JPH01168632A - Production of 4,4"-dihydroxyterphenyl - Google Patents

Abstract

PURPOSE:To industrially and advantageously obtain the title compound useful as a raw material for polymers, such as polyesters, polycarbonates and polyurethanes, by subjecting tetrakis(4-hydroxyphenyl)-cyclohexane to decomposing dehydrogenation reaction. CONSTITUTION:A compound expressed by formula I [two benzene rings (a) are linked to the same carbon atom on the cyclohexane ring] is subjected to decomposing dehydrogenation reaction at 100-400 deg.C, preferably 150-300 deg.C temperature to improve disadvantages of conventional methods, such as expensive raw materials which are hardly available in high purity in addition to troublesome operation and many required steps, and afford the aimed compound expressed by formula II by an industrially satisfiable method. Furthermore, the above-mentioned raw material is obtained by reacting cyclohexanedione with phenol in the presence of a catalyst. Although decomposition and dehydrogenation reactions can be carried out in separate steps in the afore-mentioned reaction, both are efficiently performed in one step.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel method for producing 4.4''-dihydroxyterphenyl.
Two benzene rings (a) are bonded to the same cyclohexane ring carbon, and tetrakis(4-hydroxyphenyl)-cyclohexane is subjected to a decomposition and dehydrogenation reaction, and is represented by the formula 4,4. “-Regarding a completely new method for producing dihydroxyterphenyl.

4.4”-dihydroxyterphenyl is polyester,
It is useful as a raw material for polymers such as polycarbonate and polyurethane, and in particular, 4.4''-dihydroxy-p-terphenyl is a compound expected to be used as a raw material for liquid crystal polymers.

[Conventional technology]

As a method for producing 4,41-dihydroxyterphenyl, a method using reduction, diazotization, and hydrolysis of 4,4''-dinitroterphenyl has been proposed [Journal
of American Chemical Society (J, Aw
, Chea+, Soc, Dish 632 (1944)).

[Problem that the invention seeks to solve]

However, the conventional methods described above have problems such as complicated operations and multiple steps, expensive raw materials, and difficulty in obtaining highly pure raw materials. isn't it.

[Means to solve the problem]

In order to improve the drawbacks of the conventional method mentioned above, the present inventors have developed a 4.4"
-We have conducted extensive research on the method for producing dihydroxyterphenyl, discovered a new method, and arrived at the present invention.

That is, the present invention involves subjecting tetrakis(4-hydroxyphenyl)-cyclohexane represented by formula (1) (in the formula, two benzene rings (a) are bonded to the same cyclohexane ring carbon) to a decomposition and dehydrogenation reaction. This is a novel method for producing 4,4''-dihydroxyterphenyl represented by the formula (■).

Tetrakis(4-hydroxyphenyl)-cyclohexane represented by formula (I) used as a raw material in the reaction of the present invention can be used as a catalyst for cyclohexanedione and phenol as described in JP-A-56-55328, for example. It can be obtained by reacting in the presence of

The present invention provides tetrakis (
4,4''-dihydroxyterphenyl is obtained by decomposing and dehydrogenating 4-hydroxyphenyl)-cyclohexane.

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. Efficient decomposition catalysts include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, lithium hydroxide, etc., alkaline earth metal hydroxides such as magnesium hydroxide, barium hydroxide, etc., carbonates, acetic acid, etc. salts, phenoxides, and salts of weak organic acids.

Further, MW4 includes acids such as p-toluenesulfonic acid, 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 amount used is usually 0 parts by weight per 100 parts by weight of tetrakis(4-hydroxyphenyl)-cyclohexane of formula (1).
．． It ranges from 1 to 40 parts by weight, preferably from 1 to 20 parts by weight.

