JPWO2015108167A1 - Method for producing cyclobutanetetracarboxylic acid derivative - Google Patents

Abstract

Providing a high-yield production method of cyclobutanetetracarboxylic acid-1,2: 3,4-dianhydride derivative useful as a raw material for polyimide and the like. A maleic anhydride compound represented by the following formula (1) is subjected to a photodimerization reaction in a reaction solvent of 100 mass times or more with respect to the maleic anhydride compound. , 3,4-Cyclobutanetetracarboxylic acid-1,2: 3,4-dianhydride. (In the formula, R represents an alkyl group having 1 to 20 carbon atoms.)

Description

  The present invention relates to a method for producing an alicyclic tetracarboxylic dianhydride that can be a raw material monomer such as polyimide for optical materials.

In general, a polyimide resin is widely used as an electronic material such as a protective material or an insulating material in a liquid crystal display element or a semiconductor because of its high mechanical strength, heat resistance, insulation, solvent resistance, and the like. Recently, the use as an optical communication material such as an optical waveguide material is also expected.
In recent years, the development of this field has been remarkable, and correspondingly, higher and higher properties are required for the materials used. That is, it is expected not only to be excellent in heat resistance and solvent resistance, but also to have a large number of performances depending on the application.

  However, wholly aromatic polyimide resins that use aromatic tetracarboxylic dianhydride and aromatic diamine as raw materials exhibit a deep amber color and are colored, so there are problems in applications that require high transparency. doing. On the other hand, the polyimide resin which formed the polyimide precursor by the polycondensation reaction of alicyclic tetracarboxylic dianhydride and aromatic diamine, and imidized this precursor is relatively little coloring, and is highly transparent. It is known (see Patent Documents 1 and 2).

  As alkylcyclobutanoic acid dianhydride, which is one of alicyclic tetracarboxylic dianhydrides, which is a raw material for the above-mentioned relatively less colored and highly transparent polyimide, Patent Document 3 shows the following scheme. As described above, 1,3-dimethylcyclobutane-1,2,3,4-tetracarboxylic acid-1,2: 3,4-dianhydride is obtained by photodimerization reaction of citraconic anhydride (abbreviated as MMA). Product (1,3-DMCBDA) and 1,2-dimethylcyclobutane-1,2,3,4-tetracarboxylic acid-1,2: 3,4-dianhydride (1,2-DMCBDA) Is disclosed.

一方、１，３−ＤＭＣＢＤＡと１，２−ＤＭＣＢＤＡとを対比した場合、対称性の高い構造を有する異性体である前者の１，３−ＤＭＣＢＤＡが、後者の１，２−ＤＭＣＢＤＡよりも分子量の高いポリイミドが製造でき、より有用性が高いことが知られている。
しかし、特許文献３には、１，３−ＤＭＣＢＤＡと１，２−ＤＭＣＢＤＡとの混合物が得られることは記載されているが、対称性の高い構造を有する有用性の高い異性体である、前者の１，３−ＤＭＣＢＤＡを選択的に、かつ高収率で製造することについての記載はない。

On the other hand, when 1,3-DMCBDA is compared with 1,2-DMCBDA, the former 1,3-DMCBDA, which is an isomer having a highly symmetric structure, has a molecular weight higher than that of the latter 1,2-DMCBDA. It is known that a high polyimide can be produced and is more useful.
However, although Patent Document 3 describes that a mixture of 1,3-DMCBDA and 1,2-DMCBDA is obtained, the former is a highly useful isomer having a highly symmetric structure. There is no description on the selective and high yield production of 1,3-DMCBDA.

Japanese Patent Publication No. 2-24294 Japanese Unexamined Patent Publication No. 58-208322 Japanese Unexamined Patent Publication No. 4-106127

  The object of the present invention is to use a specific maleic anhydride compound as a raw material, and by its photodimerization reaction, 1,2-dialkylcyclobutane-1,2,3,4-tetracarboxylic acid-1,2 as compared with the conventional method. : 1,3-dialkylcyclobutane-1,2, which is a highly useful isomer having a highly symmetric structure than 3,4-dianhydride (hereinafter also referred to as 1,2-DACBDA) Novel production capable of improving selectivity of 3,4-tetracarboxylic acid-1,2: 3,4-dianhydride (hereinafter also referred to as 1,3-DACBDA) and producing it in high yield It is to provide a method.

