1724 0.066* C11 0.62784 (18) 0.20805 (14) 0.6183 (3) 0.0395 (5) C12 0.52948 (18) 0.16387 (15) 0.6742 (3) 0.0451 (6) H12A 0.5231 0.1704 0.8009 0.054* H12B 0.5430 0.1110 0.6531 0.054* C13 0.42057 (18) 0.18528 (15) 0.5804 (3) 0.0451 (6) H13A 0.3602 0.1681 0.6495 0.054* H13B 0.4157 0.2395 0.5705 0.054* C14 0.31120 (17) 0.15273 (13) 0.3047 (3) 0.0366 (5) C15 0.30246 (19) 0.11137 (14) 0.1457 (3) 0.0422 (6) supplementary materials sup-5Acta Cryst. (2012). E68, m995–m996 C16 0.2019 (2) 0.10971 (17) 0.0517 (3) 0.0562 (7) H16 0.1951 0.0822 −0.0531 0.067* C17 0.1113 (2) 0.14773 (18) 0.1089 (3) 0.0621 (8) H17 0.0443 0.1455 0.0436 0.075* C18 0.1206 (2) 0.18863 (17) 0.2619 (3) 0.0551 (7) H18 0.0597 0.2144 0.3007 0.066* C19 0.22021 (18) 0.19193 (15) 0.3598 (3) 0.0442 (6) H19 0.2262 0.2206 0.4629 0.053* C20 0.4006 (2) 0.06922 (17) 0.0836 (3) 0.0593 (7) H20A 0.3801 0.0429 −0.0241 0.089* H20B 0.4254 0.0339 0.1731 0.089* H20C 0.4589 0.1040 0.0622 0.089* H1N 0.463 (2) 0.1487 (15) 0.361 (3) 0.052 (9)* Atomic displacement parameters (Å2) U11 U22 U33 U12 U13 U23 Fe 0.04343 (19) 0.0331 (2) 0.02940 (16) −0.00300 (14) −0.00236 (12) −0.00362 (14) O1 0.0637 (11) 0.0499 (13) 0.0697 (12) −0.0005 (9) −0.0097 (9) 0.0184 (10) N1 0.0387 (11) 0.0526 (14) 0.0366 (9) 0.0025 (10) 0.0018 (9) −0.0108 (10) C1 0.0475 (12) 0.0382 (14) 0.0286 (10) −0.0034 (11) −0.0008 (9) −0.0081 (10) C2 0.0543 (14) 0.0534 (17) 0.0253 (10) 0.0012 (12) −0.0033 (9) −0.0030 (10) C3 0.0615 (15) 0.0616 (19) 0.0371 (12) 0.0104 (14) −0.0174 (11) −0.0100 (13) C4 0.0417 (13) 0.066 (2) 0.0525 (14) −0.0044 (13) −0.0062 (11) −0.0228 (14) C5 0.0523 (13) 0.0360 (14) 0.0470 (12) −0.0104 (11) −0.0011 (11) −0.0123 (11) C6 0.0605 (16) 0.063 (2) 0.0455 (13) 0.0130 (14) −0.0213 (12) −0.0222 (14) C7 0.0712 (18) 0.063 (2) 0.0509 (15) −0.0302 (16) 0.0080 (13) −0.0229 (15) C8 0.092 (2) 0.0336 (15) 0.0512 (14) 0.0059 (15) −0.0086 (14) −0.0064 (12) C9 0.0569 (15) 0.0592 (19) 0.0537 (14) 0.0019 (14) 0.0053 (12) −0.0216 (14) C10 0.0856 (19) 0.0499 (17) 0.0303 (11) −0.0067 (15) 0.0063 (12) −0.0028 (12) C11 0.0498 (13) 0.0404 (14) 0.0276 (10) −0.0020 (11) −0.0043 (9) −0.0072 (10) C12 0.0511 (13) 0.0520 (16) 0.0317 (10) −0.0039 (12) −0.0020 (10) −0.0023 (11) C13 0.0446 (12) 0.0535 (16) 0.0372 (11) 0.0015 (12) 0.0017 (10) −0.0112 (11) C14 0.0387 (11) 0.0341 (13) 0.0369 (11) −0.0062 (10) 0.0008 (9) 0.0024 (10) C15 0.0497 (13) 0.0415 (15) 0.0354 (11) −0.0109 (11) 0.0018 (10) −0.0002 (10) C16 0.0656 (17) 0.0599 (19) 0.0420 (12) −0.0195 (14) −0.0068 (12) −0.0023 (13) C17 0.0501 (15) 0.078 (2) 0.0561 (15) −0.0146 (15) −0.0152 (12) 0.0190 (15) C18 0.0456 (14) 0.0583 (19) 0.0612 (15) 0.0025 (13) 0.0007 (12) 0.0160 (14) C19 0.0446 (13) 0.0440 (15) 0.0437 (12) 0.0000 (11) 0.0008 (10) 0.0024 (11) C20 0.0690 (17) 0.0640 (19) 0.0454 (13) −0.0064 (15) 0.0067 (12) −0.0200 (14) Geometric parameters (Å, º) Fe—C7 2.028 (3) C7—C8 1.395 (4) Fe—C1 2.031 (2) C7—H7 0.9300 Fe—C9 2.031 (2) C8—C9 1.397 (4) Fe—C8 2.034 (3) C8—H8 0.9300 Fe—C2 2.034 (2) C9—C10 1.389 (4) Fe—C5 2.037 (2) C9—H9 0.9300 Fe—C6 2.037 (2) C10—H10 0.9300 supplementary materials sup-6Acta Cryst. (2012). E68, m995–m996 Fe—C10 2.039 (2) C11—C12 1.507 (3) Fe—C4 2.045 (2) C12—C13 1.515 (3) Fe—C3 2.049 (2) C12—H12A 0.9700 O1—C11 1.212 (3) C12—H12B 0.9700 N1—C14 1.393 (3) C13—H13A 0.9700 N1—C13 1.449 (3) C13—H13B 0.9700 N1—H1N 0.74 (2) C14—C19 1.388 (3) C1—C5 1.431 (3) C14—C15 1.407 (3) C1—C2 1.432 (3) C15—C16 1.380 (3) C1—C11 1.469 (3) C15—C20 1.503 (3) C2—C3 1.408 (3) C16—C17 1.379 (4) C2—H2 0.9300 C16—H16 0.9300 C3—C4 1.413 (4) C17—C18 1.365 (4) C3—H3 0.9300 C17—H17 0.9300 C4—C5 1.414 (3) C18—C19 1.385 (3) C4—H4 0.9300 C18—H18 0.9300 C5—H5 0.9300 C19—H19 0.9300 C6—C7 1.406 (4) C20—H20A 0.9600 C6—C10 1.406 (4) C20—H20B 0.9600 C6—H6 0.9300 C20—H20C 0.9600 C7—Fe—C1 120.96 (11) C1—C5—Fe 69.19 (13) C7—Fe—C9 67.46 (11) C4—C5—H5 126.1 C1—Fe—C9 164.08 (11) C1—C5—H5 126.1 C7—Fe—C8 40.19 (11) Fe—C5—H5 126.2 C1—Fe—C8 154.66 (11) C7—C6—C10 107.3 (2) C9—Fe—C8 40.20 (11) C7—C6—Fe 69.41 (14) C7—Fe—C2 109.60 (10) C10—C6—Fe 69.88 (14) C1—Fe—C2 41.25 (9) C7—C6—H6 126.3 C9—Fe—C2 152.81 (11) C10—C6—H6 126.3 C8—Fe—C2 119.71 (11) Fe—C6—H6 126.0 C7—Fe—C5 154.91 (12) C8—C7—C6 108.3 (2) C1—Fe—C5 41.17 (9) C8—C7—Fe 70.14 (15) C9—Fe—C5 125.61 (11) C6—C7—Fe 70.12 (15) C8—Fe—C5 162.90 (11) C8—C7—H7 125.8 C2—Fe—C5 69.00 (10) C6—C7—H7 125.8 C7—Fe—C6 40.47 (11) Fe—C7—H7 125.5 C1—Fe—C6 109.19 (10) C7—C8—C9 107.6 (3) C9—Fe—C6 67.52 (11) C7—C8—Fe 69.67 (16) C8—Fe—C6 67.82 (11) C9—C8—Fe 69.81 (15) C2—Fe—C6 128.99 (10) C7—C8—H8 126.2 C5—Fe—C6 119.76 (11) C9—C8—H8 126.2 C7—Fe—C10 67.72 (11) Fe—C8—H8 125.9 C1—Fe—C10 127.57 (10) C10—C9—C8 108.7 (2) C9—Fe—C10 39.91 (11) C10—C9—Fe 70.32 (14) C8—Fe—C10 67.56 (11) C8—C9—Fe 69.99 (15) C2—Fe—C10 166.37 (11) C10—C9—H9 125.6 C5—Fe—C10 107.41 (11) C8—C9—H9 125.6 C6—Fe—C10 40.37 (11) Fe—C9—H9 125.6 supplementary materials sup-7Acta Cryst. (2012). E68, m995–m996 C7—Fe—C4 164.04 (13) C9—C10—C6 108.0 (2) C1—Fe—C4 68.63 (9) C9—C10—Fe 69.76 (14) C9—Fe—C4 106.77 (10) C6—C10—Fe 69.75 (13) C8—Fe—C4 125.95 (12) C9—C10—H10 126.0 C2—Fe—C4 68.27 (10) C6—C10—H10 126.0 C5—Fe—C4 40.53 (10) Fe—C10—H10 126.0 C6—Fe—C4 152.92 (12) O1—C11—C1 121.1 (2) C10—Fe—C4 118.16 (11) O1—C11—C12 121.6 (2) C7—Fe—C3 127.89 (12) C1—C11—C12 117.2 (2) C1—Fe—C3 68.51 (10) C11—C12—C13 115.0 (2) C9—Fe—C3 118.55 (11) C11—C12—H12A 108.5 C8—Fe—C3 107.98 (11) C13—C12—H12A 108.5 C2—Fe—C3 40.32 (9) C11—C12—H12B 108.5 C5—Fe—C3 68.25 (11) C13—C12—H12B 108.5 C6—Fe—C3 166.04 (12) H12A—C12—H12B 107.5 C10—Fe—C3 151.91 (12) N1—C13—C12 110.61 (18) C4—Fe—C3 40.37 (11) N1—C13—H13A 109.5 C14—N1—C13 121.34 (19) C12—C13—H13A 109.5 C14—N1—H1N 120 (2) N1—C13—H13B 109.5 C13—N1—H1N 115 (2) C12—C13—H13B 109.5 C5—C1—C2 107.3 (2) H13A—C13—H13B 108.1 C5—C1—C11 125.2 (2) C19—C14—N1 121.6 (2) C2—C1—C11 127.4 (2) C19—C14—C15 119.5 (2) C5—C1—Fe 69.63 (13) N1—C14—C15 118.9 (2) C2—C1—Fe 69.49 (13) C16—C15—C14 118.4 (2) C11—C1—Fe 123.35 (14) C16—C15—C20 121.5 (2) C3—C2—C1 108.0 (2) C14—C15—C20 120.1 (2) C3—C2—Fe 70.41 (13) C17—C16—C15 121.8 (2) C1—C2—Fe 69.26 (11) C17—C16—H16 119.1 C3—C2—H2 126.0 C15—C16—H16 119.1 C1—C2—H2 126.0 C18—C17—C16 119.6 (2) Fe—C2—H2 125.9 C18—C17—H17 120.2 C2—C3—C4 108.5 (2) C16—C17—H17 120.2 C2—C3—Fe 69.26 (12) C17—C18—C19 120.4 (3) C4—C3—Fe 69.64 (13) C17—C18—H18 119.8 C2—C3—H3 125.7 C19—C18—H18 119.8 C4—C3—H3 125.7 C18—C19—C14 120.3 (2) Fe—C3—H3 126.9 C18—C19—H19 119.8 C3—C4—C5 108.4 (2) C14—C19—H19 119.8 C3—C4—Fe 69.99 (14) C15—C20—H20A 109.5 C5—C4—Fe 69.44 (13) C15—C20—H20B 109.5 C3—C4—H4 125.8 H20A—C20—H20B 109.5 C5—C4—H4 125.8 C15—C20—H20C 109.5 Fe—C4—H4 126.4 H20A—C20—H20C 109.5 C4—C5—C1 107.8 (2) H20B—C20—H20C 109.5 C4—C5—Fe 70.03 (14) supplementary materials sup-8Acta Cryst. (2012). E68, m995–m996 Hydrogen-bond geometry (Å, º) Cg is the centroid of the C14–C19 ring. D—H···A D—H H···A D···A D—H···A C12—H12A···O1i 0.97 2.38 3.182 (3) 139 C19—H19···Cg1i 0.93 2.98 3.838 (3) 160 Symmetry code: (i) x, −y+1/2, z+1/2. Ultrasound-Assisted Synthesis of 3-(Arylamino)-1-ferrocenylpropan-1-ones by Anka Pejovic´a), Dragana Stevanovic´a), Ivan Damljanovic´a), Mirjana Vukic´evic´b), Sladjana B. Novakovic´c),Goran A. Bogdanovic´c), Tatjana Mihajilov-Krstevd), Niko Radulovic´*e), and Rastko D. Vukic´evic´*a) a) Department of Chemistry, Faculty of Science, University of Kragujevac, R. Domanovic´a 12, RS-34000 Kragujevac (e-mail: vuk@kg.ac.rs) b) Department of Pharmacy, Faculty of Medicine, University of Kragujevac, S. Markovic´a 69, RS-34000 Kragujevac c) Vincˇa Institute of Nuclear Sciences, Laboratory of Theoretical Physics and CondensedMatter Physics, University of Belgrade, P.O. Box 522, RS-11001 Belgrade d) Department of Biology and Ecology, Faculty of Science and Mathematics, University of Nisˇ, Visˇegradska 33, RS-18000 Nisˇ e) Department of Chemistry, Faculty of Science and Mathematics, University of Nisˇ, Visˇegradska 33, RS-18000 Nisˇ (phone:þ 381-628049210; fax: þ 381-18533014; e-mail: nikoradulovic@yahoo.com) A successful aza-Michael addition of arylamines to a conjugated enone, acryloylferrocene, has been achieved by ultrasonic irradiation of the mixture of these reactants and the catalyst, i.e., montmorillonite K-10. This solvent-free reaction, yielding ferrocene containing Mannich bases, 3-(arylamino)-1- ferrocenylpropan-1-ones, considered as valuable precursors in organic synthesis, has been performed by using a simple ultrasonic cleaner. Among 17 synthesized b-amino ketones, three were new ones, and these were fully characterized by spectroscopic means. X-Ray crystallographic analysis of three of these crystalline products enabled the insight into the conformational details of these compounds. All compounds were evaluated for their antibacterial activities against six Gram-positive and five Gram- negative strains in a microdilution assay. The observed promising antibacterial activity (with aMIC value of 25 mg/ml (ca. 0.07 mmol/ml) as the best result for almost all tested compounds against Micrococcus flavus) seems not only to be compound but also bacterial species-specific. Introduction. – Ferrocene, an unusually stable metalorganic compound, has attracted the most widespread attention of chemists among all non-natural compounds. Since its discovery in 1951 [1] [2], a plethora of studies dealing with ferrocene (which is now commercially available, and a relatively non-expensive compound), and/or its derivatives were carried out. This unprecedented interest is a consequence of several unique features of these compounds. By classical methods of organic chemistry, ferrocene could be easily functionalized to derivatives that possess an outstanding stability in both aqueous and non-aqueous media. Thus, ferrocenes have applications in numerous fields, particularly in those such as organic synthesis, catalysis, electronic absorption, and nonlinear optical materials [3] [4]. Since the iron core of these compounds is able to exist in both Fe2þ and Fe3þ, they possess very interesting redox properties and, therefore, offer interesting possibilities for the formation of electro- chemical actuators or switches [5]. Furthermore, bioconjugates containing ferrocene represent a new class of biomaterials, with the organometallic unit serving as a Helvetica Chimica Acta – Vol. 95 (2012) 1425  2012 Verlag Helvetica Chimica Acta AG, Zrich molecular scaffold, a sensitive probe, a chromophore, a biological marker, a redox- active site, a catalytic site, etc. [6]. Biological properties of this class of compounds are particularly interesting. The earliest attempts to apply ferrocenes in medicine were unsuccessful [7] [8], but it did not discourage chemists to search for new possibly biologically active derivatives of this metallocene. Several new compounds of this kind have been synthesized and biologically evaluated against certain diseases, and it turned out that many ferrocenyl compounds display interesting cytotoxic, antitumor, antimalarial, and antimicrobial activities [9 – 18]. All these investigations were prompted by the known fact that a formal substitution of an aromatic group from a compound possessing a certain property (e.g., biological/pharmacological activity) might lead to a product with this feature being much more manifested. It was the main drawing force in many synthetic projects concerning ferrocenes: a plethora of new molecules were designed to be derivatives or analogs of known compounds (that already possess desired properties) in which a certain group was replaced with the ferrocene unit (expecting an improved property). The present study also follows this strategy. Namely, in the scope of a broader synthetic project, we needed recently some 3-(arylamino)-1-ferrocenylpropan-1-ones. In general, such compounds (b-amino ketones) have many applications, among which the most important ones are surely the synthesis of pharmaceuticals [19 – 22]. The introduction of a ferrocene nucleus into these molecules could be of a particular interest. The most frequently used general synthetic approach to these compounds is the Mannich reaction [19] [23] [24], but serious disadvantages of this approach exist and mostly encompass the drastic reaction conditions, long reaction times (causing many side reactions), and an inability of the use of primary amines in the synthesis of secondary ones (since the latter are also good substrates of the same reaction giving tertiary amines containing two 3-oxo groups). A very good alternative to this reaction is the aza-Michael addition, i.e., the conjugate addition of amines to the olefinic bond of a,b-unsaturated CO groups [25]. The literature survey revealed that the addition of aliphatic amines to Michael acceptors proceeds readily (even without a catalyst [26] [27]), whereas aromatic ones do not undergo this reaction easily because of their lower nucleophilicity, particularly when mild conditions and environmentally friendly catalysts were used [28 – 32]. Considering these literature findings, we developed recently a suitable method for the synthesis of 3-(arylamino)-1-ferrocenylpropan-1-ones by microwave irradiation of acryloyl ferro- cene and the corresponding arylamines at the surface of montmorillonite K-10, without a solvent in good-to-excellent yields [33]. In continuation of our permanent interest in the synthesis of different ferrocene derivatives containing two or more heteroatoms (interesting from both synthetic and medicinal chemistry points of view) [18] [34 – 36], herein we wish to report that this synthesis might be accomplished using a simple and cheap ultrasonic cleaner instead of the microwave oven. Since almost all products are crystal substances, suitable for X-ray analysis, in addition to the spectral data of newly synthesized compounds, we will compare here the structural features (molecular structure and ability to form intermolecular interactions) of some of the obtained Mannich bases with those of recently reported derivatives [33]. Our previous results on the antibacterial activity of these compounds encouraged us to screen the synthesized compounds against a broader panel of bacterial strains (in total eleven different bacteria) in order to provide a better understanding of the intrinsic features of these Helvetica Chimica Acta – Vol. 95 (2012)1426 compounds, responsible for their activity, and to possibly point out to the ones with higher or improved activity (in this context, the currently obtained minimal inhibitory concentrations (MIC) data together with those reported in [33] were subjected to an agglomerative hierarchical clustering analysis). Results and Discussion. – Synthesis. The main advantages of the method described in our previous work for the synthesis of the title compounds over the classical ones are the simplicity, high efficiency, and the use of an environmentally friendly catalyst [33]. Even better results with respect to these parameters have been reported recently for the catalyst-free addition of aliphatic amines to conjugate systems of ferrocene analogs of chalcones supported by the ultrasonic irradiation [30]. However, as the authors reported, this reaction failed when aromatic amines were used as the nucleophiles. In our hands, on the other hand, the addition of aniline (2a) to acryloylferrocene (1) under conditions described in [33] gave the corresponding b-amino ketone (3a ; Scheme), but in a relatively poor yield (<40%). Since our microwave-assisted synthesis of the same compound starting from the same reactants was successful only in the presence of the catalyst (montmorillonite K-10) [33], we assumed that the addition of less nucleophilic aromatic amines to the conjugate system of enones might be facilitated also by the simultaneous action of this environmentally benign catalyst and ultrasonic irradiation. Avery recent report, demonstrating once again that ultrasound has a positive effect on the conjugate addition of amines to Michael acceptors (appeared when the present manuscript has already been finished), confirms validity of this idea [37]. Thus, when a mixture of 1 (1 mmol), 2a (2 mmol), and montmorillonite K-10 (100 mg) was irradiated in an ultrasonic cleaner for 1 h, b-amino ketone 3a was obtained in high yield (80%). To check the generality of this reaction, additional 16 arylamines, 2b – 2q (Scheme), have been submitted to the same reaction conditions. The results are compiled in Table 1, and show that a simple and cheap ultrasonic cleaner can be used to accomplish the aza-Michael reaction as successfully as a microwave oven. An overview of the data collected in Table 1 reveals that the yields of the corresponding b-amino ketones 3a – 3q depend on the structure of the starting amines 2a – 2q in an expected manner. Namely, when the starting amines contain an electron- withdrawing group, the yield of the correspondingMannich base is lower. Thus, in the case of amines containing a C¼O group (i.e., 2l – 2n), the corresponding b-amino ketones were obtained in slightly lower yields (Table 1, Entries 12 – 14) than in the case of aniline, whereas the presence of a strong electron-withdrawing group, i.e., the NO2 group (amines 2o – 2q), causes a more considerable decrease of the yields (Table 1, Entries 15 – 17). Scheme. Ultrasound-Assisted Synthesis of 3-(Arylamino)-1-ferrocenylpropan-1-ones Helvetica Chimica Acta – Vol. 95 (2012) 1427 Helvetica Chimica Acta – Vol. 95 (2012)1428 Table 1. Structures of 3-(Arylamino)-1-ferrocenylpropan-1-ones, 3a – 3q , and the Corresponding Starting Amines 2a – 2q , Respectively, as Well as the Yields of the Reaction Entry Amine Product Yielda) 1 2a 3a 80 2 2b 3b 90 3 2c 3c 80 4 2d 3d 85 5 2e 3e 82 6 2f 3f 90 7 2g 3g 91 8 2h 3h 95 9 2i 3i 93 Spectral Characterization. The three newly synthesized compounds, 3l – 3n, described in this work (the rest of the compounds from Table 1, 3a – 3k and 3o – 3q, have been already reported in [33] including their spectral data) have been fully characterized by standard spectroscopic techniques (IR, and 1H- and 13C-NMR), as Helvetica Chimica Acta – Vol. 95 (2012) 1429 Table 1 (cont.) Entry Amine Product Yielda) 10 2j 3j 90 11 2k 3k 89 12 2l 3l 77 13 2m 3m 75 14 2n 3n 70 15 2o 3o 35 16 2p 3p 61 17 2q 3q 59 a) Yields of isolated products based on the starting acryloylferrocene. well as elemental analyses. All spectral data were fully consistent with the proposed structures and with those reported in [33]. In the IR spectra of 3l – 3n, sharp, medium intensity absorptions of NH stretching vibrations are observed below 3400 cm1, indicating that all NH groups are involved in H-bonding interactions. The CO stretching vibration band of the 1’-ferrocene-carbonyl group appears in the range 1667 – 1677 cm1, suggesting the existence of inter- and/or intramolecular H-bonds to the CO functional group. The C¼O absorptions of the Ac group show a similar trend and are all at higher frequencies when compared to the corresponding aminoacetophenones. The 1H- and 13C-NMR spectra of compounds 3l – 3n display all signals expected for the proposed composition. With few exceptions (typically, the CH2 C-atom signals having close values of their chemical shifts and overlapped signals), the H- and C-atom resonances could be assigned on the basis of chemical-shift theory, signal intensities and multiplicities, substituent effects, and by comparison with literature data [38] for the corresponding aminoacetophenones. The 1H-NMR data for the three newly synthesized compounds are typical of monosubstituted ferrocene (a characteristic intensity pattern of 2 :2 : 5 for the cyclopentadienyl (Cp) H-atoms of ferrocene). Two slightly deshielded triplets (or better pseudotriplets) are observed for the Cp ring H-atoms at 4.51 – 4.53 and 4.77 – 4.80 ppm. The low-field pseudotriplet is assigned to the H-atoms at C(2) and C(5), whereas the high-field pseudotriplet is assigned to the ring H-atoms at C(3) and C(4). These are downfield of the singlets assigned to the unsubstituted Cp ring at d(H) 4.11 – 4.17, which is characteristic for ferrocenes with electron-withdrawing substituents (due to deshielding with the increased delocalization of electron density toward the C¼O substituent [39]). The involvement of the NH H-atom in 3l in intramolecular H-bonding may be inferred from the chemical shift of this H-atom (9.01 ppm) in its 1H-NMR spectrum, while, in the other two compounds, the NH is more probably involved in intermolecular H-bonding, and their signals are shifted upfield (d(H) 4.43 and 4.81, for 3m and 3n, resp.). These slightly acidic H-atoms undergo a slow exchange reaction in CDCl3 and the signal splits by coupling to the H-atoms of the adjacent CH2 group (resulting in broad triplets with a coupling constant of ca. 6 Hz). The slow exchange on the NMR time scale of these NH H-atoms seems to be a characteristic of these ferrocene containing compounds rather than of the Ph analogs (compounds obtained when the ferrocene nucleus is interchanged with a benzene ring), since the latter do not show this coupling and give broad singlets for the NH H-atoms [33]. The off-resonance H-atom decoupled 13C-NMR spectra of 3l – 3n exhibited the expected number of peaks in the aliphatic, aromatic, and CO regions. The CO C-atom signals appear at d(C) 202.1 – 203.4 and 196.3 – 200.8 (for the FcCO and MeCO group, resp.). The 13C resonances of the CH2CH2 fragment in all three compounds were relatively non-sensitive to the position of the acyl substituent on neighboring phenylamino group and could be found in the following ranges: d(C) 37.4 – 37.9 and 38.0 – 38.8. The same applies for the chemical shifts of the substituted Cp ring (d(C) 69.2 – 69.3 (C(3’) and C(4’)) and 72.4 – 72.6 (C(2’) and C(5’))). The chemical equivalence of HC(2’,5’) and HC(3’,4’) atom pairs evidences a free and fast rotation around the CC bond between the Cp rings and their substituents. Helvetica Chimica Acta – Vol. 95 (2012)1430 X-Ray Crystal Structure of 3c, 3k, and 3l. The three 3-(arylamino)-1-ferrocenyl- propan-1-ones, presented in Fig. 1, crystallize in different crystal systems: monoclinic (space group C2/c), triclinic (P1¯) , and orthorhombic (P212121) for 3c, 3k, and 3l, respectively. The Cp rings within their ferrocene units are nearly parallel (the maximum dihedral angle of 1.6(2)8 is found in 3c) and exhibit conformations which are close to the eclipsed ones. The torsion angle C1Cg1Cg2C6, relating the eclipsed C-atoms through the corresponding Cp centroids, is equal to 13.1(5), 6.4(5), and 1.2(5)8 for 3c, 3k, and 3l, respectively. In each of the structures, the Fe ·· · Cg1 distance (Cg1 is centroid Helvetica Chimica Acta – Vol. 95 (2012) 1431 Fig. 1. Molecular structures of 3c (a) , 3k (b), and 3l (c) with the atom numbering scheme. Displacement ellipsoids are drawn at the 40% probability level. Dashed lines in 3l indicate N1H ···O2 and C6H ··· O2 intramolecular interactions of the substituted Cp ring) is, in average, by 0.01  shorter than the distance toward the unsubstituted ring (Fe ·· · Cg2). This is in accordance with the previously observed trend for similar ferrocene derivatives [33] [40]. As defined by the O1C11C1C5 torsion angle ( 5.8(4), 1.9(5), and  5.3(4)8 in 3c, 3k, and 3l, resp.), the corresponding C1¼O1 carbonyl fragment is almost co-planar with the substituted Cp ring. A similar co-planarity between the aromatic ring and the closely attached atoms can also be observed within the arylamino moiety. The torsion angle N1C14C15C16 is equal to 176.2(3), 174.9(3), and 179.9(3)8 in 3c, 3k, and 3l, respectively. A number of selected structural parameters (Table 2) show values closely comparable with those recently reported for crystal structures of compounds 3j, 3p, and 3o [33]. It is interesting to notice that, despite the allowed free rotation around the constituting single bonds, and the variation in type and position of the arylamino substituents, the C1C11C12C13N1 fragment within all six crystal structures displays a rather similar conformation. This is indicated by the similarity of the torsion angles C1C11C12C13 and C11C12C13N1, whose values of  165.6(2)/76.2(3),  172.5(3)/76.4(4), and  178.6(2)/71.1(3)8 in 3c, 3k, and 3l, respectively, are consistent with those reported for 3j, 3p, and 3o [33]. Among the presently discussed compounds, the most significant difference can be detected by a comparison of the C12C13N1C14 torsion angle, which indicates a different orientation of the arylamino moiety in 3l (176.4(3)8) with respect to its orientation in 3c and 3k (69.4(4) and 70.6 (4)8). The corresponding dihedral angle between the Fe1/C1/Cg1 plane (dividing the substituted Cp ring) and the best plane of the Ph ring has the values 85.1(5), 87.4(5), and 32.2(5)8 in 3c, 3k, and 3l, respectively. In comparison with the previously described structures, one can observe that the Table 2. Selected Bond Lengths and Angles of 3c, 3k, and 3l 3c 3k 3l Bond lengths [] O1C11 1.222(3) 1.218(4) 1.227(3) N1C14 1.389(4) 1.373(4) 1.355(4) N1C13 1.439(4) 1.445(5) 1.448(4) C1C11 1.477(3) 1.468(4) 1.469(4) C11C12 1.506(3) 1.509(4) 1.510(4) C12C13 1.524(3) 1.516(5) 1.505(4) C16C20 1.510(5) – – C17Cl1 – 1.738(4) – C15C20 – – 1.471(4) C20O2 – – 1.223(3) Bond angles [8] O1C11C1 120.9(2) 121.8(3) 120.4(3) O1C11C12 121.1(2) 121.6(3) 121.4(3) C1C11C12 117.9(2) 116.6(3) 118.2(3) C11C12C13 112.9(2) 112.8(3) 113.5(3) N1C13C12 113.6(2) 114.4(3) 111.3(2) C14N1C13 122.2(2) 121.5(3) 124.7(3) Helvetica Chimica Acta – Vol. 95 (2012)1432 structural features of 3c and 3k closely resemble those of 3j and 3p. Accordingly, it can be suggested that the conformation observed for these four compounds is favorable in the cases where the arylamino moiety has the substituent at C(3’’’) or C(4’’’). The conformation of 3l is, on the other hand, similar to that of 3o and quite different from those of 3c, 3k, 3j, and 3p. One possible explanation for the different orientations of the arylamino moieties in 3l and 3o structures (comparing to 3c, 3k, 3j, and 3p) could be found in their ability to form an intramolecular H-bond between the substituent at C(2’’’) and the rest of the molecule (see Fig. 1, c). Regardless of the type of substituents present in the arylamino moiety, conforma- tionally similar derivatives possess a similar way of the intermolecular arrangement. As previously described for 3j and 3p, the crystal packing of 3c and 3k is also characterized by the formation of discrete H-bonding dimers where centrosymmetrically related molecules associate through pairs of strong NH ···O interactions (Table 3, Fig. S11)). This is not the case with 3l where the corresponding C¼O O-atom is engaged in two weak CH ···O interactions which lead to a more extended, chain-like molecular arrangement (Table 3). The crystal packing of 3l is, however, comparable to that of 3o, which, although containing additional acceptor sites (two O-atoms of the NO2 substituent), involves exactly the same sets of atoms in intermolecular H-bonding (Fig. S21)). The arylamino NH donor of 3l (Fig. 1,c), as well as that of 3o, is engaged only in the intramolecular H-bonding to the corresponding Ac and NO2 substituents, respectively. Biology. Several ferrocenyl compounds display interesting cytotoxic, antitumor, antimalarial, antifungal, antibacterial, and DNA-cleaving activities [16]. In our previous work, we have demostrated that 3-(arylamino)-1-ferrocenylpropan-1-ones possess a certain degree of antibacterial potential, especially against an important human pathogen S. aureus [33]. This time we have retested compounds 3a – 3k and 3o – Table 3. Geometrical Parameters of H-Bonds, and Selected CH · · ·O Interactions of 3c, 3k, and 3l. The CH ···O interactions are given, if H ···O distance is shorter than 2.7 , and CH ···O angle is larger than 1008. DH ···A d(DH) [] d(D ···A) [] d(H ···A) [] /(DH ···A) [8] 3ca) N1H1N ···O1i 0.77(3) 3.036(3) 2.27(3) 172(3) C4H4 ··· N1ii 0.93 3.483(4) 2.62 156 3kb) N1H1N ···O1i 0.82(4) 3.054(4) 2.26(4) 162(3) 3lc) N1H1N ···O2 0.75(3) 2.669(4) 2.07(3) 137(3) C6H6 ···O2 0.93 3.487 (5) 2.60 159 C2H2 ···O1i 0.93 3.326 (3) 2.54 143 C12H2b ···O1ii 0.97 3.235(4) 2.57 126 a) Symmetry codes: i  xþ 1/2,  yþ 1/2,  z ; ii xþ 1/2, yþ 1/2, z. b) Symmetry codes: i  xþ 2,  yþ 1,  zþ 2. c) Symmetry codes: i x 1, y, z ; ii x 1/2,  yþ 1/2,  zþ 2. Helvetica Chimica Acta – Vol. 95 (2012) 1433 1) Supplementary Material may be obtained upon request from the authors. 