JPH08268808A - New 2-(nonsubstituted or substituted) (benzyloxy or phenoxy)-4-substituted-6-meta-substituted phenoxypyridine, its production and herbicide - Google Patents

Abstract

PURPOSE: To obtain a new 2-(nonsubstituted or substituted) (benzyloxy or phenoxy)-4-substituted-6-meta-substituted phenoxypyridine by specifically combining substitutent groups at the 4-position of a pyridine ring and at the 3-position of a phenoxy ring. CONSTITUTION: This new 2-(nonsubstituted or substituted) (benzyloxy or phenoxy)-4-substituted-6-meta-substituted phenoxypyridine is shown by formula I (R is a 1-4C alkoxy or cyano; X is a halogen, a 1-4C alkoxy, a 1-4C alkyl, a 1-4C haloalkoxy, a 1-4C haloalkyl, a 1-4C haloalkylthio, a 3-5C alkenyloxy, etc; Y is CF3 , difluoromethoxy, trifluoromethoxy, etc.; (m) is 0 or 1; (n) is 0-5) such as (2-benzyloxy-4-methoxy-6-(meta-trifluoromethylphenoxy)pyridine. The compound of formula I is obtained by reacting a 2-(nonsubstituted or substituted) (benzyloxy or phenoxy)-4-substituted-6-halogenopyridine of formula II (Z is a halogen) with a meta-substituted phenol of formula III.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to 2- (unsubstituted or substituted) (benzyloxy or phenoxy) -4-substituted-6-meta-substituted phenoxypyridine, a process for producing the same and herbicides containing the compound of the present invention as an active ingredient. Regarding agents.

[0002]

PRIOR ART Certain herbicidal 2- (unsubstituted or substituted) (benzyloxy or phenoxy) -4-substituted-6
The -substituted phenoxypyridine is disclosed in JP-A-6-40813. Also, US Pat.
Among the compounds represented by the general formula in the specification of No. 8, 2-benzyloxypyridine derivatives having herbicidal activity are described.

[0003]

Various kinds of herbicides have been proposed up to now, but they show a reliable herbicidal effect with a low dose which has the advantage of reducing the amount present in the environment. There is still a need for herbicides having excellent herbicidal effects, such as herbicides, herbicides that show selectivity between crops and weeds regardless of changes in environmental conditions, and herbicides that do not cause phytotoxicity in subsequent crops with double cropping. strong. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a reliable herbicidal effect with a low dose, show selectivity between crops and weeds, and produce excellent phytotoxicity in subsequent crops in double cropping. The present invention provides a compound having a herbicidal effect and a herbicide therefor.

[0004]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present inventors have found various industrially useful pyridine derivatives, and have various relationships between chemical structures and physiological activities on plants. As a result of repeated research, when an alkoxy group and a cyano group were introduced at the 4-position of the pyridine ring,
In contrast to the compounds (A) to (D) described below, which are disclosed as suitable compounds in JP-A-6-40813, and the compound (E) which is abstracted as a compound described in the publication in Chemical Abstracts. Then, they found that the herbicidal activity was high.

That is, we have proposed a novel 2- (unsubstituted or substituted) (benzyloxy) having a high herbicidal activity never seen before by a specific combination of substituents at the 4-position of the pyridine ring and the 3-position of the phenoxy ring. Or phenoxy) -4
A -substituted-6-meta-substituted phenoxypyridine compound was found.

That is, the first gist of the present invention is 2- (unsubstituted or substituted) (benzyloxy or phenoxy) -4-substituted-6-meta-substituted phenoxypyridine represented by the following general formula (I). (Hereinafter, it may be abbreviated as the compound of the present invention).

[0007]

Embedded image

(Wherein R is a C ₁ -C ₄ alkoxy group or a cyano group, X is a halogen atom, a C ₁ -C ₄ alkoxy group,
C ₁ -C ₄ alkyl group, C ₁ -C ₄ haloalkoxy groups, C ₁ -C ₄ haloalkyl groups, C ₁ -C ₄ haloalkylthio group, C ₃ -C ₅ alkenyloxy group or a C ₃ -C ₅ alkynyloxy Base, Y
Is a trifluoromethyl group, a difluoromethoxy group, a trifluoromethoxy group or a trifluoromethylthio group, m is 0 or 1, n is an integer of 0 to 5, and when n is 2 or more, X may be the same or different. Good. )

The second gist of the present invention is 2- (unsubstituted or substituted) (benzyloxy or phenoxy) -4-substituted-6-halogenopyridine represented by the general formula (II) and the general formula (III 2) (Unsubstituted or substituted) (benzyloxy or phenoxy) -4 represented by the general formula (I) characterized by reacting a meta-substituted phenol represented by
It relates to a method for producing a -substituted-6-meta-substituted phenoxypyridine.

