Reaction of α-nitroacrylates with acetylacetone

Full text of DOI:10.1134/S1070428012070196

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2012, Vol. 48, No. 7, pp. 1005–1006. © Pleiades Publishing, Ltd., 2012.
Original Russian Text © L.V. Baichurina, R.I. Baichurin, N.I. Aboskalova, M.M. Zobacheva, V.M. Berestovitskaya, 2012, published in Zhurnal
Organicheskoi Khimii, 2012, Vol. 48, No. 7, pp. 1007–1008.
SHORT
COMMUNICATIONS
Reaction of α-Nitroacrylates with Acetylacetone
L. V. Baichurina, R. I. Baichurin, N. I. Aboskalova,
M. M. Zobacheva, and V. M. Berestovitskaya
Herzen State Pedagogical University of Russia, nab. r. Moiki 48, St. Petersburg, 191186 Russia
e-mail: kohrgpu@yandex.ru
Received March 16, 2012
DOI: 10.1134/S1070428012070196
1
Aryl- and hetaryl-substituted α-nitroacrylates are
preparatively accessible compounds and promising
building blocks for the design of novel linear and
heterocyclic structures [1].
and H NMR spectra. The IR spectra of V–VIII con-
tained strong absorption bands due to stretching vibra-
tions of the acetyl and ester carbonyl groups (1700–
1710, 1740–1755 cm−1) and unconjugated nitro group
(1560–1565, 1360 cm−1). According to the H NMR
1
α-Nitrocinnamic acid esters I–III and their thio-
phene-containing analog IV successfully react with
an equimolar amount of acetylacetone in anhydrous
methanol in the presence of sodium methoxide at 0–
5°C to give addition products V–VIII. On heating in
methanol in the presence of triethylamine (60°C, 2 h),
adducts V and VII are converted into the correspond-
ing tetrasubstituted dihydrofurans IX and X. Presum-
ably, the latter are formed via intramolecular O-alkyla-
tion of the enol form of V–VIII with elimination of
nitrous acid. Compound X was also synthesized in
one-pot mode by heating α-nitroacrylate III with ace-
tylacetone in acetonitrile in the presence of triethyl-
amine (60°C, 2 h). The structure of adducts V–VIII
was confirmed by their elemental compositions and IR
data, compounds V–VIII were isolated as single dia-
1
stereoisomers. In the H NMR spectrum of V in
CDCl3, the HA, HB, and HX protons gave rise to an ABX
spin system, and their signals were located at δ 5.47,
4.57, and 4.59 ppm, respectively. Signals at δ 1.24 (t)
and 4.17 ppm (q) were assigned to the ester ethoxy
group, and methyl protons in the acetyl fragments
resonated at δ 1.86 and 2.25 ppm. Aromatic proton
signals were observed at δ 7.25–7.30 ppm (m).
The assumed structure of dihydrofuran derivatives
IX and X is confirmed by the similarity of their spec-
tral parameters to those reported for the same com-
pounds synthesized by different methods [2–4]. The
coupling constant for HA and HB (3J 4.88–4.98 Hz)
O
O
O
Me
MeOH–MeONa
0–5°C
Me
R
Me
Me
OH
MeOH, Et3N, 60°C
HX
O2N
R = Ph, 4-Me2NC6H4
R
HB
COOEt
V–VIII
HA
O2N
COOEt
NO2
O
O
R
+
COOEt
Me
Me
O
I–IV
R
Me
MeOH, Et3N, 60°C
R = 4-Me2NC6H4
HB
HA
–HNO2
Me
COOEt
O
IX, X
I, V, IX, R = Ph; II, VI, R = 4-MeOC6H4; III, VII, X, R = 4-Me2NC6H4; IV, VIII, R = thiophen-2-yl.
1005

