JPS61106560A - Phenylurea compound and herbicide containing - Google Patents

Abstract

NEW MATERIAL:A phenylurea compound shown by the formula I [R1 is lower alkyl, or lower alkoxy; X is O, or S; R2 is phenyl, 3-halogeno-4.5-(CH=CH)2-, or 3-halogeno-4.5-(CH2)4; Y is H or halogen]. EXAMPLE:N-(4-Phenylpyridazine-6-oxyphenyl)-N,N'-dimethylurea. USE:A herbicide useful as a herbicide for paddy fields of rice plants, or a herbicide for plowed fields, having no fear of phytotoxicity to crops in terms of structure and showing improved selective herbicidal activity. PREPARATION:A compound shown by the formula II is reacted with a compound shown by the formula III in the presence of a deoxidizer and an inorganic base such as sodium hydride, anhydrous potassium carbonate, anhydrous sodium carbonate, etc., to give a compound shown by the formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to compounds of the general formula (I) (wherein R represents a lower alkyl group or a lower alkoxy group, X represents an oxygen or sulfur atom, and R2 represents a phenyl group) , 3-halogeno-4,5+0H=CH+2 group or 6-valogeno-4,5- (-CH2f, group, y represents hydrogen atom or halo, gen atom) and their The invention relates to herbicides containing one or more herbicides.

The herbicide according to the present invention is useful in agriculture and horticulture.

BACKGROUND OF THE INVENTION A great deal of research has been conducted on phenylurea compounds, and herbicides useful in agriculture and horticulture have been developed and put into practical use. Typical examples of these are 5
-(3,4-dichlorophenyl)-1,1-dimethylurea [British Patent 776,069;
- (3,4-dichlorophenyl)-1-methoxy-1
-Methylurea [US Pat. No. 2,960.534; Riniro/] and the like. Further, Japanese Patent Application Laid-Open No. 58-59958, US Pat. No. 5,947,437, etc. are known.

Problems to be Solved by the Invention In recent years, many compounds have been developed and put into practical use as herbicides for paddy fields. However, due to changes in agricultural practices and an increase in the number of part-time farmers, there is a need for herbicides for paddy fields with new characteristics. For example, many of the herbicides currently in use cannot be treated unless treated as soon as possible after puddling.
A high weeding effect cannot be expected. Therefore, there is a need for compounds that exhibit sufficient herbicidal effects even when applied late in the season.

A large number of herbicides for field crops have been developed and put into practical use, just like those for paddy fields, but the timing of application of many herbicides currently in use is before sowing of field crops and within a few days after sowing. It is not possible to use chemicals that can cause chemical damage to field crops if they are not used before the weeds germinate or immediately after the germination, and before the germination of the weeds. In addition, foliar treatment agents that are applied during the growing season of crops and weeds are required to have high selectivity between the weeds and crops, and they must not cause chemical damage to the crops even if they kill weeds. has been done.

The above-mentioned phenylurea herbicides that have been put to practical use are only used in fields for soil treatment before weed germination or for treatment immediately after weed germination. In the treatment of foliage during the weed growing season, it is rarely put to practical use because it is not sufficiently effective or causes severe chemical damage to crops.

The urea-based compound disclosed in JP-A-58-59958 largely overcomes the drawbacks of the prior art and has excellent herbicidal properties, but since it has a phenoxyethoxy group or a pyridyloxyethoxy group in its structure, There is a risk of causing phenoxyacetic acid-like chemical damage to crops. In other words, since phenoxyethanol or pyridylox-7ethanol is produced by decomposition, the risk of causing chemical damage similar to that of 7-enoxyacetic acid systems such as 2.4-D cannot be avoided, depending on the type of crop, application method, cultivation conditions, weather conditions, etc. .

Furthermore, the phenylurea compounds disclosed in US Pat. No. 3,947,437 cannot be put to practical use due to their activity against weeds and their phytotoxic effects on crops.

The present invention overcomes the drawbacks of the prior art and provides herbicidally active compounds having excellent properties and agricultural and horticultural herbicides containing these compounds as active ingredients.

In other words, as a herbicide for paddy fields, it does not cause any chemical damage to paddy rice and is effective even when applied late in the process.As a herbicide for field cultivation, it shows selectivity for various crops when applied to foliage, and is highly effective in controlling weeds. An object of the present invention is to provide a compound having a new structure that is structurally free from the risk of causing chemical damage to crops.

