Preparation method of 3-ethoxy-2, 4-trifluoromethylpentane

Abstract

The invention discloses a preparation method of 3-ethoxy-2, 4-trifluoromethylpentane, and relates to the technical field of fluorine chemical industry, the preparation method comprises the following steps: in the presence of a special solvent, alkali metal fluoride and a phase transfer catalyst, carrying out alkylation reaction on 1, 1, 1, 2, 4, 5, 5, 5-octafluoro-2, 4-bis (trifluoromethyl)-3-pentanone and an alkylation reagent to obtain 3-ethoxy-2, 4-trifluoromethylpentane. The method comprises the following steps: reacting 3-ethoxy-2, 4-trifluoromethylpentane with a solvent to obtain 3-ethoxy-2, 4- According to the preparation method of the 3-ethoxy-2, 4-trifluoromethylpentane, provided by the invention, the commercial hydrofluoroether is adopted as a special solvent, the yield can reach 70%, the yield is greatly improved, the preparation method of the 3-ethoxy-2, 4-trifluoromethylpentane provided by the invention is high in reaction speed, short in reaction time, complete in conversion within 48 small tests, high in raw material utilization rate and suitable for industrial production, and the preparation method of the 3-ethoxy-2, 4-trifluoromethylpentane is suitable for industrial production. And industrial production can be realized more easily.

Description

Technical Field

[0001] The invention relates to the technical field of fluorine chemical industry, and in particular to a method for preparing 3-ethoxy-2,4-trifluoromethylpentane. Background Art

[0002] Electronic fluorinated liquid is a colorless and transparent liquid with moderate solubility and good material compatibility. It has an ozone depletion potential (ODP) of 0 and a low global warming potential (GWP). It is mainly composed of fluorides and has the characteristics of being non-conductive, non-flammable, non-toxic, and residue-free. It also has thermal and chemical stability. These characteristics make electronic fluorinated liquid very suitable for use in high-tech fields such as semiconductor wafer manufacturing, electronic reliability testing, and immersion cooling of data center servers. With the deepening of the replacement of CFCs (chlorofluorocarbons) and HCFCs (hydrochlorofluorocarbons), 3M has developed a hydrofluoroether product called Novec. TM HFE-7100 / 7200 / 7300 / 7500 (the chemical structures of HFE-7100, 7200, 7300, and 7500 are perfluoroisobutyl methyl ether, perfluoroisobutyl ethyl ether, perfluorohexyl methyl ether, and perfluoroheptyl ethyl ether, respectively) are designated as Acceptable (can be used without restrictions) as cleaning agents and refrigerants on the CFC Alternatives List (SNAP List) determined by the EPA (U.S. Environmental Protection Agency), providing an ideal solution for companies that promote green procurement.

[0003] HFE-7500 is a non-flammable fluid with very low global warming potential (GWP = 100). Its excellent inertness and dielectric properties make it an ideal replacement for high GWP fluids such as PFCs (perfluorocarbons) and PFPEs (perfluoropolyethers) in a variety of applications. HFE-7500 engineered fluid can be used as a heat transfer liquid for cooling reactors in the pharmaceutical and chemical processing industries. In the semiconductor industry, it is an ideal choice for automatic test equipment (ATE) and wafer handling equipment that require extremely low temperatures. In addition, HFE-7500 can also be used as an automatic cascade refrigerant.

[0004] The only publicly disclosed synthetic route for 3-ethoxy-2,4-trifluoromethylpentane HFE-7500 is 3M's patent US20080139683A1 (the corresponding Chinese patent is CN101541723A), which uses 1,1,1,2,4,5,5,5-octafluoro-2,4-bis(trifluoromethyl)-3-pentanone as raw material, and reacts with diethyl sulfate under the action of alkali metal and phase transfer catalyst to generate 3-ethoxy-2,4-trifluoromethylpentane. The defect of this synthetic process is that the reaction yield is only 6.1%. In addition, the reaction cycle is very long, requiring more than 89 hours, and the production efficiency is very low. Therefore, it is urgent to optimize this process to meet the requirements of industrial production. Summary of the invention

[0005] The object of the present invention is to provide a method for preparing 3-ethoxy-2,4-trifluoromethylpentane to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solution: a method for preparing 3-ethoxy-2,4-trifluoromethylpentane, the preparation method comprising: in the presence of a special solvent, an alkali metal fluoride and a phase transfer catalyst, 1,1,1,2,4,5,5,5-octafluoro-2,4-bis(trifluoromethyl)-3-pentanone and an alkylating agent undergo an alkylation reaction to obtain 3-ethoxy-2,4-trifluoromethylpentane.

