反应详情

To a solution of 3-(3-chlorophenyl)-3-methylbutan-2-one (15 g, 76 mmol) in CHCl3 (100 mL) was added chlorosulfuric acid (101 mL, 20 eq) at 0° C. over 2 h. Next SOCl2 (20 mL) was added dropwise to the reaction mixture over 30 min under nitrogen. The reaction mixture was slowly warmed to room temperature and stirred overnight. The mixture was slowly added to ice-water and then extracted with EtOAc. The combined extracts were washed with brine, dried over MgSO4 and evaporated. The residue was purified by chromatography (silica, Hex/EtOAc=9:1 to 4:1) to give 2-chloro-4-(2-methyl-3-oxobutan-2-yl)benzene-1-sulfonyl chloride as a yellow solid (9.8 g, 43%). 1H NMR (400 MHz, CDCl3) δ 8.12 (d, J=8.4 Hz, 1H), 7.54 (s, 1H), 7.37 (d, J=2.2 Hz, 1H), 2.03 (s, 3H), 1.56 (s, 6H).

1. extractionextracted with EtOAc
2. washThe combined extracts were washed with brine
3. dry with materialdried over MgSO4
4. customevaporated
5. customThe residue was purified by chromatography (silica, Hex/EtOAc=9:1 to 4:1)