To a solution of 6-Chloro-pyridine-3-sulfonic acid [3-chloro-4-(naphthalen-2-ylsulfanyl)-phenyl]-amide (94, 55 mg, 0.12 mmol) in CH2Cl2 (2 mL), was added dropwise a solution of m-chloroperoxybenzoic acid (mCPBA, Aldrich, 36 mg, 0.2 mmol) in CH2Cl2 (1 mL). The resulting mixture was stirred at ambient temperature for 1 hour and diluted with EtOAc (60 mL). The organic layer was washed with saturated aqueous NaHCO3 solution (50 mL), twice with brine solution (50 mL), dried over Na2SO4, and concentrated under vacuum. The crude solid was chromatographed (10-25% EtOAc in hexane) to yield 17 mg (30%) of 103 as an off white solid.
