Lr. Collazo et al., A CONVENIENT CONVERSION OF PRIMARY AMINES INTO THE CORRESPONDING HALIDES-RADICAL PROMOTED HALODEAMINATION VIA N-SUBSTITUTED-N-TOSYLHYDRAZINES, Tetrahedron letters, 35(43), 1994, pp. 7911-7914
Treatment of 1-substituted-1-tosylhydrazines with 2 equivalents of NCS
or NBS in dry THF in presence of light affords the corresponding alky
l halides in good yields. This reaction presumably involves the initia
l formation of a stabilized hydrazyl radical which is halogenated in a
radical chain process. Elimination of p-toluenesulfinic acid and extr
usion of nitrogen leads to the corresponding alkyl halide. This route
provides an improved method for halodeamination under neutral reaction
conditions.