(式中、Ｒは炭素数１〜２０のアルキル基を表す。)
２．Ｒがメチル基である、上記１に記載の製造方法。
３．無水マレイン酸化合物に対して１００〜３００質量倍の反応溶媒中で光二量化反応させる、上記１又は２に記載の製造方法。
４．反応溶媒の使用量が、無水マレイン酸化合物に対して１５０〜２５０質量倍の反応溶媒中で光二量化反応させる、上記１又は２に記載の製造方法。
５．反応溶媒が、有機カルボン酸のエステル若しくは無水物、又は炭酸エステルである、上記１〜４のいずれかに記載の製造方法。
６．反応溶媒が、酢酸エチル又は炭酸ジメチルである、上記１〜５のいずれかに記載の製造方法。
７．ベンゾフェノン、アセトフェノン、ベンズアルデヒド、電子求引性基が置換したベンゾフェノン、電子求引性基が置換したアセトフェノン、電子求引性基が置換したベンズアルデヒド、又はアントラキノンからなる増感剤の存在下に行う、上記１〜６のいずれかに記載の製造方法。
８．前記電子求引性基が、フルオロ基、クロロ基、ブロモ基、ヨード基、ニトロ基、シアノ基、及びトリフルオロメチル基からなる群から選ばれる少なくとも１種である、上記７に記載の製造方法。
９．電子求引性基の数が１〜５である、上記７又は８に記載の製造方法。
１０．無水マレイン酸化合物に対し０．１〜２０モル％の増感剤を用いる、上記６〜９のいずれかに記載の製造方法。
１１．反応温度が０〜２０℃である、上記１〜１０のいずれかに記載の製造方法。As a result of intensive studies to solve the above-mentioned problems, the present inventors have found a novel production method for achieving the above object and completed the present invention.
The present invention has the following gist.
1. The maleic anhydride compound represented by the following formula (1) is photodimerized in a reaction solvent 100 mass times or more with respect to the maleic anhydride compound. , 2,3,4-cyclobutanetetracarboxylic acid-1,2: 3,4-dianhydride (1,3-DACBDA) derivative.

(In the formula, R represents an alkyl group having 1 to 20 carbon atoms.)
2. 2. The production method according to 1 above, wherein R is a methyl group.
3. 3. The production method according to 1 or 2 above, wherein the photodimerization reaction is performed in a reaction solvent 100 to 300 times by mass with respect to the maleic anhydride compound.
4). 3. The production method according to 1 or 2 above, wherein the reaction solvent is used in a photodimerization reaction in a reaction solvent of 150 to 250 times by mass with respect to the maleic anhydride compound.
5. The manufacturing method in any one of said 1-4 whose reaction solvent is ester or anhydride of organic carboxylic acid, or carbonate ester.
6). 6. The production method according to any one of 1 to 5 above, wherein the reaction solvent is ethyl acetate or dimethyl carbonate.
7). In the presence of a sensitizer consisting of benzophenone, acetophenone, benzaldehyde, benzophenone substituted with an electron withdrawing group, acetophenone substituted with an electron withdrawing group, benzaldehyde substituted with an electron withdrawing group, or anthraquinone, The manufacturing method in any one of 1-6.
8). 8. The production method according to 7 above, 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. 9. The production method according to 7 or 8 above, wherein the number of electron withdrawing groups is 1 to 5.
10. The manufacturing method in any one of said 6-9 using 0.1-20 mol% sensitizer with respect to a maleic anhydride compound.
11. The manufacturing method in any one of said 1-10 whose reaction temperature is 0-20 degreeC.

