REACTION OF 2,2-DINITROMALONONITRILE WITH ARYLALKENES
1285
Scheme 2.
Ar
Ar
Ar
NO2
CN
NO2
CN
I
+
+
NO2
NO2
+
Ar
CH2
X, XI
Ar
Ar
NC
NC
A
XII, XIII
XIV
X, XII, Ar = Ph; XI, XIII, R = 4-MeOC6H4.
The structure of compounds VI–IX was confirmed
by their IR and H NMR spectra and elemental anal-
pounds and alkylmagnesium halides with isolation of
intermediate alcohols and their subsequent dehydration
according to [8]; the physical constants of arylalkenes
were consistent with published data.
1
yses. Compounds XII–XIV were identified by com-
paring their melting points with those of authentic
samples. The IR spectra of VI and VII contained
absorption bands at 1550 and 1380 cm–1, which are
typical of stretching vibrations of nitro group, and
a band at 1070–1030 cm–1 due to vibrations of the
O–N–O fragment in the heteroring [4]. Compounds
VIII and IX displayed in the IR spectra two couples of
absorption bands at 1550/1380 and 1580/1310 cm–1
due to the presence of two nonequivalent nitro groups.
Reaction of 2,2-dinitromalononitrile (I) with
arylalkenes (general procedure). A solution of
10 mmol of alkene II or III or 5 mmol of alkene IV,
V, X, or XI in diethyl ether was added to a solution of
5 mmol of 2,2-dinitromalononitrile (I) in 10 ml of an-
hydrous diethyl ether on cooling to 0±5°C. The mix-
ture was kept for 10 days at 25°C, the solvent was
evaporated, and the residue was purified by chroma-
tography on a 10×500-mm column charged with ac-
tivated silica gel (Silicagel 100–400 μm) using chloro-
form (compounds VI, VII), benzene (VIII, IX, XII,
XIII), or diethyl ether (XIV) as eluent.
1
The H NMR spectra of VI–IX were consistent with
the assumed structures and were similar to those of
structurally related model compounds of the isoxazole
1
[5] and nitroalkane series [6]. In the H NMR spectra
of VI and VII, apart from multiplets belonging to
aromatic protons and signals from protons in the nitro-
alkyl fragment, we observed signals in the region
δ 2.81–5.46 ppm from protons in the tetrahydroisoxa-
zole ring.
2-(2-Nitro-1-phenylethoxy)-5-phenyltetrahydro-
1,2-oxazole-3,3-dicarbonitrile (VI). Yield 0.464 g
(25%), mp 115°C. IR spectrum, ν, cm–1: 2245 (CN);
1
1550, 1380 (NO2); 1070–1030 (ONO). H NMR spec-
trum, δ, ppm: 3.14 d (2H, CH2), 4.28 d (2H, CH2), 5.46 t
(1H, CH), 5.82 t (1H, CH), 7.53–7.62 m (10H, C6H5).
Found, %: C 62.46; H 4.22; N 15.18. C19H16N4O4. Cal-
culated, %: C 62.64; H 4.40; N 15.38.
Thus, unlike 2,2-dinitrobutanenitrile, reactions of
2,2-dinitromalononitrile with arylalkenes are charac-
terized by higher selectivity, and they lead to the
formation of previously unknown 5-phenyltetrahydro-
isoxazole-3,3-dicarbonitriles or 2-(1-aryl-2-nitroethyl)-
2-nitromalononitriles which attract interest from both
theoretical and practical viewpoints.
2-(2-Nitro-1-phenylpropoxy)-4-methyl-5-phenyl-
tetrahydro-1,2-oxazole-3,3-dicarbonitrile (VII).
Yield 0.519 g (27%), mp 127°C. IR spectrum, ν, cm–1:
2245 (CN); 1550, 1380 (NO2); 1070–1030 (ONO).
1H NMR spectrum, δ, ppm: 1.29 d (3H, CH3), 1.34 d
(3H, CH3), 2.81 m (1H, CH), 4.25 m (1H, CH), 5.44 d
(1H, CH), 5.80 d (1H, CH), 7.56–7.65 m (10H, C6H5).
Found, %: C 64.11; H 4.96; N 14.07. C21H20N4O4. Cal-
culated, %: C 64.29; H 5.10; N 14.29.
EXPERIMENTAL
The IR spectra were recorded on an IKS-29 spec-
trometer from solutions in chloroform with a concen-
tration of 40 mg/ml (cell path length 0.1 mm). The
1H NMR spectra were obtained on a Bruker DRX
500 SF instrument at 500 MHz using DMSO-d6 as sol-
vent and hexamethyldisiloxane as internal reference.
The progress of reactions was monitored, and the
purity of products was checked, by TLC on Silufol
UV-254 plates using acetone–hexane (2:3) as eluent;
development with iodine vapor.
2-Nitro-2-(1-nitro-2-phenylpropan-2-yl)malono-
nitrile (VIII). Yield 0.698 g (51%), mp 49°C. IR spec-
trum, ν, cm–1: 2250 (CN); 1580, 1310 (NO2); 1550,
1
1380 (NO2). H NMR spectrum, δ, ppm: 1.70 s (3H,
CH3), 4.23 s (2H, CH2), 7.59 m (5H, C6H5). Found, %:
C 52.38; H 3.47; N 20.24. C12H10N4O4. Calculated, %:
C 52.55; H 3.65; N 20.44.
2,2-Dinitromalononitrile (I) was synthesized ac-
cording to the procedure described in [7]. Arylalkenes
were prepared from the corresponding carbonyl com-
2-[1-(4-Methoxyphenyl)-2-nitroethyl]-2-nitro-
malononitrile (IX). Yield 0.914 g (63%), mp 54°C.
IR spectrum, ν, cm–1: 2250 (CN); 1580, 1310 (NO2);
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 47 No. 9 2011