CN113912520A

CN113912520A - Photoacid generators and process for producing the same

Info

Publication number: CN113912520A
Application number: CN202111204968.2A
Authority: CN
Inventors: 傅志伟; 潘新刚; 梅崇余; 纪兴跃
Original assignee: Jiangsu Hantuo Optics Material Co ltd
Current assignee: Xuzhou B&c Chemical Co ltd
Priority date: 2021-10-15
Filing date: 2021-10-15
Publication date: 2022-01-11

Abstract

The invention discloses a photoacid generator and a preparation method thereof, belonging to the technical field of organic synthesis. The general structural formula of the photoacid generator is as follows:

wherein R is₁Is an alicyclic hydrocarbon group, R₂Is alkylene, R₃Is hydrogen or alkyl. The preparation method of the photoacid generator comprises the steps of reacting a compound III and a compound II in a first solvent through ion exchange, and purifying to obtain the photoacid generator I. The invention synthesizes a new photoacid generator and the synthesis method has high yield and high purity.

Description

Photoacid generators and process for producing the same

Technical Field

The invention relates to the technical field of organic synthesis, in particular to a photoacid generator and a preparation method thereof.

Background

The photoacid generator is the main component of a chemically amplified resist, and is a photosensitive compound that decomposes under light to generate an acid (H +). These acids act as catalysts to cleave pendant acid labile groups on the polymer during Post Exposure Bake (PEB) and generate new acids, which cleave the pendant groups changing the polarity of the polymer.

The chemical structures of the anion and cation of the photoacid generator can determine or affect the characteristics and properties of the photoacid generator, e.g., the structure of different anions can lead to different photoacid activity generated after the photoresist is irradiated, and different chemical compositions, shapes, and sizes can also lead to significant changes in the solubility, diffusivity, stability, volatility, acidity, and catalytic activity of the photoacid generator or its conjugate.

Chinese patent CN101727004A discloses a photoacid generator, but the anion and cation structures in the photoacid generator disclosed in the patent contain more benzene ring structures, and the absorption of the benzene ring structure at 193nm is large, which may affect the exposure of the bottom layer of the photoresist. Therefore, there is a need in the art for photoacid generators that can improve the resolution of photoresists.

Disclosure of Invention

The invention aims to provide a novel photoacid generator and a preparation method thereof.

To achieve the above and other related objects, the present invention provides a photoacid generator having a general structural formula as follows:

wherein R is₁Is an alicyclic hydrocarbon group, R₂Is alkylene, R₃Is hydrogen or alkyl.

Further, at least one of the following technical characteristics is also included:

a1) the R is₁Selected from adamantyl;

a2) the R is₂Is C₁～C₆An alkylene group of (a);

a3) the R is₃Is hydrogen or C₁～C₆An alkyl group.

Further, the photoacid generator is selected from one of the following structures:

the anion of the photoacid generator contains adamantyl, namely an alicyclic structure with a larger volume, so that the acid diffusion in the post-baking process can be effectively inhibited, and the resolution of the photoresist is improved.

The preparation method of the photoacid generator comprises the steps of A, carrying out ion exchange reaction on a compound III and a compound II in a first solvent to obtain a photoacid generator I; the reaction route is as follows:

wherein R is₁Is an alicyclic hydrocarbon group, R₂Is alkylene, R₃Is hydrogen or alkyl, X is halogen.

Further, in the step a, at least one of the following technical features is also included:

b1) the molar ratio of the compound III to the compound II is 1: 1-1: 2;

b3) the first solvent comprises a mixed solution of dichloromethane and water;

b3) the preparation method further comprises the following steps: and (3) after the reaction, carrying out purification, wherein the purification process specifically comprises the steps of layering the reaction liquid, washing the organic phase with water, drying and filtering.

Further comprises a step B of heating and cyclizing the compound II-1 in a second solvent, and purifying to obtain the compound II:

wherein, R is₃Is hydrogen or alkyl, and X is halogen.

Further, in the step B, at least one of the following technical features is also included:

c1) the second solvent is a mixed solution of acetone and water; preferably, the volume ratio of acetone to water is 1: 1;

c2) the preparation method further comprises the following steps: and (3) after the reaction, purifying, wherein the purification process specifically comprises the steps of concentrating the reaction solution, adding methyl tert-butyl ether, stirring for layering, removing a methyl tert-butyl ether organic phase, extracting a water phase by using dichloromethane, combining dichloromethane organic phases, drying, filtering, concentrating and crystallizing.

