Hoechst Aktiengesellschaft

Harald Kappesser

Gerhard Diekhaus

Helmut Bahrmann

Peter Lappe

Ernst Wiebus

Heinz Kalbfell

Jurgen Weber

Helmut Springer

Peter Heymanns

Kurt Schalapski

Carl Dieter Frohning

Wolfgang Greb

Wilhelm Gick

Wolfgang Zgorzelski

Georg Dambkes

Wolfgang Hofs

Dieter Frohning

Eberhard Von Mulmann

Sulfuric acid which contains dilute organic phosphorus compounds and other impurities and is obtained, for example, during preparation of sulfonated arylphosphines, is purified by extraction with an amine which is sparingly soluble or insoluble in water.

Process for removing organic phosphorous compounds and other impurities

Waste gas obtained in the hydroformylation of olefinically unsaturated compounds in the presence of an aqueous catalyst solution comprising water-soluble rhodium complexes (1st reaction stage) is fed to a homogeneous reaction system in which residual amounts of the olefinically unsaturated compounds from the first reaction stage are reacted in a homogeneous reaction system (2nd reaction stage).

Process for the hydroformylation of olefinically unsaturated compounds

Isomeric mixtures of pentanoic acids are prepared by subjecting butene-1/butene-2 mixtures to hydroformylation to form aldehyde mixtures, followed by oxidation of the aldehyde mixtures which have been separated off from the reaction product. The hydroformylation is carried out in a heterogeneous system in the presence of rhodium catalysts which are dissolved in water. The mixture of isomeric 5 carbon monocarboxylic acids produced, when esterified with polyhydric alcohols, yields mixtures of isomeric esters which are useful as lubricants for refrigerant compressors operated with chlorine-free, at least partly fluorinated hydrocarbons as the refrigerant.

Mixtures of isomeric pentanoic acids, esters prepared therefrom, and

A process for the recovery of rhodium from aqueous solutions of complexes thereof wherein the solutions are treated with oxygen in the presence of a water soluble salt of a carboxylic acid and, in a second stage, further treated with a hypochlorite, whereby oil soluble rhodium compounds are formed which can readily be separated from the aqueous solution.

Process for the recovery of rhodium from aqueous solutions containing

A process for the preparation of alpha-alkylacroleins from aldehydes and formaldehyde. The reaction takes place in the presence of a secondary amine and a carboxylic acid having up to 5 carbon atoms, and is performed in two stages so that, in the first stage, part of the carboxylic acid is added to the reaction mixture and, in the second stage, the remaining carboxylic acid is added.

Process for the preparation of .alpha.-alkylacroleins

Growing community of inventors

Oberhausen, Germany

Harald Kappesser