ISSN 1070-4280, Russian Journal of Organic Chemistry, 2014, Vol. 50, No. 3, pp. 452–453. © Pleiades Publishing, Ltd., 2014.
Original Russian Text © B.V. Murashevich, K.A. Shreiber, N.V. Toropin, K.S. Burmistrov, 2014, published in Zhurnal Organicheskoi Khimii, 2014, Vol. 50,
No. 3, p. 460.
SHORT
COMMUNICATIONS
Unusual Reaction of 4-[2-(4-Nitrobenzylidene)hydrazinylidene]-
cyclohexa-2,5-dienone with Propan-1-amine
B. V. Murashevich, K. A. Shreiber, N. V. Toropin, and K. S. Burmistrov
Ukrainian State University of Chemical Technology, pr. Gagarina 8, Dnepropetrovsk, 49005 Ukraine
e-mail: murashevich@yahoo.com
Received July 31, 2013
DOI: 10.1134/S1070428014030294
We previously reported that, unlike other quinone
imines, 4-(2-benzylidenehydrazinylidene)cyclohexa-
2,5-dienones react with nucleophiles according to the
1,8-addition pattern. This reaction path was observed
in their reactions with hydrogen halides [1] and secon-
dary aliphatic [2] and primary aromatic amines [3].
procedure described in [4]; its melting point coincided
with that given in [4] (mp 139–141°C).
4-[5-Ethyl-3-(4-nitrophenyl)-1H-1,2,4-triazol-1-
yl]phenol (II). Propan-1-amine, 2 mL (33 mmol), was
added to a solution of 2 g (7.9 mmol) of compound I in
200 mL of propan-2-ol, and the mixture was stirred for
45 min and left to stand for 3 days. The mixture was
then treated with 100 mL of dichloroethane and
200 mL of water and vigorously shaken, and the
organic phase was separated, washed with dilute acetic
acid and several portions of water, and evaporated
under reduced pressure to a small volume. The residue
was evaporated at room temperature, and the precip-
itate was filtered off, washed several times with warm
hexane, and dried. Yield 1.71 g (71%), mp 180–182°C.
1H NMR spectrum (DMSO-d6), δ, ppm: 1.26 t (3H,
CH3), 2.78 q (2H, CH2), 6.92 d and 7.39 d (2H each,
NO2C6H4, J = 8.6 Hz), 8.27 d and 8.33 d (2H each,
HOC6H4, J = 8.8 Hz), 10.00 s (1H, OH). 13C NMR
spectrum (DMSO-d6), δC, ppm: 11.51 (CH3), 19.34
(CH2); 115.6 (2C), 123.9 (2C), 128.46 (C) (HOC6H4);
We have found that 4-[2-(4-nitrobenzylidene)hy-
drazinylidene]cyclohexa-2,5-dienone (I) reacts with
propan-1-amine to give 4-[5-ethyl-3-(4-nitrophenyl)-
1H-1,2,4-triazol-1-yl]phenol (II). This reaction is un-
usual since the triazole ring is formed via oxidation of
the α-methylene group of propylamine under very mild
conditions. Obviously, the process involves interme-
diate formation of amidrazone A (1.8-addition product
in the quinoid form) which was detected in the reaction
mixture by TLC. However, all attempts to isolate it
resulted in its oxidative cyclization to triazole II. The
1
13
structure of II was proved by H and C NMR spec-
troscopy, mass spectrometry, and elemental analysis.
4-[2-(4-Nitrobenzylidene)hydrazinylidene]cyclo-
hexa-2,5-dienone I was synthesized according to the
Me
HN
N
N
N
N
NH2
+
Me
O
NO2
O
NO2
I
A
HO
N
N
N
NO2
Et
II
452