Five-membered 2,3-dioxoheterocycles: LXXXVII.* [4+2]-cycloaddition of alkyl vinyl ethers and 3,4-dihydro-2H-pyran to 4,5-diaroyl-1H-pyrrole-2,3- diones

Article abstract of DOI:10.1134/S1070428012080118

1-Aryl-4,5-diaroyl-1H-pyrrole-2,3-diones react with alkyl vinyl ethers and 3,4-dihydro-2H-pyran affording 1,4-diaryl-7a-aroyl-6-ethoxy-7,7a- dihydropyrano[4,3-b]pyrrole-2,3(1H,6H)-diones and 1,4-diaryl-9baroyl- 1,7,8,9,9a-hexahydro-5aH-pyrano[3',2':5,6]py

Full text of DOI:10.1134/S1070428012080118

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2012, Vol. 48, No. 8, pp. 1103−1106. © Pleiades Publishing, Ltd., 2012.
Original English Text © P.S. Silaichev, N.V. Kudrevatykh, A.N. Maslivets, 2012, published in Zhurnal Organicheskoi Khimii, 2012, Vol. 48, No. 8, pp. 1106−1108.
Five-Membered 2,3-Dioxoheterocycles:
LXXXVII.* [4+2]-Cycloaddition of Alkyl Vinyl Ethers
and 3,4-Dihydro-2H-pyran to 4,5-Diaroyl-1H-pyrrole-2,3-diones
P. S. Silaicheva,b, N. V. Kudrevatykhb, and A. N. Maslivetsa,b
aInstitute of Natural Sciences at Perm State University, Perm, 614990 Russia
e-mail: koh2@psu.ru
bPerm State University, Perm, Russia
Received July 2, 2011
Abstract—1-Aryl-4,5-diaroyl-1H-pyrrole-2,3-diones react with alkyl vinyl ethers and 3,4-dihydro-2H-pyran
affording 1,4-diaryl-7a-aroyl-6-ethoxy-7,7a-dihydropyrano[4,3-b]pyrrole-2,3(1H,6H)-diones and 1,4-diaryl-9b-
aroyl-1,7,8,9,9a-hexahydro-5aH-pyrano[3',2':5,6]pyrano[4,3-b]-pyrrole-2,3-diones respectively.
DOI: 10.1134/S1070428012080118
1H-Pyrrole-2,3-diones were found to be very active
in Diels–Alder reactions [2, 3]. The conjugated system
C5=C4–C=O of 4-benzoyl-1-phenyl-5-ethoxycarbonyl-
1H-pyrrole-2,3-dione enters as a diene into [4+2]-cy-
cloaddition with a C=C bond of polar olefins resulting
in a regioselective building of a pyrano[4,3-b]pyrrole
heterocyclic system [4, 5]. 1-Aryl-4,5-diaroyl-1H-
pyrrole-2,3-dione similarly reacted with styrene, and
the structure of the formed 1,4-diaryl-7a-aroyl-6-phenyl-
7,7a-dihydropyrano[4,3-b]pyrrole-2,3(1H,6H)-diones
was proved for the first time by XRD study [6]. The
reactions of alkoxyethylenes with 4,5-diaroyl-1H-pyrrole-
2,3-diones have not been examined before.
IVa–IVd and 1,4-diaryl-9b-aroyl-1,7,8,9,9a-hexahydro-
5aH-pyrano[3',2':5,6]pyrano[4,3-b]pyrrole-2,3-diones
Va–Ve respectively.
Compounds IVa–IVd, Va–Ve are light-yellow or
colorless crystalline substances of a high melting point,
readily soluble in common organic solvents, nsoluble in
alkanes and water.
The IR spectra of compounds IVa–IVd, Va–Ve con-
tain the bands of the stretching vibrations of lactam C2=O
and keto C3=O carbonyl groups in the form of a single
broad or two narrow bands in the region 1703–1736 cm–1,
and of the aroyl carbonyl group at 1674–1692 cm–1. The
position of absorption bands of C2=O and C3=O groups in
the IR spectra of compounds IVa–IVd, Va–Ve coincides
with their position
(1720–1730 cm–1) in the IR pectra of (3R*,4aR*)-
4,4a,6,7-tetrahydro-6,7-dioxo-1,5-diphenyl-3-ethoxy-
4a-ethoxycarbonyl-5H-pyrano[4,3-b]pyrrole (VI) and
(5aR*,9aS*,9bR*)-2,3,8,9,9a,9b-hexahydro-2,3-dioxo-
1,4-diphenyl-9b-ethoxycarbonyl-1H-pyrano-[3',2':5,6]
pyrano[4,3-b]pyrrole (VII) [4].
