JP2009051848A - Production process of biphenyltetracarboxylic acid tetraester - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a production process of a biphenyltetracarboxylic acid tetraester, performing oxidative dimerization reaction of a phthalic acid diester in the presence of a palladium compound-containing catalyst at a high temperature while molecular oxygen is supplied in a reaction mixture solution, wherein the production process requires neither specific equipment nor complex operation, can utilize the catalyst effectively, easily control the reaction and continuously produce, and is economical and improved. <P>SOLUTION: A production process of a biphenyltetracarboxylic acid tetraester is characterized by carrying out, in parallel, a step of continuously or intermittently supplying to a reactor a catalyst containing a phthalic acid diester and a palladium compound, a step of conducting oxidative dimerization reaction of the phthalic acid diester in a temperature range of ≥140°C but <250°C while supplying molecular oxygen to the reactor, and a step of continuously or intermittently removing a portion of the reaction mixture from the reactor. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is an improved process for producing biphenyltetracarboxylic acid tetraester by subjecting phthalic acid diester to an oxidative dimerization reaction at high temperature in an atmosphere containing molecular oxygen in the presence of a catalyst containing a palladium compound. Relates to a manufacturing method.

  It is known that a diphenyltetracarboxylic acid tetraester is produced by subjecting a phthalic acid diester to an oxidation dimerization reaction at high temperature in an atmosphere containing molecular oxygen in the presence of a catalyst containing a palladium compound. In this production method, there is a problem that a catalyst composed of a palladium compound is easily deactivated during the reaction, and various studies have been made to solve this problem.

In Patent Document 1, an orthophthalic acid ester is supplied to a reaction system with a gas containing molecular oxygen in the presence of a catalyst composed of a palladium salt, a basic bidentate ligand, and a copper salt. A method for producing a biphenyl tetracarboxylic acid ester is disclosed in which oxidative coupling is performed, and then the catalyst component is sequentially added to the reaction system 1 to 10 times for oxidative coupling.
In Patent Document 2, a phthalate ester is continuously or intermittently replenished with β-diketones to a reaction system at high temperature in an atmosphere containing molecular oxygen in the presence of a palladium salt and a copper salt. A method for producing a biphenyltetracarboxylic acid ester that is oxidatively coupled is disclosed.
Patent Document 3 discloses a method for producing biphenyltetracarboxylic acid tetraester by subjecting O-phthalic acid diester to an oxidative dimerization reaction in the presence of a catalyst comprising a palladium salt, a basic bidentate ligand and a copper salt. In US Pat. No. 6,057,836, it is disclosed that a catalyst component is introduced into a circulation line while the reaction liquid is circulated through a circulation line attached to the reaction tank, and the catalyst component is sequentially replenished to the reaction tank.
In Patent Document 4, a powdery palladium salt having a specific surface area of 0.5 m ² / g or more and a basic bidentate ligand compound are used, and catalyst components are sequentially added to dimerize the O-phthalic acid diester. A method for producing 3,3 ′, 4,4′-biphenyltetracarboxylic acid tetraester is disclosed.

  All of these methods are methods in which catalyst components are added sequentially, and compared with a method in which catalyst components are added all at once, the catalyst can be used effectively and the reaction yield can be increased. However, these methods require special equipment and complicated operation for sequentially adding the catalyst components, and the concentration of each catalyst component in the reaction mixture rapidly changes when the catalyst components are added. Control was not easy, and there was room for improvement in obtaining a high reaction yield with high reproducibility and high selectivity of the desired product. Furthermore, when the reaction is continued for a long period of time while adding a large amount of catalyst components by the method of sequentially adding catalyst components, the desired product causes a side reaction with the raw material compound sequentially, resulting in a large amount of by-products. It was difficult to obtain a high reaction yield and high selectivity of the desired product with good reproducibility over a long period of time, and there was room for improvement.

  Furthermore, all the production methods of the above-mentioned patent documents are based on batch operations. For this reason, these production methods require complicated operations such as heating and cooling at the start and end of the reaction, and from an economic standpoint, in addition to energy loss due to heating and cooling. There is a problem that the loss of the material is unavoidable because the apparatus is opened for each preparation with the batch operation, and there is room for improvement. However, the patent document does not show any specific means or methods for a continuous manufacturing method.

JP-A-60-51150 JP 61-106541 A JP-A 64-48 JP 2000-186063 A

  In the present invention, phthalic acid diester is produced by supplying molecular oxygen to the reaction mixture in the presence of a catalyst containing a palladium compound and subjecting it to an oxidative dimerization reaction at a high temperature. In the method, no special equipment or complicated operation is required, the catalyst can be used effectively, the reaction can be easily controlled, it can be continuously produced, and more economical, An object is to provide an improved manufacturing method.

  That is, the present invention includes a step of continuously or intermittently supplying a phthalic acid diester and a catalyst containing a palladium compound to a reaction apparatus, and an oxidation dimerization reaction of a phthalic acid diester while supplying molecular oxygen to the reaction apparatus. The biphenyltetracarboxylic is characterized in that the step of performing the reaction in a temperature range of 140 ° C. or higher and lower than 250 ° C. and the step of continuously or intermittently removing a part of the reaction mixture from the reaction apparatus are performed in parallel. The present invention relates to a method for producing an acid tetraester. Maintaining the phthalic acid diester and the catalyst containing the palladium compound before being supplied to the reactor in a temperature range of 50 ° C. to 100 ° C., the catalyst containing the palladium compound, the palladium compound, the bidentate ligand, and A bidentate ligand containing a copper compound, wherein the bidentate ligand can be complexed with palladium by two nitrogen atoms, two oxygen atoms, or a nitrogen atom and an oxygen atom. And that the copper compound is either copper propionate, copper normal butyrate, bis (acetylacetonato) copper, or an anhydride or hydrate of copper pivalate.

