Purification method of high-purity di-p-tolyl iodonium trifluoromethanesulfonate

Abstract

The invention discloses a purification method of high-purity di-p-tolyl iodonium trifluoromethanesulfonate, which is used for separating and extracting di-p-tolyl iodonium trifluoromethanesulfonate and isomers thereof in a specific solvent according to different solubility of the di-p-tolyl iodonium trifluoromethanesulfonate and the isomers thereof in the specific solvent. The purification method comprises the following steps: S1, dissolving di-p-tolyl iodonium trifluoromethanesulfonate by utilizing an alcohol solvent, adding an adsorbent, and carrying out suction filtration to obtain filtrate; s2, pure water is added into the filtrate to separate out crystals, and the crystals are filtered and dried; s3, mixing the crystal with a solvent, keeping the temperature at 40-70 DEG C, and stirring for dissolving; s4, cooling to 0-30 DEG C, fully stirring to separate out crystals, and filtering and drying; and S5, repeating the steps S3 to S4. According to the purification method, the purity of the di-p-tolyl iodonium trifluoromethanesulfonate can be improved from 90-95% to 99.9% or above, and the quality of the di-p-tolyl iodonium trifluoromethanesulfonate far exceeds the best quality of di-p-tolyl iodonium trifluoromethanesulfonate in the current market.

Description

Technical Field

[0001] The invention relates to the technical field of compound purification, and in particular to a method for purifying di-p-tolyl iodonium trifluoromethanesulfonate. Background Art

[0002] Photocuring technology is an emerging green technology. It refers to the technology that absorbs light energy to produce active bodies under the action of photoinitiators, so that materials can be quickly converted from liquid to solid. Compared with traditional thermal curing technology, photocuring technology has the characteristics of low production cost and high efficiency; excellent product performance and wide applicability; less pollution, low toxicity and low energy consumption in the production process. In the modern society with increasing environmental awareness, it has attracted widespread attention. The development of photocuring technology mainly depends on the development of photoinitiators. The performance requirements for them mainly include: high photoinitiator efficiency, good solubility, good storage performance, strong thermal stability, non-toxic and non-irritating, low cost and easy to obtain. According to the properties and initiation mechanism, photoinitiators can be divided into two categories: free radical initiators and ionic photoinitiators. Among them, ionic photoinitiators are mainly cationic initiators. They are not affected by oxygen inhibition, have fast curing speed, low curing shrinkage, fast and thorough polymerization reaction, low toxicity, strong adhesion and good mechanical properties. Compared with free radical initiators, they have significant advantages, so they are widely used in coatings, printing inks, information technology, 3D printing and other fields. The most representative cationic photoinitiators are onium salt-type initiators, mainly diaryliodonium salts, triarylsulfonium salts and ferrocenium salts. They have simple preparation processes, good thermal stability and storage stability, and high photodecomposition efficiency. Therefore, they have a wide range of applications and there are many reports of commercial applications. As a structurally symmetrical diaryl iodonium salt, di-p-tolyl iodonium trifluoromethanesulfonate is composed of two symmetrical aryl roots and an anion, and has good photosensitivity and photoinitiator activity. Compared with asymmetrical diaryl iodonium salts, symmetrical aryl roots have good thermal stability and are easy to be synthesized organically. As an anion part, trifluoromethanesulfonate has good solubility, and the anion has weak nucleophilicity and will not react with carbon cations to prevent the polymerization process. It is an efficient and stable cationic photoinitiator and has important applications in photoresist curing processes. However, the problem faced by di-p-tolyl iodonium trifluoromethanesulfonate at present is that the synthesis process is simple, but isomers are easily produced during the synthesis process and are difficult to remove, resulting in the low purity of the produced di-p-tolyl iodonium trifluoromethanesulfonate, usually below 95%, which seriously affects its scope of application. Therefore, it is necessary to purify di-p-tolyl iodonium trifluoromethanesulfonate to obtain high-purity di-p-tolyl iodonium trifluoromethanesulfonate. The existing purification method is usually to use an organic solvent washing method for purification, that is, to select a poor solvent of di-p-tolyl iodonium trifluoromethanesulfonate to repeatedly wash the polymer to dissolve other impurities in the product to improve the purity. However, this method cannot completely remove the isomers, and the purity is generally 95-98%, which is difficult to meet the application requirements. Therefore, it is necessary to develop a purification process for di-p-tolyl iodonium trifluoromethanesulfonate with higher purity. Summary of the invention

[0003] Technical problem to be solved: The technical problem to be solved by the present invention is to provide a method for purifying high-purity di-p-tolyl iodonium trifluoromethanesulfonate.

