[Cl:1][C:2]1[C:3]([CH3:13])=[CH:4][C:5]([O:11][CH3:12])=[C:6]([C:8](=[O:10])[CH3:9])[CH:7]=1.[Br:14]N1C(=O)CCC1=O>C(O)(=O)C>[Br:14][C:4]1[C:5]([O:11][CH3:12])=[C:6]([C:8](=[O:10])[CH3:9])[CH:7]=[C:2]([Cl:1])[C:3]=1[CH3:13]To a stirred solution of 1-(5-chloro-2-methoxy-4-methylphenyl)ethanone (5.00 g, 25.2 mmol, from Oakwood) in acetic acid (100 mL) was added N-bromosuccinimide (4.93 g, 27.7 mmol) and the resulting mixture heated at 100° C. for 18 hours. After cooling to ambient temperature, the reaction mixture was concentrated in vacuo, then neutralized with sat. sodium bicarbonate, filtered off insoluble succinimide. The filtrate was extracted with EtOAc. The combined organic layers were washed with brine, dried over sodium sulfate, and then concentrated to dryness under reduced pressure. The residue was purified on silica gel, eluting with 0 to 50% EtOAc in hexanes, to give the desired products (2.66 g, 38%). LCMS calculated for C10H11BrClO2(M+H)+: m/z=277.0; found: 277.0. 1H NMR (DMSO-d6, 300 MHz): δ 7.70 (1H, s), 3.77 (3H, s), 2.57 (3H, s), 2.50 (3H, s) ppm.
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