3-ethoxy-2,4-trifluoromethylperfluoropentane

Abstract

The application belongs to the field of fluorinated chemicals, and particularly relates to a synthesis method of 3-ethoxy-2,4-trifluoromethyl perfluoropentane, which specifically comprises the following steps: under the condition that a solvent and a phase transfer catalyst exist, a stable intermediate is formed by perfluorobutyryl fluoride and a carbonate in a dry reaction kettle, and an alkylation reaction is carried out with an alkylating agent R-C2H5 to obtain the product 3-ethoxy-2,4-trifluoromethyl perfluoropentane. In the method, a commercial alkali metal carbonate is used as a reactant, the yield can reach 85% by optimizing the synthesis conditions, the yield is greatly improved, the reaction speed is fast, the reaction time is short, the conversion can be completed within 24 hours, the raw material is more easily obtained and has high utilization, and the industrial production is more easily realized.

Description

Technical Field

[0001] This invention belongs to the field of fluorochemicals, specifically relating to a method for synthesizing 3-ethoxy-2,4-trifluoromethylperfluoropentane. Background Technology

[0002] 3-Ethoxy-2,4-trifluoromethylperfluoropentane is a non-flammable fluid with extremely low global warming potential (GWP = 100). Its excellent inertness and dielectric properties make it an ideal alternative to high-GWP fluids such as PFCs (perfluorocarbons) and PFPEs (perfluoropolyethers) in a variety of applications. 3-Ethoxy-2,4-trifluoromethylperfluoropentane engineering fluid can be used as a heat transfer fluid for cooling reactors in the pharmaceutical and chemical processing industries. In the semiconductor industry, it is ideal for automated test equipment (ATE) and wafer processing equipment requiring extremely low temperatures. Furthermore, 3-Ethoxy-2,4-trifluoromethylperfluoropentane can also be used as an automated cascade refrigerant.

[0003] The currently disclosed synthetic route for 3-ethoxy-2,4-trifluoromethylperfluoropentane is 3M's patent US20080139683A1 (corresponding Chinese patent CN101541723A). It uses 1,1,1,2,4,5,5,5-octafluoro-2,4-bis(trifluoromethyl)-3-pentanone as a starting material, reacting it with diethyl sulfate in the presence of an alkali metal and a phase-transfer catalyst to produce 3-ethoxy-2,4-trifluoromethylpentane. The drawbacks of this synthetic process are a reaction yield of only 6.1%, and a very long reaction cycle, requiring over 89 hours, resulting in very low production efficiency. Therefore, there is an urgent need to optimize this process to meet the requirements of industrial-scale production. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for synthesizing 3-ethoxy-2,4-trifluoromethylperfluoropentane.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for synthesizing 3-ethoxy-2,4-trifluoromethylperfluoropentane, using the following formula (I):

[0007] (I).

[0008] Specifically, the process includes the following steps: In the presence of a solvent and a phase transfer catalyst, perfluorobutyryl fluoride (molecular formula (CF3)2CFCOF, the same below) and carbonate form a stable intermediate in a dry reaction vessel, and then undergo an alkylation reaction with the alkylating agent R-C2H5 to obtain the product 3-ethoxy-2,4-trifluoromethylperfluoropentane.

[0009] The molar ratio of the perfluorobutyryl fluoride to the carbonate is 1:0.5~5; preferably 1:1; preferably, the carbonate is an alkali metal carbonate, more preferably one or more of cesium carbonate, sodium carbonate, and potassium carbonate.

[0010] The molar ratio of perfluorobutyryl fluoride to the phase transfer catalyst is 1:0.01~1, preferably 1:0.1; the phase transfer catalyst is selected from one or more combinations of tetrabutylammonium bromide, 12-crown ether-4, 15-crown ether-5, and 18-crown ether-6.

[0011] The molar ratio of perfluorobutyryl fluoride to the alkylating agent is 1:0.5~5, preferably, the molar ratio of perfluorobutyryl fluoride to the alkylating agent is 1:0.5~1; the alkylating agent is one or more of iodoethane, diethyl sulfate, and diethyl carbonate.

[0012] The solvent is selected from one or more combinations of ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and tetraethylene glycol dimethyl ether.

[0013] The synthesis method of 3-ethoxy-2,4-trifluoromethylperfluoropentane specifically includes the following steps: adding solvent, phase transfer catalyst, and alkaline carbonate to a dry reaction vessel, then adding perfluorobutyryl fluoride to the reaction vessel, maintaining the temperature of the reaction vessel at a certain temperature, and starting stirring; after 1-4 hours, adding alkylating agent to the reaction vessel to react and obtain the product.