3q against additional three Gram-positive (Listeria monocytogenes, Micrococcus flavus, and Sarcina lutea) and two Gram-negative (Klebsiella pneumoniae and Shigella sonnei) bacteria, while the remaining, newly synthesized compounds 3l – 3n were evaluated against the full panel of eleven bacterial strains. The results of the MIC determination as well as of the minimal bactericidal activity (MBC) are presented in Tables 4 and 5 as the averages of five repetitions. The compounds have again been shown to possess inhibitory action on the growth of all bacteria withMIC values in the range of 0.025 and 25.00 mg/ml. Almost as a rule,MBC values were several folds higher than those of MIC, suggesting a better inhibitory than bactericidal activity. The only exception was the case of P. aeruginosa where the MIC against all tested strains was a cidal one. The most sensitive bacterium turned out to be aGram-positiveM. flavuswith MIC value lower than 25 mg/ml andMBC being 25 mg/ml, but even this best result was one hundred times lower compared to the effect caused by tetracycline on the same bacterium. Once more, a Gram-positive strain, Bacillus cereus, was the most resistant one among the assayed, with the highest MIC values (66.5 mmol/ml) for 3l – 3n. Although having the least significant action on the growth of B. cereus, these three compounds were generally among the most active ones against all other bacteria, including the pathogenic K. pneumoniae (MIC 2.08 – 8.32 mmol/ml), L. monocytogenes (MIC 8.32 – 16.6 mmol/ml), and S. soneii (MIC 4.16 – 8.32 mmol/ml). To better interpret the results obtained in antibacterial assays, we have statistically compared the obtained MIC values of compounds 3a – 3q against all eleven bacteria (results from the current work and those obtained in our previous study [33]). The Table 4. Minimal Inhibitory (MIC) and Minimal Bactericidal Concentrations (MBC) of the Synthesized Compounds 3a – 3k and 3o – 3q Compound MIC/MBC [mmol/ml] Gram () bacteria Gram (þ) bacteria Klebsiella pneumoniae Shigella sonnei Listeria monocytogenes Micrococcus flavus Sarcina lutea 3a 9.36/75.0 18.8/37.5 9.36/37.5 < 0.0750/0.0750 0.150/0.150 3b 8.99/36.0 18.0/72.0 8.99/36.0 < 0.0720/0.0720 0.144/0.144 3c 2.25/18.0 18.0/72.0 2.25/4.50 < 0.0720/0.0720 0.144/0.144 3d 8.99/36.0 4.50/36.0 1.12/4.50 < 0.0720/0.0720 0.144/0.144 3e 4.16/66.6 16.6/66.6 4.16/66.6 < 0.0666/0.0666 0.133/0.133 3f 8.88/35.5 2.22/35.5 8.88/35.5 < 0.0712/0.0712 0.142/0.142 3g 17.8/35.5 17.8/35.5 17.8/35.5 < 0.0712/0.0712 0.142/0.142 3h 4.44/35.5 17.8/35.5 4.44/35.5 < 0.0712/0.0712 0.142/0.142 3i 2.12/33.9 17.0/33.9 2.12/17.0 < 0.0680/0.0680 0.136/0.136 3j 8.49/136 8.49/67.9 4.24/17.0 < 0.0680/0.0680 0.136/0.136 3k 8.49/33.9 2.12/33.9 2.12/33.9 < 0.0680/0.0680 0.136/0.136 3o 2.06/66.0 16.5/66.0 2.06/4.12 < 0.0661/0.0661 0.132/0.132 3p 4.12/33.0 8.25/33.0 4.12/33.0 < 0.0661/0.0661 0.0661/0.132 3q 0.529/16.5 16.5/66.0 0.529/8.25 < 0.0661/0.0661 0.132/0.132 Tetracyclinea) 2.25/2.25 2.25/2.25 36.0/36.0 0.563/0.563 55.4/55.4 a)MIC/MBC values are given in nmol/ml. Helvetica Chimica Acta – Vol. 95 (2012)1434 results of agglomerative hierarchical clustering (AHC) analyses are presented in Fig. 2. The dendrogram indicates the existence of six groups of compounds. Compounds 3l – 3nwere separated from the rest of the compounds, making the two highly related clades C5 and C6. The presence of an additional CO (AcO) group seems to have differentiated them from the other compounds, and resulted in the greatest decrease in activity against B. cereus, while retaining a significant degree of activity towards other bacteria as mentioned above (this is clearly observable from the centroid characteristics of these clades). The rest of the groups do not have such a clear-cut subdivision of the compounds. A number of subclades consist of compounds having substituents of similar electronic character, e.g., electron-withdrawing ones in 3h, 3q, 3i, and 3o of class C3 second, and that are regiochemically the same (having substituents in the same position on the benzene ring), e.g., 3i and 3o, C3 class; 3j and 3p, class C4; and 3d and 3k, the same class. This analysis also showed that clade C1 (a single compound, 3b, making up this group) is the most related to, but still statistically different, from, clade C2 (again only one compound in this class, i.e. 3g). The two compounds appear to be differentiated by the activity against Salmonella enterica, the latter being less active. These observations confirm the notion that, in general, compounds having an electron- acceptor functionality appeared not to be more or less effective in inhibiting the growth of all bacteria than compounds possessing an electron-donating substituent or no substituent at all. Although it is reasonable to expect that the ortho-regioisomers could have a steric impediment towards an interaction with the receptor of the test organisms, and this is substantiated by the corresponding mentioned grouping of these isomers, the extent of the activity does not seem to hold out on this hypothesis. The activity seems not only to be compound but also bacterial species-specific. It seems worthwhile to note that the activity of the compounds does not follow a trend of decreasing hydrophilic character (estimated [41] log Po/w values for the Ph analogs of compounds were used for Helvetica Chimica Acta – Vol. 95 (2012) 1435 Table 5. Minimal Inhibitory (MIC) and Minimal Bactericidal Concentrations (MBC) of the Synthesized Compounds 3l – 3n Bacterial strains MIC/MBC [mmol/ml] 3l 3m 3n Tetracycinea) Gram () bacteria Escherichia coli 0.533/0.533 0.533/0.533 0.267/0.533 3.51/3.51 Klebsiella pneumoniae 2.08/16.6 2.08/8.32 8.32/16.6 2.25/2.25 Pseudomonas aeruginosa 0.533/0.533 1.07/1.07 0.533/0.533 7.02/7.02 Salmonella enterica 1.07/1.07 2.08/2.08 0.267/0.533 7.02/7.02 Shigella sonnei 4.16/16.6 4.16/8.32 8.32/8.32 2.25/2.25 Gram (þ) bacteria Bacillus cereus 66.5/66.5 66.5/66.5 66.5/66.5 3.51/3.51 Clostridium perfringens 16.6/33.3 16.6/33.3 66.5/66.5 3.51/3.51 Listeria monocytogenes 8.32/16.6 16.6/16.6 8.32/8.32 36.0/36.0 Micrococcus flavus < 0.0666/0.0666 < 0.0666/0.0666 < 0.0666/0.0666 0.563/0.563 Sarcina lutea 0.267/0.533 0.267/0.533 0.0666/0.0666 55.4/55.4 Staphylococcus aureus 0.267/0.533 0.267/0.533 1.07/1.07 0.202/0.202 a)MIC/MBC values are given in nmol/ml. this purpose), hence, indicating that the well-known fact that the solubility of antimicrobials in the bilipid cell membranes may play a significant role in the activity, here has little if any importance. Thus, further work is necessary to establish the true mechanism of action of these ferrocenyl derivatives. Overall, these results are highly promising and suggest that a more detailed study of the antimicrobial (including the antifungal one) activity of this class of compounds could identify further derivatives with improved antibacterial properties. Conclusions. – We described, herein, a new, easily performable procedure for the conjugate addition of arylamines to acryloylferrocene to yield the corresponding N- aryl-3-amino-1-ferrocenylpropan-1-ones in good to excellent yields. This synthesis was Fig. 2. Dendrogram (AHC analysis) and its expansion (left) representing antibacterial activity (theMIC values of compounds 3a – 3q against eleven bacterial strains) dissimilarity relationships of the seventeen compounds 3a – 3q obtained by Euclidean distance dissimilarity, using aggregation criterion-Wards method. Six groups of the compounds were found: C1 –C6 (from left to right). Helvetica Chimica Acta – Vol. 95 (2012)1436 performed with montmorillonite K-10 as the catalyst, supported by ultrasonic irradiation. We unambiguously showed that both the catalyst and the irradiation play an important role in this synthesis. The procedure requires short reaction times, employs an environmentally friendly and non-expensive catalyst, as well as an ultrasonic cleaner, a cheap and simple apparatus, which almost every laboratory possesses. Among 17 compounds synthesized in this way, three were also characterized by single-crystal X-ray analysis. The investigation of their crystal structures and the comparison with recently reported ones suggest two favored conformations for 3- (arylamino)-1-ferrocenylpropan-1-ones. One of the factors influencing the conforma- tion could be the position of the substituent in the arylamino moiety. The conforma- tionally similar derivatives show considerable similarity in their manner of crystal packing. The results of antibacterial assays are highly promising and urge for a more mechanistic-oriented study of antimicrobial (both antibacterial and antifungal) activities of such compounds that could possibly identify further derivatives with improved activity. The observed antibacterial activity seems not only to be compound- (position of the substituent on the ring and its electron-donating/accepting properties) but also bacterial species-specific. This work was supported by the Ministry of Education and Science of the Republic of Serbia (grant 172034). We thank Prof. Vladimir Divjakovic´ for the diffraction data of compounds 3k and 3l. Experimental Part General Remarks. All chemicals were commercially available and used as received, except that the solvents were purified by distillation. Column chromatography (CC): silica gel 60 (230 – 400 mesh ASTM; Merck). TLC: silica gel 60 on Al plates, layer thickness 0.2 mm (Merck). M.p. (uncorrected): Mel-Temp cap. melting-point apparatus, model 1001. IR Spectra: Perkin-Elmer FTIR 31725-X spectrophotometer. 1H- and 13C-NMR spectra: in CDCl3, Varian Gemini (200 MHz) spectrometer; chemical shifts in d(H) [ppm], rel. to the residual solvent H-atoms or 13CDCl3 as the internal standards (CDCl3: 7.26 ppm for 1H and 77.0 ppm for 13C). Elemental analysis of C, H, and N: Carlo Erba 1106 microanalyser; results in agreement with the calculated values. The reactions (ultrasonic-assisted syntheses) were performed by placing the probe with the reactants and the catalyst in an ultrasonic cleaner. AnElmasonic S30 (Elma, Germany) ultrasound bath was used at a frequency of 37 kHz, with an effective ultrasonic power of 30 W and a peak of 240 W. General Procedure for the Synthesis of the Mannich Bases 3a – 3q. A test tube containing a well- homogenized mixture of 240 mg (1 mmol) of acryloylferocene, 2 mmol of the corresponding arylamine, and 100 mg of montmorillonite K-10 was placed in the ultrasonic cleaner and irradiated for 1 h. Then, CH2Cl2 (10 ml) was added to the mixture, and the contents were filtered off. The solid residue was washed with CH2Cl2, and the collected org. solns. were dried (Na2SO4) overnight. After the evaporation of the solvent, the crude mixture was fractioned by flash chromatography on a SiO2 column. The amines eluted with toluene, whereas the Mannich bases 3a – 3q were washed from the column by a mixture of hexane and AcOEt 9 :1 (v/v). In all cases, the complete excess of the amines was recovered. The spectral data of compounds 3a – 3k and 3o – 3q can be found in [33], whereas the data of the newly synthesized ones 3l – 3n are given below. 3-[(2-Acetylphenyl)amino]-1-ferrocenylpropan-1-one (3l). M.p. 1198. IR (KBr): 3322, 1667, 1630, 1567, 1515, 1503, 1458, 1250, 1228, 1205, 1168, 1146, 1107, 949, 752, 609. 1H-NMR (200 MHz, CDCl3): 9.01 (t, J¼ 5.8, NH); 7.75 (dd, J¼ 8.1, 1.6, HC(3’’’)); 7.40 (ddd, J¼ 8.6, 7.1, 1.6, HC(5’’’)); 6.83 (br. d, J¼ 8.6, HC(6’’’)); 6.61 (ddd, J¼ 8.1, 7.1, 1.1, HC(4’’’)); 4.80 (pseudo-t, HC(2’), HC(5’)); 4.51 (pseudo-t, HC(3’), HC(4’)); 4.17 (s, HC(1’’), HC(2’’), HC(3’’), HC(4’’), HC(5’’)); 3.68 (dt, J¼ 6.9, 5.8, CH2(3)); 3.08 (br. t, J¼ 7.0, CH2(2)); 2.57 (s, Me). 13C-NMR (50 MHz, CDCl3): 202.1 (C(1)); 200.8 Helvetica Chimica Acta – Vol. 95 (2012) 1437 (COMe); 150.6 (C(1’’’)); 135.1, 132.8 (C(3’’’), C(5’’’)); 117.8 (C(2’’’)); 114.2, 111.5 (C(4’’’), C(6’’’)); 78.8 (C(1’)); 72.4 (C(2’), C(5’)); 69.8 (C(1’’), C(2’’), C(3’’), C(4’’), C(5’’)); 69.3 (C(3’), C(4’)); 38.8, 37.4 (C(2), C(3)); 27.9 (Me). Anal. calc. for C21H21FeNO2 (375.2419): C 67.22, H 5.64, N 3.73; found: C 67.30, H 5.67, N 3.71. 3-[(3-Acetylphenyl)amino]-1-ferrocenylpropan-1-one (3m). M.p. 1068. IR (KBr): 3363, 1677, 1652, 1600, 1519, 1473, 1453, 1283, 1263, 1106, 826, 782, 688. 1H-NMR (200 MHz, CDCl3): 7.30 – 7.22 (m, overlapping peaks, HC(2’’’), HC(4’’’), HC(5’’’)); 6.84 (ddd, J¼ 8.2, 2.6, 1.3, HC(6’’’)); 4.77 (pseudo-t, J¼ 2.0, HC(2’), HC(5’)); 4.51 (pseudo-t, J¼ 2.0, HC(3’), HC(4’)); 4.43 (br. t, J¼ 5.9, NH); 4.11 (s, HC(1’’), HC(2’’), HC(3’’), HC(4’’), HC(5’’)); 3.62 (pseudo-q, J¼ 5.9, CH2(3)); 3.04 (t, J¼ 5.9, CH2(2)); 2.57 (s, Me).13C-NMR (50 MHz, CDCl3): 203.4 (C(1)); 198.7 (COMe); 147.9 (C(1’’’)); 138.2 (C(3’’’)); 129.4 (C(5’’’)); 118.2, 118.0 (C(4’’’),C(6’’’)); 111.1 (C(2’’’)); 78.7 (C(1’)); 72.5 (C(2’), C(5’)); 69.8 (C(1’’), C(2’’), C(3’’), C(4’’), C(5’’)); 69.2 (C(3’), C(4’)); 38.6, 37.9 (C(2), C(3)); 26.7 (Me). Anal. calc. for C21H21FeNO2 (375.2419): C 67.22, H 5.64, N 3.73; found: C 67.23, H 5.60, N 3.72. 3-[(4-Acetylphenyl)amino]-1-ferrocenylpropan-1-one (3n): M.p. 1828. IR (KBr): 3330, 1665, 1647, 1600, 1584, 1456, 1361, 1283, 1263, 1180, 1042, 959, 825, 584. 1H-NMR (200 MHz, CDCl3): 7.84 (AA’XX’, Jo¼ 8.9, Jm¼ 2.4, HC(3’’’), HC(5’’’)); 6.61 (AA’XX’, Jo¼ 8.9, Jm¼ 2.4, HC(2’’’), HC(6’’’)); 4.81 (br. t, J¼ 5.9, NH); 4.78 (pseudo-t, J¼ 2.0, HC(2’), HC(5’)); 4.53 (pseudo-t, J¼ 2.0, HC(3’), HC(4’)); 4.11 (s, HC(1’’), HC(2’’), HC(3’’), HC(4’’), HC(5’’)); 3.66 (pseudo-q, J¼ 5.9, CH2(3)); 3.04 (t, J¼ 5.9, CH2(2)); 2.49 (s, Me).13C-NMR (50 MHz, CDCl3): 203.0 (C(1)); 196.3 (COMe); 151.6 (C(1’’’)); 130.9 (C(3’’’), C(5’’’)); 126.8 (C(4’’’)); 111.4 (C(2’’’), C(6’’’)); 78.6 (C(1’)); 72.6 (C(2’), C(5’)); 69.8 (C(1’’), C(2’’), C(3’’), C(4’’), C(5’’)); 69.2 (C(3’), C(4’)); 38.0, 37.9 (C(2), C(3)); 26.0 (Me). Anal. calc. for C21H21FeNO2 (375.2419): C 67.22, H 5.64, N 3.73; found: C 67.18, H 5.59, N 3.70. X-Ray Crystallography. Single crystals suitable for X-ray-analysis of 3c, 3k, and 3l were obtained by a slow evaporation from a mixture of CH2Cl2 and hexane. The diffraction data for 3k and 3l were collected on Oxford Diffraction Xcalibur Sapphire3 Gemini, while those for 3c were collected on Enraf Nonius CAD4 diffractometer, both equipped withMoKa radiation (l¼ 0.71073 ). In the case of 3k and 3l, data were processed with CrysAlis software [42] with multi-scan absorption corrections applied using SCALE3 ABSPACK [42]. The data for 3c were processed with XCAD4-CAD4 data reduction program [43]. All three crystal structures were solved with SHELXS [44] and refined using SHELXL [44]. The refinement of the crystal structure 3k revealed the presence of a disordered solvent molecule which could not be reliably modeled. The examination of the structure with SQUEEZE/SOLV procedures included in PLATON [45] indicated the presence of one solvent-accessible void per unit cell with the estimated volume of 205 3. The volume of the cavity and the shape of the residual electron density suggest the incorporation of one toluene molecule. This solvent was used during the synthetic procedure for the chromatographic elution of the amine. The contribution of the solvent to the scattering factors was suppressed using the SQUEEZE procedure. A new data set, free of solvent contribution, was then used in the final refinement. In all three structures, the H1-atom attached to N1 was located by difference Fourier synthesis and refined isotropically. All other H-atoms were placed at geometrically calculated positions with the CH distances fixed to 0.93 from C(sp2); 0.96 and 0.97  from Me and CH2 C(sp3), resp. The corresponding isotropic displacement parameters of the H-atoms were equal to 1.2 Ueq and 1.5 Ueq of the parent C(sp2) and C(sp3), resp. The crystallographic data are compiled in Table 6. Figures were produced using ORTEP-3 [46] and MERCURY, Version 2.4 [47]. The software used for the preparation of the materials for publication: WinGX [48], PARST [49], PLATON [45]. Crystallographic data for 3c, 3k, and 3l have been deposited at the Cambridge Crystallographic Data Centre (CCDC) with the deposition Nos. CCDC-846998, 846999, and 847000, resp. These data can be obtained free of charge via http://www.ccdc.cam.ac.uk/data_request/cif (or from the Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: þ 44 1223 336033; e- mail: deposit@ccdc.cam.ac.uk). Biology. Test Microorganisms. The synthesized 3-(arylamino)-1-ferrocenylpropan-1-ones, 3a – 3q, were assayed for antibacterial activity against a panel of strains belonging to the American Type Culture Collection (ATCC). Compounds 3a – 3q were tested against three Gram-positive (Listeria monocyto- Helvetica Chimica Acta – Vol. 95 (2012)1438 genes ATCC 7644, Micrococcus flavus ATCC 40240, and Sarcina lutea ATCC 9341) and two Gram- negative bacteria (Klebsiella pneumoniae ATCC 10031 and Shigella sonnei ATCC 25931). The three newly synthesized compounds, 3l – 3n, were additionally tested against three Gram-positive (Bacillus cereus ATCC 10876, Clostridium perfringens ATCC 19404, and Staphylococcus aureus ATCC 6538) and three Gram-negative bacteria (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, and Salmonella entericaATCC 13076). All of these bacterial strains were maintained on nutrient agar at 378. Screening of Antibacterial Activity. Antibacterial activity was evaluated using a broth microdilution method according to NCCLS [51]. Minimum inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) were determined as described in [52]. Stock solns. of the compounds 3a – 3qwere prepared in 10% (v/v) aq. DMSO in the concentration range of 0.025 – 50.00 mg/ml (the diluting factor 2). Tetracycline served as a positive control, while the solvent (10% DMSO(aq.)) was used as the negative one. Statistical Analyses. Agglomerative hierarchical clustering (AHC) was performed using the Excel program plug-in XLSTAT (version 2011.4.04). The method was applied utilizing the MIC values of compounds 3a – 3q from this work and those reported in [33] against eleven bacterial strains as original variables without any recalculation. AHC was performed using Pearson dissimilarity (as aggregation Helvetica Chimica Acta – Vol. 95 (2012) 1439 Table 6. Crystallographic Data for 3c, 3k, and 3l 3c 3k 3l Empirical formula C20H21FeNO C22.5H22ClFeNO C21H21FeNO2 Formula weight 347.23 413.71 375.24 Color Dark-orange Dark-orange Dark-orange Crystal size [mm3] 0.30 0.26 0.22 0.22 0.19 0.12 0.23 0.20 0.18 Temp. [K] 293(2) 293(2) 293(2) Wavelength [] 0.7107 0.71073 0.71073 Crystal system Monoclinic Triclinic Orthorhombic Space group C2/c P1¯ P212121 Unit cell parameters a [] 18.365(4) 7.3916(4) 5.8045(2) b [] 7.3680(10) 10.2424(5) 14.7344(5) c [] 25.355(2) 13.8640(7) 20.2616(9) a [8] 90 95.634(4) 90 b [8] 97.908(13) 102.539(4) 90 g [8] 90 99.872(4) 90 V [3] 3398.2(9) 999.4(3) 1732.9(1) Z 8 2 4 Dcalc [Mg/m3] 1.357 1.375 1.438 m [mm1] 0.891 0.899 0.884 q Range for data collection [8] 1.62 to 25.97 3.04 to 29.08 3.32 to 29.03 Reflections collected 3320 7398 5655 Independent reflections, Rint 3320 4497, 0.0235 3447, 0.0284 Refinement method Full-matrix least-squares on F 2 Full-matrix least-squares on F 2 Full-matrix least-squares on F 2 Data/restraints/parameters 3320/0/212 4497/0/212 3447/0/231 Flack parameter [50]  0.01(2) Goodness-of-fit on F 2 0.995 1.028 1.030 R1/wR2 indices [I > 2s(I)] 0.0421/0.1076 0.0613/0.1621 0.0429/0.0735 R1/wR2 indices (all data) 0.0736/0.1161 0.0829/0.1759 0.0563/0.0792 Largest diff. peak and hole [e A3] 0.358/ 0.389 0.609/ 0.254 0.265/ 0.272 criteria simple linkage, unweighted pair-group average, and complete linkage were used) and Euclidean distance (aggregation criterion: weighted pair-group average, unweighted pair-group average andWards method). The definition of the groups was based on Pearson correlation, using complete linkage and unweighted pair-group average method. REFERENCES [1] T. J. Kealy, P. L. Pauson, Nature 1951, 168, 1039. [2] S. A. Miller, J. A. Tebboth, J. F. Tremaine, J. Chem. Soc. 1952, 632. [3] A. Togni, T. Hayashi, Ferrocenes: Homogenous Catalysis, Organic Synthesis, Material Science, VCH, Weinheim, Germany, 1995. [4] A. Togni, R. L. Haltermann, Metallocenes, Wiley-VCH, Weinheim, Germany, 1998. [5] K. Wang, S. Mun˜oz, L. Zhang, R. Castro, A. E. Kaifer, G. W. Gokel, J. Am. Chem. Soc. 1996, 118, 6707. [6] T. Moriuchi, T. Hirao, Top. Organomet. Chem. 2006, 17, 143. [7] B. Loev, M. Flores, J. Org. Chem. 1961, 26, 3595. [8] F. D. Popp, S. Roth, J. Kirby, J. Med. Chem. 1963, 6, 83. [9] C. Biot, G. Glorian, L. A. Maciejewski, J. S. Brocard, O. Domarle, G. Blampain, P. Millet, A. J. Georges, H. Abessolo, D. Dive, J. Lebibi, J. Med. Chem. 1997, 40, 3715. [10] D. Osella, M. Ferrali, P. Zanello, F. Laschi, M. Fontani, C. Nervi, G. Cavigiolio, Inorg. Chim. Acta 2000, 306, 42. [11] G. Jaouen, S. Top, A. Vessie`res, R. Alberto, J. Organomet. Chem. 2000, 600, 23. [12] D. R. van Staveren, N. Metzler-Nolte, Chem. Rev. 2004, 104, 5931. [13] E. W. Neuse, J. Inorg. Organomet. Polym. Mater. 2005, 15, 3. [14] C. S. Allardyce, A. Dorcier, C. Scolaro, P. J. Dyson, Appl. Organomet. Chem. 2005, 19, 1. [15] G. Jaouen, W. Beck, M. J. McGlinchey, in Bioorganometallics: Biomolecules, Labeling, Medicine, Ed. G. Jaouen, Wiley-VCH, Weinheim, 2006. [16] M. F. R. Fouda, M. M. Abd-Elzaher, R. A. Abdelsamaia, A. A. Labib, Appl. Organomet. Chem. 2007, 21,613. [17] O. Payen, S. Top, A. Vessie`res, E. Brule´, M.-A. Plamont, M. J. McGlinchey, H. Mller-Bunz, G. Jaouen, J. Med. Chem. 2008, 51,1791. [18] I. Damljanovic´, M. Vukic´evic´, N. Radulovic´, R. Palic´, E. Ellmerer, Z. Ratkovic´, M. D. Joksovic´, R. D. Vukic´evic´, Bioorg. Med. Chem. Lett. 2009, 19, 1093. [19] M. Tramontini, L. Angiolini, Mannich-Bases, Chemistry and Uses, CRC, Boca Raton, FL, 1994. [20] S. Ebel, Synthetische Arzneimittel, VCH, Weinheim, 1979. [21] P. Traxler, U. Trinks, E. Buchdunger, H. Mett, T. Meyer, M. Mller, U. Regenass, J. Rçsel, N. Lydon, J. Med. Chem. 1995, 38, 2441. [22] J. R. Dimmock, K. K. Sidhu, M. Chen, R. S. Reid, T. M. Allen, G. Y. Kao, G. A. Truitt, Eur. J. Med. Chem. 1993, 28, 313. [23] M. Tramontini, L. Angiolini, Tetrahedron 1990, 46, 1791. [24] M. Arend, B. Westermann, N. Risch, Angew. Chem., Int. Ed. 1998, 37, 1044. [25] P. Perlmutter, Conjugated Addition Reactions in Organic Synthesis, Pergamon Press, Oxford, 1992. [26] B. C. Ranu, S. Banerjee, Tetrahedron Lett. 2007, 48, 141. [27] R. Kumar, P. Chaudhary, S. Nimesh, R. Chandra, Green Chem. 2006, 8, 356. [28] R. Trivedi, P. Lalitha, S. Roy, Synth. Comm. 2008, 38, 3556. [29] M. M. Hashemi, B. Eftekhari-Sis, A. Abdollahifar, B. Khalili, Tetrahedron 2006, 62, 672. [30] J.-M. Yang, S.-J. Ji, D.-G. Gu, Z.-L. Shen, S.-Y. Wang, J. Organomet. Chem. 2005, 690, 2989. [31] N. S. Shaikh, V. H. Deshpande, A. V. Bedekar, Tetrahedron 2001, 57, 9045. [32] L.-W. Xu, J.-W. Li, C.-G. Xia, S.-L. Zhou, X.-X. Hu, Synlett 2003, 15, 2425. [33] I. Damljanovic´, D. Stevanovic´, A. Pejovic´, M. Vukic´evic´, S. B. Novakovic´, G. A. Bogdanovic´, T. Mihajilov-Krstev, N. Radulovic´, R. D. Vukic´evic´, J. Organomet. Chem. 2011, 696, 3703. [34] M. Joksovic´, Z. Ratkovic´, M. Vukic´evic´, R. D. Vukic´evic´, D. Rastko, Synlett 2006, 16, 2581. Helvetica Chimica Acta – Vol. 95 (2012)1440 [35] I. Damljanovic´, M. Cˇolovic´, M. Vukic´evic´, D. Manojlovic´, N. Radulovic´, K. Wurst, G. Laus, Z. Ratkovic´, M. Joksovic´, R. D. Vukic´evic´, J. Organomet. Chem. 2009, 694, 1575. [36] M. Joksovic´, V. Markovic´, Z. D. Juranic´, T. Stanojkovic´, L. S. Jovanovic´, I. S. Damljanovic´, K. Me´sza´ros Sze´cse´nyi, N. Todorovic´, S. Trifunovic´, R. D. Vukic´evic´, J. Organomet. Chem. 2009, 694, 3935. [37] D. Bandyopadhyay, S. Mukherjee, L. C. Turrubiartes, B. K. Banik, Ultrason. Sonochem. 2012, 19, 969. [38] riodb01.ibase.aist.go.jp/sdbs/ accessed on December 12th, 2011. [39] M. I. Levenberg, J. H. Richards, J. Am. Chem. Soc. 1964, 86, 2634. [40] Z. Ratkovic´, S. B. Novakovic´, G. A. Bogdanovic´, D. Sˇegan, R. D. Vukic´evic´, Polyhedron 2010, 29, 2311. [41] R. Wang, Y. Fu, L. Lai, J. Chem. Inf. Comput. Sci. 1997, 37, 615. [42] Oxford Diffraction, CrysAlis CCD and CrysAlis RED, Versions 1.171.32.24., Oxford Diffraction Ltd., Abington, England, 2008. [43] K. Harms, S. Wocadlo, XCAD4 - CAD4 Data Reduction, XCAD-4, Program for Processing CAD-4 Diffractometer Data, University of Marburg, Germany, 1995. [44] G. M. Sheldrick, Acta Crystallogr., Sect. A 2008, 64, 112. [45] A. L. Spek, J. Appl. Crystallogr. 2003, 36, 7. [46] L. J. Farrugia, J. Appl. Crystallogr. 1997, 30, 565. [47] C. F. Macrae, P. R. Edgington, P. McCabe, E. Pidcock, G. P. Shields, R. Taylor, M.Towler, J. van de Streek, J. Appl. Crystallogr. 2006, 39, 453. [48] L. J. Farrugia, J. Appl. Cryst. 1999, 32, 837. [49] M. Nardelli, J. Appl. Crystallogr. 1995, 28, 659. [50] H. D. Flack, Acta Crystogr., Sect. A 1983, 39, 876. [51] NCCLS – National Committee for Clinical Laboratory Standards, Document M100-S11, Perform- ance standards for antimicrobial susceptibility testing. National committee for clinical laboratory Standard, Wayne, PA, USA, 2003. [52] N. Radulovic´, M. Dekic´, Z. Stojanovic´-Radic´, S. Zoranic´, Chem. Biodiversity 2010, 7, 2783. Received January 7, 2012 Helvetica Chimica Acta – Vol. 95 (2012) 1441     li iza hlo vic´ uk 12, 69, 3 a r t i c l e i n f o attention as antimitotic antitumor agents [3–5]. In addition, they are interesting as intermediates in the synthesis of other pharma- ceuticals and active compounds [6,7]. The early procedures for the synthesis of these aza analogues of flavanones included either base [8–11] or acid [12,13] catalyzed isomerisation of the corresponding 20-aminochalcones. However, many new catalytic systems for this intramolecular aza-Michael-type cyclization have been developed in the recent years, such as montmorillonite K-10 [14,15] and aromatic ring with the ferrocene nucleus in some organic com- pounds possessing a certain property (such as biological activity, for example) might lead to a product with this property markedly more prominent than that of the parent compound. With this in mind and given our permanent interest in ferro- cene chemistry [29–31], herein we report on the synthesis and spectral, electrochemical and structural characterization of three new ferrocene containing dihydroquinolinones – 2-ferrocenyl- 2,3-dihydroquinolin-4(1H)-one, 6-chloro- and 6-bromo-2-ferroce- nyl-2,3-dihydroquinolin-4(1H)-ones. Our intention was also to investigate the biological activity of this class of compounds and, ⇑ Corresponding author. Tel.: +381 34 30 02 68; fax: +381 34 33 50 40. Polyhedron 31 (2012) 789–795 Contents lists available at e .eE-mail address: vuk@kg.ac.rs (R.D. Vukic´evic´).of tetracycline.  2011 Elsevier Ltd. All rights reserved. 1. Introduction Quinoline and its derivatives have many applications, whereas the use of these compounds as pharmaceutics is surely among the most important ones. For example, quinolone antimicrobial agents play the central role in the management of a broad range of infections, like respiratory and urinary tracts infections, sexually transmitted diseases, gastrointestinal, abdominal infections, etc. [1]. 