A new combination of reagent (ZnCl2/TBAB) system has been developed for the preparation of dihydropyrimidinones by using aldehyde, acetoacetic ester and urea or thiourea. These improved reaction condition allow the preparation of a wide variety of substituted dihydropyrimidinones in high yields and purity under mild reaction conditions. Some of the dihydropyrimidinones were showed moderate in vitro