Continuous synthesis method of polyfluoroaryl borate

Abstract

The invention provides a continuous synthesis method of polyfluoro aryl borate, which comprises the following steps: step 1, respectively pumping a certain concentration of lithium alkylide solution and a certain concentration of polyfluoro aryl halide solution into a tubular reactor with a screw stirring function by adopting a constant flow pump; a low-temperature circulating liquid material for controlling the temperature is arranged outside the tubular reactor and inside the stirring shaft, and the adding speed and the adding proportion of the material can be adjusted through the pumping speed of the constant flow pump; 2, after the materials react and are pushed for a period of time, a boron trihalide solution is pumped into a third reaction opening through a constant flow pump to react with the polyfluoro aryl lithium obtained in the first step reaction, and the obtained solution is stirred and pushed by a screw to flow out of a continuous reaction tube and enter a product collector; and 3, carrying out post-treatment such as hydrolysis, extraction and drying on the mixture in the product collector to obtain a polyfluoroaryl borate product. According to the method, the industrial large-scale production requirement is more favorably realized, and meanwhile, the production speed and the safety of the polyfluoroaryl borate are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of fine chemical synthesis, and in particular relates to a continuous synthesis method of polyfluoroaryl borate. Background Art

[0002] As an important co-catalyst of metallocene catalyst system, polyfluoroaryl borate has a very important use in the field of olefin polymerization. This polyfluoroaryl borate anion can effectively disperse the negative charge of the boron center to make it a weakly coordinated anion, and as a balance of the cationic metal center in olefin polymerization, it exhibits unique catalytic performance. The use of polyfluoroaryl borate co-catalysts can greatly reduce the amount of methylaluminoxane and alkyl aluminum used in the olefin polymerization industry. The existing preparation technology of polyfluoroaryl borate is mainly based on the intermittent quenching process of aryl Grignard reagent and aryl lithium. The intermittent quenching production process of aryl Grignard reagent has the problems of long production time, long heating time, cumbersome operation, and high production energy consumption. The polyfluoroaryl lithium salt method has the characteristics of fast reaction speed, high yield, single product, and convenient post-processing. However, polyfluoroaryl lithium is very unstable at room temperature and has the risk of explosion, so the preparation of polyfluoroaryl lithium and its subsequent reactions need to be carried out at a low temperature below -70 degrees. Too low a temperature will increase energy consumption, which is not conducive to large-scale production. Compared with traditional intermittent reactors, microchannel reactors have the characteristics of fast reaction mixing, fast reaction heat exchange, wide reaction temperature range, and fast reaction speed, and can be used for some reactions with greater risks. However, sufficient stirring cannot be formed inside the microchannel reactor, which is not suitable for reactions with precipitated substances. Polyfluoroaryl lithium salts have poor solubility in ether media and are easily precipitated in the reaction solution, causing microchannel blockage. Therefore, microchannel reactors without stirring are not suitable for the reaction of preparing polyfluoroborates from polyfluoroaryl lithium. Continuous flow reactors with internal stirring have the advantages of fast heat transfer, uniform material mixing, and fast reaction speed, and can be used in some high-energy consumption and high-risk reactions. Summary of the invention

[0003] The object of the present invention is to provide a continuous synthesis method of polyfluoroaryl borate, aiming to solve the problems raised in the above background technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Figure 1 Schematic diagram of the tubular reactor structure.

[0005] To achieve the above object, the present invention provides the following technical solution: a tubular reactor with screw stirring is used for reaction, which can fully mix and transport the generated solid materials. On the other hand, low-temperature coolant can be circulated outside the tubular reactor and inside the hollow stirring shaft, which effectively reduces the temperature gradient of the reaction liquid and is conducive to the temperature control of the reaction liquid. This continuous reaction has a small liquid holding capacity and low danger, and the screw stirring is conducive to the flow of materials, which is very suitable for industrial scale-up production.

[0006] A continuous synthesis method of polyfluoroaryl borate comprises the following steps:

[0007] Step 1: A solution of a certain concentration of alkyl lithium and a certain concentration of halogenated polyfluoroaromatic hydrocarbon is pumped into a tubular reactor with a screw stirrer by a high-pressure constant flow pump. A low-temperature circulating liquid is provided outside the tubular reactor and inside the stirring shaft to control the temperature of the materials. The material addition speed and addition ratio can be adjusted by the pumping speed of the constant flow pump;

[0008] Step 2: After the material stays for a period of time, a trihalide boron solution is pumped into the third reaction port with a high-pressure constant flow pump to react with the polyfluoroaryl lithium obtained in the first step, and the obtained solution is pushed out of the continuous reaction tube by a screw stirring and enters a product collector;

[0009] In the third step, the mixture in the product collector is subjected to post-treatments such as hydrolysis, extraction, and drying to obtain a polyfluoroaryl borate product.

