Synthesis of angular trioxacyclo-pentaphenanthrenes by the reaction of substituted 2-furanones with malonic acid dinitrile

Full text of DOI:10.1007/s10593-011-0789-x

Chemistry of Heterocyclic Compounds, Vol. 47, No. 4, July 2011 (Russian original Vol. 47, No. 4, April, 2011)
LETTERS TO THE EDITOR
SYNTHESIS OF ANGULAR TRIOXACYCLO-
PENTAPHENANTHRENES BY THE REACTION OF
SUBSTITUTED 2-FURANONES WITH
MALONIC ACID DINITRILE
T. V. Anis'kova1* and A. Yu. Yegorova1
Keywords: 3-(2-hydroxyphenylmethylidene)-5-R-3H-furan-2-ones, malonic acid dinitrile, 6-amino-
5-imino-2-R-11bH-3,4,7-trioxacyclopenta[c]phenanthrenes.
In previous work [1], we showed that the reaction of 3-arylmethylidene-5-R-3H-furan-2-ones with
malonic acid dinitrile leads to the formation of 6-amino-4-aryl-2-R-4H-furo[2,3-b]pyran-5-carbonitriles. In a
continuation of a study of this reaction, we investigated the effect of substituents in the arylmethylidene
fragment on the structure of the compounds formed.
The reaction of 3-(2-hydroxyphenylmethylidene)-5-R-3H-furan-2-ones 1 and 2 with malonic acid dini-
trile was carried out by heating the reagents at reflux in DMSO solution in the presence of a catalytic amount of
triethylamine. The reagent ratio was 1:1. The reaction led to the formation of 6-amino-5-imi-
no-2-R-11bH-3,4,7-trioxacyclopenta[c]phenanthrenes 3 and 4.
OH
O
O
CN
CN
DMSO
Et3N
NH
NH2
+
NH2
R
R
O
O
O
O
NH
R
O
O
1, 2
3a, 4a
3b, 4b
1, 3a,b R = Ph; 2, 4a,b R = p-Tol
___________
* To whom correspondence should be addressed; e-mail: aniskovatv@mail.ru.
1 N. G. Chernyshevsky Saratov State University, 83 Astrakhanskaya St., Saratov 410012, Russia.
__________________________________________________________________________________________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 621–623, April, 2011. Original
article submitted March 10, 2011.
0009-3122/11/4704-0514©2011 Springer Science+Business Media, Inc.
514

No conclusion can be drawn concerning the predominance of one of the possible tautomeric forms (a or
b) on the basis of the available spectral data and quantum-chemical calculation results.
OH
CN
b
R
OH
CN
CN
O
O
NH2
O
CN
CN
1, 2
+
R
O
O
a
NH2
R
CN
O
O
R
CN
O
N
O
H
A
O
O
NH
NH2
NH2
R
R
O
O
O
O
NH
3b, 4b
3a, 4a
The first step probably proceeds through addition of malonic acid dinitrile at the activated C=C bond of
the substituted furan-2-one to give a Michael adduct. Subsequent stabilization of this adduct may occur in
several ways. Pathway a involves initial participation of the hydroxyl group of the aromatic substituent, leading
to formation of substituted chromenes. The reaction does not stop at this step and further reaction of the cyano
group and carbonyl group of the heterocycle leads to final products 3 and 4. The possibility of formation of
tetracyclic bridged products A does not realize.
Pathway b entails initial reaction of a cyano group with the carbonyl group of the heterocycle to give
furopyran systems, whose stabilization also leads to final reaction products 3 and 4.
1
13
The H and C NMR spectra were taken on a Varian-400 spectrometer at 400 and 100 MHz, respec-
tively in CDCl3 at 20–25°C with TMS as internal standard. Thin-layer chromatography was carried out on
Silufol UV-254 plates using 2:2:1 hexane−ethyl acetate−chloroform as the eluent. The plates were developed
with iodine vapor.
6-Amino-5-imino-2-R-11bH-3,4,7-trioxacyclopenta[c]phenanthrenes 3 and 4. Several drops of
triethylamine were added to a mixture of arylmethylidene-3H-furan-2-one 1 or 2 (0.01 mol) and malononitrile
(0.01 mol) in DMSO solution. The reaction mixture was heated at reflux for 4–5 h, poured into ice water, and
neutralized by adding dilute hydrochloric acid. The crystals formed were filtered off and recrystallized from
hexane.
6-Amino-5-imino-2-phenyl-11bH-3,4,7-trioxapenta[c]phenanthrene (3) was obtained in 87% yield;
1
mp 191–193°C. H NMR spectrum, , ppm: 4.31 (1H, s, CH); 6.52 (1H, s, =CH); 7.35–7.69 (9H, m, Ar); 7.91
(1H, s, NH); 8.92 (2H, s, NH2). 13C NMR spectrum, , ppm: 25.92, 97.65, 116.55, 118.32, 119.12, 118.32,
515

120.45, 121.54, 125.32, 126.65, 127.67, 128.05, 128.76, 129.63, 131.76, 132.04, 132.20, 157.99, 168.95. Found,
%: C 73.00; H 4.54; N 8.69. C20H14N2O3 .Calculated, %: C 72.72; H 4.27; N 8.48.
6-Amino-5-imino-2-(4-methylphenyl)-11bH-3,4,7-trioxacyclopenta[c]phenanthrene (4) was obtained
in 89% yield; mp 197–199C. 1H NMR spectrum, , ppm: 2.34 (3H, s, CH3); 4.36 (1H, s, CH); 6.52 (1H, s, =CH);
13
7.35–7.69 (8H, m, Ar); 7.92 (1H, s, NH); 8.87 (2H, s, NH2). C NMR spectrum, , ppm: 21.45, 26.56, 99.43,
114.25, 116.33, 118.43, 119.32, 122.47, 124.79, 128.65, 129.12, 129.75, 130.65, 131.36, 132.54, 134.14, 137.32,
159.06, 170.15. Found, %: C 73.57; H 4.94; N 7.68. C21H16N2O3. Calculated, %: C 73.24; H 4.68; N 8.13.
This work was carried out with the financial support of the Russian Federation President's Grant for
State Support of Young Russian Scientists No. MK-2054.2011.3 and Russian Basic Research Fund Grant
10-03-00640-a.
REFERENCES
1.
T. V. Anis'kova and A. Yu. Egorova, Khim. Geterotsikl. Soedin., 836 (2009) [Chem. Heterocycl. Comp.,
45, 662 (2009)].
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