Hoechst Aktiengesellschaft

Andreas Seidel

Erhard Jagers

Peter Prinz

Heinz Erpenbach

Alfred Hauser

Norbert Weferling

Reinhard Gradl

Peter Heymanns

Winfried Lork

Dieter Peters

Karen Pottkamper

Hermann Berwe

Dimitrios Mouratidis

A process for the removal of aldehydes and acetals from industrially prepared acetic acid, wherein the contaminated acetic acid is reacted in the presence of a Bronstedt acid and 0.05 to 1% by weight of water and, if required, of 3 to 10 equivalents, calculated on aldehyde and acetal, of a high boiling polyhydric alcohol, and isolating the purified acetic acid by fractional distillation.

Process for the removal of aldehydes and acetals from industrially

To produce tert-butyl chloroacetate by addition of chloroacetic acid to isobutene, the reaction is carried out in the absence of catalysts and solvents in a pressure vessel at a temperature of 80.degree. to 110.degree. C. under the pressure which establishes itself of 3 to 12 bar over a period of 1 to 12 hours. After the pressure vessel is cooled, the cooled product mixture is withdrawn and it is worked up by distillation under reduced pressure without prior neutralization.

Process for producing tert.-butyl chloroacetate

In a process for preparing methyltris(m-sulfonatophenyl)phosphonium iodide trisodium salt, the sodium salt of trisulfonated triphenylphosphine and methanol are introduced as the initial charge, a solution of methyl iodide in methanol is added dropwise at elevated temperature, and after an additional reaction time the reaction product is evaporated to dryness in vacuo. Methyltris(m-sulfonatophenyl)phosphonium iodide trisodium salt can be used to prepare carboxylic acids and/or their esters by carbonylation of saturated aliphatic alcohols having from 1 to 20 carbon atoms or their halo, ester or ether derivatives over a rhodium catalyst in the presence of water and methyl iodide under a CO partial pressure of from 0.3 to 200 bar at a temperature of from 100.degree. to 240.degree. C., provided methyltris(m-sulfonatophenyl)phosphonium iodide trisodium salt and carboxylic acid are added to the liquid phase prior to carbonylation.

Preparation of methyltris(m-sulfonatophenyl) phosphonium iodide

In a process for the stabilization of a solution of ethylmagnesium carbonate in ethanol, which has been prepared by the reaction of a suspension of magnesium ethylate in ethanol with carbon dioxide, 0.2 to 1.0% by weight of water, based on the ethylmagnesium carbonate solution, is added to the solution or its starting materials.

Process for the stabilization of ethanolic ethylmagnesium carbonate

Waste acetic acid, which is contaminated by nitrogen compounds and also by hardly hydrolyzable halogen compounds, is purified by adding a complex-forming metal or one of the compounds thereof and a basic compound. The resultant mixture is kept at a temperature between 25.degree. and 118.degree. C. over a period of time of 1 to 6 hours. Finally, purified acetic acid is removed from the mixture by distilling.

Process for the purification of waste acetic acid

A process for removing metallic corrosion products from carbonylation reactions which are carried out under anhydrous conditions and in which methyl acetate and/or methanol and/or dimethyl ether are reacted over a noble metal catalyst system which comprises a noble metal of group VIII of the periodic table of the elements, a co-catalyst, such as iodide or bromide, in particular methyl iodide, and a promoter, such as an organophosphonium or organoammonium salt, and if appropriate a lithium salt, to give acetic acid and/or acetic anhydride is described, the process comprising

Process for removing metallic corrosion products from carbonylation

In a process for removing the metallic corrosion products from a contaminated catalyst solution produced on carbonylation of methanol and/or methyl acetate and/or dimethyl ether and containing carbonyl complexes of noble metals from group VIII of the Periodic Table of the elements, quaternary organo-phosphorus compounds as organic promoters, metallic corrosion products and acetic acid, acetic anhydride, ethylidene diacetate and, in some cases, undistillable organic compounds, the catalyst solution is treated with water, the noble metal carbonyl complex and the undistillable organic compounds, if present, being precipitated, while the organic promoter and the metallic corrosion products remain in solution; the aqueous phase is separated from the precipitated noble metal carbonyl complex and the organic promoter is extracted from the aqueous phase using C.sub.4 -C.sub.8 -alkanols, the promoter is recovered by evaporating the extractant, the promoter is recombined with the precipitated nobel metal carbonyl complex and with the undistillable organic compounds, if present, and the purified catalyst solution is recycled into the process after addition of acetic acid and/or acetic anhydride; finally, the aqueous phase with the metallic corrosion products is purged.

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Cologne, Germany

Andreas Seidel