JPH04243851A - Production of 4'-hydroxybiphenyl-4-carboxylic acid - Google Patents

Abstract

PURPOSE:To produce 4'-hydroxybiphenyl-4-carboxylic acid useful as a raw material for engineering plastics and liquid crystal compounds from an inexpensive raw material in high efficiency at a low cost. CONSTITUTION:The objective 4'-hydroxybiphenyl-4-carboxylic acid can be produced by using bis(4-biphenyl)carbonate as a raw material, reacting the raw material with preferably >=2 times equivalent (based on the compound) of a compound of formula I (X is group of formula II or formula III; R is alkyl or aryl) (preferably oxalyl chloride or N,N-dimethylcarbanmoyl chloride, especially oxalyl chloride) and preferably >=2 times equivalent, especially >=3 times equivalent (based on the above raw material) of a Lewis acid (e.g. FeCl3 or AlCl3) preferably at -50 to +200 deg.C (especially at -10 to +150 deg.C) and hydrolyzing the reaction product.

Description

[Detailed description of the invention]

0001

FIELD OF THE INVENTION The present invention relates to a method for producing 4'-hydroxybiphenyl-4-carboxylic acid. More specifically, 4'-hydroxybiphenyl-4 is useful as a synthetic raw material for engineering plastics and liquid crystal compounds.
-Regarding a novel production method capable of efficiently producing carboxylic acids.

0002

2. Description of the Related Art 4'-Hydroxybiphenyl-4-carboxylic acid is useful as a raw material for the synthesis of engineering plastics and liquid crystal compounds, and its demand has increased in recent years. Conventionally, the method for producing such 4'-hydroxybiphenyl-4-carboxylic acid is as follows: (1) After methoxylating P-phenylphenol, an acetyl group is introduced at the 4-position, and this is oxidized to exchange it with a carboxyl group. A method of restoring a methoxy group to a hydroxyl group to obtain the desired product (J.A.C.S.
58,1738), ■

0003

[C4] and

0004

[C5] make me react

[0005]

[Chemical 6] and then exchange the methoxy group with a hydroxyl group to obtain the desired product (Bull. Chem. Soc. Japan,
30 508 (1957). ■

[0006]

A method of diazotizing [Chemical 7] and then hydrolyzing it to obtain the desired product (F
．． P 735,846). ■

[0007]

A method of dehydrogenating [Chemical 8] to obtain the desired product (JP-A-64-7
9137, 64-75445). ■P-phenylphenol with N,N-substituted carbamic acid chloride

000
8]

[Chemical formula 9] (Y is an alkyl group or an aryl group) is carbamated, followed by amidation with N,N-substituted carbamic acid chloride, which is then heated and hydrolyzed to obtain the desired product (JP-A No. 63-1999) No. 119440). ■

0009
]

[Chemical formula 10] react with iodine in the presence of an oxidizing agent.

0010

[Chemical formula 11] After that, a method of obtaining the target product by reacting with carbon monoxide and then alkaline hydrolysis (Japanese Patent Application Laid-Open No. 63-104
No. 945, No. 63-99036). etc. are being attempted. However, these methods use expensive raw materials and reagents or require complicated steps, and cannot be said to be industrially suitable production methods. For example, in method ■, N, N
The substituted carbamic acid chloride is required to be at least twice the mole of P-phenylphenol. In addition, in the Kolbe-Schmitt reaction, which is generally used to industrially produce aromatic hydroxycarboxylic acids, when P-phenylphenol is used as a raw material,

[0011]

This method is not suitable as a method for producing 4'-hydroxybiphenyl-4-carboxylic acid because only the following compound can be obtained in high yield.

0012

OBJECTS OF THE INVENTION An object of the present invention is to provide an economical and efficient method for producing 4'-hydroxybiphenyl-4-carboxylic acid, which eliminates the drawbacks of the conventional methods described above.

[0013]

BRIEF SUMMARY OF THE INVENTION That is, the present invention provides bis(4-biphenyl) carbonate with the following formula (I) in the presence of a Lewis acid.

