JPH0873402A - Production of biphenylmonocarboxylic acid - Google Patents

Abstract

PURPOSE: To reduce by-products and produce the subject compound in high yield by oxidizing a monoisopropylbiphenyl which is an inexpensive raw material with O2 in an aliphatic monocarboxylic acid solvent in the presence of a Co and/or Mn catalyst. CONSTITUTION: This method for producing biphenylmonocarboxylic acid comprises oxidizing a monoisopropylbiphenyl with molecular oxygen in the presence of a cobalt catalyst or manganese catalyst using <=3C aliphatic monocarboxylic acid as an oxidation reaction solvent. The monoisopropylbiphenyl of raw material may be a single compound not containing an isomer or a mixture of isomers. Acetic acid is especially preferably used as the solvent. An acetic acid salt of cobalt or manganese is preferably used as the oxidation catalyst. Further, a bromine compound may preferably be used together with the catalyst. Either one kind of a copper catalyst, a zinc catalyst, a cerium catalyst or lead catalyst can jointedly be used. Since production of the by-products is decreased by action of these metal ions, purification is made advantageous. The crude product is purified by recrystallizing acetic acid with crude product.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing biphenylmonocarboxylic acid (hereinafter abbreviated as BCA), and more specifically, it produces BCA by oxidizing monoisopropylbiphenyl (hereinafter abbreviated as MIPB) with molecular oxygen. On how to do. BCA is a compound useful as a raw material for highly functional polymers such as liquid crystal compounds.

[0002]

2. Description of the Related Art There are various methods for manufacturing BCA. However, the conventional methods have disadvantages which are unfavorable when they are carried out industrially. For example, Japanese Patent Laid-Open No. 62-
185055 discloses that iodinated biphenyl or brominated biphenyl is used as a raw material, and water is added to the iodinated biphenyl or a solvent system containing water in the presence of a catalyst containing a basic substance and a transition metal compound. A method of reacting with carbon monoxide in an amount equal to or greater than the halogen of brominated biphenyl is described. In this method, the raw materials are expensive, and waste liquid containing halogen etc. is by-produced,
There is a drawback that a problem of waste liquid treatment occurs.

Japanese Unexamined Patent Publication (Kokai) No. 1-83046 describes a method of oxidizing 4-ethylbiphenyl with chromic acid or alkali permanganate as a raw material. This method has a drawback that waste liquid containing chromium or the like is produced as a by-product, which causes a problem of waste liquid treatment. JP-A-4-128252
The publication describes a method in which an acylated biphenyl is used as a raw material and is oxidized with an oxidation catalyst containing a bromine compound and a heavy metal selected from cobalt, manganese, and cerium in the presence of alkyl-substituted benzenes. This method has the disadvantages that the raw materials are expensive and that alkyl-substituted benzenes are required.

In Japanese Patent Laid-Open No. 4-159247, an acylated biphenyl is used as a raw material and is oxidized with an oxidation catalyst containing a heavy metal selected from cobalt, manganese and cerium and a bromine compound in the presence of an alkyl-substituted biphenyl. How to do is described. This method has the disadvantages that the raw materials are expensive and that alkyl-substituted biphenyls are required.

JP-A-4-221341 discloses that an acylated biphenyl is used as a raw material and is oxidized with an oxidation catalyst containing a heavy metal selected from cobalt, manganese, and cerium and a bromine compound in the presence of a specific aldehyde. How to do is described. This method has the disadvantages that the raw materials are expensive and that a specific aldehyde is required. Japanese Patent Application Laid-Open No. 6-92898 describes a method of oxidizing ethylbiphenyl as a raw material and using a cobalt compound, a manganese compound and a bromine compound as a catalyst. This method has the drawback that raw materials are difficult to obtain at low cost.

[0006]

As described above, in all of the conventional methods, the problem that raw materials cannot be obtained cheaply, the problem that a waste liquid containing chromium and the like is by-produced,
It has drawbacks such as a problem that a large amount of by-products are produced. It is an object of the present invention to provide a method for manufacturing BCA that overcomes the above-mentioned drawbacks of the prior art. That is, an object of the present invention is to provide a method for producing BCA from an inexpensive raw material and without producing a waste liquid which is difficult to process as a by-product.

