JPH11263762A - Production of amic acid compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject compound under mild conditions simply and in high yield by reacting a specific Schiff base with a specific saturated aliphatic dicarboxylic halide in a specific solvent for dehalogenation/hydrogenation. SOLUTION: This amic acid compound shown by formula III, e.g. N-(2- ethoxyethyl)-N-(1-phenylethenyl)oxamic acid, is obtained by reacting (A) a Schiff base shown by formula I [R<1> is an aryl which may contain a hetero atom selected from the group consisting of O, S and N; R<2> and R<3> are each H or an alkyl, where R<2> and R<3> are connected to each other to form a cycloalkyl ring; R<4> is an alkyl; and (m) is 1 to 6], e.g. N-(1-phenyl)ethylidene- ethoxymethylamine) with (B) a saturated aliphatic dicarboxylic halide shown by formula II [X is a halogen; and (n) is 0 to 4] in (C) a solvent, e.g. pentane, having a dielectric constant of 8 or less for dehalogenation/hydrogenation at -20 to 120 deg.C for 0.1 to 30 h.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing an amic acid compound. Specifically, the present invention provides a method for producing an amic acid compound in a high yield by reacting a Schiff base compound with a saturated aliphatic dicarboxylic acid halide.

[0002]

2. Description of the Related Art An amic acid compound represented by the above general formula (3) is useful as an intermediate for producing a pesticidal drug substance. For example, Japanese Patent Publication No. 5-15699 discloses an N- (1-alkenyl) -chloroacetamide compound or the like as a herbicide raw material, but it can also be used as a production intermediate of these compounds.

[0003] As a method for producing such an amide acid compound, an amide acid ester is obtained by reacting a Schiff base compound or an amine compound with a half ester of a dicarboxylic acid, and then the ester portion is hydrolyzed. There is a way to get

However, in the above-mentioned method using a half ester of amic acid, the ester moiety must be hydrolyzed under severe conditions of heating to reflux in the presence of an acid or alkali, and such conditions are unstable. It cannot be applied to a simple compound.

It is considered that such a problem can be solved by using a dicarboxylic acid instead of a half ester of a dicarboxylic acid in the above method, since the ester hydrolysis step can be omitted. However,
There are few reports on such a method, and the only one examined by the present inventors is the Journal of Chromatography, page 359 (1).
986) merely shows an example in which a Schiff base compound and oxamic acid chloride are reacted in the presence of a dichloromethane solvent. Looking at the result of the reaction, a compound in which both terminals of oxamic acid chloride have reacted (hereinafter, in the present invention, a compound in which both terminals of saturated aliphatic dicarboxylic acid halide have reacted is referred to as a dimer) )
Was generated, and the desired amic acid compound could not be obtained at all.

[0006]

As described above, a method for efficiently producing an amic acid compound has not been known until now. An object of the present invention is to provide a method for producing an amic acid compound easily and in a high yield under mild conditions.

[0007]

Means for Solving the Problems The present inventors have intensively studied to solve the above problems. As a result, when a Schiff base compound represented by the above formula (1) is used as a starting material and reacted with a saturated aliphatic dicarboxylic acid halide in the presence of a specific solvent, one of the saturated aliphatic dicarboxylic acid halides is reacted. It was found that only the acid halide moiety was dehalogenated, and that all of these reactions proceeded under mild conditions near room temperature and quantitatively,
The present invention has been completed.

That is, the present invention provides the following general formula (1)

[0009]

Embedded image

(Wherein R ¹ is a substituted or unsubstituted aryl group or a substituted or unsubstituted one or two heteroatoms selected from the group consisting of oxygen, sulfur and nitrogen atoms) A heteroaryl group of R ²
And R ³ are each independently a hydrogen atom or an alkyl group; R ² and R ³ may be linked to each other to form a cycloalkyl ring; R ⁴ is a substituted or unsubstituted alkyl group; m represents an integer of 1 to 6. ) And a Schiff base compound represented by the following general formula (2)

[0011]

Embedded image

(Where X represents a halogen atom, and n represents 0)
Represents an integer of from 4 to 4. ) Is reacted with a saturated aliphatic dicarboxylic acid halide represented by the following formula (3) in a solvent having a dielectric constant of 8 or less to obtain a compound represented by the following general formula (3):

[0013]

Embedded image

Wherein R ¹ , R ² , R ³ , R ⁴ , m and n
Is the same as the general formula (1) and the general formula (2). A method for producing an amic acid compound, characterized by obtaining an amic acid compound represented by｝.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION As a raw material in the production method of the present invention, a Schiff base compound represented by the above general formula (1) (hereinafter, also referred to as a raw Schiff base) is used.

