Facile synthesis of thiourea derivatives in ionic liquid

The synthesis of cinnamoyl thiourea derivatives from cinnamoyl isothiocyanate (CIT) with substituted aniline (RC6H4NH2) was investigated in the mostly used ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate, [Bmim][BF4]. Significant enhancements in reactivity, yield and reaction rate were achieved. The products could be recovered by simple filtration. [Bmim][BF4] could be recycled simply by removing water under vacuum and reused at least 9 times without significant decrease in activity.