Further, the method comprises a step C of reacting a compound II-3 with a compound II-2 in the presence of a first alkaline compound, and purifying to obtain a compound II-1; the synthetic route is as follows:

wherein, R is₃Is hydrogen or alkyl, and X is halogen.

Further, in the step C, at least one of the following technical features is also included:

d1) the first basic compound is at least one selected from triethylamine, sodium hydroxide, potassium hydroxide, DIPEA and sodium methoxide;

d2) the molar ratio of the compound II-2 to the first basic compound is 1: 1-1: 3;

d3) the preparation method further comprises the following steps: and (3) purifying after the reaction, wherein the purification process specifically comprises the steps of adding water, extracting with dichloromethane, layering, combining dichloromethane organic phases, drying, filtering and concentrating.

Further comprising a step D of chlorinating the compound III-1 and then reacting the chlorinated compound with the compound III-2 under the condition of a second alkaline compound to obtain a compound III; the reaction route is as follows:

wherein R is₁Is an alicyclic hydrocarbon group, R₂Is alkylene, and M is alkali metal.

Further, in the step D, at least one of the following technical features is also included:

e1) the molar ratio of the compound III-2, the compound III-1 and the second basic compound is 1:1.5: 1.5-1: 3: 3;

e2) the second basic compound is at least one selected from triethylamine, sodium hydroxide, potassium hydroxide, DIPEA and sodium methoxide;

e3) the reaction temperature is 20-40 ℃, and the reaction time is 12-24 hours;

e4) the preparation method further comprises the following steps: and (3) after the reaction, carrying out purification, wherein the purification process specifically comprises the steps of adding methanol for quenching, filtering, concentrating the filtrate, pulping by using methyl tert-butyl ether, removing the supernatant, adding dichloromethane for dissolving, washing by using deionized water, and concentrating the organic phase.

Further comprises a step E of reacting the compound III-4 with the compound III-3 in a third solvent in the presence of a catalyst, and purifying to obtain a compound III-2; the reaction route is as follows:

wherein R is₂Is alkylene, and M is alkali metal.

Further, in the step E, at least one of the following technical features is also included:

f1) the molar ratio of the compound III-4 to the compound III-3 is 1: 3-1: 8;

f2) the catalyst is selected from at least one of p-toluenesulfonic acid monohydrate, sulfuric acid, thionyl chloride and hydrochloric acid;

f3) the reaction temperature is 60-80 ℃, and the reaction time is 12-24 hours; please confirm the value range;

f4) the third solvent is one selected from 1, 2-dichloroethane, toluene, n-hexane and cyclohexane;

f5) the preparation method further comprises the following steps: and (3) purifying after the reaction, wherein the purification process specifically comprises the steps of reduced pressure distillation, pulping, filtering and drying.

Further comprising a step G of reacting methyl fluorosulfonyl difluoroacetate III-6 with a third basic compound to obtain a compound III-5; further comprising a step F of reacting the compound III-5 in the presence of an acidic compound to obtain a compound III-4; the reaction route is as follows:

wherein M is an alkali metal

g1) in the step G, the molar ratio of the fluorosulfonyl difluoroacetic acid methyl ester III-6 to the alkaline compound is 1: 1-1: 10;

g2) in step G, the third basic compound is selected from one of sodium hydroxide, potassium hydroxide, sodium methoxide, sodium tert-butoxide, tetrabutylammonium hydroxide;

g3) in the step G, the reaction temperature is 25-100 ℃, and the reaction time is 1-24 hours;

g4) in the step F, the molar ratio of the fluorosulfonyl difluoroacetic acid methyl ester III-6 to the acidic compound is 1: 1-1: 5;

g5) in step F, the acidic compound is selected from one of toluenesulfonic acid monohydrate, hydrochloric acid or sulfuric acid;

g6) in the step F, the reaction temperature is 25-80 ℃, and the reaction time is 1-10 hours.

Compared with the prior art, the synthetic photoacid generator is a novel photoacid generator, and the synthetic method has high yield and high purity.