[0010] Organic solvent described in the present invention can be a single organic solvent or a mixture of multiple organic solvents, and this organic solvent can be alkanes, ethers, tetrahydrofuran derivatives, aromatic hydrocarbons, wherein preferably ethers and tetrahydrofurans. This medium can comprise one or more ethers, tetrahydrofurans, and can also contain one or more other types of components, such as alkanes, aromatic hydrocarbons under different circumstances. Any one in multiple monoethers or polyethers can be used, including diethyl ether, diisopropyl ether, dibutyl ether, tetrahydrofuran, 1,4-dioxane, cyclohexyl methyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether and tetraethylene glycol dimethyl ether. Tetrahydrofuran and methyl tert-butyl ether are preferred organic solvents in the implementation of the present invention.

[0011] The halogen atom in the "halogenated polyfluoroaromatic hydrocarbon" in the process of the present invention may be a chlorine atom, a bromine atom or an iodine atom and depends on the halogen atoms present in the reaction mixture. A bromine atom is preferred.

[0012] The polyfluoroaromatic hydrocarbons in the "halogenated polyfluoroaromatic hydrocarbons" of the present invention are understood to be fluorine-containing aromatic hydrocarbons having at least two fluorine atoms, or at least two perfluoroalkyl groups, or at least one fluorine atom and at least one perfluoroalkyl group directly bonded to the aromatic ring when not specified. Preferably, at least two fluorine atoms or at least two perfluoroalkyl groups are directly bonded to the aromatic ring. Each position on the aromatic ring of the fluoroaromatic hydrocarbon that is not a fluorine atom or a perfluoroalkyl group may be substituted with a hydrogen atom, an alkyl group, or an alkoxy group. The aromatic ring of the fluoroaromatic hydrocarbon includes, but is not limited to, benzene, naphthalene, anthracene, biphenyl, and phenanthrene. Benzene and naphthalene are preferred moieties. Perfluoroalkyl groups include alkyl and aryl perfluorinated compounds; including but not limited to trifluoromethyl, pentafluoroethyl, pentafluorophenyl, and heptafluoronaphthyl. The alkyl substituent of the aryl group is preferably C1 to C 24 Alkyl or C6 to C 30 Aryl or aralkyl. Examples including but not limited to methyl, ethyl, isopropyl, tert-butyl, cyclopentyl, methylcyclohexyl, decyl, phenyl, tolyl, xylyl, benzyl, naphthyl. The alkoxy group preferably has C1 to C 24 Alkyl moiety. Alternative but not limited examples of alkoxy are methoxy, ethoxy, isopropoxy, cyclohexyl and methylcyclopentyloxy. Examples of fluoroaryl groups that may be present on the borate moiety in the present invention include 3,5-bis(trifluoromethyl)phenyl, 2,4,6-tris(trifluoromethyl)-phenyl, 4-[tri(isopropyl)silyl]-tetrafluorophenyl, 4-[dimethyl(tert-butyl)silyl]-tetrafluorophenyl, 4′-(methoxy)-octafluoro-1-biphenyl-4-yl, 2,3-bis(pentafluoroethyl)-naphthyl, 2-(isopropoxy)-hexafluoronaphthyl, 9,10-bis(heptafluoropropyl)-heptafluoroanthracenyl, 9,10-bis(p-tolyl)-heptafluorophenanthryl.

[0013] Preferably, at most two substituents on the ring of the fluoroaryl are hydrocarbon groups, perfluoroalkyl groups, and the remaining substituents are fluorine atoms. Preferred fluoroaryl groups are those in which all substituents are fluorine atoms. Examples of such groups are pentafluorophenyl, nonafluoro-1-biphenyl-4-yl, nonafluoro-1-biphenyl-3-yl, 1-heptafluoronaphthyl, 2-heptafluoronaphthyl, 7-nonafluoroanthracenyl, 9-nonafluorophenanthrenyl and similar groups. Preferred perfluoroaryl groups include pentafluorophenyl and heptafluoronaphthyl.

