Preparation method of 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate

Abstract

The invention discloses a preparation method of 4-tert-butylphenyl-diphenyl sulfonium p-toluenesulfonate, which comprises the following specific steps: S1, preparing an intermediate: taking 4-tert-butylphenyl magnesium bromide and diphenyl sulfoxide as raw materials, carrying out substitution reaction under the action of an initiator to generate (4-(tert-butyl) phenyl) diphenyl sulfur bromide, and extracting and purifying to obtain the intermediate; s2, preparation of 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate: carrying out reflux reaction on the intermediate and sodium p-toluenesulfonate in an organic solvent, after the reflux reaction is finished, carrying out water washing, liquid separation and solvent spin-drying to obtain a crude product of the target product 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate, and filtering to obtain the 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate. Carrying out rotary evaporation impurity removal, washing and liquid separation on the crude product, and spin-drying a solvent to obtain a 4-tert-butylphenyl-diphenyl sulfonium p-toluenesulfonate product; the product prepared by the method is high in purity and yield, meets the quality requirements of the raw material of the resist for the photoresist, is superior to other processes in the prior art, and is suitable for industrial popularization.

Description

Technical Field

[0001] The invention belongs to the technical field of organic synthesis and relates to a method for preparing a sulfonium salt as an etching resist for photoresist, in particular to a method for preparing 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate. Background Art

[0002] Sulfonium salts absorb energy of certain wavelengths in the ultraviolet or visible regions, generating free radicals and cations, which then initiate polymerization and crosslinking of monomers. These compounds are often used as photoacid generators in chemically amplified photoresists. The introduction of hydrophilic groups, such as sulfonic acid, into sulfonium salts can also effectively suppress the formation of speckle defects.

[0003] The target product of the present invention, 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate, is such a photoacid generator, has a CAS number of 145639-75-4, and has a structural formula as shown in Formula 1.

[0004]

[0005] A key step in preparing these products is the preparation of the corresponding intermediate triphenylsulfonium salt, namely (4-(tert-butyl)phenyl)diphenylsulfonium bromide. For example, Chinese invention patent application No. 200610113557.1 uses sulfoxides and specific benzenes as raw materials, catalyzed by thionyl chloride and aluminum chloride, to produce the corresponding triphenylsulfonium salt. However, the reaction yield is very low, reaching only 50% at most. Therefore, further research and development of synthetic routes and preparation processes is needed to develop a preparation method suitable for industrialization and with higher product yields. Summary of the Invention

[0006] The purpose of the present invention is to overcome the shortcomings of the existing technology and improve the product yield. A synthetic route for 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate is designed, and preparation conditions such as catalysts are studied to prepare a product that meets the quality requirements of photoresist product raw materials.

[0007] The technical solution adopted by the present invention is a method for preparing 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate. The key is to prepare the above-mentioned 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate by a two-step method, and the specific steps are:

[0008] S1. Preparation of an intermediate: 4-tert-butylphenylmagnesium bromide and diphenyl sulfoxide are used as raw materials, and a substitution reaction occurs in an organic solvent under the action of an initiator to generate (4-(tert-butyl)phenyl)diphenylsulfonium bromide, and the intermediate is obtained after extraction and purification. The molar ratio of diphenyl sulfoxide, 4-tert-butylphenylmagnesium bromide and initiator is 1:2-3:2-3. The temperature of the substitution reaction is 0°C to 30°C, and the substitution reaction time is 1h to 3h.

[0009] S2. Preparation of 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate: The intermediate is subjected to reflux reaction with sodium p-toluenesulfonate in an organic solvent. After the reflux reaction is completed, the crude product of the target product 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate is obtained by washing with water, separating the liquids, and drying the solvent by spin-drying. The crude product is subjected to rotary evaporation to remove impurities, washing, separating the liquids, and drying the solvent by spin-drying to obtain the product of 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate, the structure of which is shown in Formula 1.

[0010]

[0011] Specifically, the initiator is any one or a combination of trimethylsilyl chloride or diisobutylaluminum hydride; the initiator is added dropwise at a rate of 0.008 mol / min to 0.01 mol / min.

[0012] Preferably, the initiator is trimethylchlorosilane and diisobutylaluminum hydride in a molar ratio of 1:0.1-0.3.

