Organic compounds -- part of the class 532-570 series – Organic compounds – Carboxylic acids and salts thereof
Reexamination Certificate
2000-07-05
2002-11-05
Rotman, Alan L. (Department: 1625)
Organic compounds -- part of the class 532-570 series
Organic compounds
Carboxylic acids and salts thereof
C562S499000, C562S508000, C562S537000, C562S538000
Reexamination Certificate
active
06476258
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a process for producing anaryloxyacetic acid, particularly to a process for producing an aryloxyacetic acid wherein an oxygen-containing gas is made act on an aryloxyethanol in an aqueous medium using a specific catalyst.
A process in which an oxygen-containing gas is made act on an aryloxyethanol by using a platinum-based catalyst in an alkali aqueous medium has been known as a process for producing an aryloxyacetic acid. For example, there have been known a process which uses platinum, or palladium and bismuth, or lead as a catalyst (JP-A-62-28940), a process which uses palladium and silver as a catalyst (JP-A-3-500653), and a process which uses palladium and antimony or tellurium as a catalyst (JP-A-3-38544).
However, these catalysts have a problem that catalyst components were eluted into the reaction mass after completion of the reactions. This problem has hindered recycling of the catalyst.
The present inventors have conducted extensive study to find a catalyst whose components are suppressed to be eluted into a reaction mass, and have found that catalysts comprising a combination of palladium and an indium compound and/or a copper compound are excellent in anti-elution property.
In known process for producing aryloxyacetic acid, the production is carried out in the presence of one or more equivalence ratio of alkali based on the raw material, aryloxyethanol. The present inventors have also conducted extensive study on a process which is carried out in the practical absence of alkali, and have found that among platinum-based catalysts, only catalysts containing platinum as a main component can exhibit an effect as an oxidation catalyst even in the practical absence of alkali.
The present inventors have made further investigation and have accomplished the present invention.
SUMMARY OF THE INVENTION
The present invention provides an industrially advantageous process for producing an aryloxyacetic acid represented by the formula (2):
wherein m represents an integer of 1 or 2, n represents an integer from 0 to 4. Ar represents an aromatic hydrocarbon ring, each Rs independently represents an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, a cycloalkoxy group, an aryloxy group, a halogen atom, an alkylcarbonyl group, an arylcarbonyl group, a carboxyl group or a nitro group,
comprising a step in which an oxygen-containing gas is made act on an aryloxyethanol represented by the formula (1):
(R)n-Ar&Parenopenst;O—CH
2
.CH
2
.OH)
m
(1)
wherein m, n, Ar and R, respectively, have the same meanings as defined above,
under conditions of using a catalyst comprising palladium and an indium compound and/or a copper compound in an aqueous medium and in the presence of 0.5 m or more equivalent of alkali per one mole of the aryloxyethanol represented by the formula (1); or
under conditions of using a platinum catalyst, in an aqueous medium and in the absence of alkali or in the presence of less than 0.5 m equivalent of alkali per one mole of the aryloxyethanol represented by the formula (1).
PREFERRED EMBODIMENTS OF THE INVENTION
The present invention uses an aryloxyethanol represented by the above general formula (1) as a raw material In the formula, Ar represents an aromatic hydrocarbon ring. Examples of the aromatic hydrocarbon ring include benzene ring or naphthalene ring. When Ar is a benzene ring, the aryloxyethanol of formula (1) is represented by the general formula (1-1):
wherein m, n, and R, respectively, have the same meanings as defined above.
In these formulae, each Rs independently represent an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, a cycloalkoxy group, an aryloxy group, a halogen atom, an alkylcarbonyl group, an arylcarbonyl group, a carboxyl group or a nitro group.
Examples of the alkyl group as R include linear or branched hydrocarbon groups having from 1 to 12 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, t-butyl, pentyl, isopentyl, t-amyl, hexyl, isohexyl, heptyl, isoheptyl, t-octyl, isooctyl, nonyl, isononyl, decyl, ilsodecyl, undecyl, isoundecyl, dodecyl and isododecyl. Among them, linear or branched hydrocarbon groups having from 1 to 6 carbon atoms are preferred.
Examples of the cycloalkyl group include cyclic hydrocarbon groups having from 5 to 9 carbon atoms such as cyclopentyl and cyclohexyl Examples of the aryl group include phenyl and naphthyl. Examples of the alkoxy group include alkoxy groups having an alkyl moiety with from about 1 to about 12 carbon atoms, such as methoxy, ethoxy, propoxy, butoxy, isobutoxy, t-butoxy, pentoxy, isopentoxy, hexoxy and isohexoxy. Examples of the cycloalkoxy group include cyclopentoxy and cyclohexoxy Examples of the aryloxy group include phenoxy and naphthoxy.
