JPH11310579A - 2,3-dihydrobenzofuran-2-carboxylic acid amide derivative and agrochemical product therefrom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a new compound scarcely having crop injury to rice plant of an important crop, having an excellent herbicidal activity to various kinds of weeds such as wild milled and useful as an agrochemical product, esp. as a herbicide. SOLUTION: This compound is expressed by formula I (wherein, R1 and R2 are each H, a lower alkyl or combined with each other into a saturated ring; Ar is naphthyl, benzothiazol-2-yl, or the like), e.g. N-(α,α- dimethylbenzyl)-2,3-dihydrobenzofuran-2-carboxylic acid amide. The compound of formula I is obtained by reacting 2,3-dihydrobenzofuran-2-carboxylic acid or its reactive derivative with an amine of formula II (e.g. α,α- dimethylbenzylamine or the like) directly or in a solvent such as dichloromethane pref. at a temp. of 0-100 deg.C or at the boiling temperature of the solvent, usually for 1-24 h.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a novel 2,3-dihydrobenzofuran-2-carboxylic acid amide derivative, and a pesticide containing the compound as an active ingredient, particularly a herbicide.

[0002]

2. Description of the Related Art Various amide compounds exhibiting herbicidal activity have been conventionally known, such as fatty acid amide compounds and chloroacetamide compounds. However, it has never been reported that the 2,3-dihydrobenzofuran-2-carboxylic acid amide derivative according to the present invention has little phytotoxicity to useful plants and has excellent herbicidal activity. On the other hand, conventionally known amide compounds exhibiting herbicidal activity have not always been sufficiently satisfactory in terms of selectivity and the like.

[0003]

The problem to be solved by the present invention is to provide a novel 2,3-dihydro compound having little phytotoxicity to rice, which is an important crop, and having excellent herbicidal activity against various weeds. An object of the present invention is to provide a benzofuran-2-carboxylic acid amide derivative and an agricultural chemical, particularly a herbicide containing the amide derivative as an active ingredient.

[0004]

Means for Solving the Problems The present inventors have synthesized various amide compounds and studied various pharmacological activities thereof. As a result, a novel 2,3-dihydrobenzofuran-2-carboxylic acid amide derivative was obtained. The present inventors have found that the herbicidal activity against paddy weeds is particularly high and the safety against rice is extremely high, and the present invention has been completed.

That is, the present invention provides: (a) the following general formula (I)

[0006]

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(Wherein R ₁ and R ₂ each independently represent a hydrogen atom or a lower alkyl group, and R ₁ and R ₂ may form a saturated carbocyclic ring; Ar is a naphthyl group, A benzothiazol-2-yl group or a phenyl group having a substituent selected from the group consisting of an unsubstituted or lower alkyl group, a phenyl group, a halogen atom, a nitro group, and a haloalkyl group.) Dihydrobenzofuran-2-
Carboxylic acid amide derivatives,

(B) In the general formula (I), R ₁ and R ₂
Is a methyl group, and Ar is a naphthyl group, a benzothiazol-2-yl group, or a phenyl group having a substituent selected from the group consisting of an unsubstituted or lower alkyl group, a phenyl group, a halogen atom, a nitro group, and a haloalkyl group. 2,3-dihydrobenzofuran-2-carboxylic acid amide derivative according to (a),

(C) The compound represented by the general formula (I) is a (-)-2,3-dihydrobenzofuran-2-carboxylic acid amide derivative, Benzofuran-2-carboxylic acid amide derivative,

(D) a pesticide containing the 2,3-dihydrobenzofuran-2-carboxylic acid amide derivative according to any one of the above (a) to (c) as an active ingredient; and (e) It contains a herbicide containing the 2,3-dihydrobenzofuran-2-carboxylic acid amide derivative according to any one of the above (a) to (c) as an active ingredient.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The 2,3-dihydrobenzofuran-2-carboxylic acid amide derivative according to the present invention will be specifically described below. The symbols in the table have the following meanings. Me: methyl group, Et: ethyl group, Pr: propyl group, Bu: butyl group, Ph: phenyl group

[0012]

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[0013]

[Table 1]

[0014]

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[0015]

[Table 2]

The 2,3-dihydrobenzofuran according to the present invention
The 2-carboxylic acid amide derivative is prepared by reacting 2,3-dihydrobenzofuran-2-carboxylic acid (II) or a reactive derivative thereof with a corresponding amine (II) as shown in the following reaction formula (1).
With I) directly or in the presence of a solvent.

