A method for preparing metal triflate by using high gravity reaction

Abstract

The application belongs to the field of fine chemical industry and environmental protection, and particularly relates to a method for preparing metal triflate by using high gravity reaction. The method comprises the following steps: 1, using trifluoromethylsulfonyl chloride and anhydrous HF gas as raw materials to generate trifluoromethylsulfonyl fluoride gas; 2, performing gas-liquid contact reaction of the trifluoromethylsulfonyl fluoride gas with an alkali metal solution to obtain a mixed solution; 3, performing solid-liquid separation on the mixed solution by using a filter press, and the liquid phase is a triflate salt solution; 4, drying the triflate salt solution by using a spray dryer to obtain a solid-phase product triflate salt. The method uses trifluoromethylsulfonyl chloride and anhydrous HF as raw materials to replace triflic acid in the traditional method, and utilizes high gravity reaction, so that the production cost is greatly reduced. The process is simple, the obtained product triflate metal salt has low impurity content, is superior to the industry standard, the process is zero emission, and has good economic value and social value.

Description

Technical Field

[0001] This application belongs to the fields of fine chemicals and environmental protection, and relates to the synthesis technology of fine pharmaceutical intermediates, specifically to a method for preparing trifluoromethanesulfonic acid metal salts using a supergravity reaction. Background Technology

[0002] Metal trifluoromethanesulfonic acid salts are derivatives of trifluoromethanesulfonic acid, typically using the trifluoromethanesulfonate ion as a ligand for some transition metals. These salts act as catalysts for various reactions, exhibiting exceptional thermodynamic and chemical stability (the anhydrous salts of sodium, boron, and silver have melting points exceeding 350°C). They do not release F- even in the presence of strong nucleophiles. Under mild reaction conditions, they possess high activity, good selectivity, high yield, low toxicity, and recyclability, making them widely attractive. They can catalyze various reactions, including electrophilic substitution, nucleophilic substitution, and addition reactions, and can be used for highly efficient catalysis in all-aqueous phases. Their applications are extensive in organic synthesis, including Friedel-Crafts reactions, acetal reactions, alkylation and hydroamylation, allylation, ring-forming and ring-opening reactions, oxidation and reduction reactions, and rearrangement reactions. In recent years, metal trifluoromethanesulfonic acid salts have been widely used as Lewis acid catalysts in organic chemistry for the synthesis of aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, and amino acids.

[0003] Neutralization is the traditional production process for trifluoromethanesulfonic acid metal salts. Current technologies involve using trifluoromethanesulfonic acid and metal salts (such as sodium carbonate and lithium carbonate) as raw materials in a traditional stirred tank reactor. The two react under vacuum to produce trifluoromethanesulfonic acid metal salts. The generated CO2 gas is separated by continuous stirring and vacuum precipitation, yielding the trifluoromethanesulfonic acid metal salt product. Neutralization production of trifluoromethanesulfonic acid metal salts has the advantages of simple equipment and easy operation, making it the most commonly used method. However, due to the inability to separate precipitated water in a timely manner and insufficient mixing, it suffers from low product yield, low conversion rate, reaction-separation mismatch, and high impurity content. Furthermore, the raw material trifluoromethanesulfonic acid is expensive and a strong organic acid, requiring high corrosion resistance of equipment and piping materials, posing significant safety risks. Therefore, this method has high production costs.

[0004] From the perspective of market development requirements and the progress of domestic and international production technologies, the future production of trifluoromethanesulfonate metal salts will mainly focus on reducing production costs, improving conversion rates, and increasing purity. Lowering costs and achieving high purity are current market demands, and reducing the production cost of trifluoromethanesulfonate metal salts necessitates reducing the cost of raw materials. This invention directly uses low-cost trifluoromethanesulfonyl chloride as a raw material, synthesizing the intermediate trifluoromethanesulfonyl fluoride through a catalytic reaction with anhydrous HF, and further synthesizing trifluoromethanesulfonyl metal salts through a reaction with an alkali metal solution. This invention leverages the advantages of hypergravity technology in enhancing micro-mixing, proposing the use of a hypergravity reactor as the reaction device, employing a combined reaction + separation + drying process to improve the product quality and production efficiency of trifluoromethanesulfonate metal salts.

