ISSN 1070-4280, Russian Journal of Organic Chemistry, 2012, Vol. 48, No. 4, pp. 616–617. © Pleiades Publishing, Ltd., 2012.
Original Russian Text © V.L. Gein, R.O. Dyrenkov, N.A. Kornienko, M.I. Vakhrin, P.A. Slepukhin, 2012, published in Zhurnal Organicheskoi Khimii, 2012,
Vol. 48, No. 4, pp. 616–617.
SHORT
COMMUNICATIONS
Formation of Alkyl 1-Methyl-3,9-dioxo-2-phenyl-2,3,4,9-tetra-
hydro-1H-pyrrolo[3,4-b]quinoline-1-carboxylates by Thermolysis
of Alkyl 1,5-Diaryl-4-methyl-2,3,6-trioxo-1,2,3,4,5,6-hexahydro-
pyrrolo[3,4-b]pyrrole-4-carboxylates
V. L. Geina, R. O. Dyrenkova, N. A. Kornienkoa, M. I. Vakhrina, and P. A. Slepukhinb
a Perm State Pharmaceutical Academy, ul. Polevaya 2, Perm, 614000 Russia
e-mail: geinvl48@mail.ru
b Postovskii Institute of Organic Synthesis, Ural Division, Russian Academy of Sciences,
ul. S. Kovalevskoi/Akademicheskaya 20/22, Yekaterinburg, 620990 Russia
Received June 15, 2011
DOI: 10.1134/S1070428012040306
Several examples of thermal decomposition of pyr-
rolediones have been reported. For instance, cycliza-
tion of N-arylimidoyl(acyl)ketenes to substituted quin-
olinones was described, and the acyl carbonyl group
was not involved in the process [1, 2].
δ 3.63 ppm (IV) or a triplet a quartet at δ 1.08 and
4.12 ppm from the ethoxy group (V), and a singlet
from the NH proton at δ 12.91–13.04 ppm. The struc-
ture of compound V was unambiguously determined
by X-ray analysis of its single crystal obtained by slow
crystallization from acetic acid (see figure).
Presumably, thermal decarbonylation of fused pyr-
roledione I or II generates unsymmetrical di(imidoyl)-
ketene III which is stabilized via CH-acylation by the
ketene fragment of the ortho-position in the phenyl
substituent.
Methyl 1-methyl-3,9-dioxo-2-phenyl-2,3,4,9-
tetrahydro-1H-pyrrolo[3,4-b]quinoline-1-carbox-
ylate (IV). A mixture of 1.0 mmol of compound I in
30 ml of anhydrous decane was heated for 30–60 min
under reflux. The mixture was cooled, and the precip-
itate was filtered off. Yield 2.1 g (55%), mp 265–
267°C (from acetic acid). IR spectrum, ν, cm–1: 3210
(N–H), 1750 (C=O), 1728 (C3=O), 1628 (C9=O).
1H NMR spectrum, δ, ppm: 1.72 s (3H, CH3), 3.63 s
(3H, OCH3), 7.23–8.14 m (9H, Harom), 12.91 s (1H,
We were the first to study thermolysis of pyrrole-
2,3-dione fused to a dihydropyrrole ring. Heating of
compounds I and II in boiling anhydrous decane over
a period of 30–60 min led to the formation of alkyl
1-methyl-3,9-dioxo-2-phenyl-2,3,4,9-tetrahydro-1H-
pyrrolo[3,4-b]quinoline-1-carboxylates IV and V. The
products were isolated as colorless crystalline sub-
stances which were soluble in DMF, DMSO, and hot
acetic acid. The IR spectra of IV and V contained
absorption bands due to stretching vibrations of the
ester (1728–1750 cm–1), lactam (1720–1728 cm–1), and
ketone carbonyl groups (1624–1628 cm–1) and amino
group (3210 cm–1). Compounds IV and V showed in
1
the H NMR spectra signals from aromatic protons,
a triplet from the methyl group in position 1 at δ 1.72–
1.73 ppm, a singlet from the ester methoxy group at
O
O
O
O
O
Me
Me
O
Me
RO
Ph
·
RO
Ph
RO
Ph
N
O
N
N
–CO
N
N
N
H
O
Ph
O
O
I, II
III
IV, V
I, IV, R = Me; II, V, R = Et.
616
Gein
