A method for preparing a photoresist monomer containing an exo-exo bi-norbornane structure

Abstract

The present invention relates to the technical field of organic synthesis, and in particular to a method for preparing a photoresist monomer containing an exo-exo configuration bis-norbornane structure, wherein the preparation method comprises: constructing an intermediate M1 of an exo-exo configuration bis-norbornane structure by DA addition of norbornene and cyclopentadiene; promoting configuration reversal by hydration addition with a strong acid catalyst to obtain an intermediate M2 of an exo-exo configuration bis-norbornane; oxidizing the alcohol hydroxyl intermediate M2 to a ketone to obtain an intermediate M3; obtaining an endo configuration intermediate M4 by Grignard nucleophilic addition reaction of M3; obtaining an exo configuration intermediate M5 by chlorination of M4 with hydrogen chloride; hydrolyzing the chlorinated product of M5 under the catalysis of a phase transfer catalyst to obtain an exo configuration intermediate M6 with ethyl and alcohol hydroxyl configuration reversal; and obtaining a compound containing a bis-norbornane structure by esterification with methacryloyl chloride. The preparation method is simple and green in reaction, has high safety, and is convenient for industrial production.

Description

Technical Field

[0001] The invention relates to a method for preparing a photoresist monomer containing an exo-exo bi-norbornane structure, and belongs to the technical field of organic synthesis. Background Art

[0002] Photoresist, also known as photoresist, is a light-sensitive mixed liquid, mainly composed of photoinitiator, photoresist resin, monomer, solvent and other additives. It is used as an anti-corrosion coating material in the photolithography process. Its solubility changes through irradiation or radiation of ultraviolet light, electron beam, ion beam, X-ray, etc., thereby realizing the transfer of fine patterns. Photoresists are classified into two categories according to the image they form: positive and negative. According to the exposure light source and radiation source, they are divided into ultraviolet photoresists, deep ultraviolet photoresists, X-ray glues, electron beam glues, ion beam glues, etc. Photoresists are mainly used in fine processing operations such as display panels, integrated circuits and semiconductor discrete devices.

[0003] In recent years, the development of photolithography has made great breakthroughs in miniaturization, and the corresponding requirements for resist patterns are also to be further miniaturized. It is also necessary to form a good resist pattern with less exposure, that is, the high sensitivity of the resist material. Furthermore, for the radiation-sensitive linear composition used in the development step, the critical dimension uniformity (CDU) when forming the hole pattern is small, and there is less development residue.

[0004] The JP2021001955A patent application of Japan JSR Corporation discloses a photoresist composition, providing a dry radiation linear composition and a resist pattern forming method that can form a resist pattern with high sensitivity, small CDU, and suppressed development defects. The compound of the present invention is applied in its composition formula. Due to the large spatial volume of the di-norbornane structure as an acid dissociative group, the sensitivity can be significantly improved and the reduction of development residue can be significantly improved. It has the advantages of high sensitivity, small LWR, small CDU, and effective suppression of development residue. In the resist pattern forming method of WO2016043004A1 patent application of Fujifilm Corporation of Japan, the compound of the present invention is used as a polymer monomer to form a line and space pattern with a spacing of less than 40nm or a hole pattern with an aperture of less than 20nm with high quality. Shin-Etsu Chemical Co., Ltd.'s JP2020193151A5 patent application uses the compound of the present invention as a polymer monomer to provide a photoresist composition with high sensitivity, small line width roughness (LWR), and small CDU, and a pattern forming method using the photoresist composition. Shin-Etsu Chemical Co., Ltd.'s European patent application EP1004568A2 discloses a method for synthesizing the target compound, but the process involves three steps: dehydration of p-toluenesulfonic acid to olefins, oxidation of m-chloroperbenzoic acid to epoxy, and then hydrolysis with lithium aluminum hydride. The process has the disadvantages of a long reaction route, harsh reaction conditions, and high risk.

[0005] The structural formula of the photoresist monomer compound containing an exo-exo bi-norbornane structure is:

[0006] .

[0007] The photoresist composition prepared by using the photoresist monomer compound has the advantages of high sensitivity, low LWR, low CDU and effective suppression of development residues, etc. However, the current preparation method of the compound generally has the disadvantages of long reaction route, harsh reaction conditions, high risk, etc., and is not suitable for industrial production. Summary of the invention

[0008] The invention aims at the deficiencies in the prior art and provides a method for preparing a photoresist monomer containing an exo-exo bi-norbornane structure. A key intermediate of the exo-exo bi-norbornane structure is constructed in a simple and low-cost synthesis method, and the exo-endo configuration flipping of ethyl and alcoholic hydroxyl groups is achieved in a green and safe synthesis method, thereby synthesizing (1R, 2S, 4R, 4αR, 5S, 8R, 8αR)-2-ethyldecahydro-1, 4: 5, 8-dimethylnaphthalene-2-yl methylacrylate in high yield. The obtained product has the advantages of high purity and low metal ion content. The synthesis process of the invention is more suitable for industrial production because of its simplicity, greenness, safety and low cost.

[0009] The technical solution of the present invention to solve the above technical problems is as follows: a method for preparing a photoresist monomer containing an exo-exo bi-norbornane structure, wherein the preparation method of the photoresist monomer is:

[0010] S1. Preparation of intermediate M1:

[0011] ;

[0012] The intermediate M1 is obtained by reacting norbornene with cyclopentadiene by DA addition reaction under heating and pressure in the presence of a polymerization inhibitor, and then post-processing.

[0013] S2. Preparation of intermediate M2:

[0014] ;

[0015] The intermediate M1 is subjected to a reflux reaction under the catalysis of a strong acid catalyst, and then undergoes a hydration reaction with configuration inversion, followed by post-treatment to obtain the intermediate M2;

[0016] S3, preparation of intermediate M3:

[0017] ;

[0018] The intermediate M2 is oxidized and then post-treated to obtain the intermediate M3;

[0019] S4, preparation of intermediate M4:

[0020] ;

[0021] Intermediate M3 reacts with ethylmagnesium chloride Grignard reagent through nucleophilic addition reaction and then undergoes post-treatment to obtain intermediate M4;

[0022] S5, preparation of intermediate M5:

[0023] ;

[0024] Intermediate M5 is prepared by chlorination reaction of intermediate M4 with hydrogen chloride;

[0025] S6, preparation of intermediate M6:

[0026] ;

[0027] The intermediate M5 is hydrolyzed in the presence of a phase transfer catalyst and then post-treated to obtain the intermediate M6;

[0028] S7. Preparation of target compound:

[0029] ;

[0030] The intermediate M6 is reacted with methacryloyl chloride via esterification and then post-treated to obtain the target compound.

[0031] Furthermore, the specific operation of step S1 is: in a reactor, 1 equivalent of norbornene, 0.1-5.0% times the mass of norbornene as a polymerization inhibitor, and 0.8-2.0 equivalents of cyclopentadiene are fully mixed, and after the system is fully replaced with an inert gas, the temperature is raised to 160-200° C. and the reaction is kept warm for 10-12 hours. After the reaction is completed, the reaction liquid is subjected to vacuum distillation and purification to obtain an intermediate M1.

[0032] Furthermore, the polymerization inhibitor is any one of phenothiazine, 2,6-di-tert-butyl-p-methylphenol, p-methoxyphenol, and hydroquinone, or a combination of two thereof.

[0033] Furthermore, the specific operation of step S2 is: fully mix 1 equivalent of intermediate M1 and 0.2~2.0 equivalents of strong acid catalyst, heat to 80~130°C and keep warm for reaction for 10~12h, after the reaction is completed, cool to room temperature, extract the reaction solution with dichloromethane, adjust the pH of the extract to 7~8 with sodium bicarbonate solution, wash with water, and remove the solvent from the organic phase under reduced pressure; the obtained product is recrystallized and refined to obtain intermediate M2.

[0034] Furthermore, the strong acid catalyst is any one of formic acid, methanesulfonic acid, p-toluenesulfonic acid, and sulfuric acid, or a combination of two thereof; and the concentration of the strong acid catalyst is 5% to 50%.

