A continuous flow reaction process for the synergistic catalytic reduction to prepare triphenylphosphine

Abstract

The application discloses a continuous flow reaction method for preparing triphenylphosphine through synergistic catalytic reduction, and relates to the technical field of triphenylphosphine preparation. The manufacturing method comprises the following steps: after a first reaction kettle is replaced by dry protective gas for three times, a solvent and triphenylphosphine oxide are added, and stirring is carried out until the solvent and triphenylphosphine oxide are completely dissolved; a second reaction kettle is added with a solvent and a chlorinating agent, and stirring is carried out until the solvent and the chlorinating agent are completely dissolved; a catalyst is added into a solution in a third reaction kettle, continuous stirring is carried out, and the solution is continuously punched into a continuous flow packing tube provided with a local electric field enhancement generator and preprocessed by the solvent; reaction liquid at a discharge port of the continuous flow packing tube is collected, filtered and concentrated, a solvent is recovered, and triphenylphosphine is obtained through crystallization and refining. When the application is operated, only reaction liquid needs to be configured in the reaction kettle, and the packing in the continuous flow packing tube needs to be supplemented regularly, so that stable and continuous reaction can be realized, and the reaction process is greatly simplified, the safety risk is reduced, and the production efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of triphenylphosphine preparation technology, and in particular relates to a continuous flow reaction method for the preparation of triphenylphosphine by synergistic catalytic reduction. Background Technology

[0002] The molecular formula of triphenylphosphine is C 18 H 15 Triphenylphosphine (P) is an important ligand for homogeneous catalysts used in petrochemical and fine chemical production. Through technological improvements, it can be better applied to novel petroleum processing catalysts; novel biocatalysis technologies and catalysts; novel and efficient catalysts for environmental protection; novel catalysts for organic synthesis; novel and efficient catalysts for polyolefins; new materials for catalyst supports and various novel co-catalytic materials; it can also be used as functional fine chemicals; novel papermaking chemicals; novel oilfield chemicals suitable for protective mining and improving oil recovery rates; novel surfactants; high-performance, water-based functional coatings and auxiliaries; novel textile dyeing and finishing auxiliaries; high-performance environmentally friendly adhesives; novel safe and environmentally friendly pigments and dyes; and high-performance environmentally friendly leather chemicals. Triphenylphosphine can also serve as an intermediate in the chemical synthesis of various important chemical products, such as β-carotene, cefprozil, and cefdinir.

[0003] Chinese Publication No. CN109433203A discloses a method for electrolytic reduction and regeneration of triphenylphosphine. The method involves using triphenylphosphine oxide as a raw material, adding a catalyst, and then electrolytically reducing the triphenylphosphine. The catalyst comprises an active component and a support. The active component contains Pt and W elements, and the support is ZnO. Preferably, based on the weight of the catalyst, the Pt content is 1–5 wt%, more preferably 1.5–4.5 wt%; the W content is 5–12 wt%, more preferably 6–10 wt%; and the ZnO content is 80–94 wt%, more preferably 81–90 wt%. The catalyst, using ZnO as a support and containing Pt and W elements, is expensive and cumbersome to produce. Furthermore, the electrolytic method requires a large amount of electrical energy, and the entire reaction takes a long time, which is not conducive to industrial production.

[0004] For example, Chinese patent application CN101270132A discloses a method for producing triphenylphosphine from triphenylphosphine oxide. The method uses triphenylphosphine oxide, toluene, trichlorosilane, trimethylamine, methanol, ammonia, and water as raw materials, and sequentially carries out reaction synthesis, distillation of impurities, separation of mother liquor, recovery of toluene, and drying of the filter to obtain white carbon black, distilled water, and ammonium chloride. The entire process takes 8 to 10 hours, the reaction time is long, and the entire operation is cumbersome, requiring constant solution transfer, which can easily cause material leakage, resulting in low production efficiency and making it unsuitable for industrial production.

[0005] For example, Chinese Patent Publication No. CN108409785B discloses a method for preparing triphenylphosphine by reduction, which uses triphenylphosphine oxide as raw material and phenylphosphine dichloride or diphenylphosphine chloride as reducing agent, and carries out a reduction reaction under the action of a catalyst to obtain triphenylphosphine. In this technical solution, the temperature of the reduction reaction is 100-200℃ and the time of the reduction reaction is 8-24h. It needs to be carried out in a high-temperature environment, which results in low production efficiency and is not conducive to industrial production. Summary of the Invention

[0006] The purpose of this invention is to provide a continuous flow reaction method for the synergistic catalytic reduction of triphenylphosphine. During operation, only the reaction solution needs to be prepared in the reaction vessel, and the reducing agent is added periodically to the packing tube to achieve a stable and continuous reaction. This greatly simplifies the reaction process, reduces safety risks, and improves production efficiency, solving the problems of long reaction time, low production efficiency, and unfavorable conditions for industrial production in existing triphenylphosphine preparation processes.

