Method for preparing triphenylphosphine through reduction regeneration of triphenylphosphine oxide
By controlling the water content and reaction pressure of the triphenylphosphine oxide solution, the problems of pollution and low yield in the reduction and regeneration of triphenylphosphine oxide were solved, achieving efficient trichlorosilane recycling and high product yield.
Patent Information
- Application Number
- CN202410619736.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-20
- Publication Date
- 2025-11-21
AI Technical Summary
The existing technology for the reduction and regeneration of triphenylphosphine oxide has problems such as serious pollution, high cost, low yield, and difficulty in recycling trichlorosilane.
By controlling the water content of the triphenylphosphine oxide solution to <1020ppm and carrying out the reduction reaction under a pressure of 50-95kPa, the hydrogen chloride generated in the reaction is removed in time, limiting the formation of silicon tetrachloride, and thus enabling the unlimited reuse of trichlorosilane.
It achieves high raw material conversion rate and high product yield, ensures the recycling and reuse of trichlorosilane, and reduces production costs and environmental pollution.
Smart Images
Figure BDA0004846485300000031 
Figure BDA0004846485300000032 
Figure BDA0004846485300000033
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to a method for reducing and regenerating triphenylphosphine from triphenylphosphine oxide, and belongs to the technical field of chemical product production and resource recycling. BACKGROUND
[0002] Triphenylphosphine is an organic phosphorus compound with the chemical formula C 18 H 15 P. Triphenylphosphine is a white to yellow crystalline or powdery solid, which can be well dissolved in non-polar solvents such as benzene and diethyl ether, but not in water. Triphenylphosphine is relatively stable at room temperature, but can be oxidized by oxygen and moisture in the air.
[0003] However, the reaction using triphenylphosphine in industrial production usually produces toxic triphenylphosphine oxide, which is seriously polluting. At present, the domestic "three wastes" problem has not been solved, and the price of triphenylphosphine is high, and the consumption is large, so the technology of reducing and regenerating triphenylphosphine from triphenylphosphine oxide is more urgent. BASF company uses phosgene to convert triphenylphosphine oxide into dichloride, and then reduces it to triphenylphosphine with red phosphorus. This technology involves phosgene, a major hazard source. There is also a technology of reducing triphenylphosphine oxide with borane, which needs to be carried out in an autoclave, and borane is highly toxic and belongs to controlled chemicals, which is not easy to purchase in large quantities and is not suitable for industrial production. In addition, titanium compounds and negative hydrogen compounds can also be used as reducing agents, but they also do not have industrial prospects.
[0004] CN116082398A discloses a process for continuously synthesizing triphenylphosphine. Triphenylphosphine-organic solvent mixed solution and trichlorosilane are pumped into a microchannel reactor for reduction reaction. The reaction temperature of the reduction reaction is 80-160℃, the reaction pressure is 0.1-2.0MPa, and the reaction residence time is less than 10min. The molar ratio of triphenylphosphine oxide to trichlorosilane is 1:1.0-1.2. 2) The reaction product is cooled, washed with water, distilled to remove the solvent, recrystallized, and dried to obtain triphenylphosphine. However, this process has the problem of easy blocking. SUMMARY
[0005] To solve the problems existing in the prior art, the purpose of the present application is to provide a method for reducing and regenerating triphenylphosphine from triphenylphosphine oxide, which can realize high raw material conversion rate, high product yield and unlimited reuse of trichlorosilane.
[0006] To achieve the purpose of the present application, the following technical solutions are provided:
[0007] The application discloses a method for preparing triphenyl phosphine by reducing and regenerating triphenyl phosphine oxide, and is characterized by comprising the following steps: mixing triphenyl phosphine oxide and a solvent, and then performing dehydration treatment; controlling the water content in the mixed solution after dehydration to be less than 1020 ppm; adding trichlorosilane into the mixed solution after dehydration to perform reduction reaction; and controlling the pressure of the reaction system to be 50-95 kPa to generate triphenyl phosphine.
