Basf Aktiengesellschaft

Basf Corporation

Erwin Brunner

Franz Merger

Klaus Volkamer

Peter Stops

Max Strohmeyer

Alfred Lindner

Karl Gerhard Baur

Gerhard Sandrock

Rolf Hartmuth Fischer

Hugo Fuchs

Leopold Hupfer

Josef Ritz

Gerald Neubauer

Claus-Ulrich Priester

Ulrich Wagner

Heinz Auer

Volker Diehl

Juergen Paetsch

Michael Kopietz

Peter Hettinger

Hans Hellbach

Hans V Schwarz

Eckhardt Brandt

Eckart Schubert

Heribert Deck

Rudolf Weigand

A process for preparing essentially pure 3-chlorophthalic anhydride from a mixture in which 3-chlorophthalic anhydride is present in addition to 4,5-dichlorophthalic anhydride, which involves first distilling off a mixture of 3-chlorophthalic anhydride and 4,5-dichlorophthalic anhydride, so that the obtained bottoms is essentially free of 4,5-dichlorophthalic anhydride, and then by distillation of the obtained bottoms, recovering 3-chlorophthalic anhydride in a second distillation step. The starting mixture is preferably prepared without solvent in a melt by incomplete chlorination of phthalic anhydride using FeCl.sub.3 as a catalyst.

Preparation of 3-chlorophthalic anhydride

The invention relates to a process for removing water traces from a liquid phosgene stream in chemical processes which employ a phosgenation step. Water traces are removed from a liquid phosgene stream containing at least 60 weight percent phosgene by contacting the stream with a strongly basic macroreticular anion exchange resin which catalyzes the reaction between phosgene and the water traces.

Removal of water from a phosgene recycle stream

A process for recovering caprolactam from oligomers and/or polymers of caprolactam comprises the following steps:

Recovery of caprolactam from oligomers and/or polymers of caprolactam

Trialkylamines and methyl formate are recovered from reaction mixtures obtained in the preparation of trimethylolalkanes by reaction of n-alkanals with from 2.2 to 4.5 moles of formaldehyde in aqueous solution in the presence of from 0.6 to 3 mole of trialkylamine, each quantity based on 1 mole of alkanal, and subsequent hydrogenation in a process wherein the crude reaction mixture

Recovery of trialkylamines and methyl formate from mixtures obtained in

A method of separating .gamma.-butyrolactone from a mixture containing ethanol, tetrahydrofuran, water, n-butanol, 1,4-butanediol, diethyl succinate and .gamma.-butyrolactone, by distillation in vacuum columns.

Method of separating .gamma.-butyrolactone from mixtures containing

A process for the preparation of nicotinamide by amidation of a nicotinic acid/nicotinamide melt, vacuum distillation of the amidation mixture, removal of the nicotinamide as the bottom product and recycling of the top product, depleted with respect to nicotinamide, into the amidation stage together with addition of fresh amounts of nicotinic acid.

Preparation of nicotinamide

A process for conjointly preparing methyl tert.-butyl ether and obtaining isobutene from an isobutene-containing C.sub.4 -hydrocarbon mixture. In the process the C.sub.4 -hydrocarbon mixture is reacted, in one or more etherification stages, with methanol and a primary C.sub.3 - or C.sub.4 -alcohol in the presence of an acid condensing agent, the resulting reaction mixture or mixtures are then separated into a fraction containing the unconverted hydrocarbons, the methyl tert.-butyl ether and a fraction containing the C.sub.3 - or C.sub.4 -alkyl tert.-butyl ether. Thereafter, the C.sub.3 - or C.sub.4 -alkyl tert.-butyl ether is decomposed at an elevated temperature, in the presence of an acid catalyst, into isobutene and primary C.sub.3 - or C.sub.4 -alcohol.

Process for conjointly preparing methyl tert.-butyl ether and obtaining

A process for obtaining isobutene from a C.sub.4 -hydrocarbon mixture containing isobutene, by reacting the mixture with a primary alcohol in the presence of an acid condensing agent and decomposing the resulting tertiary ether in the presence of an acid catalyst at an elevated temperature, wherein a primary C.sub.3 - or C.sub.4 -alcohol is used.

Process for obtaining isobutene from C.sub.4 -hydrocarbon mixtures

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Weinheim, Germany

Erwin Brunner