ISSN 1070-4280, Russian Journal of Organic Chemistry, 2013, Vol. 49, No. 8, pp. 1246−1247. © Pleiades Publishing, Ltd., 2013.
Original English Text © A.V. Chervyakov, A.N. Maslivets, 2013, published in Zhurnal Organicheskoi Khimii, 2013, Vol. 49, No. 8, p. 1259.
SHORT
COMMUNICATIONS
Unusual Addition of Alcohols to Pyrrolo[1,2-ꢀ]pyrazinetrione
A. V. Chervyakov and A. N. Maslivets
Perm State National Research University, Perm, 614990 Russia
e-mail: koh2@psu.ru
Received March 27, 2012
DOI: 10.1134/S1070428013080289
4-Acyl-substituted 1Н-pyrrole-2,3-diones and
hetareno[е]pyrrole-2,3-diones, 3-acylpyrrolo[2,1-с]
[1,4]-benzoxazine-1,2,4-triones and 3-acylpyrrolo[1,2-а]
quinoxaline-1,2,4(5Н)-triones, reversibly add ОН-
nucleophiles to the carbon atom in the position 5 of the
1Н-pyrrole-2,3-dione ring with the formation of the
corresponding 4-acyl-3-hydroxy-2,5-dihydro-1Н-pyrrol-
2-ones [1].
the carbonyl group in the position 3 of the 1Н-pyrrole-
2,3-dione ring, but at the oxygen atom of the benzoyl
group with the formation of an intramolecular hydrogen
bond with the oxygen atom of the carbonyl group in the
position 1.
(E)-8-[Hydroxy(phenyl)methylene]-8a-methoxy-
2-phenyltetrahydropyrrolo[1,2-a]pyrazine-1,6,7(2H)-
trione (IIа). 0.01 mol of compound I in 20 ml of
anhydrous methanol was boiled for 5 min, cooled, the
precipitate was filtered off. Yield 70%, mp 151–153°С
(decomp., from methanol). IR spectrum, ν, cm–1: 3170
br (OH in intramolecular H-bond), 1720 (С6=O), 1710
(C7=O), 1614 (C1=O in intramolecular H-bond). 1Н NMR
spectrum, δ, ppm: 3.17 s (3H, OMe), 3.89 t (2H, CH2,
J 5.5 Hz), 4.10 t (2H, CH2, J 5.5 Hz), 7.25–7.78 group
of signals (8H, Ph + C6H3), 8.0 d [2H, Hо in C(OH)Ph],
11.77 br.s (1H, OH).
At boiling 8-benzoyl-2-phenyl-3,4-dihydro-
pyrrolo[1,2-а]pyrazine-1,6,7(2H)-trione (I) in methanol
and ethanol we obtained (E)-8a-alkoxy-8-[hydroxy-
(phenyl)methylene]-2-phenyltetrahydropyrrolo[1,2-a]
pyrazine-1,6,7(2H)-triones IIа, IIb.
Ph
N
Ph
N
.
.
.
O
O
O
H
AlkOH
O
O
OAlk
(E)-8-[Hydroxy(phenyl)methylene]-2-phenyl-8a-
ethoxytetrahydropyrrolo[1,2-a]pyrazine-1,6,7(2H)-
trione (IIb). 0.01 mol of compound I in 20 ml of
anhydrous ethanol was boiled for 4 min, cooled, the
precipitate was filtered off. Yield 70%, mp 147–149°С
(decomp., from ethanol). IR spectrum, ν, cm–1: 3150 br
(OH in intramolecular H-bond), 1717 (С6=O, C7=O),
N
N
Ph
Ph
O
O
O
IIа, Ib
I
Alk = Me (а), Et (b).
1
1611 (C1=O in intramolecular H-bond). Н NMR
spectrum, δ, ppm: 1.05 t (3H, CH3, J 7.0 Hz), 3.44 q (2H,
CH2O, J 7.0 Hz), 3.89 t (2H, CH2, J 5.5 Hz), 4.10 t (2H,
СH2, J 5.5 Hz), 7.25–7.80 group of signals (8H, Ph +
C6H3), 8.0 d [2H, Hо в C(OH)Ph], 11.75 br.s (1H, OH).
Pyrrolopyrazinetrione (I) reacted with alcohols with
the addition of the OH group of the alcohols to the carbon
atom in the position 5 of the 1Н-pyrrole-2,3-dione ring
as had been found previously in the case of the studied
1Н-pyrrole-2,3-diones [1], but in the addition products
IIа, IIb the proton is localized not at the oxygen atom of
IR spectra of compounds obtained were recorded on
a spectrophotometer Perkin Elmer Spectrum Two from
1246
Chervyakov