Drawings

FIG. 1 is a liquid chromatogram of compound MII-1 of example 1;

FIG. 2 is a liquid chromatogram of compound MII of example 1;

FIG. 3 is a nuclear magnetic spectrum of compound MII of example 1;

FIG. 4 is a liquid chromatography mass spectrum of compound MII of example 1;

FIG. 5 is a liquid chromatography mass spectrum of compound IIIIII-5 of example 1;

FIG. 6 is a liquid chromatogram of Compound IIIIII-4 of example 1

FIG. 7 is a liquid chromatography mass spectrum of compound IIII-2 of example 1;

FIG. 8 is a nuclear magnetic spectrum of compound IIIIII-2 of example 1;

FIG. 9 is a liquid chromatography mass spectrum of compound IIIM of example 1;

FIG. 10 is a liquid chromatogram of compound IIIM of example 1;

FIG. 11 is a nuclear magnetic spectrum of compound IIII of example 1;

FIG. 12 is a liquid chromatogram of the photoacid generator MI in example 1;

FIG. 13 is a nuclear magnetic spectrum of the photoacid generator MI in example 1.

Detailed Description

The technical solution of the present invention will be further specifically described below by way of specific examples. It is to be understood that the practice of the invention is not limited to the following examples, and that any variations and/or modifications may be made thereto without departing from the scope of the invention.

In the present invention, the equipment, raw materials, etc. used are commercially available or commonly used in the art. The methods in the following examples are conventional in the art unless otherwise specified.

The photoacid generator consists of a cationic structure and an anionic structure.

Example 1

1-1. Synthesis of cation Structure

Synthesis of Compound MII-1

1, 4-dibromobutane MII-3 (1118.46g, 5.18mol) and triethylamine (78.4g, 0.775mol) were added to a 2L reaction flask, stirred at room temperature, 4-tert-butylphenol MII-2 (86g, 0.517mol) was added dropwise, and stirred overnight at room temperature after completion of the dropwise addition. Direct sampling and TLC detection, wherein the developing solvent is EtOAc/PE-1/5, Rf of compound MII-1 is about 0.6, Rf of 4-tert-butyl thiophenol MII-2 is about 0.4, and no obvious MII-2 point is obtained.

After the reaction, 5% diluted hydrochloric acid (250mL) and water (500mL) were added to the reaction mixture, and the mixture was extracted with dichloromethane, the layers were separated, the resulting organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated to remove dichloromethane, and then the excess 1, 4-dibromobutane was recovered by distillation under reduced pressure, and the yellow liquid residue remaining at the bottom of the flask was compound MII-1, having a mass of 150g, a molar yield of 96.26%, and a purity by HPLC (as shown in FIG. 1) of 92.6%.

1, 4-dibromobutane is directly used as a solvent in the reaction, triethylamine is added as an acid-binding agent, so that after the reaction is finished, water is firstly added to wash to remove triethylamine hydrobromide in the system, then redundant 1, 4-dibromobutane is distilled and recovered, and the obtained residue is the compound MII-1.

Synthesis of Compound MII

A2L reaction flask was charged with Compound MII-1 (150g, 0.498mol), water (450mL) and acetone (450mL) and heated to reflux for 5 h. Sampling is carried out directly, and TLC detection is carried out, wherein the developing solvent is EtOAc/PE ═ 1/5, Rf of the compound MII is ≈ 0.6, and Rf of the compound MII-1 is ≈ 0, so that the obvious compound MII-1 is not generated.

After the reaction, the acetone was removed by concentration under reduced pressure, methyl tert-butyl ether (450mL) was added and stirred, the layers were separated, the organic phase was discarded, the aqueous phase was extracted with dichloromethane (300 mL. times.3), the dichloromethane phases were combined, dried over anhydrous sodium sulfate, filtered, concentrated to remove most of the dichloromethane, tetrahydrofuran (450mL) was added, stirred at 0-5 ℃ for 30min to precipitate a large amount of white solid, filtered, and dried under reduced pressure to give compound MII with a mass of 50g, a molar yield of 33.33%, and a purity of HPLC (as shown in FIG. 2) of 97.5%.