An object of the present invention is MIP, which is an inexpensive raw material.
It is to provide a method for producing BCA from B, and to provide a method for producing BCA with a high yield and a small amount of by-products. Another object of the present invention is to provide a method for purifying 4-BCA crude crystals with high purity as a method for purifying specific BCA.

[0008]

The present invention is characterized by oxidizing MIPB with molecular oxygen in the presence of a cobalt catalyst and / or a manganese catalyst using an aliphatic monocarboxylic acid having 3 or less carbon atoms as a solvent. It is in the manufacturing method of BCA. The present invention also resides in a method for producing purified 4-BCA, which comprises recrystallizing crude 4-BCA with acetic acid for purification.

Raw Material The MIPB used as a raw material in the present invention may be a single MIPB containing no isomer or a mixture of isomers. From the viewpoint of the efficiency of the oxidation reaction and the purity of the obtained product, the purity of MIPB used as a raw material is the BCA to be produced (for example, 4-BC).
MIPB having an isopropyl group at the position corresponding to A)
The purity of (for example, 4-MIPB) is preferably 70.
The amount is preferably at least wt%, more preferably at least 90 wt%.

Solvent In the present invention, an aliphatic monocarboxylic acid having 3 or less carbon atoms is used as a solvent for the oxidation reaction of MIPB. Examples of the aliphatic monocarboxylic acid having 3 or less carbon atoms include formic acid, acetic acid, propionic acid and the like. Of these, acetic acid is particularly preferable. As the solvent used in the present invention, one having a content of an aliphatic monocarboxylic acid having 3 or less carbon atoms of 50% by weight or more, preferably 70% by weight or more, more preferably 90% by weight or more is suitable. The amount of the solvent used is 1 to 40 times, preferably 2 to 20 times the weight of the raw material.

Oxidation Catalyst The cobalt catalyst and manganese catalyst used as the oxidation catalyst contain cobalt (Co) and manganese (Mn) as active components, respectively. The cobalt catalyst and the manganese catalyst are used in a state of being dissolved in a solvent (reaction liquid). The cobalt catalyst and manganese catalyst may be of any form as long as they can be dissolved in the reaction solution in the oxidation reaction system, and the type and form thereof are not particularly limited.

Examples of the cobalt catalyst and the manganese catalyst include metallic manganese, metallic cobalt and various manganese compounds and cobalt compounds. Manganese compounds and cobalt compounds include manganese and cobalt oxides;
Hydroxides; inorganic salts such as carbonates, basic carbonates and halides; salts with organic carboxylic acids such as formic acid, acetic acid, propionic acid, naphthenic acid and aromatic carboxylic acids. Of these, bromide and fatty acid salts are preferable, and acetate is particularly preferable.

The amount of cobalt catalyst and / or manganese catalyst used is 0.05 to 20 mmol, preferably 0.25 to 20 mmol, respectively, as cobalt atom and manganese atom per 100 g of the solvent, whether used alone or in combination. It is good to set it to 10 mmol.

In a preferred embodiment of the present invention, a cobalt catalyst and / or a manganese catalyst are used in combination with a bromine compound as the oxidation catalyst. The bromine compound used as the catalyst produces bromine ions in the reaction system.
In the present invention, the action of bromine ions increases the production rate of BCA. The bromine compound is not particularly limited as long as it produces a bromine ion in the oxidation reaction system, and its type and form are not particularly limited.

Examples of the bromine compound which is effective as a catalyst include molecular bromine, inorganic substances such as hydrogen bromide and hydrobromide, and organic compounds such as ethyl bromide and bromoacetic acid. Among these, from the viewpoint of the effect of the present invention, hydrogen bromide,
Potassium bromide and ammonium bromide are preferred. The amount of the bromine compound used is 0.05 to 20 mmol, preferably 0.25 to 1 as a bromine atom per 100 g of the solvent.
It is good to set it to 0 mmol.

