Method for synthesizing methylsulfonyl fluoride from byproduct sulfuryl chloride fluorine

Abstract

The invention belongs to the technical field of organic synthesis, and particularly relates to a method for synthesizing methylsulfonyl fluoride from byproduct sulfuryl chloride fluorine. The method for synthesizing methylsulfonyl fluoride from byproduct sulfuryl chloride fluorine comprises the following steps: firstly, preparing a methylmagnesium chloride solution; then adding sulfuryl chloride fluorine into the reaction container, cooling to-15 DEG C to 5 DEG C, dropwise adding a methylmagnesium chloride solution while stirring under an anaerobic condition, and carrying out a heat preservation reaction after dropwise adding to obtain a methylsulfonyl fluoride reaction solution; and finally, adding water into the reaction liquid for quenching, standing for liquid separation to obtain a water phase and an organic phase, treating the water phase to obtain magnesium chloride (hexahydrate), and refining the organic phase to obtain methylsulfonyl fluoride. According to the method for synthesizing the methylsulfonyl fluoride from the byproduct sulfuryl chloride fluorine, the treatment problem of the byproduct sulfuryl chloride fluorine is solved, the raw material cost in the synthesis process is low, and the obtained methylsulfonyl fluoride is high in purity and yield.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic synthesis, and particularly relates to a method for synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride fluoride. Background Art

[0002] Methylsulfonyl fluoride is a fine chemical product and has important applications in the fields of organic synthesis, pharmaceuticals, etc. In the field of organic synthesis, it is an important sulfonylation reagent and can be used to introduce a sulfonyl group into organic molecules. In drug research and development, it can be used as an intermediate to participate in the synthesis of some drug molecules. Through its sulfonylation effect, the structure of drug molecules can be modified, thereby improving the physicochemical properties, biological activity, pharmacokinetic properties, etc. of drugs. Methylsulfonyl fluoride can be used for the modification of polymer materials. By introducing it into the polymer structure, the surface properties, hydrophilicity, thermal stability, etc. of the polymer can be changed. It is also applied in the synthesis of some pesticides and plant growth regulators.

[0003] Currently, the preparation of methylsulfonyl fluoride mainly uses methylsulfonyl chloride as the raw material and conducts a fluorination reaction in an aqueous solution of potassium fluoride. Potassium fluoride is used as a reactant, enabling the chlorine atom in methylsulfonyl chloride to be replaced by a fluorine atom, thereby generating methylsulfonyl fluoride. However, methylsulfonyl chloride and potassium fluoride are expensive, and the obtained methylsulfonyl fluoride has low purity and low yield, and there are relatively large problems with three wastes.

[0004] Patent CN112661676A discloses a method for synthesizing methylsulfonyl fluoride by the fluorination reaction of methylsulfonyl chloride with anhydrous hydrogen fluoride, mainly using nickel fluoride, antimony pentafluoride, antimony trifluoride, and potassium fluoride as catalysts. Although the yield and purity are improved to a certain extent, methylsulfonyl chloride and fluoride catalysts are expensive, resulting in high production costs, and the problem of three wastes has not been fundamentally solved.

[0005] Patent CN101747237A discloses a method for preparing methylsulfonyl fluoride CH3SO2F from methylsulfonyl chloride CH3SO2Cl. In the reaction, water, potassium fluoride, and methylsulfonyl chloride are mixed, or an aqueous solution of potassium fluoride is mixed with methylsulfonyl chloride to carry out a fluorination reaction to obtain the product methylsulfonyl fluoride and the by-product potassium chloride. Still using methylsulfonyl chloride and potassium fluoride as raw materials, the essential problems in the process brought by them cannot be solved. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the above-mentioned defects existing in the prior art, provide a method for synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride fluoride, solve the problem of treating by-product sulfuryl chloride fluoride, have low raw material cost during the synthesis process, and obtain methylsulfonyl fluoride with high purity and high yield.

[0007] The method for synthesizing methylsulfonyl fluoride from by - product sulfuryl chloride fluoride according to the present invention comprises the following steps: First, prepare a methylmagnesium chloride solution; then add sulfuryl chloride fluoride to a reaction vessel, cool it to - 15°C to 5°C, and under anhydrous and anaerobic conditions, stir and drop - wise add the methylmagnesium chloride solution. After the dropping is completed, keep the temperature for reaction to obtain a methylsulfonyl fluoride reaction solution; finally, quench the reaction solution with water, let it stand for liquid - separation to obtain an aqueous phase and an organic phase. The aqueous phase is treated to obtain magnesium chloride, and the organic phase is refined to obtain methylsulfonyl fluoride.