  According to the present invention, it is a mixture of 1,3-DACBDA and 1,2-DACBDA by photodimerization reaction of a specific maleic anhydride compound, but it has a highly symmetric structure as compared with the conventional method. As a result of the high selectivity of 1,3-DACBDA, which is a useful isomer, and increasing the conversion rate of the photodimerization reaction of maleic anhydride compound, a production method capable of obtaining 1,3, -DACBDA in high yield is provided. The

  1,2,3,4-cyclobutanetetracarboxylic acid-1,2: 3,4-dianhydride represented by formula (2) by photodimerization reaction of maleic anhydride compound represented by formula (1) The production method of (1,3-DACBDA) is represented by the following reaction scheme.

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

As a C1-C20 alkyl group, any of a linear or branched saturated alkyl group or a linear or branched unsaturated alkyl group may be sufficient.
Specific examples thereof include 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, 2-methyl-n-pentyl, 1,1-dimethyl-n- Saturated alkyl groups such as butyl, 1-ethyl-n-butyl, 1,1,2-trimethyl-n-propyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-dodecyl, n-eicosyl 1-methylvinyl, 2-allyl, 1-ethylvinyl, 2-methylallyl, 2-butenyl, 2-methyl-2-butenyl, 3-methyl-2-butenyl, 3-methyl-3-butenyl, 2-hexenyl, 4 Methyl-3-pentenyl, 4-methyl-4-pentenyl, 2,3-dimethyl-2-butenyl, 1-ethyl-2-pentenyl, 3-dodecenyl, propargyl, 3-butynyl, 3-methyl-2-propynyl, And unsaturated alkyl groups such as 9-decynyl.
Note that n represents normal, i represents iso, s represents secondary, and t represents tertiary.

  Examples of the maleic anhydride compound represented by the formula (1) include citraconic anhydride, 2-ethyl maleic anhydride, 2-isopropyl maleic anhydride, 2-n-butyl maleic anhydride, 2-t-butyl anhydride. Maleic acid, 2-n-pentylmaleic anhydride, 2-n-hexylmaleic anhydride, 2-n-heptylmaleic anhydride, 2-n-octylmaleic anhydride, 2-n-nonylmaleic acid Anhydride, 2-n-decylmaleic anhydride, 2-n-dodecylmaleic anhydride, 2-n-eicosylmaleic anhydride, 2- (1-methylvinyl) maleic anhydride, 2- ( 2-allyl) maleic anhydride, 2- (1-ethylvinyl) maleic anhydride, 2- (2-methylallyl) maleic anhydride, 2- (2-butenyl) maleic anhydride, 2- ( -Hexenyl) maleic anhydride, 2- (1-ethyl-2-pentenyl) maleic anhydride, 2- (3-dodecenyl) maleic anhydride, 2-propargylmaleic anhydride, 2- (3-butynyl) ) Maleic anhydride, 2- (3-methyl-2-propynyl) maleic anhydride, 2- (9-decynyl) maleic anhydride and the like. Among these, since the photoreaction proceeds efficiently, citraconic anhydride, 2-ethylmaleic anhydride, 2-isopropylmaleic anhydride, 2-n-butylmaleic anhydride, 2-t-butylmaleic anhydride, 2 -N-pentylmaleic anhydride, 2-n-hexylmaleic anhydride, 2-n-heptylmaleic anhydride, 2-n-octylmaleic anhydride, 2-n-nonylmaleic anhydride, 2 -N-decylmaleic anhydride, 2-n-dodecylmaleic anhydride and the like are preferable, citraconic anhydride, 2-ethylmaleic anhydride, 2-isopropylmaleic anhydride, 2-n-butylmaleic anhydride, 2-t-butylmaleic anhydride, 2-n-pentylmaleic anhydride, or 2-n-hexylmaleic anhydride is more preferred.

  As the reaction solvent, an organic solvent generally used in a photochemical reaction is used. On the other hand, as a solvent that can be employed industrially, (1) a carbonyl compound having a high photosensitizing effect, (2) the raw material maleic anhydride compound has high solubility, and the decomposition reaction of the produced CBDA derivative compound is carried out. Low solubility of CBDA derivative compound to suppress, (3) High solubility of by-product, CBDA derivative compound can be purified only by washing with the same solvent, (4) Not low boiling point that has danger of flammability And a CBDA derivative compound that does not remain in the compound, has a boiling point of around 50 to 150 ° C., (5) safe for the environment, (6) stable during photoreaction, (7) inexpensive. It must be satisfied. From these viewpoints, hexane, heptane, acetonitrile, acetone, chloroform and the like can also be used as the reaction solvent. As the reaction solvent, an organic carboxylic acid ester or anhydride, or a carbonic acid ester is preferred.