[0004] Technical solution: A method for purifying high-purity di-p-tolyl iodonium trifluoromethanesulfonate, comprising the following steps: S1. dissolving the crude di-p-tolyl iodonium trifluoromethanesulfonate in an alcohol solvent, wherein the volume ratio of di-p-tolyl iodonium trifluoromethanesulfonate to the alcohol solvent is 1:1-3, then adding an adsorbent to remove impurities, preserving at 30-50°C, and then filtering to obtain a filtrate; S2. Add pure water to the filtrate obtained in S1 to precipitate crystals, wherein the volume ratio of the alcohol solvent to pure water is 1:1 to 5, and filter and dry to obtain di-p-tolyl iodonium trifluoromethanesulfonate crystals; S3. The crystals obtained in S2 are mixed with an organic solvent, wherein the volume ratio of the di-p-tolyl iodonium trifluoromethanesulfonate crystals to the organic solvent is 1:1 to 5, and the mixture is heated at 40 to 70°C and stirred until the crystals are completely dissolved to obtain a saturated solution; S4. The saturated solution obtained in S3 is cooled to 0-30°C and stirred until crystals precipitate, and the crystals are filtered and dried to obtain di-p-tolyl iodonium trifluoromethanesulfonate; S5. Repeat steps S3 to S4 to obtain high-purity di-p-tolyl iodonium trifluoromethanesulfonate. Preferably, the alcohol solvent in step S1 is any one of methanol, ethanol or propanol. Preferably, the adsorbent in step S1 is any one of activated carbon, diatomaceous earth or silica gel. Preferably, the organic solvent in step S3 is any one of methyl isobutyl ketone, tert-butyl methyl ether, isopropanol or butanone, or a combination of two or more thereof. Preferably, the stirring speed in step S3 is 100-200 r / min, and the stirring time is 2-8 h. Preferably, the stirring speed in S4 is 30-50 r / min, and the insulation time is 0.5-3 h. Preferably, the step S5 is repeated 2 to 3 times. Preferably, the yield of high-purity di-p-tolyl iodonium trifluoromethanesulfonate in step 5 is 80-90%, and the purity is ≥99.9%. Beneficial effects: Compared with the prior art, the present invention has the following characteristics: The purification method of di-p-tolyl iodonium trifluoromethanesulfonate of the present invention is based on the principle of separating and extracting di-p-tolyl iodonium trifluoromethanesulfonate and its isomers due to their different solubility in a specific solvent. The overall process includes physical changes such as dissolution, adsorption, and precipitation, and does not involve chemical changes. The process is stable and controllable, and is simple and easy to operate. The solvent and adsorbent used are both common chemicals, which are low in cost, low in toxicity, good in stability, and suitable for industrial production. As a structurally symmetrical diaryl iodonium salt, di-p-tolyl iodonium trifluoromethanesulfonate is composed of two symmetrical aryl radicals and an anion trifluoromethanesulfonate with weak nucleophilicity. It has good photosensitivity and photoinitiator activity, strong thermal stability, good solubility, and has important applications in photoresist curing processes. However, although the synthesis process of di-p-tolyl iodonium trifluoromethanesulfonate is simple, isomers are easily produced during the synthesis process and are difficult to remove, resulting in low product purity, which is not conducive to its large-scale production and application. It is necessary to remove impurities through a purification process to improve the product purity of di-p-tolyl iodonium trifluoromethanesulfonate. Crystallization refers to the process in which a solid substance is precipitated from a melt, solution, or steam in the form of crystals. It is usually divided into four categories: solution crystallization, melt crystallization, sublimation, and precipitation. Among them, solution crystallization is a purification method widely used in industry. It is a method of making a solution reach an oversaturated state by a certain method, and then precipitating a solute as a purified product. It mainly includes cooling crystallization, evaporation crystallization, and dissolution crystallization. The cooling crystallization method is a crystallization method in which the solution reaches a saturated state at a relatively high temperature, and the solubility of the solute decreases after the temperature is lowered, thereby precipitating crystals. The solution crystallization method is a crystallization method in which the solute is dissolved in a solvent, and another solvent that is miscible with the original solvent is added to reduce the solubility of the solute in the original solvent, thereby precipitating solute crystals. In industrial production, a single crystallization method is usually used for purification. The process is simple but the product purity is limited. The combination of the solution crystallization method and the cooling crystallization method can further improve the purity and yield of the product. In addition, the precipitation temperature during the purification process is relatively low, and the crystallization time is significantly shortened, which greatly reduces the process cost. In the present invention, alcohol solvents such as methanol, ethanol, and propanol have different solubility for di-p-tolyl iodonium trifluoromethanesulfonate and other impurities, so they can be used as main solvents to purify di-p-tolyl iodonium trifluoromethanesulfonate, and low-level alcohols and water are mutually soluble, and water is used as a solvent that repels the solute in the dissolution crystallization, which can reduce the solubility of di-p-tolyl iodonium trifluoromethanesulfonate in alcohol solvents, thereby precipitating high-purity crystals. In addition, porous materials such as diatomaceous earth, activated carbon, etc. are added to physically adsorb other impurities, so that multiple impurities can be removed simultaneously. The high-purity crystals obtained by the solution crystallization method are further purified by the cooling crystallization method. The solubility of di-p-tolyl iodonium trifluoromethanesulfonate and its isomers in solvents such as methyl isobutyl ketone, tert-butyl methyl ether, butanone, etc. is different in terms of temperature. A saturated solution of di-p-tolyl iodonium trifluoromethanesulfonate is prepared at a higher temperature, and then the solution is cooled to