Organic compounds -- part of the class 532-570 series – Organic compounds – Carboxylic acids and salts thereof
Patent
1993-09-13
1994-06-14
Prescott, Arthur C.
Organic compounds -- part of the class 532-570 series
Organic compounds
Carboxylic acids and salts thereof
C07C 5116
Patent
active
053211561
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention relates to a process for the production of alkali metal salts of 3-hydroxypropionic acid by oxidation of propane-1,3-diol in aqueous alkaline solution in the presence of a palladium catalyst.
STATEMENT OF RELATED ART
3-Hydroxypropionic acid and its salts are valuable building blocks in organic synthesis. 3-Hydroxypropionic acid is normally prepared by addition of water onto acrylic acid or by reaction of ethylene chlorohydrin with sodium cyanide and subsequent hydrolysis of the .beta.-propiolactone formed [Ullmann's Encyclopoedia of Industrial Chemistry, 5th Edition, Vol. A-13, pages 507-517]. Both processes involve the handling of toxic substances. Accordingly, a search was made for a process by which toxicologically safe propane-1,3-diol, which can readily be obtained in high yields from glycerol by fermentation, could be converted by oxidation into 3-hydroxypropionic acid or alkali metal salts thereof.
The oxidation of propane-1,3-diol, hereinafter referred to in brief as diol, in presence of a noble metal catalyst is known from the literature. Thus, published Japanese patent application JP 56/5433 (Sanyo) claims a process for the production of malonic acid by reaction of propane-1,3-diol with oxygen or an oxygen-containing gas. The process is preferably carried out in the presence of a platinum group catalyst. According to the Sanyo application, malonic acid can be obtained in high yields using 3.3% by weight palladium, based on the diol.
DESCRIPTION OF THE INVENTION
Object of the Invention
The problem addressed by the present invention was to provide a process by which propane-1,3-diol could be oxidized in high yields to 3-hydroxypropionic acid.
Summary of the Invention
According to the invention, this problem has been solved by a process for the production of an alkali metal salt of 3-hydroxypropionic acid by reaction of propane-1,3-diol with oxygen or an oxygen-containing gas in aqueous alkaline solution in the presence of a palladium-containing supported catalyst, characterized in that the catalyst is used in a quantity corresponding to 0.1 to 3.0% by weight of palladium, based on propane-1,3-diol.
Description of the Preferred Embodiments
Palladium on a solid support, for example active carbon or aluminum oxide, is used as the catalyst, the quantity of palladium in the catalyst being from 0.5 to 10% by weight and preferably from 2 to 5% by weight, based on the support.
The practicability of the process according to the invention is attributable to the fact that the predominant formation of 3-hydroxypropionic acid (selective oxidation of propane-1,3-diol) takes priority over the competitive formation of malonic acid (complete oxidation of propane-1,3-diol) where the low catalyst concentration according to the invention, based on the diol, is used.
In one preferred embodiment of the invention, the quantity of palladium present in the catalyst, based on propane-1,3-diol, is between 0.1 and 1.0% by weight.
It has been found that high yields of 3-hydroxypropionic acid are obtained even when, over and above the palladium present, the catalyst additionally contains platinum and/or bismuth. The total quantity of platinum and/or bismuth should be at most twice the quantity by weight of palladium. Particularly good results have been obtained with a catalyst containing 4% by weight of palladium, 1% by weight of platinum and 5% by weight of bismuth on powdered active carbon.
The catalyst is normally activated before use. This is readily done by dispersing the catalyst in water and subsequently contacting it with inert gases, for example hydrogen and/or nitrogen, to displace adhering oxygen.
The catalyst may be repeatedly reused in the process according to the invention without any losses of yield having to be accepted. On the contrary, it has even been found that the catalyst only develops its full activity after it has been used at least once to three times.
The concentration of the diol in the reaction mixture is not subject to any particular limitations,
REFERENCES:
patent: 3897489 (1975-07-01), Sheng
patent: 4082788 (1978-04-01), Mims
patent: 4296242 (1981-10-01), Nagabhushan et al.
patent: 4435598 (1984-03-01), Hinnenkamp
Chemical Abstracts, vol. 86, No. 13, Mar. 28, 1977, Columbus, Ohio; Abstract No. 89185k.
Behr Arno
Botulinski Andreas
Carduck Franz-Josef
Schneider Michael
Henkel Kommanditgesellschaft auf Aktien
Jaeschke Wayne C.
Prescott Arthur C.
Szoke Ernest G.
Wisdom, Jr. Norvell E.
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