Oxidation of substituted phenols with chlorine dioxide

Article abstract of DOI:10.1134/S1070428011100083

Chlorine dioxide was used to oxidize sterically hindered phenols and their derivatives (2,6-di-tert-butylphenol, 2,6-diisobornylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,6-diisobornyl-4-methylphenol, and 3,5-diisobornyl-4-hydroxybenzaldehyde) in organic solvent. Pleiades Publishing, Ltd., 2011.

Full text of DOI:10.1134/S1070428011100083

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2011, Vol. 47, No. 10, pp. 1501–1503. © Pleiades Publishing, Ltd., 2011.
Original Russian Text © I.V. Loginova, I.Yu. Chukicheva, A.V. Kuchin, 2011, published in Zhurnal Organicheskoi Khimii, 2011, Vol. 47, No. 10,
pp. 1475–1477.
Oxidation of Substituted Phenols with Chlorine Dioxide
I. V. Loginova, I. Yu. Chukicheva, and A. V. Kuchin
Institute of Chemistry, Komi Research Center, Ural Division, Russian Academy of Sciences,
ul. Pervomaiskaya 48, Syktyvkar, 167982 Russia
e-mail: loginova-iv@chemi.komisc.ru
Received February 16, 2011
Abstract—Chlorine dioxide was used to oxidize sterically hindered phenols and their derivatives (2,6-di-tert-
butylphenol, 2,6-diisobornylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,6-diisobornyl-4-methylphenol, and
3
,5-diisobornyl-4-hydroxybenzaldehyde) in organic solvent.
DOI: 10.1134/S1070428011100083
Quinone derivatives constitute important groups of
natural compounds such as dyes, pigments, antibiotics,
vitamins, etc. Plastoquinones and ubiquinones play
an important role in photosynthesis and electron
transfer precesses due to their ability to absorb visible
light [1]. Formerly, quinones were used in the manu-
facture of dyes. In recent time, the scope of application
of quinone derivatives rapidly extends. They are used
as reagents in synthesis, polymer modifiers and stabi-
lizers, and catalysts of chemical reactions. Develop-
ment of procedures for the synthesis of quinones from
sterically hindered phenols attracts interest from the
practical viewpoint.
two protons in the quinone ring (δ 6.62 ppm). Com-
pound IIb displayed in the C NMR spectrum signals
from carbon atoms in the isobornyl groups, C=C car-
1
3
bon atoms in the quinone ring resonated at δ 132.39
C
and 153.34 ppm, and signals from carbonyl carbon
atoms were located at δ 187.88 and 188.59 ppm.
C
Oxidation of 4-methyl-substituted phenols IIIa and
IIIb with ClO afforded 2,6-dialkyl-4-hydroxy-4-
2
methyl-2,5-cyclohexadien-1-ones IVa and IVb. No
chlorination products were detected in the reaction
mixtures. The spectral parameters of compound IVa
were consistent with those reported in [11]. When
phenol IIIa was oxidized in pyridine on cooling, the
substrate-to-oxidant molar ratio being 1:3, a mixture
Oxidation of phenols with various oxidants was
studied in sufficient detail [2–7]. Oxidation of phenols
with chlorine dioxide (ClO ) was studied in [8–10]; it
was shown that 2,6-disubstituted phenols are thus
oxidized to the corresponding 1,4-quinones (yield 67–
2
Scheme 1.
OH
O
R
R
R
R
ClO2
9
5%) or diphenoquinones; 2,4-disubstituted phenols
react with ClO to form 4-alkyl-p-quinols.
2
In the present work we examined oxidation of
sterically hindered phenols Ia, Ib, IIIa, and IIIb with
chlorine dioxide in pyridine on cooling or in dimethyl-
formamide at 20°C (Scheme 1). The oxidation of
O
Ia, Ib
IIa, IIb
OH
O
O
R
R
R
R
R
+
R
2
,6-di-tert-butylphenol (Ia) gave 2,6-di-tert-butylben-
ClO
2
zoquinone (IIa) [8]. By oxidation of 2,6-diisobornyl-
phenol (Ib) we obtained previously unknown 2,6-di-
isobornyl-1,4-benzoquinone (IIb). Its structure was
confirmed by IR and NMR spectroscopy. The IR spec-
O
Me
OH
Me
OH
Me
IIIa, IIIb
IVa, IVb
Va
–
1
trum of IIb contained an absorption band at 1653 cm ,
Me
Me
which is typical of carbonyl stretching vibrations in
Me
R = t-Bu (a),
(b).
