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SHORT COMMUNICATIONSTriazolecarboxylic acids and their derivatives attract interest as promising starting compounds for the synthesis of energy-rich substances [1][2][3][4][5] and medical agents [6]. We have synthesized a new representative of this series, 3(5)-nitroamino-1,2,4-triazole-5(3)-carbohydrazide. The synthesis was performed in three ways: (1) reaction of previously described [7] hydrazide I with excess hydrazine hydrate on heating;(2) hydrazinolysis of known [7] nitroaminotriazolecarboxylate II, and (3) intramolecular heterocyclization of hydrazide III in alkaline medium. Here, compounds II and III are readily obtained from I. Hydrazide IV is a colorless high-melting crystalline substance. It reacted with aromatic aldehydes in the presence of a catalytic amount of acetic acid to give the corresponding hydrazones V-IX. The structure of compounds IV-IX was confirmed by the spectral data. The 1 H NMR spectrum of hydrazide IV contained broadened signals from protons of the N 2 N-NH group at δ 5.00 and 9.80 ppm, which are typical of many hydrazine derivatives [8]; signals from the HNNO 2 proton and NH proton in the heteroring appear as a rule in a very weak field [9, 10]. In the 1 H NMR spectra of hydrazones V-IX, protons of the =CH and HNCO groups resonated at δ 8.45-8.80 and 12.30-12.78 ppm, respectively. Hydrazones V-IX characteristically showed in the IR spectra absorption bands due to vibrations of the NH (3455-3360 and 3290-3200 cm -1 ) and C=O groups (1690-1670 cm -1 ); in addition, a number of strong bands belonging to stretching vibrations of the C=N and N-NO 2 groups and bending vibrations of the N-H group were present in the region 1610-1550 cm -1 [10,11]. In the electron spectra of hydrazones V-IX we observed long-wave absorption bands at λ max 296-356 nm (log ε 4.17-4.46); the red shift relative to the corresponding band in the spectrum of initial com-V, Ar = Ph; VI, Ar =