Br[C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([CH3:8])[C:3]=1[F:9].C([Li])CCC.[F:15][CH2:16][C:17](OCC)=[O:18]>C1COCC1>[F:15][CH2:16][C:17]([C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([CH3:8])[C:3]=1[F:9])=[O:18]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.
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