JPWO2015108169A1 - Method for producing cyclobutanetetracarboxylic acid derivative - Google Patents

Abstract

Providing an efficient method for producing 1,3-dialkyl 1,2,3,4-cyclobutanetetracarboxylic acid-1,2: 3,4-dianhydride derivatives useful as raw materials for polyimide and the like. The maleic anhydride compound represented by the following formula (1) is represented by the formula (2) by photodimerization reaction in the presence of a sensitizer in a solvent containing a fatty acid ester having 1 to 4 carbon atoms. 1,3-dialkyl 1,2,3,4-cyclobutanetetracarboxylic acid-1,2: 3,4-dianhydride derivative. (In the formula, R represents an alkyl group having 1 to 20 carbon atoms.)

Description

  The present invention relates to a novel method for producing a cyclobutanetetracarboxylic acid derivative useful as a raw material for polyimide and the like.

Cyclobutanetetracarboxylic acid derivatives are useful compounds as raw materials for polyimide and the like. As a method for producing the compound, a photodimerization reaction of a maleic anhydride derivative is known (Patent Documents 1 to 5).
However, even if a sensitizer is used, the photoreaction efficiency in the method for producing a cyclobutanetetracarboxylic acid derivative by the photodimerization reaction of maleic anhydride derivatives disclosed in Patent Documents 1 to 5 is not always sufficient.
For example, Patent Document 1 discloses a method for producing 1,2,3,4-cyclobutanetetracarboxylic acid-1,2: 3,4-dianhydride (CBDA) in a solvent having a carbonyl group such as ketones. The photodimerization reaction of maleic anhydride at is disclosed. However, Patent Document 1 describes that the use of acetophenone, benzophenone, anthraquinone, and the like used as a sensitizer is ineffective, but rather does not exist to give better results (page (2) of Patent Document 1). The last line in the lower right column to the fourth line in the upper left column of (3) page).

  As described above, conventionally, a method for producing 1,2,3,4-cyclobutanetetracarboxylic acid-1,2: 3,4-dianhydride (CBDA) by photodimerization reaction of maleic anhydride is a raw material anhydrous. Although maleic acid is relatively inexpensive and simple and useful as a production method, the photoreaction efficiency is not sufficient and there is a problem with the yield of the target product.

  In addition, as represented by Patent Document 2 and the following scheme, 1,3-dimethylcyclobutane-1,2,3,4-tetracarboxylic acid is obtained by a photodimerization reaction of citraconic anhydride (abbreviated as MMA). -1,2: 3,4-dianhydride (1,3-DMCBDA) and 1,2-dimethylcyclobutane-1,2,3,4-tetracarboxylic acid-1,2: 3,4-dianhydride It is disclosed that a mixture of (1,2-DMCBDA) is obtained.

一方、１，３−ＤＭＣＢＤＡと１，２−ＤＭＣＢＤＡとの異性体を対比した場合、対称性の高い構造を有する前者の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２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、有用性の高い前者の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 the isomers of 1,3-DMCBDA and 1,2-DMCBDA are compared, the former 1,3-DMCBDA having a highly symmetric structure has a higher molecular weight than the latter 1,2-DMCBDA. It is known that polyimide can be produced and is more useful.
However, although Patent Document 2 describes that a mixture of 1,3-DMCBDA and 1,2-DMCBDA can be obtained, the highly useful former 1,3-DMCBDA is selectively used, and There is no description about manufacturing in high yield.

Japanese Unexamined Patent Publication No. 59-212495 Japanese Unexamined Patent Publication No. 4-106127 Japanese Unexamined Patent Publication No. 2003-192585 Japanese Unexamined Patent Publication No. 2006-347931 Japanese Unexamined Patent Publication No. 2008-69081

  An object of the present invention is to subject a maleic anhydride compound represented by the following formula (1) to a photodimerization reaction, to achieve the desired 1,3-dialkyl-1,2,3 with high photoreaction efficiency and high yield. , 4-Cyclobutanetetracarboxylic acid-1,2: 3,4-dianhydride (hereinafter, also referred to as 1,3-DACBDA) derivative.