[0014] The alkyl lithium reagent used in the method of the present invention is some common alkyl lithium reagents, which include but are not limited to methyl lithium, ethyl lithium, butyl lithium, isopropyl lithium, pentyl lithium, hexyl lithium, octyl lithium, allyl lithium, and phenyl lithium. A single variety of the above alkyl lithium reagents can be used, or a mixture of several alkyl lithium reagents can be used. Butyl lithium reagent is preferred.

[0015] In the practice of the present invention, the boron trihalide includes boron trifluoride, boron trichloride, boron tribromide, boron triiodide or any mixed halogen boron trihalide, and solvent complex forms of these compounds. Boron trichloride is preferred in the practice of the present invention.

[0016] The temperature range of the screw tube reactor in the present invention can be -20°C to -80°C. More preferably, the temperature range is -30°C to -40°C.

[0017] The following examples are given for illustrative purposes and are not intended to limit the scope of the present invention.

[0018] Example 1

[0019] The device used is a continuous flow reactor with internal screw stirring, referring to Figure 1 System device diagram. The coolant is injected into the outer jacket of the reactor and the inside of the screw stirring paddle through a low-temperature circulation pump, and the temperature is set to -30°C. The ether solution of pentafluorobromobenzene (1.0 mol / L) and the solution of butyl lithium (1.0 mol / L) are pumped in from ports A and B, respectively, at a pumping rate of 100 mL / min. The reaction solution is pushed by the screw in the reactor and reaches port C after 10 minutes. The hexane solution of boron trichloride (1.0 mol / L) is pumped in from port C through a high-pressure constant flow pump and mixed with the reaction solution at a pumping rate of 100 mL / min. The mixed solution is pushed by the screw stirring and stays in the reactor for 10 minutes before being discharged from the outlet into the post-treatment reactor. The crude product is hydrolyzed, extracted, concentrated, and recrystallized to obtain lithium tetrakis(pentafluorophenyl)borate with a yield of 80%.

[0020] Example 2

[0021] The device used is a continuous flow reactor with internal screw stirring, referring to Figure 1 System device diagram. The coolant is injected into the outer jacket of the reactor and the inside of the screw stirring paddle through a low-temperature circulation pump, and the temperature is set to -50°C. The ether solution of pentafluorobromobenzene (1.0 mol / L) and the solution of butyl lithium (1.0 mol / L) are pumped in from ports A and B, respectively, at a pumping rate of 50 mL / min. The reaction solution is pushed by the screw in the reactor and reaches port C after 20 minutes. The hexane solution of boron trichloride (1.0 mol / L) is pumped in from port C through a high-pressure constant flow pump and mixed with the reaction solution at a pumping rate of 50 mL / min. The mixed solution is pushed by the screw stirring and stays in the reactor for 20 minutes before being discharged from the outlet into the post-treatment reactor. The crude product is hydrolyzed, extracted, concentrated, and recrystallized to obtain lithium tetrakis(pentafluorophenyl)borate with a yield of 92%.

[0022] Example 3

[0023] The device used is a continuous flow reactor with internal screw stirring, referring to Figure 1System device diagram. The coolant is injected into the outer jacket of the reactor and the inside of the screw stirring paddle through a low-temperature circulation pump, and the temperature is set to -80°C. The ether solution of pentafluorobromobenzene (1.0 mol / L) and the solution of butyl lithium (1.0 mol / L) are pumped in from ports A and B respectively, with a pumping rate of 100 mL / min. The reaction liquid is pushed by the screw in the reactor and reaches port C after 10 minutes. The hexane solution of boron trichloride (1.0 mol / L) is pumped in from port C through a high-pressure constant flow pump and mixed with the reaction liquid, with a pumping rate of 100 mL / min. The mixed solution is pushed by the screw stirring and stays in the reactor for 10 minutes, then discharged from the outlet and enters the post-treatment reactor. The crude product is hydrolyzed, extracted, concentrated, and recrystallized to obtain lithium tetrakis(pentafluorophenyl)borate with a yield of 93%.

[0024] Example 4

[0025] The device used is a continuous flow reactor with internal screw stirring, referring to Figure 1 System device diagram. The coolant is injected into the outer jacket of the reactor and the inside of the screw stirring paddle through a low-temperature circulation pump, and the temperature is set to -40°C. The ether solution of pentafluorobromobenzene (1.0 mol / L) and the solution of butyl lithium (1.0 mol / L) are pumped in from ports A and B, respectively, at a pumping rate of 200 mL / min. The reaction liquid is pushed by the screw in the reactor and reaches port C after 5 minutes. The hexane solution of boron trichloride (1.0 mol / L) is pumped in from port C through a high-pressure constant flow pump and mixed with the reaction liquid at a pumping rate of 200 mL / min. The mixed solution is pushed by the screw stirring and stays in the reactor for 5 minutes before being discharged from the outlet into the post-treatment reactor. The crude product is hydrolyzed, extracted, concentrated, and recrystallized to obtain lithium tetrakis(pentafluorophenyl)borate with a yield of 92%.

