Green and environment-friendly method for preparing triphenylphosphine

Abstract

The invention relates to a method for preparing triphenylphosphine, which comprises the following steps: carrying out heat treatment on a diphenylphosphine chloride raw material at 280-480 DEG C to prepare the triphenylphosphine, and the content of phenyldichlorophosphine in the diphenylphosphine chloride raw material is not more than 35 weight percent based on the total weight of the diphenylphosphine chloride raw material.

Description

Technical Field

[0001] This invention relates to a method for preparing triphenylphosphine, which can obtain triphenylphosphine through a one-step reaction. Technical Background

[0002] Triphenylphosphine has a wide range of applications in the chemical industry. It is an important catalyst for the synthesis of fine chemicals; a catalyst for petroleum processing; a novel biocatalytic technology and catalyst; a novel and efficient catalyst for environmental protection; a novel catalyst for organic synthesis; a novel and efficient catalyst for polyolefins; a new material for catalyst supports and various novel co-catalytic materials; it can also be used as a functional fine chemical; a novel papermaking chemical; a novel oilfield chemical suitable for protective extraction and enhanced oil recovery; a novel surfactant; a high-performance, water-based functional coating and auxiliaries; a novel textile dyeing and finishing auxiliaries; a high-performance environmentally friendly adhesive; a novel safe and environmentally friendly pigment and dye; and a high-performance environmentally friendly leather chemical. Triphenylphosphine can also serve as an intermediate in the chemical synthesis of various important chemical products, such as β-carotene, cefprozil, and cefdinir.

[0003] The main methods for industrial production of triphenylphosphine include (1) the Grignard method (sodium method): using metallic sodium, which is stirred at high speed, to react with chlorobenzene and phosphorus trichloride to produce triphenylphosphine. This method is technically demanding, especially the sodium sand equipment. It is necessary to solve the problem of sodium dispersion and avoid the presence of water during operation, as highly reactive sodium is prone to violent reaction with water and explosion. Therefore, there are significant safety hazards and high risk in the production process. (2) the Grignard reagent method (Grignard method): this method uses phenyl magnesium halide and phosphorus trichloride as raw materials. The reactants are heated to produce triphenylphosphine through the reaction, accompanied by a small amount of byproduct - triphenylphosphine oxide. This method has disadvantages such as high cost, low yield, and poor economic benefits. (3) the Friedel-Cloughs method: this method uses thiophosphonochloride to react with benzene in the presence of excess aluminum trichloride to produce triphenylphosphine sulfur, which is then desulfurized (reduced) with iron filings or sodium naphthalene to obtain triphenylphosphine. However, the triphenylphosphine product reduced by iron powder is of poor quality and has a yellowish color. Furthermore, the use of aluminum trichloride and iron powder as catalysts will generate a large amount of solid waste that is difficult to treat and will cause environmental pollution. (4) Triphenylphosphine oxide reduction method, but the reducing agent used in the triphenylphosphine oxide reduction method is relatively expensive.

[0004] In conclusion, there is an urgent need to develop a green, environmentally friendly, low-cost, high-quality, and simple method for synthesizing triphenylphosphine. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing triphenylphosphine, which is green, environmentally friendly, safe, low-cost, high-quality and simple to operate. Furthermore, this method does not require the use of solvents or co-solvents and the raw materials are readily available.

[0006] The technical solution for achieving the above-mentioned objectives of this invention can be summarized as follows:

[0007] 1. A method for preparing triphenylphosphine, comprising heat-treating a diphenylphosphine chloride raw material at a temperature of 280-480°C to prepare triphenylphosphine, wherein the content of phenyl diphosphine chloride in the diphenylphosphine chloride raw material does not exceed 35% by weight, based on the total weight of the diphenylphosphine chloride raw material.

[0008] 2. According to the method of embodiment 1, the content of phenyl dichloride in the diphenylphosphine raw material is not more than 30% by weight, preferably not more than 28% by weight, more preferably not more than 22% by weight, even more preferably not more than 15% by weight, especially not more than 8% by weight, particularly not more than 3% by weight, most preferably not more than 1% by weight, for example not more than 0.5% by weight, based on the total weight of the diphenylphosphine raw material.