In the 1H NMR spectra of compounds IVa–IVd along-
side the signals of the protons of aromatic rings, methyl
and alkoxy groups doublet of doublets signals of the
methine proton H6 (5.64–5.83 ppm) are present, and also
of the methylene protons C7H2 (2.37–3.34 ppm) giving
a typical ACX system. The position and multiplicity of
Aiming at the investigation of the effect of an aroyl
fragment in the position 5 of 1H-pyrrole-2,3-diones on
the direction of the cycloaddition we studied the reac-
tions of 1-aryl-4,5-diaroyl-1H-pyrrole-2,3-diones Ia–Ig
[6, 7] with alkyl vinyl ethers IIa, IIb and 3,4-dihydro-
2H-pyran (III).
The heating of 1-aryl-4,5-diaroyl-1H-pyrrole-2,3-
diones Ia–Ig with alkyl vinyl ethers IIa, IIb in a ratio
1:1.5 in anhydrous benzene for 20–30 min an with
3,4-dihydro-2H-pyran (III) in a ratio 1:1.5 in toluens for
60–70 min (till the disappearance of the bright red color
of pyrrolediones) furnished 1,4-diaryl-7a-aroyl-6-alkoxy-
7,7a-dihydropyrano[4,3-b]pyrrole-2,3(1H,6H)-diones
_______________
* For Communication LXXXVI, see [1].
1103

SILAICHEV et al.
1104
Ar1
Ph
O
O
O
O
ROCH=CH2
O
IIа, IIb
RO
EtO
O
O
O
N
Ar2
IVа_IVd
Ar1
N
EtOOC
Ar1
O
Ph
O
O
VI
Ph
Ar1
Ar1
O
N
Ar2
Iа_Ig
O
O
O
O
O
III
O
O
O
N
N
Ar2
Vа_Ve
Ar1
Ph
EtOOC
VII
O
I, Ar1 = Ph, Ar2 = C6H4Me-4 (a); Ar1 = Ar2 = C6H4Me-4 (b); Ar1 = C6H4Me-4, Ar2 = Ph (c); Ar1 = C6H3Me2-2,5, Ar2 = Ph (d); Ar1 =
C6H3Me2-2,5, Ar2 = C6H4OMe-4 (e); Ar1 = C6H4Me-4, Ar2 = C6H4OMe-4 (f); Ar1 = C6H3Me2-2,5, Ar2 = C6H4Me-4 (g); II, R = Et
(a), Bu (b); IV, Ar1 = C6H4Me-4, R = Et, Ar2 = Ph (a); Ar1 = Ar2 = C6H4Me-4, R = Et (b); Ar1 = Ar2 = C6H4Me-4, R = Bu (c); Ar1 =
C6H3Me2-2,5, Ar2 = C6H4OMe-4, R = Et (d); V, Ar1 = Ph, Ar2 = C6H4Me-4 (a); Ar1 = Ar2 = C6H4Me-4 (b); Ar1 = C6H4Me-4, Ar2 =
C6H4OMe-4 (c); Ar1 = C6H3Me2-2,5, Ar2 = Ph (d); Ar1 = C6H3Me2-2,5, Ar2 = C6H4Me-4 (e).
proton signals belonging to H6 and C7H2 in the 1H NMR
spectra of compounds IVa–IVd are very simlar to those
of the protons H6 (d.d, 1H, 5.86 ppm) and C7H2 (d.d, 2H,
1.98–3.06 ppm) of pyrano-[3',2':5,6]pyrano[4,3-b]pyrrole
fragment in the 1H NMR spectrum of compound VI [4].
in the positions 2, 3, 5a, 9a, and 9b in the pyrano[3',2':5,6]
pyrano[4,3-b]pyrrole-2,3-dione fragment in the 13C NMR
spectrum of compound VII [4].
The formation of compounds IVa–IVd, Va–Ve is evi-
dently due to the involvement of the conjugated system of
bonds O=C–C4=C5 belonging to pyrrolediones Ia–Ig in
the thermally initiated [4+2]-cycloaddition to a polarized
C=C bond of alkoxyethylenes IIa, IIb, III.
