CN-121990882-A - Preparation method of nonafluoroisobutyl ether

CN121990882ACN 121990882 ACN121990882 ACN 121990882ACN-121990882-A

Abstract

The invention discloses a preparation method of nonafluoroisobutyl ether, which comprises the steps of S1, adding a polar aprotic solvent, crown ether, a fluorine-containing phase transfer catalyst, metal fluoride and an alkylating reagent into a reaction device, S2, adding perfluoro-isobutyryl fluoride into the reaction device at a speed of 1.5-2.5 g/min, wherein the temperature of the reaction device is-20-10 ℃, and S3, after ventilation is finished, raising the temperature of the reaction device to 20-50 ℃, and stopping the reaction after maintaining for 0.5-5 h. The invention adopts the perfluoro-isobutyryl fluoride and the metal fluoride to fully react at low temperature, then the temperature is raised, the intermediate product reacts with the alkylating reagent, the reaction condition is mild, the reaction time is short, and the reaction selectivity is improved.

Inventors

ZHANG GUANGYU
LI WEI
HE SHUANGCAI
XU SIYI
ZHANG YU
ZHAO JIABAO
NI HANG

Assignees

浙江蓝天环保高科技股份有限公司
中化蓝天集团有限公司

Dates

Publication Date: 20260508
Application Date: 20241105

Claims (10)

1. A preparation method of nonafluoroisobutyl ether is characterized by comprising the following steps: S1, adding a polar aprotic solvent, crown ether, a fluorine-containing phase transfer catalyst, metal fluoride and an alkylating reagent into a reaction device; S2, adding perfluoro-isobutyryl fluoride into a reaction device at a speed of 1.5-2.5 g/min, wherein the temperature of the reaction device is-20-10 ℃; and S3, after ventilation is finished, raising the temperature of the reaction device to 20-50 ℃, and stopping the reaction after maintaining for 0.5-5 h.
2. A process for preparing nonafluoroisobutyl ether according to claim 1, wherein the perfluoroisobutyryl fluoride is introduced into the reaction apparatus in a gaseous phase.
3. The method for preparing nonafluoroisobutyl ether according to claim 1 or 2, wherein S3, after the completion of aeration for 30 to 120 minutes, the temperature of the reaction device is raised to 20 to 50 ℃ and the reaction is stopped after the reaction is maintained for 0.5 to 5 hours.
4. The method for preparing nonafluoroisobutyl ether according to claim 1, wherein the alkylating agent is at least one selected from the group consisting of dimethyl sulfate, dimethyl carbonate, diethyl sulfate and diethyl carbonate.
5. A process for preparing nonafluoroisobutyl ether according to claim 1, wherein the crown ether is at least one member selected from the group consisting of benzo-15-crown-5, 18-crown-6, dibenzo-18-crown-6 and dicyclohexyl-18-crown-6.
6. The method for preparing nonafluoroisobutyl ether according to claim 1, wherein the fluorine-containing phase transfer catalyst is at least one selected from the group consisting of tetrabutylammonium fluoride, hexafluorobisphenol A, tetra-n-butyldihydroammonium trifluoride and tetramethylammonium fluoride.
7. The method for producing nonafluoroisobutyl ether according to claim 1, wherein the metal fluoride is at least one selected from the group consisting of potassium fluoride, cesium fluoride and sodium fluoride.
8. The method for preparing nonafluoroisobutyl ether according to claim 1, wherein the polar aprotic solvent is at least one selected from the group consisting of N, N-dimethylformamide, N-dimethylacetamide, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, ethylene glycol diethyl ether and acetonitrile.
9. The method for producing nonafluoroisobutyl ether according to claim 1, wherein the molar ratio of the perfluoro-isobutyryl fluoride to the metal fluoride is 1 (1-5), the molar ratio of the perfluoro-isobutyryl fluoride to the alkylating agent is 1 (0.9-3), and the molar/volume ratio of the perfluoro-isobutyryl fluoride to the polar aprotic solvent is 0.5-5 mol/L.
10. The method for producing a nonafluoroisobutyl ether according to claim 1, wherein the molar ratio of the metal fluoride to the crown ether is (10 to 15): 1, and the molar ratio of the perfluoro-isobutyryl fluoride to the fluorine-containing phase transfer catalyst is (80 to 120): 1.

