A highly efficient method for the oxidation of sulfides to sulfoxides using oxalic acid dihydrate in the presence of hydrogen peroxide has been developed. A versatile procedure for the oxidation of sulfides to sulfoxides without any over-oxidation to sulfones has been reported. This procedure cleanly oxidizes sulfides to the corresponding sulfoxides in excellent yields at ambient temperature.
3-Carboxypyridinium chlorochromate (CPCC) in the presence of aluminium chloride is a very efficient reagent for the selective oxidation of sulfides to sulfoxide and sulfones in solution and under microwave irradiation. It is noteworthy that different functional groups including carboncarbon double bonds, ketones, oximes, aldehydes, ethers, and acetals were tolerated under these reaction conditions.Key words: sulfoxides, sulfones, oxidation, chlorochromate, Lewis acid.