Synthesis of biologically active cyclic derivatives of 5(6)-amino substituted benzimidazoles

U okviru ovog rada provedena je sinteza acikličkog 2-benzimidazolil supstituiranog akrilonitrila 6 te njegovog cikličkog analoga benzimidazo[1,2-a]kinolina 7. Spojevi su priređeni klasičnim reakcijama organske sinteze te aminacijom potpomognutom mikrovalnim zračenjem. Benzimidazolil-supstituirani akrilonitril 6 priređen iz 2-cijanometil-5(6)- piperidinilbenzimidazola 4 i o-klorbenzaldehida 5, dok je benzimidazo[1,2-a]kinolin 7 priređen termičkom ciklizacijom akrilonitrila 6 u sulfolanu pri čemu je dobivena smjesa dva regioizomera. Strukture priređenih spojeva potvrđene su 1H i 13C NMR spektroskopijom. Spojevi 3-7 okarakterizirani su UV/Vis i fluormetrijskom spektroskopijom.This work presents the synthesis of novel 2-benzimidazolyil-substituted acrylonitrile 6 and it's cyclic analog, benzimidazo[1,2-ɑ]qinoline 7. Novel compounds were prepared by using a classical reactions of organic chemistry and microwave assisted amination. Benzimidazolyilsubstituted acrylonitrile 6 was prepared in reaction of 2-cyanomethyl-5(6)- piperidinylbenzimidazole 4 with o-chlorobenzaldehyde 5. Benzimidazo[1,2-ɑ]quinoline 7 was prepared by thermal cyclization of acrylonitrile 6 in sulfolane as a mixture of two regioisomers. The structures of all compounds were determined by means of 1H and 13C NMR and UV/Vis and fluorimetric spectroscopy

Synthesis, Computational Analysis, and Antiproliferative Activity of Novel Benzimidazole Acrylonitriles as Tubulin Polymerization Inhibitors: Part 2

We used classical linear and microwave-assisted synthesis methods to prepare novel Nsubstituted, benzimidazole-derived acrylonitriles with antiproliferative activity against several cancer cells in vitro. The most potent systems showed pronounced activity against all tested hematological cancer cell lines, with favorable selectivity towards normal cells. The selection of lead compounds was also tested in vitro for tubulin polymerization inhibition as a possible mechanism of biological action. A combination of docking and molecular dynamics simulations confirmed the suitability of the employed organic skeleton for the design of antitumor drugs and demonstrated that their biological activity relies on binding to the colchicine binding site in tubulin. In addition, it also underlined that higher tubulin affinities are linked with (i) bulkier alkyl and aryl moieties on the benzimidazole nitrogen and (ii) electron-donating substituents on the phenyl group that allow deeper entrance into the hydrophobic pocket within the tubulin’s -subunit, consisting of Leu255, Leu248, Met259, Ala354, and Ile378 residues

Synthesis of biologically active cyclic derivatives of 5(6)-amino substituted benzimidazoles

U okviru ovog rada provedena je sinteza acikličkog 2-benzimidazolil supstituiranog akrilonitrila 6 te njegovog cikličkog analoga benzimidazo[1,2-a]kinolina 7. Spojevi su priređeni klasičnim reakcijama organske sinteze te aminacijom potpomognutom mikrovalnim zračenjem. Benzimidazolil-supstituirani akrilonitril 6 priređen iz 2-cijanometil-5(6)- piperidinilbenzimidazola 4 i o-klorbenzaldehida 5, dok je benzimidazo[1,2-a]kinolin 7 priređen termičkom ciklizacijom akrilonitrila 6 u sulfolanu pri čemu je dobivena smjesa dva regioizomera. Strukture priređenih spojeva potvrđene su 1H i 13C NMR spektroskopijom. Spojevi 3-7 okarakterizirani su UV/Vis i fluormetrijskom spektroskopijom.This work presents the synthesis of novel 2-benzimidazolyil-substituted acrylonitrile 6 and it's cyclic analog, benzimidazo[1,2-ɑ]qinoline 7. Novel compounds were prepared by using a classical reactions of organic chemistry and microwave assisted amination. Benzimidazolyilsubstituted acrylonitrile 6 was prepared in reaction of 2-cyanomethyl-5(6)- piperidinylbenzimidazole 4 with o-chlorobenzaldehyde 5. Benzimidazo[1,2-ɑ]quinoline 7 was prepared by thermal cyclization of acrylonitrile 6 in sulfolane as a mixture of two regioisomers. The structures of all compounds were determined by means of 1H and 13C NMR and UV/Vis and fluorimetric spectroscopy

Synthesis and spectroscopic characterization of novel N-substituted benzimidazole derivatives

