Facile Synthesis and Characterization of New 2,3-Disubstituted Benzimidazole Derivatives
Olayinka O. Ajani *
Department of Chemistry, School of Natural and Applied Sciences, CST, Covenant University, Km 10, Idiroko Road, PMB 1023, Ota, Ogun State, Nigeria
Emmanuel K. Ezeoke
Department of Chemistry, School of Natural and Applied Sciences, CST, Covenant University, Km 10, Idiroko Road, PMB 1023, Ota, Ogun State, Nigeria
Abiola Edobor-Osoh
Department of Chemistry, School of Natural and Applied Sciences, CST, Covenant University, Km 10, Idiroko Road, PMB 1023, Ota, Ogun State, Nigeria
Alice O. Ajani
Nigerian Stored Products Research Institute, Onireke, Ibadan, Oyo State, Nigeria
*Author to whom correspondence should be addressed.
Abstract
Benzimidazoles are known to represent a class of medicinally important compounds which are extensively used as antibacterial agents. Hence, a series of five 2-substituted benzimidazole precursors (1a-e) were synthesized via [4 + 1] condensation and imino compound (1f) by simple condensation in the presence of Conc. HCl as catalyst. Synthetic modification of N-1 position was achieved in order to obtain new 5-chloro-2,4-dinitrophenyl bearing 1,2-disubstituted benzimidazole 2a-e and 2f, and 3-chlorobenzyl bearing 1,2-disubstituted benzimidazole 3a-e and 3f in good to excellent yields using a facile approach. The chemical structures of all synthesized compounds were confirmed using spectroscopic means such as UV-visible, IR, Mass spectra, 1H and 13C NMR as well as C, H, N elemental analytical data.
Keywords: Heterocycle, benzimidazole, cycloaddition, carboxylic acid, spectroscopy