Ultrasound aided solvent-free synergy: an improved synthetic approach to access 3,4-dihydropyrimidin-2(1 H )-ones

A remarkably simple synthetic method has been described for the access of structurally diverse 3,4-dihydropyrimidin-2(1H)-ones in excellent yields in the presence of 2,4,6-trichloro-1,3,5-triazine (TCT) as an efficient source of hydrochloric acid under ultrasound radiation. In this tandem reaction, a range of aldehydes, β-diketo esters and urea were made to condense together via one-pot, solvent-free synthetic strategy. Use of metal-free catalyst, readily accessible substrates, high production rate and ease of work-up are the imperative features of this protocol.