TW201542560A - Method for producing cyclobutane tetracarboxylic acid derivative - Google Patents

Abstract

Provided is an efficient method for producing a 1,2,3,4-cyclobutane tetracarboxylic acid-1,2:3,4-dianhydride derivative which is useful as a raw material of polyimide or the like. The present invention is a method for producing a 1,2,3,4-cyclobutane tetracarboxylic acid-1,2:3,4- dianhydride derivative represented by formula (2) by photodimerization of a maleic anhydride compound represented by formula (1) in a diester carbonate solvent. (1) (2) (In the formula, R is an alkyl group having 1 to 20 carbon atoms.).

Description

Method for producing cyclobutane tetracarboxylic acid derivative

The present invention relates to a process for producing an alicyclic tetracarboxylic dianhydride which is a raw material monomer of a polyphthalic acid or a polyimine which can be used for an optical material.

Generally, polyimine resins are widely used as electronic materials for liquid crystal display elements, semiconductor protective materials, and insulating materials because of their high mechanical strength, heat resistance, insulation, and solvent resistance. In addition, it is expected to be used as a material for optical communication such as a material for optical waveguides.

In recent years, attention has been paid to the development of its field, and correspondingly, various higher characteristics have been required for the materials used. That is, it is expected to have not only excellent heat resistance and solvent resistance but also performance for many applications.

However, in particular, all aromatic polyimine resins exhibit a thicker amber color and are colored, so problems arise with respect to applications requiring high transparency.

Another known method for achieving transparency is to form a polyimine precursor by polycondensation reaction of an alicyclic tetracarboxylic dianhydride with an aromatic diamine, and then the precursor is imidized by hydrazine. When polythenimine is produced, polyimine which has less coloration and high transparency can be obtained (refer to Patent Documents 1 and 2).

The previous synthesis of alkylcyclobutyric acid dianhydride was carried out by photodimerization of citraconic acid (abbreviated as MMA) to obtain 1,3-dimethylcyclobutane-1,2,3. 4-tetracarboxylic acid-1,2:3,4-dianhydride (abbreviated as 1,3-DM-CBDA) and 1,2-dimethylcyclobutane-1,2,3,4-tetracarboxylic acid a mixture of -1,2:3,4-dianhydride (abbreviated as 1,2-DM-CBDA) (refer to Patent Document 3).

In addition, when comparing 1,3-DMCBDA with 1,2-DMCBDA, it is known that 1,3-DMCBDA has a higher molecular weight than the latter 1,2-DMCBDA, and has a higher symmetry structure. Applicability.

However, Patent Document 3 only describes that a mixture of 1,3-DMCBDA and 1,2-DMCBDA is obtained, and the former 1,3-DMCBDA which can selectively produce an isomer having high applicability in a high yield has not been described.

Prior technical literature Patent literature

Patent Document 1: Japanese Special Fair 2-24294

Patent Document 2: Japanese Laid-Open Patent Publication No. SHO 58-208322

Patent Document 3: Japanese Patent Laid-Open No. 4-106127

An object of the present invention is to provide a photodimerization reaction of a maleic anhydride compound represented by the following formula (1), which can produce a 1,3-dimer having an isomer of a high symmetry structure with high photoreaction efficiency and high yield. A method of alkyl-1,2,3,4-cyclobutanetetracarboxylic acid-1,2:3,4-dianhydride (hereinafter also referred to as 1,3-DACBDA) derivative.

In order to solve the above problems, the inventors of the present invention have intensively studied and found that the selectivity of a 1,3-DACBDA derivative having an isomer having a high symmetry structure can be improved in a high yield when a specific solvent is used.

The present invention is based on the novel findings, which have the following gist.

A process for producing a 1,2,3,4-cyclobutanetetracarboxylic acid-1,2:3,4-dianhydride derivative represented by the formula (2), which is characterized in that it is a solvent of a carbonic acid diester The photo-dimerization reaction of the maleic anhydride compound represented by the following formula (1) is carried out. (wherein 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 4 carbon atoms.

3. The production method according to the above 1 or 2, wherein the carbonic acid diester is a diester of an alkyl group having a carbon number of 1 to 4 carbonic acid.

4. The production method according to any one of the above 1 to 3, wherein the carbonic acid diester is dimethyl carbonate or diethyl carbonate.

