[C:1]([O:4][C:5]1[CH:12]=[CH:11][C:8]([CH:9]=[O:10])=[CH:7][C:6]=1[O:13][CH3:14])(=[O:3])[CH3:2].C([O-])(=O)C.[Na+].II.[Br:22]Br>C(O)(=O)C.O>[C:1]([O:4][C:5]1[CH:12]=[C:11]([Br:22])[C:8]([CH:9]=[O:10])=[CH:7][C:6]=1[O:13][CH3:14])(=[O:3])[CH3:2]To a mixture of 4-acetoxy-3-methoxybenzaldehyde (75.7 g), anhydrous sodium acetate (76 g) and iodine (0.8 g) in acetic acid (300 ml) is added bromine (21 ml). The mixture is warmed to 45° C. for about 1 hour, then stirred stirred at room temperature for 3 days, poured into water (700 ml) and filtered. The solid is dissolved in toluene and the solution washed with brine, dried over magnesium sulfate, filtered and concentrated in vacuo. The residue is recrystallized twice from hexanes to give the desired product.
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