[CH3:1][O:2][C:3]([C:5]1[C:13]2[O:12][C:11]([CH3:14])=[CH:10][C:9]=2[CH:8]=[CH:7][CH:6]=1)=[O:4].[Br:15]Br>C(Cl)Cl.CCOC(C)=O>[CH3:1][O:2][C:3]([C:5]1[C:13]2[O:12][C:11]([CH3:14])=[C:10]([Br:15])[C:9]=2[CH:8]=[CH:7][CH:6]=1)=[O:4]A solution of 2-methyl-benzofuran-7-carboxylic acid methyl ester (0.55 g, 2.87 mmol), prepared according to a literature procedure (Ishikawa, T.; Nagai, K.; Ohkubo, N.; Ishii, H. Heterocycles 1994, 39, 371), in CH2Cl2 (15 mL) at 0° C. is treated with bromine (147 μL, 2.87 mmol). The reaction is stirred at 0° C. for 30 min, then at RT overnight. The reaction is diluted with EtOAc 960 mL); washed with 5% Na2S2O3 (2×20 mL); brine (20 mL); dried with Na2SO4, filtered and concentrated gives the title compound (0.79 g, 2.87 mmol, 100%). 1H NMR (CDCl3): δ 2.55 (s, 3H), 4.00 (s, 3H), 7.33 (t, J=7.5 Hz, 1H), 7.63 (dd, J=7.9, 0.9 Hz, 1H), 7.93 (dd, J=7.9, 0.9 Hz, 1H) ppm.
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