[0007] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0008] This invention relates to a continuous flow reaction method for the synergistic catalytic reduction of triphenylphosphine, comprising:

[0009] Step 1: Fill the first reaction vessel with protective gas, add solvent and triphenylphosphine oxide, stir to fully dissolve, and set aside for use;

[0010] Step 2: Fill the second reactor with protective gas, add solvent and chlorinating agent, stir to fully dissolve, and set aside for use;

[0011] Step 3: At room temperature, the solutions from the first and second reaction vessels are fed into a tubular reactor equipped with a local electric field enhancement generator in equal proportion to prepare triphenylphosphine dichloride.

[0012] Step 4: Collect the reaction liquid, add the catalyst, stir continuously, and then flow the mixture after adding the catalyst through a continuous flow packed tube reactor with a local electric field enhancement generator at a uniform speed to obtain the effluent.

[0013] Step 5: Distill and concentrate the obtained effluent to recover the solvent, and recrystallize to obtain triphenylphosphine.

[0014] As a preferred embodiment of the present invention, in step 4, the catalyst is dimethyltin, trimethyltin, dibutyltin, tributyltin, dioctyltin, or tetraphenyltin; or the catalyst is any one or more of triethylaluminum, tributylaluminum, triisobutylaluminum, or diethylaluminum chloride.

[0015] As a preferred embodiment of the present invention, in step 4, the continuous flow packed tube is filled with a reducing agent, which is any one or more of aluminum, zinc, iron, magnesium, calcium, sodium, and potassium.

[0016] As a preferred embodiment of the present invention, the molar ratio of triphenylphosphine oxide in step 1 to chlorinating agent in step 2 is 1:1-1:2.

[0017] As a preferred embodiment of the present invention, the molar ratio of triphenylphosphine oxide to solvent in step 1 is 1:3-1:10; and the molar ratio of triphenylphosphine oxide to catalyst in step 4 is 1:0.01-1:0.1.

[0018] As a preferred embodiment of the present invention, in step 1, the protective gas is any one or more of nitrogen and argon; the solvent is any one or more of 1,2-dichloroethane, acetonitrile, dichloromethane, toluene, and chlorobenzene organic solvents.

[0019] In a preferred embodiment of the present invention, in step 2, the chlorinating agent is one or more of triphosgene, oxaloyl chloride, trichlorosilane, trichlorogermanane, phosphorus trichloride, phosphine pentachloride, and thionyl chloride.

[0020] As a preferred embodiment of the present invention, in steps 3 and 4, the voltage of the local electric field enhancement generator is 5~20V, and the field emission current density is 10~500mA / cm². 2 .

[0021] The present invention has the following beneficial effects:

[0022] This invention, based on a synergistic catalytic reaction system employing physical catalysis (local electric field enhanced catalysis) and chemical catalysis (novel catalysts), ensures that the entire catalytic reaction production method is low-cost, highly safe, highly efficient, and low-pollution. It can utilize safer chlorinating agents and unconventional catalysts. Furthermore, due to the continuous reaction, operation only requires preparing the reaction solution in the reactor and periodically adding reducing agent to the packed tube reactor to achieve stable and continuous production. This greatly simplifies the reaction process, improves production efficiency, eliminates the need for extensive manual batch operations, minimizes material leakage, saves production time and labor, reduces production safety risks, and has significant industrialization value.

[0023] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a logic flow diagram of a continuous flow reaction method for the synergistic catalytic reduction preparation of triphenylphosphine according to the present invention. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] A continuous flow reaction method for the synergistic catalytic reduction preparation of triphenylphosphine includes:

[0028] Step 1: Fill the first reaction vessel with protective gas, add solvent and triphenylphosphine oxide, stir to fully dissolve, and set aside for use;

[0029] Step 2: Fill the second reactor with protective gas, add solvent and chlorinating agent, stir to fully dissolve, and set aside for use;

[0030] Step 3: At room temperature, the solutions from the first and second reaction vessels are fed into a tubular reactor equipped with a local electric field enhancement generator in equal proportion to prepare triphenylphosphine dichloride.

