[N+](=[CH:3][C:4](=[O:13])[CH2:5][C:6]1[CH:11]=[CH:10][C:9]([I:12])=[CH:8][CH:7]=1)=[N-].[BrH:14].C(=O)(O)[O-].[Na+]>C(O)(=O)C>[Br:14][CH2:3][C:4](=[O:13])[CH2:5][C:6]1[CH:11]=[CH:10][C:9]([I:12])=[CH:8][CH:7]=11-Diazo-3-(4-iodophenyl)propan-2-one (13) (1.27 g, 4.43 mmol) was dissolved in acetic acid (20 mL) and cooled to 0° C. To this was added 47% hydrobromic acid (1.55 mL, 13.3 mmol) and stirred for an hour after warming to room temperature. After neutralization by adding saturated aqueous solution of sodium bicarbonate, the product was extracted with ethyl acetate (×3) and the organic layer was washed sequentially with saturated aqueous solution of sodium bicarbonate (×1) and saturated brine (×1), and dried over anhydrous sodium sulfate. After filtration, the mixture was concentrated under reduced pressure and the residue was purified by silica gel flash column chromatography (n-hexane/ethyl acetate=7/1) to give 1-bromo-3-(4-iodophenyl)propan-2-one (16) as a colorless solid (1.42 g, 4.18 mmol, 94.4%).
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