[0017]

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The reaction temperature at that time can be appropriately set within the range of 0 to 100 ° C. or the boiling point of the solvent. The reaction time varies depending on the compound to be used, the type of the solvent, and the like.
24 hours. In addition, in order to produce the 2,3-dihydrobenzofuran-2-carboxylic acid amide derivative of the present invention, 2,3-dihydrobenzofuran-2-reacted with an amine compound.
Reactive derivatives of carboxylic acids include the corresponding acid anhydrides, acid halides, carboxylic esters, and the like.

Among the 2,3-dihydrobenzofuran-2-carboxylic acids represented by the general formula (II) or reactive derivatives thereof, appropriate reaction auxiliaries depending on the kind of the compound to be used,
For example, dicyclohexylcarbodiimide, water-soluble carbodiimide, carbonyldiimidazole, N-methyl-2
Chloropyridinium halogenide, phosphorus pentachloride, phosphorus trichloride, phosphorus oxychloride, oxalyl chloride, thionyl chloride, triethylamine, pyridine, dimethylaniline and the like can be used.

As the optically active form of the compound represented by the general formula (I), for example, an optically active form such as (S)-(-)-methylbenzylamine as shown in the following reaction formula (2) is used. By subjecting the racemic 2,3-dihydrobenzofuran-2-carboxylic acid (II) to optical resolution and reacting the resulting optically active 2,3-dihydrobenzofuran-2-carboxylic acid with an amine. can do.

The optically active substance used for this optical resolution is
There is no particular limitation as long as it is a known and conventional optical resolving agent, and specifically, for example, (S)-(-)-1- (1-octyl) ethylamine, (-)-cis-N-benzyl-2 −
(Hydroxymethyl) cyclohexylamine, (l)-
Amphetamine and the like.

[0022]

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The 2,3-dihydrobenzofuran-2- of the present invention
Pesticides, especially herbicides, containing a carboxylic acid amide derivative as an active ingredient have almost no harm to rice, which is an important crop, as their action characteristics, and are harmful weeds that cause problems in paddy fields, for example, grasses such as grasshoppers. It has an excellent herbicidal effect on perennial weeds such as Cyperaceae weeds such as Pleurotus japonicus, Pleurotus japonicus and P. persicae, annual perennial weeds such as oak, and excellent selectivity.

Further, the herbicide according to the present invention can be effectively used in various treatment methods such as flooded soil treatment, soil treatment, and soil admixture treatment over a wide range from the emergence of weeds to the growing season after emergence. be able to.

When the compound of the present invention is used as a pesticide, it is possible to use the drug substance alone as a form of use. However, usually, solid and liquid carriers used in the preparation of pesticides, dispersants, Mixing auxiliary agents such as diluents, emulsifiers, spreading agents and thickeners, wetting agents, liquids, oils, powders,
It can be used after being formulated into a dosage form such as a granule or a sol (flowable).

Examples of solid and liquid carriers include talc, clay, bentonite, kaolin, diatomaceous earth, montmorillonite, mica, vermiculite, gypsum, calcium carbonate, white carbon, wood powder, starch, alumina, silicate, and sugar polymer. , Waxes, water, alcohols (methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, ethylene glycol, benzyl alcohol, etc.), petroleum fractions (petroleum ether, kerosene, solvent naphtha, etc.), Aliphatic or alicyclic hydrocarbons (n-hexane, cyclohexane, etc.),

Aromatic hydrocarbons (toluene, xylene,
Ethylbenzene, chlorobenzene, cumene, methylnaphthalene, etc.), ethers (isopropyl ether, tetrahydrofuran, etc.), ketones (acetone, methyl ethyl ketone, cyclohexanone, methyl isobutyl ketone, etc.), esters (ethyl acetate, butyl acetate, ethylene glycol acetate, Amyl acetate, etc.), acid amides (dimethylformamide,

Dimethylacetanilide, etc.), nitriles (acetonitrile, propionitrile, acrylonitrile, etc.), sulfoxides (dimethylsulfoxide, etc.),
Alcohol ethers (ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, etc.)
And the like.