U okviru ovog rada provedena je sinteza novih i potencijalno biološki aktivnih N-supstituiranih derivata benzimidazola 12–14 i 31–43 te 2-benzimidazolil supstituiranog akrilonitrila 49. Novi spojevi priređeni su klasičnim reakcijama organske sinteze kao i sintezama potpomognutim mikrovalnim zračenjem. Višestupnjevitom linearnom sintezom priređeni su glavni prekursori, N-supstituirani derivati 5-cijano-2-cijanometilbenzimidazola 8–10, N-supstituirani derivati 2-cijanometilbenzimidazola 20–22 te 2-cijanometil-5(6)-piperidinilbenzimidazol 47. Derivati akrilonitrila s cijano grupom na benzimidazolskoj jezgri 12–14 priređeni su aldolnom kondenzacijom N-supstituiranih derivata 5-cijano-2-cijanometilbenzimidazola 8–10 s 4-N,N-dimetilaminobenzaldehidom 11. Spojevi 13 i 14 izolirani su kao E-izomeri dok je spoj 12 dobiven kao smjesa geometrijskih izomera u omjeru 1 (12b): 3 (12a). Derivati akrilonitrila 31–43 priređeni su reakcijama aldolne kondenzacije N-supstituiranih derivata 2-cijanometilbenzimidazola 20–22 s odgovarajućim aromatskim i heteroaromatskim aldehidima 23-30. Akrilonitrili 32 i 34–43 su izolirani kao E-izomeri, dok su spojevi 31 i 33 dobiveni kao smjesa geometrijskih izomera u omjeru 1 (31b): 2 (31a) i 1 (33b): 5 (33a). Piperidinil-supstituirani derivat akrilonitrila 49 priređen je reakcijom aldolne kondenzacije između 2-cijanometil-5(6)-piperidinilbenzimidazola i 4-dimetilaminobenzaldehida u obliku tautomera 49a i 49b. Struktura svih novopriređenih spojeva potvrđena je 1H i 13C NMR spektroskopijom te masenom spektrometrijom.This work presents the synthesis of novel potentially biologically active N-substituted benzimidazole derivatives 8–10 and 20–22 and 2-benzimidazolyl-substituted acrylonitrile 49. Novel compounds were prepared by classical reactions of organic chemistry and by microwave assisted reactions. Corresponding main precursors, N-substituted 5-cyano-2-cyanomethylbenzimidazoles 8–10, N-substituted 2-cyanomethylbenzimidazoles 20–22 and 2-cyanomethyl-5(6)-piperidinyl-benzimidazole 47 were prepared by using multi-step linear synthesis. Acrylonitrile derivatives with cyano group on the benzimidazole nuclei 12–14 were prepared by aldol condensation of N-substituted 5-cyano-2-cyanomethylbenzimidazoles 8–10 and 4-N,N-dimethyl-aminobenzaldehyde 11. Compounds 13 and 14 were isolated as E-isomers while compound 12 was isolated as a mixture of two geometric isomers in a 1 (12b): 3 (12a) ratio. Acrylonitrile derivatives 31–43 were prepared by aldol condensation of N-substituted 2-cyanomethylbenzimidazoles 20–22 with corresponding aromatic and heteroaromatic aldehydes 23–30. Compounds 32 and 34–43 were isolated as E-isomers while compounds 31 and 33 were isolated as a mixture of two geometric isomers in a 1 (31b): 2 (31a) and 1 (33b): 5 (33a) ratio. Piperidinyl-substituted acrylonitrile derivative 49 was prepared by aldol condensation of 2-cyanomethyl-5(6)-piperidinylbenzimidazole and 4-N,N-dimethylaminobenzaldehyde as a mixture of two tautomers 49a and 49b. The structures of all compounds were determined by means of 1H and 13C NMR spectroscopy as well as mas spectrometry

Synthesis and spectroscopic characterization of novel N-substituted benzimidazole derivatives

U okviru ovog rada provedena je sinteza novih i potencijalno biološki aktivnih N-supstituiranih derivata benzimidazola 12–14 i 31–43 te 2-benzimidazolil supstituiranog akrilonitrila 49. Novi spojevi priređeni su klasičnim reakcijama organske sinteze kao i sintezama potpomognutim mikrovalnim zračenjem. Višestupnjevitom linearnom sintezom priređeni su glavni prekursori, N-supstituirani derivati 5-cijano-2-cijanometilbenzimidazola 8–10, N-supstituirani derivati 2-cijanometilbenzimidazola 20–22 te 2-cijanometil-5(6)-piperidinilbenzimidazol 47. Derivati akrilonitrila s cijano grupom na benzimidazolskoj jezgri 12–14 priređeni su aldolnom kondenzacijom N-supstituiranih derivata 5-cijano-2-cijanometilbenzimidazola 8–10 s 4-N,N-dimetilaminobenzaldehidom 11. Spojevi 13 i 14 izolirani su kao E-izomeri dok je spoj 12 dobiven kao smjesa geometrijskih izomera u omjeru 1 (12b): 3 (12a). Derivati akrilonitrila 31–43 priređeni su reakcijama aldolne kondenzacije N-supstituiranih derivata 2-cijanometilbenzimidazola 20–22 s odgovarajućim aromatskim i heteroaromatskim aldehidima 23-30. Akrilonitrili 32 i 34–43 su izolirani kao E-izomeri, dok su spojevi 31 i 33 dobiveni kao smjesa geometrijskih izomera u omjeru 1 (31b): 2 (31a) i 1 (33b): 5 (33a). Piperidinil-supstituirani derivat akrilonitrila 49 priređen je reakcijom aldolne kondenzacije između 2-cijanometil-5(6)-piperidinilbenzimidazola i 4-dimetilaminobenzaldehida u obliku tautomera 49a i 49b. Struktura svih novopriređenih spojeva potvrđena je 1H i 13C NMR spektroskopijom te masenom spektrometrijom.This work presents the synthesis of novel potentially biologically active N-substituted benzimidazole derivatives 8–10 and 20–22 and 2-benzimidazolyl-substituted acrylonitrile 49. Novel compounds were prepared by classical reactions of organic chemistry and by microwave assisted reactions. Corresponding main precursors, N-substituted 5-cyano-2-cyanomethylbenzimidazoles 8–10, N-substituted 2-cyanomethylbenzimidazoles 20–22 and 2-cyanomethyl-5(6)-piperidinyl-benzimidazole 47 were prepared by using multi-step linear synthesis. Acrylonitrile derivatives with cyano group on the benzimidazole nuclei 12–14 were prepared by aldol condensation of N-substituted 5-cyano-2-cyanomethylbenzimidazoles 8–10 and 4-N,N-dimethyl-aminobenzaldehyde 11. Compounds 13 and 14 were isolated as E-isomers while compound 12 was isolated as a mixture of two geometric isomers in a 1 (12b): 3 (12a) ratio. Acrylonitrile derivatives 31–43 were prepared by aldol condensation of N-substituted 2-cyanomethylbenzimidazoles 20–22 with corresponding aromatic and heteroaromatic aldehydes 23–30. Compounds 32 and 34–43 were isolated as E-isomers while compounds 31 and 33 were isolated as a mixture of two geometric isomers in a 1 (31b): 2 (31a) and 1 (33b): 5 (33a) ratio. Piperidinyl-substituted acrylonitrile derivative 49 was prepared by aldol condensation of 2-cyanomethyl-5(6)-piperidinylbenzimidazole and 4-N,N-dimethylaminobenzaldehyde as a mixture of two tautomers 49a and 49b. The structures of all compounds were determined by means of 1H and 13C NMR spectroscopy as well as mas spectrometry

