Etidronic acid catalyzed simple, facile and generalized synthetic protocol for preparation of 2-substituted-1H-benzo[d]imidazole-6-carboxylates

Abstract

A facile and efficient cyclo-condensation reaction of substituted ortho-phenylenediamines with an aldehyde or carboxylic acid using etidronic acid to furnish hitherto unreported Methyl 4-methyl-2-substituted- 1H-benzo[d]imidazole-6-carboxylatederivatives was described. A new and efficient protocol was developed as a homogenous catalyst for the synthesis of benzimidazoles under conventional and microwave irradiated reaction atmosphere. This methodology has the advantage of excellent yields with short reaction time and highly robust & practical reaction arrangement.