As can be seen by comparing the general formulas (1) and (3), the structure of the target amic acid compound is basically determined by the structure of the starting Schiff base.
For this reason, the above R ¹ , R ² , R ³ ,
R ⁴ and m are each appropriately selected depending on the structure of the amic acid compound as the target substance.

In the general formula (1), R ¹ comprises a substituted or unsubstituted aryl group or one or two hetero atoms selected from the group consisting of oxygen, sulfur and nitrogen. It is a substituted or unsubstituted heteroaryl group.

Preferred examples of the unsubstituted aryl group in R ¹ include a phenyl group, an anthranyl group,
A group having 6 to 14 carbon atoms such as a phenanthrenyl group is exemplified. Examples of suitable groups as the unsubstituted heteroaryl group include a furyl group, a thienyl group, a pyrrolyl group, a pyridyl group, a pyrimidinyl group, a benzofuryl group, a benzothienyl group, an indolyl group, a quinolyl group, a thiazolyl group, and a pyrazolyl group. And heteroaryl groups having 3 to 8 carbon atoms, such as a group, an oxazolyl group and a benzooxazolyl group.

In the above R ¹ , the substituted aryl group and the substituted heteroaryl group include, as the above unsubstituted groups, an alkyl group such as a methyl group, an ethyl group and a propyl group;
Chlorine atom, bromine atom, iodine atom, halogen atom such as fluorine atom, alkoxy group such as methoxy group, ethoxy group, propoxy group, alkylthio group such as methylthio group, ethylthio group, propylthio group, cyano group, nitro group, and amino And a group substituted with a group. Specific examples of a substituted aryl group and a substituted heteroaryl group that can be suitably used include a methylphenyl group, an ethylphenyl group, a propylphenyl group, a butylphenyl group, a hexylphenyl group, a dimethylphenyl group, and a methyl (ethyl) phenyl group. , Ethyl (prolyl) phenyl, chlorophenyl, bromophenyl, fluorophenyl, dichlorophenyl, methoxyphenyl, ethoxyphenyl, propoxyphenyl, dimethoxyphenyl, cyanophenyl, nitrophenyl, chloro (methyl)
Phenyl, methyl (methoxy) phenyl, methylthiophenyl, (trifluoromethyl) phenyl,
(Dimethyl) aminophenyl group, chloro (nitro) phenyl group, methylnaphthyl group, chloronaphthyl group, methoxynaphthyl group, dimethylnaphthyl group, methylfuryl group,
Methoxythienyl group, chlorothienyl group, methylthienyl group, methylpyrrolyl group, chloropyrrolyl group, methylpyridyl group, chloropyridyl group, dimethoxypyrimidinyl group, methoxybenzofuryl group, chlorobenzofuryl group,
Examples include a methylbenzothienyl group, a methylindolyl group, a methylquinolyl group, a methylthiazolyl group, a methylpyrazolyl group, a methyloxazolyl group, and a methylbenzooxazolyl group.

In the general formula (1), R ² and R ³ are each independently a hydrogen atom or an alkyl group, and R ² and R ³ may be mutually connected to form a cycloalkyl ring.

Preferred examples of the alkyl group include methyl, ethyl, propyl, i-propyl, butyl, i-butyl, s-butyl, t-butyl, pentyl, hexyl, and heptyl. Examples thereof include a linear or branched alkyl group having 1 to 12 carbon atoms such as a group, an octyl group, a nonyl group, and a decyl group.

Preferred examples of the cycloalkyl ring formed when R ² and R ³ are linked to each other include cyclopentyl and cyclohexyl.

