GENERAL PROCEDURE: A mixture of sodium aryl sulfite (1 mmol), copper(II) acetate (0.5 mmol) and acetonitrile (1 mL) was stirred in air at 60°C for 3 hours. After completion of the reaction, the mixture was cooled to room temperature and filtered through filter paper. Subsequently, the organic phase was evaporated under reduced pressure and the residue was purified by fast column chromatography (silica gel, eluent ethyl acetate/petroleum ether=1/10) to afford the target product 4,4'-difluorodiphenyl sulfone. All products were known compounds and their structures were confirmed by 1H NMR, 13C NMR and high resolution mass spectrometry (HRMS).
