JPH02196745A - Production of 3,3'-diprimary alkyl-4,4'-dihydroxybiphenyl - Google Patents

Abstract

PURPOSE:To readily obtain the subject compound which is a highly functional polymer material with hardly any by-products by oxidatively dimerizing a 2-primary alkyl-6-tertiary alkylphenol as a raw material and removing the tertiary alkyl group. CONSTITUTION:A 2-primary alkyl-6-tertiary alkylphenol is used as a raw material to carry out oxidative dimerization (e.g. using a transition metal compound, strong basic alkali metal compound, etc., as a catalyst and oxygen as an oxidizing agent). The reaction is carried out at 160-200 deg.C temperature. the tertiary alkyl group is then eliminated in the next step to afford the objective compound. The tertiary alkyl group is eliminated by a method for, e.g. using an acid catalyst and/or heating. The reaction is conducted >=110 deg.C, preferably 125-230 deg.C temperature, depending on the kind of the acid catalyst, etc. Sulfuric acid, etc., are used as the acid catalyst.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to 3,3'-diglymary-alkyl-4 represented by 3,3'-trimethyl-4,4'-dihydroxybiphenyl...'4 , 4'-dihydroxybiphenyl.

[Conventional technology]

3.3'-Dimethyl-4,4'-dihydroxybiphenylm Like other biphenol-conducting conductors, this is used in highly functional polymeric materials. In recent years, aromatic polyesters containing a biphenol skeleton as one component are one of the high-performance heat-resistant polymer materials known as liquid crystal polymers, but improvements have been made in the balance between material moldability, processability, etc., and material physical properties. In order to achieve this, it is being considered to introduce substituents into some or all of the monomers. Similarly, it has been proposed to replace part or all of the bisphenol moiety with diphenols in polyarylates, polycarnates, polycarbonate resins, and the like.

As the biphenols used here, various alkyl-substituted or halogenated biphenols are known, but among them, 3,3'-dimethyl-4.4 has a methyl group, which is the simplest alkyl group. '-Dihydroxybiphenyl is attracting attention as a monomer that can impart moldability to g-rated, r; remers without significantly impairing their physical properties. Furthermore, other substituted biphenols include aromatic polyethers and aromatic polyethers. It is a compound that can be used as a raw material for rietherimide, aromatic polyesteramide, etc., and the development of an industrially convenient manufacturing method is required.

3.3'-Thmethyl-4,4'-dihydroxypic-denyl is synthesized by using a Pd compound as a catalyst for the halide 2-methyl-4-chloro-phenol, which corresponds to JP-A No. 56-53631. A method for duplicating the information is disclosed.

[Problem to be solved by the invention]

However, although this method has a high reaction rate, it requires a high purity raw material halide, and the selectivity is low, so it is often dechlorinated as an impurity. -Cresol is high tK
It has been reported that this occurs. When a general KPd compound is used as a catalyst, the halodane atom directly bonded to the aromatic ring tends to be easily eliminated, and this method cannot be said to fully overcome this problem.

[Means to solve the problem]

As a result of intensive research in view of the above situation, the present inventors used 2-primary-alkyl-6-tertiary-alkylphenol as a raw material and subjected it to t-m conversion to produce 3.3'-diglymary-alkyl. After obtaining -5,5'-si-tertiary-alkyl-4e4'-no and droxypiphenyl, detertiary alkylation is performed to produce 3.3'-no! in high yield with few by-products. The present inventors have discovered that limely-alkyl-4,4'-nohydroxybiphenyl can be easily produced, and have completed the present invention.

That is, the present invention provides 2-brimary-alkyl-6-
3,3'-no! which is characterized by double oxidation of tertiary alkylphenol and elimination of the tertiary alkyl group after death. A method is provided for the production of limely-alkyl-4,4'-nohydrogycypiphenyl.