[0013] Preferably, the above organic solvent is dichloromethane or dichloroethane.

[0014] Furthermore, the extraction and purification in step S1 is that after the reaction is completed, the pH value of the reaction solution is adjusted to acidic, the liquid is allowed to stand and separated, the organic phase is retained, the aqueous phase is extracted again with an organic solvent, the organic phases are combined and then dried, shaken and decolorized, and the liquid is allowed to stand again, the lower layer of liquid is retained, the solvent is dried, and then pulped, filtered, and dried to obtain the above-mentioned intermediate.

[0015] Specifically, the solvent used for the shaking decolorization in step S1 is dichloromethane and tert-methyl ether in a volume ratio of 1:2.

[0016] Furthermore, in step S2, the temperature of the reflux reaction is 80° C. to 105° C., and the reflux reaction time is 6 h to 24 h; and the molar ratio of the intermediate to sodium p-toluenesulfonate is 1:1.2 to 1.5.

[0017] Furthermore, activated carbon fibers are added to the reaction system before the reflux reaction is carried out.

[0018] Preferably, the above-mentioned activated carbon fiber preparation method is to soak the viscose fiber in a polyethylene glycol solution, then soak it in a phosphoric acid solution and boil it, take it out and then dry it; soak the dried viscose fiber in a silver salt aqueous solution, take it out and then dry and carbonize it.

[0019] Preferably, the polyethylene glycol solution is a polyethylene glycol aqueous solution with a mass concentration of 5%, the phosphoric acid solution is a phosphoric acid aqueous solution with a mass concentration of 5%, and the silver salt aqueous solution is an aqueous solution of silver nitrate.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The synthetic route of the present invention uses 4-tert-butylphenylmagnesium bromide and diphenyl sulfoxide as raw materials to obtain the intermediate (4-(tert-butyl)phenyl)diphenylsulfonium bromide, which is then subjected to a reflux reaction with sodium p-toluenesulfonate in an organic solvent. The resulting product has a purity of over 99.5%. The preparation process of the present invention can control the metal impurity content to within 100 ppb, and the resulting product fully meets the quality requirements for a raw material for photoresist. More importantly, the total yield of the present invention reaches up to 78%, which is superior to other existing processes and is suitable for industrial promotion and application.

[0022] The diphenyl sulfoxide in the present invention belongs to the aryl sulfoxide class, which is capable of undergoing a range of organic transformations, such as Sonogashira reactions with terminal alkynes, borylation with B2pin2, amination with amines, phosphorylation with P(O)-H compounds, and etherification with alcohols. Aryl sulfoxides can also effectively participate in transition-metal-catalyzed cross-coupling reactions with Grignard reagents. Previously reported diaryl sulfoxides are mostly cross-coupling reactions with Grignard reagents using transition metal catalysts such as nickel and palladium.

[0023] The 4-tert-butylphenylmagnesium bromide used in the present invention is a Grignard reagent. However, the present invention has discovered that directly using 4-tert-butylphenylmagnesium bromide and diphenyl sulfoxide as raw materials, in the presence of an initiator, a substitution reaction occurs rapidly at relatively low temperatures to produce the corresponding sulfonium salt. This is because the initiator activates the sulfur-oxygen double bond in diphenyl sulfoxide, reacting with 4-tert-butylphenylmagnesium bromide to form a composite salt containing magnesium ions, bromide ions, and hydroxide. When the reaction is quenched with ice water and hydrochloric acid is added, the magnesium ions, bromide ions, and hydroxide in the composite salt are removed, leaving only the corresponding sulfonium salt. The present invention has a short reaction time and low temperature for preparing the sulfonium salt, completing the reaction within 3 hours at 30°C. The present invention also uses trimethylsilyl chloride and diisobutylaluminum hydride as initiators, which can reduce the reaction temperature to 20°C, preventing the boiling phenomenon that occurs when using low-boiling-point solvents such as dichloromethane, greatly improving the safety of the reaction.

[0024] Furthermore, the present invention discovered during research that the reflux reaction time in the second step was relatively long, reaching 24 hours. The research also found that the use of special silver ion-loaded activated carbon fibers can adsorb the generated sodium bromide without participating in the reaction, promoting the forward reaction, shortening the reaction time, and improving reaction efficiency. After the reaction is completed, the used activated carbon fibers can be further recycled and reactivated for use in subsequent preparation processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1This is the H NMR spectrum of sample 1 of the product of the present invention.

