Polyhalogenoaromatic compounds. Part 50. Reactions of 4-benzyloxytetrahalogenopyridines with nucleophiles

Abstract

Reaction of 4-benzyloxy-3,5-dichloro-2,6-difluoro-(1; R = CH₂Ph) and 4-benzyloxytetrachloropyridine (2; R = CH₂Ph) with various nucleophiles (N,N-dimethylhydrazine, piperidine, N,N,N′,N′-tetramethylethane-1,2-diamine, triphenylphosphine) occurs unexpectedly at the benzylic methylene group with alkyl–oxygen cleavage to give the corresponding benzylammonium (4) or triphenylphosphonium salt (9) respectively. The molecular structure of the salt derived from 4-benzyloxytetrachloropyridine and N,N-dimethylhydrazine was confirmed by an X-ray study. Preliminary experiments of utilising the benzyl cleavage for the preparation of various benyzl derivatives (PhCH₂X;X = CI, Br, I, CN, N₃) are described.