Synthesis and structural characterization of novel benzimidazole and benzothiazole derivatives as potential antiproliferative agents with antioxidative activity

U ovom radu opisana je sinteza nekoliko klasa derivata benzimidazola i benzotiazola kojima je ispitana antiproliferativna i antioksidativna aktivnost. U linearnoj višestupanjskoj sintezi novih konjugata benzazola primijenjeni su klasični sintetski pristupi kao i neke suvremene sintetske metode, uključujući sintezu u ekološki prihvatljivim otapalima ili sintezu potpomognutu mikrovalovima. Novi akrilonitrilni derivati N-supstituiranih derivata benzazola 32‒71 i 77‒107 priređeni su aldolnom kondenzacijom odgovarajućih cijanometilbenzazola s benzaldehidima supstituirani promjenjivim brojem metoksi i hidroksi skupina te 4-N,N-dimetilamino i 4-N,N-dietilamino skupinom. Derivati Schiffovih baza supstituirani benzimidazolom 117‒132 priređeni su kondenzacijom N-supstituiranih 2-aminobenzimidazola 108‒115 s odgovarajućim 4-N,N-dimetilamino i 4-N,N-dietilamino supstituiranim benzaldehidima. Derivati iminokumarina i kumarina 134‒149 te amidino-supstituirani derivati kumarina 164‒175 priređeni su ciklokondenzacijom različito supstituiranih 2-hidroksibenzaldehida s odgovarajućim 2-cijanometilbenzimidazolima, te iz kumarinskih aldehida reakcijom kondenzacije s odgovarajućim 4-amidino-supstituiranim 1,2-fenilendiaminima uz korištenje p-benzokinona kao oksidansa. Amidino-supstituirani benzimidazoli 193‒216 priređeni su kondenzacijom 5-supstituiranih salicilaldehida s odgovarajućim 4-amidino-supstituiranim 1,2-fenilendiaminima. Amidino-supstituirani benzotiazoli 179‒181 i 216‒227 priređeni su iz različito supstituiranih 2-hidroksibenzaldehida i odgovarajućih zwitter iona u ledenoj octenoj kiselini. Metoksi-supstituirani karboksamidi 235‒262 priređeni su kondenzacijom benzoilnih klorida s N-supstituiranim derivatima 2-aminobenzimidazola. Hidroksi-supstituirani amidni derivati N-benzimidazola 263‒268 i 280‒286 priređeni su uklanjanjem zaštitnih metoksi skupina, korištenjem BBr3 na niskim temperaturama, te benzilnih zaštitnih skupina katalitičkim hidrogeniranjem uz Pd/C u metanolu. Amidino-supstituirani derivati benzamida 289‒293 priređeni su kiselo-kataliziranom Pinnerovom reakcijom iz odgovarajućih cijano-supstituiranih polaznih spojeva. Strukture novosintetiziranih spojeva potvrđene su 1H i 13C NMR spektroskopijom, a nekim je spojevima struktura dodatno okarakterizirana i masenom spektrometrijom. Svim priređenim spojevima ispitana je antiproliferativna aktivnost in vitro na niz staničnih linija humanih karcinoma i zdravih stanica, dok je ispitivanje antioksidativne aktivnosti in vitro provedeno primjenom spektroskopskih metoda DPPH, FRAP i ABTS. Amidino-supstituiranim derivatima 164‒175 i 179‒181 ispitana je antiviralna aktivnost in vitro na nekoliko sojeva virusa, te su neki od derivata pokazali jako dobru i selektivnu aktivnost prema pojedinim sojevima virusa. Derivatima Schiffovih baza 117‒132 te amidino-supstituiranim benzazolima 193‒216 i 217‒228 ispitana je i antibakterijska aktivnost prema Gram pozitivnim i Gram negativnim bakterijama. Iz dobivenih rezultata ispitivanja biološke aktivnosti i SAR studije, utvrđeno je da na antioksidativnu aktivnost značajno utječe broj metoksi i hidroksi skupina na fenilnom prstenu, te supstituent na dušikovom atomu benzimidazolne jezgre. Najizraženiji utjecaj na povećanje antiproliferativne aktivnosti pokazuje 4-N,N-dietilamino skupina smještena na položaju 7 kumarinskog prstena i fenilnom prstenu akrilonitrilnih derivata, te izobutilni supstituent na N atomu benzimidazolne jezgre. Nekima od najaktivnijih derivata benzazola dodatno su ispitani mehanizmi biološkog djelovanja, te je tako utvrđeno da neki derivati akrilonitrila i iminokumarina djeluju kao inhibitori polimerizacije tubulina, dok je amidnim derivatima ispitana i antioksidativna aktivnost u stanicama. Dokazano je i da najbolju antivirusnu aktivnost ima kumarinski derivat benzimidazola supstituiran nesupstituiranim amidinom koji inhibira ranu fazu replikacijskog ciklusa virusa, odnosno sintezu virusne RNK.This thesis describes the synthesis of several classes of benzimidazoles and