[0035] Further, the specific operation of step S3 is as follows: under the protection of inert gas, 0.8~2.0 equivalents of oxalyl chloride are dissolved in dichloromethane, stirred and cooled to -85~-55°C, an equivalent amount of DMSO is dissolved in dichloromethane, and the dichloromethane solution of DMSO is slowly added dropwise to the dichloromethane system of oxalyl chloride at an internal temperature of -85~-55°C for reaction, and the reaction is kept warm for 0.5~1h; 1 equivalent of intermediate M2 is dissolved in dichloromethane, the internal temperature is controlled at -85~-55°C, and the dichloromethane solution of intermediate M2 is slowly added dropwise to the reaction system, and the reaction is kept warm for 0.5~1h, and then the internal temperature is controlled at -85~-55°C, and 2.0~5.0 equivalents of triethylamine are added dropwise to the system, and the reaction is kept warm for 1~2h, and then the system is naturally heated to room temperature under stirring, and the reaction is continued at room temperature for 0.5~1h;

[0036] After adding dilute hydrochloric acid dropwise to the reaction solution to adjust the pH to 2-5, the organic phase is separated and washed with water until neutral. After the organic phase is decompressed to remove the solvent, it is purified by vacuum distillation to obtain the intermediate M3.

[0037] Furthermore, the specific operation of step S4 is: under the protection of inert gas, dissolving 1 equivalent of intermediate M3 in tetrahydrofuran, controlling the internal temperature at 20-60°C, adding dropwise to 1-2 equivalents of ethylmagnesium bromide Grignard reagent to react, and keeping the reaction at 20-60°C for 0.5-1h; pouring the reaction solution into dilute hydrochloric acid to quench the reaction, washing the organic phase with water to neutrality, removing the solvent under reduced pressure, and refining the obtained product by recrystallization to obtain intermediate M4.

[0038] Furthermore, the specific operation of step S5 is: dissolving 1 equivalent of intermediate M4 in an organic solvent, adding 1-3 equivalents of hydrogen chloride, and reacting at 0-50° C. for 0.5-1 h. After the reaction solution is adjusted to pH 6-7 with aqueous sodium bicarbonate solution, the organic phase containing the intermediate M5 is directly used for the next reaction.

[0039] Furthermore, the specific operation of step S6 is: to the organic phase containing the intermediate M5 obtained in step S5, add 0.1~1.0 equivalent of phase transfer catalyst and water, control the temperature at 10~50°C, keep the reaction for 6-8h, wash the reaction solution with water until neutral, remove the solvent from the organic phase under reduced pressure, and then refine the obtained product by recrystallization with an organic solvent to obtain intermediate M6.

[0040] Furthermore, the specific operation of step S7 is: dissolving 1 equivalent of intermediate M6 and 1-4 equivalents of acid-binding agent in dichloromethane, controlling the internal temperature at -30-40°C, slowly dropping 1-4 equivalents of methacryloyl chloride, and keeping the temperature for reaction for 6-8 hours. After the reaction is completed, adding ammonia water to the system to quench the reaction; washing the reaction solution with deionized water until neutral, adding an inhibitor to the obtained organic phase, removing the solvent under reduced pressure, and refining by reduced pressure distillation to obtain the target compound.

[0041] The beneficial effects of the present invention are:

[0042] The preparation method of the present invention constructs the parent structure of exo-exo binorbornane by promoting configuration inversion through hydration addition under acidic conditions, and then synthesizes a methacrylate photoresist monomer containing the exo-exo binorbornane structure. The present invention adopts a simple and low-cost method to obtain the exo-exo binorbornane structure, and then synthesizes (1R, 2S, 4R, 4αR, 5S, 8R, 8αR)-2-ethyldecahydro-1,4:5,8-dimethylnaphthalene-2-yl methacrylate. The product has a HPLC purity of more than 99.8%, a GPC purity of more than 99.9%, a single metal ion content of less than 1 ppb, a simple and green reaction, high safety, and is convenient for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 For the intermediate M1 of Example 1 1 H-NMR spectrum;

[0044] Figure 2 for Figure 1 The chemical shift is 0.7-2.5 1 H-NMR spectrum;

[0045] Figure 3 For the intermediate M1 of Example 1 13 C-NMR spectrum;

[0046] Figure 4 For the intermediate M2 of Example 1 1 H-NMR spectrum;

[0047] Figure 5 for Figure 4 The chemical shift is 1.0-1.9 1 H-NMR spectrum;

[0048] Figure 6 For the intermediate M2 of Example 1 13 C-NMR spectrum;

[0049] Figure 7 For the intermediate M3 of Example 1 1 H-NMR spectrum;

[0050] Figure 8 for Figure 7 The chemical shift is 0.7-2.9 1 H-NMR spectrum;

[0051] Fig. 9 For the intermediate M3 of Example 1 13 C-NMR spectrum;

[0052] Fig.10 For the intermediate M4 of Example 1 1 H-NMR spectrum;

[0053] Fig.11 For the intermediate M4 of Example 1 13 C-NMR spectrum;

[0054] Fig.12 For the intermediate M5 of Example 1 1 H-NMR spectrum;

[0055] Fig.13 for Fig.12 The chemical shift is 0.4-2.6 1 H-NMR spectrum;

[0056] Fig.14 For the intermediate M5 of Example 1 13 C-NMR spectrum;

[0057] Fig.15 For the intermediate M6 of Example 1 1 H-NMR spectrum;

[0058] Fig.16 For the intermediate M6 of Example 1 13 C-NMR spectrum;

[0059] Fig.17 For the target compound of Example 1 1 H-NMR spectrum;

[0060] Fig.18 for Fig.17 The chemical shift is 0.4-2.7 1 H-NMR spectrum;

[0061] Fig.19 For the target compound of Example 1 13 C-NMR spectrum. DETAILED DESCRIPTION

[0062] The specific implementation of the present invention is described in detail below. The present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed.

[0063] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used are only for describing specific embodiments and are not intended to limit the present invention.

[0064] A method for preparing a photoresist monomer containing an exo-exo bi-norbornane structure, the preparation method of the photoresist monomer comprising:

[0065] ;

[0066] S1. Preparation of intermediate M1:

[0067] The intermediate M1 is obtained by reacting norbornene with cyclopentadiene by DA addition reaction under heating and pressure in the presence of a polymerization inhibitor, and then post-processing.

[0068] S2. Preparation of intermediate M2:

[0069] The intermediate M1 is subjected to a reflux reaction under the catalysis of a strong acid catalyst, and then undergoes a hydration reaction with configuration inversion, followed by post-treatment to obtain the intermediate M2; the reaction mechanism of step S2 is:

[0070] ;

[0071] S3, preparation of intermediate M3:

[0072] The intermediate M2 is oxidized and then post-treated to obtain the intermediate M3;

[0073] S4, preparation of intermediate M4:

[0074] Intermediate M3 reacts with ethylmagnesium chloride Grignard reagent through nucleophilic addition reaction and then undergoes post-treatment to obtain intermediate M4;

[0075] S5, preparation of intermediate M5:

[0076] Intermediate M5 is prepared by chlorination reaction of intermediate M4 with hydrogen chloride;

[0077] S6, preparation of intermediate M6:

[0078] The intermediate M5 is hydrolyzed in the presence of a phase transfer catalyst and then post-treated to obtain the intermediate M6;

[0079] S7. Preparation of target compound:

[0080] The intermediate M6 is reacted with methacryloyl chloride via esterification and then post-treated to obtain the target compound.

[0081] Specifically, the specific operation of step S1 is: in a reactor, 1 equivalent of norbornene, 0.1-5.0% times the mass of norbornene as a polymerization inhibitor, and 0.8-2.0 equivalents of cyclopentadiene are fully mixed, and after the system is fully replaced with an inert gas, the temperature is raised to 160-200° C. and the reaction is kept warm for 10-12 hours. After the reaction is completed, the reaction liquid is subjected to vacuum distillation and purification to obtain an intermediate M1.

[0082] Specifically, in step S1, the polymerization inhibitor is any one of phenothiazine, 2,6-di-tert-butyl-p-methylphenol, p-methoxyphenol, and hydroquinone, or a combination of two thereof.

[0083] Preferably, in step S1, the polymerization inhibitor is phenothiazine, and the amount of the polymerization inhibitor added is 1% times the mass of norbornene.

[0084] Preferably, in step S1, the insulation reaction temperature is 170-180°C.

[0085] Preferably, the amount of cyclopentadiene used is 1 equivalent.

[0086] Specifically, the specific operation of step S2 is: fully mix 1 equivalent of intermediate M1 and 0.2~2.0 equivalents of strong acid catalyst, heat to 80~130°C and keep warm for reaction for 10~12h, after the reaction is completed, cool to room temperature, extract the reaction solution with dichloromethane, adjust the pH of the extract to 7~8 with sodium bicarbonate solution, wash with water, and remove the solvent from the organic phase under reduced pressure; the obtained product is recrystallized and refined to obtain intermediate M2.

[0087] Specifically, in step S2, the strong acid catalyst is any one of formic acid, methanesulfonic acid, p-toluenesulfonic acid, and sulfuric acid, or a combination of two thereof; and the concentration of the strong acid catalyst is 5% to 50%.

