Reaction of 2-methoxycarbonylamino-3,3-dichloroacrylonitrile with phenylhydrazine in the presence of triethylamine

Full text of DOI:10.1134/S1070363211030327

ISSN 1070-3632, Russian Journal of General Chemistry, 2011, Vol. 81, No. 3, pp. 613–614. © Pleiades Publishing, Ltd., 2011.
Original Russian Text © S.A. Chumachenko, O.V. Shablykin, V.S. Brovarets, 2011, published in Zhurnal Obshchei Khimii, 2011, Vol. 81, No. 3, pp. 518–
519.
LETTERS
TO THE EDITOR
Reaction of 2-Methoxycarbonylamino-3,3-dichloroacrylonitrile
with Phenylhydrazine in the Presence of Triethylamine
S. A. Chumachenko, O. V. Shablykin, and V. S. Brovarets
Institute of Bioorganic and Petroleum Chemistry, National Academy of Sciences of Ukraine,
ul. Murmanskaya 1, Kiev, 02094 Ukraine
e-mail: brovarets@bpci.kiev.ua
Received October 19, 2010
DOI: 10.1134/S1070363211030327
It was found previously that the reaction of 2-
methoxycarbonylamino-3,3-dichloroacrylonitrile I with
an excess of phenylhydrazine occurs initially through
the substitution of two labile chlorine atoms by the
phenylhydrazine residues followed by the intra-
molecular cyclization due to the addition of phenyl-
hydrazine fragment to the cyano group to form 5-amino-
pyrazole [1].
the cyanide ion under the action of aryl hyd-razines
[1, 2].
1-Aryl-5-oxo-4,5-dihydro-1H-1,2,4-triazole-3-
carbaldehyde aryl hydrazones VI are formed as the
final products via some intermediate stages (see
transformation II→VI in the scheme). The structure of
1
compounds VIa and VIb was confirmed by the H
NMR, IR spectroscopy, mass spectrometry and X-ray
diffraction studies.
As shown in the present report, these reagents react
otherwise in the presence of triethylamine, giving rise
to substituted triazol-5-ones VI. The presence of
triethylamine in the reaction mixture promotes ap-
parently the increase in the amount of the reactive N-
methoxycarbonylimine tautomer II, which elimi-nates
1-Aryl-5-oxo-4,5-dihydro-1H-1,2,4-triazole-3-
carbaldehyde (VIa, VIb) aryl hydrazones. To a solu-
tion of 10 mmol of I in 20 ml of methanol 30 mmol of
triethylamine and 20 mmol of the appropriate aryl
hydrazine were added. The mixture was stirred for
H
N
Cl
Cl
Cl
Et3N
ArNHNH2, Et3N
H
H
MeO
MeO
N
O
N
_Et3N HCN
Cl
Cl
Cl
Me
O
CN
O
CN
O
NH
HN
Ar
II
I
IIIa, IIIb
_MeOH
H
N
H
Cl
H
Cl
Cl
H
Cl
ArNHNH2, 2Et3N
_2Et3N HCl
N
N
O
O
CH NNHAr
O
N NH
N N
N N
Ar
Ar
Ar
IVa, IVb
Va, Vb
VIa, VIb
Ar = Ph (a), 4-ClC6H4 (b).
613

614
CHUMACHENKO et al.
12 h at 20–25°C. Then the precipitate was filtered off,
washed first with water and then with a small amount
of 2-propanol.
20.54. M 346, 348. С15Н11Cl2N5О. Calculated, %: С
51.74; Н 3.18; N 20.11; Cl 20.36. M 347.
The IR spectra were recorded on a Vertex 70 spec-
1
trometer from KBr pellets. The Н NMR spectra were
Compound VIa. Yield 52%, mp 270–272°C
(ethanol). IR spectrum, ν, cm–1: 1707 (С=О), 3162 (NH),
obtained on a Varian-300 spectrometer (300 Hz) in
DMSO-d6 relative to internal TMS. The mass spectra
were taken on an Agilent 1100/DAD/MSD VL G1965
instrument. Melting points were measured on a Fisher-
Johns device.
1
3293 (NH). Н NMR spectrum, δ, ppm: 6.83–8.03 m
(10НAr), 7.58 s (1Н, NН), 10.92 s (1Н, СН), 12.35 br.s
(1Н, NН). Found, %: С 64.73; Н 4.72; N 25.25. M
278, 280. С15Н13N5О. Calculated, %: С 64.51; Н 4.69;
N 25.07. M 279.
REFERENCES
1. Brovarets, V.S., Pil’o, S.G., Chernega, A.N., Roma-
nenko, A.A., and Drach, B.S., Zh. Obshch. Khim., 1999,
vol. 69, no. 10, p. 1646.
2. Popil’nichenko, S.V., Brovarets, V.S., Chernega, A.N.,
and Drach, B.S., Dokl. Nats. Akad. Nauk Ukrainy, 2005,
no. 4, p. 128.
Compound VIb. Yield 58%, mp 290–292°С
(ethanol). IR spectrum, ν, cm–1: 1717 (С=О), 3173 (NH),
3321 (NH). Н NMR spectrum, δ, ppm: 7.25–8.18 m
(8НAr), 7.60 s (1Н, NН), 11.10 s (1Н, СН), 12.45 br.s
(1Н, NН). Found, %: С 51.97; Н 3.21; N 20.38 Cl
1
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 81 No. 3 2011