Efficient Synthesis of 3,4-Dihydropyrimidin-2-ones in Low Melting Tartaric Acid – Urea Mixtures

A general, efficient and green method for the synthesis of dihydropyrimidinones is described under mild conditions employing low melting mixtures of L-(+)-tartaric acid and urea derivatives as a novel reaction medium. The melt plays a triple role: as solvent, as catalyst and as reactant, furnishing highly functionalized dihydropyrimidinones in good to excellent yields