Sulfide Oxidation to Sulfone Using Sodium Chlorite and Hydrochloric Acid in Organic Solvents

Organosulfur compounds are appealing owing to the diverse oxidation states accessible by sulfur, allowing the precise adjustment of their properties. In this study, we report a practical oxidation method that converts sulfides to sulfones by generating chlorine dioxide in situ from sodium chlorite (NaClO₂) and hydrochloric acid (HCl) in organic solvents. Diphenyl sulfide was effectively oxidized to diphenyl sulfone in yields of up to 96% under optimized conditions, with high selectivity in ethyl acetate and acetonitrile solvents. The method is compatible with a wide range of substrates, including various aryl, benzyl, and alkyl sulfides, although reactivity diminishes with sterically hindered or electron-rich substrates. This scalable and environmentally friendly process overcomes challenges associated with aqueous oxidants, such as substrate solubility and side reactions, providing a robust alternative for sulfone synthesis.