[0088] Preferably, in step S2, the strong acid catalyst is concentrated sulfuric acid, and the concentration of the strong acid catalyst is 10%.

[0089] Preferably, in step S2, the insulation reaction temperature is 100°C.

[0090] More specifically, in step S2, the solvent used for the recrystallization is any one of n-heptane, n-hexane, petroleum ether, benzene, toluene, and xylene; preferably, the solvent used for the recrystallization is n-heptane.

[0091] Specifically, the specific operation of step S3 is: under the protection of inert gas, 0.8 to 2.0 equivalents of oxalyl chloride are dissolved in dichloromethane, and the temperature is cooled to -85 to -55°C (preferably -75 to -65°C) with stirring, and an equivalent amount of DMSO is dissolved in dichloromethane, and the dichloromethane solution of DMSO is slowly added dropwise to the dichloromethane system of oxalyl chloride under the internal temperature of -85 to -55°C (preferably -75 to -65°C) to react, and the reaction is kept warm for 0.5 to 1h; 1 equivalent The intermediate M2 is dissolved in dichloromethane, and the internal temperature is controlled at -85~-55°C (preferably -75~-65°C) to slowly drip the dichloromethane solution of the intermediate M2 into the reaction system, and the reaction is kept at this temperature for 0.5~1h. Then, the internal temperature is controlled at -85~-55°C (preferably -75~-65°C) to drip 2.0~5.0 equivalents of triethylamine into the system, and the reaction is kept at this temperature for 1~2h. Then, the system is naturally heated to room temperature under stirring, and the reaction is continued at room temperature for 0.5~1h.

[0092] Dilute hydrochloric acid (mass concentration of dilute hydrochloric acid is 10%) is added dropwise to the reaction solution to adjust the pH to 2-5, and then the organic phase is separated and washed with water until neutral. After the organic phase is decompressed to remove the solvent, it is purified by vacuum distillation to obtain the intermediate M3.

[0093] Preferably, in step S3, the amount of oxalyl chloride used is 1.0-1.2 equivalents, more preferably 1.0 equivalent; the amount of triethylamine used is 3 equivalents.

[0094] Specifically, the specific operation of step S4 is: under the protection of inert gas, dissolve 1 equivalent of intermediate M3 in tetrahydrofuran, control the internal temperature at 20~60°C, add it dropwise to 1~2 equivalents of ethylmagnesium bromide Grignard reagent to react, and keep the reaction at 20~60°C for 0.5~1h; pour the reaction solution into dilute hydrochloric acid to quench the reaction, wash the organic phase with water to neutrality, remove the solvent under reduced pressure, and refine the obtained product by recrystallization to obtain intermediate M4.

[0095] Preferably, in step S4, the amount of ethylmagnesium bromide Grignard reagent used is 1.2 equivalents.

[0096] Preferably, in step S4, the reaction temperature is 25-30°C.

[0097] More specifically, in step S4, the solvent used for the recrystallization is any one of n-heptane, n-hexane, petroleum ether, toluene, ethanol, and methanol; preferably, the solvent used for the recrystallization is n-heptane.

[0098] Specifically, the specific operation of step S5 is: dissolving 1 equivalent of intermediate M4 in an organic solvent, adding 1-3 equivalents of hydrogen chloride, and reacting at 0-50° C. for 0.5-1 h. After the reaction solution is adjusted to pH 6-7 with sodium bicarbonate aqueous solution, the organic phase containing the intermediate M5 is directly used for the next reaction.

[0099] Preferably, in step S5, the hydrogen chloride may be a gas or an aqueous solution of hydrogen chloride, and the mass concentration of the aqueous solution of hydrogen chloride is 30-100%, more preferably 50%.

[0100] Preferably, in step S5, the amount of hydrogen chloride used is 1.5 equivalents.

[0101] Preferably, in step S5, the insulation reaction temperature is 20-30°C.

[0102] Specifically, the specific operation of step S6 is: add 0.1~1.0 equivalent of phase transfer catalyst and water to the organic phase containing intermediate M5 obtained in step S5, control the temperature at 10~50°C, keep the reaction for 6~8h, wash the reaction solution with water until neutral, remove the solvent from the organic phase under reduced pressure, and then refine the product by recrystallization with an organic solvent to obtain intermediate M6.

[0103] More specifically, in step S6, the phase transfer catalyst is at least one of 18-C-6, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium fluoride, tetrabutylammonium hydroxide, tetrapropylammonium hydroxide, tetraethylammonium hydroxide, and tetramethylammonium hydroxide.

[0104] Preferably, the transfer catalyst is tetrabutylammonium bromide.

[0105] Preferably, in step S6, the amount of phase transfer catalyst used is 0.3 equivalents.

[0106] Preferably, in step S6, the reaction temperature is 30-40°C.

[0107] Preferably, in step S6, the organic solvent used for the recrystallization is any one of n-hexane, n-heptane, petroleum ether, toluene, ethanol, methanol, or a combination of two thereof; n-heptane is more preferably used.

[0108] Specifically, the specific operation of step S7 is: dissolving 1 equivalent of intermediate M6 and 1 to 4 equivalents of acid-binding agent in dichloromethane, controlling the internal temperature at -30 to 40°C, slowly dropping 1 to 4 equivalents of methacryloyl chloride, and keeping the temperature to react for 6 to 8 hours. After the reaction is completed, adding ammonia water to the system to quench the reaction; washing the reaction solution with deionized water until neutral, adding 0.001 to 0.100% by mass (relative to the theoretical amount of the target compound) of inhibitor to the obtained organic phase, removing the solvent under reduced pressure, and refining by reduced pressure distillation to obtain the target compound.

[0109] More specifically, in step S7, the acid binding agent is any one of pyridine, DBU, triethylamine, and diethylamine, or a combination of two thereof; preferably, triethylamine is used.

[0110] Preferably, in step S7, the amount of the acid binding agent used is 2 equivalents, and the amount of the methacryloyl chloride used is 2 equivalents.

[0111] Preferably, in step S7, the reaction temperature is -10~0°C.

[0112] More specifically, in step S7, the polymerization inhibitor is at least one of phenothiazine, T501, p-methoxyphenol, and hydroquinone; preferably, T501 is used.

[0113] Preferably, in step S7, the amount of the inhibitor used is 0.01% of the theoretical amount of the target product.

[0114] The following are preparation examples of photoresist monomers containing exo-exo bis-norbornane structures. The reagents and solvents involved in the preparation examples are obtained from commercial sources and are used without further purification unless otherwise specified.

[0115] The unit of chemical shift δ is ppm, referenced to CDCl3 ( 1 H-NMR = 7.26 and 13 C-NMR = 77.16). Multiplicities are indicated as follows: s (singlet); d (doublet); t (triplet); q (quartet); dd (double of doublets); ddd (double of doublets); td (triplet of doublets); dt (double of triplets); m (multiplet); br (broad).

[0116] Example 1

[0117] Step S1, synthesis of intermediate M1:

[0118] 282.5 g (3 mol) of norbornene, 2.8 g (1% wt, based on norbornene) of phenothiazine, and 198.3 g (3 mol) of cyclopentadiene were added to a 2L stainless steel autoclave. After the system was fully replaced with nitrogen, the temperature was raised to 170-180°C and the reaction was maintained for 12 hours. During the reaction, the system pressure gradually increased to 0.6-0.7 MPa as the temperature increased.

[0119] After the reaction was completed, the reaction solution was subjected to vacuum distillation and purified. Under a vacuum degree of 100 Pa, the 58-63°C fraction was collected and distilled to obtain 340.4 g of intermediate M1 with a yield of 70.8% (based on norbornene). The intermediate M1 was in the form of a colorless liquid with a GC purity of 94.6%, and contained 3.0% of isomers.

[0120] like Figure 1-Figure 2 As shown, 1H NMR (400MHz, CDCl3): δ 5.912~5.922 (t, 2H), 2.805~2.819 (m, 2H), 2.015~2.062 (m, 1H), 1.992 (br.s, 2H), 1.926 (br.s, 2H), 1.344~1.403 (m, 2H), 1 .253~1.276 (dt, J=7.6, 1.6Hz, 1H), 1.125~1.144 (br.d, J=7.6Hz, 1H), 0.946~1.001 (m, 2H), 0.507~0.531 (d, J=9.6Hz, 1H).

[0121] like Figure 3 As shown, 13 C-NMR (100MHz, CDCl3): δ 135.292 (2C), 52.940, 48.724, 46.779 (2C), 37.925 (2C), 33.833 (2C), 31.964 (2C).