In a preferred embodiment of the present invention, as the oxidation catalyst, in addition to the cobalt catalyst and / or the manganese catalyst (and the bromine compound), any one of a copper catalyst, a zinc catalyst, a cerium catalyst and a lead catalyst is further used. Types can be used together. These generate copper ions, zinc ions, cerium ions, or lead ions in the reaction system. In the present invention, by the action of these metal ions, the production of by-products is reduced, and purification is advantageous.

Examples of compounds effective as copper catalysts, zinc catalysts, cerium catalysts, and lead catalysts include copper, zinc, cerium, and lead oxides; hydroxides, carbonates, basic carbonates,
Inorganic salts such as halides; formic acid, acetic acid, propionic acid,
Examples thereof include salts with organic carboxylic acids such as naphthenic acid and aromatic carboxylic acids. Among these, bromide and fatty acid salts are preferable, and acetate is particularly preferable, from the viewpoint of the effect of the present invention. The copper catalyst, zinc catalyst, cerium catalyst and lead catalyst are used in an amount of 1/200 to 100 in terms of metal atom ratio with respect to the smaller one of the cobalt catalyst and the manganese catalyst.
It is 1/5.

Molecular oxygen used for oxidation The molecular oxygen used for oxidation of MIPB is not particularly limited, but oxygen gas or air is preferable. When oxygen gas is used, it can be diluted to an arbitrary concentration with an inert gas such as nitrogen, argon or helium. Air is preferred for industrial implementation. Oxidation of MIPB with molecular oxygen is carried out by introducing molecular oxygen together with raw materials into the reactor and stirring the reaction system.
By blowing molecular oxygen into the reaction system, it can be carried out by bringing MIPB and molecular oxygen into contact with each other.

Reaction conditions (reaction type) The oxidation reaction of MIPB is carried out by introducing MIPB as a raw material into the oxidation reaction system containing the solvent and the oxidation catalyst at once, and gradually supplying it at a constant supply rate. It can be done by. In the latter case, the efficiency of the kettle is improved, and an even better result can be obtained in terms of productivity. In this case, the feed rate of the raw material is 200 c of solvent.
With respect to c, MIPB is preferably 50 to 200 mmol / h. In this case, the amount of the solvent is 1 to 40 times, preferably 2 to 20 times by weight the total amount of the raw materials finally supplied.

(Reaction temperature) The oxidation reaction of MIPB is 80
It is good to carry out at -240 ° C, preferably 100-200 ° C.

(Reaction Pressure) The reaction pressure may be set so that the reaction solvent maintains a liquid phase at the reaction temperature, and is usually
It is preferably about ^{1 to} 40 kg / cm ² -abs. Generally, the higher the oxygen partial pressure in the system, the faster the oxidation reaction of MIPB proceeds. From a practical point of view, the oxygen partial pressure is 0.1 kg / cm ² -abs or more, preferably 0.2.
The reaction pressure is preferably about 10.0 kg / cm ² -abs.

When the reaction solution obtained by recrystallizing MIPB containing 4-MIPB as a main component is cooled, 4-BCA is precipitated. By subjecting this to solid-liquid separation by a usual method, a crude crystal of 4-BCA can be recovered. As a method for purifying the crude 4-BCA crystals, a method such as recrystallization can be employed. For example, acetic acid is preferably used as a solvent when high-purity 4-BCA is to be obtained by recrystallization.
A specific example of the recrystallization operation in this case is shown below.

First, crude crystals of 4-BCA (crude 4-B) recovered from the reaction solution obtained by the oxidation reaction of 4-MIPB.
To CA), glacial acetic acid was added and the mixture was heated to the reflux temperature to dissolve the crude crystals, and then the crystals were precipitated by cooling. next,
The precipitated 4-BCA crystals are collected by solid-liquid separation.
The cooling rate at this time is not particularly limited. Although it depends on the amount of acetic acid used, crystals are usually sufficiently precipitated by cooling until the temperature becomes 80 ° C. or lower. Considering the purity of the purified product, it is preferable to cool it to 20 ° C. or lower in terms of yield.

