JPS61171473A - Phenylurea compound and herbicide containing same - Google Patents

Abstract

NEW MATERIAL:The compound of formula I (R1 is CH3 or OCH3; X is O or S; R2 is 3-chloro-4-methyl or 3-chloro-5-methyl; y is H or Cl). EXAMPLE:N-[3-(3-chloro-4-methylpyridazin-6-oxy)phenyl]-N',N'-dimethylu rea. USE:A herbicide useful for agricultural and horticultural purposes. It is safe to paddy rice plant when applied as a herbicide for paddy field and exhibits the herbicidal effect even by the treatment of the weeds in the growing stage after 12 days from the transplantation of the paddy rice plant. It is useful also as a herbicide for plowed land having selectivity to wheat, corn, cotton, etc. It exhibits excellent herbicidal effect against the weeds in plowed land such as large crab-grass, cock-spur grass, etc., and is safe to various crops. PREPARATION:The compound of formula I can be produced by reacting the compound of formula II with the compound of formula III preferably in an inert solvent, in the presence of an acid acceptor such as anhydrous K2CO3, etc., at 50-150 deg.C for 1-10hr.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is based on the general formula (1) (wherein, avian represents a methyl group or a methoxy group, X represents an oxygen or sulfur atom, and 4-methyl group or 6-chloro-5-methyl group, and y represents a hydrogen atom or a chlorine atom.
It relates to herbicides containing more than one species.

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

[Prior art]

A large amount of research has been conducted on phenylurea compounds, and herbicides useful in agriculture and horticulture have been developed and put into practical use. This is 5 as a representative example of Rano.
-(!1,4-dichloro07znyl) -i, i-dimethylurea [British patent 776.069; Teiuro/],
s-(3,4-dichlorophenyl-1-methoxy-
Examples include 1-methylurea [US Pat. No. 2,960,554; Riniron]. Further, Japanese Patent Application Laid-Open No. 58-59958, US Pat. No. 3,947,437, etc. are known.

[Problem that the invention seeks to solve]

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 expected to have a high herbicidal effect unless they are applied as soon as possible after puddling. Therefore, there is a need for compounds that exhibit sufficient herbicidal effects even when applied later in the season.

Many herbicides for field crops have been developed and put into practical use, just like those for paddy fields, but the timing of application of most herbicides currently used is before and after sowing of field crops. Chemicals that may cause chemical damage to field crops cannot be used unless they are used before or immediately after the germination of weeds and before the germination of crops.Also, it is not possible to use chemicals that may cause chemical damage to field crops. The foliage treatment agent used for this purpose must be highly selective between weeds and crops, and must not cause chemical damage to crops even if it kills weeds.

The above-mentioned phenylurea herbicides that have been put to practical use are only used in the field in soil treatment before weed germination or treatment immediately after weed germination.

Although sufficient effects cannot be achieved in the treatment of foliage during the growing season of weeds, 1, 2, 2, □00, 4 (not put to practical use).

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. That is, since phenoxyethanol or pyridyloxyethanol is produced by decomposition, the risk of causing chemical damage similar to phenoxyacetic acid-based products 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 Patent No. 3,94 Otsu 467 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 treated later in the day.As a herbicide for field cultivation, it shows selectivity for various crops when applied to foliage and has excellent weed control effects. 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 effects for solving the problem] In order to solve the above problem, as a result of repeated research on phenylurea compounds, pyridazinyloxy or pyridazinylthio derivatives were found to be excellent choices that can overcome the above problem. The present invention was completed based on the discovery that it has specific herbicidal activity.

That is, the phenylurea compound according to the present invention has the general formula (I) (wherein, 几 represents a methyl group or a methoxy group.

