ABSTRACT
Dihydropyrimidines are prepared by a one-pot cyclocondensation of aldehydes, β-ketoesters and urea with p-toluenesulfonic acid-catalyzed condensation reaction. Yields are significantly higher than utilizing classical Biginelli reaction conditions.
ACKNOWLEDGMENTS
The work was supported by the NSFC (29872011 and 29572039), Educational Ministry of China and Educational Department of Hebei Province (99014), Science and Technology Commission of Hebei Province.