TWI649323B - Method for producing cyclobutane tetracarboxylic acid derivative - Google Patents

Abstract

The present invention is to provide an efficient 1,3-dialkyl1,2,3,4-cyclobutanetetracarboxylic acid-1,2: 3,4-dianhydride derivative suitable for raw materials such as polyimide. Manufacturing method.

This is to produce a photodimerization reaction of a maleic anhydride compound represented by the following formula (1) in a solvent containing a fatty acid ester having 1 to 4 carbon atoms in the presence of a sensitizer to produce the formula (2) Method of 1,3-dialkyl1,2,3,4-cyclobutanetetracarboxylic acid-1,2: 3,4-dianhydride derivative.

(In the formula, R represents an alkyl group having 1 to 20 carbon atoms.)

Description

Method for producing cyclobutane tetracarboxylic acid derivative

The present invention relates to a novel method for producing a cyclobutane tetracarboxylic acid derivative suitable for a raw material such as polyimide.

A cyclobutane tetracarboxylic acid derivative is a compound suitable for use as a raw material such as polyimide. A method for producing the compound is known, for example, a photodimerization reaction of a maleic anhydride derivative (Patent Documents 1 to 5).

However, in the method for producing a cyclobutanetetracarboxylic acid derivative by a photodimerization reaction of a maleic anhydride derivative disclosed in Patent Documents 1 to 5, even if a sensitizer is used, the photoreaction efficiency is not necessarily sufficient. .

For example, the production method of 1,2,3,4-cyclobutanetetracarboxylic acid-1,2: 3,4-dianhydride (CBDA) disclosed in Patent Document 1 is in a solvent having a carbonyl group such as a ketone. A photodimerization reaction of maleic anhydride is performed. However, Patent Document 1 has described that the use of acetophenone, benzophenone, and anthracene roller as a sensitizer has no effect, and it would rather have good results when it does not exist. (3) The left column of the upper paragraph of the page is 4 lines).

As mentioned above, 1,2,3,4-cyclobutanetetracarboxylic acid-1,2: 3,4-dianhydride (CBDA) was previously produced by photodimerization of maleic anhydride. The method is that the maleic anhydride of the raw material is relatively low in price, and is simple and applicable as a manufacturing method, but its photoreaction efficiency is not sufficient, and there is a problem in the yield of the target substance.

In addition, Patent Document 2 discloses that as shown in the following scheme, 1,3-dimethylcyclobutane-1,2,3,4-tetracarboxylic acid is obtained by photodimerization of citraconic anhydride (MMA for short). Acid-1,2: 3,4-dianhydride (1,3-DMCBDA) and 1,2-dimethylcyclobutane-1,2,3,4-tetracarboxylic acid-1,2: 3,4 -A mixture of dianhydride (1,2-DMCBDA).

In addition, when comparing the isomers of 1,3-DMCBDA and 1,2-DMCBDA, it is known that 1,3-DMCBDA, which has a highly symmetric structure, can produce a polymer with a molecular weight higher than that of 1,2-DMCBDA. Amine, so it has higher applicability.

Patent Document 2 describes that a mixture of 1,3-DMCBDA and 1,2-DMCBDA can be obtained, but it does not describe that the former 1,3-DMCBDA, which has high applicability and can be produced at high yield, is optional.

Prior art literature Patent literature

Patent Document 1: Japanese Patent Application Laid-Open No. 59-212495

Patent Document 2: Japanese Unexamined Patent Publication No. 4-106127

Patent Document 3: Japanese Patent Application Laid-Open No. 2003-192685

Patent Document 4: Japanese Patent Application Laid-Open No. 2006-347931

Patent Document 5: Japanese Patent Application Laid-Open No. 2008-69081

An object of the present invention is to provide a 1,3-dialkyl-1,2,3 for the purpose of producing a photodimerization reaction of a maleic anhydride compound represented by the following formula (1) with high photoreaction efficiency and high yield. A method of a derivative of 1,4-cyclobutanetetracarboxylic acid-1,2: 3,4-dianhydride (hereinafter also referred to as 1,3-DACBDA).