benzothiazoles in order to investigate their antiproliferative and antioxidant activity. By using multi-step linear synthesis of new benzazole conjugates, classical synthetic approaches as well as some modern synthetic methods, including synthesis in environmentally friendly solvents or microwave-assisted synthesis, were applied. New acrylonitrile derivatives of N-substituted benzazoles 32‒71 and 77‒107 were prepared by aldol condensation of the corresponding cyanomethylbenzazoles with benzaldehydes with a variable number of methoxy and hydroxy groups and 4-N,N-dimethylamino and 4-N,N-diethylamino groups. Benzimidazole derived Schiff bases 117‒132 were prepared by condensation of N-substituted 2-aminobenzimidazoles 108‒115 with corresponding 4-N,N-dimethylamino and 4-N,N-diethylamino-substituted benzaldehydes. Iminocoumarin and coumarine derivatives 134‒149 and amidino-substituted coumarine derivatives 164‒175 obtained by cyclocondensation of substituted 2-hydroxybenzaldehydes with corresponding 2-cyanomethylbenzimidazoles as well as from coumarine aldehydes with corresponding 4-amidino-substituted 1,2-phenylenediamines using p-benzoquinone as an oxidant. Amidino-substituted benzimidazoles 193‒216 were synthesized within the condensation of 5-substituted salicylaldehydes with corresponding 4-amidino-substituted 1,2-phenylenediamines. Amidino-substituted benzothiazoles 179‒181 i 216‒227 were prepared by condensation of differently substituted 2-hydroxybenzaldehydes and corresponding zwitter ions in glacial acetic acid. Methoxy-substituted carboxamides 235‒262 were prepared by condensation of benzoyl chlorides with N-substituted 2-aminobenzimidazole derivatives. Hydroxy-substituted amide derivatives of N-benzimidazole 263‒268 and 280‒286 obtained by removing protective methoxy groups, using BBr3 at low temperatures, and benzyl protective groups by catalytic hydrogenation with Pd/C in methanol. Amidino-substituted benzamide derivatives 289‒293 were synthesized via acid-catalyzed Pinner reaction from the corresponding cyano-substituted starting precursors. Structures of all newly prepared compounds were confirmed by 1H and 13C NMR spectroscopy while some of them were additionally characterized by mass spectrometry. All prepared compounds were tested for their antiproliferative activity in vitro on a number of human cancer cell lines as well as normal fibroblasts, while antioxidant activity in vitro was performed using spectroscopic DPPH, FRAP and ABTS methods. Amidino-substituted derivatives 164‒175 and 179‒181 were tested for antiviral activity in vitro on several virus strains, and some compounds have shown pronounced and selective activity against some viruses. Schiff base derived benzazoles 117‒132 and amidino-substituted benzazoles 193‒216 and 217‒228 were tested for antibacterial activity against Gram positive and Gram negative bacteria. Results obtained from evaluation of biological activity and SAR studies, revealed that the antioxidant activity is affected by the number of methoxy and hydroxy groups on the phenyl ring as well as the substituent on the nitrogen atom of the benzimidazole nucleus. The strongest impact on the enhancement of antiproliferative activity was observed by 4-N,N-diethylamino group placed at the position 7 on coumarin ring and phenyl ring of acrylonitrile derivatives. The isobutyl substituent on the N atom of the benzimidazole core has the greatest influence on increasing the activity of the synthesized compounds. Some of the most active benzazole derivatives were additionally evaluated to study their mechanisms of biological action and it was confirmed that some of the acrylonitrile and iminocoumarin derivatives have proven to be tubuline polymerization inhibitors, while for amide derivatives the antioxidative activity was tested also in the cells. It has been proven that the most promising antiviral activity has been possessed by coumarine derived benzimidazole substituted with amidine group, being inhibitor of an early step in the replication cycle of virus, respectively the synthesis of viral RNA

Synthesis and spectroscopic characterization of novel N-substituted benzimidazole derivatives