[0005] Hypergravity technology is a novel technique for enhancing multiphase flow and reaction processes. It utilizes a rotating packed bed to simulate a hypergravity environment, enabling the mixing, mass transfer, and separation of reaction media under hypergravity conditions. A motor-driven rotor rotates at high speed, generating a powerful hypergravity field (centrifugal force can reach 1000 times the force of gravity). Under this centrifugal force, molecular diffusion and interphase mass transfer between molecules of different sizes are much faster than under conventional gravity. Gas and liquid phases flow into contact within porous media or channels under hypergravity conditions hundreds to thousands of times stronger than Earth's gravity. The enormous shear forces and rapidly renewing phase interfaces increase the interphase mass transfer rate by 1-3 orders of magnitude compared to traditional towers (or reactors), significantly enhancing micro-mixing and mass transfer processes. The magnitude of the hypergravity field can be controlled by adjusting the rotation speed, and the residence time of materials in the hypergravity field is very short and can be stably controlled. This technology can enhance reaction processes and significantly improve conversion rates.

[0006] Compared to traditional batch reactors, the production of trifluoromethanesulfonic acid metal salts using a supergravity reaction offers several advantages: smaller equipment size and easier installation, reducing investment costs and environmental impact; extremely short material residence time within the equipment (approximately 10-100 ms), suitable for processing and selectively absorbing heat-sensitive materials; simple operation with automatic process control, facilitating continuous production; easy start-up and shutdown with a short time to steady-state operation; self-cleaning function, preventing packing material from clogging due to particulate impurities, and easy packing replacement, resulting in convenient equipment maintenance.

[0007] In the prior art, methods for preparing trifluoromethanesulfonic acid metal salts are known, for example, as described below.

[0008] Chinese patent CN201911386729.6 discloses a method for synthesizing alkali metal trifluoromethanesulfonate, comprising: 1) adding anhydrous calcium chloride and alcohol to a reactor, evacuating the reactor, controlling the temperature inside the reactor to -40 to 25°C, introducing an excess of sulfonyl fluoride compound, and reacting for 2-3 hours; 2) after the reaction is completed, discharging the unreacted sulfonyl fluoride compound and distilling to obtain an ester compound; 3) adding an alkali metal hydroxide to the ester compound, stirring the reaction for 2-5 hours, filtering, and drying to obtain the trifluoromethanesulfonate metal salt. This method uses a traditional batch reactor, which has a complex process principle, makes it difficult to control the byproducts, and the reaction process is intermittent. The material transfer process is primitive, and the removal of impurities during distillation and purification is difficult. In the process of scaling up, the reactor occupies a large area and has a low degree of automation, among other disadvantages.

[0009] Chinese patent 201911384957.X discloses a method for the continuous hydrolysis preparation of trifluoromethanesulfonic acid, comprising: 1) continuously neutralizing and hydrolyzing trifluoromethanesulfonyl fluoride gas and an alkali metal hydroxide solution in a falling film reactor to obtain a reaction solution; 2) extracting the solution with a solvent after drying to obtain a trifluoromethanesulfonic acid metal salt; and 3) preparing trifluoromethanesulfonic acid by reacting the trifluoromethanesulfonic acid metal salt with concentrated sulfuric acid. This method involves a trifluoromethanesulfonic acid metal salt, which is an intermediate product with low purity and high water content. Furthermore, the solution extraction process increases safety risks and introduces new impurities. Summary of the Invention

[0010] In order to overcome the above-mentioned problems in the prior art, this application provides a method for preparing trifluoromethanesulfonic acid metal salts using a supergravity reaction.

[0011] This application provides a method for preparing trifluoromethanesulfonic acid metal salts using a supergravity reaction, employing the following technical solution:

[0012] A method for preparing trifluoromethanesulfonic acid metal salts using a supergravity reaction includes the following steps:

[0013] I. Using trifluoromethanesulfonyl chloride and anhydrous HF gas as raw materials, trifluoromethanesulfonyl fluoride gas is generated by reaction under the catalysis of a composite catalyst at a temperature of 80-100℃ and a pressure of 0.05-0.1MPa.