[0009] 3. According to the method of embodiment 1 or 2, the content of the diphenylphosphine chloride in the diphenylphosphine chloride raw material is at least 65% by weight, preferably at least 70% by weight, more preferably at least 80% by weight, even more preferably at least 88% by weight, and even more preferably at least 95% by weight, for example at least 98% by weight, based on the total weight of the diphenylphosphine chloride raw material.

[0010] 4. The method according to any one of embodiments 1-3, wherein the heat treatment temperature is 300-450°C, preferably 320-400°C, and more preferably 330-390°C.

[0011] 5. According to the method of embodiment 4, the heat treatment temperature is particularly 340-370°C, especially 345-360°C, most preferably 345-355°C, for example about 350°C.

[0012] 6. The method according to any one of embodiments 1-5, wherein the maximum pressure (gauge pressure) during the heat treatment process is at least 0.05 MPa, preferably at least 0.08 MPa, for example 0.05-6 MPa, more preferably 0.08-5 MPa, and even more preferably 0.1-2 MPa or 0.1-0.3 MPa.

[0013] 7. The method according to any one of embodiments 1-6, wherein the heat treatment is carried out under autogenous pressure.

[0014] 8. The method according to any one of embodiments 1-7, wherein the heat treatment time is at least 0.4 hours, preferably 0.4-12 hours, more preferably 0.6-8 hours, especially 0.8-8 hours, most preferably 1.5-2.5 hours, for example about 2 hours.

[0015] 9. The method according to any one of embodiments 1-8, wherein the phosphorus trichloride content in the diphenylphosphine chloride raw material is not more than 5% by weight, preferably not more than 2% by weight, more preferably not more than 1% by weight, for example not more than 0.5% by weight or not more than 0.1% by weight, based on the total weight of the diphenylphosphine chloride raw material.

[0016] 10. The method according to any one of embodiments 1-9, wherein the heat treatment is carried out under stirring.

[0017] 11. The method according to any one of embodiments 1-10, wherein the product mixture obtained by said method comprises triphenylphosphine, phenylphosphine dichloride and diphenylphosphine chloride.

[0018] 12. The method according to embodiment 11, wherein the content of triphenylphosphine in the reaction mixture after heat treatment is at least 15% by weight, preferably at least 20% by weight, for example 15-60% by weight or 20-50% by weight, based on the total weight of triphenylphosphine, phenylphosphine dichloride and diphenylphosphine dichloride in the reaction mixture.

[0019] 13. The method according to any one of embodiments 1-12, wherein the method comprises heat-treating the diphenylphosphine chloride feedstock at a temperature of 300-450°C, wherein the maximum pressure (gauge pressure) during the heat treatment process is at least 0.05 MPa, and the heat treatment time is at least 0.4 hours;

[0020] The diphenylphosphine chloride raw material contains at least 65% by weight of diphenylphosphine chloride, no more than 30% by weight of phenylphosphine dichloride, and no more than 5% by weight of phosphorus trichloride, based on the total weight of the diphenylphosphine chloride raw material.

[0021] 14. The method according to any one of embodiments 1-13, wherein the method comprises heat-treating the diphenylphosphine chloride feedstock at a temperature of 345-355°C, wherein the maximum pressure (gauge pressure) during the heat treatment process is 0.15-0.3 MPa (preferably the heat treatment is carried out under autogenous pressure), and the heat treatment time is 1.5-2.5 hours;

[0022] The diphenylphosphine chloride raw material contains at least 98% by weight of diphenylphosphine chloride, no more than 1% by weight of phenylphosphine dichloride, and no more than 0.1% by weight of phosphorus trichloride (preferably free of phosphorus trichloride), based on the total weight of the diphenylphosphine chloride raw material.

[0023] The beneficial effects of this invention are as follows:

[0024] (1) The method of the present invention is green, environmentally friendly, safe, low-cost, high-quality and simple to operate.

[0025] (2) The method of the present invention uses diphenylphosphine chloride as raw material, without the need to add other co-solvents, and the raw material is simple and easy to obtain.

