JPS6328914B2 - - Google Patents

Description

[Detailed description of the invention]

This invention is based on the general formula [However, in the formula, X and Z represent a hydrogen atom or a halogen atom, Y represents a halogen atom, a trifluoromethyl group, or a methoxy group, and R represents a

[Formula] (However, R ₁ and R ₂ represent a lower alkyl group, a hydrogen atom, or a chloromethyl group, or R ₁ and R ₂ may be linked to each other to form a saturated alicyclic body. )or

[Formula] (wherein R ₃ represents a hydrogen atom or a methyl group). The present invention provides a novel diphenyl ether derivative represented by the following formula, and also provides a herbicide containing this novel diphenyl ether derivative as an active ingredient. Many herbicides containing diphenyl ether derivatives as active ingredients have been proposed for a long time, and many are commercially available. enyl ether), CNP (2′,4′,6′-trichloro-4
-nitrodiphenyl ether) and TOPE (3'-methyl-4-nitrodiphenyl ether). These conventionally known diphenyl ether herbicides have excellent ability to treat annual grass weeds that generally occur in rice fields. However, the ability to treat various weeds,
In addition, they have a common characteristic of being inferior in herbicidal effect against annual broad-leaved weeds and perennial weeds, and causing chemical damage to transplanted rice, such as browning of leaf sheaths, falling leaves, and inhibition of tillering. Also, this type of derivative, as in the case of other organic compounds,
Due to differences in chemical structure due to differences in the type, number, or position of substituents, there are often unexpected differences in herbicidal effects, size, slowness, or chemical damage to crops. The inventors have conducted various studies with the aim of obtaining industrially useful diphenyl ether derivatives that have not been previously described in literature. As a result, the general formula (However, in the formula, X, Y, Z and R have the same meanings as above.) We have succeeded in synthesizing a new diphenyl ether derivative represented by The present inventors have discovered that it has an excellent herbicidal effect on various crops, and that it is completely free from phytotoxicity to various crops, toxicity to humans, livestock, fish and shellfish, and no off-odor, and has thus arrived at this invention. The diphenyl ether derivative in this invention has the ability to wither weeds before and after they emerge when sprayed on soil, which is the ability to treat both soil and foliage. It is effective against a wide range of weeds such as grass weeds and broad-leaved weeds. In addition, conventionally known diphenyl ether herbicides
No chemical damage to transplanted rice, such as browning of leaf sheaths, falling leaves, or suppression of tillering, which is commonly observed, was observed. Table 1 lists examples of novel diphenyl ether derivatives in this invention. In the herbicide of the present invention, salts of these diphenyl ether derivatives are also useful as active ingredients.

