Abstract: The present invention relates to a process for preparing vinylphosphonic acids of the formula ##STR1## in which m is an integer from 1 to 20 by heating 2-chloroethylphosphonic acids of the formula ##STR2## in which n is an integer equal to or smaller than m, if desired in the form of a solution, in the absence or presence of a catalyst to a temperature of 180 to 350.degree. C. and eliminating hydrogen chloride and, where appropriate, water under atmospheric pressure or reduced pressure and, if desired, hydrolysing the vinylphosphonic acids of the formula (I).

Abstract: The invention relates to a process for the preparation of acesulfam salts by reaction of salts of amidosulfonic acid with diketene to give a salt of acetoacetamidosulfonic acid (I), ring closure by the action of at least about an equivalent amount of SO.sub.3, at least this ring closure reaction being carried out in the presence of a halogenated, aliphatic hydrocarbon as an inert solvent, treatment of the cyclization product with water and conversion of the resulting acesulfam-H (II) into the form of a non-toxic salt, which comprises, in the work-up by distillation of the resulting crude solvent, after removal of water and low-boilers and recovery of solvent sufficiently pure for reuse in the preparation of compounds (I) and/or (II), directly returning :he remaining, solvent-containing distillation residue, without further purification, into the system downstream of the reaction vessel for carrying out the ring closure reaction.

Abstract: Process for preparing alkanephosphonic anhydrides of the formula (I) ##STR1## where R is straight-chain or branched unsubstituted C.sub.1 -C.sub.6 -alkyl and n.gtoreq.3, which comprises pyrolytically eliminating water from an alkanephosphonic acid of the formula (II) or a pyroalkanephosphonic acid of the formula (III) ##STR2## where R is straight-chain or branched C.sub.1 -C.sub.6 -alkyl, without addition of solvent and removing the water from the reaction mixture by means of an inert gas stream.

Abstract: Process for the continuous preparation of dialkyl vinylphosphonates using catalysts at temperatures of from 150.degree. to 270.degree. C. by dissociation of dialkyl acetoxyethanephosphonates at a pressure of from 5 to 500 mbar in contact with a liquid, catalytically active medium while drawing off the dialkyl vinylphosphonates formed and other volatile reaction products as vapors, by conveying the liquid medium in forced circulation via an evaporator while feeding in fresh dialkyl acetoxyethanephosphonate, if desired admixed with catalyst, corresponding to the distillation of dialkyl vinylphosphonates and other volatile compounds, and drawing off non-volatile material formed as byproduct from the liquid circuit to maintain constant conditions.

Abstract: Method of separating vinylphosphonic acid from crude mixtures.The invention relates to a method for separating vinylphosphonic acid from crude mixtures, the separation being carried out by extraction with alcohols and/or ketones, which in each case comprise at least 5 carbon atoms.According to the invention, vinylphosphonic acid can be obtained in high purity and good yield from highly contaminated crude mixtures.

Abstract: Process for the preparation of pure propanephosphonic anhydride, which comprises distilling crude, impure propanephosphonic anhydride having an average degree of polymerization of 20 to 200 and containing less than 0.5% by weight of water by heating to 230 to 300.degree. C. under a pressure of 0.1 to 100 mbar, pure propanephosphonic anhydride having an average degree of polymerization of 20 to 60 being obtained.

Abstract: The invention relates to a process for the preparation of a catalyst which contains palladium and/or compounds thereof and alkali metal compounds, and additionally cadmium compounds and/or gold and/or compounds thereof, on support particles which have been pressed from SiO.sub.2 or an iO.sub.2 -Al.sub.2 O.sub.3 mixture with the aid of a binder which comprisesa) washing the roasted support particles with an acid which does not react with SiO.sub.2 or SiO.sub.2 -Al.sub.2 O.sub.3 mixtures, until no further cations of the binder employed during pressing of the support particles are released from the support particles;b) then impregnating the support particles with palladium, and gold or cadmium;c) then bringing the impregnated support particles into contact with a solution of a base at least until the thickness of the nobel metal shell generated in this way on the support particles no longer changes substantially; andd) then impregnating the support particles with an alkali metal compound.

