An effective synthesis of 3,4-dihydropyrimidin-2(1H)-one derivatives using ionic liquid 1-n-butyl-3-methylimmidazolium hexafluorophosphate ([bmim]PF₆) as the catalyst from aldehydes, 1,3-dicarbonyl compounds and urea (thiourea) under microwave irradiation is described. This new method has the advantage of high yields (80-95% for aromatic aldehydes) and short reaction time (3-5 min).
