NaOH-promoted one-pot aryl isothiocyanate synthesis under mild benchtop conditions

In this work, we have established a green synthesis of aryl isothiocyanates promoted by the low-cost and readily available NaOH from aryl amines and carbon disulfide in a one-pot procedure. The developed protocol features no extra desulfurating reagents and mild benchtop conditions, in which NaOH serves as both the base and the desulfurating reagent to decompose the dithiocarbamate intermediate. Fourteen examples of aryl amines bearing electronic neutral, rich and poor substituents, as well as benzylamine, have proved to be compatible substrates in the developed method to furnish the corresponding isothiocyanates. The reaction has been performed on a gram scale to further demonstrate its synthetic utility. Compared to the reported base-promoted synthesis of aryl isothiocyanates that requires the use of special equipment, such as the ball mill or the microwave reactor, the simplicity in operation and scalability enables this method to efficiently access a variety of aryl isothiocyanates.