[0008] The steps for preparing the methylmagnesium chloride solution are as follows: Under continuous protection of nitrogen (with the flow rate controlled at 50 - 100 mL / min), after crushing magnesium, select magnesium fine particles or magnesium shavings with a particle size between 0.1 - 0.5 mm, accurately weigh them and quickly transfer them to reaction vessel 1. According to 1 L of dry tetrahydrofuran solvent corresponding to each mole of magnesium, seal the reaction vessel, and slowly introduce methyl chloride with a purity of more than 99.5% through a gas introduction device. At the same time, turn on the heating device and gradually raise the temperature of the reaction system to 50 - 60°C. During this stage, closely observe the temperature and pressure changes in the reaction vessel. When there are phenomena such as a rapid rise in temperature and a slight increase in pressure, it indicates that the reaction has been successfully initiated. Subsequently, adjust the heating device and the cooling system to maintain the reaction temperature at 30 - 40°C to ensure the smooth progress of the exothermic reaction. React for 3 - 5 h. After the reaction is completed, wait for the reaction system to cool to room temperature to obtain the methylmagnesium chloride solution.

[0009] The nitrogen flow rate is 50 - 100 mL / min, and 1 L of tetrahydrofuran is added per mole of magnesium powder.

[0010] The molar ratio of sulfuryl chloride fluoride to methylmagnesium chloride is 1:1 to 1.1.

[0011] Stir and drop - wise add the methylmagnesium chloride solution with a stirring speed of 200 - 300 r / min.

[0012] The dropping time of the methylmagnesium chloride solution is 0.5 - 2 h, and after the dropping is completed, keep the temperature for reaction for 2 - 5 h.

[0013] The aqueous phase is subjected to crystallization and drying treatment to obtain magnesium chloride.

[0014] The organic phase is washed with water for liquid - separation, then anhydrous sodium sulfate is added for drying. The dried organic phase is distilled to remove the solvent, and then vacuum distillation is carried out at a vacuum degree of - 0.08 to - 0.1 MPa and a temperature of 55 - 65°C to obtain methylsulfonyl fluoride.

[0015] When quenching the reaction solution with water, the volume of water is the same as that of the reaction solution.

[0016] The by-product sulfuryl chloride fluoride has a purity of ≥98%. Sulfuryl chloride fluoride is a prohibited substance for transportation. Due to its low boiling point and high saturated vapor pressure, the storage conditions are harsh, generally requiring ≤ -20°C. For the above reasons, the by-product sulfuryl chloride fluoride generated during the production process is generally converted into sulfuryl fluoride in-situ or hydrolyzed with water to produce sulfuric acid and hydrofluoric acid. In the present invention, sulfuryl chloride fluoride reacts with methylmagnesium chloride to produce a high-value-added product, methylsulfonyl fluoride, which not only solves the above problems but also increases the product added value.

[0017] Specifically, the method for synthesizing methylsulfonyl fluoride from the by-product sulfuryl chloride fluoride includes the following steps: (1) Adjust the temperature in the reaction vessel to -15°C - 5°C through the temperature control system. After accurately measuring sulfuryl chloride fluoride, add it to the reaction vessel. Start the stirrer and set the stirring speed to 200 - 300 r / min to make sulfuryl chloride fluoride mix evenly, and introduce nitrogen for replacement. The replacement time is not less than 30 min to exhaust the air in the reaction vessel and ensure that the reaction system is in an anaerobic environment.

[0018] (2) Slowly drop the methylmagnesium chloride solution into the reaction vessel, control the molar ratio of sulfuryl chloride fluoride to methylmagnesium chloride within the range of 1:1 - 1.1, and control the dropping time within 0.5 - 2 h. The dropping speed should be such that the temperature of the reaction system does not fluctuate violently. After the dropping is completed, maintain the reaction temperature and continue stirring for 2 - 5 h until the purity of methylsulfonyl fluoride no longer changes.

[0019] (3) After the reaction is completed, slowly add water equal to the volume of the reaction solution to the reaction vessel under nitrogen protection for quenching to consume the unreacted methylmagnesium chloride reagent. The addition of water should be carried out slowly to prevent dangerous situations caused by a large amount of heat and gas generated due to violent reaction.