[0031] Step 4: Collect the reaction liquid, add the catalyst, stir continuously, and then flow the mixture after adding the catalyst through a continuous flow packed tube reactor with a local electric field enhancement generator at a uniform speed to obtain the effluent.

[0032] Step 5: Distill and concentrate the obtained effluent to recover the solvent, and recrystallize to obtain triphenylphosphine.

[0033] In the following Examples 1-3, all are carried out in accordance with the following... Figure 1 The manufacturing process shown is carried out.

[0034] Example 1

[0035] After the 5L reactor ① was purged with dry nitrogen three times, 2.5Kg of acetonitrile and 1Kg of triphenylphosphine oxide were added and stirred until fully dissolved;

[0036] After the 1L reactor ② was purged with dry nitrogen three times, 0.33Kg of acetonitrile and 0.47Kg of oxaloyl chloride were added and stirred until homogeneous.

[0037] Turn on the power to the local electric field enhancement generator for the tubular reactor, set the field emission voltage to 10V, and the field emission current density to 200mA / cm². 2 ; Connect a flow meter to the outlet of reactor ① and set the flow rate to 700 g / min; connect a flow meter to reactor ② and set the flow rate to 160 g / min; turn on the back pressure of reactor ① and reactor ②, and simultaneously open the outlet valves of both reactors. The mixture enters the tubular reactor through the mixer and reacts at room temperature.

[0038] Collect the reaction solution in reaction vessel ③, add 32g of trimethyltin catalyst, stir continuously until homogeneous, turn on the power supply of the local electric field enhancement generator for the continuous flow packed tube reactor, set the field emission voltage to 10V, and the field emission current density to 200mA / cm². 2 The feed solution was injected into a pre-solvent-pretreated continuous flow packed tube at a flow rate of 400 g / min. The reaction solution was collected at the outlet of the continuous flow packed tube, concentrated by distillation, the solvent was recovered, and the solution was crystallized to obtain 893 g of triphenylphosphine, with a yield of 89.3%.

[0039] Example 2

[0040] After the 5L reactor ① was purged with dry nitrogen three times, 2.0Kg of 1,2-dichloroethane and 0.5Kg of triphenylphosphine oxide were added and stirred until fully dissolved;

[0041] After the 1L reactor ② was purged with dry nitrogen three times, 1.0Kg of 1,2-dichloroethane and 0.2Kg of triphosgene were added and stirred until homogeneous.

[0042] Turn on the power to the local electric field enhancement generator for the tubular reactor, set the field emission voltage to 15V, and the field emission current density to 300mA / cm². 2 ; Connect a flow meter to the outlet of reactor ① and set the flow rate to 500 g / min; connect a flow meter to reactor ② and set the flow rate to 140 g / min; turn on the back pressure of reactor ① and reactor ②, and simultaneously open the outlet valves of both reactors, and let the material enter the tubular reactor through the mixer for ambient temperature reaction;

[0043] Collect the reaction solution in reactor ③, add 1g of dibutyltin catalyst, stir continuously until homogeneous, turn on the power supply of the local electric field enhancement generator for the continuous flow packed tube reactor, set the field emission voltage to 10V, and the field emission current density to 200mA / cm². 2 The feed solution was injected into a pre-solvent-pretreated continuous flow packed tube at a flow rate of 400 g / min. The reaction solution was collected at the outlet of the continuous flow packed tube, concentrated by distillation, the solvent was recovered, and the solution was crystallized to obtain 451 g of triphenylphosphine, with a yield of 90.2%.

[0044] As can be seen from Examples 1-2 above, the entire process prepared by the method of the present invention, based on the synergistic catalysis of physical and chemical reactions, allows for instantaneous reaction upon material contact in both ordinary tubular reactors and packed tube reactors. Therefore, the entire process generally does not exceed 30 minutes, meaning the overall process of the present invention is short, has high production efficiency, and is conducive to industrial-scale mass production. The present invention uses a chemical catalyst, which reduces the activation energy required for the reaction, and at the same time uses a local electric field enhancement generator to provide sufficient reaction energy. Therefore, the present invention can be carried out at room temperature, with mild and easily controllable reaction conditions. Furthermore, the continuous flow reaction is carried out in the packed tube, eliminating the need for extensive manual batch operations, preventing material leakage, saving production time and labor, and greatly improving production efficiency and safety controllability.

