JPS5862128A - Preparation of p-phenylphenol compound or its ether - Google Patents

Abstract

PURPOSE:To prepare the titled substance useful as a raw material for the preparation of a phenolic resin for particular use, in high yield, by using a specific 4-substituted phenol or its ether and a styrene compound as starting materials, and heating the materials at a specific temperature in a liquid phase in the presence of a hydrogenative reduction catalyst. CONSTITUTION:The compound of formula III (R<1> is H, OH or lower alkyl; R<2> is H or lower alkyl) can be prepared by using a 4-substituted phenol of formulaIor formula II or its ether (e.g. p-cyclohexenylphenol) and a styrene compound such as isopropenylbenzene as starting materials, and heating the materials in a liquid phase at 210-290 deg.C, preferably 220-270 deg.C in the presence of a hydrogenative reduction catalyst, preferably in an aromatic hydrocarbon solvent. The amount of the styrene compound is usually 1-10mol, preferably 1.5-6mol per 1mol of the compound of formulaIor formula II. A Pd-carrier catalyst is especially suitable as the above catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing p-phenylphenols or their ethers. More specifically, the present invention provides a method that can produce p-phenylphenols or their ethers more selectively and in higher yields than conventionally known methods.

p-Phenylphenols, raw materials for the production of phenolic resins for special uses such as varnishes, adhesives, coating treatment agents, etc.
It is used as a manufacturing intermediate for pharmaceuticals and agricultural chemicals, and as a fungicide.

Conventionally, many methods have been proposed as methods for producing p-phenylphenols. For example, biphenyl is sulfonated to p-phenylbenzenesulfonic acid,
A method has been proposed for producing p-phenylphenol by melting and decomposing it in the presence of a base and then precipitating it with acid. However, in addition to requiring large amounts of acids and bases, these methods usually require 320 ml of melt decomposition.
The disadvantage is that the reaction must be carried out under severe reaction conditions at a temperature of 400°C.

There is also a need for a method that does not have the drawbacks of the sulfonated melt method described above, and several methods have been proposed.

For example, one method is
No. 50 discloses that 1,1-bis(4-hydroxyphenyl)cyclohexane is reacted with 200 to 3
A method has been proposed for producing p-phenylphenol by heating it to a temperature of 50° C. to cause a decomposition and dehydrogenation reaction. However, as a result of repeating any of the examples in the publication, many by-products were produced, the selectivity to p-phenylphenol was 41 to 66 mol%, and the yield of p-phenylphenol based on the raw material was 41 to 66 mol%.
It was found that the mol% was extremely low. In addition, as other methods, Japanese Patent Publication No. 44-5584, Japanese Patent Publication No. 45-70
47 and Japanese Patent Publication No. 45-7046, etc., 1,1-bis(4-hydroxyphenyl)cyclohexane obtained by a condensation reaction of 2 moles of phenol and cyclohexanone is decomposed to produce p-cyclohexenyl. A method has been proposed in which p-phenylphenol is obtained by converting phenol into phenol and then subjecting it to a dehydrogenation reaction.

Among the above-mentioned known documents, Japanese Patent Publication No. 45-7047 describes p-cyclohexenylphenol obtained by the above-mentioned method in a gas phase at 300 to 450°C in the presence of a dehydrogenation catalyst and in the presence of hydrogen. The proposed method is to produce p-phenylphenol by causing a dehydrogenation reaction by heating to a temperature of 100 to 200°C in the coexistence of a dehydrogenation catalyst and a hydrogen acceptor such as α-methylstyrene. A method of producing p-phenylphenol by causing a dehydrogenation reaction by heating has been proposed. However, the former method has the drawback that the yield of p-phenylphenol is 79 to 95 mol%, and the activity of the catalyst is significantly reduced, and the latter method has the disadvantage that the yield of p-phenylphenol is 49 to 95 mol%. A method has been proposed for producing p-phenylphenol by heating xenylphenol in the presence of sulfur as a hydrogen acceptor to cause a dehydrogenation reaction, but the yield is extremely low at 47 to 77 mol%. There is a drawback.

The present inventors have investigated a method for selectively producing p-phenylphenols or their ethers in high yield by improving the above-mentioned drawbacks in the production of p-phenylphenols by conventional methods. By heating specific 4-substituted phenols or their ethers and styrenes to a specific temperature in the presence of a hydrogenation reduction catalyst in a liquid phase,
The inventors have discovered that the above object can be achieved and have arrived at the present invention.

That is, the present invention provides a compound represented by the general formula (1) or the general formula [厘]' (wherein R1 represents a hydrogen atom, a hydroxyl group, or a lower alkyl group, and R2 represents a hydrogen atom or a lower alkyl group). General formula [Kuma] C formula characterized by heating 4-substituted phenols or their ethers and styrenes in a liquid phase in the presence of a hydrogenation reduction catalyst to a temperature in the range of 210 to 290°C Medium, R1 and R2
represents the same group as above. ) is a method for producing p-phenylphenols or their ethers.

The 4-substituted phenols or ethers thereof used in the method of the present invention have the general formula [I] or the general formula [I] [seal] (wherein R1 represents a hydrogen atom, a hydroxyl group, or a lower alkyl group). and R2 represents a hydrogen atom or a lower alkyl group.

) is a compound represented by Here, R1 and R2
The lower alkyl group is usually an alkyl group having 1 to 4 carbon atoms, preferably an alkyl group having 1 to 2 carbon atoms, and specifically, a methyl group, an ethyl group, an n-
Propyl group, isopropyl group, n-butyl group, 5ea
Examples include -butyl group, tert-butyl group, and isobutyl group. Specifically, the 4-substituted phenols or ethers thereof represented by the general formula (1) or general formula (1) include 4-cyclohexenylphenol S2-methyl-4-cyclohexenylphenol-5-methyl-4- Cyclohexenylphenol, 4-
Examples include cyclohexenylresorcinol, 4-cyclohexenylanisole, 2-methyl-4-cyclohexenylanisole, and 3-methyl-4-cyclohexenylanisole. In addition, 4-substituted phenols represented by the general formula (It) or ethers thereof, specifically, 4-cyclohexylphenol-2-methyl-4-cyclohexylphenol, 3-methy/L'-
Examples include 4-cyclohexylphene and '-ol. Among these 4-substituted phenols or ethers thereof, compounds in which R1 and B2 in the general formula (1) are hydrogen atoms or methyl groups are preferred, and 4-cyclohexenylphenol is particularly preferred.

Similarly, compounds in which R1 is a hydrogen atom or a methyl group and R25Z is a hydrogen atom in the general formula (1) are preferred, and 4-cyclohexylphenol is particularly preferred.

The 4-cyclohexenylphenol represented by the general formula [1] used in the method of the present invention can be produced by a conventionally known method. For example, as represented by the following formula [1v], 1,1-bis(4-hydroxyphenyl)cyclohexanes are obtained by condensing phenols and cyclohexanones in the presence of an acidic catalyst, and this is further converted to the following formula [1v]. v〕
It can be obtained by causing a cleavage reaction in the presence of a basic catalyst or a weakly acidic catalyst, as shown in the following. Further, the ether can be obtained by alkylating the 4-cyclohekimonylphenol with a known alkylating agent such as dialkyl sulfuric acid.

In addition, 4-cyclohexylphenols represented by the general formula [I] or its ethers are 4-cyclohexylphenols represented by the general formula [I] in the presence of a known hydrogenation reduction catalyst such as a palladium catalyst. can be easily obtained by hydrogen reduction.

The styrenes used in the method of the present invention are styrene, its nuclear substituted product or its side chain substituted product. Specifically, the styrenes include styrene, α-methylstyrene, α-ethylstyrene, β-methylstyrene, and β-methylstyrene.
Ethylstyrene, 0-vinyltoluene, m-vinyltoluene, p-vinyltoluene, 0-isopropenyltoluene, m-isopropenyltoluene, p-impropenyltoluene, 〇-isopropenylcumene, m-isopropenylcumene, p- Isopropenylcumene, 0-diisopropenylbenzene, m-diimpropenylbenzene, p
-Diisopropenylbenzene and the like can be exemplified. Among these styrenes, it is preferable to use styrene substituted at the α-position or its nuclear-substituted product because p-phenylphenols can be obtained selectively and in high yield, and in particular, isopropenylbenzene or its nucleus is preferably used. Preference is given to using substituents. The proportion of these styrenes to be used is generally 1 to 10 mol, preferably 1.5 to 6 mol, per 1 mol of the 4-ft substituted phenol or its ether.

Examples of the catalyst used in the method of the present invention include hydrogenation-reduction catalysts used in ordinary catalytic hydrogenation-reduction reactions. Specifically, Raney nickel, reduced nickel, nickel ld [nickel supported catalysts supported on various supports such as earth, alumina, pumice, silica gel, acid clay; cobalt catalysts such as Raney cobalt, reduced cobalt, and cobalt/supported catalysts; Copper catalysts such as Raney copper, reduced copper, copper/supported catalyst; palladium black, palladium oxide,
Colloidal palladium, palladium/carbon-palladium/
Palladium catalysts such as barium sulfate, palladium/barium carbonate, palladium/magnesium oxide, palladium/calcium oxide, palladium/alumina; platinum black, colloidal platinum, platinum/sponge, platinum oxide, platinum sulfide, platinum/
Platinum catalysts such as platinum/supported catalysts such as carbon; rhodium catalysts such as colloidal rhodium, rhodium/carbon, and rhodium oxide; platinum group catalysts such as ruthenium catalysts; rhenium catalysts such as nyrenium heptoxide, rhenium/carbon; copper chromium oxides Catalysts; molybdenum oxide catalysts; vanadium oxide catalysts; tungsten oxide catalysts and the like can be exemplified. Among these hydrogenation reduction catalysts, it is preferable to use a palladium catalyst, and it is particularly preferable to use a palladium/carrier catalyst, and it is especially preferable to use palladium/carbon or palladium/alumina. In some cases, the hydrogenation reduction catalyst may be used after being pretreated with hydrogen or an alcohol such as methanol or ethanol in a conventional manner before being used in the reaction. The ratio of these hydrogenation-reduction catalysts used is usually 0.001 to 0.2 gram atom, preferably 0.004 gram atom of the metal atom of the hydrogenation-reduction catalyst per mole of the 4-substituted phenol or its ether. to 0.1 gram atom.

In the method of the present invention, the reaction between the 4-substituted phenol represented by the general formula (I) or the general formula [Iris] or its ether and the styrene must be carried out in a liquid phase. For this purpose, a liquid mixture consisting only of the 4-substituted phenols or their ethers and the styrenes can be reacted in the presence of the hydrogenation reduction catalyst, or the 4-substituted phenols or their ethers, the A liquid mixture consisting of styrenes and a solvent can also be reacted in the presence of the hydrogenation reduction catalyst. Further, the temperature during the reaction needs to be in the range of 210 to 290°C, preferably in the range of 220 to 270°C. Temperature during reaction is 210℃
If the temperature is lower than 290°C, the reaction rate will be low, which is industrially disadvantageous; if the temperature is higher than 290°C, the reaction rate will be high, but undesirable side reactions will occur, resulting in poor selectivity to p-phenylphenols or their ethers. Not only does the yield decrease, but the activity of the catalyst also decreases significantly.

In addition, the pressure during the reaction is sufficient as long as the mixture in the reaction system maintains a liquid phase state, and is usually 5 to 60℃.
kg/an2-a, preferably 40 kg of 10 pieces
/(7112-G) In the method of the present invention, the hydrogen transfer reaction between the 4-substituted phenols or ethers thereof and the styrenes is usually carried out in the presence of an inert gas such as nitrogen, helium, or argon. To be carried out below.

In the method of the present invention, the reaction is usually carried out in the presence of a solvent. Specific examples of reaction solvents include ethers such as ethylene glycol monomethyl dimethyl, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, diethylene glycol monomethyl ether, tetrahydrofuran, dioxane, dipropyl ether, and diphenyl ether, ethanol, isopropanol, and ethylene glycol. Examples include alcohols such as diethylene glycol, triethylene glycol and propylene glycol, nitriles such as acetonitrile, propionitrile and benzonitrile, and aromatic hydrocarbons such as benzene, toluene, xylene-mesitylene, ethylbenzene, cumene and cymene. be able to. Among these solvents, it is preferable to use aromatic hydrocarbons, and it is particularly preferable to use benzene, toluene, and cumene. The proportion of these solvents used is
The weight ratio of the 4-substituted phenol or its ether to the ether is usually 0.2 to 20, preferably 0.5.
The range is from 1 to 10.

