Method for preparing methylsulfonyl fluoride from methylsulfonyl chloride

Abstract

The invention relates to a method for preparing methylsulfonyl fluoride from methylsulfonyl chloride, which comprises the following steps: by taking methylsulfonyl chloride as a raw material, adding a fluorination catalyst and anhydrous hydrogen fluoride as a fluorinating agent, and continuously reacting in an HL microchannel reactor to prepare methylsulfonyl fluoride, the HL microchannel reactor is of a three-stage nested microchannel structure, a first-stage mixing area is a conical spiral channel, a second-stage reaction area is a snakelike corrugated channel, and a third-stage extension area is a straight channel. The reaction rate is high, the unit consumption of anhydrous hydrogen fluoride serving as a fluorinating agent is low, the raw material cost is saved, the preparation cost is greatly reduced, and compared with a conventional tank reactor, the HL microchannel reactor is high in reaction rate, convenient to clean, capable of saving manpower, capable of achieving continuous preparation and convenient to achieve large-scale industrialization.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for preparing methylsulfonyl fluoride from methylsulfonyl chloride, belonging to the field of fine chemical industry. BACKGROUND

[0002] Methylsulfonyl fluoride CH3SO2F is an important basic raw material for synthesizing novel functional chemical products in the field of fine chemical industry, mainly used as a raw material for fine chemical synthesis and an analytical reagent, and also used as a raw material for preparing synthetic trifluoromethylsulfonyl fluoride by electrochemical method.

[0003] Chinese patent CN101747238A relates to a method for preparing methylsulfonyl fluoride CH3SO2F from the separation of the material after the reaction of methylsulfonyl chloride and potassium fluoride, and the steps of the method are as follows: (1) mixing water, potassium fluoride KF and methylsulfonyl chloride CH3SO2Cl, or mixing an aqueous solution of potassium fluoride KF and methylsulfonyl chloride CH3SO2Cl, and carrying out fluorination reaction; (2) adding a neutralizing agent for neutralization reaction; (3) cooling and crystallizing; (4) carrying out solid-liquid separation on the obtained material; (5) carrying out liquid-liquid separation on the liquid phase obtained in the previous step, and the oil phase enters the next step; (6) adding a dehydrating agent for dehydration treatment; (7) carrying out solid-liquid separation on the material obtained in the previous step; (8) carrying out separation by reduced pressure distillation on the liquid phase obtained in the previous step, and the gaseous phase is condensed to obtain the product methylsulfonyl fluoride CH3SO2F. Methylsulfonyl chloride is used as the raw material, potassium fluoride is used as the fluorinating agent, and fluorination is carried out in water, acetonitrile and other reaction solvents to prepare methylsulfonyl fluoride. In addition to the target product, potassium chloride is also generated, which leads to batch operation in the production process, involves many manual operations, increases the labor cost and time cost in production, and methylsulfonyl chloride and methylsulfonyl fluoride are toxic substances, which also pose a threat to the safety of production operators. Therefore, it is particularly important to realize continuous preparation of methylsulfonyl fluoride from methylsulfonyl chloride. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a method for preparing methylsulfonyl fluoride from methylsulfonyl chloride, which saves raw material cost, greatly reduces production cost, avoids conventional tank reactors, does not need to clean the residues in the tank, saves labor, and can be continuously prepared and easily realized on a large scale.

[0005] In order to achieve the purpose of the present application, the following technical solutions are provided:

[0006] A method for preparing methylsulfonyl fluoride from methylsulfonyl chloride, comprising the following steps: using methylsulfonyl chloride as the raw material, adding a fluorination catalyst, and using anhydrous hydrogen fluoride as the fluorinating agent, and continuously reacting in an HL microchannel reactor to prepare methylsulfonyl fluoride.

[0007] The HL micro-channel reactor is a three-stage nested micro-channel structure, the first-stage mixing zone is a conical spiral channel, the second-stage reaction zone is a serpentine corrugated channel, and the third-stage extension zone is a straight channel.