2-Aryl-2,3-dihydroquinolin-4(1H)-ones, in their turn, besides possessing analgesic activity [2], nowadays attract considerable SiO2 impregnated with NaHSO4 [16], through the use of microwave irradiation, SiO2 supported TaBr5 [17] and Yb(OTf)3 [18], SiO2 and Al2O3 supported CeCl3 [19], ZnCl2 combined with a polymer sup- ported selenium reagent [20], molecular iodine [21], polyethylene glycol [22], ionic liquids [23], SbCl3 [24], silica chloride [25], ZnCl2 [26], etc. Although ferrocene containing quinoline derivatives have already been synthesized (see, for example [27,28]), to the best of our knowledge there are no reports on the synthesis of neither 2-ferrocenyl-2,3-dihydroquinolin-4(1H)-ones nor 2-ferrocenyl- quinolin-4(1H)-ones. It is well known that the interchange of anArticle history: Received 27 September 2011 Accepted 7 November 2011 Available online 15 November 2011 Keywords: Ferrocene 2-Aminoacetophenones 2,3-Dihydroquinolin-4(1H)-ones Cyclic voltammetry Crystal structure Antimicrobial activity0277-5387/$ - see front matter  2011 Elsevier Ltd. A doi:10.1016/j.poly.2011.11.006a b s t r a c t Syntheses of three new ferrocene containing heterocycles – 2-ferrocenyl-2,3-dihydroquinolin-4(1H)-one and its 6-chloro and 6-bromo derivatives – starting from 2-aminoacetophenones and ferrocenecarboxal- dehyde was achieved in two steps. The aldol condensation of these substrates gave the corresponding 20- aminochalcones in the first stage, whereas a further intramolecular cyclization gives the final products. This cyclization was performed by either a solvent-free microwave irradiation (500 W/5 min) of a mix- ture of chalcones and mortmorillonite K-10 or by using an acidic catalyst (the mixture of acetic and orthophosphoric acid). The latter method, which can be performed by simple stirring at room tempera- ture or by irradiation in an ultrasonic bath, gave much better results. The obtained compounds were spec- trally and electrochemically (cyclic voltammetry) fully characterized, as well as by single-crystal X-ray analysis. A microdilution assay revealed that the three dihydroquinolinones can be regarded as potential lead compounds in the discovery of new antimicrobial drugs due to their very strong and unselective activity towards pathogenic bacteria and one yeast with MIC values (0.01–10.0 lg/mL) lower than thatcVincˇa Institute of Nuclear Sciences, Laboratory of Theoretical Physics and Condensed Matter Physics, PO Box 522, 11001 Belgrade, Serbia dDepartment of Chemistry, Faculty of Science and Mathematics, University of Niš, Višegradska 33, 18000 Niš, SerbiaAntimicrobial ferrocene containing quino electrochemical and structural character 3-dihydroquinolin-4(1H)-one and its 6-c Anka Pejovic´ a, Ivan Damljanovic´ a, Dragana Stevano Goran A. Bogdanovic´ c, Niko Radulovic´ d, Rastko D. V aDepartment of Chemistry, Faculty of Science, University of Kragujevac, R. Domanovic´a bDepartment of Pharmacy, Faculty of Medicine, University of Kragujevac, S. Markovic´a Polyh journal homepage: wwwll rights reserved.nones: Synthesis, spectral, tion of 2-ferrocenyl-2, ro and 6-bromo derivatives a, Mirjana Vukic´evic´ b, Sladjana B. Novakovic´ c, ic´evic´ a,⇑ 34000 Kragujevac, Serbia 4000 Kragujevac, Serbia SciVerse ScienceDirect dron l sevier .com/locate /poly (2b) and 1-(2-amino-5-bromophenyl)ethanone (2c)) and 100 mg tography (SiO2, hexane/ethyl acetate 9:1, v/v). edroMethod C: A round bottom flask containing the solution of chal- cones 2a–c, 1 mmol in the above mentioned mixture of acetic andof NaOH in 10 mL of ethanol was stirred overnight at room temper- ature. The solvent was evaporated and to the residue 10 mL H2O was added. The solution was neutralized with 2 M HCl (litmus pa- per), extracted with CH2Cl2 (three 20 mL portions) and the com- bined organic layers dried overnight (anhydrous Na2SO4). The solvent was evaporated and the residue chromatographed over a short pad of SiO2 (hexane/ethyl acetate 9:1, v/v). After the evapo- ration of the solvent, the obtained solids (chalcones 3a–c) were submitted to an intramolecular cyclization reaction by applying one of the following three methods: Method A: Chalcones 3a–c (1 mmol) were mixed with 100 mg of montmorillonite K-10 in a mortar with a pestle, placed into a Tef- lon cuvette and irradiated for 5 min in a microwave oven at 500W, without the presence of a solvent. After 10 min of cooling down to room temperature, the crude mixture was extracted with ethyl acetate and the obtained solution dried overnight (anhydrous Na2SO4). The solvent was evaporated and the residue purified by column chromatography (SiO2, hexane/ethyl acetate 9:1, v/v). Method B: Chalcones 3a–c (1 mmol) were dissolved in the mix- ture of 3 mL glacial acetic acid and 3 mL of 90% orthophosphoric acid and stirred at room temperature for 50 min. The reaction mix- ture was poured into ice–water mixture, extracted with ethyl ace- tate (three 25 mL portions), the obtained solution washed with NaHCO3, and dried overnight over anhydrous Na2SO4. After the sol- vent was evaporated, the residue was purified by column chroma-thus, we decided to screen their antimicrobial activity against sev- eral bacteria and one fungal strain. 2. Experimental 2.1. Materials and instruments All chemicals were commercially available and used as re- ceived, except that the solvents were purified by distillation. Microwave Labstation for Synthesis, MicroSynth, Milestone appa- ratus equipped with pressure and temperature control units was used for the microwave assisted syntheses. Ultrasonic cleaner Elmasonic S 10, 30 W was used for the ultrasonically supported synthesis. Chromatographic separations were carried out using silica gel 60 (Merck, 230–400 mesh ASTM), whereas silica gel 60 on Al plates, layer thickness 0.2 mm (Merck) was used for TLC. Melting points (uncorrected) were determined on a Mel-Temp capillary melting points apparatus, model 1001. Microanalysis of carbon, hydrogen and nitrogen were carried out with a Carlo Erba 1106 microanalyser; their results agreed favorably with the calculated values. The 1H and 13C NMR spectra of the samples in CDCl3 were recorded on a Varian Gemini (200 MHz) spectrometer. Chemical shifts are expressed in d (ppm), relative to the residual solvent pro- tons or 13CDCl3 as internal standards (CHCl3: 7.26 ppm for 1H and 77 ppm for 13C). IR measurements were carried out with a Perkin– Elmer FTIR 31725-X spectrophotometer. 2.2. Preparation of quinolinones 4a–c The solution of 214 mg (1 mmol) of ferrocenecarboxaldehyde (1), 1 mmol of the corresponding o-aminoacetophenone (1-(2-ami- nophenyl)ethanone (2a), 1-(2-amino-5-chlorophenyl)ethanone 790 A. Pejovic´ et al. / Polyhphosphoric acids (around 6 mL), was placed in an ultrasonic clea- ner and irradiated for 50 min. The reaction mixture was worked up as given in Method B.2.2.1. 2-Ferrocenyl-2,3-dihydroquinolin-4(1H)-one (4a) M.p. 150 C; 1H NMR (200 MHz, CDCl3, ppm) d = 7.86 (dd, J = 7.7, 1.4 Hz, 1H, H5), 7.33 (ddd, J = 7.7, 6.3, 1.4 Hz, 1H, H7), 6.77 (brt, J  7.4 Hz, 1H, H6), 6.72 (brd, J = 7.7 Hz, 1H, H8), 4.65 (brs, 1H, NH), 4.45 (dd, J = 12.4, 4.6 Hz, 1H, H2), 4.27–4.31 (m, 1H, Fc), 4.19–4.25 (m, 8H, Fc, 5H from the unsubstituted Cp and 3H from the substituted Cp), 2.87 (ddd, J = 16.2, 4.6, 1.2 Hz, 1H, H3eq), 2.74 (dd, J = 16.2, 12.4 Hz, 1H, H3ax); 13C NMR (200 MHz, CDCl3, ppm): d = 193.5 (C4), 151.2 (8a), 135.3 (C7), 127.6 (C5), 118.9 (C4a), 118.1 (C6), 115.7 (C8), 89.3 (C10), 68.5 (C100–C500), 68.3, 68.2 (C20, C50), 66.7, 66.1 (C30, C40), 52.9 (C2), 45.9 (C3); IR (KBr): m = 3323, 3078, 2991, 1651, 1608, 1507, 1480, 1321, 769 cm1. Anal. Calc. for C19H17FeNO: C, 68.90; H, 5.17; N, 4.23. Found: C, 68.87; H, 5.14; N, 4.25%. 2.2.2. 6-Chloro-2-ferrocenyl-2,3-dihydroquinolin-4(1H)-one (4b) M.p. 144 C; 1H NMR (200 MHz, CDCl3, ppm): d = 7.82 (d, J = 2.5 Hz, 1H, H5), 7.26 (dd, J = 8.5, 2.5 Hz, 1H, H7), 6.66 (d, J = 8.5 Hz, 1H, H8), 4.66 (brs, 1H, NH), 4.45 (dd, J = 13.5, 4.0 Hz, 1H, H2), 4.25–4.28 (m, 1H, Fc), 4.20–4.24 (m, 8H, Fc, 5H from the unsubstituted Cp and 3H from the substituted Cp), 2.87 (ddd, J = 16.5, 4.0, 1.5 Hz, 1H, H3eq), 2.73 (dd, J = 16.5, 13.5 Hz, 1H, H3ax); 13C NMR (200 MHz, CDCl3, ppm): d = 192.4 (C5), 149.5 (C8a), 135.2 (C7), 126.9 (C5), 123.5 (C6), 119.6 (C4a), 117.3 (C8), 88.9 (C10), 68.6, 68.4 (C20, C50), 68.3 (C100–C500), 66.6, 66.1 (C30, C40), 52.9 (C2), 45.4 (C3); IR (KBr): m = 3340, 2924, 1657, 1615, 1501, 1480, 1408, 1294, 816 cm1. Anal. Calc. for C19H16ClFeNO: C, 62.41; H, 4.41; N, 3.83. Found: C, 62.37; H, 4.44; N, 3.79%. 2.2.3. 6-Bromo-2-ferrocenyl-2,3-dihydroquinolin-4(1H)-one (4c) M.p. 179 C; 1H NMR (200 MHz, CDCl3, ppm): d = 7.96 (d, J = 2.5 Hz, 1H, H5), 7.38 (dd, J = 8.5, 2.5 Hz, 1H, H7), 6.61 (d, J = 8.5 Hz, 1H, H8), 4.66 (brs, 1H, NH), 4.44 (dd, J = 13.0, 3.5 Hz, 1H, H2), 4.25–4.27 (m, 1H, Fc), 4.20–4.24 (m, 8H, Fc, 5H from the unsubstituted Cp and 3H from the substituted Cp), 2.87 (ddd, J = 16.5, 4.0, 1.5 Hz, 1H, H3eq), 2.73 (dd, J = 16.5, 13.0 Hz, 1H, H3ax); 13C NMR (200 MHz, CDCl3, ppm): d = 192.2 (C4), 149.9 (C8a), 137.8 (C7), 130.0 (C5), 120.1 (C4a), 117.6 (C8), 110.4 (C6), 88.8 (C10), 68.5, 68.4 (C20, C50), 68.3 (C100–C500), 66.6, 66.1 (C30, C40), 52.7 (C2), 45.3 (C3); IR (KBr): m = 3327, 2924, 1657, 1600, 1494, 1394, 1284, 820 cm1. Anal. Calc. for C19H16BrFeNO: C, 55.65; H, 3.93; N, 3.42. Found: C, 55.60; H, 3.97; N, 3.41%. 2.3. X-ray crystallography Single-crystal X-ray analysis of three ferrocene derivatives: 2-ferrocenyl-2,3-dihydroquinolin-4(1H)-one (4a), 6-chloro-2-ferr- ocenyl-2,3-dihydroquinolin-4(1H)-one (4b) and 6-bromo-2-ferr- ocenyl-2,3-dihydroquinolin-4(1H)-one (4c) was performed. X-ray diffraction data for all three compounds were collected at room temperature and using two single-crystal diffractometers, Enraf– Nonius CAD4 (for 4a) and Oxford Diffraction Xcalibur Sapphire3 Gemini (for 4b and 4c). Both diffractometers were equipped with Mo Ka radiation (k = 0.71073 Å). X-ray data 4b and 4c were processed with CrysAlis software [33] with multi-scan absorption corrections applied using SCALE3 ABSPACK [33]. All three crystal structures were solved with SHELXS [34] and re- fined using SHELXL [34]. The H1n atom attached to N1 was located by difference Fourier synthesis and refined isotropically. All other H atoms were placed at geometrically calculated positions with the C–H distances fixed to 0.93 from C(sp2); 0.97 and 0.98 Å from methylene and methine C(sp3), respectively. The corresponding n 31 (2012) 789–795isotropic displacement parameters of the hydrogen atoms were equal to 1.2 Ueq and 1.5 Ueq of the parent C(sp2) and C(sp3), respectively. 3.1. Synthesis 4b 4c C19 H16 Cl Fe N O C19 H16 Br Fe N O 365.63 410.09 Color, crystal shape orange, prism orange, prism orange, prism Crystal size (mm3) 0.27  0.24  0.23 0.25  0.22  0.19 0.21  0.18  0.18 293(2) 293(2) 0.71073 0.71073 monoclinic monoclinic P21/c P21/c 13.7845(6) 14.1005(7) 8.0608(3) 7.9990(3) 13.9697(4) 14.0146(5) 90 90 94.997(3) 96.104(4) Reflections collected 3109 Independent reflections (Rint) 2977 (0.0210) edron 31 (2012) 789–795 7912.4. Electrochemistry Cyclic voltammetry experiments were performed at room tem- perature under an argon atmosphere in a three-electrode cell usingA summary of the crystallographic data is given in Table 1. Fig- ures were produced using ORTEP-3 [35] and MERCURY, Version 2.4 [36]. The software used for the preparation of the materials for presen- tation: WINGX [37], PLATON [38], PARST [39]. Data/restraints/parameters 2977/0/203 Goodness-of-fit (GOF) on F2 1.094 Final R1/wR2 indices [I > 2r(I)] 0.0733/0.2334T (K) 293(2) k (Å) 0.71073 Crystal system monoclinic Space group P21/c Unit cell dimensions a (Å) 12.991(4) b (Å) 8.482(2) c (Å) 13.972(3) a () 90 b () 98.80(2) c () 90 V (Å3) 1521.4(7) Z 4 Dcalc (mg/m3) 1.446 l (mm1) 0.991 F(000) 688 h range for data collection () 1.59–25.98Table 1 Crystallographic data for 4a, 4b and 4c. Compound 4a Empirical formula C19 H17 Fe N O Formula weight 331.19 A. Pejovic´ et al. / Polyhan Autolab potentiostat (PGSTAT 302N). The working electrode was a platinum disk (2 mm diameter). The counter electrode was a platinum wire, and an Ag/AgCl electrode was used as the refer- ence one. 2.5. Biology 2.5.1. Test microorganisms The synthesized dihydroquinoliones 4a–c were tested against a panel of microorganisms (American Type Culture Collection strains), including Gram-positive (Bacillus cereus ATCC 10876, Staphylococcus aureus ATCC 6538 and Clostridium perfringens ATCC 19404) and Gram-negative bacteria (Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 10031 Proteus vulgaris ATCC 8427, Pseudomonas aeruginosa ATCC 27853 and Salmonella enterica ATCC 13076), as well as against a yeast Candida albicans ATCC 10231. Bacterial strains were maintained on Nutrient agar (37 C), while the pathogenic yeast was cultured (30 C) on potato dextrose agar (PDA). 2.5.2. Screening of antimicrobial activity Antimicrobial activity was evaluated using a broth microdilu- tion method according to NCCLS [40]. Minimum inhibitory concen- trations (MIC) and minimal bactericidal/fungicidal concentrations (MBC/MFC) were determined as described in full detail in Radul- ovic´ et al. [41]. Stock solutions of the compounds 4a–c were pre- pared in 10% (v/v) aqueous dimethyl sulfoxide (DMSO) in the concentration range 0.01–10000 lg/mL (the diluting factor 2). Tet-Synthesis of the title compounds followed the concept of an intramolecular aza Michael addition, mentioned in the introduc-racycline and nystatin served as positive controls, while the sol- vent (10% DMSO(aq)) was used as a negative control. 3. Results and discussion 90 90 1546.33(10) 1571.74(11) 4 4 1.571 1.733 1.151 3.505 752 824 2.97–29.11 3.21–29.03 8320 7835 3573 (0.0290) 3622 (0.0334) 3573/0/212 3622/0/212 1.098 1.132 0.0475/0.0906 0.0562/0.1054tory section. In the first step of this protocol ferrocenecarboxalde- hyde (1) was subjected to a simple mixed aldol condensation with three o-aminoacetophenones 2a–c, followed by an isomerisation of the obtained chalcone analogues 3a–c to quinolines 4a–c during the second stage (Scheme 1). The preparation of the derivatives 3a–c (60–90%) was accomplished by stirring the ethanol solution of reactants and NaOH overnight. Prompted by a recent report on the easy, environmentally benign and efficient synthesis of 2- aryl-2,3-dihydroquinolin-4(1H)-one from 20-aminochalcones un- der mild reaction conditions (70–80%) [14], we adsorbed com- pounds 3a–c on the montmorillonite K-10 clay surface and Fe N O H Fe H2N O Fe H2N O O + 1 2a-c 3a-c a)X=H; b)X=Cl, c)X=Br X X X 4a-c K-10,MW or AcOH/H3PO4r.t. or AcOH/H3PO4,r.t.,)))))) NaOH 3a-c 6 78 8a 3 2 4 1'2' 3' 4' 1'' 2''3'' 4'' 5' 54a Scheme 1. Synthesis and numbering scheme of 2-ferrocenyl-2,3-dihydroquinolin- 4(1H)-ones 4a–c. 3340 cm ). The H NMR spectra of 4b and 4c showed a character- edroistic doublet at 7.82 and 7.96 ppm, respectively, with the coupling constant of 2.5 Hz, in both 4b and 4c, that can be ascribed to the C5 proton. A proton under the influence of a carbonyl anisotropy and with a meta interaction in these spectra clearly confirms the pres- ence of a chlorine or bromine at the sixth position. The 13C NMR spectra of the dihydroquinolinones 4a–c exhibit signals in the aro- matic, carbonyl and aliphatic regions. The assignment of 13C reso- nances was achieved on the basis of chemical shift theory, signal intensities, substituent effects and by comparison with literature data [42] for analogues. The carbonyl carbon (C-4) in these com- pounds resonates in a narrow range, dC 192.2–193.5 ppm, and is relatively insensitive to the presence and nature of the halogens in 4b and 4c. However, the difference in electronegativities of the halogens (Cl > Br) and the nature of the heavy atom is clearly dem- onstrated by the larger value of chemical shifts of the directly bonded carbon C6 (123.5 and 110.4 for 4b and 4c, respectively)submitted it to microwave irradiation. However, in our hands, this procedure gave only very poor yields (11–14%; Table 2, Method A) of the target 2-ferrocenyl-2,3-dihydroquinolin-4(1H)-ones 4a–c. Our attempts to improve the yields by varying reaction conditions (increase of the amount of catalyst and the time of exposure to MW) did not produce better results. We decided, then, to perform this synthesis through the use of orthophosphoric acid as the catalyst [12,13]. Again when the origi- nal reaction conditions were adopted (heating at reflux) [12], very poor yields of the quinolinones 4a–c were attained. But when the reaction was conducted at room temperature, compounds 4a–c were obtained in much higher yields – up to 60% (Method B, Table 2). The best yields, however, were arrived at if the reaction was carried out with orthophosphoric acid but also promoted by ultra- sonic irradiation (70–74%; Table 2, Method C). 3.2. Spectral characterisation The three synthesized compounds (4a–c) were characterized by spectral (1H and 13C NMR, IR) and chemical means (elemental anal- ysis), and the accumulated data agreed favourably with the pro- posed structures. The IR spectra, as expected, displayed a carbonyl stretch (1651–1657 cm1) and N–H vibration (3323– 1 1 Table 2 Yields of the synthesized quinolinones 4a–c. o- Aminoacetophenone Quinolinone Yielda (%) Method Ab Method Bb Method Cb 2a 4a 14 60 70 2b 4b 13 41 73 2c 4c 11 36 74 a Isolated yield based on the starting ferrocenecarboxaldehyde. b See Section 2. 792 A. Pejovic´ et al. / Polyhand the reversal of the same for the adjacent carbons C5 (130.0 and 133.1 for 4b and 4c, respectively) and C7 (135.2 and 137.8 for 4b and 4c, respectively), when the two halogenated analogues are mutually compared. If the parent compound 4a is compared to an azaflavanone analogue (2-phenyl-2,3-dihydroquinolin-4(1H)- one) [42], the 13C resonances of the A- and C-ring nuclei of 4a illus- trate their insensitivity towards the interchange of the phenyl group for the ferrocenyl one (C2-52.9/58.5, C3-45.9/46.6, C4- 193.6/193.2, C4a-118.9/119.1, C5-127.6/127.6, C6-118.1/118.4, C7-135.3/135.4, C8-115.7/115.9, C8a-151.2/151.5, for 4a/phenyl analogue [42], respectively). This once again puts out a pro argu- ment for the general viewpoint of the effect that a benzene–ferro- cene substitution produces. Perhaps worth mentioning, the spectral data, and especially the 13C NMR shifts in CDCl3, for 2-phe-nyl-2,3-dihydroquinolin-4(1H)-one given in the paper by Lee et al. [43] show a deviation from all the other published ones (e.g. [42,44]) and from the ones obtained in this study for the ferrocenyl analogue 4a. The conformation of the dihydroquinolinone ring of compounds 4a–c could be inferred from their 1NMR. The large value of the cou- pling of H2 with one of the C3 protons (12.4, 13.5 and 13.0 Hz, for 4a–c, respectively) is only compatible with a diaxial antiperiplanar arrangement of H2 and H3ax and this clearly establishes the con- formation of the dihydroquinolinone ring as a half-chair with the 2-ferrocenyl substituent in pseudoequatorial position. A conspicu- ous feature of the 1H NMR spectra of 4a–c was an additional small splitting of the signal of H3eq (1.2, 1.5 and 1.5 Hz, for 4a–c, respec- tively). This splitting can arise from a four-bond NH–H3eq interac- tion. Due to the known stereospecificity of the four-bond couplings this provides additional evidence for the quasi perfect tetrahedral geometry of N, C2 and C3 atoms, and, hence, for the half-chair con- formation of the ring. Observation of the NH–H3eq long-range splitting implies a slow NH-exchange on the NMR time scale (>1 s1, estimated from the magnitude of the residual NH–CH cou- pling constant). The expected three-bond coupling between NH and H2, on the other hand, causes only a broadening of the H2mul- tiplet lines when measured in CDCl3-solution. 3.3. Structural comparisons of 4a, 4b and 4c All three compounds have very similar molecular geometry (Fig. 1 and Fig. S1). The ferrocene unit in 4b and 4c display a con- formation close to eclipsed (Fig. S1). The C1–Cg1–Cg2–C10 torsion angle is 7.6 in 4b and 7.9 in 4c (Cg1 and Cg2 are centroids of the corresponding Cp rings). In 1, the cyclopentadienyl (Cp) rings are somewhat more eclipsed and the C1–Cg1–Cg2–C10 torsion an- gle is 3.3. In all three compounds the Cp rings within ferrocenyl unit are almost parallel with interplanar angles 2.6(6), 3.4(2) and 3.7(4) for 4a, 4b and 4c, respectively. The Cg1–Cg2 distance (3.29 Å) and the Cg1–Fe–Cg2 angle (178.5, 177.4 and 178.5) are also very similar for all crystal structures. Bond lengths (Table 3) show that only C–C and C–N pure single bonds exist in the N1–C11–C12–C13 fragment for all three com- pounds. Corresponding bond lengths for all molecules are very similar except to some extent for the C1–C5 bond. Conformation and geometrical parameters of the N1–C11 six- membered ring is very similar for all three compounds. This ring is twisted around the C11–C12 bond. Bond angles within the ring vary from 108.0(5) to 121.2(6) but all corresponding angles for all three compounds are comparable (Table 4). Comparison of some torsion angles within the ring are given in Table 4 for the three compounds. A closer analysis of the unit cell dimensions reveals some inter- esting points. Namely, all three compounds crystallize in the monoclinic system and the same space group, P21/c. The unit cell dimensions are similar and, as expected, due to the presence of bromine, the unit cell volume for 3 is the largest (1521.4(7), 1546.33(10) and 1571.74(11) Å3 for 4a, 4b and 4c, respectively). However, surprisingly, the length of the unit cell edge c is almost equal for all three crystal structures (Table 1). A ready explanation can be found in the existence of the N1–H  O1 hydrogen bond. This H-bond is the only classical hydrogen bond in all three crystal structures. It forms a chain of molecules exactly along the c axis keeping the molecules in almost the same orientation and distance for all three ferrocene derivatives (Fig. S2). The N1  O1 distance is 3.144(8), 3.098(3) and 3.104(4) Å for 4a, 4b and 4c, respectively (The N1–H  O1 angle, ranging from 176(5) to 179(7), is very n 31 (2012) 789–795close to 180 for all crystal structures). Besides the N1–H  O1 hydrogen bond there is no other (even weak) H-bond in the three crystal structures. However, numerous edroA. Pejovic´ et al. / Polyhintermolecular CH/p interactions exist in the crystal packing of all three compounds. Some selected CH/p interactions are illustrated in Fig. S3. The greatest difference in the packing of molecules for the three Fig. 1. Molecular structures of 4a (a), 4b (b) and 4c (c) with the atom numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. Additional projections are shown in the Supplementary material file (Fig. S1). Table 3 Selected bond lengths (Å). 4a 4b 4c O1–C13 1.241(8) 1.218(3) 1.217(5) N1–C19 1.375(9) 1.366(3) 1.358(5) N1–C11 1.470(8) 1.455(4) 1.457(6) C1–C5 1.443(11) 1.413(4) 1.413(7) C10–C11 1.503(8) 1.499(4) 1.496(6) C11–C12 1.534(8) 1.499(4) 1.499(5) C12–C13 1.511(9) 1.507(4) 1.513(6) C13–C14 1.460(9) 1.474(4) 1.472(6) C14–C15 1.405(9) 1.394(4) 1.390(6) C14–C19 1.427(9) 1.408(3) 1.410(5) C15–C16 1.368(11) 1.361(4) 1.360(6) C16–C17 1.411(11) 1.391(4) 1.400(6) C17–C18 1.373(11) 1.365(4) 1.352(6) C18–C19 1.410(9) 1.410(4) 1.411(6)crystal structures is illustrated in Fig. S4. Obviously, two neighbor- ing molecules are significantly more distant in the case of crystal structure 4a. (Although the mutual orientation of the two mole- cules is almost the same for all three crystal structures.) An expla- nation may be found in the fact that only compounds 4b and 4c possess halogen substituents (X = Cl and Br for 4b and 4c, respec- tively) which participate in the C–H  X intermolecular interac- tions between two molecules. These interactions although very weak, are stabilizing and keep the van der Waals surfaces of two molecules close to each other (Fig. S4). The unoccupied space be- tween molecules in the crystal structure of 4a, gives a ‘‘Potential Solvent Accessible Area’’ of 37.2 Å3.Table 4 Selected bond and torsion angles (). 4a 4b 4c C19–N1–C11 119.2(5) 119.4(2) 119.7(3) N1–C11–C10 108.3(5) 109.1(2) 109.7(3) N1–C11–C12 108.0(5) 108.7(2) 108.4(4) C10–C11–C12 114.7(6) 115.8(2) 115.9(4) C13–C12–C11 112.0(6) 112.4(2) 112.6(4) O1–C13–C14 122.8(6) 123.1(2) 123.1(4) O1–C13–C12 120.6(6) 121.4(2) 121.4(4) C14–C13–C12 116.5(5) 115.5(2) 115.4(3) C19–C14–C13 119.3(6) 119.6(2) 119.5(4) N1–C19–C14 121.2(6) 120.7(2) 121.0(4) C19–N1–C11–C12 47.8(8) 48.0(3) 47.8(5) N1–C11–C12–C13 54.6(8) 54.7(3) 54.3(5) C11–C12–C13–C14 35.2(9) 34.3(4) 34.5(6) Table 5 Electrochemical data of compounds 4a–c. Compound Eox1 (V) Eox2 (V) Ered (V) E1/2 (V) DE (mV) 4a 0.458 0.1340 0.360 0.409 98 4b 0.476 0.1373 0.378 0.427 98 4c 0.473 0.1401 0.381 0.427 92 n 31 (2012) 789–795 7933.4. Electrochemistry Cyclic voltammetry experiments in acetonitrile containing 0.1 mol/L of lithium perchlorate as the supporting electrolyte have been performed to evaluate the electrochemical properties of com- pounds 4a–c. On the basis of some preliminary investigations we chose the potential window between 0 and 1.5 V. The voltammo- grams obtained for compound 4a are presented here (Fig. 2) as a representative example, whereas the data of the other compounds are summarised in Table 5. As it can be seen from Fig. 2, curve a, the ferrocene containing quinolinone 2a exhibited at the first scan two well defined oxida- tion waves on the forward potential sweep (O1, at 0.458 and O2, at 1.340 V, respectively) and one reduction wave on the back poten- tial sweep (R1, at 0.592 V). The reduction peak R1 appeared also when the potential was reversed after O1, and, therefore, O1 and R1 should correspond to interdependent electrochemical events. Since the difference between the values of these two potentials is close to the theoretical one, O1 and R apparently belong to a reversible redox couple, appearing due to the presence of the ferro- cene nucleus. Their position lays more than 50 mV higher than that of the unsubstituted ferrocene (Fig. 2, curve c). This might be attributed to a slightly raised electro-positivity of the carbon atom connected to the cyclopentadienyl ring (caused by the negative inductive effect of the nitrogen atom). Both the anodic (O1) and cathodic (R1) peak currents are proportional to the square root of the scan rate (as depicted in Fig. 3), and their ratio is independent of the scan rate, indicating a diffusion-controlled process. An irreversible electrochemical event is responsible for the occurrence of the second oxidation wave (O2) at 1.340 V, since the corresponding reduction wave interdependent to O2 was not observed. To the best of our knowledge, there are no literature re- ports on the cyclic voltammetry of 2,3-dihydroquinolin-4(1H)-one or its derivatives. One can assume a certain degree of similarity with the cyclic voltammetry of N-alkyl anilines [45–47], and we believe that an electron transfer from the nitrogen atom to anode occurs at this potential. The product of this event should be a rad- ical cation, which surely undergoes some irreversible transforma- tions, because of its high reactivity. In the case of the above mentioned anilines this species gives products that can be detected by cyclic voltammetry at the second and subsequent scans [45– lective activity against all tested microorganisms with MIC values Fig. 3. Anodic and cathodic peak currents obtained at different scan rates of 1 mM solution of 2-ferrocenyl-2,3-dihydroquinolin-4(1H)-one (4a) at the platinum electrode (2 mm diameter) in a 0.1 M acetonitrile solution of LiClO4. Table 6 Antimicrobial activity of 4a–c. Compound 4a 4b (lg/mL) MIC MBC MIC MBC Gram-positive bacteria B. cereus 0.40 20.0 0.31 10.0 S. aureus 0.39 5.00 0.10 5.00 C. perfringens 2.25 20.0 1.25 10.0 Gram-negative bacteria E. coli 2.25 20.0 0.31 10.00 K. pneumoniae 0.05 5.00 0.01 1.25 P. vulgaris 0.40 10.0 0.40 5.00 P. aeruginosa 10.0 40.0 5.00 20.0 S. enterica 1.25 20.0 0.62 5.00 Yeast C. albicans 1.25 10.0 0.45 20.0 nt, not tested. Fig. 2. Cyclic voltammograms of 1 mM solution of 2-ferrocenyl-2,3-dihydroquin- olin-4(1H)-one at the platinum electrode (2 mm diameter) by a 0.1 Vs1 scan rate in a 0.1 M acetonitrile solution of LiClO4: (a) the first scan, (b) the second scan, (c) 1 mM ferrocene and (d) electrolyte. 