Synthesis, Characterization and Antimicrobial Properties of Novel Benzimidazole Amide Derivatives Bearing Thiophene Moiety

In the present investigation, novel amide derivatives of benzimidazole (4a-f) with different thiophene acids (a-f) coupled in the presence of 1-[Bis (dimethylamino) methylene]-1H-1, 2, 3-triazolo [4, 5-b] pyridinium 3-oxide hexafluorophosphate (HATU) reagent at room temperature and as-synthesized derivatives were characterized by (1H-NMR and 13C-NMR) proton and carbon magnetic resonance, and high-performance liquid chromatography (HPLC) analytical techniques. The amide derivatives were tested for in vitro antimicrobial and antifungal activity and ciprofloxacin was used as standard. The antifungal activity was tested with Carbendazim and Fenbendazole cell lines using clotrimazole standard drug. The results indicated the potential activity toward S. bacillus with compounds having IC 50 of 4 (a), 4 (b), 4 (d) and 4 (e) against antimicrobial strains with IC50 of 51.8 μm, 57.4 μm, 54.5 μm and 56.5 μm respectively. However, compounds 4 (a), 4 (c) and 4 (d) showed greater inhibitions against Carbendazim fungal cell line with IC50 of 22.9, 26.8 and 28.8 μm. On the other hand IC50 values of the Fenbendazole for compounds 4 (a), 4(c) and 4 (d) were found to be 12.7, 10.2 and 12.7 μm, respectively. The thiophene-substituted benzimidazole amide derivatives are the potential candidate drug for antibacterial and antifungal activity.