JPH09143014A - Weed control agent composition for upland field - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the above highly selective composition containing a specific 1,2,4-triazole derivative as an active ingredient, expressing excellent herbicidal activities against weeds in upland fields at extremely low doses, providing no chemical damage to agricultural crops. SOLUTION: This agent contains a benzofuran skeleton-having 1,2,4-triazole derivative of formula I (R<1> , R<2> are each H, methyl; R<3> , R<4> are each a halogen, a lower alkyl, a lower alkoxy, a lower haloalkyl, a lower haloalkoxy, cyano; R<5> is methyl, ethyl; X is 0, S). The upland fields are preferably upland fields wherein soybeans, cotton or wheat and barley are cultured. The compound of formula I is preferably used at a dose of 10-100g/10 are. The compound of formula I is obtained, e.g. by reacting a (thio)semicarbazide compound of formula II with trifluoroacetic anhydride. Important weeds in the uplant fields are Amaranthus retroflexus, Echinochloa crus-galli, Corchorus capsularis, Rumex obtusifolius, Cyperus microiria, Arenaria serpyllifolia L., etc.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a composition for controlling weeds in upland fields and a method for using the same.

[0002]

To date, many herbicides have been found, some of which are widely used for weed control of agricultural crops.

US Pat. No. 5,108,486 discloses that
It has been disclosed that certain 4-phenyl-1,2,4-triazole derivatives have herbicidal activity. However, although the above-mentioned specification describes test examples under field conditions, it does not necessarily show sufficient herbicidal activity, and does not contain any data showing selectivity for agricultural crops. Further, JP-A-7-188220 discloses that a certain 4-phenyl-1,2,4-triazole derivative has herbicidal activity and is effective as a herbicide composition for paddy fields. However, there is no teaching in the above specification whether or not the triazole derivative is effective for controlling weeds in upland fields.

[0004]

Based on the above background, the present inventors are interested in 4-phenyl-1,2,4-triazole derivatives, and continue to study the crop selectivity of the derivatives in detail. Came. As a result, US Pat. No. 510
The general formula (I) having a benzofuran skeleton, which is neither disclosed nor suggested in the specification of 8486 and JP-A-7-188220.

[0005]

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[In the formula, R ¹ and R ² are the same or different and each represents a hydrogen atom or a methyl group. R ³ and R ⁴ are the same or different and each is a halogen atom, a lower alkyl group, a lower alkoxy group,
A lower haloalkyl group, a lower haloalkoxy group or a cyano group is shown. R ⁵ represents a methyl group or an ethyl group. X represents an oxygen atom or a sulfur atom. ] 1,2,4-
It was found that triazole derivatives have no phytotoxicity to rice in flooded soil treatment tests and have extremely high selectivity to completely eradicate important weeds in paddy fields with a low dosage (Japanese Patent Application No. 6-154796 and Japanese Patent Application No. 6-154796). Flat 7-229876
issue).

The present inventor further studied in detail the herbicidal activity and crop selectivity for the purpose of applying the 1,2,4-triazole derivative represented by the general formula (I) to other fields. It was surprisingly found that the above-mentioned triazole derivative exhibits excellent herbicidal activity at a very low dose against upland weeds and has extremely high selectivity with no phytotoxicity against agricultural crops. . The present invention has been completed based on such findings.

That is, the present invention relates to a composition for controlling weeds in upland fields, which comprises a 1,2,4-triazole derivative represented by the above general formula (I) as an active ingredient, and a method of using the same.

According to the present invention, there is provided a field weed control composition which shows an excellent control effect on important weeds in the field and is harmless to agricultural crops.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the above general formula (I), R ³
And the groups represented by R ⁴ are specifically as follows.

As the halogen atom, for example, a fluorine atom,
Examples include a chlorine atom, a bromine atom and an iodine atom.

