A Simple Construction of 2-Phenylimino-1,3-thiazolidin-4-ones

Abstract

A new methodology for the construction of 2-phenylimino-1,3thiazolidin-4-one skeleton is described.Reaction of maleic anhydride (5a) or maleimides (5b, 5c) with thiourea (6) gave the corresponding 2-imino-1,3thiazolidin-4-ones ( 7) and ( 9) respectively.The reaction proceeded with high yield in polar solvents.In non-polar solvents at high temperature, however, isothiocyanate (8) was formed as a by-product presumably by the pyrolysis of thiourea ( 6).The proposed mechanism of the reaction was discussed.