[0122] Step S2, synthesis of intermediate M2:

[0123] Add 160.3 g (1 mol) of intermediate M1 and 1000.0 g (wt = 10%, containing 1 mol of sulfuric acid) of dilute sulfuric acid into a 2L three-necked flask, raise the temperature to 100°C and reflux for 12 h.

[0124] After the reaction was completed, the temperature was lowered to room temperature, and the reaction solution was extracted with 500 mL of dichloromethane. The extract was adjusted to pH 7-8 with a 10% by mass sodium bicarbonate solution, and then washed once with 300 mL of water. The organic phase was decompressed to remove the solvent to obtain a brown solid, which was purified by recrystallization with n-heptane to obtain 131.3 g of intermediate M2, with a yield of 73.6% (based on intermediate M1). It was in the form of a white solid with a GC purity of 96.5%.

[0125] like Figure 4-Figure 5 As shown, 1H NMR (400MHz, CDCl3): δ 3.683~3.699 (d, J=6.4Hz, 1H), 2.073~2.124 (t, 3H), 2.009 (s, 1H), 1.813~1.851 (dt, J =10.8, 2.0Hz, 1H), 1.769~1.807 (dt, J=10.8Hz, 1H), 1.567~1.623 (dd, J=12.8, 6.8Hz, 1 H), 1.534 (s, 1H), 1.365~1.409 (m, 2H), 1.192~1.275 (m, 3H), 1.129~1.167 (ddd, J=13.2 , 4.4, 2.0Hz, 1H), 1.033~1.092 (dd, J=6.8, 2.4Hz, 2H), 0.848~0.875 (d, J=10.8Hz, 1H).

[0126] like Figure 6 As shown, 13 C-NMR (100MHz, CDCl3): δ 75.286, 52.422, 48.627, 48.339, 44.046, 40.012, 39.974, 39.504, 35.614, 31.321, 30.976, 30.717.

[0127] Step S3, synthesis of intermediate M3:

[0128] Under nitrogen protection, add 76.2g (0.60mol) oxalyl chloride and 400mL dichloromethane to a 2L three-necked flask, stir and cool to -75~-65℃. Dissolve 46.8g (0.60mol) DMSO in 100mL dichloromethane and slowly drop it into oxalyl chloride. The reaction is exothermic. Control the drop rate to maintain the temperature in the system at -75~-65℃. After about 1h of dropwise addition, keep the temperature at -75~-65℃ for 1h. Take 107.0g (0.60mol) of intermediate M2 and add 100mL dichloromethane to dissolve it, then slowly drop it into the reaction system. The reaction is exothermic. Control the drop rate to maintain the temperature in the system at -75~-65℃. After about 1h of dropwise addition, keep the temperature at -75~-65℃ for 1h. Then 182.1g (1.80mol) of triethylamine was dripped into the system. The system gradually became viscous due to the precipitation of a large amount of salt. It was necessary to increase the stirring rate to prevent the system from agglomerating. The reaction was highly exothermic. The dripping speed needed to be controlled to maintain the temperature in the system at -75~-65℃. After about 2h of dripping, the system was kept at -75~-65℃ for 2h. The cooling medium was removed, and the system was allowed to naturally rise to room temperature under stirring. The system was kept at this temperature for 1h, and the solid gradually dissolved.

[0129] 300.0g of dilute hydrochloric acid (wt=10%) was added dropwise to the reaction solution to adjust the pH to 2-5, and then the mixture was separated in a separatory funnel and washed with water until neutral. After the organic phase was decompressed to remove the solvent, it was purified by vacuum distillation. At a vacuum degree of 150Pa, the fraction of 110-115°C was collected to obtain 86.0g of intermediate M3, with a yield of 81.3% (based on intermediate M2). The intermediate was in the form of a yellow oily liquid with a GC purity of 91.8%, and contained 6.2% of isomers.

[0130] like Figure 7-Figure 8 As shown, 1 H NMR (400MHz, CDCl3): δ 2.547 (br.s, 1H), 2.501 (s, 1H), 2.289 (s, 1H), 2.229~2.273 (m, 2H), 1.964~2.018 (dd, J =17.2, 4.4Hz, 1H), 1.853~1.880 (dt, J=10.8, 2.0Hz, 1H), 1.764~1.820 (dd, J=17.6, 4.8H z, 1H), 1.678~1.696 (d, J=7.2Hz, 1H), 1.616~1.634 (d, J=7.2Hz, 1H), 1.434~1.481 (m, 2H ), 1.315~1.345 (d, J=12.0Hz, 1H), 1.114~1.153 (m, 2H), 0.960~0.987 (d, J=10.8Hz, 1H).

[0131] like Fig. 9 As shown, 13 C-NMR (100MHz, CDCl3): δ 216.354, 54.223, 51.885, 48.023, 45.762, 40.760, 40.060, 39.859, 35.920, 34.061, 30.659, 30.372.

[0132] Step S4, synthesis of intermediate M4:

[0133] Under nitrogen protection, add 11.7g (0.48mol) magnesium chips to a 1L three-necked flask and start stirring. Dissolve 52.3g (0.48mol) ethyl bromide in 200mL tetrahydrofuran, control the internal temperature at 25~30℃ and drip the ethyl bromide solution into the magnesium chips for reaction. The reaction is exothermic and the dripping is completed in about 1h. Keep the temperature at 25~30℃ for reaction for 1h. The magnesium chips gradually disappear and a light black and slightly turbid Grignard reagent is obtained. Dissolve 70.5g (0.40mol) of intermediate M3 in 100mL tetrahydrofuran, control the internal temperature at 25~30℃ and drip it into the Grignard reagent for reaction. The reaction is exothermic and the dripping is completed in about 1h. Keep the temperature at 25~30℃ for reaction for 1h.

[0134] The reaction solution was poured into a dilute hydrochloric acid prepared by mixing 17.5g (0.48mol, wt%=36%) concentrated hydrochloric acid and 100mL water to quench the reaction, and then 300mL toluene was added and stirred evenly, and then transferred to a separatory funnel and washed with water until neutral, and the organic phase was decompressed to remove the solvent to obtain 82.8g of yellow solid. The obtained product was refined by recrystallization from n-heptane to obtain 67.7g of intermediate M4, with a yield of 82.1% (based on intermediate M3), and its state was white or light yellow solid, with a GC purity of 97.7%. Its melting point was tested by differential scanning calorimetry (DSC) and microscopy: 114.8~118.7℃.

[0135] like Fig.10 As shown, 1 H NMR (400MHz, CDCl3): δ 2.201~2.220 (d, J=7.6Hz, 1H), 2.093 (s, 1H), 2.044 (br.s, 2H), 1.974 (s, 1H), 1.869~1.917 (m, 2H), 1.481~1.562 (m, 4H), 1.397~1.421 (m, 2H), 1.318 (s, 1H), 1.140~1.239 (m, 2H), 1.079~1.107 (d, J=11.2Hz, 1H), 0.968~1.009 (dd, J=12. 8. 4.0Hz, 1H), 0.889~0.925 (t, J=7.2Hz, 3H), 0.872~0.899 (br.d, J=10.8, 1H).

[0136] like Fig.11 As shown, 13 C-NMR (100MHz, CDCl3): δ 80.106, 52.824, 49.614, 47.257, 44.161, 41.679, 40.453, 39.859, 36.169, 35.039, 34.492, 31.522, 30.544, 7.709.

[0137] Step S5, synthesis of intermediate M5:

[0138] Add 61.9 g (0.30 mol) of intermediate M4 and 300 mL of toluene into a 1 L three-necked flask, add 32.9 g (0.45 mol, wt% = 50%) of concentrated hydrochloric acid dropwise at 20-30 °C, and keep the reaction at this temperature for 1 h.

[0139] After the reaction, the pH value was adjusted to 6-7 with 10% sodium bicarbonate aqueous solution, and the solution was transferred to a separatory funnel to separate the aqueous phase. Intermediate M5 existed in the organic phase with a GC purity of 92.8%, and was directly used for the next step with a yield of 100%.

[0140] The intermediate M5 is in pure form as a white solid (at 2-8°C), and its melting point as measured by differential scanning calorimetry (DSC) and microscopy is 17.2-22.0°C.

[0141] like Figure 12-13 As shown, 1 H NMR (400MHz, CDCl3): δ 2.341 (s, 1H), 2.135~2.172 (m, 2H), 2.092 (br.s, 2H), 1.787~2.016 (m, 5H), 1.557~1.575 (d, J=7.2Hz , 1H), 1.400~1.432 (m, 3H), 1.270~1.288 (d, J=7.2Hz, 1H), 1.035~1.129 (m, 5H), 0.865~0.906 (m, 1H).

