Reaction of N-alkyl(aryl)aminocarbonyl-1,4-benzoquinone monoimines with alcohols

Article abstract of DOI:10.1134/S1070428009050054

Reactions of N-alkyl(aryl)aminocarbonyl-3,5-dimethyl-1,4-benzoquinone monoimines with alcohols led to the formation of products of 1,2-addition, quinolide compounds. They are the final products in reactions with alkyl derivatives, but in event of aryl der

Full text of DOI:10.1134/S1070428009050054

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2009, Vol. 45, No. 5, pp. 674−680. © Pleiades Publishing, Ltd., 2009.
Original Russian Text © A.P. Avdeenko, S.A. Konovalova, A.G. Sergeeva, G.V. Palamarchuk, O.V. Shishkin, 2009, published in Zhurnal
Organicheskoi Khimii, 2009, Vol. 45, No. 5, pp. 692−698.
Reaction of N-Alkyl(aryl)aminocarbonyl-1,4-benzoquinone
Monoimines with Alcohols
A. P. Avdeenkoa, S. A. Konovalovaa, A. G. Sergeevaa,
G. V. Palamarchukb, and O. V. Shishkinb
aDonbass State Machinebuilding Academy, Kramatorsk, 84313 Ukraine
e-mail: chimist@dgma.donetsk.ua
bInstitute of Single Crystals, National Academy of Sciences of Ukraine
Received May 6, 2008
Abstract—– Reactions of N-alkyl(aryl)aminocarbonyl-3,5-dimethyl-1,4-benzoquinone monoimines with alcohols
led to the formation of products of 1,2-addition, quinolide compounds. They are the final products in reactions
with alkyl derivatives, but in event of aryl derivatives they underwent cyclization with the subsequent elimination
of the alcohol molecule to provide 4,7a-dimethyl-1-aryl-7,7a-dihydro-1H-benzimidazole-2,6-diones.
DOI: 10.1134/S1070428009050054
We formerly reported on a synthesis of a new class
of quinone imines, N-alkyl(aryl)aminocarbonyl-1,4-benzo-
quinone monoimines [1], whose structure combined
elements of quinone imines and substituted ureas extend-
ing the range of reactivity of these compounds.
[ArSO2, ArSO2N=C(Me), ArSO2N=C(Ph), MeCO] and
the character of substituents in the positions 3and 5 quinoid
ring (Me, Cl) do not affect the activity of the C=N bond
in the reaction with alcohols [4, 5]. The governing
influence belongs to the spatial arrangement of the
substituent at the nitrogen ring and the bulk of the
incoming AlkO group; these factors produce important
effect on the reaction rate and the possibility of the
process to occur [4, 5].
A characteristic feature of various N-substituted 3,5-
dimethyl-1,4-benzoquinone monoimines I containing an
activated sterically strained C=N bond is a ready occur-
rence of 1,2-addition to give products of quinolide structure
III [2, 3] (Scheme 1).
We formerly suggested that the activated sterically
strained C=N bond of quinone imines was present at the
values of the bond angle C=N–X > 130 deg [5]. In the
1H NMR spectra of 3,5-dimethyl(3,5-dichloro)-1,4-benzo-
quinone imines which characteristically are involved into
the 1,2-addition the signals of protons H2,6 appear as one
singlet. This fact is due to the large inversion rate around
the C=N bond in the 1H NMR time scale and also may
Owing to the spatial effect of substituents in the
positions 3 and 5 of the quinoid ring the 3,5-disubstituted
1,4-benzoquinone monoimines contain an enhanced bond
angle C=N–X resulting in the activation of the C=N bond
[3–6] and the nucleophile addition occurs by the path of
the 1,2-addition. The character of the substituent at the
nitrogen atom of the N-substituted p-quinone imine
Scheme 1.
(Cl)Me
X N
H(Me,Cl)
(Cl)Me
X NH
H(Me,Cl)
O
Alk OH
+
O
AlkO
II
(Cl)Me
H(Me,Cl)
(Cl)Me
H(Me,Cl)
I
III
X =ArSO2,ArSO2NC(Me),ArSO2N=C(Ph),Ac;Alk = Me, Et, Pr, i-Pr.
674

REACTION OF N-ALKYL(ARYL)AMINOCARBONYL-1,4-BENZOQUINONE MONOIMINES
675
Scheme 2.
R1
R1
R1
Me
Z
3
R1
R2
Me
O
Z
2
O
7
6
3
2
6
5
4
H
AlkO
Y N2
H
3
a
a
1
4
7
HN
N
O
5
6
Y
N1
1
4
O
R2
N3
2
AlkOH
O
_
+
O
HN1
a
a
AlkOH
O
7
7
3
4
R2
H
2
5
6
3
1
N
AlkO
5
IIa–IIe
R2
N
Y
Z
O
Me
H
Me
Z
Y
IVa–IVh
Va–Vn
VIa–VIg
VIIa–VIIe
II,Alk = Me (a), Et (b), Pr (c), i-Pr (d), Bu (e); IV,Y= Ph (a–d), 4-LeC6M4 (e), Bu (f), t-Bu (g), Cy (h), Z = Me (a–c, e–h), Cl (d),
R1 = R2 = H (a, d–h), Cl (c); R1 = Cl, R2 = H (b); V, VI, Y= Ph (a–d, g, h), 4-LeC6M4 (e, f), Bu (i, j), t-Bu (k, l), Cy (m, n), Z = Me
(a–g, i–n), Cl (h), R1 = R2 = H (a–f, h–n), R1 = R2 = Cl (g),Alk=Me (a, e, g–i, k, m), Et (b, f, l, n), Pr (c, j), Bu (d); VII, Y= Ph (a,
c–e), 4-LeC6M4 (b), R1 = R2 = H (a, b), Cl (e); R1 = Cl, R2 = H (c), R1 = H, R2 = Cl (d).
