procedure for the manufacture of 3,5,6 - trichlorpyridin - 2 olympics and their salts and intermediates for use in the procedure

摘要

Novel aryl and heteroaryl 4-cyano-2,2,4-trichlorobutyrates are prepared by reacting a corresponding aryl or heteroaryl trichloroacetate with acrylonitrile in the presence of a catalyst. Also provided is a novel process for producing 3,5,6-trichloropyridin-2-ol comprising cyclization of an aryl or heteroaryl 4-cyano-2,2,4-trichlorobutyrate in an inert organic solvent at elevated temperatures, in the presence of anhydrous hydrogen chloride.