The present inventors made intensive research in order to solve the above-mentioned problems, and found that the use of a specific solvent is different from the previous disclosures of Patent Document 1 and the like. The photoreaction rate of the maleic anhydride compound and the selectivity of the 1,3-DACBDA derivative, which is an isomer with a highly symmetrical structure, are improved and manufactured in high yield.

The present invention is based on the novel findings described above and has the gist described below.

1. A method for producing a 1,3-dialkyl1,2,3,4-cyclobutanetetracarboxylic acid-1,2: 3,4-dianhydride derivative represented by formula (2), characterized in that: To perform a photodimerization reaction of a maleic anhydride compound represented by the following formula (1) in the presence of a sensitizer in a solvent containing a fatty acid ester having 1 to 4 carbon atoms,

(In the formula, R represents an alkyl group having 1 to 20 carbon atoms.)

2. The production method according to the above 1, wherein R is an alkyl group having 1 to 6 carbon atoms.

3. The manufacturing method according to 1 or 2 above, wherein the amount of the solvent used is 3 to 300 times the mass of the maleic anhydride compound.

4. The manufacturing method according to any one of the above 1 to 3, wherein the fatty acid ester having a carbon number of 1 to 4 is a formula: R ¹ COOR ² (wherein R ¹ is a hydrogen atom, or the carbon number is preferably An alkyl group of 1 to 4 and R ² is an alkyl ester of a fatty acid represented by an alkyl group having 1 to 4 carbon atoms.

5. The production method according to any one of 1 to 4 above, wherein the solvent is a sub-solvent containing a carbonic acid diester.

6. The manufacturing method according to any one of 1 to 5 above, wherein the sensitizer is benzophenone, acetophenone, or benzaldehyde.

7. The manufacturing method according to any one of 1 to 6 above, wherein The chemist is benzophenone substituted with an electron-drawing group, acetophenone substituted with an electron-drawing group, or benzaldehyde substituted with an electron-drawing group.

8. The manufacturing method according to the above 7, wherein the electron-withdrawing group is at least one selected from the group consisting of a fluoro group, a chloro group, a bromo group, an iodo group, a nitro group, a cyano group, and a trifluoromethyl group.

9. The manufacturing method according to the above 7 or 8, wherein the number of the pulled electron groups is 1 to 5.

10. The manufacturing method according to any one of 1 to 9 above, wherein the used amount of the sensitizer is 0.1 to 20 mole% relative to the maleic anhydride compound.

11. The manufacturing method according to any one of 1 to 10, wherein the reaction temperature is 0 to 20 ° C.

The present invention uses a cheap maleic anhydride compound as a raw material, and performs a photodimerization reaction by a photoreaction rate, and is different from the previous disclosure such as Patent Document 1 in that the maleic anhydride compound is performed in the presence of a sensitizer. The photodimerization reaction can increase the photoreaction rate of the maleic anhydride compound, and increase the selectivity of the 1,3-DACBDA derivative, which is an isomer with a highly symmetrical structure, and is manufactured in high yield.

FIG. 1 is a graph showing the relationship between the light irradiation time and the residual amount of citraconic anhydride in Example 1, Comparative Examples 1 and 2 of the present invention.

Embodiment of the invention

By the photo-dimerization reaction of the maleic anhydride compound represented by the formula (1), 1,3-dialkyl-1,2,3,4-cyclobutanetetracarboxylic acid- The method of the 1,2: 3,4-dianhydride derivative is shown in the following reaction scheme.

In the formula, R represents an alkyl group having 1 to 20 carbon atoms, preferably 1 to 12, more preferably 1 to 6, and particularly preferably methyl.

The alkyl group having 1 to 20 carbon atoms may be a linear or branched saturated alkyl group, or a linear or branched unsaturated alkyl group.

Specific examples thereof are methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, n-pentyl, 1-methyl- n-butyl, 2-methyl-n-butyl, 3-methyl-n-butyl, 1,1-dimethyl-n-propyl, n-hexyl, 1-methyl-n-pentyl Methyl, 2-methyl-n-pentyl, 1,1-dimethyl-n-butyl, 1-ethyl-n-butyl, 1,1,2-trimethyl-n-propyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-dodecyl, n-icosyl, 1-methylvinyl, 2-allyl, 1-ethyl Vinyl, 2-methylallyl, 2-butene 2-methyl-2-butenyl, 3-methyl-2-butenyl, 3-methyl-3-butenyl, 2-hexenyl, 4-methyl-3-pentene 4-methyl-4-pentenyl, 2,3-dimethyl-2-butenyl, 1-ethyl-2-pentenyl, 3-dodecenyl, propargyl, 3 -Butynyl, 3-methyl-2-propynyl, 9-decynyl and the like.

