JPH0662497B2 - Process for producing 3,3 ', 4,4'-biphenyltetracarboxylic acid - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for dehalogenating and dimerizing 4-halogenoorthophthalic acid ester to produce 3,3 ′, 4,4′-biphenyltetracarboxylic acid. .

[Conventional technology]

Conventionally, as to the method for producing 3,3 ′, 4,4′-biphenyltetracarboxylic acid, 4-halogenoorthophthalic acid salt was dissolved with an alkali hydroxide as described in JP-A-55-20705. In the aqueous solution, a catalyst in which a metal palladium is supported on a carrier and a small amount of methanol are present, and the mixed solution is heated to 50 ° C to 150 ° C and reacted for 0.2 to 30 hours. Are known.

[Problems to be solved by the invention]

However, in this method, the yield is 29% to 58.6%.
The degree is not so good. 3,3 ', 4, obtained from this 3,3', 4,4'-biphenyltetracarboxylic acid
4'-biphenyltetracarboxylic dianhydride is applicable to applications such as a raw material for a polymer and an epoxy curing agent, and is industrially obtained in a high yield, for example, in a yield of about 80% or more. It is desirable as a raw material for various polymers in terms of price. If the yield is not good, for example, the cost of heat resistant polyimide becomes high.

An object of the present invention is to provide a method capable of producing 3,3 ′, 4,4′-biphenyltetracarboxylic acid with high yield and easy recovery in a dehalogenation dimerization reaction of 4-halogeno-orthophthalic acid ester. Especially.

[Means for solving problems]

The above-mentioned object is to obtain 4-halogeno-orthophthalic acid ester,
In an aqueous solution of 2 moles or more of a base such as alkali hydroxide dissolved in water (vs. 4-halogenoorthophthalic acid ester), a noble metal such as metallic palladium is allowed to exist together with a catalyst and a formate supported on a carrier. By heating and reacting this mixed solution, 3,3 ', 4,4'-biphenyltetracarboxylic acid can be obtained in high yield and easily recovered.

[Action]

The formate salt used in the present invention is a hydrogen donor (Hydrogen dope) for the dehalogenation dimerization reaction of 4-halogenophthalic acid ester with a catalyst in which a precious metal is supported on a carrier and a base.
nor) is a better catalyst. By using this, a catalyst in which a precious metal is supported on a carrier, a catalyst for a base, and a catalyst for alcohols produced from 4-halogenophthalic acid ester by a hydrolysis reaction are activated, and a high yield of about 80% or more is obtained. The yield is 3,3 ', 4,4'-biphenyltetracarboxylic acid.

Examples of the 4-halogenoorthophthalic acid ester used in the present invention include 4-bromoorthophthalic acid dimethyl ester, 4-bumolo-orthophthalic acid diethyl ester, 4-bromoorthophthalic acid dipropyl ester, 4
Bromo orthophthalic acid dimethyl butyl ester, and the above-mentioned 4-bromo orthophthalic acid monoalkyl ester, 4-chloro orthophthalic acid dimethyl ester, 4-chloro orthophthalic acid diethyl ester, 4-
Chloroorthophthalic acid dipropyl ester, 4-chloroorthophthalic acid dibutyl ester, and the above-mentioned 4-chloroorthophthalic acid monoalkyl ester, 4 respectively.
-Iodoorthophthalic acid monoalkyl ester, 4-iodoorthophthalic acid dialkyl ester and the like can be mentioned. Preferred are 4-bromoorthophthalic acid monoalkyl ester and 4-bromoorthophthalic acid dialkyl ester.

Known production methods of 4-halogeno-orthophthalate and its ester [for example, Ayling (J. Khem. Soc.
29,253), JP-A-56-45438, British Patent 628,401, Hano Waldman (J. Prakt. Chem., 1 ).
26 , 65-68, 193)], in addition to 4-halogeno-orthophthalate and its ester, some 3-halogeno-orthophthalate and its ester, 4,5-
Contains dihalogeno orthophthalate and its ester, unreacted orthophthalate and its ester,
A mixture of halogenoorthophthalates is obtained.