[0020] (4) Let it stand for liquid separation, separate the aqueous phase, transfer the organic phase to a separating funnel, add water for washing (the amount of water is 1 / 2 - 1 times the volume of the organic phase), shake for 5 - 10 min, then let it stand for layering, and separate the aqueous phase and mix it with the previously separated aqueous phase; repeat the washing operation on the organic phase 2 - 3 times, collect all the separated aqueous phases; subject all the separated aqueous phases to crystallization and drying treatment to obtain magnesium chloride (hexahydrate).

[0021] (5) Transfer the organic phase to a dry flask, add anhydrous sodium sulfate (the amount of anhydrous sodium sulfate is 5 - 10% of the volume of the organic phase), start the stirrer, set the stirring speed to 150 - 200 r / min, and stir for 0.5 - 1 h to make anhydrous sodium sulfate fully contact with the organic phase to remove the trace water in the organic phase. After the stirring is completed, remove the anhydrous sodium sulfate solid by suction filtration to obtain a liquid containing methylsulfonyl fluoride.

[0022] (6) Transfer the dried organic phase to a distillation apparatus for distillation. During the process, closely observe the changes in the liquid in the distillation flask until no more distillate is distilled out. Recover the tetrahydrofuran solvent to obtain crude methylsulfonyl fluoride.

[0023] (7) Transfer the crude methylsulfonyl fluoride to a rectification column. Control the vacuum degree of the rectification column at -0.08 to -0.1 MPa and the bottom temperature at 55 - 65 °C. Collect the distillate to obtain a high-purity methylsulfonyl fluoride product.

[0024] The present invention uses by-product sulfuryl chloride fluoride as the starting material. At low temperature, methylmagnesium chloride is added dropwise to sulfuryl chloride fluoride to form methylsulfonyl fluoride and magnesium chloride, and then separation and purification are carried out to obtain methylsulfonyl fluoride.

[0025] The reaction principle and reaction equation are as follows: CH3Cl + Mg → CH3MgCl; SO2ClF + CH3MgCl → CH3SO2F + MgCl2.

[0026] Due to the electrophilicity of the sulfur atom in sulfuryl chloride fluoride (SO2ClF), methylmagnesium chloride (CH3MgCl) acts as a strong nucleophile (source of methyl anion), directly attacks the sulfur atom, replaces the chlorine or fluorine atom (in sulfuryl chloride fluoride, both the chlorine and fluorine atoms connected to the sulfur atom may be replaced, but the chlorine atom is more easily replaced by the methyl group due to its lower bond energy (the bond energy of S-Cl is lower than that of S-F)) to form methylsulfonyl fluoride (CH3SO2F). This reaction belongs to a nucleophilic substitution reaction. Since methylmagnesium chloride (CH3MgCl) has strong basicity and high reactivity, it can proceed spontaneously without additional catalysts. The amount of sulfuryl chloride fluoride and reaction conditions are controlled during the reaction to make the reaction produce methylsulfonyl fluoride and prevent side reactions such as the further reaction of the generated methylsulfonyl fluoride with Grignard reagent to form dimethyl sulfone.

[0027] Compared with the prior art, the beneficial effects of the present invention are: (1) For the method of synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride fluoride of the present invention, the raw material utilization rate is high, the by-products are few, and the cost is low.

[0028] (2) For the method of synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride fluoride of the present invention, the reaction conditions are mild, the reaction is carried out under normal pressure and is easy to control.

[0029] (3) For the method of synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride fluoride of the present invention, the product purity is high, the post-treatment is simple, and it is suitable for industrialization. Description of the Drawings

[0030] Figure 1 It is the gas chromatogram of the methylsulfonyl fluoride prepared in Example 4. Detailed Description of the Invention

[0031] The present invention will be further described below in conjunction with specific embodiments.

[0032] The raw materials and auxiliaries used in the following examples and comparative examples are all commercially available products.

[0033] The by-product used is sulfuryl chloride fluoride produced in the production of sulfuryl fluoride. When collecting the distillate of methylsulfonyl fluoride, the set temperature is 60 °C, and the actual temperature fluctuates within 60 ± 5 °C. The set vacuum degree is -0.09 MPa, and the actual value fluctuates within -0.09 ± 0.01 MPa.

