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