Hoechst Aktiengesellschaft

Dieter Freudenberger

Hans Fernholz

Friedrich Wunder

Werner H Muller

Bernhard Wojtech

Knut Riedel

Gunter Jacobsen

Walter Steppich

The invention relates to a process for the extraction of carboxylic acids from aqueous solutions with a carboxylic acid content below 8% by weight. A mixture of an aliphatic amine with a total carbon number of at least 10 and a phenol or naphthol is used as extracting agent. The molar ratio of phenol:amine or alkylated phenol:amine or naphthol:amine is in the range from 0.1:1 to around 1.1:1.

Process for the extraction of carboxylic acids from dilute aqueous

A process for separating p-benzoquinone as quinhydrone from the reaction solution obtained in the oxidation of phenol with oxygen in the presence of copper salts and of nitriles as the solvent, which comprises suspending and/or dissolving solid hydroquinone in this reaction solution, precipitating the p-benzoquinone contained therein as quinhydrone and separating it from the reaction solution.

Process for separating p-benzoquinone from the reaction products of

Process for the preparation of ethylene glycol by hydrogenating glycolic acid in the presence of catalysts containing elements or compounds of elements from at least two of the groups VIII, VIIb and Ib of the Periodic System.

Process for the preparation of ethylene glycol

Vinylacetic acid and optionally .gamma.-butyrolactone are prepared by reacting an allyl compound substituted by oxygen functions with carbon monoxide in the presence of a heavy metal catalyst. When the reaction is carried out with an allyl ether or a carboxylic acid allyl ester, water is added. Vinylacetic acid is obtained in a very good yield in simple and economic manner.

Process for the manufacture of vinyl acetic acid

.gamma.-BUTYROLACTONE, WHICH IS AN IMPORTANT PRELIMINARY PRODUCT FOR THE PREPARATION OF BUTANEDIOL-(1,4) AND OF PYRROLIDONE, IS MANUFACTURED BY CATALYTIC HYDROGENATION OF MALEIC ACID, MALEIC ACID ANHYDRIDE, SUCCINIC ACID, SUCCINIC ACID ANHYDRIDE, OR FUMARIC ACID, OR OF A MIXTURE OF TWO OR MORE OF THESE COMPOUNDS, USING A CATALYST CONTAINING A MIXTURE OF AN ELEMENT OF THE VIII.sup.th subgroup of the periodic system of elements or of one of its compounds with an element of the I.sup.st subgroup of the periodic system of elements or of one of its compounds. The process is highly selective, and the yields of .gamma.-butyrolactone are, therefore, excellent.

Process for the catalytic manufacture of .gamma.-butyrolactone

Vinylacetic acid and optionally .gamma.-butyrolactone are prepared by reacting an allyl compound substituted by oxygen functions with carbon monoxide in the presence of a heavy metal catalyst. When the reaction is carried out with an allyl ether or a carboxylic acid allyl ester water is added. Vinylacetic acid is obtained in a very good yield in simple and economic manner.

Process for the manufacture of vinyl acetic acid and optionally of .gamma.-

Process for the continuous preparation of hydroxypivalaldehyde by the reaction of isobutyraldehyde with aqueous formaldehyde in a cascade of stirred vessels in the presence of an alcohol and of an alkali metal hydroxide as a catalyst.

Growing community of inventors

Hofheim am Taunus, Germany

Dieter Freudenberger