[0008] In some embodiments, the solvent is selected from at least one of chlorinated or non-chlorinated benzene solvents or alkane solvents, preferably selected from one or more of benzene, toluene, xylene, n-hexane, cyclohexane, methylcyclohexane, n-heptane, dichloromethane, dichloroethane, chloroform, chlorobenzene, dichlorobenzene.
[0009] In some embodiments, the mass ratio of the solvent to triphenyl phosphine oxide is (1.5-10):1, for example, 1.5:1, 2:1, 2.5:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, etc., preferably (2-5):1.
[0010] In some embodiments, the water content in the mixed solution after dehydration is controlled to be less than 1020 ppm, for example, 1000 ppm, 999 ppm, 990 ppm, 950 ppm, 900 ppm, 850 ppm, 800 ppm, 700 ppm, 600 ppm, 500 ppm, 400 ppm, 300 ppm, 200 ppm, 150 ppm, 100 ppm, 80 ppm, 50 ppm, etc., or less, preferably, the water content in the mixed solution after dehydration is controlled to be less than 600 ppm.
[0011] In some embodiments, the triphenyl phosphine oxide and the solvent are mixed and then subjected to dehydration treatment, and the specific treatment method is not particularly limited as long as the prior art method can make the water content in the mixed solution less than 1020 ppm, for example, rectification, adsorption, membrane separation and crystallization dehydration method, etc., but is not limited thereto.
[0012] In some embodiments, the molar ratio of the trichlorosilane to the raw material triphenyl phosphine oxide is (1.5-10):1, for example, 1.5:1, 2:1, 2.5:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, etc., preferably (2-4):1.
[0013] The inventors of the application have unexpectedly found that after the reaction, the excessive trichlorosilane is separated and recovered, and silicon tetrachloride is generated, the presence of the silicon tetrachloride can affect the reuse of the trichlorosilane, and can cause the decrease of the conversion rate and the yield of the reaction, and the reason for causing the adverse phenomenon is that water is introduced into the material of the reduction reaction, and the mechanism is as follows:
[0014] The reduction reaction of triphenyl phosphine oxide and trichlorosilane generates triphenyl phosphine, dichlorosilane oxide and hydrogen chloride.
[0015]
[0016] The above reaction is beneficial to the reaction to proceed to the right if the generated hydrogen chloride is removed from the reaction system in time; otherwise, not only the reaction conversion rate and yield will be affected, but also the substance Cl3SiOH will be generated.
[0017]
[0018] The introduction of water into the material of the reduction reaction and the generated hydrogen chloride can provide an acidic environment to catalyze the substance Cl3SiOH to generate the substance Cl3SiOSiCl3 through water polycondensation.
[0019]
[0020] The substance Cl3SiOSiCl3 is decomposed to generate
[0021]
[0022] The present application controls the water content of the triphenyl phosphine oxide solution after dehydration to be less than 1020 ppm, controls the pressure of the reaction system so that the generated hydrogen chloride is removed in time, and finally achieves the purpose of limiting the generation of silicon tetrachloride.
[0023] In some embodiments, the reduction reaction, the temperature of the system is controlled to be 50-100°C, for example, 50°C, 55°C, 60°C, 65°C, 70°C, 72°C, 80°C, 85°C, 90°C, 95°C, 100°C, etc., and the addition time is 10-120 min, for example, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, 100 min, 110 min, 120 min, etc.
[0024] In some embodiments, after the addition of trichlorosilane is completed, the temperature of the reaction system is maintained at 50-100°C, for example, 50°C, 55°C, 60°C, 65°C, 70°C, 72°C, 80°C, 85°C, 90°C, 95°C, 100°C, etc., and the reaction is continued for 1-6 h, for example, 1 h, 2 h, 3 h, 4 h, 4.5 h, 5 h, 6 h, etc.
[0025] In some embodiments, the pressure of the reduction reaction is 50-95 kPa, for example 50 kPa, 55 kPa, 60 kPa, 65 kPa, 70 kPa, 75 kPa, 78 kPa, 80 kPa, 85 kPa, 90 kPa, 95 kPa, preferably 60-80 kPa.