5. The production method according to the above 4, wherein the solvent contains methyl formate, ethyl formate, methyl acetate, ethyl acetate, n-propyl acetate, i-propyl acetate, methyl propionate, and ethyl propionate A solvent other than an ester, n-propyl propionate, i-propyl propionate, ethylene glycol dicarboxylate, or a carbonic acid diester of ethylene glycol diacetate.

6. The production method according to any one of the above 1 to 5, wherein the total amount of the solvent used in the reaction is from 3 to 300 parts by mass based on the maleic anhydride compound.

7. The production method according to any one of the above 1 to 5, wherein the total amount of the solvent used in the reaction is from 3 to 10 parts by mass based on the maleic anhydride compound.

8. The production method according to any one of the above 1 to 7, wherein a sensitizer is used.

9. The production method according to the above 8, wherein the sensitizer is benzophenone, benzaldehyde, benzophenone substituted by an electron-derived group, acetophenone substituted by an electron-derived group, and Substituting benzaldehyde or hydrazine with an electron-seeking group.

10. The production method according to the above 9, wherein the electron-derived group is at least selected from the group consisting of a fluorine group, a chlorine group, a bromine group, an iodine group, a nitro group, a cyano group, and a trifluoromethyl group. One.

11. The manufacturing method according to the above 9 or 10, wherein the number of electron-seeking groups is 1 to 5.

12. The production method according to any one of the above 8-11, wherein the sensitizer is used in an amount of 0.1 to 20 mol% based on the maleic anhydride compound.

The production method according to any one of the above 1 to 12, wherein the reaction temperature is 0 to 20 ° C

The production method of the present invention can improve the production of 1,2,3,4-cyclobutanetetracarboxylic acid-1,2:3,4-dianhydride derivative by photodimerization of a maleic anhydride compound, Selectivity of 3-dialkylcyclobutane-1,2,3,4-tetracarboxylic acid-1,2:3,4-dianhydride.

The invention will be described in more detail below.

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

In the formula, R represents a carbon number of 1 to 20, more preferably 1 to 12, and particularly preferably an alkyl group of 1 to 6.

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.

Specifically, for example, 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 Base, 2-methyl-n-pentyl, 1,1-dimethyl-n-butyl, 1-ethyl-n-butyl, 1,1,2-trimethyl-n-propyl, a saturated alkyl group of n-heptyl, n-octyl, n-fluorenyl, n-fluorenyl, n-dodecyl, n-icosyl, etc., 1-methylvinyl, 2-allyl Base, 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 An unsaturated alkyl group such as a 2-propynyl group or a 9-decynyl group.

Further, n represents positive, i represents difference, s represents a pair, and t represents a tertiary.

A maleic anhydride compound represented by the formula (1) - for example, citraconic anhydride, 2-ethyl maleic anhydride, 2-isopropylmaleic anhydride, 2-n-butyl maleic anhydride, 2-t-butyl Kamaine anhydride, 2-n-pentyl maleic anhydride, 2-n-hexyl maleic anhydride, 2-n-heptyl maleic anhydride, 2-n-octyl maleic anhydride, 2-n-fluorenyl Maleic anhydride, 2-n-mercapto maleic anhydride, 2-n-dodecyl maleic anhydride, 2-n-eicosyl maleic anhydride, 2-(1-methylvinyl) Malay Anhydride, 2-(2-allyl)maleic anhydride, 2-(1-ethylvinyl)maleic anhydride, 2-(2-methylallyl)maleic anhydride, 2-(2-butyl Alkenyl) maleic anhydride, 2-(2-hexenyl)maleic anhydride, 2-(1-ethyl-2-pentenyl)maleic anhydride, 2-(3-dodecenyl)malan Anhydride, 2-propargylmaleic anhydride, 2-(3-butynyl)maleic anhydride, 2-(3-methyl-2-propynyl)maleic anhydride, 2-(9-nonynyl) ) Maleic anhydride, etc.