U okviru ovog rada provedena je sinteza novih i potencijalno biološki aktivnih N-supstituiranih derivata benzimidazola 12–14 i 31–43 te 2-benzimidazolil supstituiranog akrilonitrila 49. Novi spojevi priređeni su klasičnim reakcijama organske sinteze kao i sintezama potpomognutim mikrovalnim zračenjem. Višestupnjevitom linearnom sintezom priređeni su glavni prekursori, N-supstituirani derivati 5-cijano-2-cijanometilbenzimidazola 8–10, N-supstituirani derivati 2-cijanometilbenzimidazola 20–22 te 2-cijanometil-5(6)-piperidinilbenzimidazol 47. Derivati akrilonitrila s cijano grupom na benzimidazolskoj jezgri 12–14 priređeni su aldolnom kondenzacijom N-supstituiranih derivata 5-cijano-2-cijanometilbenzimidazola 8–10 s 4-N,N-dimetilaminobenzaldehidom 11. Spojevi 13 i 14 izolirani su kao E-izomeri dok je spoj 12 dobiven kao smjesa geometrijskih izomera u omjeru 1 (12b): 3 (12a). Derivati akrilonitrila 31–43 priređeni su reakcijama aldolne kondenzacije N-supstituiranih derivata 2-cijanometilbenzimidazola 20–22 s odgovarajućim aromatskim i heteroaromatskim aldehidima 23-30. Akrilonitrili 32 i 34–43 su izolirani kao E-izomeri, dok su spojevi 31 i 33 dobiveni kao smjesa geometrijskih izomera u omjeru 1 (31b): 2 (31a) i 1 (33b): 5 (33a). Piperidinil-supstituirani derivat akrilonitrila 49 priređen je reakcijom aldolne kondenzacije između 2-cijanometil-5(6)-piperidinilbenzimidazola i 4-dimetilaminobenzaldehida u obliku tautomera 49a i 49b. Struktura svih novopriređenih spojeva potvrđena je 1H i 13C NMR spektroskopijom te masenom spektrometrijom.This work presents the synthesis of novel potentially biologically active N-substituted benzimidazole derivatives 8–10 and 20–22 and 2-benzimidazolyl-substituted acrylonitrile 49. Novel compounds were prepared by classical reactions of organic chemistry and by microwave assisted reactions. Corresponding main precursors, N-substituted 5-cyano-2-cyanomethylbenzimidazoles 8–10, N-substituted 2-cyanomethylbenzimidazoles 20–22 and 2-cyanomethyl-5(6)-piperidinyl-benzimidazole 47 were prepared by using multi-step linear synthesis. Acrylonitrile derivatives with cyano group on the benzimidazole nuclei 12–14 were prepared by aldol condensation of N-substituted 5-cyano-2-cyanomethylbenzimidazoles 8–10 and 4-N,N-dimethyl-aminobenzaldehyde 11. Compounds 13 and 14 were isolated as E-isomers while compound 12 was isolated as a mixture of two geometric isomers in a 1 (12b): 3 (12a) ratio. Acrylonitrile derivatives 31–43 were prepared by aldol condensation of N-substituted 2-cyanomethylbenzimidazoles 20–22 with corresponding aromatic and heteroaromatic aldehydes 23–30. Compounds 32 and 34–43 were isolated as E-isomers while compounds 31 and 33 were isolated as a mixture of two geometric isomers in a 1 (31b): 2 (31a) and 1 (33b): 5 (33a) ratio. Piperidinyl-substituted acrylonitrile derivative 49 was prepared by aldol condensation of 2-cyanomethyl-5(6)-piperidinylbenzimidazole and 4-N,N-dimethylaminobenzaldehyde as a mixture of two tautomers 49a and 49b. The structures of all compounds were determined by means of 1H and 13C NMR spectroscopy as well as mas spectrometry

Synthesis and structural characterization of novel benzimidazole and benzothiazole derivatives as potential antiproliferative agents with antioxidative activity