  Further, the reactor comprises a plurality of reactors connected in series, and a step of continuously or intermittently supplying a phthalic acid diester and a catalyst containing a palladium compound to the first reactor, and each reaction A step of continuously or intermittently removing a part of the reaction mixture from the reactor and sequentially introducing it to the next reactor, and a step of carrying out an oxidative dimerization reaction of phthalic diester while supplying molecular oxygen to each reactor And a step of continuously or intermittently taking out a part of the reaction mixture from the last reactor in parallel. The present invention relates to a method for producing the biphenyltetracarboxylic acid tetraester.

  The present invention relates to a method for producing biphenyl tetracarboxylic acid tetraester by supplying molecular oxygen to a reaction system in the presence of a catalyst containing a palladium compound and subjecting phthalic acid diester to an oxidative dimerization reaction at a high temperature. No special equipment or complicated operation is required, the catalyst can be used effectively, the reaction can be controlled easily, it can be produced continuously, and it is more economical and improved. Manufacturing methods can be provided.

  The method for producing a biphenyltetracarboxylic acid tetraester of the present invention comprises a step of continuously or intermittently supplying a phthalic acid diester and a catalyst containing a palladium compound to a reaction apparatus as a uniformly stirred mixture; A step of performing an oxidative dimerization reaction of phthalic acid diester in a temperature range of 140 ° C. or higher and lower than 250 ° C. while supplying gaseous oxygen, and a step of continuously or intermittently taking out a part of the reaction mixture from the reaction apparatus, Is a manufacturing method characterized in that they are performed in parallel. During the reaction of this production method, the catalyst containing the active palladium compound in the reaction mixture is maintained uniformly and at a suitable predetermined concentration.

Specifically, first, a raw material phthalic acid diester and a catalyst containing a palladium compound are supplied to the reactor until a predetermined amount is reached. Then, during the subsequent continuous reaction, by adjusting the supply amount of the raw material phthalic acid diester and the catalyst containing the palladium compound to the reactor and the amount of the reaction mixture taken out from the reactor are adjusted to be approximately equal. The phthalic acid diester oxidation dimerization reaction is carried out while maintaining the predetermined amount of the reaction mixture in the reaction apparatus. As a result, since the raw material phthalic acid diester, catalyst, and the like are maintained at a preferable predetermined amount and predetermined concentration in the reactor, it is possible to always favorably carry out the oxidation dimerization reaction of the phthalic acid diester.
The step of supplying the phthalic acid diester and the catalyst containing the palladium compound to the reaction device and the step of taking out the reaction mixture from the reaction device are performed in parallel with the supply and removal being performed in parallel. As long as the amount of the reaction mixture is maintained at a predetermined amount and the oxidation dimerization reaction can be continuously performed, the supply step and the extraction step may be continuous or intermittent. Absent.
However, the process of supplying the raw material phthalic acid diester and the catalyst containing the palladium compound to the reactor and the process of taking out the reaction mixture from the reactor do not require complicated operations or complicated facilities, and are simple. Since it can be easily carried out using a liquid feed pump or the like, it is preferable to carry out continuously.

In the present invention, the raw material phthalic acid diester and the catalyst containing a palladium compound are a mixture in which the phthalic acid diester and the catalyst containing a palladium compound are uniformly stirred with a predetermined composition ratio suitable for the oxidation dimerization reaction. The mixed solution is preferably supplied to the reactor as a uniformly dissolved solution.
Unlike the conventional method in which the catalyst components are added sequentially, the present invention provides an active palladium compound in the reaction mixture by supplying the phthalic acid diester and the catalyst containing the palladium compound to the reactor as a uniformly stirred mixture. It becomes possible to keep the concentration of the catalyst containing the catalyst constant at a suitable predetermined concentration for a long period of time.
Supplying the raw material phthalic acid diester and the catalyst containing the palladium compound separately has the disadvantage that separate supply facilities are required, as well as variations in the concentration of the raw material and the catalyst in the reaction mixture. Therefore, it becomes difficult to control the reaction, and problems such as a decrease in the amount of the target compound produced and an increase in the amount of by-products are likely to occur. The reaction yield is highly reproducible and the desired product is highly selective. It becomes difficult to obtain. Furthermore, even when the raw material phthalic acid diester and the catalyst containing the palladium compound are supplied together, the concentration of the raw material and the catalyst will vary in the reaction mixture unless it is supplied as a uniformly stirred mixture. It becomes difficult to control, and problems such as a decrease in the amount of the target compound produced and an increase in the amount of by-products are likely to occur, and a high reaction yield with high reproducibility and high selectivity of the desired product can be obtained. It becomes difficult.

Furthermore, in the present invention, it is particularly preferable to supply the raw material phthalic acid diester and the catalyst containing the palladium compound to the reaction apparatus as a uniformly dissolved mixed solution. If the catalyst containing the palladium compound does not dissolve in the phthalic acid diester, the phthalic acid diester and the catalyst containing the palladium compound are continuously stirred and supplied using a large stirrer or catalyst supply device so that a uniform mixed state is always maintained. Inconvenience such as having to occur may occur.
When a raw material phthalic acid diester catalyst containing a palladium compound is uniformly dissolved in advance so as to have a predetermined concentration suitable for the oxidation dimerization reaction, and the mixed solution is supplied, the phthalic acid diester in the reaction mixture On the other hand, since it becomes easy to maintain the concentration of the catalyst containing a palladium compound active with respect to a suitable predetermined concentration, reaction control becomes extremely easy.

  Furthermore, the raw material phthalic acid diester and the catalyst containing the palladium compound are heated to a temperature of 50 ° C. to 100 ° C., dissolved, and supplied to the reaction apparatus in the temperature range of 50 ° C. to 100 ° C. It is preferable to hold it. Such heating helps uniform dissolution of the catalyst, and when supplied to the reaction apparatus, variation in the catalyst concentration and temperature in the reaction mixture is suppressed to facilitate control of the reaction. When the mixed solution is maintained at a temperature exceeding 100 ° C., the phthalic acid diester and the catalyst containing the palladium compound cause a stoichiometric oxidation dimerization reaction even though the reaction rate is slow, and the reoxidation rate due to the lack of molecular oxygen. Is extremely slow, which is not preferable because palladium may be deposited and a predetermined amount (concentration) of catalyst may not be supplied.

