This invention relates to an improved process for the preparation of cyclohexylphenol. More particularly, itrelates to the process of preparation of 4-cyclohexylphenol by the alkylation of phenolwith cylcohexanol or cyclohexene using a catalytic method. Still more particularly itrelates to the said process using H-Mordenite or H-beta as selective catalyst . Paracyciohexylphenol (4-cyclohexylphenol) is widely used as an intermediate in the manufacture of dyestuffs, more particularly in the manufacture of colorants for plastics. In the prior art processes, Cyclohexyphenol is prepared by the use of catalyst like polyphosphoric acid, sulfiiric acid, and phosphoric acid, at temperatures between 100-180°C in an autoclave. The duration of the experiment varied from 3-8h. The main disadvantage is that the product contains a mixture of ortho and para isomers and not selective towards para- isomer.
US 3367981 report the use of transitional aluminas but the reaction temperatures are around 300°C. They reported a product containing 2-alkylphenol and 2,6-dialkylphenol. However, this method is not selective for 4-cyclohexylphenol. Engelhard Industries Inc. (Fr. 1451784) reported the preparation of 17-35 mole% of paracyclohexylphenol by the hydrogenation of para phenyl phenols using acetic acid and Pd-C at 110-20°C in cylcohexane as solvent.
Use of cationic ion exchange resins, zeolites, clays, aluminas and FeCl3 are also reported as catalyst for this reaction. But none of these methods report any solid catalytic material, which is Eco-friendly and selective (more than 70%), to 4-cyclohexylphenol. It is therefore desirable to have the catalytic material, which is selective for 4-cyclohexylphenol (>70%) and which is devoid of some of the drawbacks of the earlier processes.
It is therefore desirable to provide a selective, Eco-friendly catalytic process for the
preparation of 4-cyclohexylphenol. The inventors of the present invention have
observed that the use of Zeolite catalyst of the mordenite or beta type provides the
method for the preparation of cyclohexylphenol and overcome some of the drawbacks
of the earlier methods.
The object of the present invention therefore is to provide a process for the production
of 4-cyclohexylphenol in high selectivity using a Zeolite catalyst of mordenite or beta
type.
Accordingly, the present invention provides an improved process for the production of

4-cyclohexylphenol which comprises reacting cyclohexanol or cyclohexene. with phenol in
presence of acatalyst at a temperature ranging between 140°-220°C for a period ranging between 2 to 12hrs, bringing the reaction mixture to an ambient temperature, quenching the mixture

to obtain the product and separdtin the product from the catalyst with suitable solvent
to obtain the desired material.
In one of the embodiment of the present invention, the ratio of Phenol to cyclohexanol or
Cyclohexe in the reaction mixture is in the range of 1:1 to 5:1
*
In another embodiment the ratio of the catalyst with the reaction mixture is 1:10. In yet another embodiment the reaction temperature is between 140°-220°C. In yet another embodiment the reaction time was varied from 2-12h.

In yet another embodiment the catalyst used is selected from H-mordenite and H-beta. The process of the present invention is described herein below with reference to following examples, which are illustrative only and should not be construed to limit the scope of the present invention in any manner.
Example - 1 describes the process for preparation of the catalyst H-Mordenite as follows
Synthesis of Zeolite Mordenite
Synthetic mordenite is prepd. by hydrothermal reaction of a raw material contg. SiO2, Al2O3, alkali metal, and tetraethylammonium halide as the mineralizer. The compn. of the raw material has the mole ratios SiO2/A12O3 = 15-30, M2O/I = 0.5-2.0,1/SiO2 = 0.1-1.0 and H2O/I = 20-500 (M = alkali metal). Thus, 2.8 g Al powder and 24 g NaOH were dissolved in 200 mL H2O, then the resulting soln. was mixed with 300 g colloidal SiO2 (contg. 30 wt.% SiO2) and 94.6 g tetraethylammonium bromide, well-stirred, and heated at 150° for 72 h to form mordenite of high purity. The product was filtered, washed free of sodium, dried at 120°C for 10 h, calcined at 520°C for 16h. The so obtained Na-form of the zeolite was exchanged repetadaly with ammonium nitrate to obtain the ammonium form which on calcinations at 500°C results in the Hi-form of the Mordenite. The SiO2/Al2O3 ratio is 29. The zeolite thus obtained was used in the present study.
Example - 2 describes the process for preparation of the catalyst H-beta as described as follows.
Synthesis of Zeolite Beta.
Samples of zeolite beta SiO2/Al2O3 ratio 30 was synthesized using a reaction mixture having a molar composition, a (TEA)2O : b SiO2: A12O3: c Na2O: d H2O
where (TEA)+ is tetraethyl ammonium cation, a,c,d are constants, while b was in the range 30.
The reaction gel was prepared by mixing approproate amounts of fumed silica (Sigma 400 type S-5005), sodium hydroxide (A.R.grade), Sodium aluminate (43.8% AI2O3,
39% Na2O and 17.2% H2O), 40% aqueous solution of tetraethyl ammonium
hydroxide (Alfa), and distilled water. In a typical synthesis procedure, a sample having
SiO2/Al2O3 ratio 28, was prepared by mixing 0.62g of NaOH with 12.78g of fumed
silica, in 80g of distilled water. The resultant solution was stirred in a polythene
beaker, and a mixture of 23.89g of TEAOH (40% solution) and 1.17g of sodium
aluminate in l0g of distilled water was added. The molar composition of the gel
formed was
6.5 (TEA)2O : 40 SiO2: Al2O3 : 3 Na2O: 1200 H2O
The homogeneous mixture thus obtained was transferred to a stainless steel autoclave
(capacity 250ml) The autocalve was kept in an overn maintained at 150°C. After
completion of the crystallization (6-9 days), the autoclave was quenched to room
temperature in cold water. The solid material thus obtained was filtered, washed with
deionised water and dried at 120°C. The solid was further calcined in a flow of dry air,
at 520°C, for 20 hr., to obtain the sodium form of the zeolite
Zeolite beta sample with SiO2/AI2O3 ratio 30 prepared in the manner is used fa the
present study.
Examples 3 to 14 describe the process for the preparation of cyclohexylphenol.
Example - 3
This example shows the effect of temperature on the product formation. The catalyst
was powdered well to mesh size (10-20). The catalyst is then calcined at 450°C for 6h.
The reactants are taken in the required molar ratio (by mixing both the reactants
cyclohexanol and phenol in the respective ratios 1:1) in stainless steel autoclave
followed by addition of a catalyst (H-mordenite) in a weight percent ratio of 1:10 (1 is
catalyst and 10 is reaction mixture). The autoclave is closed and kept it in a heating
system at a desired temperature varying for a period of 6h. For each run a different
temperatuir was maintained. The temperature of the reaction was varied between 140-200°C. Afar that, the autoclave is quenched and the products are separated from the catalyst by Itration and washing. The filtrate was analyzed by gas chromatographic method. The results are shown in Table-1 Table-1

(Table Removed 1)
2-CP = 2-cylohexylphenol, 4-CP = 4-cyclohexylphenol, Poly-CP = polycyclohexylphenol, Ether = Cyclohexylphenyl ether, Temp = Temperature
Example-
This example illustrates the effect of mole ratio on the product formation. The catalyst was powdered well to mesh size (10-20). The catalyst is then calcined at 450°C for 6h time. The rectants are taken in the required molar ratio in stainless steel autoclave and followed by lie addition of 10 weight percent of a catalyst (H-mordenite). The autoclave isloosed and kept in a heating system at a temperature of 200°C for a period of 6h. In each run a different mole ratio was maintained. The molar ratio of the reactants (cyclohexanol : phenol) was varied between 1:1 to 1:5. After that, the autoclave isquenched and the products are separated from the catalyst by filtration and washing. The filtrate was analyzed by gas chromatographic method. The results are shown in Table-2
Table-2

(Table Removed 2)
2-CP = 2-cyclohexylphenol, 4-CP = 4-cyclohexylphenol, Poly-CP = Polycyclohexylphenol, Ether = Cyclohexylphenyl ether,
Example - 5
The effect of time on the product formation is shown in this example. The catalyst was powdered well to mesh size (10-20). The catalyst is then calcined at 450°C for 6h time. The catalyst (10 wt% of the reactants) was added to reactant mixture (Cyclohexanol and Phenol) taken in the required molar ratio (1:1) in stainless steel autoclave. The autoclave is closed and kept in a heating system for a desired period of time at a temperature of 200°C. In each run a different period of time was maintained. The reaction time was varied between 2 to 12h. After that, the autoclave is quenched and the products are separated from the catalyst by filtration and washing. The filtrate was analyzed by gas chromato graphic method. The results are tabulated in Table-3. Table-3

(Table Removed 3)
2-CP = 2-cyclohexylphenol, 4-CP = 4-cyclohexylphenol, Poly-CP = Polycyclohexylphenol, Ether = Cyclohexylphenyl ether
Example - 6
In this example the effect of temperature on the product formation is shown. The catalyst was powdered well to mesh size (10-20). The catalyst(H-mordenite, 10 weight percent of the reactant) is then calcined at 450°C for 6h time and then added to a stainless steel autoclave containing the reactants (Cyclohexene and Phenol) in the required molar ratio (1:1). The autoclave is closed and kept in a heating system at a desired temperature for a period of 6h. In each run a different temperature was maintained. The temperature of the reaction was varied between 140-200°C. After that, the autoclave is quenched and the products are separated from the catalyst by filtration and washing. The filtrate was analyzed by gas chromatographic method. The results are shown in Table-4 Table -4

(Table Removed 4)
2-CP = 2-cyclohexylphenol, 4-CP = 4-cyclohexylphenol, Poly-CP = Polycyclohexylphenol, Ether = Cyclohexylphenyl ether,
Example - 7
This example illustrates the effect of mole ratio on the product formation. The catalyst
was powdered well to mesh size (10-20). The catalyst is then calcined at 450°C for 6h time. The reactants are taken in the required molar ratio in stainless steel autoclave and followed by the addition of 10 weight percent of a catalyst (H-mordenite). The autoclave is closed and kept in a heating system at a temperature of 200°C for a period of 6h. In each run a different mole ratio was maintained. The molar ratio of the
reactants (Cyclohexene : phenol) was varied between 1:1 to 1:5. After that, the autoclave is quenched and the products are separated from the catalyst by filtration and washing. The filtrate was analyzed by gas chromatographic method. The results are shown in Table-5 Table -5

(Table Removed 5)
2-CP = 2-cyclohexylphenol, 4-CP = 4-cyclohexylphenol, Poly-CP = Polycyclohexylphenol, Ether = Cyclohexylphenyl ether,
Example - 8
The effect of time on the product formation is shown in this example. The catalyst was powdered well to mesh size (10-20). The catalyst is then calcined at 450°C for 6h time. The catalyst (H-mordenite, 10 wt% of the reactants) was added to reactant mixture (Cyclohexene and Phenol) taken in the required molar ratio (1:1) in stainless steel autoclave. The autoclave is closed and kept in a heating system for a desired period of time at a temperature of 200°C. In each run a different period of time was maintained. The reaction time was varied between 2 to 12h. After that, the autoclave is quenched and the products are separated from the catalyst by filtration and washing. The filtrate was analyzed by gas chromatographic method. The results are shown in Table-6
Table -6

(Table Removed 6)
2-CP = 2-cyclohexylphenol, 4-CP = 4-cyclohexylphenol, Poly-CP = Polycyclohexylphenol, Ether = Cyclohexylphenyl ether,
Example - 9
This example shows the effect of temperature on the product formation. The catalyst was powdered well to mesh size (10-20). The catalyst is then calcined at 450°C for 6h. The reactants are taken in the required molar ratio (by mixing both the reactants cyclohexanol and phenol in the respective ratios 1:1) in stainless steel autoclave followed by addition of a catalyst (H-Beta) in a weight percent ratio of 1:10 (1 is catalyst and 10 is reaction mixture). The autoclave is closed and kept it in a heating system at a desired temperature varying for a period of 6h. In each run a different temperature was maintained. The temperature of the reaction was varied between 140-200°C. After that, the autoclave is quenched and the products are separated from the catalyst by filtration and washing. The filtrate was analyzed by gas chromatographic method. The results are shown in table-7 Table-7

(Table Removed 7)

2-CP = 2-cyclohexylphenol, 4-CP = 4-cyclohexylphenol, Poly-CP = Polycyclohexylphenol, Ether = Cyclohexylphenyl ether, Temp = Temperature
Example - 10
This example illustrates the effect of mole ratio on the product formation. The catalyst was powdered well to mesh size (10-20). The catalyst is then calcined at 450°C for 6h time. The reactants are taken in the required molar ratio in stainless steel autoclave and followed by the addition of a catalyst (H-Beta). The autoclave is closed and kept in a heating system at a temperature of 200°C for a period of 6h. In each run a different mole ratio was maintained. The molar ratio of the reactants (Cyclohexanol: phenol) was varied between 1:1 to 1:5. After that, the autoclave is quenched and the products are separated from the catalyst by filtration and washing. The filtrate was analyzed by gas chromatographic method. The results are shown in Table-8 Table-8

