Diversity Oriented p-TSA Catalyzed Efficient and Environmentally Benign Synthetic Protocol for the Synthesis of Structurally Diverse Heteroannulated Benzothiazolopyrimidines

摘要

Diversity oriented synthetic protocol has been presented for the synthesis of structurally diverse drug -like small molecules. The present method involves three-component domino reaction of 2-aminobenzothiazoles, thiophene-2-carbaldehyde and carbonyl compounds in the presence of a catalytic amount of p-toluenesulphonic acid (p-TSA) as a recyclable and reusable eco-friendly acid catalyst in aqueous- alcoholic medium (C_2H_5OH- H_2O:v:v/ 1:5). The synthesis of structurally diverse heterocycles in very high yields (92-97%) from easily available starting materials, operational simplicity, mild reaction con-ditions, use of nontoxic and reusable acid catalyst, environmentally benign solvent system and shorter reaction time (10-48 min) at comparatively low temperature are special features of the present synthetic protocol.