[0034] The methylmagnesium chloride solutions used below are all prepared through the following steps: Under continuous protection of nitrogen (with the flow rate controlled at 80 mL / min), after magnesium is crushed, magnesium fine particles or magnesium chips with a particle size between 0.1 - 0.5 mm are selected. After accurate weighing, they are quickly transferred to a reaction vessel. According to 1 L of dry tetrahydrofuran solvent corresponding to each mole of magnesium, the dry tetrahydrofuran solvent is added, and the reaction vessel is sealed. Purity 99.5% methyl chloride is slowly introduced through a gas introduction device. At the same time, the heating device is turned on, and the temperature of the reaction system is gradually raised to 50 °C. When the temperature rises rapidly and the pressure increases slightly, the reaction is successfully initiated. Subsequently, the heating device and the cooling system are adjusted to maintain the reaction temperature at 35 °C for 3 h. After the reaction ends, when the reaction system cools to room temperature, a methylmagnesium chloride solution is obtained. The molar concentration of methylmagnesium chloride is measured using the titration indication method. The measurement method is as follows: Take a conical flask, add distilled water, and slowly add 5 mL of the methylmagnesium chloride solution sample with a pipette. Shake well, add 1 to 3 drops of methyl orange indicator until the solution should turn yellow, and titrate with a hydrochloric acid standard solution (concentration C HCl ), until the solution changes from yellow to red and the precipitate completely dissolves. At this time, record the volume V HCl of the hydrochloric acid standard solution consumed. Then titrate with a sodium hydroxide standard solution (concentration C NaOH ), until the solution changes from red to orange and just a precipitate precipitates. At this time, record the volume V NaOH of the sodium hydroxide standard solution consumed. Concentration calculation: The concentration W of the measured methylmagnesium chloride solution sample is calculated through the following formula: W = (C HCl × V HCl - C NaOH × V NaOH ) / 5, W represents the concentration of the measured sample, in mol / L; C HCl , in mol / L; V HCl , in mL; C NaOH , in mol / L; V NaOHThe unit is mL.

[0035] Example 1 The method for synthesizing methylsulfonyl fluoride from by - product sulfuryl chloride fluoride includes the following steps: (1) Adjust the temperature in the reaction vessel to - 15°C through the temperature control system. Weigh 200 g of by - product sulfuryl chloride fluoride with a purity of 98% accurately and add it to the reaction vessel. Turn on the stirrer, set the stirring speed to 250 r / min, and introduce nitrogen for replacement. The replacement time is 30 min.

[0036] (2) Control the dropping rate of 1.94 L of methylmagnesium chloride solution (the molar concentration of methylmagnesium chloride is detected to be 0.85 mol / L) through the constant - pressure funnel valve and drop it into the reaction vessel. Control the molar ratio of sulfuryl chloride fluoride to methylmagnesium chloride at 1:1. The dropping time is 0.5 h. After the dropping is completed, keep the reaction temperature and continue to stir and react for 2 h to obtain the reaction solution of methylsulfonyl fluoride.

[0037] (3) After the reaction is completed, slowly add water equal to the volume of the reaction solution to the reaction vessel for quenching under nitrogen protection.

[0038] (4) Let it stand for liquid - liquid separation, separate the aqueous phase, transfer the organic phase to a separatory funnel, add water for washing (the amount of water is 1 / 2 of the volume of the organic phase), shake for 5 min, then let it stand for layering, separate the lower aqueous phase and mix it with the previously separated aqueous phase; repeat the washing operation for the organic phase 2 times, collect all the separated aqueous phases; subject all the separated aqueous phases to crystallization and drying treatment to obtain magnesium chloride (hexahydrate).

[0039] (5) Transfer the organic phase to a dry flask, add anhydrous sodium sulfate (the amount of anhydrous sodium sulfate is 5% of the volume of the organic phase), turn on the stirrer, set the stirring speed to 180 r / min, stir for 0.5 h. After the stirring is completed, obtain the liquid containing methylsulfonyl fluoride through suction filtration.

[0040] (6) Transfer the liquid containing methylsulfonyl fluoride to a distillation device for distillation. During the process, closely observe the change of the liquid in the distillation flask until no more distillate is distilled out, and recover the solvent to obtain crude methylsulfonyl fluoride.

[0041] (7) Transfer the crude methylsulfonyl fluoride to a rectification column, control the vacuum degree of the rectification column at - 0.08 to - 0.1 MPa, the bottom temperature of the column at 55 - 65°C, collect the distillate, obtain 144 g of methylsulfonyl fluoride product, detect its purity to be 99.2%, and calculate its yield to be 88.7%.

