Chemie Linz Gesellschaft M.b.h.

Chemie Linz Gmbh

Hubert Stuckler

Engelbert Kloimstein

Wilhelm Dobramysl

Lorenz Farnleitner

Herbert Kaiser

A process for the preparation of color-stable levulinic acid by saponification of acetylsuccinates with aqueous mineral acids, by continuously treating the starting products with steam in counter-current in a reactor cascade, the reaction being carried out above the boiling point of the alcohol being formed in the reaction or above the boiling point of the aqueous azeotrope being formed.

Process for the preparation of storage-stable levulinic acid

Process for the preparation of pure 1-phenyl-3-carbalkoxy-5-hydroxypyrazoles of the general formula ##STR1## in which R denotes methyl or ethyl, by reaction of acetylsuccinic esters with phenyldiazonium chloride and a base with pK.sub.B value of 3.6 to -1.5 at a pH of 4 to 9 in an aqueous medium to give the corresponding phenylhydrazone, which is cyclized at a pH of 7 to 9.5, with warming and with the addition of ammonia, to give the ammonium salt of the hydroxypyrazole. Compound I is formed by acidification.

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Linz, Austria

Hubert Stuckler