2-Primary-alkyl- used as a raw material in the present invention
The 6-tertiary alkylphenol has, for example, 1 to 7 carbon atoms! Those having a primary alkyl group and a tertiary alkyl group having 4 to 8 carbon atoms are mentioned, and among them, 2-methyl-6-tert-butylphenol and 2-ethyl-6-tert-butylphenol are preferable, and in particular, 2-methyl-6-tert-butylphenol is preferable. -Methyl-6-tertiary-
Butylphenol is preferred.

The oxidative duplexation of 6-tert-alkylphenol in 2-f limeal is carried out using, for example, a transition metal compound, a strongly basic alkali metal compound, etc. as a catalyst and oxygen as an oxidizing agent.

Examples of transition metal compounds used here include compounds containing first transition metal ions such as iron, cobalt, manganese, and copper, and their forms include inorganic salts such as sulfates, nitrates, and chlorides; Organic acid salts such as carcinic acid, citric acid, citric acid, sulfonic acid, amines, sulfides, citric acid, etc.
These include complexes with ligands such as polybases, porphyrins, and phthalocyanines, and metal soaps such as long-chain carbon powders. The transition metal compound used here is generally 2
-7" transition metal ion content per mole of primary alkyl-6-tertiary alkylphenol is 0
．． 0001 to 0.001 mol, and when multiple types of metal ions are used, they may be used so that the total amount of these metal ions falls within the above-mentioned range.

The dimerization reaction of 2-primary-alkyl-6-tertiary-alkylphenol is carried out in the melt, preferably with 1
It is carried out at 60-200°. In order to smoothly proceed with the reaction using transition metal ions as a catalyst, it is desirable that transition metal ions be dissolved in the system, and for this purpose, metal soaps are preferred. Metal soaps containing transition metals are often used diluted with solvents such as mineral turpentine and toluene, and after adding them to the reaction system, the reaction temperature in the system is high, and these solvents is distilled out of the system, and the reaction proceeds in a state where the metal soaps are completely mixed with the 2-f:primary alkyl-6-tertiary alkylphenol. At the same time as this 2-f2 imasofurkyl-6-tert-alkylphenol and oxygen gas or oxygen-containing gas, preferably dry air, are introduced into the catalyst, the dicapping reaction is started, and the water produced is introduced into the system together with the waste gas. removed outside. The reaction is usually completed in 2 to 10 hours, and the reaction rate of 2-brimary-alkyl-6-tert-alkylphenol is 85 to 90 qI.
It rises at 11. For example, in a catalyst system containing iron, not only biphenols, which are diphenols of phenol, but also small amounts of diphenoquinones, which are oxidized compounds of phenol, may be produced as by-products, but in this case, the catalytic activity of transition metal compounds is Inactivation is achieved by adding a small amount of compounds such as amine, sulfide, and thiol compounds to inactivate the
Next, a gas inert to the reaction such as N2 gas is replaced with an oxygen-containing gas and introduced into the system, while heating is continued for a short time (0,5
2 hours), the 2-primary-alkyl-6-tertiary-alkylphenol remaining in the system reacts with the diphenoquinones, and the 3,3'-diprimary-alkyl-5,5'-ditertiary phenol reacts with the diphenoquinone. -Alkyl-
The reaction can be completed by producing 4,4'-dihydroxybiphenyl. In this oxidized compound, a strongly basic alkali metal compound such as an alkali metal hydroxide, an alkali metal oxide, an alkali metal alkoxide, an alkali metal phenoxide, etc. can be selected as a catalyst instead of the above-mentioned transition metal compound. Among the strongly basic alkali metal compounds, alkali metal hydroxides are preferred, and examples of the alkali metal hydroxides include sodium hydroxide and potassium hydroxide. The amount used is 0.001 to 0.05 mol per 1 mol of 2-terminal alkyl-6-tertiary alkylphenol. -alkyl-6-tertiary-alkylphenol;
Subsequently, the water produced is distilled off by heating. Internal temperature 1
After maintaining the temperature at 50° C. or higher, an oxygen-containing gas is introduced into the system in the same way as when a transition metal compound is selected as a catalyst (K) to start the reaction. Although it varies depending on the catalyst and reaction conditions, it generally takes 4 to 13 hours to complete the reaction, and at this time the conversion rate of 2-terminal alkyl-6-tertiary alkylphenol is 80 to 90%. reach up to. If a nophenoquinone derivative is generated in the system, if necessary, neutralize the strongly basic alkali metal compound in the system, cut off the introduction of oxygen-containing gas, introduce an inert gas, and heat the system. Residual 2 - Grimly - Full Kill -
3. React with 6-tertiary alkylphenol.
Conversion to 3'-diprimary-alkyl-5,5'-ditertiary-alkyl-4,4'-dihydroxybiphenyl.