[0026] (3) Diphenylphosphine chloride is a liquid, which is easy to handle and does not require the use of solvents, thus avoiding solvent pollution.

[0027] (4) This invention can obtain triphenylphosphine with a high yield and a high triphenylphosphine / raw material weight ratio. The price of triphenylphosphine is much higher than that of diphenylphosphine chloride, therefore the method of this invention has extremely high industrial value. Detailed Implementation

[0028] This invention relates to a method for preparing triphenylphosphine, which includes heat-treating a diphenylphosphine chloride raw material at a temperature of 280-480°C to prepare triphenylphosphine, wherein the content of phenyl diphosphine chloride in the diphenylphosphine chloride raw material does not exceed 35% by weight, based on the total weight of the diphenylphosphine chloride raw material.

[0029] In one embodiment, the content of phenyl dichloride in the diphenylphosphine raw material is not more than 30% by weight (e.g., 28% by weight, 26% by weight, 25% by weight, 22% by weight, 20% by weight, 18% by weight, 15% by weight, 12% by weight, 10% by weight, 8% by weight, 5% by weight, 3% by weight, 2% by weight, 1% by weight, 0.5% by weight, or 0.1% by weight), preferably not more than 28% by weight, more preferably not more than 22% by weight, even more preferably not more than 15% by weight, especially not more than 8% by weight, particularly not more than 3% by weight, most preferably not more than 1% by weight, for example not more than 0.5% by weight, based on the total weight of the diphenylphosphine raw material.

[0030] In one embodiment, the content of diphenylphosphine chloride in the diphenylphosphine chloride feedstock is at least 65% by weight (e.g., 68% by weight, 70% by weight, 75% by weight, 80% by weight, 85% by weight, 88% by weight, 90% by weight, 91% by weight, 92% by weight, 93% by weight, 95% by weight, 98% by weight, 99% by weight, 99.5% by weight, or 99.9% by weight), preferably at least 70% by weight, more preferably at least 80% by weight, even more preferably at least 88% by weight, and even more preferably at least 95% by weight, for example at least 98% by weight, based on the total weight of the diphenylphosphine chloride feedstock. For example, the content of diphenylphosphine chloride in the diphenylphosphine chloride feedstock is 65-99.5% by weight, 70-99.5% by weight, 80-99.5% by weight, 80-98% by weight, 85-95% by weight, or 90-95% by weight.

[0031] According to the present invention, the heat treatment temperature is 280-480°C, for example 280°C, 290°C, 300°C, 310°C, 320°C, 330°C, 340°C, 345°C, 350°C, 355°C, 360°C, 370°C, 380°C, 390°C, 400°C, 410°C, 420°C, 430°C, 440°C, or 450°C. In one embodiment, the heat treatment temperature is 290-450°C, 300-450°C, preferably 320-400°C or 330-390°C, more preferably 330-380°C. In a preferred embodiment, the heat treatment temperature is particularly 340-370°C, especially 345-360°C, most preferably 345-355°C, for example, about 350°C.

[0032] In one embodiment, the maximum pressure (gauge pressure) during the heat treatment process is at least 0.05 MPa (e.g., 0.08 MPa, 0.1 MPa, 0.15 MPa, 0.2 MPa, 0.25 MPa, 0.3 MPa, 0.5 MPa, 0.8 MPa, 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa), preferably at least 0.08 MPa, for example 0.05-6 MPa, more preferably 0.08-5 MPa, and even more preferably 0.1-4 MPa, 0.1-3 MPa, 0.1-2 MPa, 0.1-1 MPa, 0.1-0.8 MPa, 0.1-0.5 MPa, 0.15-0.3 MPa.

[0033] Before feeding materials, the reactor can be evacuated, for example to -50 kPa or lower (i.e., 50 kPa or lower than atmospheric pressure), preferably -80 kPa or lower (i.e., 80 kPa or lower than atmospheric pressure), thereby reducing the maximum pressure during the heat treatment process. Alternatively, an inert gas, such as nitrogen, can be introduced into the reactor before heat treatment to increase the maximum pressure during the process.

[0034] In a preferred embodiment, the heat treatment is performed under autogenous pressure.

