Method for synthesizing methylsulfonyl fluoride with by-product sulfuryl chloride fluoride

Abstract

The present invention belongs to the technical field of organic synthesis, and in particular to a method for synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride. The method for synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride according to the present invention comprises the following steps: first preparing a methylmagnesium chloride solution; then adding sulfuryl chloride to a reaction vessel, cooling to -15°C~5°C, and adding the methylmagnesium chloride solution dropwise with stirring under anaerobic conditions, and dropping and finishing the insulation reaction to obtain a methylsulfonyl fluoride reaction solution; finally, quenching the reaction solution with water, standing and separating the liquid to obtain an aqueous phase and an organic phase, treating the aqueous phase to obtain magnesium chloride (hexahydrate), and refining the organic phase to obtain methylsulfonyl fluoride. The method for synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride provided by the present invention solves the problem of processing by-product sulfuryl chloride, has low raw material cost during the synthesis process, and has high purity and high yield of the obtained methylsulfonyl fluoride.

Description

Technical Field

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

[0002] Methylsulfonyl fluoride is a fine chemical product with important applications in organic synthesis, pharmaceuticals, and other fields. In organic synthesis, it is an important sulfonylating reagent used to introduce sulfonyl groups into organic molecules. In drug development, it serves as an intermediate in the synthesis of some drug molecules. Through its sulfonylation, it can structurally modify drug molecules, thereby improving their physicochemical properties, biological activity, and pharmacokinetic characteristics. Methylsulfonyl fluoride can be used to modify polymer materials by incorporating it into polymer structures to alter their surface properties, hydrophilicity, and thermal stability. It is also used in the synthesis of some pesticides and plant growth regulators.

[0003] Currently, the preparation of methylsulfonyl fluoride primarily involves a fluorination reaction using methylsulfonyl chloride as a raw material in an aqueous potassium fluoride solution. Potassium fluoride, as a reactant, replaces the chlorine atoms in methylsulfonyl chloride with fluorine atoms, thereby producing methylsulfonyl fluoride. However, methylsulfonyl chloride and potassium fluoride are expensive, and the resulting methylsulfonyl fluoride has low purity and yield, resulting in significant waste generation.

[0004] Patent CN112661676A discloses a method for producing methylsulfonyl fluoride by fluorination of methylsulfonyl chloride with anhydrous hydrogen fluoride. Nickel fluoride, antimony pentafluoride, antimony trifluoride and potassium fluoride are mainly used as catalysts. Although the yield and purity are improved to a certain extent, the high prices of methylsulfonyl chloride and fluoride catalysts result in high production costs, and the "three wastes" problem is not 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 potassium fluoride solution is mixed with methylsulfonyl chloride to undergo a fluorination reaction, yielding methylsulfonyl fluoride as the product and potassium chloride as the byproduct. This method still uses methylsulfonyl chloride and potassium fluoride as raw materials, and fails to address the inherent process issues. Summary of the Invention

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

[0007] The method for synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride fluoride comprises the following steps: first, preparing a methylmagnesium chloride solution; then, adding the sulfuryl chloride fluoride into a reaction container, cooling the temperature to -15°C to 5°C, adding the methylmagnesium chloride solution dropwise with stirring under anhydrous and oxygen-free conditions, and performing a heat preservation reaction after the addition is terminated to obtain a methylsulfonyl fluoride reaction liquid; finally, quenching the reaction liquid with water, allowing it to stand for separation to obtain an aqueous phase and an organic phase, treating the aqueous phase to obtain magnesium chloride, and refining the organic phase to obtain methylsulfonyl fluoride.

[0008] The steps for preparing the methylmagnesium chloride solution are as follows: Under a continuous nitrogen atmosphere (controlled at a flow rate of 50-100 mL / min), magnesium is crushed. Fine magnesium particles or shavings with a particle size between 0.1 and 0.5 mm are selected, accurately weighed, and quickly transferred to reaction vessel 1. One liter of dry tetrahydrofuran solvent is added per mole of magnesium. The reaction vessel is sealed, and monochloromethane with a purity of at least 99.5% is slowly introduced through a gas inlet. Simultaneously, the heating device is turned on to gradually raise the temperature of the reaction system to 50-60°C. During this stage, the temperature and pressure in the reaction vessel must be closely monitored. A rapid temperature rise and a slight increase in pressure indicate that the reaction has been successfully initiated. Subsequently, the heating device and cooling system are adjusted to maintain the reaction temperature at 30-40°C to ensure a smooth exothermic reaction. The reaction is continued for 3-5 hours. After completion, the reaction system is cooled to room temperature to obtain the methylmagnesium chloride solution.