As a result of diligent research to solve the above-mentioned problems, the present inventors, as a result of using a specific solvent, differed from the conventional disclosure of Patent Document 1 and the like, and in the presence of a sensitizer, anhydrous maleic acid. By photodimerizing the acid compound, the photoreaction rate of the maleic anhydride compound is improved, and the selectivity of the 1,3-DACBDA derivative, which is an isomer having a highly symmetric structure, is improved. It discovered that it could manufacture with a yield.
This invention is based on said novel knowledge, and has the summary described below.

(式中、Ｒは炭素数１〜２０のアルキル基を表す。)
２．Ｒが炭素数１〜６のアルキル基である、上記１に記載の製造方法。
３．溶媒の使用量が、無水マレイン酸化合物に対し３〜３００質量倍である、上記１又は２に記載の製造方法。
４．炭素数１〜４の脂肪酸エステルが、式：Ｒ^１ＣＯＯＲ^２（但し、Ｒ^１は水素、又は炭素数が好ましくは１〜４のアルキル基であり、Ｒ^２は炭素数が１〜４のアルキル基である。）で表される脂肪酸アルキルエステルである、上記１〜３のいずれかに記載の製造方法。
５．溶媒が、炭酸ジエステルの副溶媒を含む、上記１〜４のいずれかに記載の製造方法。
６．増感剤が、ベンゾフェノン、アセトフェノン、又はベンズアルデヒドである、上記１〜５のいずれかに記載の製造方法。
７．増感剤が、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、又は電子求引性基が置換したベンズアルデヒドである、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．増感剤の使用量が、無水マレイン酸化合物に対し０．１〜２０モル％である、上記１〜９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。1. In the formula (2), the maleic anhydride compound represented by the following formula (1) is photodimerized in the presence of a sensitizer in a solvent containing a fatty acid ester having 1 to 4 carbon atoms. A method for producing a represented 1,3-dialkyl 1,2,3,4-cyclobutanetetracarboxylic acid-1,2: 3,4-dianhydride derivative.

(In the formula, R represents an alkyl group having 1 to 20 carbon atoms.)
2. 2. The production method according to 1 above, wherein R is an alkyl group having 1 to 6 carbon atoms.
3. The manufacturing method of said 1 or 2 whose usage-amount of a solvent is 3-300 mass times with respect to a maleic anhydride compound.
4). The fatty acid ester having 1 to 4 carbon atoms is represented by the formula: R ¹ COOR ² (where R ¹ is hydrogen or an alkyl group having preferably 1 to 4 carbon atoms, and R ² is an alkyl having 1 to 4 carbon atoms. The production method according to any one of 1 to 3 above, which is a fatty acid alkyl ester represented by:
5. The manufacturing method in any one of said 1-4 whose solvent contains the subsolvent of carbonic acid diester.
6). 6. The production method according to any one of 1 to 5, wherein the sensitizer is benzophenone, acetophenone, or benzaldehyde.
7). The production method according to any one of 1 to 6 above, wherein the sensitizer is benzophenone substituted with an electron withdrawing group, acetophenone substituted with an electron withdrawing group, or benzaldehyde substituted with an electron withdrawing group. .
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 1-9 whose usage-amount of a sensitizer is 0.1-20 mol% 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, an inexpensive maleic anhydride compound raw material is subjected to a photodimerization reaction at a photoreaction rate, so that maleic anhydride is present in the presence of a sensitizer, unlike the conventional disclosure of Patent Document 1 and the like. By photodimerizing the compound, the photoreaction rate of the maleic anhydride compound is improved, and the selectivity of the 1,3-DACBDA derivative, which is an isomer having a highly symmetric structure, is improved. It can be produced in high yield.

It is a graph which shows the correlation of light irradiation time and the residual amount of citraconic anhydride in Example 1 and Comparative Examples 1 and 2 of the present invention.

  1,3-dialkyl-1,2,3,4-cyclobutanetetracarboxylic acid-1,2: 3 represented by formula (2) by photodimerization reaction of maleic anhydride compound represented by formula (1) , 4-dianhydride derivative 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, more preferably 1 to 6 carbon atoms, and methyl is particularly preferable.