[0035] In one embodiment, the heat treatment time is at least 0.4 hours (e.g., 0.5 hours, 0.8 hours, 1 hour, 1.2 hours, 1.5 hours, 1.8 hours, 2 hours, 2.2 hours, 2.5 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, or 12 hours), preferably 0.4-12 hours, more preferably 0.6-8 hours, especially 0.8-8 hours, 1-7 hours, 1-5 hours, 1.5-4 hours, and most preferably 1.5-2.5 hours, for example, about 2 hours.

[0036] In one embodiment, the phosphorus trichloride content in the diphenylphosphine chloride feedstock is no more than 5% by weight (e.g., 4% by weight, 3% by weight, 2% by weight, 1% by weight, 0.5% by weight, 0.2% by weight, 0.1% by weight, or 0.05% by weight), preferably no more than 2% by weight, more preferably no more than 1% by weight, for example, no more than 0.5% by weight or no more than 0.1% by weight, based on the total weight of the diphenylphosphine chloride feedstock. In one embodiment, the diphenylphosphine chloride feedstock is free of phosphorus trichloride.

[0037] In one embodiment, the triphenylphosphine content in the diphenylphosphine chloride feedstock is no more than 6% by weight (e.g., 5% by weight, 4% by weight, 3% by weight, 2% by weight, 1% by weight, 0.5% by weight, 0.2% by weight or 0.1% by weight), preferably no more than 5% by weight, more preferably no more than 1% by weight, for example no more than 0.5% by weight or no more than 0.1% by weight, based on the total weight of the diphenylphosphine chloride feedstock.

[0038] In one embodiment, the heat treatment is carried out under stirring. The stirring rate can be, for example, 50-700 r / min, such as 100-600 r / min, or 200-500 r / min or 300-450 r / min.

[0039] Before stirring, the diphenylphosphine chloride feedstock can be preheated, for example to 40-90°C, preferably to 50-80°C, such as 60-80°C.

[0040] In one embodiment, the product mixture obtained by the method comprises triphenylphosphine, phenylphosphine dichloride, and diphenylphosphine chloride.

[0041] In one embodiment, the triphenylphosphine content in the reaction mixture after heat treatment is at least 15% by weight (e.g., 16% by weight, 18% by weight, 20% by weight, 25% by weight, 30% by weight, 35% by weight, 40% by weight, 45% by weight, 50% by weight, 55% by weight, or 60% by weight), preferably at least 20% by weight or at least 25% by weight, or even at least 30% by weight, for example 15-60% by weight, 15-50% by weight, 20-60% by weight, 20-50% by weight, 25-40% by weight, 25-35% by weight, based on the total weight of triphenylphosphine, phenylphosphine dichloride, and diphenylphosphine chloride in the reaction mixture.

[0042] In one embodiment, the weight ratio of the amount of triphenylphosphine in the reaction mixture to the total amount of diphenylphosphine chloride in the diphenylphosphine chloride feedstock after heat treatment can be at least 0.15 (e.g., 0.16, 0.18, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, or 0.6), preferably at least 0.16, at least 0.18, or at least 0.2, or even at least 0.3, for example, 0.15-0.6, 0.18-0.6, preferably 0.2-0.5, 0.25-0.5, 0.25-0.4, or 0.25-0.35.

[0043] In one embodiment, the method includes heat-treating a diphenylphosphine chloride feedstock at a temperature of 300-450°C, wherein the maximum pressure (gauge pressure) during the heat treatment process is at least 0.05 MPa, and the heat treatment time is at least 0.4 hours.

[0044] The diphenylphosphine chloride raw material contains at least 65% by weight of diphenylphosphine chloride, no more than 30% by weight of phenylphosphine dichloride, and no more than 5% by weight of phosphorus trichloride, based on the total weight of the diphenylphosphine chloride raw material.

[0045] In one embodiment, the method includes heat-treating a diphenylphosphine chloride feedstock at a temperature of 320-400°C, wherein the maximum pressure (gauge pressure) during the heat treatment process is 0.05-6 MPa, and the heat treatment time is 0.4-12 hours.