[0008] In the HL micro-channel reactor, the mixed solution or mixed slurry of methylsulfonyl chloride and high-efficiency liquid fluorination catalyst is continuously fed, and anhydrous hydrogen fluoride is continuously fed, the materials are broken and mixed by using a dynamic mixing device in the reactor, high-speed mixing and rapid reaction are achieved, the reaction liquid is continuously output, the reaction liquid is transported to a product storage tank by a delivery pump of the reactor for subsequent purification treatment, and methylsulfonyl fluoride is obtained.

[0009] Preferably, the mass ratio of methylsulfonyl chloride to fluorination catalyst is 1000:(1-10), and the molar ratio of anhydrous hydrogen fluoride to methylsulfonyl chloride is (1.05-5):1.

[0010] Preferably, the temperature for preparing methylsulfonyl fluoride is controlled at 30-100 DEG C, and the residence time in the HL micro-channel reactor is set to 10-120 seconds.

[0011] Preferably, the fluorination catalyst is antimony pentafluoride, antimony trifluoride, potassium fluoride, zinc fluoride or calcium fluoride.

[0012] Preferably, the HL micro-channel reactor uses Hastelloy C276 as the main material, and a 50-micron PTFE coating layer is added on the Hastelloy base to cover the gas-liquid interface area, resist HF corrosion, reduce catalyst adhesion, and increase the service life by 3 times.

[0013] Preferably, a static mixing unit is arranged in the first-stage mixing zone, and a piezoelectric ceramic pulse generator is additionally arranged in the static mixing unit, and the frequency of the piezoelectric ceramic pulse generator is 100-500 Hz.

[0014] Preferably, the angle of the corrugation of the serpentine corrugated channel relative to the fluid flow direction is 45 DEG, and a baffle is arranged in the straight channel of the third-stage extension zone.

[0015] The HL micro-channel reactor is designed as a three-stage nested micro-channel structure, the fluid dynamics are optimized for different reaction stages by partition design, the problem of easy clogging of solid-liquid slurry is solved, the first-stage mixing zone is a conical spiral channel, a static mixing unit is arranged therein, and a piezoelectric ceramic pulse generator (frequency 100-500 Hz) is additionally arranged, so that the solid catalyst particles (such as SbF3, KF, etc.) in the slurry are instantaneously dispersed to avoid sedimentation, the mixing efficiency is increased by 40% compared with the traditional micro-channel, the pre-mixing of methylsulfonyl chloride / catalyst slurry and HF is realized, the second-stage reaction zone is a serpentine corrugated channel, the corrugation angle is 45 DEG, the turbulent flow is intensified by periodic diameter change, and the mass transfer efficiency is improved, the third-stage extension zone is a straight channel + an arranged baffle, the residence time is extended to 10-120 seconds, and the reaction is ensured to be complete.

[0016] Preferably, the temperature of the primary mixing zone is 30-40 DEG C, the temperature of the secondary reaction zone is 30-100 DEG C, and the temperature of the tertiary extension zone is 20-30 DEG C.

[0017] The HL micro-channel reactor increases the temperature control and mixing system, and precisely controls the temperature in different zones.

[0018] Preferably, the mass ratio of methylsulfonyl chloride to catalyst is 1000:(2-5), and the molar ratio of hydrogen fluoride to methylsulfonyl chloride is (1.1-1.3):1.

[0019] Preferably, the residence time in the HL micro-channel reactor is set to 30-60 seconds, and the temperature of the secondary reaction zone is 50-80 DEG C.

[0020] The present application has the following advantages:

[0021] The method is carried out in an HL micro-channel reactor, and a mixed solution or mixed slurry of methylsulfonyl chloride CH3SO2Cl and a fluorination catalyst, and anhydrous hydrogen fluoride HF are introduced.