Nuclear magnetic spectrum of compound xii (shown in fig. 3): 1H NMR (400MHz, CDCl 3): δ 7.29(q, J ═ 8.5Hz,4H),3.40(t, J ═ 6.7Hz,2H),2.91(t, J ═ 7.1Hz,2H), 2.05-1.89 (m,2H),1.78(dt, J ═ 14.5,7.2Hz,2H), 1.40-1.23 (m, 10H).

MS spectrum of compound xii (shown in fig. 4), LC-MS (ES +): m + 221.0.

No other by-products are generated in the reaction, and impurities in the system can only be brought in the first step, so that after the reaction is finished, acetone is concentrated to remove, then methyl tert-butyl ether is added to wash and remove small-polarity fat-soluble impurities (the compound MII is salt dissolved in water), then dichloromethane is used to extract the compound MII, after dichloromethane is concentrated to remove, tetrahydrofuran is added to separate out white solid, and the compound MII with qualified purity is obtained. After the tetrahydrofuran is added, the second intermediate can explode out, so that stirring is influenced, and special attention is required; the compound MII needs to be protected from light.

1-2, synthesis of anionic structure

Synthesis of Compound IIII-5

Methyl fluorosulfonyl difluoroacetate M III-6 (50g, 0.260mmol) was added to a 1L reaction flask, the temperature was reduced to 0-10 ℃, water (170g) was added thereto, and the mixture was stirred at 0-10 ℃. Sodium hydroxide (34.36g, 0.859mmol) and water (80g) were made into a solution, which was then added dropwise to the reaction system with the internal temperature controlled not to exceed 10 ℃. After the dropwise addition, the temperature is raised to 100 ℃ for reaction for 3 hours. After the reaction is finished, cooling to 0-10 ℃, adjusting the pH of the system to about 8 by using concentrated hydrochloric acid, then filtering by using diatomite to remove a small amount of suspended matters in the system, and concentrating the filtrate under reduced pressure to dryness to obtain 68.17g of white solid containing M III-5 with the yield of more than 100% (containing inorganic salt). The white solid was fed in the next step without purification.

MS spectrum (shown in FIG. 5) of compound M III-5, LC-MS (ES-): m-175.0.

The dropping speed of the sodium hydroxide solution is not too fast, the heat release is violent in the early stage of the dropping, and the heat release is stable in the later stage. The pH of the system should not be too low (preferably not less than 8) by adjusting the pH with concentrated hydrochloric acid to prevent part of the sulfonic acid groups from dissociating.

A1L reaction flask was charged with the white solid containing MIII-5 from the previous step (68.17g), acetonitrile (668g), p-toluenesulfonic acid monohydrate (69.31g, 0.364mmol) and heated to reflux for 3 h.

After the reaction is finished, the temperature is reduced to room temperature, the reaction product is filtered, the filter cake is washed by a small amount of acetonitrile, the filter cake (moisture 100g) is discarded as solid waste, the filtrate is concentrated to be dry to obtain 50g of viscous substance, methyl tert-butyl ether (MTBE) (500mL) is added, the temperature is increased to reflux and pulping is carried out for 1h, a large amount of white solid exists in the system, the reaction product is reduced to room temperature and filtered, the filter cake is leached by a small amount of MTBE and dried to obtain a compound M III-4, the white solid is 37.75g, the molar yield is 73.23% (based on the compound M III-6, the two-step total yield), the HPLC (shown in figure 6) purity 91.19% (the retention time is close to that of p-toluenesulfonic acid, and an ultraviolet detector is used for analysis, so that the data can not be accurate).

The MTBE is fully stirred when the oily viscous substance obtained after the solvent is removed by rotation, and the system can be quickly solidified to separate out solid at the moment, so that the stirring is influenced. The compound IIIII-4 is easy to absorb moisture, and needs to be taken out and stored.

Synthesis of Compound IIII-2

Compound M III-4 (113g, 0.570mmol), 1, 2-dichloroethane (1359g), p-toluenesulfonic acid monohydrate (21.70g, 0.114mmol) and ethylene glycol M III-3 (177.05g, 2.852mmol) were added to a 2L four-necked flask and magnetically stirred, warmed to reflux, partitioned with water and stirred for 6 h.

