JPS60149573A - Phenylurea derivative - Google Patents

Abstract

NEW MATERIAL:A 3-trifluoromethyl-1,2,4-oxadiazol-5-yl-methoxyphenylured derivative expressed by formula I (Y is H or halogen; Z is methyl or methoxy). EXAMPLE:N-[ 3-Chloro-4-( 3-trifluoromethyl-1,2,4-oxadiazol-5-yl-methoxy )phenyl ]- N',N'-dimethylurea. USE:A herbicide, exhibiting high selectivity for corn, and having a wide weeding spectrum and good selectivity even by application to main crops after germination thereof in a small amount of application. PREPARATION:For example, a compound expressed by formula II (Hal is halogen) is reacted with a compound expressed by formula III in an organic solvent preferably in the presence of a dehydrophalogenating agent to afford the aimed compound expressed by formula I .

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to novel phenylurea derivatives. More particularly, the present invention relates to novel oxadiazolylmethoxyphenylurea conductors having excellent herbicidal properties that exhibit a high degree of selectivity for corn.

Regarding oxadiazolylmethoxyphenylurea derivatives, 1,2,4-oxadiazole compounds are disclosed in JP-A-58-113177 as a type of five-membered heterocycle. That is, 5-substituted-1,2°4-ogisadiazol-3-ylmethoxyphenylurea and 3-substituted-
1,2,4-oxadiazol-5-yl-methoxyphenylurea type compounds are described. however,
In the former 1.2.4-oxadiazol-3-yl series, only phenyl and alkyl groups are shown as substituents at the 5-position of the 1.2.4-oxadiazole ring; , and the latter 1,2,4-oxadiazole-5
In the -yl series, a phenyl group (the publication compound 41
25) and a phenyl group substituted with a nitro group or a chlorine atom (compounds A100-105), and the 3 of the 1.2.4-oxadiazole ring is shown.
There is no description or suggestion of a 1,2,4-oxadiazol-5-yl-)xyphenylurea compound having a trifluoromethyl group at the position. In addition, the herbicidal activity, which is a characteristic of the compound, is slightly
There are only suggestions regarding 5.

On the other hand, in recent years, it has become essential to use herbicides to protect important crops such as corn, soybeans, wheat, rice, cotton, and beets from weed damage and to increase yields. These herbicides are foliage-contact type herbicides that can be applied after germination depending on the grass species and amount, and can be expected to reduce the amount of pesticide used, compared to soil treatment type herbicides that are applied before germination. is desired.

However, since foliar contact type herbicides also come into contact with crops, extremely high selectivity is required. Therefore, although many soil wall treatment types have been developed, there are very few foliage contact types. Currently, foliar contact type phenylurea herbicides include isoproturon (3-(4-isopropylphenyl)-1,1-dimethylurea) and metoxuron (3-(
3-chloro-4-methoxyphenyl)-1,1-dimethylurea], metapenzthiazuron (3-(2-benzothiazolyl)-1,3-dimethylurea), etc., and chloroxuron (for diving). 3-(4-(4-methoxyphenoxy)phenyl)-1,1-dimethylurea]
However, there are only a few phenylurea-based foliar contact herbicides that target corn. Also, these herbicides require large application rates.

The present inventors have overcome the technical problems of the above-mentioned phenylurea herbicides, and have developed a phenylurea herbicide that requires a small application amount, has a wide herbicidal spectrum, and has good selectivity even when sprayed on major crops after germination. As a result of intensive research efforts to develop a herbicidal agent, we succeeded in creating a 3-trifluoromethyl-1,2,4-oxadiazol-5-yl-methoxyphenylurea-based compound, and its herbicidal activity was It was confirmed that the objective was completely achieved, and the present invention was completed.

That is, the present invention is a 3-trifluoromethyl-1,2,4-oxadiazol-5-yl-methoxyphenylurea derivative represented by the following general formula m.

(Left below) [In the formula, Y represents a hydrogen atom or a halogen atom, and Z represents a methyl group or a methoxy group. ] The compound of the present invention is characterized by having a trifluoromethyl group at the 3-position of the 1,2,4-oxadiazole ring, and a methoxyphenylurea moiety bonded to the 5-position, and its structural characteristics The following characteristics are exhibited. That is, the compound of the present invention has a high degree of selectivity for corn, has a wide herbicidal spectrum, and exhibits its herbicidal activity sufficiently in an extremely small amount compared to conventional herbicides. is a compound with unexpected and excellent properties.

