Organic Process Research & Development 2002, 6, 132−137
Alkylation of Phenol with Tertiary Butyl Alcohol over Zeolites
A. V. Krishnan, Keka Ojha, and Narayan C. Pradhan*
Department of Chemical Engineering, Indian Institute of Technology, Kharagpur - 721 302, India
Abstract:
concentration on the progress of the reaction have not been
Alkylation of phenol was carried out with tert-butyl alcohol
investigated systematically. Alkylation of phenol and catechol
with isobutyl alcohol has been studied using a variety of
(TBA) producing p-tert-butyl phenol over a variety of zeolite
3
catalysts, namely, zeolite Beta, 13X zeolite, Ce-exchanged 13X
zeolite, and zeolite prepared from fly ash. Zeolite Beta showed
the highest activity for the reaction under otherwise identical
conditions. The activity of 13X zeolite was found to increase
with an increase in cerium content in the catalyst, which was
accomplished through ion exchange. The activity of zeolite
superacid catalysts.
4
Tsvetkov et al. have reported that the reaction between
phenol and higher olefins at 130 °C in the presence of KU-2
cation exchanger provides a 90.5% yield of monoalkyl
5
phenol. Shkaraputra et al. have developed a mathematical
model for the alkylation of phenol and R-olefins using KU-2
(
obtained from fly ash by hydrothermal treatment) in catalyzing
cation exchanger as the catalyst.
Zieborak and co-workers have reported the synthesis of
p-cumyl phenol (PCP) in the presence of cation-exchange
6
the reaction was tested with highly encouraging results. The
effects of various parameters such as reaction temperature,
reactant ratio (mole ratio of phenol to that of tert-butyl alcohol),
and catalyst loading on the rate of reaction were also studied.
The alkylation reaction was found to be surface-reaction
controlled with negligible interparticle mass-transfer resistance.
7
resin Amberlyst 15. Macho et al. studied the reaction of
phenol with a mixture of R-methyl styrene (AMS) and AMS
dimers in the presence of active earth, polyphosphates, and
zeolites in the temperature range 60-240 °C. The alkylation
of phenol with R-methyl styrene and several alkenes has been
studied using both heterogeneous as well as homogeneous
Introduction
8
catalysts. The ortho/para product ratio was reported to vary
The alkylation reaction of phenol with tert-butyl alcohol
is of industrial relevance and also of academic interest. The
product, p-tert-butyl phenol (p-TBP) is used as a raw material
for the production of a variety of resins, durable surface
coatings, varnishes, wire enamels, printing inks, and so forth.
Other applications of p-TBP include surface-active agents,
rubber chemicals, antioxidants, fungicides, and petroleum
additives. Although both homogeneous and heterogeneous
catalysts are used in alkylation reaction systems, the trend
is definitely towards solid heterogeneous catalysts, especially
zeolites due to the inherent advantages of their higher
activity, better selectivity, ease of separation from reaction
products, chemical stability, reusability, environmental friend-
liness, and absence of corrosion problems. The present work
is concerned with the alkylation of phenol with tert-butyl
alcohol (TBA) for producing p-tert-butyl phenol, primarily
using a variety of heterogeneous catalysts.
considerably for different olefins, between solid catalysts and
homogeneous catalysts, and also between macroporous
cation-exchange resins Amberlyst 15 and partly Ag -
+
exchanged Amberlyst 15.
The ortho/para product distribution in the alkylation of
phenol with alkenes has been shown to vary with the nature
9
of the olefin. Widdecke and Klein reported a ratio of 67:33
for ortho- and para-alkylated products in the alkylation of
phenol with propylene in the presence of dry Amberlyst 15
1
0
at 98 °C. Lysenko et al. studied the alkylation of phenol
with isobutylene and butenes and observed that the yields
3 3 6 4 6 4
of p-(CH ) CC H OH (from isobutylene) and p-MeCHEtC H -
OH (from butenes) were 95.4 and 49.3%, respectively.
1
1
Crozat et al. have claimed to have obtained tert-butyl
phenol from reaction of phenol and methyl tertiary butyl ether
(MTBE) (1:1 ratio) in the presence of Amberlyst 15 as
catalyst. They have reported a ratio of 2- to 4-tert-butyl
phenol of 0.5 at 63% conversion of phenol. Chandra and
Published literature on the alkylation of phenol with
alcohols is very scanty. Moreover, very few studies have
been done using the zeolite catalysts for the phenol tert-
butylation, except for a few reports on the study of the
(3) Rajadhyaksha, R. A.; Chaudhari, D. D. Ind. Eng. Chem. Res. 1987, 26,
1276.
(4) Tsvetkov, O. N.; Monastvrskii, V. N.; Shirokov, A. N.; Kovenev, K. D.
reaction over SiO
2
2 3
-Al O catalyst in gas or liquid phases.
Chem. Abstr. 1972, 76, 585385.
(5) Shkaraputa, L. N.; Lediev, R. Y.; Lebedev, E. V.; Sklyar, V. T.; Manoilo,
Alkylation of phenolic compounds by isobutanol has been
studied using zinc chloride, phosphoric acid, 70% sulphuric
A. M.; Danilenko, V. V. Khim. Tekhnol. (KieV) 1973, 6, 41; Chem. Abstr.
1974, 80, 70466g.
1,2
acid, aluminium chloride, and cation-exchange resin. Most
of the studies have been carried out using large quantities
of the catalysts, and the effects of parameters such as catalyst
(6) Zieborak, Z.; Rutajezak, W.; Kowalska, H. Chem. Stosowana 1981, 3-4,
41.
7) Macho, V.; Matuskova, M.; Kavala, M.; Holuik, J. Chem. Abstr. 1981, 95,
6891.
8) Chaudhuri, B.; Sharma, M. M. Ind. Eng. Chem. Res. 1991, 30, 227.
3
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*
To whom correspondence should be addressed. E-mail: ncp@
(9) Widdecke, H.; Klein, J. Chem. Ing. Tech. 1981, 53, 94.
(10) Lysenko, A. P.; Yakumna, G. I.; Zelentsova, M. I. Chem. Abstr. 1975, 83,
27778.
(11) Crozat, M. C.; Barriac, J. M.; Aikawa, L. T.; Bornholdt, L.; Braz, P. Chem.
Abstr. 1982, 96, 142455.
che.iitkgp.ernet.in.
(
1) Isagulyants, V. I. Gaz. Prom. Im. Gubkina 1957, 24, 286; Chem. Abstr.
960, 54, 13497i.
2) Scheriesheism, A. Friedel-Crafts Relat. React. 1964, II, Part 1, 477-595.
1
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Vol. 6, No. 2, 2002 / Organic Process Research & Development
10.1021/op010077n CCC: $22.00 © 2002 American Chemical Society
Published on Web 02/27/2002