KR20220162884A - Method for producing cyclobutane tetracarboxylic acid derivative - Google Patents

Abstract

(식 중, R 은 탄소수 1 ∼ 20 의 알킬기를 나타낸다.)Provision of an efficient production method for a 1,2,3,4-cyclobutanetetracarboxylic acid-1,2:3,4-2 anhydride derivative useful as a raw material for polyimide or the like. 1,2,3,4-cyclobutanetetracarboxylic acid-1,2 represented by formula (2) by photodimerization of the maleic anhydride compound represented by formula (1) below in a diester carbonate solvent : Method for preparing 3,4-2 anhydride derivatives.
[Formula 1]

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

Description

Method for producing cyclobutane tetracarboxylic acid derivative {METHOD FOR PRODUCING CYCLOBUTANE TETRACARBOXYLIC ACID DERIVATIVE}

The present invention relates to a method for producing an alicyclic tetracarboxylic dianhydride that can serve as a raw material monomer for polyamic acid and polyimide for optical materials.

In general, polyimide resins are widely used as electronic materials such as protective materials and insulating materials in liquid crystal display elements and semiconductors due to their characteristics such as high mechanical strength, heat resistance, insulation, and solvent resistance. In recent years, use as a material for optical communication, such as a material for an optical waveguide, is also expected.

In recent years, the development in this field has been remarkable, and correspondingly, more and more advanced properties are required for the materials used. That is, it is expected to not only be excellent in heat resistance and solvent resistance, but also to combine a number of performances according to the application.

However, in particular, wholly aromatic polyimide resins have a problem in applications requiring high transparency because they exhibit a deep amber color and are colored.

On the other hand, as one method of realizing transparency, a polyimide precursor is formed by a polycondensation reaction of alicyclic tetracarboxylic dianhydride and aromatic diamine, and the precursor is imidized to produce a polyimide, which is relatively colored. It is known that a highly transparent polyimide can be obtained with a small amount (see Patent Documents 1 and 2).

Conventionally, in the synthesis of alkylcyclobutanoic dianhydride, 1,3-dimethylcyclobutane-1,2 is obtained by a photodimerization reaction of citraconic acid anhydride (abbreviated as MMA) as shown in the following scheme. ,3,4-tetracarboxylic acid-1,2: 3,4-2 anhydride (abbreviated as 1,3-DM-CBDA) and 1,2-dimethylcyclobutane-1,2,3,4-tetra A mixture of carboxylic acid-1,2:3,4-di anhydride (abbreviated as 1,2-DM-CBDA) is obtained (see Patent Document 3).

[Formula 1]

On the other hand, when 1,3-DMCBDA and 1,2-DMCBDA are compared, the former 1,3-DMCBDA having a highly symmetric structure can produce a polyimide having a higher molecular weight than the latter 1,2-DMCBDA. , and it is known that the usefulness is higher.

However, although it is described in Patent Document 3 that a mixture of 1,3-DMCBDA and 1,2-DMCBDA is obtained, the former 1,3-DMCBDA, which is an isomer with high usefulness, is produced selectively and in high yield. There is no record of what

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

An object of the present invention is to photodimerize a maleic anhydride compound represented by the following formula (1) to obtain 1,3-dialkyl- which is an isomer having a highly symmetric structure with high photoreaction efficiency and high yield. It is to provide a method capable of producing a 1,2,3,4-cyclobutanetetracarboxylic acid-1,2:3,4-2 anhydride (hereinafter, also referred to as 1,3-DACBDA) derivative.

As a result of intensive research in order to solve the above problems, the inventors of the present invention have found that when a specific solvent is used, the selectivity of 1,3-DACBDA derivatives, which are isomers having a structure with high symmetry, is improved and can be produced in high yield. found out what could be

The present invention is based on these novel findings and has the following summary.

1. 1,2,3,4-cyclobutanetetracarboxylic acid represented by formula (2), characterized by carrying out a photodimerization reaction of a maleic anhydride compound represented by formula (1) below in a diester carbonate solvent. -1,2: Method for preparing 3,4-2 anhydride derivatives.

[Formula 2]

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

2. The production method described in 1 above, wherein R is an alkyl group having 1 to 4 carbon atoms.

3. The production method described in the above 1 or 2, wherein the diester carbonate is a diester of an alkyl having 1 to 4 carbon atoms of carbonic acid.

4. The manufacturing method in any one of said 1-3 whose diester carbonate is dimethyl carbonate or diethyl carbonate.

5. The solvent is 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 diformate, or The production method according to 4 above, comprising a solvent other than diester carbonate which is ethylene glycol diacetate.

