JPH0399032A - Production of 4,4'-dihydroxibiphenyl - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for producing 4,4°-dihydroxybiphenyl (hereinafter abbreviated as 4,4'-BPL), and in particular to a method for producing 4,4°-dihydroxybiphenyl (hereinafter abbreviated as 4,4'-BPL). Birbiphenyl (hereinafter referred to as 4,
4,4°-BPL, in which the peroxide obtained by oxidizing 4°-DIPBP) with molecular oxygen is acid-decomposed.
4.4°-BPL, which is the object of the present invention, is a compound useful as raw rice for liquid crystal polymers, heat-resistant resins, etc.

[Prior art] As a conventional method for manufacturing 4.4°-BPL, 2.6°
- A method of oxidative coupling of di-t-butylphenol and debutylation of the obtained compound, a method of sulfonating biphenyl and melting with alkali, etc. are known.
There were problems as an industrial manufacturing method, such as the purification process being complicated and large amounts of inorganic salts produced as by-products. On the other hand, there is a method in which alkylbenzenes are oxidized with molecular oxygen to form the corresponding hydroperoxides, which are then decomposed with acid to obtain phenols. For example, a method for producing hydroquinone from p-diisobrobylbenzene via p-diisobrobylbenzene dihydroberoxide (Japanese Unexamined Patent Application Publication No. 4-117)
8-72144), and a method for producing 2,6-dihydroxynaphthalene from 2,6-diisoprobylnaphthalene through 2,6-diisoprobylnaphthalene dihydrocarbon reduction (Japanese Patent Application Laid-Open No. 61-93156). ) etc. are known. As an example of applying this method to 4.4°-DIPBP, 4.
A method is disclosed in which 4DIPBP is oxidized to produce 4.4゛-diisobrobylbiphenyl dihydride oxide (hereinafter abbreviated as DHP), and this is decomposed with acid to obtain 4.4゜-B P L. ing.

[Problem to be Solved by the Invention 1] In the method described in JP-A-64-75440, in addition to DHP, substances shown in the following table are produced as oxidation products.

Products Among these products, 4-(2-hydroxyisopropyl)-4°-(2-hydro-hydroxyisopropylbiphenyl (abbreviated as HHP), 4.4°-bis(
2-Hydroxyisobuvir)biphenyl (DC in the table above)
A) is 4.4゜- BL when it is directly acid-decomposed.
Since P is not produced and the dehydration products are 4-(4-isobropenylphenyl)phenol and 4.4゜-diisobutypenylbiphenyl, peroxidation is required for 1 mole of 2-hydroxyisopropyl group. 4.4'-BPL has also been obtained from HHP and DCA by carrying out acid decomposition in the coexistence of 1 mole or more of hydrogen.

However, in this method, 4.4'- B P L
In order to increase the yield of 4.4'-D I PBP
When the conversion rate from D I{ P + H H P + D CA to A is increased, the proportion of DHP among these decreases, and the proportion of HHP and OCA increases. In particular, 4-
(2-hydrobyl)-4-isobrobyl biphenyl (abbreviated as MHP in the table above). 4-I
2-hydroxyisobrobyl)-4°-isobrobyl biphenyl (abbreviated as MCA in the table above) and unreacted 4.4D
If the reaction is carried out until the proportion of substances with unreacted isobrobyl groups such as I-PBP is 10% or less, the proportion of DHP in the produced DHP + HHP + DCA will be less than 35%, and the excess added during acid decomposition will decrease. The amount of hydrogen oxide is
There is a problem in that the amount increases by the amount of 2-hydroxyisobrobyl groups.

An object of the present invention is to increase the selectivity of D H P in the above oxidation reaction, use less hydrogen peroxide, and 4.
Industrially advantageous 4,4°- with high yield of 4°-BPL
An object of the present invention is to provide a method for manufacturing BPL.

[Means for Solving the Problems 1] The present invention solves the above problems by increasing the selectivity of DHP by allowing urea to coexist during the oxidation reaction of 4.4'-DIPBP. .

That is, the present invention provides a method for producing 4,4゛-dihydroxybiphenyl in which 4,4゛-diisobutylbiphenyl is oxidized with molecular oxygen and the resulting product is acid-decomposed, and the oxidation reaction is carried out using urea and/or urea. This is a method for producing dihydroxybiphenyl from 4.4° to 4.4°, which is characterized in that it is carried out in the presence of a surfactant or a derivative thereof and a surfactant.

Emetic doctor = 4.4'-D T P B The oxidation reaction of P with a molecular base is generally carried out in a basic solvent.