[0014]

[Chemical formula 13] [Here, X is

[0015]

[Chemical formula 14] as well as

[0016]

[Image Omitted] R is an alkyl group or an aryl group. This is a method for producing 4'-hydroxybiphenyl-4-carboxylic acid, which is characterized by reacting with a compound represented by the following formula and hydrolyzing the same.

The present invention will be explained in detail below.

In the method according to the present invention, bis(4-biphenyl) carbonate, which is the starting material, can be synthesized more easily than P-phenylphenol, which can be synthesized in large quantities industrially, so the process using this as a raw material is economically viable. It's advantageous. Such bis(4-biphenyl) carbonate can be synthesized by various reactions, such as ■P-
It can be obtained by a method such as a method in which phenylphenol and diphenyl carbonate are reacted in the presence of a suitable catalyst, and a method in which phosgene is allowed to act on P-phenylphenol.

Bis(4-biphenyl) thus obtained
For carbonate, in the presence of Lewis acid, the above formula (I)
React the compound shown in

As the compound represented by the above formula (I),
Specifically, N,N-dialkyl-substituted carbamic acid chlorides such as oxalic acid chloride, N,N-dimethylcarbamic acid chloride, N,N-diethylcarbamic acid chloride, and N,N-dialkylcarbamic acid chloride such as N,N-diphenylcarbamic acid chloride, Examples include N-alkyl-N-aryl-substituted carbamic acid chlorides such as N-diaryl-substituted carbamic acid chloride and N-methyl-N-phenylcarbamic acid chloride. Among these, oxalic acid chloride and N,N-dimethylcarbamic acid chloride are preferred. Particularly preferred is oxalyl chloride.

In the above reaction, a Lewis acid is used as a catalyst. Lewis acids include FeCl3, AlCl3
The usage amount of these Lewis acids, such as Bis(
The amount is preferably 2 times or more, particularly preferably 3 times or more, relative to 4-biphenyl) carbonate.

The amount of compound (I) used is bis(4-
Biphenyl) carbonate is preferably used in an equivalent amount of 2 times or more.

The solvent used in the reaction can be a stable solvent that does not cause side reactions in the reaction system and is generally used as a Friedel-Crafts reaction solvent, but in particular aromatic halogenated solvents such as chlorobenzene and dichlorobenzene can be used. Hydrocarbon solvents are particularly preferred.

The reaction temperature may be any temperature as long as the above reaction proceeds, but if it is too low, the reaction will be slow, and if it is too high, side reactions will occur, so there is an appropriate range. This range is -50°C to 200°C, more preferably -10°C to 150°C.

The end point of the reaction can be determined by quantifying the amount of hydrogen halide produced as a result of the reaction.

After the reaction is completed, the reaction mixture is poured into a solution of methanol, water, etc. to decompose unreacted Lewis acid.

In this case, when water is used as a solvent for the decomposition treatment, the carbonyl compound is recovered as the corresponding carboxylic acid. On the other hand, when an alcohol such as methanol is used, a corresponding carboxylic acid ester is produced.

These compounds can be purified by conventional methods such as recrystallization, if necessary. Next, these carboxylic acids and/or carboxylic esters are hydrolyzed.

The hydrolysis reaction can be easily carried out by conventionally known methods, and is preferably carried out in an aqueous solution containing an alkaline compound or an acid. The alkali compound may be selected from hydroxides of alkali metals such as sodium, potassium, and lithium, and the acid may be H
Although Cl, HBr, etc. are used, an alkali compound is usually used.

At this time, the preferable amount of the alkali compound used is that the compound to be hydrolyzed is bis(4-
In the case of carboxydiphenyl) carbonate, the amount is 2 times or more equivalent to the carbonate, and in the case of ester of bis(4-carboxydiphenyl) carbonate, it is 4 times or more the equivalent. The hydrolysis reaction can be carried out under normal pressure or increased pressure, and heating is preferably applied in order to accelerate the reaction rate. In this case, the temperature suitable for the reaction is 30-2
It is about 00℃.