In the method of the present invention, 3,3 ', 4,4'-biphenyltetracarboxylic acid was obtained in high yield as a product by dehalogenation dimerization, even though it was a mixture of the above halogeno-orthophthalic acid ester. 2,3 ', 4,4'
-Less than expected to produce biphenyltetracarboxylic acid. Therefore, in the dehalogenation dimerization reaction of the 4-halogeno-orthophthalic acid ester of the present invention, even a mixture of 4-halogeno-orthophthalic acid salt and its ester,
It is possible to use only 4-halogeno-orthophthalic acid ester.

Examples of the base used in the present invention include alkali metal hydroxides such as potassium hydroxide, sodium hydroxide and lithium hydroxide, alkaline earth metal hydroxides such as calcium hydroxide, and carbonates such as potassium carbonate. At least one compound selected from salts, bicarbonates such as potassium bicarbonate, and alkoxides such as potassium may be mentioned. Examples of other bases include tetra-lower ammonium (1 to 3 carbon atoms) ammonium hydroxide such as tetramethylammonium hydroxide and tetraethylammonium hydroxide. Particularly preferred are potassium hydroxide and sodium hydroxide. The amount of the base used is such that the pH of the aqueous solution obtained by hydrolyzing the halogeno orthophthalic acid monoalkyl ester or the halogeno orthophthalic acid dialkyl ester is 7 or more, preferably 10 or more, that is, the above halogeno orthophthalic acid ester. 2 moles or more, particularly 2.1 to 5.0 moles are preferable with respect to the mixture. When the amount of the base used is 2.0 mol or less, the desired 3,3 ', 4,4'-
The yield of biphenyltetracarboxylic acid is extremely low and the reaction is not completed. Further, when the amount used is 5.0 mol or more, a side reaction such as generation of a phthalate salt due to dehalogenation may occur, resulting in a decrease in yield.

Moreover, as a catalyst in which a precious metal used in the present invention is carried on a carrier, for example, palladium (pd) -charcoal carbon (C),
A pd-alumina, pd-calcium carbonate or other pd-supported catalyst is particularly preferable, and a pd-charcoal carbon catalyst is particularly preferable. The content rate of pd in the catalyst in which this pd is carried on the carrier is 1
It is preferably from 0 to 10% by weight, and particularly preferably from 2.0 to 8.0% by weight. Also, platinum (pt) -carbon, ruthenium (R
u) -carbon, Ru-alumina, rhodium (Rh) -carbon,
Rh-alumina and the like can be mentioned, and the content of Pt, Ru, Rh and the like in the catalyst in which these precious metals are supported on the carrier is 1.0 to 10% by weight.

The amount of the catalyst used in the present invention in which a precious metal is supported on a carrier varies depending on the type of the catalyst, the reaction temperature, the reaction time, and other conditions, but generally the precious metal is used with respect to the mixture of halogeno-orthophthalic acid ester. Converted to 0.005
The amount may be in the range of about 5% by weight, particularly about 0.01 to 2% by weight. If the amount used is 0.005% by weight or less, the reaction does not proceed, the yield is poor, and if it is 5% by weight or more, the cost becomes high.

The dehalogenation dimerization reaction of 4-halogeno-orthophthalic acid ester has a reaction temperature of 70 to 150 ° C, preferably 90 to 150 ° C.
It is performed in the range of 120 ° C. When the reaction temperature is 70 ° C. or lower, the reaction rate is slow and it takes a long time to complete the reaction, which is not efficient. On the other hand, at a temperature of 150 ° C. or higher, the yield of the desired 3,3 ′, 4,4′-biphenyltetracarboxylic acid may decrease due to warping during the reaction or a side reaction. The reaction time is related to the amount of the above catalyst, the reaction temperature, etc.
It is usually 1 to 20 hours. It is preferably carried out for 3 to 10 hours.

As the solvent used for the dehalogenation dimerization reaction of 4-halogeno-orthophthalic acid ester, for example, water is particularly preferable.

The reaction pressure may be normal pressure, but in the dechlorination dimerization reaction of 4-chloroorthophthalic acid ester, the reaction is slow, so under a pressure of 10 kg / cm ² or less, preferably 5 kg / cm ² or less. If so, the yield is improved.