In this way, a 3.3'-digital primary of 95 or more
Alkyl-5,5'-tuta-shari-furkyl-4,4
The product containing '-dihydroxybiphenyl can be subjected to the next detertiary alkylation reaction as it is, but it is usually bathed in a suitable solvent such as toluene or xylene, and heated if necessary. The remaining catalyst was removed by washing with water or dilute acid under dissolution conditions, and highly pure 3,3'-diprimary alkyl-5,5'-diprimary alkyl-4,4 was obtained by cooling crystallization. '-dihydroxybiphenyl can be obtained. Here, 3,3'-dibrymary-alkyl-5 obtained by crystallization
, 5'-ditertiary-alkyl-4,4'-dihydroxybiphenyl usually has a purity of 98 or higher and is of sufficient quality to be used in the subsequent detertiary alkylation step.

3,3'-diglymally-alkyl-5,5'-ditertiary-alkyl-4,4'- obtained in the previous step
The tertiary alkyl group of dihydroxybiphenyl can be easily removed by acid catalyst and/or heating. 3,3'-diglymary-alkyl-5
, 5'-Tata-Shari-furkyl-4,4'-dihydroxybiphenyl is dissolved in a hydrocarbon or ether solvent with a boiling point of 100°C or higher, rIl, )! l! Removal of the di-tertiary alkyl group is accomplished by heating to reflux in the presence of medium iI.

As the reconstituted water 3Fl solvent with a boiling point of 100°C or higher used here, aromatic hydrocarbons such as toluene, xylene, mesitylene, cymene, and ethylhexene are suitable;
As the ether solvent, nophenyl ether, pennol ether, anisole, 7-enethole, etc. are used. The amount of these solvents used is not particularly limited, but preferably the total amount of 3,3'-diprimary-alkyl-5,5'-ditertiary-alkyl-4,47-no and droxybiphenyl is mixed at the very beginning of the reaction. A melting bolt, i.e. 3.
It is preferred to use 0.5 to 3 times the amount of 3'-diglymary-alkyl-5,5'-ditertiary-alkyl-4,4'-dihydroxybiphenyl.

The temperature at which it warps varies depending on the type of acid catalyst used and the child.
Generally, the temperature is 110°C or higher, up to the boiling point of the solvent used, preferably 125°C to 230°C; excessively raising the reaction temperature is not preferred as it may cause thermal decomposition of the acid catalyst.

As acid catalysts, sulfur, p-toluenesulfonic acid, phenolsulfonic acid, and other arylsulfones #R are generally used, but in combination with or in place of these, activated clay,
Solid acid catalysts such as zeolites can also be used. These acid catalysts #1 are usually 3,3'-diglymer-
Alkyl-5,5'-ditertiaryalkyl-4,4
0.1 to 100 parts of '-dihydrokitabifer
&θ weighted portion is used, and this lid may be filled with the entire amount at the beginning, or may be added sequentially for the purpose of sub-regulating the degassing rate.

This degassing reaction varies depending on reaction conditions such as reaction temperature, amount of catalyst, etc., and it is usually difficult to select suitable reaction conditions.
It can be completed in ~16 hours. After the reaction is completed, the reaction solution is cooled, and the desired 3,3'-diglymary-alkyl-4,4'-dihydroxybiphenyl is precipitated and filtered at a temperature of 50°C or higher. 3,3'-diglymary-alkyl-4, from which the remaining homologues of the ditertiary alkyl group have been completely removed.
4'-dihydroxybiphenyl is obtained as off-white crystals.

