A metal-free, acid-free and chemoselective N-dealkylation-N-nitrosation or C-nitration of N-alkyl anilines has been developed. tert-Butyl nitrite (TBN) efficiently promotes the synthesis of N-nitrosoanilines, nitroanilines and N-nitroso-nitroanilines with good to excellent yields and chemoselectivities. The selective reduction of N-nitrosoanilines and N-nitroso-nitroanilines was smoothly achieved, affording phenylhydrazine, 2-nitroaniline and 1,2-benzenediamine derivatives.