[0026] In some embodiments, the dehydration treatment is at least one of rectification, adsorption, membrane separation, and crystallization.
[0027] In some embodiments, the method further comprises a step of distilling the reaction solution to separate and recycle the trichlorosilane.
[0028] The reaction device for the reduction reaction of the present application is not particularly limited, for example, it can be a conventional reactor in the prior art. The present application does not make special description, and the prior art can be referred to.
[0029] The reaction product of the present application is cooled, washed with water, distilled to remove the solvent, recrystallized, and dried to obtain triphenylphosphine. The specific post-treatment method and process can be referred to the prior art, and the present application is not particularly limited. In the present application, the recycling method of trichlorosilane is, for example, distilling the reaction solution after the reduction reaction, collecting the light fraction, and stopping the distillation when the fraction temperature reaches the boiling point temperature of the solvent. The collected light fraction is trichlorosilane, which can be recycled.
[0030] Compared with the prior art, the present application has the following positive effects:
[0031] The present application controls the water content of the triphenylphosphine oxide solution after dehydration to be less than 1020 ppm, controls the pressure of the reaction system to remove the generated hydrogen chloride in time, and finally achieves the effect of limiting the generation of silicon tetrachloride. In this way, high raw material conversion rate, high product yield, and recycling of trichlorosilane can be achieved. DETAILED DESCRIPTION
[0032] In order to better understand the technical solutions of the present application, the content of the present application will be further described below in combination with examples, but the content of the present application is not limited to the following examples. The chemical reagents involved in the examples can be purchased through commercial channels.
[0033] Some of the raw materials used or possibly used in the examples are described below:
[0034] Triphenylphosphine oxide: water content 2113 ppm, Guangdong Fangxin Biotechnology Co., Ltd.
[0035] Trichlorosilane: Shanghai Maikelin Biochemical Technology Co., Ltd.
[0036] n-Heptane, o-dichlorobenzene, toluene, methylcyclohexane, chlorobenzene: Shanghai Aladdin Biochemical Technology Co., Ltd.
[0037] Analytical method:
[0038] Liquid chromatography instrument model: Agilent 1260.
[0039] Liquid analysis column: Agilent ZORBAX SB Phenyl liquid chromatography column (Stable Bond), 250mm*4.6mm*5um (80A).
[0040] Chromatographic conditions: Column temperature: 40℃; Detector: UV 260nm; Flow rate: 1.0ml / min; Mobile phase: methanol and pure water.
[0041] Example 1
[0042] The raw material triphenyl phosphine oxide (35g, 0.126mol) and n-heptane (350g) were added to a 1000ml three-necked flask, and after mixing, atmospheric dehydration was carried out using a rectifying column, the number of plates of the rectifying column was 25, first full reflux for 30min, then 15g fraction was collected from the top of the column, and the remaining system was the dehydrated triphenyl phosphine oxide solution, the water content was 16ppm.
[0043] Trichlorosilane (170.36g, 1.26mol) was added dropwise to the dehydrated triphenyl phosphine oxide solution within 120min, the system temperature was maintained at 50℃ during the dropwise addition, and after the addition of trichlorosilane was completed, the system temperature was maintained at 50℃ for 6h, and the system pressure was maintained at 95kPa during the whole reaction process. After detection and analysis, the conversion rate of triphenyl phosphine oxide was 100%, and the yield of triphenyl phosphine was 99.09%.
[0044] The reaction liquid was subjected to atmospheric distillation, and the light fraction was collected, and when the fraction temperature reached the boiling point temperature of n-heptane, the operation was stopped. Sampling analysis showed that the collected light component was trichlorosilane, and no silicon tetrachloride was detected.
[0045] The same experimental conditions as described above (except that the collected light component trichlorosilane was all reused, and the fresh trichlorosilane was added as needed), the experimental results were that the conversion rate of triphenyl phosphine oxide was 100%, and the yield of triphenyl phosphine was 99.13%.
