Ammonium Chloride Catalyzed One‐Pot Synthesis of 3,4‐Dihydropyrimidin‐2‐(1H)‐ones under Solvent‐Free Conditions.

Abstract Ammonium chloride as a very inexpensive and readily available reagent, and efficiently catalyzes one-pot, three component, Biginelli condensation reactions of aldehydes, 1,3-dicarbonyl compounds and urea or thiourea under solvent-free conditions to afford the corresponding 3,4-dihydropyrimidin-2-(1H)-ones in high yields at 100°C.