An efficient microwave-promoted three-component synthesis of thiazolo[3,2-a]pyrimidines catalyzed by SiO2–ZnBr2 and antimicrobial activity evaluation

2,5-substituted-6-(4-nitrophenyl)-5H-thiazolo[3,2-a]pyrimidin-7-amines. This method, optimized under microwave conditions, was highly efficient and environmentally benign and delivered the desired products in good yields (89–96%) in short reaction time (