DMITRIEV et al.
932
nucleophilic addition of the β-CH group in the enol
tautomer of dimedone at the carbon atom in position 3
of the pyrrole ring, and subsequent addition of the
enolic hydroxy group to the cyano carbon atom closes
pyran ring, yielding final products IIa and IIb.
(C2′), 178.63 (C=O, ester), 195.30 (C5). Found, %:
C 71.02; H 5.47; N 8.08. C31H29N3O5. Calculated, %:
C 71.11; H 5.58; N 8.03.
Ethyl 2-amino-3-cyano-7,7-dimethyl-2′,5-dioxo-
1′,5′-diphenyl-1′,2′,5,6,7,8-hexahydrospiro[chro-
mene-4,3′-pyrrole]-4′-carboxylate (IIb) was synthe-
sized in a similar way. Yield 74%, mp 243–244°C
(from ethyl acetate–acetone, 1:1). IR spectrum, ν,
cm–1: 3453, 3279, 3167 (NH2), 2199 (CN), 1721
The described reaction is a rare example of spiro
heterocyclization of monocyclic 1H-pyrrole-2,3-diones
in three-component condensation with nucleophiles,
leading to difficultly accessible spiro[chromene-4,3′-
pyrrole] heterocyclic system.
1
(C2′=O), 1690 (C=O, ester), 1663 (C5=O). H NMR
spectrum, δ, ppm: 0.91 t (3H, CH2CH3, J = 7.2 Hz),
1.02 s (3H, Me), 1.09 s (3H, Me), 2.23 d and 2.35 d
(1H each, 8-H, J = 16.4 Hz), 2.41 d and 2.69 d (1H
each, 6-H, J = 17.3 Hz), 3.83 m (2H, OCH2), 7.02–
7.32 m (10H, C6H5), 7.40 br.s (2H, NH2). Found, %:
C 70.73; H 5.43; N 8.13. C30H27N3O5. Calculated, %:
C 70.71; H 5.34; N 8.25.
Ethyl 2-amino-1′-benzyl-3-cyano-7,7-dimethyl-
2′,5-dioxo-5′-phenyl-1′,2′,5,6,7,8-hexahydrospiro-
[chromene-4,3′-pyrrole]-4′-carboxylate (IIa). Pyr-
roledione Ia, 1.0 mmol, was dissolved in 20 ml of an-
hydrous benzene, 1.0 mmol of malononitrile, 1.0 mmol
of dimedone, and 1.0 mmol of triethylamine were
added, the mixture was heated for 2 h under reflux and
cooled, and the precipitate was filtered off and recrys-
tallized from toluene. Yield 89%, mp 243–244°C. IR
spectrum, ν, cm–1: 3399, 3328, 3214 (NH2), 2191
(CN), 1734 (C2′=O), 1674 (C=O, ester; C5=O).
1H NMR spectrum, δ, ppm: 0.84 t (3H, CH2CH3, J =
7.4 Hz), 1.01 s (3H, Me), 1.08 s (3H, Me), 2.22 d and
2.35 d (1H each, 8-H, J = 15.6 Hz), 2.40 d and 2.69 d
(1H each, 6-H, J = 17.7 Hz), 3.77 m (2H, OCH2),
4.47 s (2H, CH2Ph), 7.06–7.41 m (12H, Harom, NH2).
13C NMR spectrum, δC, ppm: 13.41 (CH3CH2), 26.19
(Me), 28.15 (Me), 31.91 (C7), 39.89 (C8), 43.91 (C4),
47.71 (CH2Ph), 49.80 (C6), 55.05 (C3), 58.75 (OCH2),
110.19 (C4′), 111.32 (C4a), 117.52 (CN), 126.47–136.51
(Carom), 154.70 (C5′), 159.77 (C8a), 161.48 (C2), 164.77
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 instrument at 400 and 100 MHz, re-
spectively, using DMSO-d6 as solvent and tetramethyl-
silane as internal reference.
This study was performed under financial support
by the Russian Foundation for Basic Research (project
no. 08-03-01032).
REFERENCE
1. Shemchuk, L.A., Chernykh, V.P., and Red’kin, R.G.,
Russ. J. Org. Chem., 2008, vol. 44, p. 1789.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 46 No. 6 2010