The compound of the present invention represented by general formula (I) can be produced, for example, by the method shown below.

(Left below) [In the formula, Hat represents a halogen atom, Y represents a hydrogen atom or a halogen atom, and Z represents a methyl group or a methoxy group. ] That is, 3-trifluoromethyl-1,2,4-oxadiane-5-yl-methyl halide [set] and N-hydroxyphenyl-N'-methylurea derivative [1] are preferably decomposed in an organic solvent. Manufactured by reaction in the presence of a hydrogen halide agent.

The reaction is carried out using 1 to 2 pmol equivalents, preferably 1 to 1.2 molar equivalents of compound [11] relative to compound r1[11, under water cooling or at the reflux temperature of the solvent, preferably from room temperature to 100 degrees Celsius. It is carried out for 1 to 20 hours at a temperature in the vicinity.

Examples of solvents include aromatic hydrocarbons such as toluene and xylene; ethers such as diethyl ether, tetrahydrofucine, and dioxane; halogenated hydrocarbons such as chloroform and carbon tetrachloride; ethyl acetate, acetone, acetonitrile, dimethylformamide, and dimethyl sulfoxide. Organic solvents such as

As the dehydrohalogenation agent, for example, pyridine, triethylamine, potassium hydroxide, sodium carbonate, sodium ethylate, sodium hydride, etc. are used. By using the dehydrohalogenating agent in an amount of 1 to 3 equivalents, preferably 1 to 1.5 equivalents, based on the compound r1, the reaction can be carried out in high yield.

After completion of the reaction, the compound of the present invention can be isolated by treating the reaction mixture according to conventional methods such as recrystallization and column chromatography.

Further, one of the intermediates [11] used in this reaction is a novel compound not described in any literature, and can be produced, for example, by the method shown below.

That is, it is produced by reacting trifluoroacetamidoxime r with a haloacetic acid halide (VII or haloacetic anhydride (■)), preferably in an organic solvent.

The reaction is carried out with compound M or [VI] from 1 to
The reaction is carried out using 10 times equivalent, preferably 1 to 3 times equivalent, at 35° C. to the reflux temperature of the solvent for 30 minutes to 20 hours.

Organic solvents include aromatic hydrocarbons such as toluene and xylene; ethers such as diethyl ether and tetrahydrofuran; halogenated hydrocarbons such as chloroform and carbon tetrachloride; lower fatty acids such as acetic acid and propionic acid: chloroacetic acid, 2 - Halogenated lower fatty acids such as chloropropionic acid: ethyl acetate, acetone, acetonitrile, dimethylformamide, dimethyl sulfoxide, etc. are used.

The compounds of the present invention thus obtained are shown in Table 1.

Table-1 Compound A Structural formula The compounds of the present invention are Japanese blueberry, Japanese bluegrass, Japanese grasshopper, Japanese whiteweed, pigweed, Koakaza, Japanese knotweed, Japanese redweed, Ebisu japonica, American hornwort, Japanese fir tree, Maruba morning glory, Japanese thornweed, Japanese dogweed, Japanese pigweed, It has a herbicidal effect on broad-leaved weeds such as sperihyu, oxalis, chickweed, shepherd's purse, yellowtail, and poppy, as well as grass weeds such as wild oat, silverwort, foxtail grass, johnson grass, wild oat, oxalis, sycamore, sycamore, and grasshopper. It is particularly effective against broad-leaved weeds. The compound of the present invention can also be sprayed on weeds before they germinate or during the growing season.

Furthermore, the compounds of the present invention can be applied to corn, soybeans, cotton, sunflowers, sugarcane, wheat such as beets, wheat, and other cereals, but are particularly effective against corn because they have extremely high selectivity. Weeds can be efficiently eradicated by contacting a small amount with the leaves during the growing season. Even for crops that are slightly damaged by the compounds of the present invention, spraying techniques should be devised so that the compounds of the present invention, which are active ingredients, do not get on the stems and leaves of these crops and are sprayed on weeds growing underneath. etc., it can be widely applied. Therefore, in addition to the above-mentioned fields for crops, it is also applicable to fields such as lawns, orchards, forest nurseries, and non-agricultural lands.

When applying the compound of the present invention to a site where weeding is required, it is possible to spray the compound as it is, but it can also be mixed with various conventional carriers or diluents, and in some cases with the addition of auxiliary agents. Even better results can be obtained by processing it into a formulation such as a hydrating powder, emulsion, powder, or granule.