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

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

[0011] Methyl magnesium chloride solution was added dropwise with stirring at a speed of 200-300 r / min.

[0012] The methylmagnesium chloride solution is added dropwise for 0.5-2 hours, and the reaction is kept warm for 2-5 hours after the addition is completed.

[0013] The aqueous phase is crystallized and dried to obtain magnesium chloride.

[0014] The organic phase is washed with water and separated, and then dried by adding anhydrous sodium sulfate. The dried organic phase is distilled to remove the solvent, and then further subjected to reduced pressure distillation at a vacuum degree of -0.08 to -0.1 MPa and a temperature of 55-65°C to obtain methylsulfonyl fluoride.

[0015] When the reaction solution is quenched by adding water, the volume of water is the same as the volume of the reaction solution.

[0016] The by-product sulfuryl chloride fluoride has a purity of ≥98%. Sulfuryl chloride fluoride is a substance prohibited from transportation. Due to its low boiling point and high saturated vapor pressure, it has stringent storage conditions, generally requiring a temperature of ≤-20°C. For these reasons, the by-product sulfuryl chloride fluoride produced during the production process is generally converted into sulfuryl fluoride on-site or hydrolyzed with water to produce sulfuric acid and hydrofluoric acid. The present invention uses sulfuryl chloride fluoride and methyl magnesium chloride to react to produce a high-value-added methylsulfonyl fluoride product, which not only solves the above problems but also increases the added value of the product.

[0017] Specifically, the method for synthesizing methylsulfonyl fluoride from the by-product sulfuryl chloride fluoride comprises the following steps:

[0018] (1) The temperature in the reaction vessel is adjusted to -15°C-5°C by a temperature control system. Sulfuryl chloride fluoride is accurately measured and added to the reaction vessel. The stirrer is turned on and the stirring speed is set to 200-300 r / min to mix the sulfuryl chloride fluoride evenly. Nitrogen is introduced for displacement for no less than 30 minutes to exhaust the air in the reaction vessel and ensure that the reaction system is in an oxygen-free environment.

[0019] (2) Slowly add the methylmagnesium chloride solution dropwise to the reaction vessel, control the molar ratio of sulfuryl chloride to methylmagnesium chloride within the range of 1:1~1.1, control the addition time within 0.5-2h, and the addition speed is appropriate so that the temperature of the reaction system does not fluctuate violently. After the addition is completed, maintain the reaction temperature and continue stirring for 2-5h until the purity of methylsulfonyl fluoride no longer changes.

[0020] (3) After the reaction is completed, water equal to the volume of the reaction liquid is slowly added to the reaction vessel under nitrogen protection to quench the reaction in order to consume the unreacted methylmagnesium chloride reagent. The water addition process needs to be carried out slowly to prevent the generation of large amounts of heat and gas due to the violent reaction, which may lead to dangerous situations.

[0021] (4) Allow the mixture to stand for separation, separate the aqueous phase, transfer the organic phase to a separatory funnel, add water for washing (the amount of water is 1 / 2-1 of the volume of the organic phase), shake for 5-10 minutes, allow the mixture to stand for separation, separate the aqueous phase and mix it with the aqueous phase separated previously; repeat the washing operation for the organic phase 2-3 times, collect all the separated aqueous phases; all the separated aqueous phases are crystallized and dried to obtain magnesium chloride (hexahydrate).