As the lower alkyl group, for example, methyl,
Examples thereof include linear or branched alkyl groups having 1 to 6 carbon atoms, such as ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, and hexyl groups.

Examples of the lower alkoxy group include linear or branched alkoxy groups having 1 to 6 carbon atoms such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, tert-butoxy, pentyloxy and hexyloxy groups. it can.

Examples of the lower haloalkyl group include trifluoromethyl, trichloromethyl, chloromethyl, bromomethyl, fluoromethyl, iodomethyl, difluoromethyl, dibromomethyl, 2-chloroethyl, 2,
2,2-trifluoroethyl, 2,2,2-trichloroethyl, 3-bromopropyl, 3-chloropropyl,
2,3-dichloropropyl, 4,4,4-trichlorobutyl, 4-fluorobutyl, 5-chloropentyl, 3-
Chloro-2-methylpropyl, 5-bromohexyl,
As a substituent such as a 5,6-dichlorohexyl group, a linear or branched alkyl group having 1 to 3 halogen atoms and 1 to 6 carbon atoms can be exemplified.

Examples of the lower haloalkoxy group include:
Trifluoromethoxy, trichloromethoxy, chloromethoxy, bromomethoxy, fluoromethoxy, iodomethoxy, difluoromethoxy, dibromomethoxy, 2-
Chloroethoxy, 2,2,2-trifluoroethoxy,
2,2,2-Trichloroethoxy, 3-bromopropoxy, 3-chloropropoxy, 2,3-dichloropropoxy, 4,4,4-trichlorobutoxy, 4-fluorobutoxy, 5-chloropentyloxy, 3-chloro- 2-
Methylpropoxy, 5-bromohexyloxy, 5,6
Examples of the substituent such as -dichlorohexyloxy group include a linear or branched alkoxy group having 1 to 3 halogen atoms and 1 to 6 carbon atoms.

Among the compounds of the present invention represented by the general formula (I), the following compounds are particularly preferable.

Compounds of the general formula (I) in which R ¹ is a methyl group and R ² is a hydrogen atom; compounds of the general formula (I) in which R ¹ is a methyl group and R ³ and R ⁴ are both halogen atoms; A compound of the general formula (I) in which ¹ is a methyl group, R ³ and R ⁴ are both lower alkyl groups; a general formula (I) in which R ¹ is a methyl group, R ³ is a lower alkyl group, and R ⁴ is a halogen atom. A compound of
Compounds of the general formula (I) in which R ¹ is a methyl group, R ³ is a halogen atom, R ⁴ is a lower alkyl group; R ¹ is a methyl group, R ³
Is a lower alkoxy group, the compound of the general formula R ⁴ is a halogen atom (I); R ¹ is a methyl group, R ³ is a lower haloalkyl group, a compound of the general formula R ⁴ is a halogen atom (I); R ¹ A compound of the general formula (I) in which R is a methyl group, R ³ is a cyano group, and R ⁴ is a halogen atom; General formula (I) in which R ¹ is a methyl group, R ³ is a halogen atom, and R ⁴ is a lower alkoxy group. Compound of.

The compound represented by the general formula (I) of the present invention is produced, for example, by the method shown in the following reaction formula-1.

[0019]

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[Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ and X
Is the same as above. According to the above Reaction Scheme-1, the compound of the present invention has the general formula (I
It is produced by reacting the (thio) semicarbazide represented by I) with trifluoroacetic anhydride in the absence of a solvent or in a suitable solvent. Examples of the solvent used in this reaction include aromatic hydrocarbons such as benzene and toluene, halogenated hydrocarbons such as dichloromethane, 1,2-dichloroethane and chloroform, and mixed solvents thereof. The ratio of the (thio) semicarbazide of the general formula (II) to trifluoroacetic anhydride to be used is not particularly limited, but usually the latter is about 0.5 to 3 times mol, preferably the former. It is preferable that the molar ratio is about 1 to 1.5 times. The above reaction proceeds well in the temperature range from room temperature to the boiling point of the solvent used, and in the compound of the present invention of the general formula (I), when Y is an oxo form, it is usually 20 to 50 hours. The reaction is completed in about 1 to 5 hours in the case of a thiono form in which Y represents a sulfur atom. In the above Reaction Scheme-1, the (thio) semicarbazide of the general formula (II) used as the starting material can be easily prepared according to the method known from the corresponding anilines, for example, the method described in US Pat. No. 4,514,419. Can be manufactured. Trifluoroacetic anhydride, which is the other starting material, is a compound that is easily available industrially.