carbonyl-3,5-dimethyl-1,4-benzoquinone monoimines IVf–
IVh the required time did not exceed 1–2 h. The reaction
completion was checked by TLC by the absence in the
mixture of the initial quinone imine. It was found that in
reactions of N-arylaminocarbonyl-3,5-dimethyl-1,4-
benzoquinone monoimines IVa–IVc, and IVe up to four
compounds were present in the mixture during the
process, including the initial quinone imine.
indicate the presence of the activated sterically strained
C=N bond [3, 4, 6].
According to XRD findings 3,5-dimethyl-N-phenyl-
aminocarbonyl-1,4-benzoquinone monoimine contains the
angle C=N–C of 126.26 deg [1], considerably less than
the suggested limit for the demonstration of the reactivity
of the activated sterically strained C=N bond. This value
is close to those of the angles C=N–X (of the order of
magnitude 126 deg) of many N-substituted 1,4-benzo-
quinone imines lacking substituents in the positions 3 and
5 of the quinoid ring and consequently lacking the activat-
ed sterically strained C=N bond [7, 8]. But in the 1H NMR
spectrum of N-alkyl-(aryl)aminocarbonyl-3,5-dimethyl-
1,4-benzoquinone monoimines (in contrast to the 2,6-di-
methyl-substituted derivatives) the protons H2,6 give rise
to a singlet [1], indicating the fast process of Z,E-iso-
merization in the NMR time scale and therefore the
possibility of the 1,2-addition reaction with alcohols.
N-Alkyl(cyclohexyl)aminocarbonyl-3,5-dimethyl-1,4-
benzoquinone monoimines IVf–IVh in reaction with
alcohols afforded only the products of 1,2-addition,
quinolide structures 4-[alkyl-(cyclohexyl)aminocarbonyl]-
4-alkoxy-3,5-dimethylcyclohexa-2,5-dien-1-ones Vi–Vn.
1
The characteristic feature of the H NMR spectra of
these compounds is the presence of a singlet from the
protons H2,6 in the region δ 6.24–6.30 ppm, of a singlet
of protons of the OMe group (in the case of methanol
addition) at δ 2.99–3.01 ppm, and of signals of two NH
groups at δ 5.16–5.40 and 4.42–4.88 ppm.
Aiming at the revealing the presence of the activated
sterically strained C=N bond in N-alkyl-(aryl)amino-
carbonyl-3,5-dimethyl-1,4-benzoquinone monoimines we
investigated in this research the reaction of N-alkyl(aryl)-
aminocarbonyl-1,4-benzoquinone monoimines IVa–IVh
with substituents Me or Cl in the positions 3 and 5 of the
quinoid ring with alcohols IIa–IIe (see the scheme).
The reactions of N-arylaminocarbonyl-1,4-benzo-
quinone monoimines IVa–IVc and IVe yielded as final
products 1-aryl-4,7a-dimethyl-7,7a-dihydro-1H-benzimid-
azole-2,6-diones VIIa–VIIe. The characteristic feature
1
of the H NMR spectra of these compounds is the
presence of a doublet of doublets in the region δ 2.87–
3.15 ppm corresponding to two hydrogen atoms attached
to the sp3-hybridized atom C7. In the 13C NMR spectrum
of compound VIIa appear signals of two nonequivalent
methyl groups: one of them is linked to the sp3-hybridized
atom C7a (δ 69.88 ppm) and its signal is observed at δ
17.38 ppm, the other methyl group is attached to the sp2-
hybridized atom C4 and its peak appears at δ 24.30 ppm.
sp3-Hybridized atom C7 gives rise to the signal at
The reaction was carried out by boiling the quinone
imine in anhydrous alcohol till the disappearance of the
yellow color of the initial quinone imine solution. The
reaction duration depended on the structure of the quinone
imine. For instance, in reaction with methanol it took 1–
2 min with 3,5-dimethyl-N-phenylamino-carbonyl-1,4-
benzoquinone monoimine (IVa) and 5 h with 2,6-dichloro
derivative IVc. In the case of N-alkyl(cyclohexyl)amino-
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 5 2009

AVDEENKO et al.
676
phenylaminocarbonyl-3,5-dichloro-1,4-benzoquinone
monoimine (IVd) the compound of quinolide structure
Vh was the final product analogously to alkyl derivatives
Vi–Vn.
δ 50.67 ppm. The IR spectra of compounds VIIa–VIIe
demonstrated that the NH and OH groups were lacking
in their structure. It should be noted that the formation of
benzimidazoles VIIa–VIIe is unusual for the class of
quinone imines.