[0022] (5) The organic phase is transferred to a dry flask, and anhydrous sodium sulfate is added (the amount of anhydrous sodium sulfate is 5-10% of the volume of the organic phase). The stirrer is turned on and the stirring speed is set to 150-200 r / min. The stirring is carried out for 0.5-1 h to allow the anhydrous sodium sulfate to fully contact with the organic phase to remove trace moisture in the organic phase. After the stirring is completed, the anhydrous sodium sulfate solid is removed by suction filtration to obtain a liquid containing methylsulfonyl fluoride.

[0023] (6) The dried organic phase is transferred to a distillation apparatus for distillation. During the process, the changes in the liquid in the distillation flask are closely observed until no more fraction is distilled out. The tetrahydrofuran solvent is recovered to obtain crude methylsulfonyl fluoride.

[0024] (7) The crude methylsulfonyl fluoride is transferred to a distillation tower, the vacuum degree of the distillation tower is controlled at -0.08~-0.1MPa, the bottom temperature of the tower is controlled at 55-65℃, and the distillate is collected to obtain a high-purity methylsulfonyl fluoride product.

[0025] The invention adopts by-product sulfuryl chloride fluoride as a starting raw material, and adds methyl magnesium chloride dropwise into the sulfuryl chloride fluoride at low temperature to generate methyl sulfonyl fluoride and magnesium chloride, which are then separated and purified to obtain methyl sulfonyl fluoride.

[0026] The reaction principle and reaction equation are as follows:

[0027] CH3Cl +Mg→CH3MgCl;

[0028] SO2ClF+CH3MgCl→CH3SO2F +MgCl2.

[0029] Since the sulfur atom in sulfuryl chloride (SO2ClF) is electrophilic, methylmagnesium chloride (CH3MgCl) acts as a strong nucleophile (source of methyl anions) to directly attack the sulfur atom, replacing the chlorine or fluorine atom (in sulfuryl chloride, both chlorine and fluorine atoms connected to the sulfur atom may be replaced, but the chlorine atom is more easily replaced by a methyl group due to its lower bond energy (the S-Cl bond energy is lower than the SF bond)) to produce methylsulfonyl fluoride (CH3SO2F). This reaction is a nucleophilic substitution reaction. Since methylmagnesium chloride (CH3MgCl) has strong alkalinity and high reactivity, it can proceed spontaneously without additional catalysts. During the reaction, the amount of sulfuryl chloride and reaction conditions are controlled to produce methylsulfonyl fluoride, preventing the generated methylsulfonyl fluoride from further reacting with the Grignard reagent to produce dimethyl sulfone and other side reactions.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] (1) The method for synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride fluoride of the present invention has high raw material utilization rate, few by-products and low cost.

[0032] (2) The method of synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride fluoride of the present invention has mild reaction conditions, normal pressure reaction, and is easy to control.

[0033] (3) The method of synthesizing methylsulfonyl fluoride from the by-product sulfuryl chloride fluoride of the present invention has high product purity, simple post-processing, and is suitable for industrialization. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is the gas chromatogram of methylsulfonyl fluoride prepared in Example 4. DETAILED DESCRIPTION

[0035] The present invention will be further described below with reference to specific embodiments.

[0036] The raw materials and additives used in the following examples and comparative examples are all commercially available products.

[0037] The byproduct used was sulfuryl chloride fluoride produced by the production of sulfuryl fluoride. When collecting the methylsulfonyl fluoride fraction, the temperature was set at 60°C, and the actual temperature fluctuated between 60±5°C. The vacuum was set at -0.09 MPa, and the actual temperature fluctuated between -0.09±0.01 MPa.

