Purification method and production method of difluoromethyl-1, 2, 2, 2-tetrafluoroethyl ether
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.
1. A purification method of difluoromethyl-1,2,2,2-tetrafluoroethyl ether, comprising: bringing a mixture containing difluoromethyl-1,2,2,2-tetrafluoroethyl ether of the formula (1) and a trihalomethane into contact with a base in the presence of water and a phase transfer catalyst, thereby decomposing the trihalomethane
2. The purification method of difluoromethyl-1,2,2,2-tetrafluoroethyl ether according to claim 1 , wherein the trihalomethane is chloroform.
3. The purification method of difluoromethyl-1,2,2,2-tetrafluoroethyl ether according to claim 1 , wherein the phase transfer catalyst is an ammonium salt phase transfer catalyst.
4. The purification method of difluoromethyl-1,2,2,2-tetrafluoroethyl ether according to claim 1 , wherein the phase transfer catalyst is used in an amount of 0.001 mass % to 30 mass % based on the total mass of the difluoromethyl-1,2,2,2-tetrafluoroethyl ether.
5. The purification method of difluoromethyl-1,2,2,2-tetrafluoroethyl ether according to claim 1 , wherein the base is an alkali metal hydroxide.
6. The purification method of difluoromethyl-1,2,2,2-tetrafluoroethyl ether according to claim 5 , wherein the alkali metal hydroxide is used in an amount of 0.001 mass % to 100 mass % based on the total mass of the difluoromethyl-1,2,2,2-tetrafluoroethyl ether.
7. The purification method of difluoromethyl-1,2,2,2-tetrafluoroethyl ether according to claim 1 , wherein the mixture is brought into contact with the base in the presence of the phase transfer catalyst at a temperature of 5° C. to 50° C.
8. A production method of difluoromethyl-1,2,2,2-tetrafluoroethyl ether comprising:
forming dichloromethyl-1,2,2,2-tetrafluoroethyl ether of the formula (3) by chlorination of methyl-1,2,2,2-tetrafluoroethyl ether of the formula (2) with chlorine; and
forming difluoromethyl-1,2,2,2-tetrafluoroethyl ether of the formula (1) by fluorination of the dichloromethyl-1,2,2,2-tetrafluoroethyl ether with anhydrous hydrogen fluoride
and further comprising purifying difluoromethyl-1,2,2,2-tetrafluoroethyl ether by the purification method according to claim 1 .