[0046] The diphenylphosphine chloride raw material contains at least 70% by weight of diphenylphosphine chloride, no more than 28% by weight of phenylphosphine dichloride, and no more than 2% by weight of phosphorus trichloride, based on the total weight of the diphenylphosphine chloride raw material.

[0047] In one embodiment, the method includes heat-treating a diphenylphosphine chloride feedstock at a temperature of 330-390°C, wherein the maximum pressure (gauge pressure) during the heat treatment process is 0.08-5 MPa, and the heat treatment time is 0.8-8 hours.

[0048] The diphenylphosphine chloride raw material contains at least 91% by weight of diphenylphosphine chloride, no more than 8% by weight of phenylphosphine dichloride, and no more than 1% by weight of phosphorus trichloride, based on the total weight of the diphenylphosphine chloride raw material.

[0049] In one embodiment, the method includes heat-treating a diphenylphosphine chloride feedstock at a temperature of 340-370°C, wherein the maximum pressure (gauge pressure) during the heat treatment process is 0.1-2 MPa, and the heat treatment time is 0.8-8 hours.

[0050] The diphenylphosphine chloride raw material contains at least 95% by weight of diphenylphosphine chloride, no more than 1% by weight of phenylphosphine dichloride, and no more than 0.5% by weight of phosphorus trichloride, based on the total weight of the diphenylphosphine chloride raw material.

[0051] In one embodiment, the method includes heat-treating a diphenylphosphine chloride feedstock at a temperature of 345-360°C, wherein the maximum pressure (gauge pressure) during the heat treatment process is 0.15-0.3 MPa, and the heat treatment time is 1-7 hours.

[0052] The diphenylphosphine chloride raw material contains at least 95% by weight of diphenylphosphine chloride, no more than 1% by weight of phenylphosphine dichloride, and no more than 0.1% by weight of phosphorus trichloride, based on the total weight of the diphenylphosphine chloride raw material.

[0053] In one embodiment, the method includes heat-treating a diphenylphosphine chloride feedstock at a temperature of 345-355°C, wherein the maximum pressure (gauge pressure) during the heat treatment process is 0.15-0.3 MPa (preferably the heat treatment is carried out under autogenous pressure), and the heat treatment time is 1.5-2.5 hours.

[0054] The diphenylphosphine chloride raw material contains at least 98% by weight of diphenylphosphine chloride, no more than 1% by weight of phenylphosphine dichloride, and no more than 0.1% by weight of phosphorus trichloride (preferably free of phosphorus trichloride), based on the total weight of the diphenylphosphine chloride raw material.

[0055] In one embodiment, the method includes preheating the diphenylphosphine chloride feedstock to 50-90°C, then starting stirring, followed by heat treatment of the diphenylphosphine chloride feedstock at 345-355°C, wherein the maximum pressure (gauge pressure) during the heat treatment process is 0.15-0.3 MPa (preferably the heat treatment is carried out under autogenous pressure), and the heat treatment time is 1.5-2.5 hours.

[0056] The diphenylphosphine chloride raw material contains at least 98% by weight of diphenylphosphine chloride, no more than 1% by weight of phenylphosphine dichloride, and no more than 0.1% by weight of phosphorus trichloride (preferably free of phosphorus trichloride), based on the total weight of the diphenylphosphine chloride raw material.

[0057] The method of the present invention is carried out under the protection of an inert gas, such as nitrogen. Before carrying out the method of the present invention, the reactor is purged with an inert gas (such as nitrogen), for example, purging 2-5 times, preferably 3-5 times.

[0058] The product mixture of the method of the present invention can be separated by post-processing, such as distillation.