[0038] The methylmagnesium chloride solutions used below were prepared by the following steps: Under continuous nitrogen protection (flow rate controlled at 80 mL / min), magnesium was crushed, and fine magnesium particles or magnesium chips with a particle size between 0.1 and 0.5 mm were selected, accurately weighed, and quickly transferred to a reaction vessel. Dry tetrahydrofuran solvent was added at a rate of 1 L of tetrahydrofuran per mol of magnesium. The reaction vessel was sealed, and 99.5% pure methyl chloride was slowly introduced through a gas inlet device. At the same time, a heating device was turned on to gradually raise the temperature of the reaction system to 50°C. When the reaction was completed, the reaction was completed. 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 and react for 3 hours. After the reaction is completed, the reaction system is cooled to room temperature to obtain a methylmagnesium chloride solution. The molar concentration of methylmagnesium chloride is determined by titration indicator method. The determination method is as follows: take a conical flask, add distilled water, use a pipette to take 5mL of methylmagnesium chloride solution sample and slowly add it, shake it thoroughly, add 1 to 3 drops of methyl orange indicator until the solution turns yellow, and use hydrochloric acid standard solution (concentration C HCl ) until the solution changes from yellow to red and the precipitate is completely dissolved. At this time, record the volume of hydrochloric acid standard solution consumed (V) HCl Then use sodium hydroxide standard solution (concentration C NaOH ) Titrate until the solution changes from red to orange and a precipitate just forms. At this point, record the volume of sodium hydroxide standard solution consumed (V) NaOH Concentration calculation: The concentration W of the tested methyl magnesium chloride solution sample is calculated by the following formula: W = (C HCl ×V HCl -C NaOH ×V NaOH ) / 5,

[0039] W represents the concentration of the sample being tested in mol / L;

[0040] C HCl , unit is mol / L;

[0041] V HCl, unit is mL;

[0042] C NaOH , unit is mol / L;

[0043] V NaOH The unit is mL.

[0044] Example 1

[0045] The method for synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride fluoride comprises the following steps:

[0046] (1) The temperature in the reaction vessel was adjusted to -15°C by means of a temperature control system. 200 g of the by-product sulfuryl chloride fluoride with a purity of 98% was accurately weighed and added to the reaction vessel. The agitator was turned on and the stirring speed was set to 250 r / min. Nitrogen was introduced for displacement for 30 min.

[0047] (2) 1.94 L of methyl magnesium chloride solution (the molar concentration of methyl magnesium chloride was detected to be 0.85 mol / L) was added dropwise to the reaction vessel through a constant pressure funnel valve to control the dropping rate. The molar ratio of sulfuryl chloride to methyl magnesium chloride was controlled at 1:1. The dropping time was 0.5 h. After the addition was completed, the reaction temperature was maintained and the stirring reaction was continued for 2 h to obtain a reaction solution of methylsulfonyl fluoride.

[0048] (3) After the reaction is completed, water equal to the volume of the reaction solution is slowly added to the reaction vessel under nitrogen protection to quench the reaction.

[0049] (4) Allow the mixture to stand for 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 minutes, allow the mixture to stand for separation, separate the lower aqueous phase and mix it with the previously separated aqueous phase; repeat the washing operation for the organic phase twice, collect all the separated aqueous phases; all the separated aqueous phases are crystallized and dried to obtain magnesium chloride (hexahydrate).

[0050] (5) The organic phase was transferred to a dry flask, and anhydrous sodium sulfate was added (the amount of anhydrous sodium sulfate was 5% of the volume of the organic phase). The stirrer was turned on and the stirring speed was set to 180 r / min. The mixture was stirred for 0.5 h. After the stirring was completed, the mixture was filtered to obtain a liquid containing methylsulfonyl fluoride.

[0051] (6) The liquid containing methylsulfonyl fluoride is transferred to a distillation apparatus for distillation. During the process, the changes in the liquid in the distillation flask are closely observed until no more fraction is distilled out. The solvent is recovered to obtain crude methylsulfonyl fluoride.

[0052] (7) The crude methylsulfonyl fluoride was transferred to a distillation tower, the vacuum degree of the distillation tower was controlled at -0.08~-0.1MPa, the bottom temperature was controlled at 55-65℃, and the distillate was collected to obtain 144g of methylsulfonyl fluoride product. The purity was detected to be 99.2%, and the yield was calculated to be 88.7%.

[0053] Example 2

[0054] The method for synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride fluoride comprises the following steps:

[0055] (1) The temperature in the reaction vessel was adjusted to 5°C by a temperature control system. 200 g of 98% pure by-product sulfuryl chloride fluoride was accurately weighed and added to the reaction vessel. The stirrer was turned on and the stirring speed was set to 200 r / min. Nitrogen was introduced for displacement for 30 min.

