Method for producing norborneneimide derivatives

Abstract

This invention provides a method for producing norborneneimide derivatives using a simple manufacturing process and with a high reaction conversion rate. [Solution] A method for producing norborneneimide derivatives, comprising a reaction step of reacting a 5-norbornene-2,3-dicarboxylic acid anhydride represented by the following formula (1) with an aniline compound in the presence of an organic solvent with a boiling point of 120°C or higher. JPEG2026085818000009.jpg48170

Description

[Technical Field]

[0001] This invention relates to a method for producing norborneneimide derivatives. [Background technology]

[0002] Hydrogenated cyclic olefin ring-opening polymers, obtained by hydrogenating cyclic olefin ring-opening polymers resulting from ring-opening polymerization of cyclic olefin monomers, are widely used as molding materials for optical elements such as optical lenses due to their excellent transparency, low moisture absorption, heat resistance, insulation, and chemical resistance. In recent years, among cyclic olefin ring-opening polymers, development has been carried out by ring-opening polymerization of norborneneimide derivatives as cyclic olefin monomers, and various synthesis methods for norborneneimide derivatives have been proposed.

[0003] For example, Non-Patent Document 1 describes a method for synthesizing N-phenyl-exo,endo-norbornene 5,6-dicarboximide as a norborneneimide derivative by reacting norbornene-5,6-dicarboxylic acid anhydride with aniline in the presence of toluene, then filtering and drying the resulting precipitate to obtain amicoic acid, and then heating the amicoic acid, sodium acetate anhydride, and acetic anhydride. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Gas Transport and Ionic Transport in Membranes Based on Polynorbornenes with Functionalized Imide Side Groups, Macromolecules 2007, 40, 563-570 [Overview of the project] [Problems that the invention aims to solve]

[0005] In recent years, there has been a demand for the mass industrial production of norborneneimide derivatives as raw materials for cyclic olefin ring-opening polymers. Therefore, the inventors investigated a simple manufacturing process to produce norborneneimide derivatives with a high reaction conversion rate. Specifically, the inventors investigated reacting 5-norbornene-2,3-dicarboxylic acid anhydride with an aniline compound without using a solvent. However, it was found that while norborneneimide derivatives could be obtained with a high reaction conversion rate without a solvent, problems arose such as the reaction solution solidifying and becoming impossible to stir. Therefore, the inventors conducted further studies and conceived the idea of ​​increasing the amount of aniline compound, a liquid raw material, to improve the fluidity of the reaction solution and suppress solidification. However, it was found that while increasing the amount of aniline compound without using a solvent could suppress solidification of the reaction solution, it also increased the number of steps required to remove unreacted aniline compound after the reaction, thus not simplifying the manufacturing process. Furthermore, the conventional technique described above, which uses toluene as a solvent, could not obtain norborneneimide derivatives with a high reaction conversion rate.

[0006] Therefore, the present invention aims to provide a method for producing norborneneimide derivatives with a high reaction conversion rate using a simple manufacturing process. [Means for solving the problem]

[0007] The inventors diligently conducted research with the aim of solving the above problems. The inventors have found that when producing norborneneimide derivatives by reacting 5-norbornene-2,3-dicarboxylic acid anhydride with a predetermined aniline compound, using an organic solvent with a boiling point above a predetermined temperature simplifies the manufacturing process while enabling high reactivity conversion of the norborneneimide derivatives. We discovered that it is possible to manufacture it at a rate, and thus completed the present invention.

[0008] That is, the present invention aims to advantageously solve the above problems. The present invention provides a method for producing a norbornene imide derivative, comprising a reaction step of reacting a 5-norbornene-2,3-dicarboxylic anhydride represented by the following formula (1) with an aniline compound represented by the following formula (2) in the presence of an organic solvent having a boiling point of 120 °C or higher. [Chemical formula] [Chemical formula] (In formula (2), R1 to R5 each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an alkyl group optionally having a substituent, a cycloalkyl group optionally having a substituent, an alkenyl group optionally having a substituent, an alkynyl group optionally having a substituent, an alkoxy group optionally having a substituent, an aromatic hydrocarbon ring group optionally having a substituent, or an aromatic heterocyclic group optionally having a substituent, and two or more of R1 to R5 may combine to form a ring.) In the present invention, "optionally having a substituent" means that it may have one or more substituents.

[0009] [2] In the method for producing a norbornene imide derivative according to [1] above, it is preferable that the SP value of the organic solvent is 8.5 (cal / cm 3 ,

[0010] , , <0,000,095> ). 1 / 2 or more and 12.5 (cal / cm 3 ). 1 / 2 If the SP value is within the above predetermined range, the reaction conversion rate to the norbornene imide derivative can be further improved.

[0010] [3] In the method for producing a norbornene imide derivative according to [1] or [2] above, it is preferable that the organic solvent has at least one amide group. By using an organic solvent having at least one amide group, the reaction conversion rate to the norbornene imide derivative can be further improved.

[0011] [4] In any of the methods for producing the norborneneimide derivative described in [1] to [3] above, it is preferable that the organic solvent is at least one selected from the group consisting of dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. Using the above-mentioned predetermined organic solvent can further improve the reaction conversion rate to the norborneneimide derivative.

[0012] [5] In the method for producing any of the norborneneimide derivatives described in [1] to [4] above, it is preferable that the reaction step is carried out by a dehydration condensation reaction at 110°C or higher. If the reaction step is a dehydration condensation reaction at a reaction temperature of 110°C or higher, the conversion rate to the norborneneimide derivative can be further improved.