6. The manufacturing method in any one of said 1-5 whose usage-amount of all the solvents used for reaction is 3-300 mass times the maleic anhydride compound.

7. The manufacturing method in any one of said 1-5 whose usage-amount of all the solvents used for reaction is 3-10 mass times with respect to maleic anhydride compound.

8. The manufacturing method in any one of said 1-7 using a sensitizer.

9. The production method described in 8 above, wherein the sensitizer is benzophenone, benzaldehyde, benzophenone substituted with an electron withdrawing group, acetophenone substituted with an electron withdrawing group, benzaldehyde substituted with an electron withdrawing group, or anthraquinone.

10. The production method according to 9 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 iodine group, a nitro group, a cyano group, and a trifluoromethyl group.

11. The manufacturing method described in 9 or 10 above, wherein the number of electron withdrawing groups is 1 to 5.

12. The manufacturing method in any one of said 8-11 whose usage-amount of a sensitizer is 0.1-20 mol% with respect to the maleic anhydride compound.

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

According to the production method of the present invention, in the production of a 1,2,3,4-cyclobutanetetracarboxylic acid-1,2:3,4-2 anhydride derivative by photodimerization of a maleic anhydride compound, The selectivity of 1,3-dialkylcyclobutane-1,2,3,4-tetracarboxylic acid-1,2:3,4-2 anhydride can be improved.

Hereinafter, the present invention will be described in more detail.

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

[Formula 3]

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

As the C1-C20 alkyl group, any of a linear or branched saturated alkyl group or a linear or branched unsaturated alkyl group may be used.

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- Saturation of butyl, 1-ethyl-n-butyl, 1,1,2-trimethyl-n-propyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-dodecyl, n-eicosyl, etc. Alkyl group, 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 , unsaturated alkyl groups such as propargyl, 3-butynyl, 3-methyl-2-propynyl, and 9-decynyl.

In addition, n represents normal, i represents iso, s represents secondary, and t represents tertiary, respectively.

As an example of the maleic anhydride compound represented by Formula (1), citraconic acid anhydride, 2-ethyl maleic anhydride, 2-isopropyl maleic anhydride, 2-n-butyl maleic anhydride, 2-t-butyl maleic anhydride Maleic acid, 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, 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, 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 and 2-(9-decynyl) maleic anhydride.

Since the photoreaction proceeds efficiently, among these, citraconic anhydride, 2-ethyl maleic anhydride, 2-isopropyl maleic anhydride, 2-n-butyl maleic anhydride, 2-t-butyl maleic 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 or 2-n-dodecylmaleic anhydride is preferable, and citraconic acid anhydride, 2-ethyl maleic anhydride, 2-isopropyl maleic anhydride, 2-n-butyl maleic anhydride, 2 - t-butyl maleic anhydride, 2-n-pentyl maleic anhydride, or 2-n-hexyl maleic anhydride, etc. are more preferable.

Although it is the reaction solvent which plays an important role in this photoreaction, the reaction solvent is diester carbonate. As diester carbonate, among these, an alkyl diester whose carbonic acid carbon number is preferably 1 to 4, more preferably 1 to 3, and particularly preferably 1 or 2 is preferable. Specifically, dimethyl carbonate or diethyl carbonate is preferable, and dimethyl carbonate is particularly preferable.

In the present invention, diester carbonate and a sub-solvent other than diester carbonate can also be used in combination. Such solvents 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, i-butyl propionate, ethylene glycol diformate, ethylene glycol diacetate, ethylene glycol dipropionate etc. can be mentioned.

Among these, more preferable 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, and ethylene glycol dipole. Mate, ethylene glycol diacetate, etc., and the most preferable solvent is ethyl acetate.

The excellent feature of the method for producing a DACBDA derivative using a diester carbonate as a solvent is that despite the high solubility of the maleic anhydride compound as a raw material, the solubility of the resulting CBDA compound is low and precipitates as crystals, so that the DACBDA compound It is possible to suppress side reactions such as reverse reactions to maleic anhydride compounds from or formation of oligomers.

The amount of the solvent used is 3 to 300 times by mass, more preferably 3 to 250 times by mass relative to the maleic anhydride compound.

In addition, the amount of the reaction solvent used is preferably small when the reaction is to be accelerated or when the yield of the product is to be increased. For example, when the concentration of the maleic anhydride compound is increased, the reaction is accelerated and quantity increases Therefore, when the reaction is to be accelerated or when the yield of the product is to be increased, the amount of the solvent used is preferably 3 to 10 times by mass relative to 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-vapor lamp, a medium-pressure mercury-vapor lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a xenon lamp, an electrodeless lamp, a light emitting diode, and the like are preferable in terms of providing a CBDA derivative compound in a specific high yield. Especially, a high-pressure mercury-vapor lamp, an ultra-high-pressure mercury-vapor lamp, or a light emitting diode is preferable.