[0056] (2) 2.10 L of methyl magnesium chloride solution (the molar concentration of methyl magnesium chloride was detected to be 0.83 mol / L) was added at a rate controlled by a constant pressure funnel valve. The molar ratio of sulfuryl chloride to methyl magnesium chloride was controlled at 1:1.1. The addition time was 2 h. The addition rate was appropriate so that the temperature of the reaction system did not fluctuate violently. After the addition was completed, the reaction temperature was maintained and the stirring reaction was continued for 5 h to obtain a reaction solution containing methylsulfonyl fluoride.

[0057] (3) After the reaction is completed, water equal to the volume of the reaction solution is slowly added to the reaction vessel under nitrogen protection to quench the reaction.

[0058] (4) Allow the mixture to stand for separation, separate the aqueous phase, transfer the organic phase to a separatory funnel, add water for washing (the amount of water is 1 times the volume of the organic phase), shake for 5 minutes, allow the mixture to stand for separation, 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; all the separated aqueous phases are crystallized and dried to obtain magnesium chloride (hexahydrate).

[0059] (5) The organic phase was transferred to a dry flask, and anhydrous sodium sulfate was added (the amount of anhydrous sodium sulfate was 10% of the volume of the organic phase). The stirrer was turned on and the stirring speed was set to 150 r / min. The mixture was stirred for 1 h. After the stirring was completed, the mixture was filtered to obtain a liquid containing methylsulfonyl fluoride.

[0060] (6) The liquid containing methylsulfonyl fluoride is transferred to a distillation apparatus for distillation. During the process, the changes in the liquid in the distillation flask are closely observed until no more fraction is distilled out. The solvent is recovered to obtain crude methylsulfonyl fluoride.

[0061] (7) The crude methylsulfonyl fluoride was transferred to a distillation tower, the vacuum degree of the distillation tower was controlled at -0.08~-0.1MPa, the bottom temperature was controlled at 55-65℃, and the distillate was collected to obtain 146g of methylsulfonyl fluoride product. The purity was detected to be 99.3%, and the yield was calculated to be 90.0%.

[0062] Example 3

[0063] The method for synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride fluoride comprises the following steps:

[0064] (1) The temperature in the reaction vessel was adjusted to -5°C by means of a temperature control system. The by-product sulfuryl chloride fluoride with a purity of 98% was accurately weighed and added to the reaction vessel. The agitator was turned on and the stirring speed was set to 200 r / min. Nitrogen was introduced for displacement for 60 min.

[0065] (2) 1.95 L of methyl magnesium chloride solution (the molar concentration of methyl magnesium chloride was detected to be 0.86 mol / L) was added at a rate controlled by a constant pressure funnel valve. The molar ratio of sulfuryl chloride to methyl magnesium chloride was controlled at 1:1.02. The addition time was 1 h. The addition rate was appropriate so that the temperature of the reaction system did not fluctuate violently. After the addition was completed, the reaction temperature was maintained and the stirring reaction was continued for 3 h to obtain a reaction solution of methylsulfonyl fluoride.

[0066] (3) After the reaction is completed, water equal to the volume of the reaction solution is slowly added to the reaction vessel under nitrogen protection to quench the reaction.

[0067] (4) Allow the mixture to stand for separation, separate the aqueous phase, transfer the organic phase to a separatory funnel, add water for washing (the amount of water is 1 times the volume of the organic phase), shake for 10 minutes, allow the mixture to stand for separation, 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; all the separated aqueous phases are crystallized and dried to obtain magnesium chloride (hexahydrate).

[0068] (5) The organic phase was transferred to a dry flask, and anhydrous sodium sulfate was added (the amount of anhydrous sodium sulfate was 8% of the volume of the organic phase). The stirrer was turned on and the stirring speed was set to 200 r / min. The mixture was stirred for 1 h. After the stirring was completed, the mixture was filtered to obtain a liquid containing methylsulfonyl fluoride.

[0069] (6) The liquid containing methylsulfonyl fluoride is transferred to a distillation apparatus for distillation. During the process, the changes in the liquid in the distillation flask are closely observed until no more fraction is distilled out. The solvent is recovered to obtain crude methylsulfonyl fluoride.