[0022] (1) The method of the present application uses an HL micro-channel reactor as a reaction device to prepare methylsulfonyl fluoride.

[0023] (2) The method of the present application uses an HL microchannel reactor as a reaction device to prepare methylsulfonyl fluoride, increases the temperature control and mixing system, and precisely controls the temperature in different zones, with three independent temperature control modules: the inlet zone (30-40℃): low temperature to prevent HF from vaporizing too quickly; the reaction zone (50-80℃): main reaction temperature zone with ±1℃ precision; the outlet zone (20-30℃): rapid cooling to terminate the reaction. Precise temperature control in different zones avoids the problem of temperature control difficulty in multiple stages of synthesis, saves manpower, and improves reaction rate;

[0024] (3) The addition of a high-efficiency catalyst reduces the energy conditions required for the reaction, increases the reaction speed, and improves the reaction yield;

[0025] (4) The use of hydrogen fluoride as a fluorinating agent has lower unit consumption than potassium fluoride, saving raw material costs and significantly reducing production costs, thereby improving product market competitiveness;

[0026] (5) Hydrogen fluoride as a fluorinating agent produces hydrogen chloride as a byproduct, which has a large difference in boiling point with methylsulfonyl fluoride, making it easy to separate and purify subsequently. After separation, hydrogen chloride can also be sold as a byproduct;

[0027] (6) No water is introduced as a solvent, which avoids the hydrolysis of methylsulfonyl chloride and methylsulfonyl fluoride, and no water-soluble impurities are introduced, resulting in high product purity. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 The figure is a structural diagram of the HL microchannel reactor of the present application.

[0029] In the figure, 1 is a first mixing zone, and 11 is a piezoelectric ceramic pulse generator.

[0030] 2 is a second reaction zone.

[0031] 3 is a third extension zone, and 31 is a baffle.

[0032] 4 is a delivery pump.

[0033] 5 is a temperature control module. DETAILED DESCRIPTION

[0034] In order to make the purpose, scheme and advantages of the technical solutions of the present application clearer, the present application will be described in detail below with specific examples, but not as a limitation on the patent.

[0035] Device example:

[0036] For example, Figure 1As shown, the HL microchannel reactor is designed as a three-layer nested microchannel structure, and the partition design optimizes fluid dynamics for different reaction stages, solves the problem of easy blockage of solid-liquid slurry, and improves the mixing efficiency by 40% compared with the traditional microchannel. The first mixing zone 1 is a conical spiral channel with a built-in static mixing unit, and a piezoelectric ceramic pulse generator 11 (frequency 300 Hz) is added to make the solid catalyst particles in the slurry instantaneously dispersed to avoid sedimentation. The pre-mixing of methylsulfonyl chloride / catalyst slurry and HF is realized. The second reaction zone 2 is a serpentine corrugated channel with a corrugation angle of 45°, which can strengthen the turbulence through periodic diameter change and improve the mass transfer efficiency. The third extension zone 3 is a straight channel with built-in baffles 31, which can extend the residence time to 10-120 seconds to ensure complete reaction. The outlet zone of the third extension zone of the HL microchannel reactor is provided with a conveying pump 4, which can convey the methylsulfonyl fluoride crude product to the product storage tank for subsequent purification treatment.

[0037] The HL microchannel reactor is provided with three independent temperature control modules 5, which control the mixing zone (30-40°C), the reaction zone (30-100°C) with a precision of ±1°C, and the third extension zone (20-30°C).

[0038] The HL microchannel reactor is made of Hastelloy C276 as the main material, and a 50μm PTFE coating layer is added on the Hastelloy alloy substrate to cover the gas-liquid interface area.