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- 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 -Pente , 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 Is mentioned.
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-pentyl maleic anhydride, 2-n-hexyl maleic anhydride, 2-n-heptyl maleic anhydride, 2-n-octyl maleic anhydride, 2-n-nonyl maleic 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- (2-hexenyl) maleic anhydride Acid, 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. Since the photoreaction proceeds efficiently, citraconic anhydride, 2-ethyl maleic anhydride, 2-isopropyl maleic anhydride, 2-n-butyl maleic anhydride, 2-t-butyl maleic anhydride, 2 -N-pentyl maleic anhydride, 2-n-hexyl maleic anhydride, 2-n-heptyl maleic anhydride, 2-n-octyl maleic anhydride, 2-n-nonyl maleic anhydride, 2-n-decyl anhydride Maleic acid or 2-n-dodecylmaleic anhydride is preferred. Citraconic anhydride, 2-ethylmaleic anhydride, 2-isopropylmaleic anhydride, 2-n-butylmaleic anhydride, 2-t-butylmaleic anhydride Acid, 2-n-pentyl maleic anhydride, or 2-n-hexyl maleic anhydride is more preferred.

  The photoreaction of the present invention is carried out in the presence of a sensitizer by adding a (photo) sensitizer into the reaction system. Any sensitizer may be used as long as it has a photosensitizing action, and examples thereof include benzophenone, benzaldehyde, and anthraquinone.

  Among them, benzophenone substituted with an electron withdrawing group, acetophenone substituted with an electron withdrawing group, or benzaldehyde substituted with an electron withdrawing group is particularly preferable. Examples of the electron withdrawing group in this case 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, A chloro group, a bromo group, a cyano group, or a trifluoromethyl group is preferred. Particularly preferred electron withdrawing groups are fluoro groups or chloro groups. Although the number of electron withdrawing groups is 1-10, 1-5 are preferable and 1-3 are especially preferable.

  In the sensitizer, benzophenone, acetophenone, benzaldehyde, or benzaldehyde, the substitution position of the electron withdrawing group includes an ortho position, a meta position, and a para position with respect to the carbonyl group. Is preferred. When the number of electron withdrawing groups is 2 or more, the electron withdrawing groups may be the same or different. Moreover, the case where the carbonyl group which has an electron withdrawing effect in an ortho position bridge | crosslinks (anthraquinone) may be sufficient.

  Specific examples of benzophenone or 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'-dinitrobenzophenone, 2-chloro-5-nitrobenzophenone, 1,3-bis (4-fluorobenzoyl) benzene, 1,3-bis (4-chlorobenzoyl) benzene, 2,6-dibenzoylbenzonitrile 1,3-dibenzoyl-4,6-dinitrobenzene, anthraquinone and the like. Of these, 4,4'-difluorobenzophenone or 4,4'-dichlorobenzophenone is preferable.

  Specific examples of acetophenone or 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 or an electron withdrawing group include benzaldehyde, 2-fluorobenzaldehyde, 3-fluorobenzaldehyde, 4-fluorobenzaldehyde, 2-chlorobenzaldehyde, 3-chlorobenzaldehyde, 4-chlorobenzaldehyde, 2-cyano. Benzaldehyde, 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- Toro 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 used may be an amount that accelerates the photoreaction rate, but is preferably 0.1 to 20 mol%, more preferably 0.1 to 5 mol% with respect to the maleic anhydride compound. is there. One sensitizer may be used alone, or two or more sensitizers may be used in combination. From the standpoint of ease of treatment after the reaction, it is preferably used alone.

In the photoreaction of the present invention, it is essential to use a fatty acid ester having 1 to 4 carbon atoms as a reaction solvent because the photoreaction rate is accelerated. The fatty acid ester having 1 to 4 carbon atoms, preferably 1 to 2 carbon atoms 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 is an alkyl group having 1 to 4 carbon atoms, more preferably 1 to 3 carbon atoms). 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-acetate -Butyl, i-butyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, i-propyl propionate, n-butyl propionate or i-butyl propionate. In particular, methyl acetate, ethyl acetate, n-propyl acetate, i-propyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, or i-propyl propionate are preferred. One or more of these can be used.

  In addition, although a C1-C4 fatty acid ester can also be used independently as a reaction solvent, other subsolvents can be used. The secondary solvent used in this case is (1) a carbonyl compound having a high photosensitization effect, and (2) high solubility of the raw material maleic anhydride compound, which suppresses the decomposition reaction of the produced CBDA derivative compound. Therefore, the solubility of the CBDA derivative compound is low, (3) the solubility of the by-product is high, and the CBDA derivative compound can be purified only by washing with the same solvent. (4) The boiling point is not low and there is no danger of flammability. Moreover, in order not to remain in the CBDA derivative compound product, it is a compound having a boiling point of around 100 ° C., (5) safe for the environment, (6) stable during photoreaction, (7) inexpensive, etc. Satisfaction is preferred.

