JPH0667912B2 - Pyridazinone derivative, method for producing the same, and herbicide - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel compound, a method for producing the same, and a herbicide containing the compound as an active ingredient.

[Conventional technology]

In the cultivation of agricultural and horticultural crops, many herbicides have come to be used for controlling weeds, which have required a great deal of labor. However, there is a struggle to develop a drug that has a certain effect because it causes phytotoxicity to crops, remains in the environment and pollutes, and can be used completely in a low dose.

The following herbicides having a pyridazinone skeleton similar to the compounds of the present invention are known. This product is mainly (General name: Pyrazone) Widely used as a herbicide for controlling broadleaf weeds that occur in the field of sugar beet.

[Problems to be solved by the invention]

An object of the present invention is to industrially advantageously produce a novel pyridazinone derivative, and to provide a herbicide having a wide range of selectivity between crops and weeds, a highly effective and reliable complete herbicide.

[Means for solving problems]

The present invention has the general formula [In the formula, X is a hydrogen atom or a fluorine atom, Y is a halogen atom, R is a group represented by the formula -ZR ₁ , wherein Z is an oxygen atom or a sulfur atom, R ₁ is a hydrogen atom or a phenoxy group. , A carboxy group, a lower alkoxy group, a lower alkylthio group, a cycloalkoxycarbonyl group, a cyano group, a phenyl group or a lower alkoxycarbonyl group which may be substituted with (a lower alkoxycarbonyl group or a lower alkylthio group) Shows good fatty acid hydrocarbon groups. } Or a group represented by formula -COOR ₂ (in the formula, R ₂ represents a hydrogen atom or a lower alkoxycarbonyl group, a lower alkoxy group or a lower alkyl group optionally substituted with a phenyl group). ] The compound represented by these, its manufacturing method, and a herbicide containing this compound as an active ingredient.

The compound of the present invention exhibits a broad activity against various weeds at an extremely low dose, and exhibits high selectivity to crops such as rice, wheat, corn and soybean. This compound is effective in any treatment method such as soil treatment before the emergence of weeds and foliar application treatment after the emergence of weeds. Due to its high activity and broad herbicidal activity, this compound is also effective for controlling weeds in forests, lawns, open spaces other than agricultural land. In the production of the compound of the present invention, the formula 1,3,4,5,6,7-hexahydro-
3-hydroxy-isobenzofuran-1-one and the general formula Is condensed with a hydrazine derivative represented by

Condensation conditions are heating in acetic acid at 50 ° C. to 118 ° C. (reflux) or azeotropic dehydration in a solvent such as benzene, toluene or xylene. After completion of the reaction, the desired product can be obtained by performing usual post-treatment.

The starting compound represented by the formula [II] is, for example, tetrahydrophthalic anhydride in a solvent such as DMF or THF.
It can be easily obtained by reducing with a reducing agent such as BH ₄ .

When R ₁ or R ₂ in the general formula [I] of the compound of the present invention is other than a hydrogen atom, the compound of the present invention can also be produced according to the following reaction formula, and depending on the substituent, this reaction is more preferable. In some cases it is advantageous.

(a) R = -YR ₁ (However, R ₁ is not a hydrogen atom.) (b) R = COOR ₂ (However, R ₂ is not a hydrogen atom.) The structure of the present invention was determined by IR, NMR, MASS and the like.

〔Example〕

 Next, the present invention will be described in detail with reference to examples.

Example 1 Synthesis of 2- (4-chloro-2-fluoro-5-hydroxyphenyl) -5,6,7,8-tetrahydrobenzo [d] pyridazin-1 (2H) -one [Compound No. 1
9]: 6.0 g of 1,3,4,5,6,7-hexahydro-3-hydroxy-isobenzofuran-1-one and 9.8 g of 4-chloro-2-fluoro-5-hydroxyphenylhydrazine hydrochloride were added to 50 ml of acetic acid. , More sodium acetate 4.8
g and heat to reflux for 2 hours. After cooling, the reaction solution was added to ice water, and the precipitated crystals were collected by filtration, washed with water and dried to give 8.5 g.
I got the object. Melting point 231-232 ° C Example 2 2- {4-chloro-2-fluoro-5- (2-propynyloxy) phenyl} -5,6,7,8-tetrahydrobenzo [d] pyridazine-1 (2H)- On synthesis.
(Compound No. 2): 2- (4-chloro-2-fluoro-5-hydroxyphenyl) -5,6,7,8-tetrahydrobenzo [d] pyridazin-1 (2H) -one (1 g) in acetonitrile (30 ml)
In addition, 0.40 g of propargyl bromide and 0.47 g of anhydrous potassium carbonate were added thereto, and the mixture was heated under reflux for 3 hours. After cooling the reaction solution, the precipitated inorganic matter was filtered off, acetonitrile was distilled off under reduced pressure, water and ether were added, the ether layer was separated and dried over anhydrous magnesium sulfate, and the ether was distilled off. The residue was purified by column chromatography, 1.
0 g of the desired product was obtained.