Examples of the auxiliary include nonionic surfactants (polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene alkyl phenyl ether, polyoxyethylene sorbitan alkyl ester, sorbitan alkyl ester, etc.),
Anionic surfactants (alkylbenzene sulfonate, alkyl sulfosuccinate, polyoxyethylene alkyl sulfate, aryl sulfonate, etc.),

Cationic surfactants (alkylamines, polyoxyethylene alkylamines, quaternary ammonium salts, etc.), amphoteric surfactants (alkylaminoethylglycine, alkyldimethylbetaine, etc.), polyvinyl alcohol, hydroxy Examples include propylcellulose, carboxymethylcellulose, gum arabic, gum tragacanth, xanthan gum, polyvinyl acetate, gelatin, casein, sodium alginate and the like.

The content of the active ingredient compound in the pesticide according to the present invention, particularly in the herbicide, varies depending on the form of preparation.
Usually 0.01 to 20% by weight for powders and 1 to 5 for wettable powders
0% by weight, 0.01 to 10% by weight for granules, 0.1 to 50% by weight for emulsions, 0.1 to 50% by weight for flowables, 1 to 50% by weight for dry flowables,
Preferably, 0.1 to 3% by weight for powders and 1 for wettable powders.
0 to 40% by weight, 0.1 to 5% by weight for granules, 1 to 30% by weight for emulsions, 1 to 30% by weight for flowables, and 10 to 40% by weight for dry flowables.

The content of the adjuvant is from 0 to 80% by weight, and the content of the carrier is an amount obtained by subtracting the contents of the active ingredient compound and the adjuvant from 100% by weight. The application amount of the herbicide of the present invention varies depending on the occurrence of weeds, the environment, the formulation used, and the like, but the amount of the active ingredient of the compound is 0.002 to 2 kg per hectare, preferably 0.025 to 0 kg. It is desirable to select from the range of 0.6 kg.

The herbicide containing the compound of the present invention is mixed with one or more other herbicides, or a pesticide such as a fungicide, an insecticide, a plant growth regulator, a fertilizer, a soil conditioner and the like. It can be used, and a mixed preparation with these can be used.

[0034]

EXAMPLES Next, the present invention will be described in detail with reference to Production Examples, Preparation Examples and Test Examples as examples, but the present invention is not limited to these examples.

Examples 1-31 Synthesis of N- (α, α-dimethylbenzyl) -2,3-dihydrobenzofuran-2-carboxylic acid amide A catalytic amount of N, N-dimethylformamide and 2,3-dihydro 0.26 ml of oxalyl chloride was added to 4 ml of a dichloromethane solution of 0.5 g of benzofuran-2-carboxylic acid at room temperature.
Was added dropwise and stirred for 2 hours. After evaporating the solvent under reduced pressure, α,
The solution was added at room temperature to 5 ml of a dichloromethane solution of 0.42 g of α-dimethylbenzylamine and 0.7 g of triethylamine.

After the completion of the reaction, the reaction solution was washed with 1N hydrochloric acid and dried over anhydrous magnesium sulfate. After concentration under reduced pressure by an evaporator, purification was performed by silica gel chromatography (developing solvent: dichloromethane), and N- (α, α) of the present invention was purified.
-Dimethylbenzyl) -2,3-dihydrobenzofuran-2-carboxylic acid amide 0.77 g was obtained.

Next, the physical properties of the compounds of the present invention of Examples 2 to 31 obtained in the same manner as in Example 1 are shown in Tables 3 to 8.
Shown in The compound numbers correspond to the compound numbers in Tables 1 and 2.

[0038]

[Table 3]

[0039]

[Table 4]

[0040]

[Table 5]

[0041]

[Table 6]

[0042]

[Table 7]

[0043]

[Table 8]

Next, Formulation Examples and Test Examples will be given. The numbers in the Formulation Examples are percentages by weight. (Example 32) Formulation Example 1 (Wettable powder) Active ingredient (Compound No. 12) 7.5% Polyoxyethylene alkylaryl ether 5.0% White carbon 10.0% Clay 77.5% Wettable powder.

(Example 33) Formulation Example 2 (Emulsion) Active ingredient (Compound No. 20) 20.0% Polyoxyethylene alkyl aryl ether 10.0% Cyclohexanone 10.0% Xylene 60.0% Uniformly dissolved above To obtain an emulsion.

(Example 34) Formulation Example 3 (Granules) Active ingredient (Compound No. 25) 5.0% Bentonite 40.0% Clay 50.0% Sodium ligninsulfonate 5.0% More than uniformly mixed and pulverized Then, after adding water and kneading, the mixture was granulated and dried to obtain granules.