Abstract: The invention relates to a process for the preparation of a catalyst which contains palladium and/or compounds thereof and alkali metal compounds, and additionally cadmium compounds and/or gold and/or compounds thereof, on support particles which have been pressed from SiO.sub.2 or an iO.sub.2 -Al.sub.2 O.sub.3 mixture with the aid of a binder which comprisesa) washing the roasted support particles with an acid which does not react with SiO.sub.2 or SiO.sub.2 -Al.sub.2 O.sub.3 mixtures, until no further cations of the binder employed during pressing of the support particles are released from the support particles;b) then impregnating the support particles with palladium, and gold or cadmium;c) then bringing the impregnated support particles into contact with a solution of a base at least until the thickness of the nobel metal shell generated in this way on the support particles no longer changes substantially; andd) then impregnating the support particles with an alkali metal compound.

Abstract: The invention relates to a method for making a catalyst which contains palladium and/or its compounds and, if desired, additionally gold and/or gold compounds and which contains as activators alkali metal compounds and, if desired, additionally cadmium compounds on a support which is composed of SiO.sub.2 or an SiO.sub.2 -Al.sub.2 O.sub.3 mixture having a surface area of 50-250 m.sup.2 /g and a pore volume of 0.4-1.2 ml/g and whose particles have a particle size of 4 to 9 mm, 5 to 20% of the pore volume of the support being formed of pores having radii of 200 to 3000 .ANG. and 50 to 90% of the pore volume being formed of pores having radii of 70 to 100 .ANG.. The support particles are compressed with the aid of an Li, Mg, Al, Zn or Mn salt of a C.sub.2 -C.sub.20 carboxylic acid or a mixture of such salts as binder.

Abstract: A process for the preparation of diesters of carboxymethylphosphonic acid of the formula: (RO).sub.2 P(O)CH.sub.2 CO.sub.2 H, in which R is a straight-chain or branched alkyl radical having 1 to 20 carbon atoms, a cycloaliphatic radical having 5 to 8 carbon atoms, a phenyl or naphthyl radical which can be substituted, an aralkyl radical having 7 to 10 carbon atoms, or in which the (RO).sub.2 P group forms a ring having 2 to 5 carbon atoms which can be substituted, characterized in that dialkyl ester of 2-hydroxyethylphosphonic acid of the formula (RO).sub.2 P(O)CH.sub.2 CH.sub.2 OH, in which R has the abovementioned meaning, is reacted with oxygen in the presence of water and a catalyst which contains at least one metal selected from the platinum metals group.

Abstract: The invention relates to a process for the isolation of vinyl acetate which involves not combining the bottom product of the recylced gas washings with the water-saturated vinyl acetate but rather introducing it to further multiple distillation columns from the gas mixture formed in the reaction of ethylene with acetic acid and oxygen over catalysts containing palladium or palladium compounds in the gas phase.

Abstract: A process for the preparation of alkyl esters of alkenylphosphinic acid, having the general formula I ##STR1## wherein R.sup.1 represents H or CH.sub.3, R.sup.2 alkyl having from 1 to 4 carbon atoms or phenyl and R.sup.3 alkyl having from 1 to 8 carbon atoms, which comprises cleaving an alkyl ester of 2-acetoxyethyl phosphinic acid, having the general formula II ##STR2## wherein R.sup.1, R.sup.2 and R.sup.3 have the meaning indicated above, in contact with a liquid catalytically acting medium and at a partial pressure of the total of the components of the reaction system in the range of from 1 to 500 mbar, and drawing off the resulting alkyl esters of alkenyl phosphinic acid and other volatile reaction products.The invention also relates to compounds of the formula I ##STR3## wherein (a) R.sup.1 represents H, R.sup.2 represents alkyl having from 1 to 4 carbon atoms or phenyl and R.sup.3 represents isobutyl or alkyl having from 5 to 8 carbon atoms, or(b) R.sup.1 represents CH.sub.3, R.sup.

Abstract: The invention relates to a process for the preparation of vinyl acetate in the gas phase from ethylene, acetic acid and oxygen or oxygen-containing gases on a catalyst which contains palladium and/or compounds thereof and if appropriate additionally gold and/or gold compounds and, as activators, alkali metal compounds and if appropriate additionally cadmium compounds, on a support. The support consists of cylindrical particles with curved front faces. The support material is aerogenic SiO.sub.2 or an aerogenic SiO.sub.2 -Al.sub.2 O.sub.3 mixture having a surface area of 50-250 m.sup.2 /g and a pore volume of 0.4-1.2 ml/g, which is formed to the extent of at least 50% by pores having a diameter of 50-200 .ANG..

