反应详情

温度

-10 °C

At −78° C., 17.62 ml of 1.59 M n-butyl lithium-THF solution was added dropwise to 100 ml of THF solution containing 4.73 ml of tetramethylpiperidine. This was stirred at −10° C. for 10 minutes, cooled to −78° C., mixed with 5.00 g of tert-butyl 2,4-difluorobenzoate dissolved in 20 ml of THF and then stirred for 1 hour. Subsequently, 7.23 ml of DMF was added dropwise thereto, and the mixture was stirred for 1 hour, mixed with 5.34 ml of acetic acid and then risen to room temperature. This was mixed with an appropriate amount of purified water, extracted with ethyl acetate and dried with anhydrous magnesium sulfate. After concentration, the thus formed residue was purified by a silica gel column chromatography to obtain 5.65 g (100%) of tert-butyl 2,4-difluoro-3-formylbenzoate (Reference Example 4-1) from a hexane-ethyl acetate (20:1-10:1) eluate.

1. temperaturecooled to −78° C.
2. stirringstirred for 1 hour
3. stirringthe mixture was stirred for 1 hour
4. customrisen to room temperature
5. extractionextracted with ethyl acetate
6. dry with materialdried with anhydrous magnesium sulfate
7. concentrationAfter concentration
8. customthe thus formed residue was purified by a silica gel column chromatography