反应详情

A 1.0M solution of sec-BuLi (21.5 ml, 21.5 mmol) was added dropwise to a stirred solution of O-tert-butyldimethylsilyl-2,5-difluorophenol (5.0 g, 20 mmol) in THF (20 mL) at -78° C. After 0.5 hr DMF (1.9 ml, 24.6 mmol) was added dropwise while the temperature was kept below -70° C. After 30 min, the mixture was allowed to warm to room temperature over 30 min. To the mixture was added 3N HCl (30 ml) and stirring was continued for 30 min. The mixture was extracted with ether (100 ml) and the extract was washed with water (100 ml), brine (100 ml), dried (sodium sulfate) and evaporated. Column chromatography (silica gel) of the residue eluting with n-hexane gave 3.56 g (64%) of the titled compound as a colorless oil.

1. customwas kept below -70° C
2. waitwas continued for 30 min
3. extractionThe mixture was extracted with ether (100 ml)
4. washthe extract was washed with water (100 ml), brine (100 ml)
5. dry with materialdried (sodium sulfate)
6. customevaporated
7. washColumn chromatography (silica gel) of the residue eluting with n-hexane