(Table Removed 8)
2-CP = 2-cyclohexylphenol, 4-CP = 4-cyclohexylphenol, Poly-CP = Polycyclohexylphenoi, Ether = Cyclohexylphenyl ether, Temp = Temperature
Example- 11
The effect of time on the product formation is shown in this example. The catalyst was
powdered well to mesh size (10-20). The catalyst (H-Beta) is then calcined at 450°C for 6h time. The catalyst (10 wt% of the reactants) was added to reactant mixture (Cyclohexanol and phenol) taken in the required molar ratio (1:1) in stainless steel autoclave. The autoclave is closed and kept in a heating system for a desired period of
time at a temperature of 200°C. In each run a different period of time was maintained. The reaction time was varied between 2 to 12h. After that, the autoclave is quenched and the products are separated from the catalyst by filtration and washing. The filtrate was analyzed by gas chromatographic method, chromatographic method. The results are tabulated in Table-9. Table -9

(Table Removed 9)
2-CP = 2-cyclohexylphenol, 4-CP = 4-cyclohexylphenoI, Poly-CP = Polycyclohexylphenol, Ether = Cyclohexylphenyl ether,
Example - 12
In this example the effect of temperature on the product formation is shown. The catalyst was powdered well to mesh size (10-20). The catalyst H-Beta is then calcined at 450°C for 6h time, then added to a stainless steel autoclave containing the reactants (Cyclohexene and Phenol) in the required molar ratio. The autoclave is closed and kept in a heating system at a desired temperature for a period of 6h. In each run a different temperature was maintained. The temperature of the reaction was varied between 140-268°C. After that, the autoclave is quenched and the products are separated from the catalyst by filtration and washing. The filtrate was analyzed by gas chromatographic method. The results are shown in Table-10
Table -10

(Table Removed 10)
2-CP = 2-cyclohexylphenol, 4-CP = 4-cyclohexylphenol, Poly-CP = Polycyclohexylphenol, Ether = Cyclohexylphenyl ether, Temp = Temperature
Example - 13
This example shows the effect of mole ratio on the product formation. The catalyst was powdered well to mesh size (10-20). The catalyst is then calcined at 450°C for 6h time. The reactants are taken in the required molar ratio and mixing both of the reactants (cyclohexene and phenol) in the respective ratios in a stainless steel autoclave and adding a catalyst (H-Beta) to a weight percent ratio of 10. The autoclave is closed and kept it in a heating system at a temperature of 200°C for a period of 6h. The reaction was carried out by maintaining the desired temperature of the autoclave for a required period of time. After that, the autoclave is quenched and the products are separated from the catalyst by filtration and washing. The filtrate was analyzed by gas chromatographic method. The results are shown in Table-11 Table-11

(Table Removed 11)
2-CP = 2-cyclohexylphenol, 4-CP = 4-cyclohexylphenol, Poly-CP = Poiycyclohexylphenol, Ether = Cyclohexylphenyl ether,
Example - 14
The effect of time on the product formation is shown in this example. The catalyst was powdered well to mesh size (10-20). The catalyst (H-Beta) is then calcined at 450°C for 6h time. The catalyst (10 wt% of the reactants) was added to reactant mixture taken in the required molar ratio (1:1) in stainless steel autoclave. The autoclave is closed and kept in a heating system for a desired period of time at a temperature of 200°C. In each run a different period of time was maintained. The reaction time was varied between 2 to 12h. After that, the autoclave is quenched and the products are separated from the catalyst by filtration and washing. The filtrate was analyzed by gas chromatographic method, chromatographic method. The results are tabulated in Table-12. Table -12

(Table Removed 12)
2-CP = 2-cyclohexylphenol, 4-CP = 4-cyclohexylphenol, Poly-CP = Polycyclohexylphenol, Ether = Cyclohexylphenyl ether,

We Claim:
1. An improved process for the production of 4-cyclohexylphenol which
comprises reacting cyclohexanol or cyclohexene with phenol in presence of a catalyst at atemperature ranging between 140°-220°C for a period ranging between 2to 12hrs, bringing the reaction mixture to A an ambient temperature,

quenching the mixture to obtain the product and separating the product
from the catalyst with a suitable solvent to obtain the product.
2. An improved process as claimed in claim 1, wherein the catalysts used is selected fromH-mordenite or H-beta, which is prepared by the ocedures given.
3. An improved process as claimed in claims 1 and 2, wherein the phenol to cyclohexdnol or cyclohexene mole ratio is in the range of 1:1 to 5:1.

4. An improved process as claimed in claims 1 to 3, wherein the reaction temperature is varied between 140-220°C.

5. An improvedprocess as claimed in claims 1 to 4, wherein reaction time was varied from 2-12h.

6. An improved process for the preparation of cyclohexylphenoi as fully described hereinbefore with reference to examples 3 to 14,