Abstract: A process for the production of dialkyl esters of vinyl phosphonic acid which comprises subjecting dialkyl esters of 2-acetoxyethane phosphonic acid to cleavage by contacting with a liquid catalytically acting medium at a temperature in the range from 150.degree. to 270.degree. C. and under a pressure such that the partial pressures of the total of the components of the reaction system is in the range from 1 to 500 mbar, and drawing off the resulting dialkyl esters of vinyl phosphonic acid and other volatile reaction products.

Abstract: The invention relates to a process for the isolation of vinyl acetate from a gas mixture containing vinyl acetate, ethyl acetate, water and carbon dioxide formed in the reaction of ethylene with acetic acid and oxygen in the gas phase over catalysts containing palladium or palladium compounds. The gas mixture leaving the reaction zone is passed into a distillation column and the gas mixture leaving the top thereof is cooled. The gas which is not condensed during the cooling is washed with acetic acid in a washing column, an acetic acid solution containing vinyl acetate being obtained. The bottom product from the distillation column is passed to a second distillation column and a side stream containing ethyl acetate is removed from an enrichment zone above the bottom thereof, all or some of the bottom product from the second distillation column, which product chiefly consists of acetic acid, being used for the wash in the washing column. The top vapor of the second distillation column is cooled.

Abstract: The invention relates to a process for the manufacture of unsaturated carboxylic acid esters by the reaction of olefins or cyclo-olefins with oxygen and carboxylic acids in the gaseous phase, in the presence of a catalyst which contains elements of the subsidiary group VIII of the periodic system and/or compounds thereof, and an alkali metal acetate, at temperatures of from 100.degree. to 250.degree. C. and pressures of from 0.5 to 21 bar absolute, wherein from 1 to 8000 parts per million (by weight), calculated on the carboxylic acid used, of organic chlorine compounds are added to the reaction mixture.

Abstract: A process is provided for the preparation of practically formic acid-free acetic acid by oxidation of acetaldehyde in the liquid phase with oxygen or oxygen-containing gases in the presence of mixtures of cobalt, nickel and manganese salts as catalysts.

Abstract: The carriers contain common active components, namely noble metals of the 8th sub-group or compounds thereof, and as activators alkali metal compounds, alkaline earth metal compounds or cadmium compounds. The carriers, too, consist of common materials, such as silicic acid. A novel feature is to be seen in the shape of the carrier particles which are designed as rod sections having a star-shaped cross section (FIGS. 1 to 7) or as ribbed rods (FIG. 8). In relation to the apparent density and thus in relation to the amount of noble metal employed, a considerably higher space-time yield is reached than with carrier particles of a conventional shape.

Abstract: The carriers contain common active components, namely noble metals of the 8th sub-group or compounds thereof, and as activators alkali metal compounds, alkaline earth metal compounds or cadmium compounds. The carriers, too, consist of common materials, such as silicic acid. A novel feature is to be seen in the shape of the carrier particles which are designed as rod sections having a star-shaped cross section (FIGS. 1 to 7) or as ribbed rods (FIG. 8). In relation to the apparent density and thus in relation to the amount of noble metal employed, a considerably higher space-time yield is reached than with carrier particles of a conventional shape.

Abstract: Process for separating water from a gas mixture, obtained in the manufacture of vinyl acetate by reacting ethylene with acetic acid and oxygen in contact with catalysts containing palladium or palladium compounds in the gaseous phase said gas mixture consisting essentially of acetic acid, vinyl acetate, water, carbon dioxide and ethylene, wherein(a) the gas mixture leaving the reaction zone is condensed to give a condensate containing the major portion of acetic acid, vinyl acetate and water and(b) an acetic acid solution containing the residual amount of vinyl acetate and water being prepared by absorption of the non-condensed gas in acetic acid, is characterized in that(c) the condensate obtained in step (a) and the solution obtained in step (b) are introduced separately from each other into the same distillation column, the feeding point of the condensate being above the feeding point of the solution, the water is distilled off at the head of said column as azeotrope together with the vinyl acetate and(d)