Abstract The reactions of isomeric tetrachlorocyanopyridines with potassium ethylxanthate were studied. It was found that tetrachloro-2-cyanopyridine was converted successively into 4-mono-and then 3, 4-bisethylxanthate derivatives. In the presence of potassium ethylxanthate the last derivative undergoes intramolecular cyclization with the formation of derivatives of 1, 3-dithiolo [4, 5-c] pyridine. In the case of other initial polychloropyridines ...