[0046] Example 2
[0047] The raw material triphenyl phosphine oxide (265g, 0.952mol) and o-dichlorobenzene (397.5g) were added to a 1000ml three-necked flask, and after mixing, atmospheric dehydration was carried out using a rectifying column, the number of plates of the rectifying column was 5, first full reflux for 30min, then 15g fraction was collected from the top of the column, and the remaining system was the dehydrated triphenyl phosphine oxide solution, the water content was 1017ppm.
[0048] Trichlorosilane (193.48 g, 1.43 mol) was added dropwise to the dehydrated triphenyl phosphine oxide solution over 10 min, and the temperature of the system was maintained at 100°C during the dropwise addition. After the addition of trichlorosilane was completed, the temperature of the system was maintained at 100°C for 1 h, and the pressure of the system was maintained at 50 kPa during the entire reaction process. After detection and analysis, the conversion rate of triphenyl phosphine oxide was 100%, and the yield of triphenyl phosphine was 99.02%.
[0049] The reaction solution was subjected to atmospheric distillation, and light fractions were collected. When the temperature of the fraction reached the boiling point temperature of o-dichlorobenzene, the operation was stopped. Sampling analysis showed that the collected light component was trichlorosilane, and no silicon tetrachloride was detected.
[0050] The experimental results were the same as the previous experimental conditions (except that the collected light component trichlorosilane was all reused, and fresh trichlorosilane was added as needed). The conversion rate of triphenyl phosphine oxide was 100%, and the yield of triphenyl phosphine was 99.01%.
[0051] Example 3
[0052] The raw material triphenyl phosphine oxide (125 g, 0.449 mol) and toluene (375 g) were added to a 1000 mL three-necked flask, and after mixing, atmospheric dehydration was performed using a rectifying column. The number of plates of the rectifying column was 9, full reflux was performed for 30 min, then 15 g of fraction was collected from the top of the column, and the remaining system was the dehydrated triphenyl phosphine oxide solution, with a water content of 533 ppm.
[0053] Trichlorosilane (182.53 g, 1.35 mol) was added dropwise to the dehydrated triphenyl phosphine oxide solution over 45 min, and the temperature of the system was maintained at 70°C during the dropwise addition. After the addition of trichlorosilane was completed, the temperature of the system was maintained at 70°C for 3 h, and the pressure of the system was maintained at 70 kPa during the entire reaction process. After detection and analysis, the conversion rate of triphenyl phosphine oxide was 100%, and the yield of triphenyl phosphine was 99.72%.
[0054] The reaction solution was subjected to atmospheric distillation, and light fractions were collected. When the temperature of the fraction reached the boiling point temperature of toluene, the operation was stopped. Sampling analysis showed that the collected light component was trichlorosilane, and no silicon tetrachloride was detected.
[0055] The experimental results were the same as the previous experimental conditions (except that the collected light component trichlorosilane was all reused, and fresh trichlorosilane was added as needed). The conversion rate of triphenyl phosphine oxide was 100%, and the yield of triphenyl phosphine was 99.68%.
[0056] Example 4
[0057] The raw material triphenyl phosphine oxide (75 g, 0.27 mol) and methylcyclohexane (375 g) were added into a 1000 mL three-necked flask, and after mixing, normal pressure dehydration was performed using a rectification column with 15 plates, first full reflux for 30 min, then 15 g of distillate was collected from the top of the column, and the remaining system was the dehydrated triphenyl phosphine oxide solution with water content of 128 ppm.
[0058] Trichlorosilane (146.02 g, 1.08 mol) was added dropwise into the dehydrated triphenyl phosphine oxide solution within 60 min, the system temperature was maintained at 80°C during the dropwise addition, and after the dropwise addition of trichlorosilane was completed, the system temperature was maintained at 80°C for 4 h, and the system pressure was maintained at 80 kPa during the entire reaction process. After detection and analysis, the conversion rate of triphenyl phosphine oxide was 100%, and the yield of triphenyl phosphine was 99.57%.
