Using (2-chlorophenyl)methanesulfonamide (450 mg, 2.19 mmol) as starting material, tris(dibenzylideneacetone)dipalladium (100 mg, 0.109 mmol), 2-di-tert-butylphosphino-2',4',6'-triisopropylbiphenyl (186 mg, 0.438 mmol), and potassium carbonate (605 mg, 4.38 mmol) were added in a microwave reaction flask, followed by addition of tetrahydrofuran (THF, 8.8 mL) as solvent. The reaction mixture was stirred at 80 °C for 13 hours. Upon completion of the reaction, the reaction was quenched with saturated ammonium chloride solution. Subsequently, the solvent was removed by rotary evaporator and the obtained residue was purified by column chromatography (eluent: cyclohexane/acetone) to give the final 1,3-dihydro-2,1-benzisothiazole-2,2-dioxide as a white solid (296 mg, 80% yield). The product was characterized by 1H NMR (500 MHz, CDCl3): δ = 7.31-7.26 (m, 1H), 7.26-7.23 (m, 1H), 7.07 (td, J = 7.6, 0.9 Hz, 1H), 6.90 (d, J = 8.0 Hz, 1H), 6.48 (bs, 1H), 4.39 (s, 2H).HPLC analysis (Method C) showed retention time Rt = 1.69 min.