  In the present invention, the preferred composition ratio of the phthalic acid diester and the catalyst containing the palladium compound is such that the palladium compound is usually 0.00001-fold mol or more, particularly 0.00005-fold mol or more, relative to the phthalic acid diester, 0.01 times mole or less, especially 0.001 times mole or less, but since the palladium compound is 0.00093 times mole or less with respect to the phthalic acid diester, the catalyst containing the palladium compound is easily dissolved during the oxidation dimerization reaction. This is suitable in the present invention.

In the present invention, the oxidative dimerization reaction of phthalic acid diester is carried out in a temperature range of 140 ° C. or higher, preferably 200 ° C. or higher, and less than 250 ° C., preferably 240 ° C. or lower.
When the reaction temperature of the phthalic acid diester oxidation dimerization reaction exceeds 250 ° C., the catalyst containing the palladium compound is deactivated not only by the oxidation dimerization reaction but also deactivated by thermal decomposition. Therefore, reaction control becomes difficult, and the yield of the oxidation dimerization reaction product is remarkably reduced. On the other hand, if it is less than 140 ° C., the oxidation dimerization reaction rate is not sufficient, which is not preferable.

In addition, in the conventional method in which the phthalic acid diester is oxidized and dimerized at a high temperature while supplying molecular oxygen in the presence of a catalyst containing a palladium compound, in the conventional method in which the catalyst is added sequentially, at what timing and at what amount, Since it is difficult to directly detect how much active catalyst remains in the actual reaction mixture, it cannot be determined corresponding to the actual decrease in catalyst activity each time. That is, it is difficult to obtain sufficient reproducibility by controlling the reaction by sequential addition of the catalyst.
On the other hand, in the present invention, the raw material phthalic acid diester and the catalyst containing the palladium compound are continuously supplied at a predetermined composition ratio so that the desired oxidation dimerization reaction proceeds. As a result, if the reaction temperature of the oxidation dimerization reaction is in the temperature range of 140 ° C. or more and less than 250 ° C., the active catalyst concentration in the reactor can be maintained at a suitable constant concentration, so that the oxidation dimerization reaction is easy. Can be controlled. That is, in the present invention, an oxidation dimerization reaction that is continuously controlled for a long period of time can be suitably carried out without a special apparatus or a complicated operation for sequential addition of the catalyst.

In the present invention, the reactor is particularly preferably composed of a plurality of reactors connected in series, preferably 2 to 6 reactors. In the case of a single reactor, it is difficult to prevent a part of the catalyst having a sufficiently high activity immediately after being supplied from being taken out of the reaction apparatus, so that it is not advantageous in that the catalyst is effectively used.
The reactor is composed of a plurality of reactors connected in series, and the raw material phthalic acid diester and a catalyst containing a palladium compound are continuously or intermittently supplied to the first reactor, and each reactor The reaction mixture is continuously or intermittently removed from the reaction vessel and sequentially introduced into the next reactor while supplying molecular oxygen in each reactor to carry out the oxidative dimerization reaction of the phthalic diester, and finally By continuously or intermittently removing the reaction mixture from the reactor, it is possible to effectively suppress removal of a catalyst having a sufficiently high activity immediately after being supplied from the reactor. Easy to use.

When the reaction apparatus is constituted by a plurality of reactors connected in series, the amount of the reaction mixture present in each reactor of the reaction apparatus is maintained at a predetermined amount during the continuous reaction. That is, after the reaction mixture in each reactor reaches a predetermined amount, the supply amount of the raw material phthalic acid diester and the catalyst containing the palladium compound to the first reactor and the next reaction from each reactor The amount of the reaction mixture sequentially introduced into the reactor and the amount of the reaction mixture taken out from the last reactor are adjusted so as to be approximately equal.
As a result, in each reactor, the raw material phthalic acid diester, the catalyst, the reaction product, and the like are maintained at a preferable predetermined amount and predetermined concentration, so that the oxidation dimerization reaction of the phthalic acid diester can be suitably performed. It becomes possible.

  In the present invention, the reaction temperature of the oxidation dimerization reaction when the reaction apparatus is constituted by a plurality of reactors connected in series may be the same or different in each reactor. In particular, the reaction temperature of each reactor is in the temperature range of 140 ° C. or more and less than 250 ° C., and the reaction temperature of the (n + 1) th reactor is preferably higher than the reaction temperature of the nth reactor. . (Here, n is an integer of 1 or more.)

  The phthalic acid diester used in the present invention is represented by the chemical formula (1).

［ここで、Ｒ１は、それぞれ独立に、アルキル基、又は、アリール基であり、置換基を持っていてもよい。］
本発明で使用するフタル酸ジエステルは、具体的には、フタル酸ジメチル、フタル酸ジエチル、フタル酸ジプロピル、フタル酸ジブチル、フタル酸ジオクチル、フタル酸ジフェニルなどを好適に挙げることができる。
フタル酸ジエステルは、フタル酸、フタル酸無水物、フタル酸ハロゲン化物と、末端に水酸基を有する化合物、例えば、低級脂肪族アルコールや芳香族アルコールなどとを反応して容易に得ることができる。

[Wherein R1 is each independently an alkyl group or an aryl group, and may have a substituent. ]
Specific examples of the phthalic acid diester used in the present invention include dimethyl phthalate, diethyl phthalate, dipropyl phthalate, dibutyl phthalate, dioctyl phthalate, and diphenyl phthalate.
The phthalic acid diester can be easily obtained by reacting phthalic acid, phthalic anhydride, or phthalic acid halide with a compound having a hydroxyl group at the terminal, such as a lower aliphatic alcohol or aromatic alcohol.

