Ultrasound Promoted Synthesis of Bis(substituted pyrazol-4-ylcarbonyl)-Substituted Thioureas

A series of novel bis(substituted pyrazol-4-ylcarbonyl)-substituted thioureas have been synthesized by the reactions of substituted pyrazol-4-ylcarbonyl isothiocyanates with different diamines under ultrasound irradiation and classical heating method at 20-25 °C. In general, substantial improvement in rates and modest yields increases were observed when reactions were carried out under sonication, compared with the classical heating method. The structures of these compounds have been elucidated by elemental and spectral (IR, (1)H-NMR) analysis.