JPH04261138A - Production of diaryldicarboxylic acid - Google Patents

Abstract

PURPOSE:To produce a high-purity diaryldicarboxylic acid in high yield at a low production cost by using an inexpensive copper-based catalyst in a smaller catalytic amount than that of a conventional expensive cobalt-based catalyst. CONSTITUTION:The above-mentioned method is a method for producing a diaryldicarboxylic acid as follows. A dialkyl-substituted diaryl compound is used as a raw material and oxidized with a molecular oxygen-containing gas in the liquid phase in an organic solvent to produce the objective diaryldicarboxylic acid. In the process, a catalyst system composed of copper and bromine, a catalyst system composed of copper, bromine and manganese, a catalyst system composed of copper, bromine and a heavy metal, a catalyst system composed of copper, bromine, manganese and a heavy metal or a catalyst system composed of copper, bromine, an amine compound and a heavy metal is used as a catalyst to carry out the reaction.

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 diaryldicarboxylic acids by liquid-phase oxidation of dialkyl-substituted diaryl compounds with molecular oxygen in an organic solvent.

0002

BACKGROUND OF THE INVENTION Diaryldicarboxylic acids are important compounds used as copolymerization components in fibers, films, plasticizers, synthetic resins, etc.

[0003] As a method for producing this diaryldicarboxylic acid, cobalt, manganese,
A method of oxidizing 4,4'-dimethylbiphenyl with molecular oxygen in the presence of a catalyst system consisting of bromine and bromine is known.
Khim. 40(4), 935-6 (1967))
, ■ A method for oxidizing 4,4'-diethylbiphenyl (see JP-A-2-32041 and JP-A-63-63638), ■ A method for oxidizing 4,4'-diisopropylbiphenyl (see JP-A-63-63638) -Refer to Publication No. 122645)
, (2) A method of oxidizing 4,4'-dicyclohexylbiphenyl (see Japanese Patent Application Laid-Open No. 16831/1983), etc. are known.

[0004] Furthermore, JP-A-63-310846 discloses a method for producing various diaryldicarboxylic acids using a catalyst system similar to that described above.

[0005]

[Problems to be Solved by the Invention] In the method (2) above, 4,4'-biphenyldicarboxylic acid is obtained in a yield of 79 mol% by performing oxidation in an acetic acid solvent using a catalyst consisting of cobalt and bromine. However, since it is necessary to use an expensive cobalt catalyst as much as 20% by weight based on the raw material, there is a problem in that the manufacturing cost is high. Moreover, the yield is also not sufficient.

[0006] In addition, in the method (2) above, the reaction is carried out using a catalyst consisting of cobalt, manganese, and bromine in an acetic acid solvent, but 4,4
In order to obtain '-biphenyldicarboxylic acid, it is necessary to use a catalyst containing expensive cobalt in an amount of 15% by weight or more based on the substrate, which also increases the production cost.

[0007] In addition, in the method (2) above, the reaction is carried out using a catalyst consisting of cobalt, manganese, and bromine in an acetic acid solvent in an amount of 15% by weight or more based on the raw materials, and the yield is 35.8%. The yield is low (mol%).

[0008] Also, in method (1) above, the reaction is carried out using the same catalyst component as in methods (2), (2), and (3) at 30% by weight or more based on the raw materials, and the yield is 40% by mole. The yield is still low.

[0009] In addition, in the method (2) above, diaryldicarboxylic acid is produced from various dialkyl-substituted diaryl compounds at a high yield of 90 mol% or more using a catalyst system containing cobalt and bromine as essential components. However, according to studies conducted by the inventors of the present application, it was found that the product was deeply colored. This is due to the cobalt catalyst itself and the production of a large amount of easily colored by-products and tar-like substances.

[0010] Furthermore, since an expensive cobalt catalyst is essential, it is difficult to say that it is industrially sufficient in terms of production cost.

[0011] As described above, the above conventional method uses an expensive cobalt catalyst, and also requires a large amount of a catalyst system containing this cobalt catalyst, so that it is not industrially satisfactory in terms of manufacturing cost. Further, it cannot be said that a method for producing a less colored diaryldicarboxylic acid in high yield from a dialkyl-substituted diaryl compound using the above-mentioned conventional catalyst has yet been established.

