摘要:
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.
摘要:
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).
摘要:
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.2 represents alkyl having from 1 to 4 carbon atoms or phenyl and R.sup.3 represents alkyl having from 1 to 8 carbon atoms.
摘要:
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.
摘要:
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..
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
N,N'-Diacetylethylene diamine (DAED) is produced by first adding the stoichiometric amount of acetic acid (2 mols per mol of ethylene diamine) at least partially in the form of aqueous acetic acid to ethylene diamine, distilling off in a second step the water contained in the reaction mixture, adding acetic acid in excess to the remaining product, distilling off the aqueous acetic acid formed and recycling it into the first process step. The DAED remains as sump product after distillation of the acetic acid.
摘要:
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.