The reaction of quinone imine IVb with methanol
provided two isomeric products VIIc and VIId in the
ratio 3:7, namely, the cyclization occurred at both C=C
bonds of the quinolide ring, prevailingly at the C=C bond
containing the chlorine atom in the position 2 of the initial
quinone imine IVb revealing the regioselectivity of the
process. It is possible to presume based on the data in
[5] that the alkoxy group in quinolide compounds V is
located above the plane of the quinolide ring, and the Y–
N2HC(O)N1H moiety, below this plane. As a result of
the rotation around the N1–C(O) bond in compounds V
the second nitrogen atom (N2H) might occur either close
in the space to atom C3 or to atom C5 leading to the
regioselectivity of cyclization.
As already mentioned, in the reactions of aryl
derivatives IVa–IVc and IVe TLC revealed in the reaction
mixture three reaction products. In order to establish their
structure we sampled the reaction mixture every 3–5 min
in the course of the process between quinone imines IVa
and IVe and alcohols IIa–IIe. We selected the samples
containing one of the components in the maximum
amount, recrystallized them, and investigated the product
by 1H NMR spectroscopy. Owing to this procedure we
succeeded to isolate in the individual state inter-mediate
compounds except for compounds of quinolide structure
Va–Vg that were obtained only in the mixtures with
compounds VIa–VIg. This is evidently due to the close
values of the reaction rates of the formation of compounds
Va–Vg and of cyclic products 7a-alkoxy-3-aryl-3a,7-
dimethyl-3a,7a-dihydro-1H-benzimidazole-2,5(3H,4H)-
diones VIa–VIg. The attempts to separate these
compounds by crystallization failed because of their
similar solubility. It was also impossible to isolate individual
quinolide compounds Va–Vg by column chromatography
for their Rf values were close to those of compounds
VIa–VIg and VIIa–VIIg. The transition to the final cyclic
structure VII apparently occurred only after accumulation
of intermediate product VI, therefore we succeeded in
isolation of individual compounds VIa, VIe, and VIf and
in establishing their characteristics. In the reactions of
quinone imine IVa with 1-propanol and 1-butanol
analogous compounds VIc and VId were only detected
by TLC. Compounds VIg and VIIe were obtained as
a mixture with each other. Their separation was impossible
because of low yields for alongside the cyclization quinone
imine IVc suffered a hydrolysis. Quinone imines IV did
not react with 2-propanol due to the large volume of the
isopropyl group.
1
In the H NMR spectra of compounds VIa–VIf
appear the following signals: a characteristic doublet of
doublets belonging to two hydrogen atoms linked to C4 in
the region δ 2.73–2.76 ppm, signals of alkoxy groups
protons, and a singlet of the NH group in the region δ
6.40–6.69 ppm. According to the 13C NMR spectra one
of the methyl groups is attached to the sp3-hybridized
atom C3a (δ 47.90 ppm).
In order to reliably establish the structure of the cyclic
products obtained XRD analysis was performed on
a single crystal of 3a,7-dimethyl-7a-methoxy-3-phenyl-
3a,7a-dihydro-1H-benzimidazole-2,5(3H,4H)-dione (VIa)
(see the figure). The six-membered ring of compound
VIa C1–C6 is in the conformation intermediate between
semichair and sofa (folding parameters S 0.61, Θ 43.95,
Ψ 16.44 [9]). Atoms C2–5 are located in the same plane
with an accuracy of 0.006 , atoms C1 and C6 deviate
from the plane by –0.189(6) and –0.662(6) respective-
ly. The five-membered heterocycle C4C5N2C7N1 is
present in a twist-conformation (atoms C4 and C5 deviate
from the least-mean-squares plane of the other atoms of
the ring by –0.237 and –0.272 ). The two rings are
joined by the cis-type [torsion angle O3C4C5C8 33.9(2)
deg].
Atoms N1 and N2 have strongly flattened trigonal-
pyramidal configuration. The sum of bond angles at the
nitrogen atoms amounted to 354 and 353.6 deg
respectively.
Hence we established that in the reaction of quinone
imines IVa–IVc and IVe with alcohols the products of
the first stage of the process were 1,2-addition products
of quinolide structure, 4-alkoxy-4-(aryl-aminocarbonyl)-
3,5-dimethyl(3,5-dichloro)cyclohexa-2,5-dien-1-ones Va–
Vg. Further they readily underwent cyclization giving 7a-
alkoxy-3-aryl-3a,7-dimethyl-3a,7a-dihydro-1H-benzimid-
azole-2,5(3H,4H)-diones VIa–VIg. The latter eliminated
a molecule of alcohol converting finally into dihydro-
benzimidazole derivatives VIIa–VIIe. In the case of N-
The methoxy group is practically coplanar with the
N1–C4 bond [torsion angle N1C4O3C16 9.0(2) deg]. The
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REACTION OF N-ALKYL(ARYL)AMINOCARBONYL-1,4-BENZOQUINONE MONOIMINES
677
2
phenyl substituent is turned with respect to the amide
N1
fragment [torsion angle C7N2C9C14 58.3(2) deg] resulting
in breaking of the conjugation and in elongation of the
14
7
16
13
N2–C9 bond to 1.442(2)
value of 1.426 Å [10].
compared to the average
N2
9
8
12
3
4
5
3
In the crystal the molecules of compound VIa form
centrosymmetric dimers owing to the intermolecular
hydrogen bond N1–H1A…O22 (1–x,–y,1–z) (H…O
distance 2.02 A, N–H…O angle 165 deg).