The present invention was made in view of the above, and its object is to use a new inexpensive catalyst system using a dialkyl-substituted diaryl compound as a raw material, thereby achieving a high yield with a smaller amount of catalyst than before. It is an object of the present invention to provide a production method capable of obtaining diaryldicarboxylic acid with low coloring at a high rate.

[0013]

[Means for Solving the Problems] In order to solve the above problems, the inventors of the present application have solved the above problems by formula (I)

[0014]

[C3]

(In the formula, -A- is a direct bond, -O-, -S
-, -SO2 -, -CO-, -CH2 -, and R and R' represent an alkyl group or an alicyclic hydrocarbon group having 1 to 6 carbon atoms, which may be the same or different. ) is oxidized in a liquid phase with a molecular oxygen-containing gas in an organic solvent,
General formula (II)

[0016]

[C4]

(In the formula, -A'- is a direct bond, -O-, -
Represents either SO2 - or -CO-. ) We investigated various catalysts as oxidation catalysts in the method for producing the diaryldicarboxylic acid represented by (2), and found that a catalyst system consisting of copper and bromine, a catalyst system consisting of copper, bromine, and a heavy metal element, and a catalyst system consisting of copper, bromine, and an amine compound. By using a catalyst system consisting of copper, bromine, an amine compound, and a heavy metal element, the amount of catalyst is reduced and the cost is lower than that of the conventionally used catalyst system consisting of cobalt, manganese, and bromine. They also discovered that the desired diaryldicarboxylic acid can be obtained in high yield and purity, and have completed the present invention.

That is, the present invention provides a method for producing diaryldicarboxylic acid by using a dialkyl-substituted diaryl compound as a raw material and subjecting it to liquid-phase oxidation with a molecular oxygen-containing gas in an organic solvent. It is characterized by allowing

Examples of the above-mentioned catalyst system include those having the following configuration.

(1) Catalyst system consisting of copper and bromine (the atomic ratio of copper and bromine is 0.0 when copper:bromine=1:a).
1≦a≦100).

(2) Catalyst system consisting of copper, bromine, and manganese (the atomic ratio of copper, bromine, and manganese is 0.1≦a≦10, assuming that copper:bromine:manganese=1:a:b)
0, 0.1≦b≦100).

(3) A catalyst system consisting of copper, bromine, manganese, and heavy metals (the atomic ratio of copper, bromine, manganese, and X is copper:bromine:manganese:heavy metal=1:a:b:c) 0.1≦a≦100, 0.1≦b≦100
0.1≦c≦100. ) (4) Catalyst system consisting of copper, bromine, and heavy metals (the atomic ratio of copper, bromine, and heavy metals is 0.1, assuming copper:bromine:heavy metals = 1:a:c)
≦a≦100, 0.1≦c≦100).

(5) A catalyst system consisting of copper, bromine, and an amine compound (the ratio of the number of atoms of copper and bromine elements and the number of moles of the amine compound is copper:bromine:amine compound=1:a:d
Then, 0.1≦a≦100, 0.1≦d≦100).

(6) A catalyst system consisting of copper, bromine, an amine compound, and a heavy metal (the ratio of the number of atoms of copper, bromine, and heavy metal and the number of moles of the amine compound is copper:bromine:amine compound:heavy metal=1:a :d:e, then 0.1≦a≦10
0, 0.1≦d≦100, 0.1≦e≦100)
.

[0025] The copper compounds contained as these catalyst components include, for example, copper carboxylates such as formic acid, acetic acid, and naphthenic acid, and organic compounds such as copper acetylacetonate complexes, or copper hydroxides. Examples include inorganic compounds such as compounds, oxides, chlorides, bromides, and nitrates. Note that these copper salts may be anhydrous salts or hydrated salts.

[0026] Examples of the above-mentioned bromine include various bromine compounds such as hydrogen bromide, ammonium bromide, and metal bromides.

[0027] The heavy metal in the catalysts (3), (4), and (6) is one or more metal elements selected from the group consisting of vanadium, manganese, iron, cobalt, nickel, palladium, and cerium. Examples of the form of the compound used include salts similar to those of the copper compound described above.