[0014] The alkylation reaction temperature is -10℃ to 70℃, preferably 10℃ to 40℃; the alkylation reaction time is 1 to 24 hours, preferably 20 hours.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] The method for synthesizing 3-ethoxy-2,4-trifluoromethylperfluoropentane provided by this invention uses commercially available alkali metal carbonates as reactants. By optimizing the synthesis conditions, the yield can reach 85%, which is a significant improvement. Moreover, the reaction is fast and the reaction time is short, and the conversion can be completed within 24 hours. At the same time, the raw materials are more readily available and have a high utilization rate, making it easier to realize industrial production. Attached Figure Description

[0017] Figure 1 The chromatogram is for 3-ethoxy-2,4-trifluoromethylperfluoropentane;

[0018] Figure 2 This is the mass spectrum of 3-ethoxy-2,4-trifluoromethylperfluoropentane. Detailed Implementation

[0019] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and preferred embodiments.

[0020] Example 1: A method for synthesizing ethoxy-2,4-trifluoromethylperfluoropentane, comprising the following steps: Ethylene glycol dimethyl ether (180.0 g, 2 mol), tetrabutylammonium bromide (32.2 g, 0.1 mol), and sodium carbonate (106.0 g, 1 mol) were added to a dry reaction vessel. Perfluorobutyryl fluoride (216.0 g, 1 mol) was then added to the reaction vessel. The reaction vessel temperature was maintained at 20°C, and stirring was started. After 4 hours, iodoethane (156.0 g, 1 mol) was added to the reaction vessel. After 20 hours, the reaction was completed. The liquid phase was collected by filtration, allowed to stand for separation, and the lower liquid phase was collected. After distillation, 131.1 g of the target product, 3-ethoxy-2,4-trifluoromethylperfluoropentane, was obtained. Figure 1 , 2 The chromatograms and mass spectra are shown respectively, with a yield of approximately 63%.

[0021] Example 2: A method for synthesizing ethoxy-2,4-trifluoromethylperfluoropentane, comprising the following steps: adding tetraethylene glycol dimethyl ether (222.1 g, 1 mol), 15-crown ether-5 (22.0 g, 0.1 mol), and cesium carbonate (163.0 g, 0.5 mol) to a dry reaction vessel, followed by the addition of perfluorobutyryl fluoride (216.0 g, 1 mol). The reaction vessel temperature was maintained at 10°C, and stirring was started. After 4 hours, diethyl sulfate (77.0 g, 0.5 mol) was added to the reaction vessel. After 20 hours, the reaction was completed. The liquid phase was collected by filtration, allowed to stand for separation, and the lower liquid phase was collected. After distillation, 147.7 g of the target product 3-ethoxy-2,4-trifluoromethylperfluoropentane was obtained, with a yield of approximately 70%.

[0022] Example 3: A method for synthesizing ethoxy-2,4-trifluoromethylperfluoropentane, comprising the following steps: Diethylene glycol dimethyl ether (402.0 g, 3 mol), 18-crown ether-6 (26.4 g, 0.1 mol), and potassium carbonate (138.0 g, 1 mol) were added to a dry reaction vessel. Then, perfluorobutyryl fluoride (216.0 g, 1 mol) was added to the reaction vessel. The reaction vessel temperature was maintained at 40°C, and stirring was started. After 4 hours, diethyl carbonate (118.0 g, 1 mol) was added to the reaction vessel. After 20 hours, the reaction was completed. The liquid phase was collected by filtration, allowed to stand for separation, and the lower liquid phase was collected. After distillation, 166.6 g of the target product, 3-ethoxy-2,4-trifluoromethylperfluoropentane, was obtained, with a yield of approximately 80%.

[0023] Example 4: A method for synthesizing ethoxy-2,4-trifluoromethylperfluoropentane, comprising the following steps: Diethylene glycol dimethyl ether (402.0 g, 3 mol), 18-crown ether-6 (26.4 g, 0.1 mol), and potassium carbonate (138.0 g, 1 mol) were added to a dry reaction vessel. Then, perfluorobutyryl fluoride (216.0 g, 1 mol) was added to the reaction vessel. The reaction vessel temperature was maintained at 20°C, and stirring was started. After 4 hours, diethyl carbonate (118.0 g, 1 mol) was added to the reaction vessel. After 20 hours, the reaction was completed. The liquid phase was collected by filtration, allowed to stand for separation, and the lower liquid phase was collected. After distillation, 177.0 g of the target product, 3-ethoxy-2,4-trifluoromethylperfluoropentane, was obtained, with a yield of approximately 85%.

[0024] Example 5: A method for synthesizing ethoxy-2,4-trifluoromethylperfluoropentane, comprising the following steps: Diethylene glycol dimethyl ether (402.0 g, 3 mol), 18-crown ether-6 (26.4 g, 0.1 mol), potassium carbonate (138.0 g, 1 mol), perfluorobutyryl fluoride (216.0 g, 1 mol), and diethyl carbonate (118.0 g, 1 mol) are added in a single batch to a dry reaction vessel. The reaction vessel temperature is maintained at 40°C, and stirring is started. After 24 hours, the reaction is complete. The liquid phase is collected by filtration, allowed to stand for separation, and the lower liquid phase is collected. After distillation, 89.5 g of the target product, 3-ethoxy-2,4-trifluoromethylperfluoropentane, is obtained, with a yield of approximately 43%.

