反应详情

温度

-30 °C

A solution of 4.0 g of 4-bromo-N,N-dimethylaniline in 50 ml of dry tetrahydrofuran at -78° C. was treated with 23.5 ml of 1.7M tert-butyllithium in pentane under nitrogen over 5 minutes with rapid stirring. After 0.5 hour, the slurry was warmed to -30° C. and added to a solution of 4.0 g of α,α-difluorophenylacetate in 50 ml of dry tetrahydrofuran at -78° C. After 1 hour at -78° C., the solution was allowed to warm to room temperature and stirred overnight. The solution was poured into water and extracted with ethyl acetate. Evaporation left a solid which was purified by flash chromatography (1:1 ethyl acetate-hexane) to give a powder. Recrystallization from ethyl acetate-hexane gave 1.75 g of 2,2-difluoro-1-[4-(dimethylamino)phenyl]-2-phenylethanone, m.p. 115°-116° C.

1. waitAfter 1 hour at -78° C.
2. temperatureto warm to room temperature
3. extractionextracted with ethyl acetate
4. customEvaporation
5. waitleft a solid which
6. customwas purified by flash chromatography (1:1 ethyl acetate-hexane)
7. customto give a powder
8. customRecrystallization from ethyl acetate-hexane