The ester of the organic carboxylic acid is represented by the formula: R ¹ COOR ² (where R ¹ is hydrogen or an alkyl group having 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and R ² has a carbon number. 1 to 4 and more preferably 1 to 3 alkyl groups).
Preferred examples of the organic carboxylic acid ester 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-acetate -Propyl, n-butyl acetate, i-butyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, i-propyl propionate, n-butyl propionate, i-butyl propionate. Furthermore, ethylene glycol diformate, ethylene glycol diacetate, ethylene glycol dipropionate and the like can be used.
As the anhydride of an organic carboxylic acid, the ^{formula: (R 1 CO) 2 O} (. However, R ¹ is a preferred embodiment be included as defined above) are preferably those represented by. Preferred examples thereof are propionic anhydride, butyric anhydride, trifluoroacetic anhydride, or acetic anhydride. Of these, acetic anhydride is preferred because 1,3-DACBDA can be obtained at a higher recovery rate.

  The carbonic acid ester is preferably a carbonic acid dialkyl ester having 1 to 3 carbon atoms, more preferably 1 or 2 carbon atoms. Preferred examples include dimethyl carbonate, diethyl carbonate, dipropyl carbonate, or a mixture thereof.

Among these, preferred reaction solvents are ethyl formate, methyl acetate, ethyl acetate, i-propyl acetate, i-butyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, i-propyl propionate, ethylene glycol di- Formate, ethylene glycol diacetate, dimethyl carbonate, or diethyl carbonate, and the most preferred solvent is ethyl acetate or dimethyl carbonate.
Each of the above solvents may be used alone or in combination of two or more. However, when used alone, there is an advantage that the treatment after the reaction is easy.
In the present invention, when the reaction solvent contains ethyl acetate, dimethyl carbonate, diethyl carbonate, or ethylene glycol diacetate, the 1,3-DACBDA of the produced 1,3-DACBDA is formed despite the high solubility of the raw maleic anhydride compound. Since the target compound is precipitated as a crystal during the reaction due to low solubility, side reactions such as reverse reaction from DACBDA to maleic anhydride compound and oligomer formation can be suppressed.

  In the present invention, the amount of the reaction solvent used is important, and by using a very large amount of the reaction solvent, 1,3-DACBDA in the resulting mixture of 1,3-DACBDA and 1,2-DACBDA It has been found that the selectivity of increases. That is, the reaction solvent is present in an amount of 100 mass times or more, preferably 100 to 300 mass times, more preferably 150 to 250 mass times with respect to the maleic anhydride compound as a raw material. The selectivity of 3-DACBDA is increased, and a product having a high content of 1,3-DACBDA can be obtained.

In the photoreaction of the present invention, the wavelength of light is 200 to 400 nm, more preferably 250 to 350 nm, and particularly preferably 280 to 330 nm. As the light source, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a xenon lamp, an electrodeless lamp, a light-emitting diode and the like are preferably used because they give a CBDA derivative compound in a particularly high yield.
Further, by changing the light source cooling tube from quartz glass to Pyrex (registered trademark) glass as a photochemical reaction device, coloring polymer adhesion to the light source cooling tube and impurities are reduced, and the yield of the CBDA derivative compound is improved.
The reaction temperature is preferably from −20 to 80 ° C., since a polymer is by-produced when the temperature is high, and the solubility of the maleic anhydride compound is reduced and the production efficiency is decreased when the temperature is low. -10 to 50 ° C. In particular, at 0 to 20 ° C., the production of by-products is greatly suppressed, and 1,3-DACBDA is obtained with high selectivity and yield.

