JP5280115B2 - Method for producing p-phenylenebis (trimellitic acid monoester anhydride) - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for economically and efficiently producing high-purity TMHQ (trimellitic acid monoester acid anhydride) (p-phenylene-bis). <P>SOLUTION: The method for producing the p-phenylene-bis (trimellitic acid monoester acid anhydride) by reacting an acid chloride of trimellitic anhydride with hydroquinone in the presence of a base includes using acetonitrile as a reaction solvent. As a result, a water-washing operation for removing a by-produced hydrochloride is made unnecessary, and a treating operation for returning a hydrolyzed product to an original material is also made unnecessary. Therefore, the impurity inhibiting high purification is not formed. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to p-phenylenebis (trimellitic acid monoester anhydride, which is useful as a raw material for polyimide resins, etc. by reacting trimellitic anhydride chloride obtained by acid chloride trimming anhydride with hydroquinone. ) Efficiently.

  Conventionally, as a method for producing p-phenylenebis (trimellitic acid monoester anhydride), hydroquinone is diacetylated with acetic anhydride, and this is reacted with trimellitic anhydride at 250 to 300 ° C. for transesterification. A method for producing phenylenebis (trimellitic acid monoester anhydride) (hereinafter sometimes abbreviated as “TMHQ”) has been proposed (Non-patent Document 1, Patent Document 1). In addition, a method for producing trimellitic anhydride esters by dehydrating ester of trimellitic anhydride and aliphatic diols at 210 to 230 ° C. has been proposed (Patent Document 2). However, it is not a good idea to expose diols that are not thermally stable to such a high temperature, and it is difficult to adopt industrially as a method for producing high-purity TMHQ.

  On the other hand, as a method for producing trimellitic acid ester anhydride without being exposed to the high temperature as described above, a method of dehydrochlorination using trimellitic anhydride chloride and diols as raw materials has been proposed.

  For example, Patent Document 3 discloses a method for producing 2,2-bis (trimellitoxyphenyl) propane using trimellitic anhydride chloride and bisphenol A as raw materials. In this method, tetrahydrofuran (hereinafter abbreviated as “THF”) is used as a solvent, pyridine is added as a hydrochloric acid scavenger, and dehydrochlorination is carried out to synthesize 2,2-bis (trimeritoxyphenyl) propane. After the reaction, by-product pyridine hydrochloride is removed by filtration, THF is distilled off, and the product obtained is recrystallized with acetic anhydride to produce TMHQ. However, when TMHQ is produced by reacting trimellitic anhydride chloride with hydroquinone by this method, not only TMHQ but also a substance containing pyridine remains in the solution. For this reason, it is necessary to recrystallize with acetic anhydride as described in the examples of this document, but this method does not properly remove by-products and does not increase the purity of the product.

  In Patent Document 4, TMHQ is produced using trimellitic anhydride chloride and hydroquinone as raw materials. In this method, toluene is used as a solvent, and pyridine is used as a hydrochloric acid scavenger. After reaction under reflux, the solid is separated by filtration, washed with water, and dried to obtain a crude product. The crude product is then heat-treated with acetic anhydride and recrystallized from N, N-dimethylformamide (hereinafter abbreviated as “DMF”) to produce TMHQ. However, in this production method, since pyridine hydrochloride formed as a by-product in the reaction is precipitated in the reaction solution together with TMHQ, it is necessary to wash only the solid matter to remove only pyridine hydrochloride. For this reason, a part of produced | generated TMHQ will hydrolyze. In order to restore this hydrolyzate, heat treatment with acetic anhydride is required, which is not a reasonable method.

  In Patent Document 5, pyridine is added using acetonitrile as a solvent, and 3,5,6-trichloro-4-chloroformylphthalic anhydride is reacted with hydroquinone to react with 3,5,6-trichloro-4-chloroformyl. A method for producing phthalic anhydride hydroquinone has been proposed. In this method, the reaction is carried out at −18 ° C., and the product is separated by filtration, washed several times with chloroform and dried to give 3,5,6-trichloro-4-chloroformyl as a monomer for optical communication. Manufactures phthalic anhydride hydroquinone. However, since the document does not describe the purity of the product obtained by this method, it is unclear whether the method is excellent in productivity. Moreover, it is not practical and industrially satisfactory, such as using chloroform with a large environmental load for washing, and having a reaction temperature of −18 ° C.