In the 1H NMR spectra of compounds Va–Ve alongside
the signals of the protons of aromatic rings and the groups
attached thereto the signals are present of the methylene
protons C8H2 and C9H2 (1.14–1.80 ppm), a multiplet of
the methine proton H9a (3.14–3.21 ppm), a multiplet of the
methylene protons C7H2 (3.81–3.86 ppm), and a doublet of
the methine proton H5a (5.94–6.10 ppm). The position and
multiplicity of the signals of thes protons in the 1H NMR
spectra of compounds Va–Ve are very similar to those of
protons C8H2 and C9H2 (m, 4H, 1.41–1.73 ppm), H9a (m,
1H, 2.97 ppm), C7H2 (m, 2H, 3.88–3.90 ppm), and H5a (d,
1H, 6.29 ppm) of pyrano-[3',2':5,6]pyrano[4,3-b]pyrrole
fragment in the 1H NMR spectrum of compound VII [4].
In the 13C NMR spectrum of compound Vd alongside
the signals of the carbon atoms of aromatic substituents,
methyl and methylene groups signals are observed of the
carbon atoms of the aroyl carbonyl group at 202.80 ppm,
of keto (C3=O) and lactam (C2=O) carbonyl groups of the
pyrroledione ring at 177.20 and 161.94 ppm respectively,
and also the signals of carbon atoms in the positions 5a,
9a, and 9b of the pyrano[3',2':5,6]pyrano[4,3-b]pyrrole-
2,3-dione fragment at 98.20, 32.01, and 68.89 ppm re-
spectively, very similar to the position of the carbon atoms
EXPERIMENTAL
IR spectra of compounds obtained were recorded
on a spectrophotometer FSM-1201. NMR spectra were
registered on a spectrometer Bruker AM-400 [operating
frequencies 400 (1H) and 100 (13C) MHz] in DMSO-
d6, internal reference TMS. The homogeneity of the
compounds synthesized was proved by TLC on Silufol
plates, eluents benzene–ethyl acetate, 5:1, ethyl acetate,
development in iodine vapor or under UV irradiation.
4-(4-Tolyl)-7a-(4-toluoyl)-1-phenyl-6-ethoxy-7,7a-
dihydropyrano[4,3-b]pyrrole-2,3(1H,6H)-dione (IVa).
To a solution of 1.0 mmol of compound Ic in 50 ml of
anhydrous benzene was added a solution of 1.5 mmol
of ethyl vinyl ether (IIa) in 5 ml of anhydrous benzene,
the mixture was heated for 25 min at 60–70°C, cooled,
the separated precipitate was filtered off. Yiled 89%, mp
189–190°C (benzene–hexane, 1 : 1). IR spectrum, cm–1:
1
1723 (C2=O, C3=O), 1674 (C7a–C=O). H NMR spec-
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 48 No. 8 2012

FIVE-MEMBERED 2,3-DIOXOHETEROCYCLES: LXXXVII.
1105
trum, δ, ppm: 1.25 t (3H, Me, J 7.2 Hz), 2.37 s (3H, Me),
2.41 s (3H, Me), 2.42 d.d (1H, C7H2, J 12.4, 8.8 Hz), 3.04
d.d (1H, C7H2, J 12.4, 5.2 Hz), 3.81 s (3H, OMe), 3.84
m (1H, OCH2), 4.08 m (1H, OCH2), 5.83 d.d (1H, H6,
J 8.8, 5.2 Hz), 6.95–7.29 group of signals (10H, C6H4 +
2C6H3). Found, %: C 74.79; H 5.67; N 2.87. C30H27NO5.
Calculated, %: C 74.83; H 5.65; N 2.91.
Ia in 25 ml of anhydrous toluene was added a solution
of 1.2 mmol of 3,4-dihydro-2H-pyran (III) in 5 ml of
toluene, the mixture was boiled for 1 h, cooled, the
separated precipitate was filtered off. Yield 84%, mp
235–236°C (toluene). IR spectrum, cm–1: 1728 (C2=O),
1
1715 (C3=O), 1690 (C9b–C=O). H NMR spectrum, δ,
ppm: 1.20–1.80 group of signals (4H, 2CH2), 2.34 s (3H,
Me), 3.17 m (1H, H9a), 3.86 m (2H, C7H2), 6.10 d (1H,
H5a, J 3.6 Hz), 7.23–7.77 group of signals (14H, 2C6H5,
C6H4). Found, %: C 75.10; H 5.24; N 2.89. C30H25NO5.