[0070] (7) The crude methylsulfonyl fluoride was transferred to a distillation tower, the vacuum degree of the distillation tower was controlled at -0.08~-0.1MPa, the bottom temperature was controlled at 55-65℃, and the distillate was collected to obtain 149g of methylsulfonyl fluoride product. The purity was detected to be 99.6%, and the yield was calculated to be 91.8%.

[0071] Example 4

[0072] The method for synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride fluoride comprises the following steps:

[0073] (1) The temperature in the reaction vessel was adjusted to 0°C by a temperature control system. 200 g of the by-product sulfuryl chloride fluoride with a purity of 98% was accurately weighed and added to the reaction vessel. The stirrer was turned on and the stirring speed was set to 300 r / min. Nitrogen was introduced for displacement for 30 min.

[0074] (2) 2.04 L of methyl magnesium chloride solution (the molar concentration of methyl magnesium chloride was detected to be 0.85 mol / L) was added at a dropping rate controlled by a constant pressure funnel valve. The molar ratio of sulfuryl chloride to methyl magnesium chloride was controlled at 1:1.05. The addition time was 1.5 h. The dropping rate was appropriate so that the temperature of the reaction system did not fluctuate violently. After the addition was completed, the reaction temperature was maintained and the stirring reaction was continued for 4 h to obtain a reaction solution of methylsulfonyl fluoride.

[0075] (3) After the reaction is completed, water equal to the volume of the reaction solution is slowly added to the reaction vessel under nitrogen protection to quench the reaction.

[0076] (4) Allow the mixture to stand for separation, separate the aqueous phase, transfer the organic phase to a separatory funnel, add water for washing (the amount of water is 1 times the volume of the organic phase), shake for 10 minutes, allow the mixture to stand for separation, 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; all the separated aqueous phases are crystallized and dried to obtain magnesium chloride (hexahydrate).

[0077] (5) The organic phase was transferred to a dry flask, and anhydrous sodium sulfate was added (the amount of anhydrous sodium sulfate was 8% of the volume of the organic phase). The stirrer was turned on and the stirring speed was set to 200 r / min. The mixture was stirred for 0.5 h. After the stirring was completed, the mixture was filtered to obtain a liquid containing methylsulfonyl fluoride.

[0078] (6) The liquid containing methylsulfonyl fluoride is transferred to a distillation apparatus for distillation. During the process, the changes in the liquid in the distillation flask are closely observed until no more fraction is distilled out. The solvent is recovered to obtain crude methylsulfonyl fluoride.

[0079] (7) The crude methylsulfonyl fluoride was transferred to a distillation tower, the vacuum of the distillation tower was controlled at -0.08~-0.1MPa, the bottom temperature was controlled at 55-65℃, and the distillate was collected to obtain 151g of methylsulfonyl fluoride product, and its purity was detected to be 99.8%. Figure 1 As shown, the yield was calculated to be 93.1%.

[0080] Comparative Example 1

[0081] The method for synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride fluoride comprises the following steps:

[0082] (1) Accurately weigh 200 g of the by-product sulfuryl chloride fluoride with a purity of 98% and add it to the reaction vessel. Turn on the stirrer and set the stirring speed to 300 r / min. Then introduce nitrogen for displacement. The displacement time is 30 min. The temperature control system adjusts the temperature in the reaction vessel to 30 °C (the temperature is initially at 7 °C. After the addition of methyl magnesium chloride, the temperature rises and is finally controlled at 30 °C).

[0083] (2) 2.04 L of methyl magnesium chloride solution (the molar concentration of methyl magnesium chloride was detected to be 0.85 mol / L) was added at a constant pressure funnel valve to control the dropping rate, and the molar ratio of sulfuryl chloride to methyl magnesium chloride was controlled at 1:1.05. The dropping time was controlled at 1.5 h. After the addition was completed, the reaction temperature was maintained at 30 ° C and the stirring reaction was continued for 4 h to obtain a reaction solution of methylsulfonyl fluoride.

[0084] (3) After the reaction is completed, water equal to the volume of the reaction solution is slowly added to the reaction vessel under nitrogen protection to quench the reaction.

