反应详情

温度

-78 °C

A solution of 1-bromo-2-fluoro-3-methylbenzene (7.0 g, 37.0 mmol) in THF (60 mL) was brought to −78° C. followed by the dropwise addition of butyllithium (15.55 ml, 38.9 mmol). The resulting mixture was stirred at −78° C. for 1 h then neat ethyl 2-fluoroacetate (3.76 ml, 38.9 mmol) was added dropwise. After 30 min the reaction went to completion. The reaction was quenched at −78° C. with saturated NH4Cl, warmed to rt and transferred to a separatory funnel. The aqueous phase was extracted with EtOAc and the combined organic extracts were washed with brine, dried over Na2SO4, filtered, concentrated and chromatographed on silica gel using 0-10% EtOAc/hexanes to afford a colorless oil that turned into a white solid as 2-fluoro-1-(2-fluoro-3-methylphenyl)ethanone (5.03 g, 29.6 mmol, 80% yield). MS m/z=171 [M+H]+. Calculated for C9H8F2O: 170.05.

1. customwas brought to −78° C.
2. waitAfter 30 min the reaction went to completion
3. customThe reaction was quenched at −78° C. with saturated NH4Cl
4. temperaturewarmed to rt
5. customtransferred to a separatory funnel
6. extractionThe aqueous phase was extracted with EtOAc
7. washthe combined organic extracts were washed with brine
8. dry with materialdried over Na2SO4
9. filtrationfiltered
10. concentrationconcentrated
11. customchromatographed on silica gel using 0-10% EtOAc/hexanes
12. customto afford a colorless oil that