In addition, as a photochemical reaction device, by changing the light source cooling tube from quartz glass to Pyrex (registered trademark) glass, the adhesion of colored polymers to the light source cooling tube and impurities is reduced, and the yield of CBDA derivative compounds can be improved. desirable.

The reaction temperature is preferably -20 to 80 ° C., and more preferably - from the viewpoint that when the reaction temperature is high, a polymer is produced as a by-product, and when the temperature is low, the solubility of the maleic anhydride compound decreases and the production efficiency decreases. It is 10-50 degreeC. In particular, in the temperature range of 0 to 20°C, generation of by-products is significantly suppressed, and CBDA derivative compounds are obtained with high selectivity and yield.

The reaction time varies depending on the amount of maleic anhydride compound, the type of light source, the amount of irradiation, etc., but is carried out for a period of time until the unreacted maleic anhydride compound reaches 0 to 40%, preferably 0 to 10% can do.

The reaction time is specifically, using a high pressure mercury lamp or light emitting diode as a light source, using dimethyl carbonate or ethyl acetate as a reaction solvent, and using 4,4'-difluorobenzophenone or 4,4'- as a sensitizer. Using dichlorobenzophenone, it is usually 1 to 200 hours, preferably 1 to 100 hours, and more preferably 1 to 60 hours under conditions of a reaction temperature range of 0 to 20°C.

In addition, conversion rate can be calculated|required by analyzing a reaction liquid by gas chromatography etc.

When the reaction time becomes longer, the conversion rate of the maleic anhydride compound increases, and the amount of the CBDA derivative compound precipitated increases, the produced CBDA derivative compound begins to adhere to the outer wall (reaction liquid side) of the light source cooling pipe, resulting in concurrent decomposition reaction. Coloration of the crystal by the crystal, decrease in light efficiency (yield per unit power x time) is observed. Therefore, in order to raise the conversion rate of a maleic anhydride compound, it is unpreferable to apply in 1 batch for a long time with the fall of production efficiency practically.

In addition, although it is possible to carry out a reaction by a batch type or a flow type, a batch type is preferably used.

In addition, the pressure at the time of reaction may be normal pressure or pressurized pressure, and it does not matter which one. Preferably, it is normal pressure.

Moreover, the manufacturing method of this invention can also be implemented by adding a sensitizer. Examples of the sensitizer include benzophenone, 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 iodine group, a nitro group, a cyano group, and a trifluoromethyl group, and a fluoro group, a chloro group , a bromo group, a cyano group, and a trifluoromethyl group are preferred. A particularly preferable electron withdrawing group is a fluoro group or a chloro group.

Although the number of electron withdrawing groups is 1-10, 1-5 are preferable, and 1-3 are preferable from the point of the effect of this invention.

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, but an ortho position or a para position is preferable.

When the number of electron withdrawing groups is two or more, the electron withdrawing groups may be the same or different. Alternatively, it may be a case where two electron withdrawing groups substituted at ortho positions combine to form a carbonyl group (anthraquinone).

Specific examples of benzophenone and benzophenone substituted with an electron withdrawing group include benzophenone, 2-fluorobenzophenone, 3-fluorobenzophenone, 4-fluorobenzophenone, 2-chlorobenzophenone, and 3-chloro. Benzophenone, 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, 1,3-dibenzoyl-4,6-dinitrobenzene, anthraquinone, and the like. have.

Among 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, and 2'-chloroacetophenone. , 3'-chloroacetophenone, 4'-chloroacetophenone, 2'-cyanoacetophenone, 3'-cyanoacetophenone, 4'-cyanoacetophenone, 2'-nitroacetophenone, 3'-nitro Acetophenone, 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 these, 4'-fluoroacetophenone, 4'-chloroacetophenone, 2',4'-difluoroacetophenone, 3',4'-difluoroacetophenone, 2',4'-dichloro Acetophenone or 3',4'-dichloroacetophenone is preferable.

Benzaldehyde and benzaldehyde substituted with 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-di Fluorobenzaldehyde, 3,4-difluorobenzaldehyde, 2,4-dichlorobenzaldehyde, 3,4-dichlorobenzaldehyde, 2-chloro-5-nitrobenzaldehyde, 4-chloro-2-nitrobenzaldehyde , 4-chloro-3-nitrobenzaldehyde, 5-chloro-2-nitrobenzaldehyde, 2-fluoro-5-nitrobenzaldehyde, 4-fluoro-3-nitrobenzaldehyde, 5-fluoro-2- Nitrobenzaldehyde etc. are mentioned.

