A Cost-effective and Green Synthesis of Isothiocyanates

Irritant, expensive, or toxic desulfurating agents are usually used in the synthesis of isothiocyanates from amines, CS2, and appropriate bases, accompanied by a tedious workup. A more practical and green method has been developed. Cheap and non-toxic CaO was used as both a base and a desulfurating agent in the synthesis of isothiocyanates. Both alkyl and aryl isothiocyanates are easily synthesized in moderate to high yield from amines, CS2, and CaO under mild conditions. A simple and practical synthetic approach for isothiocyanates from amines, CS2, and CaO was developed. CaO acts as both a base and a desulfurating agent in the reactions, simplifying the reaction system and reducing cost as well as side products. Moderate to high yields were obtained at room temperature in 48 hours which included alkyl and aryl isothiocyanates.