Preparation method of bis (4-tert-butylphenyl) iodine hexafluorophosphate

Abstract

The invention relates to a preparation method of bis (4-tert-butylphenyl) iodine hexafluorophosphate, and belongs to the technical field of photoinitiators. According to the method, reaction conditions are optimized according to the reaction principle of free radical chain initiation and chain growth, in the step (1), by adjusting the adding mode of an oxidizing agent, the oxidizing agent accounting for 38.46%-45.45% of the molar mass of the whole oxidizing agent is added into a container and stirred to be uniform, the reaction is carried out for 40 min or above, then the remaining oxidizing agent is prepared into a saturated aqueous solution to be added, and the reaction is carried out for 30 min or above; the reaction lasts for 2-3 days, the reaction efficiency of free radicals in the reaction is greatly increased, the reaction yield can be increased to 90% or above, and the requirement of large-batch production can be met.

Description

Technical Field

[0001] This invention relates to a method for preparing bis(4-tert-butylphenyl)iodohexafluorophosphate, belonging to the field of photoinitiator technology. Background Technology

[0002] In recent years, cationic photoinitiator curing technology has seen tremendous development and has been successfully applied in various fields such as photocurable coatings, inks, adhesives, electronic packaging materials, and photoresists. Among them, bis(4-tert-butylphenyl)iodohexafluorophosphate is a cationic photoinitiator of the diaryliodonium salt class. It has high initiation efficiency and, due to its extremely high high-temperature stability, has a very broad application prospect.

[0003] However, bis(4-tert-butylphenyl)iodonium salts belong to the diaryl iodonium salt family, and their synthesis process is complex with low raw material utilization. Currently, an article titled "Synthesis of Symmetrical Diaryl Iodonium Salts" reports a small-scale trial yield of approximately 68% using tert-butylbenzene and 4-tert-butyliodobenzene as raw materials via concentrated sulfuric acid and oxidant catalysis. However, this reaction route only demonstrates the feasibility of the reaction principle; due to limitations in material costs and market prices, it lacks practical production significance.

[0004] Therefore, it is of great significance to develop a preparation method that is simple to operate, has a high yield, and meets the requirements of actual production. Summary of the Invention

[0005] To overcome the low yield problem in existing methods for preparing bis(4-tert-butylphenyl)iodohexafluorophosphate, the present invention aims to provide a method for preparing bis(4-tert-butylphenyl)iodohexafluorophosphate. This method optimizes the reaction conditions based on the reaction principle of free radical chain initiation and chain propagation. By adjusting the addition method of the oxidant, the reaction efficiency of free radicals in the reaction is significantly increased, raising the reaction yield to over 90%, and meeting the requirements for mass production.

[0006] To achieve the objectives of this invention, the following technical solutions are provided.

[0007] A method for preparing bis(4-tert-butylphenyl)iodine hexafluorophosphate, the method comprising the following steps: (1) This step is carried out in an environment of -5 ℃ ~ -10 ℃ and nitrogen protection: 4-tert-butyliodobenzene and tert-butylbenzene are used as raw materials, stirred and mixed evenly in a container, concentrated sulfuric acid is added, and then 38.46% ~ 45.45% of the total oxidant molar mass fraction of the oxidant is quickly added to the container and stirred evenly. The reaction is carried out for more than 40 min, and then the remaining oxidant is prepared into a saturated aqueous solution and slowly added. The reaction is carried out for 2 to 3 days.

[0008] Further, the molar ratio of 4-tert-butyl iodine : benzene tert-butyl benzene : concentrated sulfuric acid and oxidant is 1 : 1.05 ~ 1.4 : 2 : 1.1 ~ 1.3.

