KR20030026612A - Process for Preparing Exo-rich Norbornene Ester - Google Patents

Abstract

PURPOSE: Provided is a process for producing exo-rich norbornene ester easily in a high yield by only controlling the reaction temperature without adding a catalyst and a solvent. CONSTITUTION: The exo-rich norbornene ester is produced by reacting cyclopentadiene, dicyclopentadiene, or a mixture thereof with methyl or butyl acrylate in the molar ratio of 1:1-1:10 at a temperature of 160-300deg.C for 0.5-24 hours under the pressure of 1-20 in the presence of a polymerization inhibitor selected from the group consisting of aniline, cyclohexane, phenol, 4-ethoxyphenol, nitrobenzene, hydroquinone, benzoquinone, copper dichloride, and 2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl.

Description

Process for Preparing Exorich Norbornene Ester {Process for Preparing Exo-rich Norbornene Ester}

The present invention relates to a method for producing an exorisch norbornene ester, and more particularly, comprising the step of reacting at 160 to 300 ℃ by mixing methyl or butyl acrylate to cyclopentadiene, dicyclopentadiene or a mixture thereof It relates to a method for producing an exorisch norbornene ester.

Norbornene esters are used as raw materials for thermoplastic norbornene polymers. This polymer is a new material that is used for digital video discs (DVD) and photoresist (PR) for ArF because various properties such as high transparency and low water absorption ability can be displayed for high density information storage.

In order to obtain the above characteristics, the chemical structure of the norbornene ester used as the monomer of the thermoplastic norbornene polymer is important. Therefore, there is a need for a synthetic technology that can control the ratio of norbornene isomers (endo and exo isomers). Norbornene esters are prepared by Diels-Alder reaction of cyclopentadiene with alpha-olefins, whereby a mixture of endo and exo isomers is made. When the endo compound is used during the polymerization of norbornene polymer, the functional group in the substituent of the endo compound reacts strongly with the metal catalyst first, so that the polymer is not formed by the double bond and the metal catalyst is combined to exist in the state. Previous studies have reported that metals used as catalysts form complexes with endo compounds before they participate in the reaction, so it is recommended to use exo-rich compounds for the polymerization of norbornene polymers. . In addition, since the physical properties of the polymer are improved when the polymer is prepared using a high purity exo compound, it is very important to establish reaction conditions for producing an exo rich compound in the synthesis of norbornene ester.

Looking at the method for the synthesis of norbornene ester by the reaction of cyclopentadiene and alkyl acrylate is known a method using a Lewis acid catalyst. Lewis acid catalysts are preferred because the donor-acceptor interaction between the dienophile and the catalyst can lower the energy gap and thus facilitate the reaction. As these catalysts, ZnCl ₂ , ZnBr ₂ , BF ₃ (OEt ₂ ), EtAlCl ₂ , Et ₂ AlCl, TiCl ₄ , AlCl ₃ , SnCl ₄ , SbCl _5, and the like have been reported. In 1984 Danishefsky et al. (Tetrah. Lett. 26 (21), 2507 (1985)) described Yb (fod) ₃ (where fod is tris (6,6,7,7,8,8,8-heptafluoro-). 2,2-dimethyl-3,5-octanedioonate) was subjected to Diels-Alder reaction of CH ₂ CHCHO and cyclopentadiene, with exo: endo = 1: 15, 86% yield. In the method using the Lewis acid catalyst, the reaction conditions were room temperature and the yield was relatively high, but exo: endo = 0.3: 0.7 or more could not be obtained. In addition, these catalysts have a disadvantage in that a relatively large amount of catalyst is required and side reactions such as isomerization and recombination occur. Meanwhile, clay (K10-Montmorillonite, EP-11), zeolite-HY, γ-alumina, Mg-silicate, kaolinite, and silica-alumina are used to overcome the problems caused by recovery and reuse of liquid phase catalysts such as Lewis acid catalyst. Methods using the catalyst system have been reported, for example, Mayoral et al. (Catal. Lett. 37 (1996) 261-266) reported that exo: endo = 2: 7 for norbornenemethyl esters in EP-11 catalysts. The results were reported. Different solvents can be used to control the exo: endo ratio, and Mayoral et al. (J. Mol. Catal. 68 (1991) L31-L34) exo by varying the type of solvent in the reaction of methyl acrylate and cyclopentadiene. It was found that the: endo ratio changed from 1: 11.2 to 1: 3.4. It has been reported that the use of supercritical water yields an exo: endo ratio of 1: 1.3 under the reaction conditions of 281 ° C. and 0.5 hours in the reaction of ethyl acrylate and cyclopentadiene (Kprzenski et al., Tetrahed. Lett. 38 (197) 5611). However, no method of preparing norbornene esters in which exo isomers are contained more than endo isomers has not been reported.