[0013] [6] A method for producing any norborneneimide derivative described in [1] to [5] above, wherein the SP value of the organic solvent is 9.5 (cal / cm³). 3 ) 1 / 2 The following is preferable, and it is preferable to divide the aniline compound into two or more parts and react it with the 5-norbornene-2,3-dicarboxylic acid anhydride. Even when an organic solvent with an SP value of less than or equal to the above predetermined value is used, the decrease in the reaction conversion rate to norborneneimide derivative can be suppressed by dividing the aniline compound into two or more parts and reacting it.

[0014] [7] The method for producing any norborneneimide derivative according to any of the above [1] to [6] preferably further includes a purification step of purifying the norborneneimide derivative obtained in the reaction step using at least one adsorbent selected from the group consisting of activated clay, silica gel, activated alumina, and activated carbon. Further purification of the above step can effectively remove impurities that cause discoloration of the norborneneimide derivative, and the norborneneimide derivative can be suitably used as a raw material for cyclic olefin ring-opening polymers that require high transparency.

[0015] [8] In the method for producing any of the norborneniimide derivatives described in [1] to [7] above, it is preferable that the norborneniimide derivative is N-2,6-diisopropylphenyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide or N-2,6-dimethylphenyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide. According to the method for producing norborneniimide derivatives of the present invention, N-2,6-diisopropylphenyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide or N-2,6-dimethylphenyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide, which are suitable as raw materials for cyclic olefin ring-opening polymers, can be suitably produced. [Effects of the Invention]

[0016] According to the present invention, it is possible to provide a method for producing norborneneimide derivatives with a high reaction conversion rate using a simple manufacturing process. [Modes for carrying out the invention]

[0017] Embodiments of the present invention will be described in detail below. The method for producing norborneneimide derivatives of the present invention can be suitably used to produce norborneneimide derivatives (norborneneimide monomers) as raw materials for cyclic olefin ring-opening polymers used as molding materials for optical elements such as optical lenses.

[0018] (Method for producing norborneneimide derivatives) The present invention provides a method for producing norborneneimide derivatives (hereinafter also simply referred to as "the present invention's method") which includes a reaction step of reacting a 5-norbornene-2,3-dicarboxylic acid anhydride represented by the following formula (1) with an aniline compound represented by the following formula (2) in the presence of an organic solvent having a boiling point of 120°C or higher, and optionally further includes other steps such as a purification step. [ka] [ka] (In formula (2), R1 to R5 each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an optionally substituted alkyl group, an optionally substituted cycloalkyl group, an optionally substituted alkenyl group, an optionally substituted alkynyl group, an optionally substituted alkoxy group, an optionally substituted aromatic hydrocarbon ring group, or an optionally substituted aromatic heterocyclic group, and two or more of R1 to R5 may be bonded together to form a ring.)

[0019] Here, the halogen atoms that can constitute R1 to R5 are not particularly limited, and examples include chlorine atoms, fluorine atoms, bromine atoms, iodine atoms, etc.

[0020] The alkyl groups that may have substituents to constitute R1 to R5 are not particularly limited and include alkyl groups having 1 to 10 carbon atoms that may have substituents. The alkyl groups having 1 to 10 carbon atoms that may have substituents can be linear or branched, and examples include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-pentyl group, neopentyl group, hexyl group, octyl group, nonyl group, and decyl group. Among these, methyl group and isopropyl group are preferred. Specific examples of substituents in "alkyl groups having 1 to 10 carbon atoms that may have substituents" include, for example, halogen atoms such as chlorine, fluorine, bromine, and iodine; cyano groups; nitro groups; unsubstituted alkyl groups having 1 to 10 carbon atoms such as methyl, ethyl, and propyl groups; unsubstituted alkenyl groups having 2 to 6 carbon atoms such as vinyl and allyl groups; alkyl groups having 1 to 10 carbon atoms in which one or more hydrogen atoms are substituted with halogen atoms such as fluorine, such as trifluoromethyl groups; alkoxy groups having 1 to 10 carbon atoms such as methoxy, ethoxy, and isopropoxy groups; and so on. The number of substituents may be one or more. If there are multiple substituents, they may be the same or different from each other.

[0021] The cycloalkyl groups that may have substituents to constitute R1 to R5 are not particularly limited and include cycloalkyl groups with 3 to 12 carbon atoms that may have substituents. Examples of cycloalkyl groups with a range of 3 to 12 include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cyclooctyl groups. Specific examples of substituents in "cycloalkyl groups having 3 to 12 carbon atoms that may have substituents" include the same substituents that can be present in the aforementioned "alkyl groups having 1 to 10 carbon atoms that may have substituents." The number of substituents may be one or multiple. If there are multiple substituents, they may be the same or different from one another.

[0022] The alkenyl group that may have substituents to constitute R1 to R5 is not particularly limited and includes alkenyl groups having 2 to 10 carbon atoms that may have substituents. The alkenyl group having 2 to 10 carbon atoms that may have substituents can be linear or branched, and examples include vinyl group, propenyl group, isopropenyl group, butenyl group, isobutenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, and decenyl group. Specific examples of substituents for the "alkenyl group having 2 to 10 carbon atoms which may have substituents" include the same substituents that the "alkyl group having 1 to 10 carbon atoms which may have substituents" described above may have. The number of substituents may be one or more. If there are multiple substituents, they may be the same or different from each other.

