[Br:1][C:2]1[C:7]([C:8](=[O:10])[CH3:9])=[CH:6][CH:5]=[CH:4][N:3]=1.[Br:11]Br>C(O)(=O)C.C(OCC)(=O)C.C(=O)(O)[O-].[Na+]>[Br:11][CH2:9][C:8]([C:7]1[C:2]([Br:1])=[N:3][CH:4]=[CH:5][CH:6]=1)=[O:10]A solution of 1-(2-bromopyridin-3-yl)ethanone (2.10 g, 10.5 mmol) in acetic acid (28.0 mL) was treated with bromine (595 μL, 11.5 mmol) and heated at 90° C. for 1 h. The reaction mixture was diluted with ethyl acetate and saturated aqueous sodium bicarbonate solution. The aqueous layer was separated and further extracted with ethyl acetate (2×80 mL). The combined organic layers were washed with brine, dried over magnesium sulfate, filtered, and concentrated to give the crude product. Purification by flash column chromatography (10% ethyl acetate/hexanes to 30% ethyl acetate/hexanes) gave the desired product (2.15 g, 73%). LCMS calculated for C7H6Br2NO (M+H)+: m/z=277.9, 279.9, 281.9. found: 277.7, 279.7, 281.8.
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