An object of the present invention is to remove a compound A from sevoflurane containing fluoromethyl-1,1,3,3,3-pentafluoroisopropenyl ether (compound A) so as to collect high-purity sevoflurane. The present invention concerns a method for producing sevoflurane containing substantially no compound A, comprising the following steps of: bringing a composition containing hydrogen fluoride (HF) and water at a mass ratio of 1:1 to 1:30 into contact with a 1st organic liquid containing sevoflurane and a compound A, thereby obtaining a 2nd organic liquid containing the compound A in an amount that is lower than that in the 1st organic liquid (step 1a); and distilling the 2nd organic liquid under the presence of a degradation inhibitor, thereby obtaining sevoflurane containing substantially no compound A as a main distillation fraction (step 2).

An object of the present invention is to remove a compound A from sevoflurane containing fluoromethyl-1,1,3,3,3-pentafluoroisopropenyl ether (compound A) so as to collect high-purity sevoflurane. The present invention concerns a method for producing sevoflurane containing substantially no compound A, comprising the following steps of: bringing a composition containing hydrogen fluoride (HF) and water at a mass ratio of 1:1 to 1:30 into contact with a 1st organic liquid containing sevoflurane and a compound A, thereby obtaining a 2nd organic liquid containing the compound A in an amount that is lower than that in the 1st organic liquid (step 1a); and distilling the 2nd organic liquid under the presence of a degradation inhibitor, thereby obtaining sevoflurane containing substantially no compound A as a main distillation fraction (step 2).

A method of purifying crude sevoflurane comprising (i) providing crude sevoflurane and an aqueous base to a first centrifugal separator, wherein the crude sevoflurane comprises sevoflurane and hexafluoroisopropanol; (ii) mixing the crude sevoflurane and the aqueous base in the first centrifugal separator; and (iii) separating the sevoflurane from the aqueous base in the first centrifugal separator, thereby purifying the crude sevoflurane.

A method of purifying crude sevoflurane comprising (i) providing crude sevoflurane and an aqueous base to a first centrifugal separator, wherein the crude sevoflurane comprises sevoflurane and hexafluoroisopropanol; (ii) mixing the crude sevoflurane and the aqueous base in the first centrifugal separator; and (iii) separating the sevoflurane from the aqueous base in the first centrifugal separator, thereby purifying the crude sevoflurane.

Provided herein are halogenated ether compounds of Formula (I), Formula (II), or Formula (III):

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Also provided are electrolytes comprising one or more compounds of Formula (I), Formula (II), or Formula (III) and electrochemical cells comprising electrolytes comprising one or more compounds of Formula (I), Formula (II), or Formula (III).

Described herein are three methods for making halogenated fluorinated ether-containing compounds using a fluorinated olefin or hexafluoropropylene oxide.

Described herein are three methods for making halogenated fluorinated ether-containing compounds using a fluorinated olefin or hexafluoropropylene oxide.

Disclosed is a method for producing a hexafluoroisopropanol, including the steps of (a) purifying a mixture containing hexafluoroacetone and at least 1,1,1-trifluoro-2,2-dichloroethane as an impurity, thereby obtaining a purified hexafluoroacetone containing 120 ppm or lower of the 1,1,1-trifluoro-2,2-dichloroethane; and (b) bringing hydrogen (H.sub.2) into contact with the purified hexafluoroacetone in the presence of a catalyst, thereby hydrogenating the hexafluoroacetone into the hexafluoroisopropanol. It is possible by this method to produce the hexafluoroisopropanol with a short reaction time and a high conversion. Therefore, it is possible to particularly advantageously produce fluoromethyl hexafluoroisopropyl ether (sevoflurane) by using the hexafluoroisopropanol produced by the method.

Disclosed is a method for producing a hexafluoroisopropanol, including the steps of (a) purifying a mixture containing hexafluoroacetone and at least 1,1,1-trifluoro-2,2-dichloroethane as an impurity, thereby obtaining a purified hexafluoroacetone containing 120 ppm or lower of the 1,1,1-trifluoro-2,2-dichloroethane; and (b) bringing hydrogen (H.sub.2) into contact with the purified hexafluoroacetone in the presence of a catalyst, thereby hydrogenating the hexafluoroacetone into the hexafluoroisopropanol. It is possible by this method to produce the hexafluoroisopropanol with a short reaction time and a high conversion. Therefore, it is possible to particularly advantageously produce fluoromethyl hexafluoroisopropyl ether (sevoflurane) by using the hexafluoroisopropanol produced by the method.

The present application provides an electrolyte solution for a sodium-ion battery, comprising a sodium salt of formula NaBO.sub.aF.sub.xR.sub.y.sup.z, a fluoroalkyl ether, and other ethers except for the fluoroalkyl ether, wherein a, x, y, and z are as defined in the specification. The electrolyte solution according to the present application has good stability, particularly oxidation resistance and good solvability of sodium ions, thus broadening an electrochemical window of a corresponding sodium-ion battery, enhancing coulombic efficiency, and improving cycling performance and safety performance. The present application further provides a secondary battery, a battery module, a battery pack, and an electrical apparatus using the electrolyte solution for a sodium-ion battery.