The reaction of phenol with 1-methylcycloalkenes in the presence of phosphorus-containing zeolite y

Article abstract of DOI:10.1134/S0965544107060059

The results of cycloalkylation of phenol with 1-methylcyclopentene and 1-methylcyclohexene in the presence of phosphoric acid-impregnated zeolite are presented. Optimal conditions for the synthesis of 4(1-methylcycloalkyl)phenols were found. It was shown

Full text of DOI:10.1134/S0965544107060059

ISSN 0965-5441, Petroleum Chemistry, 2007, Vol. 47, No. 6, pp. 409–411. © Pleiades Publishing, Ltd., 2007.
Original Russian Text © Ch.K. Rasulov, A.G. Azizov, L.B. Zeinalova, R.K. Azimova, S.I. Abasova, A.A. Rashidova, 2007, published in Neftekhimiya, 2007, Vol. 47, No. 6, pp. 442–444.
The Reaction of Phenol with 1-Methylcycloalkenes
in the Presence of Phosphorus-containing Zeolite Y
Ch. K. Rasulov, A. G. Azizov, L. B. Zeinalova, R. K. Azimova, S. I. Abasova, and A. A. Rashidova
Institute of Petrochemical Processes, National Academy of Sciences of Azerbaijan, Baku, Azerbaijan
e-mail: ipcp@baku-az.net
Received February 7, 2007
Abstract—The results of cycloalkylation of phenol with 1-methylcyclopentene and 1-methylcyclohexene in
the presence of phosphoric acid-impregnated zeolite are presented. Optimal conditions for the synthesis of
4(1-methylcycloalkyl)phenols were found. It was shown that the yield of the desired products under the optimal
conditions is 86.4–89.6% of the theoretical value. The structure of 4(1-methylcycloalkyl)phenols was estab-
lished by means of spectral and chemical analysis techniques.
DOI: 10.1134/S0965544107060059
Cycloalkylation of phenols with cyclic compounds of hot filtration (40–50°C) and subjected to fractional
in the presence of acetic acid, sulfuric acid, boron trif-
luoride, aluminum chloride, or the KU-2 or KU-23 ion
exchange resin as a catalyst is characterized by a low
yield of the desired product, the multistage character of
the process, and the toxicity of the catalysts, in addition
to other disadvantages [1–8].
distillation. First, unreacted methylcyclene was dis-
tilled off at atmospheric pressure; then, unreacted phe-
nol and the desired product were collected under vac-
uum (10 mm Hg). The purity of the substances was
determined by measuring their physicochemical
parameters, and the structure was confirmed by spectral
data.
In this paper, we report the results of cycloalkylation
of phenol with 1-methylcyclopentene (1-MCP) and
1-methylcyclohexene (1-MCH) catalyzed by zeolite Y
impregnated with phosphoric acid (zeolite-P).
The chromatographic analysis of the alkylate was
performed on an LKhM-72 gas chromatograph with a
thermal conductivity detector. The column length was
2 m; the solid support was Chromaton N-AW DMC
(acid washed, silanized with dimethylchlorosilane),
0.2 0.25 mm fraction; and the stationary phase was
5% SE-30 (methylsiloxane elastomer). The initial col-
umn temperature was 50°C; the final temperature,
280°C; the temperature programming rate, 10°C/min;
the carrier-gas (helium) flow rate, 50 ml/min; the evap-
orator temperature, 355°C; and the detector tempera-
ture, 300°C. The internal standard method based on set-
ting zero the total sum of peak areas was used for cal-
culation.
EXPERIMENTAL
To prepare 4(1-methylcycloalkyl)phenols, freshly
distilled reagent-grade phenol; 98% pure 1-methylcy-
clopentene with bp 74–75.5°C, n2D0 1.4347, and ρ420
0.7782; and 98.8% pure 1-methylcyclohexene with bp
110–111°C, nD20 1.4500 and ρ240 0.8200 were used.
The orthophosphoric acid-based catalyst used in the
cycloaddition reaction of phenol with methylcyclenes
was prepared via thorough mixing alumina gel with a
cracking catalyst (zeoliteY, SiO2 : Al2O3 = 4 : 8; degree
of ion exchange, 97%). The resulting material was
shaped by forcing through a die (1.6 mm in diameter),
pelletized, and calcined. Then, the catalyst was impreg-
nated with 10% orthophosphoric acid (on P2O5 basis),
heated to evaporate water, dried in an oven at 100°C,
and calcined with a continuous temperature rise from
200 to 600°C.
Infrared spectra were recorded on an UR-20 spec-
trophotometer, and proton NMR spectra were mea-
sured with a Varian T-60 instrument in CCl4 using tet-
ramethylsilane as an internal standard.
RESULTS AND DISCUSSION
The reaction of phenol with 1-methylcyclopentene
and 1-methylcyclohexene in the presence of the cata-
The product was separated from the catalyst by means lyst zeolite-P yields 4(1-methylcycloalkyl)phenols:
The cycloaddition reaction of phenol with methyl-
cyclenes was carried out in a laboratory batch reactor.
409

410
RASULOV et al.
CH3
CH3
H3C
H3C
OH
HO
+
HO
To find optimal conditions that ensure the maximal tyl)phenol from 47.5 to 86.4% is observed during the
yield of 4(1-methylcycloalkyl)phenols, we studied the first three hours of the reaction; then, the yields drops to
influence of temperature, reaction time, the phenol to 76.6%. The decline in the yield indicates that a long res-
1-methylcycloalkene mole ratio, and the amount of the idence of para-substituted phenol in the reaction zone
catalyst on the yield and composition of the products.
creates conditions for the introduction of another
cyclene molecule to form the di- and trisubstituted
product, a fact that is corroborated by experimental
data. The yield of 4(1-methylcyclopentyl)phenol was
86.4% at the 1 : 1 phenol : 1-MCP molar ratio; an
increase in the amount of phenol or cyclene did not pro-
duce a favorable effect and the yield remained at the
same level. The study of the dependence of the yield of
the cycloalkylation product on the amount of the cata-
lyst showed that the use of the catalyst at the 10 wt %
(of phenol mass) level is optimal; even a considerable
increase in the amount of the catalyst had no substantial
effect on the yield of the product.
The reaction temperature was varied from 60 to
130°C; the reaction time, from 2 to 6 h; the phenol :
1-methycycloalkene molar ratio, from 2 : 1 to 1 : 2; and
the amount of the catalyst, from 5 to 20 wt % (of feed-
stock mass). The figure shows the results of experi-
ments on the alkylation of phenol with 1-methylcyclo-
pentene in the presence of the zeolite-P catalyst. At a
temperature of 80°C, the highest yield of 4(1-methylcy-
clopentyl)phenol, 86.4%, is reached; an increase in
temperature to 100°C leads to a decrease in the product
yield to 79.3%. As the reaction time increases from 2 to
5 h, an increase in the yield of 4(1-methylcyclopen-
Thus, the optimal conditions for the preparation of
4(1-methylcyclopentyl)phenol are the reaction temper-
ature of 80°C, the reaction time of 3 h, the phenol :
1-MCP molar ratio of 1 : 1, and the amount of the cat-
alyst of 10% (of mass of phenol fed); the yield of the
desired product is 86.4% (of theoretical value).
Yield, %
3
80
Similar results were obtained for 4(1-methylcyclo-
hexyl)phenol; under the optimal conditions, the yield of
4(1-methylcyclohexyl)phenol was 89.6 of the theoreti-
cal yield. The physicochemical characteristics of
4(1-methylcycloalkyl)phenols are given in the table.
2
1
4
70
60
The products were identified by means of 1H NMR
1
and IR spectroscopy. The H NMR spectrum of
4(1-methylcyclopentyl)phenol displays a singlet due to
CH3 group at 1.22 ppm; a broad singlet due to the satu-
rated hydrocarbon ring (δ 1.77 ppm); a singlet in the
OH region at 5–6 ppm, which is shifted upfield by dilu-
tion; and a multiplet of the 1,4-disubstituted benzene
ring, which approximately resembles a type AB spec-
trum with an average chemical shift of 6.87 ppm and a
coupling constant of ν = 8.5 0.5 Hz. The intensity
ratio of these four signals is 3 : 8 : 1 : 4, respectively.
50
60
2
80
4
100
120
Temperature, °ë
6
8
Time, h
The IR spectrum of 4(1-methylcyclopentyl)phenol
contains absorption bands at 825, 1240, 1510, and
1592–1610 cm–1 characteristic of the para-substituted
benzene ring and a band at 3220 cm–1 (associated OH
group).
2:1
1:1
1:2
Phenol : 1-MCP ratio, mol/mol
5
10
20
Amount of catalyst, %
The gem-substituted five-membered cycle is charac-
terized by absorption bands at 2920 and 1859 cm–1
(stretching vibrations of OH groups) and 1440 cm–1
Yield of 4(1-methylcyclopentyl)phenol depending on
(1) temperature, (2) reaction time, (3) reactants ratio, and
(4) amount of catalyst.
PETROLEUM CHEMISTRY Vol. 47 No. 6 2007