Means and Action for Solving the Problems In order to solve the above problems, as a result of repeated research on phenylurea compounds, it was found that pyridazinyl-□-:1xy or pyridazinylthio derivatives overcome the above problems. found that it has excellent selective herbicidal activity.
The invention has been completed.

That is, the phenylurea compound according to the present invention has the general formula (1) (wherein R□ represents a lower alkyl group or lower alkoxy group, X represents an oxygen or sulfur atom, R2 is a phenyl group, 3-)・Rogeno 4.5-(-CH=CH±
2 or 6-valogeno 4.5-(-CH2-)-,
represents a group, and y represents a hydrogen atom or...Rogge/atom. ) is a novel compound represented by

As is clear from the general formula (1), the phenylurea compound according to the present invention has a significantly different structure from conventionally known phenylurea compounds, and is structurally free from the risk of phytotoxicity to crops. The compound of the present invention is effective against various paddy field weeds as a herbicide for paddy fields and has selectivity for paddy rice, and can be used as a herbicide for wheat, corn, orchid, and is selective for paddy rice.
It has selectivity for dice, cotton, etc., and exhibits an excellent herbicidal effect on field weeds such as crabgrass, foxtail grass, field weed, field weed, blueberry, whiteweed, chickweed, Japanese knotweed, Japanese fir, and Japanese morning glory.

The phenylurea compound according to the present invention can be synthesized, for example, by the reaction shown by reaction formula (1).

(In the formula, R□ represents a lower alkyl group or a lower alkoxy group, X represents an oxygen or sulfur atom, R2 is a phenyl group, 6-balogen-4.5-(-C!H=CH+
2 group or 3-].roronno45-f represents a CH2h group, and y represents a hydrogen atom or a halogen atom. )
.

Due to the physical properties of the starting materials, it is often desirable to carry out this reaction in the presence of a solvent. Most inert organic solvents can be used as the solvent, but polar solvents such as dioxane, tetrahydrofuran, dimethylformamide, dimethyl sulfoxide are preferred.

Further, as the deoxidizing agent, commonly used bases can be used, but preferably inorganic bases such as sulfur hydride, anhydrous potassium carbonate, and anhydrous sodium carbonate are preferable.

The reaction temperature and reaction time vary depending on the solvent and deoxidizing agent used, but the reaction temperature is 50 to 150°C, preferably 80 to 130°C, and the reaction time is 1 to 10 hours, preferably 2 to 5 hours. .

When using the compound of the present invention as an agricultural and horticultural herbicide, the application amount and application concentration will vary depending on the target crop and weed type, the application period, the dosage form of the compound, various environmental conditions, etc. 90.1～
10Ky is suitable, preferably 0.2 to 2Ky.

When the compound of the present invention is used as a herbicide, it may be combined with one or more other herbicides, pesticides such as insecticides, fungicides, and plant growth regulators, soil conditioners, or fertilizing substances. Not only can they be used in combination, but also mixed formulations with these are also possible.

Although the compounds of the invention may be applied as such, they are preferably mixed with carriers including solid or liquid diluents and applied in the form of compositions. By "carrier" is meant an inorganic or organic substance, synthetic or natural, which is incorporated to aid in the delivery of the active ingredient to the site to be treated and to facilitate storage, transport and handling of the active ingredient compound. Suitable solid carriers include clays such as montmorillonite and kaolinite, inorganic substances such as diatomaceous earth, china clay, melk, vermicileite, gypsum, calcium carbonate, silica gel, and ammonium sulfate, and vegetable organic substances such as soybean flour, sawdust, and wheat flour. Examples include substances and urea.

Suitable liquid carriers include aromatic hydrocarbons such as toluene, xylene and cumene, paraffinic hydrocarbons such as kerosene and mineral oil, halogenated hydrocarbons such as carbon tetrachloride, chloroform and dichloroethane, and ketones such as acetone and methyl ethyl ketone. compounds, dioxane, tetrahydrofuran, etc., alcohols such as methanol, furopanol, ethylene glycol, dimethylformamide,
Examples include dimethylformhokind and water.