The catalyst containing a palladium compound used in the present invention is a palladium compound catalyst, a catalyst comprising a combination of a palladium compound and a ligand, a catalyst comprising a combination of a palladium compound and a copper compound, or a palladium compound and a ligand. A catalyst comprising a combination with a copper compound.
In particular, a catalyst comprising a combination of a palladium compound, a bidentate ligand and a copper compound is suitable because the yield of the oxidation dimerization reaction product is high and a specific isomer can be selectively produced. .

Examples of the palladium compound used in the present invention include palladium chloride, palladium bromide, palladium iodide, palladium nitrate, palladium sulfate, palladium acetate, palladium trifluoroacetate, palladium propionate, palladium pivalate, palladium trifluoromethanesulfonate, bismuth. (Acetylacetonato) palladium and bis (1,1,1,5,5,5-hexafluoroacetylacetonato) palladium and the like can be mentioned, particularly palladium acetate, palladium propionate, palladium pivalate. Palladium trifluoroacetate and palladium nitrate are preferred because of their high catalytic activity.
In the present invention, the preferred composition ratio of the phthalic acid diester and the catalyst containing the palladium compound is such that the palladium compound is 0.00001 times mol or more, particularly 0.00005 times mol or more, and 0.01 times the phthalic acid diester. In particular, since the catalyst containing the palladium compound is easily dissolved in the phthalic acid diester at the time of the oxidation dimerization reaction, the palladium compound is less than 0.001 times the molar amount, especially 0.001 times the molar amount or less. This is preferred in the present invention. The reaction proceeds even if the amount of the palladium compound is less than 0.00001 mol per mol of the starting phthalic acid diester, but this is not preferable because the reaction rate becomes slow. Further, the palladium compound may be used in an amount exceeding 0.01 mol per mol of the starting phthalic acid diester, but it is not economical in view of the catalyst cost.

  The ligand used in the present invention is preferably a bidentate ligand capable of coordinating with palladium in a bidentate, and in particular, a bidentate capable of forming a complex with a palladium salt by two nitrogen atoms. A ligand, a bidentate ligand capable of complexing with a palladium salt by two oxygen atoms, and a bidentate ligand capable of complexing with a palladium salt by a nitrogen atom and an oxygen atom. Is preferred.

  As the bidentate ligand that forms a complex with a palladium salt by two nitrogen atoms, for example, the bidentate ligand represented by the chemical formula (2) and the chemical formula (3) can be preferably used.

［ここで、Ｒ２は、それぞれ独立に、水素原子、ハロゲン原子、水酸基、ニトロ基、アミノ基、アルキル基、アルコキシ基、又は、アリール基である。アルキル基、アルコキシ基、及び、アリール基は置換基を有することもできる。］

[Wherein R2 is independently a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, an amino group, an alkyl group, an alkoxy group, or an aryl group. The alkyl group, alkoxy group, and aryl group may have a substituent. ]

［ここで、Ｒ３は、それぞれ独立に、水素原子、ハロゲン原子、水酸基、ニトロ基、アミノ基、アルキル基、アルコキシ基、又は、アリール基である。アルキル基、アルコキシ基、及び、アリール基は置換基を有することもできる。］
これらの配位子を用いると、対称性のビフェニルテトラカルボン酸テトラエステルを選択的に得ることが可能になる。具体的には、非対称二量化生成物である２，３，３’，４’−ビフェニルテトラカルボン酸テトラエステルの生成を抑制し、対称二量化生成物である３，３’，４，４’−ビフェニルテトラカルボン酸テトラエステルを選択的に生成させることができる。

[Wherein R3 is independently a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, an amino group, an alkyl group, an alkoxy group, or an aryl group. The alkyl group, alkoxy group, and aryl group may have a substituent. ]
When these ligands are used, symmetrical biphenyltetracarboxylic acid tetraesters can be selectively obtained. Specifically, the formation of 2,3,3 ′, 4′-biphenyltetracarboxylic acid tetraester which is an asymmetric dimerization product is suppressed, and 3,3 ′, 4,4 ′ which is a symmetric dimerization product. -Biphenyltetracarboxylic acid tetraesters can be selectively produced.

  As specific examples of the bidentate ligands represented by the chemical formula (2) and the chemical formula (3), 1,10-phenanthroline and 2,2′-bipyridyl can be preferably exemplified. In particular, 1,10-phenanthroline is suitable because it has a high effect of promoting the oxidative dimerization reaction and has high solubility in the phthalic acid diester of the complex compound when coordinated to palladium.

Furthermore, as a bidentate ligand capable of forming a complex with a palladium salt by two oxygen atoms, for example, acetylacetone, benzoylacetone, 1,3-diphenyl-1,3-propanedione, 1,1,1 -Trifluoroacetylacetone, 2,4-hexanedione, 2,4-heptanedione, 1,1,1-trifluoro-2,4-hexanedione, 1,1,1,5,5,5-hexafluoroacetylacetone Preferred examples include β-diketones such as
Examples of the bidentate ligand that can form a complex with a palladium salt by a nitrogen atom and an oxygen atom include pyridinecarboxylic acid, pyridinecarboxylic acid methyl ester, pyridinecarboxylic acid ethyl ester, pyrazinecarboxylic acid, and pyrazinecarboxylic acid. Nitrogen-containing heterocyclic compounds having an oxygen atom as a substituent such as methyl ester, pyrazinecarboxylic acid ethyl ester, quinolinecarboxylic acid, isoquinolinecarboxylic acid, hydroxyquinoline, 2-benzoylpyridine, 2-pyridylamide, and N, N-dimethyl Preferable examples include fatty chain amines having an oxygen atom as a substituent such as glycine and N, N-dimethylacetamide.
When a bidentate ligand compound that can be complexed with a palladium salt by the above-mentioned two oxygen atoms or a bidentate ligand compound that can be complexed with a palladium salt by a nitrogen atom and an oxygen atom, Asymmetric dimerization product can be selectively obtained. Specifically, the formation of 3,3 ′, 4,4′-biphenyltetracarboxylic acid tetraester of symmetric dimerization product is suppressed, and 2,3,3 ′, 4′-biphenyl of asymmetric dimerization product is suppressed. Tetracarboxylic acid tetraesters can be selectively produced.