[0023] The alkynyl groups that may have substituents to constitute R1 to R5 are not particularly limited and include alkynyl groups having 2 to 10 carbon atoms that may have substituents. The alkynyl groups having 2 to 10 carbon atoms that may have substituents can be linear or branched, and examples include ethynyl group, propynyl group, 2-propynyl group (propargyl group), butynyl group, 2-butynyl group, 3-butynyl group, pentynyl group, 2-pentynyl group, hexynyl group, 5-hexynyl group, heptynyl group, octinyl group, 2-octinyl group, nonanyl group, decanyl group, 7-decanyl group, and the like. Specific examples of substituents for the "alkynyl group having 2 to 10 carbon atoms which may have substituents" include the same substituents that the "alkyl group having 1 to 10 carbon atoms which may have substituents" described above may have. The number of substituents may be one or more. If there are multiple substituents, they may be the same or different from each other.

[0024] The alkoxy groups that may constitute R1 to R5 are not particularly limited and include alkoxy groups having 1 to 10 carbon atoms that may have substituents. The alkoxy groups having 1 to 10 carbon atoms that may have substituents can be linear or branched, and examples include methoxy groups, ethoxy groups, propoxy groups, isopropoxy groups, butoxy groups, octoxy groups, etc. Specific examples of substituents for the "alkoxy group having 1 to 10 carbon atoms which may have substituents" include the same substituents that the "alkyl group having 1 to 10 carbon atoms which may have substituents" described above may have. The number of substituents may be one or more. If there are multiple substituents, they may be the same or different from each other.

[0025] The aromatic hydrocarbon ring groups that may have substituents that can constitute R1 to R5 are not particularly limited and include aromatic hydrocarbon ring groups having 6 to 30 carbon atoms that may have substituents. Examples of aromatic hydrocarbon ring groups having 6 to 30 carbon atoms that may have substituents include phenyl groups and naphthyl groups. Examples include groups such as anthracenyl groups. Specific examples of substituents for the "aromatic hydrocarbon ring group having 6 to 30 carbon atoms which may have substituents" include the same substituents that the "alkyl group having 1 to 10 carbon atoms which may have substituents" described above may have. The number of substituents may be one or more. If there are multiple substituents, they may be the same or different from each other.

[0026] The aromatic heterocyclic groups that may have substituents that can constitute R1 to R5 are not particularly limited and include aromatic heterocyclic groups having 6 to 30 carbon atoms that may have substituents. Examples of aromatic hydrocarbon ring groups having 6 to 30 carbon atoms that may have substituents include furanyl group, 1-benzofuranyl group, 2-benzofuranyl group, pyrrolyl group, indolyl group, thienyl group, benzo[c]thienyl group, benzo[b]thienyl group, pyridyl group, pyrazinyl group, pyrimidinyl group, triazolyl group, triazinyl group, pyrrolyl group, imidazolyl group, pyrazolyl group, thiazolyl group, benzothiazolyl group, oxazolyl group, and benzoxazolyl group. Specific examples of substituents for the "aromatic heterocyclic group having 6 to 30 carbon atoms that may have substituents" include the same substituents that the "alkyl group having 1 to 10 carbon atoms that may have substituents" described above may have. The number of substituents may be one or multiple. If there are multiple substituents, they may be the same or different from each other.

[0027] The ring formed by the bonding of two or more R1 to R5 may be monocyclic or polycyclic. The ring formed by the bonding of two or more R1 to R5 is not particularly limited and may include aromatic hydrocarbon rings, aromatic heterocyclic rings, non-aromatic hydrocarbon rings, and polycyclic fused rings formed by the fusion of two or more of these rings. Specific examples of the above-mentioned aromatic hydrocarbon ring are not limited to those mentioned above, but include aromatic hydrocarbon rings having 6 to 30 carbon atoms, such as benzene rings, naphthalene rings, and anthracene rings. Among these, benzene rings are preferred. Furthermore, aromatic heterocycles are not particularly limited and include aromatic heterocycles having 2 to 30 carbon atoms, such as furan rings, benzofuran rings, pyrrole rings, indole rings, thiophene rings, benzothiophene rings, pyridine rings, pyrazine rings, pyrimidine rings, triazole rings, triazine rings, pyrroline rings, imidazole rings, pyrazole rings, thiazole rings, benzothiazole rings, thienothiazole rings, oxazole rings, and benzoxazole rings. Furthermore, specific examples of non-aromatic hydrocarbon rings include cycloalkyl rings with 3 to 12 carbon atoms, such as cyclopropyl rings, cyclobutyl rings, cyclopentyl rings, cyclohexyl rings, and cyclooctyl rings.

[0028] In particular, among the aniline compounds represented by formula (2), compounds in which one or more of R1 to R5 in formula (2) are "alkyl groups having 1 to 10 carbon atoms which may have substituents" and the rest are hydrogen atoms are preferred, compounds in which two of R1 to R5 are "alkyl groups having 1 to 10 carbon atoms which may have substituents" and the rest are hydrogen atoms are more preferred, and compounds in which R1 and R5 are "alkyl groups having 1 to 10 carbon atoms which may have substituents" and the rest are hydrogen atoms are even more preferred. Furthermore, as the aniline compound represented by formula (2), from the viewpoint of obtaining N-2,6-dimethylphenyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide (hereinafter sometimes abbreviated as "NBXI"), which is suitably used as a norborneneimide derivative, a compound in which R1 and R5 in formula (2) are methyl groups and the remainder are hydrogen atoms (i.e., 2,6-dimethylaniline) is preferred. Also, as the aniline compound represented by formula (2), N-2,6-di- From the viewpoint of obtaining sopropylphenyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide (hereinafter sometimes abbreviated as "NBDII"), a compound in which R1 and R5 in formula (2) are isopropyl groups and the remainder are hydrogen atoms (i.e., 2,6-diisopropylaniline) is preferred. As for the aniline compound represented by formula (2), an aniline in which all of R1 to R5 in formula (2) are hydrogen atoms can be used in the production of N-phenyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide (sometimes abbreviated as "NBPI").

