Ultrasound-promoted One-pot Synthesis of 2-Thioxo-dihydropyrimidine Derivatives Bearing Piperidinylamide Moiety

A convenient and efficient one-pot synthesis of 2-thioxo-dihydropyrimidine derivatives bearing piperidinylamide moiety is described. The reactions were carried out in 81-91% yields via the condensation of 1-(piperidin-1- yl)butane-1,3-dione with aromatic aldehyde and thiourea in ethanol catalyzed by p-toluenesulfonic acid at room temperature under ultrasound irradiation. The advantages of this methodology are convenient operation, mild conditions, short reaction times and high yields.