N, N-Dimethylpentafluoroaniline enters easily into reactions with a mixture of nitric and sulphuric acids or nitric acid with conversion of the side chain. In the reactions with mixtures of HNO3 and H2SO4, the formation of N-nitroso-N-methyl and N-nitro-N- methylpentafluoroanilines is observed. The ratio of these products was found to depend on the ratio of the acids: the formation of N-nitro-N-methylpentafluoroaniline increases with ...