Among these, 4-fluorobenzaldehyde, 4-chlorobenzaldehyde, 2,4-difluorobenzaldehyde, 3,4-difluorobenzaldehyde, 2,4-dichlorobenzaldehyde, or 3,4- Dichlorobenzaldehyde and the like are preferred.

The amount of the sensitizer to be used may be any amount that accelerates the photoreaction rate, and is not particularly limited, but is preferably 0.1 to 20 mol%, more preferably 0.1 to 5 mol% based on the maleic anhydride compound.

As the sensitizer, the above benzophenone derivatives, acetophenone derivatives, or benzaldehyde derivatives may be used independently, or one or more of them may be used in coexistence. desirable.

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

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

The organic solvent used for washing the filtrate is not particularly limited, but the use of a solvent with high product solubility is not preferable because the target compound migrates to the filtrate and the recovery rate decreases. For this reason, as the organic solvent used for washing the filtrate, methyl formate, ethyl formate, n-propyl formate, i-propyl formate, n-butyl formate, i- formate, which are reaction solvents used for photodimerization reaction, are used. 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, n-butyl propionate, propionic acid i-butyl, ethylene glycol diformate, ethylene glycol diacetate, ethylene glycol dipropionate, dimethyl carbonate, diethyl carbonate, etc., or a solvent that does not dissolve or react with the product, such as toluene, hexane , heptane, acetonitrile, acetone, chloroform, acetic anhydride, these mixed solvents, etc. are mentioned. Among them, ethyl acetate, dimethyl carbonate, acetic anhydride and the like are preferable, and ethyl acetate or dimethyl carbonate is more preferable.

Example

Examples will be given below to specifically explain the present invention, but the present invention is not limited thereto.

In addition, the analysis method used in the Example is as follows.

<GC analysis conditions>

Device: GC-2010 Plus (manufactured by SHIMADZU),

Column: DB-1 (manufactured by GL Sciences) 0.25 mm × 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 (20 min) - 40 °C/min - 220 °C (15 min), split Ratio: 1:50, internal standard: butyl lactate.

< ^1H NMR analysis conditions>

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

Solvent: DMSO-d6, Inner standard: tetramethylsilane (TMS).

<Melting point analysis conditions>

Apparatus: DSC1 (manufactured by Mettler-Toledo),

Temperature: 35 °C - 5 °C/min - 400 °C, Pan: Au (closed).

Comparative Example 1

[Formula 4]

Under a nitrogen atmosphere, in a 30 ml Pyrex (registered trademark) glass test tube, citraconic anhydride (CA) 0.10 g (0.89 mmol), and methyl acetate 20 g (270 mmol, 200 wt pear) was injected and dissolved by stirring with a magnetic stirrer. Thereafter, the mixture was irradiated with a 100 W high-pressure mercury vapor lamp for 4 hours while stirring at 5 to 10°C. As a result of quantitative analysis of the reaction solution by gas chromatography after irradiation, the residual rate of citraconic acid anhydride (CA) was 29.9%. Further, 2 g of the reaction liquid in the reactor was sampled, and the solvent was distilled off at 70 to 80 Torr with an evaporator. 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 = 42.6: 57.4) was confirmed.

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

[Formula 5]

In a nitrogen atmosphere, in a 30 ml Pyrex (registered trademark) glass test tube, 0.10 g (0.89 mmol) of citraconic acid anhydride (CA), and 20 g (222 mmol) of citraconic acid anhydride (CA), 200 wt pear) was injected and dissolved by stirring with a magnetic stirrer. Thereafter, the mixture was irradiated with a 100 W high-pressure mercury vapor lamp for 4 hours while stirring at 15 - 20°C. As a result of quantitative analysis of the reaction solution by gas chromatography after irradiation, the residual rate of citraconic acid anhydride (CA) was 26.2%. Further, 2 g of the reaction liquid in the reactor was sampled, and the solvent was distilled off at 70 to 80 Torr with an evaporator. 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) was confirmed.

Comparative Examples 2 to 28 and Example 2

A series of operations were carried out in the same manner as in Comparative Example 1 by adding 200 wt times of each solvent relative to citraconic acid anhydride (CA), and in the same manner as in Comparative Example 1, the remaining ratio of citraconic acid anhydride (CA), And the production ratio of 1,3-DM-CBDA and 1,2-DM-CBDA (1,3-DM-CBDA: 1,2-DM-CBDA) was calculated.