As the carrier or diluent, commonly used solid or liquid carriers are used. Examples of solid carriers include talc, bentonite, clay, kaolin, diatomaceous earth, white carbon, etc., and examples of liquid carriers include water, alcohol, dioxane, acetone, cyclohexane, cyclohexanone, dimethylformamide, benzene, xylene, toluene, etc. . As adjuvants, surfactants such as alkyl sulfate esters, alkyl sulfates, polyoxyethylene glycol ethers, polyoxyethylene alkylaryl ether, polyoxyethylene sorbitan monoalkylate, etc., and mata such as carboxymethyl cellulose, sodium alginate, polyvinyl alcohol, Various auxiliary agents such as gum arabic are used.

The content of the active ingredient, which is the compound of the present invention, in the various formulations obtained as described above varies depending on the formulation, but is 0.1 to 99% by weight, preferably 1 to 80% by weight. For example, 5 to 80% by weight for wettable powders, 10 to 60% by weight for emulsions, and 1 to 15% by weight for granules.
% by weight is preferred.

The dosage of the compound of the present invention can be adjusted as appropriate depending on the application situation, usage method, type of target grass species, growth stage, and usage time, but in general, the active ingredient is 90% ha.
05 to 10 kg, preferably 0.1 to 4 kg.

The compound of the present invention can also be used as a labor-saving control agent by appropriately mixing with other fungicides, insecticides, acaricides, herbicides, plant growth regulators, etc. In particular, when used in combination with other herbicides, it not only reduces the amount of chemicals used and saves labor, but also expands the herbicidal spectrum due to the synergistic action of both herbicides and increases the effectiveness due to the synergistic action. You can expect it. Other removers include, for example, 2-chloro-4-ethylamino-6-isopropylamino-S-triazine (atrazine), 2-(2-chloro-4-ethylamino-s
- triazine herbicides such as -triazin-6-yl-amino)-2-methylpropionitrile (cyanazine),
N-methoxymethyl-2゜6-danityl-α-chloroacetanilide (azichlor), 2-chloro-N-(2
-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide (metolachlor)
amide herbicides such as S-ethyl-N, N-di-n-propylthiol carbamate (EPTC), thiol carbamate herbicides such as S-ethyl-N, N-diisobutylthiol carbamate (butyrate), 3- Isopropyl/L--I H-21113-benzothiadiazine-(4)-3H-one-2,2-dioxide (pentacine) Further examples include N-phenyl carbamate herbicides, diphenyl ether herbicides, etc. .

Next, the present invention will be explained in more detail with reference to Examples and Test Examples.

Example 1 (1) Production of intermediate [■] [■] [Vrl [! [1 41.5 f (0.32 mol) of trifluoroacetamidoxime was dissolved in 18Qd acetic acid, and further 56.4 r (0.33 mol) of chloroacetic anhydride was added.

The solution was gradually heated and kept at reflux temperature for 1 hour, then poured into ice water, stirred, and extracted three times with 200 d of ether. The ether layer was washed five times with a saturated aqueous sodium bicarbonate solution and then dried over anhydrous magnesium sulfate. The desiccant was taken from door to door and distilled to produce 5-chloro (yield 55%) (2) Production of compound &1 of the present invention Sodium hydride (oil base 60%) 4.5 f
139 mJ of dimethylformamide to which 1 mol) was added was cooled to 10-15°C, and 19.8 r (0°11
120 moles of dimethylformamide was added dropwise with stirring. This solution was then brought to room temperature and 0.5
After stirring for an hour, 5-chloromethyl-3-trifluoromethyl-1,2,4-oxadiazole 26.1 r
(0.14 mol) was added dropwise. This mixture was further stirred at room temperature for 3 hours, then poured into ice water, stirred, and the precipitated crystals were suctioned and filtered. By air-drying the crystals and recrystallizing them from toluene/isopropyl ether, the crystals had a melting point of 108.
．． 5-109.5°C N-(-4-(3-)lifluoromethyl-1゜2.4-oxadiazol-5-yl-methoxy)phenyl) -*N'N dithylurea 10.9
9 was obtained. (Yield 30%) Example 2 Production of Compound A2 of the Invention In (2) of Example 1, N-(3-1'
N-[3-chloro-4-
23.7 f of (3-trifluoromethyl-1,2,4-oxadiazol-5-yl-methoxy)phenyl)-N,N-dimethylurea was obtained.

