[CH3:1][O:2][C:3]1[N:8]=[CH:7][C:6]([C:9]2[C:18]([CH3:19])=[CH:17][C:12]([C:13]([O:15][CH3:16])=[O:14])=[CH:11][C:10]=2[CH3:20])=[CH:5][CH:4]=1.C([O-])(=O)C.[K+].[Br:26]Br.[OH-].[Na+]>C(O)(=O)C.C(OCC)(=O)C>[Br:26][C:4]1[CH:5]=[C:6]([C:9]2[C:18]([CH3:19])=[CH:17][C:12]([C:13]([O:15][CH3:16])=[O:14])=[CH:11][C:10]=2[CH3:20])[CH:7]=[N:8][C:3]=1[O:2][CH3:1]Methyl 4-(6-methoxypyridin-3-yl)-3,5-dimethylbenzoate (Step B, 1.31 g, 4.83 mmol) and potassium acetate (2.369 g, 24.14 mmol) were dissolved in acetic acid (24 mL). Bromine (0.622 mL, 12.07 mmol) was added and the reaction was stirred at 80° C. The reaction was monitored by LCMS. Once complete, it was cooled to room temperature, diluted with ethyl acetate and added to a separatory funnel. Aqueous sodium hydroxide was added to neutralize the reaction. The reaction was partitioned between water and ethyl acetate, and the aqueous was extracted a second time with ethyl acetate. The combined organics were washed with brine, then dried over sodium sulfate, filtered and evaporated. The crude isolate was purified by silica gel chromatography, eluting with 2 column volumes of 4% Ethyl acetate in hexanes, followed by a gradient of 4-10% ethyl acetate/hexanes over 6 column volumes, followed by a gradient of 10-20% ethyl acetate/hexanes over 5 column volumes to give the title compound. 1H NMR (CDCl3, 500 MHz) δ7.88 (d, 1H), 67.79 (s, 2H), 67.63 (d, 1H), 64.07 (s, 3H), 63.93 (s, 3H), 62.11 (s, 6H).
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