Here, since acid dianhydrides such as TMHQ may be hydrolyzed by moisture in the air, a method of recrystallizing with acetic anhydride to suppress hydrolysis or to return the hydrolyzate to its original state, A method of recrystallization with a mixed solution of acetic anhydride and acetic acid has been proposed (Patent Document 3, Non-Patent Document 2). Although these are more rational methods, the manufacturing process is complicated and it is difficult to manufacture a high-purity product.
Japanese Patent Laid-Open No. 11-199578 Japanese Examined Patent Publication No. 52-46940 Japanese Patent No. 2605453 JP-A-10-70157 Japanese Patent No. 3490010 Journal of Polymer Science: Part A: Polymer Chemistry, Vol. 37 (1999) 211-218 Pure Appl. Chem., A39 (8) (2002) 815-824

  An object of the present invention is to provide a method for producing TMHQ having high purity more economically and efficiently.

  In the method for producing p-phenylenebis (trimellitic acid monoester anhydride) by reacting trimellitic anhydride chloride with hydroquinone, the present inventors have found that the production methods that have been proposed so far are complicated. The inventors have intensively studied a simple method that does not require an operation, that is, an operation of removing by-product pyridine hydrochloride by washing with water and a treatment of hydrolyzate produced for washing with water.

  In addition, TMHQ is easily hydrolyzed, so it cannot be highly purified by a recrystallization method using acetic anhydride, which is considered to be rational as a purification method to prevent this, or a recrystallization method using a mixed solution of acetic anhydride and acetic acid. investigated.

  As a result, TMHQ is easily solvolyzed in acetic anhydride, and acetoxyphenyl trimellitic acid ester having the structure represented by the following formula (1) is used as an impurity that cannot be removed by purification methods such as solvent washing and recrystallization. Found to generate. That is, the recrystallization method using a solvent mainly composed of acetic anhydride, which has been conventionally considered to be rational, produces the ester, so that it is essentially impossible to achieve high purity. Obtained knowledge.

This impurity was identified based on the LCMS analysis result.
In order not to generate the ester which is the above impurity, a solvent mainly composed of acetic anhydride should not be used after the reaction. Then, the filtrate obtained by the reaction is washed with water to dissolve the pyridine hydrochloride. It is necessary to avoid operation. Therefore, the reaction solvent is required to be one in which TMHQ is hardly dissolved and pyridine hydrochloride is easily dissolved.

  From this point of view, by using acetonitrile as a solvent for reacting trimellitic anhydride chloride with hydroquinone, the above problems can be solved, and special purification operations (mainly water washing and acetic anhydride are mainly used). It has been found that high-purity TMHQ can be produced without heating with a solvent.

  The present invention, which has been completed based on the above findings, is a method for producing p-phenylenebis (trimellitic acid monoester acid anhydride) by reacting trimellitic anhydride chloride with hydroquinone in the presence of a base. A method for producing p-phenylenebis (trimellitic acid monoester anhydride), characterized in that acetonitrile is used for the reaction.

The preferable aspect in said manufacturing method is as follows.
The base is pyridine.
The reaction between trimellitic anhydride chloride and hydroquinone was completed by dropping an acetonitrile solution of hydroquinone into acetonitrile solution of trimellitic anhydride chloride in a reaction vessel while maintaining the internal temperature at 10 to 40 ° C. Thereafter, the system temperature is maintained at 15 to 40 ° C.

  According to the present invention, since the by-product hydrochloride is removed without performing a water washing operation, a treatment operation for restoring the hydrolyzate (for example, a heating operation in a solvent containing acetic anhydride as a main component). Do not need. For this reason, impurities difficult to be removed by the purification shown in the above formula (1) are not generated, and it is realized to produce TMHQ industrially advantageously.

Hereinafter, the manufacturing method of p-phenylenebis (trimellitic acid monoester anhydride) (TMHQ) according to the present invention will be described in detail.
In the present invention, acetonitrile is used as a reaction solvent in a method for producing TMHQ by reacting trimellitic anhydride chloride with hydroquinone.

  The amount of acetonitrile used may be an amount that can dissolve trimellitic anhydride chloride and hydroquinone. The amount of acetonitrile used to dissolve the trimellitic anhydride chloride is usually 1.0 to 3.0 times, preferably 1.5 to 2.0 times the weight of trimellitic anhydride chloride charged. The amount of acetonitrile used to dissolve hydroquinone is usually 7.0 to 12.0 times, preferably 9.0 to 10.0 times the weight of hydroquinone charged.

  If the amount of acetonitrile used is less than this range, the hydrochloride produced as a by-product in the reaction becomes difficult to dissolve, so there is a concern that the product quality will deteriorate. Conversely, if the amount used is larger than this range, it is economically disadvantageous. The base used as the hydrochloric acid scavenger is a conventionally known base as long as the hydrochloride is dissolved in acetonitrile, and pyridine is particularly preferable. What is necessary is just to mix a base in the acetonitrile solution of hydroquinone.