[0014] 2. Trifluoromethanesulfonyl fluoride gas is washed with water to remove impurities, and then introduced into a supergravity reaction with an alkali metal solution at a fixed flow rate ratio to carry out a gas-liquid contact reaction, thereby obtaining a mixed solution of trifluoromethanesulfonate metal salts.

[0015] 3. The mixed solution obtained in step 2 is subjected to solid-liquid separation using a filter press. The liquid phase is a trifluoromethanesulfonate solution, and the solid phase is a metal fluoride.

[0016] IV. The trifluoromethanesulfonate solution obtained in step three is dried by a spray dryer to obtain the solid product trifluoromethanesulfonate.

[0017] In one specific implementation, in step one, the composite catalyst is composed of MnO2 and CrF3 supported on AlF3, and the mass ratio of MnO2 and CrF3 in the composite catalyst is 1-3% and 3-5%, respectively.

[0018] In one specific implementation scheme, in step one, the mass ratio of the trifluoromethanesulfonyl chloride to anhydrous HF is 1:(1.05~1.2).

[0019] In one specific implementation scheme, in step two, the alkali metal solution includes any one of NaOH, Ba(OH)2, and Ca(OH)2 alkali solutions, and the mass concentration of the alkali metal solution is 20% to 40%.

[0020] In one specific feasible implementation, the filter press has a filtration accuracy of 7 μm.

[0021] In one specific implementation scheme, in step four, the drying conditions of the spray dryer are: controlling the air inlet temperature at 320-330℃, controlling the air outlet temperature at 130-140℃, and controlling the atomizer rotation speed at 15000-18000 r / min.

[0022] In one specific feasible implementation, the solid product trifluoromethanesulfonate contains ≥99.5% trifluoromethanesulfonate metal salt, ≤100ppm F-, and ≤500ppm H2O.

[0023] This application has the following beneficial effects:

[0024] This application's method uses trifluoromethanesulfonyl chloride and anhydrous HF as raw materials to replace trifluoromethanesulfonic acid in traditional methods. It employs a new chemical process intensification technology, leveraging the advantages of high-gravity reactions to significantly reduce raw material and equipment investment costs. Furthermore, the process is simple to operate, highly automated, and yields a trifluoromethanesulfonic acid metal salt with low impurity content (moisture ≤500ppm, F- ≤100ppm, purity ≥99.5%), exceeding industry standards. The byproduct, metal fluoride, has a purity ≥98%. The process achieves zero emissions, possessing significant economic and social value and is easily promoted. Attached Figure Description

[0025] Figure 1 This is a flowchart of the method provided in this application. Detailed Implementation

[0026] The following is in conjunction with the appendix Figure 1 The present application will be further described in detail with reference to the embodiments.

[0027] This application aims to provide a method for preparing trifluoromethanesulfonic acid metal salts using a supergravity reaction, which mainly includes the following steps:

[0028] Step 1: A chromium-based composite catalyst is added to a tubular reactor. Under conditions of 80–100℃ and 0.05–0.1 MPa, trifluoromethanesulfonyl chloride and anhydrous HF gas are introduced to carry out a fluorination reaction, synthesizing trifluoromethanesulfonyl fluoride gas. The reaction equation is as follows:

[0029]

[0030] Step 2: Using the trifluoromethanesulfonyl fluoride produced in Step 1 as raw material, after washing with water to remove impurities, it is introduced into a hypergravity reaction system with an alkali metal solution at a fixed flow rate ratio. The gas-liquid contact reaction is carried out under high-speed rotation conditions to synthesize a mixed solution of trifluoromethanesulfonate metal salts. The reaction equation is as follows:

[0031] CF3SO2F+2AOH————→CF3SO3A+AF↓+H2O

[0032] Step 3: The mixed solution after the reaction is subjected to solid-liquid separation by a filter press, and the impurities after the reaction are absorbed by the vent and discharged in compliance with standards.

[0033] Step 4: After the trifluoromethanesulfonate solution obtained in Step 3 is placed into a storage tank, it is sent into a spray dryer by a transfer pump and evaporated to obtain the solid product, trifluoromethanesulfonate metal salt.