[0059] Normal pressure distillation was performed on the reaction liquid, and light components were collected, and when the distillate temperature reached the boiling point temperature of methylcyclohexane, the operation was stopped. Sampling analysis showed that the collected light components were trichlorosilane, and no silicon tetrachloride was detected.
[0060] The experimental results were the same as the previous experimental conditions (the difference was that the collected light components trichlorosilane were all reused, and fresh trichlorosilane was added as needed), the conversion rate of triphenyl phosphine oxide was 100%, and the yield of triphenyl phosphine was 99.61%.
[0061] Example 5
[0062] The raw material triphenyl phosphine oxide (75 g, 0.27 mol) and methylcyclohexane (375 g) were added into a 1000 mL three-necked flask, and after mixing, normal pressure dehydration was performed using a rectification column with 15 plates, first full reflux for 30 min, then 15 g of distillate was collected from the top of the column, and the remaining system was the dehydrated triphenyl phosphine oxide solution with water content of 128 ppm.
[0063] Trichlorosilane (146.02 g, 1.08 mol) was added dropwise into the dehydrated triphenyl phosphine oxide solution within 60 min, the system temperature was maintained at 80°C during the dropwise addition, and after the dropwise addition of trichlorosilane was completed, the system temperature was maintained at 80°C for 4 h, and the system pressure was maintained at 80 kPa during the entire reaction process. After detection and analysis, the conversion rate of triphenyl phosphine oxide was 100%, and the yield of triphenyl phosphine was 99.57%.
[0064] Normal pressure distillation was performed on the reaction liquid, and light components were collected, and when the distillate temperature reached the boiling point temperature of methylcyclohexane, the operation was stopped. Sampling analysis showed that the collected light components were trichlorosilane, and no silicon tetrachloride was detected.
[0065] The experimental results were the same as the previous experimental conditions (the difference was that the collected light components trichlorosilane were all reused, and fresh trichlorosilane was added as needed), the conversion rate of triphenyl phosphine oxide was 100%, and the yield of triphenyl phosphine was 99.61%.
[0066] Comparative Example 1
[0067] Compared with Example 3, after the addition of trichlorosilane was completed, the system temperature was maintained at 70°C and the reaction was continued for 3 h, the whole reaction process was carried out under normal pressure, and other conditions were completely the same. After detection and analysis, the conversion rate of triphenyl phosphine oxide was 91.81%, and the yield of triphenyl phosphine was 87.32%.
[0068] The reaction liquid was subjected to normal pressure distillation, and the light fraction was collected. When the fraction temperature reached the boiling point temperature of toluene, the operation was stopped. Sampling analysis showed that the collected light component was trichlorosilane, which contained 5.17% of silicon tetrachloride by detection.
[0069] The experimental results were the same as the previous experimental conditions (the difference was that the collected light component trichlorosilane was all reused, and the insufficient was added with fresh trichlorosilane). The conversion rate of triphenyl phosphine oxide was 90.32%, and the yield of triphenyl phosphine was 85.28%.
[0070] Comparative Example 2
[0071] The raw material triphenyl phosphine oxide (125 g, 0.449 mol) and toluene (375 g) were added to a 1000 mL three-necked flask, and after mixing, dehydration was carried out by normal pressure distillation. 15 g of distillate was collected, and the remaining system was the dehydrated triphenyl phosphine oxide solution, with a water content of 1048 ppm.
[0072] Trichlorosilane (182.55 g, 1.35 mol) was added dropwise to the dehydrated triphenyl phosphine oxide solution within 45 min, the system temperature was maintained at 70°C during the dropwise addition, and the system temperature was maintained at 70°C for 3 h after the addition of trichlorosilane was completed. The whole reaction process maintained the system pressure at 70 kPa. After detection and analysis, the conversion rate of triphenyl phosphine oxide was 95.69%, and the yield of triphenyl phosphine was 89.21%.
