Abstract
A total of seven novel benzimidazoles were synthesized by a 4-step reaction starting from 4-fluoro-3-nitrobenzoic acid under relatively mild reaction conditions. The synthesized compounds were screened for their antimycobacterial activity against M. tuberculosis H(37)Rv (MTB-H(37)Rv) and INH-resistant M. tuberculosis (INHR-MTB) strains using agar dilution method. Three of them displayed good activity with MIC of less than 0.2 mu M. Compound ethyl 1-(2-(4-(4-(ethoxycarbonyl)-2-aminophenyl)piperazin-1-yl) ethyl)-2-(4-(5-(4-fluorophenyl)pyridin-3-ylphenyl-1H-benzo[d]imidazole-5-carboxylate (5g) was found to be the most active with MIC of 0.112 mu M against MTB-H(37)Rv and 6.12 mu M against INHR-MTB, respectively.