[0034] In addition, the solid metal fluoride obtained in step 3 is sent to a vibration dryer for further drying to remove moisture, and the resulting byproduct metal fluoride can also be packaged and sold.

[0035] Furthermore, the tubular reactor in step 1 is made of nickel alloy, and heating tiles are installed on the outer wall with a heating power of 5KW.

[0036] Furthermore, the composite catalyst in step 1 is composed of MnO2 and CrF3 supported on AlF3. The mass ratio of MnO2 and CrF3 in the composite catalyst can be 1-3% and 3-5%, respectively. In the specific embodiments below, the mass ratio of MnO2 in the composite catalyst is 2%, and the mass ratio of CrF3 in the composite catalyst is 4%.

[0037] Furthermore, the hypergravity reactor used in step 2 is made of 316L stainless steel, and the core part is a rotor filled with PTFE packing. The rotor is driven by an electric motor to rotate at a high speed of 3000 r / min.

[0038] Furthermore, in step 2 of the hypergravity reactor, the gas phase is tangentially introduced into the outer cavity of the rotor through the gas inlet pipe, and enters the packing material from the outer edge of the rotor under the action of gas pressure. The liquid is introduced into the inner cavity of the rotor through the liquid inlet pipe and sprayed onto the inner edge of the rotor through the nozzle. After the reaction, the liquid is thrown by the rotor onto the outer shell and collected, then leaves the hypergravity reactor through the liquid outlet pipe. The gas leaves the rotor from the center and is led out through the gas outlet pipe, completing the mass transfer and reaction process.

[0039] Furthermore, in step 2, an online pH monitor is installed at the bottom discharge pipe of the reactor to automatically adjust the alkali metal feed rate and control the pH of the solution after the reaction to be 6-8. In the specific embodiments described below, the pH is controlled to be 7.

[0040] Furthermore, the storage tank in step 4 is a jacketed type with a built-in disturbance device and a temperature detection system. The temperature of the storage tank is regulated to be less than 70°C by cooling water.

[0041] Furthermore, the rotation speed of the atomizer in step 4 is 15000-18000 r / min. In the specific embodiments described below, the rotation speed of the atomizer is 18000 r / min.

[0042] Example 1

[0043] A method for preparing trifluoromethanesulfonic acid metal salts using a supergravity reaction includes the following steps:

[0044] Step 1: Trifluoromethanesulfonyl chloride and anhydrous HF are introduced into a nickel alloy tubular reactor at a mass ratio of 1:1.05. The reaction temperature is controlled at 80℃ and the pressure at 0.05MPa by adjusting the heating element. The reactor has a volume of 5L and is filled with a composite catalyst. The product composition is approximately 97% trifluoromethanesulfonyl fluoride, and approximately 3% HF, SO2, etc.

[0045] Step 2: The trifluoromethanesulfonyl fluoride produced in Step 1 is washed with water in a washing tower to remove impurities. The fluoride gas is then introduced into the gas phase inlet, while a 20% NaOH solution is introduced into the liquid phase inlet into the centrifugal reactor. The molar ratio of the two feeds is 1:0.51. The reactor is made of 316L stainless steel with an anti-corrosion coating on the inner wall. The hourly throughput is 1 m³. 3 / h, the rotor packing is PTFE structured packing, the speed is 3000r / min driven by the motor, the gas-liquid contact reaction is carried out to synthesize a mixed solution of sodium trifluoromethanesulfonate. The liquid is thrown by the rotor to the outer shell and collected and then leaves the hypergravity reactor through the outlet pipe. The amount of acyl fluoride gas is adjusted to control the pH of the outlet solution to 7.

[0046] Step 3: The sodium trifluoromethanesulfonate mixed solution from Step 2 is subjected to solid-liquid separation using a filter press with a filtration accuracy of 7 μm. After pressing and filtration, the filter cake is dried by nitrogen purging for 4 hours. The moisture content of the filter cake is 15%. The impurities after the reaction are absorbed by the vent and discharged in compliance with standards.

[0047] Step 4: After the sodium trifluoromethanesulfonate aqueous solution obtained in Step 3 is put into the storage tank, the detection indicators are 35% solubility and 60ppm F. Then, it is sent into the spray dryer by screw conveyor pump. The spray drying conditions are 320℃ inlet temperature, 130℃ outlet temperature, and 18000r / min atomizer speed to obtain solid sodium trifluoromethanesulfonate product. The product indicators are shown in Table 1.

