Dsm Chemie Linz Gmbh

Dsm Fine Chemicals Austria Nfg Gmbh & Co. Kg

Chemie Linz Gesellschaft M.b.h.

Dsm Fine Chemicals Austria Gmbh

Eduard Perndorfer

Klaus Reiter

Karl Heinz Giselbrecht

Engelbert Kloimstein

Karlheinz Giselbrecht

Wolfram Hendel

Karl Schermanz

Christian Burger

Rudolf Hermanseder

Josef Schaller

Antonia Praus

Manfred Schoftner

Rudolf Neuhofer

Process for the preparation of 2,3-pyridinedicarboxylic acids

Process for preparing glyoxylic esters or their hydrates in which a water-soluble salt of a maleic or fumaric monoester or a mixture thereof is reacted with ozone in aqueous solution at temperatures of from 0 to 50.degree. C., and the corresponding glyoxylic ester or its hydrate is isolated from the resulting reaction mixture.

Process for preparing glyoxylic esters and their hydrates

Process for the purification of o-phthalaldehyde in which an alcoholic solution containing the crude, unpurified o-phthalaldehyde is adjusted to a pH between 0 and 3 at a temperature between 0.degree. and 60.degree. C., then an alkaline solution is added, and the corresponding dialkoxyphthalan is extracted from the organic phase and purified by distillation and, when required, converted into the purified o-phthalaldehyde by hydrolysis.

Process for the purification of o-phthalaldehyde

A process for preparing an aqueous o-phthalaldehyde-glutaraldehyde solution which comprises converting an acetal of the o-phthalaldehyde in a 10 to 60% strength aqueous glutaraldehyde solution into o-phthalaldehyde at room temperature up to 100.degree. C. by eliminating the corresponding alcohol, and removing the eliminated alcohol to give the aqueous o-phthalaldehyde-glutaraldehyde solution.

Process for preparing aqueous o-phthalaldehyde-glutaraldehyde solutions

Process for the preparation of alpha, omega-alkanedicarboxylic acids of the general formula I ##STR1## in which A is an alkylene radical having 4-14 C atoms by reacting a cycloalkene of the general formula II ##STR2## in which A has the abovementioned meaning with ozone in the presence of an inert solvent, catalytically hydrogenating the peroxide solution formed, followed by oxidation of the dialdehyde formed to the diacid of the formula I in the presence of an inert aprotic solvent.

Process for the preparation of alpha, omega-alkanedioic acids

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Traun, Austria

Eduard Perndorfer