4-phenylsulfonyl-2,3,5,6-tetrachloropyridine: synthesis and synthetic utility

4-phenylsulfonyl-2,3,5,6-tetrachloropyridine was synthesized from the reaction of sodium phenylsulfinate with pentachloropyridine in optimized reaction condition. the reaction of some mono- and bidentate n and o nucleophiles with 4-phenylsulfonyl-2,3,5,6-tetrachloropyridine was studied in order to assess the impact of electron-withdrawing functional group (phso2−) upon regiochemistry of aromatic nucleophilic substitution. substitution generally occurs at 4-position of pyridine ring, by less steric hindrance nucleophiles although mixtures of products (ortho- and para-substituted) are obtained with more steric hindrance cases. the structures of all the compounds were confirmed by ir, 1h nmr and 13c nmr spectroscopy as well as elemental analysis and x-ray crystallography.