Production process of trifluoromethylsulfonyl chloride

Abstract

The invention relates to the technical field of chemical synthesis, in particular to a production process of trifluoromethylsulfonyl chloride, which comprises the following steps: (1) adding a solvent and sodium trifluoromethanesulfinate into a stirring kettle, stirring to obtain a sodium trifluoromethanesulfinate solution, adding water, sodium hypochlorite and hydrochloric acid into another stirring kettle, and stirring to obtain a hypochlorous acid solution; (2) reacting the sodium trifluoromethanesulfinate solution with the hypochlorous acid solution in a micro-channel reactor to obtain a mixed solution; (3) settling the mixed solution in a settling tank, and pumping out 4 / 5 volume of supernatant liquid in the settling tank to a tower kettle of the rectifying tower; and (4) collecting the front fraction in the tower kettle of the rectifying tower, heating the tower kettle after the extraction is completed, starting to extract trifluoromethylsulfonyl chloride from the tower top, and completing the extraction of trifluoromethylsulfonyl chloride when the temperature of the tower top is reduced to 32 DEG C. According to the production process, raw materials are simple, a catalyst is not needed, energy is saved, consumption is reduced, and the obtained trifluoromethylsulfonyl chloride product is high in purity and yield.

Description

Technical Field

[0001] The invention relates to the technical field of chemical synthesis, and in particular to a production process of trifluoromethylsulfonyl chloride. Background Art

[0002] Trifluoromethanesulfonyl chloride (CAS No. 421-83-0) is volatile at room temperature and can be used to prepare important organic compounds such as trifluoromethanesulfonic acid, trifluoromethanesulfonate, and di(trifluoromethylsulfonyl)imide salts. It is also an indispensable basic raw material for the synthesis of many pesticides, pharmaceutical compounds, and organic catalysts. As an important fine chemical intermediate, trifluoromethanesulfonyl fluoride is in great demand both at home and abroad, and is becoming a hot product in the field of fine chemical intermediates.

[0003] The commonly used method for synthesizing trifluoromethylsulfonyl chloride at present is electrochemical fluorination, among which the most famous is Simons electrolytic fluorination process, which uses methylsulfonyl chloride as raw material and performs electrolytic fluorination in liquid anhydrous hydrogen fluoride to obtain trifluoromethylsulfonyl chloride. However, in the organic electrochemical fluorination process, there is a local operating current density of the electrode that is too large, resulting in the precipitation of fluorine gas at the anode, which is prone to safety accidents. At the same time, the electrochemical fluorination process is relatively complicated and the process is difficult to control. There is also a process in which sodium trifluoromethylsulfinate and chlorine react under an ice bath, and the reaction condition is to cool in an ice-water mixture, and the reaction temperature fluctuates greatly, and it is possible to partially decompose, resulting in the reaction process being possibly incomplete and the yield being low. And the above methods all use chlorine, which is a major source of danger, and has high storage and use requirements. Excess chlorine also needs to be subsequently recycled and processed, which increases the complexity of the process, and the industrialization investment is large, and there is a potential hazard to the health of the operator. Summary of the invention

[0004] Aiming at the problems of environmental pollution and low yield in the preparation process of trifluoromethylsulfonyl chloride, the present invention provides a production process of trifluoromethylsulfonyl chloride.

[0005] The technical solution of the present invention is as follows: A production process of trifluoromethylsulfonyl chloride comprises the following steps: (1) adding a solvent and sodium trifluoromethanesulfinate to a stirred tank and stirring to obtain a sodium trifluoromethanesulfinate solution, and adding water, sodium hypochlorite and hydrochloric acid to another stirred tank and stirring to obtain a hypochlorous acid solution; (2) reacting a sodium trifluoromethanesulfinate solution and a hypochlorous acid solution in a microchannel reactor to obtain a mixed solution; (3) The mixed solution is allowed to settle in a settling tank, and 4 / 5 of the volume of the upper liquid in the settling tank is pumped out to the bottom of the distillation tower; (4) The front fraction is collected in the bottom of the distillation tower. After the extraction is completed, the bottom of the tower is heated up and trifluoromethylsulfonyl chloride begins to be extracted from the top of the tower. When the top temperature drops to 32°C, the extraction of trifluoromethylsulfonyl chloride is completed.

[0006] Furthermore, in step (1), the solvent is water, methanol, ethanol or ethyl acetate.