In addition, n is positive, i is different, s is vice, and t is uncle.

The maleic anhydride compound represented by the formula (1), for example, citraconic anhydride, 2-ethylmaleic anhydride, 2-isopropylmaleic anhydride, 2-n-butylmaleic anhydride, 2-t-butyl Maleic anhydride, 2-n-pentylmaleic anhydride, 2-n-hexylmaleic anhydride, 2-n-heptylmaleic anhydride, 2-n-octylmaleic anhydride, 2-n-nonyl Maleic anhydride, 2-n-decylmaleic anhydride, 2-n-dodecylmaleic anhydride, 2-n-icosylmaleic anhydride, 2- (1-methylvinyl) maleate Anhydride, 2- (2-allyl) maleic anhydride, 2- (1-ethylvinyl) maleic anhydride, 2- (2-methylallyl) maleic anhydride, 2- (2-butane Alkenyl) maleic anhydride, 2- (2-hexenyl) maleic anhydride, 2- (1-ethyl-2-pentenyl) maleic anhydride, 2- (3-dodecenyl) maleic anhydride Anhydride, 2-propargylmaleic anhydride, 2- (3-butynyl) maleic anhydride, 2- (3-methyl-2-propynyl) maleic anhydride, 2- (9-decynyl ) Maleic anhydride and so on. In order to perform the photoreaction more efficiently, citraconic anhydride, 2-ethylmaleic anhydride, 2-isopropylmaleic anhydride, 2-n-butylmaleic anhydride, and 2-t-butylmaleate are preferred. Maleic anhydride, 2-n-pentylmaleic anhydride, 2-n-hexylmaleic anhydride, 2-n-heptylmaleic anhydride, 2-n-octylmaleic anhydride, 2-n-nonylmaleic anhydride Acid anhydride, 2-n-decylmaleic anhydride, or 2-n-dodecylmaleic anhydride, etc., more preferably citraconic anhydride, 2-ethylmaleic anhydride, 2-isopropylmaleic anhydride, 2-n-butylmaleic anhydride, 2-t-butylmaleic anhydride, 2-n-pentylmaleic anhydride, or 2-n-hexane Maleic anhydride.

The photoreaction of the present invention is carried out by adding a (photo) sensitizer to the reaction system. The sensitizer may be anything having a photosensitizing effect, such as benzophenone, benzaldehyde, anthraquinone, and the like.

The sensitizer is particularly preferably benzophenone substituted with a pull electron group, acetophenone substituted with a pull electron group, or benzaldehyde substituted with a pull electron group. The electron-drawing group at this time is, for example, at least one selected from the group consisting of a fluoro group, a chloro group, a bromo group, an iodo group, a nitro group, a cyano group, and a trifluoromethyl group, and is preferably a fluoro group, a chloro group, Bromo, cyano or trifluoromethyl. Particularly preferred zirconium is fluorine or chloro. The number of drawn electron groups is 1 to 10, preferably 1 to 5, and particularly preferably 1 to 3.

The substitution position of the sensitizer in the benzophenone, acetophenone, and benzaldehyde is relative to the carbonyl group such as ortho, meta, para, and preferably ortho or para. When the number of the electron-drawing groups is 2 or more, the electron-drawing groups may be the same or different. In addition, the carbonyl group with an electron-drawing effect in the ortho position can be crosslinked (anthracene roll).

