JPH0420420B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing 4,4'-biphenyldicarboxylic acid.

4,4'-biphenyldicarboxylic acid (hereinafter referred to as BPDC)
) is useful as a material for high-performance polyester resin or aramid resin having heat resistance and high strength, and various methods have been proposed for its production. However, all of the methods proposed so far have drawbacks such as being complicated or having low yields, and the reality is that it is difficult to provide an economical method for producing BPDC.

While investigating the carbonylation reaction of aromatic compounds with carbon monoxide using a hydrogen fluoride-boron fluoride catalyst, the present inventor discovered that in the carbonylation reaction of alkyl biphenyl, the aromatic group in which the alkyl group is present initially becomes the carbonyl group. We found that the 4'-position of other aromatic groups was carbonylated very selectively, even though it was expected that the 4'-position would be carbonylated. The inventors have discovered that BPDC can be obtained in high yield and have arrived at the present invention. That is, in the present invention, 4-alkylbiphenyl is reacted with carbon monoxide in the presence of a hydrogen fluoride-boron fluoride catalyst to form 4-alkyl-
This is a method for producing 4,4'-biphenyldicarboxylic acid by obtaining 4'-formylbiphenyl and then oxidizing it with a molecular oxygen-containing gas.

The 4-alkylbiphenyl used as a raw material in the present invention includes 4-methylbiphenyl, 4-ethylbiphenyl, 4-isopropylbiphenyl, etc., and these can be obtained by various methods. For example, 4-methylbiphenyl can be recovered from high-boiling oil by-product in the benzene manufacturing process by demethylating toluene. It can also be easily obtained by hydrogenating 4-formylbiphenyl (4-biphenylaldehyde), which is obtained by carbonylating biphenyl by reacting it with carbon monoxide in the presence of a hydrogen fluoride-boron fluoride catalyst. By this method, 4-methylbiphenyl can be obtained from biphenyl in a yield of 95% or more.

The conditions for carbonylation of biphenyl are, for example, hydrogen fluoride and boron fluoride as catalysts,
10:1-1.5:1, preferably 5-6:1.2-1.3:
1 in the presence of a solvent such as benzene, at a carbon monoxide partial pressure of 5 to 30 Kg/cm ² G, preferably 10 to 20
Kg/ ^cm2G , reaction temperature 5-20℃, preferably 5-10
It can be done at ℃. The conditions for hydrogenation are, for example, in the presence of a palladium catalyst supported on activated carbon, hydrogen pressure 5 to 50 Kg/cm ² G, preferably 10 to 30 G.
Kg/ ^cm2G , reaction temperature 100-200℃, preferably 120
~150℃.

4-Ethylbiphenyl and 4-isopropylbiphenyl are currently produced for use as heat transfer oils by alkylating biphenyl with ethylene or propylene. It is easy to get the product.

As a method for carbonylating 4-alkylbiphenyl, a conventional method for carbonylating alkylbenzenes, which has already been established as an industrial production process for aromatic aldehydes, can be applied.

The reaction conditions are, for example, alkyl biphenyl:
Using a catalyst composition of boron fluoride: hydrogen fluoride = 1:1.1-1.7:5-10 (mole ratio), carbon monoxide partial pressure 10-20
By reacting for 15 to 30 minutes at Kg/cm ² G and reaction temperature of 0 to 20°C, the reaction proceeds smoothly and the desired 4-alkyl-4'- is produced in extremely high yield and high selectivity.
Formylbiphenyl (4,4'-alkylbiphenylaldehyde) can be obtained.

Induction of BPDC by oxidation of 4-alkyl-4'-formylbiphenyl is also relatively easy, and can be carried out using various catalyst systems in the presence of a solvent such as acetic acid.
In either case, BPDC can be obtained in high yield.

As described above, the present invention provides a method for rationally producing useful BPDC from easily available raw materials through simple steps, and has high industrial value.

Example 1 (Carbonylation of alkylbiphenyl) Biphenyl was carbonylated with CO using HF- _BF3 catalyst to produce 4-biphenylaldehyde (selectivity
The following carbonylation was carried out using 4-methylbiphenyl obtained by reducing the aldehyde group with methyl using a Pd/carbon catalyst as a raw material.

