[F:1][C:2]1[CH:12]=[CH:11][C:5]([C:6]([O:8]CC)=[O:7])=[CH:4][C:3]=1[CH:13]=[CH2:14].O.[OH-].[Li+].[CH2:18]1COCC1>O>[CH:13]1([C:3]2[CH:4]=[C:5]([CH:11]=[CH:12][C:2]=2[F:1])[C:6]([OH:8])=[O:7])[CH2:14][CH2:18]1To a solution of compound 3 ethyl 4-fluoro-3-vinylbenzoate (Preparation 54, 87 g, 0.42 mol, 1 eq) in THF (470 mL) and water (400 mL) was added lithium hydroxide monohydrate (35.1 g, 0.84 mol, 2.0 eq). The resulting mixture was stirred at 40° C. overnight. THF was removed in vacuum, then 6N hydrogen chloride solution was added dropwise until pH=2. The mixture was extracted with ethyl acetate (3×600 mL). The organic phase was dried over sodium sulfate and concentrated in vacuo to give title compound as a white solid (60.8 g, 0.34 mol, 81%).
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