JPS6361300B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for producing an oxime compound, and more particularly, to a method for producing an oxime compound by a novel reaction using a substituted oxime compound having a 2-alkenyloximino group as a starting material. . (Prior art) Since oxime compounds have a highly chemically active hydroxyl group, it is necessary to protect other functional groups as substituted oxime compounds that can withstand various reaction conditions when performing desired conversions. .
Conventionally, a method for deprotecting a protected oxime compound after the desired reaction and returning it to a hydroxyimino group is to hydrogenate an oxime compound having a benzyloxyimino group [Helv.Chim.
Acta, 60 , 2294 (1977)] and a method of treating a compound having a phenylthiomethoxyimino group with a mercury compound [J.Org.Chem, 38 , 3749 (1973)]. However, the former method cannot be used for oxime compounds having double bonds, and the latter method requires a large amount of mercury compounds, which poses problems such as difficulty in practical use. [Problems to be Solved by the Invention] Therefore, the present inventors have made intensive studies to solve these technical drawbacks, and have developed a novel product using an oxime compound having a 2-alkenyloximino group as a starting material. They discovered a reaction and completed the present invention. [Means for Solving the Problems] Thus, according to the present invention, a substituted oxime compound having a 2-alkenyloxyimino group is brought into contact with a platinum group metal compound catalyst in the presence of formic acid or a salt thereof, and 2-alkenyloxy A method for producing an oxime compound is provided, which comprises converting an imino group to a hydroxyimino group. In the present invention, a substituted oxime compound having a 2-alkenyloxyimino group represented by the general formula [] is used as a starting material. In the formula, R ₁ , R ₂ , R ₃ , R ₄ and C ₅ represent hydrogen or a hydrocarbon residue such as a methyl group, an ethyl group, a phenyl group, etc., and X is an oxime obtained by removing a hydroxyimino group from an oxime compound. Represents a residue of a compound. Specific examples of the 2-alkenyl group in the above formula include allyl group, methallyl group, crotyl group,
Prenyl group, 2-pentenyl group, 2-ethyl-2
-Butenyl group, cinnamyl group, geranyl group, neryl group, etc. are exemplified. The number of carbon atoms in the 2-alkenyl group may be appropriately selected in consideration of the separation of the alkene produced after the reaction, the ease of obtaining raw materials, etc., but those having 10 or less carbon atoms are usually used. In particular, when the number of carbon atoms is 5 or less, the by-produced alkene can be removed from the system in gaseous form. The number of 2-alkenyloxyimino groups in the oxime compound is usually one, but is not limited to this, and may have two or more 2-alkenyloxyimino groups. On the other hand, the oxime compound represented by X=N-OH (X is the same as above) is not particularly limited, and may be any aliphatic, alicyclic, or aromatic compound. . In addition, carbon-carbon double bonds, carbon-carbon triple bonds, carboxyl groups, hydroxyl groups, amino groups, carbonyl groups, epoxy groups, cyano groups, sulfonyl groups, sulfone groups, ester bonds, (including lactones), ether bond,
It may contain one or more reactive sites such as thioether bonds, acetal bonds, acid amide bonds, chlorine atoms, etc. Although the molecular weight of such an oxime compound does not significantly affect the reaction, those having a molecular weight of 5,000 or less, particularly those having a carbon number of 100 or less are used. The substituted oxime compound represented by the above general formula [] may be synthesized by a conventional method. For example, in the case of allyloxyiminocyclohexane, a method in which cyclohexanone oxime and allyl bromide are reacted in the presence of a base is used. Therefore, it can be easily synthesized. In the present invention, a catalyst consisting essentially of a platinum group metal compound, preferably a platinum group metal compound and a ligand, is used in the reaction. The platinum group metal compound is a salt or complex of palladium, ruthenium, platinum, rhodium, etc., and specific examples thereof include tris(dibenzylideneacetone)nipalladium(o), tris(tribenzylideneacetylacetone)tripalladium(o) , palladium acetate, palladium propionate, palladium butyrate, palladium benzoate, palladium acetylacetonate, palladium nitrate, palladium sulfate,
Examples include palladium chloride, dihydrotetrakis(triphenylphosphine)ruthenium, ruthenium acetylacetonate, platinum acetate, platinum acetylacetonate, and the like. Among the platinum group metals, palladium is preferable in terms of reactivity, and it is particularly preferable to use zero-valent olefin complexes or divalent organic compounds. The ligand used is an electron-donating compound having a group element of the periodic table, namely nitrogen, phosphorus, arsenic or antimony, as a coordinating atom;
Specific examples include nitrogen-containing compounds such as pyridine, quinoline, trimethylamine, triethylamine, tributylamine, α,α′-dipyridyl, and 1,10-phenanthroline; triethylphosphine, tri-n-butylphosphine, and triphenyl. phosphine, tri-o-tolylphosphine,
Tri-p-biphenylphosphine, tri-o-methoxyphenylphosphine, phenyldiphenoxyphosphine, triethylphosphite, tri-
n-butyl phosphite, tri-n-hexyl phosphite, triphenyl phosphite, tri-
Phosphorus-containing compounds such as o-tolylphosphite, triphenylthiophosphite, α,β-ethylenedi(diphenyl)phosphine, α,β-ethylenedi(diethyl)phosphine, α,β-ethylenedi(dibutyl)phosphine, etc.; triethyl arsenic Examples include arsenic-containing compounds such as , tributylarsenic, and triphenylarsenic; antimony-containing compounds such as tripropylantimony and triphenylantimony. Among these, phosphorus-containing compounds are preferred in terms of reaction activity, selectivity, economic efficiency, and the like. The amount of such a ligand used is usually 0.1 mole or more per mole of the platinum group metal compound, and from the viewpoint of reaction activity, it is preferably used in an amount of 1 mole or more, particularly 2 to 20 moles. The amount of catalyst used in the present invention is appropriately selected, but usually the platinum group metal compound is used per 100 moles of raw material.