794 A. Pejovic´ et al. / Polyhedron 31 (2012) 789–795ranging from 0.01 to 10.0 lg/mL, but with usually one order or two of magnitude larger MBC/MFC values. Some of the compounds proved to be more potent in inhibiting the growth of bacteria than the used positive control (the commercially available tetracycline). The bromo-compound 4c, that was the most active of all three, had MIC in all cases lower that that of tetracycline, although its anti- 4c Tetracycline Nystatin MIC MBC MIC = MBC MIC = MFC 0.31 10.0 1.56 nt 0.07 5.00 0.09 nt 0.15 10.0 1.56 nt 0.07 10.0 1.56 nt 0.01 2.50 0.05 nt 0.10 5.00 0.11 nt 1.25 10.0 3.12 nt 0.15 20.0 3.12 nt47], but here we did not observe any similar behaviour, most prob- able due to the overlapping with the electrochemical response of the ferrocene unit. The electrochemical properties of compounds 4a–c are apparently interesting and surely deserve additional investigations, but both the extent and the type of the future inves- tigations exceed the scope of this work. 3.5. Biology To date, the contribution of ferrocene to antibacterial, anti- fungal and other biological properties of ferrocene-containing compounds remains uncertain. Some authors believe that ferro- cene fulfills a structural role, possibly that of a hydrophobic spacer in place of a phenyl ring [48]. Others proposed a more ‘‘active’’ role for ferrocene, namely as a source of ferricenium (Fe3+) or reactive oxygen species that had a direct influence on activity [49]. In addi- tion to this, dihydroquinoline moiety is found in a wide variety of natural products and an extensive array of medicinally interesting compounds [50,51]. Motivated by these ideas and our previous re- sults [29–32], we decided to screen compounds 4a–c for their in vitro antimicrobial activity on a group of representative Gram- positive, Gram-negative bacteria and one human pathogen fungal strain. The antimicrobial activities of the substances expressed as MIC and MBC/MFC are reported in Table 6. In particular, 4a and its halogen derivatives 4b and 4c showed a very strong and unse-0.31 20.0 nt 0.04 candidal activity was weaker than that of nystatin (but still close to it). In general, the activity noted against Gram-negative bacteria compared to Gram-positive ones was lower as expected from the structure of their cell walls, with the G() bacterium P. aeruginosa that turn out to be the most resistant strain in this test (this also stands for tetracycline). However, the most susceptible microor- ganism was also a G() bacterium K. pneumoniae with a MIC value antibacterial and antifungal properties. formed by cyclic voltammetry, showed that these compounds 172034). References [1] A.S. Wagman, M.P. Wentland, in: J.B. Taylor, D.J. Triggle (Eds.), Comprehensive Medicinal Chemistry II, vol. 7, Elsevier, Amsterdam, 2006, pp. 567–596. [2] M.S. Atwal, L. Bauer, S.N. Dixit, J.E. Gearien, R.W. Morris, J. Med. Chem. 8 (1965) 566. [3] Y. Xia, Z.-Y. Yang, P. Xia, K.F. Bastow, Y. Tachibana, S.-C. Kuo, E. Hamel, T. Hackl, K.-H. Lee, J. Med. Chem. 41 (1998) 1155. [4] S.-X. Zhang, J. Feng, S.-C. Kuo, A. Brossi, E. Hamel, A. Tropsha, K.-H. Lee, J. Med. A. Pejovic´ et al. / Polyhedron 31 (2012) 789–795 795Appendix A. Supplementary data CCDC 839535, 839536 and 839537 contain the supplementary crystallographic data for 4a, 4b and 4c. These data can be obtained free of charge via http://www.ccdc.cam.ac.uk/conts/retriev- ing.html, or from the Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: (+44) 1223 336 033; or e-mail: deposit@ccdc.cam.ac.uk. Supplementary data associated with this article can be found, in the online version, at doi:10. 1016/j.poly.2011.11.006.exhibit two oxidation waves and a reduction one corresponding to one reversible redox pair and a certain irreversible event. In a microdilution assay, the three compounds showed a very strong and unselective activity against the tested pathogenic bacteria and a yeast with MIC values ranging from 0.01 to 10.0 lg/mL. In all cases the bromo-derivative had lower MIC values that those of tetracycline. The obtained results make these compounds excel- lent leads for the development of new more potent ferrocene-con- taining antimicrobial agents. Acknowledgements We thank Prof. Vladimir Divjakovic´ for collecting the diffraction data of 4b and 4c compounds. This work was supported by the Ministry of Education and Science of the Republic of Serbia (Grant4. Conclusion Three new ferrocene containing 2,3-dihydroquinolin-4(1H)- ones were synthesized and fully characterised by spectral, chemi- cal and crystallographic data. Electrochemical investigations, per-of 0.01 lg/mL for the halogen-containing compounds and 0.05 lg/ mL for 4a. It seems worthwhile to note that the activity of the compounds follows a trend of decreasing hydrophilic character (estimated [52] logPo/w values for the phenyl analogues of com- pounds 4a–c are 2.901, 3.564 and 3.740, respectively), hence, indi- cating that the solubility of the compounds in the bilipid cell membranes may play a significant role in the observed activity. However, further work is necessary in establishing the true Modus operandi. Overall, these results are highly promising and suggest that a more detailed study of the antimicrobial activity of this class of compounds could identify further derivatives with improvedChem. 43 (2000) 167. [5] L.N. Bheemanapalli, A. Kaur, R. Arora, Sangeeta, R.R. Akkinepally, N.M. Javali, Med. Chem. Res., in press. doi:10.1007/s00044-011-9688-z. [6] O.V. Singh, R.S. Kapil, Synth. Commun. 23 (1993) 277. [7] O. Prakash, D. Kumar, R.K. Saini, S.P. Singh, Synth. Commun. 24 (1994) 2167. [8] C. Mannich, M. Dannehl, Chem. Ber. 71 (1938) 1899. [9] H. de Diesbach, H. Kramer, Helv. Chim. Acta 28 (1945) 1399. [10] G. Janzso, E.M. Philbin, Tetrahedron Lett. (1971) 3075. [11] A.L. Tökés, L. Szilágy, Synth. Comm. 17 (1987) 1235. [12] J.A. Donnelly, D.F. Farrell, J. Org. Chem. 55 (1990) 1757. [13] J.S. Mahanty, M. De, P. Das, N.G. Kundu, Tetrahedron 53 (1997) 13397. [14] R.S. Varma, R.K. Saini, Synlett (1997) 857. [15] R. Varma, J. Heterocyclic Chem. 36 (1999) 1565. [16] K.H. Kumar, P.T. Perumal, Can. J. Chem. 84 (2006) 1079. [17] N. Ahmed, J.E. van Lier, Tetrahedron Lett. 47 (2006) 2725. [18] J. Li, L. Jin, C. Yu, W. Su, J. Chem. Res. (2009) 170. [19] N. Ahmed, J.E. van Lier, Tetrahedron Lett. 48 (2007) 13. [20] E. Tang, B. Chen, L. Zhang, W. Li, J. Lin, Synlett (2011) 707. [21] L. Wu, B. Niu, W. Li, F. Yan, Bull. Korean Chem. Soc. 30 (2009) 2777. [22] D. Kumar, G. Patel, B.G. Mishra, R.S. Varma, Tetrahedron Lett. 49 (2008) 6974. [23] D. Kumar, G. Patel, A. Kumar, R.K. Roy, J. Heterocyclic Chem. 46 (2009) 791. [24] R.N. Bhattacharya, P. Kundu, G. Mait, Synth. Commun. 40 (2010) 476. [25] M. Muthukrishnan, M. Mujahid, V. Punitharasu, D.A. Dnyaneshwar, Synth. Commun. 40 (2010) 1391. [26] J.I. Lee, H.J. Jung, J. Korean Chem. Soc. 51 (2007) 106. [27] W.J. Lee, J.M. Chea, Y. Jahng, Bull. Korean Chem. Soc. 30 (2009) 3061. [28] M. Zora, Ö. Veliog˘lu, J. Organomet. Chem. 693 (2008) 2159. [29] M.D. Vukic´evic´, K. Wurst, A.G. Müller, G. Laus, R.D. Vukic´evic´, Polyhedron 24 (2005) 533. [30] I. Damljanovic´, M. Vukic´evic´, N. Radulovic´, R. Palic´, E. Ellmerer, Z. Ratkovic´, M.D. Joksovicc´, R.D. Vukic´evic´, Bioorg. Med. Chem. Lett. 19 (2009) 1093. [31] Z. Ratkovic´, S.B. Novakovic´, G.A. Bogdanovic´, D. Šegan, R.D. Vukic´evic´, Polyhedron 29 (2010) 2311. [32] D. Ilic´, I. Damljanovic´, D. Stevanovic´, M. Vukic´evic´, N. Radulovic´, V. Kahlenberg, G. Laus, R.D. Vukic´evic´, Polyhedron 29 (2010) 1863. [33] Oxford Diffraction (2008). CrysAlis CCD and CrysAlis RED. Versions 1.171.32.24. Oxford Diffraction Ltd., Abington, England. [34] G.M. Sheldrick, Acta Crystallogr., Sect. A 64 (2008) 112. [35] L.J. Farrugia, J. Appl. Crystallogr. 30 (1997) 565. [36] C.F. Macrae, P.R. Edgington, P. McCabe, E. Pidcock, G.P. Shields, R. Taylor, M. Towler, J. van de Streek, J. Appl. Crystallogr. 39 (2006) 453. [37] L.J. Farrugia, J. Appl. Crystallogr. 32 (1999) 837. [38] A.L. Spek, J. Appl. Crystallogr. 36 (2003) 7. [39] M. Nardelli, J. Appl. Crystallogr. 28 (1995) 659. [40] NCCLS – National Committee for Clinical Laboratory Standards, Document M100-S11. Performance standards for antimicrobial susceptibility testing. National committee for clinical laboratory Standard, Wayne, PA, USA, 2003. [41] N. Radulovic´, M. Dekic´, Z. Stojanovic´-Radic´, S. Zoranic´, Chem. Biodivers. 7 (2010) 2783. [42] M.J. Mphahlele, P.T. Kaye, Magn. Reson. Chem. 36 (1998) 69. [43] M.-S. Park, J.-I. Lee, Bull. Korean Chem. Soc. 25 (2004) 1269. [44] J.-I. Lee, J.-S. Youn, Bull. Korean Chem. Soc. 29 (2008) 1853. [45] Z. Galus, R.N. Adams, J. Phys. Chem. 67 (1963) 862. [46] J. Bacon, R.N. Adams, J. Am. Chem. Soc. 90 (1968) 6596. [47] R. Ojani, J.-B. Raoof, B. Norouzi, J. Mater. Sci. 44 (2009) 4095. [48] P. Beagley, M.A.L. Blackie, K. Chibale, C. Clarkson, R. Meijboom, J.R. Moss, P.J. Smith, H. Su, Dalton Trans. 39 (2003) 3046. [49] J.C. Swarts, D.M. Swarts, M.D. Mare, E.W. Neuse, C. La Madeleine, J.E. Van Lier, Anticancer Res. 21 (2001) 2033. [50] A.R. Katrizky, S. Rachwal, B. Rachwal, Tetrahedron 52 (1996) 15031. [51] J.C. Craig, P.E. Person, J. Med. Chem. 14 (1971) 1221. [52] W. Renxiao, F. Ying, L. Luhua, J. Chem. Inf. Comput. Sci. 37 (1997) 615.     th o ic va a University of Kragujevac, R. Domanovica 12, 34000 Kragujevac, Serbia nd Math l Science Phytoch e, Univer Zorana y of Theo inable O their favorable in- incorporation of the d an additional aro- olytic effect. . All rights reserved. pore for chloride ion transport [4,5]. A number of GABAA agonists bind to an allosteric site (BZD-binding pocket) located on the cooperative effect channel opening BAA receptor, i.e. w of chloride ions hibition/hyperpo- novel compounds ed to improve the g drugs [2]. In that class of GABAA-targeting anxiolytics. In that respect, a small library of 1,3-thiazolidin-4-oneeferrocene hybrids (N-substituted 2- ferrocenyl-1,3-thiazolidin-4-ones; 13 compounds in total) was designed on the following three premises: (i) Therapeutically speaking, besides as anxiolytics, GABAA agonists are frequently used as anticonvulsant, sedative-hypnotic, and muscle-relaxant drugs [4]. In recent years, there is a growing tendency towards the use of anticonvulsants as an alternative treatment for some * Corresponding author. ** Corresponding author. E-mail addresses: nikoradulovic@yahoo.com, vangelis0703@yahoo.com Contents lists availab European Journal of M journal homepage: http: / /www European Journal of Medicinal Chemistry 83 (2014) 57e73(N.S. Radulovic), vuk@kg.ac.rs (R.D. Vukicevic).types; different subunit isoforms are possible), together forming a sense, the aim of this study was the design and synthesis of a novelKeywords: 2-Ferrocenyl-1,3-thiazolidin-4-ones Anxiolytic agents Ligand docking GABAA receptor complex GABAA benzodiazepine-binding site high, dose-dependent, anxiolytic activity of the new compounds might be due to teractions with the benzodiazepine-binding site of the GABAA receptor complex. The ferrocene core and fine tuning of the distance between the thiazolidinone core an matic ring were judged to be crucial structural requirements for the observed anxi © 2014 Elsevier Masson SAS 1. Introduction Since their discovery in the mid-1950s, drugs targeting the g- aminobutyric acid A receptor (GABAA agonists; e.g., the family of benzodiazepine, BZD, compounds) have been and still are the first choice in the treatment of anxiety [1e4]. The fully functional GABAA receptor is a membrane-bound heteropentameric protein consist- ing of an assembly of different subunits (usually a, b and g-sub- GABAA receptor complex and exert a positive that results in increased frequency of chloride (there are other modulatory sites on the GA barbiturate, neuroactive steroid etc.) [4,5]. The flo causes excitation/depolarization, shunting or in larization of neurons [6]. The development of that target the GABAA system is driven by the ne effectiveness and lessen the side effects of existinAccepted 25 May 2014 Available online 28 May 2014 most potent compound, 2-ferrocenyl-3-(4-methoxyphenylethyl)-1,3-thiazolidin-4-one, was inferred from experiments with known GABAA-targeting agents. Ligand docking experiments revealed that theDepartment of Chemistry, Faculty of Science a c Department of Pharmacy, Faculty of Medicina d Institute of Organic Chemistry with Centre of e Department of Physiology, Faculty of Medicin f Faculty of Medicine, University of Nis, Bulevаr g Vinca Institute of Nuclear Sciences, Laborator h SynBioC Research Group, Department of Susta a r t i c l e i n f o Article history: Received 22 April 2014 Received in revised form 5 May 2014http://dx.doi.org/10.1016/j.ejmech.2014.05.062 0223-5234/© 2014 Elsevier Masson SAS. All rights reematics, University of Nis, Visegradska 33, 18000 Nis, Serbia s, University of Kragujevac, S. Markovica 69, 34000 Kragujevac, Serbia emistry, Bulgarian Academy of Sciences, Bl. 9, Acad. G. Bonchev Str., Sofia 1113, Bulgaria sity of Nis, Bulevаr Zorana ĐinCica 81, 18000 Nis, Serbia ĐinCica 81, 18000 Nis, Serbia retical Physics and Condensed Matter Physics, PO Box 522, 11001 Belgrade, Serbia rganic Chemistry and Technology, Ghent University, Coupure Links 653, B-9000 Gent, Belgium a b s t r a c t Herein, we report on the synthesis, spectral, crystallographic and electrochemical properties of a small library of N-substituted 2-ferrocenyl-1,3-thiazolidin-4-ones, designed as novel GABAA benzodiazepine- binding site ligands. The anxiolytic properties of the title compounds were evaluated in several different in vivo models, whereas the involvement of the GABAA receptor complex in the activity of thea Department of Chemistry, Faculty of Science, bNiko S. Radulovic b, *, Rastko D. Vukicevic a, **Original article Discovery of anxiolytic 2-ferrocenyl-1,3- GABAA receptor interaction via the benz Anka Pejovic a, Marija S. Denic b, Dragana Stevanov Mirjana Vukicevic c, Kalina Kostova d, Maya Tavlino Nikola M. Stojanovic f, Goran A. Bogdanovic g, Polinserved.iazolidin-4-ones exerting diazepine-binding site a, Ivan Damljanovic a, -Kirilova d, Pavle Randjelovic e, Blagojevic b, Matthias D'hooghe h, le at ScienceDirect edicinal Chemistry .e lsevier .com/locate/ejmech anxiety disorders in individuals who are partially responsive or nonresponsive to conventional therapy [1,7]. It was previously shown that certain 1,3-thiazolidin-4-one derivatives act as anti- convulsants [8e11]; however, their possible use as anxiolytic agents has not been pursued thus far. (ii) A number of studies have shown that the introduction of the ferrocene core (Fc), or a formal exchange of an existing aromatic ring with Fc, may significantly enhance a molecule’s (desirable) bioactive properties [12e18]. For example, ferrocene analogues of the antimalarial drug chloroquine are active against chloroquine-resistant strains of Plasmodium fal- ciparum; one of these, ferroquine, made it to clinical trials [19,20]. The Fc unit might act as a hydrophobic spacer and/or lipophilicity/ bioavailability enhancer (enabling easier passage through cell membranes) [20]. It is also known that the ferrocene Fe2þ/Fe3þ redox chemistry might contribute to the bioactivity of ferrocene derivatives [21]. (iii) Despite possessing unique features, the library compounds isosterically resemble the known BZD-type anxiolytics (Fig. 1), i.e., we hypothesized that they could fulfill known BZD- binding site requirements, and thus could potentially have a high affinity towards the GABAA receptor [22]. Anxiolytic properties of all library compounds were evaluated in several different in vivo models (light/dark, open field, horizontal wire and diazepam-induced sleep tests). The involvement of the GABAA receptor complex was assessed using the known GABAA- targeting agents flumazenil (competitive antagonist), picrotoxin (GABAA channel blocker), pentylenetetrazol and isoniazid (con- vulsants). In order to rationalize the obtained experimental results and disclose structureeactivity relationships, i.e., to gain insight into the possible interactions of the title compounds with the GABAA receptor (possible involvement of BZD-binding site), ligand docking experiments were performed based on the recently published unified a1b2g2 GABAA receptor model (this is believed to be the most abundant receptor subtype) [23]. Alongside with these results, we present detailed data on the spectral and electro- chemical properties, as well as the crystal structure of the studied heterocycle-organometallic hybrids. 2. Results and discussion 2.1. Library design The starting point for the library design was the notion that 1,3- thiazolidin-4-ones, as is the case for GABAA agonists, are known to act as anticonvulsants [8e11]. However, their possible use as anxiolytic agents has not been explored previously. The idea was to prepare a series of 1,3-thiazolidin-4-one derivatives with key structural attributes of well-known GABAA agonists (BZD-type compounds). We started from Cook's et al. pharmacophore/receptor model for agonists and inverse agonists at the GABAA (BZD-binding site) [22]. For example, the central structural features of the GABAA agonist diazepam (Fig. 1a), fitted into the mentioned model, is the 1H-1,4-diazepin-2(3H)-one core, which is fused to a chlorobenzene ring and bears a phenyl substituent. The hypothetical pharmaco- phore triangle is depicted in red (edges, angles and vertices of the triangle are defined in Fig. 1b). According to Cook's et al. model, potential GABAA agonists should be able to interact with the following (sub)sites of the receptor: (i) an H-bond acceptor (A2), (ii) an H-bond donor (H1), (iii) a ‘bifunctional’ hydrogen-bond donor/ acceptor site (H2/A3), (iv) four lipophilic pockets (L1, L2, L3, and LDi), and (v) three sterically forbidden sites (S1, S2, and S3) (Fig. 1a). Hydrogen-bond donor sites H1 and H2, hydrogen bond acceptor A2 (A1- e is A. Pejovic et al. / European Journal of Medicinal Chemistry 83 (2014) 57e7358Fig. 1. a) Pharmacophore model [7] for the BZD-binding site of the GABAA receptor lipophilic pockets), with diazepam as template; the hypothetical pharmacophore triangl pharmacophore triangle. c) and d) Fitting of N-substituted 2-ferrocenyl-1,3-thiazolidin-4-one of the references to colour in this figure legend, the reader is referred to the web version oA3-H-bond acceptor, H1, H2eH-bond acceptor, S1eS3-sterically forbidden sites, L1-L3- given in red. b) Edges (lA, lB, lC), angles (a, b, g) and vertices (A, B, C) of the hypothetical s into the proposed model for ligands targeting the GABAA complex. (For interpretation f this article.) and lipophilic region L1 were assigned as four basic anchor points on the receptor protein-complex [22]. We believe that certain 1,3- thiazolidin-4-one derivatives should also be able to fit this model. We initially placed the thiazolidinone core at the position (vertex A) of the analogous heterocyclic moiety from the diazepam molecule (1H-1,4-diazepin-2(3H)-one ring; Fig. 1c and d): the 1,3- thiazolidin-4-one carbonyl unit is a strong H-bond acceptor (possible interactions with H1 receptor (sub)site), while the diva- lent sulfur atom could either act as a weak H-bond acceptor or eventually may form a favorable Sep interaction with the appro- priate arene system at the receptor-binding site [24]. Now, we had to “expand” the molecule as to fit the pharmacophoric triangle. Thus, the 1,3-thiazolidin-4-one substitution pattern was chosen in away tomatch, as closely as possible, the value of angle a, while the identity of the substituents had to comply with lA, lB, lC (triangle edges), b and g (triangle angles) values (Fig. 1b). We decided one of the substituents to be the ferrocene core, as we expected that it would nicely fit L1/L2 (Fig. 1c) or L3 (Fig. 1d) lipophilic pockets and could possibly act as an “activity enhancer” [12e21]. Finally, we have chosen to vary the identity of the substituent attached to the nitrogen atom (R, Scheme 1), in order to gain an insight into possible SAR relationships. Two main types of R substituents were included in the study: aliphatic (n-alkyl chains of differing lengths, A. Pejovic et al. / European Journal of Me3aef; “aliphatic analogues”) and aromatic (with benzene/furan/ thiophene cores, 3gem; “aromatic analogues”). Within the “aro- matic” series (which might be more active, e.g. due to possible favorable pep interaction), we have varied the length of the e(CH2)ne (n ¼ 0e2) spacer between the N-atom and the aromatic core. This was done to finely tune lA, lB and lC values, as well as to probe if higher conformational freedom of the molecule would influence the net activity. Another reason for the synthesis of 3i, 3j (heteroaromatics) and 3g (methoxyphenyl group) was the fact that these compounds contain additional H-acceptors (S/O-atoms) that could increase the ligand's affinity towards the receptor. 2.2. Chemistry Among many reported protocols towards the synthesis of 1,3- thiazolidin-4-ones [11,25], the reaction of a-mercapto carboxylic acids with imines, known for more than sixty years [26,27], seemsScheme 1. Synthesis of N-substituted 2-ferrocenyl-1,3-thiazolidin-4-ones (3aem).to be the most convenient one. The reaction employs readily available substrates and is easy to perform. There are three experimental variants of the synthesis: (i) Reaction of a-mercapto carboxylic acids with imines obtained in a separate experiment (as it had originally been conducted) [26]; this approach was previously employed in the synthesis of several 2-ferrocenyl-1,3- thiazolidin-4-ones, but the achieved yields were very poor (1.6e10.8%) [28]; (ii) A continuous process using a water separator and the same solvent for both steps (the synthesis of imines and their condensation with a-mercapto carboxylic acids) [27]; (iii) a one-pot three-component technique with the use of a suitable dehydrating agent [29e31]. We have chosen the latter, one-pot approach for the synthesis of the target N-substituted 2- ferrocenyl-1,3-thiazolidin-4-ones (3aem). The method utilizes ferrocenecarboxaldehyde (1, FcCHO), an appropriate primary amine (2aem), thioglycolic acid and DCC as a dehydrating agent in THF (Scheme 1). This approach was previously employed for the synthesis of analogous compounds [29,31], with the ratio of re- actants being amine/aldehyde/mercapto acid¼ 1/2/3. However, in this case the yields based on the used aldehydes are necessarily less than 50%. This was not a reasonable approach in our case, since FcCHO (1) was the most valuable (expensive) reactant. Hence, we tried to improve the original protocol in order to ach- ieve higher reaction yields with regard to FcCHO. We found that optimal results were obtained by a 25min ultrasonic irradiation of the reaction mixture consisting of an amine, FcCHO and thio- glycolic acid in the ratio 1/1/2. The corresponding N-substituted 2-ferrocenyl-1,3-thiazolidin-4-ones (3aem, Scheme 1) were ob- tained in moderate-to-high yields, calculated by taking 1 as the limiting reagent (See Experimental section). Compounds 3aem were spectroscopically characterized by IR, UVeVis, MS, 1H and 13C NMR spectroscopy (see Experimental section and Supporting Information). The obtained spectral data agreed favorably with the expected structures for all compounds [15,17,32e37]. Several well-resolved IR bands associated with characteristic vibrations of the 2-ferrocenyl substituted 1,3- thiazolidin-4-one coreeC]C stretching, Csp2-H stretching, C]O stretching and the symmetrical deformation of the thiazolidinone CH2 group (scissoring)ewere observed for nearly all compounds [32]. An assortment of other bands, characteristic for the specific functional groups of individual compounds, were also observable in the corresponding spectra. For example, in the spectra of 3g, 3h and 3kem, the arrangements of the CeH out-of-plane bending bands in the 680e900 cm1 region reflected the substitution patterns of the benzene ring, whereas the asymmetrical stretching and symmet- rical deformation of the CH3 group in N-alkyl and methoxy substituted compounds were observed as medium intensity bands around 2960 cm1 and 1380 cm1, respectively. In general, UVeVis spectra of 3aem were marked by the pres- ence of the ferrocene chromophore [18]. The band around 200 nm was the most intense one, assignable to p / p* transitions, and was characteristic for the ferrocenyl moiety. The bands at c.a. 320 nm (although not noted in for all compounds) and 430 nm, which were about 100 times weaker than that at 200 nm, most probably corresponded to d / p* and ded transitions of the ferrocene core, respectively. The 1H NMR spectra contained typical signals for a mono- substituted ferrocene (dt (or m) at ~4.4 ppm, a multiplet at ~4.3 ppm and a singlet at ~4.2 ppm; last two signals were found to overlap occasionally) [18] and were also characterized by the presence of an ABX spin system formed by the methine (at ~5.34e5.90 ppm) and methylene protons (at ~3.60e3.81 ppm) of the thiazolidinone scaffold [33]. Generally speaking, when compared to the corresponding protons in 2,3-diaryl-1,3- dicinal Chemistry 83 (2014) 57e73 59thiazolidin-4-ones and 3-alkyl-2-aryl-1,3-thiazolidin-4-ones, the ring methine and methylene protons were slightly shifted upfield by the presence of the ferrocene unit [33,34]. Similarly, signals at c.a. 85.0, 70.3, 69.7, 69.0, 68.5 and 67.7 ppm, observable in the 13C NMR spectra of the library compounds, could be attributed to the ferrocene moiety [15] while the other characteristic signals, at about 169, 61 and 33 ppm were those corresponding to the carbonyl-, methine and methylene carbons of the thiazolidinone ring, respectively [35]. Depending on the nature of the substituent attached to the N-atom, other expected signals in both 1H and 13C NMR spectra were noted. Thus, in the spectra of 3g, 3h and 3kem, there were typical signals in the aromatic region, while the spectra of 3i and 3j contained characteristic signals of the thiophen-2-yl and furan-2-yl AMX systems. The fragmentation pattern in the mass spectra of 3aem was a similar one to the previously reported for 2,3-diaryl-1,3- thiazolidin-4-ones, with the most striking differences relating to the base peak [36]. In the cases of 3aem, the base peak was the molecular ion as well; this suggests that the introduction of a ferrocene unit onto the thiazolidinone core increased the stability of corresponding [M]þ. Other characteristic ions observable in the MS spectra of 3aem,m/z 186 ([(C5H5)2Fe]þ), 121 ([C5H5Fe]þ) and 56 ([Fe]þ), were those characteristic for a monosubstituted ferrocene derivative [37]. Moreover, in spectra of almost all compounds, the second most intense peak corresponded to a [FcCHNHR]þ ion. Additional abundant ions in the mass spectra of N-aryl or N-ary- lalkyl derivatives were formed by scission of the CeN bond (eg. [C6H5]þ at m/z 77 for 3k, or [C7H7]þ at m/z 91 for 3h). C1Cg1Cg2C6 torsion angle of only 0.2 (Cg1 and Cg2 are the centroids of the corresponding Cp rings; designations of the atoms are given on Fig. 2). However, the Cp rings slightly deviated from the parallel orientation (the dihedral angle between two the Cp rings was 4.0(2)). The conformation of the thiazolidinone ring could be described as being close to an envelope, and the present orientation of the C14eC19 phenyl ring was influenced by an intramolecular CeH…p interaction between the C6eH6 group and the phenyl ring as a p-acceptor (Fig. 1). There were no classical H- bonds and p…p intermolecular interactions in the crystal packing of 3k. The S1eC13 heterocyclic five-membered ring (thiazolidone A. Pejovic et al. / European Journal of Medicinal Chemistry 83 (2014) 57e7360Fig. 2. Perspective view of 3k with the atom-numbering scheme. Displacement el- lipsoids are drawn at 40% probability level. The C6eH6…p intramolecular interaction2.3. Crystallographic analysis The structural features of thiazolidin-4-one 3k as a represen- tative example were also studied by a single-crystal X-ray structure analysis (Fig. 2 and Supporting Information). Two ferrocenyl Cp rings adopted an almost ideally eclipsed geometry with theis represented by a dotted red line. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)core) is directly bound to the C1eC5 cyclopentadiene ring via a single bond (C1eC11) with a bond distance of 1.504 (3) Å. However, the longest CeC bond in the crystal structure of 3k was the C12eC13 bond, situated within the heterocyclic ring, while the remaining CeC bonds had p-character (Table 1). The S1 atom forms two SeC bonds which are significantly different in bond length, 1.849 (2) and 1.796 (3) Å for the S1eC11 and S1eC13, respectively. Around the sulfur atom, the C11eS1eC13 angle was considerably smaller than the rest of bond angles within the S1eC13 five- membered ring (Table 1). The sum of bond angles around N1 (359.8) indicates trigonal geometry, i.e. sp2 hybridization of N1. The conformation of the thiazolidinone ring could be described as being close to an envelope since the C11, N1, C12 and C13 atoms were nearly coplanar (root-mean-square deviation from a mean plane of the fitted atoms was only 0.032 Å). The S1 atom was dis- placed from the C11eN1eC12eC13 mean plane by 0.622 (4) Å. The present ring conformation was also in agreement with the bond character of N1eC12 since this bond is the only one (within the ring) which had p-character and consequently forced a coplanar position of the C11, N1, C12 and C13 atoms. The dihedral angle between the C11eN1eC12eC13 plane and the C14eC19 phenyl ring was 58.57 (8). However, it seems that the present orientation of the C14eC19 phenyl ring was influenced by an intramolecular CeH … p interaction between the C6eH6 group and the phenyl ring as a p-acceptor (Fig. 1). A perpendicular distance of the H6 on the phenyl ring was only 2.74 Å (H6 … Cg ¼ 2.80 Å, C6eH6 … Cg¼ 131). The dihedral angle between the phenyl and the C6eC10 cyclopentadiene rings of 69.4 (1) was also in agreement to the existence of this intramolecular interaction. Thus this CeH… pwas the only apparent intramolecular interaction in the crystal struc- ture of 3k and it probably additionally stabilized the present mo- lecular conformation. Therewere no classical H-bonds in the crystal packing of 3k. The reason for this could be found in the fact that molecules of 3k do not possess any significant H-bond donors, such as OeH or NeH (Fig. 3 and S1). The C12eO1 carbonyl group may be recognized as the best H-bond acceptor in 3k but it formed only a single weak hydrogen bond (C15eH15…O1, Figure S1, Supporting Information) with H… O distance shorter than 2.60 Å. Although 3k is comprised of three aromatic rings, it is interesting to note that this molecule did not form any p … p intermolecular interactions. The C6eC10 Table 1 Selected bond lengths (Å) and bond angles () in the crystal structure of 3k. Bonds (Å) Angles () S1eC13 1.796 (3) C13eS1eC11 90.69 (11) S1eC11 1.840 (2) C12eN1eC14 122.4 (2) O1eC12 1.215 (3) C12eN1eC11 117.0 (2) N1eC12 1.360 (3) C14eN1eC11 120.42 (18) N1eC14 1.437 (3) N1eC11eS1 103.52 (14) N1eC11 1.464 (3) N1eC12eC13 111.4 (2) C1eC11 1.504 (3) C12eC13eS1 107.04 (18) C12eC13 1.513 (4) green lines) and two C13eH13a … p (dotted red lines) intermolecular interactions. (For the web version of this article.) A. Pejovic et al. / European Journal of Medicinal Chemistry 83 (2014) 57e73 61unsubstituted Cp ring participated in an intermolecular CeH … p interaction as a p-acceptor (Figure S2, Supporting Information) while the C14eC19 phenyl ring contributed to the same interaction as a CeH donor. Probably the most interesting association of the molecules of 3k in solid state was the formation of centrosymmetric dimers. Namely, two molecules within the dimer (Fig. 3) were inter- connected by four interactions, two CeH … S and two CeH … p. Although these interactions are considered weak, their cumulative effect and the fact that two molecules are in a centrosymmetric arrangement most likely resulted in such stable dimers. 2.4. Conformational analysis In line with the results of the crystallographic analysis of 3k, previous NMR and X-ray studies of 2,3-diaryl-1,3-thiazolidin-4- ones have showed that the favorable geometry of the heterocyclic ring corresponds to an envelope conformation, with the out-of- plane sulfur atom (conformations A and B, Fig. 4). Such geometry minimizes strain within the ring and ensures co-planarity of the carbonyl group and the N-aryl system (the latter enabling effective Fig. 3. The centrosymmetric dimer of 3k formed via two C13eH13b … S1 (dashed interpretation of the references to colour in this figure legend, the reader is referred tooverlap of the corresponding orbitals). It was previously established that conformer A (Fig. 4), with a pseudo-axial C2 aryl substituent (AR’), represented the preferred solid-state geometry, while conformer B (pseudo-equatorial AR’, Fig. 4) was the dominant one in solution [34,38]. This is in agreementwith the crystal structure of 3k. In order to explore the solution conformation (most probably that connected to the activity of the compounds) of our library compounds and to compare it to previous conformational features of 1,3-thiazolidin-4-one derivatives [34,38], we have performed a detailed 1D/2D NMR spectral study (DEPT, HSQC, HMBC (Fig. 5), Fig. 4. 2,3-Diaryl-1,3-thiazolidin-4-ones conformers.1He1H COSY and NOESY) of 3a-m, suggesting that the geometry with the pseudo-axial HX (conformer B, Figs. 4 and 6) was the preferred one in solution as opposed to the solid-state one (see also Supporting Information). The results obtained for compound 3g are summarized in Table 2, and Figs. 5 and 6. The use of higher mag- netic field (400MHz) and DMSO-d6 as deuterated solvent enabled a clear resolution of the ABX splitting pattern of the thiazolidinone methine (C2HX) and methylene protons (C5HAHB) (Table 2). The larger in value (in comparison to HB) coupling of the methine proton HX with the methylene proton HA, appearing at lower field, indicated that these protons should be mutually anti-oriented. At the same time, the methine proton showed a nOe crosspeak with the upperfield methylene proton (and vice versa), suggesting that HX and HB are spatially near one to another. Based on the calculated A and B geometries of 3g (MM þ force field), the distances of HX‒ C5HB in A (more than 4 Å) and B (around 3 Å) differed significantly in value (Fig. 6). This suggested that the geometry with the pseudo- axial HX (conformer B, Figs. 4 and 6) was the preferred one in so- lution as opposed to the solid-state one; otherwise, one would expect the HXeHB nOe crosspeak not to appear. Furthermore, the ferrocene proton H50 should be considerably closer to the NeCH2 (ca. 2 Å) than to the AreCH (ca. 4 Å) protons in conformer B, while2 the opposite should be true for conformer A. Thus, the fact that H5’ Fig. 5. Important HMBC interactions of 3g. proton showed nOe crosspeaks with NeCH2, but did not interact with AreCH2 protons, corroborated the assumption that B was the out that all thiazolidinones exhibit a reversible one-electron redox Fig. 6. Preferred solid-state (A) and solution (B) conformers of 3g, minimized using MM þ some atoms, double and CeFe bonds (conformer A) are omitted for clarity. A. Pejovic et al. / European Journal of Me62preferred 3g geometry in solution (Fig. 6). There are two more pairs of diastereotopic protons in 3g left unassigned. The protons of the CH2 directly attached to nitrogen were shifted slightly downfield when compared to those next to the aromatic ring. A previous NMR study of 2-aryl-3-benzyl-1,3- thiazolidin-4-ones pointed to a large chemical shift difference (of approximately 1.5 ppm) between diastereotopic benzylic protons and the downfield shift of one of the protons was explained by stronger hydrogen bonding, as well as to hindered rotation around the N- and benzyl C-bond [34]. A similar trend was visible in the spectra of the herein studied benzyl (3h), 2-furfuryl (3i) and 2- thenyl (3j) derivatives, with the mentioned shift differences of about 1.1 ppm for the geminal NeCH2 protons. The shift difference for the corresponding protons in 3g was considerable lower (0.37 ppm), suggesting a higher degree of conformational freedom with respect to rotation about the NeC bond in NeCH2CH2. 2.5. Electrochemistry As mentioned above, the Fe2þ/Fe3þ redox chemistry is known to contribute to the bioactivity of ferrocene derivatives [18]. Because of this, we decided to evaluate the electrochemical properties of the new compounds 3aem. This was done by means of cyclic Table 2 1 13H NMR (DMSO-d6, 400 MHz) and C NMR (DMSO-d6, 100 MHz) data for 3g (atom labels can be found in Fig. 5). Position 1H NMR 13C NMR 10 / 85.5 20 4.42 (m, 1H) 67.2 30 4.34e4.31 (m, 2H) e overlapped 68.3 40 69.4 50 4.49 (dt, J ¼ 2.4, 1.4, 1.4 Hz, 1H) 70.2 100 , 200 , 300 , 400 and 500 4.24 (m, 5H) 68.7 1000 / 130.4 2000 and 6000 6.99 (AA'BB', J ¼ 8.6 Hz, 2H) 129.4 3000 and 5000 6.82 (AA'BB', J ¼ 8.6 Hz, 2H) 113.8 4000 / 157.7 N-CHAHB 3.34 (ddd, J ¼ 13.6, 10.1, 5.8 Hz, 1H) 43.7 N-CHAHB 2.97 (ddd, J ¼ 13.6, 9.8, 5.8 Hz, 1H) 43.7 CHAHB-Ar 2.60 (ddd, J ¼ 13.2, 10.1, 5.8 Hz, 1H) 31.9 CHAHB-Ar 2.26 (ddd, J ¼ 13.2, 9.8, 5.8 Hz, 1H) 31.9 S-CHAHB-C]O 3.61 (dd, J ¼ 15.4, 1.6 Hz, 1H) 32.4 S-CHAHB-C]O 3.56 (dd, J ¼ 15.4, 1.0 Hz, 1H) 32.4 NeCHeS 5.57 (br. s, 1H) 60.3 OeCH3 3.71 (s, 3H) 54.9 C¼O / 169.5couple at a very similar potential (E1/2 ¼ þ487 to þ512, Table S1). Since the ferrocene unit of compounds 3aem is connected to an electron withdrawing group, these potentials are considerably more positive than that of the unsubstituted ferrocene. As repre- sentative examples, the voltammograms of 3a and 3k are depicted in Figure S3. Differences between anodic and cathodic peak po- tentials (Table S1) were close to the theoretical value; both anodic and cathodic peak currents were proportional to the square root of the scan rate (as illustrative examples graphs for 3a and 3k are given in Figure S4), and their ratio is independent of the scan rate, indicating a diffusion-controlled process. 2.6. Pharmacological studies The synthesized thiazolidinone derivatives 3aem were evalu- ated for their CNS-modulating properties using the light/dark (LD), open field (OF), horizontal wire (HW) and diazepam-induced sleep tests. The results of the experiments are presented in Table 3 and Figure S5 (Supporting Information).voltammetry in acetonitrile containing 0.1 mol/L lithium perchlo- rate as the supporting electrolyte. Since preliminary measurements conducted with 3a showed that this compound exhibits only a single redox couple (E1/2 ¼ þ499 mV) in the potential range between500 andþ1000mV (belonging to the ferrocene unit), we performed cyclic voltammetry experiments with all other com- pounds in the potential range between 0 and þ1000 mV. It turned force field. Important NOESY interactions are also shown on conformer B. Notation of dicinal Chemistry 83 (2014) 57e73During the LD test, all library compounds increased the time mice spent in the brightly illuminated area, and decreased time spent in the dark one, in a dose-dependent manner (Table 3). However, 3g was the only compound that significantly increased the number of crossings between the mentioned compartments at all applied doses, and in almost the same fashion as diazepam did. The effects of other library compounds drastically varied in the number of crossings and were dependent on the dose administered. All of the tested compounds had increased (statistical signifi- cance) the latency of the first crossing from the illuminated compartment to the dark one (this referred to those groups that had transitions at all). This could be the result of an anxiolytic-like action of the thiazolidinone derivatives that is also a characteristic of benzodiazepines [39]. The increased latency of the first transition between compartments could be a reflection of the reduction of exploratory activity, which was observed for most of the herein studied compounds (the open field test). Nevertheless, this is a controversial parameter, commonly not discussed in studies on ) an ns f MeTable 3 Effect of thiazolidinone derivatives 3aem, diazepam and vehicle on anxiety (LD test Compound Dose (mg/kg) Light/dark (LD) test Time spent in light box No. of transitio 3a 25 204 ± 7a 2.5 ± 0.5 50 218 ± 4a 2.5 ± 0.2 100 285 ± 10a 1.0 ± 0.5b 3b 25 199 ± 12a 3.0 ± 0.2a 50 224 ± 10a 1.5 ± 0.2 100 289 ± 10a 1.0 ± 0.2a 3c 25 203 ± 8a 3.0 ± 0.8c 50 219 ± 16a 2.0 ± 0.5 100 292 ± 12a 1.5 ± 0.2 3d 25 213 ± 10a 2.0 ± 0.5 50 223 ± 11a 1.5 ± 0.2 100 300 ± 0a 0 ± 0a 3e 25 220 ± 13a 3.0 ± 0.2a 50 231 ± 12a 2.5 ± 0.2 100 294 ± 12a 1.5 ± 0.5 3f 25 193 ± 8a 3.5 ± 0.5a 50 213 ± 8a 2.0 ± 0.5 100 276 ± 9a 1.5 ± 0.2 3g 25 144 ± 10a 3.5 ± 0.8b a a A. Pejovic et al. / European Journal oexperimental anxiety; compounds cause a decrease in locomotion and thus give false positive results [40]. To circumvent this situation, all new drugs are screened for nonspecific increases or decreases (aspects of sedation) in general locomotion in a novel arena (OF test). Anxiety behavior in rodents, observed during the OF test, is a consequence of individual (out of the group) testing of animals and agoraphobia. In these situations, rodents show a thigmotaxic behavior, identified by spontaneous preference for the periphery of the apparatus and reduced ambu- lation [41]. At lower doses, almost all tested substances increased the number of squares crossed in the OF apparatus (Table 3), whereas at higher doses a reversed effect was observed. This indicated the possible sedative/hypnotic or muscle relaxant effect of the library compounds. The impact on animal movement in the OF test depended on the structure of the group attached to the nitrogen atom. For example 3h, with a benzyl group in the side chain, caused a suppression of themotor activity in the OF test even at low doses. The introduction of a heteroatom into the aromatic ring, as in 3i and 3j, resulted in an increase of locomotion in the lowest dose (25 mg/kg), although at higher doses the mentioned reversal of effect was noted. Elongation of the side chain with a methylene unit and the introduction of a methoxy group onto the 50 224 ± 9 5.0 ± 0.5 100 257 ± 10a 8.5 ± 0.8a 3h 25 271 ± 11a 1.5 ± 0.2c 50 300 ± 0a 0 ± 0a 100 300 ± 0a 0 ± 0a 3i 25 221 ± 10a 2.0 ± 0.2 50 277 ± 9a 1.0 ± 0.5b 100 300 ± 0a 0 ± 0a 3j 25 207 ± 12a 1 ± 1c 50 300 ± 0a 0 ± 0a 100 300 ± 0a 0 ± 0a 3k 25 132 ± 11a 3.0 ± 0.2a 50 194 ± 10a 2.5 ± 0.2 100 279 ± 12a 1.5 ± 0.5 3l 25 121 ± 11c 2.0 ± 0.2 50 175 ± 11a 2.5 ± 0.2 100 267 ± 15a 1.5 ± 0.5 3m 25 117 ± 16 2.5 ± 0.2 50 181 ± 13a 1.5 ± 0.8 100 300 ± 0a 0 ± 0a DZP 2 184 ± 12a 10.5 ± 0.5a VEH 10 99 ± 9 2.0 ± 0.25 All substances (in the doses of 25, 50, 100 mg/kg for the experimental substances; DZP (2 Data are presented as mean ± SD, n ¼ 6. a p < 0.001; b p < 0.01; c p < 0.05 vs. vehicle.d locomotor activity (OF test) in mice. Open field (OF) test Time of the first transition No. of squares crossed No. of rearings 39 ± 15b 99 ± 11 6.4 ± 0.9c 42 ± 15b 101 ± 9 4.4 ± 0.7 195 ± 9a 100 ± 9 3.9 ± 0.9 47 ± 9a 123 ± 9a 6.9 ± 0.6b 106 ± 12a 106 ± 9c 5.8 ± 0.9 164 ± 11a 98 ± 9 5.5 ± 0.9 37 ± 7b 98 ± 10 5.2 ± 0.4 68 ± 12a 87 ± 11 5.0 ± 0.7 94 ± 11a 64 ± 10 4.2 ± 0.6 46 ± 9a 113 ± 12b 8.0 ± 0.6a 42 ± 11a 98 ± 9 6.8 ± 0.4b 0 ± 0a 92 ± 2 4.5 ± 0.3 51 ± 10a 99 ± 15 5.7 ± 0.9 63 ± 12a 97 ± 10 5.2 ± 0.8 89 ± 6a 90 ± 11 4.8 ± 0.9 72 ± 9a 100 ± 9 5.5 ± 0.2 93 ± 9.a 104 ± 10 5.1 ± 0.3 101 ± 8a 97 ± 13 4.9 ± 0.2 56 ± 8a 75 ± 16 12.4 ± 0.5a a c a dicinal Chemistry 83 (2014) 57e73 63aromatic ring (3g) caused a dose-dependent increase in the num- ber of squares crossed. To rule out the possible muscle relaxant effect, mice were sub- mitted to an HW test. All animals treated with thiazolidinone de- rivatives (at all doses) were capable of grasping a wire within the 10 s period (displaying 100% of activity), whereas diazepam (2 mg/ kg; causing a failure to grasp in 50% of cases) decreased the ability of animals to grasp the wire (data not shown). The observed depressant activity of 3aem during the OF sug- gested central mechanisms and not a peripheral neuromuscular blockade, as opposed to diazepam (at higher doses 10mg/kg) that affects both mechanisms [42,43], as the library compounds did not exhibit amuscle relaxant activityevenat doses as high as 100mg/kg. Strictly speaking, having all of this in mind and taking into ac- count that the most reliable parameters for the assessment of anxiolytic drugs are the increase in time spent in the illuminated area, the number of crossings between light and dark compart- ments and increase of locomotion [44], under our experimental conditions, only substance 3g could be regarded as possessing purely anxiolytic properties. Because of the fact that the title compounds were designed to target the GABAA receptor, we decided to experimentally assess its 61 ± 7 51 ± 13 14.0 ± 0.7 74 ± 8a 35 ± 10a 15.5 ± 0.3a 84 ± 5a 75 ± 16 2.3 ± 0.8 0 ± 0a 51 ± 13c 3.6 ± 0.5 0 ± 0a 35 ± 10a 5.1 ± 0.8 89 ± 12a 144 ± 3a 7.2 ± 0.3a 106 ± 11a 123 ± 10a 8.1 ± 0.6a 0 ± 0a 114 ± 9b 8.6 ± 0.9a 57 ± 5a 157 ± 11a 8.3 ± 0.7a 0 ± 0a 145 ± 7a 9.5 ± 0.6a 0 ± 0a 107 ± 8c 10.1 ± 0.9a 54 ± 10a 143 ± 12a 7.4 ± 0.8a 64 ± 10a 124 ± 14a 6.7 ± 0.4b 71 ± 9a 100 ± 10 5.4 ± 0.9 44 ± 6a 135 ± 15a 8.7 ± 0.6a 50 ± 10a 162 ± 12a 9.5 ± 0.7a 99 ± 8a 108 ± 13c 5.3 ± 0.6 32 ± 6a 144 ± 11a 8.5 ± 0.6a 63 ± 7a 98 ± 10 6.6 ± 0.8b 0 ± 0a 86 ± 15 2.4 ± 0.9 69 ± 3a 145 ± 10a 7.6 ± 3.1a 16 ± 6 80 ± 21 4.1 ± 2.1 mg/kg); Vehicle (VEH, 10 mL/kg)), were administrated 1 h prior to the experiment. g/kg etwe zepa g/k etwe p < A. Pejovic et al. / European Journal of Medicinal Chemistry 83 (2014) 57e7364Fig. 7. Effect of vehicle (white column), diazepam (1 mg/kg; black column) and 3g (50 m the animals spent in the light compartment (first graph), on the number of crossings b Values are expressed as mean ± SD, n ¼ 6, (a) p < 0.0001 vs. FLU þ vehicle, FLU þ dia Fig. 8. Effect of vehicle (white column), diazepam (1 mg/kg; black column) and 3g (50 m the animals spent in the light compartment (first graph), on the number of crossings b Values are expressed as mean ± SD, n ¼ 6, (a) p < 0.0001 vs. PIC þ vehicle and 3g; (b)possible involvement in the anxiolytic action of the library com- pounds. For this purpose, we have chosen 3g, the most potent derivative with no CNS depressant or myorelaxant activity. We were additionally encouraged by the fact that 3g and diazepam (GABAA agonist) displayed similar activity in the LD test. In order to evaluate the involvement of the GABA receptor, 3g was further tested in the LD paradigm in combination with flumazenil (FLU, a competitive antagonist of GABAA receptor that antagonize both agonists and inverse agonists [45]) and picrotoxin (PIC, a noncompetitive GABAA receptor chloride channel antagonist (one can rather say channel blocker) [46]) (Figs. 7 and 8) and in pentylenetetrazol (PTZ)/isoniazid (INH)-induced convulsion tests (Table 4). From Figs. 7 and 8, one can see that FLU and PIC, in both the vehicle and diazepam groups, produced an expected result: they decreased the time animals spent in the light compartment, decreased the number of crossings between compartments and decreased the time of the first transition. For the groups that received FLU/PIC and 3g, the observed parameters were modified compared to the results of the animals that received 3g alone, in the same dose (50 mg/kg). For example, the time that the animals from Table 4 Anticonvulsant effect of the vehicle (olive oil), 3g and diazepam in the pentylenetetrazo Substance Dose PTZ Seizure onset (sec) On Vehicle 10 mL/kg 39 ± 1 1 3g 50 mg/kg 62 ± 2a 3 Diazepam 1 mg/kg 601 ± 25a 13 Data are presented as mean ± SD, n ¼ 6. a p < 0.001 vs. vehicle., striped column) following flumazenil (FLU; 3 mg/kg by ip) treatment on the time that en compartments (second graph) and on the time of the first transition (third graph). m and 3g; (b) p < 0.0001 vs. FLU þ vehicle, FLU þ diazepam; (c) p < 0.001 vs. 3g. g; striped column) following picrotoxin (PIC; 1 mg/kg by ip) treatment on the time that en compartments (second graph) and on the time of the first transition (third graph). 0.0001 vs. PIC þ diazepam.group FLUþ3g spent in the light compartment was decreased for almost a third of the time of animals from group 3g (Fig. 7), whereas the time group PICþ3g animals spent in the light compartment was decreased for more than a half of the time of animals from group 3g (Fig. 8). Likewise, the number of crossings between compartments and the time of the first transition were only partially reduced by FLU and PIC (but to a greater extent by PIC) when compared with the values noted for the animals from group 3g. However, compound 3g still displayed some degree of anxiolytic activity even in FLU and PIC pretreated animals (statis- tically significant differences existed between 3g and vehicle pre- treated groups). Also, statistically significant differences between groups that received the combination of FLU/PIC and 3g and those that were administered with FLU/PIC and diazepam suggested the existence of additional effects that are probably due to other mechanisms involved in its anxiolytic action. The hypnotic/sedative activity of the library compounds was estimated using the diazepam (20 mg/kg)-induced sleep model. Almost all substances had no significant effect on the onset of sleep, except for three compounds that caused a prolongation of this period (3kem, having an aryl group directly attached to the le (PTZ) e and isoniazid (INH) e induced seizures in mice. INH set of HLTE (sec) Seizure onset (sec) % of living mice in 30 min 06 ± 10 1244 ± 26 0 38 ± 14a 2207 ± 43a 100 24 ± 38a 2197 ± 17a 100 activity (the results are presented in Table 4) compared to diaz- epam (1 mg/kg), but it significantly increased the convulsion threshold compared to vehicle pre-treated animals. These results further confirm the possible involvement of 3g in signal trans- duction through GABA systems. The used dose of 3g (50 mg/kg) applied after a specific GABAA antagonist could have been supramaximal and in this way could have masked its competitive effect for this receptor. Even after the application of a nonselective antagonist (PIC), 3g exerted some degree of anxiolytic activity in the experimental animals suggesting that there are also other mechanisms involved in the activity of 3g. The accumulated in vivo data regarding the possible interaction of the library compounds and the GABAA receptor complex motivated us to perform in silico experiments that could provide further (pro/ con) evidences for the proposed mechanism of action. 2.7. Molecular docking The ligand-based [22] design of 3aem relied on the structure of GABAA targeting BZD-type anxiolytics. In order to further explore whether the library compounds fit into the BZD-binding site and to possibly rationalize the results of in vivo experiments, we have decided to dock 3aem, as well as the appropriate standard drugs used in biological assays, into the extracellular domain of the GABAA receptor (anxiolytic agents (usually) bind to this domain). Although the crystal structure for the GABAA receptor is not yet f Medicinal Chemistry 83 (2014) 57e73 65nitrogen atom), but all of the tested library compounds significantly increased, in a dose-dependent manner, the duration of the sleep. These results suggested a central nervous system depressant ac- tivity and possible sedative properties of these thiazolidinone- ferrocene hybrids (Fig. S5). The tested hybrids had manifested a profound influence on the diazepam-induced sleep. Compounds 3aef, with an alkyl chain of variable length attached to the nitrogen atom, were the most active ones as they increased the sleeping period, in a dose-dependent manner, almost three-fold. The lowest effect was noted in the case of compound 3h (which possesses a CH2Ph group) treatment, where only its highest dose caused a statistically significant different prolongation of the diazepam- induced sleep. Once again the introduction of an oxygen or a sul- fur atom (3i and 3j) into the aromatic rings resulted in a significant alteration of activity. These sedative properties can be related to the activation of benzodiazepine and/or GABA sites of the GABA re- ceptor complex. This is in accordance with a previous report on several thiazolidinone derivatives, tested at a dose of 100 mg/kg, that were found to potentiate the effect of a more general sedative, sleep-inducing agent (pentobarbital) [11]. The effects of sleep la- tency shortening and increase of total sleep time, as well as the enhancement of electroencephalogram power in the delta fre- quency range are some of the hypnotic drug characteristics (at higher doses) and it is considered to involve more pronounced depression of the CNS than sedation [47]. A matter that should be kept in mind when discussing the ac- tivity of our thiazolidinone derivatives is the differentiation of ef- fects produced by benzodiazepine-type compounds binding to different GABAA receptor subtypes (a1, a2 and a3) [43]. The a1 GABAA receptor is known to mediate sedative, amnesic, and part of the anticonvulsant effects, while the a2 GABAA (and not a3 GABAA) receptor mediates the anxiolytic effects of diazepam. It was observed that a2 GABAA receptor (expressed on motor neurons and in the superficial layer of the dorsal horns) were primarily involved in the myorelaxant activity of diazepam, whereas at higher doses it was observed that a3 GABAA receptors are also included [43]. These results allow at least a partial explanation for the observed activity of the tested thiazolidinone-ferrocene hybrids. One can speculate that most of them possess higher affinity for a1 GABAA receptors (due to their activity in the OF and diazepam-induced sleep tests) than for a2/a3 GABAA receptors that are involved in myorelaxant activity (negative results in HW test). For example, 3h decreased the number of crossings in the OF test more than two folds when compared to the results of the vehicle pretreated animals (Table 3), but it did notmodify the performance of mice in the HW test. It also prolonged, although not to a great extent, the diazepam-induced sleep (Figure S5, Supporting information). Furthermore, other compounds, such as 3i, 3k and 3m, decreased the number of crossings in the OF test only at doses of 100 mg/kg, did not modify animal performance in the HW test, but prolonged the diazepam- induced sleep (two folds when compared to diazepam), also sug- gesting their higher affinity for a1 GABAA rather than for a2 and a3 GABAA receptors. Anticonvulsant effects of the library compounds were also studied in order to determine the possible interaction of 3g with the GABAA receptor complex. For that reason we utilized pentyle- netetrazole (PTZ) and isoniazid (INH) that are known to interrelate with the GABA neurotransmitter itself and the GABA complex. PTZ not only produces epileptiform activity but also mimics the seizure induced behavioral changes that are very similar to temporal lobe epilepsy in humans and, thus, it has a predictive relevance regarding the clinical spectrum of activity of experimental com- pounds. It is also interesting to mention that neither PTZ nor INH- binding sites on GABA receptors belong to the GABA or PIC sites of A. Pejovic et al. / European Journal othe GABA receptor complex [48]. Compound 3g exerted modestavailable, there are several homology models that are in good agreement with experimental findings [23,49]. Among them, we have chosen a recently reported unified model of a1b2g2 GABAA receptor complex (the most abundant subunit combination), based on the glutamate-gated chloride ion channel (Fig. 9) [23]. The BZD- binding site is located on the extracellular surface of the receptor (Figs. 9 and 10) and it includes amino acid residues from 6 noncontiguous regions (these are usually designated as Loops AeF, Fig. 10A) of subunits a and g [23,49]. For several classical benzo- diazepines even specific amino acid residues that contribute to the binding are uncovered. For example, it is known that the molecule Fig. 9. Unified homology model of the GABAA receptor complex [24] (the show perspective from the side of the receptor's extracellular domain). a1, b2 and g2 subunits are given in blue, green and gray, respectively; BZD- and GABA-binding sites are marked with arrows; the most favorable docking poses of 3g are given in red (F1eF5 families of nodes). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.) A. Pejovic et al. / European Journal of Medicinal Chemistry 83 (2014) 57e7366of diazepam interacts with a1His101, a1Asn102 (Loop A), a1Gly157 (Loop B), a1Val202, a1Ser205, a1Thr206 and a1Val211 (Loop C) [23,49]. All in silico experiments were performed as blind dockings, covering the entire extracellular domain of the receptor. We assumed that by limiting the search space to the BZD-binding pocket only we could lose valuable information on other possible favorable interactions between 3aem and the GABAA receptor, or could even get false “positive results”; it is known that several compounds (e.g. GABA (g-aminobutyric acid), picrotoxin) do not Fig. 10. The most preferred docking mode of 3g at the BZD-binding site (F1): A emolecular s Loop D e pale cyan, Loop E e bright green, Loop F e olive green); B e overlay of 3g (solid re found in the 4 Å-radius sphere around 3g and diazepam, D e 3g and the nearby amino a spatially close entities). Color coding of the receptor subunits: a1 (secondary structure, amino and labels)-light gray, b2 (secondary structure)-green. (For interpretation of the references Fig. 11. The most preferred F4-docking mode of 3g: Ae3g (solid red line) and the nearby am lines group spatially close entities). Color coding of the receptor subunits: a1 (secondary stru acid residues and labels) e green, g2 (secondary structure) e light gray. (For interpretation o of this article.)have a unique GABAA receptor binding site (Fig. 9) [50]. Addition- ally, blind docking also allowed validation of the docking experi- ments. Although the entire extracellular domain of the receptor was explored, the most favorable calculated pose for diazepam (binding energy 8.6 kcal/mol) was in agreement with the previ- ous experimental findings (Fig. 10AeC). This mainly referred to the mutual spatial arrangement and the distance between diazepam and several a1/g2 subunit amino acid residues, experimentally confirmed to be important for the binding. For example, a1His101, a1Asn102, a1Val202, a1Ser205, a1Val211 “fell”within the 4 Å radius urface of BZD pocket Loops AeF (Loop A e gray, Loop B e pale blue, Loop C e dark blue, d line) and diazepam (solid black line) at the BZD-binding site; C e amino acid residues cid residues (4 Å-radius sphere), a simplified representations (red dashed lines group acid residues (C) or labels (D))-dark blue, g2 (secondary structure, amino acid residues to colour in this figure legend, the reader is referred to the web version of this article.) ino acid residues (4 Å-radius sphere), B e a simplified representations of A (red dashed cture, amino acid residues (A) or labels (B)) e dark blue, b2 (secondary structure, amino f the references to colour in this figure legend, the reader is referred to the web version f Mesphere around diazepam; the criteria that functional groups sepa- rated by less than 7 Å have the potential to interact, and that those within 4 Åmay form salt bridges or hydrogen bonds, are generally accepted [23,49]. The main results of more than 150 individual docking experi- ments are summarized in Figs. 9e11, S6. With a few exceptions (which were not, energetically speaking, among the most favorable ones), all found binding modes for 3aem clustered them into five different families of poses (F1eF5; these designations will also be used for the appropriate regions of the receptor further on, Fig. 9). Modes belonging to F1 family (at the interface of a1/g2 subunits) placed the molecules into the BZD-binding site (Fig. 9 and Fig. 10AeC). F2 modes were situated at the “top” of Loops B and E, while those from F3, and F4 and F5 families occupied pockets at the interface of a1/b2 and g2/b2 subunits, respectively (Fig. 9). All docked compoundswithin all families had binding energies (for the search criteria, see Experimental section) from 6.0 to 9.2 kcal/ mol. Nevertheless, in most cases, for a single compound, the best F1eF5 modes were mutually comparable and usually differed in less than 0.5 kcal/mol. As discussed in previous subsections, the 2,3-disubstituted 1,3- thiazolidin-4-one ring is known to predominantly exist in one of the two different geometries (Fig. 4). Although AutoDock Vina [51] includes the possibility of a flexible dock (single bonds could be regarded as rotatable), it does not allow ring geometry to be changed. For this reason, the docking experiments (flexible ligands) were performed with two different input geometries of 3aem (these corresponded to the preferred solution and solid-state conformers). Generally speaking, the input geometry had (some) influence on the net docking results, but not as pronounced as one might expect. The same families of binding sites (F1eF5) were found for both input geometries, but the binding energies of the conformer pairs differed to some level. For example, mutual overlay of the best F1eF5 modes for compound 3g, calculated starting from the two different input conformers (A and B, Fig. 4), are shown in Figure S6. It is interesting that, according to the calculated values of the corresponding binding energies, conformer B fitted better into F1eF3 regions of the receptor (Fig. 9), while geometry A showed more affinity towards F4/F5. Except for 3d, 3e (aliphatic N-substituents) and 3kem (without a “spacer” between the N-atom and the aromatic core), the library compounds were successfully docked into the BZD-binding site (Fig. 10). According to the obtained results, compounds with a (CH2)xAr substituent (x ¼ 1, 2; “aromatic” analogues) attached to the N-atom should better interact with the GABAA-BZD-binding pocket. The binding energy calculated for derivatives from the “aliphatic series” (3aec and 3f) ranged from 6.4 (3f) to 7.4 kcal/ mol (3a), whereas for “aromatic” analogues (3gej), it was found to be from 7.1 to 8.8 kcal/mol. In general, all of the docked com- pounds/geometries displayed a unique, energetically favorable F1- pose. Contrary to that, multiple different orientations of a single ligand were allowed within F2eF5 regions. This suggested that F2eF5 pockets were “too big” for the studied compounds, and that different types of other ligands might also fit (this was, for example, the case with GABAA-targeting drugs we used in vivo and in silico experiments; docking results are not shown). In other words, one could expect these regions to be much less specific (in respect to the geometry, volume and spatial distribution of structural char- acters) and even unimportant for the activity (otherwise a large number of different compounds could induce channel opening). Thus, one could assume that the anxiolytic activity of the title compounds might be (at least partially) due to their strong affinity towards the GABAA-BZD-binding site. Hence, it seems that the re- sults of the in silico simulations corroborate those of the in vivo A. Pejovic et al. / European Journal oexperiments. The two compounds with the highest calculatedaffinity (binding energies) for the BZD-binding site were 3g and 3h (Fig. S6), and in vivo results pointed to 3g as the most promising new anxiolytic (for this reason further discussion will be mainly focused on this compound). The opposite was true for 3d, 3e and 3kem. One should note that the length of the N-alkyl chain, or the presence/absence of a spacer between theN-atom and the aromatic core, seems to be critical for interaction with the BZD-binding pocket. One of the explanations (within the “aromatic” series) could be found in the fact that spacers confer a certain degree of conformational freedom to the molecule. Thus, critical structural features of the active molecules may adopt favorable, diazepam- like spatial arrangements. Without the spacer, the molecule is much more constrained and possibly certain structural attributes (aromatic core) cannot avoid unfavorable interactions with “forbidden” regions of the receptor (Fig. 1). A similar reasoning could be true for 3d and 3e (N-octyl and N-decyl derivatives). Hit compound 3g was docked within the BZD-binding site in a similar way as diazepam or flumazenil molecules were. The resi- dues of the following 15 amino acids were within the 4 Å sphere (strong interactions expected) [49] around 3g: a1HIS101, a1ASN102 (Loop A); a1LYS155, a1VAL202, a1SER204, a1GLY207, a1GLU208, a1TYR209, a1VAL211 (Loop C); g2PHE77 (Loop D); g2ARG144 (Loop E); g2THR193, g2ARG194, g2SER195 and g2ARG197 (Loop F), Fig.10C and D. Several residues, namely a1HIS101, a1VAL202, a1SER204, a1TYR209, a1VAL211, g2PHE77, are known to be important for BZD binding [23,49]. Additional 20 residues were within a 7 Å-sphere (possible interactions) around 3g: a1PHE99, a1GLY103, a1GLU137, a1PRO153, a1SER158, a1TYR159, a1GLY200, a1GLN203, a1SER205, a1THR206, a1VAL210, a1MET212, a1THR213, g2TYR58, g2ASN60, g2THR142, g2GLU189, g2ASP192, g2LEU198 and g2TRP196. Among this, a1TYR159 (Loop B), a1GLY200 (Loop C), a1SER205 (Loop C) and a1THR206 (Loop C) are important for the binding of diazepam-type anxiolytics to the GABAA receptor [23,49]. During the design of compounds 3a-m, we assumed two possible “overlay-modes” of diazepam and the title compounds (Fig. 1C and D). According to the docking results, the orientation shown in Fig. 1D was energetically (more) favorable: the ferrocene core pointed towards the same direction as did the diazepam phenyl group. This was true for both input conformers of 3g (A and B, Fig. 4 and S6). Interestingly, despite the different overall geom- etries of 3g-A and 3g-B, the ferrocene moieties of both of them perfectly “overlapped” within the BZD-binding site. This could indicate that the ferrocene core fitted perfectly within this part of the binding pocket. In fact, the ferrocene core introduced quite unique structural features (“length”, volume, hydrophobicity) to the molecule. For example, the distance between the two, (almost) parallel, aromatic Cp rings was around 3.5 Å. While one of the Cp rings was positioned in a similar manner as the diazepam phenyl group (Fig. 10 and S6), the second one enabled additional binding interactions, not possible in the case of diazepam (Fig. 10C and D). Interestingly, F4-docking poses (interface of a1 and b2 subunits, Figs. 9 and 11) were positioned in the pocket that was rather analogous to the BZD-binding site: it included almost the same a1 amino-acid residues (vicinity of a1 Loops A, B and C). The calculated binding energies of the most favorable F1 poses for 3g (8.8 kcal/mol), diazepam (8.6 kcal/mol) and flumazenil (8.5 kcal/mol) suggested that 3g should have a comparable or even stronger affinity towards the GABAA receptor when compared to the mentioned two. Nevertheless, the standard anxiolytics were (slightly) more active in in vivo assays. One of the possible expla- nations for such discrepancy could be sought in the fact that (the most) favorable 3g F1eF5 poses were all of comparable binding energy. This means that one could expect, under in vivo conditions, several different “F1eF5 type” ligand-receptor complexes to be dicinal Chemistry 83 (2014) 57e73 67formed. As it is reasonable to assume that only thosewith 3g bound spectrometer with the usual pulse sequences. The IR measure- f Meto the BZD site (F1-type ligandereceptor complex) would actually enable channel opening, the active concentration of 3gwould then necessarily be much lower when compared to the nominally applied one. We could even roughly estimate the hypothetical fractional distribution of the different docking poses (and different types of ligand-receptor complexes), based on the differences in the corresponding binding energies, under the approximation that they follow the Boltzmann distribution. Under these assumptions (we approximated body temperature to be 310 K; all generated F1eF5 poses were taken into account), less than 10% of 3g receptor associated molecules (c.a. 75% of which in the geometry that was preferred in solution) would be bound to the BZD pocket and induce channel opening. The remaining 3g-receptor complexes would have differently oriented 3gwithin F2eF5 regions andmight not result in a “positive outcome” (channel opening). In other words, the majority of 3gmolecules might be bound to the receptor stronger than diazepam, but in a way that does not induce the appropriate receptor response. 3. Conclusions Herein we reported the design, synthesis, spectral, crystallo- graphic and electrochemical characterization of a small library ofN- substituted 2-ferrocenyl-1,3-thiazolidin-4-ones (3aem, 13 com- pounds in total). These compoundswere designed starting from the structure of benzodiazepine-type anxiolytics, known to act via the GABAA-BZD-binding site. Substituents introduced onto the 1,3- thiazolidin-4-one core were chosen in a way as to enable favor- able interactions with the BZD-binding pocket. This turned out to be especially true for the ferrocenyl substituent, which allowed acquiring BZD-analogs with two aromatic (Cp) rings in close proximity (c.a. 3.5 Å), “positioned” in parallel. We assumed that such an arrangement would enable additional favorable in- teractions with the benzodiazepine-binding site. In vivo experi- ments (light/dark, open field, horizontal wire and diazepam- induced sleep tests; the involvement of the GABAA-receptor com- plex in the activity of the most potent compound (3g) was evalu- ated using known GABAA-targeting agents) confirmed that the designed compounds, especially 2-ferrocenyl-3-(4- methoxyphenylethyl)-1,3-thiazolidin-4-one (3g), possess (strong) anxiolytic properties. The docking experiments (favorable geome- tries of 3a-m were inferred from crystallographic and NMR ana- lyses) corroborated the assumptions made during the design of 3a- m and justified the introduction of the ferrocene core into the molecules; this metallocene seems to perfectly fit into the BZD- binding site. Alongside the ferrocene core, both in vivo and in sil- ico experiments confirmed that the introduction of CH2-spacers between the 1,3-thiazolidin-4-one N-atom and an additional (hetero)aromatic ringwas important for their activity. To the best of our knowledge, hybrids of ferrocene and 1,3-thiazolidin-4-one were not previously studied for anxiolytic properties. Thus, the herein presented data might be regarded as a start of a new chapter in the design of new thiazolidinone-ferrocene based anxiolytics. It is also reasonable to expect that further work on related ferrocene containing BZD-analogues might also result in even better GABAA- targeting compounds. 4. Experimental section 4.1. Chemistry 4.1.1. General All commercially available chemicals and solvents were used without further purification. TLC experiments were performed on A. Pejovic et al. / European Journal o68alumina-backed silica gel 40 F254 plates (Merck, Darmstadt,ments were carried out on a PerkineElmer Spectrum One FT-IR spectrometer using KBr disks. UV spectra (in CH3CN) were measured using a UV-1650 PC Shimadzu spectrophotometer. High- resolution mass spectrometry (HRMS) analysis was performed us- ing a JEOL Mstation JMS 700 instrument (JEOL, Germany). The GC/ MS analyses were performed on a HewlettePackard 6890N gas chromatograph equipped with fused silica capillary column DB- 5MS (5% phenylmethylsiloxane, 30 m  0.25 mm, film thickness 0.25 mm, Agilent Technologies, USA) and coupled with a 5975B mass selective detector from the same company. If necessary, alongside the GC analyses, the purity was determined by high performance liquid chromatography (HPLC). HPLC was performed using an Agilent Technologies HPLC system 1200 series (Wald- bronn, Germany) equipped with a quaternary pump, vacuum degasser, thermostated autosampler, thermostated column compartment and a diode array detector. Chromatographic sepa- ration was carried out using Eclipse Plus C18 column (50 mm  4.6 mm, particle size 1.8 mm; Agilent Technologies, Waldbronn, Germany). Purity of all final compounds was 95% or higher. The microanalyses were carried out by the microanalyses service of the Institute of Organic Chemistry, Bulgarian Academy of Sciences. Cyclic voltammetry experiments were performed at room temperature in a standard three-electrode cell using an Autolab potentiostat (PGSTAT 302 N). The working electrode was a plat- inum disk (2 mm diameter; Metrohm). The counter electrode was a platinum wire, whereas an Ag/AgCl electrode was used as the reference. Prior to experiments, the working electrode was pol- ished using Metrohm polishing kit 6.2802.000 (extremely fine aluminum oxide on a cloth), followed by washing with distilled water. Melting points were measured on a Mel-Temp cap. melting- points apparatus, model 1001, and the given values are uncorrec- ted. Ultrasonic cleaner Elmasonic S 10, 30 W was used for the ul- trasonically supported synthesis. 4.1.2. General procedure for the synthesis of 2- Ferrocenylthiazolidin-4-ones (3aem) An ice-cooled solution of the corresponding primary amine (1 mmol) and ferrocenecaboxaldehyde (214 mg, 1 mmol) in THF (2 mL) was irradiated in an ultrasonic bath for 5 min, followed by the addition of thioglycolic acid (184 mg, 2 mmol). After further irradiation for 5 min, DCC (206 mg, 1 mmol) was added to the resulting mixture and irradiation continued for another 15 min under the same conditions. DCU was removed by filtration, the solvent evaporated and the residue taken up in EtOAc (30 mL). The organic layer was washedwith 5% aq. solution of citric acid, H2O, 5% aq. solution of NaHCO3 and brine, successively, and dried overnight (anh. Na2SO4). After the evaporation of the solvent, the crude mixture was purified by column chromatography (SiO /hexane -Germany). The spots on TLC were visualized by UV light (254 nm) and by sprayingwith 50% (v/v) aqueous H2SO4 or phosphomolybdic acid (12 g) in EtOH (250 mL) followed by heating. Chromatographic separations were carried out using silica gel 60 (particle size dis- tribution 40e63 mm) purchased fromMerck (Darmstadt, Germany), whereas silica gel 60 on Al plates, layer thickness 0.2 mm (Merck) was used for TLC. Proton (1H) and Carbon (13C) NMR spectra were recorded on a Bruker Avance III 400 spectrometer (400 MHz for 1H, 100 MHz for 13C) and a Varian Gemini 200 spectrometer (200 MHz for 1H, 50 MHz for 13C). Solutions were prepared in either deuter- ochloroform (CDCl3) or deuterated dimethylsulfoxide (DMSO-d6) with chemical shifts (in ppm) referenced to TMS and/or deuterated solvent as an internal standard. 2D experiments (1He1H COSY, NOESY, HSQC and HMBC) were run on the Bruker Avance III 400 dicinal Chemistry 83 (2014) 57e732 EtOAc 9:1, v/v). 21 29 456.20235. Found: 456.20239; Anal. Calcd for C25H37FeNOS: C, f Me4.1.2.3. 2-Ferrocenyl-3-hexyl-1,3-thiazolidin-4-one (3c). Yield 72%, yellow solid, mp 72 C; IR (KBr): nmax 3095.2 (arC-H), 2954.3 ((CH3)as), 2926.8 ((CH2)as), 2856.8 ((CH2)s), 1671.0 (C]O), 1441.0 (d(CH2)scissoring), 1409.3, 1377.2 (d(CH3)s), 1298.2, 1225.7, 1105.9, 1000.7, 818.2; UVeVis (CH3CN): lmax (log ε) 430 (2.33), 203 (4.89) nm; 1H NMR (200 MHz, CDCl3): d 5.52 (br. s, 1H, NeCHeS), 4.43 (m, 1H, HeC (50)), 4.16e4.33 (overlapping peaks, 8H, HeC (100), HeC (200), HeC (300), HeC (400), HeC (50 '), HeC (20), HeC (30), HeC (40)), 3.62 (AA', 2H, SCH2C]O), 3.31 (ddd, J ¼ 13.9, 8.6, 5.3 Hz, 1H, CHAHBN), 2.80 (ddd, J¼ 13.9, 8.6, 5.3 Hz,1H, CHAHBN),1.08e1.46 (m, 8H, (CH2)4CH3), 0.85 (t, J ¼ 6.5 Hz, 3H, CH3); 13C NMR (50 MHz, CDCl3): d 170.1 (C]O), 85.1 (C (10)), 70.0, 69.8 (C (20), C (50)), 69.0 (C (100), C (200), C (300), C (400), C (500)), 68.4, 67.7 (C (30), C (40)), 61.4 (NeCHeS), 42.4 (CH2N), 33.4 (SCH2C]O), 31.3, 26.8, 26.4 (CH2CH2CH2CH2CH3), 22.4 (CH2CH3), 13.9 (CH3); MS (EI, 70 eV) m/z (%): 371 [M]þ. (100), 338 (2.4), 298 (58), 263 (2.1), 240 (2.2), 213 (10.6), 199 (5.5), 186 (18.5), 166 (7.8), 148 (6.4), 121 (28.2), 97 (2.6), 77 (2), 56 (8.7), 43 (5.5); HRMS (ESI): m/z calculated for C19H25FeNOS þ Hþ [M þ Hþ]: 372.10845. Found: 372.10840; Anal. Calcd for C H FeNOS: C, 61.46%; H, 6.79%; Fe, 15.04%; N, 3.77%; S,4.1.2.2. 2-Ferrocenyl-3-pentyl-1,3-thiazolidin-4-one (3b). Yield 78%, orange solid, mp 90 C; IR (KBr): nmax 3091.6 (arC-H), 2952.9 ((CH3)as), 2930.2 ((CH2)as), 2871.6 ((CH3)s), 2856.4 ((CH2)a), 1662.6 (C]O), 1458.7 (d(CH2)scissoring), 1401.9, 1380.6 (d(CH3)s), 1307.9, 1104.3, 1001.8, 820.2; UVeVis (CH3CN): lmax (log ε) 422 (2.40), 315 (2.68), 203 (4.71) nm; 1H NMR (200 MHz, CDCl3): d 5.52 (br. s, 1H, NeCHeS), 4.43 (m, 1H, HeC (50)), 4.21e4.32 (overlapping peaks, 8H, HeC (100), HeC (200), HeC (300), HeC (400), HeC (50 '), HeC (20), HeC (30), HeC (40)), 3.62 (AA', 2H, SCH2C]O), 3.35 (ddd, J ¼ 13.9, 8.7, 5.2 Hz, 1H, CHAHBN), 2.84 (ddd, J ¼ 13.9, 8.7, 5.2 Hz, 1H, CHAHBN), 1.1e1.48 (m, 6H, (CH2)3), 0.84 (t, J ¼ 6.8 Hz, 3H, CH3); 13C NMR (50MHz, CDCl3): d 170.1 (C]O), 85.1 (C (10)), 70.0, 69.8 (C (20), C (50)), 69.0 (C (100), C (200), C (300), C (400), C (500)), 68.4, 67.7 (C (30), C (40)), 61.4 (NeCHeS), 42.3 (CH2N), 33.4 (SCH2C]O), 28.8, 26.6, 22.2 (CH2CH2CH2CH3), 13.9 (CH3); MS (EI, 70 eV) m/z (%): 357 [M]þ. (100), 324 (2.8), 284 (67), 264 (1.6), 249 (2.6), 230 (6.9), 213 (10.4), 199 (6.5), 186 (18.8), 166 (8), 148 (6.6), 121 (26.4), 97 (2.5), 77 (2), 56 (7.3), 43 (3.3); HRMS (ESI): m/z calculated for C18H23FeNOS þ Hþ [M þ Hþ]: 358.09280. Found: 358.09283; Anal. Calcd for C18H23FeNOS: C, 60.51%; H, 6.49%; Fe, 15.63%; N, 3.92%; S, 8.95%. Found: C, 60.83%; H, 6.64%; N, 3.64%; S, 8.80%.4.1.2.1. 3-Butyl-2-ferrocenyl-1,3-thiazolidin-4-one (3a). Yield 71%, orange oil; IR (neat): nmax 3094.9 (arC-H), 2957.6 ((CH3)as), 2930.9 ((CH2)as), 2871.3 ((CH3)s), 1669.4 (C]O), 1442.0 (d(CH2)scissoring), 1410.0, 1377.0 (d(CH3)s), 1297.0, 1105.8, 819.6; UVeVis (CH3CN): lmax (log ε) 422 (2.56), 202 (4.51) nm; 1H NMR (200 MHz, CDCl3): d 5.51 (br. s, 1H, NeCHeS), 4.41 (m, 1H, HeC (50)), 4.14e4.31 (overlapping peaks, 8H, HeC (100), HeC (200), HeC (300), HeC (400), HeC (500), HeC (20), HeC (30), HeC (40)), 3.61 (AA', 2H, SCH2C]O), 3.36 (ddd, J ¼ 13.8, 8.4, 5.4 Hz, 1H, CHAHBN), 2.82 (ddd, J ¼ 13.8, 8.4, 5.4 Hz, 1H, CHAHBN), 1.11e1.40 (m, 4H,CH2CH2CH3), 0.83 (t, J ¼ 6.8 Hz, 3H, CH3); 13C NMR (50 MHz, CDCl3): d 170.2 (C]O), 85.1 (C (10)), 70.0, 69.8 (C (20), C (50)), 69.0 (C (100), C (200), C (300), C (400), C (500)), 68.0, 67.7 (C (30), C (40)), 61.3 (NeCHeS), 42.0 (CH2N), 33.4 (SCH2C]O), 29.0 (CH2CH2N), 19.9 (CH2CH3), 13.7 (CH3); MS (EI, 70 eV) m/z (%): 343 [M]þ. (100), 310 (2.4), 270 (61.7), 230 (6), 213 (7.8), 199 (5.1), 186 (17.3), 166 (8.2), 148 (7.9), 121 (28.4), 97 (2.7), 77 (2.2), 56 (10.1), 41 (2.6); HRMS (ESI): m/z calculated for C17H21FeNOSþHþ [MþHþ]: 344.07715. Found: 344.07709; Anal. Calcd for C17H21FeNOS: C, 59.48%; H, 6.17%; Fe, 16.27%; N, 4.08%; S, 9.34%. Found: C, 59.14%; H, 6.28%; N, 3.73%; S, 9.54%. A. Pejovic et al. / European Journal o19 25 8.64%. Found: C, 61.31%; H, 6.90%; N, 3.65%; S, 8.83%.65.92%; H, 8.19%; Fe, 12.26%; N, 3.08%; S, 7.04%. Found: C, 66.50%; H, 7.85%; N, 3.54%; S, 7.52%. 4.1.2.6. 3-Hexadecyl-2-ferrocenyl-1,3-thiazolidin-4-one (3f). Yield 62%, orange solid, mp 75 C; IR (KBr): nmax 3090.8 (arC-H), 2951.1 ((CH3)as), 2917.6 ((CH2)as), 2870.7 ((CH3)s), 2849.1 ((CH2)a), 1664.1 (C]O), 1464.6 (d(CH2)scissoring), 1402.3, 1380.9 (d(CH3)s), 1307.9, 1104.9, 1002.2, 823.0; UVeVis (CH3CN): lmax (log ε) 441 (2.20), 324 (2.25), 203 (4.72) nm; 1HNMR (200MHz, CDCl3): d 5.52 ((br. s,1H, NeCHeS), 4.43 (m, 1H, HeC (50)), 4.18e4.32 (overlapping peaks, 8H, HeC (100), HeC (200), HeC (300), HeC (400), HeC (50 '), HeC (20), HeC (30), HeC (40)), 3.62 (AA', 2H, SCH2C]O), 3.33 (ddd, J¼ 13.8, 8.4, 5.4 Hz,1H, CHAHBN), 2.82 (ddd, J ¼ 13.8, 8.4, 5.4 Hz, 1H, CHAHBN), 1.03e1.39 (m, 28H, (CH2)14CH3), 0.88 (t, J ¼ 6.6 Hz, 3H, CH3); 13C NMR (50 MHz, CDCl3): d 170.1 (C]O), 85.2 (C (10)), 70.0, 69.8 (C (20), C (50)), 69.0 (C (100), C (200), C (30 '), C (400), C (500)), 68.5, 67.8 (C (30), C (40)), 61.4 (NeCHeS), 42.4 (CH2N), 33.5 (SCH2C]O), 31.9, 29.2e29.7, 26.9, 26.7 ((CH2)13CH2CH3), 22.7 (CH2CH3), 14.1 (CH3); MS (EI, 70 eV) m/z (%): 511 [M]þ. (100), 478 (0.6), 438 (18.7), 397 (0.4), 366 (0.5), 344 (1.4), 324 (0.9), 287 (1.6), 260 (1.4), 230 (11), 213 (6.2), 199 (7.1), 186 (11.4), 166 (6.3), 148 (4.2), 121 (12.9), 97 (1.6), 69 (2.4), 57 (5.3), 43 (12.3); HRMS (ESI): m/z calculated for C H FeNOS þ Hþ [M þ Hþ]:Anal. Calcd for C21H29FeNOS: C, 63.16%; H, 7.32%; Fe, 13.98%; N, 3.51%; S, 8.03%. Found: C, 63.09%; H, 7.15%; N, 3.49%; S, 8.00%. 4.1.2.5. 3-Dodecyl-2-ferrocenyl-1,3-thiazolidin-4-one (3e). Yield 90%, yellow solid, mp 70 C; IR (KBr): nmax 2959.8 ((CH3)as), 2920.9 ((CH2)as), 2851.9 ((CH2)a), 1664.1 (C]O), 1466.0 (d(CH2)scissoring), 1402.0, 1384.6 (d(CH3)s), 1287.5, 1122.7; UVeVis (CH3CN): lmax (log ε) 430 (2.61), 324 (2.74), 203 (4.71) nm; 1H NMR (200 MHz, CDCl3): d 5.52 (br. s, 1H, NeCHeS), 4.44 (m, 1H, HeC (50)), 4.17e4.34 (overlapping peaks, 8H, HeC (10 '), HeC (20 '), HeC (30 '), HeC (40 '), HeC (50 '), HeC (20), HeC (30), HeC (40)), 3.62 (AA', 2H, SCH2C]O), 3.33 (ddd, J ¼ 14.0, 8.6, 5.4 Hz, 1H, CHAHBN), 2.83 (ddd, J ¼ 14.0, 8.6, 5.4 Hz, 1H, CHAHBN), 1.04e1.41 (m, 20H, (CH2)10), 0.87 (t, J ¼ 6.5 Hz, 3H, CH3); 13C NMR (50 MHz, CDCl3): d 170.1 (C]O), 85.2 (C (10)), 70.0, 69.8 (C (20), C (50)), 69.0 (C (100), C (200), C (300), C (400), C (500)), 68.4, 67.7 (C (30), C (40)), 61.4 (NeCHeS), 42.4 (CH2N), 33.4 (SCH2C] O), 31.8, 29.1e29.6, 26.9, 26.7 ((CH2)9CH2CH3), 22.6 (CH2CH3), 14.1 (CH3); MS (EI, 70 eV) m/z (%): 455 [M]þ. (100), 422 (1.1), 382 (32.3), 347 (0.8), 310 (0.7), 288 (3.1), 230 (10.1), 213 (7.1), 199 (6.8), 186 (13.9), 166 (6.6), 148 (4.6), 121 (17.4), 97 (1.8), 69 (1.8), 55 (4.3), 43 (8.5); HRMS (ESI): m/z calculated for C25H37FeNOS þ Hþ [M þ Hþ]:4.1.2.4. 