2-Nitroguanidine derivatives. New synthesis of 5(3)-substituted 3(5)-nitroamino-1,2,4-triazoles

Full text of DOI:10.1023/B:RUJO.0000036089.08617.1c

Russian Journal of Organic Chemistry, Vol. 40, No. 4, 2004, p. 593. Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 4, 2004, p. 619.
Original Russian Text Copyright © 2004 by Metelkina, Novikova.
SHORT
COMMUNICATIONS
2-Nitroguanidine Derivatives. New Synthesis
of 5(3)-Substituted 3(5)-Nitroamino-1,2,4-triazoles
E. L. Metelkina and T. A. Novikova
St. Petersburg State Institute of Technology, Moskovskii pr. 26, St. Petersburg, 190013 Russia
Received June 28, 2003
We previously showed that 2-nitroguanidine reacts
with alkyl- and phenylhydrazines to give 2-alkyl(or
aryl)amino-2-nitroguanidine [1]. There are no pub-
lished data on reactions of 2-nitroguanidine with
carboxylic acid hydrazides. We anticipated that the
lower basicity of carboxylic acid hydrazides, as com-
pared to alkyl- and phenylhydrazines will favor their
reaction with 2-nitroguanidine under conditions of
base catalysis.
5(3)-Methyl-3(5)-nitroamino-1,2,4-triazole (I).
A solution of 4.48 g (0.08 mol) of potassium hydroxide
in 30 ml of water was added with stirring to a suspen-
sion of 8.32 g (0.08 mol) of 2-nitroguanidine and
5.92 g (0.08 mol) of acetohydrazide in 50 ml of water.
The mixture was heated for 3 h at 75–78°C, cooled to
18–20°C, and acidified with concentrated hydrochloric
acid to pH 1–2. A finely crystalline solid precipitated
and was filtered off, washed with cold water, and dried
at 50–60°C. Yield 8.55 g (75%), decomposition point
208°C. UV spectrum, λmax, nm (logε): 291 (4.11).
Found, %: C 25.96; H 3.34; N 49.12. C3H5N5O2.
Calculated, %: C 25.87; H 3.49; N 48.95.
We have found that 2-nitroguanidine reacts with
acetohydrazide and benzohydrazide at 75–78°C in the
presence of an equimolar amount of potassium
hydroxide; the subsequent acidification of the reaction
mixture with hydrochloric acid yields 5(3)-substituted
3(5)-nitroamino-1,2,4-triazoles I and II. Presumably,
the process involves intermediate formation of 1-acyl-
amino-2-nitroguanidine which readily undergoes intra-
molecular cyclization to triazoles I and II. The
properties of compounds I and II were consistent with
those reported in [2, 3].
5(3)-Phenyl-3(5)-nitroamino-1,2,4-triazole (II)
was synthesized in a similar way from 4.16 g
(0.04 mol) of 2-nitroguanidine and 4.88 g (0.04 mol)
of benzohydrazide in 30 ml of water and 2.24 g
(0.04 mol) of potassium hydroxide in 15 ml of water.
Yield 5.5 g (75%), decomposition point 219°C (from
aqueous methanol, 1:1). UV spectrum, λmax, nm
(logε): 298 (4.19). Found, %: C 49.90; H 3.12;
N 32.38. C9H7N5O2. Calculated, %: C 49.84; H 3.22;
N 32.26.
NNO2
NH2
O
C
+
H2N
C
R
NH NH2
NNO2
The UV spectra were measured on an SF-9 spectro-
photometer in water.
O
R
C
R
NH NH
C
NH2
REFERENCES
HN
N
1. Metelkina, E.L. and Novikova, T.A., Zh. Org. Khim.,
NHNO2
1993, vol. 29, p. 2390.
N
2. Henry, R.A., J. Am. Chem. Soc., 1950, vol. 72, p. 5343.
I, II
3. Chipen, G.I., Grinshtein, V.Ya., and Preiman, R.P.,
I, R = Me; II, R = Ph.
Zh. Obshch. Khim., 1962, vol. 32, p. 454.
1070-4280/04/4004-0593 © 2004 MAIK “Nauka/Interperiodica”