A New Biginelli Reaction Procedure Using Potassium Hydrogen Sulfate as the Promoter for an Efficient Synthesis of 3,4-Dihydropyrimidin-2(1H)-one

Simple and improved conditions have been found to carry out the Biginelli reaction for the synthesis of 3,4-dihydropyrimidin-2(1H)-one derivatives. This synthesis was performed using potassium hydrogen sulfate as the promoter in glycol solution. Compared with the classical Biginelli reaction conditions, this new method has the advantage of excellent yields (85-99%) and short reaction time (0.5-2 h).