Reactions of chlorinated pyridines at 4-position: synthesis, structure and reactivity of a variety of tetrachloropyridyl niterene

Heterocyclic chemistry is, of course, of central importance to the pharmaceutical industry and many commercially important life-science products contain at least oneheterocyclic sub-unit within their structures [1]. The chemistry of pentachloropyridine is dominated by nucleophilic aromatic substitution reactions [2]. Pentachloropyridinereacts with nucleophiles in both the 4- and 2- positions. The general rule seems to be that bulky nucleophiles are more likely to attack the less hindered 2- position, whilstsmall nucleophiles substitute the 4- position in another hand solvent effects is important too [3]. Herein we wish to report the reactivity of aldehydes toward perchloroaryazide (4-azido-2, 3, 5, 6-tetrachloropyridine that was synthesis with sodium azide and pentachloropyridine [7]) in the presence of N,N-dimethyltiourea and DMSO as solvent (fig-1). The structures of compounds were confirmed with 1HNMR, 13C-NMR and IR spectroscopy.In conclusion, we have shown that some N-(perchloropyridin-4-yl) benzamide derivatives could be synthesized from insertion of nitrene result of 4-azido-2, 3, 5, 6- tetrachloropyridine into C-H band of aldehydes. Moreover, 2 may be an excellent starting compound for the synthesis of highly reactive monomeric tetrachloropyridyl derivatives which could not be further identified