[0026] Example 5

[0027] The device used is a continuous flow reactor with internal screw stirring, referring to Figure 1 System device diagram. The coolant is injected into the outer jacket of the reactor and the inside of the screw stirring paddle through a low-temperature circulation pump, and the temperature is set to -35°C. The ether solution of pentafluorobromobenzene (1.0 mol / L) and the solution of butyl lithium (1.0 mol / L) are pumped in from ports A and B, respectively, at a pumping rate of 200 mL / min. The reaction solution is pushed by the screw in the reactor and reaches port C after 5 minutes. The hexane solution of trimethyl borate (1.0 mol / L) is pumped in from port C through a high-pressure constant flow pump and mixed with the reaction solution at a pumping rate of 100 mL / min. The mixed solution is pushed by the screw stirring and stays in the reactor for 10 minutes before being discharged from the outlet into the post-treatment reactor. The crude product is hydrolyzed, extracted, concentrated, and recrystallized to obtain lithium tetrakis(pentafluorophenyl)borate with a yield of 75%.

[0028] Example 6

[0029] The device used is a continuous flow reactor with internal screw stirring, referring to Figure 1 System device diagram. The coolant is injected into the outer jacket of the reactor and the inside of the screw stirring paddle through a low-temperature circulation pump, and the temperature is set to -35°C. The methyl tert-butyl ether solution (1.0 mol / L) of pentafluorobromobenzene and the solution of butyl lithium (1.0 mol / L) are pumped in from ports A and B, respectively, at a pumping rate of 200 mL / min. The reaction liquid is pushed by the screw in the reactor and reaches port C after 5 minutes. The hexane solution of boron trichloride (1.0 mol / L) is pumped in from port C through a high-pressure constant flow pump and mixed with the reaction liquid at a pumping rate of 200 mL / min. The mixed solution is pushed by the screw stirring and stays in the reactor for 5 minutes before being discharged from the outlet into the post-treatment reactor. The crude product is hydrolyzed, extracted, concentrated, and recrystallized to obtain lithium tetrakis(pentafluorophenyl)borate with a yield of 91%.

[0030] Example 7

[0031] The device used is a continuous flow reactor with internal screw stirring, referring to Figure 1 System device diagram. The coolant is injected into the outer jacket of the reactor and the inside of the screw stirring paddle through a low-temperature circulation pump, and the temperature is set to -40°C. The isopropyl ether solution of pentafluorobromobenzene (1.0 mol / L) and the solution of butyl lithium (1.0 mol / L) are pumped in from ports A and B, respectively, at a pumping rate of 100 mL / min. The reaction liquid is pushed by the screw in the reactor and reaches port C after 10 minutes. The hexane solution of boron trichloride (1.0 mol / L) is pumped in from port C through a high-pressure constant flow pump and mixed with the reaction liquid at a pumping rate of 100 mL / min. The mixed solution is pushed by the screw stirring and stays in the reactor for 10 minutes before being discharged from the outlet into the post-treatment reactor. The crude product is hydrolyzed, extracted, concentrated, and recrystallized to obtain lithium tetrakis(pentafluorophenyl)borate with a yield of 97%.

[0032] Example 8

[0033] The device used is a continuous flow reactor with internal screw stirring, referring to Figure 1System device diagram. The coolant is injected into the outer jacket of the reactor and the inside of the screw stirring paddle through a low-temperature circulation pump, and the temperature is set to -35°C. The ether solution of 2,4,6-trifluorobromobenzene (1.0 mol / L) and the solution of butyl lithium (1.0 mol / L) are pumped in from ports A and B respectively, with a pumping rate of 100 mL / min. The reaction liquid is pushed by the screw in the reactor and reaches port C after 10 minutes. The hexane solution of triethyl borate (1.0 mol / L) is pumped in from port C through a high-pressure constant flow pump and mixed with the reaction liquid, with a pumping rate of 100 mL / min. The mixed solution is pushed by the screw stirring and stays in the reactor for 10 minutes, then discharged from the outlet and enters the post-treatment reactor. The crude product is hydrolyzed, extracted, concentrated, and recrystallized to obtain lithium tetrakis(2,4,6-trifluorophenyl)borate with a yield of 82%.