After being hydrolyzed in this way, 4
'-Hydroxybiphenyl-4-carboxylic acid can be precipitated and recovered. This can be purified by recrystallization or the like.

[0032]

According to the present invention, 4'-hydroxybiphenyl-4-carboxylic acid, which is useful as a raw material for engineering plastics and liquid crystal compounds, can be efficiently produced using bis(4-biphenyl) carbonate, which is available at low cost. We can provide a manufacturing method. Therefore, its significance from an industrial perspective is extremely large.

[0033]

[Examples] The present invention will be explained below with reference to Examples. In the examples, "parts" means "parts by weight" unless otherwise specified. Note that the present invention is not limited in any way by the examples.

[0034]

[Reference example] 102 parts of P-phenylphenol, 68.6 parts of diphenyl carbonate, 0.3 parts of potassium carbonate,
It was charged into a 300 ml glass flask equipped with a side tube and a stirrer, and heated to 300 ml over 1 hour from 200°C under a nitrogen stream.
The temperature was raised to .degree. C., and the reaction was further carried out by heating at 300.degree. C. for 3 hours. After the phenol distilled from the side pipe reached the specified amount, the reaction was terminated. After washing the reaction mixture with water, it was recrystallized from xylene to obtain a white solid. This was washed with methanol, filtered, and after drying bis(4-biphenyl) carbonate

[0035]

embedded image 68 parts were obtained. The unreacted raw material P-phenylphenol recovered from the methanol filtrate was used as a raw material for the next reaction.

[0036]

[Example 1] Bis(4-biphenyl) carbonate 33
part (0.09 mol), oxalyl chloride 34.3 parts (
0.27 mol), aluminum chloride 39.8 parts (0.3
mol), 400 parts of monochlorobenzene was charged into a three-necked 1 liter flask equipped with a stirrer, and the mixture was heated to 115 parts under a nitrogen stream.
The reaction was carried out at ℃ for 12 hours.

After the reaction was completed, the reaction mixture was poured into 1 liter of water for precipitation. 100 ml of methylene chloride was added to this to extract the soluble content. This was concentrated under reduced pressure using an evaporator to obtain 59.7 parts of solid matter. This was added to 300 ml of water along with 38 parts of excess sodium hydroxide,
Heat treatment was performed under reflux conditions for 8 hours. 2 g of activated carbon was added to the mixture and filtered while hot. After cooling, concentrated hydrochloric acid was added to the mixture to precipitate it out, and the resulting precipitate was collected by filtration. The precipitate was washed three times with methylene chloride and then dried at 60°C for 3 hours to form a white powder of 4'-hydroxyphenyl-4-.
13.2 parts of carboxylic acid were obtained. Purity test by HPLC confirmed that the purity was 99.3%.

[0038]

[Example 2] 4'-Hydroxyphenyl-4-carboxylic acid 15.4
I got the department. It was confirmed by HPLC that the purity was 99.0%.

[0039]

[Example 3] Bis(4-biphenyl) carbonate 50
(0.137 mol), 44 parts (0.409 mol) of N,N-dimethylcarbamic acid chloride, 59.4 parts (0.445 mol) of aluminum chloride, and 400 parts of monochlorobenzene in 1 liter equipped with a stirring device. The mixture was charged into a three-necked flask and reacted at 110° C. for 12 hours under a nitrogen stream. The subsequent experimental operations were performed in the same manner as in Example 1 to obtain 12.1 parts of 4'-hydroxyphenyl-4-carboxylic acid in the form of a white powder. Purity 99.99% by HPLC.
It was confirmed that it was 2%.

Claims (1)

[Claims] Claim 1: Bis(4-biphenyl) carbonate and the following formula (I) [Formula 1] [Here, X is [Formula 2] and [Formula 3]. R is an alkyl group or an aryl group. A method for producing 4'-hydroxybiphenyl-4-carboxylic acid, which comprises reacting a compound represented by the following formula in the presence of a Lewis acid, and then hydrolyzing the same.