[CH:1]([C:4]([CH3:14])([N:7]1[C:11](=[O:12])[CH:10]=[CH:9][C:8]1=[O:13])[C:5]#[N:6])([CH3:3])[CH3:2].[Br:15]Br>C(O)(=O)C>[Br:15][C:9]1[C:8](=[O:13])[N:7]([C:4]([CH:1]([CH3:3])[CH3:2])([CH3:14])[C:5]#[N:6])[C:11](=[O:12])[CH:10]=1To a solution of α-isopropyl-α-methyl-2,5-dioxo-3-pyrroline-1-acetonitrile (50 g, 0.25 mol) in acetic acid (500 ml) heated at 75° C. is added bromine (40.76 g, 0.255 mol) in acetic acid (80 ml) dropwise with stirring. The reaction is maintained at 85° overnight and evaporated to a syrup, which is dissolved in methylene chloride (300 ml), is cooled to 5° C. to which triethylamine (34.78 ml) is added. After stirring for 2 hours the brown methylene chloride solution is diluted with ether and a white precipitate is formed. This is extracted with water (400 ml) and the organic layer is dried over anhydrous magnesium sulfate, then passed through a 2 inch bed of silica gel with methylene chloride to elute. The eluate is obtained as a dark brown oil. Anal. calcd. for C10H10N2O2Br: C, 44.29; H, 4.09; N, 10.33. Found: C, 43.37; H, 4.05; N, 10.07.
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