JPS6089444A - Production of biphenyltetracarboxylic acid - Google Patents

Abstract

PURPOSE:To obtain the titled compound in high yield, by hydrolyzing biphenyltetracarboxylic acid tetraalkyl ester is simple water in the presence of a catalyst comprising a specific amount of p-toluenesulfonic acid, thereby enabling the uniform reaction even under atmospheric pressure. CONSTITUTION:A biphenyltetracarboxylic acid tetra(1-3C alkyl) ester (abbreviated as BPTE), preferably biphenyltetracarboxylic acid tetramethyl ester, etc. obtained by the dehydrogenative dimerization of dimethyl o-phthalate in the presence of O2 and a Pd-containing catalyst, is made to react with >=3mol, preferably 4-10mol of p-toluenesulfonic acid (based on 1mol of BPTE) in water under atmospheric pressure at 80-110 deg.C, preferably near the boiling point of the reaction mixture, for 0.5-20hr, and hydrolyzed while distilling the produced methanol out of the system to obtain the objective compound. The amount of water used as the solvent is preferably 2-10pts.wt. per 1pt. of BPTE.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to biphenyltetracarboxylic acid (under Lj, BPT
This relates to the manufacturing method of O.

Biphenyltetracarboxylic dianhydride, which is a raw material for polyimide resin, is usually tetramethyl biphenyltetracarboxylate obtained by trimerizing ortho-phthalic dimethyl.
Hereinafter referred to as B P and T Ivl), B
: Produced by making PTO and then dehydrating it. In this method, the hydrolysis reaction of BPTM is usually carried out using an acid catalyst such as mf acid, but in this method, the raw material BPTM dissolves in the solvent and the reaction system does not become homogeneous. and the reaction tends not to proceed well. However, since BPTM does not substantially dissolve in water at the reaction temperature under normal pressure, water alone as a solvent does not result in a homogeneous reaction system and BPTM is not substantially hydrolyzed.

Therefore, conventional 5. Methods for dissolving B PTM include, for example, a method using an acetic acid-water mixture as a solvent, or a 1so-so reaction under pressure.

A method was adopted in which the process was carried out at a high temperature of ℃.

However, when an acetic acid-water mixture is used as a solvent, methanol, which is a by-product of the hydrolysis reaction, reacts with acetic acid to produce methyl acetate, which not only results in a loss of acetic acid equivalent to the reaction amount, but also Recovery of acetic acid from the solvent is troublesome. In addition, hydrolysis at high temperature under pressure 11
In the case of carrying out the reaction 1, there is an advantage that it can be carried out using only water as a solvent, but it is not economical because it requires a pressure-resistant apparatus and uses a large amount of thermal energy.

In view of the above-mentioned circumstances, the present inventors have determined that the bifacial tetraalkyl ester (provided that the alkyl group is an alkyl group having 1 to 3 carbon atoms, and As a result of various methods to proceed with the hydrolysis reaction of the same alkyl group (hereinafter referred to as BPTE), we found that by using a specific amount of a specific catalyst, even in the case of water alone as a solvent, The inventors have completed the present invention by discovering that the raw material BPTE is dissolved in the solvent, the reaction system becomes homogeneous, and the hydrolysis reaction of BPTE is carried out satisfactorily.

That is, 1. The gist of the present invention is to hydrolyze biphenyltetracarboxylic acid tetraalkyl ester (however, the alkyl group is an alkyl group having a carbon number of up to 3 and has the same alkyl group and has a low taste). A method for producing biphenyltetracarboxylic acid, characterized in that the hydrolysis reaction is carried out using one dose of paratoluene sulfone 3% by mole relative to the tetraalkyl ester of biphenyltetracarboxylic acid as a catalyst. The invention consists in a method for producing biphenyltetracarboxylic acid.

The present invention will be explained in further detail below.

In the present invention, BPTE is hydrolyzed in the presence of a catalyst to produce BP.
Iyaki Manabu, which manufactures T(1!), uses BPTM, which is usually obtained by dehydrogenating and trimerizing dimethyl ornophthalate using a palladium-containing catalyst in the presence of oxygen, as the BPTK used as a raw material. This ortho-
Dehydrogen trimerization of dimethyl phthalate is typically S to io.

k! ? It is carried out at a temperature of 100-200 °C under an oxygen partial pressure of /cri, and in this reaction BPTMij'
Yu, 3.37q'-B PTM (Koroshita, α-isomer and 3. 'I, abuse'-BPTM (hereinafter referred to as S
-isomer) is recovered as a mixture of isomers, mainly 1. In the BPTM used in the present invention, the proportion of S-isomer and α-isomer is not particularly limited, but the mixture obtained by this reaction is usually used after its separation. For isomers, O,! i~/, S borrowed S-
The isomer is retained.

