JPH06256251A - Production of 4'-acetylbiphenyl-4-carboxylic acid - Google Patents

Abstract

PURPOSE:To provide a method for profitably producing 4'-acetylbiphenyl-4- carboxylic acid. CONSTITUTION:This is a method for producing 4'-acetylbiphenyl-4-carboxylic acid comprises oxidizing 4'-acetyl-4-methylbiphenyl with molecular oxygen in the presence of cobalt in a solution containing at least 50wt.% of a lover aliphatic monocarboxylic acid.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing 4'-acetylbiphenyl-4-carboxylic acid from 4'-acetyl-4-methylbiphenyl. 4'-acetylbiphenyl-
4-Carboxylic acid is a useful 4'-hydroxybiphenyl- as a raw material for the synthesis of liquid crystal compound intermediates and highly functional polymers.
It is useful as a raw material for 4-carboxylic acid.

[0002]

2. Description of the Related Art This 4'-hydroxybiphenyl-4-carboxylic acid can be obtained very easily by oxidizing 4'-acetylbiphenyl-4-carboxylic acid with an oxidizing agent.

A method for producing this 4'-acetylbiphenyl-4-carboxylic acid by solvolysis of 4'-acetyl-4-cyanobiphenyl in water or alcohol has been proposed (JP-A-64- 75415). However, 4'-acetyl-4-cyanobiphenyl, which is the starting material of this method, is derived from biphenyl, but this synthetic operation is complicated and is not a very preferable method.

On the other hand, with respect to 4'-hydroxybiphenyl-4-carboxylic acid, for example, p-phenylphenol is carbamate-ized with carbamic acid chloride, amidated with carbamic acid chloride in the presence of aluminum chloride, and then hydrolyzed. Method of disassembling (Japanese Patent Laid-Open No. 63-11944)
No. 0), a dibrominated or diiodinated biphenyl is monocarbonylated with carbon monoxide, and then the remaining bromine or iodine is hydrolyzed to substitute with a hydroxyl group (JP-A-63-
No. 99036) is known. However, 4'-hydroxybiphenyl was obtained from biphenyl through these methods.
The production of -4-carboxylic acid complicates the reaction process and is not an industrially advantageous method.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and an object of the present invention is industrially advantageous 4'-
It is to provide a method for producing acetylbiphenyl-4-carboxylic acid.

[0006]

The method for producing 4'-acetylbiphenyl-4-carboxylic acid according to the present invention is 4'-acetyl.
It consists of oxidizing 4-methylbiphenyl with molecular oxygen in the presence of cobalt in a solution containing at least 50% by weight of a lower aliphatic monocarboxylic acid.

The 4'-acetyl-4-methylbiphenyl used in the present invention is obtained by methylating biphenyl in the presence of an alkylation catalyst such as aluminum chloride, and converting the obtained 4-methylbiphenyl into an acylation catalyst such as aluminum chloride. Acetylation in the presence of an acetylating agent such as acetic anhydride or acetyl chloride provides a good yield and is economical.

The present invention selectively oxidizes the methyl group of 4'-acetyl-4-methylbiphenyl.
This oxidation produces at least 50 lower aliphatic monocarboxylic acids.
Performed in a solution containing wt%. In this case, the lower aliphatic monocarboxylic acid is a monocarboxylic acid having 1 to 5 carbon atoms, and formic acid, acetic acid, propionic acid or the like is preferably used. Although bromoacetic acid, which is a bromide of these, can be used, acetic acid is most preferable in practical use. The lower aliphatic monocarboxylic acid may be used as a mixture with another solvent, for example, a benzene solvent such as monochlorobenzene or dichlorobenzene. In this case, the carboxylic acid is 50% by weight.
If the above content is not contained, the oxidation reaction will not proceed sufficiently.

Cobalt is used as the metal catalyst species used in this step. In addition to cobalt, manganese, cerium,
The presence of other metals such as nickel, iron, copper and zinc does not cause any problems. This metal catalyst is
Although they can be used in the form of a simple metal, those in the form of compounds such as inorganic salts such as oxides, hydroxides, carbonates and halides, and organic acid salts of fatty acids such as formic acid, acetic acid and propionic acid can be used. It is preferable because it has high solubility in a solvent.
Particularly, an organic acid salt of a lower aliphatic monocarboxylic acid used as a solvent is preferable. Further, the metal catalyst is preferably used together with bromine such as molecular bromine, hydrogen bromide, sodium bromide, potassium bromide and ammonium bromide as a cocatalyst because the catalytic activity of the metal is improved.

As the molecular oxygen used as an oxidant, pure oxygen or industrial exhaust gas can be used, but it is most preferable to use air industrially.

The solvent used in the oxidation step, the amount of 4'-acetyl-4-methylbiphenyl as the metal catalyst and the raw material and the ratio thereof are not particularly limited, but the metal catalyst is practically used as the solvent 1 Each metal type is 0.0 per liter
When 1 to 0.5 mol and bromine as a co-catalyst are used together, it is preferable to use bromine in an element ratio of 0.01 to 5 with respect to the total amount of metals in the metal catalyst.

The reaction temperature of this reaction is preferably 40 to 220 ° C. The reaction system may be a batch system, a continuous system or a semi-batch system. The product of this reaction is 4'-acetylbiphenyl-4-carboxylic acid, 4,4'-
Obtained as a mixture of biphenyldicarboxylic acid and unreacted 4'-acetyl-4-methylbiphenyl. From this mixture, 4'-acetylbiphenyl-4-carboxylic acid can be isolated by a known method such as acid precipitation or recrystallization.

