Organic compounds -- part of the class 532-570 series – Organic compounds – Carboxylic acid esters
Reexamination Certificate
2000-01-07
2001-11-06
Padmanabhan, Sreeni (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Carboxylic acid esters
C568S449000, C568S471000, C568S472000, C568S473000
Reexamination Certificate
active
06313343
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a method of production of &agr;-oxoaldehyde by vapor phase reaction, and a method of production of &agr;-oxocarboxylate by vapor phase reaction.
Glyoxal and pyruvic aldehyde (methyl glyoxal) as typical &agr;-oxoaldehyde are chemical compounds very useful in industrial fields, used as various products such as a fiber processing agent, a paper processing agent, a soil hardening agent, or as intermediate materials for various products. Further, glyoxylate as typical &agr;-oxocarboxylate is an industrially useful chemical compound: for example, sodium polyacetal carboxylate, which is obtained from polymer of glyoxylate, is used as a builder for detergents and the like. Further, glyoxylic acid obtained by hydrolysis of glyoxylate is a very useful compound especially for intermediate materials of various products such as medical products, cosmetics, perfumes, and agricultural chemicals.
BACKGROUND ART
Conventionally, a method of production of &agr;-oxoaldehyde by oxidative dehydrogenation of alkylene glycol in the presence of a silver catalyst has been known. For example, the following methods are known: a method of obtaining glyoxal at a yield in the 60% order by oxidative dehydrogenation of ethylene glycol, which is the simplest alkylene glycol, with use of metallic silver (silver crystal) as a catalyst, whose particle diameter is in a range of 0.1 mm to 2.5 mm (the Japanese Examined Patent Publication 54011/1986 (Tokukosho 61-54011, Date of Publication: Nov. 20, 1986); and, a method of obtaining glyoxal at a yield of, for example, 82% by oxidative dehydrogenation of ethylene glycol with use, as a catalyst, of metallic silver modified with a phosphorus-containing compound (the Japanese Publication for Laid-Open Patent Application No. 38227/1983 [Tokukaisho 58-38227, Date of Publication: Mar. 5, 1983], the Japanese Publication for Laid-Open Patent Application No. 59933/1983 [Tokukaisho 58-59933, Date of Publication: Apr. 9, 1983], the Chinese Patent No. 85100530 [Date of Publication: Apr. 1, 1985], Catalysis letters, 36(1996) 207-214 [received Jul. 10, 1995, Accepted Oct. 11, 1995]). Also known are: a method of obtaining glyoxal at a yield of 84% by oxidative dehydrogenation of ethylene glycol to which a vaporized phosphorus-containing compound has been added, with use of a granulated metallic silver as a catalyst (the Japanese Publication for Laid-Open Patent Application No.232835/1991 [Tokukaihei 3-232835, Date of Publication: Oct. 16, 1991]); and, a method of obtaining glyoxal at a yield in the 70% order by oxidative dehydrogenation of ethylene glycol with use of, as a catalyst, metallic silver carried by a carrier such as silicon carbide or silicon nitride (The Japanese Examined Patent Publication No.32648/1996 [Tokukohei 8-32648, Date of Publication: Mar. 29, 1996]). In these methods, since glyoxal highly tends to be polymerized, a lot of water (1-3.5 times of ethylene glycol in molarity) is supplied (together with other materials) to a reaction system, so that glyoxal produced is taken out in, for example, a 40-percent-by-weight (wt %) aqueous solution state, as a manufactured product.
The foregoing methods, however, cannot be regarded as methods capable of producing glyoxal at a sufficiently high yield and at a high concentration.
On the other hand, the inventors of the present invention, etc., have proposed, as a method of producing &agr;-oxocarboxylate from &agr;-oxoaldehyde, a method wherein &agr;-oxoaldehyde and alcohol as materials are oxidative-esterified with use of oxygen and a catalyst (the Japanese Publication for Laid-Open Patent Application No.118650/1997 [Tokukaihei 9-118650, Date of Publication: May 6, 1997]). By the foregoing method, by, for example, heating 40 wt % aqueous solution of glyoxal as the simplest &agr;-oxoaldehyde available in the market, glyoxal in a gaseous state is obtained as a material. To supply vaporized glyoxal to a reaction system, however, sometimes involves difficulties from the viewpoint of industrial application, since the polymerizability of glyoxal is very high. Besides, it follows that glyoxylate as &agr;-oxocarboxylate is obtained in the presence of water in the reaction system, and hence, glyoxylate is sometimes hydrolyzed thereby, possibly along with other factors, causing the yield to decrease.