〔Example〕

Example 1 In a 300 ml four-necked flask equipped with a thermometer, a reflux condenser and a stirrer, 90 mol% of 4-bromoorthophthalic acid dimethyl ester, 0.3 mol% of 3-bromoorthophthalic acid dimethyl ester and orthophthalic acid were added. 26.6 g of a colorless liquid consisting of 9.7 mol% of acid dimethyl ester, 16.8 g of potassium hydroxide and 70 g of water were added, and then metallic palladium (pd) -carbon catalyst (pd content 5 wt%, water content 50 wt%). %) 2.5 g and stir at 90-110 ° C. for about 1 hour. After that, 13.6 g of sodium chylate was added little by little and stirred to carry out a debromination dimerization reaction for 5 hours. To determine the yield, after completion of the reaction, the reaction mixture was cooled, the pd-C catalyst was removed by filtration, and hydrochloric acid was added to the reaction filtrate to make it acidic (1 or more).
It was precipitated as 3 ', 4,4'-biphenyltetracarboxylic acid. The yield was 13.1 g.

Examples 2 to 4 Using a mixture of 4-bromoorthophthalic acid dimethyl ester and the like used in Example 1, potassium hydroxide, water, and pd-C, sodium formate 10.2 g, 17 g, and 20.4 g, respectively. When carried out according to the method of Example 1,
As 3,3 ', 4,4'-biphenyltetracarboxylic acid, 12.5 g, 12.2 g and 12.1 g were obtained in high yield.

Examples 5-8 Instead of the mixture of 4-bromoorthophthalic acid dimethyl ester and the like used in Example 1, 4-bromoorthophthalic acid diethyl ester, 4-bromoorthophthalic acid dipropyl ester, 4-bromoorthophthalic acid Using phthalic acid dibutyl ester, other catalyst, base, water,
Experimental conditions were carried out according to the method of Example 1,
As 3,3 ′, 4,4′-biphenyltetracarboxylic acid, 12.6 g, 12.0 g, and 11.8 g were obtained in high yield, respectively.

Comparative Example 1 4-bromoorthophthalic acid sodium salt 8 was placed in a 300 ml four-necked flask equipped with a thermometer, a reflux condenser and a stirrer.
27.5 g of a pale yellow powder consisting of 0.9 mol%, 3-bromoorthophthalic acid sodium salt 0.9 mol%, orthophthalic acid sodium salt 18.2 mol%, potassium hydroxide 13.2 g, and water 60 g are added. Dissolved, then methanol 4.6 ml, metallic palladium-carbon catalyst (pd content 5 wt
%, Water content 50% by weight) was added to prepare 3,3 ′, 4,4′-biphenyltetracarboxylic acid salt according to Example 1. As in Example 1, 3,3 ', 4,4'-
It was precipitated as biphenyltetracarboxylic acid to obtain the yield. The yield is 8.3 g, which is about 30.7% lower.

Comparative Example 2 The procedure of Comparative Example 3 was repeated except that 7.4 ml of butyl alcohol was used in place of the methanol used in Comparative Example 1.
3 ', 4,4'-biphenyltetracarboxylic acid salt was synthesized. The yield was obtained by precipitating as the above-mentioned biphenyltetracarboxylic acid. The yield is 1 g and the yield is low at about 7.3%.

〔The invention's effect〕

As described above, according to the method for producing 3,3 ′, 4,4′-biphenyltetracarboxylic acid of the present invention, there is an effect that the target product can be easily obtained in high yield. . For example, the yield could be improved by about 25% or more compared with the conventional one.

Claims (1)

[Claims] 1. A method for producing 3,3 ′, 4,4′-biphenyltetracarboxylic acid by a dehalogenation dimerization reaction of 4-halogenoorthophthalic acid, wherein 4-halogenoorthophthalic acid ester is dissolved in water. Base 2
In an aqueous solution of a mole or more (to orthophthalic acid ester),
A catalyst in which a noble metal is supported on a carrier, a formate salt is present, and a mixed solution thereof is heated to cause a reaction.
Process for producing 3 ', 4,4'-biphenyltetracarboxylic acid.