Method for preparing a polyfluorinated compound

A process for preparing a polyfluorinated compound of formula

• Ar—R1 (I),
• wherein Ar—R1 (I) is an aromatic ring system
• wherein
• R1 is selected from the group consisting of SF4Cl, SF3, SF2CF3, TeF5, TeF4CF3, SeF3, IF2, SeF2CF3 and IF4,
• X2 is N or CR2,
• X3 is N or CR3,
• X4 is N or CR4,
• X5 is N or CR5,
• X6 is N or CR6, and
• the total number of nitrogen atoms in the aromatic ring system is between 0 and 3,
• wherein R2, R3, R4, R5 and R6 are independently selected from the group consisting of hydrogen, fluoro, chloro, bromo, nitro, trifluoromethyl, 2,2,2-trifluoroethyl, pentafluorosulfanyl, phthalimido, azido, benzyloxy, trifluoromethoxy, 2,2,2-trifluoroethoxy, methoxycarbonyl, ethoxycarbonyl, methylcarbonyl, ethylcarbonyl, acetoxy, t-butyl, phenylcarbonyl, benzylcarbonyl, 3-trifluoromethylphenyl, phenylsulfonyl, methylsulfonyl, chlorophenyl, methyldoxolonyl, methyl, isopropyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, fluoromethyl, fluoroethyl and phenyl,
• or if X5 is CR5 and X6 is CR6R5 and R6 may form together a saturated or unsaturated five or six membered ring system comprising one or more nitrogen, wherein the five or six membered ring system may be substituted with one or more residues R7 having the same definition as R2 to R6, and
• with the proviso that
• if R1 is SF3, at least one of R2 and R6 is neither hydrogen nor fluoro and if R1 is not SF3, R2 and R6 are independently from each other either hydrogen or fluoro and if at least one of X2, X3, X4, X5 and X6 is nitrogen, at least one of R2, R3, R4, R5 and R6 is not hydrogen
• the process involving the following reaction step
• reacting a starting material selected from the group consisting of
• Ar2S2, Ar2Te2, Ar2Se2, ArSCF3, ArTeCF3, ArI, ArSeCF3, ArSCH3, and ArSCl,
• wherein Ar has the same definition as above,
• with trichloroisocyanuric acid (TCICA) of the formula
• in the presence of an alkali metal fluoride (MF).