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[Table] These diphenyl ether derivatives in this invention can be synthesized, for example, by the following reaction steps. (However, X, Y, Z and R in the formula have the same meanings as above.) The above reaction is preferably carried out by adding an alkali in the presence of a suitable solvent, and the alkali used is KOH, NaOH, etc. A strong alkali such as is suitable. Examples of the solvent used in the reaction include dioxane, dimethylsulfoxide, dimethylformamide, dimethylacetamide, or a mixed solvent thereof. The reaction temperature is not particularly limited and is suitably carried out at room temperature to 60°C or lower. Next, a synthesis example of this invention will be given. Synthesis example 1 2-chloro-4-trifluoromethyl-3'-
Synthesis of {(1,4-dioxaspiro-[4,4]nonan-2-yl)methoxy}-4'-nitrodiphenyl ether (compound number 6) 2,4-bis(2-chloro-4-trifluoro Methylphenoxy) nitrobenzene 3.2g (0.006
mole) and 1,2-cyclopentylidene glycerin
1.3 g (0.008 mol) was dissolved in 20 ml of dioxane, 0.5 g (0.008 mol) of potassium hydroxide was added, and the mixture was heated and stirred at about 50° C. for 8 hours. The reaction solution was then cooled, water was added, and the precipitated oil was extracted with benzene. The extract was washed with water, dried over sodium sulfate, and the benzene was distilled off. The residue was applied to a silica gel column to give a pale yellow oily 2-chloro-4-trifluoromethyl-3'-
{(1,4-dioxaspiro-[4,4)nonane-
2-yl)methoxy}-4'-nitrodiphenyl ether (n ²⁵ _D 1.5411) was obtained in an amount of 2.1 g (yield 70%). Synthesis Example 2 Synthesis of 2,4,6-trichloro-3'-{(1,3-dioxolan-4-yl)methoxy}-4'-nitrodiphenyl ether (Compound No. 32) 2,4-bis(2 ,4,6-trichlorophenoxy)nitrobenzene 2.5g (0.005 mol) and 1,
After dissolving 0.7 g (0.007 mol) of 2-methylidene glycerin in 10 ml of dioxane, potassium hydroxide
0.5 g (0.008 mol) was added, and the mixture was heated and stirred at about 50° C. for 3 hours. The reaction solution was then cooled, water was added, and the precipitated oil was extracted with benzene. The extract was washed with water, dried over sodium sulfate, and the benzene was distilled off. The residue was reconsolidated with ethanol to form colorless crystals of 2,
0.9 g (yield 45
%)Obtained. Synthesis example 3 2-chloro-4-trifluoromethyl-3'-
Synthesis of (1,3-dioxa-5-cyclohexyloxy)-4'-nitrodiphenyl ether (compound number 40) 2.5 g of 2,4-bis(2-chloro-4-trifluoromethylphenoxy)nitrobenzene ( 0.005
mole) and 1,3-methylidene glycerin 0.7g
(0.007 mol) was dissolved in 10 ml of dioxane, 0.5 g (0.008 mol) of potassium hydroxide was added, and the mixture was heated to about 50°C.
The mixture was heated and stirred for 8 hours. Then, the reaction solution was cooled,
After adding water and extracting the precipitated oil with benzene, the extract was washed with water, dried over sodium sulfate, and the benzene was distilled off. The residue was recrystallized from ethanol to give colorless crystals of 2
-chloro-4-trifluoromethyl-3'-(1,
3-dioxa-5-cyclohexyloxy)-
4′-Nitrodiphenyl ether (melting point 105.5-108
1.2 g (yield: 60%) of When the diphenyl ether derivatives of this invention are used as herbicides, they can be used in granules, powders, emulsions, hydrated formulations, etc. using inert solid carriers, liquid carriers, emulsified dispersions, etc., in accordance with the practice of agricultural chemical formulations. It can be used in any dosage form such as tablets, oils, aerosols, smokes, etc. Examples of these inert carriers include talc, clay, kaolin, diatomaceous earth, calcium carbonate, potassium chlorate, saltpetre, wood flour, nitrocellulose, starch, benzene, xylene, n-hexane, gum arabic, vinyl chloride, Examples include carbon dioxide gas, freon, propane, butane, etc. Further, auxiliary agents for formulation, such as spreading agents, diluents, surfactants, solvents, etc., may be appropriately added. Furthermore, it can also be used by appropriately mixing with fungicides, insecticides, other agricultural chemicals, urea, ammonium sulfate, ammonium phosphorous, potassium salts and other fertilizer substances, soil improvers, and the like. Next, examples of the herbicide according to the present invention will be given. In addition, parts in each example mean parts by weight. Example 1 2-chloro-4-trifluoromethyl-3'-
{(1,4-dioxaspiro-[4,4]nonane-
2-yl)methoxy}-4'-nitrodiphenyl ether (compound No. 6) 8 parts, bentonite 30 parts, talc 59 parts, neopellex powder [trade name: Kao Atlas Co., Ltd.] 1 part, and The mixture was homogeneously mixed with 2 parts of sodium ligninsulfonate, and then a small amount of water was added and kneaded, followed by granulation and drying to obtain granules. Example 2 2-chloro-4-trifluoromethyl-3'-
{(2,2-dimethyl-1,3-dioxolane-4
-yl)methoxy}-4'-nitrodiphenyl ether (compound number 25) 50 parts, kaolin 48
1 part and 2 parts of Neopellex powder were uniformly mixed and then ground to obtain a wettable powder. Example 3 2,4,6-trichloro-3'-{(1,3-dioxolan-4-yl)methoxy}-4'-nitrodiphenyl ether (compound No. 32) 50
40 parts of xylene, 5 parts of dimethylformamide, and toxanone [Product name: Sanyo Chemical Industries, Ltd.] 5 parts
The mixture was uniformly mixed and dissolved to obtain an emulsion. Example 4 2-chloro-4-trifluoromethyl-3'-
(1,3-dioxa-5-cyclohexyloxy)
-4′-Nitrodiphenyl ether (compound number 40
5 parts of the compound), 50 parts of talc, and 45 parts of kaolin were uniformly mixed to obtain a powder. Next, the effects of the herbicide in this invention will be specifically explained using experimental examples. In addition, the test compound number in each experimental example is the same as the compound number mentioned above. Experimental Example 1 Paddy Soil Treatment Experiment Fill a 1/5000 are Wagner pot with Ube soil (alluvial clay soil), plant seeds of Japanese millet that have awakened from dormancy, tubers of Cyperus japonica, tubers of Paddy spp. Seeds of Japanese cypress, bulrush, Japanese cypress, and Kikashigusa were sown in the upper layer, and paddy rice seedlings (variety: Nipponbare) at the 2nd and 3rd leaf stage were transplanted, and water was added to create a flooded state at a depth of 3 cm. Next, each drug (wettable powder prepared according to Example 2) was added to a solution with an active ingredient concentration of 1000 ppm.
It is diluted with water so that ) was uniformly dropped in a predetermined amount using a pipette and kept in a glass room at an average temperature of 25°C. Three weeks after the chemical treatment, the herbicidal effects of each test compound were investigated. The result is the second
Shown in the table. The herbicidal effects in Table 2 were based on the following criteria. 5: Complete death 4: Major harm 3: Medium harm 2: Minor harm 1: Slight harm 0: No harm (normal development)

