GB1267169

1,267,169. Dehydrochlorinating polychloroethanes. E. V. SONIN, A. L. ENGLIN, I. F. PEMENOV, M. G. AVETIAN, O. V. POLOZOV, A. S. GOLEV, J. A. TREGER, and V. N. ANTIPOV. 23 Oct., 1969, No. 51882/69. Heading C2C. Polychloroethylenes are prepared by dehydrochlorinating a polychloroethane in the vapour phase at 250‹ to 500‹ C. under a pressure of 2 to 30 atmospheres in the presence of a reaction initiator, e.g. oxygen, a halogen, or a compound such as hexachloroethane which is capable of liberating free radicals under the reaction conditions. The initiator is preferably present in an amount of from 0.2 to 0.9% by weight based on the weight of the polychloroethylene feed. Examples describe the preparation of vinylidene chloride and cis- and transdichloroethylenes from trichloroethane, and the preparation of trichloroethylene from tetrachloroethane.