  These bidentate ligands are preferably added in an amount of 0.1 to 5 moles, more preferably 0.5 to 1.5 moles per mole of the palladium compound. If the amount is less than 0.1 times mol, sufficient selectivity cannot be obtained. When an amount exceeding 5 times mole is used, the catalyst activity may be lowered.

In the present invention, by using a copper compound together with a palladium compound as a catalyst, the deactivation of the catalyst can be suppressed even if the oxygen partial pressure during the reaction is lowered. Therefore, by using a copper compound together with a palladium compound, an oxidation dimerization reaction can be performed under normal pressure or a pressure close to normal pressure, which is particularly preferable in the production method of the present invention.
Examples of the copper compound used in the present invention include copper acetate, copper propionate, copper normal butyrate, copper 2-methylpropionate, copper pivalate, copper lactate, copper butyrate, copper benzoate, copper trifluoroacetate, bis ( Acetylacetonato) copper, bis (1,1,1,5,5,5-hexafluoroacetylacetonato) copper, copper chloride, copper bromide, copper iodide, copper nitrate, copper nitrite, copper sulfate, phosphorus Preferable examples include acid copper, copper oxide, copper hydroxide, copper trifluoromethanesulfonate, copper paratoluenesulfonate, and copper cyanide. In particular, copper acetate, copper propionate, normal butyric acid copper, pivalic acid copper, and bis (acetylacetonato) copper are suitable because they have a high effect of accelerating the oxidative dimerization reaction. Among them, copper propionate, Since normal butyric acid copper, pivalic acid copper and bis (acetylacetonato) copper are easily dissolved in the raw material phthalic acid diester, they can be very suitably used in the production method of the present invention.
These copper compounds can be used in the form of either anhydrides or hydrates.
In this invention, 0.01-10 times mole is preferable with respect to a palladium compound, and, as for the addition amount of a copper compound, 0.1-2.0 times mole is suitable especially. If the amount of the copper compound is less than 0.01 times mol, the oxygen partial pressure during the reaction cannot be lowered, and if it exceeds 10 times mol, it becomes economically disadvantageous.

  In the present invention, a reaction solvent may or may not be used. Industrially, it is preferable to carry out the reaction substantially without using a reaction solvent. In the case of using a reaction solvent, examples thereof include organic acid esters such as ethylene glycol diacetate and dimethyl adipate, and ketone compounds such as n-butyl methyl ketone, methyl ethyl ketone, and isopropyl ethyl ketone. The amount used is, for example, 10000 volume times or less, preferably 1000 volume times or less, relative to the starting phthalic acid diester.

  In the present invention, molecular oxygen may be supplied as pure oxygen gas, but considering the risk of explosion, the oxygen content is about 5% by volume to 50% by an inert gas such as nitrogen gas or carbon dioxide gas. It is preferable to use an oxygen-containing mixed gas diluted to about% or air. Further, the oxygen-containing mixed gas or air is bubbled so as to be uniformly distributed in the reaction solution at a supply rate of about 1 to 20000 ml / min, particularly 10 to 10000 ml / min per 1000 ml of the reaction solution, preferably using a filter. It is preferable to supply by bubbling or the like.

  In the present invention, the oxidative dimerization reaction can be carried out under normal pressure or 200 atm or less, particularly 50 atm or less, but it is preferable to react at normal pressure because the equipment and operation become simple. In the present invention, the oxidation dimerization reaction is preferably performed at an oxygen partial pressure of 0.01 to 200 atm, preferably 0.05 to 50 atm.

  The reaction apparatus used in the present invention is not particularly limited, but a single-reactor or multi-reactor, one-reactor, fully mixed reactor, multi-tubular heat exchange tubular reactor Alternatively, a tower reactor can be used. Further, the material of the reactor is not particularly limited, but for example, a glass or sus reactor can be suitably used.

The production method of the biphenyltetracarboxylic acid tetraester of the present invention will be described in more detail with reference to schematic diagrams showing exemplary embodiments of the reaction apparatus shown in FIGS. The present invention is not limited to this embodiment.
In FIG. 1, in a raw material tank 1, a raw material mixed solution obtained by mixing and dissolving a raw material phthalic acid diester and a catalyst at a predetermined ratio is held at a predetermined temperature. The raw material mixture is introduced into the reactor 4 from the raw material supply conduit 3 by the liquid feed pump 2 at a predetermined speed. The reactor 4 includes a heating device (not shown in the drawing), a stirring device 5, an air supply conduit 6, a reaction mixture extraction conduit 7, a gas extraction conduit 8, and the like. The raw material mixture composed of phthalic acid diester and catalyst introduced into the reactor is oxidized and dimerized by bubbling a predetermined amount of air from the air supply conduit 6 into the reaction mixture at a predetermined temperature under stirring. A reaction takes place. The gas extraction conduit 8 is opened to the atmosphere via a low-boiling substance and a phthalic acid diester recovery unit (not shown in the figure) for the vapor pressure by a cooling condenser, and air is introduced by bubbling. The gas in the reactor is exhausted out of the reactor through the gas extraction conduit 8. A reaction mixture of approximately the same amount as the amount of the raw material mixture supplied to the reactor 4 is taken out from the reaction mixture take-out conduit 7 via the liquid feed pump 9. The reaction mixture in the reactor is maintained at a predetermined temperature during the reaction, and is maintained at a substantially constant amount by making the amount of the raw material mixture to be supplied and the amount of the reaction mixture to be taken out substantially equal. .