[0059] In one embodiment, the diphenylphosphine chloride feedstock can be prepared using chlorobenzene and yellow phosphorus as feedstocks. The resulting reaction mixture typically contains light components, such as chlorobenzene and phosphorus trichloride, as well as phenylphosphine dichloride, diphenylphosphine chloride, and triphenylphosphine. In the reaction mixture, the amount of triphenylphosphine typically does not exceed 6% by weight, for example, 1-6% by weight or 2-6% by weight, based on the total weight of phenylphosphine dichloride, diphenylphosphine chloride, and triphenylphosphine. The reaction is carried out at high temperatures (e.g., 300-500°C or 300-400°C) and elevated pressures (e.g., 0.01-8.0 MPa or 0.01-6.0 MPa, preferably autogenous pressure). The diphenylphosphine chloride feedstock of the present invention can be prepared by removing chlorobenzene, phosphorus trichloride, and most of the phenylphosphine dichloride from the reaction mixture, or by additionally adding diphenylphosphine chloride to a diphenylphosphine-rich product mixture obtained after removing chlorobenzene, phosphorus trichloride, and most of the phenylphosphine dichloride from the reaction mixture.

[0060] In this technical solution, purification costs are saved because there is no need to purify diphenylphosphine chloride.

[0061] Example

[0062] The features of the present invention are further illustrated below through examples, but these examples do not constitute a limitation thereof. Unless otherwise specified, specific conditions were applied in the examples. Reagents or instruments used, unless otherwise specified, are all commercially available products. Pressures mentioned in the examples are gauge pressures.

[0063] raw material:

[0064] Diphenylphosphine chloride: Hubei Gurun Technology Co., Ltd., purity ≥99.5%, triphenylphosphine content 0.1%-0.3%, does not contain phosphorus trichloride.

[0065] Phosphorus dichloride: Hubei Gurun Technology Co., Ltd., purity ≥99.5%, biphenyl ≤0.2%, phosphorus trichloride-free.

[0066] Content determination:

[0067] Gas chromatography was used to analyze each component, and quantification was performed using the correction and normalization method.

[0068] Example 1:

[0069] The 5L synthesis reactor was purged three times with nitrogen. 300g of diphenylphosphine chloride was added to the reactor, the reactor valve was closed, and stirring was started at a rate of 350-400 rpm. The temperature was then raised to a maximum of 340℃ and held for 2 hours after 70-80 minutes. The maximum pressure during the reaction was 0.1 MPa. The reaction produced 32.2g of phenylphosphine dichloride and 87.3g of triphenylphosphine, with 168.2g of diphenylphosphine chloride remaining, and approximately 12g of impurities. Of the three phenylphosphides obtained, triphenylphosphine accounted for 30.3 wt%.

[0070] Example 2:

[0071] The 5L synthesis reactor was purged three times with nitrogen. 300g of diphenylphosphine chloride was added to the reactor, the reactor valve was closed, and stirring was started at a rate of 350-400 rpm. After 70-80 minutes, the temperature was raised to a maximum of 350℃ and held for 2 hours. The maximum pressure during the reaction was 0.15 MPa. The reaction produced 39.4g of phenylphosphine dichloride and 93.2g of triphenylphosphine, with 154.4g of diphenylphosphine chloride remaining, and approximately 13g of impurities. Of the three phenylphosphides obtained, triphenylphosphine accounted for 32.5 wt%.

[0072] Example 3:

[0073] The 5L synthesis reactor was purged three times with nitrogen. 300g of diphenylphosphine chloride was added to the reactor, the reactor valve was closed, and stirring was started at a rate of 350-400 rpm. The temperature was then raised to a maximum of 360℃ and held for 2 hours after 70-80 minutes. The maximum pressure during the reaction was 0.25 MPa. The reaction produced 34.0g of phenylphosphine dichloride and 86.4g of triphenylphosphine, with 162.9g of diphenylphosphine chloride remaining, and approximately 16g of impurities. Of the three phenylphosphides obtained, triphenylphosphine accounted for 30.5 wt%.

[0074] Example 4:

[0075] The 5L synthesis reactor was purged three times with nitrogen. 300g of diphenylphosphine chloride was added to the reactor, the reactor valve was closed, and stirring was started at a rate of 350-400 rpm. After 70-80 minutes, the temperature was raised to a maximum of 380℃ and held for 2 hours. The maximum pressure during the reaction was 0.4 MPa. The reaction produced 45.4g of phenylphosphine dichloride and 75.4g of triphenylphosphine, with 153.1g of diphenylphosphine chloride remaining and approximately 26g of impurities. Of the three phenylphosphides obtained, triphenylphosphine accounted for 27.5 wt%.

