Halogenation of N-substituted para-quinone monoimines and para-quinone monoximes ethers: IX. Halogenation of N-aroyl-2,6(3,5)-dimethyl-1,4-benzoquinone monoimines and their reduced forms

Article abstract of DOI:10.1134/S1070428009110128

At the halogenation of N-aroyl-2,6(3,5)-dimethyl-1,4-benzoquinone imines we found the halogenation of methyl groups to occur. The bromination of N-aroyl-2,6-dimethyl-1,4-benzoquinone imines yielded 3,6-dibromo-2,6-dimethyl-5-aroyloxycyclohex-2-ene-1,4-dio

Full text of DOI:10.1134/S1070428009110128

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2009, Vol. 45, No. 11, pp. 1651−1662. © Pleiades Publishing, Ltd., 2009.
Original Russian Text © A.P. Avdeenko, S.A. Konovalova, O.N. Ludchenko, G.V. Palamarchuk, O.V. Shishkin, 2009, published in Zhurnal Organicheskoi
Khimii, 2009, Vol. 45, No. 11, pp. 1660−1670.
Halogenation of N-Substituted para-Quinone Monoimines
and para-Quinone Monoximes Ethers: IX.*
Halogenation of N-Aroyl-2,6(3,5)-dimethyl-1,4-benzoquinone
Monoimines and Their Reduced Forms
A. P.Avdeenkoa, S. A. Konovalovaa, O. N. Ludchenkoa, G. V. Palamarchukb, and O. V. Shishkinb
aDonbass State Machinebuilding Academy, Kramatorsk, 84313 Ukraine
e-mail: chimist@dgma.donetsk.ua
bResearch and Development Combine “Institute of Single Crystals,”
National Academy of Sciences of the Ukraine, Ukraine
Received June 7, 2008
Abstract—At the halogenation of N-aroyl-2,6(3,5)-dimethyl-1,4-benzoquinone imines we found the halogenation
of methyl groups to occur. The bromination of N-aroyl-2,6-dimethyl-1,4-benzoquinone imines yielded 3,6-dibromo-
2,6-dimethyl-5-aroyloxycyclohex-2-ene-1,4-diones due to the strong acceptor property of the ArCO group and
high redox potentials of N-aroyl derivatives. In the chlorination of N-aroyl-3,5-dimethyl-1,4-benzoquinone imines
the chlorine addition to the C=C bond of the quinoid ring proceeded both by the trans- and syn-scheme.
DOI: 10.1134/S1070428009110128
The halogenation of N-arenesulfonyl-2,6(3,5)-dimethyl-
1,4-benzoquinone imines and their reduced forms is fairly
well understood [2], and products of various degree of
halogenation were obtained. The halogenation of
4-arenesulfonylamido-3,5(2,6)-dimethylphenols proceed-
ed either through a successive oxidation, an addition of
hydrogen halide, oxidation, and repeated addition of
hydrogen halide, or through the electrophilic substitution
of the hydrogen in the benzene ring. In event of the
halogenation of quinone imines first a halogen molecule
added to the double bond of the quinoid ring providing
cyclohexene structures suffering the dehydrohalogena-
tion. The latter in case of 2,6-dimethyl derivatives are
highly unstable due to the possibility of the Z,E-iso-
merization. The only cyclohexene structures stable against
the dehydrohalogenation are those existing as E-isomers
(trans-position of the ArSO2 group with respect to the
double C=C bond of the cyclohexene ring).
sulfonyl-1,4-benzoquinone monoimines would be different
since the redox reactions related to the conversion of
N-substituted p-aminophenols in N-substituted p-quinone
imines and vice versa are important in the halogenation
of N-substituted p-quinone imines and their reduced forms
[4]. Besides the ArCO substituent at the nitrogen is
a much stronger acceptor than ArSO2, and this should
necessarily affect the activity and reactivity of the C=C
bonds of the quinoid ring.
The halogenation of N-aroyl-2,6(3,5)-dimethyl-1,4-
benzoquinone monoimines and their reduced forms was
not investigated formerly. The halogenation of N-aroyl-
(arenesulfonyl)-2,6-diisopropyl(di-tert-butyl)-1,4-benzo-
quinone monoimines was investigated in [1, 5]. It was
revealed that the chlorination of the C=C bond of the
quinoid ring could take both the route of trans- and syn-
addition. In the case of N-aroyl-2,6-di-tert-butyl deriv-
atives an uncommon for N-substituted p-quinone imines
replacement of the tert-butyl group by a chlorine atom
was found due presumably just to the influence of the
ArCO group on the quinoid ring.
N-Aroyl-1,4-benzoquinone monoimines possess higher
redox potentials than N-arenesulfonyl-1,4-benzoquinone
monoimines [3]. Therefore it is expectable that the
processes of the halogenation of N-aroyl- and N-arene-
* For Communication, see [1].
The goal of this research is the determination of the
1651

AVDEENKO et al.
1652
Scheme 1.
Me
OH
Br
Me
O
Br2
NH
Ar
C
O
O
Me
H
Hlg
Va, Vb, VIa_VId
Me
Pb(OAc)4
Me
O
C
Br
O
Br2
Ar
Ar
XIIIa, XIIIb
O
C
N
O
Me
OH
Me
O
C
Hlg2
Ar
Me
Hlg
NH
VIIa, VIIb, VIIIa_VIIId
Me
OH
IIa_IId
O
Me
Me
Ar
C NH
O
C
Hlg2
Ar
N
O
Pb(OAc)4
Me
Br
CH2Br
IXa, IXb
Ia, Id
O
N
O
Ar C
Br
Xa, Xb
CH2Br
H Hlg
Me
Hlg
N
O
C
O
Ar
Hlg
Me
XIa, XIb, XIIa_XIId
Ar = C6H5 (a), 4-MeC6H4 (b), 4-NO2C6H4 (c), 4-ClC6H4 (d); Hlg = Cl (V, VII, XI), Br (VI, VIII, XII).
obtained by acylation of the corresponding aminophenols
with aromatic acids anhydrides.
features of the N-aroyl-2,6(3,5)-dimethyl-1,4-benzo-
quinone monoimines halogenation and their comparison
with the halogenation of the corresponding N-arene-
sulfonyl derivatives.
Quinone imines Ia, Ib, IIIa, and IIIb and amino-
phenols IIa, IIb, IVa, and IVb were subjected to the
chlorination with gaseous chlorine and the bromination
with molecular bromine in CHCl3, CH3CO2H, DMF,
a mixture DMF–CH3CO2H, 1:5, at various temperatures
and different ratios initial substrate–halogen.
We carried out the halogenation of N-aroyl-2,6-
dimethyl-1,4-benzoquinone monoimines Ia and Ib, of
their reduced forms (4-amino-2,6-dimethylphenols IIa–
IId), and also of 3,5-dimethyl-1,4-benzoquinone
monoimines IIIa, IIIb, and 4-amino-3,5-dimethylphenols
IVa and IVb.
The results of the halogenation of N-aroyl-2,6-
dimethyl-1,4-benzoquinone monoimines Ia and Ib and of
their reduced forms IIa–IId are presented in Scheme 1.
1,4-Benzoquinone monoimines Ia, Ib, IIIa, and IIIb
were prepared by oxidation with lead tetraacetate in
acetic acid of the corresponding 4-amino-2,6(3,5)-
dimethylphenols IIa, IIb, IVa, and IVb. The latter were
Similarly to 4-amino-N-arenesulfonyl-2,6-dimethyl-
phenols [2] the 4-amino-N-aroyl-2,6-dimethyl-phenols
attacked by the Hlg2 molecule suffer the oxidation to
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 11 2009

HALOGENATION OF N-SUBSTITUTED para-QUINONE MONOIMINES: IX.
1653
quinone imine followed by the hydrohalogenation giving
4-amino-N-aroyl-3-halo-2,6-dimethylphenols Va, Vb,
VIa–VId. The latter might also form by the electrophilic
substitution by the halogen of the hydrogen atom in the
benzene ring of aminophenols IIa–IId.
IXb where in one methyl group a hydrogen atom was
replaced by a bromine atom. The formation in a high yield
in this reaction of aminobromomethylphenols is possible
only in the presence of bromine free radicals in the reaction
mixture. The lack of methyl group bromination in the
analogous N-arenesulfonyl derivatives suggests an
assumption that the bromine radicals form predominantly
or even exclusively as a result of an active oxidation of
hydrogen bromide with the present in the system or arising
in the course of the reaction quinone imines Ia and Ib.
The reaction occurs only in event of N-aroyl derivatives
since the redox potentials of N-aroyl-1,4-benzoquinone
monoimines are higher than those of the N-arenesulfonyl-
1,4-benzoquinone monoimines.
The halogenation of both quinone imines Ia and Ib
and aminophenols IIa–IId at the ratios initial substrate–
halogen from 1 : 1 to 1 : 3.5 afforded N-aroyl-3-halo-
2,6-dimethyl-1,4-benzoquinone monoimines VIIa, VIIb,
VIIIa–VIIId that formed likely by the dehydrohalo-
genation of the cyclohexene structures arising at the
addition of the Hlg2 molecule to the C=C bond of the
quinoid ring. The compounds of the cyclohexene
structure easily undergo the dehydrohalogenation,
therefore in contrast to the reactions of the N-arene-
sulfonyl-2,6-dimethyl-1,4-benzoquinone monoimines they
have not been isolated from the reaction mixture.
Quinone imines VII and VIII were also obtained from
the corresponding aminophenols Va, Vb, VIa–VId by
their oxidation with lead tetraacetate.
The bromination of quinone monoimines Ia and Ib at
the ratio initial substrate–bromine 1:4 provided N-aroyl-
5-bromo-6-bromomethyl-2-methyl-1,4-benzoquinone
monoimines Xa and Xb that were also obtained by the
oxidation of aminophenols IXa and IXb with lead
tetraacetate in acetic acid (Scheme 1).
It should be noted that the stability of the cyclohexene
structure depends on the ability of the unshared electron
pairs of nitrogen or oxygen atoms to eject the proton
from the sp3-hybridized carbon owing to the interaction
nσN(O) → σ*C–Heq. In E-isomers at the trans-location
of the substituent at the nitrogen the cyclohexene struc-
tures are more stable because the interaction nσN →
σ*C–Heq leading to the proton ejection is impossible.
In Z-isomers the unshared electron pair of the nitrogen
facilitates the ejection of the hydrogen from the plane of
the cyclohexene ring and the occurrence of the
dehydrohalogenation.
Stable cyclohexene structures XIa, XIb, XIIb–XIId
were obtained both from quinone imines I, VII, and VIII
and from aminophenols II, V, and VI at a significant excess
of the halogen. Due to the possibility of the existence of
the semiquinoid structure XIa, XIb, XIIb–XIId in the
form only of E-isomer (trans-location of theArCO group
with respect to the C=C bond of the cyclohexene ring)
they do not suffer the dehydrohalogenation and they are
the final products of the reaction.
The bromination of quinone imines VIIIa and VIIIb
and aminophenols VIa and VIb can take an “abnormall”
route with a rearrangement resulting in the introduction
of an aroyloxy group into the ring of the quinone imine
fragment giving finally cyclohexene-1,4-diones XIIIa and
XIIIb. The main transitions occurring between the
halogen-containing compounds are shown in Scheme 1.
In the cyclohexene structures formed on the addition
of a single halogen molecule to the N-aroyl-2,6-dimethyl-
1,4-benzoquinone monoimines just the existence of
a Z-iso-mer is possible. Compared to the N-arenesulfonyl
derivatives the more electron-acceptor aroyl group leads
to the increased acidity of the hydrogen atom in the
ortho-position to the imine carbon facilitating the
subsequent dehydrohalogenation of the cyclohexene
structures and consequently the failure of their isolation
from the reaction mixture.
The structure of aminophenols Va, Vb, VIa–VId was
proved by the 1H NMR spectra of their oxidation products
VIIa, VIIb, VIIIa–VIIId (Scheme 1) for the spectra of
the latter were more informative. In the 1H NMR spectra
of quinone imines VIIa, VIIb, VIIIa–VIIId a quartet
was observed in the region δ 6.74–6.81 ppm, characteristic
of H5 proton of the quinoid ring, and a doublet at δ 1.97–
1.99 ppm belonging to the protons of a methyl group located
at the C=C bond containing a hydrogen atom. The signal
of the methyl group attached to the C=C bond containing
a halogen appeared as a singlet in the region δ 2.26–
2.32 ppm.
Unlike the N-arenesulfonyl derivatives N-aroyl-2,6-
dimethyl-1,4-benzoquinone imines Ia and Ib and
aminophenols IIa–IId at the bromination in CH3CO2H,
CHCl3, and DMF at the ratios initial substrate–bromine
from 1:4 to 1:5 formed in over 50% yield 4-amino-N-
aroyl-5-bromo-6-bromomethyl-2-methyl-phenols IXa and
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 11 2009

AVDEENKO et al.
1654
Fig. 1. The structure of 5-benzoyloxy-3,6-dibromo-2,6-dimethylcyclohex-2-ene-1,4-dione (XIIIa) by XRD data.
In the 1H NMR spectrum of aminophenol IXa a singlet
ring atoms by 0.45 and –0.27 . The methyl group at the
C6 is axially oriented, and the C6–Br1 bond is directed
equatorially [torsion angles C8C6C5C4 –85.8(6),
Br1C6C5C4 155.9(4) deg] that results in the formation of
the shortened intramolecular contact C2···H8A 2.77 (sum
of the van der Waals radii equals 2.87 [6]).
is present at δ 4.85 ppm characteristic of two hydrogen
1
atoms of the CH2Br group. In the H NMR spectra of
quinone imines Xa and Xb the proton signals of the
CH2Br group were observed at δ 4.69 ppm. The char-
acteristic signals of the H5 protons of the quinoid ring
appeared in the region δ 6.85–6.86 ppm. In the 1H NMR
spectra of cyclohexene compounds XIa, XIb, XIIb–
XIId the singlet of the H5 proton at the sp3-hybridized
carbon is shifted upfield (δ 4.96–5.23 ppm). In the spectra
in the characteristic regions the singlets are observed of
two methyl groups, located at sp3- and sp2-hybridized
carbon atoms.
The ester substituent is strongly flattened [torsion angle
C15C10C9O2 13.3(9) deg], is equatorially oriented with
respect to the tetrahydro ring [torsion angle O4C1C2C3
165.6(4) deg], and is located nearly normal to the C1–C2
bond [torsion angle C9O4C1C2 105.2(5) deg].
It should be noted that the spatial arrangement of the
substituents at the sp3-hybridized carbon atoms C5 and
C6 is untypical for the cyclohexene compounds: H atom
and Me group are locked trans-diaxially with respect to
the plane of the cyclohexene ring , and the Br1 atom and
the aroyloxy group are in the equatorial position. This
location of the substituents makes it possible to give some
assumptions on the route of the formation of this com-
pound. Inasmuch as both the aroyloxy substituent and
the bromine atom are located in the equatorial position
their addition to the C=C bond might occur only by the
trans-scheme, namely, by the successive trans-diaxial
addition of the bromine cation followed by the addition of
the aroyloxy group, whereas the “abnormal” axial location
of the methyl group and the equatorial position of the
bromine atom arise due to the subsequent inversion of
the cyclohexene fragment caused by the minimization of
the spatial interaction between the bulky methyl and
aroyloxy groups.
In the spectra of cyclohexene-1,4-diones XIIIa and
XIIIb the signal of the H5 proton attached to the sp3-
hybridized carbon appeared in the region δ 6.17–
6.19 ppm, unususl for the signals of the hydrogen atoms
of the ring in the quinone imines or cyclohexene
compounds. The chemical shifts of two singlets belonging
to the methyl groups indicate their location at sp3- and
sp2-hybridized carbon atoms.
In the 13C NMR spectrum of cyclohexene-1,4-dione
XIIIa two signals are present (δ 182.20 and 187.33 ppm)
characteristic of C1 and C4 of two C=O groups, and also
two upfield signals (δ 58.98 and 77.70 ppm) characteristic
of sp3- hybridized carbon atoms.
In order to additionally confirm the structure of
compounds XIIIa and XIIIb we carried out the XRD
analysis of 5-benzoyloxy-3,6-dibromo-2,6-dimethylcyclo-
hex-2-ene-1,4-dione (XIIIa) (Fig. 1).
Tetrahydro ring in the molecule XIIIa exists in the
conformation of distorted semichair. The atoms C1 and
C6 deviate from the least-mean-square plane of the other
The results of the halogenation of N-aroyl-3,5-dimethyl-
1,4-benzoquinone monoimines IIIa and IIIb and their
reduced forms IVa and IVb are presented in Scheme 2.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 11 2009

HALOGENATION OF N-SUBSTITUTED para-QUINONE MONOIMINES: IX.
1655
Scheme 2.
Me
O
OH
Hlg
Ar
NH
C
Me
O
Pb(OAc)4
Me
Ar
C N
O
XIVa, XIVb
XVa, XVb
HHlg
Me
Hlg
XVIa, XVIb,
XVIIa, XVIIb
Hlg
OH
Me
NH
Me
O
C
Ar
Hlg2 or
Me
NH
Hlg
Pb(OAc)4
O
Ar C
XVIIIa, XVIIIb
Hlg2
OH
Hlg
XIXa, XIXb
Me
O
Me
Ar
N
C
O
HHlg
IVa, IVb
Hlg2
Me
Hlg
Hlg
Hlg
Me
Hlg
XXa, XXb
XXIa, XXIb
O
Me
Ar
C N
O
O
C
Hlg2
N
O
Ar
Cl2
Me
Hlg
Me
IIIa, IIIb
XXIIa, XXIIb
XXIIIa, XXIIIb
Cl
Cl
Me
Cl
O
C
Ar
N
O
Cl
XXIVa, XXIVb
Ar = C6H5 (a), 4-MeC6H4 (b); Hlg = Cl (XIV, XVI, XVIII, XX, XXII); Hlg = Br (XV, XVII, XIX, XXI, XXIII).
ClH2C
tion, and hydrohalogenation with a molecule HHlg by
the route of 1,4-addition. The assumed halogenation
scheme is confirmed by the fact that the yield of
aminophenols XVIIIa, XVIIIb, XIXa, XIXb in the
halogenation of quinone imines IIIa and IIIb reached
over 50% at the ratio initial substance–halogen 1:1.
The halogenation of quinone imines IIIa and IIIb and
aminophenols IVa and IVb differs considerably from the
halogenation of the corresponding N-arylsulfonyl deriva-
tives [2] owing to the different stability of the cyclohexene
compounds formed at the addition of the first Hlg2
molecule to the quinone imine. They are relatively stable
for the N-arenesulfonyl derivatives and they are isolated
in the individual state, and for the N-aroyl derivatives
this products are extremely unstable and prone to the
dehydrohalogenation as also the cyclohexene compounds
formed at the addition of the second Hlg2 molecule.
Therefore the first common least halogenated products
in the halogenation both of quinone imines IIIa and IIIb
and aminophenols IVa and IVb are 4-amino-N-aroyl-2,6-
dihalo-3,5-dimethylphenols XVIIIa, XVIIIb, XIXa,
XIXb. They formed from quinone imines IIIa and IIIb
through the addition of a molecule Hlg2, dehydrohalogena-
Intermediate N-aroyl-2-halo-3,5-dimethyl-1,4-benzo-
quinone monoimines XVIa, XVIb, XVIIa, XVIIb were
prepared from quinone imines IIIa and IIIb by their
hydrohalogenation to 4-amino-N-aroyl-2-halo-3,5-di-
methylphenols followed by the oxidation with lead
tetraacetate. Quinoneimines XVI and XVII are easily
hydrohalogenated with the formation of aminophenols
XVIII and XIX.
4-Amino-N-aroyl-2-halo-3,5-dimethylphenols XIV and
XV are the least halogenated products which can be
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 11 2009

AVDEENKO et al.
1656
obtained (V, VI, XIV, XV, XVIII, and XIX) as compared
with the products prepared from N-arenesulfonyl deriv-
atives [2].
obtained by the halogenation of aminophenols IVa and
IVb. When subjected to the halogenation aminophenols
XIV and XV are converted into aminophenols XVIII and
XIX. Quinone imines III and their reduced forms IV in
the halogenation at the large ratio initial substance–halogen
from 1:2 to 1:10 yield N-aroyl-2,6-dihalo-3,5-dimethyl-1,4-
benzoquinone monoimines XXa, XXb, XXIa, XXIb and
stable “semiquinoid” compounds 4-aroyl-imino-2,5,6,6-
tetrahalo-3,5-dimethylcyclohex-2-en-1-ones XXIIa,
XXIIb, XXIIIa, XXIIIb. The main transitions occurring
between the halogen-containing compounds are shown
in Scheme 2.
The structure of aminophenols XIVa, XIVb, XVa,
XVb, XVIIIa, XVIIIb, XIXa, XIXb was proved by the
1H NMR spectra of their oxidation products, quinone
imines XVIa, XVIb, XVIIa, XVIIb, XXa, XXb, XXIa,
XXIb. In the 1H NMR spectra of quinone imines XVIa,
XVIb, XVIIa, XVIIb signals are present belonging to
the protons of the quinoid ring (δ 6.57–6.58 ppm, quartet)
amd two signals from the methyl groups: a singlet at δ
2.31–2.38 ppm and a doublet at δ 2.07–2.09 ppm. In the
1H NMR spectra of quinone imines XXa, XXb, XXIa,
XXIb one singlet signal is observed from both methyl
groups in the region δ 2.28–2.34 ppm. The equivalence
of CH3 groups demonstrates the fast relative to the NMR
time scale Z,E-isomerization at the C=N bond, the
topomerization characteristic of an activated sterically
strained C=N bond [7].
Thus the chlorination and the bromonation of quinone
imines IIIa and IIIb and aminophenols IVa and IVb
follows in general the same scheme. The difference
appears in the fact that the stable, not suffering the
dehydrochlorination cyclohexene compounds XXIIa and
XXIIb are prone to deeper chlorination with the replace-
ment of one hydrogen by chlorine in the methyl group
attached to the sp2-hybridized carbon atom giving 4-aroyl-
imino-5-methyl-2,5,6,6-tetrachloro-3-chloromethylcyclo-
hex-2-ene-1-ones XXIVa and XXIVb. The latter were
also obtained by the chlorination of aminophenols IV and
quinone imines XX.
For the 1H NMR spectra of cyclohexene compounds
XXIIa, XXIIb, XXIIIa, XXIIIb a presence is char-
acteristic of two singlet peaks of two methyl groups
attached respectively to an sp2-hybridized atom C3 of
the cyclohexene ring (δ 2.21–2.30 ppm), and to an sp3-
1
hybridized atom C5 (δ 2.08–2.20 ppm). In the H NMR
Note that because of higher redox potentials of
N-aroyl-1,4-benzoquinone monoimines compared with the
corresponding N-arenesulfonyl-1,4-benzoquinone mono-
imines the isolation of the reduced forms of the former is
increased. Therefore a wider range of aminophenols was
spectra of compounds XXIVa and XXIVb instead of the
signal of the methyl group at the sp2-hybridized carbon
atom appears a singlet (δ 4.69–4.70 ppm) from the
protons of the CH2Cl group.
Fig. 2. The structure of 4-benzoylimino-5-methyl-2,5,6,6-tetrachloro-3-chloromethylcyclohex-2-ene-1-one (XXIVa) by XRD
data.
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HALOGENATION OF N-SUBSTITUTED para-QUINONE MONOIMINES: IX.
1657
13C NMR spectra of quinone imines XVIb, XXa, XXb,
EXPERIMENTAL
XXIa, XXIb contain the characteristic signals of carbon
atoms of C=O and C=N groups in the region δ 171.7–
176.3 and 151.3–153.4 ppm respectively.
1H and 13C NMR spectra were registered on a spec-
trometer Varian VXR-300 at operating frequencies 300
and 75.4 MHz, internal reference TMS. Reaction
mixtures were analyzed by TLC on Silufol UV-254 plates
(eluent benzene–hexene, 10:1), spots visualized under UV
irradiation.
For proving the structure of compounds XXIVa and
XXIVb and revealing the presence of the halogenated
methyl groups in the N-aroyl derivatives of 1,4-benzo-
quinone monoimines 4-benzoylimino-5-methyl-2,5,6,6-
tetrachloro-3-chloromethylcyclohex-2-ene-1-one (XXIVa)
was subjected to XRD study (Fig. 2).
Crystals of XIIIa monoclinic, C15H12O4Br2, at 293 K
a 22.8263(8), b 12.7206(6), c 10.5778(4) , β 91.933(3)
deg, V 3069.7(2) 3, Mr 416.05, Z 8, space group C2/C,
dcalc 1.801 g/cm3, μ(MoKa) 5.29 mm–1, F(000) 1632.
parameters of the unit cell and intensities of 13003
reflections (2672 independent, Rint 0.072) were measured
on a diffractometer Xcalibur-3 (MoKa radiation,
CCD-detector, graphite monochromator, ù-scanning,
2θmax 50 deg).
Crystals of XXIVa triclinic, C15H10Cl5NO2, at 293 K
a 8.839(1), b 10.284(1), c 11.179(1) , α 113.382(7), β
109.339(7), γ 98.217(8) deg, V 834.8(1) 3, Mr 413.49, Z
2, space group P1¯, dcalc 1.645 g/cm3, μ(MoKa) 0.88 mm–
1, F(000) 416. Parameters of the unit cell and intensities
of 5780 reflections (2881 independent, Rint 0.024) were
measured on a diffractometer Xcalibur-3 (MoKa radiation,
CCD- detector, graphite monochromator, ù-scanning,
2θmax 51 deg).
Tetrahydro ring in the molecule XXIVa exists in the
conformation of semichair. The atoms C2 and C3 deviate
from the least-mean-square plane of the other atoms of
the ring by 0.37 and –0.34 respectively.
In the crystal compound XXIVa exists in the form of
two conformers (A and Β) with the axial and equatorial
orientation of the methyl group at the atom C2 in the ratio
68:32 [torsion angles C6C1C2C8A –76.2(5), C6C1C2C8Β
–
165.4(6) deg]. The C7–Cl5 bond is directed virtually normal
to the endocyclic double bond C5–C6 [torsion angle
C5C6C7Cl5 83.2(2) deg]. This orientation of the
substituents at the saturated carbon atoms of the
tetrahydro ring results in the formation of intramolecular
shortened contacts Cl1···H8A 2.75 (sum of the van der
Waals radii 3.06 [6]), Cl1···H8F 2.61 (3.06 ), Cl2···C6
3.43 (3.61 ), Cl2···H8D 2.76 (3.06 Å), Cl3···Cl5 3.62 (3.80
), Cl3···H7B 2.69 (3.06 ), Cl4A···C10 3.32 (3.61 ),
Cl4B···C5 3.50 (3.61 Å), Cl4B···C6 3.33 (3.61 Å), N1···H7A
2.42 (2.66 ).
The structures were solved by the direct method
applying the program package SHELXTL [9]. The
hydrogen atoms positions were revealed from the
difference synthesis of electron density (except for the
disordered part of the XXIVa structure where the
positions of hydrogen atoms were calculated geometrical-
Conformer Ais sterically strained as shows the strongly
shortened intramolecular contact Cl4A···C9 2.86 (3.61 ).
This evidently causes the deviation of N1 atom from the
plane of the fragment C4C5C6C1 [torsion angle N1C1C6C5
–167.7(1) deg] and virtually normal orientation of the
carbonyl group to the double bond C1–N1 [torsion angle
O2C9N1C1 79.1(2) deg].
It should be noted that the bonds C3–Cl1 1.763(2) and
N1–C1 1.268(2) are shorter than their average values
1.805 and 1.279 [8] respectively.
ly) and were refined either by the rider model with Uiso
=
nUeq of the nonhydrogen atom linked to the given
hydrogen (n = 1.5 for the methyl group, 1.2 for the other
hydrogen atoms) (XIIIa) or isotropically (XXIVa). For
the crystal of XIIIa the extinction was taken into account
semiempirically from the multiscanning data [10] (Tmin
0.324, Tmax 0.624). In refining structure XXIVa the
restrictions were applied to the bond lengths C2–C8A and
C2–C8Β in the disordered fragment [1.53(1) ], and the
anisotropic thermal parameters for the pairs of carbon
and chlorine atoms were taken equal. The structures were
refined along F2 by the full-matrix least-mean-squares
method in an anisotropic approximation for nonhydrogen
atoms till wR2 0.122 for 12970 reflections [R1 0.057 for
2249 reflextions with F > 4σ(F), S 1.09] for structure
XIIIa; till wR2 0.080 for 5761 reflections [R1 0.031 on
2881 reflections with F > 4σ(F), S 1.054] for structure
As a whole the axial position of the methyl group at
the sp3-hybridized C5 atom is not characteristic of such
compounds. The data obtained suggest that the addition
of the chlorine atoms at the chlorination of quinone imines
XXIIa and XXIIb, same as in the case of 2,6-diisopropyl
derivatives [5] may occur both by the trans- (the
equatorial position of the methyl group) and the syn-
scheme (the axial position of the methyl group).
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 11 2009

AVDEENKO et al.
1658
XXIVa. The final atomic coordinates, the geometrical
parameters of the molecules, and the crystallographic data
were 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). The
data are available from the files CCDC 681164 (structure
XIIIa) and 681166 (structure XXIVa).
Yield 93%, mp 237–239°C. Found, %: N 5.82, 5.90.
C15H15NO2. Calculated, %: N 5.80.
4-Amino-3,5-dimethyl-N-(4-methylbenzoyl)-
phenol (IVb). Yield 81%, mp 248–249°C. Found, %:
N 5.49, 5.58. C16H17NO2. Calculated, %: N 5.49.
Chlorination of N-aroyl-1,4-benzoquinone mono-
imines Ia, Ib, IIIa, IIIb, VIIa, VIIb, XVIa, XVIb, XXa,
XXb, 4-amino-N-aroylphenols IIa, IIb, IVa, IVb, Va,
Vb, XIVa, XIVb, XVIIIa, XVIIIb and cyclohexene
compounds XXIIa, XXIIb. Through a solution of
2 mmol of the compound under study in 3 ml of CHCl3,
or of AcOH, DMF, a mixture DMF–AcOH, 1:5, was
passed a flow of dry chlorine at a rate 15–20 ml/min at
a desired temperature. The ratio initial substance–chlorine
was monitored by the added weight and it was varied in
the range 1:1–1:4. The precipitate was filtered off and
recrystallized from acetic acid.
N-Aroyl-2,6(3,5)-dimethyl-1,4-benzoquinone
monoimines Ia, Ib, IIIa, IIIb and 4-amino-N-aroyl-
2,6(3,5)-dimethylphenols IIa–IId, IVa, IVb were
synthesized by procedures from [11, 12]. The products
were recrystallized from acetic acid.
N-Benzoyl-2,6-dimethyl-1,4-benzoquinone
monoimine (Ia). Yield 95%, mp 119–120°C. 1H NMR
spectrum, δ, ppm: 2.05 br.s (6H, 2,6-Me2), 6.84 br.s (2H,
H3,5), 7.47–7.94 m (5H, Ph). Found, %: N 5.78, 5.92.
C15H13NO2. Calculated, %: N 5.85.
2,6-Dimethyl-N-(4-methylbenzoyl)-1,4-benzo-
quinone monoimine (Ib). Yield 98%, mp 92–94°C.
1H NMR spectrum, δ, ppm: 2.04 br.s (6H, 2,6-Me2),
2.43 s (3H, Me in 4-MeC6H4), 6.84 br.s (2H, H3,5), 7.27–
7.82 m (4H, 4-MeC6H4, J 8.1 Hz). Found, %: N 5.51,
5.69. C16H15NO2. Calculated, %: N 5.53.
Compounds Va and Vb were obtained by the chlorina-
tion of aminophenols IIa and IIb in AcOH, or DMF, the
mixture DMF–AcOH, 1:5, at 30–40°C and the ratio
initial substance–chlorine 1:1; compounds VIIa and VIIb,
at the chlorination of quinone monoimines Ia and Ib (the
ratio initial substance–chlorine 1:1) and aminophenols IIa
and IIb (the ratio initial substance–chlorine 1:2) inAcOH,
or the mixture DMF–AcOH, 1:5, at 50–60°C; com-
pounds XIa and XIb, at the chlorination of quinone
monoimines Ia and Ib and aminophenols IIa and IIb in
CHCl3, or AcOH, the mixture DMF–AcOH, 1:5, at 40–
50°C and the ratio initial substance–chlorine 1:3, at the
chlorination of aminophenols Va and Vb in AcOH (the
ratio initial substance–chlorine 1:2.5), in the mixture
DMF–AcOH, 1:5 (the ratio initial substance–chlorine
1:4) at 35–45°C, at the chlorination of quinone mono-
imines VIIa and VIIb inAcOH (the ratio initial substance–
chlorine 1:1), in the mixture DMF–AcOH, 1:5 (the ratio
initial substance–chlorine 1:2.5) at 40–50°C.
4-Amino-N-benzoyl-2,6-dimethylphenol (IIa).
Yield 91%, mp 187–188°C. Found, %: N 5.82, 5.94.
C15H15NO2. Calculated, %: N 5.80.
4-Amino-2,6-dimethyl-N-(4-methylbenzoyl)-
phenol (IIb). Yield 96%, mp 181–182°C. Found, %:
N 5.46, 5.63. C16H17NO2. Calculated, %: N 5.49.
4-Amino-2,6-dimethyl-N-(4-nitrobenzoyl)phenol
(IIc). Yield 87%, mp 262.5–254°C. Found, %: N 9.56,
9.80. C15H14N2O4. Calculated, %: N 9.78.
4-Amino-2,6-dimethyl-N-(4-chlorobenzoyl)-
phenol (IId). Yield 90%, mp 184–186°C. Found, %:
N 5.79, 5.01. C15H14ClNO2. Calculated, %: N 5.08.
N-Benzoyl-3,5-dimethyl-1,4-benzoquinone
monoimine (IIIa). Yield 84%, mp 84–85°C. H NMR
spectrum, δ, ppm: 2.11 br.s (6H, 2,6-Me2), 6.46 br.s (2H,
H3,5), 7.48–7.85 m (5H, Ph). Found, %: N 5.81, 5.86.
C15H13NO2. Calculated, %: N 5.85.
4-Amino-N-benzoyl-2,6-dimethyl-3-chlorophenol
(Va). Yield 96%, mp 211–212°C. Found, %: Cl 11.99,
12.45. C15H14ClNO2. Calculated, %: Cl 12.89.
1
4-Amino-2,6-dimethyl-N-(4-methylbenzoyl)-3-
chlorophenol (Vb). Yield 70%, mp 184–186°C. Found,
%: Cl 11.87, 12.08. C15H16ClNO2. Calculated, %: Cl 12.24.
3,5-Dimethyl-N-(4-methylbenzoyl)-1,4-benzo-
quinone monoimine (IIIb). Yield 90%, mp 114–115°C.
1H NMR spectrum, δ, ppm: 2.10 br.s (6H, 2,6-Me2),
2.44 s (3H, Me in 4-MeC6H4), 6.45 br.s (2H, H3,5), 7.28–
7.73 d.d (4H, 4-MeC6H4, J 8.1 Hz). Found, %: N 5.38,
5.48. C16H15NO2. Calculated, %: N 5.53.
N-Benzoyl-2,6-dimethyl-3-chloro-1,4-benzoqui-
none monoimine (VIIa). Yield 55%, mp 102–104°C.
1H NMR spectrum, δ, ppm: 1.99 d (3H, 6-Me, J 1.2 Hz),
2.27 s (3H, 2-Me), 6.75 q (1H, H5, J 1.2 Hz), 7.47–
7.94 m (5H, Ph). Found, %: Cl 12.85, 12.98. C15H12ClNO2.
Calculated, %: Cl 12.95.
4-Amino-N-benzoyl-3,5-dimethylphenol (IVa).
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HALOGENATION OF N-SUBSTITUTED para-QUINONE MONOIMINES: IX.
1659
2,6-Dimethyl-N-(4-methylbenzoyl)-3-chloro-1,4-
benzoquinone monoimine (VIIb). Yield 55%, mp 142–
144°C. 1H NMR spectrum, δ, ppm: 1.97 d (3H, 6-Me,
J 1.5 Hz), 2.26 s (3H, 2-Me), 2.44 s (3H, 4-MeC6H4),
6.74 q (1H, H5, J 1.5 Hz), 7.28–7.82 d.d (4H, 4-MeC6H4,
J 8.4 Hz). Found, %: Cl 11.94, 12.22. C16H14ClNO2.
Calculated, %: Cl 12.32.
5-Me), 2.22 s (3H, 3-Me), 7.54–7.87 m (5H, Ph).
13C NMR spectrum, δ, ppm: 18.61 (3-Me), 23.46 (5-Me),
75.05 (C5), 88.82 (C6), 128.85 (C2' ), 129.08 (C32 ), 131.81
'
(C1' ), 134.00 (C4 ), 136.01 (C2), 143.89 (C3), 155.79 (C4),
175.05 (C=O aroyl), 175.52 (C1). Found, %: Cl 37.05,
37.42. C15H11Cl4NO2. Calculated, %: Cl 37.41.
3,5-Dimethyl-4-(4-methylbenzoyl)imineO-
2,5,6,6-tetrachlorocyclohex-2-en-1-one (XXIIb).
Yield 68 %, mp 118–120°C. 1H NMR spectrum, δ, ppm:
2.19 s (3H, 5-Me), 2.21 s (3H, 3-Me), 2.44 s (3H,
4-MeC6H4), 7.30–7.77 d.d (4H, 4-MeC6H4, J 7.8 Hz).
13C NMR spectrum, δ, ppm: 18.59 (3-Me), 21.79 (4-Me'),
23.42 (5-Me), 75.25 (C5), 88.95 (C6), 128.91 (C2'), 129.15
(C1' ), 129.79 (C3'), 135.83 (C2), 144.08 (C3), 145.06
(C4'), 155.46 (C4), 175.10 (C=O aroyl), 175.55 (C1).
Found, %: Cl 35.69, 35.80. C16H13Cl4NO2. Calculated,
%: Cl 36.06.
4-Benzoylimino-2,6-dimethyl-3,5,6-trichloro-
cyclohex-2-en-1-one (XIa). Yield 79%, mp 72–73°C.
1H NMR spectrum, δ, ppm: 1.84 s (3H, 6-Me), 2.28 s
(3H, 2-Me), 4.96 s (1H, H5), 7.47–7.99 m (5H, Ph).
Found, %: Cl 30.01, 30.62. C15H12Cl3NO2. Calculated,
%: Cl 30.86.
2,6-Dimethyl-4-(4-methylbenzoyl)imino-3,5,6-
trichlorocyclohex-2-en-1-one (XIb). Yield 70%, mp
1
62–64°C. H NMR spectrum, δ, ppm: 1.83 s (3H,
6-Me), 2.29 s (3H, 2-Me), 2.43 s (3H, 4-MeC6H4),
4.96 s (1H, H5), 7.27–7.87 d.d (4H, 4-MeC6H4,
J 8.4 Hz). Found, %: Cl 29.56, 29.73. C16H14Cl3NO2.
Calculated, %: Cl 29.66.
4-Benzoylimino-5-methyl-3-chloromethyl-
2,5,6,6-tetrachlorocyclohex-2-en-1-one (XXIVa).
Yield 87%, mp 120–122°C. 1H NMR spectrum, δ, ppm:
2.10 s (3H, 5-Me), 4.70 s (2H, CH2Cl), 7.50–7.94 m (5H,
Ph). 13C NMR spectrum, δ, ppm: 23.03 (5-Me), 38.89
(CH2Cl), 73.74 (C5), 88.80 (C6), 128.85 (C22 ), 129.05
(C32 ), 131.42 (C12 ), 134.10 (C42 ), 137.49 (C2), 142.78
(C3), 151.81 (C4), 174.20 (C=O aroyl), 175.60 (C1).
Found, %: Cl 42.51, 42.77. C15H10Cl5NO2. Calculated,
%: Cl 42.87.
4-Amino-N-benzoyl-3,5-dimethyl-2-chlorophenol
(XIVa). Yield 87%, mp 249–250°C. Found, %: Cl 12.75,
12.92. C15H14ClNO2. Calculated, %: Cl 12.86.
4-Amino-3,5-dimethyl-N-(4-methylbenzoyl)-2-
chlorophenol (XIVb). Yield 51%, mp 228–230°C.
Found, %: Cl 12.03, 12.37. C16H16ClNO2. Calculated,
%: Cl 12.24.
5-Methyl-4-(4-methylbenzoyl)imino-2,5,6,6-
tetrachloro-3-chloromethylcyclohex-2-en-1-one
(XXIVb). Yield 85%, mp 79–80°C. 1H NMR spectrum,
δ, ppm: 2.09 s (3H, 5-Me), 2.45 s (3H, 4-MeC6H4),
4.69 s (2H, CH2Cl), 7.30–7.83 d.d (4H, 4-MeC6H4,
J 8.4 Hz). 13C NMR spectrum, δ, ppm: 21.79 (4'-Me),
23.45 (5-Me), 38.92 (CH2Cl), 74.06 (C5), 88.94 (C6),
128.93 (C12 ), 129.10 (C2'), 129.77 (C3'), 137.37 (C2),
142.99 (C3), 145.15 (C4'), 151.87 (C4), 174.39 (C=O
aroyl), 175.71 (C1). Found, %: Cl 41.24, 41.52.
C16H12Cl5NO2. Calculated, %: Cl 41.46.
4-Amino-N-benzoyl-3,5-dimethyl-2,6-dichloro-
phenol (XVIIIa). Yield 78%, mp 273–274°C. Found,
%: Cl 12.57, 12.80. C15H13Cl2NO2. Calculated, %: Cl 22.86.
4-Amino-N-(4-methylbenzoyl)-3,5-dimethyl-2,6-
dichlorophenol (XVIIIb). Yield 70%, mp 297–298°C.
Found, %: Cl 21.54, 21.93. C16H15Cl2NO2. Calculated,
%: Cl 21.87.
N-Benzoyl-3,5-dimethyl-2,6-dichloro-1,4-benzo-
quinone monoimine (XXa). Yield 88%, mp 140–141°C.
1H NMR spectrum, δ, ppm: 7.49–7.85 m (5H, Ph),
2.29 s (6H, 3,5-Me). Found, %: Cl 22.76, 22.94.
C15H11Cl2NO2. Calculated, %: Cl 23.01.
Bromination of N-aroyl-1,4-benzoquinone mono-
imines Ia, Ib, IIIa, IIIb, VIIIa–VIIId, XVIIa, XVIIb,
XXIa, XXIb, 4-amino-N-aroylphenols IIa–IId, IVa,
IVb, VIa, VIb, XVa, XVb, XIXa, XIXb. To a solution
of 2 mmol of the compound under study in 3 ml of CHCl3,
or AcOH, DMF, the mixture DMF–AcOH, 1:5, was
added dropwise at stirring a solution of bromine in an
appropriate solvent at the desired temperature to the
necessary ratio initial substance–bromine in the range
1:1–1:10. The precipitate was filtered off and
recrystallized from acetic acid.
3,5-Dimethyl-N-(4-methylbenzoyl)-2,6-dichloro-
1,4-benzoquinone monoimine (XXb). Yield 88%, mp
160–161°C. 1H NMR spectrum, δ, ppm: 2.28 s (6H, 3,5-
Me2). 2.45 s (3H, Me in 4-MeC6H4), 7.30–7.73 d.d (4H,
4-MeC6H4, J 8.1 Hz). Found, %: Cl 21.64, 21.93.
C16H13Cl2NO2. Calculated, %: Cl 22.01.
4-Benzoylimino-3,5-dimethyl-2,5,6,6-tetra-
chlorocyclohex-2-en-1-one (XXIIa). Yield 38%, mp
1
98.5–100°C. H NMR spectrum, δ, ppm: 2.20 s (3H,
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 11 2009

AVDEENKO et al.
1660
1
Compounds VIa–VId were obtained at the bromina-
158–159°C. H NMR spectrum, δ, ppm: 1.97 d (3H,
6-Me, J 1.5 Hz), 2.31 s (3H, 2-Me), 2.44 s (3H,
4-MeC6H4), 6.79 q (1H, H5, J 1.5 Hz), 7.28–7.83 d.d
(4H, 4-MeC6H4, J 8.4 Hz). Found, %: Br 24.02, 24.54.
C16H14BrNO2. Calculated, %: Br 24.05.
tion of quinone monoimines Ia and Ib and aminophenols
IIa–IId in CHCl3 at 30–40°C and the ratio initial sub-
stance–bromine 1:4; compounds VIIIa–VIIId, at the
bromination of quinone monoimines Ia and Ib (the ratio
initial substance–bromine 1:1) in AcOH, or the mixture
DMF–AcOH, 1:5, and aminophenols IIa–IId (the ratio
initial substance–bromine 1:2) in DMF at 30–40°C;
compounds IXa and IXb, at the bromination of quinone
monoimines Ia and Ib and aminophenols IIa and IIb in
AcOH, or the mixture DMF–AcOH, 1:5, at the ratio initial
substance–bromine 1:4 at 30–40°C; compounds Xa and
Xb, at the bromination of quinone monoimines Ia and Ib
in DMF at the ratio initial substance–bromine 1:4 at 40–
50°C; compounds XIIb–XIId, at the bromination of
quinone monoimine Ib (the ratio initial substance–bromine
1:5) in AcOH or the mixture DMF–AcOH, 1:5, of
aminophenols IIb–IId (the ratio initial substance–
bromine 1:10) in DMF, of quinone monoimines VIIIb–
VIIId (the ratio initial substance–bromine 1:3) in the
mixture DMF–AcOH, 1:5, at 30–40°C; compounds
XIIIa and XIIIb, at the bromination of aminophenols
VIa and VIb and quinone monoimines VIIIa and VIIIb
in the mixture DMF–AcOH, 1:5, at the ratio initial
substance–bromine 1:3 at 50–60°C.
3-Bromo-2,6-dimethyl-N-(4-nitrobenzoyl)-1,4-
benzoquinone monoimine (VIIIc). Yield 43%, mp
1
184–186°C. H NMR spectrum, δ, ppm: 2.02 d (3H,
6-Me, J 1.5 Hz), 2.33 s (3H, 2-Me), 6.82 q (1H, H5,
J 1.5 Hz), 8.12–8.36 d.d (4H, 4-NO2C6H4, J 9.0 Hz).
Found, %: Br 21.75, 22.04. C15H11BrN2O4. Calculated,
%: Br 22.00.
3-Bromo-2,6-dimethyl-N-(4-chlorobenzoyl)-1,4-
benzoquinone monoimine (VIIId). Yield 69%, mp
1
139–141°C. H NMR spectrum, δ, ppm: 1.99 d (3H,
6-Me, J 1.8 Hz), 2.31 s (3H, 2-Me), 6.79 q (1H, H5,
J 1.8 Hz), 7.45–7.89 d.d (4H, 4-ClC6H4, J 8.7 Hz). Found,
%: Br + Cl 32.48, 32.79. C15H11BrClNO2. Calculated,
%: Br + Cl 32.71.
4-Amino-N-benzoyl-5-bromo-6-bromomethyl-2-
methylphenol (IXa).Yield 96%, mp 201–202°C. 1H NMR
spectrum, δ, ppm: 2.21 s (3H, 2-Me), 4.85 s (2H, CH2Br),
7.25 s (1H, H3), 7.50–7.99 m (5H, Ph), 9.93 br.s (2H,
NH, OH). Found, %: Br 39.77, 39.94. C15H13Br2NO2.
Calculated, %: Br 40.04.
4-Amino-N-benzoyl-3-bromo-2,6-dimethyl-
phenol (VIa). Yield 83%, mp 211–213°C. Found, %:
Br 24.61, 24.85. C15H14BrNO2. Calculated, %: Br 24.96.
4-Amino-5-bromo-6-bromomethyl-2-methyl-N-
(4-methylbenzoyl)phenol (IXb). Yield 58%, mp 225–
226°C. Found, %: Br 38.36, 38.56. C16H15Br2NO2.
Calculated, %: Br 38.68.
4-Amino-3-bromo-2,6-dimethyl-N-(4-methyl-
benzoyl)phenol (VIb). Yield 86%, mp 196–198°C.
Found, %: Br 23.73, 23.82. C16H16BrNO2. Calculated,
%: Br 23.91.
3,5,6-Tribromo-2,6-dimethyl-4-(4-methyl-
benzoyl)-iminocyclohex-2-en-1-one (XIIb). Yield
21%, mp 110–112°C. 1H NMR spectrum, δ, ppm: 2.02 s
(3H, 6-Me), 2.35 s (3H, 2-Me), 2.44 s (3H, 4-MeC6H4),
5.23 C (1H, H5), 7.29–7.90 d.d (4H, 4-MeC6H4,
J 8.1 Hz). Found, %: Br 48.70, 48.95. C16H14Br3NO2.
Calculated, %: Br 48.72.
4-Amino-3-bromo-2,6-dimethyl-N-(4-nitro-
benzoyl)phenol (VIc). Yield 92%, mp 250–251°C.
Found, %: Br 21.78, 22.10. C15H13BrN2O4. Calculated,
%: Br 21.88.
4-Amino-3-bromo-2,6-dimethyl-N-(4-chloro-
benzoyl)phenol (VId). Yield 61%, mp 215–218°C.
Found, %: Br + Cl 32.14, 32.47. C15H13BrClNO2.
Calculated, %: Br + Cl 32.53.
3,5,6-Tribromo-2,6-dimethyl-4-(4-nitrobenzoyl)-
iminocyclohex-2-en-1-one (XIIc). Yield 43%, mp 182–
183°C. 1H NMR spectrum, δ, ppm: 2.05 d (3H, 6-Me),
2.38 s (3H, 2-Me), 5.26 s (1H, H5), 8.17–8.37 d.d (4H,
4-NO2C6H4, J 8.7 Hz). Found, %: Br 45.68, 45.91.
C15H11Br3N2O4. Calculated, %: Br 45.84.
N-Benzoyl-3-bromo-2,6-dimethyl-1,4-benzo-
quinone monoimine (VIIIa). Yield 52%, mp 84–85°C.
1H NMR spectrum, δ, ppm: 1.98 d (3H, 6-Me, J 1.5 Hz),
2.32 s (3H, 2-Me), 6.81 q (1H, H5, J 1.5 Hz), 7.47–
7.94 m (5H, Ph). Found, %: Br 25.01, 25.24.
C15H12BrNO2. Calculated, %: Br 25.11.
3,5,6-Tribromo-2,6-dimethyl-4-(4-chlorobenzo-
yl)iminocyclohex-2-en-1-one (XIId). Yield 69%, mp
1
144–146°C. H NMR spectrum, δ, ppm: 2.03 d (3H,
3-Bromo-2,6-dimethyl-N-(4-methylbenzoyl)-1,4-
benzoquinone monoimine (VIIIb). Yield 18%, mp
6-Me), 2.36 s (3H, 2-Me), 5.24 s (1H, H5), 7.46–7.95 m
(4H, 4-ClC6H4, J 8.4 Hz). Found, %: Br + Cl 53.56,
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 11 2009

HALOGENATION OF N-SUBSTITUTED para-QUINONE MONOIMINES: IX.
1661
53.71. C15H11Br3ClNO2. Calculated, %: Br + Cl 53.70.
benzoyl)iminocyclohex-2-en-1-one (XXIIIb). Yield
74%, mp 131–133°C. 1H NMR spectrum, δ, ppm: 2.08 s
(3H, 5-Me), 2.29 s (3H, 3-Me), 2.42 s (3H, 4-MeC6H4),
7.29–7.80 d.d (4H, 4-MeC6H4, J 8.1 Hz). Found, %:
Br 55.12, 55.56. C15H13Br4NO2. Calculated, %: Br 55.98.
5-Benzoyloxy-3,6-dibromo-2,6-dimethyl-
cyclohex-2-ene-1,4-dione (XIIIa). Yield 47%, mp 160–
162°C. 1H NMR spectrum, δ, ppm: 1.97 s (3H, 6-Me),
2.37 s (3H, 2-Me), 6.19 s (1H, H5), 7.44–7.98 (5H, Ph).
13C NMR spectrum, δ, ppm: 18.66 (2-Me), 23.41 (6-Me),
58.98 (C6), 77.70 (C5), 127.90 (C1' ), 128.69 (C2'), 130.03
(C3'), 134.12 (C4'), 137.71 (C3), 148.19 (C2), 164.02
(C=O aroyl), 182.20 (C4), 187.33 (C1). Found, %:
Br 38.38, 38.71. C15H12Br2O4. Calculated, %: Br 38.41.
Hydrochlorination of N-aroyl-1,4-benzoquinone
monoimines IIIa, IIIb, XVIa, XVIb. Through a solu-
tion of 0.01 mol of N-aroyl-1,4-benzoquinone monoimines
IIIa, IIIb, XVIa, XVIb in 5 ml of dry chloroform was
passed a flow of dry gaseous hydrogen chloride for 15–
20 min. The reaction mixture got clear, and a colorless
precipitate separated. The precipitate was filtered off and
recrystallized from acetic acid.
3,6-Dibromo-2,6-dimethyl-5-(4-methylbenzoyl)-
oxycyclohex-2-ene-1,4-dione (XIIIb). Yield 7%, mp
145–146°C. 1H NMR spectrum, δ, ppm: 1.95 s (3H, 6-
Me), 2.36 s (3H, 2-Me), 2.42 s (3H, 4-MeC6H4), 6.17
s (1H, H5), 7.24–7.86 d.d (4H, 4-MeC6H4), J 8.1
Hz). Found, %: Br 36.84, 36.98. C16H14Br2O4.
Calculated, %: Br 37.16.
Obtained aminophenols XIVa, XIVb, XVIIIa, XVIIIb
were identical to the chlorination products of quinone
monoimines IIIa and IIIb and of aminophenols IVa and
IVb.
4-Amino-N-benzoyl-2-bromo-3,5-dimethyl-
phenol (XVa). Yield 98%, mp 256–257°C. Found, %:
Br 24.77, 24.90. C15H14BrNO2. Calculated, %: Br 24.96.
Hydrobromination of N-aroyl-1,4-benzoquinone
monoimines IIIa, IIIb, XVIIa, XVIIb. To a solution
of 0.01 mol of N-aroyl-1,4-benzoquinone monoimines
IIIa, IIIb, XVIIa, XVIIb in 10 ml of acetic acid was
added at stirring 2 ml of 46% hydrobromic acid. The
reaction mixture got clear, and a colorless precipitate
separated. The precipitate was filtered off and
recrystallized from acetic acid.
4-Amino-2-bromo-3,5-dimethyl-N-(4-methyl-
benzoyl)phenol (XVb). Yield 59%, mp 244–246°C.
Found, %: Br 23.44, 23.81. C16H16BrNO2. Calculated,
%: Br 23.91.
4-Amino-N-benzoyl-2,6-dibromo-3,5-dimethyl-
phenol (XIXa). Yield 92%, mp 265–266°C. Found, %:
Br 39.33, 39.74. C15H13Br2NO2. Calculated, %: Br 40.04.
Obtained aminophenols XVa, XVb, XIXa, XIXb were
identical to the bromination products of quinone mono-
imine IIIa and IIIb and of aminophenols IVa and IVb.
4-Amino-2,6-dibromo-3,5-dimethyl-N-(4-
methylbenzoyl)phenol (XIXb). Yield 73%, mp 281–
282°C. Found, %: Br 38.69, 38.90. C16H15Br2NO2.
Calculated, %: Br 38.68.
N-Aroyl-1,4-benzoquinone monoimines Xa, Xb,
XVIa, XVIb, XVIIa, XVIIb were obtained by oxidation
of aminophenols IXa, IXb, XIVa, XIVb, XVa, XVb with
lead tetraacetate by procedure [12] and were recrystalliz-
ed from acetic acid.
N-Benzoyl-2,6-dibromo-3,5-dimethyl-1,4-benzo-
quinone monoimine (XXIa). Yield 85%, mp 160–
162°C. 1H NMR spectrum, δ, ppm: 2.34 s (6H, 3,5-Me2),
7.49–7.85 m (5H, Ph). Found, %: Br 40.11, 40.75.
C15H11Br2NO2. Calculated, %: Br 40.25.
N-Benzoyl-5-bromo-6-bromomethyl-2-methyl-
1,4-benzoquinone monoimine (Xa). Yield 30%, mp
1
113–115°C. H NMR spectrum, δ, ppm: 2.03 d (3H,
2-Me, J 1.5 Hz), 4.69 s (2H, CH2Br), 6.86 q (1H, H3,
J 1.5 Hz), 7.49–7.94 m (5H, Ph). Found, %: Br 39.97,
39.99. C15H11Br2NO2. Calculated, %: Br 40.25.
2,6-Dibromo-3,5-dimethyl-N-(4-methylbenzoyl)-
1,4-benzoquinone monoimine (XXIb). Yield 60%, mp
1
155–156°C. H NMR spectrum, δ, ppm: 2.33 s (6H,
3,5-Me2), 2.45 s (3H, 4-MeC6H4), 7.29–7.73 d.d (4H,
4-MeC6H4, J 8.1 Hz). Found, %: Br 38.57, 38.88.
C16H13Br2NO2. Calculated, %: Br 38.87.
5-Bromo-6-bromomethyl-2-methyl-N-(4-methyl-
benzoyl)-1,4-benzoquinone monoimine (Xb). Yield
27%, mp 124–126°C. 1H NMR spectrum, δ, ppm: 2.02 d
(3H, 2-Me, J 1.2 Hz), 2.44 s (3H, 4-MeC6H4), 4.69 s
(2H, CH2Br), 6.85 q (1H, H3, J 1.2 Hz), 7.29–7.82 d.d
(4H, 4-MeC6H4, J 8.1 Hz). Found, %: Br 38.55, 38.78.
C16H13Br2NO2. Calculated, %: Br 38.87.
4-Benzoylimino-2,5,6,6-tetrabromo-3,5-di-
methylcyclohex-2-en-1-one (XXIIIa). Yield 15%, mp
1
166–168°C. H, δ, ppm: 2.09 s (3H, 5-Me), 2.30 s (3H,
3-Me), 7.43–7.92 m (5H, Ph). Found, %: Br 56.73, 56.85.
C15H11Br4NO2. Calculated, %: Br 57.39.
N-Benzoyl-3,5-dimethyl-2-chloro-1,4-benzo-
quinone monoimine (XVIa). Yield 88%, mp 110–
2,5,6,6-Tetrabromo-3,5-dimethyl-4-(4-methyl-
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 11 2009

AVDEENKO et al.
1662
111°C. 1H NMR spectrum, δ, ppm: 2.09 d (3H, 5-Me,
J 1.5 Hz), 2.31 s (3H, 3-Me), 6.58 q (1H, H6, J 1.5 Hz),
7.49–7.85 m (5H, Ph). Found, %: Cl 12.78, 13.02.
C15H12ClNO2. Calculated, %: Cl 12.95.
Ludchenko, O.N., Zh. Org. Khim., 2008, vol. 44, p. 818.
2. Avdeenko, A.P. and Konovalova, S.A., Zh. Org. Khim.,
2006, vol. 42, 689.
3. Burmistrov, K.S. and Burmistrov, S.I., Zh. Org. Khim., 1980,
3,5-Dimethyl-N-(4-methylbenzoyl)-2-chloro-1,4-
benzoquinone monoimine (XVIb). Yield 79%, mp 85–
86°C. 1H NMR spectrum, δ, ppm: 2.08 d (3H, 5-Me,
J 1.5 Hz), 2.31 s (3H, 3-Me), 2.44 s (3H, Me in
4-MeC6H4), 6.57 q (1H, H6, J 1.5 Hz), 7.29–7.73 d.d
(4H, 4-MeC6H4, J 7.8 Hz). Found, %: Cl 12.07, 12.18.
C16H14ClNO2. Calculated, %: Cl 12.32.
vol. 16, 1487.
4. Avdeenko,A.P. and Marchenko, I.L., Zh. Org. Khim., 2001,
vol. 37, 869; Avdeenko, A.P., Marchenko, I.L., and
Konovalova, S.A., Zh. Org. Khim., 2001, 37, 82;Avdeen-
ko,A.P., Konovalova, S.A., and Ludchenko, O.N., Zh. Org.
Khim., 2006, vol. 42, 702.
5. Avdeenko,A.P., Pirozhenko, V.V., Shishkin, O.V., Shishki-
na, S.V., Konovalova, S.A., and Ludchenko, O.N., Zh. Org.
Khim., 2008, vol. 44, 547.
N-Benzoyl-2-bromo-3,5-dimethyl-1,4-benzo-
quinone monoimine (XVIIa). Yield 89%, mp 116–
118°C. 1H NMR spectrum, δ, ppm: 2.08 d (3H, 5-Me,
J 1.5 Hz), 2.38 s (3H, 3-Me), 6.62 q (1H, H6, J 1.5 Hz),
7.49–7.85 m (5H, Ph). Found, %: Br 25.15, 25.43.
C15H12BrNO2. Calculated, %: Br 25.11.
6. Zefirov, Yu.V. and Zorkii, P.M., Usp. Khim., 1989, vol. 58,
713.
7. Avdeenko,A.P. and Menafova, Yu.V., Zh. Org. Khim., 1999,
vol. 35, 902.
2-Bromo-3,5-dimethyl-N-(4-methylbenzoyl)-1,4-
benzoquinone monoimine (XVIIb). Yield 73%,
mp 100–101°C. 1H NMR spectrum, δ, ppm: 2.07 d (3H,
5-Me, J 1.5 Hz), 2.37 s (3H, 3-Me), 2.44 s (3H,
4-MeC6H4), 6.60 q (1H, H6, J 1.5 Hz), 7.28–7.73 d.d
(4H, 4-MeC6H4, J 7.8 Hz). Found, %: Br 23.76, 23.96.
C16H14BrNO2. Calculated, %: Br 24.05.
8. Burgi, H.-B. and Dunitz, J.D., Structure Correlation, VCH.
Weinheim., 1994, vol. 2, p. 741.
9. 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.
10. Blessing, R.H., Acta Crystallogr. A., 1995, vol. 51, p. 33.
11. Avdeenko, A.P., Burmistrov, K.S., Dubina, V.L., and
REFERENCES
Skripets, V.I., Ukr. Khim. Zh., 1980, vol. 46, p. 1081.
12. Adams, R. and Looker, J.H., J. Am. Chem. Soc., 1951,
1. Avdeenko, A.P., Pirozhenko, V.V., Shishkin, O.V.,
Palamarchuk, G.V., Zubatyuk, R.I., Konovalova, S.A.,
vol. 73, p. 1145.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 11 2009