Reaction of N,N'-di(methoxycarbonyl)-p-benzoquinonediimine with Meldrum's acid and its analogs

Article abstract of DOI:10.1023/B:RUJO.0000043715.53702.cf

Reactions of 2,2-dimethyl-4,6-dioxo-1,3-dioxane (Meldrum's acid), 2,2-tetramethylene-4,6-dioxo-1,3-dioxane and 2,2-pentamethylene-4,6-dioxo-1,3- dioxane in the presence of MeONa gave rise instead of expectable products of Michael 1,4-addition the correspo

Full text of DOI:10.1023/B:RUJO.0000043715.53702.cf

Russian Journal of Organic Chemistry, Vol. 40, No. 5, 2004, pp. 690 -692. Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 5, 2004,
pp. 723-725.
Original Russian Text Copyright Ó 2004 by Velokorodov.
Reaction of N,N '-Di(methoxycarbonyl)-p-benzoquinonediimine
with Meldrum’s Acid and its Analogs
A.V. Velikorodov
Astrakhan State University, Astrakhan, 414000 Russia
e-mail: avelikorodov@mail.ru
Received September 27, 2003
Abstract—Reactions of N,N'-dimethoxycarbonyl-p-benzoquinonediimine in dioxane with 2,2-dimethyl-4,6-dioxo-
1,3-dioxane (Meldrum's acid), 2,2-tetramethylene-4,6-dioxo-1,3-dioxane and 2,2-pentamethylene-4,6-dioxo-1,3-dioxane
in the presence of MeONa gave rise instead of expectable products of Michael 1,4-addition the corresponding
N,N'-di(methoxycarbonyl)-p-benzoquinonediimines substituted in the ring.
We formerly studied [1, 2] reactions of N,N'-di(meth-
oxycarbonyl)-p-benzoquinonediimine (I) with b-diketones,
b-diketoesters, and b-tosyl-substituted carbonyl com-
pounds that depending on the reaction conditions and on
the nature of the CH-acid afforded either the correspond-
ing products of Michael addition or indolization products.
Compounds IIIa–c are crystalline substances of cream
color melting with decomposition, well soluble in ethyl ether,
chloroform, ethanol, and other polar solvents
The probable reaction mechanism may be represented
as follows [7]:
1&2 0H
2
At the same time among published data [3, 4] the in-
formation on N,N'-di(alkoxycarbonyl)-p-benzoquinone-
diimine reactions with polymethylenemalonates, rather
strong CH-acids, is practically lacking. For instance, the
acidity of 2,2-dimethyl-4,6-dioxo-1,3-dioxane (pKa 5.1) [5]
is comparable to that of dimedone (pKa 5.2) [6].
2
ꢀ
5
2
2
5ꢀ
1&2 0H
,,D F
,
In the present study we investigated reactions of
benzoquinonediimine I with 2,2-dimethyl-4,6-dioxo-1,3-
dioxane (IIa), 2,2-tetramethylene-4,6-dioxo-1,3-dioxane
(IIb), and 2,2-pentamethylene-4,6-dioxo-1,3-dioxane
(IIc). The process was performed by keeping an equimo-
lar reagents mixture in anhydrous dioxane in the pres-
ence of sodium methoxide under TLC monitoring.
Using the data of elemental analysis, IR, and 1H NMR
spectroscopy we established that the reaction products
were the respective substituted in the ring N,N'-di(meth-
oxycarbonyl)-p-benzoquinonediimines (IIIa–c) (see
table).
1&2 0H
2
0H21D
'LR[DQH
2 5
2 5ꢀ
2
1&2 0H
,,,D F
II, III, R = R' = Me (a); R, R' = (CH ) (b); R, R' = (CH ) (c).
2 4
2 5
The nucleophilic attack of CH-acid on the quinoid ring
results in formation of intermediate (A) that is apparently
stabilized by hydride ion elimination (see scheme). The
validity of this scheme is supported by the lack in the
reaction mixture of p-di(methoxycarboxamido)benzene [8]
that excludes the possibility of compounds IIIa–c forma-
tion from the products of 1,4-addition by Michael reac-
tion through their oxidation with benzoquinonediimine I.
Actually, in the IR spectra of compounds IIIa–c the
–1
absorption bands in the region 3300–3400 cm charac-
teristic of stretching vibrations of NH group are lacking,
–1
but are present absorption bands at 1620 cm , corre-
sponding to the stretching vibrations of C=N group. In
the H NMR spectrum signals of aromatic protons are
absent but appear signals of quinoid protons in the region
6.65–7.02 ppm
EXPERIMENTAL
1H NMR spectra were registered on spectrometer
Bruker AC-200 (200.13 MHz) in CDCl3, internal refer-
1
1070-4280/04/4005-0690Ó2004 MAIK “Nauka/Interperiodica”