[0013]

EXAMPLE 4'-Acetylbiphenyl-4- in this example
The yield of carboxylic acid was identified and quantified by gas chromatography, high performance liquid chromatography and gas chromatograph mass spectrometry.

Example 1 2.33 g (11.1 mmol) of 4'-acetyl-4-methylbiphenyl was added to cobalt (II) acetate.
Tetrahydrate 1.37 g (5.50 mmol), sodium bromide 0.0
54 g (0.52 mmol) and 50 ml acetic acid were placed in a reaction vessel,
While stirring, oxygen gas was blown into the solution at a rate of 300 ml per minute, and the solution was heated to 90 ° C. under normal pressure. When the reaction was carried out for 2 hours, 2.61 g of a white product containing 2.34 g (yield 87.8 mol%) of 4'-acetylbiphenyl-4-carboxylic acid was obtained.

To this, 100 ml of a 1.3% aqueous sodium hydroxide solution was added, and after stirring for 30 minutes, the insoluble matter was collected by filtration. 50 ml of 2% sulfuric acid solution in this insoluble matter
Was added, the mixture was stirred for 20 minutes, and the solid matter was filtered and dried. As a result, 2.21 g (yield 83.0 mol%) of 4'-acetylbiphenyl-4-carboxylic acid having a purity of 98% or more was obtained.

Example 2 0.686 g (2.75 mmol) of cobalt (II) acetate tetrahydrate was used, and the reaction was carried out for 2 hours in the same manner as in Example 1 except that 4'- 2.51 g of a white product containing 2.06 g of acetylbiphenyl-4-carboxylic acid (yield 77.2 mol%) was obtained.

(Example 3) When the reaction temperature was 70 ° C and the reaction was carried out for 6 hours in the same manner as in Example 1, except that
2.59 g of a white product containing 2.50 g of 4'-acetylbiphenyl-4-carboxylic acid (yield 93.6 mol%) was obtained.

Example 4 The reaction temperature was set to 60 ° C., and the reaction was carried out for 6 hours in the same manner as in Example 1, except that
2.56 g of a white product containing 2.44 g (yield 91.4 mol%) of 4'-acetylbiphenyl-4-carboxylic acid was obtained.

Example 5 1.09 g (4.40 mmol) of cobalt (II) acetate tetrahydrate was used and manganese (II) acetate was further added.
Example 1 was added with 0.270 g (1.10 mmol) of tetrahydrate.
When the reaction was carried out for 2 hours in the same manner as described above, 2.14 g of 4'-acetylbiphenyl-4-carboxylic acid (yield 80.3 mol
%) Was obtained, giving 2.55 g of a yellowish white product.

Example 6 Example 6 was carried out except that 0.686 g (2.75 mmol) of cobalt acetate (II) tetrahydrate and 0.673 g (2.75 mmol) of manganese (II) acetate tetrahydrate were used. When the reaction was carried out for 2 hours in the same manner as in Example 5, 2.53 g of a yellowish white product containing 1.15 g (yield 43.0 mol%) of 4'-acetylbiphenyl-4-carboxylic acid was obtained.

EXAMPLE 7 1.09 g (4.40 mmol) of cobalt (II) acetate tetrahydrate was used and further cerium (III) acetate was used.
When the reaction was performed for 2 hours in the same manner as in Example 1 except that 0.369 g (1.10 mmol) of monohydrate was added, 4'-
Acetylbiphenyl-4-carboxylic acid 2.11 g (yield 79.
2.56 g of a pale yellow product containing 1 mol%) are obtained.

(Example 8) Cobalt acetate (I) was added to 13.88 g (66.0 mmol) of 4'-acetyl-4-methylbiphenyl.
I) tetrahydrate 1.37 g (5.50 mmol), manganese (II) acetate
0.270 g (1.10 mmol) tetrahydrate, potassium bromide 1.3
6 g (13.2 mmol), acetic acid 200 ml and chlorobenzene 1
00 ml was placed in a 0.5 liter titanium autoclave, stirred under a pressure of 30 kgf / cm2, and air was supplied at 160 per hour.
When the reaction was carried out at 120 ° C for 30 minutes while blowing it into the solution at a rate of 4 liters, 4'-acetylbiphenyl
15.25 g of a yellowish white product containing 13.35 g of 4-carboxylic acid (yield 83.5 mol%) was obtained.

(Example 9) Cobalt (II) acetate was added to 20.13 g (95.7 mmol) of 4'-acetyl-4-methylbiphenyl.
2.74 g (11.0 mmol) tetrahydrate, nickel (II) acetate 4
Hydrate 0.547 (2.20 mmol), potassium bromide 1.36 g
(13.2 mmol) and 300 ml of acetic acid were placed in a titanium autoclave of 0.5 liter, stirred under a pressure of 25 kgf / cm2, and reacted at 150 ° C. for 30 minutes while blowing air into the solution at a rate of 160 liters per hour. I went to
22.64 g of a yellowish white product containing 14.33 g of 4'-acetylbiphenyl-4-carboxylic acid (yield 62.3 mol%) was obtained.

[0024]

INDUSTRIAL APPLICABILITY The present invention is industrially advantageous in that 4'-acetyl-4-methylbiphenyl to 4'-acetylbiphenyl-
It has a special effect that 4-carboxylic acid can be produced.

Claims (1)

[Claims] 1. A 4'-acetyl-4-methylbiphenyl,
A method for producing 4'-acetylbiphenyl-4-carboxylic acid, which comprises oxidizing with a molecular oxygen in the presence of cobalt in a solution containing at least 50% by weight of a lower aliphatic monocarboxylic acid.