Silica sulfuric acid/ethylene glycol as an efficient catalyst for the synthesis of benzo[4,5]imidazo[1,2-a]pyrimidine-3-carbonitrile derivatives

Abstract

A simple and efficient eco-friendly method was developed for the synthesis of new benzo[4,5]imidazo[1,2-a]pyrimidine-3-carbonitrile derivatives in excellent yields. The synthesis was achieved through the reaction of 2-aminobenzimidazole, aldehydes and active nitriles (malononitrle or ethyl cyanoacetae) in the presence of silica sulfuric acid/ethylene glycol. This protocol offers very short reaction times (in some cases, reaction times were reduced to five minutes), high yields and low cost. This method thus provides an improvement over the existing methods.

GRAPHICAL ABSTRACT

Keywords:

• 2-Aminobenzimidazole
• benzo[4,5]imidazo[1,2-a]pyrimidine
• nitrile compounds
• silica sulfuric acid

Additional information

Funding

This work was supported by National Research Center, Egypt through Ph.D. degree.