[0029] <Reaction Process> In the reaction step, 5-norbornene-2,3-dicarboxylic acid anhydride, used as a starting material, and the aniline compound are reacted in the presence of an organic solvent with a boiling point of 120°C or higher to obtain a norborneneimide derivative represented by the following formula (3). Specifically, the reaction between 5-norbornene-2,3-dicarboxylic acid anhydride and the aniline compound produces the corresponding amic acid, which is then dehydrated to obtain the norborneneimide derivative represented by the following formula (3) (dehydration condensation reaction). [ka] (In equation (3), the definitions of R1 to R5 are the same as those in equation (2).)

[0030] In the production method of the present invention, it is presumed that carrying out the reaction in the presence of an organic solvent with a boiling point of 120°C or higher suppresses the termination of the reaction at amic acid, thereby improving the reaction conversion rate to norborneneimide derivatives.

[0031] Furthermore, the manufacturing method of the present invention typically does not use catalysts or acid anhydrides such as sodium acetate anhydride or acetic anhydride in the reaction step. Also, the manufacturing method of the present invention typically does not include a step to isolate amic acid, which is a reaction intermediate, from the reaction solution.

[0032] The amount (moles) of the aniline compound used is not particularly limited, but it is preferably 1.0 times or more, more preferably 1.1 times or more, preferably 2.0 times or less, and more preferably 1.3 times or less, relative to the amount (moles) of 5-norbornene-2,3-dicarboxylic acid anhydride used. If the amount of the aniline compound used is above the lower limit, it reacts sufficiently with 5-norbornene-2,3-dicarboxylic acid anhydride, and the reaction conversion rate to norborneneimide derivative is further improved. Also, if the amount of the aniline compound used is below the upper limit, no excess unreacted aniline compound remains after the reaction, and as a result, the number of recrystallization steps described later can be reduced, further simplifying the manufacturing process.

[0033] [organic solvent] The above organic solvent is required to have a boiling point of 120 °C or higher. When an organic solvent with a boiling point of less than 120 °C is used, the reaction conversion rate to the norbornene imide derivative deteriorates. From the viewpoint of further increasing the reaction conversion rate to the norbornene imide derivative, the boiling point of the organic solvent is preferably 125 °C or higher, more preferably 130 °C or higher, preferably 210 °C or lower, and more preferably 160 °C or lower. In the present invention, the boiling point of the organic solvent refers to the boiling point at normal pressure. The organic solvent may be used alone or in combination of two or more in any ratio.

[0034]

[0035] Further, from the viewpoint of increasing the reaction rate to shorten the reaction time and further increasing the reaction conversion rate to the norbornene imide derivative, the above organic solvent has an SP value of 8.5 (cal / cm 3 ) 1 / 2 or higher, preferably 9.5 (cal / cm 3 ) 1 / 2 or higher, more preferably 16.0 (cal / cm 3 ) 1 / 2 or lower, preferably 12.5 (cal / cm 3 ) 1 / 2 or lower, more preferably.

[0036] Here, the SP value refers to the solubility parameter. The SP value can be calculated using the method described in Hansen Solubility Parameters A User's Handbook, 2nd Edition (CRCPress). Furthermore, the SP value of an organic compound can also be estimated from its molecular structure. Specifically, it can be calculated using simulation software that can calculate the SP value from the SMILE formula (for example, "HSPiP" (http: / / www.hansen-solubility.com)). This simulation software determines the SP value based on the theory described in "Hansen SOLUBILITY PARAMETERS A User's Handbook Second Edition" by Charles M. Hansen.

[0037] Organic solvents with an SP value within the above range are not particularly limited as long as they have a boiling point of 120°C or higher, such as o-xylene (SP value: 8.8 (cal / cm³)). 3 ) 1 / 2 ), m-xylene (SP value: 8.8 (cal / cm³) 3 ) 1 / 2 ), p-xylene (SP value: 8.8 (cal / cm³) 3 ) 1 / 2 ), chlorobenzene (SP value: 9.5 (cal / cm³) 3 ) 1 / 2 ), dimethylacetamide (SP value: 10.8 (cal / cm³) 3 ) 1 / 2 ), dimethylformamide (SP value: 12.1 (cal / cm³) 3 ) 1 / 2 ), N-methylpyrrolidone (SP value: 11.3 (cal / cm³) 3 ) 1 / 2 ), cyclohexanone (SP value: 9.9 (cal / cm³) 3 ) 1 / 2 ), cyclohexanol (SP value: 11.4 (cal / cm³) 3 ) 1 / 2 ), butyl acetate (SP value: 8.5 (cal / cm³) 3 ) 1 / 2), diethylformamide (SP value: 10.6 (cal / cm³) 3 ) 1 / 2 ) are some examples.