[0025] Comparative Example 1: (Patent US2008139683A1 / CN101541723A) Preparation of ethoxy-2,4-trifluoromethylperfluoropentane, specifically including the following steps: In a 2L flask, add 302g (0.83mol) of a mixture of 96.0% (CF3)2CFC(O)CF(CF3)2[1,1,1,2,4,5,5,5-octafluoro-2,4-bis(trifluoromethyl)-3-pentanone] and 4.0% CF3CF2CF2C(O)CF(CF3)2[1,1,1,2,4,4,5,5,6,6,6-undecano-2-trifluoromethyl-3-hexanone] of perfluoroheptanone, 300mL of anhydrous ethylene glycol dimethyl ether, 59.5g (1.02mol) potassium fluoride, and 11.1g of methyltrialkylammonium chloride (Adogen™). 464) phase transfer catalyst and 174 g (1.12 mol) diethyl sulfate were added, and the mixture was heated to 52 °C for 89 hours with stirring. At the end of 89 hours, the flask was cooled to room temperature, and 230 g of 45% potassium hydroxide solution and 95 g of water were added. The resulting mixture was subjected to azeotropic distillation using a Dean Stark separator, during which the lower fluorinated compound was separated. The fluorinated compound phase was washed twice with an equal volume of water and dried with magnesium sulfate. 53.0 g of product (CF3)2CFCF(OC2H5)CF(CF3)2 [ethoxy-2,4-trifluoromethylperfluoropentane] was given with a purity of 37.6% (yield 6.1%, structure confirmed by GC-MS).

[0026] The above comparison shows that the yield of the method for preparing ethoxy-2,4-trifluoromethylperfluoropentane provided in Comparative Example 1 is 6.1%; the yield of ethoxy-2,4-trifluoromethylperfluoropentane provided in Example 4 of this invention can reach 85%, a significant increase in yield. Furthermore, the reaction time in Comparative Example 1 is 89 hours, while the reaction time of this invention can be completed within 24 hours, demonstrating a faster reaction rate and shorter reaction time, making it suitable for industrial production. Additionally, the potassium fluoride raw material used in Comparative Example 1 is cheaper and more readily available than the potassium carbonate used in Example 4 of this invention, making it suitable for industrial production. Therefore, the method for preparing ethoxy-2,4-trifluoromethylperfluoropentane of this invention has a higher yield, faster reaction rate, and lower cost, meeting the needs of industrial production.

[0027] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for synthesizing 3-ethoxy-2,4-trifluoromethylperfluoropentane, characterized in that, The preparation is carried out using the following formula (I): （I）； Specifically, the steps include the following: in the presence of a solvent and a phase transfer catalyst, perfluorobutyryl fluoride and carbonate form a stable intermediate in a dry reaction vessel, and then undergo an alkylation reaction with the alkylating agent R-C2H5 to obtain the product 3-ethoxy-2,4-trifluoromethylperfluoropentane. The phase transfer catalyst is selected from one or more combinations of tetrabutylammonium bromide, 12-crown ether-4, 15-crown ether-5, and 18-crown ether-6; The alkylating agent is selected from one or more combinations of iodoethane, diethyl sulfate, and diethyl carbonate; The solvent is selected from one or more combinations of ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and tetraethylene glycol dimethyl ether; The alkylation reaction temperature is -10℃ to 70℃.

2. The method for synthesizing 3-ethoxy-2,4-trifluoromethylperfluoropentane according to claim 1, characterized in that, The molar ratio of perfluorobutyryl fluoride to carbonate is 1:0.5~5.

3. The method for synthesizing 3-ethoxy-2,4-trifluoromethylperfluoropentane according to claim 1, characterized in that, The carbonate mentioned is an alkali metal carbonate.

4. The method for synthesizing 3-ethoxy-2,4-trifluoromethylperfluoropentane according to claim 1, characterized in that, The carbonate is one or more of cesium carbonate, sodium carbonate, and potassium carbonate.

5. The method for synthesizing 3-ethoxy-2,4-trifluoromethylperfluoropentane according to claim 1, characterized in that, The molar ratio of perfluorobutyryl fluoride to the phase transfer catalyst is 1:0.01~1.

6. The method for synthesizing 3-ethoxy-2,4-trifluoromethylperfluoropentane according to claim 1, characterized in that, The molar ratio of the perfluorobutyryl fluoride to the alkylating agent is 1:0.5~5.

7. The method for synthesizing 3-ethoxy-2,4-trifluoromethylperfluoropentane according to claim 1, characterized in that, Specifically, the steps include: adding solvent, phase transfer catalyst, and alkaline carbonate to a dry reaction vessel, then adding perfluorobutyryl fluoride to the reaction vessel, maintaining the temperature of the reaction vessel at a certain temperature, and starting stirring; after 1-4 hours, adding alkylating agent to the reaction vessel to react and obtain the product.

8. The method for synthesizing 3-ethoxy-2,4-trifluoromethylperfluoropentane according to claim 7, characterized in that, The alkylation reaction time is 1 to 24 hours.

Images