[0042] Example 2 The method for synthesizing methylsulfonyl fluoride from by - product sulfuryl chloride fluoride includes the following steps: (1) Adjust the temperature in the reaction vessel to 5 °C through the temperature control system. Weigh 200 g of by-product sulfuryl chloride fluoride with a purity of 98% accurately and add it to the reaction vessel. Start the stirrer, set the stirring speed to 200 r / min, and introduce nitrogen for replacement. The replacement time is 30 min.

[0043] (2) Control the dropping rate of 2.10 L of methylmagnesium chloride solution (the molar concentration of methylmagnesium chloride is detected to be 0.83 mol / L) through the valve of the constant-pressure funnel, control the molar ratio of sulfuryl chloride fluoride to methylmagnesium chloride at 1:1.1, the dropping time is 2 h, and the dropping speed should be such that the temperature of the reaction system does not fluctuate violently. After the dropping is completed, keep the reaction temperature and continue to stir and react for 5 h to obtain a reaction solution containing methylsulfonyl fluoride.

[0044] (3) After the reaction is completed, slowly add water equal to the volume of the reaction solution to the reaction vessel for quenching under nitrogen protection.

[0045] (4) Let it stand for liquid separation, separate the aqueous phase, transfer the organic phase to a separating funnel, add water for washing (the amount of water used is 1 time the volume of the organic phase), shake for 5 min, then let it stand for layering, separate the lower aqueous phase and mix it with the previously separated aqueous phase; repeat the washing operation for the organic phase 3 times, collect all the separated aqueous phases; subject all the separated aqueous phases to crystallization and drying treatment to obtain magnesium chloride (hexahydrate).

[0046] (5) Transfer the organic phase to a dry flask, add anhydrous sodium sulfate (the amount of anhydrous sodium sulfate used is 10% of the volume of the organic phase), start the stirrer, set the stirring speed to 150 r / min, stir for 1 h, and after the stirring is completed, obtain a liquid containing methylsulfonyl fluoride through suction filtration.

[0047] (6) Transfer the liquid containing methylsulfonyl fluoride to a distillation device for distillation. During the process, closely observe the changes in the liquid in the distillation flask until no more distillate distills out, and recover the solvent to obtain crude methylsulfonyl fluoride.

[0048] (7) Transfer the crude methylsulfonyl fluoride to a rectification column, control the vacuum degree of the rectification column at -0.08 to -0.1 MPa, the temperature at the bottom of the column at 55 - 65 °C, collect the distillate, obtain 146 g of methylsulfonyl fluoride product, detect its purity to be 99.3%, and calculate its yield to be 90.0%.

[0049] Example 3 The method for synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride fluoride includes the following steps: (1) Adjust the temperature in the reaction vessel to -5°C through the temperature control system. Weigh accurately the by-product sulfuryl chloride fluoride with a purity of 98% and add it to the reaction vessel. Start the stirrer, set the stirring speed to 200 r / min, and introduce nitrogen for replacement. The replacement time is 60 min.

[0050] (2) Control the dropping rate of 1.95 L of methylmagnesium chloride solution (the molar concentration of methylmagnesium chloride is detected to be 0.86 mol / L) through the valve of the constant pressure funnel, control the molar ratio of sulfuryl chloride fluoride to methylmagnesium chloride at 1:1.02, the dropping time is 1 h, and the dropping speed should be such that the temperature of the reaction system does not fluctuate violently. After the dropping is completed, maintain the reaction temperature and continue to stir and react for 3 h to obtain the reaction solution of methylsulfonyl fluoride.

[0051] (3) After the reaction is completed, slowly add water equal to the volume of the reaction solution to the reaction vessel for quenching under nitrogen protection.

[0052] (4) Let it stand for liquid separation, separate the aqueous phase, transfer the organic phase to a separatory funnel, add water for washing (the amount of water used is 1 times the volume of the organic phase), shake for 10 min, then let it stand for layering, separate the lower aqueous phase and mix it with the previously separated aqueous phase; repeat the washing operation for the organic phase 3 times, collect all the separated aqueous phases; subject all the separated aqueous phases to crystallization and drying treatment to obtain magnesium chloride (hexahydrate).

[0053] (5) Transfer the organic phase to a dry flask, add anhydrous sodium sulfate (the amount of anhydrous sodium sulfate used is 8% of the volume of the organic phase), start the stirrer, set the stirring speed to 200 r / min, stir for 1 h, and after the stirring is completed, obtain the liquid containing methylsulfonyl fluoride through suction filtration.

