The present invention relates to a method for preparing a perfluorodialkyl ether, comprising the steps of: (A) preparing a perfluorodialkyl ether from a compound represented by Formula 1 in the presence of a metal fluoride; and (B) isolating the perfluorodialkyl ether, and to an apparatus for preparing perfluorodialkyl ether, comprising: a reactor for preparing a perfluorodialkyl ether from a compound represented by Formula 1 in the presence of a metal fluoride; a reactant supplier for introducing the compound represented by Formula 1 into the reactor; and a discharge unit for discharging the perfluorodialkyl ether from the upper portion of the reactor.

The present invention relates to a method for preparing a perfluorodialkyl ether, comprising the steps of: (A) preparing a perfluorodialkyl ether from a compound represented by Formula 1 in the presence of a metal fluoride; and (B) isolating the perfluorodialkyl ether, and to an apparatus for preparing perfluorodialkyl ether, comprising: a reactor for preparing a perfluorodialkyl ether from a compound represented by Formula 1 in the presence of a metal fluoride; a reactant supplier for introducing the compound represented by Formula 1 into the reactor; and a discharge unit for discharging the perfluorodialkyl ether from the upper portion of the reactor.

A purification method of desflurane (difluoromethyl-1,2,2,2-tetrafluoroethyl ether of the formula (1)) includes bringing a mixture containing desflurane and a trihalomethane into contact with a base in the presence of a phase transfer catalyst, thereby decomposing the trihalomethane. By this method, only the trihalometane contained as a by-product in the desflurane is decomposed without causing decomposition of the desflurane, whereby the desflurane is obtained with high purity. ##STR00001##

A purification method of desflurane (difluoromethyl-1,2,2,2-tetrafluoroethyl ether of the formula (1)) includes bringing a mixture containing desflurane and a trihalomethane into contact with a base in the presence of a phase transfer catalyst, thereby decomposing the trihalomethane. By this method, only the trihalometane contained as a by-product in the desflurane is decomposed without causing decomposition of the desflurane, whereby the desflurane is obtained with high purity. ##STR00001##

A purification method of desflurane (difluoromethyl-1,2,2,2-tetrafluoroethyl ether of the formula (1)) includes bringing a mixture containing desflurane and a trihalomethane into contact with a base in the presence of a phase transfer catalyst, thereby decomposing the trihalomethane. By this method, only the trihalometane contained as a by-product in the desflurane is decomposed without causing decomposition of the desflurane, whereby the desflurane is obtained with high purity.

##STR00001##

A purification method of desflurane (difluoromethyl-1,2,2,2-tetrafluoroethyl ether of the formula (1)) includes bringing a mixture containing desflurane and a trihalomethane into contact with a base in the presence of a phase transfer catalyst, thereby decomposing the trihalomethane. By this method, only the trihalometane contained as a by-product in the desflurane is decomposed without causing decomposition of the desflurane, whereby the desflurane is obtained with high purity.

##STR00001##

Fluoral is obtained by gas-phase fluorination of chloral in the presence of a catalyst and then reacted with trimethyl orthoformate, thereby readily forming 1,2,2,2-tetrafluoroethyl methyl ether as an intermediate for production of desflurane. 1,2,2,2-Tetrafluoroethyl difluoromethyl ether (desflurane) is produced with high yield from the thus-formed 1,2,2,2-tetrafluoroethyl methyl ether by chlorination and fluorination. This method enables efficient industrial-scale production of desflurane useful as an inhalation anesthetic.

Fluoral is obtained by gas-phase fluorination of chloral in the presence of a catalyst and then reacted with trimethyl orthoformate, thereby readily forming 1,2,2,2-tetrafluoroethyl methyl ether as an intermediate for production of desflurane. 1,2,2,2-Tetrafluoroethyl difluoromethyl ether (desflurane) is produced with high yield from the thus-formed 1,2,2,2-tetrafluoroethyl methyl ether by chlorination and fluorination. This method enables efficient industrial-scale production of desflurane useful as an inhalation anesthetic.

There are provided a solvent composition containing tDCE, which does not exert an adverse effect on the global environment, has high solubility and incombustibility, and can maintain initial incombustibility even in use accompanied by a phase change, a cleaning method using the solvent composition, a coating film-forming composition including the solvent composition, and a method of forming a homogeneous coating film using the coating film-forming composition. A solvent composition includes: tDCE; at least one HFE (A) selected from HFE-347pc-f, HFE-365mf-c, and HFE-467sc-f; and at least one HFC (X) selected from cHFC-447, and HFC-76-13sf, in which a ratio of tDCE with respect to a total amount of tDCE, HFE (A), and HFC (X) is 65 to 80 mass %, a ratio of HFE (A) with respect to the total amount is 5 to 25 mass %, and a ratio of HFC (X) with respect to the total amount is 5 to 25 mass %.

The production of solvents for applications such as heat transfer, cleaning, and degreasing, for example. In particular, the production of solvents derived from 1-chloro-3,3,3-trifluoro-propene, such as chloro and/or fluoro substituted alkanes and chloro and/or fluoro substituted trifluoropropenyl ethers.