The basic compound used is preferably an alkali metal compound. For example, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide; alkali metal carbonates such as sodium carbonate and potassium carbonate;
Alkali metal bicarbonates such as sodium hydrogen carbonate and potassium hydrogen carbonate; alkali metal phosphates such as sodium phosphate, potassium phosphate, sodium hydrogen phosphate, potassium hydrogen phosphate, sodium dihydrogen phosphate, and potassium dihydrogen phosphate; salts, and alkali metal boron compounds such as sodium tetraborate. These can be used alone or in combination of two or more in any proportion. These alkali metal compounds are added to the reaction system as an aqueous solution, and the concentration in the aqueous solution is preferably 30% by weight or less.

The basic aqueous solution may be used in an amount that maintains the pH of the reaction system at 8 or higher, and specifically, it is 0.1 to 10 parts by weight, preferably 0.3 parts by weight, based on 4.4-DIPBPI parts by weight. ~5
This is the range of parts by weight. If it is less than 0.1 part by weight, the oxidation reaction will not proceed sufficiently, and if more than IO part by weight is used, the effect will not change, but the amount of basic waste liquid will increase, which is not preferable.

Urea or its derivatives used as additives include:
Monoalkylurea such as urea, methylurea, 1.1-dimethylurea, l. Dialkyl urea such as 3-dimethylurea, trialkylurea such as trimethylurea, tetraalkylurea such as tetramethylurea, cyanuric acid,
Examples include isocyanuric acid and melamine. These can be used alone or in a mixture of two or more in any proportion.

The amount of urea and its derivatives used is 4.4"DIP of raw materials.
0.01-20% by weight based on BP, preferably 0.0
It ranges from 5 to 10% by weight, particularly preferably from 0.1 to 5% by weight. If the amount is less than 0.01% by weight, the effect of addition will not be exhibited, and even if the amount is more than 20% by weight, the effect will not change.

The surfactant used in the method of the present invention is not particularly limited, and includes, for example, fatty acid soaps, alkyl sulfonates, alkylbenzene and alkylnafucrene sulfonates,
These include alkyl ether sulfonates, alkyl phosphates, and alkyl ether phosphates. These surfactants may be used alone or in combination of two or more types of surfactants in any ratio.

The amount of surfactant to be used is 0.01 to 5% by weight, preferably 0.01% by weight, based on the raw material 4.4°-DIPBP. Ol~
2% by weight, particularly preferably in the range from 0.05 to 1% by weight. If the amount is less than 0.001% by weight, no effect will be exhibited, and if it is used in an amount greater than 5% by weight, the effect will not change. Oxygen gas or air is used as molecular oxygen for oxidation. When using oxygen gas, it may be diluted to an arbitrary concentration with an inert gas such as nitrogen, argon, or helium.

During oxidation reactions, in order to shorten the induction time of the reaction,
Preferably, radical initiators are used. Specific examples of the radical reaction initiator include 2,2°-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), cumene hydroperoxide, L-butylhydroperoxide, etc. can be mentioned.

Further, an oxidation reaction product containing DHP obtained by the oxidation reaction of 4.4°-BPL can also be used as a reaction initiator.

The amount of radical reaction initiator used is 4.4°-D of the raw material.
0 for I RBP. The range is from 0.005 to 5% by weight.

The oxidation reaction was performed by adding 4.4°-D I P to the above basic aqueous solution.
This is carried out by adding BP, urea and/or its derivatives, a surfactant, and a radical reaction initiator, and supplying molecular oxygen while stirring.

Reaction temperature is 60-150°C, preferably 80-130°C
is within the range of If the temperature is lower than 60°C, the reaction rate will be extremely slow, and if the temperature is higher than 150°C, the decomposition of the hydroperoxide will be significantly accelerated, which is not preferred.

The pressure during the reaction may be normal pressure or pressurized, but the pressure may be between normal pressure and 1
Preferably, the reaction is carried out under a pressure of 0 kg/c1G.

The reaction time varies depending on conditions such as reaction temperature, but is usually 4 to 48 hours.

The oxidation product obtained by this oxidation reaction contains DHP as a main component, and HHP, DCA. MHP.
It is a mixture containing MCA etc.

The above oxidation products are collected by filtration and the pH of the washing solution is 3~3.
Wash with acid until it shows 7. Then, it was dissolved in an organic solvent and subjected to acid decomposition using an acid catalyst and hydrogen peroxide. 4.4”-
Get BPL.

