Mechanochemical Approach for the Selective Synthesis of 1,2-Disubstituted Benzimidazoles and Their Molecular Docking Studies

A greener, scalable and mild mechanochemical protocol has been developed using readily available aromatic aldehydes and o-phenylenediamine in the presence of urea nitrate catalyst to afford 1,2-disubstituted benzimidazoles in few seconds. The highly efficient urea nitrate catalyzed synthesis proceeded via carbonyl activation-cyclization-atmospheric oxidation pathway. The method involved short reaction time (20–30 s), solvent free, easy preparation of catalyst, recyclable catalyst, easy isolation, high yield (92%–99%) at room temperature. Green chemistry matrix of synthesized compounds exhibited low e-factor (0.11), high atom-economy (90.74%), high reaction mass efficiency (89.9%) and excellent eco-score (78.5%). The molecular docking study of all the synthesized compounds for antibacterial and centromere associated protein inhibitor activity gave potential hits via presence of high interaction pattern. Compound 3b (−26.7009 kJ/mol) and 3k (−25.0285 kJ/mol) exhibited highest docking score with the selected 2XCS and 1T5C proteins, respectively.