Specific examples of benzophenone, or benzophenone substituted with an electron-drawing group, are benzophenone, 2-fluorobenzophenone, 3-fluorobenzophenone, 4-fluorobenzophenone, 2 -Chlorobenzophenone, 3-chlorobenzophenone, 4-chlorobenzophenone, 2-cyanobenzophenone, 3-cyanobenzophenone, 4-cyanobenzophenone, 2-nitrobenzophenone, 3-nitrobenzophenone, 4-nitrobenzophenone, 2,4'-dichlorobenzophenone, 4,4'-difluorobenzophenone , 4,4'-dichlorobenzophenone, 4,4'-dibromobenzophenone, 3,3'-bis (trifluoromethyl) benzophenone, 3,4'-dinitro Benzophenone, 3,3'-Dinitrobenzophenone, 4,4'-Di Nitrobenzophenone, 2-chloro-5-nitrobenzophenone, 1,3-bis (4-fluorobenzofluorene) benzene, 1,3-bis (4-chlorobenzofluorene) benzene, 2, 6-diphenylfluorene benzonitrile, 1,3-diphenylfluorene-4,6-dinitrobenzene, anthracene roller, etc. Among them, 4,4'-difluorobenzophenone or 4,4'-dichlorobenzophenone is preferred.

Specific examples of acetophenone or acetophenone substituted with an electron-drawing group, for example, acetophenone, 2'-fluoroacetophenone, 3'-fluoroacetophenone, 4'-fluoroacetophenone, 2'-chloro Acetophenone, 3'-chloroacetophenone, 4'-chloroacetophenone, 2'-cyanoacetophenone, 3'-cyanoacetophenone, 4'-cyanoacetophenone, 2'- Nitroacetophenone, 3'-Nitroacetophenone, 4'-Nitroacetophenone, 2 ', 4'-Difluoroacetophenone, 3', 4'-Difluoroacetophenone, 2 ' , 4'-dichloroacetophenone, 3 ', 4'-dichloroacetophenone, 4'-chloro-3'-nitroacetophenone, 4'-bromo-3'-nitroacetophenone, 4'-fluoro-3'-nitroacetophenone and the like. Among them, 4'-fluoroacetophenone, 4'-chloroacetophenone, 2 ', 4'-difluoroacetophenone, 3', 4'-difluoroacetophenone, 2 ', 4'- Ethyl chloride, or 3 ', 4'-dichloroethene.

Benzaldehyde, or benzaldehyde substituted by an electron group such as benzaldehyde, 2-fluorobenzaldehyde, 3-fluorobenzaldehyde, 4-fluorobenzaldehyde, 2-chlorobenzaldehyde, 3-chlorobenzaldehyde, 4-chloro Benzaldehyde, 2-cyanobenzaldehyde, 3-cyanobenzaldehyde, 4-cyanobenzaldehyde, 2-nitrobenzaldehyde, 3-nitrobenzaldehyde, 4-nitrobenzaldehyde, 2,4-dibenzaldehyde Fluorobenzaldehyde, 3,4-difluorobenzaldehyde, 2,4-dichlorobenzaldehyde, 3,4-dichlorobenzaldehyde, 2-chloro-5-nitrobenzaldehyde, 4-chloro-2-nitro Benzaldehyde, 4-chloro-3-nitrobenzaldehyde, 5-chloro-2-nitrobenzaldehyde, 2-fluoro-5-nitrobenzaldehyde, 4-fluoro-3-nitrobenzaldehyde, 5-fluoro -2-nitrobenzaldehyde, etc. Among them, 4-fluorobenzaldehyde, 4-chlorobenzaldehyde, 2,4-difluorobenzaldehyde, 3,4-difluorobenzaldehyde, 2,4-dichlorobenzaldehyde, or 3,4-dichloro is preferred. Benzyl aldehyde.

The sensitizing dose used may be an amount that accelerates the photoreaction rate, but it is preferably 0.1-20 mol%, and more preferably 0.1-5 mol% relative to the maleic anhydride compound. The sensitizer can be used alone or in combination of two or more. For ease of handling after the reaction, it is preferably used alone.

In the photoreaction of the present invention, since the photoreaction speed is accelerated, the reaction solvent needs to use fatty acid esters having 1 to 4 carbon atoms. Fatty acid esters having 1 to 4 carbon atoms, preferably 1 to 2 are again represented by the formula: R ¹ COOR ² (wherein R ¹ is hydrogen, or the carbon number is preferably 1 to 4, and more preferably 1 or 2) Alkyl, R ² is a fatty acid alkyl ester represented by a carbon number of 1 to 4, more preferably 1 to 3). Preferred examples include methyl formate, ethyl formate, n-propyl formate, i-propyl formate, n-butyl formate, i-butyl formate, methyl acetate, ethyl acetate, n-propyl acetate , I-propyl acetate, n-butyl acetate, i-butyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, i-propyl propionate, n-butyl propionate, Or i-butyl propionate. Particularly preferred are methyl acetate, ethyl acetate, n-propyl acetate, i-propyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, or i-propyl propionate, etc. One kind or two or more kinds can be used.

