Catalytic assemble of 2-amino-5,6-dimethyl-1H-benzimidazole with carboxylic acids and evaluation of their antimicrobial and antioxidant activities

ObjectivesA series of N-(5,6-dimethyl-1H-benzimidazol-2-yl) substituted carboxamide was synthesized using the reaction of 2-amino-5,6-dimethyl-1H-benzimidazolewithvarious bioactive aromatic heterocyclic carboxylic acids and fatty acids with several catalysts.MethodsThe structures of the synthesized compounds were confirmed using 1H and 13C nuclear magnetic resonance (NMR) and mass spectroscopic methods. The title compounds were screened for antimicrobial and antioxidant activity.ResultsCompounds 3e, 3f, 3g, 3h, 3j and 3l exhibit promising antimicrobial activity against the tested microorganisms with minimal inhibitory concentration (MIC) values of 250-750 μg/ml. Compounds 3g, 3h and 3j show prominent radical scavenging and ferrous ion chelating activity, with IC50 values of 49.00 ± 65 to 57.18 ± 89 μg/ml.ConclusionAll of the synthesized compounds show good antimicrobial and antioxidant activities. This study reveals that the incorporation of a heterocyclic ring and open-chain counterparts at the second position of the benzimidazole ring yields more potent biologically active compounds.