Praseodymium methanesulfonate catalyzed one-pot synthesis of 3,4-dihydropyrimidin-2-(1H)-ones.

A series of 3,4-dihydropyrimidin-2-(1H)-ones compounds was synthesized efficiently by a one-pot cyclocondensation of an aldehyde, 1,3-dicarbonyl compound, and urea in absolute ethanol under refluxing temperature using praseodymium methanesulfonate as catalyst. After the reaction, the catalyst can be easily recovered and reused several times without distinct decrease in reaction yields.