Synthesis and in vitro antimicrobial activity of some novel substituted benzimidazole derivatives having potent activity against MRSA

The novel benzimidazole derivatives ( 3, 5, 8, 9, 12– 14, 18– 41) were prepared in this paper and the antimicrobial activities of these compounds against Staphylococcus aureus, methicillin-resistant S. aureus (MRSA, standard and clinical isolates), Bacillus subtilis, Escherichia coli and Candida albicans were evaluated. Compounds 24– 26 which have no substitution of N-1 position displayed better antibacterial activities than those of standards (ciprofloxacin, ampicillin and sultamicillin) against both the drug-resistant bacteria (MRSA, standard and clinical isolates). These derivatives ( 24– 26), 2,5,6-trihalogenobenzimidazole analogues ( 8, 12), 5,6-dichloro-2-amino derivative ( 13), and 5-chloro-2-(4-benzyloxyphenyl)benzimidazole ( 35) exhibited the most potent antibacterial activity with MIC 3.12 μg/ml against S. aureus. [Display omitted]