Abstract: A process is provided for the preparation of difluoroacetic acid from tetrafluoroethylene. The process comprises reacting tetrafluoroethylene with an aqueous solution of an inorganic base, optionally in the presence of an organic solvent.

Abstract: The present invention relates to a method for preparing a halogenoacetyl fluoride and the derivatives thereof. The inventive method for preparing a halogenoacetyl fluoride acid is characterized in that said method includes: a step of preparing a halogenoacetyl halide by photo-oxidation of a halogenoethylene compound in conditions such that the transformation rate of the halogenoethylene compound into halogenoacetyl halide is no higher than 80%, producing a reaction mixture essentially including halogenoacetyl halide and the excess halogenoethylene compound; a step of partial fluorination of the mixture obtained by reacting the latter with hydrofluoric acid suitable for obtaining a mixture of halogenoacetyl fluoride and the excess halogenoethylene compound; a step of separating the halogenoacetyl fluoride and the excess halogenoethylene compound. The invention can be used, specifically, for preparing the trichloroacetyl fluoride used as an intermediate species in the production of trifluoroacetic acid.

Abstract: A process is provided for the preparation of difluoroacetic acid from tetrafluoroethylene. The process comprises reacting tetrafluoroethylene with an aqueous solution of an inorganic base, optionally in the presence of an organic solvent.

Abstract: The invention relates to a method for preparing bromodifluoroacetic compounds which comprises converting a 1,1-diflouro-1,2-dibromodihaloethane with oleum having 50-70% SO3 to a bromodifluoroacetyl halide (bromide or chloride) and then in reacting the latter directly with either an alcohol, or with water.

Abstract: Process for the preparation of perfluorocarboxylic acids of the formula RF—COOH, salts thereof and esters thereof from perfluoroalkyl iodides of the formula RF′—I, in which RF and RF′ are cyclic, branched or linear, saturated or unsaturated perfluoroalkyl radicals, by activating the perfluoroalkyl iodides in the presence of oxygen and in organic solvents.

Abstract: Process for the preparation of perfluorocarboxylic acids of the formula RF—COOH, salts thereof and esters thereof from perfluoroalkyl iodides of the formula RF′—I, in which RF and RF′ are cyclic, branched or linear, saturated or unsaturated perfluoroalkyl radicals, by activating the perfluoroalkyl iodides in the presence of oxygen and in organic solvents.

Abstract: A fluorinated oligomer having COOH groups at both end and a &rgr;50° value of 1,000 to 10,000 is produced by swelling a fluorine rubber crosslinking product in an organic solvent, followed by decomposition in the presence of a base and a peroxide. The obtained fluorinated oligomer is soluble in solvent and thus easy to separate from fillers, etc., and can be effectively used as a chain-elongating agent for epoxy resin, isocyanate resin, oxazoline resin, etc.

Abstract: A process is disclosed for preparing polyhaloacyl fluorides such as trifluoroacetyl fluoride and difluoroacetyl fluoride by oxidizing 1-chloro-1,2,2,2-trifluoroethanes and 1,1-dichloro-2,2-difluoroethane, respectively with oxygen.

Abstract: A process for preparing compounds corresponding to the formula RCFXC(O)Cl, in which X is fluorine or chlorine and R is fluorine or a perfluorinated C1- C10-alkyl group, preferably chlorodifluoroacetyl chloride, by photochemical oxidation of R122 (CF.sub.2 ClCHCl.sub.2) and the preparation of trifluoroacetyl chloride by photochemical oxidation of R123 (CF.sub.3 CHCl.sub.2) with oxygen under irradiation. The reaction is preferably carried out without pressurization and without addition of elemental chlorine.

Abstract: The invention relates to an ecologically favorable process for the hydrolytic decomposition of halogen-containing compounds of the formula CX.sub.4 or CHX.sub.3 or mixtures of these compounds, in which X as halogen is chlorine or bromine or a combination thereof, in an aqueous-alkaline medium, which comprises first keeping the aqueous-alkaline reaction mixture comprising the abovementioned halogen-containing compounds at a temperature of between 0.degree. and 1000.degree. C. under the autogenous pressure which is formed in a closed reaction vessel for a period of up to 10 hours and then subjecting the mixture to a heat treatment at a temperature of between 70.degree. and 150.degree. C. under the autogenous pressure which is formed therein, in the presence of sulfite. The process according to the invention is particularly suitable for hydrolytic decomposition of halogen-containing reaction products from aqueous-alkaline hypohalite oxidations.

Abstract: The halogenotetrafluoropropionic acid 3-iodotetrafluoropropionic acid of the formula ICF.sub.2 CF.sub.2 COOH, it is prepared by reacting iodine, tetrafluoroethylene and ethylene in a one-pot reaction under specific conditions, reacting the resulting compound ICF.sub.2 CF.sub.2 CH.sub.2 CH.sub.2 I with a base in order to eliminate hydrogen iodide and oxidizing the compound ICF.sub.2 CF.sub.2 --CH.dbd.CH.sub.2 thus obtained to give 3-iodotetrafluoropropionic acid. The halogenotetrafluoropropionic acid is an advantageous starting compound for the preparation of valuable unsaturated compounds containing functional groups.

Abstract: A process for producing trifluoroacetic acid and trifluoroacetyl chloride from 1,1-dichloro-2,2,2-trifluoroethane, oxygen and water as starting materials, characterized in that the starting materials are reacted in a vapor phase in a reactor of perfect mixing type to avoid local heating, under a condition not to liquefy the starting materials and reaction products, while continuously supplying the starting materials and continuously withdrawing the reaction products, so as to obtain a reaction mixture comprising trifluoroacetyl chloride as the main product and trifluoroacetic acid as an accompanying product.

Abstract: A process for preparing perfluoroalkanecarboxylic acids, wherein a perfluoroiodoalkane, R.sub.F I, is reacted with trichloroethylene in an acidic solvent in the presence of zinc, and the 2-perfluoroalkyl-1,1-dichloroethylene thus obtained is oxidized with the aid of permanganate, R.sub.F representing a straight chain or branched perfluoro radical containing one to 20 carbon atoms, together with certain novel perfluoroalkyldichloroethylenes having four or more carbon atoms so obtained.

Abstract: A process is described for the preparation of perfluorocarboxylic acids by oxidizing perfluoroalkylalkenes with permanganate in aqueous solution, catalytic amounts of at least one quaternary ammonium salt containing alkyl and/or arylalkyl groups being added. It is possible by these means to prepare even perfluorocarboxylic acids having a fairly long chain in a high state of purity in a readily controllable reaction and in a good space-time yield.

Abstract: Saturated perfluoroalkane-1-carboxylic acids having 6 to 14 C atoms are prepared by reacting the corresponding 1-iodoperfluoroalkanes at temperatures of 100.degree. to 180.degree. C. with fuming sulfuric acid containing 15 to 45% by weight of dissolved sulfur trioxide. The two liquid phases which are formed are separated. The lighter phase is mixed with 0.3 to 6% of its weight of water and is distilled at a pressure of 0.3 to 100 kPa. The heavier phase is mixed with 0.7 to 1.5 moles of water per mole of sulfur trioxide employed and is cooled to 0.degree. to +30.degree. C. and the precipitated iodine is filtered off. After the addition of sulfur trioxide, the liquid filtrate can be re-used.Perfluoroalkan-1-oic acids are obtained in a high state of purity and the bulk of the iodine is recovered in the elementary form.