ISSN 1070-4280, Russian Journal of Organic Chemistry, 2012, Vol. 48, No. 3, p. 475. © Pleiades Publishing, Ltd., 2012.
Original Russian Text © A.G. Tyrkov, A.B. Sheremetev, O.I. Serebryakov, 2012, published in Zhurnal Organicheskoi Khimii, 2012, Vol. 48, No. 3, p. 472.
SHORT
COMMUNICATIONS
Reaction of Ethyl Cyano(dinitro)acetate
with 3-Amino-1,2,5-oxadiazole-4-carbonitrile Oxide
A. G. Tyrkov, A. B. Sheremetev, and O. I. Serebryakov
Astrakhan State University, pl. Shaumyana 1, Astrakhan, 414000 Russia
e-mail: tyrkov@rambler.ru
Received May 7, 2011
DOI: 10.1134/S107042801203027X
Ethyl cyano(dinitro)acetate was reported to react
with benzonitrile and 3-nitrobenzonitrile oxides under
mild conditions according to the 1,3-dipolar cycloaddi-
tion pattern with formation of ethyl (3-aryl-1,2,4-
oxadiazol-5-yl)dinitroacetates [1]. We found that re-
placement of the benzene ring in the initial nitrile
oxide by 1,2,5-oxadiazole changes the reaction direc-
tion. Ethyl cyano(dinitro)acetate (I) reacted with
3-amino-1,2,5-oxadiazole-4-carbonitrile oxide (II) to
give ethyl 4-amino-1,2,5-oxadiazole-3-carboxylate
(III) and aci-dinitroacetonitrile ammonium salt (IV)
instead of expected 3,5-disubstituted 1,2,4-oxadiazole.
l = 500 mm) charged with activated silica (Silicagel
100–400 μm). Compound III was eluted with benzene,
and compound IV, with acetone.
Ethyl 4-amino-1,2,5-oxadiazole-3-carboxylate
(III). Yield 0.324 g (41%), mp 67–68°C. IR spectrum,
1
ν, cm–1: 3436, 3324 (NH2), 1725 (C=O). H NMR
spectrum, δ, ppm: 1.32 t (3H, CH3), 4.41 q (2H, CH2),
6.35 br.s (2H, NH2). 13C NMR spectrum, δC, ppm: 13.8
(CH3), 62.2 (CH2), 139.4 (C3), 156.3 (C4), 158.6
(C=O). Mass spectrum, m/z (Irel, %): 157 (14) [M]+, 58
(100), 55 (48), 53 (53), 43 (22). Found, %: C 38.03;
H 4.28; N 26.55. C5H7N3O3. Calculated, %: C 38.22;
H 4.46; N 26.75. M 157.13.
O
NH2
O
aci-Dinitroacetonitrile ammonium salt (IV).
Yield 0.164 g (22%), mp 179°C [4].
NC
N
+
OEt
N
O2N
NO2
O
N
The IR spectra were recorded in KBr on an Infra-
1
13
I
II
lyum FT-02 spectrometer. The H and C NMR spec-
tra were measured on a Bruker Avance II 300 SF
instrument at 300 and 75 MHz, respectively, in
DMSO-d6 using HMDS as internal reference. The
mass spectrum (electron impact, 70 eV) was obtained
on a Finnigan SSQ-7000 instrument with direct sample
admission into the ion source (vaporizer temperature
90–150°C). The progress of the reaction and the purity
of the isolated compounds were monitored by TLC on
Silufol UV-254 plates using acetone–hexane (2:3) as
eluent; development with iodine vapor.
NH2
CN
O
Et2O
+
O– NH4
N
O2N
N
OEt
O
N
O
III
IV
In this reaction, the cyano group in molecule I does
not act as dipolarophile, presumably due to reduction
of the reactivity of compound II as 1,3-dipole as
a result of change of the substituent at the nitrile oxide
fragment. The structure of compound III was deter-
mined on the basis of its IR, H and 13C NMR, and
1
REFERENCES
mass spectra and elemental composition. Initial ester I
was synthesized as described in [2], and nitrile oxide II
was prepared according to [3].
A solution of 5 mmol of compound II in 100 ml of
anhydrous diethyl ether was added at 20°C to a solu-
tion of 5 mmol of compound I in 10 ml of anhydrous
diethyl ether. The mixture was kept for 2 days at 25°C
and evaporated, and the residue was subjected to col-
umn chromatography on a glass column (d = 10 mm,
1. Tyrkov, A.G., Pashchenko, K.P., Ladyzhnikova, T.D., and
Altukhov, K.V., Izv. Vyssh. Uchebn. Zaved., Ser. Khim.
Khim. Tekhnol., 2004, no. 7, p. 148.
2. Parker, C., Tetrahedron, 1962, vol. 17, p. 109.
3. Rheiboldt, H., Justus Liebigs Ann. Chem., 1927, vol. 451,
p. 161.
4. Parker, C., Emmons, W., Pagano, A., Rolewricz, H., and
McCallum, K., Tetrahedron, 1962, vol. 17, p. 79.
475
Tyrkov
