JPH0441471A - Method for producing 2-nitro-5-(substituted phenoxy)benzohydroxymic acid derivative - Google Patents

Abstract

PURPOSE:To obtain a compound useful as a herbicide in a modest condition in high yield with using raw materials of a low cost by reacting nitrobenzohydroximic acid derivative with substituted phenols in the presence of fluoride. CONSTITUTION:5-halogeno-2-nitrobenzohydroximic acid derivative expressed by formula I (R is H, lower alkyl or agriculturally soluble salt ion; R<1> is lower alkyl; R<2> is H or lower alkyl; w is halogen excepting F) is subjected to coupling reaction with substituted phenols expressed by formula II (X and Y are halogen; Z is H or alkali metal) in a solvent such as dimethyl sulfoxide and in the presence of alkali metal fluoride or quaternary ammonium fluoride at 0-40 deg.C to afford the aimed compound expressed by formula III. 0.5-10 mol the compound expressed by formula II and 0.01-10 mol fluoride are used per 1 mol of the compound expressed by formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing 2-nitro-5-(substituted phenoxy)benzohydroxymic acid derivatives, and more particularly, the present invention relates to a method for producing 2-nitro-5-(substituted phenoxy)benzohydroxymic acid derivatives, and more particularly, the present invention relates to a method for producing 2-nitro-5-(substituted phenoxy)benzohydroxymic acid derivatives, and more specifically, the following formula (I) OR'R"OR' R useful as a herbicide: ” In the formula, X and Y each represent the same or different halogen atom, R represents a hydrogen atom, a lower alkyl group, or an agriculturally soluble salt ion, R' represents a lower alkyl group, and R8 represents a hydrogen atom or a lower alkyl group. The present invention relates to a method for producing a 2-nitro-5-(substituted phenoxy)benzohydroxymic acid derivative represented by the following formula.

PRIOR ART Conventionally, as a method for producing the compound of formula (I), it has been known to synthesize according to the steps shown in Reaction Formula A below [see Japanese Patent Laid-Open No. 63-215605].

Reaction formula (A) In the formula, X, Y, R, R', [/"R"i:E have the same meaning as above.

However, the conventional method using a halogenated alkyl compound in the presence of a base in the reaction has the drawback of low selectivity for 0-alkylation.

Furthermore, when R1 in the above formula is a methyl group, diazomethane can be used, but diazomethane is toxic and
This is not an industrially preferred method as it is highly explosive.

Furthermore, as a method for producing 2-nitro-5-(substituted pyridyloxy)benzohydroxymic acid derivative (IV), which is a similar compound to the compound of formula (I), a method shown in the following reaction formula B is described (patent application (See Hei 1-93216).

(v) (Vl) In reaction formula C), it was found that under heated reaction conditions, a decrease in yield was unavoidable due to the formation of decomposition by-products, and that the reaction hardly proceeded under conditions below room temperature.

Reaction formula (C) (IV) In the formula, X represents a hydrogen atom or a halogen atom, and X'
represents bromine, chlorine or fluorine, Y represents a halogen atom, R represents a hydrogen atom, an alkali metal atom or a lower alkyl group, R1 represents a lower alkyl group, R2 represents a hydrogen atom or a lower alkyl group represents.

The present inventors attempted to apply the reaction formula B to the method for producing 2-nitro-5-(substituted phenoxy)benzohydroxymic acid derivative (I) (anti-OR' R2 in which X and Y each represents a halogen atom, R
represents a hydrogen atom, a lower alkyl group or an agriculturally soluble salt ion, R1 represents a lower alkyl group, R2 represents a hydrogen atom or a lower alkyl group, and W represents a halogen atom other than a fluorine atom.

Problems to be Solved Compounds in which W is fluorine, which is not included in the formula (II), will react with the substituted phenol of the formula (n[) under mild conditions below room temperature. This can be easily considered, and this fact has been confirmed by the present inventors, but the raw material fluorine derivative is more expensive than other halogen derivatives.

The object of the present invention is to obtain an excellent herbicidally active compound of the above formula (
The object of the present invention is to find a method for producing the compound I) in good yield using industrially cheaper raw materials and under mild conditions below room temperature.

SUMMARY OF THE INVENTION The present inventors have developed a commercially available 7-enyl ether represented by formula (I) that exhibits high herbicidal activity with a small application amount, has a wide herbicidal spectrum, and has good selectivity for major crops. Intensive research efforts were made to establish the perfect manufacturing method.

As a result, by conducting the reaction in the presence of an alkali metal fluoride or quaternary ammonium heptatide, it is possible to carry out the reaction under milder conditions than conventional reaction conditions,
The present invention was achieved by discovering an industrially advantageous method for producing the phenyl ethers represented by formula (I), which are very useful as herbicides.