In the general formula (1), R ⁴ is a substituted or unsubstituted alkyl group, and preferred examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group and a heptyl group. Examples thereof include groups having 1 to 12 carbon atoms such as a group, an octyl group, a nonyl group, and a decyl group. Further, as the substituent of the substituted alkyl group, a chlorine atom, a bromine atom, an iodine atom, a halogen atom such as a fluorine atom, a methoxy group, an ethoxy group, an alkoxy group such as a propoxy group,
Specific examples of suitable substituted alkyl groups include alkylthio groups such as methylthio group, ethylthio group and propylthio group, alkoxycarbonyl groups such as methoxycarbonyl group and ethoxycarbonyl group, cyano group, nitro group and amino group. For example, fluoromethyl, trifluoromethyl, chloromethyl, chloroethyl, bromoethyl, chloropropyl, chlorohexyl, methoxymethyl, methoxyethyl, methoxypropyl, methoxybutyl, ethoxymethyl, ethoxymethyl Ethyl group, ethoxypropyl group, butoxymethyl group, butoxyethyl group, phenoxymethyl group, phenoxyethyl group,
Cyanopropyl group, cyanobutyl group, nitroethyl group,
Nitropropyl group, ethylthiomethyl group, propylthiomethyl group, methylthioethyl group, ethylthioethyl group,
N, N-diethylaminoethyl group, N, N-diethylaminopropyl group, phenylmethyl group, phenylethyl group, methoxythienylmethyl group, methoxycarbonylmethyl group, methoxycarbonylethyl group, ethoxycarbonylethyl group and the like.

In the general formula (1), m represents an integer of 1 to 6. (CH ₂ ) _m O particularly preferred in combination with the above R ⁴
Specific examples of the alkoxyalkyl group represented by R ⁴ include a methoxymethyl group, a methoxyethyl group, a methoxypropyl group, a methoxybutyl group, a methoxypentyl group,
Methoxyhexyl, ethoxymethyl, ethoxyethyl, ethoxypropyl, ethoxybutyl, ethoxypentyl, ethoxyhexyl, propoxymethyl, propoxyethyl, pentoxyethyl, chloromethoxymethyl, chloromethoxyethyl Chloroethoxyethyl group, methoxymethoxymethyl group, methoxyethoxymethyl group, methoxyethoxyethyl group, ethoxymethoxymethyl group, ethoxymethoxyethyl group, ethoxyethoxymethyl group, ethoxyethoxyethyl group and the like.

Of the starting Schiff bases, compounds that can be suitably used are specifically exemplified by N- (1-phenyl) ethylidene-methoxymethylamine, N- (1-phenyl) ethylidene-ethoxymethylamine, (1-phenyl) ethylidene-ethoxyethylamine, N- (1
-Phenyl) propylidene-ethoxymethylamine, N
-(1-phenyl) propylidene-ethoxyethylamine, N- (1-phenyl) propylidene-pentoxyethylamine, N- (1-phenyl) propylidene-ethoxymethoxyethylamine, N- (2-methyl-1-phenyl) propylidene- Ethoxymethylamine, N-
(2-methyl-1-phenyl) propylidene-ethoxyethylamine, N- (2-methyl-1-phenyl) propylidene-ethoxypropylamine, N- (2-methyl-1-phenyl) propylidene-chloroethoxyethylamine, N- (1-phenyl) butylidene-methoxymethylamine, N- (2-ethyl-1-phenyl) hexylidene-methoxybutylamine, N- (2-propyl-
1-phenyl) octylidene-methoxyhexylamine, N- (cyclohexylphenyl) methylidene-ethoxymethylamine, N- [2-methyl-1- (9-anthranyl)] propylidene-ethoxyethylamine, N
-[2-methyl-1- (3-oxazolyl)] propylidene-ethoxyethylamine, N- [2-methyl-1-
(P-propylphenyl)] propylidene-ethoxyethylamine, N- [2-methyl-1- (p-fluorophenyl)] propylidene-ethoxyethylamine, N-
[2-methyl-1- (p-propoxyphenyl)] propylidene-ethoxyethylamine, N- [2-methyl-
1- (p-cyanophenyl)] propylidene-ethoxyethylamine, N- [2-methyl-1- (2-pyridyl)] propylidene-ethoxyethylamine, N- [2
-Methyl-1- (2-benzofuryl)] propylidene-
Ethoxyethylamine, N- [2-methyl-1- (3-
Quinolyl)] propylidene-ethoxyethylamine, N
-[2-methyl-1- (1-naphthyl)] propylidene-ethoxyethylamine, N- [2-methyl-1- (2
-Thienyl)] propylidene-ethoxyethylamine,
N- [2-methyl-1- (p-chlorophenyl)] propylidene-ethoxyethylamine, N- [2-methyl-
1- (p-tolyl)] propylidene-ethoxyethylamine, N- [2-methyl-1- (p-methylthiophenyl)] propylidene-ethoxyethylamine, N- [2
-Methyl-1- (p-nitrophenyl)] propylidene-ethoxyethylamine, N- [2-methyl-1- (p
-Isocyanophenyl)] propylidene-ethoxyethylamine, N- [2-methyl-1- (2,4-dimethylphenyl)] propylidene-ethoxyethylamine, N
-[2-methyl-1- (2-methyl-4-thiazolyl)] propylidene-ethoxyethylamine, N- [2
-Methyl-1- (4-methoxy-2-thienyl)] propylidene-ethoxyethylamine, N- [2-methyl-
1- (4-chloro-2-pyridyl)] propylidene-ethoxyethylamine, and the like.

