反应详情

Procedure R′: A 15 mL DMF mixture of 4-bromo-N-tert-butyl-benzenesulfonamide (1022 mg, 3.5 mmol), iodomethane (0.44 mL, 7 mmol), and K2CO3 (987 mg, 7 mmol) is stirred at room temperature overnight. Water and ethyl acetate are added to the mixture. The aqueous layer is extracted several times with ethyl acetate. The combined organic layers are washed with H2O and brine, then dried over Na2SO4 and evaporated. The crude product is purified by silica-gel column chromatography (gradient: 100% CH2Cl2 to 20% EtOAc/CH2Cl2) give the intermediate 4-bromo-N-tert-butyl-N-methyl-benzenesulfonamide (1040 mg, 97% yield). MS (ES+) 251.9 (M-tBu)+, NMR (CDCl3).

1. extractionThe aqueous layer is extracted several times with ethyl acetate
2. washThe combined organic layers are washed with H2O and brine
3. dry with materialdried over Na2SO4
4. customevaporated
5. customThe crude product is purified by silica-gel column chromatography (gradient: 100% CH2Cl2 to 20% EtOAc/CH2Cl2)