In order to carry out the photoreaction more efficiently, among them, citraconic anhydride, 2-ethylmaleic anhydride, 2-isopropylmaleate, 2-n-butylmaleic anhydride, 2-t-butyl group are preferred. Maleate, 2-n-pentyl maleic anhydride, 2-n-hexyl maleic anhydride, 2-n-heptyl maleic anhydride, 2-n-octyl maleic anhydride, 2-n-fluorenyl Maleic anhydride, 2-n-decylmaleic anhydride, or 2-n-dodecylmaleic anhydride, etc., more preferably citraconic anhydride, 2-ethylmaleic anhydride, 2-isopropylmalay Anhydride, 2-n-butyl maleic anhydride, 2-t-butyl maleic anhydride, 2-n-pentyl maleic anhydride, or 2-n-hexyl maleic anhydride or the like.

An important role in the photoreaction is the reaction solvent, which is a carbonic acid diester. The carbonic acid diester is preferably an alkyl diester having a carbon number of from 1 to 4, more preferably from 1 to 3, particularly preferably 1 or 2. Specifically, it is preferably dimethyl carbonate or diethyl carbonate, and particularly preferably dimethyl carbonate.

In the present invention, a carbonic acid diester may be used in combination with a sub-solvent other than a carbonic acid diester. Such solvents are, for example, 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, I-butyl propionate, ethylene glycol dicarboxylate, ethylene glycol diacetate, ethylene glycol dipropionate, and the like.

Preferred solvents are methyl formate, ethyl formate, methyl acetate, ethyl acetate, n-propyl acetate, i-propyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, I-propyl propionate, ethylene glycol dicarboxylate, ethylene glycol diacetate, etc., and the most preferred solvent is ethyl acetate.

An excellent feature of the method for producing a DACBDA derivative using a carbonic acid diester as a solvent is that the solubility of the maleic anhydride compound is relatively high irrespective of the raw material, and since it has a low solubility with respect to the produced CBDA compound, it crystallizes. Since it is precipitated, side reactions such as a reverse reaction of a DACBDA compound to a maleic anhydride compound and formation of an oligomer can be suppressed.

The solvent is used in an amount of from 3 to 300 parts by mass, more preferably from 3 to 250 parts by mass, per mole of the maleic anhydride compound.

Further, in order to accelerate the reaction or increase the yield of the product, the amount of the reaction solvent used is preferably less, for example, the concentration of the maleic anhydride compound is relatively rich. At this time, the reaction can be accelerated and the yield of the resulting product can be increased. Therefore, in order to accelerate the reaction and increase the yield of the product, the amount of the solvent to be used is preferably from 3 to 10 parts by mass based on the maleic anhydride compound.

The wavelength of light in the photoreaction is 200 to 400 nm, more preferably 250 to 350 nm, and particularly preferably 280 to 330 nm. The CBDA derivative compound is imparted in a specific high yield, and the light source is preferably 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. Among them, high-pressure mercury lamps, ultra-high pressure mercury lamps, or light-emitting diodes are preferred.

Further, by changing the light source cooling tube of the photochemical reaction device from quartz glass to Pyrex (registered trademark) glass, it is preferable to reduce the coloring of the polymer and the impurities in the light source cooling tube, and to improve the yield of the CBDA derivative compound.

When the reaction temperature is high, the polymer is produced as a by-product, and at a low temperature, the solubility of the maleic anhydride compound is lowered to reduce the production efficiency, so that it is preferably carried out at -20 to 80 ° C, more preferably at -10 to 50 ° C. In particular, the formation of by-products can be greatly suppressed in the temperature range of 0 to 20 ° C, and the CBDA derivative compound can be obtained at a high selectivity and yield.

The reaction time varies depending on the content of the maleic anhydride compound, the kind of the light source, the amount of irradiation, and the like, and the unreacted maleic acid ester compound can be brought to 0 to 40%, preferably 0 to 10%.

Specifically, the reaction time is a high-pressure mercury lamp or a light-emitting diode in the light source, the reaction solvent is dimethyl carbonate or ethyl acetate, and the sensitizer is 4,4'-difluorobenzophenone or 4,4'-two. Chlorobenzophenone at 0~20°C In the reaction temperature range, it is usually from 1 to 200 hours, preferably from 1 to 100 hours, more preferably from 1 to 60 hours.

Further, the conversion rate can be determined by analyzing the reaction liquid by gas chromatography or the like.