In other words, the foregoing conventional methods have a drawback of being incapable of producing &agr;-oxoaldehyde at a high yield. Further, the same have a drawback of being incapable of stably obtaining a high-concentration &agr;-oxoaldehyde solution or gas. Moreover, because of these drawbacks involved in the foregoing methods, there further arises a problem that it is impossible to produce &agr;-oxocarboxylate at a high yield.
The present invention has been made in light of the foregoing conventional problems, and an object of the present invention is to provide a method wherein &agr;-oxoaldehyde, at a higher concentration than conventionally, in a solution state or in a gaseous state, can be stably produced at a higher yield than conventionally. Another object of the present invention is to provide a method wherein &agr;-oxocarboxylate is produced at a higher yield than conventionally.
DISCLOSURE OF THE INVENTION
The inventors eagerly studied a method of production of &agr;-oxoaldehyde and a method of production of &agr;-oxocarboxylate, in order to achieve the above object. As a result, it was found that &agr;-oxoaldehyde could be produced at a higher yield than conventionally by vapor phase oxidation of alkylene glycol in the presence of alcohol (a), oxygen, and a catalyst, and besides, &agr;-oxoaldehyde solution or gas could be stably obtained at a higher concentration than conventionally. Further, it was also found that &agr;-oxocarboxylate could be produced at a higher yield than conventionally by vapor phase oxidation of the &agr;-oxoaldehyde obtained by the foregoing method and, for example, alcohol (b) in the presence of oxygen and a catalyst. The present invention was completed based on these findings.
More specifically, to achieve the aforementioned object of the present invention, a method of production of &agr;-oxoaldehyde in accordance with the present invention is characterized in that alkylene glycol is oxidized in a vapor phase in the presence of alcohol (a), oxygen, and catalyst. Further, the method of production of &agr;-oxoaldehyde in accordance with the present invention is characterized in that a molar ratio of alkylene glycol to alcohol (a) is in a range of 1/100 to 5/1.
To achieve the aforementioned object of the present invention, a method of production of &agr;-oxocarboxylate in accordance with the present invention is characterized by including the steps of oxidizing alkylene glycol in a vapor phase in the presence of alcohol (a), oxygen, and a catalyst so as to obtain &agr;-oxoaldehyde, and thereafter oxidizing the &agr;-oxoaldehyde, and alcohol (b) or olefin, in a vapor phase in the presence of oxygen and a catalyst. Further, the method of production of &agr;-oxocarboxylate in accordance with the present invention is characterized in that one and same compound is used as the alcohol (a) and the alcohol (b). Moreover, the method of production of &agr;-oxocarboxylate in accordance with the present invention is characterized in that the alcohol (a) contains unreacted alcohol (b) that is contained in reactant gas resultant from vapor phase oxidation of &agr;-oxoaldehyde and alcohol (b).
For a fuller understanding of the nature and advantages of the invention, reference should be made to the ensuing detailed description taken in conjunction with the accompanying drawings.
REFERENCES:
patent: 5750768 (1998-05-01), Arita et al.
patent: 85100530 (1986-03-01), None
patent: 52-17408 (1977-02-01), None
patent: 58-38227 (1983-03-01), None
patent: 58-59933 (1983-04-01), None
patent: 58-124730 (1983-07-01), None
patent: 60-199846 (1985-10-01), None
patent: 61-54011 (1986-11-01), None
patent: 3-4104
Arita Yoshitaka
Ariyoshi Kimio
Ohta Akihiko
Saito Noboru
Alexander John B.
Conlin David G.
Edwards & Angell LLP
Nippon Shokubai Co. , Ltd.
Padmanabhan Sreeni
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