Hoechst Aktiengesellschaft

Eberhard Auer

Alexander Ohorodnik

Klaus Gehrmann

Paul Stutzke

Joachim Kandler

Wilhelm Vogt

Karl Merkenich

Stefan Schafer

Johannes Rosenthal

Klaus Henning

Gunter Lenz

The disclosure relates to an improved process for making alkanephosphonous acid esters which comprises: introducing a stoichiometric excess each of an alkyldihalogenophosphane and aliphatic alcohol into a reaction column and reacting them therein at a temperature higher than the boiling point of the reactants but lower than the boiling point of the resulting alkanephosphonous acid ester, this latter being obtained in the base portion of the reaction column and being removed therefrom; continuously expelling overhead of the reaction column a vaporous mixture consisting of by-products formed during the reaction, in the form of hydrogen halide and halide of the aliphatic alcohol, together with aliphatic alcohol in excess, and separating the mixture into its components in a series-connected distilling column, the aliphatic alcohol obtained in the base portion of the distilling column being removed therefrom and recycled into the reaction column, and selectively condensing the mixture issuing overhead with recovery of hydrogen halide gas and liquefied halide of the aliphatic alcohol.

Process for making alkanephosphonous acid esters

The invention relates to a process permitting the deposition of solid matter in mixtures containing methyldichlorophosphane to be avoided. To this end, the mixture is stabilized by admixing it with phosphoric acid or a soluble compound containing at least one acid group selected from phosphoric acid, phosphonic acid, sulfonic acid, phosphonous acid, thiophosphoric acid or dithiophosphoric acid.

Process permitting the deposition of solid matter in mixtures containing

Pure acetyl chloride containing less than 1 ppm of phosphorus is produced. To this end, crude acetyl chloride containing phosphorus compounds is intimately contacted with 1 to 20 liters of gaseous chlorine per liter of liquid crude acetyl chloride and the acetyl chloride so contacted with chlorine is subjected to fractional distillation.

Production of pure acetyl chloride

[2-(HALOGENOFORMYL)-VINYL]-ORGANYL-PHOSPHINIC ACID HALIDES OF THE GENERAL FORMULA ##STR1## in which R.sub.1 stands for an alkyl group having 1 to 8 carbon atoms, an aryl group or a substituted derivative of these groups, R.sub.2 stands for a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group or a substituted derivative of these groups, and X stands for a chlorine or bromine atom, are produced. To this end, a 2 halogenoacrylic acid or a substitution product thereof of the general formula ##STR2## in which R.sub.2 and X have the meanings given above, is reacted at 15.degree.-90.degree. C. with an organyldihalogenophosphane of the general formula

Production of [2-(halogenoformyl)-vinyl]-organyl phosphinic acid halides

Methyl-[2-(2,4,6-tribromophenylcarbamoyl-)ethyl-]phosphinic acid is made continuously. To this end, molten 2-methyl-2,5-dioxo-1-oxa-2-phospholane is reacted with molten 2,4,6-tribromoaniline at 210.degree. to 250.degree. C. in the absence of a solvent.

Production of

Production of N-substituted 2-carbamoyl phosphinic acids of the general formula: ##STR1## in which R.sup.1 stands for an alkyl group having 1 to 4 carbon atoms or an aryl group; R.sup.2 and R.sup.3 stand independently of each other for an alkyl group having 1 to 4 carbon atoms, an aryl group or a hydrogen atom; R.sup.4 stands for an alkyl group having 1 to 18 carbon atoms, an aryl group or a hydrogen atom; and R.sup.5 stands for an alkyl group having 1 to 18 carbon atoms or an aryl group. More specifically, a 2-chloroformyl phosphinic acid chloride of the general formula ##STR2## is reacted at 120.degree. to 170.degree. C with an amine of the general formula ##STR3## and resulting N-substituted 2-carbamoyl phosphinic acid chloride of the general formula ##STR4## the latter compound being obtained while hydrogen chloride is split off, is hydrolyzed with water.

Production of N-substituted 2-carbamoyl phosphinic acids

Builders for detergent and cleaning compositions. The builders comprise copolymers made from .alpha.-hydroxyacrylic acid and acrylic acid. The copolymers contain between 9 and 85 mol % of acrylic acid and have a relative viscosity within the range 0.05 and 1.0, determined on a 1 weight % solution of the copolymers in aqueous 2N-sodium hydroxide solution, at 20.degree. C.

Growing community of inventors

Erftstadt, Germany

Eberhard Auer