Abstract: The present invention aims to provide a dry etching agent having less load on global environment and capable of anisotropic etching without the use of special equipment and obtaining a good processing shape and to provide a dry etching method using the dry etching agent. The dry etching agent according the present invention contains at least a hydrofluoroalkylene oxide represented by the following chemical formula: CF3—CxHyFzO (where x=2 or 3; y=1, 2, 3, 4 or 5; and z=2x?1?y) and having an oxygen-containing three-membered ring. The dry etching method according to the present invention includes selectively etching of at least one kind of silicon-based material selected from the group consisting of silicon dioxide, silicon nitride, polycrystalline silicon, amorphous silicon and silicon carbide with the use of a plasma gas generated by plasmatization of the dry etching agent.

Abstract: The present invention provides an industrially applicable method for production of a fluorine-containing cyclopropane carboxylic acid compound useful as an intermediate for pharmaceutical and agrichemical products. A fluorine-containing cyclopropane monoester is obtained by: forming a fluorine-containing cyclic sulfate with the use of a fluorine-containing diol compound and sulfuryl fluoride (as a cyclic sulfuric esterification step); reacting the fluorine-containing cyclic sulfate with a malonic diester, thereby forming a fluorine-containing cyclopropane diester (as a cyclopropanation step); and hydrolyzing the fluorine-containing cyclopropane diester (as a hydrolysis step).

Abstract: The present invention provides an industrially applicable method for production of a fluorine-containing cyclopropane carboxylic acid compound useful as an intermediate for pharmaceutical and agrichemical products. A fluorine-containing cyclopropane monoester is obtained by: forming a fluorine-containing cyclic sulfate with the use of a fluorine-containing diol compound and sulfuryl fluoride (as a cyclic sulfuric esterification step); reacting the fluorine-containing cyclic sulfate with a malonic diester, thereby forming a fluorine-containing cyclopropane diester (as a cyclopropanation step); and hydrolyzing the fluorine-containing cyclopropane diester (as a hydrolysis step).

Abstract: The present invention aims to provide a dry etching agent having less load on global environment and capable of anisotropic etching without the use of special equipment and obtaining a good processing shape and to provide a dry etching method using the dry etching agent. The dry etching agent according the present invention contains at least a hydrofluoroalkylene oxide represented by the following chemical formula: CF3—CxHyFzO (where x=2 or 3; y=1, 2, 3, 4 or 5; and z=2x?1?y) and having an oxygen-containing three-membered ring. The dry etching method according to the present invention includes selectively etching of at least one kind of silicon-based material selected from the group consisting of silicon dioxide, silicon nitride, polycrystalline silicon, amorphous silicon and silicon carbide with the use of a plasma gas generated by plasmatization of the dry etching agent.

Abstract: The present invention provides an industrially applicable method for production of a fluorine-containing cyclopropane carboxylic acid compound useful as an intermediate for pharmaceutical and agrichemical products. A fluorine-containing cyclopropane monoester is obtained by: forming a fluorine-containing cyclic sulfate with the use of a fluorine-containing dial compound and sulfuryl fluoride (as a cyclic sulfuric esterification step); reacting the fluorine-containing cyclic sulfate with a malonic diester, thereby forming a fluorine-containing cyclopropane diester (as a cyclopropanation step); and hydrolyzing the fluorine-containing cyclopropane diester (as a hydrolysis step).

Abstract: The present invention provides an industrially applicable method for production of a fluorine-containing cyclopropane carboxylic acid compound useful as an intermediate for pharmaceutical and agrichemical products. A fluorine-containing cyclopropane monoester is obtained by: forming a fluorine-containing cyclic sulfate with the use of a fluorine-containing dial compound and sulfuryl fluoride (as a cyclic sulfuric esterification step); reacting the fluorine-containing cyclic sulfate with a malonic diester, thereby forming a fluorine-containing cyclopropane diester (as a cyclopropanation step); and hydrolyzing the fluorine-containing cyclopropane diester (as a hydrolysis step).

Abstract: It is possible to produce a fluorine-containing ?-ketocarboxylic ester hydrate by reacting a fluorine-containing ?-hydroxycarboxylic ester with sodium hypochlorite or calcium hypochlorite of 21 mass % or greater in mass percentage of composition. Furthermore, it is possible to produce a fluorine-containing ?-ketocarboxylic ester by reacting the hydrate with a dehydrating agent. Furthermore, it is possible to produce a fluorine-containing ?-ketocarboxylic ester hemiketal by reacting the fluorine-containing ?-ketocarboxylic ester hydrate with a lower alcohol or a trialkyl orthocarboxylate. Moreover, it is possible to produce a fluorine-containing ?-ketocarboxylic ester by reacting the hemiketal with a dealcoholization agent.

Abstract: In a method for obtaining an alkali metal perfluoroalkanesulfinate by reacting a perfluoroalkanesulfonyl halide with a sulfur-containing reducing agent in the presence of water, a reaction liquid containing the alkali metal sulfinate obtained after the reaction is concentrated till a specific concentration, thereby inorganic salts, which are impurities in the solution, are precipitated and removed, and a filtrate after removing the inorganic salts is subjected to an operation such as concentration and drying, thereby obtaining the target alkali metal perfluorosulfinate with a high purity and a good operability. Furthermore, an organic solvent for extraction becomes unnecessary. Therefore, it is possible to greatly reduce wastes.

Abstract: Disclosed is a method for producing a fluoroalkanesulfonic acid including (1) the step of reacting concentrated sulfuric acid and/or fuming sulfuric acid with a fluoroalkanesulfonate to cause an acid decomposition, thereby obtaining a reaction mixture containing the fluoroalkanesulfonic acid and a sulfur component; and (2) the step of adding an oxidizing agent to the reaction mixture obtained by the above step and then conducting a distillation, thereby obtaining the fluoroalkanesulfonic acid from the reaction mixture. It is possible by this method to efficiently reduce the sulfur component, thereby industrially advantageously obtaining fluoroalkanesulfonic acid of high purity.

Abstract: Disclosed is a method for producing a fluoroalkanesulfonic acid including (1) the step of reacting concentrated sulfuric acid and/or fuming sulfuric acid with a fluoroalkanesulfonate to cause an acid decomposition, thereby obtaining a reaction mixture containing the fluoroalkanesulfonic acid and a sulfur component; and (2) the step of adding an oxidizing agent to the reaction mixture obtained by the above step and then conducting a distillation, thereby obtaining the fluoroalkanesulfonic acid from the reaction mixture. It is possible by this method to efficiently reduce the sulfur component, thereby industrially advantageously obtaining fluoroalkanesulfonic acid of high purity.

Abstract: In a method for obtaining an alkali metal perfluoroalkanesulfinate by reacting a perfluoroalkanesulfonyl halide with a sulfur-containing reducing agent in the presence of water, a reaction liquid containing the alkali metal sulfinate obtained after the reaction is concentrated till a specific concentration, thereby inorganic salts, which are impurities in the solution, are precipitated and removed, and a filtrate after removing the inorganic salts is subjected to an operation such as concentration and drying, thereby obtaining the target alkali metal perfluorosulfinate with a high purity and a good operability. Furthermore, an organic solvent for extraction becomes unnecessary. Therefore, it is possible to greatly reduce wastes.