A stirred autoclave with a volume of 5 was used as the carbonylation reactor. The reactor can be cooled by a jacket of refrigerant.

1136 g (99.6% purity, 6.73 mol) of 4-methylbiphenyl was dissolved in 568 g (7.3 mol) of benzene and charged into the reactor, followed by 1200 g (60 mol) of HF and 640 g with stirring and cooling.
(9.4 mol) of BF ₃ gas was charged, and an HF-BF ₃ complex solution of 4-methylbiphenyl was prepared. CO gas was introduced while stirring and cooling, and carbonylation was carried out while maintaining the pressure of the reactor at 20 kg/cm ² G. Absorption of CO, which was accompanied by heat generation, stopped in about 15 minutes. During this time, the reaction temperature was maintained at about 10°C. After the reaction was completed, the contents were extracted into ice water, and the oil layer was washed with alkaline water and water, and 4,4'-methylbiphenylaldehyde (boiling point: 170°C/4mmHg) was obtained by distillation.
Conversion rate of 4-methylbiphenyl to aldehyde
80%, selectivity of 4,4′ isomer in aldehyde is 97%
It was hot.

4-ethylbiphenyl, which was contained in 52% of Nippon Steel Chemical's Therm S600, was separated and purified by distillation and crystallization, and used as a raw material for carbonylation.

Two autoclaves were used as carbonylation reactors. HF1100g in autoclave
After charging (55 mol), while stirring and cooling,
The reactor was kept pressurized at 20 Kg/cm ² G with CO gas. In this state, the metering pump will give you 70g per minute.
(0.38 mol) of 4-ethylbiphenyl 70wt%
Supplied as a benzene solution, 39g/min at the same time
(0.58 mol) of BF ₃ gas was fed into the reactor for 15 minutes by cylinder pressure, and after the feeding was stopped, the reaction was continued for an additional 5 minutes, and then the internal liquid was taken out and treated in the same manner. During the reaction, the heat of reaction was removed by the refrigerant in the jacket, and the internal temperature was maintained at 5°C. Preparation 4-
The yield of aldehyde based on ethylbiphenyl is
The selectivity to 4,4'-ethylbiphenylaldehyde was 98%.

Example 2 (oxidation of 4,4'-methylbiphenylaldehyde) 40 g of 4,4'-methylbiphenylaldehyde,
0.44 g of cobalt bromide hexahydrate and 0.33 g of manganese acetate tetrahydrate were charged together with 200 g of 95% acetic acid into a titanium high-speed electromagnetic stirring autoclave equipped with a gas inlet and a stirrer, and the reaction temperature was increased. Air is introduced while maintaining the temperature at 200°C and the pressure at 20Kg/cm ² G.

The reaction occurred immediately, and rapid oxygen absorption was observed. The reaction continued even when there was no substantial oxygen absorption, for a total of 1.5 hours.

The reaction solution was filtered, washed with acetic acid and water, and dried to obtain crude 4,4'-biphenyldicarboxylic acid as a powder solid.
Got 45g.

Example 3 (oxidation of 4,4'-ethylbiphenylaldehyde) 40 g of 4,4'-diethylbiphenylaldehyde,
Charge 40g of cobalt acetate tetrahydrate with 200g of 95% acetic acid into the autoclave described above, and adjust the reaction temperature.
Air is introduced while maintaining the temperature at 150°C and the pressure at 20Kg/cm ² G.

The reaction occurred immediately, and rapid oxygen absorption was observed.

The reaction was carried out for 1.5 hours. The reaction solution was treated in the same manner as described above to obtain 41 g of crude 4,4'-biphenylcarboxylic acid as a powdery solid.

Claims (1)

[Claims] 1 4-Alkylbiphenyl is reacted with carbon monoxide in the presence of a hydrogen fluoride-boron fluoride catalyst to obtain 4-alkyl-4'-formylbiphenyl, which is then oxidized with a molecular oxygen-containing gas. A method for producing 4,4'-biphenyl dicarboxylic acid, characterized by the following.