[0142] like Fig.14 As shown, 13 C-NMR (100MHz, CDCl3): δ 83.978, 52.461, 52.346, 51.762, 46.309, 41.710, 40.081, 40.033, 36.113, 34.580, 33.871, 31.571, 30.441, 10.231.

[0143] Step S6, synthesis of intermediate M6:

[0144] Add the organic phase containing intermediate M5 (theoretically containing 0.30 mol) obtained in the previous step to a 1L three-necked flask, then add 29.0 g (0.09 mol) of tetrabutylammonium bromide and 100 mL of water. Stir and heat to 30-40°C for 8 hours.

[0145] After the reaction, the reaction solution was transferred to a separatory funnel for stratification, and the organic phase was washed twice with 200 mL of deionized water to remove salt. The obtained organic phase was decompressed to remove the solvent to obtain 61.9 g of a yellow solid. The obtained solid was recrystallized and purified with n-heptane to obtain 46.9 g of intermediate M6, with a yield of 75.7% (based on intermediate M4), in the form of a white solid, and a GC purity of 99.9%. The melting point was tested by differential scanning calorimetry (DSC) and microscopy to be 87.0~94.5°C.

[0146] like Fig.15 As shown, 1H NMR (400MHz, CDCl3): δ 2.088 (br.s, 2H), 2.062 (s, 1H), 1.941 (s, 1H), 1.855~1.928 (m, 2H), 1.59 7~1.661 (qd, J=7.2, 3.6Hz, 2H), 1.500~1.544 (m, 2H), 1.391~1.445 (m, 3H ), 1.256~1.304 (m, 2H), 1.134~1.173 (dd, J=12.6, 3.0Hz, 1H), 1.058~1.1 10 (m, 2H), 0.922~0.958 (t, J=7.2Hz, 3H), 0.855~0.882 (d, J=10.8Hz, 1H).

[0147] like Fig.16 As shown, 13 C-NMR (100MHz, CDCl3): δ 81.190, 52.490, 50.420, 49.586, 45.983, 40.876, 40.176, 40.081, 36.027, 33.153, 31.533, 30.824, 30.575, 8.525.

[0148] Step S7, synthesis of target compound:

[0149] Add 61.9g (0.3mol) of intermediate M6, 60.7g (0.6mol) of triethylamine and 300mL of dichloromethane to a 1L three-necked flask, and cool to -10~0℃ with nitrogen and stirring. Slowly drip 62.7g (0.6mol) of methacryloyl chloride while controlling the internal temperature at -10~0℃. The dripping takes about 0.5h, and the reaction is kept at -10~0℃ for 8h.

[0150] After the reaction, 100mL (wt% = 10%) of ammonia water was added to the system to quench the reaction, release heat, and control the internal temperature to -10~10℃. The dripping was completed for about 0.5h, and the reaction was kept at -10~10℃ (measured internal temperature 0℃) for 0.5h. The reaction solution was transferred to a separatory funnel for stratification and washed with deionized water until neutral. 0.008g of inhibitor T501 was added to the obtained organic phase, and the solvent was removed under reduced pressure. The vacuum distillation was performed and the fraction of 135~150℃ was collected at a vacuum degree of 100Pa to obtain 66.5g of the target compound, with a yield of 80.8% (based on the intermediate M6). It was in the form of a colorless oily liquid, HPLC purity: 99.8%, GPC purity: 99.9%.

[0151] The content of single metal ions tested by ICP-MS (unit: ppb): Li: 0.0018, Na: 0.9023, Mg: 0.6664, Al: 0.1438, K: 0.4252, Ca: 0.8285, Ti: 0.0483, V: 0.0095, Cr: 0.0217, Mn: 0.0118, Fe: 1.3718, Co: 0.0029, Ni: 0.0346, Cu: 0 .2172, Zn: 0.5507, Ga: 0.0058, As: ND, Sr: 0.0196, Zr: 0.0650, Mo: ND, Ru: ND, Pd: ND, Ag: 0.0117 , Cd: ND, In: 0.0046, Sn: 0.0336, Sb: ND, Ba: 0.0204, W: ND, Au: ND, Tl: 0.0030, Pb: ND, Bi: 0.0260.

[0152] The melting point of the compound was -47.6~-42.3℃ as tested by differential scanning calorimeter (DSC) and microscope.

[0153] like Figure 17-Figure 18 As shown, 1 H NMR (400MHz, CDCl3): δ 5.911~5.918 (m, 1H), 5.361~5.377 (m, 1H), 2.456 (s, 1H), 2.122~2.215 (td, J=14.8, 7.2Hz, 1H), 2.002~2.018 (d, J=6.4Hz, 3H), 1.802~1.894 (m , 7H), 1.494~1.512 (d, J=7.2Hz, 1H), 1.250~1.341 (m, 5H), 0.997~1.074 (m, 2H), 0.796~0.823 (d, J=10.8Hz, 1H), 0.718~0.756 (t, J=7.6Hz, 3H).

[0154] like Fig.19 As shown, 13 C-NMR (100MHz, CDCl3): δ 166.274, 137.756, 124.081, 92.573, 52.575, 48.090, 47.036, 45.129, 40.59 7, 40.146, 39.983, 36.074, 33.467, 31.541, 30.420, 25.772, 18.336, 8.533.

[0155] Example 2

[0156] Step S1, synthesis of intermediate M1:

[0157] 282.5 g (3 mol) norbornene, 14.1 g (5% wt, based on norbornene) hydroquinone, and 396.6 g (6 mol) cyclopentadiene were added to a 2L stainless steel autoclave. After the system was fully replaced with nitrogen, the temperature was raised to 190-200°C and the reaction was maintained for 10 hours. During the reaction, the system pressure gradually increased to 0.6-0.7 MPa as the temperature increased.

[0158] After the reaction was completed, the reaction solution was subjected to vacuum distillation and purified. Under a vacuum degree of 100 Pa, the 58-63°C fraction was collected and distilled to obtain 338.5 g of intermediate M1 with a yield of 70.4% (based on norbornene). The intermediate M1 was in the form of a colorless liquid with a GC purity of 94.2%. It also contained 3.1% of isomers.

[0159] Step S2, synthesis of intermediate M2:

[0160] Add 160.3 g (1 mol) of intermediate M1 and a 50% aqueous formic acid solution (containing 2 mol of formic acid) into a 2L three-necked flask, raise the temperature to 90°C, and keep warm for 24 hours.

[0161] After the reaction was completed, the temperature was lowered to room temperature, and the reaction solution was extracted with 500 mL of dichloromethane. The extract was adjusted to pH 7-8 with a 10% by mass sodium bicarbonate solution, and then washed once with 300 mL of water. The organic phase was decompressed to remove the solvent to obtain a brown solid, which was purified by recrystallization with n-heptane to obtain 130.6 g of intermediate M2, with a yield of 73.2% (based on intermediate M1). It was in the form of a white solid with a GC purity of 96.4%.

[0162] Step S3: Synthesis of intermediate M3:

[0163] Under nitrogen protection, add 152.4g (1.2mol) oxalyl chloride and 400mL dichloromethane to a 2L three-necked flask, stir and cool to -85~-75℃. Dissolve 93.6g (1.2mol) DMSO in 100mL dichloromethane and slowly drop it into oxalyl chloride. The reaction is exothermic. Control the drop rate to maintain the temperature in the system at -85~-75℃. After about 1.5h of dropwise addition, keep the temperature at -85~-75℃ for 0.5h. Take 107.0g (0.60mol) of intermediate M2 and add 100mL dichloromethane to dissolve it, then slowly drop it into the reaction system. The reaction is exothermic. Control the drop rate to maintain the temperature in the system at -85~-75℃. After about 1h of dropwise addition, keep the temperature at -85~-75℃ for 1h. Then 121.4g (1.20mol) of triethylamine was dripped into the system. The system gradually became viscous due to the precipitation of a large amount of salt. It was necessary to increase the stirring rate to prevent the system from agglomerating. The reaction was highly exothermic. The dripping speed needed to be controlled to maintain the temperature in the system at -85~-75℃. After about 2h of dripping, the system was kept at -85~-75℃ for 1h. The cooling medium was removed, and the system was allowed to naturally rise to room temperature under stirring. The system was kept at this temperature for 0.5h, and the solid gradually dissolved.

[0164] 300.0g of dilute hydrochloric acid (wt=10%) was added dropwise to the reaction solution to adjust the pH to 2-5, and then the mixture was separated in a separatory funnel and washed with water until neutral. After the organic phase was decompressed to remove the solvent, it was purified by vacuum distillation. At a vacuum degree of 150Pa, the fraction of 110-115°C was collected to obtain 85.7g of intermediate M3, with a yield of 81.0% (based on intermediate M2). The intermediate was in the form of a yellow oily liquid with a GC purity of 91.7%, and contained 6.4% of isomers.