[0054] (6) Transfer the liquid containing methylsulfonyl fluoride to a distillation device for distillation. During the process, closely observe the changes in the liquid in the distillation flask until no more distillate is distilled out, and recover the solvent to obtain the crude methylsulfonyl fluoride.

[0055] (7) Transfer the crude methylsulfonyl fluoride to a rectification column, control the vacuum degree of the rectification column at -0.08 to -0.1 MPa, the temperature of the column kettle at 55 - 65°C, collect the distillate, obtain 149 g of methylsulfonyl fluoride product, detect its purity to be 99.6%, and calculate its yield to be 91.8%.

[0056] Example 4 The method for synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride fluoride includes the following steps: (1)Adjust the temperature in the reaction vessel to 0 °C through the temperature control system. Weigh 200 g of by-product sulfuryl chloride fluoride with a purity of 98% accurately and add it to the reaction vessel. Start the stirrer, set the stirring speed to 300 r / min, and introduce nitrogen for replacement. The replacement time is 30 min.

[0057] (2)Control the dropping rate of 2.04 L of methylmagnesium chloride solution (the molar concentration of methylmagnesium chloride is detected to be 0.85 mol / L) through the constant pressure funnel valve, control the molar ratio of sulfuryl chloride fluoride to methylmagnesium chloride at 1:1.05, and the dropping time is 1.5 h. The dropping speed should be such that the temperature of the reaction system does not fluctuate violently. After the dropping is completed, keep the reaction temperature and continue to stir and react for 4 h to obtain the reaction solution of methylsulfonyl fluoride.

[0058] (3)After the reaction is completed, slowly add water equal to the volume of the reaction solution to the reaction vessel for quenching under nitrogen protection.

[0059] (4)Let it stand for liquid separation, separate the aqueous phase, transfer the organic phase to a separating funnel, add water for washing (the amount of water used is 1 time the volume of the organic phase), shake for 10 min, then let it stand for layering, separate the lower aqueous phase and mix it with the previously separated aqueous phase; repeat the washing operation on the organic phase 3 times, collect all the separated aqueous phases; subject all the separated aqueous phases to crystallization and drying treatment to obtain magnesium chloride (hexahydrate).

[0060] (5)Transfer the organic phase to a dry flask, add anhydrous sodium sulfate (the amount of anhydrous sodium sulfate used is 8% of the volume of the organic phase), start the stirrer, set the stirring speed to 200 r / min, stir for 0.5 h, and after the stirring is completed, obtain the liquid containing methylsulfonyl fluoride through suction filtration.

[0061] (6)Transfer the liquid containing methylsulfonyl fluoride to a distillation device for distillation. During the process, closely observe the change of the liquid in the distillation flask until no more distillate is distilled out, and recover the solvent to obtain crude methylsulfonyl fluoride.

[0062] (7)Transfer the crude methylsulfonyl fluoride to a rectification column, control the vacuum degree of the rectification column at -0.08 to -0.1 MPa, and the temperature of the tower kettle at 55 - 65 °C, collect the distillate, obtain 151 g of methylsulfonyl fluoride product, detect its purity to be 99.8%, as Figure 1 shown, calculate its yield to be 93.1%.

[0063] Comparative Example 1 The method for synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride fluoride described above includes the following steps: (1)Accurately weigh 200 g of by - product sulfuryl chloride fluoride with a purity of 98% and add it to the reaction vessel. Start the stirrer, set the stirring speed to 300 r / min, and introduce nitrogen for replacement. The replacement time is 30 min. The temperature control system adjusts the temperature in the reaction vessel to 30 °C (the initial dropping temperature is 7 °C, and the temperature rises after dropping methylmagnesium chloride and is finally controlled at 30 °C).

[0064] (2)Control the dropping rate of 2.04 L of methylmagnesium chloride solution (the molar concentration of methylmagnesium chloride is detected to be 0.85 mol / L) through the constant - pressure funnel valve, control the molar ratio of sulfuryl chloride fluoride to methylmagnesium chloride at 1:1.05, and control the dropping time within 1.5 h. After the dropping is completed, keep the reaction temperature at 30 °C and continue stirring for 4 h to obtain the reaction solution of methylsulfonyl fluoride.

[0065] (3)After the reaction is completed, slowly add water equal in volume to the reaction solution to quench it under nitrogen protection.