In addition, as the reaction solvent, a fatty acid ester having 1 to 4 carbon atoms can be used alone, and other auxiliary solvents can also be used. The sub-solvent used at this time is preferably a carbonyl compound with (1) a high photosensitivity effect, and (2) a higher solubility with respect to the maleic anhydride compound as a raw material. In order to suppress the decomposition reaction of the generated CBDA derivative compound, Relatively low solubility with respect to CBDA derivative compounds, (3) high solubility with respect to by-products, The compound can be purified only by washing with the same solvent. (4) The compound does not have a low boiling point as a fire hazard, and it does not remain in the product of the CBDA derivative compound. The compound has a boiling point around 100 ° C. (5) It has environmental safety, (6) stability in light reaction, and (7) inexpensive.

From these viewpoints, specific examples of the sub-solvent are preferably carbonic acid diesters, and particularly, the number of carbon atoms of the alkyl group is preferably 1 to 3, and more preferably 1 or 2 dialkyl carbonates. For example, dimethyl carbonate or diethyl carbonate is preferred, and diethyl carbonate or dimethyl carbonate is particularly preferred. As the sub-solvent, ethylene glycol diformate, ethylene glycol diacetate, ethylene glycol dipropionate, propylene glycol diformate, propylene glycol diacetate, propylene glycol dipropionate, and succinic acid can be used. Glycol diesters such as alcohol diacetate.

One of the advantages of the manufacturing method of the present invention using a fatty acid ester having 1 to 4 carbon atoms as a reaction solvent is that not only the solubility to the raw material maleic anhydride compound is high, but also the solubility to the generated CBDA derivative compound is relatively high. Low, easy to crystallize the target compound during the reaction. Therefore, it is possible to suppress the side reaction from the reverse reaction from the CBDA derivative compound to the maleic anhydride compound and the formation of oligomers.

The use amount of the reaction solvent is 3 to 300 times by mass, and more preferably 4 to 250 times by mass relative to the maleic anhydride compound. These solvents may be used alone or in combination of two or more, but they are preferably used alone in view of ease of handling after the reaction. When a sub-solvent is used, the sub-solvent is preferably 0.1 to 100 times by mass and more preferably 0.1 to 10 times by mass with respect to the fatty acid ester having 1 to 4 carbon atoms on a mass basis. When the amount of the auxiliary solvent is too much, the target compound will be dissolved in the reaction solution. It is not appropriate to reduce the recovery rate.

In addition, it is better to use a small amount of the reaction solvent, for example, the concentration of the maleic anhydride compound can be increased, the reaction can be accelerated, and the product yield per time can be increased. Therefore, when it is desired to increase the reaction speed and increase the product yield, the use amount of the solvent is preferably 3 to 10 times by mass relative to the maleic anhydride compound.

The wavelength of light in this photoreaction is 200 to 400 nm, more preferably 250 to 350 nm, and particularly preferably 280 to 330 nm. The light source is low-pressure mercury lamp, medium-pressure mercury lamp, high-pressure mercury lamp, ultra-high-pressure mercury lamp, xenon lamp, electrodeless lamp, light-emitting diode, and the like. Among them, it is preferable to use a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, or a light-emitting diode to obtain the CBDA derivative compound in high yield.

In addition, by changing the light source cooling tube in the photochemical reaction device from quartz glass to Pyrex (registered trademark) glass, the colored polymer and impurities that are attached to the light source cooling tube can be reduced, and the yield of the CBDA derivative compound can be improved.

When the reaction temperature is high, polymers are by-produced, and at low temperatures, the solubility with respect to the maleic anhydride compound is reduced and production efficiency is reduced. Therefore, it is preferably performed at -20 to 80 ° C, more preferably -10 to 50 ° C. Especially in the temperature range of 0 to 20 ° C, the formation of by-products can be greatly suppressed, and CBDA derivative compounds can be obtained with high selectivity and yield.