[0038] Here, the SP value of o-xylene, etc. is 9.5 (cal / cm³). 3 ) 1 / 2 When using the following organic solvents, the aniline compound is divided into two or more parts, preferably two parts, to form 5-norbo It is preferable to react with runen-2,3-dicarboxylic anhydride. For example, when the aniline compound is divided into two parts and reacted with 5-norbornene-2,3-dicarboxylic anhydride, the 5-norbornene-2,3-dicarboxylic anhydride is reacted with a portion of the aniline compound, and then the remaining aniline compound is added and reacted further with 5-norbornene-2,3-dicarboxylic anhydride. SP value is 9.5 (cal / cm³) 3 ) 1 / 2 When using the following organic solvents, adding the aniline compound all at once may slow down the reaction and reduce the conversion rate. However, by dividing the aniline compound into two or more parts and reacting it with 5-norbornene-2,3-dicarboxylic acid anhydride, the reaction can be accelerated and the decrease in the conversion rate can be suppressed.

[0039] Here, when the aniline compound is reacted with 5-norbornene-2,3-dicarboxylic anhydride in two separate reactions, it is preferable that the amount (moles) of the aniline compound used in the first reaction is 1.1 times the amount (moles) of the 5-norbornene-2,3-dicarboxylic anhydride used, and that the amount (moles) of the aniline compound used in the second reaction is 0.2 times the amount (moles) of the 5-norbornene-2,3-dicarboxylic anhydride used. Furthermore, for the second aniline compound, it is preferable to react the first aniline compound with 5-norbornene-2,3-dicarboxylic acid anhydride for at least 10 hours before reacting it with 5-norbornene-2,3-dicarboxylic acid anhydride.

[0040] Furthermore, it is preferable that the above organic solvent has at least one amide group. Using an organic solvent having at least one amide group can further increase the reaction conversion rate to norborneneimide derivatives. The reason for this is not entirely clear, but it is presumed that because the reaction intermediate, amic acid, also has an amide group, the solubility of amic acid in the organic solvent is improved, and as a result, amic acid becomes completely dissolved in the organic solvent (a state of complete dissolution in which it can be visually confirmed that no solid material is present during the reaction), and the dehydration reaction from amic acid to norborneneimide derivatives proceeds smoothly.

[0041] Organic solvents having at least one amide group are not particularly limited as long as they have a boiling point of 120°C or higher, and examples include dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and diethylformamide.

[0042] From the viewpoint of further increasing the reaction conversion rate to norborneneimide derivatives, the above organic solvent is preferably at least one selected from the group consisting of dimethylformamide, dimethylacetamide, and N-methylpyrrolidone, more preferably dimethylformamide or dimethylacetamide, and particularly preferably dimethylformamide.

[0043] The amount (mass) of the organic solvent used is not particularly limited, but from the viewpoint of further simplifying the manufacturing process and further increasing the reaction conversion rate to norborneneimide derivatives, it is preferably 1 or more times the amount (mass) of 5-norbornene-2,3-dicarboxylic acid anhydride used, preferably 10 times or less, and more preferably 5 times or less.

[0044] [Reaction temperature] The reaction temperature (internal temperature of the reaction solution) in the above reaction step is not particularly limited. From the viewpoint of further increasing the reaction conversion rate to norborneneimide derivatives, the reaction is preferably carried out at 110°C or higher, more preferably at 120°C or higher, and even more preferably at 135°C or higher. The upper limit of the reaction temperature is not particularly limited, and the reaction can be carried out, for example, at 150°C or lower. The above reaction step is usually carried out at a temperature below the boiling point of the above organic solvent.

[0045] [Reaction pressure] The above reaction process is usually carried out under atmospheric pressure.

[0046] [Reaction time] The time of the above reaction step (reaction time) is not particularly limited, but from the viewpoint of further increasing the reaction conversion rate to norborneneimide derivatives, it is preferably 3 hours or more, more preferably 5 hours or more, preferably 21 hours or less, and more preferably 15 hours or less.

[0047] <Other processes> Other steps that may be optionally included in the manufacturing method of the present invention are not particularly limited and include, for example, a washing and extraction step, a purification step using an adsorbent, a recrystallization step, and a drying step. That is, the manufacturing method of the present invention may include at least one other step selected from the group consisting of a purification step, a recrystallization step, and a drying step. In particular, from the viewpoint of removing impurities that cause discoloration and obtaining norborneneimide derivatives as suitable raw materials for cyclic olefin ring-opening polymers that require high transparency, it is preferable that the manufacturing method of the present invention includes a purification step.

[0048] [Washing and Extraction Process] The washing and extraction step is performed after the reaction step, and involves dissolving the norborneneimide derivative obtained in the reaction step in a mixed solvent of water and an organic solvent, and then removing the aqueous phase to obtain an organic phase containing the norborneneimide derivative. The organic solvent is not particularly limited, and aromatic hydrocarbons such as toluene can be used.

[0049] [Refining process] In the purification process, the norborneneimide derivative obtained in the above reaction step is purified using an adsorbent. The purification using adsorbents is not particularly limited and includes, for example, purification by column chromatography using an adsorbent in the column, and purification by filtration using an adsorbent. Among these, purification by filtration using an adsorbent is preferred from the viewpoint of effectively removing impurities that cause discoloration and suppressing discoloration. In the case of purification by column chromatography, the reaction solution containing the norborneneimide derivative obtained in the above reaction step, or the solution obtained by adding a solvent to the organic phase containing the norborneneimide derivative obtained in the above washing and extraction step (hereinafter referred to as "the substance to be treated") is passed through a column packed with an adsorbent. In the case of purification by filtration using an adsorbent, an adsorbent is added to the substance to be treated and filtered. The purification step is preferably performed on the substance to be treated obtained in the above washing and extraction step. That is, the purification step is preferably performed immediately after the above washing and extraction step.