When the reaction time is elongated, the conversion rate of the maleic anhydride compound is increased, and the precipitation amount of the CBDA derivative compound is increased, the CBDA derivative compound formed starts to adhere to the outer wall of the light source cooling tube (reaction liquid side), and is concurrently decomposed. The reaction colorizes the crystals and reduces the light efficiency (yield per unit of electricity x time). Therefore, in order to increase the conversion rate of the maleic anhydride compound, it takes a long time for each batch to be used, and it is practically preferable to reduce the production efficiency.

Further, the reaction can be carried out batchwise or in a flow-through manner, but it is preferred to use a batch type.

Further, the pressure at the time of the reaction may be normal pressure or pressure, but is preferably normal pressure.

Further, the production method of the present invention can be carried out by adding a sensitizer. Sensitizers such as benzophenone, benzaldehyde, anthracene, benzophenone substituted by an electron-derived group, anthracene substituted by an electron-derived group, benzaldehyde substituted by an electron-derived group Wait.

The electron-derived group is at least one selected from the group consisting of a fluorine group, a chlorine group, a bromine group, an iodine group, a nitro group, a cyano group and a trifluoromethyl group, and is preferably a fluorine group, a chlorine group or a bromine group. , cyano and trifluoromethyl. A particularly preferred electron-seeking group is a fluorine group or a chlorine group.

The number of electron-referring groups is 1 to 10, preferably 1 to 5. The effect of the present invention is preferably 1 to 3.

The electron-referencing group is substituted for the position relative to the carbonyl group Bit, meta, and alignment are preferably ortho or alignment.

When the number of electron-referencing groups is 2 or more, the electron-referencing groups may be the same or different. Further, the two electron-inducing groups in place of the ortho position may form a carbonyl group (roller roll) together.

Specific examples of benzophenone and benzophenone substituted with an electron-derived group include, for example, 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'-difluorobenzonitrile Ketone, 4,4'-dichlorobenzophenone, 4,4'-dibromobenzophenone, 3,3'-bis(trifluoromethyl)benzophenone, 3,4'-two whistle Benzophenone, 3,3'-dinitrobenzophenone, 4,4'-dinitrobenzophenone, 2-chloro-5-nitrobenzophenone, 1,3-double (4-fluorophenylhydrazine) benzene, 1,3-bis(4-chlorophenylhydrazine)benzene, 2,6-diphenylbenzonitrile, 1,3-diphenylindole-4,6-dinitrobenzene, Roller and so on.

Among them, preferred is 4,4'-difluorobenzophenone or 4,4'-dichlorobenzophenone.

Specific examples of acetophenone and ethyl benzene substituted by an electron-derived group include, for example, acetophenone, 2'-fluoroethyl benzene, 3'-fluoroethyl benzene, 4'-fluoroethyl benzene, 2'- Chloroprene, 3'-chloroethylbenzene, 4'-chloroethylbenzene, 2'-cyanoethylbenzene, 3'-cyanoethylbenzene, 4'-cyanoethylbenzene, 2' -Nitroethyl benzene, 3'-nitroethyl benzene, 4'-nitroethyl benzene, 2',4'-difluoro acetophenone, 3',4'-difluoroacetam, 2 ',4'-Dichloroacetamidine, 3',4'-dichloroacetamidine, 4'-chloro-3'-nitroacetamidine, 4'-bromo-3'-nitroacetamidine , 4'-fluoro- 3'-nitroethyl benzene and the like.

Among them, preferred are 4'-fluoroethyl benzene, 4'-chloroethyl benzene, 2', 4'-difluoro acetophenone, 3', 4'-difluoroacetam, 2', 4'- Dichloroacetamidine, or 3',4'-dichloroacetamidine.

Benzaldehyde and benzaldehyde substituted by electron-derived group, such as 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-nitrogen Benzoaldehyde, 4-chloro-3-nitrobenzaldehyde, 5-chloro-2-nitrobenzaldehyde, 2-fluoro-5-nitrobenzaldehyde, 4-fluoro-3-nitrobenzaldehyde, 5- Fluoro-2-nitrobenzaldehyde and the like.

Among them, 4-fluorobenzaldehyde, 4-chlorobenzaldehyde, 2,4-difluorobenzaldehyde, 3,4-difluorobenzaldehyde, 2,4-dichlorobenzaldehyde, or 3,4-dichloro is preferred. Benzaldehyde and the like.