The present invention solves the problems of the prior art as described above, it is an object of the present invention to provide a method for producing the exoriche norbornene ester by controlling only the reaction temperature without adding a catalyst and a solvent.

That is, the present invention relates to a method for preparing an exorisch norbornene ester comprising mixing methyl or butyl acrylate with cyclopentadiene, dicyclopentadiene or a mixture thereof and reacting the mixture at 160 to 300 ° C.

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

The present invention relates to a method for producing a norbornene ester represented by the following general formula (1), more specifically cyclopentadiene, dicyclopentadiene or mixtures thereof with methyl acrylate or butyl acrylate Diels-Alder reaction exoriche It relates to a process for producing norbornene esters.

In the formula, R is a methyl group or a butyl group.

The present invention was completed by knowing that it is possible to prepare the exorisch norbornene ester by controlling the reaction temperature higher than room temperature when reacting cyclopentadiene and methyl acrylate or butyl acrylate.

In the present invention, the reaction temperature is controlled to 160 to 300 ° C., preferably 180 to 210 ° C., in order to produce exorican norbornene esters. If the reaction temperature is lower than 160 ℃ exoriche norbornene ester can not be prepared, if it exceeds 300 ℃ unreacted product increase or by-products increase to lower the yield of norbornene ester.

In addition, in the present invention, the reaction temperature is maintained at approximately 167 ℃ or more it is characterized in that the cyclopentadiene which is one of the raw materials for the production of norbornene ester can be used in place of the more stable form of the compound dicyclopentadiene. Since cyclopentadiene is generally unstable at room temperature and easily changed to dicyclopentadiene, it is very difficult to exist as pure cyclopentadiene. However, since dicyclopentadiene decomposes itself into two molecules of cyclopentadiene at 167 ° C. or higher to participate in the reaction, in the present invention, the cyclopentadiene can be used as a raw material for the reaction regardless of whether it is changed to dicyclopentadiene, Therefore, there is no need for a purification process from dicyclopentadiene to cyclopentadiene, thereby simplifying the process.

The reaction pressure is controlled above normal pressure. At pressures above atmospheric pressure, it has been found that the change in pressure does not affect the ratio of exo: endo.

The molar ratio of cyclopentadiene, dicyclopentadiene or a mixture thereof and methyl or butyl acrylate in the reactant is preferably adjusted to 1: 1 or more, preferably 1: 1 to 1:10. This is because there is a change in the progress and selectivity of the reaction. That is, when the ratio is 1: 1 or less, the yield of the reaction is low and the impurity is formed by polymerization of unreacted cyclopentadiene. Above 1:10, the amount of unreacted alkyl acrylate is too high, and it is not economical because the process for separating it takes a lot of load.

The reaction time is adjusted to 0.5 to 24 hours, preferably 1 to 16 hours. The reason is that it also affects the degree of reaction progression and the selectivity. That is, in the reaction within 0.5 hours, even if the reaction temperature is raised to 260 ℃, the excorial compound can not be obtained, if the reaction time is longer than 24 hours, the excorial compound can be obtained, but a lot of side reactions occur, the yield is lowered. In general, the longer the reaction time, the greater the exo: endo ratio but tends not to increase beyond a certain number.

In the present invention, a polymerization inhibitor may be added during the reaction in order to prevent the reactant and the product from polymerizing and polymerizing during the reaction. Specific examples of such polymerization inhibitors include aniline, cyclohexane, phenol, 4-ethoxyphenol, nitrobenzene, hydroquinone, benzoquinone, copper dichloride, and 2,2-di (4-tert-octylphenyl) -1-pi. A material selected from the group consisting of krillhydrazyl (2,2-di (4-tert-octylphenyl) -1-picrylhydrazyl) may be used, and preferably hydroquinone or benzoquinone is used, but is not limited thereto. . The addition amount of the polymerization inhibitor is preferably added so that the molar ratio of cyclopentadiene, dicyclopentadiene or mixtures thereof and the polymerization agent is in the range of 1: 0.001 to 1: 0.05, preferably 1: 0.002 to 1: 0.04. . However, the addition of the polymerization inhibitor is not essential in the present invention.