The saturated aliphatic dicarboxylic acid halide used as another raw material in the production method of the present invention (hereinafter also referred to as a raw material dicarboxylic acid halide) is represented by the general formula (2).

In the general formula (2), X represents a halogen atom. Specifically, it is selected from fluorine, chlorine, bromine and iodine, but a chlorine atom is preferred for industrial reasons. In the general formula (2), n represents an integer of 0 to 4.

Specific examples of the starting dicarboxylic acid halide used in the present invention include oxamic acid fluoride, oxamic acid chloride, oxamic acid bromide, oxamic acid iodide, malonic acid chloride, malonic acid bromide, succinamic acid chloride, and succinamic acid bromide. , Glutaric acid chloride, glutaric acid bromide, adipic acid chloride, adipic acid bromide and the like.

The target amic acid compound in the production method of the present invention is represented by the general formula (3). The structure of the compound is uniquely determined by the type of the starting Schiff base and the starting dicarboxylic acid halide to be used. Therefore,
R ¹ , R ² , R ³ , R ⁴ , m, and n in the general formula (3) are the same as those in the general formulas (1) and (2).

Specific examples of the amic acid compound represented by the general formula (3) include N- (2-methoxymethyl)
-N- (1-phenylethenyl) oxamidic acid, malonic acid, succinamic acid, glutaric acid, or adipic acid; N- (2-ethoxymethyl) -N- (1-phenylethenyl) oxamidic acid, malonic acid, Succinamic acid, glutaric acid, or adipic acid; N- (2-ethoxyethyl) -N- (1-phenylethenyl) oxamidic acid, malonic acid, succinamic acid, glutaric acid, or adipic acid; N- (2-ethoxy Methyl) -N- (1-
Phenyl-1-propenyl) oxamic acid, malonic acid,
Succinamic acid, glutaric acid, or adipic acid; N
-(2-ethoxyethyl) -N- (1-phenyl-1-
Propenyl) oxamic acid, malonic acid, succinamic acid, glutaric acid, or adipic acid; N- (2-pentoxyethyl) -N- (1-phenyl-1-propenyl)
Oxamic acid, malonic acid, succinamic acid, glutaric acid, or adipic acid; N- (2-ethoxymethoxyethyl) -N- (1-phenyl-1-propenyl) oxamic acid, malonic acid, succinamic acid, glutaric acid, or Adipic acid; N- (2-ethoxymethyl) -N-
(2-methyl-1-phenyl-1-propenyl) oxamic acid, malonic acid, succinamic acid, glutaric acid, or adipic acid; N- (2-ethoxyethyl) -N-
(2-methyl-1-phenyl-1-propenyl) oxamic acid, malonic acid, succinamic acid, glutaric acid, or adipic acid; N- (2-ethoxypropyl) -N-
(2-methyl-1-phenyl-1-propenyl) oxamic acid, malonic acid, succinamic acid, glutaric acid, or adipic acid; N- (2-chloroethoxyethyl)-
N- (2-methyl-1-phenyl-1-propenyl) oxamic acid, malonic acid, succinamic acid, glutaric acid, or adipic acid; N- (2-methoxymethyl)-
N- (1-phenyl-2-butenyl) oxamic acid, malonic acid, succinamic acid, glutaric acid, or adipic acid; N- (2-methoxybutyl) -N- (2-ethyl-1-phenyl-1-hexenyl) ) Oxamidic acid, malonic acid, succinamic acid, glutaric acid, or adipic acid; N- (2-methoxyhexyl) -N- (2-propyl-1-phenyl-1-octenyl) oxamidic acid, malonic acid, succinamic acid, Glutaric acid or adipic acid; N- (2-ethoxymethyl) -N- (cyclohexylphenyl) methenyloxamic acid, malonic acid, succinamic acid, glutaric acid, or adipic acid;