[0007] Furthermore, in step (1), the mass ratio of the solvent to sodium trifluoromethanesulfinate is 4.2-6:1.

[0008] Furthermore, in step (1), the mass ratio of water: sodium hypochlorite and hydrochloric acid is 300-400: 11-16: 24-36.

[0009] Furthermore, in step (1), the mass ratio of sodium trifluoromethanesulfinate to sodium hypochlorite is 50-70:11-16.

[0010] Furthermore, in step (2), the reaction temperature is 40-45° C., the pressure is 0.5-0.7 MPa, and the retention time is 9-15 s.

[0011] Furthermore, the remaining liquid in the settling tank in step (3) is mixed with the next batch of reaction liquid.

[0012] Furthermore, after the front fraction is removed in step (4), the temperature of the bottom of the tower is raised to 40-45° C., the reflux ratio is controlled at 2-2.5, and trifluoromethylsulfonyl chloride begins to be removed from the top of the tower.

[0013] The beneficial effects of the present invention are: The invention provides a production process of trifluoromethylsulfonyl chloride, which is simple to operate, and the raw materials include only sodium hypochlorite, hydrochloric acid, sodium trifluoromethylsulfinate and water, and no catalyst is required, so as to save energy and reduce consumption. The obtained trifluoromethylsulfonyl chloride product has high purity and high yield, and the product purity is above 99%, and the yield is above 85%. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 This is the fluorine spectrum of trifluoromethanesulfonyl chloride of Example 1.

[0016] Figure 2 This is the carbon spectrum of trifluoromethylsulfonyl chloride of Example 1. DETAILED DESCRIPTION

[0017] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0018] Example 1 (1) Add 300 L of water and 50 kg of sodium trifluoromethanesulfinate to a 500 L stirred tank and stir for 30 minutes to obtain a sodium trifluoromethanesulfinate aqueous solution; add 300 L of water, 11 kg of sodium hypochlorite and 80 kg of 30% hydrochloric acid to another 500 L stirred tank and stir for 20 minutes to obtain a hypochlorous acid solution; (2) Controlling the temperature of the microchannel reactor to 40° C., respectively pumping in a sodium trifluoromethanesulfinate aqueous solution and a hypochlorous acid solution, reacting and mixing to obtain a mixed solution, wherein the flow rate of the sodium trifluoromethanesulfinate aqueous solution is 0.5 kg / min, and the flow rate of the hypochlorous acid solution is 0.55 kg / min, and the pressure is controlled at 0.5 MPa by adjusting the outlet valve, and the retention time is 15 s; (3) The mixed solution enters an enamel sedimentation tank and settles for 3 hours. Then 4 / 5 of the volume of the upper liquid in the sedimentation tank is pumped out to the bottom of the distillation tower. The remaining liquid in the sedimentation tank is mixed with the next batch of reaction liquid. (4) The temperature of the bottom of the tower was raised to 35°C, the reflux ratio was controlled at 1.5, and the front fraction was taken out from the top of the tower. When the temperature of the top of the tower was raised to 20°C, the front fraction was completely taken out. The temperature of the bottom of the tower was continued to be raised to 40°C, the reflux ratio was controlled at 2, and trifluoromethylsulfonyl chloride began to be taken out from the top of the tower. When the temperature of the top of the tower dropped to 32°C, the product trifluoromethylsulfonyl chloride was completely taken out. The product purity was 99.0% and the yield was 85%.

[0019] Depend on Figure 1 From the fluorine spectrum, we can see that the three fluorines on the trifluoromethyl group have the same chemical environment, and the same fluorine signal peak appears at -75.04. Figure 2 From the hydrogen spectrum, we can see that the carbon on the trifluoromethyl group is affected by three fluorine atoms and splits into (3+1) quartet peaks, which are 121.85, 119.69, 117.52 and 115.36 respectively. Figure 1 and Figure 2 Comprehensive analysis shows that the product obtained in Example 1 is trifluoromethylsulfonyl chloride.