[0050] The adsorbent is not particularly limited and includes activated clay, silica gel, activated alumina, and activated carbon. These adsorbents may be used individually or in combination of two or more. Preferably, the adsorbent is selected from the group consisting of activated clay, silica gel, activated alumina, and activated carbon, with activated clay being more preferred. The amount of adsorbent used is not particularly limited, but when purification is performed by filtration, it is preferably 20% by mass or more, more preferably 25% by mass or more, and preferably 30% by mass or less relative to the material to be treated.

[0051] The solvent used for purification is not particularly limited, and organic solvents such as hydrocarbons like heptane and toluene; ethers like methyl tert-butyl ether; nitriles like acetylnitrile; ketones like acetone and methyl ethyl ketone; esters like ethyl acetate can be used. Two or more of these solvents can be used in combination. Preferably, the solvent is toluene, methyl ethyl ketone, or heptane, and more preferably a mixed solvent of toluene and heptane, or a mixed solvent of methyl ethyl ketone and heptane. The concentration of the solvent in the material to be treated is not particularly limited, but is more preferably 5% by mass or more, more preferably 10% by mass or more, and preferably 15% by mass or less.

[0052] The purification temperature is not particularly limited, but it is preferable to perform the purification at room temperature. The purification time (contact time with the adsorbent) is also not particularly limited, but it is preferable to have a time of 3 hours or more.

[0053] Impurities that cause discoloration cannot usually be removed by other purification methods such as recrystallization without the use of adsorbents, but they can be effectively removed by purification using the above-mentioned adsorbent.

[0054] [Recrystallization process] In the recrystallization step, the material to be treated is purified by recrystallization. Recrystallization is not particularly limited and can be carried out by conventionally known methods. Specifically, recrystallization can be carried out by heating the material to be treated to, for example, 70°C, then cooling it to 0°C to precipitate crystals of norborneneimide derivatives, and then separating the obtained crystals by centrifugal filtration or the like. This allows for effective removal of unreacted aniline compounds and other impurities. The solvent used for recrystallization is not particularly limited; for example, those described above in the "Purification Process" section can be used. Among these, heptane is preferred.

[0055] The recrystallization step may be performed on materials that have not been subjected to the purification step, or on materials that have been subjected to the purification step. More specifically, the recrystallization step may be performed immediately after the reaction step, immediately after the washing and extraction step, or immediately after the purification step. Among these, it is preferable to perform the recrystallization step immediately after the purification step. The materials to be treated may be concentrated before performing the recrystallization step.

[0056] In the manufacturing method of the present invention, since the above-mentioned organic solvent is used in the reaction step, solidification of the reaction solution can be suppressed even without using a large amount of liquid aniline compound. Therefore, in the manufacturing method of the present invention, it is not necessary to use a large amount of aniline compound, and it is usually not necessary to perform the recrystallization step to remove unreacted aniline compound multiple times. In the manufacturing method of the present invention, from the viewpoint of further simplifying the manufacturing process, it is preferable to perform the recrystallization step only once.

[0057] [Drying process] In the drying step, the material to be treated is dried to remove liquid components such as organic solvents, and a dry norborneneimide derivative is obtained. The drying method is not particularly limited, and conventionally known methods can be used. The drying step is not particularly limited and may be performed on materials that have not been subjected to the purification step, or on materials that have been subjected to the purification step. More specifically, the drying step may be performed immediately after the reaction step, immediately after the washing and extraction step, immediately after the purification step, or immediately after the recrystallization step. In the manufacturing method of the present invention, it is preferable to perform the drying step only once from the viewpoint of further simplifying the manufacturing process. [Examples]

[0058] The present invention will be described in detail below based on examples, but the present invention is not limited to these examples. In the following description, "%" and "parts" used to express quantities refer to mass unless otherwise specified.

[0059] (Example 1) In a 300 ml four-necked flask, 20 g of 5-norbornene-2,3-dicarboxylic acid anhydride and 16.4 g of 2,6-dimethylaniline, along with 20 g of dimethylformamide (DMF) as an organic solvent, were charged and heated in an oil bath. The mixture was then reacted under reflux at an internal temperature of approximately 135°C for 5 hours (reaction step). Afterwards, the disappearance of the starting materials (100% conversion rate) was confirmed by gas chromatography, and the reaction solution was cooled. The reaction solution was in a state of complete dissolution, with no solid matter visible to the naked eye. Next, toluene and water were added to dissolve the obtained norborneneimide derivative, and the aqueous phase was filtered off (washing and extraction step). Activated clay as an adsorbent was added to the obtained organic phase, and insoluble matter and coloring components were removed by filtration (purification step). After concentrating the obtained filtrate to some extent, heptane was added, the mixture was cooled, and recrystallization was performed (recrystallization step). The obtained solid was filtered and dried to obtain 25.6 g of N-2,6-dimethylphenyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide (NBXI) (drying step). The crystalline purity of NBXI was 100%.