(2-ethoxyethyl) -N- [2-methyl-1- (9
-Anthranyl) -1-propenyl] oxamic acid, malonic acid, succinamic acid, glutaric acid, or adipic acid; N- (2-ethoxyethyl) -N- [2-methyl-1- (3-oxazolyl) -1- Propenyl] oxamic acid, malonic acid, succinamic acid, glutaric acid, or adipic acid; N- (2-ethoxyethyl) -N-
[2-Methyl-1- (p-propylphenyl) -1-propenyl] oxamic acid, malonic acid, succinamic acid, glutaric acid, or adipic acid; N- (2-ethoxyethyl) -N- [2-methyl- 1- (p-fluorophenyl) -1-propenyl] oxamic acid, malonic acid,
Succinamic acid, glutaric acid, or adipic acid; N
-(2-ethoxyethyl) -N- [2-methyl-1-
(P-propoxyphenyl) -1-propenyl] oxamic acid, malonic acid, succinamic acid, glutaric acid, or adipic acid; N- (2-ethoxyethyl) -N-
[2-methyl-1- (p-cyanophenyl) -1-propenyl] oxamic acid, malonic acid, succinamic acid,
Glutaric acid or adipic acid; N- (2-ethoxyethyl) -N- [2-methyl-1- (2-pyridyl) -1
-Propenyl] oxamic acid, malonic acid, succinamic acid, glutaric acid, or adipic acid; N- (2-ethoxyethyl) -N- [2-methyl-1- (2-benzofuryl) -1-propenyl] oxamidic acid; Malonic acid, succinamic acid, glutaric acid, or adipic acid; N-
(2-ethoxyethyl) -N- [2-methyl-1- (3
-Quinolyl) -1-propenyl] oxamic acid, malonic acid, succinamic acid, glutaric acid, or adipic acid; N- (2-ethoxyethyl) -N- [2-methyl-
1- (1-Naphthyl) -1-propenyl] oxamic acid, malonic acid, succinamic acid, glutaric acid, or adipic acid; N- (2-ethoxyethyl) -N- [2-
Methyl-1- (2-thienyl) -1-propenyl] oxamic acid, malonic acid, succinamic acid, glutaric acid,
Or adipic acid; N- (2-ethoxyethyl) -N-
[2-methyl-1- (p-chlorophenyl) -1-propenyl] oxamic acid, malonic acid, succinamic acid,
Glutaric acid or adipic acid; N- (2-ethoxyethyl) -N- [2-methyl-1- (p-tolyl) -1-
Propenyl] oxamic acid, malonic acid, succinamic acid, glutaric acid, or adipic acid; N- (2-ethoxyethyl) -N- [2-methyl-1- (p-methylthiophenyl) -1-propenyl] oxamidic acid; Malonic acid, succinamic acid, glutaric acid, or adipic acid; N- (2-ethoxyethyl) -N- [2-methyl-
1- (p-nitrophenyl) -1-propenyl] oxamic acid, malonic acid, succinamic acid, glutaric acid, or adipic acid; N- (2-ethoxyethyl) -N-
[2-methyl-1- (p-isocyanophenyl) -1-
Propenyl] oxamic acid, malonic acid, succinamic acid, glutaric acid, or adipic acid; N- (2-ethoxyethyl) -N- [2-methyl-1- (2,4-dimethylphenyl) -1-propenyl] oxamide Acid, malonic acid, succinamic acid, glutaric acid, or adipic acid; N- (2-ethoxyethyl) -N- [2-methyl-
1- (2-Methyl-4-thiazolyl) -1-propenyl] oxamic acid, malonic acid, succinamic acid, glutaric acid, or adipic acid; N- (2-ethoxyethyl) -N- [2-methyl-1- (4-methoxy-2-thienyl) -1-propenyl] oxamic acid, malonic acid,
Succinamic acid, glutaric acid, or adipic acid; N
-(2-ethoxyethyl) -N- [2-methyl-1-
(4-chloro-2-pyridyl) -1-propenyl] oxamic acid, malonic acid, succinamic acid, glutaric acid,
Or adipic acid.

