Nitrenium ions. Reactions of N,N-dimethyl-p-benzoyloxyaniline-iminium chloride with indoles and indolizines. X-ray structure of unexpected [2-chloro-4-(4-dimethylaminophenyl-ONN-azoxy)-phenyl]dimethylamine (azoxy derivative)

N,N-Dimethyl-p-nitrosoaniline reacts with benzoyl chloride affording a complex salt containing a cation, a hybrid between a nitrenium ion and an iminium ion. The salt reacts with nucleophiles (indoles, indolizines) yielding compounds characterized by a new carbon-nitrogen bond, derived from the nitrenium ion form. According to the type of nucleophile, the reaction, to differing extents, is in competition with an electron transfer process which leads to the formation of the dimer of the nucleophile and of the azoxy corresponding to the N,N-dimethyl-p-nitrosoaniline. In one of the reactions studied, a chlorinated azoxy derivative was also isolated, and its structure was elucidated by X-ray analysis.