[0060] (Example 2) In a 300 ml four-necked flask, 20 g of 5-norbornene-2,3-dicarboxylic acid anhydride and 23.8 g of 2,6-diisopropylaniline, along with 20 g of dimethylformamide (DMF) as an organic solvent, were charged and heated in an oil bath. The mixture was reacted for 5 hours under reflux at an internal temperature of approximately 135°C (reaction step). Subsequently, the disappearance of the starting materials was confirmed by gas chromatography (conversion rate 100%), and the reaction solution was cooled. The reaction solution was in a state of complete dissolution, with no solid matter visible to the naked eye. Next, toluene and water were added to dissolve the obtained norborneneimide derivative, and the aqueous phase was filtered off (washing and extraction step). Activated clay as an adsorbent was added to the obtained organic phase, and insoluble matter and coloring components were removed by filtration (purification step). After concentrating the obtained filtrate to some extent, heptane was added, the mixture was cooled, and recrystallization was performed (recrystallization step). The obtained solid was filtered and dried to obtain 28.1 g of N-2,6-diisopropylphenyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide (NBDII). The crystalline purity of NBDII was 100%.

[0061] (Example 3) In a 300 ml four-necked flask, 20 g of 5-norbornene-2,3-dicarboxylic acid anhydride and 16.4 g of 2,6-dimethylaniline, along with 20 g of dimethylacetamide (DMA) as the organic solvent, were charged and heated in an oil bath. The reaction was carried out for 5 hours under reflux at an internal temperature of approximately 135-140°C (reaction step). Subsequently, the disappearance of the starting materials was confirmed by gas chromatography (100% reaction conversion rate), and the reaction solution was cooled. The reaction solution was in a state of complete dissolution, with no solid matter visible to the naked eye. Then, the same procedure as in Example 1 was performed to obtain NBXI. The crystalline purity of NBXI was 100%.

[0062] (Example 4) NBXI was obtained in the same manner as in Example 1, except that the amount of dimethylformamide (DMF) used as the organic solvent was changed from 20 g to 100 g. The crystalline purity of NBXI was 100%. The reaction solution was in a state of complete dissolution, as confirmed by visual inspection that no solid matter was present.

[0063] (Example 5) NBXI was obtained in the same manner as in Example 1, except that the amount of 2,6-dimethylaniline used as a raw material was changed from 16.4 g to 19.2 g. The crystalline purity of NBXI was 100%. The reaction solution was in a state of complete dissolution, as confirmed by visual inspection that no solid matter was present.

[0064] (Example 6) In a 500ml four-necked flask, add the raw material 5-norbornene-2,3-dicarbon 40 g of acid anhydride and 32.5 g of 2,6-dimethylaniline were charged with 200 g of o-xylene as an organic solvent and heated in an oil bath. The reaction was carried out for 21 hours under reflux at an internal temperature of approximately 150°C (reaction step). After that, the reaction conversion rate was confirmed to be 97% by gas chromatography and the mixture was cooled. The reaction solution was in a slurry state in which solid matter could be visually confirmed. Next, the reaction solution was concentrated to some extent, and methyl ethyl ketone (MEK) was added to dissolve the norborneneimide derivative. Activated clay was added as an adsorbent, and insoluble matter and coloring components were removed by filtration (purification step). After concentrating the obtained filtrate to some extent, heptane was added and the mixture was cooled and recrystallized (recrystallization step). The solid was filtered off and dried to obtain 39.1 g of NBXI (drying step). The crystalline purity of NBXI was 98.4%.

[0065] (Example 7) In a 300 ml four-necked flask, 40 g of 5-norbornene-2,3-dicarboxylic acid anhydride and 32.5 g of 2,6-dimethylaniline, along with 80 g of o-xylene as an organic solvent, were charged and heated in an oil bath. While refluxing at an internal temperature of approximately 150°C, 5.9 g of 2,6-dimethylaniline was added during the reaction. After 15 hours of reaction, the disappearance of the starting materials was confirmed by gas chromatography (100% reaction conversion rate), and the reaction solution was cooled. The reaction solution was in a slurry state in which solid matter could be visually confirmed. Next, the reaction solution was concentrated to some extent, and methyl ethyl ketone (MEK) was added to dissolve the norborneneimide derivative. Activated clay was then added as an adsorbent, and insoluble matter and coloring components were removed by filtration (purification step). After concentrating the obtained filtrate to some extent, heptane was added, and the mixture was cooled and recrystallized (recrystallization step). The solid was filtered and dried to obtain 39.1 g of NBXI (drying step). The crystalline purity of NBXI was 100%.

[0066] (Example 8) NBXI was obtained in the same manner as in Example 1, except that the reaction time was changed from 5 hours to 3 hours. The crystalline purity of NBXI was 100%. The reaction solution was in a state of complete dissolution, as confirmed by visual inspection that no solid matter was present.

[0067] (Comparative Example 1) 20 g of 5-norbornene-2,3-dicarboxylic acid anhydride and 16.4 g of 2,6-dimethylaniline were charged into a 300 ml four-necked flask and heated in an oil bath. After 3 hours of reaction at 120°C, the disappearance of the starting materials was confirmed by gas chromatography (100% reaction conversion rate), and the reaction mixture was cooled. The reaction mixture began to solidify during heating and solidified completely after cooling. Next, toluene was added to the obtained solid and heated to dissolve it. Heptane was added, the mixture was allowed to cool, and recrystallization was performed (recrystallization step). The obtained solid was filtered and dried to obtain 28.9 g of a pale purple solid (drying step). Methyl ethyl ketone (MEK) and activated clay as an adsorbent were added to the crude crystals, and insoluble matter and coloring components were removed by filtration (purification step). After concentrating the obtained filtrate to some extent, heptane was added, the mixture was cooled, and recrystallization was performed (recrystallization step). The solid was filtered and dried to obtain 27.7 g of NBXI (drying step). The crystal purity of NBXI was 100%.