The yield was 59%, and the melting point was 107-109°C.

Example 3 Production of Compound A4 of the Present Invention In (2) of Example 1, N-(3-hydroxyphenylene/' )-NUN-dimethylurea was replaced with
-chloro-4-hydroxyphenyl)-N-methyl-N
-N-[3
-chloro-4-(3-)lifluoromethyl-1,2,4
-oxadiazol-5-yl-methoxy)phenyl]
23.1 f of -N'-methyl-methoxyurea was obtained. Yield: 55%, melting point: 150.5-152°C.

Formulation Example 1 Wettable Powder Compound Shop 2 40 parts by weight Talc 50 parts by weight Polyoxyethylene alkylaryl ether surfactant 10 or more parts by weight are uniformly ground and mixed to obtain a wettable powder.

Formulation Example 2 Emulsion Compound A2 20 parts by weight Xylene 55 parts by weight Dimethylformamide 15 parts by weight Polyoxyethylene phenyl ether surfactant 1
An emulsion is obtained by mixing and dissolving 0 parts by weight or more.

Formulation Example 3 Granule Compound A1 5 parts by weight Bentonite 89 parts by weight Sodium ligninsulfonate 6 parts by weight or more are uniformly ground and mixed, a small amount of water is added, the mixture is stirred and kneaded, and then granulated and dried to obtain granules.

Test Example 1 Rectangular pots (30crnX 30cI
Fill up field soil, sow a certain amount of various weed seeds and diced seeds, and in a greenhouse, apply a 2.5 to 3 water diluted solution to each plant's stems and leaves so that each plant has a predetermined amount of active ingredients. Spread evenly. Twenty days after the chemical spraying, the herbicidal effect on each weed and the degree of chemical damage to the dice were judged according to the following criteria, and the results are shown in Table 2.

Judgment criteria for herbicidal effect: Degree of chemical damage (% of grass in untreated area) 5: Percentage of grass in grass 0 to 1% -: No chemical damage 4: I 1 or more to 20% ±: Slight damage 3: Il 2
0 〃～40〃 -Second minor damage 2: #40jl～601 -
1-1-: Nakayoshi 1: ll601~sos +I+: Severe damage O~103.5 mp 88.5~89.5゜mp 78.5~80゜mp123.0~124.5 mp 98-5~1. OO,0 I mp 84.5-87.0 ('J- mp 101.0-102.0 mp 90.5-92.0 Ct mp 76.5-77.5 mp168.5-170.0 mp 142 .5 to 143.5° (dec,) These results indicate that the compound of the present invention has a wide herbicidal spectrum that exhibits herbicidal activity against grass weeds and broad-leaved weeds, and is harmless to corn. , and it can be seen that it is an excellent compound that exhibits sufficient herbicidal activity with a small dose.

In particular, for the compound d%0%L, which is a compound that differs only slightly from the compound of the present invention in the substitution position of the trifluoromethyl group on the 1.2.4-oxadiazole ring and the bonding position of the methoxyphenylurea moiety. Almost no herbicidal activity is observed against grass weeds, and only slight activity is observed among broad-leaved weeds such as Japanese knotweed, and compounds e and f, which have chlorine atoms in the benzene ring, exhibit phytotoxicity. . Furthermore, in the compound a1bXc, which differs only in the presence or absence of three fluorine atoms from the compound of the present invention, a has almost no herbicidal activity against grass weeds, and has slight activity against broad-leaved weeds such as Japanese grassweed and Japanese knotweed. Although Compound b1C has some activity against broad-leaved weeds, it has caused phytotoxicity to corn.

Furthermore, the comparative compound gs)is'%j has a certain degree of herbicidal activity, but no practical activity was observed against grass weeds, and phytotoxicity was observed on corn.

From these facts, it can be said that the properties of the compound of the present invention are extremely unique among similar compounds and are beyond the predictions of those skilled in the art.

Patent applicant Mitsubishi Yuka Co., Ltd. Agent: Patent Attorney Hidetoshi Furukawa (1 other person)

Claims (1)

[Claims] 3-trifluoromethyl-1 represented by the following general formula
, 2,4-oxadiazol-5-yl-methoxyphenylurea derivative. [In the formula, Y represents a hydrogen atom or a halogen atom, and 2 represents a methyl group or a methoxy group. ]