[0028] Examples of the amine compound in the catalysts (5) and (6) include pyridine, pyrazine,
Examples include heterocyclic amine compounds such as piperazine, picoline, lutidine, and quinoline, and alkylamines that are liquid at room temperature such as ethylenediamine, monopropylamine, dipropylamine, monobutylamine, and dibutylamine. Preferred amine compounds include pyridine, pyrazine and quinoline from the standpoint of stability under oxidizing conditions, with pyridine being particularly preferred.

By the way, each of the above-mentioned catalyst systems used in the reaction functions effectively by introducing predetermined amounts of their constituent inorganic compounds and amine compounds into a solvent. However, depending on the type of solvent used, perhaps due to differences in the solubility of the above inorganic compounds in solvents,
The yield of diaryldicarboxylic acid varies. Therefore, in this case, the solvent should be acetic acid, propionic acid, etc. with 3 carbon atoms.
The following aliphatic monocarboxylic acids are preferred, and acetic acid is particularly preferred since it is economically efficient.

On the other hand, when a catalyst system containing an amine compound is used, it is also possible to use a solvent other than acetic acid. Examples of solvents used in addition to acetic acid include the aforementioned aliphatic monocarboxylic acids, benzene, nitrobenzene, monochlorobenzene, dichlorobenzene, and benzoic acid.

[0031] Copper bromide (CuBr2) is also used as a catalyst.
, cobalt bromide (CoBr2) or manganese bromide (M
Pyridine complex [Cu1-X (Co or Mn)X B
r2Py2].

In the present invention, the dialkyl-substituted diaryl compound represented by the above general formula (I) is oxidized to a diaryldicarboxylic acid represented by the above general formula (II). Here, R and R' in general formula (I) are
It is oxidized to become a COOH group, and the general formula (I)
When -A- is -S- or -CH2-,
These are also oxidized to -SO2 - and -CO-, respectively. In addition, -A- in general formula (I) is a direct bond, -O-,
In the case of -SO2- or -CO-, the general formula (II
) in ) is the same as -A-.

Examples of the dialkyl-substituted diaryl compounds include dialkyl-substituted diaryls having an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group as a substituent. Specific examples of the dialkyl-substituted diaryl compound and the obtained diaryldicarboxylic acid are as follows: 4
, 4'-dimethylbiphenyl and 4,4'-biphenyldicarboxylic acid, 3,3'-dimethylbiphenyl and 3,3'
-biphenyldicarboxylic acid, 3,4'-dimethylbiphenyl and 3,4'-biphenyldicarboxylic acid, 4,4'-
Diethylbiphenyl and 4,4'-biphenyldicarboxylic acid, 3,3'-diethylbiphenyl and 3,3'-biphenyldicarboxylic acid, 3,4'-dimethylbiphenyl and 3
, 4'-biphenyldicarboxylic acid, 4,4'-diisopropylbiphenyl and 4,4'-biphenyldicarboxylic acid, 3,3'-diisopropylbiphenyl and 3,3'-biphenyldicarboxylic acid, 3,4'-diisopropylbiphenyl and 3,4'-biphenyldicarboxylic acid, 4,4'
-dicyclohexyl biphenyl and 4,4'-biphenyl dicarboxylic acid, 4,4'-dimethyl diphenyl ether and 4,4'-diphenyl ether dicarboxylic acid, 4,4
'-Dimethylbenzophenone and 4,4'-benzophenonedicarboxylic acid, 4,4'-dimethyldiphenylsulfone and 4,4'-diphenylsulfonedicarboxylic acid, 4,
Examples include 4'-dimethyldiphenyl sulfide and 4,4'-diphenylsulfonedicarboxylic acid, bis(4-methylphenyl)methane and 4,4'-benzophenonedicarboxylic acid.

[0034] The above diaryldicarboxylic acid is specifically produced by the method shown below.

That is, an organic solvent, the dialkyl-substituted diaryl compound as a raw material, and the catalyst are added in predetermined amounts to a reaction tank, and the mixture is reacted at a predetermined temperature under pressure and stirring while supplying a molecular oxygen-containing gas.

Alternatively, a predetermined amount of an organic solvent and a catalyst are charged into a reaction tank, and while a molecular oxygen-containing gas is supplied, a dialkyl-substituted diaryl compound is continuously or intermittently supplied, and a predetermined amount of the dialkyl-substituted diaryl compound is fed under pressure and with stirring. The reaction can also be carried out at a temperature of When carrying out the reaction using this method, a portion of the raw material dialkyl-substituted diaryl compound may be added to the reaction tank in advance and reacted, or on the other hand, the reaction may be continued while a portion of the diaryldicarboxylic acid produced is extracted. You may do so.