In the method of the present invention, the desired product having the general formula p-phenylphenols or their ethers represented by [厘] are produced. The p-phenylphenols or their ethers can be isolated by treating the mixture after the completion of the reaction according to conventional methods such as distillation, crystallization, and extraction.

Next, the method of the present invention will be specifically explained using examples.

Examples 1 to 6 Internal volume 50m1! The 4-substituted phenols listed in Table 1 or their (D-
r--fAi 2.5 mmol, isopropenylbenzene 0.59 g (5 mmol), toluene 2 ml and 5% pa-carbon catalyst 0.027 g (Pa O,,015
milligram atoms), the inside of the autoclave was replaced with nitrogen, the pressure was increased to 20 kg/cys2-a with nitrogen, and the reaction was carried out at 250° C. for 0.5 hr while shaking. After cooling to room temperature, the catalyst was separated and removed from the reaction mixture by p-filtration. The separated and removed catalyst was washed with 50 ml of ethanol, and the washing liquid and p liquid were combined and subjected to gas chromatography to remove unreacted raw materials and products. The results are shown in Comparative Example 1. In actual fulh, the reaction was carried out under the same conditions as in Example 1 except that isopropenylbenzene was not added, and the post-treatment and analysis were carried out in the same manner as in Example 1. As a result, 4-7
The reaction rate of chlorhexenylphenol was 100 mol%. At this time, p-phenylphenol, p-cyclohexylphenol, diphenyl and cyclohexylbenzene were produced, and the yields were 46 mol% and 2 mol%, respectively.
They were 1 mol%, 12 mol%, and 2 mol%.

Examples 7 to 8, Comparative Examples 2 to 5 The reaction was carried out under the same conditions as in Example 1, except that the reaction temperature was changed to the temperature listed in Table 2.
Post-treatment and analysis were performed in the same manner as in Example 1. The results are shown in Table 2 (Example 9 In Example 1, 5% P (instead of 1-carbon catalyst
The reaction was carried out under the same conditions as in Example 1, except that 0.068 g (0,015 milligram atoms) of Pd-alumina catalyst was charged, and the post-treatment and analysis were carried out in the same manner as in Example 1. As a result, p- The rate of change of cyclohexenylphenol is 1
00 mol%, and the yield of p-phenylphenol is 9
It was 7 mol%.

Example 10 The post-reaction treatment and analysis were performed under the same conditions as in Example 1 except that the amount of impropenylbenzene used was 0.7ig (7 mmol). As a result, 4-cyclohexenylphenol was detected. The reaction rate was 100 mol%, and the yield of p-phenylphenol was 99 mol%.

Example 11 In Example 1, 0.97 g of p-methylisopropenylbenzene (7-5
The reaction, post-treatment and analysis were carried out under the same conditions as in Example 1, except that 4-cyclohexenylphenol (mmol) was used. The reaction rate of 4-cyclohexenylphenol was 100 mol%, and p
- The yield of phenylphenol is 95 mol%.

Applicant: Mitsui Petrochemical Industries, Ltd. Agent Kazu Yamaguchi

Claims (1)

[Claims] (1) General formula [1] or general formula (1) (1)
(1) (In the formula, R1 represents a hydrogen atom, a water group, or a lower alkyl group, and R2 represents a hydrogen atom or a lower alkyl group.) 4-substituted phenols or their ethers and styrenes; , □General formula [layer] 1 characterized by heating to a temperature in the range of 210 to 290°C in the presence of a hydrogenation reduction catalyst in a liquid phase state (wherein, R1 and R2 are the same groups as above) ) A method for producing p-phenylphenols or their ethers. (2) 4-substituted phenols or their ethers are p-
Claim No. 2, which is cyclohexenylphenol (
The method described in section 1). (3) The method according to claim (1), wherein the hydrogenation reduction catalyst is a palladium catalyst. (4) The method according to claim (1), wherein the hydrogenation reduction catalyst is a palladium carrier. (5) The method according to claim (1), wherein the reaction is carried out in the presence of an aromatic hydrocarbon solvent. (6) The method according to claim (1), wherein the reaction is carried out at a temperature of 220 to 270°C. (no) The method according to claim (1), wherein the styrene is styrene substituted with α-position f or a nuclear substituted product thereof. (8) The styrene is isopropenylbenzene or a nuclear substituted product thereof. The method according to claim (1).