Green Synthesis, Characterization and Biological Activities of some Benzimidazole Derivatives
K. F. Ansari and C. Lal
Department of Chemistry, Harcourt Butler Technological Institute, Kanpur – 208002
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Green synthesis of pharmacologically active benzimidazole derivatives has been achieved under solvent-free conditions, with incomparable atom economy. We have developed an efficient one-pot, solvent-free, green protocol for the synthesis of a series of benzimidazole derivatives in good yield. The structures of the synthesized compounds were determined by the elemental analysis and spectroscopic data. Finally, the newly synthesized compounds were screened for their antimicrobial activity. The solvent-free synthesis of benzimidazole derivatives provide better results in terms of yield, reaction time and atom economy in comparison to conventional organic synthesis. All the newly synthesized compounds were screened for their in vitro antimicrobial activity and were found to be active against gram-positive, gram-negative bacteria and fungi. It was found that the tested compounds are more effective against the Gram positive bacteria and Candida albicans. The lipophilic character and molar refractivity of all synthesized compounds were also calculated and their structure activity relationship was studied. It may be concluded that lipophilic character of the molecules plays an essential role in producing antimicrobial effect. They showed less activity against E. coli and Aspergillus flavus in comparison to reference drug. This synthesis offers attractive features such as green synthesis, reduced reaction times and higher yields, all of which make it a useful and attractive strategy for the preparation of various benzimidazole derivatives.
Keywords: Solvent-free green synthesis, benzimidazole, lipophilicity, molar refractivity, antibacterial and antifungal activity.
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