The reaction time varies depending on the amount of maleic anhydride compound, the type of light source, and the amount of irradiation, but it may be performed until the unreacted maleic anhydride compound reaches 0 to 40%, preferably 0 to 10%. it can.
Specifically, the reaction time is usually 1 to 200 hours, preferably 1 to 100 hours, and more preferably 1 to 60 hours.
The conversion rate can be easily obtained by analyzing the reaction solution by gas chromatography or the like.

When the reaction time becomes longer, the conversion rate of the maleic anhydride compound increases, and the amount of CBDA derivative compound deposited increases, the produced CBDA derivative compound begins to adhere to the outer wall (reaction liquid side) of the light source cooling tube, and the decomposition reaction The coloration of crystals due to the simultaneous use of light and a decrease in light efficiency (yield per unit of power x time) are observed. Therefore, in order to increase the conversion rate of the maleic anhydride compound, it is not preferable to spend a long time in one batch with a decrease in production efficiency in practice.
In addition, although reaction can be performed by a batch type or a distribution type, a batch type is used preferably. Further, the pressure during the reaction may be normal pressure or increased pressure, preferably normal pressure.

  In addition, the manufacturing method of this invention can also be performed by adding a sensitizer. Examples of the sensitizer include benzophenone, acetophenone, benzaldehyde, anthraquinone, benzophenone substituted with an electron withdrawing group, acetophenone substituted with an electron withdrawing group, and benzaldehyde substituted with an electron withdrawing group.

Examples of the electron withdrawing group include 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, such as a fluoro group, a chloro group, A bromo group, a cyano group, a trifluoromethyl group, and the like are preferable. Particularly preferred electron withdrawing groups are fluoro groups or chloro groups.
The number of electron withdrawing groups is 1 to 10, preferably 1 to 5, and particularly preferably 1 to 3.

Examples of the substitution position of the electron withdrawing group include an ortho position, a meta position, and a para position with respect to the carbonyl group, and an ortho position or a para position is preferable.
When the number of electron withdrawing groups is 2 or more, the electron withdrawing groups may be the same or different. Further, anthraquinone in which a carbonyl group having an electron withdrawing effect is crosslinked at the ortho position may be used.

  Specific examples of benzophenone and benzophenone substituted with an electron withdrawing group include 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′-dinitrobenzophenone, 3,3′-dinitrobenzophenone, 4 4′-dinitrobenzophenone, 2-chloro-5-nitrobenzophenone, 1,3-bis (4-fluorobenzoyl) benzene, 1,3-bis (4-chlorobenzoyl) benzene, 2,6-dibenzoylbenzonitrile, Examples include 1,3-dibenzoyl-4,6-dinitrobenzene and anthraquinone. Of these, 4,4'-difluorobenzophenone or 4,4'-dichlorobenzophenone is preferable.

  Specific examples of acetophenone and acetophenone substituted with an electron withdrawing group include acetophenone, 2′-fluoroacetophenone, 3′-fluoroacetophenone, 4′-fluoroacetophenone, 2′-chloroacetophenone, 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′-dichloroacetophenone, or 3 ′, 4′-dichloro Acetophenone is preferred.

  Examples of benzaldehyde substituted with benzaldehyde and an electron withdrawing group include benzaldehyde, 2-fluorobenzaldehyde, 3-fluorobenzaldehyde, 4-fluorobenzaldehyde, 2-chlorobenzaldehyde, 3-chlorobenzaldehyde, 4-chlorobenzaldehyde, 2-cyanobenzaldehyde. , 3-cyanobenzaldehyde, 4-cyanobenzaldehyde, 2-nitrobenzaldehyde, 3-nitrobenzaldehyde, 4-nitrobenzaldehyde, 2,4-difluorobenzaldehyde, 3,4-difluorobenzaldehyde, 2,4-dichlorobenzaldehyde, 3,4 -Dichlorobenzaldehyde, 2-chloro-5-nitrobenzaldehyde, 4-chloro-2-nitrobenzaldehyde, 4-chloro-3-ni B benzaldehyde, 5-chloro-2-nitrobenzaldehyde, 2-fluoro-5-nitrobenzaldehyde, 4-fluoro-3-nitrobenzaldehyde, 5-fluoro-2-nitrobenzaldehyde, and the like. Among these, 4-fluorobenzaldehyde, 4-chlorobenzaldehyde, 2,4-difluorobenzaldehyde, 3,4-difluorobenzaldehyde, 2,4-dichlorobenzaldehyde, or 3,4-dichlorobenzaldehyde is preferable.