[0066] (4)Let it stand for liquid - liquid separation, separate the aqueous phase, transfer the organic phase to a separating funnel, add water for washing (the amount of water is 1 time the volume of the organic phase), shake for 10 min, then let it stand for layering, separate the lower aqueous phase and mix it with the previously separated aqueous phase; repeat the washing operation for the organic phase 3 times, collect all the separated aqueous phases; subject all the separated aqueous phases to crystallization and drying to obtain magnesium chloride (hexahydrate).

[0067] (5)Transfer the organic phase to a dry flask, add anhydrous sodium sulfate (the amount of anhydrous sodium sulfate is 8% of the volume of the organic phase), start the stirrer, set the stirring speed to 200 r / min, stir for 0.5 h, and after the stirring is completed, obtain the liquid containing methylsulfonyl fluoride through suction filtration.

[0068] (6)Transfer the liquid containing methylsulfonyl fluoride to a distillation device for distillation. During the process, closely observe the changes in the liquid in the distillation flask until no more distillate is distilled out, and recover the solvent to obtain crude methylsulfonyl fluoride.

[0069] (7)Transfer the crude methylsulfonyl fluoride to a rectification column, control the vacuum degree of the rectification column at - 0.08~ - 0.1 MPa, the temperature at the bottom of the column at 55 - 65 °C, collect the distillate, obtain 115 g of methylsulfonyl fluoride product, detect its purity to be 96%, and calculate its yield to be 70.9%.

[0070] Comparative Example 2 The method for synthesizing methylsulfonyl fluoride from by - product sulfuryl chloride fluoride includes the following steps: (1) Adjust the temperature in the reaction vessel to 0 °C through the temperature control system. Weigh 200 g of by-product sulfuryl chloride fluoride with a purity of 98% accurately and add it to the reaction vessel. Start the stirrer, set the stirring speed to 300 r / min, and introduce nitrogen for replacement. The replacement time is 30 min.

[0071] (2) Control the dropping rate of 2.04 L of methylmagnesium chloride solution (the molar concentration of methylmagnesium chloride is detected to be 0.85 mol / L) through the valve of the constant pressure funnel, control the molar ratio of sulfuryl chloride fluoride to methylmagnesium chloride at 1:1.5, the dropping time is 1.5 h, and the dropping speed should be such that the temperature of the reaction system does not fluctuate violently. After the dropping is completed, keep the reaction temperature and continue to stir and react for 4 h to obtain the reaction solution of methylsulfonyl fluoride.

[0072] (3) After the reaction is completed, slowly add water equal to the volume of the reaction solution to the reaction vessel for quenching under nitrogen protection.

[0073] (4) Let it stand for liquid separation, separate the aqueous phase, transfer the organic phase to a separating funnel, add water for washing (the amount of water used is 1 time the volume of the organic phase), shake for 10 min, then let it stand for layering, separate the lower aqueous phase and mix it with the previously separated aqueous phase; repeat the washing operation for the organic phase 3 times, collect all the separated aqueous phases; subject all the separated aqueous phases to crystallization and drying treatment to obtain magnesium chloride (hexahydrate).

[0074] (5) Transfer the organic phase to a dry flask, add anhydrous sodium sulfate (the amount of anhydrous sodium sulfate used is 8% of the volume of the organic phase), start the stirrer, set the stirring speed to 200 r / min, stir for 0.5 h, and after the stirring is completed, obtain the liquid containing methylsulfonyl fluoride through suction filtration.

[0075] (6) Transfer the liquid containing methylsulfonyl fluoride to a distillation device for distillation. During the process, closely observe the changes in the liquid in the distillation flask until no more distillate is distilled out, and recover the solvent to obtain crude methylsulfonyl fluoride.

[0076] (7) Transfer the crude methylsulfonyl fluoride to a rectification column, control the vacuum degree of the rectification column at -0.08~-0.1 MPa, the temperature at the bottom of the column at 55 - 65 °C, collect the distillate, obtain 98 g of methylsulfonyl fluoride product, detect its purity to be 95.0%, and calculate its yield to be 60.4%.

[0077] Comparative Example 3 The method for synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride fluoride includes the following steps: (1)Accurately weigh 200 g of by-product sulfuryl chloride fluoride with a purity of 98% and add it to the reaction vessel. Start the stirrer, set the stirring speed to 300 r / min, adjust the temperature in the reaction vessel to 0 °C through the temperature control system, and introduce nitrogen for replacement for 30 min.