[0076] Example 5:

[0077] The 5L synthesis reactor was purged three times with nitrogen. 300g of diphenylphosphine chloride was added to the reactor, the reactor valve was closed, and stirring was started at a rate of 350-400 rpm. The temperature was then raised to a maximum of 350℃ and held for 1 hour after 70-80 minutes. The maximum pressure during the reaction was 0.15 MPa. The reaction produced 32.2g of phenylphosphine dichloride and 87.0g of triphenylphosphine, with 169.0g of diphenylphosphine chloride remaining, and approximately 11g of impurities. Of the three phenylphosphides obtained, triphenylphosphine accounted for 30.2 wt%.

[0078] Example 6:

[0079] The 5L synthesis reactor was purged three times with nitrogen. 300g of diphenylphosphine chloride was added to the reactor, the reactor valve was closed, and stirring was started at a rate of 350-400 rpm. The temperature was then raised to a maximum of 350℃ and held for 4.0 hours after 70-80 minutes. The maximum pressure during the reaction was 0.2 MPa. The reaction produced 36.9g of phenylphosphine dichloride and 84.4g of triphenylphosphine, with 165.3g of diphenylphosphine chloride remaining, and approximately 13g of impurities. Of the three phenylphosphides obtained, triphenylphosphine accounted for 29.4 wt%.

[0080] Example 7:

[0081] The 5L synthesis reactor was purged three times with nitrogen. 300g of diphenylphosphine chloride was added to the reactor, the reactor valve was closed, and stirring was started at a rate of 350-400 rpm. The temperature was then raised to a maximum of 350℃ and held for 6.0 hours after 70-80 minutes. The maximum pressure during the reaction was 0.3 MPa. The reaction produced 35.3g of phenylphosphine dichloride and 85.8g of triphenylphosphine, with 164.7g of diphenylphosphine chloride remaining, and approximately 14g of impurities. Of the three phenylphosphides obtained, triphenylphosphine accounted for 30 wt%.

[0082] Example 8:

[0083] The 5L synthesis reactor was purged three times with nitrogen. 300g of diphenylphosphine chloride was added to the reactor, the reactor valve was closed, and nitrogen pressure was increased to 1.0 MPa. Stirring was then started at a rate of 350-400 rpm. After 70-80 minutes, the temperature was raised to a maximum of 350℃ and held for 2.0 hours. The highest pressure during the reaction was 1.7 MPa. The reaction produced 40.3g of phenylphosphine dichloride and 81.7g of triphenylphosphine, with 166.4g of diphenylphosphine chloride remaining, and approximately 11g of impurities. Of the three phenylphosphides obtained, triphenylphosphine accounted for 28.3 wt%.

[0084] Example 9:

[0085] The 5L synthesis reactor was purged three times with nitrogen. 300g of diphenylphosphine chloride was added to the reactor, the valve was closed, and a negative pressure of -90kPa was applied. Stirring was started at a rate of 350-400 rpm, and the temperature was raised to a maximum of 350℃ and held for 2.0 hours after 70-80 minutes. The highest pressure during the reaction was 0.1MPa. The reaction produced 37.9g ​​of phenylphosphine dichloride and 95.0g of triphenylphosphine, with 153.5g of diphenylphosphine chloride remaining and approximately 13g of impurities. Of the three phenylphosphides obtained, triphenylphosphine accounted for 33.2wt%.

[0086] Example 10:

[0087] The 5L synthesis reactor was purged with nitrogen three times. 75g of phenylphosphine dichloride and 225g of triphenylphosphine chloride were added to the reactor. The reactor valve was closed, and stirring was started at a rate of 350-400 rpm. After 70-80 minutes, the temperature was raised to a maximum of 350°C and held for 2 hours. The maximum pressure during the reaction was 0.1 MPa. The reaction produced 69.4g of phenylphosphine dichloride and 44.8g of triphenylphosphine, with 156.5g of diphenylphosphine chloride remaining and approximately 29g of impurities. Of the three phenylphosphides obtained, triphenylphosphine accounted for 16.6 wt%.

