Facile and regioselective synthesis of thiazolidin-4-one derivatives catalyzed by basic ionic liquid [bmim]OH under ultrasonic irradiation

2-Iminothiazolidin-4-one derivatives were synthesized regioselectively in good to high yields by condensation of N,N-disubstituted thioureas and ethyl chloroacetate in the presence of basic ionic liquid bmim]OH as a catalyst under conventional and ultrasonic irradiation conditions. Under ultrasonic irradiation, the reaction furnished the desired 2-iminothiazolidinones in higher yields (76–87%) and lower reaction times (30–55 min).