Patent ID: 8304580

Claim:
A method for producing a tris(perfluoroalkanesulfonyl)methide acid salt represented by formula [1] [RfSO 2 ] 3 C n M [1] wherein Rf represents a C 1-9 straight-chain or branched-chain perfluoroalkyl group, n represents an integer that is identical with valence of the corresponding cation, and M is a cation representing an alkali metal, quaternary ammonium represented by (R 1 ) 4 N, or quaternary phosphonium represented by (R 1 ) 4 P, R 1 's represent C 1-9 , identical or different, straight-chain or branched-chain, saturated or unsaturated aliphatic hydrocarbon groups or aryl groups and hydrogen atoms of R 1 's may partially or entirely be replaced with halogen, alkyl group, amino group, nitro group, acetyl group, cyano group or hydroxyl group, comprising the steps of: (a) reacting a methylmagnesium halide represented by formula [2] CH 3 MgX [2] wherein X represents a chlorine, bromine or iodine, with a perfluoroalkanesulfonyl fluoride represented by formula [3] RfSO 2 F [3] wherein Rf represents a C 1-9 straight-chain or branched-chain perfluoroalkyl group, thereby obtaining a reaction mixture containing a tris(perfluoroalkanesulfonyl)methide acid magnesium halide represented by formula [4] [RfSO 2 ] 3 C(MgX) [4] wherein Rf and X are defined as above; and (b) directly reacting the tris(perfluoroalkanesulfonyl)methide acid magnesium halide from step (a) with at least one salt selected from the group consisting of alkali metal halides, quaternary ammonium salts, and quaternary phosphonium salts, by directly adding the at least one salt to the obtained reaction mixture from step (a), wherein the quaternary ammonium salts of step (b) are represented by the formula of (R 1 ) 4 N + .X′ − where R 1 's are defined as above, and X′ represents a halogen, acetate, alkanesulfonate, or arylsulfonate, and hydrogen atoms of X′ may partially or entirely be replaced with halogen, alkyl group, amino group, nitro group, acetyl group, cyano group or hydroxyl group, wherein the quaternary phosphonium salts of step (b) are represented by the formula of (R 1 ) 4 P + .X′ − where R 1 's and X′ are defined as above.