[0085] (4) Allow the mixture to stand for separation, separate the aqueous phase, transfer the organic phase to a separatory funnel, add water for washing (the amount of water is 1 times the volume of the organic phase), shake for 10 minutes, allow the mixture to stand for separation, 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; all the separated aqueous phases are crystallized and dried to obtain magnesium chloride (hexahydrate).

[0086] (5) The organic phase was transferred to a dry flask, and anhydrous sodium sulfate was added (the amount of anhydrous sodium sulfate was 8% of the volume of the organic phase). The stirrer was turned on and the stirring speed was set to 200 r / min. The mixture was stirred for 0.5 h. After the stirring was completed, the mixture was filtered to obtain a liquid containing methylsulfonyl fluoride.

[0087] (6) The liquid containing methylsulfonyl fluoride is transferred to a distillation apparatus for distillation. During the process, the changes in the liquid in the distillation flask are closely observed until no more fraction is distilled out. The solvent is recovered to obtain crude methylsulfonyl fluoride.

[0088] (7) The crude methylsulfonyl fluoride was transferred to a distillation tower, the vacuum degree of the distillation tower was controlled at -0.08~-0.1MPa, the bottom temperature was controlled at 55-65℃, and the distillate was collected to obtain 115g of methylsulfonyl fluoride product. The purity was detected to be 96%, and the yield was calculated to be 70.9%.

[0089] Comparative Example 2

[0090] The method for synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride fluoride comprises the following steps:

[0091] (1) The temperature in the reaction vessel was adjusted to 0°C by a temperature control system. 200 g of the by-product sulfuryl chloride fluoride with a purity of 98% was accurately weighed and added to the reaction vessel. The stirrer was turned on and the stirring speed was set to 300 r / min. Nitrogen was introduced for displacement for 30 min.

[0092] (2) 2.04 L of methyl magnesium chloride solution (the molar concentration of methyl magnesium chloride was detected to be 0.85 mol / L) was added at a rate controlled by a constant pressure funnel valve. The molar ratio of sulfuryl chloride to methyl magnesium chloride was controlled at 1:1.5. The addition time was 1.5 h. The addition rate was appropriate so that the temperature of the reaction system did not fluctuate violently. After the addition was completed, the reaction temperature was maintained and the stirring reaction was continued for 4 h to obtain a reaction solution of methylsulfonyl fluoride.

[0093] (3) After the reaction is completed, water equal to the volume of the reaction solution is slowly added to the reaction vessel under nitrogen protection to quench the reaction.

[0094] (4) Allow the mixture to stand for separation, separate the aqueous phase, transfer the organic phase to a separatory funnel, add water for washing (the amount of water is 1 times the volume of the organic phase), shake for 10 minutes, allow the mixture to stand for separation, 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; all the separated aqueous phases are crystallized and dried to obtain magnesium chloride (hexahydrate).

[0095] (5) The organic phase was transferred to a dry flask, and anhydrous sodium sulfate was added (the amount of anhydrous sodium sulfate was 8% of the volume of the organic phase). The stirrer was turned on and the stirring speed was set to 200 r / min. The mixture was stirred for 0.5 h. After the stirring was completed, the mixture was filtered to obtain a liquid containing methylsulfonyl fluoride.

[0096] (6) The liquid containing methylsulfonyl fluoride is transferred to a distillation apparatus for distillation. During the process, the changes in the liquid in the distillation flask are closely observed until no more fraction is distilled out. The solvent is recovered to obtain crude methylsulfonyl fluoride.

[0097] (7) The crude methylsulfonyl fluoride was transferred to a distillation tower, the vacuum degree of the distillation tower was controlled at -0.08~-0.1MPa, the bottom temperature was controlled at 55-65℃, and the distillate was collected to obtain 98g of methylsulfonyl fluoride product. The purity was detected to be 95.0%, and the yield was calculated to be 60.4%.

[0098] Comparative Example 3

[0099] The method for synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride fluoride comprises the following steps:

[0100] (1) Accurately weigh 200 g of the by-product sulfuryl chloride fluoride with a purity of 98% and add it to the reaction vessel. Turn on the agitator and 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 displacement for 30 minutes.