In the present invention, it is possible to prepare the exorisch norbornene ester by only controlling the reaction temperature without adding a catalyst or a solvent. In this case, the addition of the polymerization inhibitor may produce the exorisch norbornene ester in a higher yield.

Hereinafter, the present invention will be described in more detail, but the following examples are for the purpose of explanation and are not intended to limit the present invention.

Examples 1-16

As shown in Table 1, Diels-Alder reaction of cyclopentadiene (CPD) and methyl acrylate (MA) was performed under different conditions. At this time, the conversion, selectivity, and exo: endo ratio of cyclopentadiene were measured by the following method. That is, the product produced during the Diels-Alder reaction was measured by gas chromatography equipped with a flame ionization detector, and the conversion and selectivity of cyclopentadiene to determine the reaction activity were defined as follows.

1) Conversion Rate

(Moles of CPD reacted) / (moles of CPD supplied) × 100

2) selectivity

(Moles of generated norbornene esters) / (moles of generated materials) × 100

Reaction condition Measures Reaction temperature (℃) Reaction pressure (atmospheric pressure) Reactant molar ratio (DCPD: MA: HQ) Response time (hours) % Conversion Selectivity (%) EXO / (EXO + Endo) (%) Example 1 160 1 to 20 0.5: 1.16: 0.001 8 60.1 61.3 36.9 Example 2 180 1 to 20 0.5: 1.16: 0.001 8 97.5 90.0 42.6 Example 3 200 1 to 20 0.5: 1.16: 0.001 8 97.9 86.9 52.8 Example 4 220 1 to 20 0.5: 1.16: 0.001 8 98.9 69.4 54.3 Example 5 240 1 to 20 0.5: 1.16: 0.001 8 99.2 57.5 54.1 Example 6 260 1 to 20 0.5: 1.16: 0.001 8 98.6 50.6 54.1 Example 7 200 1 to 20 0.5: 1.16: 0.001 One 97.0 88.5 43.2 Example 8 200 1 to 20 0.5: 1.16: 0.001 2 97.5 88.4 47.5 Example 9 200 1 to 20 0.5: 1.16: 0.001 4 97.7 88.9 50.1 Example 10 200 1 to 20 0.5: 1.16: 0.001 6 97.7 87.2 51.7 Example 11 200 1 to 20 0.5: 1.16: 0.001 8 97.8 86.9 52.8 Example 12 200 1 to 20 0.5: 1.16: 0.001 16 97.9 84.4 54.2 Example 13 200 1 to 20 0.5: 1.0: 0.001 8 96.9 84.5 53.4 Example 14 200 1 to 20 0.5: 5.0: 0.005 8 98.2 97.0 52.4 Example 15 200 54 0.5: 5.0: 0.005 8 98.0 96.0 53.4 Example 16 200 80 0.5: 5.0: 0.005 8 97.5 97.0 52.9

DCPD: Dicyclopentadiene

MA: Methyl acrylate

HQ: hydroquinone

Examples 17-29

As shown in Table 2, Diels-Alder reaction of cyclopentadiene and butyl acrylate (BA) was performed under different conditions.

Reaction condition Measures Reaction temperature (℃) Reaction pressure (atmospheric pressure) Reactant molar ratio (DCPD: BA: HQ) Response time (hours) % Conversion Selectivity (%) EXO / (EXO + Endo) (%) Example 17 175 1 to 5 0.5: 1.16: 0.001 8 97.0 86.9 39.2 Example 18 180 1 to 5 0.5: 1.16: 0.001 8 99.0 87.4 50.2 Example 19 190 1 to 5 0.5: 1.16: 0.001 8 99.3 84.8 54.1 Example 20 200 1 to 5 0.5: 1.16: 0.001 8 99.5 77.4 54.7 Example 21 210 1 to 5 0.5: 1.16: 0.001 8 99.7 70.3 54.8 Example 22 230 1 to 5 0.5: 1.16: 0.001 8 99.4 65.3 54.7 Example 23 190 1 to 5 0.5: 1.16: 0.001 One 98.7 88.5 41.2 Example 24 190 1 to 5 0.5: 1.16: 0.001 2 98.9 87.8 45.9 Example 25 190 1 to 5 0.5: 1.16: 0.001 4 98.8 84.5 51.1 Example 26 190 1 to 5 0.5: 1.16: 0.001 6 99.0 83.4 53.0 Example 27 190 1 to 5 0.5: 1.16: 0.001 8 97.2 80.3 54.6 Example 28 190 1 to 5 0.5: 5: 0.005 8 96.3 97.1 46.2 Example 29 190 1 to 5 0.5: 10: 0.01 8 98.9 96.9 54.0