[0010]

[Chemical 9]

(Wherein R is a C ₁ -C ₄ alkoxy group or a cyano group, X is a halogen atom, a C ₁ -C ₄ alkoxy group,
C ₁ -C ₄ alkyl group, C ₁ -C ₄ haloalkoxy groups, C ₁ -C ₄ haloalkyl groups, C ₁ -C ₄ haloalkylthio group, C ₃ -C ₅ alkenyloxy group or a C ₃ -C ₅ alkynyloxy Base, Y
Is a trifluoromethyl group, a difluoromethoxy group, a trifluoromethoxy group or a trifluoromethylthio group, m is 0 or 1, n is an integer of 0 to 5, and when n is 2 or more, X may be the same or different. Good. )

[0012]

[Chemical 10] (In the formula, R, X, m and n are as described above, and Z is a halogen atom.)

[0013]

[Chemical 11] (In the formula, Y is as described above.)

The third gist of the present invention is to provide a 2,6-dihalogeno-4-substituted pyridine represented by the general formula (IV) and a general formula (II
A 2,6-di (meta-substituted phenoxy) -4-substituted pyridine represented by the general formula (I ′) characterized by reacting a meta-substituted phenol represented by (I) [compound (I, X = Y (Including the bonding position), n = 1, m = 0)].

[0015]

[Chemical 12]

(In the formula, R represents a C ₁ -C ₄ alkoxy group or a cyano group, and Y represents a trifluoromethyl group, a difluoromethoxy group, a trifluoromethoxy group or a trifluoromethylthio group.)

[0017]

[Chemical 13] (In the formula, R is as described above, and Z is a halogen atom.)

[0018]

Embedded image (In the formula, Y is as described above.)

The fourth gist of the present invention is to provide the above general formula (I
And a herbicide containing the compound of the present invention as an active ingredient.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
Among the definitions of the substituent of the compound of the present invention represented by the above general formula (I), the substituents shown in the superordinate concept include the following preferable substituents. Examples of the C ₁ -C ₄ alkyloxy group for R include a methoxy group, an ethoxy group, and a (1-methylethyl) oxy group. R 2 is more preferably a methoxy group or a cyano group.

In X, a halogen atom is a fluorine atom, a chlorine atom and a bromine atom, and a C ₁ -C ₄ alkyl group is a methyl group, an ethyl group and a 1-methylethyl group, and a C ₁ -C ₄ alkoxy group. Is a methoxy group, an ethoxy group and a (1-methylethyl) oxy group, a C _{1 to} C ₄ haloalkoxy group is a trifluoromethoxy group and a difluoromethoxy group, and a C _{1 to} C ₄ haloalkyl group is a trifluoromethyl group. group, trifluoromethylthio group in C ₁ -C ₄ haloalkylthio group, a C ₃ -C ₅ alkenyloxy group, allyloxy group _{(OCH 2 CH = CH 2)} , (2- methyl-2
-Propenyl) oxy group (OCH ₂ CH (Me) = CH ₂ ), crotyloxy group (OCH ₂ CH = CHMe), (3-methyl-2-butenyl) oxy group (OCH ₂ CH = C (Me) ₂ ), and (3-Methyl-3-butenyl) oxy group (OCH ₂ CH ₂ C (Me) = CH ₂ ), C _{3 to} C ₅ alkynyloxy groups include (2-propynyl) oxy group (OCH ₂ CCH). Can be done.

Y is a trifluoromethyl group, a difluoromethoxy group, a trifluoromethoxy group and a trifluoromethylthio group. X 1 is more preferably a fluorine atom, a chlorine atom, a methyl group, a methoxy group or a trifluoromethyl group. Moreover, m is 0 or 1, and the preferable range of n is 0 to 3.

In the combinations of the above-mentioned preferred substituents and integers, the compounds of the present invention represented by the above general formula (I) can be exemplified by the compounds of Tables 1 to 3.

[0024]

[Table 1]

[0025]

[Table 2]

[0026]

[Table 3]

A); 4-OCH ₃ in the compound (I-10) represents a methoxy group bonded at the 4-position. 2, in compound (I-8)
4-F ₂ indicates that the fluorine atom is bonded to the 2nd and 4th positions. That is, the number before the hyphen (-) indicates the bonding position, and after the hyphen (-) the substituent and the bonding position are 2
Indicates the number when there are more than one.

The 2- (unsubstituted or substituted) (benzyloxy or phenoxy) -4-substituted-6-halogenopyridine represented by the general formula (II) is represented by the general formula (V) (unsubstituted or (Substituted) (benzyl alcohol or phenol) and 2,6-dihalogeno-4 represented by the general formula (IV)
It is obtained by reacting with -substituted-6-pyridine.

[0029]

[Chemical 15] (In the formula, R, X, Y, Z, m and n are as described above.)

In the present invention, the following compounds can be exemplified as (unsubstituted or substituted) (benzyl alcohol or phenol) (V) used for producing the compound of the present invention represented by the general formula (I).

