Original Articles
Ashok D. Sagar, Sanjeev M. Red
Abstract
An efficient protocol has been developed for the Biginelli reaction using Phenyl phosphonic acid (PPA) as a novel acid catalyst by a three-component condensation of β-keto ester, aldehydes, and urea or thio-urea to give corresponding 3, 4-dihydropyrimidin-2(1H)-ones.