Synthesis, Characterization and Evaluation of Novel 6- Substituted Benzimidazole-2-carbamates as Potential Antimicrobial Agents

Objective: The aim of the present work was to synthesize and characterize a series of 6substituted benzimidazole-2-carbamic acid derivatives and evaluate them for antimicrobial activity. Methods: A novel series of 6-substituted benzimidazole-2-carbamic acid derivatives (6a-f) were synthesized by reacting substituted benzyl chlorides (2a-c) with 4-hydroxy -2nitro aniline (3) in the presence of anhydrous K2CO3 in acetone. The series of 4-benzyl oxy -2-nitro anilines (4ac) thus obtained were reduced with Raney nickel as catalyst. The 4-substituted-1, 2-phenylene diamines were then reacted with 1, 3bis (alkoxy carbonyl)-S-methyl isothiourea (5a-b) to yield the final compounds (6a-f). The structures of synthesized compounds were established by 1 Results: All compounds showed moderate to good antibacterial and antifungal activity and were nearly effective as the standard antibacterial and antifungal drugs used for comparison. The exhibited good activity against gram negative bacterial strains like K. pneumoniae and P. aeruginosa as well as against fungal strain C. albicans. H NMR and mass spectroscopy. The synthesized compounds were screened for antibacterial and antifungal activity against five pathogenic bacterial strains and two pathogenic fungal strains. Conclusion: The 6-substituted benzimidazole-2-carbamates. compounds synthesized and evaluated for pharmacological activity are promising as antimicrobial agents and are amenable for further optimization.