Synthesis and structure elucidation of new benzimidazole amidoxime derivatives

Abstract

Objectives: In our previous studies we synthesized some potent antiparasitic, anticancer and antimicrobial amidine derivatives. Despite all their potent activities, it is well known that due to their cationic charge, amidine derivatives pose a serious problem in terms of bioavailability. The main purpose of this study is to prepare amidoxime derivatives of previously synthesized potent amidine derivatives as prodrugs in order to increase their bioavailabilities. Materials and Methods: The targeted benzimidazole amidoximes were synthesized from their nitrile derivatives. The nitrile groups of these benzimidazole carbonitriles were converted to N-hydroxy benzamidine derivatives (amidoxime derivatives, 20-29) in the presence of NH2 OH.HCI and KO-t-Bu in dimethyl sulfoxide. Structures of newly synthesized amidoxime derivatives were elucidated with 1H-NMR, 13C-NMR and some 2D NMR techniques like COSY, NOESY, HSQC and HMBC. Results: A new series of benzimidazole amidoximes were synthesized and their structural elucidations were done in this study. Conclusion: In order to solve the potential bioavailability problem of potent amidine derivatives, we prepared the prodrugs of those potent amidine derivatives as their amidoxime derivatives. In vivo studies of both previous amidine derivatives and amidoxime prodrugs of those amidines which were synthesized in this study are planned to perform in our ongoing studies.