Examples of organic solvents for dissolving oxidation products include ketones such as acetone, methyl isobutyl ketone, and methyl ethyl ketone, lower alcohols such as methanol and ethanol, ethers such as diethyl ether, diisobrobyl ether, and tetrahydrofuran, acetic acid, and chloropropylene. Carboxylic acids such as acids, nitriles such as acetonitrile,
These include aromatic hydrocarbons such as benzene, toluene, and xylene, aliphatic chain hydrocarbons such as hexane, heptane, and isooctane, and aliphatic cyclic hydrocarbons such as cyclohexane. These can be used alone or in a mixture of two or more in any proportion.

Examples of acid catalysts include inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, trichloroacetic acid, p-}luenesulfonic acid, etc. Organic acids such as p-phenolsulfonic acid and oxalic acid. These include heteroboly acids such as phosphomolybdic acid and phosphotungstic acid, strongly acidic ion exchange resins, solid acids such as activated clay, silica alumina, and zeolite.

The amount of the acid catalyst to be used is 0.00% relative to the oxidation product obtained in the oxidation reaction. It is in the range of 20% by weight.

Hydrogen peroxide DHs HHP and DCA among the oxidation products.
It is used to oxidize to P and increase the yield of 4.4°-BPL. Further, it is preferable to use hydrogen peroxide because it significantly suppresses the dehydration condensation reaction of carbinols.

As hydrogen peroxide, in addition to hydrogen peroxide and its aqueous solution, substances that generate hydrogen peroxide under acid decomposition reaction conditions, such as sodium peroxide and calcium peroxide, can also be used. is preferable. The concentration of the hydrogen peroxide solution is preferably 5 to 70%.

The amount of hydrogen peroxide used is HHP. DCA. The amount is 1 to 2 mol, preferably 1 to 1.5 mol, per 1 mol of hydroxydiisoprobyl group possessed by MCA and the like.

The acid decomposition reaction is carried out by reacting an organic solvent in which the oxidation product is dissolved and hydrogen peroxide with an acid catalyst, followed by heating. The reaction temperature is 30-120'C, preferably 50-10'C.
It is in the range of 0℃. The reaction time depends on the reaction temperature, but is usually 0.5 to 12
time, preferably in the range of 1 to 8 hours.

After the reaction is completed, a base is added to the reaction product solution to neutralize the acid catalyst, and the aqueous layer is separated. The organic solvent is recovered from one organic layer to obtain the product.

[Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

All yields in the text are for 4.4'-DIPI of the raw material.
It is expressed in mol% relative to 3P.

In addition, analysis and quantitative determination were performed using high performance liquid chromatography.

In addition, as the radical reaction initiator used for the oxidation reaction in the following examples and comparative examples, a DHP-containing oxidation reaction product obtained by the following method was used.

Radical reaction opening tlij! Preparation of i into a 50 mj Hastelloy B autoclave, 4.4'-D
I P B P lO. Ogf41.9 mmol)
．． 4.5 1% by weight aqueous sodium hydroxide solution 10. 0
g and 0.01 g of 1,1-azobis(cyclohexane-1 carbonitrile) as a radical reaction initiator were charged, and oxygen was introduced until the gauge pressure reached 2 kg/cn+''. At 100°C, while stirring at 1500 rpm. , Oxygen was continuously supplied so that the internal pressure was maintained at 2 kg/cm2G, and the reaction was carried out for 22 hours.The sodium hydroxide aqueous solution was removed from the reaction mixture, and the washing liquid pi {
Washing with water was repeated until the resulting solid was dried to obtain 11.2 g of white powder, which was used as a radical reaction initiator for oxidation reactions in the following Examples and the like. Its composition is. DHP16.8%, HHP38.1%, DCA
20.6%, MHP8.8%, MCA8.7%, 4.
4°-DIPBP was 0.9% and others were 6.1%.

Example 1 50mj Hastelloy B grade crepe, 4.4'-
D I P P P 5.0 g (21.0 mmol l,
0.5% by weight aqueous sodium hydroxide solution to. Og, urea 0-1g, sodium stearate 0. 025
g and the above D prepared in advance as a radical reaction initiator.
H P-containing oxidation reaction product o. 05g was charged.

Oxygen at 2k gauge pressure. The oxidation reaction was carried out at a reaction temperature of 0° C. and stirring at 1200 rpm. The pressure of oxygen in the reaction system is 2 kg/cm
"G" was continuously introduced so that it was maintained at 5.0
0.2 ml of a wt% aqueous sodium hydroxide solution was added every 2 hours.

(2) When the reaction was carried out for 6 hours, the conversion rate of 4.4゛DIPBP was 100% and the yield of DHP was 46.2%. The yield of HHP is 31.8%, the yield of DCA is 5.4
%, and the selectivity of DHP in DHP+HHP+DCA was 55.4%. Also, MHP. The yields of MCA were 5.2% and 166%, respectively.