2-Ferrocenyl-3-octyl-1,3-thiazolidin-4-one (3d). Yield 71%, yellow solid, mp 62 C; IR (KBr): nmax 3092.9 (arC-H), 2954.1 ((CH3)as), 2923.6 ((CH2)as), 2852.4 ((CH2)s), 1661.6 (C]O), 1440.6 (d(CH2)scissoring), 1402.0, 1379.5 (d(CH3)s), 1307.2, 1105.1, 1002.0, 821.5; UVeVis (CH3CN): lmax (log ε) 422 (2.61), 329 (2.82), 203 (4.80) nm; 1H NMR (200 MHz, CDCl3): d 5.52 (br. s, 1H, NeCHeS), 4.43 (m, 1H, HeC (50)), 4.19e4.33 (overlapping peaks, 8H, HeC (100), HeC (200), HeC (300), HeC (40 '), HeC (50 '), HeC (20), HeC (30), HeC (40)), 3.62 (AA', 2H, SCH2C]O), 3.33 (ddd, J ¼ 13.9, 8.6, 5.3 Hz, 1H, CHAHBN), 2.84 (ddd, J ¼ 13.9, 8.6, 5.3 Hz, 1H, CHAHBN), 1.1e1.31 (m, 12H, (CH2)6CH3), 0.87 (t, J ¼ 6.5 Hz, 3H, CH3); 13C NMR (50 MHz, CDCl3): d 170.1 (C]O), 85.1 (C (10)), 70.0, 69.8 (C (20), C (50)), 69.0 (C (10 '), C (20 '), C (30 '), C (40 '), C (50 ')), 68.4, 67.7 (C (30), C (40)), 61.4 (NeCHeS), 42.4 (CH2N), 33.4 (SCH2C]O), 31.7, 29.1, 29.0, 26.9, 26.7 (CH2CH2CH2CH2CH2CH2CH3), 22.6 (CH2CH3), 14.0 (CH3); MS (EI, 70 eV)m/z (%): 399 [M]þ. (100), 366 (2.3), 326 (56.2), 291 (1.9), 260 (2.4), 230 (10), 213 (10.2), 199 (6.6), 186 (20.4), 166 (8.4), 148 (6), 121 (27.7), 97 (2.5), 79 (2), 56 (7.4), 41 (6.5); HRMS (ESI):m/z calculated for C H FeNOS þ Hþ [M þ Hþ]: 400.13975. Found: 400.13968; dicinal Chemistry 83 (2014) 57e73 6929 45 512.26495. Found: 512.26501; Anal. Calcd for C29H45FeNOS: C, f Me68.08%; H, 8.87%; Fe, 10.92%; N, 2.77%; S, 6.27%. Found: C, 67.83%; H, 7.85%; N, 2.88%; S, 6.26%. 4.1.2.7. 2-Ferrocenyl-3-(4-methoxyphenethyl)-1,3-thiazolidin-4-one (3g). Yield 82%, ocher solid, mp 130 C; IR (KBr): nmax 3100.2 (arC- H), 2965.2 ((OCH3)as), 2924.1 ((CH2)as), 2837.6 ((CH2)a), 1667.6 (C] O), 1511.0 (arC ¼ arC), 1458.2 (d(CH2)scissoring), 1401.1, 1304.5 (d(CH3)s), 1240.7, 1176.9, 1029.2, 817.0 (g(arC-H)); UVeVis (CH3CN): lmax (log ε) 438 (2.18), 431 (2.18), 197 (5.08) nm; MS (EI, 70 eV) m/z (%): 421 [M]þ.(100), 388 (0.2), 348 (12.5), 314 (7.1), 287 (14.8), 255 (1.8), 226 (9), 199 (7), 186 (9.5), 166 (5.4), 148 (2.4), 135 (16.5), 121 (36.6), 105 (4.3), 91 (5.9), 77 (6.6), 65 (2), 56 (8.2), 39 (1.1); HRMS (ESI): m/z calculated for C22H23FeNOSþHþ [MþHþ]: 406.09280. Found: 406.09286; Anal. Calcd for C22H23FeNOS: C, 62.71%; H, 5.50%; Fe, 13.25%; N, 3.32%; S, 7.62%. Found: C, 62.59%; H, 5.31%; N, 3.60%; S, 7.58%. 4.1.2.8. 3-Benzyl-2-Ferrocenyl-1,3-thiazolidin-4-one (3h). Yield 80%, yellow solid, mp 105 C; IR (KBr): nmax 3086.7 (arC-H), 2923.9 ((CH2)as), 1669.6 (C]O), 1495.0 (arC ¼ arC), 1434.7 (d(CH2)scissoring), 1399.4, 1299.3, 1105.7, 817.1, 746.3 (g(arC-H)), 698.4; UVeVis (CH3CN): lmax (log ε) 430 (2.24), 322 (2.38), 202 (4.78) nm; 1H NMR (200 MHz, CDCl3): d 7.30 (overlapping peaks, 3H, HeC (30 ''), HeC (40 ''), HeC (50 '')), 7.13 (m, 2H, HeC (20 ''), HeC (60 '')), 5.34 (br. s, 1H, NeCHeS), 4.96 (br. d, J ¼ 15.1 Hz, 1H, CHAHBN), 4.41 (m, 1H, HeC (50)), 4.27 (m,1H, HeC (40)), 4.15e4.23 (overlapping peaks, 6H, HeC (10 '), HeC (20 '), HeC (30 '), HeC (40 '), HeC (50 '), HeC (30)), 4.04 (dt, J ¼ 2.2, 1.1, 1.1 Hz, 1H, HeC (20)), 3.72 (AA', 2H, SCH2C]O), 3.61 (d, J ¼ 15.1 Hz, 1H, CHAHBN); 13C NMR (50 MHz, CDCl3): d 170.5 (C]O), 135.7 (C (10 '')), 128.5, 127.8 (C (20 ''), C (30 ''), C (50 ''), C (60 '')), 127.4 (C (40 '')), 84.6 (C (10)), 70.5, 69.8 (C (20), C (50)), 68.9 (C (100), C (200), C (300), C (400), C (500)), 68.2, 67.6 (C (30), C (40)), 60.5 (NeCHeS), 45.2 (CH2N), 33.3 (SCH2C]O); MS (EI, 70 eV) m/z (%): 377 [M]þ. (100), 344 (0.8), 304 (16.4), 269 (6.8), 237 (6.5), 213 (26.4), 186 (7.9), 166 (6), 146 (6.4), 121 (25.3), 91 (21.2), 65 (4.9), 56 (10), 39 (1.3); HRMS (ESI): m/z calculated for C20H19FeNOSþHþ [MþHþ]: 378.06150. Found: 378.06143; Anal. Calcd for C20H19FeNOS: C, 63.67%; H, 5.08%; Fe, 14.80%; N, 3.71%; S, 8.50%. Found: C, 63.91%; H, 4.96%; N, 3.89%; S, 8.78%. 4.1.2.9. 2-Ferrocenyl-3-furfuryl-1,3-thiazolidin-4-one (3i). Yield 99%, light orange oil; IR (neat): nmax 2924.1 ((CH2)as), 1680.3 (C]O), 1503.8 (arC ¼ arC), 1400.3, 1301.4, 1228.7, 1046.0, 1008.7, 821.5, 738.7; UVeVis (CH3CN): lmax (log ε) 431 (2.28), 422 (2.39), 204 (4.82) nm; 1H NMR (200 MHz, CDCl3): d 7.37 (dd, J ¼ 1.8, 0.7 Hz, 1H, HeC (50 '')), 6.30 (dd, J ¼ 3.2, 1.8 Hz, 1H, HeC (40 '')), 6.18 (br. d, J ¼ 3.2 Hz, 1H, HeC (30 '')), 5.48 (br. s, 1H, NeCHeS), 4.81 (br. d, J ¼ 15.6 Hz, 1H, CHAHBN), 4.43 (dt, J ¼ 2.4, 1.3, 1.3 Hz, 1H, HeC (50)), 4.18e4.34 (overlapping peaks, 8H, HeC (10 '), HeC (20 '), HeC (30 '), HeC (40 '), HeC (50 '), HeC (20), HeC (30), HeC (40)), 3.70 (d, J ¼ 15.6 Hz, 1H, CHAHBN), 3.65 (AA', 2H, SCH2C]O); 13C NMR (50 MHz, CDCl3): d 170.2 (C]O), 149.5 (C (20 '')), 142.3 (C (50 '')), 110.2, 108.6 (C (30 ''), C (40 '')), 84.3 (C (10)), 70.7, 69.8 (C (20), C (50)), 69.0 (C (10 '), C (20 '), C (30 '), C (40 '), C (50 ')), 68.4, 67.6 (C (30), C (40)), 60.7 (NeCHeS), 38.1 (CH2N), 33.2 (SCH2C]O); MS (EI, 70 eV) m/z (%): 367 [M]þ. (100), 334 (0.3), 320 (0.3), 292 (9), 259 (3.2), 244 (5.1), 230 (9.6), 213 (28.6), 186 (7.8), 166 (4.5), 146 (2.1), 129 (6.5), 121 (26.4), 94 (2.6), 81 (21.3), 56 (10.1), 39 (1.4); HRMS (ESI): m/z calculated for C18H17FeNO2S þ Hþ [M þ Hþ]: 368.04077. Found: 368.04075; Anal. Calcd for C18H17FeNO2S: C, 58.87%; H, 4.67%; Fe, 15.21%; N, 3.81v; S, 8.73%. Found: C, 58.59%; H, 4.73%; N, 3.68%; S, 8.53%. 4.1.2.10. 2-Ferrocenyl-3-thenyl-1,3-thiazolidin-4-one (3j). Yield 74%, A. Pejovic et al. / European Journal o70yellow oil; IR (neat): nmax 2924.1 ((CH2)as), 1675.8 (C]O), 1400.2,1300.6, 1232.5, 1105.7, 1038.9, 822.9, 703.0; UVeVis (CH3CN): lmax (log ε) 430 (2.32), 322 (2.33), 202 (4.89) nm; 1H NMR (200 MHz, CDCl3): d 7.21 (dd, J ¼ 5.0, 1.2 Hz, 1H, HeC (50 '')), 6.93 (dd, J ¼ 5.0, 3.4 Hz, 1H, HeC (40 '')), 6.86 (br. d, J ¼ 3.4 Hz, 1H, HeC (30 '')), 5.45 (br. s,1H, NeCHeS), 4.95 (br. d, J¼ 15.3 Hz,1H, CHAHBN), 4.43 (dt, J¼ 2.4, 1.2, 1.2 Hz, 1H, HeC (50)), 4.20e4.32 (overlapping peaks, 8H, HeC (100), HeC (200), HeC (300), HeC (400), HeC (500), HeC (20), HeC (30), HeC (40)), 3.87 (d, J ¼ 15.3 Hz, 1H, CHAHBN), 3.64 (AA', 2H, SCH2C] O); 13C NMR (50 MHz, CDCl3): d 170.2 (C]O), 138.1 (C (20 '')), 126.8, 126.6, 125.4 (C (30 ''), C (40 ''), C (50 '')), 84.3 (C (10)), 70.6, 69.9 (C (20), C (50)), 69.0 (C (100), C (200), C (300), C (400), C (500)), 68.4, 67.7 (C (30), C (40)), 60.2 (NeCHeS), 39.9 (CH2N), 33.2 (SCH2C]O); MS (EI, 70 eV) m/z (%): 383 [M]þ. (100), 334 (0.3), 308 (11.4), 290 (1.2), 275 (6), 245 (1.6), 230 (9.2), 213 (26.3), 186 (8.3), 166 (4.7), 121 (27.8), 97 (32.7), 56 (10.4), 45 (3.4); HRMS (ESI): m/z calculated for C18H17FeNOS2 þ Hþ [M þ Hþ]: 383.01010. Found: 383.01002; Anal. Calcd for C18H17FeNOS2: C, 56.40%; H, 4.47%; Fe, 14.57%; N, 3.65%; S, 16.73%. Found: C, 56.12%; H, 4.28%; N, 3.47%; S, 16.94%. 4.1.2.11. 2-Ferrocenyl-3-phenyl-1,3-thiazolidin-4-one (3k). Yield 61%, light orange solid, mp 146 C; IR (KBr): nmax 3099.4 (arC-H), 2909.6 ((CH2)as), 1673.8 (C]O), 1592.0 (arC ¼ arC), 1494.9 (arC ¼ arC), 1454.1 (d(CH2)scissoring), 1401.9, 1276.5, 1215.8, 1025.7, 810.9, 692.1 (ф(arCearC)); UVeVis (CH3CN): lmax (log ε) 439 (2.19), 431 (2.18), 203 (4.92) nm; 1H NMR (200 MHz, CDCl3): d 7.28 (m, 3H, over- lapping peaks, HeC (30 ''), HeC (40 ''), HeC (50 '')), 6.96 (dd, J ¼ 8.0, 1.7 Hz, 2H, HeC (20 ''), HeC (60 '')), 5.90 (br. s, 1H, NeCHeS), 4.47 (dt, J¼ 2.5, 1.3, 1.3 Hz,1H, HeC (50)), 4.2 (tdd, J¼ 2.5, 1.3, 0.9 Hz, 1H, HeC (40)), 4.15 (s, 5H, HeC (100), HeC (200), HeC (300), HeC (400), HeC (500)), 3.99 (td, J¼ 2.5, 2.5,1.3, 1H, HeC (30)), 3.81 (AA', 2H, SCH2C]O), 3.70 (dt, J ¼ 2.5, 1.3, 1.3 Hz, 1H, HeC (20)); 13C NMR (50 MHz, CDCl3): d 170.3 (C]O), 137.1 (C (10 '')), 129.0 (C (30 ''), C (50 '')), 127.8 (C (40 '')), 127.7 (C (20 ''), C (60 '')), 85.3 (C (10)), 70.4, 69.4 (C (20), C (50)), 68.8 (C (10 '), C (20 '), C (30 '), C (40 '), C (50 ')), 68.3, 67.2 (C (30), C (40)), 63.9 (NeCHeS), 33.6 (SCH2C]O);MS (EI, 70 eV)m/z (%): 363 [M]þ. (100), 345 (0.1), 321 (2.3), 303 (0.1), 290 (34.6), 269 (3), 255 (6), 224 (15.4), 186 (10.4), 145 (4), 121 (20.2), 104 (3.5), 77 (7.8), 56 (8.9), 39 (1.1); HRMS (ESI): m/z calculated for C19H17FeNOS þ Hþ [M þ Hþ]: 364.04585. Found: 364.04578; Anal. Calcd for C19H17FeNOS: C, 62.82%; H, 4.72%; Fe, 15.37%; N, 3.86%; S, 8.83%. Found: C, 53.01%; H, 4.83%; N, 3.55%; S, 8.98%. 4.1.2.12. 2-Ferrocenyl-3-(m-tolyl)-1,3-thiazolidin-4-one (3l). Yield 63%, light yellow solid, mp 138 C; IR (KBr): nmax 3079.4 (arC-H), 2920.3 ((CH2)as), 1673.8 (C]O),1586.6 (arC¼ arC),1490.8 (arC¼ arC), 1455.9 (d(CH2)scissoring), 1365.1, 1300.1, 1215.7, 1106.3, 1000.1, 820.8 (g(arC-H)), 692.4 (ф(arCearC)); UVeVis (CH3CN): lmax (log ε) 431 (2.23), 204 (4.96) nm; 1H NMR (200 MHz, CDCl3): d 7.18 (t, J ¼ 7.6, 7.6 Hz, 1H, HeC (50 '')), 7.05 (br. d, J ¼ 7.6 Hz, 1H, HeC (40 '')), 6.79 (overlapping peaks, 2H, HeC (20 ''), HeC (60 '')), 5.88 (br. s, 1H, NeCHeS), 4.47 (dt, J¼ 2.5, 1.3, 1.3 Hz, 1H, HeC (50)), 4.21 (tdd, J¼ 2.5, 1.3, 0.5 Hz, 1H, HeC (40)), 4.15 (s, 5H, HeC (10 '), HeC (20 '), HeC (30 '), HeC (40 '), HeC (50 ')), 4.01 (td, J ¼ 2.5, 2.5, 1.3, 1H, HeC (30)), 3.81 (AA', 2H, SCH2C]O), 3.71 (dt, J ¼ 2.5, 1.3, 1.3 Hz, 1H, HeC (20)), 2.27 (s, 3H, CH3); 13C NMR (50MHz, CDCl3): d 170.4 (C]O),139.0 (C (10 '')),137.1 (C (30 '')), 128.8, 128.7, 128.4, 124.8 (C (20 ''), C (40 ''), C (50 ''), C (60 '')), 85.5 (C (10)), 70.5, 69.4 (C (20), C (50)), 68.9 (C (10 '), C (20 '), C (30 '), C (40 '), C (50 ')), 68.3, 67.2 (C (30), C (40)), 64.0 (NeCHeS), 33.6 (SCH2C]O), 21.2 (CH3); MS (EI, 70 eV)m/z (%): 377 [M]þ. (100), 359 (0.2), 335 (2.6), 319 (0.2), 304 (41.3), 283 (3.5), 269 (6.9), 238 (18.8), 214 (8.7), 182 (12.3), 166 (7.9), 152 (9.2), 121 (25.1), 91 (11.1), 77 (1.7), 56 (10.1), 39 (1.9); HRMS (ESI): m/z calculated for C20H19FeNOS þ Hþ [M þ Hþ]: 378.06150. Found: 378.06154; Anal. Calcd for C20H19FeNOS: C, 63.67%; H, 5.08%; Fe, 14.80%; N, 3.71%; S, 8.50%. Found: C, 63.51%; H, 5.22%; N, 3.61%; S, dicinal Chemistry 83 (2014) 57e738.64%. bulb, whereas the smaller compartment was black and not illu- 4.2.3. Open field (OF) test In order to detect any association to immobility in the tests and changes in motor activity, the OF apparatus was used. The studies were carried out on mice according to a method previously described [47]. The floor of the apparatus was divided into twenty- five equal (10  10 cm) squares. Mice were placed individually into the corner of the arena and allowed to explore it freely. Behavior scores included the frequency of ambulation (the number of crossing sector lines with all four paws) and rearing (number of times mouse stood on its hind limbs). 4.2.4. Horizontal wire (HW) test The HW test was used to assess a compound's effects on the muscle tone of mice. The test apparatus was based on that described earlier [47]. The number of animals that were unable to grasp a horizontal wire, with either the forepaws, or at least with one hindpaw within 10 s was recorded. 4.2.5. Involvement of the GABA receptor complex in anxiolytic activity of compound 3g The involvement of GABAA-receptor complexes was evaluated by experiments that included the application of a competitive antagonist Flumazenil (FLU; SigmaeAldrich, St. Louis, Missouri, USA). Three groups of mice (6 per group) were given FLU (15 min before other substances) as an ip injection (3 mg/kg) and after- wards the animals were treated as follows: group I (negative con- trol group) received vehicle (olive oil) in a dose of 10mL/kg, group II (positive control group) received diazepam in a dose of 1mg/kg and a (Å) 9.0589 (4) m (mm1) 1.092 f Me4.1.2.13. 2-Ferrocenyl-3-(p-tolyl)-1,3-thiazolidin-4-one (3m). Yield 48%, light yellow solid, mp 154 C; IR (KBr): nmax 3072.5 (arC- H), 2922.8 ((CH2)as), 1672.0 (C]O), 1514.0 (arC ¼ arC), 1456.8 (d(CH2)scissoring), 1384.6 (d(CH3)s), 1366.7, 1303.8, 1006.5, 1025.7, (g(arC-H)); UVeVis (CH3CN): lmax (log ε) 432 (2.26), 204 (4.85) nm; 1H NMR (200 MHz, CDCl3): d 7.09 (AA'BB', J ¼ 8.2 Hz, 2H, HeC (30 ''), HeC (50 '')), 6.82 (AA'BB', J ¼ 8.2 Hz, 2H, HeC (20 ''), HeC (60 '')), 5.85 (br. s, 1H, NeCHeS), 4.49 (br. s, 1H, HeC (50)), 4.22 (br. s, 1H, HeC (40)), 4.17 (s, 5H, HeC (10 '), HeC (20 '), HeC (30 '), HeC (40 '), HeC (50 ')), 4.03 (br. s, 1H, HeC (30)), 3.81 (AA', 2H, SCH2C]O), 3.73 (br. s, 1H, HeC (20)), 2.29 (s, 3H, CH3); 13C NMR (50 MHz, CDCl3): d 170.5 (C] O), 137.8 (C (10 '')), 134.5 (C (40 '')), 129.7 (C (30 ''), C (50 '')), 127.6 (C (20 ''), C (60 '')), 85.5 (C (10)), 70.6, 69.4 (C (20), C (50)), 68.9 (C (10 '), C (20 '), C (30 '), C (40 '), C (50 ')), 68.4, 67.3 (C (30), C (40)), 64.0 (NeCHeS), 33.6 (SCH2C]O), 21.1 (CH3); MS (EI, 70 eV)m/z (%): 377 [M]þ. (100), 359 (0.2), 335 (2.4), 319 (0.2), 304 (35), 283 (2.8), 269 (6.5), 238 (16.5), 214 (9.8), 182 (11.9), 166 (7.4), 152 (10.4), 121 (25.9), 91 (9.4), 77 (1.9), 56 (10.9), 39 (1.8); HRMS (ESI): m/z calculated for C20H19FeNOS þ Hþ [M þ Hþ]: 378.06150. Found: 378.06152; Anal. Calcd for C20H19FeNOS: C, 63.67%; H, 5.08%; Fe, 14.80%; N, 3.71%; S, 8.50%. Found: C, 63.38%; H, 5.08%; N, 3.93%; S, 8.62%. 4.1.3. Crystallographic analysis Single-crystal diffraction data for compound 3k were collected at room temperature on an Agilent Gemini S diffractometer with graphite-monochromated MoKa radiation (l ¼ 71073 Å). Data reduction and empirical absorption corrections were accomplished using CrysAlisPro [52]. Crystal structure was solved by direct methods, using SIR2002 [53] and refined using SHELXL program [54]. All non-H atoms were refined anisotropically to convergence. All H atoms were placed at geometrically calculated positions with the CeH distances fixed to 0.93 from Csp2 and 0.97 and 0.98 Å from methylene and methine Csp3, respectively. The corresponding isotropic displacement parameters of the hydrogen atoms were equal to 1.2Ueq and 1.5Ueq of the parent Csp2 and Csp3, respectively. The crystallographic data are listed in Table 5. The PARST [55], PLATON [56] and WinGX [57] programs were used to perform geometrical calculation. Figures were produced using ORTEP-3 [58] and MERCURY, Version 2.4 [59]. 4.2. Pharmacology 4.2.1. Animals and treatment Male albino BALB/c mice (4 weeks old) weighing 20e25 g were used. The animals were kept in cages at room temperature and allowed access to food and water ad libitum. Fourteen hours before the start of the experiments the animals were sent to the lab and were given only water. The experiments were performed, in accordance with the declaration of Helsinki and European Com- munity guidelines for the ethical handling of laboratory animals (EEC Directive of 1986; 86/609/EEC) and the related ethics regula- tions of our University (01-2857-4). Experimental groups consisted of 6 animals and all animals were injected intraperitoneally (ip) with experimental substances (25, 50 and 100 mg/kg) or with control substances (diazepam (Hemofarm, Vrsac, Serbia), 2 mg/kg, or olive oil, 10 mL/kg), 1 h before the commencement of each experiment. 4.2.2. Light/dark (LD) test The light/dark transition (the apparatus was a box of the following dimensions: 40 cm 60 cm 20 cm)was used as the test of unconditioned anxiety. The apparatus had two chambers con- nected by a round opening (7.0 cm) located at floor level, in the center of the dividing wall, by which mice could cross between the A. Pejovic et al. / European Journal ochambers. A larger chamber was white and illuminated by a 60 Wminated at all. Each animal was placed at the center of the illumi- nated compartment, facing away from the round passage. The time spent in illuminated and dark places, time of the first crossing (transition), as well as the number of entries in each space, was recorded for 5 min [47].q range for data collection () 2.90 to 29.00 Reflections collected 7006 Independent reflections, Rint 3594, 0.0260 Completeness to q ¼ 26.00 99.9 Data/restraints/parameters 3594/0/208 Goodness-of-fit on F2 1.067 Final R1/wR2 indices (I > 2sI) 0.0458, 0.0849 Final R1/wR2 indices (all data) 0.0651, 0.0921 Largest diff. peak and hole (e Å3) 0.252 and 0.366b (Å) 5.8848 (3) c (Å) 29.7237 (13) a () 90 b () 96.106 (4) g () 90 V (Å3) 1575.58 (13) Z 4 Dcalc (Mg/m3) 1.531Table 5 Crystallographic data for crystal structure of 3k. Empirical formula C19 H17 Fe N O S Formula weight 363.25 Color, crystal shape Orange, prism Crystal size (mm3) 0.35  0.19  0.15 Temperature (K) 293 (2) Wavelength (Å) 0.71073 Crystal system Monoclinic Space group P21/n Unit cell dimensions dicinal Chemistry 83 (2014) 57e73 71group III (experimental) received compound 3g in a dose of 50 mg/ f Mekg [45]. After the treatments the animals were submitted to a LD test. A second set of experiments served to evaluate the interaction of compound 3gwith the picrotoxin GABAA-receptor-binding site. An ip dose of a non-competitive antagonist picrotoxin (PIC, 1 mg/kg; Tokyo Chemical Industry, Tokyo, Japan) administered 15min before other substances was used in this sense [60,61]. The treatments of positive and negative controls, as well as the experimental groups, were same as described in the previous paragraph. After the treatments the animals were submitted to a LD test. 4.2.6. Diazepam-induced sleep Sleep inducing or potentiating effects of the synthesized library compounds were investigated in experiments where a 20 mg/kg dose (ip) of diazepam was used to induce sleep in mice. The time required to induce loss of the righting reflex was defined as sleep latency, while the time that elapsed between the loss and recovery of the righting reflex was considered sleeping time [47]. 4.2.7. Anticonvulsant activity The influence of 3g on convulsions induced by pentylenetetrazol (PTZ; Alfa Aesar GmbH & Co KG, Karlsruhe, Germany) and isoniazid (ISN; Tokyo Chemical Industry, Tokyo, Japan) was studied [48]. One hour before PTZ (70 mg/kg) or INH (250 mg/kg) injections, the animals were ip treated with vehicle (olive oil, 10 mL/kg), 3g (50 mg/kg) or diazepam (1 mg/kg). After the PTZ application the onset of seizures (sec) and occurrence of hind-limb tonic exten- sions (sec) were recorded, whereas in ISN treated animals the seizure onset (min) and % of living mice in 30 min were monitored. 4.3. Statistical analysis Results were expressed as the mean ± SD. Statistically signifi- cant differences were determined by one-way analysis of variance (ANOVA) followed by Tukey's post hoc test for multiple compari- sons (Graphpad Prism version 5.03, San Diego, CA, USA). Probability values (p) less than 0.05 were considered to be statistically significant. 4.4. Docking experiments All library compounds were docked in the extracellular domain of the unified homology model of the a1b2g2 GABAA receptor, pri- marily based on the glutamate-gated chloride channel [23]. This was also done for diazepam, flumazenil, isoniazid, tetrazole, pic- rotoxinin and picrotin, which were used in the biological in vivo tests. All docking experiments were performed using AutoDock Vina 1.1.2 software, as blind dockings [62]. Extracellular domain of the receptor was divided into four partially overlapping grid boxes (GB1-GB4), that were together large enough to encompass any possible ligandereceptor complex. The centers of grid boxes were at x, y, z ¼ 27.479, 66.798, 76.015 (GB1); 27.479, 66.798, 52.838 (GB2); 6.757, 66.798, 49.491 (GB3); 6.757, 66.798, 81.154 (GB4) (Figure S7, Supporting Information); the size of each individual search space (volume of the grid box) was set to be 46  76  54 Å. Autodock Vina docking was performed using exhaustiveness value of 500, while the number of search modes was set to 20. All other parameters were used as defaults. The ligands were allowed to flexibly dock, but the receptor backbone and side chains remained rigid during the docking. For all library compounds, two different input conformations (these corresponding to the preferred geom- etries found in solid state and solution and were inferred from crystallographic and NMR analyses), generated by HyperChem 8.0 Software and minimized using molecular mechanics MM þ force A. Pejovic et al. / European Journal o72field, were used. The validity of the docking results was confirmedby AutoDock Vina ability to accurately predict the diazepam- binding site, consistent with the available experimental data [23,49]. Autodock Tools version 1.5.6 was used to convert the ligand and receptor molecules to proper file formats (pdbqt) for AutoDock Vina docking. The same program was used for the visualization of docking results [63]. The output pdbqt files for the preferred BZD- docking poses of the most active compound (3g, in vivo experi- ments) are given in Supporting Information. All in silico experi- ments were run using Intel® Core™ i7-3930K 3.20 GHz Six core unlocked CPU Processor. Transparency declarations The authors declare no conflict of interest. Acknowledgments The authors from Serbia acknowledge the financial support (Projects No. 172034 and 172061) of the Ministry of Education, Science and Technological Development of the Republic of Serbia. Appendix A. Supplementary data Supplementary data related to this article can be found at http:// dx.doi.org/10.1016/j.ejmech.2014.05.062. References [1] L.N. Ravindran, M.B. Stein, The pharmacologic treatment of anxiety disorders: a review of progress, J. Clin. Psychiatr. 71 (2010) 839e854. [2] G. Griebel, A. Holmes, 50 years of hurdles and hope in anxiolytic drug dis- covery, Nat. Rev. Drug. Discov. 12 (2013) 667e687. [3] B. Saraceno, Advancing the global mental health agenda, Int. J. Public Health 3 (2007) 140e141. [4] S. Taliani, B. Cosimelli, F. Da Settimo, A.M. Marini, C. La Motta, F. Simorini, S. Salerno, E. Novellino, G. Greco, S. Cosconati, L. Marinelli, F. Salvetti, G. L’Abbate, S. Trasciatti, M. Montali, B. Costa, C. Martini, Identification of anxiolytic/nonsedative agents among Indol-3-ylglyoxylamides acting as functionally selective agonists at the g-aminobutyric acid-a (GABAA) a2 benzodiazepine receptor, J. Med. Chem. 52 (2009) 3723e3734. [5] Q. Wang, Y. Han, H. Xue, Ligands of the GABAA receptor benzodiazepine binding site, CNS Drug. Rev. 5 (1999) 125e144. [6] G.A.R. Johnston, GABAA receptor channel pharmacology, Curr. Pharm. Des. 11 (2005) 1867e1885. [7] Q. Huang, X. He, C. Ma, R. Liu, S. Yu, C.A. Dayer, G.R. Wenger, R. McKernan, J.M. Cook, Pharmacophore/receptor models for GABAA/BzR subtypes (a1b3g2, a5b3g2, and a6b3b2) via a comprehensive ligand-mapping approach, J. Med. Chem. 43 (2000) 71e95. [8] M. Mula, S. Pini, G.B. Cassano, The role of anticonvulsant drugs in anxiety disorders: a critical review of the evidence, J. Clin. Psychopharmacol. 27 (2007) 263e272. [9] A.K. Jain, A. Vaidya, V. Ravichandran, S.K. Kashaw, R.K. Agrawal, Recent de- velopments and biological activities of thiazolidinone derivatives: a review, Bioorg. Med. Chem. 20 (2012) 3378e3395. [10] W. Cunico, C.R.B. Gomes, W.T. Vellasco Jr., Chemistry and biological activities of 1,3-Thiazolidin-4-ones, Mini-Rev. Org. Chem. 5 (2008) 336e344. [11] A. Verma, S.K. Saraf, 4-Thiazolidinone e a biologically active scaffold, Eur. J. Med. Chem. 43 (2008) 897e905. [12] S.P. Singh, S.S. Parmar, K. Raman, V.I. Stenberg, Chemistry and biological ac- tivity of thiazolidinones, Chem. Rev. 81 (1981) 175e203. [13] K.N.M. Daeffler, H.A. Lester, D.A. Dougherty, Functionally important aroma- ticearomatic and sulfur-p; interactions in the D2 dopamine receptor, J. Am. Chem. Soc. 134 (2012) 14890e14896. [14] D. Ilic, I. Damljanovic, D. Stevanovic, M. Vukicevic, P. Blagojevic, N. Radulovic, R.D. Vukicevic, Sulfur-containing ferrocenyl alcohols and oximes: new promising antistaphylococcal agents, Chem. Biodivers. 9 (2012) 2236e2253. [15] D.Z. Ilic, I.S. Damljanovic, D.D. Stevanovic, M.D. Vukicevic, N.S. Radulovic, V. Kahlenberg, G. Laus, R.D. Vukicevic, Synthesis, spectral characterization, electrochemical properties and antimicrobial screening of sulfur containing acylferrocenes, Polyhedron 29 (2010) 1863e1869. [16] A.Z. Pejovic, I.S. Damljanovic, D.D. Stevanovic, M.D. Vukicevic, S.B. Novakovic, G.A. Bogdanovic, N.S. Radulovic, R.D. Vukicevic, Antimicrobial ferrocene con- taining quinolinones: synthesis, spectral, electrochemical and structural dicinal Chemistry 83 (2014) 57e73characterization of 2-Ferrocenyl-2,3-dihydroquinolin-4(1H)-one and its 6- Chloro and 6-Bromo derivatives, Polyhedron 31 (2012) 789e795. [17] I. Damljanovic, D. Stevanovic, P. Pejovic, M. Vukicevic, S.B. Novakovic, G.A. Bogdanovic, T. Mihajlov-Krstev, N. Radulovic, R.D. Vukicevi&cacute, Antibacterial 3-(Arylamino)-1-ferrocenylpropan-1-ones: synthesis, spectral, electrochemical and structural characterization, J. Org. Chem. 696 (2011) 3703e3713. [18] Z.R. Ratkovic, Z.D. Juranic, T.P. Stanojkovic, D.D. Manojlovic, R.D. Vukicevic, N.S. Radulovic, M.D. Joksovic, Synthesis, characterization, electrochemical studies and antitumor activity of some new chalcone analogues containing ferrocenyl pyrazole moiety, Bioorg. Chem. 38 (2010) 26e32. [19] M.D. Joksovic, V.R. Markovic, Z.D. Juranic, T.P. Stanojkovic, L.J.S. Jovanovic, I.S. Damljanovic, K.F. Mesaros-Secenji, N.M. Todorovic, S.S. Trifunovic, R.D. Vukicevic, Synthesis, characterization and antitumor activity of novel n- substituted alpha-amino acids containing ferrocenyl pyrazole-moiety, J. Org. Chem. 694 (2009) 3935e3942.      benzodiazepines in three mice behavioral models, J. Psychiatr. Neurosci. 17 (1992) 72e77. [40] R.J. Blanchard, K.J. Flannelly, D.C. Blanchard, Defensive behaviour of laboratory and wild Rattus norvegicus, J. Comp. Psychol. 100 (1986) 101e107. [41] S.K. Bhattacharya, K.S. Satyan, Experimental methods for evaluation of psy- chotropic agents in rodents: I-antianxiety agents, Indian J. Exp. Biol. 35 (1997) 565e575. [42] G.R.M. Perez, I.J.A. Perez, D. Garcia, M.H. Sossa, Neuropharmacological activity of Solanum nigrum Fruit, J. Ethnopharmacol. 62 (1998) 43e48. [43] F. Crestani, K. L€ow, R. Keist, M.J. Mandelli, H. M€ohler, U. Rudolph, Molecular targets for the myorelaxant action of diazepam, Mol. Pharmacol. 59 (2001) 442e445. [44] M. Bourin, M. Hasco€et, The mouse light/dark box test, Eur. J. Pharmacol. 463 (2003) 55e65. [45] O. Grundmann, J.I. Nakajima, S. Seo, V. Butterweck, Anti-anxiety effects of Apocynum venetum L. in the elevated plus Maze test, J. Ethnopharmacol. 110 A. Pejovic et al. / European Journal of Medicinal Chemistry 83 (2014) 57e73 73[20] I.S. Damljanovic, M.D. Vukicevic, N.S. Radulovic, R.M. Palic, E. Ellmerer, Z.R. Ratkovic, M.D. Joksovic, R.D. Vukicevic, Synthesis and antimicrobial ac- tivity of some new pyrazole derivatives containing a ferrocene unit, Bioorg. Med. Chem. Lett. 19 (2009) 1093e1096. [21] C. Biot, G. Glorian, L.A. Maciejewski, J.C. Brocard, Synthesis and antimalarial activity in Vitro and in vivo of a new ferrocene-chloroquine analogue, J. Med. Chem. 40 (1997) 3715e3718. [22] P. Beagley, M.A.L. Blackie, K. Chibale, C. Clarkson, R. Meijboom, J.R. Moss, P.J. Smith, H. Su, Synthesis and antiplasmodial activity in vitro of new ferrocene-chloroquine analogues, Dalt. Trans. (2003) 3046e3051. [23] N. Metzler-Nolte, U. Schatzschneider, Bioinorganic Chemistry: a Practical Course, Walter de Gruyter GmbH & Co KG, Berlin, 1990. [24] R. Bergmann, K. Kongsbak, P.L. Sorensen, T. Sander, T.A. Balle, Unified model of the GABAA receptor comprising agonist and benzodiazepine binding sites, Plos One 8 (2013) e52323. [25] F.C. Brown, 4-Thiazolidinones, Chem. Rev. 61 (1961) 463e521. [26] H. Erlenmeyer, V. Oberlin, Zur Kenntnis der Thiazolidone-(4), Hel. Chim. Acta 30 (1947) 1329e1335. [27] A.R. Surrey, The Preparation of 4-Thiazolidones by the reaction of thioglycolic acid with Schiff bases, J. Am. Chem. Soc. 69 (1947) 2911e2912. [28] K.M. Hassan, Studies on ferrocenes and its derivatives, VI. Cyclocondensation reaction of some ferrocenyl Anils, Z. Naturforsch 33b (1978) 1508e1514. [29] R.K. Rawal, R. Tripathi, S. Kulkarni, R. Paranjape, S.B. Katti, C. Pannecouque, E. De Clercq, 2-(2,6-Dihalo-Phenyl)-3-Heteroaryl-2-ylmethyl-1,3-Thiazolidin- 4-ones: Anti-HIV agents, Chem. Biol. Drug. Des. 72 (2008) 147e154. [30] R.K. Rawal, T. Srivastava, W. Haq, S.B. Katti, An expeditious synthesis of thiazolidinones and tetathiazanones, J. Chem. Res. 5 (2004) 368e369. [31] T. Srivastava, W. Haq, S.B. Katti, Carbodiimide Mediated synthesis of 4- Thiazolidinones by one-pot three-component condensation, Tetrahedron 58 (2002) 7619e7624. [32] C.R.J. Woolston, J.B. Lee, F.J. Swinbourne, An infra-red Spectroscopic study of some substituted 1,3-Thiazolidin-4-ones, Phosphorus Sulfur 78 (1993) 223e235. [33] C.R.J. Woolston, J.B. Lee, F.J. Swinbourne, W.A. Thomas, Proton NMR Investi- gation of some substituted 1,3-Thiazolidin-4-ones, Mag. Reson. Chem. 30 (1992) 1075e1078. [34] J. Tierney, D. Sheridan, K. Kovalesky, Substituent effects for some substituted 3-Benzyl-2-phenyl-1,3-thiazolidin-4-ones using 1H and 13C NMR, Heterocycl. Commun. 