U ovom radu opisana je sinteza nekoliko klasa derivata benzimidazola i benzotiazola kojima je ispitana antiproliferativna i antioksidativna aktivnost. U linearnoj višestupanjskoj sintezi novih konjugata benzazola primijenjeni su klasični sintetski pristupi kao i neke suvremene sintetske metode, uključujući sintezu u ekološki prihvatljivim otapalima ili sintezu potpomognutu mikrovalovima. Novi akrilonitrilni derivati N-supstituiranih derivata benzazola 32‒71 i 77‒107 priređeni su aldolnom kondenzacijom odgovarajućih cijanometilbenzazola s benzaldehidima supstituirani promjenjivim brojem metoksi i hidroksi skupina te 4-N,N-dimetilamino i 4-N,N-dietilamino skupinom. Derivati Schiffovih baza supstituirani benzimidazolom 117‒132 priređeni su kondenzacijom N-supstituiranih 2-aminobenzimidazola 108‒115 s odgovarajućim 4-N,N-dimetilamino i 4-N,N-dietilamino supstituiranim benzaldehidima. Derivati iminokumarina i kumarina 134‒149 te amidino-supstituirani derivati kumarina 164‒175 priređeni su ciklokondenzacijom različito supstituiranih 2-hidroksibenzaldehida s odgovarajućim 2-cijanometilbenzimidazolima, te iz kumarinskih aldehida reakcijom kondenzacije s odgovarajućim 4-amidino-supstituiranim 1,2-fenilendiaminima uz korištenje p-benzokinona kao oksidansa. Amidino-supstituirani benzimidazoli 193‒216 priređeni su kondenzacijom 5-supstituiranih salicilaldehida s odgovarajućim 4-amidino-supstituiranim 1,2-fenilendiaminima. Amidino-supstituirani benzotiazoli 179‒181 i 216‒227 priređeni su iz različito supstituiranih 2-hidroksibenzaldehida i odgovarajućih zwitter iona u ledenoj octenoj kiselini. Metoksi-supstituirani karboksamidi 235‒262 priređeni su kondenzacijom benzoilnih klorida s N-supstituiranim derivatima 2-aminobenzimidazola. Hidroksi-supstituirani amidni derivati N-benzimidazola 263‒268 i 280‒286 priređeni su uklanjanjem zaštitnih metoksi skupina, korištenjem BBr3 na niskim temperaturama, te benzilnih zaštitnih skupina katalitičkim hidrogeniranjem uz Pd/C u metanolu. Amidino-supstituirani derivati benzamida 289‒293 priređeni su kiselo-kataliziranom Pinnerovom reakcijom iz odgovarajućih cijano-supstituiranih polaznih spojeva. Strukture novosintetiziranih spojeva potvrđene su 1H i 13C NMR spektroskopijom, a nekim je spojevima struktura dodatno okarakterizirana i masenom spektrometrijom. Svim priređenim spojevima ispitana je antiproliferativna aktivnost in vitro na niz staničnih linija humanih karcinoma i zdravih stanica, dok je ispitivanje antioksidativne aktivnosti in vitro provedeno primjenom spektroskopskih metoda DPPH, FRAP i ABTS. Amidino-supstituiranim derivatima 164‒175 i 179‒181 ispitana je antiviralna aktivnost in vitro na nekoliko sojeva virusa, te su neki od derivata pokazali jako dobru i selektivnu aktivnost prema pojedinim sojevima virusa. Derivatima Schiffovih baza 117‒132 te amidino-supstituiranim benzazolima 193‒216 i 217‒228 ispitana je i antibakterijska aktivnost prema Gram pozitivnim i Gram negativnim bakterijama. Iz dobivenih rezultata ispitivanja biološke aktivnosti i SAR studije, utvrđeno je da na antioksidativnu aktivnost značajno utječe broj metoksi i hidroksi skupina na fenilnom prstenu, te supstituent na dušikovom atomu benzimidazolne jezgre. Najizraženiji utjecaj na povećanje antiproliferativne aktivnosti pokazuje 4-N,N-dietilamino skupina smještena na položaju 7 kumarinskog prstena i fenilnom prstenu akrilonitrilnih derivata, te izobutilni supstituent na N atomu benzimidazolne jezgre. Nekima od najaktivnijih derivata benzazola dodatno su ispitani mehanizmi biološkog djelovanja, te je tako utvrđeno da neki derivati akrilonitrila i iminokumarina djeluju kao inhibitori polimerizacije tubulina, dok je amidnim derivatima ispitana i antioksidativna aktivnost u stanicama. Dokazano je i da najbolju antivirusnu aktivnost ima kumarinski derivat benzimidazola supstituiran nesupstituiranim amidinom koji inhibira ranu fazu replikacijskog ciklusa virusa, odnosno sintezu virusne RNK.This thesis describes the synthesis of several classes of benzimidazoles and benzothiazoles in order to investigate their antiproliferative and antioxidant activity. By using multi-step linear synthesis of new benzazole conjugates, classical synthetic approaches as well as some modern synthetic methods, including synthesis in environmentally friendly solvents or microwave-assisted synthesis, were applied. New acrylonitrile derivatives of N-substituted benzazoles 32‒71 and 77‒107 were prepared by aldol condensation of the corresponding cyanomethylbenzazoles with benzaldehydes with a variable number of methoxy and hydroxy groups and 4-N,N-dimethylamino and 4-N,N-diethylamino groups. Benzimidazole derived Schiff bases 117‒132 were prepared by condensation of N-substituted 2-aminobenzimidazoles 108‒115 with corresponding 4-N,N-dimethylamino and 4-N,N-diethylamino-substituted benzaldehydes. Iminocoumarin and coumarine derivatives 134‒149 and amidino-substituted coumarine derivatives 164‒175 obtained by cyclocondensation of substituted 2-hydroxybenzaldehydes with corresponding 2-cyanomethylbenzimidazoles as well as from coumarine aldehydes with corresponding 4-amidino-substituted 1,2-phenylenediamines using p-benzoquinone as an oxidant. Amidino-substituted benzimidazoles 193‒216 were synthesized within the condensation of 5-substituted salicylaldehydes with corresponding 4-amidino-substituted 1,2-phenylenediamines. Amidino-substituted benzothiazoles 179‒181 i 216‒227 were prepared by condensation of differently substituted 2-hydroxybenzaldehydes and corresponding zwitter ions in glacial acetic acid. Methoxy-substituted carboxamides 235‒262 were prepared by condensation of benzoyl chlorides with N-substituted 2-aminobenzimidazole derivatives. Hydroxy-substituted amide derivatives of N-benzimidazole 263‒268 and 280‒286 obtained by removing protective methoxy groups, using BBr3 at low temperatures, and benzyl protective groups by catalytic hydrogenation with Pd/C in methanol. Amidino-substituted benzamide derivatives 289‒293 were synthesized via acid-catalyzed Pinner reaction from the corresponding cyano-substituted starting precursors. Structures of all newly prepared compounds were confirmed by 1H and 13C NMR spectroscopy while some of them were additionally characterized by mass spectrometry. All prepared compounds were tested for their antiproliferative activity in vitro on a number of human cancer cell lines as well as normal fibroblasts, while antioxidant activity in vitro was performed using spectroscopic DPPH, FRAP and ABTS methods. Amidino-substituted derivatives 164‒175 and 179‒181 were tested for antiviral activity in vitro on several virus strains, and some compounds have shown pronounced and selective activity against some viruses. Schiff base derived benzazoles 117‒132 and amidino-substituted benzazoles 193‒216 and 217‒228 were tested for antibacterial activity against Gram positive and Gram negative bacteria. Results obtained from evaluation of biological activity and SAR studies, revealed that the antioxidant activity is affected by the number of methoxy and hydroxy groups on the phenyl ring as well as the substituent on the nitrogen atom of the benzimidazole nucleus. The strongest impact on the enhancement of antiproliferative activity was observed by 4-N,N-diethylamino group placed at the position 7 on coumarin ring and phenyl ring of acrylonitrile derivatives. The isobutyl substituent on the N atom of the benzimidazole core has the greatest influence on increasing the activity of the synthesized compounds. Some of the most active benzazole derivatives were additionally evaluated to study their mechanisms of biological action and it was confirmed that some of the acrylonitrile and iminocoumarin derivatives have proven to be tubuline polymerization inhibitors, while for amide derivatives the antioxidative activity was tested also in the cells. It has been proven that the most promising antiviral activity has been possessed by coumarine derived benzimidazole substituted with amidine group, being inhibitor of an early step in the replication cycle of virus, respectively the synthesis of viral RNA