[0007] Furthermore, the special solvent hydrofluoroether is selected from one or more combinations of 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether (HFE-347), 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (HFE-458), 1,1,2,2-tetrafluoroethyl ethyl ether, 1,1,2,3,3,3-pentafluoropropyl-2,2,2-trifluoroethyl ether, and 1H,1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether.

[0008] Furthermore, the alkali metal fluoride is selected from one or more combinations of sodium fluoride, lithium fluoride, potassium fluoride, cesium fluoride, silver fluoride and aluminum fluoride.

[0009] Furthermore, the alkylating agent is selected from one or more combinations of iodine, diethyl sulfate, diethyl carbonate, ethyl p-toluenesulfonate, and ethyl trifluoromethanesulfonate.

[0010] Furthermore, the phase transfer catalyst is selected from one or more combinations of tetrabutylammonium bromide, benzyltriethylammonium chloride, methyltrialkylammonium chloride, cyclodextrin, 15-crown-5, and 18-crown-6.

[0011] Furthermore, the molar ratio of the 1,1,1,2,4,5,5,5-octafluoro-2,4-bis(trifluoromethyl)-3-pentanone to the alkali metal fluoride is 1:1-6.

[0012] Furthermore, the molar ratio of the 1,1,1,2,4,5,5,5-octafluoro-2,4-bis(trifluoromethyl)-3-pentanone to the alkylating agent is 1:1-6.

[0013] Furthermore, the molar ratio of the 1,1,1,2,4,5,5,5-octafluoro-2,4-bis(trifluoromethyl)-3-pentanone to the phase transfer catalyst is 1:0.01-1.

[0014] Furthermore, the mass ratio of the 1,1,1,2,4,5,5,5-octafluoro-2,4-bis(trifluoromethyl)-3-pentanone to the solvent hydrofluoroether is 1:1-10.

[0015] Furthermore, the alkylation reaction temperature is -10°C to 120°C, and the alkylation reaction time is 1 to 60 hours.

[0016] The present invention provides a method for preparing 3-ethoxy-2,4-trifluoromethylpentane, which has the following beneficial effects: The preparation method of 3-ethoxy-2,4-trifluoromethylpentane provided by the present invention adopts commercial hydrofluoroether as a special solvent, and the yield can reach 70%, which greatly improves the yield; 2. The preparation method of 3-ethoxy-2,4-trifluoromethylpentane provided by the present invention has a fast reaction speed, a short reaction time, complete conversion within 48 hours of testing, a high raw material utilization rate, and is easier to realize industrial production. DETAILED DESCRIPTION

[0017] The above contents of the present invention are further described in detail below in conjunction with specific implementation plans. For technicians in this research field, this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples; all technologies implemented based on the above contents of the present invention belong to the scope of the present invention.

[0018] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods; the reagents, materials, instruments, etc. used in the following examples are all commercially available unless otherwise specified. Example

[0019] 1,1,1,2,4,5,5,5-octafluoro-2,4-bis(trifluoromethyl)-3-pentanone is subjected to an alkylation reaction with an alkylating agent to obtain 3-ethoxy-2,4-trifluoromethylpentane. The specific steps are as follows: 1,1,1,2,4,5,5,5-octafluoro-2,4-bis(trifluoromethyl)-3-pentanone (1098 g, 3.0 mmol) was added to the dry reactor, followed by 3294 g of 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, sodium fluoride (252 g, 6.0 mmol), methyltrialkylammonium chloride (121.2 g, 0.3 mmol), and dimethyl sulfate (1156.4 g, 7.5 mmol). After the addition, the reactor was closed and the temperature was raised to 90 °C. The reaction was completed in about 50 h. After the reaction was completed, 2 L of 40% potassium hydroxide solution was added for quenching. The mixture was allowed to stand for stratification, and the lower layer of liquid was collected. After washing with water and distillation, 583.7 g of pure 3-ethoxy-2,4-trifluoromethylpentane was obtained with a yield of 47%. Example

[0020] Add 1,1,1,2,4,5,5,5-octafluoro-2,4-bis(trifluoromethyl)-3-pentanone (1098g, 3.0 mmol) to the dry reactor, then add 2196 g of 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, lithium fluoride (156 g, 6.0 mmol), 18-crown ether-6 (52.9 g, 0.2 mmol), and iodoethane (1403.7 g, 9.0 mmol). After the addition, close the reactor and heat it to 80 °C. The reaction takes about 60 h to complete. After the reaction, add 2 L of 40% potassium hydroxide solution to quench, let stand and separate, collect the lower layer of liquid, wash with water, and distill to obtain 385 g of pure 3-ethoxy-2,4-trifluoromethylpentane with a yield of 31%. Example