Calculated, %: C 75.14; H 5.25; N 2.92.
Compounds IVb–IVd were similarly prepared.
1,4-Di(4-tolyl)-7a-(4-toluoyl)-6-ethoxy-7,7a-
dihydropyrano[4,3-b]pyrrole-2,3(1H,6H)-dione (IVb).
Yield 92%, mp 189–190°C (benzene–petroleum ether,
1:1). IR spectrum, cm–1: 1736 (C2=O), 1727 (C2=O),
1680 (C7a–C=O). 1H NMR spectrum, δ, ppm: 1.25 t
(3H, Me, J 7.0 Hz), 2.31 s (3H, Me), 2.37 s (3H, Me),
2.37 d.d (1H, C7H2, J 12.8, 8.8 Hz), 2.41 s (3H, Me),
3.05 d.d (1H, C7H2, J 12.8, 4.9 Hz), 3.84 m (1H, OCH2)
4.08 m (1H, OCH2), 5.82 d.d (1H, H6, J 8.8, 4.9 Hz),
6.97–7.72 group of signals (12H, 3C6H4). Found, %:
C 75.15; H 5.86; N 2.79. C31H29NO5. Calculated, %:
C 75.13; H 5.90; N 2.83.
Compounds Vb–Ve were similarly prepared.
1,4-Di(4-tolyl)-9b-(4-toluoyl)-1,7,8,9,9a-hexahy-
dro-5aH-pyrano[3',2':5,6]pyrano[4,3-b]pyrrole-2,3-
dione (Vb). Yield 81%, mp 220–221°C (toluene). IR
spectrum, cm–1: 1719 (C2=O), 1703 (C3=O), 1682 (C9b–
1
C=O). H NMR spectrum, δ, ppm: 1.18–1.73 group of
signals (4H, 2CH2), 2.33 s (3H, Me), 2.34 s (3H, Me),
2.42 s (3H, Me), 3.15 m (1H, H9a), 3.84 m (2H, C7H2),
6.08 d (1H, H5a, J 3.5 Hz), 7.19–7.70 group of signals
(12H, 3C6H4). Found, %: C 75.70; H 5.73; N 2.73.
C32H29NO5. Calculated, %: C 75.72; H 5.76; N 2.76.
6-Butoxy-1,4-di(4-tolyl)-7a-(4-toluoyl)-7,7a-
dihydropyrano[4,3-b]pyrrole-2,3(1H,6H)-dione (IVc).
Yield 78%, mp 150–151°C (benzene–petroleum ether,
1:1). IR spectrum, cm–1: 1720 (C2=O, C3=O), 1684
1-(4-Methoxyphenyl)-4-(4-tolyl)-9b-toluo-
yl-1,7,8,9,9a-hexahydro-5aH-pyrano[3',2':5,6]
pyrano[4,3-b]pyrrole-2,3-dione (Vc). Yield 91%, mp
221–223°C (toluene). IR spectrum, cm–1: 1703 (C2=O,
C3=O), 1680 (C9b–C=O). 1H NMR spectrum, δ, ppm:
1.14–1.80 group of signals (4H, 2CH2), 2.35 s (3H,
Me), 2.42 s (3H, Me), 3.14 m (1H, H9a), 3.78 s (3H,
OMe), 3.85 m (2H, C7H2), 6.03 d (1H, H5a, J 3.2 Hz),
7.03–7.70 group of signals (12H, 3C6H4). Found, %:
C 73.38; H 5.54; N 2.64. C32H29NO6. Calculated, %:
C 73.41; H 5.58; N 2.68.
1
(C7a–C=O). H NMR spectrum, δ, ppm: 0.92 t (3H, Me,
J 7.2 Hz), 1.39 m (2H, CH2), 1.60 m (2H, CH2), 2.31 s
(3H, Me), 2.37 s (3H, Me), 2.41 s (3H, Me), 3.04 d.d
(1H, C7H2, J 12.4, 4.8 Hz), 3.34 d.d (1H, C7H2, J 12.4,
8.8 Hz), 3.78 m (1H, OCH2), 4.03 m (1H, OCH2), 5.80 d.d
(1H, H6, J 8.8, 4.8 Hz), 6.97–7.72 group of signals (12H,
3C6H4). Found, %: C 75.71; H 6.31; N 2.63. C33H33NO5.
