[C:1]([O:5][C:6](=[O:9])[NH:7][NH2:8])([CH3:4])([CH3:3])[CH3:2].[CH3:10][O:11][CH2:12][CH2:13][CH2:14][C:15](O)=[O:16].Cl.C(N=C=NCCCN(C)C)C>N1C=CC=CC=1>[C:1]([O:5][C:6]([NH:7][NH:8][C:15](=[O:16])[CH2:14][CH2:13][CH2:12][O:11][CH3:10])=[O:9])([CH3:4])([CH3:3])[CH3:2]Carbazic acid tert-butyl ester (9.21 g) was dissolved in pyridine (120 ml), followed by addition of 4-methoxybutyric acid (9.06 g) and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride salt (20.0 g), and stirred at ambient temperature for 64 hours. After the reaction solution was concentrated under reduced pressure, ethyl acetate was added to the residue, which was then washed with aqueous 1 mol/liter hydrochloric acid solution, saturated aqueous sodium hydrogen carbonate solution and saturated aqueous sodium chloride, and dried over anhydrous sodium sulfate. After the solvent was evaporated under reduced pressure, N′-(4-methoxybutyryl)hydrazine carboxylic acid tert-butyl ester was obtained in yellow oil (9.30 g, 57%). The physico-chemical values are as follows.
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