[0048] Table 1: Product Specifications of Sodium Trifluoromethanesulfonate in Example 1

[0049] Component Name content / % F- / ppm <![CDATA[H2O / ppm]]> Sodium trifluoromethanesulfonate 99.67％ 82 482

[0050] Example 2

[0051] A method for preparing trifluoromethanesulfonic acid metal salts using a supergravity reaction includes the following steps:

[0052] Step 1: Trifluoromethanesulfonyl chloride and HF are used as raw materials and introduced into a nickel-tube reactor at a mass ratio of 1:1.08. The reaction temperature is controlled at 90°C by adjusting the heating element, and the reaction pressure is 0.5 MPa. The reactor volume is 5 L and it is filled with a composite catalyst. The product composition is: approximately 98.5% trifluoromethanesulfonyl fluoride, and approximately 1.5% HF, SO2, etc.

[0053] Step 2: The trifluoromethanesulfonyl fluoride produced in Step 1 is washed with water in a washing tower to remove impurities. The fluoride gas is introduced through the gas phase inlet, and a 30% (w / w) Ba(OH)₂ solution is introduced through the liquid phase inlet into the centrifugal reactor. The molar ratio of the two feeds is 1:1.05. The reactor is made of 316L stainless steel with an anti-corrosion coating on the inner wall. The hourly throughput is 1 m³. 3 / h, the rotor packing is PTFE structured packing, the speed is 3000r / min driven by the motor to carry out gas-liquid contact reaction to synthesize barium trifluoromethanesulfonate mixed solution. The liquid is thrown by the rotor to the outer shell and collected before leaving the hypergravity reactor through the outlet pipe. The amount of acyl fluoride gas inlet is adjusted to control the pH of the outlet solution to 7.

[0054] Step 3: The barium trifluoromethanesulfonate mixed solution from Step 2 is subjected to solid-liquid separation using a filter press with a filtration accuracy of 7 μm. After pressing and filtration, the filter cake is purged and dried with nitrogen for 5 hours. The moisture content of the filter cake is 13.5%. The impurities after the reaction are absorbed by the vent and discharged in compliance with standards.

[0055] Step 4: After the barium trifluoromethanesulfonate solution obtained in Step 3 is placed into the storage tank, the solubility and F-45ppm are tested. The solution is then sent to the spray dryer by a screw conveyor pump. The spray drying conditions are: inlet temperature of 325℃, outlet temperature of 135℃, and atomizer speed of 18000r / min. The solid product of trifluoromethanesulfonate metal salt is obtained. The product indicators are shown in Table 1.

[0056] Table 2: Product Specifications of Trifluoromethanesulfonic Acid Metal Salt in Example 2

[0057] Component Name content / % F- / ppm <![CDATA[H2O / ppm]]> Barium trifluoromethanesulfonate 99.85％ 64 358

[0058] Example 3

[0059] A method for preparing trifluoromethanesulfonic acid metal salts using a supergravity reaction includes the following steps:

[0060] Step 1: Trifluoromethanesulfonyl chloride and HF are introduced into a nickel-tube reactor at a mass ratio of 1:1.2. The reaction temperature is controlled at 100℃ by adjusting the heating element, and the reaction pressure is 0.1 MPa. The reactor has a volume of 5 L and is filled with a composite catalyst. The product composition is: approximately 95.5% trifluoromethanesulfonyl fluoride, and approximately 4.5% HF, SO2, COF2, etc.

[0061] Step 2: The trifluoromethanesulfonyl fluoride produced in Step 1 is washed and purified in a water washing tower. The fluoride gas is then introduced into the gas phase inlet, while a 40% Ca(OH)₂ solution is introduced into the liquid phase inlet into the centrifugal reactor. The molar ratio of the two feeds is 1:1.1. The reactor is made of 316L stainless steel with an anti-corrosion coating on the inner wall. The hourly throughput is 1 m³. 3 / h, the rotor packing is PTFE structured packing, the speed is 3000r / min driven by the motor to carry out gas-liquid contact reaction to synthesize calcium trifluoromethanesulfonate salt mixed solution. The liquid is thrown by the rotor to the outer shell and collected before leaving the hypergravity reactor through the outlet pipe. The amount of acyl fluoride gas inlet is adjusted to control the pH of the outlet solution to 6.