[0021] Add 1,1,1,2,4,5,5,5-octafluoro-2,4-bis(trifluoromethyl)-3-pentanone (1098g, 3.0 mmol) to the dry reactor, then add 2196 g of 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, potassium fluoride (156 g, 4.5 mmol), 18-crown ether-6 (23.8 g, 0.09 mmol), and diethyl sulfate (693.8 g, 4.5 mmol). After the addition, close the reactor and heat it to 60 °C. The reaction takes about 48 h to complete. After the reaction is completed, add 2 L of 40% potassium hydroxide solution to quench, let stand and separate, collect the lower layer of liquid, wash with water, and distill to obtain 807.3 g of pure 3-ethoxy-2,4-trifluoromethylpentane with a yield of 65%. Example

[0022] Add 1,1,1,2,4,5,5,5-octafluoro-2,4-bis(trifluoromethyl)-3-pentanone (1098g, 3.0 mmol) to the dry reactor, then add 2745 g of 1,1,2,2-tetrafluoroethyl ethyl ether, cesium fluoride (683.6 g, 4.5 mmol), 15-crown ether-5 (26.4 g, 0.12 mmol), and ethyl trifluoromethanesulfonate (694.7 g, 3.9 mmol). After the addition, close the reactor and heat to 100 °C. The reaction takes about 30 h to complete. After the reaction is completed, add 2 L of 40% potassium hydroxide solution to quench, let stand and separate, collect the lower layer of liquid, wash with water, and distill to obtain 844.6 g of pure 3-ethoxy-2,4-trifluoromethylpentane with a yield of 68%. Example

[0023] Add 1,1,1,2,4,5,5,5-octafluoro-2,4-bis(trifluoromethyl)-3-pentanone (732g, 2.0 mmol) to the dry reactor, then add 2562 g of 1,1,2,3,3,3-pentafluoropropyl-2,2,2-trifluoroethyl ether, silver fluoride (304.5g, 2.4 mmol), benzyltriethylammonium chloride (34.2 g, 0.15 mmol), ethyl p-toluenesulfonate (600.8 g, 3.0mmol), close the reactor after the addition, and heat to 110 ℃. The reaction takes about 40 h to complete. After the reaction is completed, add 1 L of 40% potassium hydroxide solution to quench, let stand and separate, collect the lower layer of liquid, wash with water, and distill to obtain 505.1 g of pure 3-ethoxy-2,4-trifluoromethylpentane with a yield of 61%. Example

[0024] Add 1,1,1,2,4,5,5,5-octafluoro-2,4-bis(trifluoromethyl)-3-pentanone (1098g, 3.0 mmol) to the dry reactor, then add 4392 g of 1H,1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether, aluminum fluoride (756 g, 9.0 mmol), cyclodextrin (340.5 g, 0.3 mmol), diethyl carbonate (1063.1 g, 9.0 mmol), close the reactor after the addition, and heat to 120 ℃. The reaction takes about 60 h to complete. After the reaction, add 2 L of 40% potassium hydroxide solution to quench, let stand and separate, collect the lower layer of liquid, wash with water, and distill to obtain 310.5 g of pure 3-ethoxy-2,4-trifluoromethylpentane with a yield of 25%. Example

[0025] Add 1,1,1,2,4,5,5,5-octafluoro-2,4-bis(trifluoromethyl)-3-pentanone (1098g, 3.0 mmol) to the dry reactor, then add 2196 g of 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, potassium fluoride (348.6 g, 6.0 mmol), 18-crown ether-6 (39.6 g, 0.15 mmol), and iodoethane (702 g, 4.5 mmol). After the addition, close the reactor and heat it to 70 °C. The reaction takes about 38 h to complete. After the reaction is completed, add 2 L of 40% potassium hydroxide solution to quench, let stand and separate, collect the lower layer of liquid, wash with water, and distill to obtain 869.4 g of pure 3-ethoxy-2,4-trifluoromethylpentane with a yield of 70%.