[0009] Further, the concentrated sulfuric acid is a commercially available concentrated sulfuric acid, usually with a mass fraction of 98%; when the concentrated sulfuric acid is added, it is slowly added at a speed of 2 drops / second ~ 3 drops / second. The oxidant is a conventional oxidant used in the corresponding step in the method for preparing bis (4-tert-butylphenyl) iodine hexafluorophosphate in the art, for example: sodium periodate, sodium iodate, sodium hypochlorite, sodium persulfate, ammonium persulfate, 30% hydrogen peroxide, etc.

[0010] (2) Add organic solvent A, hexafluorophosphate and water to the reaction kettle, stir for 1 day at 25 ℃ ~ 30 ℃ under nitrogen protection, to obtain a reaction product.

[0011] Further, the amount of organic solvent A, hexafluorophosphate and water is in the ratio of 1.5 kg : 1.2 mol : 0.5 kg.

[0012] The organic solvent A is a conventional organic solvent used in the corresponding step in the method for preparing bis (4-tert-butylphenyl) iodine hexafluorophosphate in the art, for example: dichloromethane, methanol, ethyl acetate, tetrahydrofuran, etc.

[0013] (3) The reaction product obtained in step (2) is subjected to liquid-liquid separation treatment, the organic phase is collected, the pH value of the organic phase is adjusted to 6 ~ 8, washed with water, separated, and the organic solvent A is removed under reduced pressure to obtain a yellow solid product, which is a crude bis (4-tert-butylphenyl) iodine hexafluorophosphate containing a small amount of impurities and pigments; after being beaten with an organic solvent B, filtration, and drying of the obtained solid, a white powder-like bis (4-tert-butylphenyl) iodine hexafluorophosphate is obtained.

[0014] Further, the pH of the organic phase is adjusted using a sodium hydroxide solution.

[0015] Further, the organic solvent A is removed under reduced pressure at 40 ℃.

[0016] Further, the obtained solid is dried in an oven at 40 ℃.

[0017] The organic solvent B is a conventional organic solvent used in the corresponding step in the method for preparing bis (4-tert-butylphenyl) iodine hexafluorophosphate in the art, for example: n-hexane, benzene, toluene, petroleum ether, etc.

[0018] In the present application, the water is usually deionized water.

[0019] Advantages (1) The application provides a preparation method of bis (4-tert-butylphenyl) iodine hexafluorophosphate, which optimizes reaction conditions according to the reaction principle of free radical chain initiation and chain growth, greatly increases the reaction efficiency of free radicals by adopting the batch feeding mode of oxidizing agent, and can improve the reaction yield to more than 90%.

[0020] (2) The application provides a preparation method of bis (4-tert-butylphenyl) iodine hexafluorophosphate, which divides the oxidizing agent into two times, first adds 38.46% to 45.45% of the oxidizing agent in terms of molar mass fraction of the whole oxidizing agent into the container and stirs uniformly, and reacts for more than 40 minutes, which is the boundary line for generating impurities, if the amount of oxidizing agent is increased, impurities will be generated.

[0021] (3) The application provides a preparation method of bis (4-tert-butylphenyl) iodine hexafluorophosphate, which divides the oxidizing agent into two times, and slowly adds the remaining oxidizing agent in the form of saturated aqueous solution to avoid high concentration of oxidizing agent and generate impurities.

[0022] (4) The application provides a preparation method of bis (4-tert-butylphenyl) iodine hexafluorophosphate, which can reduce the reaction temperature, increase the reaction time, reduce the occurrence of side reactions, and obtain high-purity products through simple purification and decolorization.

[0023] (5) The application provides a preparation method of bis (4-tert-butylphenyl) iodine hexafluorophosphate, which increases the utilization rate of raw materials, optimizes the reaction yield to more than 90%, and the purity can reach more than 99%; and through market investigation, considering factors such as raw material price, market price, labor cost and many others, the method can realize small pilot scale-up, meet the requirements of large-scale industrial production. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The nuclear magnetic hydrogen spectrum detection result of the final product prepared in Example 1.

