Improvement in process for the liquid phase dehydrohalogenation of organic halogen-containing compounds

摘要

Organic compounds of the general formula: (wherein R represents hydrogen, chlorine, bromine, fluorine or an aliphatic or aromatic radical, but not more than one R may represent an aromatic radical, and X represents chlorine, bromine or fluorine) are dehydrohalogenated by maintaining the bulk of such organic compound in the molten state within a receptacle therefor and contacting a portion of the molten organic compound with a hot surface situated below the surface of the molten organic compound and maintained at a temperature at which dehydrohalogenation of the organic compound will occur, e.g. 600-1200 DEG C. (preferably 800-1100 DEG C.). The hot surface may be heated by electrical means, for which purpose it is advantageously formed of an electrically conductive material which is substantially rigid at dehydrohalogenation temperatures and substantially resistant to attack by the organic liquid or the dehydrohalogenation products (e.g. a metal or alloy such as a chromel alloy or platinum). Examples describe the preparation of: (1), (2), (3) and (7) vinyl chloride from ethylene dichloride; (4) tetrachlorethylene from pentachlorethane; (5) isobutene from tert.-butyl chloride; (6) vinyl bromide from ethylene dibromide; (8) propylene from isopropyl chloride; (9) butadiene from 1 : 4-dichlorobutane; (10) styrene from 2-phenylethyl chloride; (11) trichlorethylene from acetylene tetrachloride; (12) 1 : 1-difluoro-2-chloroethylene from 1 : 2-dichloro-1 : 1-difluoroethane; (13) the same product from 1 : 1-difluoro-2 : 2-dichloroethane; (14) 1 : 1-difluoro-2 : 2-dichloroethylene from 1 : 1 - difluoro - 1 : 2 : 2 - trichloroethane. Additional starting materials are listed, and other suitable metals and designs thereof for heating, and methods of heating.