That is, according to the present invention, the following formula (I)OR' represents a lower alkyl group, and R2 represents a hydrogen atom or a lower alkyl group. In producing the 2-nitro-5-(substituted phenoxy)benzohydroxymic acid derivative represented by the following formula ([
) % formula % In the formula, R, R' and R: have the same meanings as above, and W represents a halogen atom other than a fluorine atom.
A halogeno-2-nitrobenzohydroxymic acid derivative and the substituted phenol represented by the following formula (I 2-nitro-5 represented by the above formula (I), which is reacted in the presence of a metal heptatride or a quaternary ammonium heptatide.
A method for producing a -(substituted phenoxy)benzohydroxymic acid derivative is provided.

By using an alkali metal fluoride or a quaternary ammonium fluoride, the method of the present invention enables the coupling reaction of compound (It) and compound (III) to be carried out at a lower temperature, and the above formula (1) This is a very useful method for producing the indicated phenyl ethers industrially with good yield.

Further, the compounds represented by formulas (I) and (II) may exist as stereoisomers (syn type and anti type), and both of these are included in the present invention.

The compound represented by the formula (II) used as a starting material in the present invention is described in detail in, for example, Japanese Patent Application No. 1-93216. Regarding the production method of substituted phenols (III), for example, J, Am, Chem, S
oc, Vol. 57, p. 2176 (1935) and Japanese Unexamined Patent Publication No. 1-207253.

DETAILED DESCRIPTION OF THE INVENTION As used herein, the term "lower" means that the group or compound to which this term is attached has no more than 6 carbon atoms, preferably no more than 4 carbon atoms.

The "lower alkyl group" may be linear or branched, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, 5eC-butyl, inbutyl, tert-butyl, n- Examples include pentyl, isoamyl, n-hexyl, and the like. In addition, "halogen atom" includes fluorine, chlorine, bromine and iodine atoms;
Examples of "alkali metals" include sodium, potassium, and lithium.

Examples of agriculturally soluble salt ions of R include inorganic salts such as sodium, potassium, lithium, and calcium, and ammonium salts such as ammonia, methylamine, ethylamine, and inglobilamine.

The alkali metal heptadide used in the present invention includes 7
Sodium tsunide, potassium heptadide, rubidium heptafluoride,
Examples include cesium heptadide.

Among these, potassium heptadide is preferred. 4
Examples of ammonium fluoride include tetrabutylammonium fluoride.

Further, these alkali metal fluorides and quaternary ammonium fluorides are not limited in any way in their shape, and are easily available for industrial use or as reagents. In addition, potassium fluoride treated with various methods, such as Calgin Dry KF (CD-KF), Spray Dry KF (SD-KF), Freeze Dry KF (FD-K
F) etc. can also be used.

The amount of alkali metal fluoride or quaternary ammonium fluoride used is not strictly limited, but is generally in the range of 0.01 to 10 mol, preferably 0.1 to 1 mol, per 1 mol of compound (■). It is appropriate to use it within. The reaction temperature varies depending on the reaction time, but is generally 0°C.
~40''O1 It is suitable to conduct the reaction preferably at a temperature in the range of 10°C to 30°C.The reaction time is 1 hour to 500 hours,
Preferably, it is appropriate to complete the reaction within a range of 1 hour to 200 hours.

In the above reaction, the compound of formula (II) for the compound of formula (n)
Although the proportion of the compound of formula (I) is not strictly limited and can vary within a wide range, it is generally
It is convenient to use the compounds of formula (I[) in amounts ranging from about 0.5 to about 10 mol, preferably from 1 to 2 mol, per mol of compound I).

The present invention can usually be carried out in the presence of a deoxidizing agent, and examples of the deoxidizing agent that can be used include sodium hydroxide, potassium hydroxide, sodium hydride, sodium carbonate, sodium hydrogen carbonate, potassium carbonate, potassium hydrogen carbonate. Preferred examples include basic inorganic compounds such as. The amount used can be selected as appropriate, but for example, about 0.5 to about 3 mol, preferably 1 to 2 mol, per 1 mol of the compound of formula (n).
Examples include amounts within the molar range.

The above reaction can be usually carried out in a solvent, and examples of solvents that can be used include dimethyl sulfoxide, sulfolane, N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, and acetonitrile. Examples include aprotic solvents such as , acetone, and tetrahydro-7rane.

The amount of solvent to be used can be changed as appropriate, for example, for formula (II)
For example, the amount used may be about 2 to about 50 times the weight of the compound.

In this way, the target compound of formula (I) can be produced.

The product obtained by the method of the invention can be separated and/or purified from the reaction mixture by methods known per se, such as extraction, recrystallization, column chromatography and the like.

Next, the method of the present invention will be explained in more detail with reference to Examples.

(i) Methyl (Z)-0-methoxycarbonylmethyl-5-chloro-2-nitrobenzohydroxymate 0.76
g(2,5+u+ole), 2,4-dichloro-3-
Methylphenol 0-44 g (2-5 mmole)
, potassium carbonate 0.52g (3.75mmole)
, potassium fluoride 0.029g (0.5mmole)
, dimethyl sulfoxide (5 ml) was stirred at room temperature for 100 hours. 30ml of water was added and extracted with ethyl acetate.