6 (2000) 105e112. [35] C.R.J. Woolston, J.B. Lee, F.J. Swinbourne, Carbon-13 NMR Investigation of some substituted 1,3-Thiazolidin-4-ones, Mag. Reson. Chem. 31 (1993) 348e351. [36] C.R.J. Woolston, J.B. Lee, F.J. Swinbourne, The effects of ring modification on the mass spectrometric fragmentation of some 2,3-Diaryl-1,3-thiazolidin-4- ones under electron impact, Phosphorus Sulfur 97 (1994) 157e163. [37] G. Innorta, F. Scagnolari, A. Modelli, S. Torroni, A. Foffani, S. Sorriso, A Reinvestigation of the mass spectra of substituted ferrocenes: Accurate fragmentation Pathways and Ionic structures by analysis of Metastable ion spectra, J. Org. Chem. 241 (1983) 375e383. [38] D. Hickel, J.M. Leger, A. Carpy, M.G. Vigorita, A. Chimirri, S. Grasso, Structure of 3-(2-Pyridyl)-2-(2-tolyl)-1,3-thiazolidin-4-one, C15H14N2OS, Acta Crystallogr. C. 39 (1983) 240e246. [39] M. Bourinn, M. Hascoet, B. Mansouri, M.C. Colombel, X. Bradwejn, Comparison of behavioral effects after single and repeated administration of four(2007) 406e411. [46] S.E. File, R.G. Lister, Do the reductions in Social interactions produced by picrotoxin and pentylenetetrazol indicate Anxiogenic actions, Neurophar- macology 23 (1984) 793e796. [47] N.S. Radulovic, A.B. Miltojevic, P.J. Randjelovic, N.M. Stojanovic, F. Boylan, Effects of methyl and isopropyl N-methylanthranilates from Choisya ternata Kunth (Rutaceae) on experimental anxiety and depression in mice, Phytother. Res. 27 (2013) 1334e1338. [48] E. Ngo Bum, M. Schmutz, C. Meyer, A. Rakotonirina, M. Bopelet, C. Portet, A. Jeker, S.V. Rakotonirina, H.R. Olpe, P. Herrling, Anticonvulsant properties of the methanolic extract of Cyperus articulatus (Cyperaceae), J. Ethnopharmacol. 76 (2001) 145e150. [49] S.M. Hanson, E.V. Morlock, K.A. Satyshur, C. Czajkowski, Structural re- quirements for eszopiclone and Zolpidem binding to GABAA receptor are different, J. Med. Chem. 51 (2008) 7243e7252. [50] T.S. Carpenter, E.Y. Lau, F.C. Lightstone, Identification of possible secondary picrotoxin-binding site on the GABAA receptor, Chem. Res. Toxicol. 26 (2013) 1444e1454. [51] O. Trott, A.J. Olson, AutoDock Vina: improving the speed and accuracy of docking with a new scoring function, efficient optimization, and multi- threading, J. Comput. Chem. 31 (2010) 455e461. [52] Agilent, CrysAlis PRO, Agilent Technologies, Yarnton, Oxfordshire, England, 2013. [53] M.C. Burla, M. Camalli, B. Carrozzini, G.L. Cascarano, C. Giacovazzo, G. Polidori, R. Spagna, SIR2002: the program, J. Appl. Crystallogr. 36 (2003) 1103. [54] G.M. Sheldrick, A short history of SHELX, Acta Crystallogr. A 64 (2008) 112e122. [55] M. Nardelli, PARST95-an update to PARST: a system of Fortran routines for calculating molecular structure parameters from the results of crystal struc- ture analyses, J. Appl. Crystallogr. 28 (1995) 659. [56] A.L. Spek, Single-crystal structure validation with the program PLATON, J. Appl. Crystallogr. 36 (2003) 7e13. [57] L.J. Farrugia, WinGX Suite for small-molecule single-crystal crystallography, J. Appl. Cryst. 32 (1999) 837e838. [58] L.J. Farrugia, WinGX and ORTEP for windows: an update, J. Appl. Crystallogr. 45 (2012) 849e854. [59] C.F. Macrae, P.R. Edgington, P. McCabe, E. Pidcock, G.P. Shields, R. Taylor, M. Towler, J. van de Streek, Mercury: visualization and analysis of crystal structures, J. Appl. Crystallogr. 39 (2006) 453e457. [60] J.F. Rodríguez-Landa, J.D. Hernandez-Figueroa, B.C. Hernandez-Calderon, M. Saavedra, Anxiolytic-like effect of phytoestrogen genistein in rats with long-term absence of ovarian hormones in the black and white model, Prog. Neuro-psychoph. 33 (2009) 367e372. [61] I.P. Barettaa, R.A. Felizardo, V.F. Bimbato, M.G.J. dos Santos, C.A.L. Kassuya, J.A. Gasparotto da Silva, S.M. de Oliveira, J. Ferreira, R. Andreatini, Anxiolytic- like effects of acute and chronic treatment with Achillea millefolium L. Extract, J. Ethnopharmacol. 140 (2012) 46e54. [62] N. Rnjan, K.F. Andreasen, S. Kumar, D. Hyde-Volpe, D.P. Arya, Aminoglycoside binding of Oxytricha nova telomeric DNA, Biochemistry 49 (2010) 9891e9903. [63] M.F. Sanner, Python: a programming language for software integration and development, J. Mol. Graph. Model. 17 (1999) 57e61.     AImprimatur: Date, Signature SYNLETT0 9 3 6 - 5 2 1 4 1 4 3 7 - 2 0 9 6 © Georg Thieme Verlag Stuttgart · New York 2015, 26, A–FKey words ferrocene, heterocycles, oxazinanes, oxazinan-2-ones, tet- rahydropyrimidin-2-ones, cyclization, amino alcohols Ferrocenes have attracted considerable interest over the years because of their versatility in many fields of research. Notable areas featuring important ferrocene derivatives in- clude asymmetric catalysis1 and bioactive compound devel- opment,2 and, as a consequence, these fields have wit- nessed a steady growth of valuable scientific contributions. The combination of chemical stability, synthetic flexibility, and pronounced biological activities has turned ferrocenes into privileged scaffolds in medicinal chemistry, especially in relationship with the design of antimalarial,3 antimicro- bial,4 and antitumor agents.3,5 Consequently, the synthesis of new ferrocene derivatives continues to play an important role in current organic chemistry. On the other hand, the vast majority of pharmacophores in medicinal chemistry accommodates a heterocyclic core fragment in their struc- ture, and this wide range of potential medicinal applica- tions has catalyzed significant advances at the interface of this study comprised (i) assessment of the synthetic/chemi- cal feasibility of γ-amino alcohol cyclizations employing 3- arylamino-1-ferrocenylpropan-1-ols as substrates to pro- duce a small library of novel ferrocenyl heterocycles and (ii) determination of the biological profile of these new struc- tures by means of antifungal/antibacterial activity tests and cytotoxicity analysis against cancer cell lines. The synthesis of the premised 3-arylamino-1-ferrocen- ylpropan-1-ols 5 commenced with the Friedel–Crafts acyla- tion of ferrocene 1 with 3-chloropropanoyl chloride in CH2- Cl2 in the presence of AlCl3 and the subsequent dehydroha- logenation of the obtained 3-chloro-1-ferrocenylpropan-1- one 2 utilizing KOAc in EtOH. Subsequently, microwave- promoted addition of a broad variety of aromatic amines across Michael acceptor 3 was realized under neat condi- tions in the presence of montmorillonite K-10, affording 3- arylamino-1-ferrocenylpropan-1-ones 4 in high yields.7a The latter ketones were then converted into the corre- sponding alcohols upon treatment with five equivalents of NaBH4 in MeOH to produce a set of twelve 3-arylamino-1- ferrocenylpropan-1-ols 5 as useful new substrates for fur-st-2015-d0022-l.fm 3/9/15 A. Pejović et al. LetterSyn lett Synthesis and Antimicrobial/Cytotoxic Assessment of Ferrocenyl Oxazinanes, Oxazinan-2-ones, and Tetrahydropyrimidin-2-ones Anka Pejovića,b Barbara Danneelsc Tom Desmetc Ba Thi Chamd Tuyen Van Nguyend Niko S. Raduloviće Rastko D. Vukićević*b Matthias D’hooghe*a a SynBioC Research Group, Department of Sustainable Organic Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium b Department of Chemistry, Faculty of Science, University of Kragujevac, R. Domanovića 12, 34000 Kragujevac, Serbia c Centre for Industrial Biotechnology and Biocatalysis, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium d Institute of Chemistry, Vietnam Academy of Science and Technology, 18-Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam e Department of Chemistry, Faculty of Science and Mathematics, University of Niš, Visegradska 33, 18000 Niš, Serbia Fe Fe OH H N R Fe N O R Fe N O R O Fe N N R O Received: 12.01.2015 Accepted after revision: 16.02.2015 Published online: DOI: 10.1055/s-0034-1380348; Art ID: st-2015-d0022-l Abstract 3-Arylamino-1-ferrocenylpropan-1-ones, prepared through aza-Michael addition of aromatic amines to 1-ferrocenylpropenone, were transformed into the corresponding 1,3-amino alcohols upon NaBH4-mediated carbonyl reduction. The latter amino alcohols were deployed as eligible substrates for the synthesis of a variety of ferro- cene-containing heterocycles including 1,3-oxazinanes, 1,3-oxazinan- 2-ones, and tetrahydropyrimidin-2-ones, which were subsequently evaluated for their antimicrobial and cytotoxic activities. cene derivatives, the design of ferrocene-containing hetero- cycles has emerged as an eligible approach toward the syn- thesis of new bioactive molecules,6 and it is conceivable to expect important new contributions within this concept in the near future. Further elaborating on our interest in ferrocene chemis- try7 and heterocyclic synthesis,8 the present manuscript re- ports on the preparation of a set of novel, ferrocene-con- taining heterocyclic compounds and the preliminary evalu- ation of their biological activity. The particular objectives of letter© Georg Thieme Verlag Stuttgart · New York — Synlett 2015, 26, A–F heterocyclic chemistry and medicinal chemistry for many years. In light of the general biological importance of het- erocyclic compounds and the medicinal interest in ferro- ther derivatization (Scheme 1,Table 1). γ-Amino alcohols in general represent versatile synthons in organic chemistry,9 and the corresponding 1,3-amino alcohol derived heterocy- BA. Pejović et al. LetterSyn lett cles are of broad interest from a biological point of view (antibacterial, antimalarial, anti-inflammatory, antitumor, etc.). The second part comprised the evaluation of ferrocenyl amino alcohols 5 as substrates for the synthesis of novel fer- rocene-containing heterocyclic compounds (Scheme 2,Ta- ble 2). As stated in the introduction, ferrocenyl heterocycles represent valuable new targets in medicinal chemistry be- cause of the combined properties of the ferrocene moiety and the heterocyclic core fragment. Scheme 1 Synthesis of 3-arylamino-1-ferrocenylpropan-1-ols 5 Fe Fe O Cl Fe O Fe O H N R Fe OH H N R AlCl3 (33 mol%) CH2Cl2, r.t., 5 h Cl Cl O (1 equiv) KOAc (1 equiv) EtOH, Δ, 2.5 h 1 2 3 montmorillonite K-10 neat, MW (500 W), 5 minR H2N (2 equiv) NaBH4 (5 equiv) MeOH, r.t., 1.5 h 5a–l 4a–l Fe OH H N R 5a–l Fe OH N R 7a–l (36–99%) OEtO Fe HN N R OEtO Fe 6a–l (36–99%) N O R Fe 8a–k (10–97%) N O R O Fe N N R O HCHO (1 equiv) THF, r.t., 12 h NaOH (4 equiv) ClCOOEt (2 equiv) toluene, Δ, 2 h NaH (4 equiv) THF, Δ, 15 s i-PrNH2 (4 equiv) Et3N (1.5 equiv), (CF3CO)2O (1.5 equiv) THF, 0 °C, 16 h BuLi (2 equiv)© Georg Thieme Verlag Stuttgart · New York — Synlett 2015, 26, A–F Scheme 2 Synthesis of ferrocenyl oxazinanes 6, oxazinanones 8, and tetrahydropyrimidinones 10 9a–l (63–96%) 10a–h (50–66%) THF, –78 °C, 1 h CIn summary, 3-arylamino-1-ferrocenylpropan-1-olsA. Pejović et al.Syn lett Table 1 Synthesis of 3-Arylamino-1-ferrocenylpropan-1-ols 5: Substi- tution Patterns and Yields Table 2 Synthesis of Ferrocenyl Oxazinanes 6, Oxazinanones 8, and Tetrahydropyrimidinones 10: Substitution Patterns and Yields Compound R Yield (%)a 5a H 90 5b 2-Me 92 5c 3-Me 90 5d 4-Me 80 5e Mes 91 5f 4-n-Bu 97 5g 2-F 93 5h 3-F 91 5i 4-F 95 5j 2-Cl 90 5k 3-Cl 98 5l 4-Cl 85 a After purification by means of column chromatography on Al2O3. Compound R Yield (%)a 6a H 78 6b 2-Me 99 6c 3-Me 98 6d 4-Me 99 6e Mes 36 6f 4-n-Bu 81 6g 2-F 84 6h 3-F 99 6i 4-F 76 6j 2-Cl 77 6k 3-Cl 85 6l 4-Cl 77 8a H 64 8b 2-Me 47 8c 3-Me 53 8d 4-Me 84 8e 4-n-Bu 80 8f 2-F 97 8g 3-F 84 8h 4-F 97 8i 2-Cl 10 8j 3-Cl 77© Georg Thieme Verlag Stuttgart 8k 4-Cl 89 10a H 61 10b 3-Me 58Letter Table 2 (continued) A first route involved the direct cyclization of amino al- cohols 5 to 6-ferrocenyl-1,3-oxazinanes 6 upon treatment with one equivalent of formaldehyde in THF, which were purified by means of column chromatography to afford ox- azaheterocycles 610 in moderate to excellent yields. 1,3-Ox- azinanes have previously been reported to be interesting systems, both from a biological11 and a synthetic12 point of view. In a second route, ferrocenyl oxazinan-2-ones 813 were premised. These systems were constructed via initial sodium hydroxide assisted N-acylation of amines 5 using two equivalents of ethyl chloroformate in toluene, followed by cyclization of the thus obtained intermediate carba- mates 7 by reaction with four equivalents of NaH in THF. The desired heterocyclic scaffolds 8 were isolated after pu- rification by means of column chromatography in low to excellent yields. Cyclic carbamates can be regarded as inter- esting compounds with a variety of applications, most no- tably as precursors for 1,3-amino alcohols,14 as chiral auxil- iaries,15 and as the core substructure in a number of biolog- ically active compounds.16 Finally, diazaheterocyclic analogues of the above-mentioned oxazaheterocycles 8 were contemplated. To that end, the hydroxyl group in sys- tems 7 was replaced with an isopropylamino substituent through reaction with four equivalents of i-PrNH2 in THF at low temperature (0 °C) in the presence of 1.5 equivalents of Et3N and 1.5 equivalents of (CF3CO)2O, affording diamino compounds 9. The fact that the OH group in compounds 7 resides in α position with regard to the ferrocene moiety, comparable to a benzylic position because of the aromatic nature of the ferrocene unit, accounts for its increased chemical reactivity. Cyclization of diamino compounds 9 was then effected upon treatment with two equivalents of BuLi in THF, yielding 4-ferrocenyltetrahydropyrimidin-2- ones 1017 in good yields after purification. Pyrimidinones in general are known to have a long track record in bioactive compound development, for example as kinase inhibitors18 or as anti-HIV agents.19 10c 4-Me 66 10d 4-n-Bu 60 10e 2-F 57 10f 4-F 63 10g 3-Cl 50 10h 4-Cl 53 a After purification by means of column chromatography (SiO2) or prepara- tive TLC chromatography (SiO2). Compound R Yield (%)a· New York — Synlett 2015, 26, A–F were deployed successfully for the synthesis of 31 new fer- rocene-containing heterocyclic scaffolds. The combination of the ferrocene group and a heterocyclic unit in one molec- DA. Pejović et al. LetterSyn lett ular framework might result in medicinally relevant new hybrid compounds because of the well-known biological properties of both entities. Variation of the substitution pattern across the aromatic ring at nitrogen results in addi- tional molecular diversity within each class of heterocyclic motifs. In the next part of this study, the novel ferrocenyl het- erocycles 6, 8, and 10 were briefly assessed with regard to their antimicrobial and cytotoxic profile. In a first screening, the antimicrobial activity of these ferrocenyl heterocycles was tested on one yeast strain (Can- dida albicans IHEM 374), one mold strain (Aspergillus flavus IHEM 5785), and four bacterial strains (Bacillus cereus LMG 6910, Escherichia coli LMG 8223, Staphylococcus aureus LMG 3195, and Klebsiella pneumonia ATCC 31488) by the disk diffusion method.20 At a concentration of 500 μg per disk, only eight samples displayed weak antibacterial activ- ity against B. cereus, and no other compound displayed an- timicrobial activity toward any of the other microorgan- isms. The eight compounds showing minor activity against B. cereus comprised oxazinan-2-ones 8b, 8f, 8g, and 8i and tetrahydropyrimidin-2-ones 10a, 10b, 10c, and 10e. In a previous study we had demonstrated the antimicrobial ef- fect of 3-arylamino-1-ferrocenylpropan-1-ones 4,7a point- ing to the potential of these ferrocene derivatives as anti- bacterial agents. From the present results, however, it can be concluded that carbonyl reduction and subsequent cy- clization of ferrocenes 4 to ferrocenyl heterocycles 6, 8, and 10 is detrimental with regard to their overall antimicrobial potency. In addition, the biological relevance of 28 ferrocenyl heterocycles with respect to their anticancer behavior was investigated in vitro against two human tumor cell lines (KB, Hep-G2). The results of these tests are depicted in Table 3. These data indicate that six compounds (6f, 6l, 8i, 8k, 10b, and 10d) exert a low cytotoxic effect against both cell lines with IC50 values <100 μM, and one of them (10d) has a moderate activity with IC50 values <50 μM. These results point to the potential of ferrocenyl heterocycles 6, 8, and 10 as templates for the design of new cytotoxic agents upon further optimization. Although a broader study is required to determine actu- al structure–activity relationships, it seems that the pres- ence of a fluoro atom or a methyl group on the aromatic ring at nitrogen is beneficial for activity against B. cereus, and the presence of a chloro atom or a n-Bu group seems to enhance the cytotoxic activity of these ferrocenyl heterocy- cles. In conclusion, 3-arylamino-1-ferrocenylpropan-1-ones were prepared through aza-Michael addition of aromatic amines to 1-ferrocenylpropenone and further transformed mediated carbonyl reduction. The latter amino alcohols were deployed as suitable substrates for the successful syn- thesis of a set of 31 new ferrocene-containing heterocycles bearing a 1,3-oxazinane, a 1,3-oxazinan-2-one, or a tetrahy- dropyrimidin-2-one scaffold. Preliminary antimicrobial and cytotoxic analyses revealed low to moderate bioactivity profiles for these new compounds. Acknowledgment The authors are indebted to Ghent University – Belgium (BOF) for fi- Table 3 Cytotoxic Analyses of Ferrocenyl Heterocycles 6, 8, and 10 Entry Compd IC50 (μM) KB IC50 (μM) Hep-G2 1 6a 332.1 238.1 2 6b 211.5 218.9 3 6c 228.6 177.2 4 6d 213.3 207.7 5 6e 279.5 >328.8 6 6f 56.3 52.2 7 6g 170.6 194.1 8 6h 164.9 205.2 9 6i >350.5 329.8 10 6j 195.1 125.8 11 6k 212.4 73.7 12 6l 60.8 50.8 13 8a >354.4 >354.4 14 8b >341.1 203.0 15 8c 194.9 185.8 16 8d >341.1 >341.1 17 8e 301.4 242.3 18 8f 147.7 63.8 19 8g 171.0 182.0 20 8h 314.0 276.4 21 8i 77.0 69.7 22 8j 80.9 104.7 23 8k 52.7 61.6 24 10a 77.8 171.3 25 10b 59.6 61.8 26 10c 174.9 137.7 27 10d 44.4 42.2 28 10f 120.3 123.8 29 ellipticine 1.3 1.4© Georg Thieme Verlag Stuttgart · New York — Synlett 2015, 26, A–F into the corresponding 1,3-amino alcohols upon NaBH4- nancial support. EA. Pejović et al. LetterSyn lett References and Notes (1) For recent reviews, see: (a) Noel, T.; Van der Eycken, J. Green Processing and Synthesis 2013, 2, 297. (b) Schaarschmidt, D.; Lang, H. Organometallics 2013, 32, 5668. (2) For a review, see: Fouda, M. F. R.; Abd-Elzaher, M. M.; Abdelsamaia, R. A.; Labib, A. A. Appl. Organomet. Chem. 2007, 21, 613. (3) For a recent review, see: Quirante, J.; Dubar, F.; Gonzalez, A.; Lopez, C.; Cascante, M.; Cortes, R.; Forfar, I.; Pradines, B.; Biot, C. J. Organomet. Chem. 2011, 696, 1011. (4) For a review, see: Scutaru, D.; Tataru, L.; Mazilu, I.; Vata, M.; Lixandru, T.; Simionescu, C. Appl. Organomet. Chem. 1993, 7, 225. (5) For a recent review, see: Braga, S. S.; Silva, A. M. S. Organometal- lics 2013, 32, 5626. (6) For a recent review, see: Pereira, C. M. P.; Venzke, D.; Trossini, G. H. G. Quim. Nova 2013, 36, 143. (7) (a) Damljanović, I.; Stevanović, D.; Pejović, A.; Vukićević, M.; Novaković, S. B.; Bogdanović, G. A.; Mihajlov-Krstev, T.; Radulović, N.; Vukićević, R. D. J. Organomet. Chem. 2011, 696, 3703. (b) Pejović, A.; Denić, M. S.; Stevanović, D.; Damljanović, I.; Vukićević, M.; Kostova, K.; Tavlinova-Kirilova, M.; Randjelović, P.; Stojanović, N. M.; Bogdanović, G. A.; Blagojević, P.; D’hooghe, M.; Radulović, N. S.; Vukićević, R. D. Eur. J. Med. Chem. 2014, 83, 73. (c) Radulović, N. S.; Zlatković, D. B.; Mitić, K. V.; Randjelović, P. J.; Stojanović, N. M. Polyhedron 2014, 80, 134. (d) Pejović, A.; Damljanović, I.; Stevanović, D.; Vukićević, M.; Novaković, S. B.; Bogdanović, G. A.; Radulović, N.; Vukićević, R. D. Polyhedron 2012, 31, 789. (e) Damljanović, I.; Vukićević, M.; Radulović, N.; Palić, R.; Ellmerer, E.; Ratković, Z.; Joksović, M. D.; Vukićević, R. D. Bioorg. Med. Chem. Lett. 2009, 19, 1093. (f) Ilić, D.; Damljanović, I.; Stevanović, D.; Vukićević, M.; Blagojević, P.; Radulović, N.; Vukićević, R. D. Chem. Biodiversity 2012, 9, 2236. (g) Radulović, N. S.; Mladenović, M. Z.; Stojanović-Radić, Z.; Bogdanović, G. A.; Stevanović, D.; Vukićević, R. D. Mol. Diversity 2014, 18, 497. (h) Damljanović, I.; Stevanović, D.; Pejović, A.; Ilić, D.; Živković, M.; Jovanović, J.; Vukićević, M.; Bogdanović, G. A.; Radulović, N. S.; Vukićević, R. D. RSC Adv. 2014, 4, 43792. (8) (a) Dolfen, J.; Kenis, S.; Van Hecke, K.; De Kimpe, N.; D’hooghe, M. Chem. Eur. J. 2014, 20, 10650. (b) De Vreese, R.; Verhaeghe, T.; Desmet, T.; D’hooghe, M. Chem. Commun. 2013, 3775. (c) Kenis, S.; D’hooghe, M.; Verniest, G.; Reybroeck, M.; Dang, Thi. T. A.; Pham The, C.; Thi Pham, T.; Törnroos, K. W.; Van Tuyen, N.; De Kimpe, N. Chem. Eur. J. 2013, 19, 5966. (d) Mollet, K.; Goossens, H.; Piens, N.; Catak, S.; Waroquier, M.; Törnroos, K. W.; Va Speybroeck, V.; D’hooghe, M.; De Kimpe, N. Chem. Eur. J. 2013, 19, 3383. (e) Mollet, K.; D’hooghe, M.; De Kimpe, N. Mini-Rev. Org. Chem. 2013, 10, 1. (f) Vervisch, K.; D’hooghe, M.; Törnroos, K. W.; De Kimpe, N. Org. Biomol. Chem. 2012, 10, 3308. (g) Vervisch, K.; D’hooghe, M.; Rutjes, F. P. J. T.; De Kimpe, N. Org. Lett. 2012, 14, 106. (h) Mollet, K.; Catak, S.; Waroquier, M.; Van Speybroeck, V.; D’hooghe, M.; De Kimpe, N. J. Org. Chem. 2011, 76, 8364. (i) Vervisch, K.; D’hooghe, M.; Törnroos, K. W.; De Kimpe, N. J. Org. Chem. 2010, 75, 7734. (9) For a review, see: Lait, S. M.; Rankic, D. A.; Keay, B. A. Chem. Rev. 2007, 107, 767. (10) 6-Ferrocenyl-3-phenyl-1,3-oxazinane (6a) Yield 78%, dark yellow solid; mp 86 °C. 1H NMR (400 MHz, 3.91 (ddt, J = 13.5, 4.3, 2.3 Hz, 1 H), 3.49 (ddd, J = 13.5, 12.7, 2.9 Hz, 1 H), 2.02 (dddd, J = 13.1, 12.7, 11.2, 4.3 Hz, 1 H), 1.78 (ddt, J =13.1, 2.9, 2.4 Hz, 1 H). 13C NMR (100 MHz, CDCl3): δ = 148.9, 129.1, 120.5, 118.4, 88.9, 81.3, 76.0, 68.6, 68.0, 67.8, 67.3, 66.0, 49.9, 29.2. MS (ES+): m/z = 348.1 [MH+]. Column chromatogra- phy (SiO2): hexane–EtOAc, 8:2 (v/v). ESI-HRMS: m/z calcd for C20H22FeNO [M + H]+: 348.1050; found: 348.1041. (11) Cassady, J. M.; Chan, K. K.; Floss, H. G.; Leistner, E. Chem. Pharm. Bull. 2004, 52, 1. (12) Meyers, A. I.; Roland, D. M.; Comins, D. L.; Henning, R.; Fleming, M. P.; Shimizu, K. J. Am. Chem. Soc. 1979, 101, 4732. (13) Gormley, G. Jr.; Chan, Y. Y.; Fried, J. J. Org. Chem. 1980, 45, 1447. (14) Widdison, W. C.; Wilhelm, S. D.; Cavanagh, E. E.; Whiteman, K. R.; Leece, B. A.; Kovtun, Y.; Goldmacher, V. S.; Xie, H.; Steeves, R. M.; Lutz, R. J.; Zhao, R.; Wang, L.; Blaettler, W. A.; Chari, R. V. J. J. Med. Chem. 2006, 49, 4392. (15) D’hooghe, M.; Dekeukeleire, S.; Mollet, K.; Lategan, C.; Smith, P. J.; Chibale, K.; De Kimpe, N. J. Med. Chem. 2009, 52, 4058. (16) (a) Singh, H.; Singh, K. Tetrahedron 1989, 45, 3967. (b) Alberola, A.; Alvarez, M. A.; Andres, C.; Gonzalez, A.; Pedrosa, R. Synthesis 1990, 1057. (c) Singh, K.; Deb, P. K.; Venugopalan, P. Tetrahedron 2001, 57, 7939. (17) 6-Ferrocenyl-3-phenyl-1,3-oxazinan-2-one (8a) Yield 64%, yellow solid; mp 148 °C. 1H NMR (400 MHz, CDCl3): δ = 7.43–7.38 (m, 2 H), 7.37–7.33 (m, 2 H), 7.29–7.24 (m, 1 H), 5.31 (dd, J = 9.5, 3.0 Hz, 1 H), 4.36 (ca. dt, J = 2.5, 1.3 Hz, 1 H), 4.28 (ca. dt, J = 2.5, 1.3 Hz, 1 H), 4.23–4.19 (m, 2 H), 4.24 (s, 5 H), 3.81 (ddd, J = 11.7, 10.2, 4.9 Hz, 1 H), 3.70 (ddd, J = 11.7, 5.5, 4.1 Hz, 1 H), 2.45 (dddd, J = 13.8, 4.9, 4.1, 3.0 Hz, 1 H), 2.28 (dddd, J = 13.8, 10.2, 9.5, 5.5 Hz, 1 H). 13C NMR (100 MHz, CDCl3): δ = 152.8, 143.1, 129.4, 126.9, 126.0, 86.3, 76.2, 69.1, 68.5, 68.4, 67.4, 66.1, 47.9, 28.9. IR (ATR): ν = 1685 (C=O) cm–1. MS (ES+): m/z = 362.1 [MH+]. Column chromatography (SiO2): hexane– EtOAc, 8:2 (v/v). ESI-HRMS: m/z calcd for C20H20FeNO2 [M + H]+: 362.0844; found: 362.0834. (18) (a) Fujiwara, M.; Baba, A.; Matsuda, H. J. Heterocycl. Chem. 1989, 26, 1659. (b) Shibata, I.; Nakamura, K.; Baba, A.; Matsuda, H. Bull. Chem. Soc. Jpn. 1989, 62, 853. (c) Baba, A.; Shibata, I.; Fujiwara, M.; Matsuda, H. Tetrahedron Lett. 1985, 26, 5167. (d) Rice, G. T.; White, M. C. J. Am. Chem. Soc. 2009, 131, 11707. (e) Nahra, F.; Liron, F.; Prestat, G.; Mealli, C.; Messaoudi, A.; Poli, G. Chem. Eur. J. 2009, 15, 11078. (f) Mangelinckx, S.; Nural, Y.; Dondas, H. A.; Denolf, B.; Sillanpää, R.; De Kimpe, N. Tetrahedron 2010, 66, 4115. (19) Davies, S. G.; Garner, A. C.; Robert, P. M.; Smith, A. D.; Sweet, M. J.; Thomson, J. E. Org. Biomol. Chem. 2006, 4, 2753. (20) (a) Park, M.; Lee, J. Arch. Pharmacol. Res. 1993, 16, 158. (b) Li, X.; Wang, R.; Wang, Y.; Chen, H.; Li, Z.; Ba, C.; Zhang, J. Tetrahedron 2008, 64, 9911. (c) McElroy, C. R.; Aricò, F.; Benetollo, F.; Tundo, P. Pure Appl. Chem. 2012, 84, 707. (d) Wang, G.; Ella-Menye, J.- R.; Sharma, V. Bioorg. Med. Chem. Lett. 2006, 16, 2177. (e) Xu, Z. R.; Tice, C. M.; Zhao, W.; Cacatian, S.; Ye, Y. J.; Singh, S. B.; Lindblom, P.; McKeever, B. M.; Krosky, P. M.; Kruk, B. A.; Berbaum, J.; Harrison, R. K.; Johnson, J. A.; Bukhtiyarov, Y.; Panemangalore, R.; Scott, B. B.; Zhao, Y.; Bruno, J. G.; Togias, J.; Guo, J.; Guo, R.; Carroll, P. J.; McGeehan, G. M.; Zhuang, L. H.; He, W.; Claremont, D. A. J. Med. Chem. 2011, 54, 6050. (21) 4-Ferrocenyl-3-isopropyl-1-phenyltetrahydropyrimidin-2- one (10a)© Georg Thieme Verlag Stuttgart · New York — Synlett 2015, 26, A–F CDCl3): δ = 7.34–7.27 (m, 2 H), 7.13–7.09 (m, 2 H), 6.93–6.87 (m, 1 H), 5.30 (dd, J = 10.7, 2.3 Hz, 1 H), 4.74 (d, J = 10.7 Hz, 1 H), 4.48 (dd, J = 11.2, 2.4 Hz, 1 H), 4.22 (ca. dt, J = 2.5, 1.3 Hz, 1 H), 4.17 (ca. dt, J = 2.5, 1.3 Hz, 1 H), 4.15–4.07 (m, 2 H), 4.12 (s, 5 H), Yield 61%, orange liquid. 1H NMR (400 MHz, CDCl3): δ = 7.34– 7.27 (m, 2 H), 7.25–7.20 (m, 2 H), 7.16–7.09 (m, 1 H), 4.46 (t, J = 3.9 Hz, 1 H), 4.24 (d × t, J = 2.4, 1.2 Hz, 1 H), 4.20–4.09 (m, 3 H), 4.16 (s, 5 H), 4.13–4.10 (m, 1 H), 3.62–3.46 (m, 2 H), 2.33–2.15 FA. Pejović et al. LetterSyn lett (m, 2 H), 1.37 (d, J = 6.8 Hz, 3 H), 1.28 (d, J = 6.8 Hz, 3 H). 13C NMR (100 MHz, CDCl3): δ = 154.5, 144.3, 128.8, 126.0, 125.2, 91.2, 69.4, 68.9, 68.4, 66.7, 66.0, 53.0, 50.9, 45.2, 31.7, 21.3, 20.9. IR: ν = 1636 (C=O) cm–1. MS (ES+): m/z = 403.2 [M + H]+. Prepar- ative chromatography (SiO2): hexane–EtOAc, 6:4 (v/v). ESI- HRMS: m/z calcd for C20H20FeNO2 [M + H]+: 403.1473; found: 403.1475. (22) Natarajan, S. R.; Doherty, J. B. Curr. Top. Med. Chem. 2005, 5, 987. (23) James, C. A.; DeRoy, P.; Duplessis, M.; Edwards, P. J.; Halmos, T.; Minville, J.; Morency, L.; Morin, S.; Simoneau, B.; Tremblay, M.; Bethell, R.; Cordingley, M.; Duan, J. M.; Lamorte, L.; Pelletier, A.; Rajotte, D.; Salois, P.; Tremblay, S.; Sturino, C. F. Bioorg. Med. Chem. Lett. 2013, 23, 2781. (24) (a) NCCLS. Method for Antifungal Disk Diffusion Susceptibility Testing of Yeasts; Approved Guideline. NCCLS document M44-A [ISBN 1-56238-532-1]. 24, (NCCLS, NCCLS, 940 West Valley Road, Suite 1400, Wayne, Pennsylvania 19087-1898 USA, 2004). (b) CLSI. Performance Standards for Antimicrobial Disk Suscepti- bility Tests; Approved Standard—Eleventh Edition. CLSI document M02-A11. Wayne, 32, (Clinical and Laboratory Standards Insti- tute, 2012).© Georg Thieme Verlag Stuttgart · New York — Synlett 2015, 26, A–F T , . . ' i - * i " r ' ! : i ' ' i , l , r , -l.q i!]|,. ii ig$f'Slt r.t AitrnH?{*H,t{.ia 6:p,si 0s€ iPee..f,r, r' n qfr$eF : rrFdhili sa npqAroxeHa Alrcepraquja y qenuHl4 H14 y AenoBuma n4ie 6nna npe*nox(eHa 3a go6nJFbe 6nno, xoje AHnnoMe npena. cvygr+Jcrcru nporpauun4q APyfHx ancor