Synthesis, characterization and DPPH scavenging activity of some benzimidazole derivatives

Abstract

A base-catalyzed conversion of aldehydes to benzimidazoles has been achieved. The compounds have been characterized by IR, NMR, micoranalysis, and GC-MS. The reaction for the formation of benzimidazoles has been monitored with 1H NMR and IR. The crystal structures of two derivatives, 2-(2-chlorophenyl)-1H-benzimidazole and 2-(1H-benzimidazol-2-yl)-4-nitrophenol, are presented. A study of the DPPH scavenging activity of these compounds showed that 2-(1H-benzimidazol-2-yl)phenol (2), 2-p-tolyl-1H-benzimidazole (3) and 2-(4-methoxyphenyl)-1H-benzimidazole (7) gave IC50 values 1974, 773 and 800 µM. KEY WORDS: Benzimidazole, o-Phenylenediamine, Aldehydes, Base catalysis, DPPH scavenging activity Bull. Chem. Soc. Ethiop. 2018, 32(2), 271-284.DOI: https://dx.doi.org/10.4314/bcse.v32i2.8