[0025] Figure 2 The high performance liquid chromatography detection result of the final product prepared in Example 1. DETAILED DESCRIPTION

[0026] The application will be described in detail below in combination with the drawings and specific embodiments, but not as a limitation on the patent.

[0027] Example 1 A preparation method of bis (4-tert-butylphenyl) iodine hexafluorophosphate, the steps of which are as follows: (1) This step is carried out at -5 ℃ ~ -10 ℃ and in a nitrogen-protected environment: 1 mol of 4-tert-butyl iodobenzene and 1.4 mol of tert-butylbenzene are mixed uniformly in a glass flask, then 2 mol of 98% concentrated sulfuric acid is slowly added at a rate of 2 drops / sec ~ 3 drops / sec, the total amount of oxidant sodium persulfate is 1.3 mol, 0.5 mol of sodium persulfate is quickly added to the glass flask and stirred uniformly, reacts for 40 min, then the remaining sodium persulfate is slowly dropped into the saturated aqueous solution, and reacts for 3 days.

[0028] (2) 1.5 kg of dichloromethane, 1.2 mol of hexafluorophosphate and 0.5 kg of deionized water are added to the reaction kettle, stirred at 25 ℃ ~ 30 ℃ and in a nitrogen-protected environment for 1 day to obtain the reaction product.

[0029] (3) The reaction product prepared in step (2) is subjected to liquid-liquid separation treatment, the organic phase is collected, the pH value of the organic phase is adjusted to 7 using 1% sodium hydroxide solution, washed with deionized water three times, each time 300 ml, liquid-liquid separation, and the dichloromethane is removed under reduced pressure at 40 ℃ to obtain a yellow solid product, which is a crude bis(4-tert-butylphenyl) iodine hexafluorophosphate containing a small amount of impurities and pigments; after beating with 700 ml of toluene, filtering, and drying the obtained solid in an oven at 40 ℃, the final product is obtained as a white powder, which is bis(4-tert-butylphenyl) iodine hexafluorophosphate, the yield is 93%, and the purity is more than 99%.

[0030] Example 2 A method for preparing bis(4-tert-butylphenyl) iodine hexafluorophosphate, the steps of which are as follows: (1) This step is carried out at -5 ℃ ~ -10 ℃ and in a nitrogen-protected environment: 1 mol of 4-tert-butyl iodobenzene and 1.05 mol of tert-butylbenzene are mixed uniformly in a glass flask, then 2 mol of 98% concentrated sulfuric acid is slowly added at a rate of 2 drops / sec ~ 3 drops / sec, the total amount of oxidant sodium persulfate is 1.1 mol, 0.5 mol of sodium persulfate is quickly added to the glass flask and stirred uniformly, reacts for 40 min, then the remaining sodium persulfate is slowly dropped into the saturated aqueous solution, and reacts for 2 days.

[0031] (2) 1.5 kg of dichloromethane, 1.2 mol of hexafluorophosphate and 0.5 kg of deionized water are added to the reaction kettle, stirred at 25 ℃ ~ 30 ℃ and in a nitrogen-protected environment for 1 day to obtain the reaction product.

[0032] (3) The reaction product prepared in step (2) was subjected to liquid separation treatment, the organic phase was collected, the pH of the organic phase was adjusted to 6 using a 1% mass fraction sodium hydroxide solution, the organic phase was washed with deionized water three times, each time 300 ml, the dichloromethane was removed by evaporation under reduced pressure at 40°C, and a yellow solid product was obtained, which was a crude bis (4-tert-butylphenyl) iodonium hexafluorophosphate containing a small amount of impurities and pigments; after beating with 700 ml of toluene, filtration was performed, and the obtained solid was dried in an oven at 40°C, and a final product in the form of a white powder was obtained, which was bis (4-tert-butylphenyl) iodonium hexafluorophosphate, the yield was 91%, and the purity was more than 99%.