The solvent, temperature, by-product amount and result are shown in the table below. In addition, the residual ratio of citraconic acid anhydride and the production ratio of 1,3-DM-CBDA and 1,2-DM-CBDA in the reaction solution obtained here were calculated, together with the results obtained in Comparative Example 1 and Example 1. shown in the table. In addition, the reaction rate in the table|surface was calculated from the number of moles of citraconic acid used, and the residual rate of citraconic acid at the time of reaction for 4 hours.

Example 3

[Formula 6]

Under a nitrogen atmosphere, in a 300 ml Pyrex (registered trademark) glass five-neck flask, 35.0 g (312 mmol) of citraconic acid anhydride (CA), and 152 g (1682 mmol) of citraconic acid anhydride (CA) 4.33 wt times) was injected and dissolved by stirring with a magnetic stirrer. Thereafter, the mixture was irradiated with a 100 W high-pressure mercury lamp for 48 hours while stirring at 10 - 15°C. The reaction liquid was confirmed to have a raw material residual rate of 23.7% by gas chromatography analysis. Then, the precipitated white crystals were taken out by filtration at 10 - 15°C, and these crystals were washed twice with 43.8 g of ethyl acetate (497 mmol, 1.25 wt times citraconic anhydride (CA)). By drying this under reduced pressure, 8.1 g of white crystals (23.1% yield) were obtained. This crystal was determined by ¹ H NMR analysis 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 ) was confirmed. In addition, the obtained crystals, filtrate, and washing liquid were quantitatively analyzed by ¹ H NMR analysis and gas chromatography, respectively, and the mass balance with respect to the injected amount was 88.9%.

Example 4

[Formula 7]

In a nitrogen atmosphere, in a 30 ml Pyrex (registered trademark) glass test tube, citraconic anhydride (CA) 0.10 g (0.89 mmol), benzophenone (BP) 0.020 g (0.11 mmol, citraconic anhydride (CA) 20% by mass) and 20 g (222 mmol, 200 times by mass relative to citraconic acid anhydride (CA)), and stirred with a magnetic stirrer to dissolve. Thereafter, the mixture was irradiated with a 100 W high-pressure mercury vapor lamp for 4 hours while stirring at 10 - 15°C. As a result of quantitative analysis of the reaction solution by gas chromatography after irradiation, the residual rate of citraconic acid anhydride (CA) was 3.9%. Further, 2 g of the reaction liquid in the reactor was sampled, and the solvent was distilled off at 70 to 80 Torr with an evaporator. 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 by ¹ H NMR analysis). ) was confirmed.

Example 5

A series of operations were carried out by adding 4,4'-dichlorobenzophenone (DClBP) as a sensitizer in the same way as in Example 4, and in the same manner as in Comparative Example 1, the residual ratio of citraconic acid anhydride (CA), And the production ratio of 1,3-DM-CBDA and 1,2-DM-CBDA (1,3-DM-CBDA: 1,2-DM-CBDA) was calculated.

The solvent, temperature, sensitizer, by-product amount and results are shown in the table below. In addition, the residual ratio of citraconic acid anhydride and the production ratio of 1,3-DM-CBDA and 1,2-DM-CBDA in the reaction solution obtained here were calculated, and the results obtained in Example 4 are shown in a table. In addition, the reaction rate in the table|surface was calculated from the number of moles of citraconic acid used, and the residual rate of citraconic acid at the time of reaction for 4 hours.

Reference example 1

[Formula 8]

A mixture containing 1,3-DM-CBDA and 1,2-DM-CBDA (1,3-DM-CBDA: 18.3 g of 1,2-DM-CBDA = 85:15) and 92 g of acetic anhydride were charged, and suspended at 25°C while stirring with a magnetic stirrer. After that, it was heated to reflux (130°C) for 4 hours. Thereafter, 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, washed twice with 18 g of ethyl acetate, and then dried under reduced pressure to obtain 14.4 g of highly pure 1,3-DM-CBDA (yield: 92%). Got it. This determination was made by ¹ H NMR analysis, indicating 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. Confirmed.

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 ℃

The cyclobutanetetracarboxylic acid derivative obtained in the present invention is a compound useful as a raw material for polyamic acid and polyimide, etc. The polyimide is used in electronic materials such as liquid crystal display elements and semiconductor protective materials and insulating materials. It is industrially and widely used as a resin composition to be.

In addition, all the content of the JP Patent application 2014-007186, the claim, and the abstract for which it applied on January 17, 2014 is referred here, and it takes in as an indication of the specification of this invention.

Claims (1)

All inventions described in the specification herein.