[0045] Comparative Example 3

[0046] After the 5L reactor ① was purged with dry nitrogen three times, 2.5Kg of acetonitrile and 1Kg of triphenylphosphine oxide were added and stirred until fully dissolved;

[0047] After the 1L reactor ② was purged with dry nitrogen three times, 0.33Kg of acetonitrile and 0.47Kg of oxaloyl chloride were added and stirred until homogeneous.

[0048] Connect a flow meter to the outlet of reactor ① and set the flow rate to 700 g / min; connect a flow meter to reactor ② and set the flow rate to 160 g / min; turn on the back pressure of reactor ① and reactor ②, and simultaneously open the outlet valves of both reactors. The mixture enters the tubular reactor through the mixer and reacts at room temperature.

[0049] The reaction liquid was collected in reaction vessel ③ and stirred continuously until homogeneous. The liquid was then injected into a pre-solvent-pretreated continuous flow packed tube at a flow rate of 400 g / min. The reaction liquid was collected at the outlet of the continuous flow packed tube, concentrated by distillation, the solvent was recovered, and the solid was obtained by crystallization. The solid was tested and found to be free of triphenylphosphine.

[0050] As can be seen from Example 3, in the specific production process of the present invention, the product triphenylphosphine cannot be obtained without the synergistic catalysis of physical and chemical methods.

[0051] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A continuous flow reaction method for the synergistic catalytic reduction of triphenylphosphine, characterized in that, include: Step 1: Fill the first reaction vessel with protective gas, add solvent and triphenylphosphine oxide, stir to fully dissolve, and set aside for use; Step 2: Fill the second reactor with protective gas, add solvent and chlorinating agent, stir to fully dissolve, and set aside for use; Step 3: At room temperature, the solutions from the first and second reaction vessels are fed into a tubular reactor equipped with a local electric field enhancement generator in equal proportion to prepare triphenylphosphine dichloride. Step 4: Collect the reaction liquid, add the catalyst, stir continuously, and then flow the mixture after adding the catalyst through a continuous flow packed tube reactor with a local electric field enhancement generator at a uniform speed to obtain the effluent. Step 5: Distill and concentrate the obtained effluent to recover the solvent, and recrystallize to obtain triphenylphosphine; In step 4, the catalyst is dimethyltin, trimethyltin, dibutyltin, tributyltin, dioctyltin, or tetraphenyltin; or the catalyst is any one or more of triethylaluminum, tributylaluminum, triisobutylaluminum, or diethylaluminum chloride. In step 4, the pipes of the continuous flow packed tube reactor are filled with a reducing agent, which is any one or more of aluminum, zinc, iron, magnesium, calcium, sodium, and potassium. In steps 3 and 4, the local electric field enhancement generator uses a nano-field effect emission structure based on a conductive metal substrate to generate charge localization enrichment and electric field enhancement; wherein, the conductive metal substrate is a metal substrate of copper foil or aluminum foil, or a non-metallic conductive substrate of carbon fiber cloth, wire rubber, or conductive polymer. The nanofield effect emission structure is a nanoneedle structure of carbon nanotubes, copper / aluminum metal nanowires / rods, or zinc oxide / indium tin oxide conductive oxide.

2. The continuous flow reaction method for the synergistic catalytic reduction preparation of triphenylphosphine according to claim 1, characterized in that, In steps 1 and 2, the molar ratio of triphenylphosphine oxide to chlorinating agent is 1:1 to 1:

2.

3. The continuous flow reaction method for the synergistic catalytic reduction preparation of triphenylphosphine according to claim 1, characterized in that, In steps 1 and 2, the protective gas is any one or more of nitrogen and argon; the solvent is any one or more of 1,2-dichloroethane, acetonitrile, dichloromethane, toluene, and chlorobenzene organic solvents; in step 2, the chlorinating agent is one or more of triphosgene, oxaloyl chloride, trichlorosilane, trichlorogermanane, phosphorus trichloride, phosphine pentachloride, and thionyl chloride.

4. The continuous flow reaction method for the synergistic catalytic reduction preparation of triphenylphosphine according to claim 1, characterized in that, In step 1, the molar ratio of triphenylphosphine oxide to solvent is 1:3-1:

10.

5. The continuous flow reaction method for the synergistic catalytic reduction preparation of triphenylphosphine according to claim 1, characterized in that, In step 4, the molar ratio of triphenylphosphine oxide to the catalyst is 1:0.01-1:0.1.

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