15
10
11
6
2
1
Hence we established in this study that although the
angle C=N–C is not typical for N-substituted 3,5-
dimethyl-1,4-benzoquinone imines (in the 3,5-dimethyl-
N-phenylamino-carbonyl-1,4-benzoquinone monoimine
the C=N–C angle was 126.6 deg [1]), these quinone
imines readily entered with alcohols into the 1,2-addition
reaction. This may originate from the more significant
deviation of atoms C4 and N from the plane of the quinoid
ring than in the quinone imines lacking substituents in the
positions 3 and 5 of the quinoid ring. Therefore the
enhanced angle (> 130 deg) is not a necessary condition
for the 1,2-addition to proceed. On 8 of indicators of the
presence of an activated sterically strained C=N bond
alongside the existence of a fast Z,E-isomerization in the
NMR time scale may be the deviation of atoms C4 and
N from the plane of the quinoid ring. For instance, in 3,5-
dimethyl-substituted quinone imines the atoms C4 and N
deviate from the least-mean-squares plane C1C2C3C5C6
1
The structure of 3a,7-dimethyl-7a-methoxy-3-phenyl-3a,7a-
dihydro-1H-benzimidazole-2,5(3H,4H)-dione (VIa) according
to XRD findings.
UV-254 plates, solvent chloroform, eluent ethanol–
chloroform, 1:10, spots visualized under UV irradiation.
XRD study of a single crystal of compound VIa was
carried out at 293 K on a diffractometer Xcalibur-3 (MoKα
radiation, CCD-detector, graphite monochromator,
ω-scanning, 2θmax 50 deg).
Crystals of compound VIa triclinic, C16H18N2O3, at
293 K a 7.425(3), b 9.788(3), c 11.262(2) , α 65.35(3),
β 85.68(2), γ 74.85(3) deg, V 717.5(4) 3, Mr 286.32,
-
Z 2, space group Pi, dcalc 1.325 g/cm3, μ(MoKα)
by 0.043 and 0.136
for 3,5-dimethyl-N-phenyl-
0.093 mm–1, F(000) 304. Parameters of the unit cell and
intensities of 4682 reflections were measured (2479
independent reflections, Rint 0.016).
aminocarbonyl-1,4-benzoquinone monoimine [1], for 3,5-
dimethyl-N-[(4-chlorophenyl)sulfonyl]-1,4-benzoquinone
monoimine, by 0.054 and 0.133 respectively [5]. In the
quinone imines without substituents in the positions 3 and
5 of the quinoid ring the deviation of atoms C4 and N
from the least-mean-squares plane C1C2C3C5C6 amounts
respectively to 0.026 and 0.047 for 2,6-di-tert-butyl-
N-(4-chlorobenzoyl)-1,4-benzoquinone monoimine [7],
The structure was solved by the direct method using
SHELXTL software [11]. The hydrogen atoms positions
were revealed from the difference synthesis of the
electron density and were refined isotropically. The
structure was refined for F2 by full-matrix least-mean-
squares method in the anisotropic approximation for
nonhydrogen atoms till wR2 0.084 for 4600 reflections
[R1 0.033 for 1882 reflections with F > 4σ(F), S 1.030].
The final atomic coordinates, geometrical parameters of
the molecule, and the crystallographic data are deposited
to the Cambridge Crystallographic Data Centre, 12 Union
Road, Cambgidge, CB2 1EZ, UK (fax: +44 1223 336033;
e-mail: deposit@ccdc.cam.ac.uk) and are available to the
request under the no. CCDC 681167.
0.031 and 0.010
for 2,6-di-tert-butyl-N-[(4-nitro-
phenyl)sulfinyl]-1,4-benzoquinone monoimine [8], the
values significantly less that for 3,5-dimethyl-substituted
1,4-benzo-quinone onoimines.
EXPERIMENTAL
1H NMR spectra were registered on a spectrometer
Varian VXR-300 at operating frequency 300 MHz in
CDCl3 solutions, internal reference TMS. IR spectrum
of compound VIIa was recorded on a spectrophotometer
UR-20 in KBr. The reaction progress was monitored and
the purity of products was checked by TLC on Silufol
N-(Alkyl)arylaminocarbonyl-1,4-benzoquinone
monoimines IVa, IVd–IVh were prepared by procedure
[1]. Characteristics of compounds IVa, IVd–IVh were
identical to the corresponding data published in [1].
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AVDEENKO et al.
678
1
3,5-Dimethyl-N-phenylaminocarbonyl-2-chloro-
62%. H NMR spectrum, δ, ppm: 1.95 s (6H, C3,5H3),
3.02 s (3H, OMe), 5.62 br.s (1H, N2H), 6.31 s (2H, H2,6),
7.08 br.s (1H, N1H), 7.14–7.45 m (5H, Ph).