[0031]

[Table 4] Examples of (unsubstituted or substituted) benzyl alcohol: benzyl alcohol 2-chlorobenzyl alcohol 3-chlorobenzyl alcohol 4-chlorobenzyl alcohol 2-fluorobenzyl alcohol 3-fluorobenzyl alcohol 4-fluorobenzyl alcohol 4-methyl Benzyl alcohol 4-methoxybenzyl alcohol 2,4-difluorobenzyl alcohol 2,6-difluorobenzyl alcohol 3,5-difluorobenzyl alcohol 3-allyloxybenzyl alcohol 3- (2-propynyl) oxybenzyl alcohol

[0032]

[Table 5] Examples of (unsubstituted or substituted) phenol: phenol 4-fluorophenol 3-methylphenol 4-methoxyphenol 3-trifluoromethylphenol 3-difluoromethoxyphenol 3-trifluoromethoxyphenol 3- (metatrifluoro Methylthio) phenol

The meta-substituted phenol (II used in the present invention
I) is metatrifluoromethylphenol, metadifluoromethoxyphenol, metatrifluoromethoxyphenol and metatrifluoromethylthiophenol. (Unsubstituted or substituted) benzyl alcohol (V
) And meta-substituted phenol (III) may be commercially available products. It is also possible to use compounds that can be produced by existing techniques. As the 2,6-dihalogeno-4-substituted pyridine represented by the above general formula (IV), a commercially available product can also be used. It is also possible to use compounds that can be produced by existing techniques. Of these, general formula (IV)
As the halogen atom of Z in the compound represented by, chlorine atom, bromine atom and iodine atom can be preferably used.

2,6-Dichloro-4-cyanopyridine is a compound described in Roczniki Chem. 1959, 33 , 387 and the like. Further, 2,6-dichloro-4-methoxypyridine and 2,6-dibromo-4-methoxypyridine are each described in J. Chem. Soc. B 1967 , (8), 758, Chem.
Ber. 1989, 122 ( 3), 589. etc. For example, the nitro group of 2,6-dichloro-4-nitropyridine described in JP-A-57-126474 is methyl alcohol,
C ₁ such as ethyl alcohol and 1-methylethyl alcohol
It can be prepared by nucleophilic substitution with ~ C ₄ alkanol.

The following can be exemplified as the solvent used in the present invention. When the production method of the present invention is performed in a solvent, one type or a mixture of two or more types is used. Aromatic hydrocarbons such as benzene, toluene, xylene and methylnaphthalene, aliphatic hydrocarbons such as petroleum ether, pentane, hexane, heptane and methylcyclohexane, halogens such as methylene chloride, chloroform, carbon tetrachloride and chlorobenzene. Hydrocarbons, dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidinone and other amides, diethyl ether, dimethoxyethane, diisopropyl ether, tetrahydrofuran, diglyme, dioxane and other ethers, and other Examples thereof include carbon sulfide, acetonitrile, ethyl acetate, pyridine, dimethyl sulfoxide, hexamethylphosphoric amide and the like.

All individual reaction steps of the process according to the invention are advantageously carried out in a solvent or solvent mixture. Further, a solvent composition composed of solvents that do not form a uniform layer with each other can be mentioned. In this case, it is appropriate to add a phase transfer catalyst such as a conventional quaternary ammonium salt or crown ether to the reaction system.

Since the production method of the present invention is a nucleophilic substitution reaction on a pyridine ring carbon atom, the use of a base is preferred. Furthermore, it is preferable to use cuprous chloride, cuprous bromide, and cuprous iodide together with the basic compound. The following basic compounds can be illustrated. Alkali metals such as lithium, sodium and potassium, alkaline earth metals such as magnesium, alkali metal alkoxides such as sodium methoxide, sodium ethoxide and potassium t-butoxide, alkalis such as sodium hydride and potassium hydride Metal hydrogen compounds, alkali metal carbonates such as potassium carbonate and sodium carbonate, alkali metal hydrogen carbonates such as potassium hydrogen carbonate and sodium hydrogen carbonate, alkali metal hydroxides such as potassium hydroxide and sodium hydroxide, hydrogenation Alkaline earth metal hydrogen compounds such as calcium, alkali metal organometallic compounds such as methyllithium, ethyllithium, n-butyllithium and phenyllithium, methylmagnesium iodide, ethylmagnesium bromide, n-butylmagnesium bromide Examples thereof include Grignard reagents such as ids, organometallic compounds of alkali metals, organocopper compounds prepared from Grignard reagents and monovalent copper salts, and alkali metal amides such as lithium diisopropylamide.

The reaction conditions in the synthesis of Chemical Formulas 9, 15 and 12 in the present invention are appropriately selected, but usually, if necessary, under pressure, respectively, in the synthetic reaction of Chemical Formula 1, It is 0.5 to 30 hours at 200 ° C., 0.5 to 10 hours at 1 to 180 ° C. in the synthetic reaction of Chemical formula 15, and 0.5 to 30 hours at 1 to 200 ° C. in the synthetic reaction of Chemical formula 12.

Although the compound of the present invention can be used as it is as a herbicide, it is usually used in the form of various forms such as powder, wettable powder, granules and emulsion together with a formulation auxiliary. At this time, one or more compounds of the present invention are usually added in an amount of 0.1 to 95% by weight, preferably 0.5 to 90% by weight, more preferably 2 to 70% by weight. Examples of carriers / diluents and surfactants used as formulation aids include solid carriers such as talc, kaolin, bentonite, diatomaceous earth, white carbon and clay.
Etc. can be mentioned. Liquid diluents include water, xylene, toluene, chlorobenzene, cyclohexane,
Cyclohexanone, acetone, dimethyl sulfoxide,
Examples thereof include dimethylformamide and alcohol.