BAICHURINA et al.
1006
indicate their trans orientation with respect to each
crystals, mp 55–56°C (from EtOH); published data [2]:
mp 57–59°C. IR spectrum, ν, cm–1: 1755, 1710 (C=O).
1H NMR spectrum, δ, ppm: 1.32 t (3H, CH3CH2),
1.94 s and 2.42 s (3H each, CH3), 4.28 q (2H, OCH2),
other [2, 3].
Compound IV was synthesized according to the
procedure described in [5], and compounds I–III were
prepared in a similar way; their properties were con-
sistent with published data [6].
4.46 d (1H, HB, 3JAB = 4.88 Hz), 4.77 d (1H, HA, 3JAB
=
4.88 Hz), 7.21–7.34 m (5H, Harom). Found, %: C 69.16;
H 6.93. C16H17O4. Calculated, %: C 69.57; H 6.52.
Ethyl 4-acetyl-2-nitro-5-oxo-3-phenylhexanoate
(V). Yield 37%, colorless crystals, mp 90–92°C (from
EtOH). IR spectrum, ν, cm–1: 1755, 1700 (C=O); 1560,
Ethyl 4-acetyl-3-(4-dimethylaminophenyl)-5-
methyl-trans-2,3-dihydrofuran-2-carboxylate (X).
Purification by column chromatography using diethyl
ether as eluent gave compound X as a yellow oily sub-
stance. Yield 38%, Rf 0.73 (Silufol UV 254; hexane–
acetone, 3:1). IR spectrum, ν, cm–1: 1750, 1710 (C=O).
1H NMR spectrum, δ, ppm: 1.32 t (3H, CH3CH2), 1.92 s
and 2.40 s (3H each, CH3), 2.93 s (6H, NCH3), 4.27 q
1
1360 (NO2). H NMR spectrum, δ, ppm: 1.24 t (3H,
CH3), 1.86 s and 2.25 s (3H each, COCH3), 4.17 q (2H,
OCH2), 4.57 d.d (1H, HB, 3JBX = 8.40, 3JAB = 4.20 Hz),
4.59 d.d (1H, HX, 4JAX = 2.53, 3JBX = 8.40 Hz), 5.47 d.d
3
4
(1H, HA, JAB = 4.20, JAX = 2.53 Hz), 7.25–7.29 m
(5H, Harom). Found, %: N 4.14. C16H19NO6. Calculated,
%: N 4.36.
3
(2H, OCH2), 4.38 d (1H, HB, JAB = 4.98 Hz), 4.73 d
(1H, HA, 3JAB = 4.98 Hz), 6.67d and 7.07 d (4H, Harom).
Ethyl 4-acetyl-3-(4-methoxyphenyl)-2-nitro-5-
oxohexanoate (VI). Yield 33%, colorless crystals,
mp 116–118°C (from EtOH). IR spectrum, ν, cm–1:
1
The H NMR spectra were recorded from solutions
in CDCl3 on a Jeol JNM-ECX400A spectrometer at
399.78 MHz using the residual proton signal of the
solvent as reference. The IR spectra were measured on
a Shimadzu IR-Prestige-21 spectrometer with Fourier
transform from solutions in chloroform (c = 0.1–
0.001 M). The elemental compositions were deter-
mined on a EuroVector EA 3000 analyzer (CHN Dual
configuration). The products were isolated and puri-
fied by recrystallization or column chromatography
on Macherey-Nagel Silica 60 (240–400 mesh) using
eluotropic solvent series [7].
1
1740, 1700 (C=O); 1565, 1360 (NO2). H NMR spec-
trum, δ, ppm: 1.23 t (3H, CH3), 1.89 s and 2.24 s (3H
each, COCH3), 3.75 s (OCH3), 4.16 q (2H, OCH2),
4.51 d.d (1H, HB, 3JAB = 5.88, 3JBX = 10.08 Hz), 4.54 d
3
3
(1H, HX, JBX = 10.08 Hz), 5.43 d (1H, HA, JAB
=
5.88 Hz), 6.80 d, 7.18 d (4H, Harom). Found, %:
C 58.20; H 5.68; N 3.53. C17H21NO7. Calculated, %:
C 58.11; H 6.02; N 3.99.
Ethyl 4-acetyl-3-(4-dimethylaminophenyl)-2-ni-
tro-5-oxohexanoate (VII). Yield 48%, yellow crys-
tals, mp 114–116°C (from EtOH). IR spectrum, ν cm–1:
This study was performed under financial support by
the Government of St. Petersburg (diploma no. 11036).
1
1740, 1700 (C=O); 1565, 1360 (NO2). H NMR spec-
trum, δ, ppm: 1.26 t (3H, CH3), 1.86 s and 2.23 s (3H
REFERENCES
each, COCH3), 2.90 s (6H, NCH3), 4.46 d.d (1H, HB,
3
3JAB = 6.90, JBX = 11.27 Hz), 4.47 q (2H, OCH2),
1. Perekalin, V.V., Lipina, E.S., Berestovitskaya, V.M., and
Efremov, D.A., Nitroalkenes. Conjugated Nitro Com-
pounds, Chichester: Wiley, 1994.
3
4.52 d (1H, HX, JBX = 11.27 Hz), 5.40 d (1H, HA,
3JAB = 6.90 Hz), 6.57 d and 7.06 d (2H each, Harom).
Found, %: N 7.32. C18H24N2O6. Calculated, %: N 7.69.
2. Zheng, J.-C., Zhu, C.-Y., Sun, X.-L., Tang, Y., and
Dai, L.-X., J. Org. Chem., 2008, vol. 73, p. 6909.
Ethyl 4-acetyl-2-nitro-5-oxo-3-(thiophen-2-yl)-
hexanoate (VIII). Yield 40%, colorless crystals,
mp 94–96°C (from EtOH). IR spectrum, ν, cm–1: 1740,
1700 (C=O); 1565, 1360 (NO2). 1H NMR spectrum, δ,
3. Yang, Z., Fan, M., Mu, R., Liu, W., and Liang, Y., Tetra-
hedron, 2005, vol. 61, p. 9140.
4. Feng, C., Lu, C., Chen, Z., Dong, N., Shi, J., and
Yang, G., J. Heterocycl. Chem., 2010, vol. 47, p. 671.
ppm: 1.24 t (3H, CH3), 2.01 s and 2.25 s (3H each,
3
5. Baichurina, L.V., Baichurin, R.I., Aboskalova, N.I., and
Berestovitskaya, V.M., Russ. J. Gen. Chem., 2010,
vol. 80, p. 2022.
COCH3), 4.19 q (2H, OCH2), 4.59 d (1H, HB, JAB
=
=
3
3
6.10, JBX = 10.68 Hz), 4.79 d.d (1H, HX, JBX
3
10.68 Hz), 5.59 d (1H, HA, JAB = 6.10 Hz), 6.90–
7.25 m (3H, Harom). Found, %: N 4.20. C14H17NO6S.
Calculated, %: N 4.28.
6. Lehnert, W., Tetrahedron, 1972, vol. 28, p. 663.
7. Becker, H.G.O., Organikum. Organisch-chemisches
Grundpraktikum, Berlin: Wissenschaften, 1964, 3rd ed.
Translated under the title Obshchii praktikum po organi-
cheskoi khimii, Moscow: Mir, 1965, p. 81.
Ethyl 4-acetyl-5-methyl-3-phenyl-trans-2,3-dihy-
drofuran-2-carboxylate (IX). Yield 48%, colorless
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 48 No. 7 2012