Perchloropyridine and chloro-cyanopyri- - dines

摘要

Prepn. of perchloropyridine and chlorocyanopyridines comprises reacting in the vapour phase mono- and di-cyano-cylobutanes and cyclobutenes wich may also be chloro-substd., no two substituents being on the same carbon atom, and excess chlorine in presence of an inert diluent gas at temps. between about 400 and 700 degrees C to give, from mono-cyano compds., perchloropyridine and, from dicyano compds., essentially perchlorocyanopyridines. The products have use as pesticides and intermediates e.g. pentachloropyridine is a herbicide and tetrachlorocyanopyridines are fungicides. Thus, from cyanocyclobutane and 1-cyano-cyclobutene pentachloropyridine is prepd., while from 1,2-dicyanocyclobutane and 1,2-dicyanocyclobutene-1 the product is a mixt. consisting essentially of 3,4,5,6-tetrachloropicolinonitrile, 2,4,5,6-tetrachloronicotinonitrile and 2,3,5,6-tetrachloroisonicotinonitrile.