1,4-benzoquinone monoimine (IVb), 3,5-dimethyl-
N-phenylaminocarbonyl-2,6-dichloro-1,4-benzo-
quinone monoimine (IVc). Through a solution of
0.07 mol of p-quinone monoimine IVa, IVb in 30 ml of
dry chloroform was passed a flow of gaseous hydrogen
chloride till the reaction mixture turned colorless, and
a colorless precipitate settled of 3,5-dimethyl-N-phenyl-
aminocarbonyl-2-chloro(2,6-dichloro)-1,4-aminophenol.
The precipitate was filtered off, washed with chloroform,
and recrystallized from the glacial acetic acid. Into the
dispersion of 0.01 mol of recrystallized 3,5-dimethyl-N-
phenylaminocarbonyl-2-chloro-(2,6-dichloro)-1,4-amino-
phenol in 5 ml of glacial acetic acid was charged
0.011 mol of lead tetraacetate at cooling and stirring of
the reaction mixture. The initial colorless precipitate
dissolved, and orange substance precipitated of 3,5-di-
methyl-N-phenyl-aminocarbonyl-2-chloro(2,6-dichloro)-
1,4-benzoquinone monoimine IVb, IVc. Into the reaction
mixture 1 ml of ethylene glycol was added, the mixture
was thoroughly stirred, cooled, and filtered. The precipitate
was washed with a little acetic acid, dried, and
recrystallized from benzene.
3,5-Dimethyl-4-phenylaminocarbonylamino-4-
ethoxycyclohexa-2,5-dien-1-one (Vb). Yield 5%.
1H NMR spectrum, δ, ppm: 0.85–0.90 t (3H, OCH2CH3),
2.11 s (6H, C3,5H3), 3.72–3.79 d.d (2H, OCH2CH3), 5.99
br.s (1H, N2H), 6.30 s (2H, H2,6), 7.18 br.s (1H, N1H),
7.26–7.50 m (5H, Ph).
3,5-Dimethyl-4-propoxy-4-phenylamino-
carbonylaminocyclohexa-2,5-dien-1-one (Vc). Yield
1
94%. H NMR spectrum, δ, ppm: 0.88–0.93 t (3H,
OCH2CH2CH3), 1.52–1.64 d.d (2H, OCH2CH2CH3),
1.98 s (6H, C3,5H3), 3.04–3.08 t (2H, OCH2CH2CH3),
5.42 br.s (1H, N2H), 6.29 br.s (2H, H2,6), 6.84 br.s (1H,
N1H), 7.07–7.30 m (5H, Ph).
4-Butoxy-3,5-dimethyl-4-phenylaminocarbonyl-
1
aminocyclohexa-2,5-dien-1-one (Vd). Yield 35%. H
NMR spectrum, δ, ppm: 0.87–3.12 m (9H, Bu), 1.98 s
(6H, C3,5H3), 5.55 br.s (1H, N2H), 6.29 s (2H, H2,6), 7.03
br.s (1H, N1H), 7.06–7.30 m (5H, Ph).
3,5-Dimethyl-4-[(4-methylphenyl)amino-
carbonylamino]-4-methoxycyclohexa-2,5-dien-1-
3,5-Dimethyl-N-phenylaminocarbonyl-2-chloro-
1,4-benzoquinone monoimine (IVb). Yield 70%, mp
1
one (Ve). Yield 82%. H NMR spectrum, δ, ppm:
1.95 br.s (6H, C3,5H3), 2.32 s (3H, 4-CH3C6H4), 3.01 s
(3H, OMe), 5.35 br.s (1H, N2H), 6.31 br.s (2H, H2,6),
6.53 br.s (1H, N1H), 7.14 s (4H, 4-CH3C6H4).
1
145–146°C. H NMR spectrum, δ, ppm: 2.26 d (3H,
C5H3), 2.37 s (3H, C3H3), 6.53 q (1H, H6), 7.10 br.s (1H,
NH), 7.14–7.52 m (5H, Ph). Found, %: N 9.60, 9.75.
C15H13ClN2O2. Calculated, %: N 9.70.
3,5-Dimethyl-4-[(4-methylphenyl)amino-
carbonylamino]-4-ethoxycyclohexa-2,5-dien-1-one
(Vf). Yield 3%. 1H NMR spectrum, δ, ppm: 0.85–0.90 t
(3H, OCH2CH3), 1.97 s (6H, C3,5H3), 2.34 s (3H,
4-CH3C6H4), 3.72–3.79 d.d (2H, OCH2CH3), 5.33 br.s
(1H, N2H), 6.27 s (2H, H2,6), 6.84 br.s (1H, N1H), 7.00–
7.21 d.d (4Harene, J 8.4 Hz).
3,5-Dimethyl-N-phenylaminocarbonyl-2,6-
dichloro-1,4-benzoquinone monoimine (IVc). Yield
42%, mp 128–129°C. 1H NMR spectrum, δ, ppm: 2.40 s
(6H, C3,5H3), 7.29 br.s (1H, NH), 7.11–7.60 m (5H, Ph).
