Ultrasound-accelerated synthesis of 3,4-dihydropyrimidin-2(1H)-ones with ceric ammonium nitrate

Ceric ammonium nitrate efficiently catalyzes the three component condensation of an aldehyde, beta -ketoester and urea in methanol to afford the corresponding dihydropyrimidinones in excellent yields under sonication. Other oxidants such as manganese triacetate and Oxone were also found to catalyze this transformation under similar conditions.