GB1017815A - Dehalogenation of organic compounds - Google Patents

Abstract

Highly fluorinated aromatic or olefinic organic compounds are obtained by contacting a fluorine-containing highly halogenated alicyclic compound containing at least one six-membered ring or a highly halogenated saturated aliphatic compound in the vapour phase with at least one metal oxide at above 200 DEG C. In specific embodiments, a highly fluorinated alicyclic compound, such as perfluorocyclohexane, perfluorocyclohexene, perfluorodecalin, perfluoromethylcyclohexane, perfluoro - dimethylcyclohexanes and perfluoroethylcyclohexane, is contacted with an oxide having a reducing lower valency state, such as magnetite, ferric oxide and chromic oxide; perfluorostyrene is obtained from perfluoroethylbenzene at 400-550 DEG C. over magnetite and/or ferric oxide; perchlorofluoro-cyclic alkanes or alkenes are dehalogenated to fluoroaromatic compounds over a variable valency metal oxide, such as an oxide of Cu, Sn, V, Mo, W, Fe or Cr; fluorinated aromatic compounds are obtained from a highly or perfluorinated cyclohexadiene over a metal oxide less basic than CaO, e.g. an oxide of Sn, V, Mo, Fe, Cr, Ti, Mn, Co, Pb, Ce or Sb, especially magnetite and/or ferric oxide: hydrogen-containing compounds may also lose HF; and fluoro-olefines are obtained from a chlorofluorocarbon or chlorofluorohydrocarbon, e.g. CFCl2.-CF2Cl or CF2Cl.CHFCl, over magnetite. Examples are given, and regeneration of the oxides is described. Oxides used in examples are magnetite, Mn3O4, SnO, V2O3, Fe2O3, MoO3, MgO, Co3O4, Cr2O3, ZnO and WO3.