A facile route to thiophene-1,1-dioxides bearing electron-withdrawing groups

No commonly available synthetic method for thiophene-1,1-dioxides with strong EWGs has been described to date. Trifluoroperacetic acid in acetonitrile in the absence of water is shown to oxidise thiophenes, including examples possessing an electron-withdrawing group such as sulfonyl or alkoxycarbonyl. An easy and ready for scale-up procedure is developed, some formerly unknown thiophene-1,1-dioxides are obtained.