a supersaturated state, thereby precipitating di-p-tolyl iodonium trifluoromethanesulfonate crystals, while the isomers cannot be precipitated, further improving the purity of the product. The combination of the solution crystallization method and the cooling crystallization method, as well as the physical adsorption of impurities and filtration, can save time and cost, reduce energy consumption, and is suitable for industrial production. Compared with the prior art, the present invention has the following advantages and positive effects: The present invention utilizes the difference in solubility between di-p-tolyl iodonium trifluoromethanesulfonate and its isomers in a specific solvent to develop a new purification process, which has a simple and clear principle, easy-to-operate steps, a safe and controllable process, low cost and high yield, and is suitable for industrial production. The solvents and adsorbents used in the present invention are mostly common chemicals, which have low cost, low toxicity, good stability, can effectively reduce process costs, and improve operational safety. The purification process developed by the present invention combines the dissolution crystallization process with the cooling crystallization process, and adds adsorption and filtration steps. Compared with a single crystallization process, it can remove multiple impurities at the same time and effectively improve the purity of the product. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 Flow chart of the purification method provided by the embodiment of the present invention Figure 2 The HPLC chromatogram of the purified product of Example 1 of the present invention is Figure 3 This is the NMR spectrum of the purified product in Example 1 of the present invention DETAILED DESCRIPTION In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. Specific preferred examples are as follows: Embodiment 1: A method for purifying high-purity di-p-tolyl iodonium trifluoromethanesulfonate comprises the following steps: S1. Dissolve 100 g of crude di-p-tolyl iodonium trifluoromethanesulfonate in 100 mL of ethanol, add activated carbon to remove impurities, and filter after heating at 30°C to obtain a filtrate; S2. Add 300 mL of pure water to the filtrate obtained in S1, filter and dry to obtain di-p-tolyl iodonium trifluoromethanesulfonate crystals; S3. The crystals obtained in S2 were mixed with 200 mL of methyl isobutyl ketone, kept warm at 60°C, and stirred at a stirring speed of 100 r / min for 2 h until the crystals were completely dissolved to obtain a saturated solution; S4. The saturated solution obtained in S3 was cooled to 0°C and kept warm for 2h, and stirred at a stirring speed of 30r / min until crystals precipitated, and the crystals were filtered and dried to obtain di-p-tolyl iodonium trifluoromethanesulfonate; S5. Repeat steps S3 to S4 to obtain high-purity di-p-tolyl iodonium trifluoromethanesulfonate; The number of repetitions in step S5 is 2 times; The yield of high-purity di-p-tolyl iodonium trifluoromethanesulfonate in step S5 is 82% and the purity is 99.91%. Embodiment 2: A method for purifying high-purity di-p-tolyl iodonium trifluoromethanesulfonate comprises the following steps: S1. Dissolve 100 g of crude di-p-tolyl iodonium trifluoromethanesulfonate in 100 mL of ethanol, add activated carbon to remove impurities, and filter after heating at 30°C to obtain a filtrate; S2. Add 300 mL of pure water to the filtrate obtained in S1, filter and dry to obtain di-p-tolyl iodonium trifluoromethanesulfonate crystals; S3. The crystals obtained in S2 were mixed with 200 mL of methyl isobutyl ketone, stirred at a stirring speed of 130 r / min, and kept at 60°C for 2 h until the crystals were completely dissolved to obtain a saturated solution; S4. The saturated solution obtained in S3 was cooled to 0°C and kept warm for 2h, and stirred at a stirring speed of 30r / min until crystals precipitated, and the crystals were filtered and dried to obtain di-p-tolyl iodonium trifluoromethanesulfonate; S5. Repeat steps S3 to S4 to obtain high-purity di-p-tolyl iodonium trifluoromethanesulfonate; The number of repetitions in step S5 is 2 times; The yield of the high-purity di-p-tolyl iodonium trifluoromethanesulfonate is 86% and the purity is 99.92%. Embodiment 3: A method for purifying high-purity di-p-tolyl iodonium trifluoromethanesulfonate comprises the following steps: S1. Dissolve 100 g of crude di-p-tolyl iodonium trifluoromethanesulfonate in 100 mL of ethanol, add activated carbon to remove impurities, and filter after heating at 30°C to obtain a filtrate; S2. Add 300 mL of pure water to the filtrate obtained in S1, filter and dry to obtain di-p-tolyl iodonium trifluoromethanesulfonate crystals; S3. The crystals obtained in S2 were mixed with 200 mL of methyl isobutyl ketone, stirred at a stirring speed of 160 r / min, and kept at 60°C for 2 h until the crystals were completely dissolved to obtain a saturated solution; S4. The saturated solution obtained in S3 was cooled to 0°C and kept warm for 2h, and stirred at a stirring speed of 30r / min until crystals precipitated, and the crystals were filtered and dried to obtain di-p-tolyl iodonium trifluoromethanesulfonate; S5. Repeat steps S3 to S4 to obtain high-purity di-p-tolyl iodonium trifluoromethanesulfonate; The number of repetitions in step S5 is 2 times; The yield of the high-purity di-p-tolyl iodonium trifluoromethanesulfonate is 83% and the purity is 99.95%. Embodiment 4: A method for purifying high-purity di-p-tolyl iodonium trifluoromethanesulfonate comprises the following steps: S1. Dissolve 100 g of crude di-p-tolyl iodonium trifluoromethanesulfonate in 100 mL of ethanol, add activated carbon to remove impurities, and filter after heating at 30°C to obtain a filtrate; S2. Add 300 mL of pure water to the filtrate obtained in S1, filter and dry to obtain di-p-tolyl iodonium trifluoromethanesulfonate crystals; S3. The crystals obtained in S2 were mixed with 200 mL of methyl isobutyl ketone, stirred at a stirring speed of 200 r / min, and kept at 60°C for 2 h until the crystals were completely dissolved to obtain a saturated solution; S4. The saturated solution obtained in S3 was cooled to 0°C and kept warm for 2h, and stirred at a stirring speed of 30r / min until crystals precipitated, and the crystals were filtered and dried to obtain di-p-tolyl iodonium trifluoromethanesulfonate; S5. Repeat