[0026] Comparative Example 1 (Patent US2008139683A1 / CN101541723A) Preparation of (CF3)2CFCF(OC2H5)CF(CF3)2 In a 2 L flask, add 96.0% (CF3)2CFC(O)CF(CF3)2 and 4.0% CF3CF2CFC(O)CF(CF3)2 of a mixture of ketone 302 g (0.83 mol), 300 mL anhydrous glycol dimethyl ether, 59.5 g (1.02 mol) potassium fluoride, 11.1 g methyltrialkylammonium chloride (Adogen TM 464) phase transfer catalyst and 174 g (1.12 mol) diethyl sulfate, and heat to 52 ° C while stirring for 89 hours. At the end of 89 hours, the flask was cooled to room temperature and 230 g 45% potassium hydroxide solution and 95 g water were added. The resulting mixture was subjected to azeotropic distillation using a Dean Stark water separator, from which the lower fluorinated compound was isolated during distillation. The fluorinated compound phase was washed twice with an equal volume of water and dried over magnesium sulfate. 53.0 g of the product (CF3)2CFCF(OC2H5)CF(CF3)2 was obtained with a purity of 37.6% (yield 6.1%, structure confirmed by GCMS).

[0027] From the above comparison, it can be seen that the yield of the preparation method of 3-ethoxy-2,4-trifluoromethylpentane provided in Comparative Example 1 is 6.1%; the yield of preparing perfluoroisobutyl methyl ether by the method provided in Example 1 of the present invention can reach 70%, and the yield is greatly improved. In addition, the reaction time in Comparative Example 1 is 89 hours, and the reaction time of the present invention can be completed within 48 hours. Therefore, the preparation method of 3-ethoxy-2,4-trifluoromethylpentane of the present invention has a higher yield, high conversion rate, high raw material utilization rate, and can meet the needs of industrial production.

[0028] The above description is only a preferred specific implementation manner of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention should be included in the scope of protection of the invention.

Claims

1. A method for preparing 3-ethoxy-2,4-trifluoromethylpentane, characterized in that: The preparation method comprises the following steps: in the presence of a special solvent, an alkali metal fluoride and a phase transfer catalyst, 1,1,1,2,4,5,5,5-octafluoro-2,4-bis(trifluoromethyl)-3-pentanone and an alkylating agent are subjected to an alkylation reaction to obtain 3-ethoxy-2,4-trifluoromethylpentane.

2. The method for preparing 3-ethoxy-2,4-trifluoromethylpentane according to claim 1, characterized in that: The special solvent hydrofluoroether is selected from one or more combinations of 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether (HFE-347), 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (HFE-458), 1,1,2,2-tetrafluoroethyl ethyl ether, 1,1,2,3,3,3-pentafluoropropyl-2,2,2-trifluoroethyl ether, and 1H,1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether.

3. The method for preparing 3-ethoxy-2,4-trifluoromethylpentane according to claim 1, characterized in that: The alkali metal fluoride is selected from one or more combinations of sodium fluoride, lithium fluoride, potassium fluoride, cesium fluoride, silver fluoride and aluminum fluoride.

4. The method for preparing 3-ethoxy-2,4-trifluoromethylpentane according to claim 1, characterized in that: The alkylating agent is selected from one or more combinations of iodine, diethyl sulfate, diethyl carbonate, ethyl p-toluenesulfonate, and ethyl trifluoromethanesulfonate.

5. The method for preparing 3-ethoxy-2,4-trifluoromethylpentane according to claim 1, characterized in that: The phase transfer catalyst is selected from one or more combinations of tetrabutylammonium bromide, benzyltriethylammonium chloride, methyltrialkylammonium chloride, cyclodextrin, 15-crown-5, and 18-crown-6.

6. The method for preparing 3-ethoxy-2,4-trifluoromethylpentane according to claim 1, characterized in that: The molar ratio of the 1,1,1,2,4,5,5,5-octafluoro-2,4-bis(trifluoromethyl)-3-pentanone to the alkali metal fluoride is 1:1-6.

7. The method for preparing 3-ethoxy-2,4-trifluoromethylpentane according to claim 1, characterized in that: The molar ratio of the 1,1,1,2,4,5,5,5-octafluoro-2,4-bis(trifluoromethyl)-3-pentanone to the alkylating agent is 1:1-6.

8. The method for preparing 3-ethoxy-2,4-trifluoromethylpentane according to claim 1, characterized in that: The molar ratio of the 1,1,1,2,4,5,5,5-octafluoro-2,4-bis(trifluoromethyl)-3-pentanone to the phase transfer catalyst is 1:0.01-1.

9. The method for preparing 3-ethoxy-2,4-trifluoromethylpentane according to claim 1, characterized in that: The mass ratio of the 1,1,1,2,4,5,5,5-octafluoro-2,4-bis(trifluoromethyl)-3-pentanone to the solvent hydrofluoroether is 1:1-10.

10. The method for preparing 3-ethoxy-2,4-trifluoromethylpentane according to claim 9, characterized in that: The alkylation reaction temperature is -10°C to 120°C, and the alkylation reaction time is 1 to 60 hours.