[Br:1][C:2]1[CH:7]=[CH:6][C:5]([CH2:8][C:9]([OH:11])=[O:10])=[C:4]([F:12])[CH:3]=1.OS(O)(=O)=O.[CH3:18]O>>[Br:1][C:2]1[CH:7]=[CH:6][C:5]([CH2:8][C:9]([O:11][CH3:18])=[O:10])=[C:4]([F:12])[CH:3]=1To a solution of 2-(4-bromo-2-fluorophenyl)acetic acid (260 g, 1.13 mol) in MeOH (2 L) was added H2SO4 (30 mL) at rt. The solution was heated to reflux overnight. Then the solvent was concentrated and distributed between EA and saturated NaHCO3 solution. The combined organic extract was washed with brine, dried over Na2SO4, filtered and concentrated. Another batch was repeated using the same procedure. Then the two batches were combined to provide methyl 2-(4-bromo-2-fluorophenyl)acetate (520 g, 94%). TLC (PE/EA=10:1, Rf=0.7). 1H NMR (400 MHz, CDCl3) δ 7.25-7.20 (m, 2H), 7.14 (t, J=8.0 Hz, 1H), 3.70 (s, 3H), 3.62 (s, 2H).
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