Melting point 142-143 ° C. Next, representative examples of the compound of the present invention are shown in Table 1 including the above-mentioned examples.

[Means for Solving Problems-Herbicides] The herbicides of the present invention contain, as an active ingredient, one or two or more of the compounds represented by the general formula [1], and have the same form as a common pesticide. . That is, the active ingredient compound is generally used in the form of a wettable powder, an emulsion, a granule, an aqueous solvent, a flowable agent, etc. by mixing an appropriate amount with a carrier. The fixed carrier includes talc, white carbon, bentonite, clay, diatomaceous earth, and the like, and the liquid carrier includes water,
Alcohol, benzene, xylene, kerosene, mineral oil, cyclohexane, cyclohexanone, dimethylformamide and the like are used. Surfactants can also be added if necessary to obtain a uniform and stable form in these formulations.

The concentration of the active ingredient in the herbicide of the present invention varies depending on the form of the above-mentioned preparation. For example, 5 to 70%, preferably 10 to 30% for wettable powder and 3 to 3 for emulsion. 70%, preferably 5-20%: In granules a concentration of 0.01-20%, preferably 0.05-10% is used.

The wettable powder and emulsion thus obtained are diluted with water to a predetermined concentration to give a suspension or emulsion, and the granules are sprayed or mixed into the soil before or after germination of weeds. It is processed. When the herbicide of the present invention is actually applied, an appropriate amount of 1 g or more of the active ingredient is applied per 10 ares.

Further, the herbicide of the present invention is a known fungicide, insecticide, acaricide,
It can also be used as a mixture with a herbicide, a plant growth regulator or the like. In particular, when used in combination with a herbicide, not only can the amount of drug used be reduced and labor can be saved, but a higher effect due to the synergistic action of the mixed drug can be expected. In that case, a combination with a plurality of known herbicides is also possible. Suitable agents to be used in combination with the herbicide of the present invention include carboxmate herbicides such as bench carb, molinate, MY-93 [S-2,2-dimethylbenzyl) 1-piperidine carbothioate], thiocarbamate herbicides. , Acid amide herbicides such as butachlor and pretilachlor,
Diphenyl ether herbicides such as clomethoxynil and bifenox, pyrazole herbicides such as pyrazolate and pyrazoxifene, sulfonylurea herbicides such as chlorsulfuron and sulfometuron-methyl, imidazoline herbicides such as imazaquin and imazapyr, MCP, M
Phenoxyalkanecarboxylic acid herbicides such as CPB, phenoxyphenoxypropionic acid herbicides such as diclofop-methyl, pyridyloxyphenoxypropionic acid herbicides such as fluazifop-butyl, and others such as piperophos, dimuron, bentazone, oxadiazone, N
TN-80.1 (2-benzothiazol-2-yloxy-N-methylacetanilide), naproanilide, HW
-52 (4-ethoxymethoxybenz-2 ', 3'-dichloroanilide), KNW-242 [1- (3-methylphenyl) -5-phenyl-1H-1,2,4, -triazole-3 -Carboxamide], S-47 [N- (2,2-
Examples thereof include cyclohexanedione-based herbicides such as dimethylbenzyl) -d-bromotert-butylacetamide, setoxydim, and alloxydim-sodium.
It is also possible to add vegetable oils and oil concentrates to these combinations.

[Example-herbicide]

Next, some formulation examples of the herbicide of the present invention will be shown, but the active ingredient compounds, additives and addition ratios can be changed within a wide range without being limited to these examples.

Example 3 Wettable powder Compound 9 of the present invention 20 parts White carbon 20 parts Diatomaceous earth 52 parts Sodium alkyl sulfate 8 parts The above components were uniformly mixed and finely pulverized to obtain a wettable powder containing 20% of the active ingredient.

Example 4 Emulsion Compound 17 of the present invention 20 parts Xylene 55 parts Dimethylformamide 15 parts Polyoxyethylene phenyl ether 10 parts The above components were mixed and dissolved to obtain an emulsion containing 20% of the active ingredient.

