Synthesis and investigation of biological properties of benzimidazolone bridged heterocyclic compounds

In this thesis, the synthesis of some heterocyclic compounds with a benzimidazolone structure that has various biological effects was carried out and their inhibition properties against important enzymes were investigated. In the first stage of synthesis studies, three different benzimidazolone compounds (1a-c) were obtained from the reaction of o-phenylenediamine compounds with urea. Piperazine-benzimidazolone hybrid compounds (2a-f) were synthesized from the reaction of 1a-c compounds with piperazine derivatives in the presence of formaldehyde. As a result of the reaction of 1a-c compounds with ethylbromoacetate, acetate derivatives (3a-c) were obtained and these compounds were converted into acetohydrazide derivatives (4a-c) by reaction with hydrazine hydrate. As a result of the reaction of 4a-c compounds with appropriate aldehydes, Schiff base derivatives (5a-f) containing furan and thiophene ring were synthesized. Again, from the reaction of 4a-c compounds with 3-(1H-benzotriazol-1-ylcarbonyl)-2H-chromen-2-one derivatives, hybrid compounds containing coumarin ring (6a-s) and with various isothiocyanates, thiosemicarbazide derivative benzimidazolones (7a-o) were synthesized. In the last step of the synthesis studies, benzimidazolone derivatives containing triazole (8a-o) and thiadiazole (9a-l) structures were obtained by intramolecular cyclization reaction of 7a-o compounds in basic and acidic medium, respectively. After elucidating the structures of the synthesized compounds with IR, 1H-NMR, 13C-APT and mass spectra, urease, lipase and acetylcholinesterase enzyme inhibition properties were investigated. The obtained compounds showed various degrees of inhibition against all three enzymes. Keywords: Benzimidazolone, Coumarin, Triazole, Thiadiazole, Enzyme inhibition