Calcium Bromide is an Efficient Catalyst for Synthesis of Dihydropyrimidones Under Microwave Condition

An efficient and ecofriendly method was developed for synthesis of a series of dihydropyrimidinone derivatives through three-component one-pot cyclocondensation between substituted benzaldehydes, beta ketoester and urea/thiourea using calcium bromide as a catalyst under microwave irradiation in a solvent-free condition. The merits of this method is solvent free approach, low catalyst loading, shorter reaction time, simple workup procedure, catalyst is easily available, inexpensive and easy to handling. Using this procedure, we synthesized 25 different biologically active dihydropyrimidine.