Development of a novel and efficient method for synthesizing N-benzyl-substituted di-benzimidazole derivatives

In this study, we developed a series of novel dibenzimidazole derivatives (5a–l) through a successful synthesis process. The procedure began with the coupling of N-methylbenzene-1,2-diamine (1) and carboxylic acid (2) using EDC·HCl and DMAP as a catalyst in an appropriate solvent. The resulting compound was then subjected to cyclization in acetic acid at 100–110 °C. The intermediate dibenzimidazole derivatives (3) were further reacted with a variety of aromatic benzyl bromides or chlorides with different substituents (4) in the presence of potassium carbonate and acetonitrile at room temperature. This conventional approach resulted in the efficient production of the target compounds with high yields in a short reaction time. The synthesis method is both environmentally friendly and cost-effective. The newly synthesized benzimidazole derivatives were characterized using advanced spectral techniques.