[N+](=C[Si](C)(C)C)=[N-].[Br:8][C:9]1[CH:14]=[CH:13][C:12]([CH2:15][C:16]([OH:18])=[O:17])=[C:11]([F:19])[CH:10]=1.[N+](=[CH2:22])=[N-]>C1(C)C=CC=CC=1.CO>[Br:8][C:9]1[CH:14]=[CH:13][C:12]([CH2:15][C:16]([O:18][CH3:22])=[O:17])=[C:11]([F:19])[CH:10]=1Diazomethyl-trimethyl-silane (11.6 mL of 2.0 M, 23.2 mmol) was added dropwise to a solution of 2-(4-bromo-2-fluoro-phenyl)acetic acid (4.50 g, 19.3 mmol) in toluene (7.7 mL) and MeOH (7.7 mL) under a nitrogen atmosphere at room temperature. A persistent yellow color remained after complete addition of diazomethane. The reaction was then quenched with a few drops of acetic acid and the solvents were removed under reduced pressure. The residue was purified by silica gel flash column chromatography using 0-10% EtOAc in hexanes to yield methyl 2-(4-bromo-2-fluoro-phenyl)acetate (4.32 g, 91%). 1H NMR (400 MHz, CDCl3) δ 7.28-7.22 (m, 2H), 7.15 (t, J=8.0 Hz, 1H), 3.71 (s, 3H), 3.63 (d, J=1.0 Hz, 2H).
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