According to the present invention, it is completely harmless to agricultural crops cultivated in upland fields and can selectively control weeds that are problematic in upland fields, and thus is extremely useful for controlling weeds in upland fields. Examples of agricultural crops cultivated in upland fields include corn, wheat, soybeans, cotton, vegetables and the like. The control composition of the present invention is particularly effective in soybean, cotton and wheat (especially wheat) cultivated areas. Examples of important weeds in upland fields include bluefin millet, millet, velvetleaf, Rumex japonicus, Cyperus cylindrica, Chionoecetes sinensis, Rhododendron japonicus, Nogeshi, and Poa annua.

When the compound of the present invention is used as a control agent for upland weeds, it is used for emulsions, wettable powders, dry flowables, flowables, water solutions, granules, fine granules, granules, powders, coatings and sprays. It can be used in various formulation forms such as a formulation, an aerosol formulation, a microcapsule formulation, a fumigation formulation, and a fumigation formulation.

As the auxiliary agent to be added to the upland weed control agent of the present invention, those generally used in this field can be widely used. For example, the amount of diatomaceous earth, kaolin, clay, bentonite, white carbon, talc, etc. can be increased. Agents, polyoxyethylene alkyl ethers, polyoxyethylene alkyl esters, nonionic surfactants such as polyoxyethylene sorbitan alkyl esters, alkylbenzene sulfonates, alkyl sulfosuccinates, alkyl sulphates, polyoxyethylene alkyl sulphates, alkyl sulphonates, Allyl sulfonate,
Examples thereof include anionic surfactants such as lignin sulfite.

Water, various organic solvents, various aerosol propellants, various natural minerals, various synthetic compounds and the like can be used as the solubilizers and diluents to be added to the upland weed control agent of the present invention. For example, as the organic solvent, benzene, toluene, xylene, ethylbenzene, chlorobenzene, alkylnaphthalene, chloroethylene, cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone, alcohols, cellosolves, dimethylformamide, dimethyl sulfoxide, acetonitrile, mineral oil fractions, etc. Used by preference. Examples of aerosol propellants include propane, butane, halogenated hydrocarbons, nitrogen, carbon dioxide and the like.

Further, the field weed control agent of the present invention may be colored with an organic or inorganic dye.

In the present invention, in producing the above-mentioned various preparations, the compound of the present invention may be prepared in an amount of about 0.1 to 95% by weight, preferably about 0.5 to 90% by weight. Good. The preparation thus obtained may be used as it is or diluted with a carrier or water, but the compound of the present invention may be contained in an amount of about 0.0001 to 100% by weight, preferably about 0.001 to 10% by weight, depending on the purpose. It is advisable to use it after diluting freely within the range.

In the use of the upland weed control agent of the present invention, it can be used in combination with other herbicides, fungicides, insecticides and the like.

In using the control agent for upland weeds of the present invention, the 1,2,4-triazole derivative represented by the above general formula (I) is 1 to 1000 g / 10 are, preferably 10 to 100 g. The upland weed control agent of the present invention is preferably used so that it is used in upland fields at a dose of / 10 ares.

[0029]

EXAMPLES The present invention will be further clarified with reference to production examples, formulation examples and test examples below. In the formulation examples, “parts” means “parts by weight”.