In the present invention, it is essential that the starting Schiff base and the starting dicarboxylic acid halide undergo a dehydrohalogenation reaction in the presence of a solvent having a dielectric constant of 8 or less. When a solvent having a dielectric constant of more than 8 is used, the conversion of the reaction decreases and the amount of dimer formed increases, and the yield of the target amic acid compound decreases.

As the solvent having a dielectric constant of 8 or less, a known solvent having a dielectric constant of 8 or less can be used without any limitation.

A specific example of a solvent having a dielectric constant of 8 or less which can be suitably used in the present invention is pentane (1.
8), aliphatic hydrocarbons such as hexane (1.9), heptane (1.9), cyclohexane (2.1), toluene (2.2), benzene (2.3), xylene (ortho or para) ) (2.3) and other aromatic hydrocarbons, 1,4-
Dioxane (2.2), diethyl ether (4.2),
Di-i-propyl ether (4.5), 1,2-dimethoxyethane (5.5), tetrahydrofuran (7.6)
Ethers such as carbon tetrachloride (2.2), halogenated hydrocarbons such as chloroform (4.9), aromatic halogenated hydrocarbons such as chlorobenzene (5.7), and butyl acetate (5.0). ), Esters such as ethyl acetate (6.0), methyl acetate (6.7), and carbon disulfide (2.6)
And the like. The number in parentheses of each solvent represents the dielectric constant at 20 ° C. (25 ° C. for ethers and heptane).

Among the above solvents, when aliphatic hydrocarbons such as hexane, aromatic hydrocarbons such as toluene, and esters such as ethyl acetate are used, the selectivity of the target amic acid compound is high. Since it can be obtained in high yield, it can be used particularly preferably.

These solvents may be used alone or in combination of two or more.

In the production method of the present invention, the starting Schiff base and the starting dicarboxylic acid halide are subjected to a dehydrohalogenation reaction in the presence of a solvent having a dielectric constant of 8 or less as described above. In particular, the process proceeds simply by contacting both starting compounds in a solvent without using a catalyst or the like. In addition, the reaction conditions at that time are not particularly different from the reaction conditions for the normal dehydrohalogenation reaction between a Schiff base compound and a saturated aliphatic dicarboxylic acid halide. Hereinafter, the reaction conditions of the dehydrohalogenation reaction in the production method of the present invention will be described.

Although the amount of the solvent having a dielectric constant of 8 or less used in the reaction is not particularly limited, the concentration of the Schiff base compound represented by the general formula (1) in the solvent is generally 0 from the viewpoint of economy and productivity. 0.1 to 50% by weight, preferably 0.5 to 40
%, More preferably in the range of 1 to 30% by weight.

In the reaction, the method of charging both raw materials is not particularly limited, and one raw material may be added to a reaction vessel and the other raw material may be used as it is or a solution dissolved or suspended in a solvent may be added. Alternatively, a solution in which a part or most of one raw material is insoluble may be added, and then the other raw material may be added. Further, both materials may be charged into the reaction vessel at the same time, or any method may be used. The reaction temperature is not particularly limited, but is usually in the range of −20 to 120 ° C., preferably in the range of −10 to 80 ° C., more preferably −, for reasons of reaction efficiency, generation of by-products, and coloring of the product. It is good to carry out in the range of 10 to 50 ° C.

The reaction can be carried out under any of normal pressure, increased pressure and reduced pressure. The time required for the reaction varies depending on the reaction temperature, the solvent, the type of the raw materials used and the like.
A reaction time of 30 hours is sufficient.

In the dehydrohalogenation reaction, hydrogen halide (hereinafter also referred to as by-product hydrogen halide) is by-produced. This by-produced hydrogen halide may coexist in the system without being removed during the reaction or may be removed out of the system without any adverse effect on the progress of the reaction. When removing the by-product hydrogen halide, the removal method is not particularly limited, for example, a hydrogen halide scavenger is removed coexisting in the reaction system, or removed by performing the reaction under reduced pressure, A method in which an inert gas such as nitrogen is blown into a reaction system to remove the inert gas may be used.

