An efficient and environmental benign synthesis of 2-benzimidazoles and 2-benzothiazoles using CeCl3-NaI as catalyst

Abstract

A one-pot condensation of an aldehyde with 1,2-phenylenediamine or 2-aminothiophenol in dimethyl carbonate at 100°C under O2 in the presence of catalytic amounts of CeCl3-NaI gave an imine intermediate, which cyclised and dehydrogenated to give 2-arylbenzimidazoles or 2-arylbenzothiazoles in good yields.