The surfactant is preferably used depending on its effect, and examples of the emulsifier include polyoxyethylene alkyl aryl ether, polyoxyethylene sorbitan monolaurate and the like. Examples of the dispersant include lignin sulfonate and dibutylnaphthalene sulfonate. Examples of the wetting agent include alkyl sulfonates and alkyl phenyl sulfonates. The above-mentioned preparations include those used as they are and those used after diluting to a predetermined concentration with a diluent such as water.

The concentration of the compound of the present invention when diluted and used is preferably in the range of 0.001 to 1.0%. Moreover, the usage-amount of this invention compound is 0.01-10 kg normally per ha, Preferably it is 0.05-5 kg. These concentrations and amounts used vary depending on the dosage form, time of use, method of use, place of use, target crop, etc., and therefore it is of course possible to increase or decrease without sticking to the above range. Furthermore, the compound of the present invention can be used in combination with other active ingredients such as fungicides, insecticides, acaricides and herbicides.

[0042]

The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

Production Example 1 (2-benzyloxy-4-methoxy-6- (metatrifluoromethylphenoxy) pyridine (Synthesis of Compound No. (I-1))) <Intermediate, 2,6-dichloro-4- Synthesis of methoxypyridine> Sodium hydride (0.44g (Ca.60% in%) was added to a tetrahydrofuran solution containing methanol (0.37g, 0.0104x1.1mol).
mineral oil), 0.0104x1.05mol) and then 2,6-
Dichloro-4-nitropyridine (2.00 g, 0.0104 mol) was added, and the mixture was stirred at room temperature for about 2 hours. Further, methanol was added until foaming stopped, and the mixture was stirred for about 1 hour. The reaction mixture was partitioned with ethyl acetate-water, washed with saturated aqueous sodium hydrogen carbonate and saturated brine, dried over anhydrous sodium sulfate, and concentrated to give a nearly pure target product. Yield 1.63g, 88% yield, solid mp 94-9
6 ° C, 1H-NMR (60MHz, CDCl ₃ , d): 3.79 (3H, s), 6.70 (2H, s)

<Synthesis of Intermediate, 2-Benzyloxy-6-chloro-4-methoxypyridine> To a tetrahydrofuran solution containing benzyl alcohol (0.58 g, 0.0045x1.2 mol), sodium hydride (0.19 g (C
a.60% in mineral oil), 0.0045x1.05 mol) was added. Then, 2,6-dichloro-4-methoxypyridine (0.8 g, 0.0045 mol) was added, and the mixture was refluxed for about 1 hour.
The reaction mixture was partitioned with ethyl acetate-saturated aqueous sodium hydrogen carbonate. The organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, concentrated, and purified with a silica gel column to obtain the desired product. yield
1.23 g, yield 86%, oil, 1H-NMR (60MHz, CDCl ₃ , δ): 3.68 (3H, s), 5.25 (2H, s), 6.
07 (1H, d, J = 2.0Hz), 6.44 (1H, d, J = 2.0Hz), 7.0-7.6 (5H, co
mplex)

<2-benzyloxy-4-methoxy-
Synthesis of 6- (metatrifluoromethylphenoxy) pyridine> Metatrifluoromethylphenol (1.29g, 0.0020x4.
Sodium hydride (0.32g (Ca.60% in mineral oil), 0.0020 x 4.0m in a dimethylformamide solution containing 0mol)
ol) was added. Then, 2-benzyloxy-6-chloro-4-methoxypyridine (0.5 g, 0.0020 mol) was added, and cuprous iodide (CuI) (0.19 g, 0.0020x0.5mo) was further added.
l) was added and the mixture was refluxed for about 4 hours. The reaction mixture was partitioned with ethyl acetate-saturated aqueous sodium hydrogen carbonate. The organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, concentrated, and purified with a silica gel column to obtain the desired product. Yield 0.29g, 39% yield,
Solid mp 46-48 ℃, 1H-NMR (60MHz, CDCl ₃ , δ): 3.69 (3H, s), 5.04 (2H, s), 5.
96 (2H, s), 7.0-7.6 (9H, complex)

Production Example 2 (2-benzyloxy-4-methoxy-6- (metatrifluoromethoxyphenoxy))
Pyridine (Synthesis of compound number (I-2)) <Synthesis of intermediate, 2,6-dibromo-4-methoxypyridine> Sodium hydride (1.49 g (Ca.60% in mineral oil), 0.
(0355x1.05mol) was washed with hexane and suspended in tetrahydrofuran to give methanol (1.70g, 0.0355x1.5mol).
After the addition of 2,6-dibromo-4-nitropyridine (1
0.00g, 0.03 55mol) was added and stirred at room temperature for about 1 hour. In addition, sodium hydride (0.2g (Ca.60% in miner
al oil), 0.0355x0.14mol) was added and stirred for about 1 hour. Then, methanol (1.0 g, 0.0355x0.9 mol) was added to confirm that there was no foaming, and the reaction solution was partitioned with ethyl acetate-saturated aqueous sodium hydrogen carbonate. The organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, and concentrated to give the desired product. yield
9.27g, yield 98%, solid mp 131-133 ° C, 1H-NMR (60MHz, CDCl ₃ , δ): 3.79 (3H, s), 6.89 (2H, s)