In FIG. 2, the reaction apparatus is composed of two reactors 4 and 11 connected in series. The reactor 4 includes a heating device (not shown), a stirring device 5, an air supply conduit 6, a reaction mixture extraction conduit 7, a gas extraction conduit 8, and the like. Similarly, the reactor 11 includes a heating device (not shown), a stirring device 12, an air supply conduit 13, a reaction mixture extraction conduit 14, a gas extraction conduit 15, and the like. Yes.
In the raw material tank 1, a raw material mixed liquid obtained by mixing and dissolving a raw material phthalic acid diester and a catalyst at a predetermined ratio is held at a predetermined temperature. The raw material mixture is introduced into the reactor 4 from the raw material supply conduit 3 by the liquid feed pump 2 at a predetermined speed. The raw material mixture introduced into the reactor 4 is bubbled with a predetermined amount of air from the air supply conduit 6 into the reaction mixture at a predetermined temperature under stirring, and an oxidation dimerization reaction is performed. The gas extraction conduit 8 is opened to the atmosphere via a low-boiling substance and a phthalic acid diester recovery unit (not shown in the figure) for the vapor pressure by a cooling condenser, and air is introduced by bubbling. The gas in the reactor is exhausted out of the reactor through the gas extraction conduit 8. An amount of the reaction mixture substantially equal to the amount of the raw material mixture supplied to the reactor 4 is taken out from the reaction mixture take-out conduit 7 via the liquid feed pump 9, and the reaction mixture is used for supplying the reaction mixture. It is supplied from the conduit 10 to the reactor 11. The reaction mixture in the reactor 4 is maintained at a predetermined temperature during the reaction, and is kept at a substantially constant amount by making the amount of the raw material mixture to be supplied and the amount of the reaction mixture to be taken out substantially equal. It is.

  The reaction mixture introduced into the reactor 11 is further agitated and dimerized by bubbling a predetermined amount of air from the air supply conduit 13 into the reaction mixture at a predetermined temperature under stirring. The gas extraction conduit 15 is opened to the atmosphere through a low-boiling substance and a phthalic diester recovery unit (not shown in the figure) for the vapor pressure by a cooling condenser, and is released by bubbling air. The gas in the reactor is exhausted out of the reactor through the gas extraction conduit 15. The reaction mixture in the reactor 11 is taken out from the reaction mixture take-out conduit 14 via the liquid feed pump 16 in an amount substantially equal to the amount of the reaction mixture supplied. The reaction mixture in the reactor 11 is kept at a predetermined temperature during the reaction, and is kept at a substantially constant amount by making the amount of the raw material mixture to be supplied and the amount of the reaction mixture to be taken out substantially equal. It is.

  FIG. 3 is a manufacturing apparatus comprising two reactors 4 and 11 connected in series as in FIG. 2, and is used in the same manner as in FIG. 2, but the reaction mixture is taken out from the reactor 4. Without introducing a liquid feed pump when introduced into the reactor 11, the reaction mixture extraction conduit is arranged at a predetermined height of the reactor 4 and the extracted reaction mixture is guided by its own weight as follows. By disposing the reactor 11 at a low position, the overflow from the reactor 4 is introduced into the reactor 11 by its own weight. Further, the reaction mixture is taken out from the reactor 11 by overflow. By doing so, it becomes easy to introduce a reaction mixture of the same amount as the supply amount of the raw material mixture from the reactor into the next reactor, and the reaction mixture in each reactor is placed in place. Since it becomes easy to keep a fixed amount, it is preferable.

In the production method of the present invention, the reaction mixture taken out from the last reactor is stored in a tank as necessary. Further, the target biphenyltetracarboxylic acid tetraester can be obtained by separating and purifying from the reaction mixture solution through a post-treatment step comprising a known means such as distillation operation or crystallization operation.
The biphenyltetracarboxylic acid tetraester obtained by the continuous production method of the present invention is extremely important as a raw material for polyimide resin, for example.
Biphenyltetracarboxylic acid tetraester can be hydrolyzed to biphenyltetracarboxylic acid by a method of hydrolysis at a high temperature and a high pressure, or a method of hydrolysis by adding an acid or an alkali. Furthermore, it can be dehydrated by heating to high temperature to obtain biphenyltetracarboxylic dianhydride. This dianhydride is useful as one of monomer raw materials in polyimide production or as an epoxy resin curing agent.

    Next, the production method of the biphenyltetracarboxylic acid tetraester of the present invention will be described more specifically by reference examples and examples. In addition, this invention is not limited to a following example.

  In the examples, phthalic acid dimethyl ester is used as a reaction raw material, but the yield and catalytic rotation of biphenyltetracarboxylic acid tetramethyl ester (hereinafter sometimes abbreviated as BPTT) as an oxidation dimerization product. Number (hereinafter also abbreviated as TON) and 3,3 ′, 4,4′-biphenyltetracarboxylic acid tetramethyl ester (hereinafter abbreviated as s-BPTT) which is an isomer in the product. ) And 2,3,3 ′, 4′-biphenyltetracarboxylic acid tetramethyl ester (hereinafter sometimes abbreviated as a-BPTT) (hereinafter abbreviated as S / A). Was calculated according to the following formula. The unit in the calculation formula is the number of moles.

