JPS632938A - Production of 4,4'-biphenol - Google Patents

Abstract

PURPOSE:To obtain the titled compound useful as an intermediate for stabilizer, dye, etc., in one step and high efficiency, by using 4,4'-bis(4-hydroxyphenyl)- cyclohexanol (a novel compound) as a raw material and subjecting the material to decomposition dehydrogenation reaction. CONSTITUTION:4,4'-Bis(4-hydroxyphenyl)-cyclohexanol which is a novel compound producible by reacting 4-hydroxycyclohexanone with phenol in the presence of a catalyst is subjected to decomposition dehydrogenation reaction in a solvent (e.g. water) in the presence of a decomposition catalyst (e.g. NaOH) and a dehydrogenation catalyst (e.g. Pd/C), preferably in the presence of a hydrogen acceptor (e.g. 2-methylstyrene) at 100-400 deg.C, preferably 150-300 deg.C. The catalyst is separated from the reaction mixture after the completion of the reaction and the objective compound is separated e.g. by crystallization. USE:Useful as a raw material for the production of a resin such as polyester, polycarbonate, polyepoxide, polyurethane, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a novel method for producing 4,4'-biphenol. More specifically, the present invention relates to a novel method for producing 4,4'-biphenol, which is characterized by subjecting 4,4-bis(4-hydroxyphenyl)-cyclohexanol to a decomposition and dehydrogenation reaction.

4.4I-biphenol is useful as a stabilizer, a dye intermediate, and a raw material for producing resins such as polyester, polyepoxide, polyurethane, or polycarbonate, 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 diazolysis of benzidine [Report of the German Chemical Society (Chemische Berichte)]
), lm335). Thereafter, it was produced by alkaline melting of thorium 4,4'-biphenyldisulfonate [US Pat. No. 2,368,361 (19
42)). In recent years, a method for obtaining biphenol by dealkylating tetratert-butyl diphenol obtained from 2,6-di-tert-butylphenol [Journal Op Organic Chemistry (J, 0.C)
, Vol. 34, p. 1160 (1969), etc.) have been well studied, and many patents have been issued. In addition, a method for dehalogenating and dimerizing halogenated phenols (JP-A-56-53631) and a method for obtaining dihalogenated biphenyls by treating them with an alkali (JP-A-54-22347)
) is also known, and various other manufacturing methods have been proposed.

[Problem that the invention seeks to solve]

The above-mentioned conventional methods have drawbacks such as harmful or expensive raw materials, problems with wastewater treatment, harsh conditions, and low yields.

[Means to solve the problem]

The present inventors have made extensive studies to improve the drawbacks of the conventional methods described above, and as a result, have discovered a new manufacturing method and have arrived at the present invention.

That is, the present invention is a novel method for producing 4,4'-biphenol, which is characterized by subjecting 4,4-bis(4-hydroxyphenyl)-cyclohexanol to a decomposition and dehydrogenation reaction.

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

Moreover, 4-hydroxycyclohexanone can be obtained by reduction of hydroquinone, oxidation of 1,4-cyclohexanediol, etc.

In the present invention, 4,4'-biphenol is obtained by decomposing and dehydrogenating 4,4-bis(4-hydroxyphenyl)cyclohexyl thus obtained.

In the present invention, although the decomposition reaction and the dehydrogenation reaction can be carried out as separate steps, it is efficient to carry out the dehydrogenation reaction in two steps.

Base or acid catalysts are used in the decomposition reaction. An efficient decomposition catalyst is sodium hydroxide.

Includes alkali metal hydroxides such as potassium hydroxide, lithium hydroxide, etc., alkaline earth metal hydroxides such as magnesium hydroxide, barium hydroxide, etc., carbonates, acetates, phenoxides, salts of organic weak acids. .

In addition, as acids, acids such as p-toluenesulfonic acid,
Included are weakly acidic acid salts such as potassium bisulfite, aluminum chloride, stannous chloride and other acidic metal chlorides.

Among these catalysts, strongly basic catalysts such as sodium hydroxide are preferred.

The dehydrogenation reaction is usually carried out in the presence of a catalyst.

The catalyst is not particularly limited as long as it is a known dehydrogenation catalyst, but examples include Raney nickel, reduced nickel, and Ire nickel.
Nickel supported catalysts supported on various supports such as algae, alumina, pumice, silica gel, acid clay, cobalt catalysts such as Raney cobalt, reduced cobalt, cobalt-supported catalysts, Raney copper, reduced copper, copper-supported catalysts, etc. Copper catalyst, palladium black.

