PROCESS FOR THE PREPARATION OF HYDROXYARYLGLYOXYLIC ACIDS AND THEIR ALKALI SALTS, AND THEIR USE IN THE PREPARATION OF SODIUM-PARA-HYDROXYPHENYL GLYOXYLATE

PCT No. PCT/FR81/00108 Sec. 371 Date Apr. 20, 1982 Sec. 102(e) Date Apr. 20, 1982 PCT Filed Aug. 27, 1981 PCT Pub. No. WO82/00821 PCT Pub. Date Mar. 18, 1982.The invention relates to a process for preparation of hydroxyarylglyoxylic acids starting from hydroxyarylglycolic acids, by catalytic oxidati...

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Bibliographic Details
Main Authors VALLEJOS, JEAN-CLAUDE, SCHOUTEETEN, ALAIN, CHRISTIDIS, YANI
Format Patent
LanguageEnglish
French
Published 15.02.1984
Subjects
ACYCLIC OR CARBOCYCLIC COMPOUNDS
CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY
CHEMISTRY
METALLURGY
ORGANIC CHEMISTRY
PERFORMING OPERATIONS
PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
THEIR RELEVANT APPARATUS
TRANSPORTING
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Summary:PCT No. PCT/FR81/00108 Sec. 371 Date Apr. 20, 1982 Sec. 102(e) Date Apr. 20, 1982 PCT Filed Aug. 27, 1981 PCT Pub. No. WO82/00821 PCT Pub. Date Mar. 18, 1982.The invention relates to a process for preparation of hydroxyarylglyoxylic acids starting from hydroxyarylglycolic acids, by catalytic oxidation in an aqueous alkaline medium to pH higher than, or equal to, 11.5, through oxygen or oxygen-containing gas, characterized in that it is carried out in homogeneous phase at a temperature lower than, or equal to, 30 DEG C., and in the presence of cupric ions, and in that at the end of the reaction, the desired acid is isolated from the reactional medium through acidification to pH of about 0.5. The sodium parahydroxyphenylglyoxylate is obtained when acidification is stopped at pH=5, at the end of the reaction.
Bibliography:Application Number: EP19810401352