The sensitizing amount to be used may be an amount which accelerates the photoreaction rate, and is not particularly limited, and is preferably 0.1 to 20 mol%, more preferably 0.1 to 5 mol%, based on the maleic anhydride compound.

The sensitizer may be used singly or in combination of one or more of the above benzophenone derivatives, acetophenone derivatives, or benzaldehyde derivatives, but it is preferred to use them separately after the reaction.

The objective compound is obtained by filtering the precipitate in the reaction liquid after photoreaction, washing the filtrate with an organic solvent, and drying under reduced pressure.

The amount of the organic solvent used for washing the filtrate may be such that the precipitate remaining in the reaction tank can be transferred to the filter. However, when the amount of the organic solvent is too large, the target substance is transferred to the filtrate to lower the recovery rate. Therefore, the amount of the organic solvent used for washing the filtrate is preferably 0.5 to 10 parts by weight, more preferably 1 to 2 parts by weight, based on the maleic anhydride compound used in the reaction.

The organic solvent to be used for washing the filtrate is not particularly limited. However, when a solvent having a high solubility with respect to the product is used, the target compound migrates to the filtrate to lower the recovery rate, which is not preferable. Therefore, the organic solvent used for washing the filtrate, for example, methyl formate, ethyl formate, n-propyl formate, i-propyl formate, n-butyl formate, formic acid i, used in the photodimerization reaction -butyl ester, methyl acetate, ethyl acetate, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, methyl propionate, ethyl propionate, propionic acid n- Propyl ester, i-propyl propionate, n-butyl propionate, i-butyl propionate, ethylene glycol dicarboxylate, ethylene glycol diacetate, ethylene glycol dipropionate, carbonic acid A methyl ester, diethyl carbonate, or a solvent which does not dissolve the product and does not react with the product, such as toluene, hexane, heptane, acetonitrile, acetone, chloroform, acetic anhydride or a mixed solvent thereof. Of these, ethyl acetate, dimethyl carbonate, acetic anhydride and the like are preferred, and ethyl acetate or dimethyl carbonate is more preferred.

Example

The invention will be specifically described below by way of examples, but the invention is not limited thereto.

Further, the analysis method used in the examples is as follows.

<GC analysis conditions>

Device: GC-2010 Plus (SHIMADZU company)

Pipe column: DB-1 (made by Giye Sai company) 0.25mm × 30m, film thickness 0.25μm

Carrier gas: He, tester: FID, sample injection amount: 1μm, inlet 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 analysis conditions>

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

Solvent: DMSO-d6, internal standard material: tetramethyl decane (TMS).

<melting point analysis conditions>

Device: DSC1 (made by Metra)

Temperature: 35 ° C - 5 ° C / min - 400 ° C, vessel: Au (sealed).

Comparative example 1

0.10 g (0.89 mmol) of citraconic anhydride (CA) and 20 g of methyl acetate (270 mmol, 200 parts by weight relative to citraconic acid (CA)) were added to a 30 mL Pyrex (registered trademark) glass test tube under nitrogen. Stir the stirrer to dissolve. Thereafter, while stirring at 5 to 10 ° C, a 100 W high pressure mercury lamp was irradiated for 4 hours. After the irradiation, the reaction liquid was quantitatively analyzed by gas chromatography, and the residual rate of citraconic anhydride (CA) was 29.9%. Further, 2 g of the reaction liquid in the reactor was taken, and the solvent was distilled off at 70-80 Torr using an evaporator. The obtained crude product was analyzed by ¹ H NMR, and was confirmed to contain a mixture of 1,3-DM-CBDA and 1,2-DM-CBDA (1,3-DM-CBDA: 1,2-DM-CBDA=42.6 :57.4).