[0101] (2) 2.04 L of methyl magnesium chloride solution (the molar concentration of methyl magnesium chloride was detected to be 0.85 mol / L) was added at a rate controlled by a constant pressure funnel valve, and the molar ratio of sulfuryl chloride to methyl magnesium chloride was controlled at 1:1.05. The addition time was 1.5 h. The addition rate was appropriate so that the temperature of the reaction system did not fluctuate violently. After the addition was completed, the reaction temperature was maintained and the stirring reaction was continued for 0.5 h to obtain a reaction solution of methylsulfonyl fluoride.

[0102] (3) After the reaction is completed, water equal to the volume of the reaction solution is slowly added to the reaction vessel under nitrogen protection to quench the reaction.

[0103] (4) Allow the mixture to stand for separation, separate the aqueous phase, transfer the organic phase to a separatory funnel, add water for washing (the amount of water is 1 times the volume of the organic phase), shake for 10 minutes, allow the mixture to stand for separation, 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; all the separated aqueous phases are crystallized and dried to obtain magnesium chloride (hexahydrate).

[0104] (5) The organic phase was transferred to a dry flask, and anhydrous sodium sulfate was added (the amount of anhydrous sodium sulfate was 8% of the volume of the organic phase). The stirrer was turned on and the stirring speed was set to 200 r / min. The mixture was stirred for 0.5 h. After the stirring was completed, the mixture was filtered to obtain a liquid containing methylsulfonyl fluoride.

[0105] (6) The liquid containing methylsulfonyl fluoride is transferred to a distillation apparatus for distillation. During the process, the changes in the liquid in the distillation flask are closely observed until no more fraction is distilled out. The solvent is recovered to obtain crude methylsulfonyl fluoride.

[0106] (7) The crude methylsulfonyl fluoride was transferred to a distillation tower, the vacuum degree of the distillation tower was controlled at -0.08~-0.1MPa, the bottom temperature was controlled at 55-65℃, and the distillate was collected to obtain 80g of methylsulfonyl fluoride product. The purity was detected to be 92%, and the yield was calculated to be 49.3%.

Claims

1. A method for synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride fluoride, characterized in that: The method comprises the following steps: first, preparing a methylmagnesium chloride solution; then, adding the by-product sulfuryl chloride fluoride into a reaction vessel, cooling the vessel to -15°C to 5°C, and dripping the methylmagnesium chloride solution under anhydrous and oxygen-free conditions with stirring for 0.5-2 hours. After the dripping is completed, the reaction is kept warm for 2-5 hours to obtain a methylsulfonyl fluoride reaction solution; finally, quenching the reaction solution with water, allowing the reaction solution to stand and separate to obtain an aqueous phase and an organic phase, treating the aqueous phase to obtain magnesium chloride, and refining the organic phase to obtain methylsulfonyl fluoride. The molar ratio of sulfuryl chloride fluoride to methyl magnesium chloride is 1:1-1.

1.

2. The method for synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride fluoride according to claim 1, wherein: The steps of preparing the methyl magnesium chloride solution are as follows: under continuous nitrogen protection, magnesium powder and tetrahydrofuran are mixed for reaction, monochloromethane is introduced, the mixture is heated to 50-60° C. to initiate the reaction, and the temperature is adjusted to maintain at 30-40° C. for reaction for 3-5 hours to obtain the methyl magnesium chloride solution.

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

4. The method for synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride fluoride according to claim 1, wherein: Methyl magnesium chloride solution was added dropwise with stirring at a speed of 200-300 r / min.

5. The method for synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride fluoride according to claim 1, wherein: The aqueous phase is crystallized and dried to obtain magnesium chloride.

6. The method for synthesizing methylsulfonyl fluoride from by-product sulfuryl chloride fluoride according to claim 5, wherein: The organic phase is washed with water and separated, and then dried by adding anhydrous sodium sulfate. The dried organic phase is distilled to remove the solvent, and then further subjected to reduced pressure distillation 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 methanesulfonyl fluoride from by-product sulfuryl chloride fluoride according to claim 1, wherein: The purity of the by-product sulfuryl chloride fluoride is ≥98%.

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