[0033] Test experiment: The final product prepared in Examples 1 and 2 was tested as follows: (1) Nuclear magnetic resonance hydrogen spectrum detection, the detection results are as follows Figure 1 , the multiplet of the product is reported as: 1 H NMR (400 MHz, Chloroform- d ) delta 8.05-7.90 (m, 4H), 7.56-7.43 (m, 4H), 1.29 (s, 18H), it can be seen that the final product is bis (4-tert-butylphenyl) iodonium hexafluorophosphate.

[0034] (2) High performance liquid chromatography detection, the results of the final product prepared in Example 1 are as follows Figure 2 , the purity is 99.27%; the results of Example 2 are similar, and the purity of the final product is 99.19%.

Claims

1. A method for preparing bis(4-tert-butylphenyl)iodohexafluorophosphate, characterized in that: (1) Step (1) is carried out in an environment of -5 ℃ ~ -10 ℃ and nitrogen protection: 4-tert-butyliodobenzene and tert-butylbenzene are used as raw materials, stirred and mixed evenly in a container, concentrated sulfuric acid is added, and then 38.46% ~ 45.45% of the total oxidant molar mass fraction of the oxidant is added to the container and stirred evenly. The reaction is carried out for more than 40 min, and then the remaining oxidant is prepared into a saturated aqueous solution and added. The reaction is carried out for 2 to 3 days. (2) Add organic solvent A, hexafluorophosphate and water to the reaction vessel, and stir the reaction for 1 day under nitrogen protection at 25 ℃ ~ 30 ℃ to obtain the reaction product; (3) The reaction product was separated into liquid and liquid phases, the organic phase was collected, the pH of the organic phase was adjusted to 6-8, washed with water, separated, and the organic solvent A was removed by vacuum evaporation to obtain crude bis(4-tert-butylphenyl)iodohexafluorophosphate; after pulping with organic solvent B, the product was filtered, the obtained solid was dried, and bis(4-tert-butylphenyl)iodohexafluorophosphate was prepared.

2. The method for preparing bis(4-tert-butylphenyl)iodohexafluorophosphate according to claim 1, characterized in that: In step (1), the molar mass ratio of 4-tert-butyliodine: phenyltert-butylbenzene: concentrated sulfuric acid and oxidant is 1: 1.05~1.4: 2: 1.1~1.

3.

3. A method for preparing bis(4-tert-butylphenyl)iodohexafluorophosphate according to claim 1 or 2, characterized in that: In step (2), the ratio of organic solvent A, hexafluorophosphate and water is 1.5 kg : 1.2 mol : 0.5 kg.

4. The method for preparing bis(4-tert-butylphenyl)iodohexafluorophosphate according to claim 1 or 2, characterized in that: In step (3), sodium hydroxide solution is used to adjust the pH of the organic phase.

5. A method for preparing bis(4-tert-butylphenyl)iodohexafluorophosphate according to claim 1 or 2, characterized in that: In step (3), organic solvent A is removed by vacuum evaporation at 40 °C; the resulting solid is dried in an oven at 40 °C.

6. A method for preparing bis(4-tert-butylphenyl)iodohexafluorophosphate according to claim 1 or 2, characterized in that: In step (1), the mass fraction of concentrated sulfuric acid is 98%; when adding concentrated sulfuric acid, it is added at a rate of 2 drops / second to 3 drops / second; The oxidizing agent is sodium periodate, sodium iodate, sodium hypochlorite, sodium persulfate, ammonium persulfate, or hydrogen peroxide with a mass fraction of 30%.

7. The method for preparing bis(4-tert-butylphenyl)iodohexafluorophosphate according to claim 1 or 2, characterized in that: In step (2), organic solvent A is dichloromethane, methanol, ethyl acetate or tetrahydrofuran.

8. The method for preparing bis(4-tert-butylphenyl)iodohexafluorophosphate according to claim 1 or 2, characterized in that: In step (3), organic solvent B is n-hexane, benzene, toluene or petroleum ether.

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