[0026] Figure 2 This is the HPLC-MS / MS analysis spectrum of sample 1 of the product of the present invention.

[0027] Figure 3 It is the HPLC spectrum of product sample 1 of the present invention. DETAILED DESCRIPTION

[0028] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] If the specific conditions are not specified in the examples, the experiments can be carried out under conventional conditions; if the manufacturers of the reagents or instruments are not specified, they are all conventional products that can be purchased from the market.

[0030] Example 1

[0031] In this embodiment, 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate is prepared, and the specific process is as follows:

[0032] S1. Preparation of intermediates:

[0033] S1-1. Dissolve 0.12 mol of diphenyl sulfoxide in 130 mL of dichloroethane. Maintain the reaction system at 30°C, and slowly add 0.33 mol of initiator trimethylchlorosilane at a rate of 0.01 mol / min. After the addition of the initiator, stir at 30°C for 30 minutes. Then, add 0.33 mol of 4-tert-butylphenylmagnesium bromide. Maintain stirring at 30°C for 3 hours after the addition.

[0034] S1-2, after completion of the reaction, quench with ice water, add hydrochloric acid solution dropwise to adjust the pH value of the reaction solution to 2.2, stand and separate, retain the organic phase, the aqueous phase is extracted again with dichloroethane solvent, the organic phases are combined and spin-dried, 50mL of dichloromethane and 100mL of methyl tert-ether are added to the solution after rotary evaporation, and a milky white liquid is obtained after shaking. The solution is allowed to stand and separate again, the lower layer is a light yellow liquid, and the upper layer is a milky white liquid. The lower layer liquid is retained, and the solvent is spin-dried, and the intermediate, i.e., (4-(tert-butyl)phenyl)diphenylsulfonium bromide, is obtained by beating, filtering, and drying, which is recorded as intermediate sample 1;

[0035] S2, preparation of 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate:

[0036] S2-1. Add 0.22 mol of intermediate sample 1, 0.30 mol of sodium p-toluenesulfonate, and 550 mL of dichloroethane solvent to a reaction flask, place 2 g of activated carbon fiber on the flat bottom, and heat to 95°C for 12 h of reflux reaction;

[0037] S2-2, cooling after the reaction, washing with water, separating the liquids, and drying the solvent to obtain a crude oily target product, 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate;

[0038] S2-3. The crude product was subjected to rotary evaporation at 140°C to remove impurities, and then dissolved with dichloroethane solvent, and washed with ultrapure water until the metal impurities meet the requirements. After liquid separation and spin drying of the solvent, a white solid 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate product was obtained, which was recorded as product sample 1.

[0039] The preparation method of activated carbon fiber in this embodiment is:

[0040] The viscose fiber was immersed in a 5% polyethylene glycol solution for 30 minutes, and then immersed in a 5% phosphoric acid solution. The phosphoric acid solution was boiled for 1 hour, and the viscose fiber was taken out and dried.

[0041] The dried viscose fiber was immersed in a 25% silver salt aqueous solution for 10 minutes, and then taken out and dried;

[0042] The viscose fiber is carbonized by heating the viscose fiber to 550° C. at a rate of 10° C. / min under inert gas protection and carbonizing the viscose fiber for 10 minutes to obtain activated carbon fiber.

[0043] Example 2

[0044] In this embodiment, 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate is prepared, and the specific process is as follows:

[0045] S1. Preparation of intermediates:

[0046] S1-1. Dissolve 0.12 mol of diphenyl sulfoxide in 120 mL of dichloromethane. Maintain the reaction system at 20°C. Slowly add 0.25 mol of trimethylsilyl chloride and 0.08 mol of diisobutylaluminum hydride as initiators at a rate of 0.008 mol / min. After the addition of the initiator, stir at 20°C for 20 minutes. Then, begin to add 0.24 mol of 4-tert-butylphenylmagnesium bromide. Maintain stirring at 20°C after the addition is complete and carry out the substitution reaction for 1 hour.