X represents oxygen or sulfur atom, R2 is 3-chloro-
It represents a 4-methyl group or a 3-chloro-5-methyl group, and y represents a hydrogen atom or a chlorine atom. ) is a new 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 paddy field herbicide and is selective for paddy rice, and as a field herbicide it is selective for wheat, corn, groundnut, soybean, cotton, etc., and is effective against field weeds. It exhibits excellent herbicidal effects on certain types of grasshoppers, foxtail grass, Japanese wild grass, Japanese grasshopper, Japanese staghorn grass, Japanese chickweed, chickweed, Japanese knotweed, Japanese fir tree, Japanese morning glory, etc.

The phenylurea compound according to the present invention can be synthesized, for example, by the reaction shown in reaction formula 0).

(In the formula, - represents a methyl group or a methoxy group, X represents an oxygen or sulfur atom, - represents a 6-chloro-4-methyl group or a 3-chloro-5-methyl group, and y represents a hydrogen atom or (Ding represents the chlorine 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 a deoxidizing agent, commonly used bases can be used, but preferably inorganic bases such as hydrogenated aluminum, anhydrous potassium carbonate, and anhydrous sodium carbonate are preferred. 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 160°C, and the reaction time is 1 to 10 hours, preferably 2 to 5 hours. good.
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, application period, compound formulation, various environmental conditions, etc. 0.1 to 10 kg is appropriate, preferably 0.2 to 2 Jc9.

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.

While the compounds of the invention may be applied neat, they are preferably applied in the form of a composition mixed with a carrier, including solid or liquid diluents. As used herein, carrier means 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 materials such as diatomaceous earth, clay, talc, vermicellite, gypsum, calcium carbonate, silica gel, and ammonium sulfate, and vegetable organic materials 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, carbon tetrachloride, chloroform, cycloethane natonohalogenated hydrocarbons, and ketones such as acetone and methyl ethyl ketone. Examples include ethers such as dioxane and tetrahydrofuran, alcohols such as methanol, propatool, and ethylene glycol, dimethylformamide, dimethyl sulfoxide, 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 isopropylhydrodiene phosphate, and others such as methylcellulose, carboxymethylcellulose, casein, and gum arabic.

However, these components are not limited to the above.

The amount of active ingredient in the composition of the compound of the present invention is usually 0 when used as a powder.
．． α is 5 to 20% by weight, 10 to 90% by weight for wettable powders, 1 to 20% by weight for granules, 5 to 50% by weight for emulsions, and 10 to 90% by weight for flowables.

〔Example〕

The manufacturability of the phenylurea compound according to the present invention will be explained below by giving specific examples.

Synthesis Example IN-(4-(5-ChloI:l-4-methylpyridazin-6-oxy)phenyl) -f N'-dimethylurea (Compound 1) N-(4-hydroxyphenyl) HCN in 100 IIL of dioxane /-dimethylurea 16J (α02
Dissolve 0.8 mole of sodium 60 thihydride in this solution.
g (0.02 mmol) was added at room temperature to form a salt.

Thereafter, 5.9 (0.02 mol) of 3,6-dichloro-4-methylpyridazine i was further added, and the mixture was stirred under reflux for 4 hours.

After cooling, the reaction solution was poured into 200 g of cold water, and the target compound 1 precipitated as crystals, which were collected and purified by washing with acetone.

Yield 5.01i, Yield 50chi, m, p, 217~2
18℃.

Synthesis Example 2N-(3-(3-chloro-4-methylpyridazine-6-oxy)phenyl] N?N/-dimethylurea (Compound 6) N7(3-hydroxyphenyl)-NζW-dimethyl in 100 ml of dimethylformamide Urea 3.6,1i
Dissolve t(α02 mol and 3.5, lit (0.02 mol) of 3.6-dichloro-4-methylpyridazine, add 5.5 g of anhydrous potassium carbonate (0.04 mol), and dissolve 110-120 Stir at ℃ for 2 hours.

After cooling, pour the reaction solution into 20° cold water.
(Crystals were precipitated. This was collected and recrystallized from ethyl acetate to obtain the target compound 3.