Description

Preparation method of nonafluoroisobutyl ether Technical Field The invention relates to the field of chemical synthesis, in particular to a preparation method of nonafluoroisobutyl ether. Background The nonafluoroisobutyl ether is a kind of chemically inert hydrofluoroether compounds. In the compound, most hydrogen atoms are replaced by fluorine atoms, the electron cloud distribution of the whole molecule can be changed remarkably, and the dipole moment and intermolecular acting force of the molecule are changed, so that the compound has good insulating property and low surface tension. Because of the special properties, the compound is a cleaning agent which is widely applied at present in the wafer cleaning and drying process in the semiconductor preparation process, the lower surface tension of the compound is favorable for protecting the fine structure from being damaged after etching in the drying process, and the compound also has the characteristics of incombustibility and strong chemical stability, and has the advantage that other types of cleaning agents such as isopropanol can not be replaced. Meanwhile, chlorine-containing compounds such as CFC-113, HCFC-141b, HCFC-225 and the like commonly used in the electronic industry can cause the damage of an ozone layer and the greenhouse effect, and the use of the chlorine-containing compounds is forbidden or limited, and the hydrofluoroether compound serving as a substitute for the compounds has the characteristics of zero ozone layer damage coefficient, low global warming potential, short atmospheric life and almost no toxicity, is not listed as volatile organic compounds, meets the requirements of environmental protection regulations, and is also accepted by the United states environmental protection agency. At present, the reported synthesis method of the nonafluorobutyl ether is single, and mainly comprises an electrolytic fluorination synthesis process developed by the 3M company in the United states. For example, patent US8193397 employs an electrolytic fluorination process to prepare perfluoro-n/isobutyryl fluoride by electrolysis of n-butyryl chloride, followed by a methylation reaction of the two isomers with dimethyl sulfate to give the product, the reaction formula is as follows: the reaction inevitably generates two isomers of perfluoro-n-butyryl fluoride and perfluoro-isobutyryl fluoride, the ratio is about 60:40, simultaneously, a large amount of hydrogen fluoride is needed in the electrolytic fluorination process, the reaction risk is large, the process difficulty is high, the yield is only 35%, and the byproducts are various micromolecular perfluoroalkanes such as hexafluoroethane, octafluoropropane and the like, so that the atomic economy is poor. Meanwhile, as the boiling point of the perfluoro-isobutyryl fluoride is about 0 ℃ under the normal pressure, under the condition that the methyl ether reaction needs, two phases of gas and liquid exist in the system, and the contact between the two phases is poor, even though the perfluoro-butyryl fluoride has higher reactivity, the perfluoro-butyryl fluoride is difficult to generate an intermediate which is soluble in a liquid phase, so that the reaction time is prolonged, the yield is lower, the side reaction is increased, for example, documents 'Journ al Of Industrial AND ENGINEERING CHEMISTRY,2007,13 (4) and 537-544' report that the perfluoro-butyryl fluoride is directly reacted with potassium fluoride and dimethyl sulfate to prepare the nonafluoro-isobutyl ether, and the highest yield of the reaction is only 64% and the selectivity of the nonafluoro-isobutyl ether is only 85% due to the poor contact between the gas-liquid two phases of the reaction. Patent CN110002968a discloses a method for preparing nonafluoro isobutyl ether by reacting perfluorobutyryl fluoride with alkylating agents such as silver fluoride, dimethyl carbonate, etc., the highest yield of the method is 83%, but the reaction time of the method is 24 hours, and expensive silver fluoride is required to be used as a fluoride ion source, so that the method is difficult to carry out large-scale production. Disclosure of Invention In order to solve the problems of long reaction time and low product yield, the inventor of the invention finds that the liquid phase perfluoro isobutyryl fluoride fully reacts with the metal fluoride at low temperature, and then the liquid phase perfluoro isobutyryl fluoride is heated to react with the alkylating reagent, so that the time is short, and the yield is greatly improved. The technical scheme of the invention is as follows: the invention provides a preparation method of nonafluoroisobutyl ether, which comprises the following steps: S1, adding a polar aprotic solvent, crown ether, a fluorine-containing phase transfer catalyst, metal fluoride and an alkylating reagent into a reaction device; S2, adding perfluoro-isobutyryl fluoride into a reaction device at a speed of 1.5-2.5 g/min, wherein