The amount of glacial acetic acid used is 3 to 10 times, preferably 5 to 7 times the weight of the crude crystals.
If the amount of glacial acetic acid used is too small, the purity of the purified product obtained will not effectively increase, and if it is too large, the recovery rate will be low and the productivity will be poor. According to this recrystallization method, 4-MI
Since it is possible to selectively remove 3-BCA or 2-BCA, which is a main by-product in producing 4-MCA by oxidizing PB, it is possible to efficiently produce high-purity 4-BCA. You can

[0025]

EFFECTS OF THE INVENTION According to the method for producing BCA of the present invention, BCA can be produced more simply and in a higher yield as compared with the conventional method. Further, BCA obtained by the method for producing BCA of the present invention has a low content of impurities other than BCA, so that BCA having a carboxyl group at a specific position with high purity (for example, purified 4-BCA) is present.
Can be easily manufactured.

[0026]

Example 1 A titanium 0.5 liter autoclave equipped with a reflux condenser and a rotary vane stirrer was added with 100 cc of glacial acetic acid and 1.87 g (7.5) of Co (OAc) ₂ .4H ₂ O as an oxidation catalyst.
mmol), Mn a _{(OAc) 2 · 4H 2 O} 1.84g
(7.5 mmol), 90% pure 4-MIPB.
82 g (45 mmol) was charged, a mixed gas of oxygen / nitrogen = 1 was supplied to increase the gauge pressure to 30 kg / cm ² , and the mixture was reacted at 180 ° C. for 4 hours while stirring at 1700 rpm.

After the reaction, the mixture was cooled to room temperature and solid-liquid separation was carried out to obtain 3.83 g of dry crystals of 4-BCA as crude crystals. As a result of analyzing the crude crystals by gas chromatography, the purity as 4-BCA was 99.4% by weight. From this value, the isolation yield of 4-BCA was calculated to be 43.
It was 1%.

Example 2 As an oxidation catalyst, 0.89 g (7.5 mm) of KBr was further added.
ol) The reaction was performed in the same manner as in Example 1 except that the addition was performed. As a result, 6.82 g of crude crystals were obtained. The purity of the crude crystals as 4-BCA was 99.9% by weight, and the isolated yield was 77.1%.

Example 3 Instead of 90% pure 4-MIPB as a raw material, 90%
The reaction was performed in the same manner as in Example 2 except that 3-MIPB having a% purity was used. As a result, 5.21 g of crude crystals were obtained. The purity of crude crystals as 3-BCA was 98.9% by weight, and the isolated yield was 70.5%.

[0030] Example 4 a reflux condenser and the rotary blade stirrer titanium 0.5 l autoclave in glacial acetic acid 200cc equipped with, as an oxidation catalyst of Co _{(OAc) 2 · 4H 2 O} 1.87g (7.5
mmol), Mn a _{(OAc) 2 · 4H 2 O} 1.84g
(7.5 mmol), 0.89 g of KBr (7.5 mm)
ol) was charged and the internal pressure was maintained at a gauge pressure of 10 kg / cm ² by a back pressure valve while continuously supplying air at a rate of 2 N liter / min, and the temperature was raised to 180 ° C. and maintained.

Initially, 90% pure 4-MIPB of the raw material
19.8 g /
It was continuously supplied at a rate of h (100 mmol / h) for 4 hours, and reacted at 180 ° C. for 4 hours while stirring at 1700 rpm. For air, use a back pressure valve to adjust the internal pressure to a gauge pressure of 10 kg.
/ Cm ² and the material was continuously supplied at a rate of 2 Nl / min until the completion of the material supply. As a result, 50.69g
The crude crystal of was obtained. The purity of the crude crystals as 4-BCA was 97.7% by weight, and the isolated yield was 76.1%.