Production Example 1 A compound of the general formula (I) in which R ¹ is a methyl group, R ² is a hydrogen atom, R ³ is a methyl group, R ⁴ is an isopropyl group, R ⁵ is a methyl group and X is an oxygen atom ( Preparation of Compound 1) Trifluoroacetic anhydride (20 mmol) was added dropwise to a suspension of semicarbazit (12 mmol) in toluene (30 ml) under ice-cooling, and after the addition was completed, the reaction mixture was further stirred at room temperature for 30 hours. The reaction solution was washed with 10% aqueous sodium carbonate solution and dried over anhydrous magnesium sulfate. The solvent was distilled off, and the residue was purified by a silica gel column (developing solvent; hexane: ethyl acetate = 2: 1) to obtain 2.12 g of the desired product (compound 2) as white crystals.

Melting point 122-123 ° C. ¹ H-NMR (CDCl ₃ ) δ ppm; 1.32 (6
H), 2.12 (3H), 2.46 (3H), 3.39.
(1H), 3.58 (3H), 6.37 (1H), 6.
83 (1H).

From the above results, it was confirmed that the obtained white crystals were the above target compound.

Each compound shown in the following Table 1 was obtained in the same manner as in Production Example 1 or Production Example 2 using appropriate starting materials.

[0034]

[Table 1]

The physical properties of the compound of Production Example 2 to the compound of Production Example 13 in Table 1 above are shown below.

Compound of Preparation Example 2: melting point 113-114 ° C. ¹ H-NMR (CDCl ₃ ) δ ppm; 2.56 (3
H), 3.92 (3H), 6.63 (1H), 7.22
(1H).

Compound of Production Example 3: Melting point 104-105 ° C. ¹ H-NMR (CDCl ₃ ) δppm; 2.35, 2.4
2 (6H), 3.89 (3H), 7.22 (1H).

Compound of Preparation Example 4: Melting point 124-125 ° C. ¹ H-NMR (CDCl ₃ ) δ ppm; 2.48 (6
H), 3.87 (3H), 6.47 (1H), 7.06
(1H).

Compound of Preparation Example 5: melting point 127-128 ° C. ¹ H-NMR (CDCl ₃ ) δppm; 2.15 (3
H), 2.53 (3H), 3.88 (3H), 6.47.
(1H), 7.02 (1H).

Compound of Production Example 6: melting point 136-137 ° C. ¹ H-NMR (CDCl ₃ ) δ ppm; 2.20 (3
H), 2.74 (3H), 3.57 (3H), 6.42
(1H), 7.02 (1H).

Compound of Production Example 7: melting point 121-122 ° C. ¹ H-NMR (CDCl ₃ ) δppm; 2.18 (3
H), 2.52 (3H), 3.90 (3H), 6.50.
(1H), 7.18 (1H).

Compound of Preparation Example 8: melting point 145-146 ° C. ¹ H-NMR (CDCl ₃ ) δ ppm; 2.20 (3
H), 2.50 (3H), 3.58 (3H), 6.48
(1H), 7.20 (1H).

Compound of Production Example 9: melting point 88 to 91 ° C. ¹ H-NMR (CDCl ₃ ) δ ppm; 2.55 (3
H), 3.85 (3H), 6.70 (1H), 7.15
(1H).

Compound of Preparation Example 10: melting point 85-88 ° C. ¹ H-NMR (CDCl ₃ ) δppm; 2.54 (3
H), 3.57 (3H), 6.70 (1H), 7.23
(1H).

Compound of Production Example 11: melting point 107-108 ° C. ¹ H-NMR (CDCl ₃ ) δppm; 2.15 (3
H), 2.44 (6H), 3.70 (3H), 6.37.
(1H), 6.75 (1H).

Compound of Production Example 12: Viscous liquid ¹ H-NMR (CDCl ₃ ) δ ppm; 2.60 (3
H), 3.90 (3H), 6.75 (1H), 7.25
(1H).