Synthesis and structural characterization of novel benzimidazole and benzothiazole derivatives as potential antiproliferative agents with antioxidative activity

U ovom radu opisana je sinteza nekoliko klasa derivata benzimidazola i benzotiazola kojima je ispitana antiproliferativna i antioksidativna aktivnost. U linearnoj višestupanjskoj sintezi novih konjugata benzazola primijenjeni su klasični sintetski pristupi kao i neke suvremene sintetske metode, uključujući sintezu u ekološki prihvatljivim otapalima ili sintezu potpomognutu mikrovalovima. Novi akrilonitrilni derivati N-supstituiranih derivata benzazola 32‒71 i 77‒107 priređeni su aldolnom kondenzacijom odgovarajućih cijanometilbenzazola s benzaldehidima supstituirani promjenjivim brojem metoksi i hidroksi skupina te 4-N,N-dimetilamino i 4-N,N-dietilamino skupinom. Derivati Schiffovih baza supstituirani benzimidazolom 117‒132 priređeni su kondenzacijom N-supstituiranih 2-aminobenzimidazola 108‒115 s odgovarajućim 4-N,N-dimetilamino i 4-N,N-dietilamino supstituiranim benzaldehidima. Derivati iminokumarina i kumarina 134‒149 te amidino-supstituirani derivati kumarina 164‒175 priređeni su ciklokondenzacijom različito supstituiranih 2-hidroksibenzaldehida s odgovarajućim 2-cijanometilbenzimidazolima, te iz kumarinskih aldehida reakcijom kondenzacije s odgovarajućim 4-amidino-supstituiranim 1,2-fenilendiaminima uz korištenje p-benzokinona kao oksidansa. Amidino-supstituirani benzimidazoli 193‒216 priređeni su kondenzacijom 5-supstituiranih salicilaldehida s odgovarajućim 4-amidino-supstituiranim 1,2-fenilendiaminima. Amidino-supstituirani benzotiazoli 179‒181 i 216‒227 priređeni su iz različito supstituiranih 2-hidroksibenzaldehida i odgovarajućih zwitter iona u ledenoj octenoj kiselini. Metoksi-supstituirani karboksamidi 235‒262 priređeni su kondenzacijom benzoilnih klorida s N-supstituiranim derivatima 2-aminobenzimidazola. Hidroksi-supstituirani amidni derivati N-benzimidazola 263‒268 i 280‒286 priređeni su uklanjanjem zaštitnih metoksi skupina, korištenjem BBr3 na niskim temperaturama, te benzilnih zaštitnih skupina katalitičkim hidrogeniranjem uz Pd/C u metanolu. Amidino-supstituirani derivati benzamida 289‒293 priređeni su kiselo-kataliziranom Pinnerovom reakcijom iz odgovarajućih cijano-supstituiranih polaznih spojeva. Strukture novosintetiziranih spojeva potvrđene su 1H i 13C NMR spektroskopijom, a nekim je spojevima struktura dodatno okarakterizirana i masenom spektrometrijom. Svim priređenim spojevima ispitana je antiproliferativna aktivnost in vitro na niz staničnih linija humanih karcinoma i zdravih stanica, dok je ispitivanje antioksidativne aktivnosti in vitro provedeno primjenom spektroskopskih metoda DPPH, FRAP i ABTS. Amidino-supstituiranim derivatima 164‒175 i 179‒181 ispitana je antiviralna aktivnost in vitro na nekoliko sojeva virusa, te su neki od derivata pokazali jako dobru i selektivnu aktivnost prema pojedinim sojevima virusa. Derivatima Schiffovih baza 117‒132 te amidino-supstituiranim benzazolima 193‒216 i 217‒228 ispitana je i antibakterijska aktivnost prema Gram pozitivnim i Gram negativnim bakterijama. Iz dobivenih rezultata ispitivanja biološke aktivnosti i SAR studije, utvrđeno je da na antioksidativnu aktivnost značajno utječe broj metoksi i hidroksi skupina na fenilnom prstenu, te supstituent na dušikovom atomu benzimidazolne jezgre. Najizraženiji utjecaj na povećanje antiproliferativne aktivnosti pokazuje 4-N,N-dietilamino skupina smještena na položaju 7 kumarinskog prstena i fenilnom prstenu akrilonitrilnih derivata, te izobutilni supstituent na N atomu benzimidazolne jezgre. Nekima od najaktivnijih derivata benzazola dodatno su ispitani mehanizmi biološkog djelovanja, te je tako utvrđeno da neki derivati akrilonitrila i iminokumarina djeluju kao inhibitori polimerizacije tubulina, dok je amidnim derivatima ispitana i antioksidativna aktivnost u stanicama. Dokazano je i da najbolju antivirusnu aktivnost ima kumarinski derivat benzimidazola supstituiran nesupstituiranim amidinom koji inhibira ranu fazu replikacijskog ciklusa virusa, odnosno sintezu virusne RNK.This thesis describes the