steps S3 to S4 to obtain high-purity di-p-tolyl iodonium trifluoromethanesulfonate; The number of repetitions in step S5 is 2 times; The yield of the high-purity di-p-tolyl iodonium trifluoromethanesulfonate is 86% and the purity is 99.94%. Embodiment 5: A method for purifying high-purity di-p-tolyl iodonium trifluoromethanesulfonate comprises the following steps: S1. Dissolve 100 g of crude di-p-tolyl iodonium trifluoromethanesulfonate in 100 mL of ethanol, add activated carbon to remove impurities, and filter after heating at 30°C to obtain a filtrate; S2. Add 300 mL of pure water to the filtrate obtained in S1, filter and dry to obtain di-p-tolyl iodonium trifluoromethanesulfonate crystals; S3. The crystals obtained in S2 were mixed with 200 mL of methyl isobutyl ketone, stirred at a stirring speed of 160 r / min, and kept at 60°C for 2 h until the crystals were completely dissolved to obtain a saturated solution; S4. The saturated solution obtained in S3 was cooled to 0°C and kept warm for 2h, and stirred at a stirring speed of 40r / min until crystals precipitated, and the crystals were filtered and dried to obtain di-p-tolyl iodonium trifluoromethanesulfonate; S5. Repeat steps S3 to S4 to obtain high-purity di-p-tolyl iodonium trifluoromethanesulfonate; The number of repetitions in step S5 is 2 times; The yield of the high-purity di-p-tolyl iodonium trifluoromethanesulfonate is 84% ​​and the purity is 99.92%. Embodiment 6: A method for purifying high-purity di-p-tolyl iodonium trifluoromethanesulfonate comprises the following steps: S1. Dissolve 100 g of crude di-p-tolyl iodonium trifluoromethanesulfonate in 100 mL of ethanol, add activated carbon to remove impurities, and filter after heating at 30°C to obtain a filtrate; S2. Add 300 mL of pure water to the filtrate obtained in S1, filter and dry to obtain di-p-tolyl iodonium trifluoromethanesulfonate crystals; S3. The crystals obtained in S2 were mixed with 200 mL of methyl isobutyl ketone, stirred at a stirring speed of 160 r / min, and kept at 60°C for 2 h until the crystals were completely dissolved to obtain a saturated solution; S4. The saturated solution obtained in S3 was cooled to 0°C and kept warm for 2h, and stirred at a stirring speed of 50r / min until crystals precipitated, and the crystals were filtered and dried to obtain di-p-tolyl iodonium trifluoromethanesulfonate; S5. Repeat steps S3 to S4 to obtain high-purity di-p-tolyl iodonium trifluoromethanesulfonate; The number of repetitions in step S5 is 2 times; The yield of the high-purity di-p-tolyl iodonium trifluoromethanesulfonate is 87% and the purity is 99.90%. The purity of the high-purity di-p-tolyl iodonium trifluoromethanesulfonate prepared in the example was tested by high performance liquid chromatography. The results of the effects of different stirring speeds in steps S3 and S4 on the purity of the product are shown in Table 1. Table 1 Effect of different stirring speeds on product purity in Examples 1 to 6 Embodiment 7: A method for purifying high-purity di-p-tolyl iodonium trifluoromethanesulfonate comprises the following steps: S1. Dissolve 100 g of crude di-p-tolyl iodonium trifluoromethanesulfonate in 100 mL of ethanol, add activated carbon to remove impurities, and filter after heating at 30°C to obtain a filtrate; S2. Add 300 mL of pure water to the filtrate obtained in S1, filter and dry to obtain di-p-tolyl iodonium trifluoromethanesulfonate crystals; S3. The crystals obtained in S2 were mixed with 200 mL of methyl isobutyl ketone, stirred at a stirring speed of 160 r / min, and kept at 60°C for 2 h until the crystals were completely dissolved to obtain a saturated solution; S4. The saturated solution obtained in S3 was cooled to 10 ° C and kept warm for 2h, and stirred at a stirring speed of 30r / min until crystals precipitated, and the crystals were filtered and dried to obtain di-p-tolyl iodonium trifluoromethanesulfonate; S5. Repeat steps S3 to S4 to obtain high-purity di-p-tolyl iodonium trifluoromethanesulfonate; The number of repetitions in step S5 is 2 times; The yield of the high-purity di-p-tolyl iodonium trifluoromethanesulfonate is 85% and the purity is 99.93%. Examples 8 to 21 are based on Examples 3 and 7, and the temperature parameters of steps S3 and S4 are changed. The purity of the prepared high-purity di-p-tolyl iodonium trifluoromethanesulfonate is detected by high performance liquid chromatography. The results are shown in Table 2. Table 2 Effect of different holding temperatures and cooling temperatures on product purity in Examples 3 and 7 to 21 Embodiment 22: A method for purifying high-purity di-p-tolyl iodonium trifluoromethanesulfonate comprises the following steps: S1. Dissolve 100 g of crude di-p-tolyl iodonium trifluoromethanesulfonate in 100 mL of ethanol, add activated carbon to remove impurities, and filter after heating at 30°C to obtain a filtrate; S2. Add 300 mL of pure water to the filtrate obtained in S1, filter and dry to obtain di-p-tolyl iodonium trifluoromethanesulfonate crystals; S3. The crystals obtained in S2 were mixed with 200 mL of tert-butyl methyl ether, stirred at a stirring speed of 160 r / min, and kept at 60° C. for 2 h until the crystals were completely dissolved to obtain a saturated solution; S4. The saturated solution obtained in S3 was cooled to 0°C and kept warm for 2h, and stirred at a stirring speed of 30r / min until crystals precipitated, and the crystals were filtered and dried to obtain di-p-tolyl iodonium trifluoromethanesulfonate; S5. Repeat steps S3 to S4 to obtain high-purity di-p-tolyl iodonium trifluoromethanesulfonate; The number of repetitions in step S5 is 2 times; The yield of the high-purity di-p-tolyl iodonium trifluoromethanesulfonate is 83% and the purity is 99.91%. Embodiment 23: A method for purifying high-purity di-p-tolyl iodonium trifluoromethanesulfonate comprises the following steps: S1. Dissolve 100 g of crude di-p-tolyl iodonium trifluoromethanesulfonate in 100 mL of ethanol, add activated carbon to remove impurities, and filter after heating at 30°C to obtain a filtrate; S2. Add 300 mL of pure water to the filtrate obtained in S1, filter and dry to obtain di-p-tolyl iodonium trifluoromethanesulfonate crystals; S3. The crystals obtained in S2 were mixed with 200 mL of isopropanol, stirred at a stirring speed of 160 r / min, and kept at 60°C for 2 h until the crystals were