Synthesis of benzimidazole by mortar–pestle grinding method

ABSTRACT

An environmentally friendly and efficient protocol for the synthesis of benzimidazoles by mortar–pestle grinding technique in the presence of acetic acid as a catalyst is reported. This mechanochemical method proceeded with the condensation of aldehyde and o-phenylenediamine followed by cyclization reaction, leading to the formation of the corresponding benzimidazoles in yields up to 97%. This protocol could also be applied for the synthesis of benzothiazoles and benzoxazoles.

GRAPHICAL ABSTRACT

KEYWORDS:

• Benzimidazoles
• mortar–pestle grinding
• acetic acid
• green chemistry

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This project was supported by Natural Science Foundation of China (no. 21472128), Natural Science Foundation of Fujian Province (nos. 2016J01686, 2016Y9051, 2017J01574, 2015J01316), and Sichuan Science and Technology Program (no. 2018JY560) for financial support.