Preparation of N-(Fluoroalkyl)anilines

In order to prepare N-(fluoroalkyl)anilines the reactions of the various fluoroalkyl areneand methanesulfonates with aniline were investigated. Sulfolane gave the best results among the solvents examined. N-(α, α, ω-Trihydroperfluoroalkyl) anilines ([8 b] and [8 c]), for example, could be prepared in sulfolane but not in other solvents (Table 1). Fluoroalkyl o-nitrobenzenesulfonates [6] proved to be a highly effective agent for N-fluoroalkylation of aniline in sulfolane (Tables 3 and 4). The reactions of N-ethylaniline with fluoroalkyl arenesulfonates in the same solvent led to ordinary N-fluoroalkylation, which was accompanied by the elimination of N-ethyl group and/or migration of the ethyl group to the para position to give the corresponding products (Scheme 3). The reactions of fluoroalkyl o-nitrobenzenesulfonates with N-(hydroxyethyl)aniline in sulfolane afforded N-hydroxyethyl-N-(fluoroalkyl)anilines in good yields.