[0068] (Comparative Example 2) In a 300 ml four-necked flask, 20 g of 5-norbornene-2,3-dicarboxylic acid anhydride and 26.6 g of 2,6-dimethylaniline were charged as starting materials and heated in an oil bath. After 3 hours of reaction, the disappearance of the starting materials was confirmed by gas chromatography (100% reaction conversion rate), and the mixture was cooled. The reaction solution was in a slurry state in which solid matter could be visually confirmed. Next, toluene was added and heated to dissolve, heptane was added and allowed to cool, and recrystallization was performed (recrystallization step). After repeating this recrystallization step once, the obtained solid was filtered and dried to obtain 27.5 g of a pale purple solid (crude crystal) (drying step). Methyl ethyl acetate was added to the obtained crude crystal. Luketone (MEK) and activated clay as an adsorbent were added, and insoluble matter and coloring components were removed by filtration (purification step). After concentrating the obtained filtrate to some extent, heptane was added, and the mixture was cooled and recrystallized (recrystallization step). The obtained solid was filtered and dried to obtain 27.7 g of NBXI (drying step). The crystalline purity of NBXI was 100%.

[0069] (Comparative Example 3) In a 500 ml four-necked flask, 20 g of 5-norbornene-2,3-dicarboxylic acid anhydride and 16.4 g of 2,6-dimethylaniline, along with 100 g of toluene as the organic solvent, were charged and heated in an oil bath. The reaction was carried out under reflux at an internal temperature of approximately 110°C for 3 hours. The reaction solution was in a slurry state in which solid matter could be visually confirmed. The reaction conversion rate was confirmed to be 78.4% by gas chromatography. No significant improvement in the reaction conversion rate was observed even when the reaction time was extended. Then, the purification, recrystallization, and drying steps were performed in the same manner as in Example 1 to obtain NBXI. [Table 1]

[0070] As shown in Table 1, in Examples 1 to 8, where 5-norbornene-2,3-dicarboxylic acid anhydride and an aniline compound were reacted in the presence of an organic solvent with a boiling point of 120°C or higher, norborneneimide derivatives can be produced with a high reaction conversion rate using a simple manufacturing process. In contrast, in Comparative Example 1, where the reaction was carried out without using an organic solvent, norborneneimide derivatives could be produced with a high reaction conversion rate. However, the reaction solution solidified, making stirring impossible. This necessitated dissolving the solid and performing multiple recrystallization steps, preventing the production of norborneneimide derivatives through a simple process. Similarly, in Comparative Example 2, where no organic solvent was used and the amount of aniline compound was increased, norborneneimide derivatives could be produced with a high reaction conversion rate. Furthermore, increasing the amount of liquid aniline compound suppressed solidification of the reaction solution. However, this necessitated multiple recrystallization and drying steps to remove excess aniline compound, preventing the production of norborneneimide derivatives through a simple process. Moreover, in Comparative Example 3, where toluene was used as the organic solvent, solidification of the reaction solution was suppressed, but norborneneimide derivatives could not be produced with a high reaction conversion rate. [Industrial applicability]

[0071] According to the present invention, it is possible to provide a method for producing norborneneimide derivatives with a high reaction conversion rate using a simple manufacturing process.

Claims

1. A method for producing a norborneneimide derivative, comprising a reaction step of reacting a 5-norbornene-2,3-dicarboxylic acid anhydride represented by the following formula (1) with an aniline compound represented by the following formula (2) in the presence of an organic solvent having a boiling point of 120°C or higher. 【Chemistry 1】 【Chemistry 2】 (In formula (2), R １ ~R ５ Each independently represents a hydrogen atom, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an optionally substituted alkyl group, an optionally substituted cycloalkyl group, an optionally substituted alkenyl group, an optionally substituted alkynyl group, an optionally substituted alkoxy group, an optionally substituted aromatic hydrocarbon ring group, or an optionally substituted aromatic heterocyclic group, R １ ~R ５ (Two or more of these may be joined together to form a ring.)

2. The SP value of the aforementioned organic solvent is 8.5 (cal / cm²). ３ ) １／２ More than 12.5 (cal / cm ３ ) １／２ The method for producing the norborneneimide derivative according to claim 1 is as follows:

3. The method for producing a norborneneimide derivative according to claim 1, wherein the organic solvent has at least one amide group.

4. The method for producing a norborneneimide derivative according to claim 1, wherein the organic solvent is at least one selected from the group consisting of dimethylformamide, dimethylacetamide, and N-methylpyrrolidone.

5. The method for producing a norborneneimide derivative according to claim 1, wherein the reaction step is carried out by a dehydration condensation reaction at 110°C or higher.

6. The SP value of the organic solvent is 9.5 (cal / cm ３ ). １／２ or less, A method for producing a norborneneimide derivative according to claim 1, comprising reacting the aniline compound with the 5-norbornene-2,3-dicarboxylic acid anhydride in two or more separate steps.

7. A method for producing a norborneneimide derivative according to claim 1, further comprising a purification step of purifying the norborneneimide derivative obtained in the reaction step using at least one adsorbent selected from the group consisting of activated clay, silica gel, activated alumina, and activated carbon.

8. A method for producing a norborneniimide derivative according to any one of claims 1 to 7, wherein the norborneniimide derivative is N-2,6-diisopropylphenyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide or N-2,6-dimethylphenyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide.

Images