After the reaction, the excess solvent was distilled off under reduced pressure, the excess ethylene glycol was distilled off under reduced pressure using an oil pump to give a pale yellow viscous product, MTBE (1.1L) was added and the product was slurried under reflux for 1h, filtered, rinsed with a small amount of MTBE, and dried to give compound M iii-2, an off-white solid 124.82g, molar yield 90.36%, purity by HPLC (as shown in fig. 8) 98.06% (retention time was very similar to p-toluenesulfonic acid, and analysis was performed using a uv detector, so this data may not be accurate).

MS spectrum (shown in FIG. 7) of compound M III-2, LC-MS (ES-): m-219.1.

Neither compound M III-4 nor compound M III-2 in this step can be developed with the existing developer, so that the end point of the reaction cannot be determined, and only the reaction time in the reference literature is used for stopping the reaction.

The compound M III-2 is apt to absorb moisture, and special attention should be paid to the post-treatment, storage and handling.

Synthesis of Compound IIII

A1L reaction flask equipped with magnetic stirring was first replaced 3 times with nitrogen, then compound M III-2 (50g, 0.207mmol) and acetonitrile (245.5g) previously dried with molecular sieves were added, stirred at room temperature, suspended in white, cooled to 0-5 ℃ and triethylamine (41.79g, 0.413mmol) was added.

Another reaction flask was charged with pre-prepared adamantane carbonyl chloride (82.060g, 0.413 mmol); dissolving 1.0eq of adamantanecarboxylic acid MIII-1 in 10V (10 times volume) of DCM, adding a catalytic amount of DMF, dropwise adding 1.5eq of thionyl chloride at 0-10 ℃, slowly heating to reflux for 2h after the dropwise addition, concentrating to dryness) and acetonitrile (245.5g) dried by a molecular sieve in advance, and preparing a solution in nitrogen atmosphere.

And (3) dropwise adding the prepared adamantane formyl chloride solution into the reaction system at the temperature of 0-5 ℃, slowly heating to room temperature after dropwise addition, and stirring for reacting for 20 hours.

After the reaction, adding a methanol quenching system, filtering suspended matters in the system by using kieselguhr, concentrating the filtrate to be dry to obtain a yellow viscous substance, pulping by using MTBE (500mL multiplied by 3), discarding a supernatant, adding dichloromethane DCM (500mL) for dissolving, washing by using deionized water (300mL multiplied by 4), concentrating an organic phase, adding new DCM, concentrating again, repeating for 3 times, adding MTBE, concentrating to be dry to obtain a crude tawny oily substance 44g, wherein the molar yield is 44.07%, and the HPLC purity is 95.51% (evaporation light detector);

adding MTBE (440mL) into a 1L reaction bottle, cooling to-60-70 ℃, then preparing a solution of the crude product and DCM (44mL), slowly dripping into the MTBE to gradually precipitate a large amount of light yellow solid, keeping the temperature of-60-70 ℃ after dripping, stirring for 1h, carrying out suction filtration, eluting a filter cake by the MTBE which is pre-cooled to-60-70 ℃, drying to obtain a compound M III, 31.5g of yellow solid, 31.55 percent of molar yield and 99.88 percent of purity by HPLC (shown in figure 10) (an evaporation light detector).

MS spectrum of compound M iii (shown in fig. 9), LC-MS (ES-): m-381.01, LC-MS (ES +): m +102.11

Nuclear magnetic spectrum of compound M iii (shown in fig. 11):¹H NMR(400MHz,CDCl3)δ8.96(s,1H),4.52(dd,J＝5.7,4.0Hz,2H),4.43–4.25(m,2H),3.17(qd,J＝7.3,4.9Hz,6H),1.99(s,3H),1.87(d,J＝2.9Hz,6H),1.70(d,J＝10.6Hz,6H),1.37(t,J＝7.3Hz,9H)。

acyl chloride is used in the reaction, and the reaction system is ensured to be anhydrous as far as possible.

The reaction time cannot be too short, the consumption of adamantane formyl chloride cannot be too small, and otherwise, the raw material M3 remains; after the reaction is finished, the redundant adamantane formyl chloride is quenched by methanol, the polarity of the quenched ester is very small, the quenched ester is easy to remove, and if the quenched ester is quenched by water, the formed adamantane formic acid is difficult to remove; the intermediate in the step can be fed later only by ensuring the purity (no methylene corresponding miscellaneous peak exists on H-NMR, or the relative content is less than 1 percent), otherwise, the intermediate can not be removed after being carried into a final product; if the purity is not sufficient, recrystallization may be carried out.