completely dissolved to obtain a saturated solution; S4. The saturated solution obtained in S3 was cooled to 0°C and kept warm for 2h, and stirred at a stirring speed of 30r / min until crystals precipitated, and the crystals were filtered and dried to obtain di-p-tolyl iodonium trifluoromethanesulfonate; S5. Repeat steps S3 to S4 to obtain high-purity di-p-tolyl iodonium trifluoromethanesulfonate; The number of repetitions in step S5 is 2 times; The yield of the high-purity di-p-tolyl iodonium trifluoromethanesulfonate is 84% ​​and the purity is 99.93%. Embodiment 24: A method for purifying high-purity di-p-tolyl iodonium trifluoromethanesulfonate comprises the following steps: S1. Dissolve 100 g of crude di-p-tolyl iodonium trifluoromethanesulfonate in 100 mL of ethanol, add activated carbon to remove impurities, and filter after heating at 30°C to obtain a filtrate; S2. Add 300 mL of pure water to the filtrate obtained in S1, filter and dry to obtain di-p-tolyl iodonium trifluoromethanesulfonate crystals; S3. The crystals obtained in S2 were mixed with 200 mL of butanone, stirred at a stirring speed of 160 r / min, and kept at 60°C for 2 h until the crystals were completely dissolved to obtain a saturated solution; S4. The saturated solution obtained in S3 was cooled to 0°C and kept warm for 2h, and stirred at a stirring speed of 30r / min until crystals precipitated, and the crystals were filtered and dried to obtain di-p-tolyl iodonium trifluoromethanesulfonate; S5. Repeat steps S3 to S4 to obtain high-purity di-p-tolyl iodonium trifluoromethanesulfonate; The number of repetitions in step S5 is 2 times; The yield of the high-purity di-p-tolyl iodonium trifluoromethanesulfonate is 86% and the purity is 99.93%. Embodiment 25: A method for purifying high-purity di-p-tolyl iodonium trifluoromethanesulfonate comprises the following steps: S1. Dissolve 100 g of crude di-p-tolyl iodonium trifluoromethanesulfonate in 150 mL of ethanol, then add activated carbon to remove impurities by adsorption, keep warm at 30 ° C and filter to obtain a filtrate; S2. Add 300 mL of pure water to the filtrate obtained in S1, filter and dry to obtain di-p-tolyl iodonium trifluoromethanesulfonate crystals; S3. The crystals obtained in S2 were mixed with 200 mL of methyl isobutyl ketone, stirred at a stirring speed of 160 r / min, and kept at 60°C for 2 h until the crystals were completely dissolved to obtain a saturated solution; S4. The saturated solution obtained in S3 was cooled to 0°C and kept warm for 2h, and stirred at a stirring speed of 30r / min until crystals precipitated, and the crystals were filtered and dried to obtain di-p-tolyl iodonium trifluoromethanesulfonate; S5. Repeat steps S3 to S4 to obtain high-purity di-p-tolyl iodonium trifluoromethanesulfonate; The number of repetitions in step S5 is 2 times; The yield of the high-purity di-p-tolyl iodonium trifluoromethanesulfonate is 82% and the purity is 99.94%. Embodiment 26: A method for purifying high-purity di-p-tolyl iodonium trifluoromethanesulfonate comprises the following steps: S1. Dissolve 100 g of crude di-p-tolyl iodonium trifluoromethanesulfonate in 100 mL of ethanol, add activated carbon to remove impurities, and filter after heating at 30°C to obtain a filtrate; S2. Add 200 mL of pure water to the filtrate obtained in S1, filter and dry to obtain di-p-tolyl iodonium trifluoromethanesulfonate crystals; S3. The crystals obtained in S2 were mixed with 200 mL of methyl isobutyl ketone, stirred at a stirring speed of 160 r / min, and kept at 60°C for 2 h until the crystals were completely dissolved to obtain a saturated solution; S4. The saturated solution obtained in S3 was cooled to 0°C and kept warm for 2h, and stirred at a stirring speed of 30r / min until crystals precipitated, and the crystals were filtered and dried to obtain di-p-tolyl iodonium trifluoromethanesulfonate; S5. Repeat steps S3 to S4 to obtain high-purity di-p-tolyl iodonium trifluoromethanesulfonate; The number of repetitions in step S5 is 2 times; The yield of the high-purity di-p-tolyl iodonium trifluoromethanesulfonate is 87% and the purity is 99.91%. Embodiment 27: A method for purifying high-purity di-p-tolyl iodonium trifluoromethanesulfonate comprises the following steps: S1. Dissolve 100 g of crude di-p-tolyl iodonium trifluoromethanesulfonate in 100 mL of ethanol, add activated carbon to remove impurities, and filter after heating at 30°C to obtain a filtrate; S2. Add 300 mL of pure water to the filtrate obtained in S1, filter and dry to obtain di-p-tolyl iodonium trifluoromethanesulfonate crystals; S3. The crystals obtained in S2 were mixed with 300 mL of methyl isobutyl ketone, stirred at a stirring speed of 160 r / min, and kept at 60°C for 2 h until the crystals were completely dissolved to obtain a saturated solution; S4. The saturated solution obtained in S3 was cooled to 0°C and kept warm for 2h, and stirred at a stirring speed of 30r / min until crystals precipitated, and the crystals were filtered and dried to obtain di-p-tolyl iodonium trifluoromethanesulfonate; S5. Repeat steps S3 to S4 to obtain high-purity di-p-tolyl iodonium trifluoromethanesulfonate; The number of repetitions in step S5 is 2 times; The yield of the high-purity di-p-tolyl iodonium trifluoromethanesulfonate is 85% and the purity is 99.92%. Embodiment 28: A method for purifying high-purity di-p-tolyl iodonium trifluoromethanesulfonate comprises the following steps: S1. Dissolve 100 g of crude di-p-tolyl iodonium trifluoromethanesulfonate in 100 mL of ethanol, add activated carbon to remove impurities, and filter after heating at 30°C to obtain a filtrate; S2. Add 300 mL of pure water to the filtrate obtained in S1, filter and dry to obtain di-p-tolyl iodonium trifluoromethanesulfonate crystals; S3. The crystals obtained in S2 were mixed with 200 mL of methyl isobutyl ketone, stirred at a stirring speed of 160 r / min, and kept at 60°C for 2 h until the crystals were completely dissolved to obtain a saturated solution; S4. The saturated solution obtained in S3 was cooled to 0°C and kept warm for 2h, and stirred at a stirring speed of 30r / min until crystals precipitated, and the crystals were filtered and dried to obtain di-p-tolyl iodonium trifluoromethanesulfonate; S5. Repeat steps S3 to S4 to obtain high-purity di-p-tolyl iodonium trifluoromethanesulfonate; The number of repetitions in step S5 is 3 times; The yield