The reaction time varies depending on the type of light source, the amount of irradiation, etc., and it can be carried out in a time up to 0 to 40%, preferably 0 to 10%, of the unreacted maleic anhydride compound. The reaction time is generally 1 ~ 200 hours. It can be 1 ~ 60 hours depending on the situation.

Increasing the reaction time will increase the conversion rate of maleic anhydride compounds. Once the amount of CBDA derivative compounds precipitates, the generated CBDA derivative compounds will begin to adhere to the outer wall (reaction liquid side) of the cooling tube of the light source, and concurrent decomposition reactions The crystals are colored to reduce the light efficiency (yield per unit power x time). Therefore, in order to increase the conversion rate of the maleic anhydride compound, and it takes a long time for each batch, it will not be practical to reduce the production efficiency.

The reaction can be carried out in a batch type or a flow type, and it is preferable to use a batch type. The pressure during the reaction may be normal pressure or increased pressure, but it is preferably normal pressure.

The CBDA derivative of the target compound is obtained by filtering the precipitate in the reaction solution after photoreaction, washing the filtrate with an organic solvent, and drying under reduced pressure.

The amount of organic solvent used for washing the filtrate is only the amount that can transfer the precipitate remaining in the reaction tank to the filter. However, if the amount of the organic solvent is too large, the target compound will be transferred to the filtrate and the recovery will be reduced. rate. Therefore, the amount of the organic solvent used to wash the filtrate is preferably 0.5 to 10 times the weight of the maleic anhydride compound used in the reaction, and more preferably 1 to 2 times the weight.

The organic solvent used for washing the filtrate is not particularly limited, but the use of a solvent having a higher solubility with respect to the product may cause the target compound to be transferred to the filtrate and lower the recovery rate, which is not suitable. Therefore, the organic solvent used for washing the filtrate is methyl formate, ethyl formate, n-propyl formate, i-propyl formate, and n- formate. Butyl, i-butyl formate, methyl acetate, ethyl acetate, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, methyl propionate, ethyl propionate , N-propyl propionate, i-propyl propionate, n-butyl propionate, i-butyl propionate, ethylene glycol diformate, ethylene glycol diacetate, ethylene glycol dipropylene Esters, dimethyl carbonate, diethyl carbonate, etc., or solvents that do not dissolve the product and do not react with the product, such as toluene, hexane, heptane, acetonitrile, acetone, chloroform, acetic anhydride, etc. Mixed solvents, etc. Among them, ethyl acetate, dimethyl carbonate, acetic anhydride and the like are preferred, and ethyl acetate or dimethyl carbonate is more preferred.

Examples

The present invention will be described in more detail with examples below, but the present invention is not limited to these.

The analysis method used in the examples is as follows.

<GC sampling method>

After taking a small amount of the reaction solution, GC analysis was performed when no solid was precipitated. When solids were precipitated, the solids were filtered to remove the solids, and then the filtrate was analyzed by GC.

<GC analysis method>

The area ratio (area value of citraconic anhydride / area value of butyl lactate) was calculated from the respective area values of citraconic anhydride and butyl lactate by quantitative analysis by gas chromatography. The area ratio obtained from the reaction solution before light irradiation was 100%, and the area ratio of citraconic anhydride was calculated from the area ratio of the reaction solution at each irradiation time. Survival rate (area ratio of each irradiation time / area ratio before light irradiation × 100).

<GC analysis conditions>

Device: GC-2010 Plus (manufactured by SHIMADZU)

Column: DB-1 (manufactured by Agilent Technologies) 0.25mm × 30m, film thickness 0.25μm

Carrier gas: He, tester: FID, sample injection volume: 1 μm, injection port temperature: 160 ° C, tester temperature: 220 ° C, column temperature: 70 ° C (20min) -40 ° C / min-220 ° C (15min) , Distribution ratio: 1:50, internal standard substance: butyl lactate.

< ¹ H-NMR sampling method>

The crystals taken out after light irradiation were dried under reduced pressure and then measured. The filtrate and washing solution were dried under reduced pressure to remove the solvent, and then the residue was measured.

