Ultrasound-assisted synthesis of dihydropyrimidine-2-thiones

Chalcone derivatives were prepared by the condensation of various substituted aryl aldehydes and acetophenone in alkaline ethanol, while pyrimidine-2-thione derivatives were prepared by the combination of chalcones and thiourea under conventional and ultrasonic conditions. Advantages of the ultrasound effect were observed and high yields of the products were obtained after 20-30 min sonication. Characterization and structural elucidation of the products was realized based on chemical, analytical and spectral analyses. The results clearly demonstrated a high efficiency of the ultrasonic systems was achieved in the chemical processes.