of the high-purity di-p-tolyl iodonium trifluoromethanesulfonate is 83% and the purity is 99.90%. The purity of the high-purity di-p-tolyl iodonium trifluoromethanesulfonate prepared in the examples was tested by high performance liquid chromatography. The purity of the products in each example is shown in Table 3. Table 3 Effect of different solvents and solvent usage on product purity in Examples 22 to 28 Comparative Example 1: A method for purifying di-p-tolyl iodonium trifluoromethanesulfonate comprises the following steps: S1. Dissolve 100 g of crude di-p-tolyl iodonium trifluoromethanesulfonate in 100 mL of ethanol, add activated carbon to remove impurities, and filter after heating at 30°C to obtain a filtrate; S2. Add 300 mL of pure water to the filtrate obtained in S1, filter and dry to obtain di-p-tolyl iodonium trifluoromethanesulfonate crystals; S3. The crystals obtained in S2 were mixed with 200 mL of ethyl acetate, stirred at a stirring speed of 160 r / min, and kept at 60°C for 2 h until the crystals were completely dissolved to obtain a saturated solution; S4. The saturated solution obtained in S3 was cooled to 0°C and kept warm for 2h, and stirred at a stirring speed of 30r / min until crystals precipitated, and the crystals were filtered and dried to obtain di-p-tolyl iodonium trifluoromethanesulfonate; S5. Repeat steps S3 to S4 to obtain di-p-tolyl iodonium trifluoromethanesulfonate product; The number of repetitions in step S5 is 2 times; The yield of the di-p-tolyl iodonium trifluoromethanesulfonate product is 86%, and the purity is 96.95%. Comparative Example 2: A method for purifying di-p-tolyl iodonium trifluoromethanesulfonate comprises the following steps: S1. Dissolve 100 g of crude di-p-tolyl iodonium trifluoromethanesulfonate in 100 mL of ethanol, add activated carbon to remove impurities, and filter after heating at 30°C to obtain a filtrate; S2. Add 300 mL of pure water to the filtrate obtained in S1, filter and dry to obtain di-p-tolyl iodonium trifluoromethanesulfonate crystals; S3. The crystals obtained in S2 were mixed with 200 mL of dichloromethane, stirred at a stirring speed of 160 r / min, and kept at 60°C for 2 h until the crystals were completely dissolved to obtain a saturated solution; S4. The saturated solution obtained in S3 was cooled to 0°C and kept warm for 2h, and stirred at a stirring speed of 30r / min until crystals precipitated, and the crystals were filtered and dried to obtain di-p-tolyl iodonium trifluoromethanesulfonate; S5. Repeat steps S3 to S4 to obtain di-p-tolyl iodonium trifluoromethanesulfonate product; The number of repetitions in step S5 is 2 times; The yield of the di-p-tolyl iodonium trifluoromethanesulfonate product is 87% and the purity is 97.1%. Comparative Example 3: A method for purifying di-p-tolyl iodonium trifluoromethanesulfonate comprises the following steps: S1. Dissolve 100 g of crude di-p-tolyl iodonium trifluoromethanesulfonate in 100 mL of ethanol, add activated carbon to remove impurities, and filter after heating at 30°C to obtain a filtrate; S2. Add 300 mL of pure water to the filtrate obtained in S1, filter and dry to obtain di-p-tolyl iodonium trifluoromethanesulfonate crystals; S3. The crystals obtained in S2 were mixed with 200 mL of methyl isobutyl ketone, stirred at a stirring speed of 160 r / min, and kept at 30°C for 2 h until the crystals were completely dissolved to obtain a saturated solution; S4. The saturated solution obtained in S3 was cooled to 0°C and kept warm for 2h, and stirred at a stirring speed of 30r / min until crystals precipitated, and the crystals were filtered and dried to obtain di-p-tolyl iodonium trifluoromethanesulfonate; S5. Repeat steps S3 to S4 to obtain di-p-tolyl iodonium trifluoromethanesulfonate product; The number of repetitions in step S5 is 3 times; The yield of the di-p-tolyl iodonium trifluoromethanesulfonate product is 84% ​​and the purity is 96.7%. Comparative Example 4: A method for purifying di-p-tolyl iodonium trifluoromethanesulfonate comprises the following steps: S1. Dissolve 100 g of crude di-p-tolyl iodonium trifluoromethanesulfonate in 100 mL of ethanol, add activated carbon to remove impurities, and filter after heating at 30°C to obtain a filtrate; S2. Add 300 mL of pure water to the filtrate obtained in S1, filter and dry to obtain di-p-tolyl iodonium trifluoromethanesulfonate crystals; S3. The crystals obtained in S2 were mixed with 200 mL of methyl isobutyl ketone, stirred at a stirring speed of 160 r / min, and kept at 90°C for 2 h until the crystals were completely dissolved to obtain a saturated solution; S4. The saturated solution obtained in S3 was cooled to 0°C and kept warm for 2h, and stirred at a stirring speed of 30r / min until crystals precipitated, and the crystals were filtered and dried to obtain di-p-tolyl iodonium trifluoromethanesulfonate; S5. Repeat steps S3 to S4 to obtain di-p-tolyl iodonium trifluoromethanesulfonate product; The number of repetitions in step S5 is 3 times; The yield of the di-p-tolyl iodonium trifluoromethanesulfonate product is 83% and the purity is 99.50%. Comparative Example 5: A method for purifying di-p-tolyl iodonium trifluoromethanesulfonate comprises the following steps: S1. Dissolve 100 g of crude di-p-tolyl iodonium trifluoromethanesulfonate in 100 mL of ethanol, add activated carbon to remove impurities, and filter after heating at 30°C to obtain a filtrate; S2. Add 300 mL of pure water to the filtrate obtained in S1, filter and dry to obtain di-p-tolyl iodonium trifluoromethanesulfonate crystals; S3. The crystals obtained in S2 were mixed with 200 mL of methyl isobutyl ketone, stirred at a stirring speed of 160 r / min, and kept at 60°C for 2 h until the crystals were completely dissolved to obtain a saturated solution; S4. The saturated solution obtained in S3 was cooled to 0°C and kept warm for 2h, and stirred at a stirring speed of 30r / min until crystals precipitated, and the crystals were filtered and dried to obtain di-p-tolyl iodonium trifluoromethanesulfonate; S5. Repeat steps S3 to S4 to obtain di-p-tolyl iodonium trifluoromethanesulfonate product; The number of repetitions in step S5 is 5 times; The yield of the di-p-tolyl iodonium trifluoromethanesulfonate product is 85%, and the purity is 99.95%. Comparative Example 6: A method for purifying di-p-tolyl iodonium trifluoromethanesulfonate comprises the following steps: S1. Dissolve 100 g of crude di-p-tolyl iodonium trifluoromethanesulfonate in 100 mL of ethanol, add activated carbon to remove impurities, and filter after heating at 30°C to obtain a filtrate; S2. Add 300 mL of pure water to the filtrate obtained in S1, filter and dry to obtain di-p-tolyl iodonium trifluoromethanesulfonate crystals; S3. The crystals obtained in S2 were mixed with 200 mL of methyl isobutyl ketone, stirred at a stirring speed of 80 r / min, and kept at 60°C for 2 h until the crystals were completely dissolved to obtain a saturated solution; S4. The saturated solution obtained in S3 was cooled to 0°C and kept warm for 2h, and stirred at a stirring speed of 30r / min until crystals precipitated, and the crystals were filtered and dried to obtain di-p-tolyl iodonium trifluoromethanesulfonate; S5. Repeat steps S3 to S4 to obtain di-p-tolyl iodonium trifluoromethanesulfonate product; The number of repetitions in step S5 is 3 times; The yield of the di-p-tolyl iodonium trifluoromethanesulfonate product is 87% and the purity is 99.65%. Comparative Example 7: A method for purifying di-p-tolyl iodonium trifluoromethanesulfonate comprises the following steps: S1. Dissolve 100 g of crude di-p-tolyl iodonium trifluoromethanesulfonate in 100 mL of ethanol, add activated carbon to remove impurities, and filter after heating at 30°C to obtain a filtrate; S2. Add 300 mL of pure water to the filtrate obtained in S1, filter and dry to obtain di-p-tolyl iodonium trifluoromethanesulfonate crystals; S3. The crystals obtained in S2 were mixed with 200 mL of methyl isobutyl ketone, stirred at a stirring speed of 160 r / min, and kept at 60°C for 2 h until the crystals were completely dissolved to obtain a saturated solution; S4. The saturated solution obtained in S3 was cooled to 0°C and kept warm for 2h, and stirred at a stirring speed of 20r / min until crystals precipitated, and the crystals were filtered and dried to obtain di-p-tolyl iodonium trifluoromethanesulfonate; S5. Repeat steps S3 to S4 to obtain di-p-tolyl iodonium trifluoromethanesulfonate product; The number of repetitions in step S5 is 3 times; The yield of the di-p-tolyl iodonium trifluoromethanesulfonate product is 86% and the purity is 99.35%. Comparative Example 8: A method for purifying di-p-tolyl iodonium trifluoromethanesulfonate comprises the following steps: S1. Dissolve 100 g of crude di-p-tolyl iodonium trifluoromethanesulfonate in 80 mL of ethanol, then add activated carbon to remove impurities by adsorption, keep warm at 30°C, and filter to obtain a filtrate; S2. Add 300 mL of pure water to the filtrate obtained in S1, filter and dry to obtain di-p-tolyl iodonium trifluoromethanesulfonate crystals; S3. The crystals obtained in S2 were mixed with 200 mL of methyl isobutyl ketone, stirred at a stirring speed of 160 r / min, and kept at 60°C for 2 h until the crystals were completely dissolved to obtain a saturated solution; S4. The saturated solution obtained in S3 was cooled to 0°C and kept warm for 2h, and stirred at a stirring speed of 30r / min until crystals precipitated, and the crystals were filtered and dried to obtain di-p-tolyl iodonium trifluoromethanesulfonate; S5. Repeat steps S3 to S4 to obtain di-p-tolyl iodonium trifluoromethanesulfonate product; The number of repetitions in step S5 is 3 times; The yield of the di-p-tolyl iodonium trifluoromethanesulfonate product is 83% and the purity is 95.7%. Comparative Example 9: A method for purifying di-p-tolyl iodonium trifluoromethanesulfonate comprises the following steps: S1. Dissolve 100 g of crude di-p-tolyl iodonium trifluoromethanesulfonate in 100 mL of ethanol, add activated carbon to remove impurities, and filter after heating at 30°C to obtain a filtrate; S2. Add 400 mL of pure water to the filtrate obtained in S1, filter and dry to obtain di-p-tolyl iodonium trifluoromethanesulfonate crystals; S3. The crystals obtained in S2 were mixed with 200 mL of methyl isobutyl ketone, stirred at a stirring speed of 160 r / min, and kept at 60°C for 2 h until the crystals were completely dissolved to obtain a saturated solution; S4. The saturated solution obtained in S3 was cooled to 0°C and kept warm for 2h, and stirred at a stirring speed of 30r / min until crystals precipitated, and the crystals were filtered and dried to obtain di-p-tolyl iodonium trifluoromethanesulfonate; S5. Repeat steps S3 to S4 to obtain di-p-tolyl iodonium trifluoromethanesulfonate product; The number of repetitions in step S5 is 3 times; The yield of the di-p-tolyl iodonium trifluoromethanesulfonate product is 85% and the purity is 96.3%. Comparative Example 10: A method for purifying di-p-tolyl iodonium trifluoromethanesulfonate comprises the following steps: S1. Dissolve 100 g of crude di-p-tolyl iodonium trifluoromethanesulfonate in 100 mL of ethanol, add activated carbon to remove impurities, and filter after heating at 30°C to obtain a filtrate; S2. Add 300 mL of pure water to the filtrate obtained in S1, filter and dry to obtain di-p-tolyl iodonium trifluoromethanesulfonate crystals; S3. The crystals obtained in S2 were mixed with 600 mL of methyl isobutyl ketone, stirred at a stirring speed of 160 r / min, and kept at 60°C for 2 h until the crystals were completely dissolved to obtain a saturated solution; S4. The saturated solution obtained in S3 was cooled to 0°C and kept warm for 2h, and stirred at a stirring speed of 30r / min until crystals precipitated, and the crystals were filtered and dried to obtain di-p-tolyl iodonium trifluoromethanesulfonate; S5. Repeat steps S3 to S4 to obtain di-p-tolyl iodonium trifluoromethanesulfonate product; The number of repetitions in step S5 is 3 times; The yield of the di-p-tolyl iodonium trifluoromethanesulfonate product is 82% and the purity is 96.85%. The purity of the high-purity di-p-tolyl iodonium trifluoromethanesulfonate prepared in the example was tested by high performance liquid chromatography. The purity before and after purification of the comparative example is shown in Table 4. Table 4 Comparative Examples 1 to 10 Crude Products and Product Purity The above is only a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Any technical solution implemented within the scope of the present invention, or any possible changes and modifications made by any person skilled in the art using the above method, all belong to the protection scope of the present invention.

