Abstract: The invention relates to a method for preparing bromodifluoroacetic compounds which comprises converting a 1,1-difluoro-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: 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: A process for the production of hydrogen bromide gas by direct combustion of bromine in hydrogen involves carrying out the combustion reaction in an apparatus chamber made of impregnated graphite, a chamber outlet composed of a cylindrical segment disposed between a converging segment and a diverging segment, and a cooling zone composed of a steel jacket in which are piled block of impregnated graphite.

Abstract: A device for the manufacture of hydrogen bromide by direct combustion of bromine in hydrogen comprising a burner, a combustion chamber of impregnated graphite and a cooling zone defined by a steel jacket in which are piled blocks of impregnated graphite.

Abstract: The invention relates to a process for manufacturing bis-silyl ureas which consists in reacting urea and a disilazane in an aliphatic nitrile and most particularly in acetonitrile. The process of the present invention applies particularly to the manufacture of bis(trimethylsilyl)urea from urea and hexamethyldisilazane.

Abstract: A process for the production of hydrogen bromide gas by direct combustion of bromine in hydrogen involves carrying out the combustion reaction in an apparatus chamber made of impregnated graphite and a cooling zone composed of a steel jacket in which are piled blocks of impregnated graphite.

Abstract: A process for the production of hydrogen bromide gas by direct combustion of bromine in hydrogen involves carrying out the combustion reaction in an apparatus chamber made of impregnated graphite and a cooling zone composed of a steel jacket in which are piled blocks of impregnated graphite.

Abstract: To prepare .alpha.,.omega.-bromochloroalkanes, a cyclic ether, to which water has optionally been added, is hydrochlorinated and then the resultant phase is reacted, without any prior purification or separation, with gaseous hydrobromic acid.

Abstract: The invention relates to a process for the preparation of .alpha.,.omega.-bromochloroalkanes. A cyclic ether is hydrobrominated and then the phase obtained is reacted, without any prior purification or separation, with thionyl chloride.

Abstract: A compound (Ia) or (Ib) is prepared by reacting, in a polar aprotic solvent, a compound (III) with a salt of a carboxylic or dicarboxylic acid (IIa) or (IIb). The reaction may be carried out under pressure, but also at normal atmospheric pressure or in the region of normal atmospheric pressure (especially between 0.10 bar and 2 bars). The product (Ia) or (Ib) formed is, in this latter case, recovered continuously as it is formed. ##STR1## R.sup.1, R.sup.2 =optionally substituted saturated or unsaturated acyclic or cyclic hydrocarbon radicals; R.sup.3 =C.sub.1 -C.sub.10 perhaloalkyl; 0<n.ltoreq.4; X=halogen.The applications of the fluoroalkyl (meth)acrylates obtained are especially: anti-dust or anti-soiling paints for various supports such as exterior coatings and metal furniture; optical fibers; contact lenses; lithography; electrophotography; heat-resistant materials; dental resins.

Abstract: A process for the preparation of 3-chloropropionic acid consists especially in simultaneously introducing hydrochloric acid gas and acrylic acid at a molar ratio of 0.7:1 to 1.3:1 into a sediment consisting of 3-chloropropionic acid optionally diluted with water or with an aqueous hydrochloric acid solution.

Abstract: For the preparation of alkyl halodifluoroacetates, a 1,1-difluorotetrahaloethane is reacted with an alcohol in the presence of air and/or oxygen and a free-radical initiator, such as for example an azo compound, e.g., azobis(isobutyronitrile).

Abstract: The invention relates to the preparation of n-perfluorooctyl bromide. The continuous process according to the invention consists in reacting bromine with 1-hydroheptadecafluoro-n-octane in the gaseous phase, at a temperature between 450.degree. and 520.degree. C. in a Br.sub.2 /C.sub.8 F.sub.17 H mole ratio which can be from 0.2 to 5 and with a contact time between 2 and 240 seconds.The C.sub.8 F.sub.17 Br selectivity is almost complete and information of toxic sub-products like perfluoroisobutene is avoided.

Abstract: This invention relates to manufacture a normally solid perfluoroalkyl bromide by thermalbromination in the gas phase of a C.sub.10 or greater perfluoroalkyl iodide, bromination is carried out in the presence of a normally liquid perfluoroalkyl bromide.This makes it possible to carry out the post-treatment operations (reduction of iodine, separation, neutralization/washing, and the like) at room temperature.

Abstract: Mixtures of isomers, e.g., mixtures of phenethyl bromide and 1-phenyl-1-bromoethane, are separated by (a) selectively condensing one such isomer with an aromatic compound bearing at least one aryl (nuclear) hydrogen atom, e.g., xylene, in the presence of a catalytically effective amount of a Friedel-Crafts catalyst, e.g., ferric chloride, and then (b) separating the product of condensation, e.g., phenylxylylethane, from the unreacted isomer.

Abstract: The invention relates to the preparation of perfluoroalkyl bromides or bromoperfluoroalkanes C.sub.n F.sub.2n+1 -Br (n=1 to 20).A perfluoroalkanesulphonyl chloride C.sub.n F.sub.2n+1 -SO.sub.2 Cl is reacted with a compound of formula: ##STR1## in which X represents a nitrogen or phosphorus atom and R.sup.1, R.sup.2, R.sup.3 and R.sup.4, which may be identical or different, each represent an optionally substituted hydrocarbon radical, it also being possible for one of these symbols to be a hydrogen atom.

Abstract: The subject of the invention is functional chlorofluoro compounds of general formula: ##STR1## in which R.sub.F denotes a perfluoroalkyl radical, n is equal to 0 or 1, X denotes a chlorine or fluorine atom or a trichloromethyl or trifluoromethyl radical, and Y denotes a chlorine atom, an optionally salified or esterified hydroxyl group or an optionally substituted amino group, the arrangement R.sub.F --CCl.sub.2 --(CCl.sub.2 --O).sub.n containing at least 3 carbon atoms.By photochlorination of the esters R.sub.F --CH.sub.2 CH.sub.2 --O--CO--X, the compounds I (n=1) are obtained, which are then rearranged to acid chlorides I (n=0, Y.dbd.Cl) from which the corresponding acids, salts, esters and amides are optionally formed (formula I with n=0 and Y=optionally salified or esterified hydroxyl or optionally substituted amino).

Abstract: The invention relates to the preparation of perfluoroalkyl bromides or bromoperfluoroalkanes, CnF.sub.2n+1 -Br (n=1 to 20).Gaseous hydrogen bromide is reacted with a perfluoroalkanesulphonyl chloride, C.sub.n F.sub.2n+1 -SO.sub.2 Cl, in the presence of a catalyst consisting of a tertiary amine or phosphine or a quaternary ammonium or phosphonium salt, at a temperature ranging from 80.degree. to 200.degree. C.

Abstract: The invention relates to the synthesis of bromofluoroacetic acids of formula: ##STR1## in which X is a hydrogen, fluorine, chlorine or bromine atom. These acids are prepared by reacting a compound of formula: ##STR2## dissolved in concentrated hydrobromic acid, X having the same meaning as above and R representing a hydrogen atom or an alkyl or aryl radical, with gaseous hydrogen bromide.