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 1

0.10 g (0.89 mmol) of citraconic anhydride (CA) and 20 g of dimethyl carbonate (222 mmol, 200 parts by weight relative to citraconic anhydride (CA)) were added to a 30 mL Pyrex (registered trademark) glass test tube under nitrogen. The magnetic stirrer was stirred to dissolve. Thereafter, while stirring at 15 to 20 ° C, a 100 W high pressure mercury lamp was irradiated for 4 hours. After the irradiation, the reaction solution was quantitatively analyzed by gas chromatography, and the residual rate of citraconic anhydride (CA) was 26.2%. Further, the reaction liquid in a 2 g reactor was taken, and the solvent was distilled off at 70-80 Torr using an evaporator. The obtained crude product was analyzed by ¹ H-NMR, and was confirmed to contain a mixture of 1,3-DM-CBDA and 1,2-DM-CBDA (1,3-DM-CBDA: 1,2-DM-CBDA=48.3 :51.7).

Comparative Examples 2 to 28, and Example 2

The series of operations were carried out in the same manner as in Comparative Example 1, and 200 parts by weight of each solvent was added to citraconic anhydride (CA), and the residual ratio of citraconic anhydride (CA) and 1,3-DM were calculated in the same manner as in Comparative Example 1. - Formation ratio of CBDA to 1,2-DM-CBDA (1,3-DM-CBDA: 1,2-DM-CBDA).

The solvent, temperature, by-product content and results are shown in the following table. Further, the residual ratio of citraconic anhydride of the obtained reaction liquid and the ratio of formation of 1,3-DM-CBDA to 1,2-DM-CBDA were calculated, and the results obtained in Comparative Example 1 and Example 1 are shown in the Table. Further, the reaction rate in the table was calculated from the number of moles of citraconic acid used and the residual ratio of citraconic acid after 4 hours of reaction.

Example 3

35.0 g (312 mmol) of citraconic anhydride (CA) and 152 g of dimethyl carbonate (1682 mmol, 4.33 parts by weight based on citraconic anhydride (CA)) were placed in a 300 mL Pytex (registered trademark) glass 5-necked flask under nitrogen. Stir with a magnetic stirrer to dissolve. Thereafter, the mixture was stirred at 10 to 15 ° C, and a 100 W high-pressure mercury lamp was irradiated for 48 hours, and the reaction liquid was analyzed by gas phase spectrometry. As a result, it was confirmed that the residual ratio of the raw material was 23.7%. Next, the precipitated white crystals were filtered by filtration at 10 to 15 ° C, and the crystals were washed twice with ethyl acetate (43.8 g, 497 mmol, 1.25 parts by weight relative to citric anhydride (CA)). After drying under reduced pressure, 8.1 g of white crystals (yield 23.1%) was obtained. The crystal was analyzed by ¹ H NMR, and was confirmed to be a mixture containing 1,3-DM-CBDA and 1,2-DM-CBDA (1,3-DM-CBDA: 1,2-DM-CBDA=90.3: 9.7 ). Further, each of the obtained crystals, the filtrate and the washing liquid were subjected to ¹ H NMR analysis and quantitative analysis by gas chromatography, and the mass balance with respect to the added amount was 88.9%.

Example 4

0.10 g (0.89 mmol) of citraconic anhydride (CA), 0.020 g (0.11 mmol, 20% by mass relative to citraconic anhydride (CA)) and 20 g of dimethyl carbonate (222 mol) of citraconic anhydride (CA) under nitrogen It was placed in a 30 mL Pyrex (registered trademark) glass test tube with respect to citraconic anhydride (CA) in an amount of 200 parts by mass, and dissolved by stirring with a magnetic stirrer. Thereafter, while stirring at 10 to 15 ° C, a 100 W high pressure mercury lamp was irradiated for 4 hours. After the irradiation, the reaction solution was quantitatively analyzed by gas chromatography, and the residual rate of citraconic anhydride (CA) was 3.9%. Further, the reaction liquid in a 2 g reactor was taken, and the solvent was distilled off at 70 to 80 Torr using an evaporator. The obtained crude product was analyzed by ¹ H NMR, and was confirmed to contain a mixture of 1,3-DM-CBDA and 1,2-DM-CBDA (1,3-DM-CBDA: 1,2-DM-CBDA=48.3 :51.7).

Example 5

A series of operations were carried out in the same manner as in Example 4, and 4,4'-dichlorobenzophenone (DCIBP) for a sensitizer was added, and the residual ratio of citraconic anhydride (CA) was calculated in the same manner as in Comparative Example 1. And the ratio of 1,3-DM-CBDA to 1,2-DM-CBDA (1,3-DM-CBDA: 1,2-DM-CBDA).