Furthermore, in order to enhance the efficacy of the compound of the present invention, the following adjuvants may be used alone or in combination depending on the purpose, taking into account the dosage form of the preparation, the application situation, etc. For the purpose of emulsification, dispersion, spreading, wetting, binding, stabilization, etc., water-soluble bases such as genin sulfonate, nonionic surfactants such as alkylbenzene sulfonate, alkyl sulfate, calcium stearate, wax, etc. lubricants, stabilizers such as inoflovir hydrodiene phosphate, and others such as methylcellulose, carboxymethylcellulose, casein, and gum arabic.

However, these components are not limited to the above.

The effective amount of the composition of the compound of the present invention is usually 0 when used as a powder.
The content is 5 to 20% by weight, 10 to 90% by weight for wettable powders, 01 to 20% by weight for granules, 5 to 50% by weight for emulsions, and 10 to 90% by weight for flowables.

EXAMPLE The method for producing a phenylurea compound according to the present invention will be explained below using specific examples, but the method is not limited thereto.

Synthesis example-1 N-(4-phenylpyridazine-6-oxyphenyl)
-N: N'-dimethylurea (compound 5) dioxane 1
N-(4-hydroxyphenyl)-Cl- in 00me
3.6 f (0.02 mol) of dimethylurea was dissolved, and 0.81 (0.02 mol) of 60% sodium hydride was added thereto at room temperature to form a salt. Thereafter, 5.85' (0.02 mol) of 6-chloro-4-phenylpyridazine was further added, and the mixture was stirred under reflux for 4 hours to react. After cooling, the reaction solution was poured into 200 g of cold water, and the desired compound 5 precipitated as crystals, which were separated and purified by washing with acetone. Yield 6.62, Yield 53
．． 9chi, m, p.

216-217℃.

Synthesis example-2 N-(3-phenylpyridazine-6-oxyphenyl)
-Nj N'-dimethylurea (compound 6) dimethylformamide 100 mA! N-(3-hydroxyphenyl)-N, N-dimethylurea 36f (0,
02 mol) and 3-chloro-4-phenylpyridazine 3
．． 8 F (0.02 mol)'f was dissolved, and 5.5 P (Df 34 mol) of anhydrous potassium carbonate was added thereto, and 1
The mixture was stirred and reacted at 10 to 120°C for 2 hours. After cooling, the reaction solution was poured into 200 mJ of cold water, and crystals were precipitated. It was recrystallized from ethyl acetate to obtain the target compound 6. Yield 4. Or, yield 60%, m, p,
185-187°C.

Next, Table 1 lists representative examples of compounds according to the present invention synthesized by a method similar to the above examples and their physical property values.

Next, examples of formulations of the herbicide of the present invention will be shown. The active ingredient compound is
It is shown by the compound number of the above-mentioned coating 1, and "parts" represent "parts by weight."

Formulation Example-1 Irrigation compound (3): 30 parts, diatomaceous earth: 47 parts, clay = 20 parts, sodium ligninsulfonate = 1 part, and sodium alkylbenzenesulfonate = 2 parts were uniformly ground and mixed to make an irrigation agent of 100 parts. I got the department.

Formulation example - 2 grains 22 parts of the drug and 1 part of ligninsulfonic acid
After adding an appropriate amount of water and kneading, the mixture was granulated in a conventional manner using an extrusion granulator, and after drying, 100 parts of granules were obtained.

Formulation Example-370 Able q Compound (9): 40 parts, carboxymethyl cellulose: 3 parts, sodium ligninsulfonate: 2 parts, dioctyl sulfosuccinate sodium salt: 1 part, and water: 54 parts using a sand glider. The mixture was wet-pulverized to obtain 100 parts of a flowable agent.

Next, the efficacy of the compounds of the present invention as herbicides will be explained using test examples.

Test Example-1 Rice paddy growing season weeding test 1151.000 are Soil Pp 5 in Wagner pot
Fill in K, add 20 to N, P2O6, and 0 each.
．． After fertilizing the entire layer of 81 with chemical fertilizer, add an appropriate amount of water and stir, and then use it to grow Japanese millet, Japanese cypress, and broad-leaved weeds (Japanese grasshopper,
Seeds of Physcomitrella japonica, Azena, etc.), Firefly, and Helaomodaka were sown and flooded. Two paddy rice seedlings (2-6 leaf stage) that had been raised in advance were transplanted into each seedling and grown in a greenhouse.

