JPH0699349B2 - 4,4 ''-Method for producing biphenol - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel method for producing 4,4′-biphenol. More specifically, it relates to a novel method for producing 4,4′-biphenol, which comprises decomposing and dehydrogenating 4,4-bis (4-hydroxyphenyl) -cyclohexanol.

4,4'-Biphenol is useful as a raw material for producing resins such as stabilizers, dye intermediates and polyesters, polyepoxides, polyurethanes and polycarbonates, and has recently attracted attention as a raw material for heat resistant resins.

[Conventional technology]

Many methods for producing 4,4'-biphenol have been proposed. Initially, it was produced by diazo decomposition of benzidine [German Chemical Society report (Chemische Berichte), 22 , 335]. After that, it is produced by alkali melting of sodium 4,4'-biphenyldisulfonate [US Patent No. 2368361 (1942)]. Recently, a method of dealkylating tetratert-butyldiphenol obtained from 2,6-ditert-butylphenol to obtain biphenol [Journal of Organic Chemistry (JOC), 34
Vol., P. 1160 (1969)], and many patents have been issued. Also known are methods for dehalogenating and dimerizing halogenated phenols (JP-A-56-53631) and methods for treating dihalogenated biphenyl with an alkali (JP-A-54-22347), and various other production methods. A method has been proposed.

[Problems to be solved by the invention]

The above-mentioned conventional methods have drawbacks such as harmful or expensive raw materials, problems in wastewater treatment, severe conditions, and low yield.

[Means for solving problems]

The present inventors have made extensive studies to improve the drawbacks of the above-mentioned conventional method, and as a result, have found a novel manufacturing method and arrived at the present invention.

That is, the present invention is 4,4-bis (4-hydroxyphenyl)
-A novel method for producing 4,4'-biphenol, which comprises decomposing and dehydrogenating cyclohexanol.

In the method of the present invention, 4,4-bis (4-hydroxyphenyl) -cyclohexanol used as a raw material is a novel compound and can be obtained by reacting 4-hydroxycyclohexanone and phenol in the presence of a catalyst. , Filed separately.

Further, 4-hydroxycyclohexanone can be obtained by reduction of hydroquinone, oxidation of 1,4-cyclohexanediol and the like.

The present invention is to obtain 4,4'-biphenol by decomposing dehydrogenation reaction of 4,4-bis (4-hydroxyphenyl) cyclohexanol thus obtained.

The raw material 4,4-bis (4-hydroxyphenyl) -cyclohexanol forms an adduct with water, phenol, alcohol and the like, but the adduct may be used as a raw material without any problem.

In the present invention, this decomposition dehydrogenation reaction can be carried out as a separate step of the decomposition reaction and dehydrogenation reaction, but it is efficient to carry out in one step.

A base or acid catalyst is used in the decomposition reaction. Efficient decomposing catalysts include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide, alkaline earth metal hydroxides such as magnesium hydroxide and barium hydroxide, carbonates and acetic acid. Includes salts, phenoxides, salts of weak organic acids.

Acids such as p-toluenesulfonic acid,
Weak acid salts such as potassium bisulfite, aluminum chloride, stannous chloride and other acidic metal chlorides are included.

Among these catalysts, a strongly basic catalyst such as sodium hydroxide is preferred.

The dehydrogenation reaction is usually carried out in the presence of a dehydrogenation catalyst. The catalyst is not particularly limited as long as it is a known dehydrogenation catalyst. For example, Raney nickel, reduced nickel, nickel-supported catalyst in which nickel is supported on various carriers such as diatomaceous earth, alumina, pumice, silica gel, acid clay, Raney cobalt,
Cobalt catalysts such as reduced cobalt, cobalt-supported catalysts, Raney copper, reduced copper, copper catalysts such as copper-supported catalysts, palladium black, palladium oxide, colloidal palladium, palladium-carbon, palladium-sulfuric acid, barium, palladium-magnesium oxide Palladium catalysts such as palladium-calcium oxide and palladium-alumina, platinum catalysts such as platinum black, colloidal platinum, platinum oxide, platinum sulfide and platinum-carbon, colloidal rhodium,
Rhodium catalysts such as rhodium-carbon and rhodium oxide, platinum group catalysts such as ruthenium catalyst, rhenium heptaoxide, rhenium catalyst such as rhenium-carbon, copper chromium oxide catalyst, molybdenum oxide catalyst, vanadium oxide catalyst, tungsten oxide catalyst, Examples thereof include silver catalysts.

