Application of Sulfamic Acid as an Eco-friendly Catalyst in an Expedient Synthesis of Benzimidazoles

Abstract

Sulfamic acid, an eco-friendly and zwitterionic solid, proved to be a very efficient catalyst for the reaction of ortho-phenylenediamine with aryl aldehydes in ethanol at room temperature to furnish both 1-arylmethyl-2-aryl-and 2-arylbenzimidazoles in very good to excellent overall yields.