[0020] Example 2 (1) Add 300 L of water and 70 kg of sodium trifluoromethanesulfinate to a 500 L stirred tank and stir for 30 minutes to obtain a sodium trifluoromethanesulfinate aqueous solution. Add 400 L of water, 16 kg of sodium hypochlorite and 120 kg of 30% hydrochloric acid to another 500 L stirred tank and stir for 20 minutes to obtain a hypochlorous acid solution. (2) The temperature of the microchannel reactor was controlled at 45°C, and a sodium trifluoromethanesulfinate aqueous solution and a hypochlorous acid solution were respectively pumped into the reactor by pumps, and the mixture was reacted to obtain a mixed solution. The flow rate of the sodium trifluoromethanesulfinate aqueous solution was 0.8 kg / min, and the flow rate of the hypochlorous acid solution was 0.93 kg / min. The pressure was controlled at 0.7 MPa by adjusting the outlet valve, and the retention time was 9.4 s. (3) The mixed solution enters an enamel sedimentation tank and settles for 4 hours. Then 4 / 5 of the volume of the upper liquid in the sedimentation tank is pumped out to the bottom of the distillation tower. The remaining liquid in the sedimentation tank is mixed with the next batch of reaction liquid. (4) The temperature of the bottom of the tower was raised to 35°C, the reflux ratio was controlled at 1.5, and the front fraction was taken out from the top of the tower. When the temperature of the top of the tower was raised to 20°C, the front fraction was completely taken out. The temperature of the bottom of the tower was continued to be raised to 45°C, the reflux ratio was controlled at 2.5, and trifluoromethylsulfonyl chloride began to be taken out from the top of the tower. When the temperature of the top of the tower dropped to 32°C, the trifluoromethylsulfonyl chloride was completely taken out. The product purity was 99.1% and the yield was 88%.

[0021] Although the present invention has been described in detail with reference to the accompanying drawings and in combination with the preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, a person of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and these modifications or substitutions shall be within the scope of the present invention. Any person of ordinary skill in the art may easily think of changes or substitutions within the technical scope disclosed by the present invention, and these shall be within the scope of protection of the present invention.

Claims

1. A production process of trifluoromethylsulfonyl chloride, characterized in that: The steps include: (1) adding a solvent and sodium trifluoromethanesulfinate to a stirred tank and stirring to obtain a sodium trifluoromethanesulfinate solution, and adding water, sodium hypochlorite and hydrochloric acid to another stirred tank and stirring to obtain a hypochlorous acid solution; (2) reacting a sodium trifluoromethanesulfinate solution and a hypochlorous acid solution in a microchannel reactor to obtain a mixed solution; (3) The mixed solution enters the settling tank for sedimentation, and 4 / 5 of the volume of the upper liquid in the settling tank is pumped out to the bottom of the distillation tower; (4) The front fraction is collected in the bottom of the distillation tower. After the extraction is completed, the bottom of the tower is heated up and trifluoromethylsulfonyl chloride begins to be extracted from the top of the tower. When the top temperature drops to 32°C, the extraction of trifluoromethylsulfonyl chloride is completed.

2. A production process for trifluoromethylsulfonyl chloride as claimed in claim 1, characterized in that: The solvent in step (1) is water, methanol, ethanol or ethyl acetate.

3. The production process of trifluoromethylsulfonyl chloride as claimed in claim 1, characterized in that: In step (1), the mass ratio of the solvent to sodium trifluoromethanesulfinate is 4.2-6:

1.

4. The production process of trifluoromethylsulfonyl chloride as claimed in claim 1, characterized in that: In step (1), the mass ratio of water: sodium hypochlorite and hydrochloric acid is 300-400: 11-16: 24-36.

5. The production process of trifluoromethylsulfonyl chloride as claimed in claim 1, characterized in that: In step (1), the mass ratio of sodium trifluoromethanesulfinate to sodium hypochlorite is 50-70:11-16.

6. The production process of trifluoromethylsulfonyl chloride according to claim 1, characterized in that: In step (2), the reaction temperature is 40-45° C., the pressure is 0.5-0.7 MPa, and the retention time is 9-15 s.

7. The production process of trifluoromethylsulfonyl chloride according to claim 1, characterized in that: The remaining liquid in the settling tank in step (3) is mixed with the next batch of reaction liquid.

8. The production process of trifluoromethylsulfonyl chloride as claimed in claim 1, characterized in that: After the front fraction is removed in step (4), the temperature of the bottom of the tower is raised to 40-45° C., the reflux ratio is controlled at 2-2.5, and trifluoromethylsulfonyl chloride begins to be removed from the top of the tower.

Images