Abstract Replacement of a halogen substituent by hydrogen in the reaction of a perfluorophenyl halide which has a basic nitrogen substituent at the para-position with an aqueous hydrogen halide was investigated. The reaction behavior of p-halogeno-N, N- dimethylperfluoroanilines with various aqueous hydrogen halides and those of p- halogenoperfluorophenyltrimethylammonium trifluoromethanesulfonates with ...