3-Bromothioanisole (8.7 g, 43 mmol) was added to dichloromethane (125 mL)
to it and cooled to 0C. To this was added 3-chloroperbenzoic acid (22.2 g, 129 mmol). m- CPBA was not completely dissolved. The reaction mixture was stirred overnight. The reaction was purged with saturated thiosulfate
sodium (150 mL) solution to quench it. The product was extracted with EtOAc (3 x 100 mL). The organic fractions
portions were combined, washed with brine (75 mL) and dried over sodium sulfate. The organic liquids were then concentrated to give 9.89 g (97%) of 3-bromophenyl methyl sulfone.