  From these viewpoints, as a specific example of the sub-solvent, a carbonic acid diester is preferable. Particularly, a carbonic acid dialkyl ester having 1 to 3 carbon atoms, more preferably 1 or 2 carbon atoms is preferable. A preferred example thereof is dimethyl carbonate or diethyl carbonate, and particularly preferred is diethyl carbonate or dimethyl carbonate. As a secondary solvent, glycol diesters such as ethylene glycol diformate, ethylene glycol diacetate, ethylene glycol dipropionate, propylene glycol diformate, propylene glycol diacetate, propylene glycol dipropionate, butylene glycol diacetate can also be used. .

  One of the excellent features of the production method using a fatty acid ester having 1 to 4 carbon atoms as a reaction solvent in the present invention is the solubility of the produced CBDA derivative compound despite the high solubility of the raw maleic anhydride compound. And the target compound is likely to precipitate during the reaction as crystals. For this reason, it is a point which can suppress side reactions, such as a reverse reaction from the CBDA derivative compound to a maleic anhydride compound, and oligomer formation.

  The usage-amount of a reaction solvent is 3-300 mass times with respect to a maleic anhydride compound, More preferably, it is 4-250 mass times. Each of the above solvents may be used alone or in combination of two or more. However, it is preferable to use them alone because of the ease of treatment after the reaction. When using a secondary solvent, the secondary 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. When the amount of the secondary solvent used is too large, the target compound is dissolved in the reaction solution, and the recovery rate is lowered, which is not preferable.

  In addition, the one where the usage-amount of a reaction solvent is smaller is preferable, for example, the density | concentration of a maleic anhydride compound is high, reaction becomes quick, and the yield of the product per time increases. Therefore, when it is desired to increase the reaction rate or to increase the yield of the product, the amount of the solvent used is preferably 3 to 10 times the mass of the maleic anhydride compound.

In this photoreaction, 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, or the like is used. Among them, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, or a light emitting diode is preferably used because it gives a CBDA derivative compound in a 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., more preferably −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 reduced when the temperature is low. 10-50 ° C. Particularly in the temperature range of 0 to 20 ° C., the production of by-products is greatly suppressed, and the CBDA derivative compound can be obtained with high selectivity and yield.

  The reaction time varies depending on the type of light source, the irradiation amount, and the like, but it can be performed until the unreacted maleic anhydride compound reaches 0 to 40%, preferably 0 to 10%. The reaction time is usually 1 to 200 hours, but can be 1 to 60 hours depending on the case.

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.
The reaction can be carried out batchwise or flow-through, but batchwise is preferably used. The pressure during the reaction may be normal pressure or increased pressure, but is preferably normal pressure.

  The target compound CBDA derivative 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.

The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples.
The analytical methods used in the examples are as follows.
<GC sampling method>
Collect a small amount of the reaction solution and perform GC analysis if no solid is precipitated. When a solid is precipitated, the solid is removed by filtration, and then the filtrate is analyzed by GC.
<GC analysis method>
The area ratio (area value of citraconic anhydride / area value of butyl lactate) is calculated from the 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 is 100%, and the residual ratio of citraconic anhydride from the area ratio of the reaction solution at each irradiation time (area ratio at each irradiation time / area ratio before light irradiation × 100) Is calculated.
<GC analysis conditions>
Apparatus: GC-2010 Plus (manufactured by SHIMADZU),
Column: DB-1 (manufactured by Agilent Technologies) 0.25 mm x 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 sampling method>
The crystal taken out after light irradiation is measured after drying under reduced pressure. In addition, the filtrate and the washing solution are subjected to vacuum drying to remove the solvent, and then the residue is measured.
^<1 H NMR analysis method>
Based on the integrated value of 1,3-DM-CBDA at 3.89 ppm, the selectivity is calculated by comparing with the integrated value of 1,2-DM-CBDA at 3.72 ppm. Specifically, assuming that the sum of the integrated values of 1,3-DM-CBDA and 1,2-DM-CBDA is 100%, each ratio ([integrated value of 1,3-DM-CBDA] or [1,2 -Integrated value of DM-CBDA] / [sum of integrated values of 1,3-DM-CBDA and 1,2-DM-CBDA] × 100).
^<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).