Found, %: N 8.64, 8.71. C15H12Cl2N2O2. Calculated, %:
N 8.67.
3,5-Dimethyl-4-methoxy-4-(phenylamino-
carbonylamino)-2,6-dichlorocyclohexa-2,5-dien-1-
one (Vg). Yield 15%. 1H NMR spectrum, δ, ppm: 2.10 s
(6H, C3,5H3), 3.00 s (3H, OMe), 6.15 br.s (1H, N2H),
7.03 br.s (1H, N1H), 7.34–7.52 m (5H, Ph).
Reactions of N-(alkyl)arylaminocarbonyl-1,4-
benzoquinone monoimines IVa–IVh with alcohols.
A solution of 2 mmol of quinone imine IVa–IVh in 8 ml
of an appropriate anhydrous alcohol was boiled in a flask
with a reflux condenser equipped with an outlet tube
packed with calcium chloride till decoloration of the
solution (TLC monitoring till the disappearance of the
initial quinone imine). The crystals precipitated on cooling
were filtered off and washed with the corresponding
alcohol. The filtrate was evaporated in order to increase
the yield of the product. The residue after the evaporation
was recrystallized from benzene.
4-Methoxy-4-phenylaminocarbonylamino-3,5-
dichlorocyclohexa-2,5-dien-1-one (Vh). Yield 95%,
mp 182–184°C. 1H NMR spectrum, δ, ppm: 3.19 s (3H,
OMe), 5.52 br.s (1H, N2H), 6.52 br.s (1H, N1H), 6.70 s
(2H, H2,6), 7.13–7.37 m (5H, Ph). Found, %: N 8.43,
8.60. C14H12Cl2N2O3. Calculated, %: N 8.56.
4-Butylaminocarbonylamino-3,5-dimethyl-4-
methoxycyclohexa-2,5-dien-1-one (Vi). Yield 82%,
mp 129–130°C. H NMR spectrum, δ, ppm: 0.87–
3,5-Dimethyl-4-methoxy-4-phenylamino-
carbonylaminocyclohexa-2,5-dien-1-one (Va). Yield
1
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REACTION OF N-ALKYL(ARYL)AMINOCARBONYL-1,4-BENZOQUINONE MONOIMINES
679
3.15 m (9H, Βu), 1.94 s (6H, C3,5H3), 3.00 s (3H, OMe),
4.88 q (1H, N2H), 5.48 br.s (1H, N1H), 6.29 s (2H, H2,6).
Found, %: N 10.45, 10.61. C14H22N2O3. Calculated, %:
N 10.52.
134.34 (C42 ), 146.68 (C6), 153.51 (C7), 157.68 (C2),
195.03 (C5). Found, %: N 9.64, 9.87. C16H18N2O3.
Calculated, %: N 9.78.
3a,7-Dimethyl-3-phenyl-7a-ethoxy-3a,7a-di-
hydro-1H-benzimidazole-2,5(3H,4H)-dione (VIb).
Yield 96%, mp 218–219°C. 1H NMR spectrum, δ, ppm:
1.22–1.27 t (3H, OCH2CH3), 1.33 s (3H, C3aH3), 2.21 d
(3H, C7H3), 2.58–2.71 d.d (2H, C4H2, J 15 Hz), 3.68–
3.75 d.d (2H, OCH2CH3), 5.91 br.s (1H, NH), 6.00 br.s
(1H, H6), 7.26–7.50 m (5H, Ph). Found, %: N 9.28, 9.40
. C17H20N2O3. Calculated, %: N 9.33.
4-Butylaminocarbonylamino-3,5-dimethyl-4-
propoxycyclohexa-2,5-dien-1-one (Vj). Yield 45%,
mp 121–122°C. 1H NMR spectrum, δ, ppm: 0.87–0.92 t
(3H, OCH2CH2CH3), 0.93–3.16 m (9H, Βu), 1.50–
1.57 d.d (2H, OCH2CH2CH3), 1.94 s (6H, C3,5H3), 3.00–
3.04 t (2H, OCH2CH2CH3), 4.81 q (1H, N2H), 5.24 br.s
(1H, N1H), 6.25 s (2H, H2,6). Found, %: N 9.41, 9.59.
C16H26N2O3. Calculated, %: N 9.52.
3a,7-Dimethyl-3-(4-methylphenyl)-7a-methoxy-
3a,7a-dihydro-1H-benzimidazole-2,5(3H,4H)-dione
(VIe). Yield 69%, mp 156–157°C. 1H NMR spectrum,
δ, ppm: 1.34 s (3H, C3aH3), 2.03 d (3H, C7H3), 2.36 s
(3H, 4-CH3C6H4), 2.52–2.71 d.d (2H, C4H2, J 15.6 Hz),
3.49 s (3H, OMε), 6.10 q (1H, H6), 6.40 br.s (1H, NH),
7.02–7.21 d.d (4H, 4-CH3C6H4, J 8.4 Hz). Found, %:
N 9.25, 9.39. C17H20N2O3. Calculated, %: N 9.33.
4-(tert-Butyl)aminocarbonylamino-3,5-dimethyl-
4-methoxycyclohexa-2,5-dien-1-one (Vk). Yield 80%,
mp 192–194°C. 1H NMR spectrum, δ, ppm: 1.27 s (9H,
t-Bu), 1.95 s (6H, C3,5H3), 2.99 s (3H, OMe), 4.68 br.s
(1H, N2H), 5.31 br.s (1H, N1H), 6.31 s (2H, H2,6). Found,
%: N 10.46, 10.62. C14H22N2O3. Calculated, %: N 10.52.
4-(tert-Butyl)aminocarbonylamino-4-ethoxy-
cyclohexa-2,5-dien-1-one (Vl). Yield 81%, mp 185–
3a,7-Dimethyl-3-(4-methylphenyl)-7a-ethoxy-
3a,7a-dihydro-1H-benzimidazole-2,5(3H,4H)-dione
(VIf). Yield 82%, mp 174–175°C. 1H NMR spectrum, δ,
ppm: 1.12–1.17 t (3H, OCH2CH3), 1.34 s (3H, C3aH3),
2.05 d (3H, C7H3), 2.36 s (3H, 4-CH3C6H4), 2.52–2.69
d.d (2H, C4H2, J 15.6 Hz), 3.64–3.70 d.d (2H, OCH2CH3),
6.11 q (1H, H6), 6.42 br.s (1H, NH), 7.00–7.21 d.d (4H,
4-CH3C6H4, J 8.4 Hz). Found, %: N 8.86, 9.01.
C18H22N2O3. Calculated, %: N 8.91.
1
186°C. H NMR spectrum, δ, ppm: 1.10–1.15 t (3H,
OCH2CH3), 1.33 s (9H, t-Bu), 1.95 s (6H, C3,5H3), 3.09–
3.13 d.d (2H, OCH2CH3), 4.42 br.s (1H, N2H), 5.33 br.s
(1H, N1H), 6.24 s (2H, H2,6). Found, %: N 9.82, 10.04.
C15H24N2O3. Calculated, %: N 9.99.
3,5-Dimethyl-4-methoxy-4-cyclohexylamino-
carbonylaminocyclohexa-2,5-dien-1-one (Vm). Yield
1
79%, mp 177–179°C. H NMR spectrum, δ, ppm: 1.00–
3.53 m (11H, cyclo-C6H11), 1.94 s (6H, C3,5H3), 3.00 s
(3H, OMe), 4.77 d (1H, N2H, J 8.1 Hz), 5.40 br.s (1H,
N1H), 6.30 br.s (2H, H2,6). Found, %: N 9.46, 9.69.
C16H24N2O3. Calculated, %: N 9.58.
3a,7-Dimethyl-7a-methoxy-3-phenyl-4,6-di-
chloro-3a,7a-dihydro-1H-benzimidazole-
1
2,5(3H,4H)-dione (VIg). Yield 30%. H NMR spec-
trum, δ, ppm: 1.46 s (3H, C3aH3), 2.57 s (3H, C7H3), 3.56 s
(3H, OMe), 4.60 s (1H, H4), 7.24–7.50 m (5H, Ph),
7.34 br.s (1H, NH).
3,5-Dimethyl-4-cyclohexylaminocarbonylamino-
4-ethoxycyclohexa-2,5-dien-1-one (Vn). Yield 35%,
mp 140–141°C. 1H NMR spectrum, δ, ppm: 1.08–3.51 m
(11H, cyclo-C6H11), 1.12–1.17 t (3H, OCH2CH3), 1.95 s
(6H, C3,5H3), 3.11–3.16 d.d (2H, OCH2CH3), 4.66 d (1H,
N2H, J 9 Hz), 5.16 s (1H, N1H), 6.26 s (2H, H2,6). Found,
%: N 9.03, 9.21. C17H26N2O3. Calculated, %: N 9.14.
4,7a-Dimethyl-1-phenyl-7,7a-dihydro-1H-benz-
imidazole-2,6-dione (VIIa). Yield 98%, mp 248–250°C.
1H NMR spectrum, δ, ppm: 1.40 d (3H, C7aH3), 2.40 d
(3H, CH3, J 1.5 Hz), 2.92–3.12 d.d (2H, C7H2,
J 15.6 Hz), 6.50 q (1H, H5), 7.29–7.50 m (5H, Ph).
13C NMR spectrum, δ, ppm: 17.38 (Me–C7a), 24.30 (Me–
C4), 50.67 (C7), 69.88 (C7a), 126.64 (C22 ),128.00 (C42 ),
129.47 (C32 ), 134.49 (C5), 135.67 (C12 ), 146.42 (C4),
163.92 (C3a), 188.56 (C2), 192.92 (C6). Found, %: N 10.97,
11.13. C15H14N2O2. Calculated, %: N 11.02.
3a,7-Dimethyl-7a-methoxy-3-phenyl-3a,7a-
dihydro-1H-benzimidazole-2,5(3H,4H)-dione (VIa).
Yield 93%, mp 180–182°C. 1H NMR spectrum, δ, ppm:
1.35 s (3H, C3aH3), 2.03 d (3H, C7H3), 2.53–2.73 d.d
(2H, C4H2, J 15.6 Hz), 3.50 s (3H, OMe), 6.09 q (1H,
H6), 6.69 br.s (1H, NH), 7.14–7.42 m (5H, Ph).
13C NMR spectrum, δ, ppm: 17.68 (Me–C7), 19.51 (Me–
C3a), 47.90 (C4), 52.03 (OMe), 67.33 (C3a), 87.93 (C7a),
128.22 (C2’), 128.37 (C22 ), 129.27 (C12 ), 129.41 (C32 ),
4,7a-Dimethyl-1-(4-methylphenyl)-7,7a-dihydro-
1H-benzimidazole-2,6-dione (VIIb). Yield 88%, mp
1
192–194°C. H NMR spectrum, δ, ppm: 1.38 s (3H,
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 5 2009

AVDEENKO et al.
680
C7aH3), 2.39 s (3H, 4-CH3C6H4), 2.39 d (3H, C4H3,
J4,5 1.5 Hz), 2.90–3.09 d.d (2H, 2H7, J 15.0 Hz),
6.49 br.s (1H, H5), 7.13–7.25 d.d (4H, 4-CH3C6H4,
J 8.1 Hz). Found, %: N 10.35, 10.50. C16H16N2O2.
Calculated, %: N 10.44.
vol. 32, p. 1540; Avdeenko, A.P., Menafova, Yu.V., and
Zhukova, S.A., Zh. Org. Khim., 1998, vol. 34, p. 237;
Avdeenko,A.P. and Zhukova, S.A., Zh. Org. Khim., 1999,
vol. 35, p. 447; Avdeenko, A.P. and Menafova, Yu.V., Zh.
Org. Khim., 1999, vol. 35, p. 913; Avdeenko, A.P. and
Menafova, Yu.V., Zh. Org. Khim., 2000, vol. 36, p. 267;
Avdeenko, A.P., Yusina,A.L., and Yagupol’skii, L.M., Zh.
Org. Khim., 2001, vol. 37, p. 1183; Fernando, C.R., Cal-
der, I.C., Ham, K.N. J. Med. Chem., 1980, vol. 23, p. 1153.
3. Avdeenko, A.P., Yusina, A.L., Menafova, Yu.V.,
Pirozhenko, V.V., Zh. Org. Khim., 1995, vol. 31, p. 1530.
4. Avdeenko,A.P. and Marchenko, I.L., Zh. Org. Khim., 2001,
vol. 37, p. 1661.
4,7a-Dimethyl-1-phenyl-5-chloro-7,7a-dihydro-
1H-benzimidazole-2,6-dione (VIIc). Yield 60%.
1H NMR spectrum, δ, ppm: 1.41 s (3H, C7aH3), 2.55 s
(3H, C4H3), 2.99–3.34 d.d (2H, C7H2, J 1.5 Hz), 7.26–
7.48 m (5H, Ph).
4,7a-Dimethyl-1-phenyl-7-chloro-7,7a-dihydro-
1H-benzimidazole-2,6-dione (VIId). Yield 26%.
1H NMR spectrum, δ, ppm: 1.54 s (3H, C7aH3), 2.45 d
(3H, C4H3, J4,5 1.2 Hz), 4.81 s (1H, H7), 6.73 q (1H, H5,
5. Avdeenko, A.P., Menafova, Yu.V., Yusina, A.L., Demen-
tii, L.V., Zh. Org. Khim., 1999, vol. 35, p. 902.
6. Avdeenko,A.P., Zh. Org. Khim., 2000, vol. 36, p. 547.
7. Avdeenko,A.P., Pirozhenko, V.V., Yagupol’skii, L.M., and
Marchenko, I.L., Zh. Org. Khim., 2001, vol. 37, p. 1043.
8. Avdeenko, A.P., Pirozhenko, V.V., Konovalova, S.A.,
Santalova, A.A., and Vakulenko, A.V., Arkivoc, 2005,
vol. VIII, p. 60.
9. Zefirov, N.S., Palyulin, V.A., Dashevskaya, E.E. J. Phys.
Org. Chem., 1990, vol. 3, p. 147.
10. Burgi, H.-B. and Dunitz, J.D., Structure Correla-
tion,Weinheim: VCH, 1994, vol. 2, p. 741.
J
4,5 1.2 Hz), 7.26–7.48 m (5H, Ph).
4,7a-Dimethyl-1-phenyl-5,7-dichloro-7,7a-
dihydro-1H-benzimidazole-2,6-dione (VIIe). Yield
55%. H NMR spectrum, δ, ppm: 1.56 s (3H, C7aH3),
1
2.57 s (3H, C4H3), 4.85 s (1H, H7), 7.24–7.50 m (5H,
Ph).
REFERENCES
1. Avdeenko, A.P., Konovalova, S.A., Sergeeva, A.G.,
Zubatyuk, R.I., Palamarchuk, G.V., and Shishkin, O.V., Zh.
Org. Khim., 2008, vol. 44, p. 1791.
11. Sheldrick, G.M., SHELXTL PLUS. PC, Version. A System
of Computer programs for the Determination of Crystal
Structure from X-ray Diffraction Data, Rev. 5.1, 1998.
2. Avdeenko, A.P., Menafova, Yu.V., Zh. Org. Khim., 1996,
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 5 2009