[0034] Example 9

[0035] The device used is a continuous flow reactor with internal screw stirring, referring to Figure 1 System device diagram. The coolant is injected into the outer jacket of the reactor and the inside of the screw stirring paddle through a low-temperature circulation pump, and the temperature is set to -65°C. The ether solution of pentafluorobromobenzene (1.0 mol / L) and the solution of butyl lithium (1.0 mol / L) are pumped in from ports A and B, respectively, at a pumping rate of 100 mL / min. The reaction solution is pushed by the screw in the reactor and reaches port C after 10 minutes. The hexane solution of boron trichloride (1.0 mol / L) is pumped in from port C through a high-pressure constant flow pump and mixed with the reaction solution at a pumping rate of 100 mL / min. The mixed solution is pushed by the screw stirring and stays in the reactor for 10 minutes before being discharged from the outlet into the post-treatment reactor. The crude product is hydrolyzed, extracted, concentrated, and recrystallized to obtain lithium tetrakis(pentafluorophenyl)borate with a yield of 88%.

[0036] Example 10

[0037] The device used is a continuous flow reactor with internal screw stirring, referring to Figure 1 System device diagram. The coolant is injected into the outer jacket of the reactor and the inside of the screw stirring paddle through a low-temperature circulation pump, and the temperature is set to -35°C. The ether solution of 2,3,5,6-tetrafluorobromobenzene (1.0 mol / L) and the solution of butyl lithium (1.0 mol / L) are pumped in from ports A and B respectively, with a pumping rate of 100 mL / min. The reaction liquid is pushed by the screw in the reactor and reaches port C after 10 minutes. The hexane solution of boron trichloride (1.0 mol / L) is pumped in from port C through a high-pressure constant flow pump and mixed with the reaction liquid, with a pumping rate of 100 mL / min. The mixed solution is pushed by the screw stirring and stays in the reactor for 10 minutes, then discharged from the outlet and enters the post-treatment reactor. The crude product is hydrolyzed, extracted, concentrated, and recrystallized to obtain lithium tetrakis(2,3,5,6-tetrafluorophenyl)borate with a yield of 89%.

[0038] Embodiment 11

[0039] The device used is a continuous flow reactor with internal screw stirring, referring to Figure 1 System device diagram. The coolant is injected into the outer jacket of the reactor and the inside of the screw stirring paddle through a low-temperature circulation pump, and the temperature is set to -35°C. The ether solution (1.0 mol / L) of 3,5-bistrifluoromethyl 1-bromobenzene and the solution (1.0 mol / L) of butyl lithium are pumped in from ports A and B respectively, with a pumping rate of 100 mL / min. The reaction solution is pushed by the screw in the reactor and reaches port C after 10 minutes. The hexane solution of boron trichloride (1.0 mol / L) is pumped in from port C through a high-pressure constant flow pump and mixed with the reaction solution, with a pumping rate of 100 mL / min. The mixed solution is pushed by the screw stirring and stays in the reactor for 10 minutes, then discharged from the outlet and enters the post-treatment reactor. The crude product is hydrolyzed, extracted, concentrated, and recrystallized to obtain lithium tetrakis(3,5-bistrifluoromethylphenyl)borate with a yield of 94%.

[0040] Example 12

[0041] The device used is a continuous flow reactor with internal screw stirring, referring to Figure 1 System device diagram. The coolant is injected into the outer jacket of the reactor and the inside of the screw stirring paddle through a low-temperature circulation pump, and the temperature is set to -40°C. The ether solution of pentafluorobromobenzene (1.0 mol / L) and the solution of butyl lithium (1.0 mol / L) are pumped in from ports A and B, respectively, at a pumping rate of 100 mL / min. The reaction liquid is pushed by the screw in the reactor and reaches port C after 10 minutes. The hexane solution of boron trichloride (1.0 mol / L) is pumped in from port C through a high-pressure constant flow pump and mixed with the reaction liquid at a pumping rate of 100 mL / min. The mixed solution is pushed by the screw stirring and stays in the reactor for 10 minutes before being discharged from the outlet into the post-treatment reactor. The crude product is hydrolyzed with potassium chloride, extracted, concentrated, and recrystallized to obtain potassium tetrakis(pentafluorophenyl)borate with a yield of 92%.