Example 9 Granules Compound of the present invention 1 5 parts Talc 40 parts Clay 38 parts Pentonite 10 parts Sodium alkyl sulfate 7 parts The above components are uniformly mixed and finely pulverized, and then granulated into particles having a diameter of 0.5 to 1.0 mm. A granule containing 5% of the active ingredient was obtained.

〔The invention's effect〕

 Next, test examples relating to the effect of the herbicide of the present invention will be shown.

Test example Paddy field test Method: 200 cm ² pots are filled with paddy field soil, seeds of Novier, Magnolia vulgaris, Omodaka and Firefly are sown, lightly covered with soil, and 2 to 3 leaf stage rice (variety: Nihonbare) 1 strain (1 strain 2 strains) Transplanted). The next day, maintaining a water depth of 2 to 3 cm, granules of each compound were treated in a predetermined dose and grown in a greenhouse. Three weeks after the chemical treatment, the growth conditions of rice and each weed were investigated according to the following criteria, and the results shown in Table 2 were obtained.

Survey standard Weeding rate Index 0% 0 20-29% 2 40-49% 4 60-69% 680-89% 8 100% 10 Moreover, the numerical values of 1, 3, 5, 7, and 9 are 0 and 2, respectively. Values between 2 and 4, 4 and 6, 6 and 8, and 8 and 10 are shown.

Test Example 2 Stem-and-foliage spraying A 200 cm ² pot was filled with soil, and various larvae of velvetleaf, red bud, Amaranthus communis, and purslane were sown on the surface, lightly covered with soil, and then grown in a greenhouse. At the time when each weed grew to a plant height of 5 to 10 cm, a chemical solution prepared by diluting an emulsion of each test compound with water was sprayed onto the foliage of the weed with a small sprayer at a ratio of 100 l / 10a. After 3 weeks, the growth condition of the weeds was investigated according to the examination criteria of Test Example 1, and the results shown in Table 3 were obtained.

Claims (3)

[Claims] 1. A general formula [In the formula, X is a hydrogen atom or a fluorine atom, Y is a halogen atom, R is a group represented by the formula -ZR ₁ , wherein Z is an oxygen atom or a sulfur atom, R ₁ is a hydrogen atom or a phenoxy group. It may be substituted with a carboxy group, a lower alkoxy group, a lower alkylthio group, a cycloalkoxycarbonyl group, a cyano group, a phenyl group or a lower alkoxycarbonyl group (which may be substituted with a lower alkoxycarbonyl group or a lower alkylthio group). Indicates an aliphatic hydrocarbon group. } Or a group represented by formula -COOR ₂ (in the formula, R ₂ represents a hydrogen atom or a lower alkoxycarbonyl group, a lower alkoxy group or a lower alkyl group optionally substituted with a phenyl group). ] The compound represented by these. 2. A formula 1,3,4,5,6,7-hexahydro-
3-hydroxy-isobenzofuran-1-one and the general formula [In the formula, X is a hydrogen atom or a fluorine atom, Y is a halogen atom, R is a group represented by the formula -ZR ₁ , wherein Z is an oxygen atom or a sulfur atom, R ₁ is a hydrogen atom or a phenoxy group. A carboxy group, a lower alkoxy group, a lower alkylthio group, a cycloalkoxycarbonyl group, a cyano group, a phenyl group or a lower alkoxycarbonyl group which may be substituted with (a lower alkoxycarbonyl group or a lower alkylthio group). Indicates an aliphatic hydrocarbon group. } Or a group represented by formula -COOR ₂ (in the formula, R ₂ represents a hydrogen atom or a lower alkoxycarbonyl group, a lower alkoxy group or a lower alkyl group optionally substituted with a phenyl group). ] It is characterized by having reacted with the compound represented by this. General formula (In the formula, X, Y and R have the same meanings as described above.) A method for producing a compound represented by the formula. 3. General formula [In the formula, X is a hydrogen atom or a fluorine atom, Y is a halogen atom, R is a group represented by the formula -ZR ₁ , wherein Z is an oxygen atom or a sulfur atom, R ₁ is a hydrogen atom or a phenoxy group. , A carboxy group, a lower alkoxy group, a lower alkylthio group, a cycloalkoxycarbonyl group, a cyano group, a phenyl group or a lower alkoxycarbonyl group which may be substituted with (a lower alkoxycarbonyl group or a lower alkylthio group) It shows a good aliphatic hydrocarbon group. } Or a group represented by formula -COOR ₂ (in the formula, R ₂ represents a hydrogen atom or a lower alkoxycarbonyl group, a lower alkoxy group or a lower alkyl group optionally substituted with a phenyl group). ] A herbicide containing one or more compounds represented by the following as an active ingredient.