[0047] S1-2, after completion of the reaction, the reaction was quenched with ice water, and hydrochloric acid solution was added dropwise to adjust the pH value of the reaction solution to 2.9. The reaction mixture was allowed to stand for separation, and the organic phase was retained. The aqueous phase was extracted again with dichloromethane, and the organic phases were combined and spin-dried. 55 mL of dichloromethane and 110 mL of methyl tert-ether were added to the solution after rotary evaporation. After shaking, a milky white liquid was obtained, which was allowed to stand for separation again. The lower layer was a light yellow liquid and the upper layer was a milky white liquid. The lower layer liquid was retained, and the solvent was spin-dried. After beating, filtering, and drying, an intermediate, i.e., (4-(tert-butyl)phenyl)diphenylsulfonium bromide, was obtained, which was recorded as intermediate sample 2;

[0048] S2, preparation of 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate:

[0049] S2-1. Add 0.22 mol of intermediate sample 2, 0.33 mol of sodium p-toluenesulfonate, and 600 mL of dichloromethane to a reaction flask without adding activated carbon fiber, and heat to 105°C for 24 h of reflux reaction;

[0050] S2-2, this step is the same as in Example 1;

[0051] S2-3. The crude product was subjected to rotary evaporation at 110°C to remove impurities, and then dissolved in dichloromethane solvent, and washed with ultrapure water until the metal impurities meet the requirements. After liquid separation and solvent drying, the product 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate was obtained as a white solid, recorded as product sample 2.

[0052] Example 3

[0053] In this embodiment, 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate is prepared, and the specific process is as follows:

[0054] S1. Preparation of intermediates:

[0055] S1-1. Dissolve 0.12 mol of diphenyl sulfoxide in 125 mL of dichloromethane. Maintain the reaction system at 15°C. Slowly add 0.25 mol of trimethylsilyl chloride and 0.03 mol of diisobutylaluminum hydride as initiators at a rate of 0.009 mol / min. After the addition of the initiator, stir at 15°C for 25 minutes. Then, begin to add 0.30 mol of 4-tert-butylphenylmagnesium bromide. Maintain stirring at 15°C for 2 hours after the addition.

[0056] S1-2, after completion of the reaction, the reaction was quenched with ice water, and hydrochloric acid solution was added dropwise to adjust the pH value of the reaction solution to 2.1. The reaction mixture was allowed to stand for separation, and the organic phase was retained. The aqueous phase was extracted again with dichloromethane, and the organic phases were combined and dried. 45 mL of dichloromethane and 90 mL of methyl tert-ether were added to the solution after rotary evaporation. After shaking, a milky white liquid was obtained, and the reaction mixture was allowed to stand for separation again. The lower layer was a light yellow liquid and the upper layer was a milky white liquid. The lower layer liquid was retained, and the solvent was dried, and then pulped, filtered, and dried to obtain an intermediate, i.e., (4-(tert-butyl)phenyl)diphenylsulfonium bromide, which was recorded as intermediate sample 3;

[0057] S2, preparation of 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate:

[0058] S2-1. Add 0.22 mol of intermediate sample 3, 0.28 mol of sodium p-toluenesulfonate, and 500 mL of dichloromethane to a reaction flask, place 3 g of activated carbon fiber on the flat bottom, and heat to 80°C for 6 h of reflux reaction;

[0059] S2-2, this step is the same as in Example 1;

[0060] S2-3. The crude product was subjected to rotary evaporation at 120°C to remove impurities, and then dissolved in dichloromethane solvent, and washed with ultrapure water until the metal impurities meet the requirements. After liquid separation and spin drying of the solvent, the product 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate was obtained as a white solid, recorded as product sample 3.

[0061] The preparation method of activated carbon fiber in this embodiment is:

[0062] The viscose fiber was immersed in a 5% polyethylene glycol solution for 20 minutes, and then immersed in a 5% phosphoric acid solution. The phosphoric acid solution was boiled for 1 hour and 20 minutes, and the viscose fiber was taken out and dried.

[0063] The dried viscose fiber was immersed in a silver salt aqueous solution with a mass concentration of 30% for 20 minutes, and then taken out and dried;

[0064] The viscose fiber is carbonized by heating the viscose fiber to 600° C. at a rate of 5° C. / min under inert gas protection and carbonizing the viscose fiber for 10 min to obtain activated carbon fiber.