[0062] Step 3: The trifluoromethanesulfonate calcium mixed solution from Step 2 is subjected to solid-liquid separation using a filter press with a filtration accuracy of 7 μm. After pressing and filtration, the filter cake is dried by nitrogen purging for 6 hours. The moisture content of the filter cake is 12%. The impurities after the reaction are absorbed by the vent and discharged in compliance with standards.

[0063] Step 4: After the calcium trifluoromethanesulfonate solution obtained in Step 3 is placed into the storage tank, the solubility and F-48ppm are tested. The solution is then fed into the spray dryer by a screw conveyor pump. The spray drying conditions are: inlet temperature of 330℃, outlet temperature of 140℃, and atomizer speed of 18000r / min. The solid product of metal trifluoromethanesulfonate is obtained. The product indicators are shown in Table 1.

[0064] Table 3: Product Specifications of Trifluoromethanesulfonic Acid Metal Salt in Example 3

[0065] Component Name content / % F- / ppm <![CDATA[H2O / ppm]]> Calcium trifluoromethanesulfonate 99.67％ 82 482

[0066] Using trifluoromethanesulfonyl chloride and anhydrous HF as raw materials to replace trifluoromethanesulfonic acid in traditional methods, this new chemical process intensification technology leverages the advantages of high-gravity reactions, significantly reducing raw material and equipment investment costs. Furthermore, the process is simple to operate, highly automated, and yields trifluoromethanesulfonic acid metal salts with low impurity content (moisture ≤500ppm, F- ≤100ppm, purity ≥99.5%), exceeding industry standards. The byproduct, metal fluoride, has a purity ≥98%. The process achieves zero emissions, possessing significant economic and social value and is easily promoted.

[0067] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for preparing trifluoromethanesulfonic acid metal salts using a centrifugal reactor, characterized in that, The steps include the following: I. Using trifluoromethanesulfonyl chloride and anhydrous HF gas as raw materials, trifluoromethanesulfonyl fluoride gas is generated by reaction under the catalysis of a composite catalyst at a temperature of 80~100℃ and a pressure of 0.05~0.1MPa; the composite catalyst is composed of MnO2 and CrF3 supported on AlF3, with the mass ratio of MnO2 and CrF3 in the composite catalyst being 1~3% and 3~5%, respectively; the mass ratio of trifluoromethanesulfonyl chloride to anhydrous HF is 1:(1.05~1.2).

2. Trifluoromethanesulfonyl fluoride gas is washed with water to remove impurities, and then introduced into a supergravity reactor with an alkali metal solution at a fixed flow rate ratio to carry out gas-liquid contact reaction, so as to obtain a mixed solution of trifluoromethanesulfonate metal salt.

3. The mixed solution obtained in step 2 is subjected to solid-liquid separation using a filter press. The liquid phase is a trifluoromethanesulfonate solution, and the solid phase is a metal fluoride. The filtration accuracy of the filter press is 7 μm.

4. The trifluoromethanesulfonate solution obtained in step 3 is dried by a spray dryer to obtain a solid product trifluoromethanesulfonate; the solid product trifluoromethanesulfonate contains ≥99.5% trifluoromethanesulfonic acid metal salt, ≤100ppm F-, and ≤500ppm H2O.

2. The method for preparing trifluoromethanesulfonic acid metal salts using a centrifugal reactor according to claim 1, characterized in that: In step two, the alkali metal solution includes any one of NaOH, Ba(OH)2, or Ca(OH)2 alkali solution, and the mass concentration of the alkali metal solution is 20% to 40%.

3. The method for preparing trifluoromethanesulfonic acid metal salts using a centrifugal reactor according to claim 1, characterized in that: In step four, the drying conditions of the spray dryer are as follows: the inlet temperature is controlled at 320~330℃, the outlet temperature is controlled at 130~140℃, and the atomizer speed is controlled at 15000~18000r / min.

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