Oxidative fluorination of N-arylsulfonamides

Abstract We report a late stage oxidative nucleophilic fluorination of N -arylsulfonamides, a class of compounds so far not considered as precursors to 4-fluorophenyl sulfonamides. By installing a para -positioned tert -butyl substituent on the aniline, oxidative fluorination takes place regioselectively in the presence of HF·pyridine and PIDA. This methodology has been shown to give good yields for a variety of ortho - and meta -functionalised N -arylsulfonamides and has been adapted for radiofluorination to give 4-[ 18 F]fluorophenyl sulfonamides under carrier added conditions.