[C:1]1(=[O:7])O[C:4](=[O:5])[CH:3]=[CH:2]1.[Br:8][C:9]1[CH:10]=[C:11]([NH2:15])[CH:12]=[CH:13][CH:14]=1.C([O-])(=O)C.[Na+].C(OC(=O)C)(=O)C>CCOCC.O>[Br:8][C:9]1[CH:10]=[C:11]([N:15]2[C:4](=[O:5])[CH:3]=[CH:2][C:1]2=[O:7])[CH:12]=[CH:13][CH:14]=1To a solution of maleic anhydride (1.71 g, 17.4 mmol) in dry ether (25 ml) was added a solution of 3-bromo-phenylamine (3.0 g, 17.4 mmol) in ether (5 ml), via slow drop-wise addition. The material was stirred for 1 hour at ambient Sodium acetate (721 mg, 8.8 mmol) and then acetic anhydride (6 ml, 63 mmol) were added and the mixture was heated for 2 hours (oil bath, 100° C.). The material was cooled to ambient and then in an ice bath. Water (50 ml) was added with vigorous stirring and the resultant precipitate was collected by filtration. The precipitate was washed with several volumes of water and finally with hexane (30 ml). The material was dried over night in the vacuum oven to afford 2.84 g of 1-(3-bromo-phenyl)-pyrrole-2,5-dione as a light yellow-white powder.
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