[CH2:1]([O:4][CH2:5][C:6]([C:8]1[CH:13]=[C:12]([Br:14])[CH:11]=[CH:10][C:9]=1[F:15])=O)[CH:2]=[CH2:3].Cl.[NH2:17][OH:18].C([O-])(=O)C.[Na+]>C(O)C>[CH2:1]([O:4][CH2:5][C:6]([C:8]1[CH:13]=[C:12]([Br:14])[CH:11]=[CH:10][C:9]=1[F:15])=[N:17][OH:18])[CH:2]=[CH2:3]To a solution of 2-(allyloxy)-1-(5-bromo-2-fluorophenyl)ethanone (118 g, 432.1 mmol) in ethanol (1.7 L) is added hydroxylamine hydrochloride (34.5 g, 496.9 mmol) and sodium ethanoate (40.8 g, 496.9 mmol) at 25° C. The reaction is heated at 70° C. for 1 hr. The reaction is cooled and the solvent is removed under reduced pressure. The residue is washed with water (1 L) and is extracted three times with dichloromethane (3×500 mL). The organic phase is dried over magnesium sulfate, filtered, and the solvent is removed under reduced pressure, to obtain the title compound as a mixture of two possible oximes (120 g, 96%). ES/MS m/e (79Br/81Br) 288, 290 (M+1).
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