Patent ID: 7642368

Claim:
A method for producing a triarylsulfonium salt represented by the general formula [4]: wherein, the two R 1 's are the same and are hydrogen atom, halogen atom, alkyl group, haloalkyl group having 1 to 4 carbon atoms, alkoxy group, acyl group, hydroxyl group, amino group, nitro group or cyano group; R represents an aryl group which may have a substituent selected from a halogen atom, an alkyl group, a haloalkyl group having 1 to 4 carbon atoms, an alkoxy group, an alkylthio group, a N-alkylcarbamoyl group and a carbamoyl group, with the proviso that R is different from and A 1 represents a strong acid residue, comprising reacting a diaryl sulfoxide represented by the general formula [1]: and an aryl Grignard reagent represented by the general formula [2]: RMgX [2] wherein, X represents a halogen atom; R represents the same as above, in the presence of an activator with high affinity for oxygen of 6.0 to 7.5 equivalents relative to the above diaryl sulfoxide, and then reacting the resultant reaction mixture with a strong acid represented by the general formula [3]: HA 1 [3] wherein, A 1 represents the same as above, or a salt thereof.