Synthesis
General procedure for the synthesis of 2-methoxybenzenesulfonyl chloride from 2-methoxybenzenethiol: To a solution of 2-methoxybenzenethiol (1 eq.) and isopropanol (CAS: 67-63-0) (2 eq.) in methylene chloride (0.15 M) was added batchwise N-bromosuccinimide (CAS: 128-08-5) or N-chlorosuccinimide (CAS: 128-09- 6) (4 or 3.5 equivalents), and the reaction was carried out at room temperature (when using NBS) or at 0 °C (when using NCS). The reaction mixture was stirred at room temperature until the starting material was undetectable by thin layer chromatography (TLC) (about 1 hour). Subsequently, the reaction mixture was diluted with cold saturated NaHCO3 solution and extracted with ethyl acetate (4 times). The organic extracts were combined, dried with Na2SO4 and concentrated in vacuum to give the crude product. Finally, pure 2-methoxybenzenesulfonyl chloride was purified by silica gel column chromatography or radial chromatography using a hexane/ethyl acetate/acetone solvent mixture as eluent to obtain pure 2-methoxybenzenesulfonyl chloride.
References
[1] Tetrahedron Letters, 2017, vol. 58, # 23, p. 2244 - 2247
[2] Green Chemistry, 2017, vol. 19, # 9, p. 2286 - 2295