The solvent, temperature, sensitizer, by-product amount and results are shown in the following table. Further, the residual ratio of citraconic anhydride of the reaction liquid obtained at this time and the ratio of formation of 1,3-DM-CBDA to 1,2-DM-CBDA were calculated, and the results obtained in Example 4 are shown in the table. Further, the reaction rate in the table was calculated from the number of moles of citraconic acid used and the residual ratio of citraconic acid at the time of reaction for 4 hours.

Reference example 1

A mixture containing 1,3-DM-CBDA and 1,2-DM-CBDA obtained by the same method as in Example 3 under a nitrogen stream (1,3-DM-CBDA: 1,2-DM-CBDA=85:15) 18.3 g, and 92 g of acetic anhydride were placed in a 200 mL four-necked flask, and stirred at 25 ° C with a magnetic stirrer to suspend. Thereafter, it was heated to reflux (130 ° C) for 4 hours. Next, the internal temperature was cooled to 25 ° C or lower, and the mixture was stirred at 25 ° C or lower for 1 hour. Thereafter, the precipitated white crystals were filtered, and the crystals were washed twice with ethyl acetate (18 g), and the obtained white crystals were dried under reduced pressure to give a high purity 1,3-DM-CBDA 14.4 g (yield 92%). ). The crystal was analyzed by ¹ H NMR. As a result, it was confirmed that the ratio of 1,3-DM-CBDA to 1,2-DM-CBDA was 1,3-DM-CBDA: 1,2-DM-CBDA = 99.5:0.5.

^{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.

Industrial use possibility

The cyclobutane tetracarboxylic acid derivative obtained by the present invention is a compound which is preferably used as a raw material of polyglycolic acid or polyimine. Industrially, the polyimine or the like is widely used as a liquid crystal display element and a semiconductor. A resin composition used for electronic materials such as protective materials and insulating materials.

Further, the entire contents of the specification, the scope of the patent application, and the abstract of the Japanese Patent Application No. 2014-007186, filed on Jan. 17, 2014, are hereby incorporated by reference.

Claims (13)

A method for producing a 1,2,3,4-cyclobutanetetracarboxylic acid-1,2:3,4-dianhydride derivative represented by the formula (2), which is characterized in that it is made in a solvent of a carbonic acid diester The maleic anhydride compound represented by the following formula (1) is subjected to photodimerization reaction, (wherein 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 4 carbon atoms. The production method according to claim 1 or 2, wherein the carbonic acid diester is a diester of an alkyl group having a carbon number of 1 to 4 carbonic acid. The production method according to any one of claims 1 to 3, wherein the carbonic acid diester is dimethyl carbonate or diethyl carbonate. The method of claim 4, wherein the solvent comprises methyl formate, ethyl formate, methyl acetate, ethyl acetate, n-propyl acetate, i-propyl acetate, methyl propionate, ethyl propionate, and C. A sub-solvent other than the n-propyl ester of acid, i-propyl propionate, ethylene glycol dicarboxylate, or the carbonic acid diester of ethylene glycol diacetate. The production method according to any one of claims 1 to 5, wherein the total amount of the solvent used in the reaction is from 3 to 300 with respect to the maleic anhydride compound. Parts by mass. The production method according to any one of claims 1 to 5, wherein a total amount of the solvent used in the reaction is from 3 to 10 parts by mass based on the maleic anhydride compound. The manufacturing method according to any one of claims 1 to 7, wherein a sensitizer is additionally used. The method of claim 8, wherein the sensitizer is benzophenone, benzaldehyde, benzophenone substituted by an electron-donating group, acetophenone substituted by an electron-donating group, and electronically cited Substituted benzaldehyde or hydrazine. The method of claim 9, wherein the electron-derived group is at least one selected from the group consisting of a fluorine group, a chlorine group, a bromine group, an iodine group, a nitro group, a cyano group, and a trifluoromethyl group. The manufacturing method of claim 9 or 10, wherein the number of electronic reference groups is 1 to 5. The production method according to any one of claims 8 to 11, wherein the sensitizer is used in an amount of 0.1 to 20 mol% based on the maleic anhydride compound. The production method according to any one of claims 1 to 12, wherein the reaction temperature is 0 to 20 °C.