[0073] The reaction liquid was subjected to normal pressure distillation, and the light fraction was collected. When the fraction temperature reached the boiling point temperature of toluene, the operation was stopped. Sampling analysis showed that the collected light component was trichlorosilane, which contained 21.49% of silicon tetrachloride by detection.
[0074] The experimental results were the same as the previous experimental conditions (the difference was that the collected light component trichlorosilane was all reused, and the insufficient was added with fresh trichlorosilane). The conversion rate of triphenyl phosphine oxide was 94.12%, and the yield of triphenyl phosphine was 86.16%.
[0075] Comparative Example 3
[0076] The raw material triphenyl phosphine oxide (125 g, 0.449 mol) and toluene (375 g) were added into a 1000 mL three-necked flask, and after mixing, the water was removed by atmospheric distillation, 15 g of distillate was collected, and the remaining system was the dehydrated triphenyl phosphine oxide solution, the water content was 1052 ppm.
[0077] Trichlorosilane (182.51 g, 1.35 mol) was added dropwise into the dehydrated triphenyl phosphine oxide solution within 45 min, the temperature of the system was maintained at 70°C during the dropwise addition, and after the dropwise addition of trichlorosilane was completed, the temperature of the system was maintained at 70°C for 3 h of continuous reaction, and the entire reaction process was carried out under atmospheric pressure. After detection and analysis, the conversion rate of triphenyl phosphine oxide was 86.51%, and the yield of triphenyl phosphine was 75.41%.
[0078] The reaction liquid was subjected to atmospheric distillation, and the light fraction was collected, and when the temperature of the fraction reached the boiling point temperature of toluene, the operation was stopped. Sampling analysis showed that the collected light component was trichlorosilane, and it also contained 31.20% of silicon tetrachloride. Under the same experimental conditions as described above (the difference was that the collected light component trichlorosilane was all reused, and the deficiency was supplemented with fresh trichlorosilane), the experimental results were that the conversion rate of triphenyl phosphine oxide was 83.87%, and the yield of triphenyl phosphine was 71.47%.
Claims
1. A method for preparing triphenylphosphine by reduction and regeneration, characterized in that, The process involves mixing triphenylphosphine oxide and a solvent, followed by dehydration treatment to ensure the water content in the dehydrated solution is <1020 ppm. Trichlorosilane is then added to the dehydrated solution for reduction, and the reaction system pressure is controlled at 50–95 kPa to generate triphenylphosphine.
2. The method according to claim 1, characterized in that, The solvent is selected from benzene and / or alkane solvents, preferably from one or more of benzene, toluene, xylene, n-hexane, cyclohexane, methylcyclohexane, n-heptane, dichloromethane, dichloroethane, chloroform, chlorobenzene, and dichlorobenzene.
3. The method according to claim 1 or 2, characterized in that, The mass ratio of the solvent to triphenylphosphine oxide is (1.5–10):1, preferably (2–5):
1.
4. The method according to claim 1, characterized in that, The water content of the dehydrated mixed solution should be controlled to be <1020ppm, preferably <600ppm.
5. The method according to claim 1, characterized in that, The molar ratio of trichlorosilane to triphenylphosphine oxide is (1.5-10):1, preferably (2-4):
1.
6. The method according to claim 1, characterized in that, In the reduction reaction, the temperature of the reaction system is controlled at 50-100°C and the addition time is 10-120 min during the trichlorosilane addition stage.
7. The method according to claim 1 or 6, characterized in that, After the addition of trichlorosilane, the reaction system temperature is maintained at 50–100°C for 1–6 hours.
8. The method according to claim 1, characterized in that, The pressure of the reduction reaction is 50-95 kPa, preferably 60-80 kPa.
9. The method according to claim 1, characterized in that, The dehydration treatment method is at least one of distillation, adsorption, membrane separation, and crystallization dehydration.
10. The method according to claim 1, characterized in that, It also includes the steps of distilling the reaction solution to separate trichlorosilane and reusing it.