< ¹ H-NMR analysis method>

Using the integrated value of 3.89 ppm of 1,3-DM-CBDA as a reference, the integrated value of 3.72 ppm of 1,2-DM-CBDA was compared to calculate the selectivity. Specifically, the sum of the integral values of 1,3-DM-CBDA and 1,2-DM-CBDA is 100%, and each ratio ([1,3-DM-CBDA integral value] or [1,2- DM-CBDA integral value] / [Sum of integral values of 1,3-DM-CBDA and 1,2-DM-CBDA] × 100).

< ¹ H-NMR analysis conditions>

Device: Fourier transform type superconducting nuclear magnetic resonance device (FT-NMR) INOVA-400 (manufactured by Varian) 400 MHz

Solvent: DMSO-d6, Internal standard substance: Tetramethylsilane (TMS).

Comparative Example 1

Under nitrogen, 35.0 g (312 mmol) of citraconic anhydride (CA) and 152 g (1720 mmol) of ethyl acetate (4.33 wt times relative to citraconic anhydride (CA)) were placed in a 300 mL Pyrex (registered trademark) glass 5-necked flask. , Stir with a magnetic stirrer to dissolve. Then, while stirring at 5 to 10 ° C, a high-pressure mercury lamp of 100 W was irradiated.

The residual rate of citraconic anhydride in the reaction solution at each irradiation time was calculated by the above analysis method.

Example 1

Under nitrogen, 35.0 g (312 mmol) of citraconic anhydride (CA), 0.290 g (1.59 mmol of benzophenone (BP), 0.5 mol% relative to citraconic anhydride (CA)), and 152 g (1720 mmol, relative It was put into a 300 mL Pyrex (registered trademark) glass 5-necked flask in a citraconic anhydride (CA) (4.33 wt times), and stirred with a magnetic stirrer to dissolve it. Then, while stirring at 5 to 10 ° C, a high-pressure mercury lamp of 100 W was irradiated.

The residual rate of citraconic anhydride in the reaction solution at each irradiation time was calculated by the above analysis method.

Example 2

35.0 g (312 mmol) of citraconic anhydride (CA) and 0.392 g (1.56 mmol of 4,4'-dichlorobenzophenone (DClBP) under nitrogen, 0.5 mol% relative to citraconic anhydride (CA)) under nitrogen, and 152 g of ethyl acetate (1720 mmol, 4.33 wt times relative to citraconic anhydride (CA)) was placed in a 300 mL Pyrex (registered trademark) glass 5-necked flask and stirred magnetically Stir to dissolve. Then, while stirring at 5 to 10 ° C, a high-pressure mercury lamp of 100 W was irradiated.

The residual rate of citraconic anhydride in the reaction solution at each irradiation time was calculated by the above analysis method. The results obtained in Comparative Example 1 and Examples 1 to 2 are shown in Table 1 and the graphs in FIG. 1.

Comparative Example 2

The same photodimerization reaction as in Comparative Example 1 was performed. The precipitated white crystals were filtered at 5-10 ° C. The crystals were washed twice with 43.8 g of ethyl acetate (497 mmol, 1.25 wt times of citraconic anhydride (CA)) and then dried under reduced pressure to obtain 5.8 g of white crystals (yield 16.6%). This crystal was analyzed by ¹ H-NMR, and it was confirmed that it contained a mixture of 1,3-DM-CBDA and 1,2-DM-CBDA (1,3-DM-CBDA: 1,2-DM-CBDA = 92.4: 7.6 ). The crystals, filtrates, and washing liquids obtained by ¹ H-NMR analysis and gas chromatography were quantitatively analyzed, and the mass balance with respect to the added amount was 93.1%.

¹ H NMR (DMSO-d6, δ ppm) (1,3-DM-CBDA): 1.38 (s, 6H), 3.89 (s, 2H).

¹ H NMR (DMSO-d6, δ ppm) (1,2-DM-CBDA): 1.37 (s, 6H), 3.72 (s, 2H).

Example 3

The same photodimerization reaction as in Example 1 was performed. The precipitated white crystals were filtered at 5-10 ° C. The crystals were washed twice with 43.8 g of ethyl acetate (497 mmol, 1.25 wt times of citraconic anhydride (CA)) and then dried under reduced pressure to obtain 8.8 g of white crystals (yield 25.2%). This crystal was analyzed by ¹ H-NMR, and it was confirmed that it contained a mixture of 1,3-DM-CBDA and 1,2-DM-CBDA (1,3-DM-CBDA: 1,2-DM-CBDA = 85.0: 15.0 ). The crystals, filtrates, and washing liquids obtained by ¹ H-NMR analysis and quantitative analysis by gas chromatography were each analyzed. As a result, the mass balance with respect to the added amount was 88.0%.

