Patent GB-583874-A (GB)
Title: Production of organic fluorine compounds
IPC: C07C43/12
Filed: 1944-04-24
Abstract: Fluorine containing organic compounds are prepared by heating a saturated hydrocarbon containing aliphatic carbon, including cycloaliphatic and alkyl-aromatic hydrocarbons, or a non-polymerisable organic compound containing oxygen, halogen other than fluorine, sulphur or an amino group, as hereinafter defined, with a fluoroethylene containing at least three halogen atoms of which at least two are fluorine, at a temperature above 50 DEG  C. and below that at which decomposition of the reactants or products would occur, and preferably, in the presence of a catalyst selected from organic or inorganic peroxygen compounds, basic catalysts or acid-type catalysts.  Fluoroethylenes specified are trifluorochloroethylene, difluorodichloroethylene, trifluorobromoethylene, trifluoro- and tetrafluoroethylene.  The saturated hydrocarbons employed are the entirely aliphatic hydrocarbons, and cycloaliphatic, and alkyl-aromatic hydrocarbons including polymeric hydrocarbons such as polyethylene and polyisobutylene.  The non-polymerisable organic compounds containing halogen other than fluorine, amino groups, oxygen or sulphur are defined as follows: (1) saturated organic compounds containing halogen (other than fluorine but with or without fluorine also), or amino, or mercapto sulphide groups; (2) saturated carbonyl compounds containing at least two carbon atoms and only carbon, hydrogen and oxygen atoms; (3) saturated organic compounds containing at least one ether linkage; (4) organic compounds containing at least one hydroxyl group but no other substituent.  Compounds of the first type include amines, mercaptans, sulphides and disulphides, and halogen substituted compounds including halogenated hydrocarbons, ethers, and carboxylic acids and their esters; acid halides; and polymeric halo-compounds such as polyvinyl chloride and polymeric asym.-dichloroethylene, they may also contain, hydroxyl, carboxyl, cyano, amino, carbonyl, alkoxy and alkyl groups.  The second type comprise ketones, aldehydes, carboxylic acids and their esters and anhydrides, esters of mono-, di-, and poly-saccharides and polyvinyl acetate.  The compounds containing at least one ether linkage include ethers, of structure ROR, acetals RHC(OR)2, ketals R2C(OR)2, where R is alkyl, cycloalkyl, alkaryl, arylalkyl or aryl, starches, celluloses, and heterocyclic ether compounds.  The fourth type are aliphatic alicyclic, aromatic and heterocyclic alcohols including monohydric alcohols, glycols, polyhydric alcohols, polymeric alcohols such as polyvinyl alcohol and hydrolysed polyvinyl acetate copolymers and phenols. The compounds prepared according to the invention may be represented by the general formula P(CX2CX2)aR where n is a positive integer from 1 to 25, -CX2CX2- is the group corresponding to the fluoroethylene employed, P is hydrogen or halogen and R is the portion of the non-polymerisable organic reactant complementary to P, PR thus representing that reactant; products are also obtained in which all the fluoroethylene units are not connected together and may be represented as P(CX2CX2)n m-R1-(CX2CX2)mP where P and n are as defined above and R1 is a divalent radical such that the non-polymerisaable reactant is PPR1 and m is an integer from 1 to 24 and is not greater than n.  The hydrocarbons and ether-type compounds are preferably reacted at temperatures between 75 DEG  and 300 DEG C. while those of the first type and the carboxyl compounds are preferably reacted at 75 DEG  to 250 DEG  C.  When an amine is employed as the non-polymerisable compound there must not be sufficient water present, including water of crystallisation in a catalyst, as would cause formation of a fluoracetamide in accordance with the process described in co-pending application 583,264.  The process of the present invention may be carried out at any pressure within the range of 0.1 to 1000 atmospheres, in a closed system or in the vapour phase; it is preferably carried out under anhydrous conditions. The products are applicable for use as solvents, heat transfer media, lubricants, insulating oils and dialectrics.  They may be halogenated, in many cases, for example by treatment with chlorine under the catalytic influence of light.  In examples, the experiments being carried out in a heated closed vessel: (1) carbon tetrachloride and tetrafluoroethylene are reacted in the presence of benzoyl peroxide yielding steam volatile and non-volatile products containing chlorine and fluorine and having 5 to 25 fluoroethylene units per unit of carbon tetrachloride in the molecule; in like manner and with similar results, chloroform, methylene chloride, sym.