Oxidation reaction product 6 obtained by filtering the reaction mixture and washing with water
．． 1% sulfuric acid was added to 2g to adjust the pH to 4. The solid matter was separated by suction filtration, and after drying the obtained solid matter, 20% of acetone was added.
g, and 1.2 g of 31% hydrogen peroxide solution (12 equivalents relative to hydroxyisobrobyl group) was added to make a homogeneous solution.

100 equipped with a dropping funnel, reflux condenser, and thermometer
5 g of acetone was placed in a four-piece rag flask and heated to reflux. 98% sulfuric acid 0. While a solution in which 6 g of hydrogen peroxide was dissolved in 5 g of acetone was continuously supplied using a bomb, an acetone solution of the oxidation product and hydrogen peroxide solution was continuously supplied from the dropping funnel. The supply was completed in 1.5 hours, and the reaction was continued for an additional 1.5 hours. A 5% aqueous sodium hydroxide solution was added to the reaction solution to adjust the pH to 6, and the aqueous layer was separated. When acetone was recovered from the organic layer, 3.8 g of a slightly yellow solid was obtained.
I got it. This contained 3.26 g of 4.4°-BPL.

DHP. HHP. The conversion rate of DCA was 100% in both cases. The yield of 4.4'-BPL was 83%. Comparative Example 1 An oxidation reaction was carried out in exactly the same manner as in Example 1, except that urea was not added.

The conversion rate of 4.4'-D I P B P was 98.6%, and the yield of DHP was 42.5%. HHP yield 24.7%,
With a DCA yield of 3.8%, the DHP selectivity in these totals was 59.8%, while MHP was 16.8%, MCA
4.4% had side effects. After filtering the reaction mixture, washing with water, and neutralizing. The amount of 31% hydrogen peroxide solution used was 1. An acid decomposition reaction was carried out under exactly the same conditions as in Example 1, except that Og (12 equivalents relative to the hydroxyisobrobyl group) was used.

As a result, 3.97 g of a slightly yellow solid was obtained. This includes 2. It contained 78 g of 4.4'-B P L.

DHP. HHP. The conversion rate of DCA was 100% in all cases, and the yield of 4.4'-B P L was 71%.

Comparative Example 2 An oxidation reaction was carried out in exactly the same manner as in Example 1, except that no surfactant was added.

The conversion rate of 4.4'-D I P B P was 98.6%, the yield of DHP was 37.0%, the yield of HHP was 26.9%,
The DCA yield was 5.2%, of which the DHP selectivity was 53%.
．． 5%, but in addition, MHPl 5.1%, MCA
5.6% had byproducts.

After the reaction mixture was filtered, washed with water, and neutralized, an acid decomposition reaction was carried out under exactly the same conditions as in Example 1. As a result, 4.03 g of a slightly yellow solid was obtained. This includes 2.70g of 4.4°-
BPL was included. DHP, HHP. O.C.
The conversion rate of A was 100% in all cases, and the yield of 4,4°-BPL was 69%.

Comparative Example 3 An oxidation reaction was carried out in exactly the same manner as in Example 1, except that no surfactant and urea were added.

The conversion rate of 4.4'-D I P B P was 94.4%, and the yield of DHP was 35.4%. 1%, HHP yield 22.0%,
DCA yield is 3.8%, of which DHP selectivity is 57%.
67%, but Ml{P22.2%, MCA 7.
5% had side effects.

After the reaction mixture was filtered, washed with water, and neutralized, an acid decomposition reaction was carried out under exactly the same conditions as in Example 1, except that the amount of 31% hydrogen peroxide solution used was 1.0 g. As a result, a pale yellow solid 4
．． 05g was obtained. This contains 2.35g of 4.4°-B
PL was included. DHP. The conversion rates of HHP and DCA were both 100%, and the yield of 4.4'-BPL was 60%.
%Met.

[Effects of the Invention] According to the method of the present invention, the presence of a urea compound and a surfactant in the oxidation reaction of 4,4°-DIPBP makes it possible to increase the DHP selectivity. The desired 4,4°-B P can be obtained in high yield through decomposition reaction.
L is obtained, and it is suitable as an industrial production method.

Claims (1)

[Claims] (1) Oxidizing 4,4'-diisopropylbiphenyl with molecular oxygen and acid decomposing the resulting product 4,4'
- A method for producing 4,4'-dihydroxybiphenyl, characterized in that the oxidation reaction is carried out in the presence of urea and/or a derivative thereof and a surfactant.