The amount of the sensitizer to be used is not particularly limited as long as the photoreaction rate is accelerated, but is preferably 0.1 to 20 mol%, more preferably 0.1 to 0.1 mol% based on the maleic anhydride compound. 5 mol%.
As the sensitizer, the above-mentioned benzophenone derivative, acetophenone derivative, or benzaldehyde derivative may be used alone or in combination of one or more of these, but when used alone, Easy to process.

  The target compound is obtained by photoreaction, filtering the precipitate in the reaction solution, washing the filtered product with an organic solvent, and drying under reduced pressure.

  The amount of the organic solvent used for washing the filtered material may be an amount that can transfer the precipitate remaining in the reaction tank to the filter, but when the amount of the organic solvent is large, the target compound is filtered. The recovery rate decreases. For this reason, the amount of the organic solvent used for washing the filtered product is preferably 0.5 to 10 times by weight, more preferably 1 to 2 times by weight of the maleic anhydride compound used for the reaction.

  Although it does not specifically limit as an organic solvent used for washing | cleaning of a filtration thing, Use of the solvent with the high solubility of a product moves to a filtrate and a recovery rate falls, and is not preferable. For this reason, as an organic solvent used for washing | cleaning of a filtration thing, the reaction solvent used for photodimerization reaction, methyl formate, ethyl formate, n-propyl formate, i-propyl formate, n-butyl formate, formic acid i. -Butyl, 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, propion N-butyl acid, i-butyl propionate, ethylene glycol diformate, ethylene glycol diacetate, ethylene glycol dipropionate, dimethyl carbonate, diethyl carbonate and the like, a solvent that does not dissolve the product and does not react with the product, For example, toluene, hexane, heptane, acetonitrile, acetone, chloroform, Acetate, and mixtures of these solvents. Of these, ethyl acetate, dimethyl carbonate, acetic anhydride and the like are preferable, and ethyl acetate or dimethyl carbonate is more preferable.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. The analytical methods used in the examples are as follows.
<GC analysis conditions>
Apparatus: GC-2010 Plus (manufactured by SHIMADZU),
Column: DB-1 (manufactured by GL Sciences) Diameter 0.25 mm × length 30 m, film thickness 0.25 um,
Carrier gas: He, detector: FID, sample injection amount: 1 um, inlet temperature: 160 ° C, detector temperature: 220 ° C, column temperature: 70 ° C (20min)-40 ° C / min-220 ° C (15min) , Split ratio: 1:50, internal standard: butyl lactate.
^<1 H NMR analysis conditions>
Apparatus: Fourier transform type superconducting nuclear magnetic resonance apparatus (FT-NMR) INOVA-400 (manufactured by Varian) 400 MHz,
Solvent: DMSO-d6, internal standard substance: tetramethylsilane (TMS).
<Melting point analysis conditions>
Equipment: DSC1 (Metler Toledo),
Temperature: 35 ° C-5 ° C / min-400 ° C, Pan: Au (sealed).

窒素雰囲気下、30 mL パイレックス（登録商標）ガラス製試験管に、シトラコン酸無水物（CA）0.10 g （0.89 mmol）、及び炭酸ジメチル20 g（222 mmol、シトラコン酸無水物（CA）に対して200 wt倍）を仕込み、マグネチックスターラーで攪拌させて溶解させた。その後、10−15℃で撹拌しながら、100W高圧水銀灯を4時間照射した。その後、反応器中の反応液を2 g採取し、エバポレーターで70−80 Torrにて溶媒留去した。得られた粗物は、¹H NMR解析によって、1,3−DM−CBDAと1,2−DM−CBDAを含む混合物（1,3−DM−CBDA：1,2−DM−CBDA = 48.3：51.7）であることを確認した。
¹H NMR ( DMSO−d6, δ ppm ) ( 1,3−DM−CBDA ): 1.38 ( s, 6H ), 3.89 ( s, 2H ).
¹H NMR ( DMSO−d6, δ ppm ) ( 1,2−DM−CBDA ): 1.37 ( s, 6H ), 3.72 ( s, 2H ).
mp. ( 1,3−DM−CBDA )：316−317℃Example 1

