[C:1]([C:5]1[CH:13]=[CH:12][C:8]([C:9](O)=[O:10])=[CH:7][C:6]=1[N+:14]([O-:16])=[O:15])([CH3:4])([CH3:3])[CH3:2].[NH3:17].C(OCC)(=O)C.CCCCCC>C(#N)C.C(OCC)(=O)C.CCCCCC>[C:1]([C:5]1[CH:13]=[CH:12][C:8]([C:9](=[O:10])[NH2:17])=[CH:7][C:6]=1[N+:14]([O-:16])=[O:15])([CH3:4])([CH3:3])[CH3:2]12.0 g (74.0 mmol) of N,N'-carbonyldiimidazole were added to a suspension of 15.03 g (67.3 mmol) of 4-t-butyl-3-nitrobenzoic acid in 150 ml of acetonitrile, and the resulting mixture was stirred for 1 hour, after which 20 ml (0.31 mol) of aqueous ammonia were added. The reaction mixture was stirred for 30 minutes, after which it was concentrated by evaporation under reduced pressure, and the concentrate was dissolved in ethyl acetate. The organic phase was washed with water, with 2 N aqueous hydrochloric acid, with water, with a saturated aqueous solution of sodium hydrogencarbonate and with a saturated aqueous solution of sodium chloride, in that order, after which it was dried over anhydrous magnesium sulfate. The solvent was removed by distillation under reduced pressure, and the resulting residue was purified by column chromatography through 150 g of silica gel, using a gradient elution method, with mixtures of ethyl acetate and hexane ranging from 1:1 to 2:1 by volume as the eluent, to give 12.68 g (yield 85%) of the title compound as crystals, melting at 114-115° C. (from ethyl acetate-hexane).
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