Metal- and solvent-free preparation of benzo[4,5]imidazo[1,2-a]pyrimidine derivatives catalysed by deep eutectic solvents

Thuy-Duy Thi Nguyen^{1, 2}, Anh Vy Truong^{1, 2}, Hoang Phuong Tran^{1, 2*}

¹Department of Organic Chemistry, Faculty of Chemistry, University of Science, Ho Chi Minh city

²Vietnam National University, Ho Chi Minh city

Received 20 March 2020; accepted 19 June 2020

 

Abstract:

A straightforward method for the preparation of benzo[4,5]imidazo[1,2-a]pyrimidine derivatives catalysed by an acidic deep eutectic solvent from choline chloride (ChCl) and phenol via the Biginelli reaction of 2-aminobenzimidazole, ethyl acetoacetate, and aldehydes has been developed under metal- and solvent-free conditions. The desired products were obtained in moderate to good yield (49-79%) and the DESs were known as an economical and environmentally friendly catalyst.

Keywords: Biginelli reaction, deep eutectic solvents, green catalyst, green chemistry.

Classification number: 2.2