Compound of Production Example 13: melting point 90-91 ° C. ¹ H-NMR (CDCl ₃ ) δppm; 2.18 (3
H), 2.45 (6H), 3.55 (3H), 6.33
(1H), 6.75 (1H).

Formulation Example 1 (10% wettable powder) Compound of the general formula (I) 10.0 parts Dikelite (Kallion clay: manufactured by Zikelite Industry Co., Ltd.) 87.3 parts Solpol 800A 1.35 parts Lunox P-65-L (manufactured by Toho Chemical Industry Co., Ltd.) 1.35 parts Formulation example 2 (10% flowable agent) Compound of general formula (I) 10.0 parts KP-1436 (25) (manufactured by Kao Corporation) ) 10.0 parts Renox 100C (manufactured by Toho Chemical Industry Co., Ltd.) 0.5 part 1% Rhodopol water (manufactured by Rhone Poulenc) 40.0 parts water 39.5 parts Test Example 1 (herbicidal activity test against upland weeds) ) The pot is filled with cultivated loam soil and an appropriate amount of mixed fertilizer, and as a test plant, Aubiyu, Novier, Strawberry, Rumex, Cyperus cylindrica, Chionoecetes sinensis, Rhododendron chinensis, Nogeshi, Scutellaria baicalensis, Soybean After sowing cotton and wheat, the soil was lightly covered. An aqueous solution prepared by diluting the 10% flowable agent prepared in Formulation Example 1000 by 1000 times was uniformly treated on the soil surface so that the treatment amount per area was 50 g / 10a, and then a test plant was grown by lower water absorption, The herbicidal effect was determined by visual observation every 1 week. The herbicidal effect was determined according to the following criteria. The results of macroscopic observation at 3 weeks are shown in Tables 2 and 3 below. The test compound numbers in Tables 2 to 3 correspond to the compound numbers in the above Production Examples. Also, for comparison, the formula

[0049]

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A compound represented by the formula (US Pat. No. 5,108,484)
No. 86 specification, this compound is referred to as “Compound A”) and a formula

[0051]

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A compound represented by the formula (JP-A-7-18822).
Table 2 also shows the results of determining the herbicidal effect in the same manner as described above using the compound described in JP-A No. 0, referred to as "Compound B").

Criteria: 5 ... 100% herbicidal rate (complete withering), 4.5 ... 90-100% herbicidal rate, 4 ... 70 herbicidal rate
~ 90%, 3 ... Herbicide rate 40-70%, 2 ... Herbicide rate 20-
40%, 1 ... grazing rate 0-20%, 0 ... grazing rate 0% (harmless).

[0054]

[Table 2]

[0055]

[Table 3]

Front page continuation (72) Inventor Mitsuyuki Murakami 615, Satoura, Satoura-cho, Naruto, Tokushima Prefecture, Naruto Research Institute, Otsuka Chemical Co., Ltd. (72) Yoshinori Endo, 615, Satoura, Satoura, Naruto, Tokushima Otsuka Chemical Co., Ltd. Naruto Institute

Claims (3)

[Claims] 1. A compound of the general formula [In the formula, R ¹ and R ² are the same or different and each represents a hydrogen atom or a methyl group. R ³ and R ⁴ are the same or different and each represents a halogen atom, a lower alkyl group, a lower alkoxy group, a lower haloalkyl group, a lower haloalkoxy group or a cyano group. R
⁵ represents a methyl group or an ethyl group. X represents an oxygen atom or a sulfur atom. ] The upland weed control agent composition containing the 1,2,4-triazole derivative represented by these as an active ingredient. 2. The upland weed control composition according to claim 1, wherein the upland is a soybean, cotton or wheat cultivated field. 3. A method of using a 1,2,4-triazole derivative according to claim 1 in a field amount of 10 to 100 g / 10 ares for use in a field crop weed control agent. .