[Br:1][C:2]1[CH:10]=[C:9]2[C:5]([CH:6]([C:12]3[CH:17]=[CH:16][CH:15]=[CH:14][C:13]=3[O:18][CH3:19])[O:7][C:8]2=[O:11])=[CH:4][CH:3]=1.[OH-].[K+].N1C=CC=CC=1.[Mn]([O-])(=O)(=O)=[O:29].[K+]>>[Br:1][C:2]1[CH:3]=[CH:4][C:5]([C:6](=[O:29])[C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][C:13]=2[O:18][CH3:19])=[C:9]([CH:10]=1)[C:8]([OH:7])=[O:11]This compound was prepared according to Ukita et al J. Med. Chem. 2001, 44, 2204. To a stirred mixture of 6-bromo-3-(2-methoxyphenyl)isobenzofuran-1(3H)-one (5.15 g, 16.1 mmol) in KOH (25% aqueous) (64.5 mL, 16.1 mmol) and pyridine (32.3 mL, 16.1 mmol) in a pressure tube was added powder potassium permanganate (3.83 g, 24.2 mmol). The reaction was heated at 100° C. After 4 h, LCMS showed ˜95% conversion to product. The reaction was cooled to rt. The mixture was filtered, and the solid residue was washed with water. The filtrate was acidified with concentrated HCl until pH=2. A sticky white solid was filtered off with the aid of water and dried to afford 5-bromo-2-(2-methoxybenzoyl)benzoic acid (4.2 g, 78% yield). m/z (ESI) 335.0 (M+H)+, 337.0 (M+3H)+.
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