During the weed growth period 12 days after transplanting paddy rice, a predetermined amount of the test compound was submerged in water using granules prepared according to the method described in Formulation Example 2 above. Thirty days after the treatment, weed growth and chemical damage to rice were observed and the results are shown in Table 2.

In this table, the degree of chemical damage to crops and the herbicidal effect on weeds are expressed by comparing the growth status of crops or weeds with the untreated air-dried type according to the evaluation criteria below. The test compounds are indicated by compound numbers in Table 1 above (the same applies hereinafter).

Evaluation criteria 〇Survival rate shown by air dry weight in pair untreated area 91-100chi1- 71-90%2-
41-70%3-
11-40%4-
6-10chi 5-
0-5% Table 2: All-carbanote results from weeding test during the paddy growing season. ” Test Example-2 Upland cultivation growing season foliage treatment weeding test 1A, 000
Fill the R planter with s kg of soil, add N,
After fertilizing the entire layer with chemical fertilizers containing 21% each of P2O5 and K2O and adjusting the soil moisture to the maximum water capacity of 60cm, certain amounts of test crop and weed seeds were sown and the soil was planted. This was placed in a greenhouse, and water was constantly managed to grow the plants. When the test plant grows to the 2nd to 6th leaf stage, the formulation example-
Using an irrigation agent prepared according to the method described in Section 1, a predetermined amount of the test compound was diluted in an amount of water equivalent to 10 7 per are, and the solution was applied to the test plants using a micro-pressure sprayer. This was placed in a greenhouse and grown under constant water management. 60 days after the chemical treatment, weed growth conditions and chemical damage to crops were observed and investigated, and the results are shown in Table 3. In this table, the degree of chemical damage to crops and the growth status of weeds were expressed according to the method shown in Test Example-1.

Effects of the Invention As is clear from the above explanation, the compound of the present invention is safe for paddy rice as a herbicide for paddy fields, and
Conventional phenylurea-based herbicides are effective even when treated during the weed growing season, and are said to be safe for various crops and effective against weeds when used for foliage treatment in field crops. It has excellent properties not found in other compounds.

Claims (8)

[Claims] (1) General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R_1 represents a lower alkyl group or lower alkoxy group, X represents an oxygen or sulfur atom, and R_2
is phenyl group, 3-halogeno-4,5-(CH=CH)
-_2 groups or 3-halogeno-4,5-(CH_2)_
It represents a 4-group, and y represents a hydrogen atom or a halogen atom. ) A phenylurea compound represented by (2) The phenylurea compound according to claim 1, wherein in the general formula (I), R_1 is a methyl group or a methoxy group. (3) The phenylurea compound according to claim 1, wherein in the general formula (I), R_2 is a 3-phenyl group. (4) In general formula (I), R_1 is a methyl group, y is a hydrogen atom, ▲ there are mathematical formulas, chemical formulas, tables, etc. ▼ ▲ there are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ mathematical formulas, chemical formulas , a table, etc.▼, or ▲a mathematical formula, a chemical formula, a table, etc.▼. (5) In the general formula (I), R_1 is a methyl group, y is a hydrogen atom, ▲ there are mathematical formulas, chemical formulas, tables, etc. ▼ ▲ there are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ mathematical formulas, chemical formulas , tables, etc. ▼, ▲ mathematical formulas, chemical formulas,
The phenylurea compound according to claim 1, which has tables, etc. ▼, ▲ has mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ has mathematical formulas, chemical formulas, tables, etc. ▼. (6) In general formula (I), R_1 is a methoxy group, y is a hydrogen atom, and ▲There are mathematical formulas, chemical formulas, tables, etc.▼▲There are mathematical formulas, chemical formulas, tables, etc.▼ of a patent claim A phenylurea compound as described in scope 1. (7) In the general formula (I), R_1 is a methyl group, y is 3-chloro-, and ▲ has a mathematical formula, chemical formula, table, etc. ▼ is ▲ has a mathematical formula, chemical formula, table, etc. ▼ A patent A phenylurea compound according to claim 1. (8) General formula (I) ▲Mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R_1 represents a lower alkyl group or lower alkoxy group, X represents an oxygen or sulfur atom, and R_2
is phenyl group, 3-halogeno-4,5-(CH=CH)
-_2 groups or 3-halogeno-4,5-(CH_2)-
represents a _4 group, and y represents a hydrogen atom or a halogen atom. ) A herbicide characterized by containing one or more types of phenylurea compounds represented by: