Organic compounds -- part of the class 532-570 series – Organic compounds – Carboxylic acids and salts thereof
Reexamination Certificate
1999-05-27
2001-08-21
Killos, Paul J. (Department: 1623)
Organic compounds -- part of the class 532-570 series
Organic compounds
Carboxylic acids and salts thereof
Reexamination Certificate
active
06278019
ABSTRACT:
TECHNICAL FIELD
The present invention relates to (1) a Process for acyloxylating side chain of alkyl substituted aromatic compounds by causing the alkyl group substituted aromatic compound and a carboxylic acid and/or a carboxylic anhydride to react with each other in the presence of an oxygen containing gas, and catalysts used for said reaction, and (2) a method for producing a cinnamic acid by causing a benzylidene diacetate to react in the presence of a basic catalyst.
Alkyl group substituted aromatic compounds acyloxylated and diacyloxylated at the side chain (in the present invention, these compounds may be simply called compounds acyloxylated at the side chain) are useful for perfumes, and benzyl alcohols and benzaldehydes obtained by hydrolyzing them are useful for intermediate products of agricultural chemicals, pharmaceuticals and perfumes and also for resin additives. Cinnamic acids are useful for intermediate products of agricultural chemicals, pharmaceuticals and perfumes.
PRIOR ARTS
As methods for producing an alkyl group substituted aromatic compound acyloxylated or diacyloxylated at the side chain from the corresponding alkyl group substituted aromatic compound, (1) Japanese Patent Publication (Kokoku) No. 51-45572 discloses a method of using a cobalt compound as a catalyst in a liquid phase in the presence of acetic anhydride, and (2) Japanese Patent Laid-Open (Kokai) No. 56-10486 and Japanese Patent Laid-Open (Kokai) No. 56-57723 disclose a method of using a cobalt compound and/or a manganese compound as a catalyst and a halogen compound as a co-catalyst in a liquid phase in the presence of acetic anhydride.
As methods for synthesis of a cinnamic acid, (3) Journal of American Chemical Society, Vol. 79, P. 220 (1957), U.S. Pat. No. 3470151, etc. disclose the Perkin reaction that a benzaldehyde reacts with acetic anhydride in the presence of sodium acetate, and (4) Journal of American Chemical Society, Vol. 69, P. 852 (1947), U.S. Pat. No. 3470151, etc. discloses the Knoevenagel condensation reaction wherein benzoaldehydes react with malonic acid in the presence of organic base catalyst such as pyridine.
DISCLOSURE OF THE INVENTION
However, in the methods for producing an alkyl group substituted aromatic compound acyloxylated or diacyloxylated at the side chain from the corresponding alkyl group substituted aromatic compound, method (1) is very low in the rate of producing the compound diacyloxylated at the side chain and also low in selectivity. Method (2) is still insufficient in production rate and also low in the selectivity of the compound diacyloxylated at the side chain, though the rate of producing the compound diacyloxylated at the side chain is improved by using a halogen compound as a co-catalyst.
Furthermore, the ammonium ions in the ammonium bromide used as a co-catalyst are oxidized during reaction, to produce 2 moles of water from 1 mole of ammonium ions. As a result, the carboxylic anhydride existing in the reaction system quickly reacts with the produced water, to be converted into the carboxylic acid. That is, if ammonium ions exist in the reaction system, the decomposition of the carboxylic anhydride acting as an acetoxylating agent occurs significantly. Furthermore, also when crystal water is contained in the catalyst or co-catalyst, the decomposition of the carboxylic anhydride occurs significantly for the same reason.
Furthermore, since the catalysts used in said methods (1) and (2) are soluble in the reaction solution, it is difficult to recover them. Even if they can be recovered, a complicated recovery operation is necessary. So, these methods are not preferable as industrial methods for producing an alkyl group substituted aromatic compound diacyloxylated at the side chain from the corresponding alkyl group substituted aromatic compound.
Moreover, in the methods for synthesis of a cinnamic acid, said methods (3) and (4) are insufficient in the yield of the cinnamic acid, and to improve the yield, acetic anhydride or malonic acid must be used in an excessive amount for the substrate. In addition, said method (4) has a problem that expensive malonic acid must be used, and is not a preferable industrial method for producing a cinnamic acid. Furthermore, the benzaldehyde as a starting raw material is relatively unstable and if it is allowed to stand in air, it is gradually oxidized, to be converted into a benzoic acid. So, its handling is difficult.
An object of the present invention is to provide a method for acyloxylating an alkyl group substituted aromatic compound at the side chain, which is high in reaction efficiency, industrially applicable and high in productivity.
Another object of the present invention is to provide catalysts used for acyloxylating an alkyl group substituted aromatic compound at the side chain, which is high in reaction efficiency and can be easily separated from the reaction solution.
A further other object of the present invention is to provide a method for producing a cinnamic acid at a high yield, which is industrially applicable and high in productivity.
To solve the above problems, the inventors studied intensively, and as a result found that if (1) a solid catalyst in which at least one selected from cobalt, cerium and manganese is supported on a solid material or (2) a catalyst containing at least one selected from cobalt oxides, cerium oxides and manganese oxides is used, an alkyl group substituted aromatic compound and a carboxylic acid and/or a carboxylic anhydride can be caused to react with each other efficiently in the presence of an oxygen containing gas, and in addition, that the catalyst can be easily separated from the reaction solution. Furthermore, it was found that (3) a compound diacyloxylated at the side chain can be produced with high selectivity if a cerium compound is used as a catalyst in the absence of a cobalt compound and a manganese compound. Moreover, it was found that (4) if a halogen compound containing neither crystal water nor ammonium ion is used when a solid catalyst in which at least one selected from cobalt, cerium and manganese is supported on a solid material or a catalyst containing at least one selected from cobalt oxides, cerium oxides and manganese oxides is used as a catalyst, or when a cerium compound is used as a catalyst in the absence of a cobalt compound and a manganese compound, while said halogen compound is used as a co-catalyst, then an alkyl group substituted aromatic compound and a carboxylic anhydride can be caused to react with each other efficiently in the presence of an oxygen containing gas, and in addition that the decomposition of the carboxylic anhydride can be inhibited. It was also found that (5) if a halogen compound is supplied to the reaction system continuously or intermittently during reaction when a solid catalyst in which at least one selected from cobalt, cerium and manganese is supported on a solid material or a catalyst containing at least one selected from cobalt oxides, cerium oxides and manganese oxides is used as a catalyst, or when a cerium compound is used as a catalyst in the absence of a cobalt compound and a manganese compound, while said halogen compound is used as a co-catalyst, then an alkyl group substituted aromatic compound and a carboxylic acid and/or a carboxylic anhydride can be caused to react with each other efficiently in the presence of an oxygen containing gas. Thus, the present invention has been completed.
Furthermore, it was found that if a benzylidene diacetate is used as a raw material as a new method for producing a cinnamic acid, the corresponding cinnamic acid can be produced at a high yield, to complete the present invention.
That is, the present invention provides a method for acyloxylating an alkyl group substituted aromatic compound at the side chain, in which an alkyl group substituted aromatic compound and a carboxylic acid and/or a carboxylic anhydride are caused to react with each other in the presence of an oxygen containing gas, to produce an alkyl group substituted aromatic compound acyloxylated
Kato Tetsuya
Minomiya Eiichi
Miyata Satoru
Nakatani Jiro
Killos Paul J.
Schnader Harrison Segal & Lewis LLP
Toray Industries Inc.
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