It is used in a proportion of 0.01 to 10 mol, preferably 0.1 to 5 mol. In addition, this usage amount is 2-
This is for a raw material having one alkenyloxyimino group, and in the case of a raw material having a plurality of 2-alkenyloxyimino groups, the amount is increased according to the number. Although the platinum group metal compound and the ligand may be reacted in advance, the catalyst is usually prepared by bringing each component into contact with each other in a reaction system. In the present invention, the reaction is carried out in the presence of formic acid or a formate salt. Specific examples of such formates include ammonium salts such as ammonium formate, pyridine formate, morpholine formate, monomethylamine formate, diellamine formate, trimethylamine formate, triethylamine formate, and triethanolamine formate; metal salts such as sodium formate and calcium formate. can be mentioned. Among these, organic amine salts of formic acid are preferred in terms of reactivity and solubility. The amount of formic acid or formate to be used is appropriately selected, but is usually one or more molecules, preferably 2 to 5 molecules, per protected oxime in the raw material. The reaction of the present invention is carried out by contacting the starting material with a catalyst in the presence of formic acid or a formate salt. According to this reaction formula, the protected hydroxyimino group is deprotected, and at the same time, an olefin corresponding to the 2-alkenyl group and carbon dioxide gas are produced as by-products. The reaction temperature is usually 20°C or higher, preferably 50°C or higher.
The temperature is 150°C, and the reaction time is usually 5 minutes to 24 hours. In addition, a diluent may be present during the reaction,
Specific examples include nitriles such as acetonitrile, propionitrile, butyronitrile, and benzonitrile; amides such as dimethylformamide, diethylformamide, dimethylacetamide, dimethylpropioamide, and N-methylpyrrolidone; tetrahydrofuran, dioxane, Ethers such as dibutyl ether, ethylene glycol dimethyl ether, etc.; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.; Esters such as methyl acetate, ethyl acetate, propyl acetate, methyl propionate, etc.; methanol, ethanol, propanol ,
Alcohols such as ter-butanol, ethylene glycol, diethylene glycol monoethyl ether, etc.; Sulfoxides such as dimethyl sulfoxide, diethyl sulfoxide, etc.; n-
Examples include hydrocarbons such as hexane, cyclohexane, benzene, toluene, and xylene. Among them, nitriles, amides, ethers, and alcohols are preferred. Furthermore, water may be added to the diluent to increase the compatibility between the formate and the raw material. These diluents typically have a starting material concentration of 1
It is used in a proportion of ~50% by weight, and its use can improve reaction activity and catalyst stability. After the reaction is completed, a highly pure oxime compound can be obtained by separating the target product from the reaction solution using conventional methods such as solvent extraction, distillation, recrystallization, etc. The oxime compounds thus obtained are compounds having various structures, such as aliphatic, alicyclic, or aromatic, and are useful as industrial chemicals, medicines, agriculture, intermediates thereof, and the like. (Effects of the Invention) Thus, according to the present invention, an easily available compound can be used as a catalyst, and the desired oxime compound can be produced with high activity and high selectivity. Further, while it was difficult to deprotect oximes having unsaturated bonds using conventional methods, the present invention allows easy deprotection while maintaining unsaturated bonds. (Example) The present invention will be described in more detail with reference to Examples below. Example 1 Allyloxyiminocyclohexane in the reactor
0.5 mol, palladium acetate 0.005 mol, triphenylphosphine 0.02 mol, triethylamine formate
Prepare 1.5 moles, 20 moles of ethanol, and 12 moles of water.
It was heated under reflux conditions and stirred for 1 hour. After the reaction,
After ethanol was distilled off under reduced pressure, 10 mol of methylene chloride was added to the residue, and the mixture was washed with saturated brine. After concentrating the solvent, the residue was purified by silica gel chromatography to obtain cyclohexanone oxime in a yield of 95 mol%. In addition, when the reaction mixture was quantitatively analyzed by gas chromatography before purification, the reaction proceeded quantitatively. Example 2 An experiment was conducted in the same manner as in Example 1 except that palladium compounds shown in Table 1 were used in place of palladium acetate. The results are shown in Table 1.

[Table] Example 3 An experiment was carried out in the same manner as in Example 1 except that formic acid compounds shown in Table 2 were used in place of triethylamine formate. For comparison, similar experiments were conducted using morpholine and sodium acetoacetate, which are known as allyl acceptors for allyl transfer reactions. The results are shown in Table 2.

[Table] Example 4 An experiment was carried out in the same manner as in Example 1 except that the ligands shown in Table 3 were used in place of triphenylphosphine and the reaction was carried out for a predetermined period of time. The results are shown in Table 3.

[Table] Example 5 An experiment was conducted in the same manner as in Example 1 except that the compounds shown in Table 4 were used as starting materials.
The results are shown in Table 4.

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Claims (1)

[Claims] 1. An oxime compound characterized by contacting a substituted oxime compound having a 2-alkenyloxyimino group with a platinum group metal compound catalyst in the presence of formic acid or a salt thereof to convert the 2-alkenyloxyimino group into a hydroxyimino group. manufacturing method.