[0042] Example 13

[0043] The device used is a continuous flow reactor with internal screw stirring, referring to Figure 1System device diagram. The coolant is injected into the outer jacket of the reactor and the inside of the screw stirring paddle through a low-temperature circulation pump, and the temperature is set to -35°C. The ether solution of pentafluorobromobenzene (1.0 mol / L) and the solution of butyl lithium (1.0 mol / L) are pumped in from ports A and B respectively, with a pumping rate of 100 mL / min. The reaction liquid is pushed by the screw in the reactor and reaches port C after 10 minutes. The hexane solution of boron trichloride (1.0 mol / L) is pumped in from port C through a high-pressure constant flow pump and mixed with the reaction liquid, with a pumping rate of 100 mL / min. The mixed solution is pushed by the screw stirring and stays in the reactor for 10 minutes, then discharged from the outlet and enters the post-treatment reactor. The crude product is hydrolyzed with sodium chloride, extracted, concentrated, and recrystallized to obtain sodium tetrakis(pentafluorophenyl)borate with a yield of 92%.

[0044] The invention is susceptible to considerable variations in practice.The foregoing description is therefore not intended to be limiting and should not be construed as limiting the invention to the particular exemplifications given hereinabove.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] The present invention adopts a tubular continuous reactor with a screw stirring to prepare polyfluoroborate, so that the reaction can be carried out continuously and the reaction conditions are milder and safer. The disadvantage that the existing reaction cannot be produced on a large scale can be effectively avoided, which is more conducive to achieving industrial large-scale production requirements, and at the same time improves the production speed and safety of polyfluoroaryl borate.

[0047] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0048] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A continuous synthesis method of polyfluoroaryl borate, characterized in that: The following steps are involved: Step 1, a certain concentration of alkyl lithium and a certain concentration of polyfluorohalogenated aromatic hydrocarbon solution are respectively pumped into a tubular reactor with a screw stirrer by a high-pressure constant flow pump, and a low-temperature circulating liquid is provided outside the tubular reactor and inside the stirring shaft to control the temperature of the materials, and the material addition speed and addition ratio can be adjusted by the pumping speed of the constant flow pump; Step 2: After the material is pushed forward in the reactor for a period of time, a trihalide boron solution is pumped into the third reaction port with a high-pressure constant flow pump to react with the polyfluoroaryl lithium obtained in the first step, and the obtained solution is pushed out of the continuous reaction tube by screw stirring and enters the product collector; In the third step, the mixture in the product collector is subjected to post-treatments such as hydrolysis, extraction, and drying to obtain a polyfluoroaryl borate product.

2. The continuous synthesis method of a polyfluoroaryl borate according to claim 1, characterized in that: In the step 1 and the step 2, a tubular continuous reactor with screw stirring is used, and circulating coolant can be introduced into the outside of the tubular continuous reactor and the inside of the stirring shaft to effectively reduce the temperature gradient of the material and facilitate the temperature balance of the material.

3. The continuous synthesis method of a polyfluoroaryl borate according to claim 1, characterized in that: In the step 1, a high-pressure constant flow pump is used to control the addition rate of the polyfluorohalogenated aromatic hydrocarbon and the alkyl lithium, and to control the residence time of the reaction mixture in the screw-stirred tubular reactor.

4. The continuous synthesis method of a polyfluoroaryl borate according to claim 1, characterized in that: The temperature in the screw-stirred tubular reactor is controlled to be in the range of -30 to -80°C by circulating low-temperature liquid.

5. The continuous synthesis method of a polyfluoroaryl borate according to claim 1, characterized in that: The time range for mixing the alkyl lithium and the polyfluoroaryl alkyl halide to the third feed port is 2-15 minutes.

6. The continuous synthesis method of a polyfluoroaryl borate according to claim 1, characterized in that: The residence time of the boron trihalide and the first step reaction solution in the screw stirring tubular reactor is 2-15 minutes.

7. The continuous synthesis method of a polyfluoroaryl borate according to claim 1, characterized in that: The ratio of polyfluoroaryl halide to alkyl lithium ranges from 1.2:1 to 1.0:

1.

8. The continuous synthesis method of a polyfluoroaryl borate according to claim 1, characterized in that: The ratio of the alkyl lithium to the boron trihalide ranges from 4.0:1 to 4.2:

1.

9. The continuous synthesis method of a polyfluoroaryl borate according to claim 1, characterized in that During the post-treatment process, direct hydrolysis can obtain lithium tetrakis(fluoroaryl)borate, and hydrolysis in the presence of sodium salt or potassium salt can obtain sodium tetrakis(fluoroaryl)borate or potassium tetrakis(fluoroaryl)borate.

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