Among these catalysts, a platinum group catalyst such as a palladium catalyst is preferable. The proportion of these dehydrogenation catalysts used is usually 0.001 to 1 mole of 4,4-bis (4-hydroxyphenyl) -cyclohexanol as metal atoms of the dehydrogenation catalyst.
0.2 gram atom, preferably in the range of 0.004 to 0.1 gram atom.

The method of the present invention can be carried out without a hydrogen acceptor, but can be carried out at a higher yield by coexisting with the hydrogen acceptor.

The hydrogen acceptor does not need to be particularly limited, but includes several types of compounds. For example, organic compounds containing ethylenic unsaturation such as ethylene and propylene, organic compounds containing acetylenic unsaturation such as acetylene and methylacetylene, organic compounds containing azo groups such as azobenzene, nitro or Examples thereof include carbonyl compounds and phenol compounds.

Among these, preferred hydrogen acceptors are organic compounds containing conjugated double bonds such as styrenes such as α-methylstyrene, nitrobenzene, maleic anhydride, methylacetylene, crotonic acid, phenol and the like. Moreover, these hydrogen acceptors are not only highly active, but also their products after hydrogenation, such as cumene in the case of α-methylstyrene,
In the case of phenol, it is better to select it so that it is useful such as cyclohexanone.

The reaction temperature is 100 to 400 ° C, preferably 150 to 300 ° C. When the reaction temperature is low, the reaction rate is low, and when it is high, side reactions may occur, which is not a good strategy.

The method of the present invention can be carried out in the gas phase, but since the melting points of the raw materials and products are high, a high temperature of 300 ° C. or higher is required in the case of the gas phase reaction, and yield, operability, energy saving, etc. Is preferably carried out in the liquid phase. At that time, it is preferable to carry out in the presence of a solvent, specifically, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, diethylene glycol monomethyl ether, tetrahydrofuran, dioxane, dipropyl ether,
Ethers such as diphenyl ether, alcohols such as ethanol, isopropanol, ethylene glycol, diethylene glycol, triethylene glycol and propylene glycol, nitriles such as acetonitrile, propionitrile and benzonitrile, fragrances such as benzene, toluene, xylene, mesitylene, ethylbenzene and cumene. Group hydrocarbons and the like can be mentioned. Water is also a preferred solvent. Further, it is possible to use the hydrogen acceptor as a solvent.

The 4,4'-biphenol produced by the method of the present invention can be taken out by a method such as crystallization after separating the catalyst from the mixture after the reaction.

〔Example〕

Add 4,4-bis (4
-Hydroxyphenyl) -cyclohexanol 17.1 g
(0.060 mol), caustic soda 2.6 g (0.065 mol), α-methylstyrene 21.3 g (0.18 mol), water 100 g and 5% Pd-
After charging 0.2 g of carbon and replacing the inside with nitrogen gas, 250
The reaction was carried out at 0 ° C for 4 hours.

After the completion of the reaction, upon cooling, some crystals had precipitated, so 30.0 g of a 20% aqueous sodium hydroxide solution was added to dissolve the crystals, and the catalyst was separated by filtration. Benzene 10 from the filtrate
After extracting and recovering α-methylstyrene and cumene with 0 ml, hydrochloric acid water was added to cause the target product to undergo acid folding. The crystals were separated by filtration, washed with water and dried to obtain 10.8 g of crystals. The purity by liquid chromatography was 85.8%, and the impurity was p-phenylphenol. The yield of 4,4'-biphenol in terms of purity was 83%.

Claims (3)

[Claims] 1. 4,4-Bis (4-hydroxyphenyl)-
A method for producing 4,4'-biphenol, which comprises decomposing and dehydrogenating cyclohexanol. 2. The method according to claim 1, wherein the cracking dehydrogenation reaction is carried out in the presence of a dehydrogenation catalyst. 3. The method according to claim 1, wherein the decomposition dehydrogenation reaction is carried out in the coexistence of a hydrogen acceptor.