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

Abstract

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.

Graphical Abstract

Keywords:

• Benzimidazole
• green chemistry
• grind-stone
• molecular docking study
• solvent-free
• urea-nitrate

Acknowledgements

The authors are grateful to Department of Chemistry, M.L.S.U. Udaipur (Raj.), India, for providing necessary laboratory and library facilities and Sophisticated Analytical Instrumentation Facility (SAIF), Chandigarh for spectral analysis.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

N. Sahiba is very much grateful to the Council for Scientific and Industrial Research (CSIR) (file no. 09/172(0088)2018-EMR-I), New Delhi for the award of Junior Research Fellowship and A. Sethiya is thankful to UGC-MANF (201819MANF-2018-19-RAJ-91971) as financial support.