Convenient and Robust Metal-Free Synthesis of Benzazole-2-Ones Through the Reaction of Aniline Derivatives and Sodium Cyanate in Aqueous Medium

Benzazole-2-one derivatives are of wide interest because of their diverse biological activities and clinical applications. Their core ring system is present in many drugs, pesticides, and pigments. Therefore, the development of novel and efficient methods for their synthesis is always interesting. In this article, we wish to report a novel, practical, and green synthesis of benzazole-2-ones by the reaction of aniline derivatives with sodium cyanate. Good to excellent yields of products have been obtained under metal- and ligand-free conditions in water as a solvent. This procedure avoids the use of time-consuming and tedious column chromatography and the products were easily isolated by simple extraction followed by washing with dichloromethane.