1
quinones. In the H NMR spectrum of IIb we observed
signals from protons in two bicyclic substituents and
H
1
501

1
502
LOGINOVA et al.
of products was formed. It was separated by column
chromatography to isolate major product IVa and 1.5%
of 1,3-di-tert-butyl-5-hydroxy-5-methyl-7-oxabicyclo-
NMR spectra were measured on a Bruker Avance-II-
300 spectrometer at 300.17 and 75.5 MHz, respec-
tively, using CDCl as solvent. The elemental composi-
3
[
4.1.0]hept-3-en-2-one (Va). The latter was identified
tions were determined on an EA1110 automatic
CHNS-O analyzer. Thin-layer chromatography was
performed on Sorbfil plates using benzene–petroleum
ether (1:1) as eluent; spots were made visible by treat-
ment with a 5% solution of potassium permanganate.
1
by comparing its melting point and H NMR and IR
spectra with the corresponding published data [6].
The IR spectrum of newly synthesized 2,6-diiso-
bornyl-4-hydroxy-4-methyl-2,5-cyclohexadien-1-one
(
1
IVb) contained absorption bands at 3423 (OH) and
A solution of chlorine dioxide in methylene
–
1
666 cm (C=O). Protons in the cyclohexadiene ring
chloride was prepared by extraction of ClO from
2
1
of IVb resonated in the H NMR spectrum at
δ 6.64 ppm, and the carbonyl carbon signal appeared in
the C NMR spectrum at δ 185.82 ppm; the C–OH
an aqueous solution with a concentration c of 8–9 g/l,
followed by drying over MgSO4.
1
3
C
2
,6-Di-tert-butylcyclohexa-2,5-diene-1,4-dione
IIa). a. 2,6-Di-tert-butylphenol, 0.2563 g (1.24 mmol),
was dissolved in 2 ml of pyridine, and 48 ml
3.72 mmol) of a solution of ClO in methylene
signal was observed at δ 62.23 ppm.
C
(
Quinone IIb was also obtained instead of the ex-
pected carboxy derivative in the oxidation of 3,5-di-
isobornyl-4-hydroxybenzaldehyde (VI) with chlorine
dioxide (Scheme 2). The yield of IIb was 80% when
the reaction was carried out in dimethylformamide at
(
2
chloride was added under stirring at 6–10°C over
a period of 60 min. The solvent was evaporated, and
the residue was subjected to column chromatography
on silica gel using chloroform as eluent. Yield 0.1353 g
2
0°C. Presumably, the reaction is accompanied by oxi-
dative decarboxylation. Chlorine dioxide is a fairly
potent oxidant, reactions with its participation occur at
a high rate, and we failed to isolate hydroxybenzoic
acid. Quinone IIb was formed in 36% yield by oxida-
tion of VI in pyridine on cooling with the use of
(
51%), orange crystals, mp 64–65°C; published data
–1
[
8]: mp 65–66°C. IR spectrum: ν 1654 cm (C=O).
1
H NMR spectrum, δ, ppm: 1.31 s (18H, t-Bu), 6.53 s
13
(
3
(
2H, CH). C NMR spectrum, δ , ppm: 29.38 (CH ),
C
3
2
6
5.89 [C(CH ) ], 130.15 (CH), 158.04 (C , C ), 188.44
3 3
3
equiv of ClO ; the product was isolated after pro-
2
C=O), 189.31 (C=O).
longed keeping of the reaction mixture.
b. A mixture of atmospheric air and ClO (from
2
Scheme 2.
an aqueous solution containing 3.45 mmol of ClO )
2
Me
was bubbled over a period of 60 min through a solu-
tion of 0.237 g (1.15 mmol) of 2,6-di-tert-butylphenol
in 10 ml of dimethylformamide at 20°C. The mixture
was then treated with an ice water acidified with
hydrochloric acid, and the precipitate was filtered off,
washed with water, and dried. Yield 0.2187 g (86%).
Me
OH
Me
ClO2
IIb
Me
Me
Me
CHO
Compounds IIb, IVa, IVb, and Va were synthe-
sized in a similar way.
VI
2
,6-Bis(1,7,7-trimethylbicyclo[2.2.1]heptane-2-
yl)cyclohexa-2,5-diene-1,4-dione (IIb). Yield 56 (a),
4% (b); yellow crystals, mp 223–225°C. IR spectrum:
Thus oxidation with chlorine dioxide of sterically
hindered phenols having a methyl group in the para
position with respect to the OH group yields 4-hy-
droxy-4-methyl-2,5-cyclohexadien-1-ones. Phenols
having no substituent in the para position with respect
to the hydroxy group, as well as 4-hydroxybenzalde-
hyde derivative, are converted into the corresponding
7
–
1
1
ν 1653 cm (C=O). H NMR spectrum, δ, ppm: 0.77 s
6H, CH ), 0.85 s and 0.86 s (12H, CH ); 1.84–1.93 m,
.63–1.52 m, and 1.39–1.34 m (12H, CH ); 1.90–
.84 m (2H) and 3.17 t (2H, J = 9 Hz) (2′-H, 4′-H),
.62 s (2H, 3-H, 5-H). C NMR spectrum, δ , ppm:
4.45 (CH ), 19.88 (CH ), 20.05 (CH ), 27.32 (CH ),
3.42 (CH ), 39.61 (CH ), 45.09 (CH), 45.31 (CH),
5.52 (C), 51.10 (C), 132.39 (C , C ), 153.34 (C , C ),
(
3
3
1
1
6
1
3
4
2
1
3
C
1
,4-benzoquinones.
3
3
3
2
EXPERIMENTAL
2
2
3
5
2
6
The IR spectra were recorded from solutions in
carbon tetrachloride on a Shimadzu IR Prestige 21
spectrometer with Fourier transform. The H and C
187.88 (C=O), 188.59 (C=O). Found, %: C 82.02:
H 9.52; O 8.46. C H O . Calculated, %: C 82.10;
H 9.47; O 8.43.
2
6
36
2
1
13
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 47 No. 10 2011

OXIDATION OF SUBSTITUTED PHENOLS WITH CHLORINE DIOXIDE
1503
2
,6-Di-tert-butyl-4-hydroxy-4-methylcyclohexa-
,5-dien-1-one (IVa). Yield 60–63%, light yellow
powder, mp 111–113°C; published data [5]: mp 111–
6–10°C, and 10 ml (0.5 mmol) of a solution of ClO in
2
2
methylene chloride was added under stirring over
a period of 60 min. When the reaction was complete,
the mixture was washed with cold water and dried over
–
1
1
12°C. IR spectrum, ν, cm : 3273 (OH), 1660 (C=O).
H NMR spectrum, δ, ppm: 1.27 s (18H, t-Bu), 1.82 s
3H, CH ), 6.67 d (2H, CH, J = 3 Hz). C NMR spec-
1
Na SO , the solvent was evaporated under reduced
2 4
1
3
(
pressure, and the crystalline residue was washed with
3
trum, δ , ppm: 29.32 [C(CH ) ], 31.28 (CH ), 34.69
ethanol. Yield of IIb 0.0184 g (36%).
C
3 3
3
2
6
[
C(CH ) ], 62.69 (C), 141.62 (CH), 145.13 (C , C ),
3 3
b. A mixture of air and ClO (from an aqueous
2
1
84.98 (C=O).
-Hydroxy-4-methyl-2,6-bis(1,7,7-trimethylbi-
cyclo[2.2.1]heptane-2-yl)cyclohexa-2,5-dien-1-one
IVb). Yield 62–78%, light yellow powder, mp 127°C.
solution containing 0.78 mmol of ClO ) was bubbled
over a period of 60 min through a solution of 0.1046 g
2
4
(
0.26 mmol) of compound VI in 10 ml of dimethyl-
formamide maintained at 20°C. The mixture was
treated with ice water acidified with hydrochloric acid,
and the precipitate was filtered off, washed with water,
and dried. Yield of IIb 0.0801 g (80%).
(
–
1
IR spectrum, ν, cm : 3423 (OH), 1666 (C=O).