Reference Example 1 (Palladium Compound Solubility)
Palladium acetate (hereinafter sometimes abbreviated as Pd (OAc) ₂ ) and a complex compound consisting of palladium acetate and 1,10-phenanthroline (hereinafter abbreviated as [(phen) Pd (OAc) ₂ ]) 500 mg of (is) added to 5 ml of phthalic acid dimethyl ester and stirred at 50 ° C. for 1 hour. After filtration through a 0.2 μm filter, the residual amount was quantified by inductively coupled plasma emission spectroscopy (ICP-AES), and the solubility was calculated. As a result, Pd (OAc) ₂ was a Pd metal with respect to 1 g of phthalic acid dimethyl ester. 12000 μg (0.022 times mol) in terms of conversion and [(phen) Pd (OAc) ₂ ] showed a solubility of 510 μg (0.00093 times mol) in terms of Pd metal with respect to 1 g of phthalic acid dimethyl ester.
In the present invention, the catalyst containing a palladium compound preferably contains a palladium compound, a bidentate ligand, and a copper compound, and the complex compound of the palladium compound and the bidentate ligand is the actual catalytic activity. Therefore, by making the palladium compound 0.00093 times mol or less with respect to the phthalic acid diester, a palladium compound and a complex compound of a bidentate ligand exhibiting actual catalytic activity as well as a palladium compound can be obtained. Is also preferable because it can be supplied to the reaction apparatus as a uniformly dissolved mixed solution.

Reference example 2 (solubility of copper compound)
The solubility of dimethyl phthalate in copper compounds was also measured. 500 mg of the copper compound was added to 5 ml of dimethyl phthalate, and stirred at 50 ° C. for 1 hour. The resultant was filtered through a 0.2 μm filter, the residual amount was quantified by inductively coupled plasma emission spectroscopy (ICP-AES), and the solubility was calculated as follows.
Copper acetate monohydrate is 17 μg (0.000052 times mole) in terms of Cu metal with respect to 1 g of dimethyl phthalate, and bis (acetylacetonato) copper is 160 μg in terms of Cu metal with respect to 1 g of phthalic acid dimethyl ester. (0.00049 times mol), copper propionate monohydrate is 110 μg (0.00034 times mol) in terms of Cu metal to 1 g of phthalic acid dimethyl ester, and normal butyric acid copper is 1 g of phthalic acid dimethyl ester. In terms of Cu metal, 120 μg (0.00037 times mol), and copper isobutyrate showed 31 μg (0.000094 times mol) in terms of Cu metal with respect to 1 g of phthalic acid dimethyl ester.
From this measurement result, bis (acetylacetonato) copper, copper propionate, and normal butyric acid copper are copper compounds that dissolve easily in phthalic acid diesters, and the reaction apparatus as a mixed solution that is uniformly dissolved in phthalic acid diesters It can be seen that it is suitable because it is easy to supply to

Example 1
A reactor as shown in FIG. 1 consisting of a 50 ml glass reactor was used. In the reactor, stirring was performed with a stirrer, the internal temperature was adjusted to 220 ° C., and A grade air was bubbled into the reaction mixture at 20 ml / min and supplied to carry out an oxidation dimerization reaction. Here, the A grade air is dry air having a dew point of −80 ° C. or less.
Phthalic acid dimethyl ester, 0.00032 times mol of palladium acetate, 0.00032 times mol of 1,10-phenanthroline, and 0.000096 times mol of copper propionate The monohydrate is uniformly dissolved by stirring at 80 ° C. for 30 minutes or more, and the solution is supplied to the reactor by a liquid feed pump while maintaining the temperature at 80 ° C., and the reaction mixture reaches a predetermined amount. After that, while performing the oxidation dimerization reaction, the reaction mixture was supplied at a rate of 10 ml / hour by the liquid feed pump so that the liquid level of the reactor was kept substantially constant, so that the amount of the reaction mixture was substantially the same as the supply amount of the raw material mixture. A continuous operation was performed by continuously extracting.
The extracted reaction mixture was cooled to room temperature, diluted with acetone, cholesterol acetate was added as an internal standard substance, and each reaction mixture extracted within 10 to 20 hours from the start of the reaction by gas chromatography. The product was quantified. The results are shown in Table 1.
The average residence time of the reaction mixture in the reaction vessel was 5 hours.

Example 2
The same operation as in Example 1 was performed except that the raw material mixture was continuously supplied to the reactor at 5 ml / hour. The results are shown in Table 1.
The average residence time of the reaction mixture in the reaction vessel was 10 hours.

Example 3
The same operation as in Example 1 was performed except that the internal temperature of the reactor was adjusted to 210 ° C. The results are shown in Table 1.
The average residence time of the reaction mixture in the reaction vessel was 5 hours.

Example 4
The same operation as in Example 2 was performed except that the internal temperature of the reactor was adjusted to 210 ° C. The results are shown in Table 1.
The average residence time of the reaction mixture in the reaction vessel was 10 hours.

Example 5
A reactor as shown in FIG. 2 consisting of two 50 ml glass reactors connected in series was used. In both reactors, stirring was performed with a stirrer, the internal temperature was adjusted to 220 ° C., and A grade air was bubbled into the reaction mixture at 20 ml / min to supply an oxidation dimerization reaction.
Phthalic acid dimethyl ester, 0.00032 times mol of palladium acetate, 0.00032 times mol of 1,10-phenanthroline, and 0.000096 times mol of copper propionate The monohydrate is uniformly dissolved by stirring at 80 ° C. for 30 minutes or more, and the solution is supplied to the reactor by a liquid feed pump while maintaining the temperature at 80 ° C., and the reaction mixture reaches a predetermined amount. After that, while performing the oxidation dimerization reaction, the reaction mixture was supplied at a rate of 10 ml / hour by the liquid feed pump so that the liquid level of the reactor was kept substantially constant, so that the amount of the reaction mixture was substantially the same as the supply amount of the raw material mixture. Continuously withdrawn and fed to the second reactor.
Even in the second reactor, after the reaction mixture reaches a predetermined amount, the reaction diluting reaction is carried out and the reaction mixture is supplied to a substantially constant amount so that the liquid level of the reactor is kept substantially constant. The same amount of the reaction mixture was continuously extracted to perform continuous operation.
The extracted reaction mixture was cooled to room temperature, diluted with acetone, cholesterol acetate was added as an internal standard substance, and each reaction mixture extracted within 10 to 20 hours from the start of the reaction by gas chromatography. The product was quantified. The results are shown in Table 1.
The average residence time of the reaction mixture in the reaction vessel was 10 hours.

