[Br:1][C:2]1[CH:3]=[CH:4][C:5]([F:11])=[C:6]([CH:8]([OH:10])[CH3:9])[CH:7]=1>O1CCOCC1.[O-2].[O-2].[Mn+4]>[Br:1][C:2]1[CH:3]=[CH:4][C:5]([F:11])=[C:6]([C:8](=[O:10])[CH3:9])[CH:7]=1To a solution of 1-(5-bromo-2-fluoro-phenyl)-ethanol 102 (105 g, 0.479 mol.) in dioxane (2 L) was added manganese dioxide (203 g, 2.35 mol.). The reaction mixture was heated under reflux for 5 hours. The reaction mixture was allowed to cool to room temperature. The reaction mixture was filtered through Celite (i.e., diatomaceous earth) and the solid was washed with ether (1 L). The combined filtrate was evaporated under reduced pressure to afford the 1-(5-bromo-2-fluoro-phenyl)-ethanone 103 (95.7 g, 0.441 mol.) which was used in the next step without further purification.
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