Synthesis and evaluation of in vitro anti-microbial and anti-tubercular activity of 2-styryl benzimidazoles

A new series of novel 5-(nitro/bromo)-styryl-2-benzimidazoles (1–12) has been synthesized by simple, mild and efficient synthetic protocol by attempted condensation of 5-(nitro/bromo)-o-phenylenediamine with trans-cinnamic acids in ethylene glycol. Screening for in vitro anti-tubercular activity against Mycobacterium tuberculosis H₃₇ Rv, anti-bacterial activity against Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae bacterial strains and anti-fungal activity against Candida albicans and Asperigillus fumigatus fungal strains were carried out. Compounds 5, 7, 8, 9, 11 showed higher anti-tubercular activity and compounds 7, 8, 10, 11, 12 have proved to be effective with MIC (μg/ml) and emerged as lead molecules showing excellent activities against a panel of microorganisms. All synthesized compounds were characterized using IR, ¹H, ¹³C NMR, GC–MS and elemental analysis.