Ultrasound-Mediated Green Synthesis of Novel Functionalized Benzothiazole[3,2-a]Pyrimidine Derivatives through a Multicomponent Reaction

Abstract

A highly efficient green protocol is described for the development of novel benzo[4,5]thiazolo[3,2-a]pyrimidine analogues through the one-pot fusion of the 2-amino-benzothiazole with different chosen aldehydes and active methylene compounds, in ethanol medium under ultrasound irradiation conditions by using ammonium acetate as a catalyst. We achieved excellent yields (94–97%) for 24 novel target products with short reaction time (10–15 min) at room temperature. We confirmed the structures of the synthesized pyrimidine analogues by NMR and HRMS spectroscopic analysis. Exceptional yields, simple workup, no column chromatography, green solvent, rapid reaction at room temperature and excellent functional group tolerance are the benefits of this protocol.