[0037] The amount of catalyst used in the present invention ranges from 0.01 to 20% by weight, more preferably 0.01 to 20% by weight based on the raw material.
．． It ranges from 5 to 15% by weight. If the concentration is lower than this range, the activity will not be sufficiently exhibited, and if the concentration is higher than the upper limit concentration, it is undesirable because of limited solubility and an increase in by-products.

[0038] In the present invention, by using an inexpensive copper-based catalyst within the above range, the amount of catalyst used is smaller than that of conventional cobalt-based catalysts, and the desired product can be advantageously obtained at a low manufacturing cost. .

As the molecular oxygen-containing gas, oxygen or a mixed gas of oxygen diluted with an inert gas can be used, but from an industrial perspective, it is preferable to use air.

[0040] When air is used as the molecular oxygen-containing gas, the reaction temperature is within a temperature range at which the reaction proceeds rapidly and at which large amounts of undesired by-products such as tar-like substances and carbonized substances are not produced. , i.e. 150-220
A temperature range of 0.degree. C. is preferred.

On the other hand, when using air, the reaction pressure may be any pressure that can maintain the liquid phase, and may be 5 to 50 kg.
/cm2 range, more preferably 10-40kg/c
m2 range.

[0042] Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto.

The conversion rate of raw materials and the yield of diaryldicarboxylic acid in Examples and Comparative Examples shall comply with the following definitions.

Conversion rate (%) = (Number of moles of raw material consumed) x 100/(Number of moles of raw material supplied) Yield of diaryldicarboxylic acid (%) = (Number of moles of diaryldicarboxylic acid produced) ×100/(number of moles of supplied raw material) In addition, the solvent and reagent used were those of JIS grade 1 or higher.

[0045]

[Example] [Example 1] Stirrer, cooler, gas blowing pipe,
Add 300 g of acetic acid as a solvent to a titanate autoclave (1 liter) with a raw material supply line and a constant differential pressure valve.
, copper acetate [Cu(OAc)2.H2O] as a catalyst.
Prepare 2 g and 3 g of potassium bromide [KBr],
After heating to 70° C., the pressure was increased to 30 kg/cm 2 with air. After that, while supplying air at a supply rate of 200 liters/hr, the internal pressure was maintained at 30 kg/cm2, and 4.
60.0 g of 4'-diisopropylbiphenyl was sequentially fed over 5 hours to cause a reaction, and then only air was fed for 1 hour to continue the reaction, and then the reaction was stopped.

When the reaction product was analyzed by liquid chromatography, as shown in Table 1, the conversion rate of 4,4'-diisopropylbiphenyl was 100%, and the yield of 4,4'-biphenyl dicarboxylic acid was 88%. Met.

The amount of the catalyst used is 8.3% by weight based on the raw material.

[Examples 2 to 15] Reactions in Examples 2 to 15 were carried out in the same reaction manner as in Example 1 above.

That is, the reaction was carried out under the same conditions as in Example 1, except that the catalyst components, their composition ratios, amounts used, reaction temperatures and reaction pressures were changed as shown in Tables 1 and 2.

[0050] The results are also shown in Tables 1 and 2.

[Example 16] The reaction was carried out under the same conditions as in Example 3, except that the composition ratio and amount of catalyst used were changed as shown in Table 2. The amount of catalyst used at this time was 7.7% by weight based on the raw material. The results are also shown in Table 2.

[Examples 17 to 19] Acetic acid 25 as a solvent
The reaction was carried out under the same conditions as in Example 3, except that 0 g was used and a catalyst consisting of copper, bromine, and manganese was used in the composition ratio shown in Table 2. In addition, the results are shown in Table 2.
It was shown to.

[Examples 20 and 21] Catalysts consisting of copper, bromine, manganese, and heavy metals (iron or cerium) were prepared in Table 2.
The reaction was carried out under the same conditions as in Example 17, except that the composition ratio shown was used. Further, the results are shown in Table 2.