Under a nitrogen atmosphere, in a 30 mL Pyrex glass test tube, 0.10 g (0.89 mmol) citraconic anhydride (CA) and 20 g (222 mmol, citraconic anhydride (CA) dimethyl carbonate 200 wt times) was added and dissolved by stirring with a magnetic stirrer. Thereafter, a 100 W high-pressure mercury lamp was irradiated for 4 hours while stirring at 10-15 ° C. Thereafter, 2 g of the reaction solution in the reactor was collected, and the solvent was distilled off by an evaporator at 70-80 Torr. According to ¹ H NMR analysis, the obtained crude product was a mixture containing 1,3-DM-CBDA and 1,2-DM-CBDA (1,3-DM-CBDA: 1,2-DM-CBDA = 48.3: 51.7).
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).
mp. (1,3-DM-CBDA): 316-317 ° C

Examples 2-7 and Comparative Examples 1-5
Using the solvent shown in Table 1 below, the presence or absence of addition of 4,4′-dichlorobenzophenone (DClBP), the amount of citraconic anhydride (CA) charged, and the amount of solvent, the series of operations was the same as in Example 1. It carried out similarly. Further, the production ratio of 1,3-DM-CBDA and 1,2-DM-CBDA (1,3-DM-CBDA: 1,2-DM-CBDA) was calculated in the same manner as in Example 1.
The following table shows the solvent, presence / absence of DCIBP addition, CA charge amount, solvent amount, and results. Further, the production ratio of 1,3-DM-CBDA and 1,2-DM-CBDA in the reaction solution obtained here was calculated, and the results are shown in the table together with the results obtained in Example 1. In Table 1, “Neat” means that the reaction was performed without a solvent. Moreover, 0.1-10 mol% of DClBP was used with respect to citraconic anhydride.

1,3-DACBDA, which is a cyclobutanetetracarboxylic acid derivative obtained in the present invention, is a compound useful as a raw material for polyamic acid, polyimide, and the like. The polyimide and the like are used as a protective material and an insulating material for liquid crystal display elements and semiconductors. It is widely used industrially as a resin composition used for electronic materials.
The entire contents of the specification, claims, and abstract of Japanese Patent Application No. 2014-007185 filed on January 17, 2014 are incorporated herein as the disclosure of the specification of the present invention. Is.

Claims (11)

The maleic anhydride compound represented by the following formula (1) is photodimerized in a reaction solvent 100 mass times or more with respect to the maleic anhydride compound. , 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.)   The production method according to claim 1, wherein R is a methyl group.   The production method according to claim 1 or 2, wherein the photodimerization reaction is performed in a reaction solvent 100 to 300 times by mass with respect to the maleic anhydride compound.   The production method according to claim 1 or 2, wherein the reaction solvent is used in a photodimerization reaction in a reaction solvent 150 to 250 times by mass with respect to the maleic anhydride compound.   The manufacturing method in any one of Claims 1-4 whose reaction solvent is ester or anhydride of organic carboxylic acid, or carbonate ester.   The production method according to claim 1, wherein the reaction solvent is ethyl acetate or dimethyl carbonate.   In the presence of a sensitizer comprising benzophenone, acetophenone, benzaldehyde, benzophenone substituted with an electron withdrawing group, acetophenone substituted with an electron withdrawing group, benzaldehyde substituted with an electron withdrawing group, or anthraquinone Item 7. The production method according to any one of Items 1 to 6.   The production 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. Method.   The manufacturing method of Claim 7 or 8 whose number of electron withdrawing groups is 1-5.   The manufacturing method in any one of Claims 7-9 using 0.1-20 mol% sensitizer with respect to a maleic anhydride compound.   The manufacturing method in any one of Claims 1-10 whose reaction temperature is 0-20 degreeC.