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.