[0039] Example 1:

[0040] A method for preparing methylsulfonyl fluoride from methylsulfonyl chloride, the process steps are as follows: mix methylsulfonyl chloride and antimony pentafluoride liquid according to the mass ratio of 500:1 and pass into the HL microchannel reactor, pass in hydrogen fluoride according to 1.2 times the amount of methylsulfonyl chloride, set the inlet zone temperature to 30°C, set the reaction zone temperature to 50°C, set the outlet zone temperature to 30°C, set the residence time to 30 seconds, and carry out continuous fluorination reaction. The reaction liquid is detected by gas chromatography analysis, and the product is methylsulfonyl fluoride, and the conversion rate is 98.7%.

[0041] Example 2:

[0042] A method for preparing methylsulfonyl fluoride from methylsulfonyl chloride, the process steps are as follows: mix methylsulfonyl chloride and antimony trifluoride solid-liquid mixture according to the mass ratio of 1000:3 and pass into the HL microchannel reactor, pass in hydrogen fluoride according to 1.2 times the amount of methylsulfonyl chloride, set the inlet zone temperature to 30°C, set the reaction zone temperature to 80°C, set the outlet zone temperature to 30°C, set the residence time to 30 seconds, and carry out continuous fluorination reaction. The reaction liquid is detected by gas chromatography analysis, and the product is methylsulfonyl fluoride, and the conversion rate is 97.5%.

[0043] Example 3:

[0044] A method for preparing methylsulfonyl fluoride from methylsulfonyl chloride, the process steps are as follows: a solid-liquid mixture of methylsulfonyl chloride and potassium fluoride is mixed according to a mass ratio of 200:1 and is introduced into an HL microchannel reactor, hydrogen fluoride is introduced according to 1.2 times the amount of methylsulfonyl chloride, the inlet zone temperature is set to 30℃, the reaction zone temperature is set to 80℃, the outlet zone temperature is set to 30℃, and the residence time is set to 50 seconds, a continuous fluorination reaction is carried out, and it is detected by gas chromatography that the product is methylsulfonyl fluoride, and the conversion rate is 95.7%.

[0045] Example 4:

[0046] A method for preparing methylsulfonyl fluoride from methylsulfonyl chloride, the process steps are as follows: a solid-liquid mixture of methylsulfonyl chloride and zinc fluoride is mixed according to a mass ratio of 200:1 and is introduced into an HL microchannel reactor, hydrogen fluoride is introduced according to 1.3 times the amount of methylsulfonyl chloride, the inlet zone temperature is set to 30℃, the reaction zone temperature is set to 50℃, the outlet zone temperature is set to 30℃, and the residence time is set to 50 seconds, a continuous fluorination reaction is carried out, and it is detected by gas chromatography that the product is methylsulfonyl fluoride, and the conversion rate is 95.4%.

[0047] Example 5:

[0048] A method for preparing methylsulfonyl fluoride from methylsulfonyl chloride, the process steps are as follows: a solid-liquid mixture of methylsulfonyl chloride and calcium fluoride is mixed according to a mass ratio of 100:1 and is introduced into an HL microchannel reactor, hydrogen fluoride is introduced according to 1.05 times the amount of methylsulfonyl chloride, the inlet zone temperature is set to 30℃, the reaction zone temperature is set to 80℃, the outlet zone temperature is set to 30℃, and the residence time is set to 10 seconds, a continuous fluorination reaction is carried out, and it is detected by gas chromatography that the product is methylsulfonyl fluoride, and the conversion rate is 95%.

[0049] Example 6:

[0050] A method for preparing methylsulfonyl fluoride from methylsulfonyl chloride, the process steps are as follows: a solid-liquid mixture of methylsulfonyl chloride and calcium fluoride is mixed according to a mass ratio of 1000:1 and is introduced into an HL microchannel reactor, hydrogen fluoride is introduced according to 5 times the amount of methylsulfonyl chloride, the inlet zone temperature is set to 40℃, the reaction zone temperature is set to 100℃, the outlet zone temperature is set to 20℃, and the residence time is set to 120 seconds, a continuous fluorination reaction is carried out, and it is detected by gas chromatography that the product is methylsulfonyl fluoride, and the conversion rate is 94.5%.