synthesis of several classes of benzimidazoles and benzothiazoles in order to investigate their antiproliferative and antioxidant activity. By using multi-step linear synthesis of new benzazole conjugates, classical synthetic approaches as well as some modern synthetic methods, including synthesis in environmentally friendly solvents or microwave-assisted synthesis, were applied. New acrylonitrile derivatives of N-substituted benzazoles 32‒71 and 77‒107 were prepared by aldol condensation of the corresponding cyanomethylbenzazoles with benzaldehydes with a variable number of methoxy and hydroxy groups and 4-N,N-dimethylamino and 4-N,N-diethylamino groups. Benzimidazole derived Schiff bases 117‒132 were prepared by condensation of N-substituted 2-aminobenzimidazoles 108‒115 with corresponding 4-N,N-dimethylamino and 4-N,N-diethylamino-substituted benzaldehydes. Iminocoumarin and coumarine derivatives 134‒149 and amidino-substituted coumarine derivatives 164‒175 obtained by cyclocondensation of substituted 2-hydroxybenzaldehydes with corresponding 2-cyanomethylbenzimidazoles as well as from coumarine aldehydes with corresponding 4-amidino-substituted 1,2-phenylenediamines using p-benzoquinone as an oxidant. Amidino-substituted benzimidazoles 193‒216 were synthesized within the condensation of 5-substituted salicylaldehydes with corresponding 4-amidino-substituted 1,2-phenylenediamines. Amidino-substituted benzothiazoles 179‒181 i 216‒227 were prepared by condensation of differently substituted 2-hydroxybenzaldehydes and corresponding zwitter ions in glacial acetic acid. Methoxy-substituted carboxamides 235‒262 were prepared by condensation of benzoyl chlorides with N-substituted 2-aminobenzimidazole derivatives. Hydroxy-substituted amide derivatives of N-benzimidazole 263‒268 and 280‒286 obtained by removing protective methoxy groups, using BBr3 at low temperatures, and benzyl protective groups by catalytic hydrogenation with Pd/C in methanol. Amidino-substituted benzamide derivatives 289‒293 were synthesized via acid-catalyzed Pinner reaction from the corresponding cyano-substituted starting precursors. Structures of all newly prepared compounds were confirmed by 1H and 13C NMR spectroscopy while some of them were additionally characterized by mass spectrometry. All prepared compounds were tested for their antiproliferative activity in vitro on a number of human cancer cell lines as well as normal fibroblasts, while antioxidant activity in vitro was performed using spectroscopic DPPH, FRAP and ABTS methods. Amidino-substituted derivatives 164‒175 and 179‒181 were tested for antiviral activity in vitro on several virus strains, and some compounds have shown pronounced and selective activity against some viruses. Schiff base derived benzazoles 117‒132 and amidino-substituted benzazoles 193‒216 and 217‒228 were tested for antibacterial activity against Gram positive and Gram negative bacteria. Results obtained from evaluation of biological activity and SAR studies, revealed that the antioxidant activity is affected by the number of methoxy and hydroxy groups on the phenyl ring as well as the substituent on the nitrogen atom of the benzimidazole nucleus. The strongest impact on the enhancement of antiproliferative activity was observed by 4-N,N-diethylamino group placed at the position 7 on coumarin ring and phenyl ring of acrylonitrile derivatives. The isobutyl substituent on the N atom of the benzimidazole core has the greatest influence on increasing the activity of the synthesized compounds. Some of the most active benzazole derivatives were additionally evaluated to study their mechanisms of biological action and it was confirmed that some of the acrylonitrile and iminocoumarin derivatives have proven to be tubuline polymerization inhibitors, while for amide derivatives the antioxidative activity was tested also in the cells. It has been proven that the most promising antiviral activity has been possessed by coumarine derived benzimidazole substituted with amidine group, being inhibitor of an early step in the replication cycle of virus, respectively the synthesis of viral RNA