[0165] Step S4, synthesis of intermediate M4:

[0166] Under nitrogen protection, add 9.7g (0.4mol) magnesium chips to a 1L three-necked flask and start stirring. Dissolve 43.6g (0.4mol) bromoethane in 200mL tetrahydrofuran, control the internal temperature at 20~25℃ and drip the bromoethane solution into the magnesium chips for reaction. The reaction is exothermic and the dripping is completed in about 1h. Keep the temperature at 20~25℃ for reaction for 1h. The magnesium chips gradually disappear and a light black and slightly turbid Grignard reagent is obtained. Dissolve 70.5g (0.40mol) intermediate M3 in 100mL tetrahydrofuran, control the internal temperature at 20~25℃ and drip it into the Grignard reagent for reaction. The reaction is exothermic and the dripping is completed in about 1h. Keep the temperature at 20~25℃ for reaction for 1h.

[0167] The reaction solution was poured into a dilute hydrochloric acid prepared by mixing 17.5g (0.48mol, wt%=36%) concentrated hydrochloric acid and 100mL water to quench the reaction, and then 300mL toluene was added and stirred evenly, and then transferred to a separatory funnel and washed with water until neutral, and the organic phase was decompressed to remove the solvent to obtain 82.2g of yellow solid. The obtained product was refined by recrystallization from toluene to obtain 67.4g of intermediate M4, with a yield of 81.7% (based on intermediate M3), which was in the form of a white or light yellow solid, and the GC purity was 97.8%.

[0168] Step S5, synthesis of intermediate M5:

[0169] Add 61.9 g (0.30 mol) of intermediate M4 and 300 mL of toluene into a 1 L three-necked flask, add 65.8 g (0.9 mol, wt% = 50%) of concentrated hydrochloric acid dropwise at 0-10 °C, and keep the reaction at this temperature for 1 h.

[0170] After the reaction, the pH value was adjusted to 6-7 with 10% sodium bicarbonate aqueous solution, and the solution was transferred to a separatory funnel to separate the aqueous phase. Intermediate M5 existed in the organic phase with a GC purity of 92.9%, and was directly used for the next step with a yield of 100%.

[0171] Step S6, synthesis of intermediate M6:

[0172] Add the organic phase containing intermediate M5 (theoretical content 0.30 mol) obtained in the previous step to a 1L three-necked flask, then add 19.5 g (0.03 mol, wt% = 40%) of tetrabutylammonium hydroxide and 100 mL of water. Stir and heat to 10-20°C for 12 hours.

[0173] After the reaction, the reaction solution was transferred to a separatory funnel for separation, and the organic phase was washed twice with 200 mL of deionized water to remove salt. The obtained organic phase was decompressed to remove the solvent to obtain 61.5 g of a yellow solid. The obtained solid was recrystallized and purified with n-heptane to obtain 46.2 g of intermediate M6, with a yield of 74.7% (based on intermediate M4), in the form of a white solid, with a GC purity of 99.9%.

[0174] Step S7, synthesis of target compound:

[0175] Add 61.9g (0.3mol) of intermediate M6, 94.9g (1.2mol) of pyridine and 300mL of dichloromethane to a 1L three-necked flask, and cool to -30~-20℃ with nitrogen and stirring. Slowly drip 125.4g (1.2mol) of methacryloyl chloride while controlling the internal temperature at -30~-20℃. The dripping takes about 0.5h, and the reaction is kept at -30~-20℃ for 12h.

[0176] After the reaction, 100 mL (wt% = 10%) of ammonia water was added to the system to quench the reaction, release heat, and control the internal temperature to -10~10℃. The dripping was completed for about 0.5h, and the reaction was kept at -10~10℃ (measured internal temperature 0℃) for 0.5h. The reaction solution was transferred to a separatory funnel for stratification and washed with deionized water until neutral. 0.008g of inhibitor phenothiazine was added to the obtained organic phase, and the solvent was removed under reduced pressure. The vacuum distillation was performed and the fraction of 135~150℃ was collected at a vacuum degree of 100Pa to obtain 66.0g of the target compound, with a yield of 80.2% (based on the intermediate M6). It was in the form of a colorless oily liquid with a HPLC purity of 99.8% and a GPC purity of 99.9%.

[0177] Example 3

[0178] Step S1, synthesis of intermediate M1:

[0179] 282.5 g (3 mol) of norbornene, 0.28 g (0.1% wt, calculated as norbornene) of p-methoxyphenol, and 158.6 g (2.4 mol) of cyclopentadiene were added to a 2L stainless steel autoclave. After the system was fully replaced with nitrogen, the temperature was raised to 160-170°C and the reaction was maintained for 11 hours. During the reaction, the system pressure gradually increased to 0.6-0.7 MPa with increasing temperature.

[0180] After the reaction was completed, the reaction solution was subjected to vacuum distillation and purified. At a vacuum degree of 100 Pa, the 58-63°C fraction was collected and distilled to obtain 336.6 g of intermediate M1 with a yield of 70.0% (based on norbornene). It was a colorless liquid with a GC purity of 94.3%, and contained 3.0% of isomers.

[0181] Step S2, synthesis of intermediate M2:

[0182] Add 160.3 g (1 mol) of intermediate M1 and a 5% aqueous solution of p-toluenesulfonic acid (containing 0.2 mol of p-toluenesulfonic acid) into a 2L pressure bottle, raise the temperature to 130°C, increase the pressure to 0.2~0.3 MPa, and keep warm for 10 hours.

[0183] After the reaction was completed, the temperature was lowered to room temperature, and the reaction solution was extracted with 500 mL of dichloromethane. The extract was adjusted to pH 7-8 with a 10% by mass sodium bicarbonate solution, and then washed once with 300 mL of water. The organic phase was decompressed to remove the solvent to obtain a brown solid, which was purified by recrystallization with n-heptane to obtain 130.1 g of intermediate M2, with a yield of 73.0% (based on intermediate M1). It was in the form of a white solid with a GC purity of 96.6%.

[0184] Step S3: Synthesis of intermediate M3:

[0185] Under nitrogen protection, add 61.0g (0.48mol) oxalyl chloride and 400mL dichloromethane to a 2L three-necked flask, stir and cool to -65~-55℃. Dissolve 37.4g (0.48mol) DMSO in 100mL dichloromethane and slowly drop it into oxalyl chloride. The reaction is exothermic. Control the drop rate to maintain the temperature in the system at -65~-55℃. After about 1h of dropwise addition, keep the temperature at -65~-55℃ for 1h. Take 107.0g (0.60mol) of intermediate M2 and add 100mL dichloromethane to dissolve it, then slowly drop it into the reaction system. The reaction is exothermic. Control the drop rate to maintain the temperature in the system at -65~-55℃. After about 1h of dropwise addition, keep the temperature at -65~-55℃ for 0.5h. Then 303.6g (3.0mol) of triethylamine was dripped into the system. The system gradually became viscous due to the precipitation of a large amount of salt. It was necessary to increase the stirring rate to prevent the system from agglomerating. The reaction was highly exothermic. The dripping speed needed to be controlled to maintain the temperature in the system at -65~-55℃. After about 2h of dripping, the temperature was kept at -65~-55℃ for 1.5h. The cooling medium was removed, and the system was naturally heated to room temperature under stirring. The temperature was kept for 1h, and the solid gradually dissolved.

[0186] Dilute hydrochloric acid (wt=10%) was added dropwise to the reaction solution to adjust the pH to 2-5, and then the mixture was separated in a separatory funnel and washed with water until neutral. After the organic phase was decompressed to remove the solvent, it was purified by vacuum distillation. At a vacuum degree of 150Pa, the fraction of 110-115°C was collected to obtain 82.4g of intermediate M3, with a yield of 77.9% (based on intermediate M2). It was in the form of a yellow oily liquid with a GC purity of 92.1%, and contained 6.0% of isomers.

[0187] Step S4: Synthesis of intermediate M4:

[0188] Under nitrogen protection, add 19.4g (0.8mol) magnesium chips to a 1L three-necked flask and start stirring. Dissolve 87.2g (0.8mol) ethyl bromide in 400mL tetrahydrofuran, control the internal temperature at 20~25℃ and drip the ethyl bromide solution into the magnesium chips for reaction. The reaction is exothermic and the dripping is completed in about 1h. Keep the reaction at 20~25℃ for 1h. The magnesium chips gradually disappear and a light black and slightly turbid Grignard reagent is obtained. Dissolve 70.5g (0.40mol) of intermediate M3 in 100mL tetrahydrofuran, control the internal temperature at 55~60℃ and drip it into the Grignard reagent for reaction. The reaction is exothermic and the dripping is completed in about 1h. Keep the reaction at 55~60℃ for 0.5h.