[0051] Comparative Example:

[0052] A method for preparing methylsulfonyl fluoride from methylsulfonyl chloride, the process steps are as follows: methylsulfonyl chloride and liquid antimony pentafluoride are mixed according to mass 500:1 and are introduced into a common reactor, hydrogen fluoride is introduced according to 1.2 times of the amount of matter of methylsulfonyl chloride, the temperature of the reactor is set to 50 DEG C, the residence time is set to 30 seconds, the reaction liquid is taken and is detected by GC-MS analysis, and it is found that the product is methylsulfonyl fluoride, and the conversion rate is 68.2%.

[0053] The present application includes but is not limited to the above embodiments, any equivalent replacement or partial improvement made under the principle of the present application shall be considered within the protection scope of the present application.

Claims

1. A method for preparing methylsulfonyl fluoride from methylsulfonyl chloride, characterized in that: The method comprises the following steps: using methanesulfonyl chloride as a raw material, adding a fluorination catalyst and anhydrous hydrogen fluoride as a fluorinating agent, and continuously reacting in an HL microchannel reactor to prepare methanesulfonyl fluoride; The HL microchannel reactor has a three-stage nested microchannel structure. The first-stage mixing zone is a tapered spiral channel, the second-stage reaction zone is a serpentine corrugated channel, and the third-stage extension zone is a straight channel.

2. The method for preparing methylsulfonyl fluoride from methylsulfonyl chloride according to claim 1, wherein The mass ratio of methanesulfonyl chloride to the fluorination catalyst is 1000:(1-10), and the molar ratio of anhydrous hydrogen fluoride to methanesulfonyl chloride is (1.05-5):

1.

3. The method for preparing methylsulfonyl fluoride from methylsulfonyl chloride according to claim 1, wherein The temperature for preparing methylsulfonyl fluoride by reaction is controlled at 30° C. to 100° C., and the residence time in the HL microchannel reactor is set to 10-120 seconds.

4. The method for preparing methylsulfonyl fluoride from methylsulfonyl chloride according to claim 1, wherein The fluorination catalyst is antimony pentafluoride, antimony trifluoride, potassium fluoride, zinc fluoride or calcium fluoride.

5. The method for preparing methylsulfonyl fluoride from methylsulfonyl chloride according to claim 1, wherein The HL microchannel reactor uses Hastelloy C276 as the main material, and adds a 50μm plasma sprayed PTFE coating on the Hastelloy substrate.

6. The method for preparing methylsulfonyl fluoride from methylsulfonyl chloride according to claim 1, wherein A static mixing unit is built into the primary mixing zone, and a piezoelectric ceramic pulse generator is added to the static mixing unit. The frequency of the piezoelectric ceramic pulse generator is 100-500 Hz.

7. The method for preparing methylsulfonyl fluoride from methylsulfonyl chloride according to claim 1, wherein The corrugation angle of the serpentine corrugated channel relative to the fluid flow direction is 45°; the straight channel in the third-level extension area has a built-in baffle.

8. The method for preparing methylsulfonyl fluoride from methylsulfonyl chloride according to claim 3, wherein: The temperature of the primary mixing zone is 30-40°C, the temperature of the secondary reaction zone is 30-100°C, and the temperature of the tertiary extension zone is 20-30°C.

9. The method for preparing methylsulfonyl fluoride from methylsulfonyl chloride according to claim 2, wherein: The mass ratio of methylsulfonyl chloride and the catalyst is 1000:(2-5), and the amount ratio of hydrogen fluoride and methylsulfonyl chloride is (1.1-1.3):

1.

10. The method for preparing methylsulfonyl fluoride from methylsulfonyl chloride according to claim 8, wherein: The residence time in the HL microchannel reactor was set to 30-60 seconds, and the temperature of the secondary reaction zone was 50-80°C.

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