[0078] (2)Control the dropping rate of 2.04 L of methylmagnesium chloride solution (the molar concentration of methylmagnesium chloride is detected to be 0.85 mol / L) through the valve of the constant pressure funnel, control the molar ratio of sulfuryl chloride fluoride to methylmagnesium chloride at 1:1.05, the dropping time is 1.5 h, and the dropping speed should be such that the temperature of the reaction system does not fluctuate violently. After the dropping is completed, keep the reaction temperature and continue to stir and react for 0.5 h to obtain the reaction solution of methylsulfonyl fluoride.

[0079] (3)After the reaction is completed, slowly add water equal to the volume of the reaction solution to the reaction vessel for quenching under nitrogen protection.

[0080] (4)Let it stand for liquid separation, separate the aqueous phase, transfer the organic phase to a separating funnel, add water for washing (the amount of water used is 1 time the volume of the organic phase), shake for 10 min, then let it stand for layering, separate the lower aqueous phase and mix it with the previously separated aqueous phase; repeat the washing operation on the organic phase 3 times, collect all the separated aqueous phases; subject all the separated aqueous phases to crystallization and drying treatment to obtain magnesium chloride (hexahydrate).

[0081] (5)Transfer the organic phase to a dry flask, add anhydrous sodium sulfate (the amount of anhydrous sodium sulfate used is 8% of the volume of the organic phase), start the stirrer, set the stirring speed to 200 r / min, stir for 0.5 h, and after the stirring is completed, obtain the liquid containing methylsulfonyl fluoride through suction filtration.

[0082] (6)Transfer the liquid containing methylsulfonyl fluoride to a distillation device for distillation. During the process, closely observe the change of the liquid in the distillation flask until no more distillate distills out, and recover the solvent to obtain crude methylsulfonyl fluoride.

[0083] (7)Transfer the crude methylsulfonyl fluoride to a rectification column, control the vacuum degree of the rectification column at -0.08 to -0.1 MPa, the temperature of the tower kettle at 55 - 65 °C, collect the distillate, obtain 80 g of methylsulfonyl fluoride product, detect its purity to be 92%, and calculate its yield to be 49.3%.

Claims

1. A method for synthesizing methylsulfonyl fluoride from by - product sulfuryl chloride fluoride, characterized in that, It includes the following steps: First, prepare a methylmagnesium chloride solution; then add by-product sulfuryl chloride fluoride into the reaction vessel, cool down to -15°C to 5°C, and under anhydrous and anaerobic conditions, stir and dropwise add the methylmagnesium chloride solution. The dropping time is 0.5 - 2 h. After the dropping is completed, keep the reaction at a constant temperature for 2 - 5 h to obtain a methylsulfonyl fluoride reaction solution; finally, quench the reaction solution with water, let it stand for liquid separation to obtain an aqueous phase and an organic phase. The aqueous phase is treated to obtain magnesium chloride, and the organic phase is refined to obtain methylsulfonyl fluoride; The molar ratio of sulfuryl chloride fluoride to methylmagnesium chloride is 1:1 - 1.

1.

2. The method for synthesizing methylsulfonyl fluoride from by - product thionyl chloride fluoride according to claim 1, wherein: The steps for preparing the methylmagnesium chloride solution are as follows: Under continuous protection of nitrogen, mix magnesium powder and tetrahydrofuran for reaction, introduce methyl chloride, heat to 50 - 60°C to initiate the reaction, adjust the temperature to maintain at 30 - 40°C for reaction for 3 - 5 h to obtain the methylmagnesium chloride solution.

3. The method for synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride fluoride according to claim 2, characterized in that: The nitrogen flow rate is 50 - 100 mL / min.

4. The method for synthesizing methylsulfonyl fluoride from by - product thionyl chloride fluoride according to claim 1, characterized in that: Stir and dropwise add the methylmagnesium chloride solution, and the stirring speed is 200 - 300 r / min.

5. The method for synthesizing methylsulfonyl fluoride from by - product thionyl chloride fluoride according to claim 1, characterized in that: The aqueous phase is subjected to crystallization and drying treatment to obtain magnesium chloride.

6. The method for synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride fluoride according to claim 5, characterized in that: The organic phase is washed with water for liquid separation, then anhydrous sodium sulfate is added for drying. The dried organic phase is distilled to remove the solvent, and then vacuum distillation is carried out at a vacuum degree of -0.08 to -0.1 MPa and a temperature of 55 - 65°C to obtain methylsulfonyl fluoride.

7. The method for synthesizing methylsulfonyl fluoride from by - product thionyl chloride fluoride according to claim 1, characterized in that: The purity of the by-product sulfuryl chloride fluoride is ≥98%.

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