As can be seen from the results of Examples 1 to 21, when a catalyst system consisting of copper and bromine or a catalyst system consisting of copper, bromine, and heavy metal elements is used as a catalyst in the production of diaryldicarboxylic acid, , even when the amount of catalyst used is 15% by weight or less based on the raw material,
4,4'-biphenyldicarboxylic acid has been obtained in a high yield of over 80%, and 4,4'-biphenyldicarboxylic acid can be obtained with a smaller amount of catalyst than conventional methods.
It is clear that the yield of '-biphenyldicarboxylic acid is improved.

Furthermore, when manganese, iron, nickel, palladium, and cerium are used as catalyst components, the crude cake after the reaction is only slightly colored, and when cobalt and vanadium are used, it is pale yellow. Was.

[Example 22] In Example 3, 4,4'-diisopropylbiphenyl was replaced with 4,4'-diisopropylbiphenyl.
The reaction was carried out under the same conditions except that 4'-dimethylbiphenyl was used and the composition ratio and amount of the catalyst were changed as shown in Table 3. The amount of catalyst used at this time was 2.7% by weight based on the raw material. Further, the results are shown in Table 3.

[Example 23] In Example 8, instead of the raw material 4,4'-diisopropylbiphenyl, 4,
The reaction was carried out under the same conditions except that 4'-dimethylbiphenyl was used and the composition ratio and amount of the catalyst were changed as shown in Table 3. The amount of catalyst used at this time is
It is 2.7% by weight based on the raw material. Further, the results are shown in Table 3.

[Example 24] In Example 10, instead of the raw material 4,4'-diisopropylbiphenyl, 4
, 4'-dimethylbiphenyl, and 0.1 g of copper acetylacetone [Cu(AA)2] as a catalyst.
Ammonium bromide [NH4Br] 0.57 g and cobalt acetate [Co(OAc)3 .4H2O] 0.57
The reaction was carried out under the same conditions except that g was used.

[0059] The amount of catalyst used at this time is 2
．． It is 1% by weight. Further, the results are shown in Table 3.

[Example 25] In Example 22, 4,4'-dimethylbiphenyl as the raw material was replaced with 4,4'-dimethylbiphenyl.
The reaction was carried out under the same conditions except that -diethylbiphenyl was used. Further, the results are shown in Table 3.

[Example 26] In Example 23, 4,4'-dimethylbiphenyl was used instead of the raw material 4,4'-dimethylbiphenyl.
The reaction was carried out under the same conditions except that -diethylbiphenyl was used. Further, the results are shown in Table 3.

[Example 27] In Example 24, 4,4'-dimethylbiphenyl as the raw material was replaced with 4,4'-dimethylbiphenyl.
The reaction was carried out under the same conditions except that -diethylbiphenyl was used. Further, the results are shown in Table 3.

[Example 28] In Example 22, 4,4'-dimethylbiphenyl as the raw material was replaced with 4,4'-dimethylbiphenyl.
The reaction was carried out under the same conditions except that -dimethyldiphenyl ether was used. Further, the results are shown in Table 3.

[Example 29] In Example 23, 4,4'-dimethylbiphenyl as the raw material was replaced with 4,4'-dimethylbiphenyl.
The reaction was carried out under the same conditions except that -dimethyldiphenyl ether was used. Further, the results are shown in Table 3.

[Example 30] In Example 22, 4,4'-dimethylbiphenyl as the raw material was replaced with 4,4'-dimethylbiphenyl.
The reaction was carried out under the same conditions except that -dimethyldiphenylsulfone was used. Further, the results are shown in Table 4.

[Example 31] In Example 23, 4,4'-dimethylbiphenyl as the raw material was replaced with 4,4'-dimethylbiphenyl.
The reaction was carried out under the same conditions except that -dimethyldiphenylsulfone was used. Further, the results are shown in Table 4.

[Example 32] In Example 22, 4,4'-dimethylbiphenyl as a raw material was replaced with 4,4'-dimethylbiphenyl.
The reaction was carried out under the same conditions except that -dimethylbenzophenone was used. Further, the results are shown in Table 3.

[Example 33] In Example 23, 4,4'-dimethylbiphenyl as the raw material was replaced with 4,4'-dimethylbiphenyl.
The reaction was carried out under the same conditions except that -dimethylbenzophenone was used. Further, the results are shown in Table 4.