Example 6
The same operation as in Example 5 was performed except that the raw material mixture was continuously supplied to the reactor at 5 ml / hour. The results are shown in Table 1.
The average residence time of the reaction mixture in the reaction vessel was 20 hours.

Example 7
The same operation as in Example 5 was performed except that the internal temperature of the reactor was adjusted to 210 ° C. The results are shown in Table 1.
The average residence time of the reaction mixture in the reaction vessel was 10 hours.

Example 8
The same operation as in Example 6 was performed except that the internal temperature of the reactor was adjusted to 210 ° C. The results are shown in Table 1.
The average residence time of the reaction mixture in the reaction vessel was 20 hours.

Comparative Example 1
The same operation as in Example 1 was performed except that the internal temperature of the reactor was adjusted to 250 ° C. The results are shown in Table 1.
The average residence time of the reaction mixture in the reaction vessel was 5 hours.

Comparative Example 2
The same operation as in Example 5 was performed except that the internal temperature of the reactor was adjusted to 250 ° C. The results are shown in Table 1.
The average residence time of the reaction mixture in the reaction vessel was 10 hours.

Example 9
A reactor as shown in FIG. 1 consisting of a 50 ml glass reactor was used. In the reactor, stirring was performed with a stirrer, the internal temperature was adjusted to 200 ° C., and A grade air was bubbled into the reaction mixture at 20 ml / min and supplied to carry out an oxidation dimerization reaction.
Phthalic acid dimethyl ester, 0.00032 times mol palladium acetate, 0.00032 times mol 2-pyridinecarboxylic acid, 0.00064 times mol trifluoroacetic acid, and the same 0.000096-fold mol of propionate copper monohydrate was dissolved by stirring at 80 ° C. for 30 minutes or more, and the solution was supplied to the reactor by a liquid feed pump while maintaining the temperature at 80 ° C., After the reaction mixture reaches a predetermined amount, while carrying out the oxidation dimerization reaction, a reaction mixture of approximately the same amount as the supply amount of the raw material mixture is added so that the liquid level of the reactor is kept substantially constant. Continuous operation was performed by continuously extracting the liquid at a rate of 10 ml / hour.
The extracted reaction mixture was cooled to room temperature, diluted with acetone, cholesterol acetate was added as an internal standard substance, and each reaction mixture extracted within 10 to 20 hours from the start of the reaction by gas chromatography. The product was quantified. The results are shown in Table 2.
The average residence time of the reaction mixture in the reaction vessel was 5 hours.

Example 10
The same operation as in Example 8 was performed except that the raw material mixture was continuously supplied to the reactor at 5 ml / hour. The results are shown in Table 2.
The average residence time of the reaction mixture in the reaction vessel was 10 hours.

Since the present invention is as described above, the following effects can be obtained.
The present invention relates to a method for producing biphenyl tetracarboxylic acid tetraester by supplying molecular oxygen to a reaction system in the presence of a catalyst containing a palladium compound and subjecting phthalic acid diester to an oxidative dimerization reaction at a high temperature. No special equipment or complicated operation is required, the catalyst can be used effectively, the reaction can be controlled easily, it can be produced continuously, and it is more economical and improved. Manufacturing methods can be provided.

The schematic diagram which shows one embodiment of the reactor used in the manufacturing method of this invention Schematic diagram showing another embodiment of the reactor used in the production method of the present invention Schematic diagram showing another embodiment of the reactor used in the production method of the present invention

Explanation of symbols

1: Raw material tanks 2, 9, 16: Liquid feed pump 3: Raw material supply conduit 4, 11: Reactor 5, 12: Stirrer 6, 13: Air supply conduit 7, 14: Reaction mixture extraction conduit 8 15: Gas extraction conduit 10: Reaction mixture supply conduit

Claims (6)

  A step of continuously or intermittently supplying a phthalic diester and a catalyst containing a palladium compound to the reactor, and an oxidative dimerization reaction of the phthalic diester while supplying molecular oxygen to the reactor is performed at 140 ° C. or higher and 250 ° C. A method for producing a biphenyltetracarboxylic acid tetraester, wherein the step of performing in a temperature range of less than ° C and the step of continuously or intermittently removing a part of the reaction mixture from the reaction apparatus are performed in parallel. .   2. The biphenyltetracarboxylic acid tetraester according to claim 1, wherein the phthalic acid diester and the catalyst containing the palladium compound before being supplied to the reactor are maintained in a temperature range of 50 to 100 ° C. Method.   The catalyst containing a palladium compound contains a palladium compound, a bidentate ligand, and a copper compound, The production of the biphenyltetracarboxylic acid tetraester according to any one of claims 1 to 2, Method.   The bidentate ligand is a bidentate ligand capable of complexing with palladium by two nitrogen atoms, two oxygen atoms, or nitrogen and oxygen atoms. 4. A method for producing a biphenyltetracarboxylic acid tetraester as described in 3.   The biphenyl tetra of claim 3, wherein the copper compound is any one of copper propionate, normal butyric acid copper, bis (acetylacetonato) copper, and anhydrous or hydrated copper pivalate. A method for producing a carboxylic acid tetraester.   A reactor comprising a plurality of reactors connected in series, the step of continuously or intermittently supplying a phthalic acid diester and a catalyst containing a palladium compound to the first reactor; A step of continuously or intermittently removing a part of the reaction mixture and sequentially introducing it to the next reactor; a step of performing an oxidative dimerization reaction of phthalic diester while supplying molecular oxygen to each reactor; The biphenyltetracarboxylic acid tetraester according to any one of claims 1 to 5, wherein the step of continuously or intermittently removing a part of the reaction mixture from the last reactor is performed in parallel. Manufacturing method.

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