[N+:1]([C:4]1[CH:5]=[C:6]2[C:11](=[CH:12][CH:13]=1)[N:10]=[CH:9][CH:8]=[CH:7]2)([O-:3])=[O:2].[Br:14]N1C(=O)CCC1=O.C(=O)(O)[O-].[Na+].C(OCC)(=O)C>S(=O)(=O)(O)O>[Br:14][C:12]1[CH:13]=[C:4]([N+:1]([O-:3])=[O:2])[CH:5]=[C:6]2[C:11]=1[N:10]=[CH:9][CH:8]=[CH:7]2To a flask containing 6-nitroquinoline (4 g, 23 mmol) in sulfuric acid (20 ml) was added N-bromo-succinimide (5.31 g, 29.9 mmol). The mixture was heated to 60° C. (oil bath) for 6 hours and then stored in a freezer overnight. The crude reaction mixture was poured into a beaker containing ice (250 ml). The material was basified by adding first solid sodium bicarbonate and then a saturated solution of sodium bicarbonate (to a pH of about 10). During this procedure ethyl acetate (60 ml) was also added. The material was filtered to remove insoluble material and the filtrate transferred to a reparatory funnel. Ethyl acetate (100 ml) was added and the biphasic material shaken. The organic phase was collected and shaken with an equal volume of brine solution. The ethyl acetate phase was collected and the aqueous phases were back extracted with ethyl acetate (2×100 ml). The combined organic phase was stripped to provide a solid. The solid from the above filtration was taken up in hot ethyl acetate (60 ml). The material was cooled to ambient, dried over magnesium sulfate and filtered. The solvent was stripped and the crude solid product was combined with the material obtained from aqueous work up. This material was crystallized from hot ethyl acetate/hexane to provide the desired product as a yellow powder (2.05 g).
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