An efficient one-pot synthesis of 3,4-dihydropyrirnidin-2-ones catalyzed by methanesulfonic acid

An efficient synthesis of 3,4-dihydropyrimidin-2-ones (DHPMs) from the aidehydes, beta-ketoesters, and urea in ethanol using methanesulfonic acid (CH3SO3H) as the catalyst is described. Compared with the classical Biginelli reaction conditions, this method has the advantage of excellent yields and short reaction time.