CATALYST RECYCLE IN LIQUID PHASE HALOGEN EXCHANGE REACTION

摘要

Mono or dichloro-(trifluoromethyl)pyridine compd. is prepd. by liq. phase reacting mono or dichloro-(trichloromethyl)pyridine compd. with HF and halogenated metal catalyst at below 250 deg.C. In the above rxn., (trifluoromethyl) pyridine compd. is recovered by distn., and distg. residues are used for catalyzation of additional fluorine for chlorine exchange.