The dehydrogenation reaction of the present invention 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, but examples include Raney nickel, reduced nickel, nickel supported catalysts in which nickel is supported on various carriers such as diatomaceous earth, alumina, pumice, silica gel, acid clay, Raney cobalt, reduced cobalt, Cobalt catalysts such as cobalt-supported catalysts,
Copper catalysts such as Raney copper, reduced copper, copper-supported catalysts, palladium such as palladium black, palladium oxide, colloidal palladium, palladium-carbon, palladium-sulfuric acid, barium, palladium-magnesium oxide, palladium-calcium oxide, palladium-alumina, etc. Catalysts, platinum catalysts such as platinum black, colloidal platinum, platinum oxide, platinum sulfide, platinum-supported catalysts such as platinum-carbon, rhodium catalysts such as colloidal rhodium, rhodium-carbon, rhodium oxide, platinum group catalysts such as ruthenium catalysts, Examples include rhenium catalysts such as nyrenium heptoxide and rhenium-carbon, copper chromium oxide catalysts, molybdenum oxide catalysts, vanadium oxide catalysts, tungsten oxide catalysts, and silver catalysts.

Among these catalysts, platinum group catalysts such as palladium catalysts are preferred. The ratio of these dehydrogenation catalysts to be used is usually 0.00% as metal atoms of the dehydrogenation catalyst per 1 mole of tetrakis(4-hydroxyphenyl)-cyclohexane of 2(1).
001-0.2 gram atoms, preferably 0.004-0
．． It is in the range of 1 gram atom.

Although the method of the present invention can be carried out without a hydrogen acceptor,
By coexisting with a hydrogen acceptor, higher yields can be obtained.

Hydrogen acceptors are not particularly limited, but include several types of compounds, such as organic compounds containing ethylenic unsaturation such as ethylene, propylene, etc., acetylenic compounds such as acetylene, methylacetylene, etc. Examples include organic compounds containing unsaturation, organic compounds containing an azo group such as azobenzene, nitro or carbonyl compounds, or 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 150-3
It is preferable to carry out the reaction in the range of 00° C. 6. If the reaction temperature is low, the reaction rate is low, and if it is high, side reactions are not likely to occur.

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
It requires a high temperature of 'C or higher, and is preferably carried out 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, water, aqueous solvents such as caustic water, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, diethylene glycol monomethyl ether, tetrahydrofuran,
Ethers such as dioxane, dipropyl ether, diphenyl ether, ethanol, isopropanol, alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, nitrites such as acetonitrile, propionitrile, benzonitrile, benzene, toluene, Examples include aromatic hydrocarbons such as xylene, mesitylene, ethylbenzene, and cumene. Furthermore, it is also possible to use the hydrogen acceptor as a solvent.

The 4,4''-dihydroxyterphenyl produced in the method of the present invention can be recovered by separating the catalyst from the mixture after the reaction is completed and then performing crystallization or the like.

[Example-1] 1.1,4.4-tetrakis(4-hydroxyphenyl)-cyclohexane was synthesized by reacting 1.4-cyclohexanedione and phenol under a hydrochloric acid catalyst.

1,1,4,4-tetrakis (
22.6 g of 4-hydroxyphenyl)-cyclohexane
(0,050 mol) was charged into a 300 II stainless steel autoclave with 0.8 g of caustic soda, 8.9 g (0,075 mol) of α-methylstyrene, 1.1 g of 5% palladium carbon, and 100 d of water. After purging with nitrogen gas, the reaction was carried out at 200°C for 6 hours.

After the reaction was completed, the pH was adjusted to 4 with hydrochloric acid and the crystals were filtered off.
Next, the crystals were heated and dissolved in methanol, and insoluble palladium on carbon was separated and recovered. 4.4 by distilling off methanol
White crystals of 1-dihydroxy-p-terphenyl 10.
8g was obtained. Purity by HPLC 89.7%, yield 73
．． It was 9%.

[Example-2] 1,1.3.3-tetrakis(4-hydroxyphenyl)-cyclohexane was synthesized in the same manner from 1.3-cyclohexanedione and phenol.

Next, replace 1, 1, 4.4 with this 1.1, 3.3
4.4 Using a body, react and treat in the same manner as in Example-1.
10. White crystals of ″-dihydroxy-m-terphenyl.
4g was obtained. Purity by HPLC 91.4%, yield 72
．． It was 5%.

Patent applicant Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Claims] (1) Formula (I) ▲Mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, two benzene rings (a) are bonded to the same cyclohexane ring carbon.) A method for producing 4,4''-dihydroxyterphenyl represented by formula (II) ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼ (II), which is characterized by subjecting phenyl)-cyclohexane to a decomposition and dehydrogenation reaction.