¹ H NMR (DMSO-d6, δ ppm) (1,3-DM-CBDA): 1.38 (s, 6H), 3.89 (s, 2H).

¹ H NMR (DMSO-d6, δ ppm) (1,2-DM-CBDA): 1.37 (s, 6H), 3.72 (s, 2H).

Example 4

The same photodimerization reaction as in Example 2 was performed, and the precipitated white crystals were collected by filtration at 5-10 ° C. The crystals were washed twice with 43.8 g of ethyl acetate (497 mmol, 1.25 wt times of citraconic anhydride (CA)), and then dried under reduced pressure to obtain 8.0 g of white crystals (yield 22.8%). This crystal was analyzed by ¹ H-NMR, and it was confirmed that it contained a mixture of 1,3-DM-CBDA and 1,2-DM-CBDA (1,3-DM-CBDA: 1,2-DM-CBDA = 86.5: 13.5 ). Moreover, the crystals, filtrates, and washing liquids obtained by ¹ H-NMR analysis and quantitative analysis by gas chromatography were each analyzed. As a result, the mass balance with respect to the added amount was 95.7%.

¹ H NMR (DMSO-d6, δ ppm) (1,3-DM-CBDA): 1.38 (s, 6H), 3.89 (s, 2H).

¹ H NMR (DMSO-d6, δ ppm) (1,2-DM-CBDA): 1.37 (s, 6H), 3.72 (s, 2H).

[Industrial use possibility]

The cyclobutanetetracarboxylic acid derivative obtained by the present invention is a compound suitable for use as a raw material of polyamic acid, polyimide, etc. The polyimide and the like can be used in the display field of televisions and the like using liquid crystal panels in the industry. And the resin composition used in the semiconductor field.

The entire contents of the Japanese Patent Application No. 2014-007187 filed on January 17, 2014, the scope of the patent application, the graphs, and the abstract are incorporated herein, and are incorporated into the disclosure of the specification of the present invention.

Claims (11)

A method for producing a 1,3-dialkyl1,2,3,4cyclobutanetetracarboxylic acid-1,2: 3,4-dianhydride derivative represented by formula (2), comprising: In a solvent of a fatty acid ester having 1 to 4 carbon atoms, a photo-dimerization reaction of a maleic anhydride compound represented by the following formula (1) is performed in the presence of a sensitizer. (In the formula, R represents an alkyl group having 1 to 20 carbon atoms.) The method of claim 1, wherein R is an alkyl group having 1 to 6 carbon atoms. The manufacturing method according to claim 1 or 2, wherein the amount of the solvent used is 3 to 300 times the mass of the maleic anhydride compound. For example, the manufacturing method of claim 1 or 2, wherein the fatty acid ester of 1 to 4 carbonic acid is a formula: R ¹ COOR ² (where R ¹ is hydrogen, or an alkyl group having 1 to 4 carbon atoms, and R ² is a carbon number 1 ~ 4 alkyl) fatty acid alkyl ester. The manufacturing method according to claim 1 or 2, wherein the solvent is a secondary solvent containing a carbonic acid diester. The method of claim 1 or 2, wherein the sensitizer is benzophenone, acetophenone or benzaldehyde. For example, the manufacturing method of claim 1 or 2, wherein the sensitizer is benzophenone substituted with an electronic group, acetophenone substituted with an electronic group, or benzaldehyde substituted with an electronic group. The method according to claim 7, wherein the electron-withdrawing group is at least one selected from the group consisting of a fluoro group, a chloro group, a bromo group, an iodo group, a nitro group, a cyano group, and a trifluoromethyl group. The manufacturing method as claimed in claim 7, wherein the number of the drawn electron groups is 1 to 5. For example, the manufacturing method of claim 1 or 2, wherein the use amount of the sensitizer is 0.1 to 20 mole% relative to the maleic anhydride compound. The manufacturing method as claimed in claim 1 or 2, wherein the reaction temperature is 0 to 20 ° C.