Organic compounds -- part of the class 532-570 series – Organic compounds – Carboxylic acid esters
Reexamination Certificate
2001-01-26
2002-12-03
Rotman, Alan L. (Department: 1625)
Organic compounds -- part of the class 532-570 series
Organic compounds
Carboxylic acid esters
C560S177000, C560S178000
Reexamination Certificate
active
06489505
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a process for producing 3,3-dimethyl-2-formylcyclopropane-carboxylic acid ester.
BACKGROUND OF THE INVENTION
3,3-dimethyl-2-formylcyclopropanecarboxylic acid ester has been known as an intermediate compound of insecticidally effective chrysanthemic acid ester derivatives.
As a process for producing 3,3-dimethyl-2-formyl-cyclopropanecarboxylic ester, for example, there have been known a method of ozone-oxidizing of chrysanthemic acid (for example, GP-B 46-24695), a method of using periodic acid (US-H49) and the like. However, these methods have been not always satisfactory in that the former method has a problem of handling of ozone having a strong toxicity and explosive property, and the latter has a problem in that expensive periodic acid is required.
SUMMARY OF THE INVENTION
According to the present invention, 3,3-dimethyl-2-formylcyclopropanecarboxylic esters can be readily produced by using hydrogen peroxide and the catalyst below.
The present invention provides:
a process for producing 3,3-dimethyl-2-formylcyclopropanecarboxylic acid ester of formula (1):
wherein R represents an alkyl group, a cycloalkyl group or an optionally substituted aralkyl group,
which comprises reacting 3,3-dimethyl-2-(2-methyl-1-propenyl)-cyclopropanecarboxylic acid ester of formula (2):
wherein R represents the same meaning as defined above, with hydrogen peroxide in the presence of at least one catalyst selected from tungstic oxide, tungstic acid, tugstate, alkylrhenium oxide, molybdic oxide, molybdate, a heteropoly acid comprising a hetero atom selected from a phosphorus, boron or silicone atom and a poly atom selected from tungsten or molybdenum and a salt of said heteropoly acid.
DETAILED DESCRIPTION
First, a description will be made to the 3,3-dimethyl-2-(2-methyl-1-propenyl)-cyclopropanecarboxylic acid ester, (chrysanthemic acid ester) of formula (2) as defined above.
Chrysanthemic acid theoretically has (+)-isomer and (−)-isomer resulting from stereochemical configuration around the asymmetric carbon atom connected with the carboxyl group and said isomers have a cis-isomer and a trans-isomer relating to the relative configuration of said carboxyl group and the propenyl group connected with the carbon atom adjacent to the said asymmetric carbon atom in the cyclopropane ring. In the present process, a chrysanthemic acid ester containing said (+)-isomer and (−)-isomer in an optional ratio or respective isomer alone can be used without affecting the stereochemistry of the product. For example, (+)-trans isomer, (−)-trans-isomer, (+)-cis isomer, or (−)-cis isomer of the above described chrysanthemic acid esters and an optional mixture thereof can be used in the present process.
Examples of the alkyl group represented by R in formulae (1) and (2) include a linear or branched lower alkyl group having 1-5 carbon atoms. Specific examples thereof include a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a n-pentyl group and the like.
Examples of the cycloalkyl group represented by R in formulae (1) and (2) include a cycloalkyl group having 3-10 carbon atoms. Specific examples thereof include a cyclopropyl,group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a menthyl group and the like.
Examples of the optionally substituted aralkyl group include a phenyl- or naphthyl-substituted (C1-C5)alkyl group, of which phenyl group or naphthyl group may be substituted with at least one group selected from the linear or branched lower alkyl group having 1-5 carbon atoms as described above, a lower alkoxy group having 1-5 carbon atoms, a halogen atom, a haloalkyl group having 1-5 carbon atoms, a phenoxy group, and an alkoxyalkyl group having 2-4 carbon atoms.
Preferred phenyl- or naphthyl-substituted alkyl group is a benzyl group.
Examples of the lower alkoxy group having 1-5 carbon atoms include a methoxy, ethoxy, isopropoxy, n-propoxy, n-butoxy, isobutoxy, s-butyl, n-pentyl group and the like.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and the like.
Examples of the haloalkyl group having 1-5 carbon atoms include a chloromethyl group, a fluoromethyl group, a trifluoromethyl group and the like.