The hydrogen halide scavenger is not particularly limited, and a known one can be used. Generally, the scavengers preferably used include triethylamine, tripropylamine, pyridine, sodium alcoholate,
And sodium carbonate.

When the reaction is carried out under the reduced pressure, the pressure range of the reduced pressure is not particularly limited, but generally it is easily removed in a pressure range of 1.3 × 10 ^{2 to} 1 × 10 ⁵ Pa.

The method for isolating and purifying the desired product, that is, the amic acid compound, from the reaction system in which the dehydrohalogenation reaction has been performed in this manner is not particularly limited, and a known method can be employed. For example, water is added after the reaction, and the residue is extracted with benzene, ether, chloroform, ethyl acetate and the like. Thereafter, if necessary, the organic layer is washed with a dilute hydrochloric acid aqueous solution or a dilute sodium hydroxide aqueous solution, and the organic layer is dried with a desiccant such as sodium sulfate, magnesium sulfate, calcium chloride and the like. Next, the solvent is distilled off, and the residue is purified by column chromatography to obtain the desired product. In addition to being isolated and purified by column chromatography, it can be purified by recrystallization, vacuum distillation or the like depending on the properties of the target product.

[0044]

The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

Example 1 A 100 ml four-necked kolben equipped with a thermometer was charged with N-
1.90 g of (1-phenyl) ethylidene-ethoxyethylamine and pentane as solvent (dielectric constant 1.8)
20 ml were added. Under ice-cooling, 6.35 g of oxamic acid chloride was slowly added dropwise thereto. After dripping the whole amount,
The liquid temperature was returned to room temperature, and the mixture was stirred for 12 hours. When the reaction solution was analyzed by high performance liquid chromatography (hereinafter abbreviated as HPLC), the composition in the reaction solution (hereinafter, also referred to as a production ratio) was represented by the concentration (% by weight) of each component,
The content was 1.5% by weight of a Schiff base compound, 97.2% by weight of an amic acid compound (target substance), and 1.3% by weight of a dimer.

Examples 2 to 54 The same procedure as in Example 1 was carried out except that the Schiff base compounds, saturated aliphatic dicarboxylic acid halides and solvents shown in Tables 1 to 6 were used. Was analyzed by HPLC, and the results are shown in Table 1.

[0047]

[Table 1]

[0048]

[Table 2]

[0049]

[Table 3]

[0050]

[Table 4]

[0051]

[Table 5]

[0052]

[Table 6]

Comparative Examples 1 to 8 The same operation as in Example 1 was carried out except that the solvents shown in Table 7 were used, and the results of HPLC analysis were shown in Table 7.

[0054]

[Table 7]

[0055]

According to the production method of the present invention, an amic acid compound useful as an intermediate for producing an agricultural chemical active substance such as a herbicide can be produced under mild conditions and with a high yield. Furthermore, a sufficiently high purity can be obtained in view of the purity, and it can be said that the production method of the present invention is extremely useful industrially.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C07D 213/40 C07D 213/40 263/06 263/06 277/28 277/28

Claims (1)

[Claims] [Claim 1] The following general formula (1) (Wherein, R ¹ is a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl comprising one or two heteroatoms selected from the group consisting of an oxygen atom, a sulfur atom and a nitrogen atom. R ² and R ³ are each independently a hydrogen atom or an alkyl group; R ² and R ³ may be linked to each other to form a cycloalkyl ring;
⁴ is a substituted or unsubstituted alkyl group, m is 1 to
Represents an integer of 6. ) And a Schiff base compound represented by the following general formula (2): (Wherein, X represents a halogen atom, and n represents an integer of 0 to 4) by a dehydrohalogenation reaction with a saturated aliphatic dicarboxylic acid halide in a solvent having a dielectric constant of 8 or less. And the following general formula (3): 中 In the formula, R ¹ , R ² , R ³ , R ⁴ , m, and n are the same as those in the general formulas (1) and (2). A method for producing an amic acid compound, characterized by obtaining an amic acid compound represented by｝.