<Synthesis of Intermediate, 2-Benzyloxy-6-bromo-4-methoxypyridine> Sodium hydride (0.55 g (Ca.60%) was added to a tetrahydrofuran solution containing benzyl alcohol (1.7 g, 0.0131 × 1.2 mol). in
mineral oil), 0.0131x1.05mol) was added. Then,
2,6-dibromo-4-methoxypyridine (3.5g, 0.0131
mol) was added and the mixture was refluxed for about 2 hours. The reaction solution was ethyl acetate
Partitioned with saturated aqueous sodium hydrogen carbonate. Wash the organic layer with saturated saline,
After drying over anhydrous sodium sulfate, the solution was concentrated and purified by a silica gel column, and the raw materials that were difficult to separate were distilled off using a tube oven to obtain the desired product. Yield 3.35g, Yield 8
7%, oil, 1H-NMR (60MHz, CDCl ₃ , δ): 3.63 (3H, s), 5.20 (2H, s), 6.04
(1H, d, J = 2.0Hz), 6.53 (1H, d, J = 2.0Hz), 7.0-7.5 (5H, comp
lex)

<2-benzyloxy-4-methoxy-
Synthesis of 6- (metatrifluoromethoxyphenoxy) pyridine> Metatrifluoromethoxyphenol (0.52g, 0.0013x2.
Sodium hydride (0.11g (Ca.60% in mineral oil), 0.0013x 2.1mol) in a dimethylformamide solution containing 2mol)
Was added. Then 2-benzyloxy-6-bromo-
4-Methoxypyridine (0.39 g, 0.0013 mol) was added, further cuprous iodide (CuI) (0.06 g, 0.0013x0.5 mol) was added, and the mixture was stirred at about 110 to 120 ° C for about 21 hours. The reaction mixture was partitioned with ethyl acetate-saturated aqueous sodium hydrogen carbonate. The organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, concentrated, purified with a silica gel column, and the raw material that was difficult to separate was distilled off using a tube oven to obtain the desired product.
Yield 0.24 g, yield 46%, oil, 1H-NMR (60MHz, CDCl ₃ , δ): 3.67 (3H, s), 5.04 (2H, s), 5.93
(2H, s), 6.7-7.4 (9H, complex)

Production Example 3 (2-benzyloxy-4-cyano-6- (metatrifluoromethylphenoxy) pyridine (Synthesis of Compound No. (I-3))) <Intermediate, 2-benzyloxy-6-chloro Synthesis of 4-cyanopyridine> Sodium hydride (0.24g (Ca.60% in mineral oil), 0.0
06x1.0mol) was suspended in 20 ml of N-methyl-2-pyrrolidinone, and benzyl alcohol (0.65g, 0.006x1.0mol)
Was added and stirred at room temperature for about 30 minutes. The mixture was cooled to about 4 ° C. with ice water, 4-cyano-2,6-dichloropyridine (1.04 g, 0.006 mol) was added, and the mixture was stirred for about 1.5 hours while cooling with ice water. Furthermore, after stirring at room temperature for about 1.5 hours, the reaction solution was partitioned with an ethyl acetate-water system. The organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, concentrated, and purified with a silica gel column to obtain the desired product. Yield 0.94 g, yield 64%, oil, 1H-NMR (60MHz, CDCl ₃ , δ): 5.33 (2H, s), 6.88 (1H, s), 7.
05 (1H, s), 7.35 (5H, s)

<2-benzyloxy-4-cyano-6
-Synthesis of (metatrifluoromethylphenoxy) pyridine> 2-benzyloxy-6-chloro-4-cyanopyridine (0.8g, 0.0033mol) and metatrifluoromethylphenol (0.58g, 0.0033x1.1mol) were added to N- Dissolved in 20 ml of methyl-2-pyrrolidinone, anhydrous potassium carbonate (0.5 g, 0.00
33x1.1 mol) was added and the mixture was stirred at about 100 ° C. for about 2.5 hours. The reaction mixture was partitioned with ethyl acetate-water, the organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, and concentrated. The residue was purified by a silica gel column and recrystallized from a small amount of n-hexane to obtain the desired product. Yield 0.89g, Yield 74
%, Solid mp 75-76 ° C, 1H-NMR (60MHz, CDCl ₃ , δ): 5.03 (2H, s), 6.6-6.7 (2H, b
s), 6.8-7.6 (9H, complex)