Claims

1. A method for purifying high-purity di-p-tolyl iodonium trifluoromethanesulfonate, characterized in that: The following steps are involved: S1. dissolving the crude di-p-tolyl iodonium trifluoromethanesulfonate in an alcohol solvent, wherein the volume ratio of di-p-tolyl iodonium trifluoromethanesulfonate to the alcohol solvent is 1:1-3, then adding an adsorbent to remove impurities, preserving at 30-50°C, and then filtering to obtain a filtrate; S2. Add pure water to the filtrate obtained in S1 to precipitate crystals, wherein the volume ratio of the alcohol solvent to pure water is 1:1 to 5, and filter and dry to obtain di-p-tolyl iodonium trifluoromethanesulfonate crystals; S3. The crystals obtained in S2 are mixed with an organic solvent, wherein the volume ratio of the di-p-tolyl iodonium trifluoromethanesulfonate crystals to the organic solvent is 1:1 to 5, and the mixture is heated at 40 to 70°C and stirred until the crystals are completely dissolved to obtain a saturated solution; S4. The saturated solution obtained in S3 is cooled to 0-30°C and stirred until crystals precipitate, and the crystals are filtered and dried to obtain di-p-tolyl iodonium trifluoromethanesulfonate; S5. Repeat steps S3 to S4 to obtain high-purity di-p-tolyl iodonium trifluoromethanesulfonate.

2. The method for purifying high-purity di-p-tolyl iodonium trifluoromethanesulfonate according to claim 1, characterized in that: The alcohol solvent in step S1 is any one of methanol, ethanol or propanol.

3. The method for purifying high-purity di-p-tolyl iodonium trifluoromethanesulfonate according to claim 1, characterized in that: The adsorbent in step S1 is any one of activated carbon, diatomaceous earth or silica gel.

4. The method for purifying high-purity di-p-tolyl iodonium trifluoromethanesulfonate according to claim 1, characterized in that: The organic solvent in step S3 is any one of methyl isobutyl ketone, tert-butyl methyl ether, isopropanol or butanone, or a combination of two or more thereof.

5. The method for purifying high-purity di-p-tolyl iodonium trifluoromethanesulfonate according to claim 1, characterized in that: The stirring speed in step S3 is 100-200 r / min, and the stirring time is 2-8 h.

6. The method for purifying high-purity di-p-tolyl iodonium trifluoromethanesulfonate according to claim 1, characterized in that: The stirring speed in S4 is 30-50 r / min, and the heat preservation time is 0.5-3 h.

7. The method for purifying high-purity di-p-tolyl iodonium trifluoromethanesulfonate according to claim 1, characterized in that: The number of repetitions in step S5 is 2 to 3 times.

8. The method for purifying high-purity di-p-tolyl iodonium trifluoromethanesulfonate according to claim 1, characterized in that: The yield of high-purity di-p-tolyl iodonium trifluoromethanesulfonate in step 5 is 80-90%, and the purity is ≥99.9%.

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