1-3 Synthesis of photoacid generators

Synthesis of photoacid generators MI

A500L reaction flask was charged with Compound MII (10.88g, 0.036mol), Compound MIII (17.12g, 0.035mol), water (170mL) and methylene chloride (170mL) and stirred at room temperature for 2 h. And (3) detecting by TLC, wherein a developing solvent is MeOH/DCM (No. 1/8), Rf (apprxeq.0.4) of the photoacid generator M I, and Rf (apprxeq.0.35) of the raw material has a question), and no obvious raw material point exists.

After the reaction, the layers were separated, and the organic phase was washed with water (170mL × 3), dried over anhydrous sodium sulfate, filtered, concentrated to remove dichloromethane, and dried by an oil pump to obtain a yellow oil, which was left overnight at room temperature and solidified to obtain a pale yellow solid, i.e., photoacid generator M i, having a mass of 21.26g, a molar yield of 100%, and a purity of 96.8% by HPLC (as shown in fig. 12).

Nuclear magnetic spectrum of photoacid generator moi (shown in fig. 13): 1H NMR (400MHz, CDCl3) δ 7.74(dd, J ═ 9.0,2.1Hz,2H),7.65(d, J ═ 8.7Hz,2H), 4.63-4.44 (m,2H),4.31(dd, J ═ 5.8,4.2Hz,2H), 4.28-4.13 (m,2H),3.65(dt, J ═ 6.0,4.5Hz,2H),2.57(dt, J ═ 11.8,6.0Hz,4H),1.98(s,3H),1.87(d, J ═ 2.7Hz,6H), 1.77-1.60 (m,6H), 1.42-1.26 (m,9H).

Dissolving triethylamine hydrobromide generated in the reaction in water, thus washing and removing the triethylamine hydrobromide by using water after the reaction is finished, simultaneously washing and removing a slight excess sulfonium intermediate, drying, and removing the solvent to obtain a qualified target product without recrystallization and purification.

Example 2

2-1. cationic structure synthesis

Synthesis of Compound NII-1: the synthesis method is the same as the synthesis method of the compound MII-1 in the example 1, except that 4-tert-butyl thiophenol MII-2 is replaced by thiophenol MII-2, other conditions are not changed, the synthesis route is as follows,

the feeding amount of thiophenol NII-2 is as follows: 56.96g, 0.517 mol.

The compound NII-1 obtained by the reaction was a colorless liquid with a mass of 120.8g, a molar yield of 95.30% and an HPLC purity of 93.3%.

Synthesis of Compound NII: the same procedure as used in example 1 for the synthesis of compound MII, except that compound MII-1 was replaced by compound NII-1, the other conditions were unchanged, the synthetic route was as follows,

the charge amount of the compound NII-1 is as follows: 122g, 0.498 mol. Reasonable feeding amount

The compound N II obtained by the reaction was a white solid with a mass of 42g, a molar yield of 35% and an HPLC purity of 99.0%.

2-2 Synthesis of photoacid generators

Synthesis of photoacid generator ni: the same synthesis method as that of the photoacid generator MI in example 1 was used, except that the compound MII was replaced with the compound NII, and other conditions were not changed, and the synthesis route was as follows,

the charge amount of the compound NII is as follows: 8.82g, 0.036 mol.

The compound N i obtained by the reaction was a white solid with a mass of 19.1g, a molar yield of 99.8% and an HPLC purity of 99.3%.

Example 3

3-1. cationic structure synthesis

Synthesis of Compound PII-1: the synthesis method is the same as the synthesis method of the compound MII-1 in the example 1, except that 4-tert-butyl thiophenol MII-2 is replaced by 2-tert-butyl thiophenol PII-2, other conditions are not changed, the synthesis route is as follows,

the feeding amount of the thiophenol PII-2 is as follows: 86g, 0.517 mol.

The compound PII-1 obtained by the reaction was a yellow liquid with a mass of 147g, a molar yield of 94.37% and an HPLC purity of 93.1%.