As can be seen from the results of Examples 22 to 33, in addition to 4,4'-diisopropylbiphenyl, 4,4'-dimethylbiphenyl, 4,4'
-diethylbiphenyl, 4,4'-dimethyldiphenyl ether, 4,4'-dimethyldiphenyl sulfone, 4
, 4'-dimethylbenzophenone, the catalyst amount is 2.1% by weight or 2.7% by weight based on the raw material.
Despite the small amount used, such as 4% by weight,
,4'-biphenyldicarboxylic acid has been obtained with a high yield of over 90%, and 4,4'-biphenyldicarboxylic acid can be obtained with a smaller amount of catalyst than conventionally.
It is clear that the yield of -biphenyldicarboxylic acid is improved.

[Example 34] In Example 17, 3,4'-diisopropylbiphenyl was substituted for the raw material.
The reaction was carried out under the same conditions except that 4'-diisopropylbiphenyl was used and the composition ratio and amount of the catalyst were changed as shown in Table 4. Further, the results are shown in Table 4.

[Example 35] In Example 20, 3,4'-diisopropylbiphenyl was replaced with 4,4'-diisopropylbiphenyl.
The reaction was carried out under the same conditions except that 3'-diisopropylbiphenyl was used and the catalyst components, composition ratios, and amounts used were changed as shown in Table 4. In addition, the results are shown in Table 4.
It was shown to.

As can be seen from the results of Examples 34 and 35, 3,4'-diisopropylbiphenyl, 3,3'-diisopropylbiphenyl,
3 with a smaller amount of catalyst than before.
, 4'-biphenyldicarboxylic acid, or 3,3'-
It is clear that the yield of biphenyldicarboxylic acid is improved.

[Examples 36 to 40] In Example 1,
As a catalyst, 3.53 g of copper bromide [CuBr] and 2.5 g of pyridine were used, and as a solvent, 250 g of benzene was used.
The reaction was carried out under the same conditions except that . Further, the results are shown in Table 5.

[Example 37] Same conditions as in Example 36 except that 1.76 g of copper bromide [CuBr], 1.70 g of manganese bromide [MnBr2], and 2.5 g of pyridine were used as catalysts. The reaction was carried out. Further, the results are shown in Table 5.

[Example 38] In Example 36, the complex [Cu0.1Co0.9Br2Py2]4 was used as a catalyst.
．． The reaction was carried out under the same conditions except that 0 g was used. Further, the results are shown in Table 5.

[Examples 39 and 40] Same as Example 38 except that o-dichlorobenzene was used as the solvent and the catalyst components, composition ratio, and amount used were changed as shown in Table 5. The reaction was carried out under the following conditions. Further, the results are shown in Table 5.

[Example 41] In Example 40, copper acetate [Cu(OAc)2.H2O]0.
1g, potassium bromide [KBr] 3.0g, pyridine 1
．． 5g, manganese acetate [Mn(OAc)2.4H2O
] The reaction was carried out under the same reaction conditions except that 4.0 g was used. Further, the results are shown in Table 5.

[Examples 42 and 43] In Example 41, 250 g of benzene was used as the solvent, and 3,4'-diisopropylbiphenyl or 3,4'-diisopropylbiphenyl was used as the raw material, respectively.
The reaction was carried out under the same conditions except that 3'-diisopropylbiphenyl was used and the catalyst components, composition ratios, and amounts used were changed as shown in Table 5. Further, the results are shown in Table 5.

As can be seen from the results of Examples 36 to 43, when using a catalyst system consisting of copper, bromine and an amine compound, or a catalyst system consisting of copper, bromine, an amine compound and a heavy metal element, Even if the catalyst amount is 15% by weight or less based on the raw material, diaryldicarboxylic acid can be obtained in high yield. Moreover, when benzene or o-dichlorobenzene is used as a solvent in addition to acetic acid, diaryldicarboxylic acid can be obtained in high yield.

[Comparative Example 1] A reaction was carried out using a conventionally used catalyst system, and a comparative study with the catalyst system according to the present invention was attempted.

That is, as a conventionally used catalyst system,
The reaction was carried out under the same conditions as in Example 1, except that 9.0 g (15% by weight of the raw materials) of the catalyst system consisting of cobalt, manganese and bromine shown in Table 6 was used. Further, the results are shown in Table 6.

From this result, it is clear that the yield of 4,4'-biphenyldicarboxylic acid is lower than that in the previous example.