In the present invention, it is also essential to use as a catalyst 3 to 70 moles of para-toluenesulfonic acid to BPTE. +=Ji of para-toluenesulfonic acid At Kawamei, BPTO can be produced well even in the reaction at normal pressure by using a specific amount u of paratoluenesulfonic acid catalyst, and even when using only water as a solvent. , raw material BPT due to the influence of para-toluenesulfonic acid.
E dissolves in the reaction system and allows the hydrolysis reaction to proceed. -! However, since the para-toluene sulfonic acid catalyst has sufficient catalytic activity, no additional catalyst is required, but sulfuric acid or the like may be added to an extent that does not impair the catalytic action of the para-toluene sulfonic acid.

Therefore, in the present invention, since the para-toluenesulfonic acid used as a catalyst also has the effect of dissolving BPTE, it is used as a solvent in addition to water, which is a reaction component, and raw material B such as acetic acid.
There is no need to use organic solvents to dissolve the PTE.

JiJ for 1 history of water is usually % / ~ 3 for BPTE
0 times by weight, preferably 1 to 10 times by weight.

The hydrolysis reaction in the present invention is usually carried out under normal pressure from g0 to /
The reaction is carried out at 10° C., preferably near the peak of the reaction mixture. In this hydrolysis reaction, methanol is produced as a by-product as the reaction progresses, but since the hydrolysis reaction is an equilibrium reaction, it is preferable in the present invention to carry out the reaction while distilling methanol off along with water from the upper part of the reactor. Further, the reaction time is usually about O,S-0 hours.

When a mixture of S-isomer and α-isomer is used as 2-cho B-isomer, the reaction mixture obtained after completion of the reaction contains J, G, which is a hydrolyzate of S-isomer, y;4t'-
Since virtually all of the BPTO is precipitated as crystals,
Usually, this is separated into 1 parts, and then, if necessary, water is distilled off and concentrated, and then, for example, the f4 solution is cooled to -5''C or lower, and the α-isomer hydrolyzate is obtained.3. .!, 'l'
-B P T'O crystals were precipitated and then ilJ
Separate. In this way, each desired BPTO can be recovered.

According to the invention, by using para-toluenesulfonic acid of a specific grade or higher as a catalyst, it is possible to hydrolyze BPTE under normal pressure using water as a sole solvent.
This is an industrially preferred method.

Next, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited to the following practical examples unless they go beyond the scope of the invention.

Example 1 B P T )A (S-
Isomer/α-isomer 1/, , 2 g) , 3 g, &
/147 (approx. o, /moO), halatoluenesulfonic acid J,'g (o, h mail) and water 6oom
[1] After making the mixture into a homogeneous solution, methanol-71 ((7) mixed vapor was distilled off from the upper part of the reactor at a temperature of 95 to 10°C, while the corresponding The hydrolysis reaction was carried out for 1 hour as shown in Table 7 while supplying water.

3. Formation in the reaction solution. lI, 3', lI'-B P
Almost all of T co precipitates as crystals, and -13
The results shown in Table 1 were obtained by one person.

EXAMPLES AND COMPARATIVE EXAMPLES/~ B'P T
The reaction was carried out in the same manner as in Example 1, except that the value of para-toluenesulfonic acid relative to M was changed as shown in Table 1. The results are shown in Table 7.

Sender: Mitsubishi Chemical Industries, Ltd. Representative Patent Attorney Hase - (7 others)

Claims (1)

[Claims] (IJ) Biphenyltetracarboxylic acid is produced by hydrolyzing biphenyltetracarboxylic acid tetraalkyl ester (however, an alkyl group is an alkyl group having a carbon number/~3 and means the same alkyl group). 1. A method for producing biphenyltetracarboxylic acid, which is characterized in that a hydrolysis reaction is carried out using paratoluenesulfonic acid in an amount of 3 or more moles of the biphenyltetracarboxylic acid tetraalkyl ester as a catalyst. (2) A method for producing biphenyltetracarboxylic acid according to claim 1, characterized in that the hydrolysis reaction is carried out under normal pressure at a boiling point of the reaction mixture close to 0. (3) Methanol as a by-product in the hydrolysis reaction. A method for producing biphenyltetracarboxylic acid according to claim 1, characterized in that the hydrolysis reaction is carried out while distilling off. (4) 7 to 10 mol based on biphenyltetracarboxylic acid tetraalkyl ester. 8. The method for producing biphenyltetracarboxylic acid according to claim 7, characterized in that the hydrolysis reaction is carried out using twice the amount of para-toluenesulfonic acid.