1
H NMR spectrum, δ, ppm: 0.67 s (3H, CH ), 0.69 s
3
(
3H, CH ), 078 s (6H, CH ), 0.82 s (6H, CH ), 1.24–
3 3 3
1
1
.30 m (4H, CH ), 1.35–1.41 m (2H, CH), 1.48–
2
REFERENCES
.51 m (4H, CH ), 1.73 s (3H, CH ), 1.78–1.86 m (4H,
2
3
CH ), 3.05 t (2H, CH, J = 9 Hz), 6.64 d (2H, 3-H, 5-H,
2
1
2
. Plemenkov, V.V., Vvedenie v khimiyu prirodnykh soedi-
nenii (Introduction to the Chemistry of Natural Com-
pounds), Kazan, 2001.
. Barton, D.H.R., Brewster, A.G., Ley, S.V., and Rosen-
feld, M.N., J. Chem. Soc., Chem. Commun., 1976,
p. 985.
1
3
J = 6 Hz). C NMR spectrum, δ , ppm: 13.79 (CH ),
C
3
1
3
4
1
9.51 (CH ), 21.30 (CH ), 27.40 (CH ), 30.82 (CH ),
3 3 2 3
3.10 (CH ), 39.27 (CH ), 43.68 (CH), 45.38 (CH),
2
2
2
6
8.23 (C), 49.73 (C), 62.23 (COH), 138.52 (C , C ),
3
5
43.46 (C , C ), 185.82 (C=O). Found, %: C 81.73;
H 10.12; O 8.15. C H O . Calculated, %: C 81.82;
2
7
40
2
3. Luo, H.B. and Xie, Y.Y., Chin. Chem. Lett., 2003, vol. 6,
H 10.10; O 8.08.
p. 555.
4
. Akhmadullin, R.M., Agadzhanyan, S.I., Mukmene-
va, N.A., and Akhmadullina, A.G., Vestn. Kazan.
Tekhnol. Univ., 2009, no. 2, p. 64.
1
,3-Di-tert-butyl-5-hydroxy-5-methyl-7-oxabi-
cyclo[4.1.0]hept-3-en-2-one (Va). Yield 1.5%, yellow
powder, mp 103°C; published data [6]: mp 102–
03°C. H NMR spectrum, δ, ppm: 1.15 s and 1.19 s
9H each, t-Bu), 1.34 s (3H, CH ), 2.48 s (1H, OH),
.56 d (1H, CH, J = 3 Hz), 6.09 d (1H, CH, J = 3 Hz).
C NMR spectrum, δ , ppm: 25.98 (CH ), 26.12
C(CH ) ], 29.28 [C(CH ) ], 32.31 [C(CH ) ], 34.63
C(CH ) ], 61.65 (C–O), 64.50 (C ), 68.97 (C ) 139.10
C), 143.10 (C ), 191.04 (C=O).
1
5. Kharasch, M.S. and Joshi, B.S., J. Org. Chem., 1957,
1
(
vol. 22, p. 1439.
. Nishinaga, A., Itahara, T., Shimizu, T., and Matsuura, T.,
J. Am. Chem. Soc., 1978, vol. 100, p. 1820.
3
6
7
3
1
3
C
3
. Omura, K., Synthesis, 2010, no. 2, p. 208.
[
[
(
3 3 3 3 3 3
1
5
8. Nam, K.C. and Kim, J.M., Bull. Korean Chem. Soc.,
994, vol. 15, p. 268.
3
3
1
3
9. Ganiev, I.M., Ganieva, E.S., and Kabal’nova, N.N.,
Oxidation of 4-hydroxy-3,5-bis(1,7,7-trimethyl-
Russ. Chem. Bull., Int. Ed., 2004, vol. 53, p. 2281.
bicyclo[2.2.1]heptane-2-yl)benzaldehyde (VI).
1
0. Ben Amor, H., De Laat, J., and Dore, M., Water Res.,
a. A solution of 0.0997 g (0.25 mmol) of 4-hydroxy-
1984, vol. 12, p. 1545.
3
,5-bis(1,7,7-trimethylbicyclo[2.2.1]heptane-2-yl)-
11. Nishinaga, A., Itahara, T., and Matsuura, T., Bull. Chem.
Soc. Jpn., 1975, vol. 48, p. 1683.
benzaldehyde (VI) in 5 ml of pyridine was cooled to
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 47 No. 10 2011