Patent GB-824229-A (GB)
Title: Improvements in or relating to halogenated organic compounds
IPC: C07C17/23
Filed: 1954-08-09
Abstract: The invention comprises: (a) compounds of the general formula n(CF2XCClY)m(R)nZ wherein X is Cl (preferred) or Br, Y is Cl or (preferably) F, Z is F, Cl, Br or I and R is a bivalent unit derived from a haloalkene or halopolyene in which fluorine is the only halogen or fluorine and chlorine the only halogens, and wherein n is 1 and m an integer up to 40 when R is derived from a haloalkene, whilst n is an integer up to 20 and m an integer up to 30 when R is derived from a halopolyene; (b) the preparation of compounds (a) by reacting, under conditions conducive to the formation of free radicals, a haloalkene or halopolyene corresponding to R with a chain transfer agent (also acting as an initiator) of the general formula CF2XCClYZ (wherein Z is Br or (preferably) I), and, if desired, stabilizing the adduct or telomer by reaction with chlorine or fluorine to replace Z by said halogen; (c) dehalogenation of compounds (a) (other than those in which Z=I) to compounds of the general formula n(CF2=CY)m(R)nZ1 (wherein Z1 is F, Cl or Br and m(R) is a chain not susceptible to dehalogenation under the prevailing reacting conditions); (d) oxidation (e.g. with potassium permanganate) of the products of (c), wherein -m(R)nZ1 is resistant to oxidation under the conditions employed, to mono- or poly-carboxylic acids of the general formula n(HOOC)m(R)nZ1; (e) reacting the products of (c) with an alkali metal bisulphite to produce a compound of the general formula n(MSO3CF2CHY)m(R)nZ1 (M=alkali metal), and, if desired, converting this to the free sulphonic acid by treatment with an acid; (f) oxidation, with molecular oxygen under conditions conducive to free radical formation, of compounds (a) in which Z is Cl, Br or I, each Z atom forms part of a group -CPQZ wherein P and Q are each Cl or F, and no portion of the molecule is more susceptible to oxidation, under the conditions employed, than the group -CPQZ, to form compounds in which each -CPQZ group is converted to an acyl halide group if the reaction is carried out under anhydrous conditions, a -COOH group if the reaction is carried out in the presence of water, or a -COOM group if the reaction is carried out in the presence of an alkali metal base; (g) conversion of an acid obtained by process (d) or (f) to its silver salt and treatment of this with chlorine, bromine or iodine to replace -COOAg by the said halogen; (h) pyrolysis of an alkali metal salt, obtained by process (f) or derived from an acid produced by process (d), and of the general formula R7CFClCF2COOM (wherein R7 is a polyfluoroalkyl or polyfluorochloroalkyl group), to form an unsaturated halogen compound of the general formula R7CF=CF2.  The stabilized products of process (b) are useful as lubricants, whilst the carboxylic acid products of processes (d) and (f) are useful as emulsifying agents in the polymerization of fluoro-olefines, as additives for petroleum products and as additives to metal plating baths.  Specifications 774,103 and 824,230 are referred to.ALSO:The invention comprises inter alia polymeric fluorine compounds, some of which are resinous, of the general formula n(CF2XCClY)m(R)nZ (wherein X is Cl (preferred) or Br, Y is Cl or (preferably) F, Z is F, Cl, Br or I and R is a bivalent unit derived from a haloalkene or halopolyene in which fluorine is the only halogen or fluorine and chlorine the only halogens, and wherein n is 1 and m an integer up to 40 when R is derived from a haloalkene, whilst n is an integer up to 20 and m an integer up to 30 when R is derived from a halopolyene), and the preparation thereof by reacting, under conditions conducive to the formation of free radicals, a haloalkene or halopolyene corresponding to R with a chain transfer agent (also acting as an initiator) of the general formula CF2XCClYZ (wherein Z is Br or (preferably I), and, if desired, stabilizing the product by reaction with chlorine or fluorine to replace Z by the said halogen. Specifications 774,103 and 824,230, [both in Group IV (b)], are referred to.