[0032] 0.62g of _{Co (OAc) 2 · 4H 2} O Example 5 As the oxidation catalyst
(2.5 mmol), Mn (OAc) ₂ .4H ₂ O was added to 0.
61 g (2.4 mmol), 0.3 g of KBr (2.5 mmol)
was used in the same manner as in Example 4 except that (mmol) was used. As a result, 55.92 g of crude crystals were obtained. The purity of this crude crystal as 4-BCA is 97.1% by weight,
The isolation yield was 71.4%.

Example 6 The feed rate of the raw materials was 17.7 g / h (90 mmol / h)
Of Cu (OAc) ₂ ·.
The reaction was performed in the same manner as in Example 5 except that 0.01 g (0.05 mmol) of H ₂ O was added. As a result, 39.9
7 g of crude crystals were obtained. The purity of this crude crystal as 4-BCA was 99.7% by weight, and the isolated yield was 60.8%.

Example 7 Instead of Cu (OAc) ₂ .H ₂ O, Zn (OAc) ₂ .multidot.
The reaction was performed in the same manner as in Example 6 except that 2H ₂ O was further added as 0.011 g (0.05 mmol) oxidation catalyst. As a result, 46.48 g of crude crystals were obtained. The purity of the crude crystals as 4-BCA was 98.3% by weight, and the isolated yield was 72.7%.

Example 8 Instead of Cu (OAc) ₂ .H ₂ O, Ce (OAc) ₂ .multidot.
The reaction was performed in the same manner as in Example 6 except that 0.017 g (0.05 mmol) of 2H ₂ O was further added as an oxidation catalyst. As a result, 46.66 g of crude crystals were obtained. The purity of the crude crystals as 4-BCA was 98.2% by weight, and the isolated yield was 72.9%.

Example 9 Instead of Cu (OAc) ₂ .H ₂ O, Pb (OAc) ₂ .multidot.
The reaction was performed in the same manner as in Example 6 except that 0.019 g (0.05 mmol) of 3H ₂ O was further added as an oxidation catalyst. As a result, 44.21 g of crude crystals were obtained. The purity of the crude crystals as 4-BCA was 98.5% by weight, and the isolated yield was 64.6%.

Example 10 A crude crystal having a 4-BCA content of 89.2% and a 3-BCA content of 8.93% was recrystallized according to the following procedure. To 8.25 g of the above crude crystals, 41.25 g of glacial acetic acid was added and heated to a reflux temperature to completely dissolve the crystals. Then, the heating was stopped and the mixture was allowed to cool to room temperature. The precipitated crystals were collected by filtration. 6.12 g of crystals were obtained by dry weight. As a result of the analysis, the purity as 4-BCA was 98.1% by weight, and the content of 3-BCA was 0.7% by weight.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yosei Konishi 4-1-2, Hirano-cho, Chuo-ku, Osaka-shi, Osaka Prefecture Osaka Gas Co., Ltd.

Claims (5)

[Claims] 1. Monoisopropyl biphenyl having 3 carbon atoms
A method for producing biphenylmonocarboxylic acid, which comprises oxidizing the following aliphatic monocarboxylic acid as a solvent with molecular oxygen in the presence of a cobalt catalyst and / or a manganese catalyst. 2. The method for producing biphenylmonocarboxylic acid according to claim 1, wherein monoisopropylbiphenyl is oxidized in the presence of a bromine compound. 3. Monoisopropyl biphenyl is added to any one of a copper catalyst, a zinc catalyst, a cerium catalyst and a lead catalyst.
The method for producing a biphenylmonocarboxylic acid according to claim 1 or 2, wherein the biphenylmonocarboxylic acid is oxidized in the presence of two. 4. The method for producing 4-biphenylmonocarboxylic acid according to claim 1, wherein the monoisopropylbiphenyl is 4-monoisopropylbiphenyl. 5. A method for producing purified 4-biphenylmonocarboxylic acid, which comprises recrystallizing crude 4-biphenylmonocarboxylic acid with acetic acid for purification.