窒素雰囲気下、300 mLパイレックス（登録商標）ガラス製5口フラスコに、無水シトラコン酸（CA）35.0 g （312 mmol）、及び酢酸エチル152 g（1720 mmol、無水シトラコン酸（CA）に対して4.33 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、5−10℃で撹拌しながら、100W高圧水銀灯を照射した。
上記の分析方法により、各照射時間における反応液中の無水シトラコン酸の残存率を算出した。Comparative Example 1

Under a nitrogen atmosphere, in a 300 mL Pyrex (registered trademark) glass 5-neck flask, 4.33 (312 mmol) of citraconic anhydride (CA) and 152 g (1720 mmol of ethyl acetate, 4.33 against citraconic anhydride (CA) wt times) was added and dissolved by stirring with a magnetic stirrer. Then, a 100 W high pressure mercury lamp was irradiated while stirring at 5-10 ° C.
By the above analysis method, the residual ratio of citraconic anhydride in the reaction solution at each irradiation time was calculated.

窒素雰囲気下、300 mLパイレックス（登録商標）ガラス製5口フラスコに、無水シトラコン酸（CA）35.0 g （312 mmol）、ベンゾフェノン（BP）0.290 g （1.59 mmol、無水シトラコン酸（CA）に対して0.5 mol％）、及び酢酸エチル152 g（1720 mmol、無水シトラコン酸（CA）に対して4.33 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、5−10℃で撹拌しながら、100W高圧水銀灯を照射した。
上記の分析方法により、各照射時間における反応液中の無水シトラコン酸の残存率を算出した。Example 1

In a nitrogen atmosphere, in a 300 mL Pyrex (registered trademark) glass 5-neck flask, 35.0 g (312 mmol) of citraconic anhydride (CA) and 0.290 g of benzophenone (BP) (1.59 mmol, citraconic anhydride (CA) 0.5 mol%) and 152 g of ethyl acetate (1720 mmol, 4.33 wt times with respect to citraconic anhydride (CA)) were charged and dissolved by stirring with a magnetic stirrer. Then, a 100 W high pressure mercury lamp was irradiated while stirring at 5-10 ° C.
By the above analysis method, the residual ratio of citraconic anhydride in the reaction solution at each irradiation time was calculated.

窒素雰囲気下、300 mLパイレックス（登録商標）ガラス製5口フラスコに、シトラコン酸無水物（CA）35.0 g （312 mmol）、4,4’−ジクロロベンゾフェノン（DClBP）0.392 g （1.56 mmol、シトラコン酸無水物（CA）に対して0.5 mol％）、及び酢酸エチル152 g（1720 mmol、シトラコン酸無水物（CA）に対して4.33 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、5−10℃で撹拌しながら、100W高圧水銀灯を照射した。
上記の分析方法により、各照射時間における反応液中のシトラコン酸無水物の残存率を算出した。比較例１及び実施例１〜２で得られた結果を、表１及び図１のグラフに示す。Example 2

Citraconic anhydride (CA) 35.0 g (312 mmol), 4,4'-dichlorobenzophenone (DClBP) 0.392 g (1.56 mmol, citraconic acid) in a 300 mL Pyrex (registered trademark) glass 5-neck flask under nitrogen atmosphere Anhydrous (CA) 0.5 mol%) and ethyl acetate 152 g (1720 mmol, 4.33 wt times with respect to citraconic anhydride (CA)) were charged and dissolved by stirring with a magnetic stirrer. Then, a 100 W high pressure mercury lamp was irradiated while stirring at 5-10 ° C.
By the above analysis method, the residual rate of citraconic anhydride in the reaction solution at each irradiation time was calculated. The results obtained in Comparative Example 1 and Examples 1-2 are shown in Table 1 and the graph of FIG.