[0189] The reaction solution was poured into a dilute hydrochloric acid prepared by mixing 17.5g (0.48mol, wt%=36%) concentrated hydrochloric acid and 100mL water to quench the reaction, and then 300mL toluene was added and stirred evenly, and then transferred to a separatory funnel and washed with water until neutral, and the organic phase was decompressed to remove the solvent to obtain 82.3g of yellow solid. The obtained product was refined by recrystallization from toluene to obtain 67.6g of intermediate M4, with a yield of 81.9% (based on intermediate M3), which was in the form of a white or light yellow solid, and GC purity: 97.6%.

[0190] Step S5, synthesis of intermediate M5:

[0191] Add 61.9 g (0.30 mol) of intermediate M4 and 300 mL of toluene into a 1 L three-necked flask, introduce 11.0 g (0.3 mol) of hydrogen chloride gas at 40-50 °C, and keep the reaction at this temperature for 0.5 h.

[0192] After the reaction, the pH value was adjusted to 6-7 with 10% sodium bicarbonate aqueous solution, and the solution was transferred to a separatory funnel to separate the aqueous phase. Intermediate M5 existed in the organic phase with a GC purity of 92.7%, and was directly used for the next step with a yield of 100%.

[0193] Step S6, synthesis of intermediate M6:

[0194] Add the organic phase containing intermediate M5 (theoretically containing 0.30 mol) obtained in the previous step to a 1L three-necked flask, then add 96.7 g (0.3 mol) of tetrabutylammonium bromide and 100 mL of water. Stir and heat to 40-50°C for 6 hours.

[0195] After the reaction, the reaction solution was transferred to a separatory funnel for separation, and the organic phase was washed twice with 200 mL of deionized water to remove salt. The obtained organic phase was decompressed to remove the solvent to obtain 61.6 g of a yellow solid. The obtained solid was recrystallized and purified with n-heptane to obtain 46.4 g of intermediate M6, with a yield of 75.0% (based on intermediate M4), which was in the form of a white solid with a GC purity of 99.9%.

[0196] Step S7, synthesis of target compound:

[0197] Add 61.9g (0.3mol) of intermediate M6, 21.9g (0.3mol) of diethylamine and 300mL of dichloromethane to a 1L three-necked flask, and cool to 30-40℃ with nitrogen stirring. Control the internal temperature at 30-40℃ and slowly drip 31.4g (0.3mol) of methacryloyl chloride. The dripping takes about 0.5h, and the reaction is kept at 30-40℃ for 6h.

[0198] After the reaction, 100 mL (wt% = 10%) of ammonia water was added to the system to quench the reaction, release heat, and control the internal temperature to 30-40 ° C. The dripping was completed for about 0.5 h, and the reaction was kept at 30-40 ° C (measured internal temperature 35 ° C) for 0.5 h. The reaction solution was transferred to a separatory funnel for stratification and washed with deionized water until neutral. 0.008 g of the inhibitor p-methoxyphenol was added to the obtained organic phase, and the solvent was removed under reduced pressure. The vacuum distillation was performed and the fraction of 135-150 ° C was collected at a vacuum degree of 100 Pa to obtain 65.9 g of the target compound, with a yield of 80.0% (based on the intermediate M6). It is a colorless oily liquid with HPLC purity of 99.8% and GPC purity of 99.9%.

[0199] Comparative Example 1

[0200] The intermediate M1 was prepared by the same method as step S1 of Example 1. However, when the hydrolysis reaction of step S2 was performed in this comparative example 1 to prepare the intermediate M2, hydrogen peroxide was used for the hydrolysis reaction, that is, the sulfuric acid catalyst in step S2 of Example 1 was replaced with an equal molar amount of hydrogen peroxide, and the other process conditions were the same as those of Example 1.

[0201] In step S2 of this comparative example 1, it was found through detection that the intermediate M2 compound could not be obtained, resulting in the failure of the entire technical route to proceed smoothly and the failure to obtain the target product. The following product was obtained in step S2 of this comparative example:

[0202] ;

[0203] It can be seen from this that in the preparation method of the present invention, a strong acid catalyst is used in step S2 to achieve the water and reaction of the configuration reversal of the intermediate M1 to obtain the intermediate M2, because under acidic conditions, carbon cations are more easily formed at the double bonds, thereby changing the connection of the bridge ring and then reversing the configuration of the bridge ring to obtain the target product, thereby achieving the smooth progress of the entire process route and finally obtaining the target product.

[0204] Comparative Example 2

[0205] The same method as steps S1-S4 of Example 1 was adopted to prepare intermediates M1, intermediate M2, intermediate M3 and intermediate M4. However, when the chlorination reaction of step S5 was carried out in this comparative example 2, the chlorination reagent hydrogen chloride in Example 1 was replaced with an equal molar amount of NCS, and the other process conditions were the same as those in Example 1.

[0206] In step S5 of this comparative example 2, it was found through detection that the intermediate M5 could not be obtained, which resulted in the failure of the entire technical route to proceed smoothly and the failure to obtain the target product. The following product was obtained in step S5 of this comparative example:

[0207] ;

[0208] It can be seen from this that in the preparation method of the present invention, the use of hydrogen chloride as a chlorination reaction reagent in step S5 can efficiently prepare the intermediate M5, because hydrogen chloride has higher selectivity when chlorinating tertiary alcohols, thereby achieving the smooth progress of the entire process route and finally obtaining the target product.

[0209] Comparative Example 3

[0210] The same method as steps S1-S5 of Example 1 was adopted to prepare intermediates M1, intermediate M2, intermediate M3, intermediate M4 and intermediate M5. However, when the hydrolysis reaction of step S6 was carried out in this comparative example 2, sodium hydroxide (1.0 equivalent) was added for the hydrolysis reaction, and the other process conditions were the same as those of Example 1.

[0211] In this comparative example 2, the compound prepared in step S6 is the same product as that in comparative example 2, and the intermediate M6 cannot be obtained, resulting in that the entire technical route cannot be carried out smoothly and the target product cannot be obtained.

[0212] It can be seen from this that the intermediate M6 can be successfully prepared using the phase transfer catalyst in step S6 of the preparation method of the present invention, because the tertiary carbon chloride ion is unstable, and under strong alkaline conditions, the side reaction of dehydrochlorination to form a double bond is more likely to occur, while under low pH conditions, the chloride ion can be more gently replaced by the hydroxyl group in the water molecule through the catalysis of the phase transfer catalyst, thereby achieving the smooth progress of the entire process route and finally obtaining the target product.

[0213] Comparative Example 4

[0214] The same method as steps S1-S5 of Example 1 was adopted to prepare intermediates M1, intermediate M2, intermediate M3, intermediate M4 and intermediate M5, but the amount of the phase transfer catalyst tetrabutylammonium bromide was increased in step S6 of this comparative example 2, and the amount of the phase transfer catalyst tetrabutylammonium bromide added in this comparative example 4 was 0.6 mol (equivalent to 2 equivalents of addition), and the other conditions were the same as in Example 1.

[0215] The yield of the intermediate M6 in step S6 of this comparative example 4 is 52.1%, and the GC purity is 96.2%. It can be seen from this that if the amount of phase transfer catalyst used in step S6 is increased, the yield and purity of the intermediate M6 will decrease, because the excessive amount of catalyst causes the reaction rate of the intermediate M6 with water to accelerate, and the rate of the side reaction of dehydrochlorination to form a double bond to accelerate due to the instability of the tertiary alcohol chloride ion. Therefore, the use of the phase transfer catalyst amount defined in the present invention is more conducive to obtaining a high-purity, high-yield intermediate M6, thereby improving the yield and purity of the final target product as a whole.

[0216] Comparative Example 5

[0217] The intermediate M1 was prepared by the same method as steps S1-S5 of Example 1, but when preparing the intermediate M2 in step S2 of this comparative example 2, the amount of sulfuric acid as a strong acid catalyst was increased. The amount of sulfuric acid added in this comparative example 5 was 3 mol (equivalent to 3 equivalents), and the other conditions were the same as in Example 1.

[0218] The yield of the intermediate M2 in step S2 of this comparative example 5 is 54.3%, and the GC purity is 90.2%. It can be seen from this that if the amount of the strong acid catalyst in step S2 is increased, the yield and purity of the intermediate M2 will decrease, because a higher acid amount will promote the etherification reaction between the target product and the raw material. Therefore, the use of the strong acid catalyst amount defined in the present invention is more conducive to obtaining a high-purity, high-yield intermediate M2, thereby improving the yield and purity of the final target product as a whole.

