反应详情

温度

60 °C

To a suspension of 2,5-difluoro-4-methylbenzoic acid (6.0 g, 3.5 mmol) in 1,2-dichloroethane (100 mL) was added 4-dimethylaminopyridine (10.65 g, 8.7 mmol), 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide:hydrochloride (16.65 g, 8.7 mmol) in 1,2-dichloroethane (60 mL) and N,N-diisopropylethylamine (15 mL, 8.60 mmol) and the mixture stirred at room temperature for 20 minutes. N,N-Dimethylsulfamide (8.64 g, 6.9 mmol) was added to the solution and the mixture heated at 60° C. under nitrogen. After 3 hours the mixture was cooled to room temperature and extracted with dichloromethane (100 mL). The extract was washed successively with 2M hydrochloric acid (2×300 mL), brine (100 mL), dried over magnesium sulfate, filtered and evaporated to afford an oil (8.40 g) which solidified at room temperature. The crude product was purified by silica gel column chromatography eluting with ethyl acetate/heptane 1:4 as eluent to afford the title compound (7.17 g, 79%) as a white solid.

1. temperatureAfter 3 hours the mixture was cooled to room temperature
2. extractionextracted with dichloromethane (100 mL)
3. washThe extract was washed successively with 2M hydrochloric acid (2×300 mL), brine (100 mL)
4. dry with materialdried over magnesium sulfate
5. filtrationfiltered
6. customevaporated