The halogen atom includes fluorine, chlorine, bromine, iodine and the like, and preferred are chlorine and bromine. Preferred alkylcarbonyl groups are lower alkylcarbonyl groups having from 1 to 6 carbon atoms such as an acetyl group. Examples of the arylcarbonyl group include a benzoyl group.
Representative examples of the ayloxyethanol include 2-phenoxyethanol, 2-(2-methylphenoxy)ethanol, 2-(3-methylphenoxy)ethanol, 2-(4-methylphenoxy)ethanol, 2-(2-ethylphenoxy)ethanol, 2-(3-ethylphenoxy)ethanol, 2-(4-ethylphenoxy)ethanol, 2-(2-propylphenoxy)ethanol, 2-(3-propylphenoxy)ethanol, 2-(4-propylphenoxy)ethanol, 2-(2-isopropylphenoxy)ethanol, 2-(3-isopropylphenoxy)ethanol, 2-(4-isopropylphenoxy)ethanol, 2-(2-cyclopentylphenoxy)ethanol, 2-(3-cyclopentylphenoxy)ethanol, 2-(4-cyclopentylphenoxy)ethanol, 2-(2-cyclohexylphenoxy)ethanol, 2-(3-cyclohexylphenoxy)ethanol, 2-(4-cyclohexylphenoxy)ethanol, 2-(biphenyl-2-yloxy)ethanol, 2-(biphenyl-3-yloxy)ethanol, 2-(biphenyl-4-yloxy)ethanol, 2-(2-naphthalene-1-ylphenoxy)ethanol, 2-(3-naphthalene-1-ylphenoxy)ethanol, 2-(3-naphthalene-1-ylphenoxy)ethanol, 2-(2-naphthalene-2-ylphenoxy)ethanol, 2-(3-naphthalene-2-ylphenoxy)ethanol, 2-(4-naphthalene-2-ylphenoxy)ethanol, 2-(2-chlorophenoxy)ethanol, 2-(3-chlorophenoxy)ethanol, 2-(4-chlorophenoxy)ethanol, 2-(2-bromophenoxy)ethanol, 2-(3-bromophenoxy)ethanol, 2-(4-bromophenoxy)ethanol, 2-(2-acetylphenoxy)ethanol, 2-(3-acetylphenoxy)ethanol, 2-(4-acetylphenoxy)ethanol, 2-(2-benzoylphenoxy)ethanol, 2-(3-benzoylphenoxy)ethanol, 2-(4-benzoylphenoxy)ethanol, 2-(naphtalene-1-yloxy)ethanol, 2-(naphtalene-2-yloxy)ethanol, 1,2-bis(hydroxyethoxy)benzene, 1,3-bis(hydroxyethoxy)benzene, and 1,4-bis(hydroxyethoxy)benzene Among them, phenoxyethanol, 1,2-bis(hydroxyethoxy)benzene, 1,3-bis(hydroxyethoxy)benzene, and 1,4-bis(hydroxyethoxy)benzene and the like are preferable. Particularly preferred is 1,3-bis(hydroxyethoxy)benzene.
The present Invention provides a process in which an oxygen-containing gas is made act on the above-mentioned aryloxyethanol represented by the formula (1)
under conditions of using a catalyst comprising palladium and an indium compound and/or a copper compound (hereinafter, abbreviated by “Pd/In,Cu catalyst”) in an aqueous medium and in the presence of 0.5 m or more equivalent of alkali per one mole of the aryloxyethanol represented by the formula (1); or
under conditions of using a platinum catalyst (hereinafter, abbreviated by “Pt catalysts”), in an aqueous medium, and in the absence of alkali or in the presence of less than 0.5 m equivalent of alkali per one mole of the aryloxyethanol represented by the formula (1).
In the present invention, when the oxygen-containing gas is made act in an aqueous medium and in the presence of 0.5 m or more equivalent of alkali per one mole of the aryloxyethanol represented by the formula (1), a catalyst comprising palladium as a first component and a copper compound and/or an indlum compound as a second component is used. An atomic ratio of the second component to palladium is generally from about 0.01 to about 20, preferably from about 0.1 to about 10.
The palladium useful in the catalyst of this invention can be in a variety of forms. Elemental palladium metal can be used. Other palladium
Ishikawa Junichi
Komatsu Masashi
Reyes Hector M
Rotman Alan L.
Sumitomo Chemical Company Limited
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