To a 0.35M solution of 3-chloro-4-(naphthalen-2-ylsulfanyl)-phenylamine (90) (150 mg, 0.53 mmol) in THF was added pyridine (Aldrich, 0.21 mL, 2.63 mmol) followed by 6-chloro-pyridine-3-sulfonyl chloride (Qorpark, 122 mg, 0.58 mmol). The resulting mixture was stirred for 15 hours. A 1M aqueous solution of HCl (20 mL) was added and the crude reaction mixture was extracted 3× with EtOAc (50 mL). The organic layers were combined and washed twice with a brine solution (100 mL), dried over Na2SO4, and concentrated under vacuum. The crude solid was chromatographed (5-15% EtOAc in hexane) to yield 140 mg (58%) of 94 as a pale yellow solid.