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[Table] Experimental Example 2 Treatment experiment of Japanese millet by growth period A 1/5000 are beaker pot was filled with Ube soil, and Japanese millet was sown, and plants at the 0.5 leaf stage, 1.0 leaf stage, and 1.5 leaf stage were grown. The water was flooded to a depth of 3 cm, and each drug (wettable powder manufactured according to Example 2 was diluted with water to have an active ingredient concentration of 1000 ppm) was uniformly dropped in a predetermined amount using a pipette. The samples were treated and maintained in a glass room with an average temperature of 25°C. Three weeks after the chemical treatment, the herbicidal effects of each test compound were investigated. The results are shown in Table 3. Note that the criteria for the herbicidal effect in Table 3 are based on Experimental Example 1.
is the same as

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[Table] Experimental example 3 Upland soil treatment experiment A 1/5000-arm Wagner pot was filled with Ube soil and used to grow corn (variety: Golden Cross Bantam), soybean (variety: Akiyoshi), radish (variety: Mino Wase), crabgrass, and wild foxtail. After sowing the seeds of . ) was sprayed uniformly under pressure onto the soil surface layer in a predetermined amount and maintained in a glass room with an average temperature of 25°C. Three weeks after the chemical treatment, the herbicidal effects of each test compound were investigated. The results are shown in Table 4. Note that the criteria for the herbicidal effect in Table 4 are based on Experimental Example 1.
is the same as

[Table] Experimental Example 4 Field Stem and Leaves Treatment Experiment A Wagner pot of 1/5000 are was filled with Ube soil, and crabgrass, whiteberry and Japanese knotweed were grown. Next, a drug prepared by diluting the hydrating agent of each test compound to 0.5 wt% with water containing 100 ppm of the spreading agent Neoesterin [trade name: manufactured by Toa Agricultural Co., Ltd.] was uniformly applied to the stems and leaves at a rate of 5 ml per pot. Pressurized spraying is applied to the average temperature.
It was maintained in a glass room at 25°C. Three weeks after the chemical treatment, the herbicidal effects of each test compound were investigated. The results are shown in Table 5. In addition, the criteria for the herbicidal effect in Table 5 are based on Experimental Example 1.
is the same as

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[Table] From the above experimental results, it was found that the herbicide of the present invention can effectively control a wide range of weeds without causing any chemical damage to crops by applying soil treatment or foliage treatment. It is recognized that this herbicide is an extremely excellent herbicide.

Claims (1)

[Claims] 1. General formula [However, in the formula, X and Z represent a hydrogen atom or a halogen atom, _Y represents a halogen atom, a trifluoromethyl group, or a methoxy group, and _R represents may represent a hydrogen atom, a chloromethyl group, or R ₁ and R ₂ may be linked together to form a saturated alicyclic product) or [Formula] (where R ₃ is a hydrogen atom or a methyl group. ). ] A diphenyl ether derivative represented by 2 General formula [However, in the formula, X and Z represent a hydrogen atom or a halogen atom, _Y represents a halogen atom, a trifluoromethyl group, or a methoxy group, and _R represents may represent a hydrogen atom, a chloromethyl group, or R ₁ and R ₂ may be linked together to form a saturated alicyclic product) or [Formula] (where R ₃ is a hydrogen atom or a methyl group. ). ] A herbicide characterized by containing a diphenyl ether derivative represented by the following as an active ingredient.