[Br:1][C:2]1[NH:3][C:4]([C:8]([OH:10])=[O:9])=[C:5]([CH3:7])[N:6]=1.N1(C2CCCCCCCCCC2)CCCCCC[CH2:15][CH2:14][CH2:13]N1.[N+:33]([C:36]1[CH:43]=[CH:42][C:39]([CH2:40]Br)=[CH:38][CH:37]=1)([O-:35])=[O:34]>C1C=CC=CC=1>[N+:33]([C:36]1[CH:43]=[CH:42][C:39]([CH2:40][N:3]2[C:4]([C:8]([O:10][CH:14]([CH3:15])[CH3:13])=[O:9])=[C:5]([CH3:7])[N:6]=[C:2]2[Br:1])=[CH:38][CH:37]=1)([O-:35])=[O:34]To a solution of 2 g (8.1×10-3 moles) of i-propyl ester of 2-bromo-4-methyl-5-imidazolecarboxylic acid in 20 ml of benzene was added 1.2 ml (8.1×10-3 moles) of diazabicycloundecane, followed by 1.7 g (8.1×10-3 moles) of p-nitrobenzylbromide. The resulting mixture was heated to reflux overnight, cooled to room temperature and filtered. Concentration in vacuo gave a golden oil. This residue was purified by medium pressure liquid chromatography on silica gel to yield 2.1 g (70%) i-propyl 1-(4-nitrobenzyl)-2-bromo-4-methyl-5-imidazolecarboxylate as a yellow oil and 600 mg (20%) of the desired product, i-propyl 2-bromo-3-(4-nitrobenzyl)-4-methyl-5-imidazolecarboxylate also a yellow oil.
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