Examples 30-39 and Comparative Examples 1-4

As shown in Table 3, Diels-Alder reaction of cyclopentadiene and methyl acrylate was carried out with different polymerization agents.

Polymerization inhibitor Reaction condition Measures Reaction temperature (℃) Reaction pressure (atmospheric pressure) Reactant molar ratio (DCPD: MA: polymerization inhibitor) Response time (hours) CDP conversion rate (%) Selectivity (%) EXO / (EXO + EXO) (%) Example 30 No addition 200 1 to 20 0.5: 1.16:- 4 96.7 64.3 50.0 Example 31 aniline 200 1 to 20 0.5: 1.16: 0.02 4 96.6 57.8 50.3 Example 32 phenol 200 1 to 20 0.5: 1.16: 0.02 4 95.7 60.6 50.2 Example 33 Nitrobenzene 200 1 to 20 0.5: 1.16: 0.02 4 96.4 82.2 50.3 Example 34 Copper dichloride 200 1 to 20 0.5: 1.16: 0.02 4 95.8 86.2 50.4 Example 35 4-ethoxyphenol 200 1 to 20 0.5: 1.16: 0.02 4 96.3 71.9 50.3 Example 36 Cyclohexanone 200 1 to 20 0.5: 1.16: 0.02 4 96.1 56.5 50.0 Example 37 DPPH 200 1 to 20 0.5: 1.16: 0.02 4 97.8 68.7 50.9 Example 38 Benzoquinone 200 1 to 20 0.5: 1.16: 0.02 4 96.7 94.5 50.4 Example 39 Hydroquinone 200 1 to 20 0.5: 1.16: 0.02 4 97.9 95.4 50.1 Comparative Example 1 Hydroquinone 30 1 to 5 0.5: 1.16: 0.014 24 90.7 90.6 32.7 Comparative Example 2 Hydroquinone 30 1 to 5 0.5: 1.16: 0.006 24 89.3 89.3 33.0 Comparative Example 3 Hydroquinone 30 1 to 5 0.5: 1.16: 0.001 24 88.3 88.3 33.4 Comparative Example 4 No addition 30 1 to 5 0.5: 1.16:- 24 90.1 90.1 32.0

DPPH: 2,2-di (4-tert-octylphenyl) -1-picrylhydrazyl

According to the present invention, by reacting at a specific temperature without the addition of a catalyst or a solvent, the exorisch norbornene ester can be produced, thereby making it easy to produce an industrially useful exoriche norbornene ester.

Claims (5)

A method for producing an exorisch norbornene ester comprising mixing methyl or butyl acrylate with cyclopentadiene, dicyclopentadiene or a mixture thereof and reacting at 160 to 300 ° C. The reaction of claim 1, wherein the reaction pressure is 1 to 20 atm, cyclopentadiene, dicyclopentadiene or a mixture thereof and the molar ratio of methyl or butyl acrylate is 1: 1 to 1:10, and the reaction time. A method for producing an exorisch norbornene ester, which is carried out under reaction conditions of 0.5 to 24 hours. The method of claim 1, wherein the addition of the polymerization inhibitor during the reaction method for producing an exorisch norbornene ester. The method of claim 3, wherein the polymerization inhibitor is aniline, cyclohexane, phenol, 4-ethoxyphenol, nitrobenzene, hydroquinone, benzoquinone, copper dichloride and 2,2-di (4-tert-octylphenyl)- A method for producing an exorisch norbornene ester, characterized in that it is selected from the group consisting of 1-picrylhydrazyl. The method of claim 3, wherein the molar ratio of the cyclopentadiene, dicyclopentadiene or a mixture thereof and the polymerization inhibitor is 1: 0.001 to 1: 0.05.