Comparative Example 2
A photodimerization reaction was carried out in the same manner as in Comparative Example 1. The precipitated white crystals were taken out by filtration at 5 to 10 ° C. The crystals were washed twice with 43.8 g of ethyl acetate (497 mmol, 1.25 wt times with respect to citraconic anhydride (CA)). Then, it was dried under reduced pressure to obtain 5.8 g of white crystals (yield 16.6%). According to ¹ H NMR analysis, this crystal was a mixture containing 1,3-DM-CBDA and 1,2-DM-CBDA (1,3-DM-CBDA: 1,2-DM-CBDA = 92.4: 7.6). I confirmed that there was. Further, as a result of quantitative analysis of the obtained crystal, filtrate and washing liquid by ¹ H NMR analysis and gas chromatography, respectively, the mass balance with respect to the charged 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 photodimerization reaction was carried out in the same manner as in Example 1. The precipitated white crystals were removed by filtration at 5-10 ° C. The crystals were washed twice with 43.8 g of ethyl acetate (497 mmol, 1.25 wt times with respect to citraconic anhydride (CA)). Then, it was dried under reduced pressure to obtain 8.8 g of white crystals (yield 25.2%). According to ¹ H NMR analysis, this crystal is a mixture containing 1,3-DM-CBDA and 1,2-DM-CBDA (1,3-DM-CBDA: 1,2-DM-CBDA = 85.0: 15.0). I confirmed that there was. Further, as a result of quantitative analysis of the obtained crystal, filtrate and washing liquid by ¹ H NMR analysis and gas chromatography, respectively, the mass balance with respect to the charged 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 photodimerization reaction was carried out in the same manner as in Example 2. The precipitated white crystals were removed by filtration at 5-10 ° C. The crystals were washed twice with 43.8 g of ethyl acetate (497 mmol, 1.25 wt times based on citraconic anhydride (CA)). Then, it was dried under reduced pressure to obtain 8.0 g (yield 22.8%) of white crystals. According to ¹ H NMR analysis, this crystal is a mixture containing 1,3-DM-CBDA and 1,2-DM-CBDA (1,3-DM-CBDA: 1,2-DM-CBDA = 86.5: 13.5). I confirmed that there was. Further, as a result of quantitative analysis of the obtained crystal, filtrate and washing liquid by ¹ H NMR analysis and gas chromatography, respectively, the mass balance with respect to the charged 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).

The cyclobutanetetracarboxylic acid derivative obtained in the present invention is a compound useful as a raw material for polyamic acid, polyimide, etc., and the polyimide is a resin composition used in the field of displays such as televisions using liquid crystal panels, and in the semiconductor field. It is used industrially as a product.
It should be noted that the entire content of the specification, claims, drawings and abstract of Japanese Patent Application No. 2014-007187 filed on January 17, 2014 is cited herein as the disclosure of the specification of the present invention. Incorporated.

Claims (11)

In the formula (2), the maleic anhydride compound represented by the following formula (1) is photodimerized in the presence of a sensitizer in a solvent containing a fatty acid ester having 1 to 4 carbon atoms. A method for producing a represented 1,3-dialkyl 1,2,3,4-cyclobutanetetracarboxylic acid-1,2: 3,4-dianhydride derivative.

(In the formula, R represents an alkyl group having 1 to 20 carbon atoms.)   The manufacturing method of Claim 1 whose R is a C1-C6 alkyl group.   The manufacturing method of Claim 1 or 2 whose usage-amount of a solvent is 3-300 mass times with respect to a maleic anhydride compound. The fatty acid ester having 1 to 4 carbon atoms is represented by the formula: R ¹ COOR ² (where R ¹ is hydrogen or an alkyl group having preferably 1 to 4 carbon atoms, and R ² is an alkyl having 1 to 4 carbon atoms. The production method according to any one of claims 1 to 3, which is a fatty acid alkyl ester represented by:   The manufacturing method in any one of Claims 1-4 in which a solvent contains the subsolvent of carbonic acid diester.   The production method according to any one of claims 1 to 5, wherein the sensitizer is benzophenone, acetophenone, or benzaldehyde.   The production according to any one of claims 1 to 6, wherein the sensitizer is benzophenone substituted with an electron withdrawing group, acetophenone substituted with an electron withdrawing group, or benzaldehyde substituted with an electron withdrawing group. Method.   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 1-9 whose usage-amount of a sensitizer is 0.1-20 mol% with respect to a maleic anhydride compound.   The manufacturing method in any one of Claims 1-10 whose reaction temperature is 0-20 degreeC.

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