Spiro heterocyclization of dimethyl 1-(4-methylphenyl)-4,5-dioxo-4,5- dihydro-1H-pyrrole-2,3-dicarboxylate by the action of 3-arylamino-5,5- dimethylcyclohex-2-en-1-ones

Full text of DOI:10.1134/S1070428011100289

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2011, Vol. 47, No. 10, pp. 1600–1601. © Pleiades Publishing, Ltd., 2011.
Original Russian Text © P.S. Silaichev, M.A. Chudinova, A.N. Maslivets, 2011, published in Zhurnal Organicheskoi Khimii, 2011, Vol. 47, No. 10,
pp. 1570–1571.
SHORT
COMMUNICATIONS
Spiro Heterocyclization of Dimethyl 1-(4-Methylphenyl)-
4,5-dioxo-4,5-dihydro-1H-pyrrole-2,3-dicarboxylate by the Action
of 3-Arylamino-5,5-dimethylcyclohex-2-en-1-ones
P. S. Silaicheva, b, M. A. Chudinovab, and A. N. Maslivetsa, b
a Institute of Natural Sciences, Perm State University, ul. Genkelya 4, Perm, 614990 Russia
b Perm State University, ul. Bukireva 15, Perm, 614990 Russia
e-mail: koh2@psu.ru
Received December 24, 2010
DOI: 10.1134/S1070428011100289
Reactions of dialkyl 4,5-dioxo-4,5-dihydro-1H-pyr-
role-2,3-dicarboxylates with enamines were reported
previously. By reaction of 1-(4-methylphenyl)-4,5-di-
oxo-4,5-dihydro-1H-pyrrole-2,3-dicarboxylate (I) with
an equimolar amount of 3-arylamino-5,5-dimethyl-
cyclohex-2-en-1-one IIa or IIb in boiling toluene
(reaction time 3–4 h) we obtained methyl 1-aryl-1′-(4-
methylphenyl)-4′-hydroxy-6,6-dimethyl-2,4,5′-trioxo-
1,1′,2,4,5,5′,6,7-octahydrospiro[indole-3,2′-pyrrole]-3′-
carboxylates IIIa and IIIb. The spectral parameters of
compounds IIIa and IIIb turned out to be quite similar
to those of model 3′-benzoyl-1-cyclohexyl-4′-hydroxy-
6,6-dimethyl-1′-phenyl-1,1′,2,4,5,5′,6,7-octahydro-
spiro[indole-3,2′-pyrrole]-2,4,5′-trione whose structure
was proved by X-ray analysis [1].
cleophilic attack by the NH group on the ester carbon-
yl carbon atom on C2 and elimination of methanol.
Methyl 4′-hydroxy-6,6-dimethyl-1′-(4-methyl-
phenyl)-2,4,5′-trioxo-1-phenyl-1,1′,2,4,5,5′,6,7-octa-
hydrospiro[indole-3,2′-pyrrole]-3′-carboxylate
(IIIa). A solution of 1.0 mmol of pyrroledione I and
1.0 mmol of enamine IIa in 20 ml of anhydrous tolu-
ene was heated for 4 h (the progress of the reaction
was monitored by TLC). The mixture was cooled, and
the precipitate was filtered off and recrystallized from
toluene. Yield 71%, mp 240–241°C (from toluene). IR
spectrum, ν, cm–1: 3170 (OH); 1750, 1701 (C2=O,
1
C5′=O, COOMe); 1628 (C4=O). H NMR spectrum, δ,
ppm: 0.55 s and 0.93 s (3H each, Me), 2.00 d (1H,
7-H, J = 16.3 Hz), 2.11 d (1H, 5-H, J = 18.5 Hz), 2.18 d
(1H, 7-H, J = 16.3 Hz), 2.30 s (3H, Me), 2.38 d (1H,
5-H, J = 18.5 Hz), 3.70 s (3H, OMe), 6.94–7.60 m
(9H, Harom), 12.08 br.s (1H, OH). 13C NMR spectrum,
δC, ppm: 20.63 (Me), 26.51 (6-Me), 27.85 (6-Me),
33.82 (C6), 35.86 (C7), 50.48 (C5), 51.56 (OMe), 68.31
Presumably, compounds IIIa and IIIb are formed
as a result of initial addition of the activated β-CH
group in cyclic enamine II to the carbon atom in posi-
tion 2 of pyrroledione I with formation of intermediate
A which undergoes intramolecular cyclization via nu-
HO
COOMe
O
COOMe
OH
Ar
O
COOMe
O
COOMe
NHAr
N
O
N
+
O
COOMe
–MeOH
N
N
Me
Me
O
4-MeC6H4
Me
Me
NHAr
C6H4Me-4
O
C6H4Me-4
O
Me
Me
I
IIa, IIb
A
IIIa, IIIb
Ar = Ph (a), 4-MeC6H4 (b).
1600

SPIRO HETEROCYCLIZATION OF DIMETHYL 1-(4-METHYLPHENYL)-...
1601
(C3), 107.94 (C3a), 109.52 (C3′), 125.26–138.03, 155.04
(C5′), 161.99 (C2), 165.04 (COO), 174.45 (C4′), 190.56
(C4). Found, %: C 69.15; H 5.34; N 5.77. C28H26N2O6.
Calculated, %: C 69.12; H 5.39; N 5.76.
The IR spectra were recorded on an FSM-1201
spectrometer from samples dispersed in mineral oil.
1
The H and 13C NMR spectra were measured on
a Bruker AM-400 spectrometer at 400 and 100 MHz,
respectively, using DMSO-d6 as solvent and tetra-
methylsilane as internal reference. The purity of the
products was checked by TLC on Silufol plates using
ethyl acetate as eluent.
Methyl 4′-hydroxy-6,6-dimethyl-1,1′-bis(4-meth-
ylphenyl)-2,4,5′-trioxo-1,1′,2,4,5,5′,6,7-octahydro-
spiro[indole-3,2′-pyrrole]-3′-carboxylate (IIIb) was
synthesized in a similar way. Yield 78%, mp 234–
236°C (from toluene). IR spectrum, ν, cm–1: 3280 (OH);
1759, 1719 (C2=O, C5′=O, COOMe); 1613 (C4=O).
1H NMR spectrum, δ, ppm: 0.56 s and 0.93 s (3H each,
Me), 2.00 d (1H, 7-H, J = 16.2 Hz), 2.10 d (1H, 5-H,
J = 18.0 Hz), 2.17 d (1H, 7-H, J = 16.2 Hz), 2.30 s (3H,
Me), 2.34 d (1H, 5-H, J = 18.0 Hz), 2.37 s (3H, Me),
3.70 s (3H, OMe), 6.93–7.37 m (8H, C6H4), 12.53 br.s
(1H, OH). Found, %: C 69.60; H 5.61; N 5.66.
C29H28N2O6. Calculated, %: C 69.59; H 5.64; N 5.60.
This study was performed under financial support
by the Ministry of Education and Science of the
Russian Federation (project no. 2.19.10).
REFERENCE
1. Bannikova, Yu.N., Maslivets, A.N., and Aliev, Z.G., Russ.
J. Org. Chem., 2004, vol. 40, p. 1791.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 47 No. 10 2011