[0065] Example 4

[0066] In this embodiment, 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate is prepared, and the specific process is as follows:

[0067] S1. Preparation of intermediates:

[0068] S1-1. Dissolve 0.12 mol of diphenyl sulfoxide in 140 mL of dichloromethane. Maintain the reaction system at 0°C. Slowly add 0.20 mol of trimethylsilyl chloride and 0.04 mol of diisobutylaluminum hydride as initiators at a rate of 0.009 mol / min. After the addition of the initiator, stir at 0°C for 35 min. Then, add 0.33 mol of 4-tert-butylphenylmagnesium bromide. Maintain stirring at 0°C for 2.5 h after the addition.

[0069] S1-2, after completion of the reaction, the reaction was quenched with ice water, and hydrochloric acid solution was added dropwise to adjust the pH value of the reaction solution to 2.6. The reaction mixture was allowed to stand for separation, and the organic phase was retained. The aqueous phase was extracted again with dichloromethane. The organic phases were combined and dried by spin-drying. 50 mL of dichloromethane and 100 mL of methyl tert-ether were added to the solution after rotary evaporation. After shaking, a milky white liquid was obtained. The reaction mixture was allowed to stand for separation again, and the lower layer was a light yellow liquid and the upper layer was a milky white liquid. The lower layer liquid was retained, and the solvent was dried by beating, filtering, and drying to obtain an intermediate, i.e., (4-(tert-butyl)phenyl)diphenylsulfonium bromide, which was recorded as intermediate sample 4;

[0070] S2, preparation of 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate:

[0071] S2-1. Add 0.22 mol of intermediate sample 4, 0.26 mol of sodium p-toluenesulfonate, and 550 mL of dichloromethane to a reaction flask, place 2.5 g of activated carbon fiber on the flat bottom, and heat to 85°C for 10 h of reflux reaction.

[0072] S2-2, this step is the same as in Example 1;

[0073] S2-3. The crude product was subjected to rotary evaporation at 125°C to remove impurities, and then dissolved in dichloromethane solvent, and washed with ultrapure water until the metal impurities meet the requirements. After liquid separation and solvent drying, the product 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate was obtained as a white solid, recorded as product sample 4.

[0074] The preparation method of activated carbon fiber in this embodiment is:

[0075] The viscose fiber was immersed in a 5% polyethylene glycol solution for 20 minutes, and then immersed in a 5% phosphoric acid solution. The phosphoric acid solution was boiled for 1 hour and 30 minutes, and the viscose fiber was taken out and dried.

[0076] The dried viscose fiber was immersed in a 20% silver salt aqueous solution for 20 minutes, and then taken out and dried;

[0077] The viscose fiber was carbonized by heating the fiber to 500° C. at a rate of 15° C. / min under inert gas protection and carbonizing the fiber for 20 min to obtain activated carbon fiber.

[0078] Comparative Example 1

[0079] The specific preparation process is the same as that of Example 3, except that in step S1-1, instead of using trimethylsilyl chloride or diisobutylaluminum hydride as the initiator, 0.30 mol of iodomethane is used as the initiator. After the dropwise addition is completed, the mixture is stirred at 15°C for 25 minutes, and then 0.30 mol of 4-tert-butylphenylmagnesium bromide is added dropwise. After the dropwise addition is completed, the mixture is stirred at 60°C and the substitution reaction is carried out for 2 hours. The subsequent steps are the same as those of Example 3 to prepare the intermediate reference substance 1.

[0080] Comparative Example 2

[0081] The specific preparation process is the same as that of Example 3, except that the initiator dropwise addition rate is changed during step S1-1, and 0.25 mol of trimethylchlorosilane and 0.03 mol of diisobutylaluminum hydride are slowly added dropwise at a rate of 0.1 mol / min. The subsequent steps are the same as those of Example 3 to prepare the intermediate reference product 2.

[0082] Analysis and testing

[0083] The sample prepared by the present invention has the appearance of a white solid. The analysis by H NMR spectrum and HPLC-MS / MS confirmed that the sample conforms to the structural characteristics of 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate. For some test patterns, see Figures 1 to 3 .

[0084] The purity of the intermediate sample, product sample and intermediate reference substance was determined by high performance liquid chromatography, and the yield was calculated by the following formula. The results are shown in Table 1.

[0085] The yield calculation formula is:

[0086] Intermediate yield = actual weight of the intermediate obtained (g) / theoretical amount calculated based on the amount of diphenyl sulfoxide used (g) × 100%.

[0087] Product yield = actual weight of the sample obtained (g) / theoretical amount calculated based on the amount of intermediate used (g) × 100%.

[0088] Table 1: Summary of purity and yield results

[0089]

[0090]

[0091] As shown in Table 1, the purity of the intermediate prepared by the present invention reaches over 90%, the purity of the final product is greater than 99.5%, and the metal impurity content is less than 100 ppb, which fully meets the quality requirements for resist raw materials for photoresist.

[0092] More importantly, the total yield of the product of the present invention reaches up to 78%, which is superior to other processes in the prior art and is suitable for industrial promotion and application.

Claims

1. The preparation method of 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate is characterized in that: The 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate is prepared by a two-step method, specifically comprising the following steps: S1. Preparation of an intermediate: 4-tert-butylphenylmagnesium bromide and diphenyl sulfoxide are used as raw materials, and a substitution reaction occurs in an organic solvent under the action of an initiator to generate (4-(tert-butyl)phenyl)diphenylsulfonium bromide. After extraction and purification, the intermediate is obtained. The molar ratio of diphenyl sulfoxide, 4-tert-butylphenylmagnesium bromide and initiator is 1:2-3:2-3. The temperature of the substitution reaction is 0°C to 30°C, and the substitution reaction time is 1h to 3h. S2. Preparation of 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate: The intermediate is subjected to reflux reaction with sodium p-toluenesulfonate in an organic solvent. After the reflux reaction is completed, the crude product of the target product 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate is obtained by washing with water, separating the liquids, and drying the solvent by spin-drying. The crude product is subjected to rotary evaporation to remove impurities, washing, separating the liquids, and drying the solvent by spin-drying to obtain the product of 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate, the structure of which is shown in Formula 1.

2. The method for preparing 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate according to claim 1, wherein: The initiator is any one or a combination of trimethylsilyl chloride and diisobutylaluminum hydride; the initiator is added dropwise at a rate of 0.008 mol / min to 0.01 mol / min.

3. The method for preparing 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate according to claim 2, wherein: The initiator is trimethylchlorosilane and diisobutylaluminum hydride in a molar ratio of 1:0.1-0.

3.

4. The method for preparing 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate according to claim 1, wherein The organic solvent is dichloromethane or dichloroethane.

5. The method for preparing 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate according to claim 1, wherein: The extraction and purification in step S1 is as follows: after the reaction is completed, the pH value of the reaction solution is adjusted to acidic, the solution is allowed to stand and separate, the organic phase is retained, the aqueous phase is extracted again with an organic solvent, the organic phases are combined and then dried, the mixture is shaken for decolorization, the solution is allowed to stand and separate again, the lower layer of liquid is retained, the solvent is dried, and the mixture is pulped, filtered, and dried to obtain the intermediate.

6. The method for preparing 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate according to claim 5, wherein: The solvent used for the shaking decolorization in step S1 is dichloromethane and tert-methyl ether in a volume ratio of 1:

2.

7. The method for preparing 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate according to claim 1, wherein: The temperature of the reflux reaction in step S2 is 80° C. to 105° C., and the reflux reaction time is 6 h to 24 h; the molar ratio of the intermediate to sodium p-toluenesulfonate is 1:1.2 to 1.

5.

8. The method for preparing 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate according to claim 1, wherein: Before the reflux reaction is carried out, activated carbon fiber is added to the reaction system.

9. The method for preparing 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate according to claim 8, wherein: The activated carbon fiber preparation method comprises the following steps: soaking viscose fiber in a polyethylene glycol solution, then soaking it in a phosphoric acid solution and boiling it, taking it out and drying it; soaking the dried viscose fiber in a silver salt aqueous solution, taking it out and drying it, and carbonizing it.

10. The method for preparing 4-tert-butylphenyl-diphenylsulfonium p-toluenesulfonate according to claim 9, wherein: The polyethylene glycol solution is a polyethylene glycol aqueous solution with a mass concentration of 5%, the phosphoric acid solution is a phosphoric acid aqueous solution with a mass concentration of 5%, and the silver salt aqueous solution is an aqueous solution of silver nitrate.

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