On the other hand, although not shown, the observation results show that a lot of tar-like substances, which are thought to be by-products, are observed in the reaction product, and the obtained 4,4'-biphenyldicarboxylic acid is colored brown. Was.

[Comparative Example 2] The reaction was carried out under the same conditions as in Example 2 except that only copper acetate among the catalyst components was removed. Further, the results are shown in Table 6.

From this result, it is clear that the yield of 4,4'-biphenyldicarboxylic acid is lower than that in the above examples. This indicates that copper is an essential component in the catalyst system related to the present invention.

[Comparative Example 3] In Example 3, potassium bromide was not added and the amount of manganese acetate used was 9.0
The reaction was carried out under the same conditions except that g. Further, the results are shown in Table 6.

The raw material conversion rate of this reaction was as low as 64%, and the yield of 4,4'-biphenyldicarboxylic acid was also as poor as 7%. This indicates that bromine is an essential component in the catalyst system related to the present invention.

[0088]

[Table 1]

[0089]

[Table 2]

[0090]

[Table 3]

[0091]

[Table 4]

[0092]

[Table 5]

[0093]

[Table 6]

[0094]

According to the method of the present invention, by using a dialkyl-substituted diaryl compound as a raw material and an inexpensive copper-based catalyst, the amount of catalyst is lower than that of the conventional expensive cobalt-based catalyst, and the yield is high. Diarylcarboxylic acid with less coloring can be obtained. That is, it is possible to industrially advantageously produce diaryldicarboxylic acid at a lower production cost than in the past, in high yield, and with high purity.

Claims (7)

[Claims] Claim 1: General formula [Formula 1] (wherein -A- is a direct bond, -O-, -S-, -SO2
-, -CO-, -CH2 -, and R and R' have 1 to 1 carbon atoms, which may be the same or different.
6 represents an alkyl group or an alicyclic hydrocarbon group. ) is subjected to liquid phase oxidation with a molecular oxygen-containing gas in an organic solvent.
] (In the formula, -A'- is a direct bond, -O-, -SO2 -,
-CO- represents either. ) Copper and bromine (the atomic ratio of copper and bromine is 0.1 when copper:bromine = 1:a)
≦a≦100. ) A method for producing diaryldicarboxylic acid, the method comprising using a catalyst system comprising: Claim 2: The catalyst system contains copper, bromine, and manganese (copper, bromine, and manganese).
The atomic ratio of bromine and manganese is copper:bromine:manganese=
If 1:a:b, 0.1≦a≦100, 0.1≦b
≦100. ) Claim 1
The method for producing the diaryldicarboxylic acid described above. 3. The catalyst system comprises copper, bromine, manganese, and
X represents one or more heavy metal elements selected from the group consisting of vanadium, iron, cobalt, nickel, palladium, and cerium, and the atomic ratio of copper, bromine, manganese, and X is copper:bromine:manganese:X= If 1:a:b:c, 0.1≦a≦100, 0.1≦b≦100, 0.1
≦c≦100. ) The method for producing diaryldicarboxylic acid according to claim 2, characterized in that the method comprises: 4. The catalyst system contains copper, bromine, and The atomic ratio of copper:bromine:X=
If 1:a:c, 0.1≦a≦100, 0.1≦c
≦100. ) Claim 1
The method for producing the diaryldicarboxylic acid described above. 5. The method for producing diaryldicarboxylic acid according to claim 1, wherein the organic solvent is acetic acid. 6. The catalyst system contains copper, bromine, and Y (Y represents an amine compound, and the ratio of the number of atoms of copper and bromine elements and the number of moles of Y is copper:bromine:Y=1:a:d Then, 0.1
≦a≦100, 0.1≦d≦100. ) The method for producing diaryldicarboxylic acid according to claim 1, characterized in that the method comprises: 7. The catalyst system is copper, bromine, Y, and Z (Y is an amine compound, Z is one or more heavy metal elements selected from the group consisting of vanadium, manganese, iron, cobalt, nickel, palladium, and cerium). represents copper, bromine, Z
The number of atoms of and the ratio of the number of moles of Y are copper:bromine:Y:Z=
If 1:a:d:e, 0.1≦a≦100, 0.1
≦d≦100, 0.1≦e≦100. ) The method for producing diaryldicarboxylic acid according to claim 6.