-tetrachloroethane, methyl chloride and trichloro-trifluoropropane are reacted with tetrafluoroethylene; (2) isobutane and tetrafluoroethylene are heated in the presence of zinc chloride or phosphoric acid yielding products having C2F4/C4H10 ratios of 1 : 1, and 2 : 1 ; similar products are obtained by reacting in like manner tetrafluoroethylene and ethane, propane, n-butane, iso-octane, n-hexane, a mixture of iso-octane and dioxane, and paraffin wax; while in one example, No. 66, n-butane and isobutane are each reacted with tetrafluoroethylene as above, in the absence of a catalyst; (3) cyclohexane is reacted with fluoroethylene both in the presence and absence of benzoyl peroxide yielding waxy solids and liquids having C2F4/C6H12 ratio of 1 : 1, 2 : 1, and 3 : 1 ; a fraction boiling at 141.5-142 DEG  C. on chlorination yields compounds corresponding to C8C8F4Cl4 and C8H7F4Cl5; monoamyl benzene is similarly reacted; (4) isopropanol is reacted with tetrafluoroethylene in the presence of benzoyl peroxide yielding steam volatile liquids and non-volatile solids, the former being compounds having 1 : 1 and 3 : 1 C2F4/C3H7OH ratios; the products react with sodium and form esters by reaction with acetic anhydride; tetrafluoroethylene is also reacted with methanol, in the presence of benzoyl peroxide, with dodecyl alcohol, cyclohexanol and phenol in the presence of metal sodium and with ethanol, yielding 1 : 1 : 2 : 2 : tetrafluoroether, in the presence of metal sodium or potassium cyanide; ethanol and 1 : 1-difluoro-1-chloroethylene are also reacted in the presence of metal sodium to yield a difluorochloro ethyl ether which on heating with silica gel is converted to the compound ClCH2.CO.OC2H5; (5) glacial acetic is reacted with tetrafluoroethylene in the presence of benzoyl peroxide yielding a product having a 4 : 1 C2F4/CH3COOH ratio; like products are obtained using propionic acid; (6) methyl chloroacetate and tetrafluoroethylene are reacted similarly yielding a solid having a 13 : 1 C2F4/C3H5ClO2 ratio; corresponding products are obtained from ethyl propionate, methyl formate, ethylene glycol diacetate, methoxyethyl-methoxyethyl acetate, diethyl sodio-malonate, diethyl malonate, ethyl succinate, and di-(2-chloroethyl) carbonate; (7) acetic anhydride and tetrafluoroethylene yield solid products and liquid products having a 2 : 1 C2F4/C4H6O3 ratio; (8) ethyl mercaptan and dimethyl sulphide are both reacted with tetrafluoroethylene, the catalysts being benzoyl peroxide and iodine respectively; (9) methylal, acetal, diethyl ether, sym.-dimethoxy ethane, dimethyl ether of ethylene glycol, 1 : 3-dioxolane, and 2-methyl-2-chloromethyl dioxolane-1 : 3 are each reacted with tetrafluoroethylene using benzoyl peroxide, lauroyl peroxide or oxygen as catalyst to yield corresponding liquid and solid products; dioxane is reacted similarly and a fraction obtained boiling at 144-162 DEG  C. on chlorination in carbon tetrachloride solution yields the compound C6H5O2F4Cl3; a mixture of ethylene glycol and diethyl ether reacted with tetrafluoroethylene in the presence of metal sodium yields mono- and di-tetrafluoroethyl glycol ethers; (10) methyl ethyl ketone, acetone and paraldehyde are each reacted with tetrafluoroethylene in the presence of benzoyl or lauroyl peroxide; (11) sodium hydroxide-treated cellulose is reacted with tetrafluoroethylene and yields a product containing 5.38 per cent fluorine; (12) ethylene oxide is reacted with tetrafluoroethylene in the presence of benzoyl peroxide yielding liquid and solid products; (13) a mixture of a hydrolysed ethylene-vinyl acetate copolymer (molar ratio 1 : 1) and dioxane is reacted in the presence of sodium methylate to yield a polymeric tetrafluoroethyl ether; (14) illustrating a vapour phase method, isobutane and tetrafluoroethylene are passed through a vertical silver tube heated electrically and the liquid products recovered by condensation of the exit gases are fractionated In addition to the catalysts mentioned above, numerous others are specified including further examples of organic and inorganic peroxygen compounds, ozone, hydrazine and its salts, trimethylamine oxide, hexachloroethane, Friedel-Crafts type catalysts such as aluminium chloride, borax and disodium phosphate Many additional examples of nonpolymerizable compounds are specified as suitable starting materials.  Specification 570,470 also is referred to.  A sample has been furnished under Sect 2(5) of a product obtained by reacting diethylamine and tetrafluoroethylene in the presence of aluminium chloride as catalyst.