Production Example 4 (Synthesis of 4-methoxy-2,6-di (metatrifluoromethylphenoxy) pyridine (Compound No. (I-18))) Metatrifluoromethylphenol (2.5 g, 0.0028x5.5mo)
15 ml of dimethylformamide is added to (l), and further sodium hydride (0.45 g (Ca. 60% in mineral oil), 0.0028x4.
0 mol) and cuprous iodide (0.25 g, 0.0028x0.47 mol) were added to a mixture of 2,6-dichloro-4-methoxypyridine (0.5 g,
0.0028 mol) was added and the mixture was refluxed for about 8 hours. Then, the reaction mixture was partitioned with ethyl acetate-saturated aqueous sodium hydrogen carbonate. The organic layer was washed with saturated brine, dried over anhydrous sodium sulfate and concentrated,
After purification with a silica gel column, low-boiling substances that are difficult to separate were distilled off using a tube oven to obtain the target product. Yield 0.13
g, yield 11%, oil, ¹ H-NMR (60MHz, CDCl ₃ , δ): 3.76 (3H, s), 6.07 (2H, s), 6.7-
7.4 (8H, complex)

Production Example 5 (Synthesis of 4-methoxy-2-phenoxy-6- (metatrifluoromethoxyphenoxy) pyridine (Compound No. (I-22))) <Intermediate, 2-bromo-4-methoxy-6 -Synthesis of phenoxypyridine> Sodium hydride (0.24 g (Ca.60% in mi) was added to a dimethylformamide solution containing phenol (0.58 g, 0.0056x1.1 mol).
neral oil), 0.0056x1.06mol) was added. Then, 2,
6-dibromo-4-methoxypyridine (1.5g, 0.0056mol)
Was added, and the mixture was stirred at about 110 ° C. for about 2 hours, and the reaction solution was partitioned with hexane-saturated aqueous sodium hydrogen carbonate. The organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, concentrated, purified by silica gel column, added with hexane, cooled, and crystallized to obtain the desired product. Yield 0.83 g, yield 53%, oil, 1H-NMR (60MHz, CDCl ₃ , δ): 3.67 (3H, s), 6.12 (1H, d, J = 2.0
Hz), 6.66 (1H, d, J = 2.0Hz), 6.8-7.5 (5H, complex)

<4-methoxy-2-phenoxy-6-
Synthesis of (metatrifluoromethoxyphenoxy) pyridine> Metatrifluoromethoxyphenol (0.47g, 0.0026x1.
Sodium hydride (0.11g (Ca.60% in mineral oil), 0.0026x1.06mol) in a dimethylformamide solution containing 1mol)
Was added. Then, 2-bromo-4-methoxy-6-phenoxypyridine (0.73 g, 0.0026 mol) was added, and further,
Add cuprous chloride (CuCl) (0.13g, 0.0026x0.5mol),
The mixture was stirred at about 120 ° C for about 8 hours. Furthermore, metatrifluoromethoxyphenol (0.47g, 0.0026x1.1mol) and sodium hydride (0.11g (Ca.60% in mineral oil), 0.0026x
1.06 mol) was added and the mixture was stirred at about 120 ° C. for about 8 hours, and the reaction solution was partitioned with hexane-saturated aqueous sodium hydrogen carbonate. The organic layer was washed with saturated brine and dried over anhydrous sodium sulfate,
After concentrating and purifying with a silica gel column, the difficult-to-separate raw materials were distilled off using a tube oven to obtain the desired product. Yield 0.66 g, 70% yield, oil, 1H-NMR (60MHz, CDCl ₃ , δ): 3.68 (3H, s), 5.8-6.2 (2H, comp
lex), 6.7-7.5 (9H, complex)

Production Example 6 (Synthesis of 4-cyano-2,6-di (metatrifluoromethylphenoxy) pyridine (Compound No. (I-23))) Sodium hydride (0.31 g (Ca. 60% in mineral oil) ), 0.
(0035x2.2 mol) was suspended in 20 ml of N-methyl-2-pyrrolidinone, and metatrifluoromethylphenol (1.24 g, 0.004
(35x2.2mol) was added, and the mixture was heated to about 60 ° C and stirred for several minutes. After cooling to room temperature, 4-cyano-2,6-dichloropyridine
(0.60 g, 0.0035 mol) was added, and the mixture was reacted at about 90 ° C for 1 hour. Then, the reaction solution was partitioned with ethyl acetate-water, the organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, concentrated, purified with a silica gel column, and recrystallized with a small amount of n-hexane to obtain the objective. I got a thing. Yield 0.91 g, yield 62%, solid mp 51-52 ° C, ¹ H-NMR (60MHz, CDCl ₃ , δ): 6.80 (2H, s), 6.8-7.5 (8H, comp
lex)

Production Example 7 (Synthesis of 4-cyano-2- (paramethoxyphenoxy) -6- (metatrifluoromethylphenoxy) pyridine (Compound No. (I-24))) <Intermediate, 2-chloro-4 Synthesis of -Cyano-6- (paramethoxyphenoxy) pyridine> Sodium hydride (0.36 g (Ca. 6) was added to a tetrahydrofuran solution containing paramethoxyphenol (1.18 g, 0.00867x1.1 mol).
60% in mineral oil), 0.00867x1.04mol) was added. Then 4-cyano-2,6-dichloropyridine (1.5 g, 0.
00867 mol) was added and the mixture was refluxed for about 2 hours. The reaction solution was partitioned with ethyl acetate-saturated aqueous sodium hydrogen carbonate, the organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, concentrated, and purified by a silica gel column to obtain the desired product. Yield 1.73g, Yield 77
%, Solid mp 99-101 ° C, 1H-NMR (60MHz, CDCl ₃ , δ): 3.71 (3H, s), 6.5-7.3 (6H, comp
lex)