The organic layer was washed twice with saturated brine, dried over anhydrous sulfuric acid and magnesium, and then the solvent was distilled off under reduced pressure, and a small amount of methanol was added to the residue to precipitate a solid. 1 crystals with methanol
After washing twice and drying, (Z)-〇-methoxycarbonylmethyl-5-2,4-dichloro-3-methylphenoxy)
0.98 g of white crystals consisting of methyl-2-nitrobenzohydroxymate was obtained. (Conversion rate 93%, yield 88%)
Melting point: 102-103°C 'H-NMRδ (ppm XTMS/CDCL) 2.54
(3H,Ar-CH,,S), 3.76(3H,OCH
s, S), 3.85 (3n, OCH3, S), 4.5
8 (2H, OCHz, S), 6.93-7-43 (4H
SAr H, m), 8.06 to 8-17 (IH, ArH
, m) (ii) (Z)-0-Methoxycarbonylmethyl-5-chloro-2-nitrobenzohydroxymate methyl 0.61 g (2, Ommole), 2,4-dichloro-
3-methylphenol 0.39g (2-2mmole
), potassium carbonate 0.55g (4, Ommole)
, tetrabutylammonium fluorite F (1,0M
1nTHF) 2-Omff(2, Ommole),
A mixture of 5 mQ of dimethyl sulfoxide was stirred at room temperature for 72 hours.

30+++Q of water was added and extracted with ethyl acetate. After washing the organic layer twice with saturated brine and drying over anhydrous magnesium sulfate, the solvent was distilled off under reduced pressure, and a small amount of methanol was added to the residue to precipitate a solid. Wash the crystals once with methanol,
After drying, 0.74 g of the desired compound was obtained. (Conversion rate 9
2%, yield 83%) (ii) (Z)-0-Methoxycarbonylmethyl-5-chloro-2-ditropenzohydroxymate methyl 0.76 g (2,5 mmole), potassium-2,4- Dichloro-3-methylphenolate 0.
59g (2°75 mmole), potassium fluoride 0
．． A mixture of 073 g (1.25 mmole) and dimethyl sulfoxide 5+nQ was stirred at room temperature for 120 hours. 30m4 of water was added and extracted with ethyl acetate. After washing the organic layer twice with saturated brine and drying over anhydrous magnesium sulfate, the solvent was distilled off under reduced pressure, and a small amount of methanol was added to the residue to precipitate a solid. The crystals were washed once with methanol and dried to obtain 0.96 g of the target compound. (Conversion rate 97
%, yield 87%) (i) Methyl (Z)-0-methoxycarbonylmethyl-5-riσ-rho-2-nitrobenzohydroxymate 3.93
g (13, Ommole), 2,4-dichloro-
3-Methylphenol 2.30g (13.0mm.

le), potassium carbonate 3.59 g (26, Ommole
), a mixture of 26 ml of dimethyl sulfoxide at 50°
The mixture was heated at C for 8 hours. After cooling, 150 ml of water was added and extracted with ethyl acetate. Wash the organic layer twice with saturated saline,
After drying over anhydrous magnesium sulfate, the solvent was distilled off under reduced pressure, and a small amount of methanol was added to the residue to precipitate a solid. The crystals were washed once with methanol and dried to give (2)-0-methoxycarbonylmethyl-5-(2,4-dichloro-3
3.62 g of methyl (-methylphenoxy)-2-ditropenzohydroxymate was obtained. (Conversion rate 95%, yield 63
%) (ii) (Z)-0-methoxycarbonylmethyl-
Methyl 5-chloro-2-ditropenzohydroxymate 0
．． 61g (2, Ommole), 2,4-dichloro-
3-Methylphenol 0.35g (2-Ommole)
A mixture of 0.55 g (4,0 mmole) of potassium carbonate and 4 mα of dimethyl sulfoxide was stirred at room temperature for 48 hours. The reaction solution was subjected to high performance liquid chromatography (HP
As a result of analysis at LC), the desired reaction product 12.
4%, unreacted methyl (Z)-0-methoxycarbonylmethyl-5-chloro-2-ditropenzohydroximate 76.3% (area percentage).

Claims (1)

[Claims] 1. The following formula (I) ▲ Numerical formula, chemical formula, table, etc. ▼ (I) In the formula, X and Y each represent the same or different halogen atom, and R is a hydrogen atom or a lower alkyl group. or represents an agriculturally soluble salt ion, R^1 represents a lower alkyl group, and R^2 represents a hydrogen atom or a lower alkyl group, a 2-nitro-5-(substituted phenoxy)benzohydroxymic acid derivative represented by In manufacturing, the following formula (I
I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) In the formula, R, R^1 and R^2 have the same meanings as above, and W
represents a halogen atom other than a fluorine atom, and a 5-halogeno-2-nitrobenzohydroxymic acid derivative represented by the following formula (III) ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼ (III) In the formula, X and Y has the same meaning as above, and Z represents a hydrogen atom or an alkali metal atom. A method for producing a 2-nitro-5-(substituted phenoxy)benzohydroxymic acid derivative represented by I).