A fluoroalkylaryliodonium compound is of the general formula
where Ar = alkylphenyl or halophenyl, A = C1-10 alkyl or alkoxy, aryl, halogen or a polymer chain, Rf = C1-20 polyfluoroalkyl or ASO2O - IAr-CH2(CF2)n where n = 1-20.
The compounds are produced by reacting a compound Rf1CH2O(OCOCF3)2 where Rf1 = C1-20 polyfluoroalkyl or (CF3COO)2 - ICH2 (CF2)n, with an aromatic compound (e.g. benzene) and a sulfonic acid, preferably in a solvent which is distilled off.
By reacting the compound (I) with aniline or an alkylaniline in methvlene chloride, a fluoroalkylaniline or derivative thereof is obtained which can be used to make a fluorine - containing azo disperse dye.