<Synthesis of 4-cyano-2- (paramethoxyphenoxy) -6- (metatrifluoromethoxyphenoxy) pyridine> Metatrifluoromethoxyphenol (0.52 g, 0.0027x1.
Sodium hydride (0.12g (Ca.60% in mineral oil), 0.0027x1.1mol) in a dimethylformamide solution containing 2mol)
Was added. Then, 2-chloro-4-cyano-6- (paramethoxyphenoxy) pyridine (0.70g, 0.0027mol) was added, and further cuprous chloride (CuCl) (0.13g, 0.0027x0.5mo).
l) was added and the mixture was stirred at about 120 ° C. for about 2 hours. After partitioning the reaction solution with hexane-saturated aqueous sodium hydrogen carbonate, the organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, concentrated, and purified with a silica gel column. The target substance was obtained by evaporation. Yield 0.7
8 g, yield 75%, oil, 1H-NMR (60MHz, CDCl ₃ , δ): 3.66 (3H, s), 6.4-7.5 (10H, com
plex)

Production Example 8 (Synthesis of 4-ethoxy-2,6-di (metatrifluoromethylphenoxy) pyridine (Compound No. (I-27))) Metatrifluoromethylphenol (1.94 g, 0.00285x4.2)
mol) in addition to dimethylformamide, and further sodium hydride (0.46g (Ca.60% in mineral oil), 0.00285x4.0m
ol) and cuprous chloride (0.28 g, 0.00285x1.00 mol) were added to the mixture, 4-ethoxy-2,6-dibromopyridine
(0.8 g, 0.00285 mol) was added, and the mixture was reacted at about 110-120 ° C for about 6 hours. Then, the reaction mixture was partitioned with ethyl acetate-saturated aqueous sodium hydrogen carbonate. The organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, concentrated, and purified with a silica gel column to remove low-boiling substances in a tube oven to obtain the desired product. Yield 1.05 g, yield 83%, oil, ¹ H-NMR (60 MHz, CDCl ₃ , δ): 1.38 (3 H, t, J = 6.9 Hz), 4.00 (2
H, q, J = 6.9Hz), 6.61 (2H, s), 6.9-7.5 (8H, complex)

By the operation according to the above Production Examples 1 to 8, Table 1
~ Other compounds shown in Table 3 were also synthesized. The properties and NMR data of these compounds are shown in Tables 6 to 8.

[0059]

[Table 6]

[0060]

[Table 7]

[0061]

[Table 8]

Formulation examples and test examples are shown below, but the carrier (diluent), the auxiliary agent, the mixing ratio thereof and the active ingredient can be varied within a wide range. “Part” in each formulation example represents part by weight.

[0063]

[Table 9] Formulation Example 1 (wettable powder) Compound No. (I-3) 50 parts Lignin sulfonate 5 parts Alkyl sulfonate 3 parts Diatomaceous earth 42 parts are mixed and pulverized to obtain a wettable powder, which is diluted with water. To use.

[0064]

[Table 10] Formulation Example 2 (emulsion) Compound No. (I-1) 25 parts xylene 65 parts Polyoxyethylene alkylaryl ether 10 parts are uniformly mixed to form an emulsion, which is diluted with water and used.

[0065]

[Table 11] Formulation Example 3 (granule) Compound No. (I-2) 8 parts Bentonite 40 parts Cray 45 parts Lignin sulfonate 7 parts Evenly mix, further add water and knead, extrusion granulation Machined into granules and used as granules.

Test Example 1 (Test of herbicidal effect by treatment of foliage and soil) The wettable powder prepared as in Formulation Example 1 above was suspended in water to a predetermined concentration. Blue-toothed gall that has been grown in this pot in pot, Yasushi mustard (same as P. aeruginosa), chickweed, lobster, dog physalis, velvetleaf,
Stem and soil were treated to give 5 g ai / 10a equivalent to chamomile, green sorghum, gall midge, and Japanese cedar (1 to 2 leaves for each test plant). 14 days after the application, the herbicidal effect was investigated according to the criteria shown in Table 12 below.

[0067]

[Table 12] Survey criteria, 1: Herbicidal rate is less than 20%, 2: Herbicidal rate is 20% or more and less than 40%, 3: Herbicidal rate is 40% or more and less than 60%, 4: Herbicidal rate is 60% or more and 80% Less than, 5: 80% or more herbicidal rate.

The results are shown in Tables 14 to 15. In Test Examples, the following compounds (A) to (D) described in JP-A-6-40813 and the compound disclosed in Chemical Abstracts as compounds described in the same patent, although not described in the publication, ( Table 1 shows E) as a comparison substance.
3 shows.

[0069]

Table 13 (A) 2,6-di (metatrifluoromethylphenoxy) pyridine (JP-A-6-40813, Example 1)
(B) 2,6-di (metatrifluoromethylphenoxy) -4-methylmercaptopyridine (JP-A-6-40)
No. 813 publication, compound of Example 2) (C) 2,6-di (metatrifluoromethylphenoxy) -4-methylpyridine (Compound of JP-A-6-40813, Example 3) (D) 2- Benzyloxy-6-metatrifluoromethylphenoxypyridine (JP-A-6-40813,
Compound of Example 5) (E) 4-chloro-2,6-di (metatrifluoromethylphenoxy) pyridine (JP-A-6-40813, Table 1 and positional isomers of the compound of Example 14 described in Table 1) (Since it is the same 4-substituted compound as the compound of the present application, this was selected.)

[0070]

[Table 14]

[0071]

[Table 15]

[0072]

[Table 16] ^A) AR: Aogatetou SA: Yasei-Karashina (same as Nora-Garden) SM: Chickweed CO: Ebisugusa SN: Dog Physalis AT: Ichibi CA: Common Bindweed MC: Chamomile SV: Enochologsa EF: Shokuobie DA: Meshishiba

[0073]

The 2- (unsubstituted or substituted) (benzyloxy or phenoxy) -4-substituted-6-meta-substituted phenoxypyridine represented by the above general formula (I) of the present invention is a novel compound. Therefore, it can be used as an active ingredient of a herbicide.

 ─────────────────────────────────────────────────── ─── Continuation of front page (31) Priority claim number Japanese Patent Application No. 7-39081 (32) Priority date Hei 7 (1995) February 4 (33) Priority claim country Japan (JP) (72) Inventor Tsutomu Sato 1-2 Ochiai, Nishiki-cho, Iwaki-shi, Fukushima Prefecture (72) Inventor Masato Arahira 16-1 Maehara Nishiki-cho, Iwaki-shi, Fukushima Prefecture

Claims (6)

[Claims] 1. 2- (Unsubstituted or substituted) (benzyloxy or phenoxy) -4 represented by the following general formula (I):
-Substituted-6-meta-substituted phenoxypyridine. Embedded image (In the formula, R represents a C ₁ -C ₄ alkoxy group or a cyano group, X
It is halogen atom, C ₁ -C ₄ alkoxy, C ₁ -C ₄ alkyl group, C ₁ -C ₄ haloalkoxy groups, C ₁ -C ₄ haloalkyl groups, C ₁ -C ₄ haloalkylthio group, C ₃ ~ C ₅ alkenyloxy group or C ₃ -C ₅ alkynyloxy group, Y is trifluoromethyl group, difluoromethoxy group, trifluoromethoxy group or trifluoromethylthio group, m is 0 or
1, n are integers from 0 to 5, and when n is 2 or more, X may be the same or different. ) 2. R is a methoxy group or a cyano group,
The compound according to claim 1, wherein m is 0 or 1. 3. A 2- (unsubstituted or substituted) (benzyloxy or phenoxy) -4-substituted-6-halogenopyridine represented by the general formula (II) and a meta-substitution represented by the general formula (III). A process for producing 2- (unsubstituted or substituted) (benzyloxy or phenoxy) -4-substituted-6-meta-substituted phenoxypyridine represented by the general formula (I), which comprises reacting with phenol. Embedded image (In the formula, R represents a C ₁ -C ₄ alkoxy group or a cyano group, X
It is halogen atom, C ₁ -C ₄ alkoxy, C ₁ -C ₄ alkyl group, C ₁ -C ₄ haloalkoxy groups, C ₁ -C ₄ haloalkyl groups, C ₁ -C ₄ haloalkylthio group, C ₃ ~ C ₅ alkenyloxy group or C ₃ -C ₅ alkynyloxy group, Y is trifluoromethyl group, difluoromethoxy group, trifluoromethoxy group or trifluoromethylthio group, m is 0 or
1, n are integers from 0 to 5, and when n is 2 or more, X may be the same or different. ) [Chemical 3] (In the formula, R, X, m and n are as described above, and Z is a halogen atom.) (In the formula, Y is as described above.) 4. A 2,6-dihalogeno-4 represented by the general formula (IV):
-Substituted pyridine and meta-substituted phenol represented by the general formula (III) are reacted, 2,6-di (meta-substituted phenoxy) -4-substituted pyridine represented by the general formula (I ') Manufacturing method. Embedded image (In the formula, R represents a C ₁ -C ₄ alkoxy group or cyano group, Y
Represents a trifluoromethyl group, a difluoromethoxy group, a trifluoromethoxy group or a trifluoromethylthio group. ) [Chemical 6] (In the formula, R is as described above and Z is a halogen atom.) (In the formula, Y is as described above.) 5. The 2- (unsubstituted or substituted) (benzyloxy or phenoxy) -4-substituted-6 according to claim 1.
-A herbicide containing meta-substituted phenoxypyridine as an active ingredient. 6. R is a methoxy group or a cyano group,
The herbicide according to claim 5, wherein m is 0 or 1.