Calculated, %: C 75.69; H 6.35; N 2.67.
7a-(2,5-Dimethylbenzoyl)-4-(2,5-dimeth-
yl-phenyl)-1-(4-methoxyphenyl)-6-ethoxy-7,7a-
dihydropyrano[4,3-b]pyrrole-2,3(1H,6H)-dione (IVd).
Yield 86%, mp 151–152°C (benzene–petroleum ether,
1:1). IR spectrum, cm–1: 1721 (C2=O, C3=O), 1686
9b-(2,5-Dimethylbenzoyl)-4-(2,5-dimethylphenyl)-
1-phenyl-1,7,8,9,9a-hexahydro-5aH-pyrano-[3',2':5,6]
pyrano[4,3-b]pyrrole-2,3-dione (Vd). Yield 79%, mp
217–218°C (toluene). IR spectrum, cm–1: 1727 (C2=O),
1717 (C3=O), 1692 (C9b–C=O). 1H NMR spectrum, δ,
ppm: 1.30–1.70 group of signals (4H, 2CH2), 2.09 s (3H,
Me), 2.10 s (3H, Me), 2.28 s (3H, Me), 2.30 s (3H, Me),
1
(C7a–C=O). H NMR spectrum, δ, ppm: 1.18 t (3H, Me,
J 6.8 Hz), 2.04 s (3H, Me), 2.06 s (3H, Me), 2.18 s (3H,
Me), 2.27 s (3H, Me), 2.38 d.d (1H, C7H2, J 12.8, 9.6 Hz),
2.96 d.d (1H, C7H2, J 12.8, 4.2 Hz), 3.77 m (1H, OCH2)
3.81 s (3H, OMe), 3.94 m (1H, OCH2), 5.64 d.d (1H, H6,
J 9.6, 4.2 Hz), 6.95–7.29 group of signals (10H, C6H4 +
2C6H3). Found, %: C 73.41; H 6.18; N 2.63. C33H33NO6.
Calculated, %: C 73.45; H 6.16; N 2.60.
3.21 m (1H, H9a), 3.82 m (2H, C7H2), 5.96 d (1H, H5a
,
J 5.1 Hz), 6.81–7.58 group of signals (11H, Ph, 2C6H3).
13C NMR spectrum, δ, ppm: 17.14 (C9), 18.78 (Me), 18.96
(Me), 20.13 (Me), 20.23 (Me), 22.71 (C8), 32.01 (C9a),
61.39 (C7), 68.89 (C9b), 98.20 (C5a), 122.50–137.22 group
of signals (CAr, C3a), 161.94 (C2), 165.16 (C4), 177.20
(C3), 202.80 (C9b–CO). Found, %: 75.95; H 5.95; N 2.67.
C33H31NO5. Calculated, %: C 75.99; H 5.99; N 2.69.
9b-Benzoyl-1-(4-tolyl)-4-phenyl-1,7,8,9,9a-hexa-
hydro-5aH-pyrano[3',2':5,6]pyrano[4,3-b]pyrrole-
2,3-dione (Va). To a solution of 1.0 mmol of compound
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 48 No. 8 2012

SILAICHEV et al.
1106
9b-(2,5-Dimethylbenzoyl)-4-(2,5-dimethylphenyl)-
in, P.A., and Maslivets,A.N., Zh. Org. Khim., 2012, vol. 48,
p. 697.
1-(4-tolyl)-1,7,8,9,9a-hexahydro-5aH-pyrano[3',2':5,6]-
pyrano[4,3-b]pyrrole-2,3-dione (Ve). Yield 77%, mp
203–205°C (toluene). IR spectrum, cm–1: 1723 (C2=O,
C3=O), 1692 (C9b–C=O). 1H NMR spectrum, δ, ppm:
1.30–1.70 group of signals (4H, 2CH2), 2.08 s (6H, 2Me),
2.28 s (3H, Me), 2.30 s (3H, Me), 2.37 s (3H, Me), 3.18 m
(1H, H9a), 3.81 m (2H, C7H2), 5.94 d (1H, H5a, J 3.0 Hz),
6.79–7.38 group of signals (10H, C6H4, 2C6H3). Found,
%: C 76.20; H 6.19; N 2.58. C34H33NO5. Calculated, %:
C 76.24; H 6.21; N 2.61.
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pirroldiony (2,3-Dihydropyrrole-2,3-diones), Perm: Izd.
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RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 48 No. 8 2012