Synthesis of Compound PII: the same procedure as that for the synthesis of compound MII in example 1, except that compound MII-1 was replaced by compound PII-1, the other conditions were unchanged, the synthetic route was as follows,

the feeding amount of the compound PII-1 is as follows: 150g, 0.498 mol.

The compound pii obtained by the reaction was a white solid with a mass of 45.6g, a molar yield of 30.4% and an HPLC purity of 99.3%.

3-2 Synthesis of photoacid generators

Synthesis of photoacid generator pi: the same synthesis method as that of the photoacid generator MI in example 1 was used, except that the compound MII was replaced with the compound PII, and other conditions were not changed, and the synthesis route was as follows,

the charge amount of the compound PII is as follows: 10.88g, 0.036 mol.

The compound Pi obtained by the reaction was an off-white solid with a mass of 21.25g, a molar yield of 99.5% and an HPLC purity of 99.0%.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

Claims

1. A photoacid generator, wherein the photoacid generator has the following general structural formula:

2. The photoacid generator of claim 1 further comprising at least one of the following technical features:

a1) the R is₁Selected from adamantyl;

a2) the R is₂Is C₁～C₆An alkylene group of (a);

a3) the R is₃Is hydrogen or C₁～C₆An alkyl group.

3. The photoacid generator of claim 2 wherein the photoacid generator is selected from one of the following structures:

4. a process for producing a photoacid generator as claimed in any one of claims 1 to 3, comprising a step a of obtaining a photoacid generator i by ion exchange reaction of a compound iii with a compound ii in a first solvent; the reaction route is as follows:

5. The method for producing a photoacid generator according to claim 4, wherein in step a, at least one of the following technical features is further included:

b1) the molar ratio of the compound III to the compound II is 1: 1-1: 2;

b3) the first solvent comprises a mixed solution of dichloromethane and water;

6. The method for producing a photoacid generator according to claim 4, further comprising a step B of subjecting compound ii-1 to cyclization under heating in a second solvent to obtain the compound ii; the reaction route is as follows:

wherein, R is₃Is hydrogen or alkyl, and X is halogen.

7. The method for producing a photoacid generator according to claim 6, wherein in step B, at least one of the following technical features is further included:

c1) the second solvent is a mixed solution comprising acetone and water;

8. The method for producing a photoacid generator according to claim 6, further comprising a step C of reacting compound ii-3 with compound ii-2 in the presence of a first basic compound to obtain compound ii-1; the synthetic route is as follows:

wherein, R is₃Is hydrogen or alkyl, and X is halogen.

9. The method for producing a photoacid generator according to claim 8, characterized by further comprising at least one of the following technical features in step C:

10. The method of claim 4 further comprising a step D of chlorinating compound iii-1 and then reacting with compound iii-2 under a second basic compound condition to obtain said compound iii; the reaction route is as follows:

11. The method for producing a photoacid generator according to claim 10, further comprising at least one of the following technical features in step D:

12. The method for producing a photoacid generator according to claim 10, further comprising step E of reacting compound iii-4 with compound iii-3 in the presence of a catalyst in a third solvent to obtain compound iii-2; the reaction route is as follows:

wherein R is₂Is alkylene, and M is alkali metal.

13. The method for producing a photoacid generator according to claim 12, wherein in step E, at least one of the following technical features is further included:

f1) the molar ratio of the compound III-4 to the compound III-3 is 1: 3-1: 8;

f3) the reaction temperature is 60-80 ℃, and the reaction time is 12-24 hours;

f4) the third solvent is selected from one of 1, 2-dichloroethane, toluene, n-hexane and cyclohexane;

14. The method of producing a photoacid generator according to claim 12, further comprising a step G of reacting methyl fluorosulfonyl difluoroacetate iii-6 with a third basic compound to obtain a compound iii-5; further comprising a step F of reacting the compound III-5 in the presence of an acidic compound to obtain a compound III-4; the reaction route is as follows:

wherein M is an alkali metal.

15. The method of claim 14, further comprising at least one of the following features:

g1) in the step G, the molar ratio of the fluorosulfonyl difluoroacetic acid methyl ester III-6 to the third basic compound is 1: 1-1: 10;