  The ratio of trimellitic anhydride chloride to hydroquinone is preferably 2.0 to 2.4 as a molar ratio. Moreover, it is preferable that the ratio with respect to the trimellitic anhydride chloride of a base shall be 1.0-1.2 as molar ratio.

  The reaction is started by dropping an acetonitrile solution of hydroquinone into a dissolved acetonitrile solution of trimellitic anhydride chloride, and the temperature in the system is set to 10 to 40 ° C, preferably 15 to 25 ° C. preferable. There is no restriction | limiting in dripping time, The dripping speed | rate which can hold | maintain predetermined temperature may be sufficient.

After completion of the dropping, the temperature in the system is reacted at 15 to 40 ° C., preferably 20 to 30 ° C. for 1 to 10 hours.
After completion of the reaction, the produced TMHQ solid is collected by filtration. By-product hydrochloride, in a preferred embodiment, pyridine hydrochloride, is dissolved in acetonitrile, and thus is removed from TMHQ simply by filtering the reaction solution.

  Next, this solid substance is dissolved by heating in an organic solvent. The organic solvent is not particularly limited as long as it does not decompose TMHQ in a solvable manner, and it is preferable to use DMF, N, N-dimethylacetamide, or any mixture thereof. The amount of the organic solvent used is 2.5 to 5.0 times by weight, preferably 3.0 to 4.0 times by weight of the TMHQ solid.

  Here, in general, these organic solvents often contain a small amount of water when available at an industrial level, and this water may generate a small amount of hydrolyzate. is there. However, since a small amount of hydrolyzate can be removed by moving to the filtrate during recrystallization, the product quality is not affected. Rather, if a dehydrated product is used only from the viewpoint of increasing the yield, it may be economically disadvantageous. Therefore, it is preferable to use what added about 1 weight% of acetic anhydride as a dehydrating agent in these organic solvents, using the organic solvent obtained on an industrial level. If it is this grade, even if the by-product shown by the said Formula (1) produces | generates, the influence which it has on purity will be slight and it is implement | achieved to make a yield and purity compatible at a high level.

  The dissolution temperature of TMHQ in an organic solvent is 60 to 110 ° C, preferably 70 to 85 ° C. If the temperature is high, coloring is a concern. On the other hand, since it becomes difficult to melt | dissolve when temperature is low, it becomes difficult to acquire a favorable purification effect.

  When TMHQ is dissolved in an organic solvent, the solution is cooled to crystallize TMHQ. The cooling temperature is −10 to 30 ° C., preferably 5 to 25 ° C. If the temperature is too low, it is difficult to transfer crystals, which is not preferable for handling. If the temperature is too high, the product yield is lowered, which is economically disadvantageous.

  The precipitated solid is filtered to separate TMHQ. The separated solid of TMHQ is washed with an organic solvent. As the organic solvent for this washing, aliphatic ketones, ethers, and aromatic hydrocarbons are used. For example, aliphatic ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, etc., ethers include tetrahydrofuran, methyl isobutyl ether, methyl isopropyl ether, etc., and aromatic hydrocarbons include benzene, toluene, xylene, ethyl benzene, and the like. Can be mentioned.

  The washed TMHQ is dried under reduced pressure at 80 ° C. for about 24 hours to produce high purity TMHQ.

  Hereinafter, the present invention will be described more specifically with reference to examples, comparative examples, and the like, but the present invention is not limited to these examples.

In the following examples and the like, the concentration indicates area% and the yield indicates mol%. Further, the analysis was performed by dissolving the sample in anhydrous methanol with heating and using high performance liquid chromatography (HPLC) under the following conditions.
Column: Intersil ODS-80A manufactured by GL Sciences Inc.
Length 250mm, inner diameter 4.2mm
Mobile phase: acetonitrile / 0.1% aqueous phosphoric acid
(Gradient of mixing volume ratio 1: 1 to 0: 1 after 20 minutes from the start)
Detector: UV (254 nm)

(Reference example)
A 2 L glass reaction vessel equipped with a reflux condenser, a temperature measuring tube and an electromagnetic stirrer was charged with 300 g (1.56 mol) of trimellitic anhydride, 550 g of toluene and 0.5 g of N, N-dimethylformamide in a nitrogen atmosphere. It is. After raising the internal temperature to 80 ° C., 204.3 g (1.71 mol) of thionyl chloride was added over 30 minutes. Then, it was made to react at this temperature for 9 hours. After the reaction, the remaining thionyl chloride and the solvent toluene were distilled off with an evaporator to obtain 375 g of trimellitic anhydride chloride having a purity of 95%.