REACTION OF N,N'-DI(METHOXYCARBONYL)-p-BENZOQUINONEDIIMINE
691
Scheme.
1&2 0H
&&2 0H
2
2
2
5
2
2 5
5ꢀ
5ꢀ
ꢀ
,,,
2
+
2
+
2
1&2 0H
1&2 0H
$
,
,,
2,2-Pentamethylene-4,6-dioxo-1,3-dioxane (IIc)
was obtained as colorless crystalline compounds by a simi-
lar procedure from 3.2 g (30.77 mmol) of malonic acid,
3.2 ml (30.77 mmol) of cyclohexanone, 0.1 g (0.526 mmol)
of p-toluenesulfonic acid monohydrate, and 5 ml of ace-
tic anhydride. Yield 3.45 g (61%), mp 94–95°C [10].
ence TMS. IR spectra were measured on spectropho-
tometer IKS-29 in wavenumber range 4000–400 cm
from mulls in mineral oil. The purity of compounds ob-
tained was checked by TLC on Silufol UV-254 plates.
–1
Meldrum's acid IIa was prepared by procedure from
[9].
Substituted N,N'-dimethoxycarbonyl-p-benzo-
quinonediimines (IIIa–c). To a solution of 1.11 g (5
mmol) of N,N'-di(methoxycarbonyl)-p-benzoquinone-
diimine (I) in 5 ml of anhydrous dioxane was added 5
mmol of CH-acid, 0.185 mmol of sodium methoxide, and
the mixture was kept at room temperature for 24 h. Then
it was poured into 50 ml of petroleum ether, and 1 drop of
glacial acetic acid was added. The reaction product was
filtered off, dried in air, and crystallized from a mixture
chloroform–petroleum ether, 1:5 (by volume).
2,2-Tetramethylene-4,6-dioxo-1,3-dioxane (IIb).
At room temperature a mixture of 6.4 g (61.5 mmol) of
finely ground malonic acid, 10 ml of freshly distilled ace-
tic anhydride, 0.2 g (1.05 mmol) of p-toluenesulfonic acid
monohydrate, and 5.5 ml (61.5 mmol) of freshly distilled
cyclopentanone was stirred till the malonic acid completely
dissolved (for 5 h). The mixture was maintained at 20°C
for 170 h, then diluted with water (30 ml), and cooled
with ice mixed with sodium chloride. The separated crys-
talline reaction product was filtered off, washed with
water on the filter, dried in air, and crystallized from a
mixture petroleum ether–ethanol, 5:2 (by volume). We
obtained 6.49 g (62%) of colorless crystalline compound
REFERENCES
1. Velikorodov,A.V. and Mochalin, V.B., Zh. Org. Khim., 1998,
vol. 34, p. 1555.
–1
IIb, mp 75–76°C. IR spectrum, H, cm : 1785, 1715
(C=O). Found, %: C 56.24; H 5.99. C8H10O4. Calcu-
lated, %: C 56.47; H 5.88.
2. Velikorodov,A.V. and Mochalin, V.B., Zh. Org. Khim., 2001,
vol. 37, p. 1100.
Yields, melting points, elemental analyses, IR, and 1H NMR spectra of compounds IIIa–c
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RUSSIAN JOURNALOF ORGANIC CHEMISTRY Vol. 40 No. 5 2004

692
VELIKORODOV
3. Fujita, S., J. Synth. Org. Chem. Japan, 1985, vol. 43, p. 153.
4. Adams, R. and Reifschneider, W., Bull. Soc. Chim., 1958,
vol. 1, p. 23.
7. Medien, H.A.A., Spectr. Acta A, 1996, vol. 52, p. 1679.
8. Maksimova, T.N. and Velikorodov, A.V., Zh. Org. Khim.,
1986, vol. 22, p. 1092.
5. Davidson, D. and Bernhard, S.A., J. Am. Chem. Soc., 1948,
vol. 70, p. 3426.
6. Metody eksperimenta v organicheskoi khimii (Methods of
Experiments in Organic Chemistry), Vaisbergera, V.A., Ed.,
Moscow: Khimiya, 1967, vol. 2, 532 p.
9. Tietze, L.-F. and Eicher, T., Reactions and Syntheses in the
Organic Chemistry Laboratory, Mill Valley, California: Uni-
versity Science Books, 1989.
10. Xu, Fu-Pei, Ding, Wei-Yu, and Da, Bao-Lin., Org. Chem.,
1991, vol. 11, p. 624.
RUSSIAN JOURNALOF ORGANIC CHEMISTRY Vol. 40 No. 5 2004