Abstract: 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 (H2) 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.

Abstract: A process of producing chlorofluoroacetones represented by a general formula where X represents independently chlorine atom or fluorine atom. The production process comprises fluorinating in a liquid phase pentachloroacetone by hydrogen fluoride in the presence of a catalyst comprising tin tetrahalide.

Abstract: A method for removing a perfluoroalkyl alcohol from a waste gas and recovering the perfluoroalkyl alcohol comprising the steps of bringing the waste gas into contact with an aqueous alkaline solution thereby to absorb the perfluoroalkyl alcohol into said solution and consequently obtain an aqueous alkaline solution containing an alkoxide of the perfluoroalkyl alcohol. Adding an acid to the aqueous alkaline solution containing the alkoxide of the perfluoroalkyl alcohol until the alkaline solution turns into an acidic solution with a pH value smaller than 5, thereby to turn said alkoxide into said perfluoroalkyl alcohol and subjecting the acidic solution to distillation to recover the perfluoroalkyl alcohol.

Abstract: 1,1,1,3,3,3-hexafluoropropane-2-ol is prepared easily and efficiently by gas-liquid reaction between hydrogen gas and a hexafluoroacetone hydrate such as trihydrate, which is liquid at room temperature, using a suitable catalyst such as active carbon-palladium catalyst. Preferably the gauge pressure of hydrogen gas is 2-10 kg/cm.sup.2, and the hydrogenolysis reaction temperature is 70.degree.-100.degree. C. The life of the catalyst can be prolonged by the addition of a small quantity of sodium hydroxide. The addition of a small quantity of aluminum hydroxide is effective in suppressing the formation of fluorine ions in the reaction liquid.

Abstract: Dehydrating decomposition of compound (I), i.e. gem-diol, hemi-acetal or hemi-ketal, by contact with sulfuric acid gives a carbonyl compound (II). ##STR1## Disclosed is a two-stage process in which the first stage is the contact of compound (I) with sulfuric acid at 90.degree.-140.degree. C. so as to partly decompose and dehydrate the compound (I), permitting the concentration of sulfuric acid to become lower than 93 wt. % but not lower than 65 wt. %, and the second stage is the contact of the product of the first-stage reaction with concentrated sulfuric acid at a temperature not higher than 60.degree. C., preventing the concentration of sulfuric acid from becoming lower than 93 wt %. For example, hexafluoroacetone is obtained from a hydrate thereof by this process using only a small amount of sulfuric acid.