Example 1
In a 1 L glass reaction vessel equipped with 125 g of trimellitic anhydride chloride obtained in Reference Example and 193 g of acetonitrile (1.5 times the weight of trimellitic anhydride chloride) by a reflux condenser, a temperature measuring tube and an electromagnetic stirrer, The mixture was charged under a nitrogen atmosphere, dissolved and cooled to an internal temperature of 15 ° C. Next, 29.9 g (0.27 mol) of hydroquinone was dissolved in 290 g of acetonitrile (9.7 times by weight of hydroquinone) and 45 g (0.57 mol) of pyridine was further added to the inner temperature of 15 ° C. with a dropping funnel. While maintaining, the solution was added dropwise to the acetonitrile solution in the reaction vessel over 1 hour. After completion of the dropwise addition, the solid product in the reaction solution obtained by stirring at an internal temperature of 15 ° C. to 25 ° C. for 5 hours was collected by filtration, and the solid was washed with 30 g of acetonitrile to obtain a white solid. As a result of analyzing this white solid by HPLC, it was found that p-phenylenebis (trimellitic acid monoester anhydride) (TMHQ) was 96.2% and pyridine 2.4%.

  This white solid was dissolved by heating (80 ° C.) in 556 g of DMF containing 3.1 g of acetic anhydride, and then recrystallized. The precipitated crystals were filtered and washed with 200 g of acetone. The washed crystals were dried under reduced pressure of 5 mmHg at 80 ° C. for 24 hours to obtain 79 g of white TMHQ having a purity of 99.8%, pyridine of 0%, and impurities represented by the above formula (1) not detected at the HPLC level. The yield based on trimellitic anhydride was 66%.

(Comparative Example 1)
125 g of trimellitic anhydride chloride and 214 g of toluene obtained in the Reference Example were charged in a 1 L glass reaction vessel equipped with a reflux condenser, a temperature measuring tube and an electromagnetic stirrer in a nitrogen atmosphere, dissolved, and the internal temperature was 80 ° C. The temperature was raised to. Next, 31.8 g (0.29 mol) of hydroquinone was dissolved in 255 g of toluene, and 45 g of pyridine was further added to the toluene solution in the reaction vessel over 2.5 hours while maintaining the internal temperature at 80 ° C. with a dropping funnel. It was dripped. After completion of dropping, the mixture was stirred for 2 hours at an internal temperature of 110 ° C. The reaction solution was cooled to room temperature, and the precipitated solid was collected by filtration. This solid contained 53.2% TMHQ and 38.7% pyridine. This solid was put into 735 g of water, stirred for 0.5 hour and then filtered off. The obtained solid was again put into 735 g of water, and similarly stirred for 0.5 hour, followed by filtration. The solid obtained by the two water washings was dried at 80 ° C. for 16 hours under a reduced pressure of 5 mmHg to obtain 135 g.

  The solid and 295 g of acetic anhydride were placed in a 2 L reaction vessel, dissolved under stirring for 2 hours under reflux, cooled to room temperature, and the precipitated crystals were collected by filtration. Thereafter, the obtained crystal was dissolved by heating (80 ° C.) with 460 g of DMF, and recrystallized by cooling to room temperature. The precipitated crystals were separated by filtration, and the obtained crystals were washed with 200 g of toluene and dried at 80 ° C. for 24 hours. Thus, 57 g of white TMHQ having a light yellowish taste containing 99.4% purity, 0% pyridine and 0.4% impurities represented by the above formula (1) was obtained. The yield based on trimellitic anhydride was 48%.

  In a comparative example in which Patent Document 4 was additionally tested, a solid product containing pyridine hydrochloride formed as a by-product (38.7% in terms of pyridine) was washed with water to remove the hydrochloride. In order to restore it, heat treatment with acetic anhydride was performed. Therefore, an impurity represented by the above formula (1) was generated and remained in the purified TMHQ.

Claims (3)

  In a method for producing p-phenylenebis (trimellitic acid monoester anhydride) by reacting trimellitic anhydride chloride with hydroquinone in the presence of a base, acetonitrile is used as a reaction solvent. A method for producing phenylenebis (trimellitic acid monoester anhydride).   The production method according to claim 1, wherein the base is pyridine.   The reaction between trimellitic anhydride chloride and hydroquinone was completed by dropping the acetonitrile solution of hydroquinone into the acetonitrile solution of trimellitic anhydride chloride in the reaction vessel while maintaining the system temperature at 10 to 40 ° C. Then, the manufacturing method of Claim 1 or 2 performed by hold | maintaining system temperature at 15-40 degreeC.