Process for the preparation of compounds containing perfluoroalkanesulfonic acid groups

A compound of the formula

• Mn+[OSO2CF3]n−,
• in which Mn+ (n=1 or 2) is
• X and Y are P or N, and
• R1, R2
• and R3 are identical or different and are each, individually or together,
• hydrogen,
• an alkyl group having from 1 to 16 carbon atoms,
• an alkylaryl group whose alkylene group has from 1 to 16 carbon atoms,
• an aryl group or
• a heterocyclic group,
• where one, two or three CH2 groups in the ring and/or the alkyl groups may be replaced by identical or different heteroatoms, preferably O, NH or N(alkyl) having from 1 to 6 carbon atoms, and
• where the ring and/or the alkyl group may be partially substituted by further groups, preferably by F, Cl, N(CnF(2n+1−x)Hx)2, O(CnF(2n+1−x)Hx), SO2(CnF(2n+1−x)Hx), CnF(2n+1−x)Hx, where 1≦n≦6 and 0≦x≦2n+1, alkylaryl, aryl and/or a heterocyclic group, and
• where the alkylaryl group, the aryl group and/or the heterocyclic group may be partially substituted by further groups, preferably F, Cl, Br, NO2, CN, alkyl, aryl or a heterocyclic group.