Reaction of sulphides with acyl nitrates; a simple and rapid method for preparing sulphoxides

Sulphides react rapidly with acyl nitrates, even at –76 °C, to give sulphoxides in high yield with no sulphone formation; either acetyl nitrate, formed from acetic anhydride and concentrated nitric acid, or, for milder conditions, benzoyl nitrate, formed from benzoyl chloride and silver nitrate, give satisfactory results.