Although this product can be put to practical use up to t, it is preferable to further recrystallize it using a solvent such as methanol, ethanol, acetone, methyl ethyl ketone, toluene, or xylene.

〔Example〕

The present invention will be specifically explained below with reference to practical examples. same,
The characters in the example are all J except for the conversion rate! I am in charge of quantity.

Example 1 2-Methyl-6-tert-butylphenol 564
Heat and melt I, and add 1.3.9 (5%) of iron heptanoate.
Turpentine solution) and manganese naphthenate 0.21! (
After death, the temperature inside the reactor was raised to 160°C, and at this temperature dry air was
When the reaction was continued for 6 hours, the conversion rate of 2-methyl-6-tert-butylphenol was 85%, and the reaction solution composition was as follows.

2-Methyl-6-tert-butylphenol and other 1% Next, the introduction of dry air was cut off, and nitrogen gas was replaced with 50%
m/mln, and further ethanolamine α2
When I was added and heated to 180° C. for 0.5 hours, the composition of the reaction solution changed as follows.

2-Methyl-6-t-butylphenol
4. Miscellaneous 1% This content was poured into xylene 200.9 mm, and after dissolving the entire amount, 0.9 mm was added. Washing was performed three times with IN dilute sulfuric acid. Further, this xylene solution was cooled to room temperature to form yellow crystals 1.
Obtained 35g9. As a result of analysis, this yellow crystal was found to be 105II.
of 3,3'-trimethyl-5,5'-ditertiary-butyl-4,4'-dihydroxybiphenyl and 291 of xylene.

After 135 g of the yellow crystals were placed in 801i xylene in a heating bath, 0.8 g of p-)luenesulfonic acid was added, and water present in the system was removed under heating under reflux. When the water in the system was completely removed, the debutylation reaction from 3,3'-methyl-5,5'-ditertiary-butyl-4,4'-nohydroxybiphenyl was started, and 6
The reaction is completed after 9 hours. The reaction solution was cooled to 30'C, and the precipitated crystals were treated with P to give 3.3'-trimethyl-4,4
'-Nohydroxybiphenyl 5&Ig was obtained.

Example 2 2-methyl-6-tert-butylphenol 164
．． Pi is heated and melted, and solid potassium hydroxide is added here to 0.84
9 was added, the temperature was raised to 150°, and the water produced by neutralization was distilled off. Subsequently, after raising the internal temperature to 170°, dry air was introduced into the system at a rate of 17014'min, and after continuing the reaction for 8 hours, the composition of the reaction solution was measured and found to be as follows.

-4,4'- and droxypiphenyl, enoquinone, 7% 2-methyl-6-tert-butylphenol, 14%, etc. Next, cut off the dry air, and replace it with nitrogen gas t-5
0.5 hours while introducing at a speed of 0.01111/min.
When heated at 180°C, the composition of the ζ-filtration reaction liquid was as follows.

2-methyl-6-tert-butylphenol
7% and 1 other.Pour the contents into Xyref 170i, and
: After dissolving with 1W, it was washed 3 times with 50% water and cooled to room temperature to give 150% yellow crystals. I got i. Analyzing this crystal
It contained 3,3'-ditertiary-butyl-5,5'-ditertiary-butyl-4,4'-no, droxypiphenyl 1171, and xylene 33Ii.

The following procedure was carried out in the same manner as in Example 1, and 3,3'-tmethyl-4,4'-nohydroxybiphenyl ezlc'4ft
.

Claims (1)

[Scope of Claims] 3,3'-Diprimary-alkyl-4, which is characterized by subjecting 1,2-primary-alkyl-6-tertiary-alkylphenol to double oxidation and then eliminating the tertiary-alkyl group. , 4'-dihydroxybiphenyl production method. 2. The primary alkyl group has 1 to 7 carbon atoms,
The method according to claim 1, wherein the tertiary alkyl group has 4 to 8 carbon atoms. 3. The method according to claim 1, wherein the primary alkyl group is a methyl group and the tertiary alkyl group is a tertiary butyl group.