Yield &7g, Yield 60cm, 7.158-140°C.

Next, Table 1 shows 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 Wettable powder compound (3): 30 parts, diatomaceous earth: 47 parts, clay = 20 parts, sodium ligninsulfonate = 1 part, and sodium alkylbenzenesulfonate = 2 parts are uniformly ground and mixed to prepare a wettable powder. Got 100 copies.

Formulation Example 2 Granule Compound (5 parts of box, 72 parts of bentonite, 2 parts of talc)
0 parts of dodecylbenzenesulfone d+)lium: 2 parts and sodium ligninsulfonate: 1 part were mixed, an appropriate amount of water was added and kneaded, and the mixture was granulated in a conventional manner using an extrusion granulator, and after drying. , 100 parts of granules were obtained.

Formulation Example 370 Apple Compound (9) = 40 parts, carboxymethyl cellulose =
6 parts, sodium ligninsulfonate: 2 parts, dioctyl sulfosuccinate sodium salt = 1 part, and water:
54 parts were wet-pulverized using a sand glider 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 115,000 are A Wagner pot was filled with soil 19, and after fertilizing the entire layer with 0.8 g each of N, P2O5, and 40 with chemical fertilizers, an appropriate amount of water was added and stirred. Japanese millet, Japanese cyperus, broad-leaved weeds [Japanese grasshopper, Kikashigusa,
Seeds of Japanese azalea, etc.], firefly, and Helaomodaka were sown and flooded. Seedlings of rice seedlings (2 to 6 leaves per plant) were transplanted to this and two plants were 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. 60 days after the treatment, weed growth and chemical damage to paddy rice were observed and investigated, and the results are shown in Table 2.

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

Evaluation criteria 〇Survival rate shown by air dry weight of pair vs. untreated area 91-100%
1-71~90%2
-41-70%3-
11~4ochi 4-
6-1o 5-
Q~ 5% sweet @
12 a + Cultivation jt11 Grass Covering Mechanism 菮菫 Sweet Age Table 2 Rice field growing season weeding test results [*Benthiocarb, 8-(4-chlorobenzyl no N
, N-diethylthiol carbamate] 1/1,000
Fill the R planter with soil 8J119, add N,
P2O, K2O and 2I each were applied to the entire layer with chemical fertilizers, and after the soil moisture was brought to the maximum capacity of 60 tons, a certain amount of test crop and weed seeds were sown and covered with soil. This was placed in a greenhouse, and water was constantly managed to grow the plants. When the test plant grew to the 2nd to 6th leaf stage, the formulation example 1
A predetermined amount of the test compound was diluted in an amount of water equivalent to 101 parts per area using a hydrating agent prepared according to the method described in 1. The sample was treated on test plants using a micro-pressure sprayer. This was placed in a greenhouse and grown under constant water management. Chemical treatment 3
After 0 days, 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 state of weeds were expressed according to the method shown in Test Example 1.

〔Effect of the invention〕

As is clear from the above description, the compound of the present invention is safe for paddy rice as a herbicide for paddy fields, and exhibits an effective herbicidal effect even when applied during the weed growth period 12 days after transplanting paddy rice. It has excellent properties not found in conventional phenylurea compounds, such as being safe for various crops and effective against weeds in field crop foliage treatments.

Claims (2)

[Claims] (1) General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R_1 represents a methyl group or a methoxy group,
X represents an oxygen or sulfur atom, R_2 represents a 3-chloro-4-methyl group or a 3-chloro-5-methyl group, and y represents a hydrogen atom or a chlorine atom. ) A phenylurea compound represented by (2) General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R_1 represents a methyl group or a methoxy group, and
represents oxygen or sulfur atom, R_2 is 3-chloro-
It represents a 4-methyl group or a 3-chloro-5-methyl group, and y represents a hydrogen atom or a chlorine atom. ) A herbicide characterized by containing one or more types of phenylurea compounds represented by: