Synthesis of 2,4,6,8-tetrasubstituted 1,5-naphthoquinones

Article abstract of DOI:10.1007/s11178-006-0008-x

Derivatives of N-aryl-5-hydroxy-1,4-naphthoquinone 4-imines react with primary amines to afford 2,4,6,8-tetrasubstituted 1,5-naphthoquinones. 2005 Pleiades Publishing, Inc.

Full text of DOI:10.1007/s11178-006-0008-x

Russian Journal of Organic Chemistry, Vol. 41, No. 11, 2005, pp. 1619-1623. Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 11, 2005,
pp. 1653-1657.
Original Russian Text Copyright Ó 2005 by Ektova, Bukhtoyarova, Shelkovnikov.
.
Synthesis of 2,4,6,8-Tetrasubstituted 1,5-Naphthoquinones
L.V. Ektova, A.D. Bukhtoyarova, and V.V. Shelkovnikov
Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Division, Russian Academy of Sciences,
Novosibirsk, 630090 Russia (3832) 308752
e-mail: vsh@nioch.nsc.ru
Received December 28, 2004
Abstract—Derivatives of N-aryl-5-hydroxy-1,4-naphthoquinone 4-imines react with primary amines to afford
2,4,6,8-tetrasubstituted 1,5-naphthoquinones.
1,5-Naphthoquinone (ana-naphthoquinone) is an
extremely unstable compound [1].Among its known stable
derivatives 4,8-di(alkylamino)- [2] and 4,8-di-(arylamino)-
1,5-naphthoquinones [3, 4] and also 2,6-bis-
[alkyl(aryl)amino]naphthazarins [4] can be cited. The
latter were suggested for use as molecular media for
nonlinear optical materials [4, 5] and as dichroic dyes in
the liquid-crystal compositions for electrooptics of the
“guest-host” type [6]. The initial compounds in the
synthesis of these 1,5-naphthoquinone derivatives were
naphthazarin and 4,8-di(amino)-1,5-naphthoquinone [4].
afforded 2,4,6,8-tetrabutylamino- (IIa), 2,4,6,8-tetra-
heptylamino- (IIb), or 2,4,6,8-tetraphenylamino-1,5-
naphthoquinone (IIc) respectively.
+
51
2
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2
1+5
%U
51+
5+1
%U
2
15
2+ 13K
+
,,jꢀꢀꢀ,,F
,j
In extension of the research on the reactivity of
N-aryl-5-hydroxy-1,4-naphthoquinone 4-imines a new
approach is developed in the present study to the
preparation of versatile tetrasubstituted 1,5-naphtho-
quinones. The essence of the approach is based on the
fact that the possibility of existence in the 1,5-naphtho-
quinoid form is inherent to the structure of 5-hydroxy-
1,4-naphthoquinone 4-imine due to a prototropic tautomeric
rearrangement [7]. Taking into account the data on
stabilization of the ana-quinoid form by introducing
electron-donor substituents into position 8 [7], we set as
the goal of this study the preparation of 1,5-naphtho-
quinone derivatives by amination of substituted N-aryl-
5-hydroxy-1,4-naphthoquinone 4-imines.
R = n-C4H9 (a), n-C7H15 (b), Ph (c).
The reaction of 2,6-dibromo-5-hydroxy-N-phenyl-1,4-
naphthoquinone 4-imine (Ib) [7] with aniline in the
presence of an oxidant gave rise to a mixture of 6-bromo-
5-hydroxy-2-phenylamino-N-phenyl-1,4-naphthoquinone
4-imine (III) and 2,6-dibromo-4,8-di(phenylamino)-1,5-
naphthoquinone (IV).
2
2
1+3K
%U
3K1+
>2@
%U
%U
N-Aryl-5-hydroxy-1,4-naphthoquinone 4-imines in
contrast to N-aryl-1,4-naphthoquinone imine lacking the
hydroxy group react with arylamines at both rings of the
naphthoquinone imine [8].
2+ 13K
2+ 13K
,E
,,,
+
3K1
2
%U
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We found that 2,6,8-tribromo-5-hydroxy-N-phenyl-1,4-
naphthoquinone 4-imine (Ia) prepared formerly from
2,4,6,8-tetrabromo-1,5-dihydroxynaphthalene [9] at boiling
with n-butylamine or n-heptylamine in ethanol under basic
catalysis (in the presence of K2CO3) or with excess aniline
%U
2
13K
+
,9
1070-4280/05/4111-1619Ó2005 Pleiades Publishing, Inc.

EKTOVA et al.
1620
2,6-Di(butylamino)- (Va) and 2,6-di(heptylamino)-4,8-
quinones VIIIa and VIIIc having in positions 2 and 6
di(phenylamino)-1,5-naphthoquinone (Vb) were obtained
by replacement of bromine in 2,6-dibromo-4,8-di-(phenyl-
amino)-1,5-naphthoquinone (IV) by n-alkylamino groups.
electron-withdrawing substituents SO2Ar.
The structure of compounds obtained was established
from spectral and analytical data. In the mass spectra of
compounds synthesized strong molecular ions peaks were
registered with m/z values corresponding to the calculated
ones. In the IR spectra of 1,5-naphthoquinones obtained
the absorption bands of stretching vibrations of the C=O
groups are strongly displaced to the low frequency region
–1
(1620–1580 cm ) in keeping with the characteristic
pattern for the carbonyl groups located in different rings
of a fused system [3, 12]. In the 1H NMR spectra of the
1,5-naphthoquinone derivatives the proton signals from
NH groups attached to positions 4 and 8 appear downfield
(12.16–14.45 ppm) due to formation of strong hydrogen
bonds as has been also observed in the spectra of the
described 4,8-di[alkyl(aryl)amino]-1,5-naphthoquinones
[2, 3] whereas the proton signals from the NHR groups
in the 2 and 6 positions are observed at 6.60–8.40 ppm
R = n-C4H9 (a), n-C7H15 (b).
Previously N-aryl-2,6,8-tri(4-tert-butylphenylthio)-5-
hydroxy-1,4-naphthoquinone 4-imines VIa and VIb were
reacted with aniline to obtain 2,6-di(4-tert-butyl-
phenylthio)-4,8-di(phenylamino)-1,5-naphthoquinone
(VIIa) [10].
The study of 4,8-di(alkylamino)-1,5-naphthaquinones
tautomerism by means of 1H [2, 3, 7] and 13C [13] NMR
spectroscopy revealed that these compounds exist in the
ana-quinoid and not in the ana-quinone imine form.
+
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5ꢀ1
2
6$U
6$U
The electron absorption spectra of 2,4,6,8-tetrasub-
stituted 1,5-naphthoquinone derivatives like those describ-
ed for 4,8-diamino-1,5-naphthoquinones [2, 3] contain in
the visible region a strong absorption band with a pronounc-
ed vibronic structure. Depending on the character of the
substituents the position of the strongest absorption
maximum varies from 577 nm for 2,4,6,8-tetraalkylamino-
1,5-naphthoquinones IIa and IIb to 763 nm for 4,8-di-
(arylamino)-2,6-di(4-tert-butylphenyl-sulfonyl)-1,5-
naphthoquinone (VIIIc). The comparison with the
spectra of 4,8-di(methylamino)-1,5-naphtho-quinone (lmax
606, 657 nm [2]) and 4,8-di(phenylamino)-1,5-naphtho-
quinone (lmax 625, 667 nm [3]) showed that introduction
of the electron-donor substituents (NHAlk) into positions
2 and 6 resulted in a blue shift of the long-wave absorption
band accompanied with growing intensity, whereas the
electron-acceptor groups ArSO2 exerted the opposite
influence. The presence in positions 2 and 6 bromine
atoms or 4-tert-butylphenylthio groups possessing –I and
+M-effects caused the red shift of lmax with the
simultaneous increase in the intensity of the absorption
band.
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2+ 15
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9,,jꢂꢀ9,,Fꢂꢀ9,,G
9,jꢀꢀꢀ9,F
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9,,,jꢂꢀ9,,,F
Ar = 4-(CH3)3CC6H4, R = Ph (a), 4-Et2NC6H4 (b),
4-C4H9OC6H4 (c); R' = Ph (a), 4-C4H9OC6H4 (c),
4-C6H13C6H4 (d).
Similarly from compounds VIb and VIc with 4-butoxy-
aniline and 4-hexylaniline were obtained the correspond-
ing 4,8-di(arylamino)-1,5-naphthoquinones VIIc and VIId
containing two arylthio groups in the positions 2 and 6.
In the electron absorption spectra of compound Va
registered in solvents of different polarity (CCl4, CHCl3,
and EtOH) a negative solvatochromism of the long-wave
absorption band was observed, similar to that described
for 4,8-diamino derivatives of 1,5-naphthoquinone [2, 3].
The oxidation of arylthio groups in 4,8-di(arylamino)-
2,6-di(4-tert-butylphenylthio)-1,5-naphthoquinones VIIa
and VIIc with m-chloroperbenzoic acid in chloroform by
procedure [11] afforded tetrasubstituted 1,5-naphtho-
RUSSIAN JOURNALOF ORGANIC CHEMISTRY Vol. 41 No. 11 2005

SYNTHESIS OF 2,4,6,8-TETRASUBSTITUTED 1,5-NAPHTHOQUINONES
1621
Compounds IIc, IV, VIIa, VIIc, and VIId were tested
as dichroic dyes in the liquid-crystal composites [14]. It
was shown that the introduction of 4-tert-butylphenylthio
groups into positions 2 and 6 of 4,8-di(arylamino)-1,5-
naphthoquinones (compounds VIIa, VIIc, and VIId)
resulted in increased value of the order parameter S and
increased contrast of the composites.
5.56 s (2H, H3,7), 6.60 br.s (2H, 2NH), 12.22 br.s (2H,
2NH). Electronic spectrum (CHCl3), lmax, nm (log e):
400 (4.30), 546 (4.08), 577 (4.38). Found: [M]+ 442.33075.
C26H42N4O2. Calculated: M 442.33076.
2,4,6,8-Tetraheptylamino-1,5-naphthoquinone
(IIb). Yield 57%, mp 130–131°C (benzene–heptane, 1:5).
–1
IR spectrum, n, cm : 1604 (C=O), 2852, 2919, 2955
1
Thus the amination of derivatives of N-aryl-5-hydroxy-
1,4-naphthoquinone 4-imines provided a possibility to go
from compounds with the para-quinoid structure to the
derivatives with the ana-quinoid structure.
(CH), 3276 (NH). H NMR spectrum, d, ppm: 0.86 t
(12H, 4CH3), 1.05–1.51 m (32H, 16CH2), 1.52–2.00 m
(8H, 4CH2), 3.19 m (4H, 2CH2), 3.36 m (4H, 2CH2),
5.53 s (2H, H3,7), 6.60 br.s (2H, 2NH), 12.16 br.s (2H,
2NH). Electronic spectrum (CHCl3), lmax, nm (log e):
400 (4.35), 536 (4.15), 577 (4.42). Found: [M]+ 610.51835.
C38H66N4O2. Calculated: M 610.51855.
EXPERIMENTAL
IR spectra were recorded on spectrophotometers UR-
20 and Vector- 22 from samples pelletized with KBr, the
electron absorption spectra in the visible region were
measured on spectrophotometers Hewlett Packard 4853
and Beckmann DU-8. 1H NMR spectra were registered
on spectrometers Bruker WP-200 SY and AM-400 in
CDCl3. Molecular mass and elemental composition of
compounds was determined from the precision
measurement of molecular ions mass on Finnigan MAT
8200 and FinniganAEI MS-900 instruments.
Synthesis of 2,4,6,8-tetraphenylamino-1,5-
naphthoquinone (IIc). A mixture of 0.5 mmol of
compound Ia and 1 mmol of aniline was heated at 150°C
for 0.5 h. The reaction mixture was poured into water
and neutralized with 5% HCl, the precipitate was filtered
off, washed with water, dried, and subjected to
chromatography on a column packed with SiO2, eluent
CHCl3. Yield 73%, mp 303–304°C (benzene). IR
–1
spectrum, n, cm : 1620 (C=O), 3030, 3060 (=CH), 3230
(NH). 1H NMR spectrum, d, ppm: 6.86 s (2H, H3,7),
7.07–7.43 m (10H, 2C6H5), 8.40 s (2H, 2NH), 13.97 s
(2H, 2NH). Electronic spectrum (CHCl3), lmax, nm
(log e): 445 (4.62), 581 (4.49), 624 (4.64). Found: [M]+
522.20654. C34H26N4O2. Calculated: M 522.20556.
Initial 2,6,8-tribromo-5-hydroxy-N-phenyl-1,4-naphtho-
quinone 4-imine (Ia) and 2,6-dibromo-5-hydroxy-N-
phenyl-1,4-naphthoquinone 4-imine (Ib) were obtained
as described in [7], 2,6,8-tribromo-N-(4-butoxyphenyl)-
5-hydroxy-1,4-naphthoquinone 4-imine (Ic) was prepared
by procedure from [9].
Reaction of 2,6-dibromo-5-hydroxy-N-phenyl-
1,4-naphthoquinone 4-imine (Ib) with aniline in the
presence of Na2S2O8. To a dispersion of 1 mmol of
compound Ib and 10 mmol of aniline in 200 ml of EtOH
was added dropwise at stirring a solution of 2 mmol of
Na2S2O8 in 20 ml of water, and the mixture was kept at
20°C for 7 days with intermittent stirring. The reaction
mixture was poured into water and neutralized with 5%
HCl, the precipitate was filtered off, washed with water,
dried, then it was dissolved in CHCl3 and subjected to
chromatography on plates with SiO2, eluent CCl4–CHCl3,
1:1. From the brown zone initial compound Ib was
isolated. Yield 5%. From the green zone was isolated
2,6-dibromo-4,8-di(phenylamino)-1,5-naphtho-
quinone (IV). Yield 24%, mp 324–325°C (benzene). IR
The monitoring of reaction progress and the checking
of the products purity was carried out by TLC on Silufol
plates, eluent CHCl3.
Synthesis of 2,4,6,8-tetraalkylamino-1,5-
naphthoquinones IIa and IIb. A mixture of 0.5 mmol
of 2,6,8-tribromo-5-hydroxy-N-phenyl-1,4-naphtho-
quinone 4-imine (Ia), 2 mmol of n-butylamine or n-heptyl-
amine, 0.2 g of K2CO3, and 40 ml of EtOH was heated
at reflux for 20 h. The reaction mixture was poured into
water and neutralized with 5% HCl, the precipitate was
filtered off, washed with water, dried, and subjected to
chromatography on a column packed with Al2O3, eluent
CCl4.
–1
1
2,4,6,8-Tetrabutylamino-1,5-naphthoquinone
spectrum, n, cm : 1577 (C=O). H NMR spectrum, d,
ppm: 7.24–7.50 m (10H, 2 C6H5), 7.94 s (2H, H3,7),
(IIa). Yield 68%, mp 131–135°C (benzene–heptane, 1:5).
–1
14.43 s (2H, 2NH). Electronic spectrum (CHCl3), lmax
,
IR spectrum, n, cm : 1605 (C=O), 2857, 2870, 2924,
nm (lge): 641 (4.49), 686 (4.69). Found: [M]+ 495.94225.
C22H14N2O2Br2. Calculated: M 495.94230. From the
violet zone was isolated 2-anilino-6-bromo-5-hydroxy-
1
2952 (CH), 3288 (NH). H NMR spectrum, d, ppm:
0.96 t (12H, 4CH3), 1.45–1.52 m (8H, 4CH2), 1.68–1.74
m (8H, 4CH2), 3.21 m (4H, 2CH2), 3.39 m (4H, 2CH2),
RUSSIAN JOURNALOF ORGANIC CHEMISTRY Vol. 41 No. 11 2005

EKTOVA et al.
1622
N-phenyl-1,4-naphthoquinone 4-imine (III). Yield
59%, mp 259–260°C (chloroform).
3.87 t (2H, CH2), 6.45 s (1H, H3(7)), 6.68 s (1H, H7(3)),
6.73 d (2H, Harom, JO 9.0 Hz), 6.87 d (2H, Harom
JO 9.0 Hz), 7.12–7.29 m (8H, Harom), 7.38 C (4H, Harom),
16.53 br.s (1H, OH). Electronic spectrum (CHCl3), lmax
nm (log e): 451 (4.60), 600 (4.61), 641 (4.62), 699 (4.63).
Found, %: C 73.99; H 6.65; N 1.70; S 11.96.
C50H55NO3S3. Calculated, %: C 73.80; H 6.76; N 1.72;
S 11.82.
,
Synthesis of 2,6-di(alkylamino)-4,8-di(phenyl-
amino)-1,5-naphthoquinones Va and Vb. A mixture
of 0.3 mmol of 2,6-dibromo-4,8-di(phenylamino)-1,5-
naphthoquinone (IV) and 1.5 mmol of n-butylamine or
n-heptylamine in 30 ml of EtOH was heated at reflux for
15 h. The reaction mixture was evaporated to the half of
its volume, then it was poured into water, the precipitate
was filtered off, washed with water, dried, and subjected
to column chromatography onAl2O3, eluent CCl4–CHCl3,
1:1.
,
Synthesis of 2,6-di(4-tert-butylphenylthio)-4,8-di-
(4-butoxyphenylamino)-1,5-naphthoquinone (VIIc).
A mixture of 0.25 mmol of compound VIc and 0.50 mmol
of 4-butoxyphenylamine in 5 ml of pyridine was heated
at 120°C for 24 h. The reaction mixture was cooled,
poured into water, neutralized with 5% HCl, the precipitate
was filtered off, washed with water, dried, and subjected
to chromatography on a column packed with SiO2, eluent
benzene. Yield 43%, mp 310–311°C (benzene–hexane,
2,6-Di(butylamino)-4,8-di(phenylamino)-1,5-
naphthoquinone (Va). Yield 62%, mp 221–223°C
–1
(benzene). IR spectrum, n, cm : 1605 (C=O), 2869, 2939,
1
2955 (CH), 3037, 3060 (=CH), 3277 (NH). H NMR
spectrum, d, ppm: 0.89 t (6H, 2CH3), 1.30–1.48 m (4H,
2CH2), 1.52–1.66 m (4H, 2CH2), 3.09 m (4H, 2CH2),
6.03 s (2H, H3,7), 6.61 t (2H, 2NH), 7.19–7.45 m (10H,
–1
1:5). IR spectrum, n, cm : 1230 (C–O–), 1580 (C=C),
1
1600 (C=O), 2950 (CH). H NMR spectrum, d, ppm:
1.01 t (6H, 2CH3, J 7.0 Hz), 1.30 s (18H, 6CH3), 1.45–
2C6H5), 13.99 br.s (2H, 2NH). Electronic spectrum, lmax
,
1.57 m (4H, 2CH2), 1.70–1.84 m (4H, 2CH2), 3.91 t (4H,
nm (lge) (CCl4): 412 (4.14), 550 (4.12), 598 (4.40);
(CHCl3): 416 (4.31), 550 (4.20), 592 (4.48); (EtOH): 415
(4.23), 550 (4.19), 584 (4.42). Found: [M]+ 482.26811.
C30H34N4O2. Calculated: M 482.26816.
2CH2, J 7.0 Hz), 6.54 s (2H, H3,7), 6.76 d (4H, Harom
,
JO 10.0 Hz), 6.96 d (4H, Harom, JO 10.0 Hz), 7.43 br.s
(8H, Harom), 14.02 s (2H, 2NH). Electronic spectrum
(CHCl3), lmax, nm (log e): 449 (4.16), 640 (4.28), 709
(4.51). Found, %: C 73.82; H 6.99; N 3.50; S 7.90.
C50H56N2O4S2. Calculated, %: C 73.89; H 6.90; N 3.45;
S 7.88.
2,6-Di(heptylamino)-4,8-di(phenylamino)-1,5-
naphthoquinone (Vb). Yield 67%, mp 213–215°C
–1
(benzene). IR spectrum, n, cm : 1607 (C=O), 2870, 2930,
1
2950 (CH), 3030, 3060 (=CH), 3280 (NH). H NMR
Synthesis of 2,6-di(4-tert-butylphenylthio)-4,8-di-
(4-hexylphenylamino)-1,5-naphthoquinone (VIId).
A mixture of 0.5 mmol of compound VIb and 3 ml of
4-hexylaniline was heated at 150°C for 2.5 h. The reaction
mixture was worked up as described above. Yield 40%,
spectrum, d, ppm: 0.86 t (6H, 2CH3), 1.18–1.42 m (16H,
8CH2), 1.52–1.69 m (4H, 2CH2), 3.08 m (4H, 2CH2),
6.03 s (2H, H3,7), 6.63 t (2H, 2NH), 7.16–7.45 m (10H,
2C6H5), 13.95 br.s (2H, 2NH). Electronic spectrum
(CHCl3), lmax, nm (lge): 419 (4.36), 560 (4.28), 592 (4.51).
Found: [M]+ 566.36213. C36H46N4O2. Calculated:
M 566.36206.
–1
mp 284–286°C (benzene). IR spectrum, n, cm : 1604
(C=O). 1H NMR spectrum, d, ppm: 0.89 t (6H, 2CH3,
J 7.0 Hz), 1.30 m (34H, 6CH3, 8CH2), 2.49 t (4H, 2CH2,
Synthesis of 2,6,8-tri(4-tert-butylphenylthio)-N-
(4-butoxyphenyl)-5-hydroxy-1,4-naphthoquinone 4-
imine (VIc). A mixture of 0.5 mmol of 2,6,8-tribromo-
N-(4-butoxyphenyl)-5-hydroxy-1,4-naphthoquinone
4-imine (Ic) and 6 mmol of 4-tert-butylthiophenol in 5 ml
of pyridine was stirred at 20°C for 45 min. The reaction
mixture was poured on ice, the separated precipitate was
filtered off, washed with water, dried, and subjected to
column chromatography on SiO2, eluent benzene. Yield
47%, mp 199–200°C (benzene–hexane, 1:5). IR spec-
J 7.0 Hz), 6.73 s (2H, H3,7), 6.85 d (4H, Harom
,
JO 8.0 Hz), 7.04 d (4H, Harom, JO 8.0 Hz), 7.41 d (4H,
Harom, JO 8.0 Hz), 7.55 d (4H, Harom, JO 8.0 Hz), 14.26 s
(2H, 2NH). Electronic spectrum (CHCl3), lmax, nm
(log e): 431 (4.05), 629 (4.28), 680 (4.50). Found, %:
C 77.51; H 7.71; N 3.19; S 8.02. C54H64N2O2S2.
Calculated, %: C 78.41; H 6.58; N 3.38; S 7.75.
Synthesis of 4,8-di(arylamino)-2,6-di(4-tert-butyl-
phenylsulfonyl)-1,5-naphthoquinones VIIIa and
VIIIc. To a solution of 0.25 mmol of 4,8-di(arylamino)-
2,6-(4-tert-butylphenylthio)-1,5-naphthoquinone VIIa or
VIIc in 20 ml of CHCl3 was added dropwise a solution
of 1.5 mmol m-chloroperbenzoic acid in 20 ml of CHCl3,
–1
trum, n, cm : 1246 (C–O–), 1583 (C=N), 1605 (C=O),
3431 (OH). 1H NMR spectrum, d, ppm: 0.98 t (3H,
CH3), 1.27 s (9H, 3CH3), 1.31 s (9H, 3CH3), 1.36 s (9H,
3CH3), 1.44–1.53 m (2H, CH2), 1.70–1.78 m (2H, CH2),
RUSSIAN JOURNALOF ORGANIC CHEMISTRY Vol. 41 No. 11 2005

SYNTHESIS OF 2,4,6,8-TETRASUBSTITUTED 1,5-NAPHTHOQUINONES
1623
and the mixture was stirred for 3 h at room temperature.
The reaction mixture was washed in a separatory funnel
with 40 ml of saturated solution of NaHCO3, then twice
with 40 ml portions of distilled water, dried with CaCl2,
the solvent was evaporated, and the residue was subjected
to column chromatography on SiO2, eluent chloroform.
The study was carried out under the financial support
of the Russian Foundation for Basic Research (grant no.
03-333-3336), Integration Project of the Siberian Division
of the RussianAcademy of Sciences no. 84, and Program
of the Russian Academy of Sciences no. 8-3.
REFERENCES
2,6-Di(4-tert-butylphenylsulfonyl)-4,8-di-
(phenylamino)-1,5-naphthoquinone (VIIIa). Yield
38%, did not melt till 360°C (benzene). IR spectrum, n,
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1976, p. 1560.
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Nishimura, A., Nonlinear Optics, 1995, vol. 10, p. 109.
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7. Ektova, L.V., Bukhtoyarova, A.D., and Petrenko, O.P., Izv.
Akad. Nauk, Ser. Khim., 1997, p. 358.
–1
cm : 1160, 1340 (SO2), 1580 (C=C), 1590 (C=O), 2970
1
(CH). H NMR spectrum, d, ppm: 1.29 s (18H, 6CH3),
7.26 d (4H, Harom, JO 8.0 Hz), 7.44–7.56 m (10H, 2C6H5),
7.96 d (4H, Harom, JO 8.0 Hz), 8.49 s (2H, H3,7), 14.30
br.s (2H, 2NH). Electronic spectrum (CHCl3), lmax, nm
(log e): 379 (3.80), 670 (4.01), 744 (4.24). Found, %:
N 3.56; S 8.78. C42H40N2O6S2. Calculated, %: N 3.83;
S 8.75.
2,6-Di(4-tert-butylphenylsulfonyl)-4,8-di(4-
butoxyphenylamino)-1,5-naphthoquinone (VIIIc).
Yield 46%, did not melt till 360°C (benzene). IR spectrum,
8. Ektova, L.V. and Fokin, E.P., Zh. Org. Khim., 1984, vol. 20,
p. 805.
–1
n, cm : 1150, 1340 (SO2), 1590 (C=C), 1600 (C=O),
9. Bukhtoyarova,A.D., Ektova, L.V.,Alekseev, S.N., and Bere-
govaya, I.V., Zh. Org. Khim., 2003, vol. 39, p. 1382.
10. Ektova, L.V. and Bukhtoyarova, A.D., Sib. Khim. Zh. (Izv.
Sib. Otd. Akad. Nauk SSSR), 1993, p. 105.
11. Iwao, M. and Kuraishi, T., Bull. Chem. Soc. Jpn., 1987,
vol. 60, p. 4051.
12. Merian, E., Chim., 1959, vol. 13, p. 181.
13. Bukhtoyarova, A.D., Ektova, L.V., Shakirov, M.M., and
Berezhnaya, V.N., Zh. Org. Khim., 2002, vol. 38, p. 894.
14. Zharkova, G.M., Strel’tsov, S.A., Khachaturyan, V.M.,
Ektova, L.V., Bukhtoyarova, A.D., and Gerasimova, T.N.,
Zh. Strukt. Khim., 1997, vol. 38, p. 808.
2960 (CH). 1H NMR spectrum, d, ppm: 0.80 t (6H, 2CH3),
0.95 s (18H, 6CH3), 1.17–1.30 m (4H, 2CH2), 1.37–
1.60 m (4H, 2CH2), 3.46 t (4H, 2CH2, J 6.0 Hz), 6.61 d
(4H, Harom, JO 8.0 Hz), 6.79 d (4H, Harom, JO 8.0 Hz),
7.12 d (4H, Harom, JO 8.0 Hz), 8.19 d (4H, Harom
,
JO 8.0 Hz), 8.64 s (2H, H3,7), 14.45 s (2H, 2NH).
Electronic spectrum (CHCl3), lmax, nm (log e): 433 (3.73),
680 (3.88), 763 (4.27). Found, %: C 68.21; H 6.37;
N 3.05; S 7.40. C50H56N2O8S2. Calculated, %: C 68.49;
H 6.39; N 3.21; S 7.31.
RUSSIAN JOURNALOF ORGANIC CHEMISTRY Vol. 41 No. 11 2005