THE REACTION OF PHENOL
Physicochemical characteristics of 4(1-methylcycloalkyl)phenols
411
Elemental composition, %
Molecular mass
Structural formula
Bp, °C/10 mm Hg
Mp, °C
calculated
found
calculated
found
176
C
H
C
H
CH3
145–148
161–164
90
96
176
190
81.8 9.1 82.3 8.4
82.1 9.5 82.4 8.8
HO
CH3
190
HO
(bending vibrations of CH2 groups). The bands at 1365
As is seen from the data presented in the table, the
found molecular mass and elemental composition of
the products agree with the calculated values.
On the basis of the experimental data, it may be con-
cluded that zeolite-P is a more effective catalyst for the
cycloalkylation reaction of phenol with 1-methylcyclo-
pentene and 1-methylcyclohexene as compared with
the known catalysts.
and 2940 cm–1 correspond to the methyl group.
The proton NMR spectrum of 4(1-methylcyclo-
hexyl)phenol exhibits four signals with an intensity
ratio of 3 : 10 : 1 : 4. The singlet at 1.12 ppm is due to
the protons of the CH3 group attached to the quaternary
carbon atom. The multiplet with a large peak
(δ 1.77 ppm) is characteristic of the saturated hydrocar-
bon cycle; the OH group yields a signal at 5–6 ppm.
The 1,4-substituted benzene ring (multiplet) corre-
sponds to a type AABB spectrum or, approximately, an
AB spectrum with an average chemical shift of
6.90 ppm and a spin–spin coupling constant of 8.5
0.5 Hz.
The IR absorption spectrum of 4(1-methylcyclo-
hexyl)phenol exhibits bands at 1505 and 1592–
1610 cm–1 (benzene ring), 3010 and 3030 cm–1 (=CH2
stretching), and 825 cm–1 (out-of-plane =CH2 bending);
the OH group is determined by the band at 1240 cm–1
and absorption in the region 3100–3500 cm–1. The
gem-substitution on the cyclohexane ring is confirmed
by the C–H stretching bands at 2920 and 2845 cm–1, as
well as the bands at 1108 and 1345 cm–1, which charac-
REFERENCES
1. K. D. Korenev, V. A. Zavorotnyi, and T. A. Lagutina,
Khim. Tekhnol. Topl. Masel, No. 1, 61 (2003).
2. RU Patent No. 2 233 262 (2003).
3. RU Patent No. 2 174 506 (2001).
4. Ch. K. Rasulov, F. A. Nabiev, R. K. Babaeva, et al., Prot-
sessy Neftekhim. Neftepererab., No. 2, 37 (2001).
5. Sh. G. Sadykhov, Ch. K. Rasulov, L. B. Zeinalova, et al.,
Neftekhimiya 20, 545 (1980).
6. Sh. G. Sadykhov, A. F. Babikov, L. B. Zeinalova, et al.,
Neftekhimiya 36, 158 (1996).
7. Ch. K. Rasulov, A. G. Azizov, F. A. Nabiev, et al., Azerb.
Khim. Zh., No. 3, 135 (2004).
8. Ch. K. Rasulov, A. G. Azizov, Ch. K. Salmanova, et al.,
Neftekhimiya 46, 306 (2006) [Pet. Chem. 46, 279
(2006)].
terize δCH in the cycle. The methyl group is character-
2
ized by bending vibration bands at 1370 and 1460 cm–1.
PETROLEUM CHEMISTRY Vol. 47 No. 6 2007