Palladium catalysts such as palladium oxide, colloidal palladium, palladium-carbon, palladium-sulfuric acid, barium, palladium-magnesium oxide, palladium-calcium oxide, palladium-alumina, platinum black, colloidal platinum, platinum oxide, platinum sulfide, platinum-carbon, etc. Platinum catalysts such as platinum-supported catalysts, rhodium catalysts such as colloidal rhodium, rhodium-carbon, rhodium oxide, platinum group catalysts such as ruthenium catalysts, rhenium catalysts such as nyrenium heptoxide, rhenium-carbon, copper chromium oxide catalysts, molybdenum oxide catalyst, vanadium oxide catalyst, tungsten oxide catalyst,
Examples include silver catalysts.

Among these catalysts, platinum group catalysts such as palladium catalysts are preferred. The ratio of these dehydrogenation catalysts used is 4,4-bis(4-hydroxyphenyl)-cyclohexanol 1
Usually o, o as the metal atom of the dehydrogenation catalyst per mole
oi~0.2 gram atom, preferably 00004~0.
It is in the range of 1 gram atom.

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

Hydrogen acceptors are not particularly limited, but include several types of compounds. For example, organic compounds containing ethylenic unsaturation such as ethylene, propylene etc., organic compounds containing acetylenic unsaturation such as acetylene, methylacetylene etc., organic compounds containing an azo group such as azobenzene etc., nitro or Examples include carbonyl compounds and phenol compounds.

Preferred hydrogen acceptors are organic compounds containing conjugated double bonds such as styrenes such as α-methylstyrene, nitrobenzene, maleic anhydride, methylacetylene, crotonic acid, and phenol. Furthermore, these hydrogen acceptors are not only highly active but also produce products after hydrogenation, such as cumene in the case of α-methylstyrene.
In the case of phenol, it is best to select a useful one such as cyclohexanone.

The reaction temperature is 100-400°C, preferably 150-30°C.
It is best to carry out the test in the range of 0°C. If the reaction temperature is low, the reaction rate will be low, and if it is high, side reactions will occur, which is not a good idea.

The method of the present invention can be carried out in a gas phase, but since the melting points of the raw materials and products are high, in the case of a gas phase reaction, the temperature is 300°C.
Since the above-mentioned high temperature is required, it is preferable to carry out the process in a liquid phase from the viewpoint of yield, operability, energy saving, etc. At that time, it is best to carry out in the presence of a solvent, specifically ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, diethylene glycol monomethyl ether,
Ethers such as tetrahydrofuran, dioxane, dipropyl ether, and diphenyl ether, ethanol, isopropanol, and alcoholic acid.

It is also possible to use alcohols such as diethylene glycol, triethylene glycol and propylene glycol, nitrites such as acetonitrile, propionitrile and benzonitrile, benzene, toluene, xylene and me-isomers as solvents.

The 4-biphenol produced in the method of the present invention can be extracted by separating the catalyst from the mixture after the reaction is completed, and then using a method such as crystallization.

〔Example〕

In a 300m1 stainless steel autoclave, 4.4-
Bis(4-hydroxyphenyl)-cyclohexanol 17゜1,! 9 (0,060 mol), caustic soda 2
．． 6g (0,065 mol), α-methylstyrene 21.
3 g (0.18 mol), 10 g water and 5% 1? After charging 0.2.9 g of d-carbon and purging the inside with nitrogen gas, the reaction was carried out at 250° C. for 4 hours.

After the reaction was completed, when the mixture was cooled, some crystals were 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. After extracting and recovering α-methylstyrene and cumene from the filtrate with 100 Tnl of benzene, hydrochloric acid water was added to acidify the target products. The crystals were filtered, washed with water, and dried to obtain crystalline product 10.8 ji.

The purity is 85.8% by liquid chromatography,
The impurity was p-phenylphenol. Also 4, 4
The yield of '-biphenol in terms of purity was 83%.

Claims (1)

[Claims] (1) A method for producing 4,4'-biphenol, which comprises subjecting 4,4-bis(4-hydroxyphenyl)-cyclohexanol to a decomposition and dehydrogenation reaction.