POLAR RADICALS XVIII. ON THE MECHANISM OF CHLORINATION BY N-CHLOROAMINES: INTERMOLECULAR AND INTRAMOLECULAR ABSTRACTION.

Article abstract of DOI:10.1016/S0040-4020(01)97198-4

The photochlorinations of the n-butyl, n-pentyl, and n-hexyltrimethylammonium chlorides, using molecular chlorine in hexachloroacetone or 15percent CD3CO2D/85percent H2SO4, or using N-chlorodimethylamine in the acid solvent are described.The ammonium group exerted a strong polar directing effect upon the site of substitution.This effect was found to be more pronounced in the more polar protic solvent.The reagent, N-chlorodimethylamine, generated the dimethylamminium radical, whose reaction showed a polar sensitivity toward hydrogen abstraction similar to that of the chlorine atom, but exhibiting a much greater secondary/primary selectivity.Comparison of the isomer distributions obtained from the self photochlorination reactions of N-chloro-n-hexylmethylamine and N-chloro-n-pentylmethylamine in the acid solvent, with the distribution pattern obtained for the chlorinations of the ammonium salts with N-chlorodimethylamine, suggested that the self chlorinations of the N-chloroamines proceed by the intramolecular hydrogen abstraction mechanism suggested previously.