(Test Example 1) Inundation soil treatment test Two days before the chemical treatment, a pot (area 60 cm ² , depth 6c)
m) was filled with field soil, and seeds of nobies, dog stalks, congers, and oysters were sown on the soil surface, and then the rice at the two-leaf stage was transplanted into a flooded state. The medicinal solution prepared to a predetermined concentration was treated in a pot, and after 20 days, the herbicidal effect and the phytotoxicity to the crop were determined (amount of applied drug: 60 g / 10 a). The growth inhibition (%), the herbicidal effect and the phytotoxicity were determined according to the criteria shown in Table 9.

[0048]

[Table 9]

The compound numbers in Table 10 are the same as described above, and the plant names are abbreviated as follows. Transplanted rice = rice, nobie = E, dogfly = Sc, konagi =
M, Tamayatsuri = Cy.

[0050]

[Table 10]

(Example 35) (S)-(-)-N- (α, α
-Dimethylbenzyl) -2,3-dihydrobenzofuran-2-
Synthesis of Carboxamides Catalytic amounts of N, N-dimethylformamide and (S)-(-)-
0.62 g of 2,3-dihydrobenzofuran-2-carboxylic acid
Oxalyl chloride (0.33 ml) was added dropwise to a dichloromethane solution (4 ml) at room temperature, followed by stirring for 2 hours. After distilling off the solvent under reduced pressure, α, α-dimethylbenzylamine 0.52
g and 0.77 g of triethylamine in 5 ml of a dichloromethane solution at room temperature.

After completion of the reaction, the reaction solution was washed with hydrochloric acid and dried over anhydrous magnesium sulfate. After concentration under reduced pressure by an evaporator, the residue was purified by silica gel chromatography (developing solvent: dichloromethane), and the (S)-(-)-N- of the present invention was purified.
0.96 g of (α, α-dimethylbenzyl) -2,3-dihydrobenzofuran-2-carboxylic acid amide was obtained. [Α] ²⁵ _D = −56.3 ° (c = 1.3, methanol)

(Test Example 2) Comparative test of herbicidal activity of racemic compound and optically active compound Compound (racemic compound) synthesized in Example 3 and Example 35
(Comparative test for herbicidal effect of the compound (optically active substance) synthesized in (1) in the same manner as in Test Example 1 (application amount: 60 g / 1)
0a) was performed. Table 11 shows the results. As is clear from Table 11, the activity of the (S)-(-)-form, which is an optically active form, was further improved than that of the racemic form. On the other hand, the (R)-(+)-form, which is the other optically active form, has little activity, and the 2,3-dihydrobenzofuran-2-carboxylic acid amide derivative of the present invention has (S )-(-)-Photochemically active was found to be important.

[0054]

[Table 11]

[0055]

Industrial Applicability The present invention provides a novel 2,3-dihydrobenzofuran-2-carboxylic acid amide derivative having little phytotoxicity to rice which is an important crop and having excellent herbicidal activity against various weeds, and An agrochemical, particularly a herbicide, containing the amide compound as an active ingredient can be provided.

Claims (5)

[Claims] 1. The following general formula (I):(Where R₁And R_TwoAre each independently a hydrogen atom or a lower
Represents a alkyl group; ₁And R_TwoAnd form a saturated carbocycle with
Ar may be a naphthyl group, benzothiazole-2-i
Group, or unsubstituted or lower alkyl group, phenyl
Group, halogen atom, nitro group, haloalkyl group
Represents a phenyl group having a substituent selected from the group; )so
2,3-dihydrobenzofuran-2-carboxylic acid
Mid derivatives. 2. In the general formula (I), R ₁ and R ₂ are a methyl group, Ar is a naphthyl group, benzothiazole-
The 2,3-dihydrobenzofuran according to claim 1, which is a 2-yl group or a phenyl group having a substituent selected from the group consisting of an unsubstituted or lower alkyl group, a phenyl group, a halogen atom, a nitro group, and a haloalkyl group. -2-Carboxamide derivatives. 3. The compound represented by the general formula (I) is (-)-
The 2,3-dihydrobenzofuran-2-carboxylic acid amide derivative according to claim 1 or 2, which is a 2,3-dihydrobenzofuran-2-carboxylic acid amide derivative. 4. An agricultural chemical containing the 2,3-dihydrobenzofuran-2-carboxylic acid amide derivative according to any one of claims 1 to 3 as an active ingredient. 5. A herbicide containing the 2,3-dihydrobenzofuran-2-carboxylic acid amide derivative according to claim 1 as an active ingredient.