Examples of the alkoxyalkyl group having 2-4 carbon atoms include a methoxymethyl group and the like.
Specific examples of the optionally substituted aralkyl group include a benzyl group, a 4-chlorobenzyl group, a 4-methylbenzyl group, a 4-methoxybenzyl group, a 4-phenoxybenzyl group, a 2,3,5,6-tetrafluorobenzyl group, a 2,3,5,6-tetrafluoro-4-methylbenzyl group, a 2,3,5,6-tetrafluoro-4-methoxybenzyl group, a 2,3,5,6-tetrafluoro-4-methoxymethylbenzyl group and the like.
Specific examples of the chrysanthemic acid ester (1) include methyl chrysanthemate, ethyl chrysanthemate, isopropyl chrysanthemate, cyclohexyl chrysanthemate, menthyl chrysanthemate, benzyl chrysanthemate, 4-chlorobenzyl chrysanthemate, 2,3,5,6-tetrafluorobenzyl chrysanthemate, 2,3,5,6-tetrafluoro-4-methylbenzyl chrysanthemate, 2,3,5,6-tetrafluoro-4-methoxybenzyl chrysanthemate, 2,3,5,6-tetrafluoro-4-methoxymethylbenzyl chrysanthemate, 4-phenoxybenzyl chrysanthemate, and the like. A (+)-trans isomer, a (−)-trans-isomer, (+)-cis isomer, (−)-cis isomer, a cis/trans or (+)/(−) mixture of the above-described chrysanthemate are also included in the specific examples.
Examples of the catalyst include tungstic trioxide, tungstic acid and tugstate such as sodium tungstate, potassium tungstate, magnesium tungstate,
molybdic trioxide, molybdic acid, and molybdate such as sodium molybdate, potassium molybdate, ammonium molybdate, bis(2,4-acetylacetonato)molybdenum dioxide and the like.
Examples of the alkylrhenium oxide include a (C
1
-C
5
)alkylrhenium trioxide such as methylrhenium trioxide, ethylrhenium trioxide, n-propylrhenium trioxide, n-butylrhenium trioxide, n-pentylrhenium trioxide or the like.
Examples of the heteropoly acid comprising a hetero atom selected from a phosphorus, boron or silicone atom and a poly atom selected from tungsten or molybdemun and a salt thereof include phosphotungstic acid, silicotungstic acid, borotungstic acid, phosphomolybdic acid, silicomolybdic acid, boromolybdic acid and a salt thereof with lithium, sodium, potassium, magnesium or calcium.
The catalysts described above may be an anhydrate or a hydrate.
An amount of the catalyst to be used is usually 0.001-0.95 mole per mol of the chrysanthemic acid ester (2).
Hydrogen peroxide is usually used as an aqueous hydrogen peroxide solution or a solution of hydrogen peroxide in an organic solvent. The concentration of hydrogen peroxide in an aqueous solution or in an organic solvent is not particularly limited but it is usually 1 to 60% by weight in view of production efficiency of the process. A commercially available aqueous hydrogen peroxide solution is usually used as it is or the concentration of the aqueous solution may be optionally adjusted, for example, by dilution, concentration or the like.
The solution of hydrogen peroxide in an organic solvent can be prepared by extracting an aqueous hydrogen peroxide solution with an organic solvent. Alternatively it may be prepared by removing water from a mixture of an aqueous hydrogen peroxide solution and an organic solvent. Said removal of water can be made by azeotropic distillation of the aqueous hydrogen peroxide solution with an organic solvent that forms an azeotrope with water or dehydration with a dehydrating agent.
An amount of hydrogen peroxide to be used is usually 1 mole or more per mol of the chrysanthemic acid ester (2) and the upper limit thereof is not particularly limited and it is usually 50 moles or less from an economical viewpoint.
For example, the reaction of 3,3-dimethyl-2-(2-methyl-1-propenyl)cyclopropanecarboxylic acid ester (2) with hydrogen peroxide may be conducted in a water-immiscible organic solvent by using dehydrate
Hagiya Koji
Komoto Ichiro
Kurihara Akio
Birch & Stewart Kolasch & Birch, LLP
Reyes Hector M.
Rotman Alan L.
Sumitomo Chemical Company Limited
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