[0219] Comparative Example 6

[0220] The same method as steps S1-S5 of Example 1 was adopted to prepare intermediates M1, intermediate M2, intermediate M3, intermediate M4 and intermediate M5, but the reaction temperature was increased in step S6 of this comparative example 6. The reaction temperature of step S6 of this comparative example 6 was 60-70°C (higher than the reaction temperature specified in the present invention), and other conditions were the same as those in Example 1.

[0221] The yield of the intermediate M6 in step S6 of this comparative example 6 is 21.4%, and the GC purity is 97.6%. It can be seen from this that if the reaction temperature of step S6 is increased, the yield and purity of the intermediate M6 will decrease. Because of the instability of tertiary alcohol chloride ions, too high a reaction temperature will accelerate the rate of the side reaction of dehydrochlorination to form double bonds. Therefore, the reaction temperature defined in the present invention is more conducive to obtaining a high-purity, high-yield intermediate M6, thereby improving the yield and purity of the final target product as a whole.

[0222] Comparative Example 7

[0223] In step S1 of this comparative example 7, when preparing the intermediate M1, the reaction temperature is lowered. In this comparative example 1, the reaction temperature is 100-110° C., and other conditions are the same as those in Example 1.

[0224] In step S1 of this comparative example 7, it was found through detection that the intermediate M1 could not be obtained, which resulted in the failure of the entire technical route to proceed smoothly and the failure to obtain the target product. The reason is that in step S1 of this comparative example, cyclopentadiene mainly undergoes a self-polymerization reaction at 100-110° C. to generate dicyclopentadiene, so that the target product could not be obtained.

[0225] It can be seen from this that in the preparation method of the present invention, step S1 must be carried out at the reaction temperature specified in the present invention to obtain the intermediate M1, thereby achieving the smooth progress of the entire process route and ultimately obtaining the target product.

[0226] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are exhaustively listed. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0227] For those skilled in the art, several modifications and improvements may be made without departing from the concept of the present invention, all of which belong to the protection scope of the present invention. The protection scope of the present invention shall be based on the attached claims.

Claims

1. A method for preparing a photoresist monomer containing an exo-exo bi-norbornane structure, characterized in that: The preparation method of the photoresist monomer is: S1. Preparation of intermediate M1: ； The intermediate M1 is obtained by reacting norbornene with cyclopentadiene by DA addition reaction under heating and pressure with the addition of a polymerization inhibitor, and then post-processing; the polymerization inhibitor is any one of phenothiazine, 2,6-di-tert-butyl-p-methylphenol, p-methoxyphenol, and hydroquinone, or a combination of two thereof; S2. Preparation of intermediate M2: ； The intermediate M1 is subjected to a reflux reaction under the catalysis of a strong acid catalyst, and then undergoes a configuration-inverted hydration reaction, followed by post-treatment to obtain the intermediate M2; the strong acid catalyst is any one of formic acid, methanesulfonic acid, p-toluenesulfonic acid, and sulfuric acid, or a combination of two thereof; S3, preparation of intermediate M3: ； The intermediate M2 is oxidized and then post-treated to obtain the intermediate M3; S4, preparation of intermediate M4: ； Intermediate M3 reacts with ethylmagnesium chloride Grignard reagent through nucleophilic addition reaction and then undergoes post-treatment to obtain intermediate M4; S5. Preparation of intermediate M5: ； Intermediate M5 is prepared by chlorination reaction of intermediate M4 with hydrogen chloride; S6, preparation of intermediate M6: ； The intermediate M5 is hydrolyzed in the presence of a phase transfer catalyst and then post-treated to obtain the intermediate M6; S7. Preparation of target compound: ； The intermediate M6 is reacted with methacryloyl chloride via esterification and then post-treated to obtain the target compound.

2. The method for preparing a photoresist monomer containing an exo-exo bi-norbornane structure according to claim 1, characterized in that: The specific operation of step S1 is as follows: in a reactor, 1 equivalent of norbornene, 0.1-5.0% times the mass of norbornene as a polymerization inhibitor, and 0.8-2.0 equivalents of cyclopentadiene are fully mixed, and after the system is fully replaced with an inert gas, the temperature is raised to 160-200° C. and the reaction is kept warm for 10-12 hours. After the reaction is completed, the reaction liquid is subjected to vacuum distillation and purification to obtain an intermediate M1.

3. The method for preparing a photoresist monomer containing an exo-exo bis-norbornane structure according to claim 1, characterized in that: The specific operation of step S2 is: fully mix 1 equivalent of intermediate M1 and 0.2-2.0 equivalents of strong acid catalyst, heat to 80-130°C and keep warm for reaction for 10-12 hours, cool to room temperature after the reaction is completed, extract the reaction solution with dichloromethane, adjust the pH of the extract to 7-8 with sodium bicarbonate solution, wash with water, and remove the solvent from the organic phase under reduced pressure; the obtained product is recrystallized and refined to obtain intermediate M2.

4. The method for preparing a photoresist monomer containing an exo-exo bis-norbornane structure according to claim 3, characterized in that: The concentration of the strong acid catalyst is 5% to 50%.

5. The method for preparing a photoresist monomer containing an exo-exo bis-norbornane structure according to claim 1, characterized in that: The specific operation of step S3 is as follows: under the protection of inert gas, 0.8-2.0 equivalents of oxalyl chloride are dissolved in dichloromethane, stirred and cooled to -85--55°C, an equivalent amount of DMSO is dissolved in dichloromethane, and the dichloromethane solution of DMSO is slowly added dropwise to the dichloromethane system of oxalyl chloride at an internal temperature of -85--55°C for reaction, and the reaction is kept warm for 0.5-1h; 1 equivalent of intermediate M2 is dissolved in dichloromethane, the internal temperature is controlled at -85--55°C, the dichloromethane solution of intermediate M2 is slowly added dropwise to the reaction system, the reaction is kept warm for 0.5-1h, and then 2.0-5.0 equivalents of triethylamine are added dropwise to the system at an internal temperature of -85--55°C, the reaction is kept warm for 1-2h, the system is naturally heated to room temperature under stirring, and the reaction is continued at room temperature for 0.5-1h; After adding dilute hydrochloric acid dropwise to the reaction solution to adjust the pH to 2-5, the organic phase is separated and washed with water until neutral. After the organic phase is decompressed to remove the solvent, it is purified by vacuum distillation to obtain the intermediate M3.

6. The method for preparing a photoresist monomer containing an exo-exo bis-norbornane structure according to claim 1, characterized in that: The specific operation of step S4 is as follows: under the protection of inert gas, 1 equivalent of intermediate M3 is dissolved in tetrahydrofuran, and the internal temperature is controlled at 20-60° C., and the mixture is added dropwise to 1-2 equivalents of ethylmagnesium bromide Grignard reagent to react, and the mixture is kept warm at 20-60° C. for 0.5-1 h; the reaction solution is poured into dilute hydrochloric acid to quench the reaction, the organic phase is washed with water until it is neutral, and the solvent is removed under reduced pressure. The obtained product is refined by recrystallization to obtain intermediate M4.

7. The method for preparing a photoresist monomer containing an exo-exo bis-norbornane structure according to claim 1, characterized in that: The specific operation of step S5 is as follows: dissolving 1 equivalent of intermediate M4 in an organic solvent, adding 1-3 equivalents of hydrogen chloride, and reacting at 0-50° C. for 0.5-1 h. After adjusting the pH of the reaction solution to 6-7 with an aqueous sodium bicarbonate solution, the organic phase containing the intermediate M5 is directly used for the next reaction.

8. The method for preparing a photoresist monomer containing an exo-exo bis-norbornane structure according to claim 1, characterized in that: The specific operation of step S6 is: add 0.1~1.0 equivalent of phase transfer catalyst and water to the organic phase containing intermediate M5 obtained in step S5, control the temperature at 10~50°C, keep the reaction for 6~8h, wash the reaction solution with water until neutral, remove the solvent from the organic phase under reduced pressure, and then refine the product by recrystallization with an organic solvent to obtain intermediate M6.

9. The method for preparing a photoresist monomer containing an exo-exo bis-norbornane structure according to claim 1, characterized in that: The specific operation of step S7 is as follows: dissolving 1 equivalent of intermediate M6 and 1-4 equivalents of acid-binding agent in dichloromethane, controlling the internal temperature at -30-40°C, slowly dropping 1-4 equivalents of methacryloyl chloride, and keeping the temperature for reaction for 6-8 hours. After the reaction is completed, adding ammonia water to the system to quench the reaction; washing the reaction solution with deionized water until neutral, adding an inhibitor to the obtained organic phase, removing the solvent under reduced pressure, and refining by reduced pressure distillation to obtain the target compound.

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