a) To 200 mL of mixed solvent (acetic acid/water/dichloromethane, 3/1/4 by volume) were added 2,6-dichlorothiophenol (10.0 g, 55.8 mmol), N-chlorosuccinimide (37.28 g, 279 mmol) and potassium acetate (2.29 g, 27.9 mmol). The reaction mixture was stirred at 0 °C and subsequently heated to room temperature. After completion of the reaction, the mixture was diluted with 200 mL of dichloromethane and washed three times with 100 mL of water. The organic layer was dried with anhydrous sodium sulfate and concentrated to give 2,6-dichlorobenzenesulfonyl chloride (11 g, 80% yield). The product was confirmed by NMR hydrogen spectroscopy (CDCl3): δ 7.57 (d, 2H), 7.47 (t, 1H).