[0088] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing triphenylphosphine, comprising heat-treating a diphenylphosphine chloride raw material at a temperature of 280-480°C to prepare triphenylphosphine, wherein the content of phenyl diphosphine chloride in the diphenylphosphine chloride raw material does not exceed 35% by weight, based on the total weight of the diphenylphosphine chloride raw material.

2. The method according to claim 1, wherein the content of phenyl dichloride in the diphenylphosphine raw material is not more than 30% by weight, preferably not more than 28% by weight, more preferably not more than 22% by weight, even more preferably not more than 15% by weight, especially not more than 8% by weight, particularly not more than 3% by weight, most preferably not more than 1% by weight, for example not more than 0.5% by weight, based on the total weight of the diphenylphosphine raw material.

3. The method according to claim 1 or 2, wherein the content of the diphenylphosphine chloride in the diphenylphosphine chloride raw material is at least 65% by weight, preferably at least 70% by weight, more preferably at least 80% by weight, even more preferably at least 88% by weight, and even more preferably at least 95% by weight, for example at least 98% by weight, based on the total weight of the diphenylphosphine chloride raw material.

4. The method according to any one of claims 1-3, wherein the heat treatment temperature is 300-450°C, preferably 320-400°C, and more preferably 330-390°C.

5. The method according to claim 4, wherein the heat treatment temperature is particularly 340-370°C, especially 345-360°C, most preferably 345-355°C, for example about 350°C.

6. The method according to any one of claims 1-5, wherein the highest pressure (gauge pressure) during the heat treatment process is at least 0.05 MPa, preferably at least 0.08 MPa, for example 0.05-6 MPa, more preferably 0.08-5 MPa, and even more preferably 0.1-2 MPa or 0.1-0.3 MPa.

7. The method according to any one of claims 1-6, wherein the heat treatment is performed under autogenous pressure.

8. The method according to any one of claims 1-7, wherein the heat treatment time is at least 0.4 hours, preferably 0.4-12 hours, more preferably 0.6-8 hours, especially 0.8-8 hours, most preferably 1.5-2.5 hours, for example about 2 hours.

9. The method according to any one of claims 1-8, wherein the phosphorus trichloride content in the diphenylphosphine chloride raw material is not more than 5% by weight, preferably not more than 2% by weight, more preferably not more than 1% by weight, for example not more than 0.5% by weight or not more than 0.1% by weight, based on the total weight of the diphenylphosphine chloride raw material.

10. The method according to any one of claims 1-9, wherein the heat treatment is carried out under stirring.

11. The method according to any one of claims 1-10, wherein the product mixture obtained by said method comprises triphenylphosphine, phenylphosphine dichloride, and diphenylphosphine chloride.

12. The method of claim 11, wherein the content of triphenylphosphine in the reaction mixture after heat treatment is at least 15% by weight, preferably at least 20% by weight, for example 15-60% by weight or 20-50% by weight, based on the total weight of triphenylphosphine, phenylphosphine dichloride and diphenylphosphine chloride in the reaction mixture.

13. The method according to any one of claims 1-12, wherein the method comprises heat-treating the diphenylphosphine chloride feedstock at a temperature of 300-450°C, wherein the maximum pressure (gauge pressure) during the heat treatment process is at least 0.05 MPa, and the heat treatment time is at least 0.4 hours; The diphenylphosphine chloride raw material contains at least 65% by weight of diphenylphosphine chloride, no more than 30% by weight of phenylphosphine dichloride, and no more than 5% by weight of phosphorus trichloride, based on the total weight of the diphenylphosphine chloride raw material.

14. The method according to any one of claims 1-13, wherein the method comprises heat-treating the diphenylphosphine chloride feedstock at a temperature of 345-355°C, wherein the maximum pressure (gauge pressure) during the heat treatment process is 0.15-0.3 MPa (preferably the heat treatment is carried out under autogenous pressure), and the heat treatment time is 1.5-2.5 hours; The diphenylphosphine chloride raw material contains at least 98% by weight of diphenylphosphine chloride, no more than 1% by weight of phenylphosphine dichloride, and no more than 0.1% by weight of phosphorus trichloride (preferably free of phosphorus trichloride), based on the total weight of the diphenylphosphine chloride raw material.