Chemistry of carbon compounds – Miscellaneous organic carbon compounds – C-metal
Patent
1976-02-24
1977-09-13
Killos, Paul J.
Chemistry of carbon compounds
Miscellaneous organic carbon compounds
C-metal
C07C 5914
Patent
active
040482251
ABSTRACT:
Pure racemic acid (dl-tartaric acid) and meso tartaric acid are produced by reaction of an alkali maleate with aqueous hydrogen peroxide in the presence of a catalyst which is an alkali molybdate or a mixture of an alkali molybdate and alkali tungstate in a process wherein the molar ratio of hydrogen peroxide to maleic acid is greater than 1:1 and the alkali salt of cis-epoxysuccinic acid formed together with the catalyst in a given case after destroying the excess hydrogen peroxide and other peroxygen compounds, are converted to free cis-epoxysuccinic acid and free molybdic acid or mixture of free molybdic acid and free tungstic acid by leading them over a strongly acidic cation exchanger, whereupon the hydrolysis of the free cis-epoxysuccinic acid to racemic acid and meso-tartaric acid can take place either in the presence of or the absence of the free molybdic acid or mixture of free molybdic acid and free tungstic acid, whereby the catalyst in the case of catalyst free hydrolysis before, and in the case of catalyst containing hydrolysis after this hydrolysis is removed with an anion exchanger and the racemic acid is then in known manner crystallized out of the catalyst free hydrolysis mixture by lowering the temperature in a given case with evaporation of water, whereupon the meso-tartaric acid remains in the mother liquor, and there is recovered from the mother liquor either by crystallization or by evaporation to dryness, in a given case in admixture with racemic acid, unreacted cis-epoxysuccinic acid and maleic acid, while the anion exchanger laden with the molybdic acid or mixture of molybdic acid and tungstic acid is regenerated in known manner with dilute aqueous alkali and, in a given case, the resulting solution of alkali molybdate or mixture of alkali molybdate and alkali tungstate, eventually after treatment with activated carbon is returned directly into the epoxidation step.
REFERENCES:
patent: 2437648 (1948-03-01), Miles
patent: 3825223 (1975-04-01), Yonemitsu et al.
Prescher Gunter
Schreyer Gerd
Deutsche Gold- und Silber-Scheideanstalt vormals Roessler
Killos Paul J.
LandOfFree
Process for the production of pure racemic acid and mesotartaric does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for the production of pure racemic acid and mesotartaric, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for the production of pure racemic acid and mesotartaric will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-273865