A New Convenient Synthesis of 5-Acyl-1,2,3,4-tetrahydropyrimidine-2-thiones/ones

An efficient one-pot synthesis of 5-acyl-1,2,3,4-tetrahydropyrimidine-2-thiones/ones is described. The synthesis is based on the reaction of readily available α-tosyl substituted thioureas or ureas with enolates of β-oxoesters or 1,3-dicarbonyl compounds followed by acid-catalyzed dehydration of the obtained 5-acyl-4-hydroxyhexahydropyrimidine-2-thiones/ones.