A novel Cu-catalysed three-component one-pot synthesis of dihydro-pyrimidin-2(1H)-ones using microwaves under solvent-free conditions

Cupric chloride dihydrate catalyzes the three-component Biginelli condensation between an aldehyde, a beta-ketoester and urea or thiourea under microwave irradiation in the absence of solvent to yield various substituted 3,4-dihydropyrimidin-2(1H)-ones. The reaction is also effective when performed at room temperature in acetonitrile or at 100 degreesC in a solvent free approach, without any side reactions as observed by Biginelli and others.