JPS588363B2 - Sonoseizohou Sonoseizohou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is based on the general formula [■] (wherein, X represents a halogen atom, and R'1 and R2 are the same or different and represent a hydrogen atom or a methyl group).

) The present invention relates to a herbicide characterized by containing a urea compound represented by the following as an active ingredient, and a method for producing the same.

The compound of the present invention represented by the general formula (I) has a herbicidal effect against a wide range of weeds, such as grass weeds such as Japanese grasshopper, Japanese grasshopper, and grasshopper, as well as grass weeds such as purslane, polygonum, snailweed, chickweed, Japanese trifoliate, and common grass.
It can kill weeds such as water chickweed and cyperus weeds in fields and paddy fields.

The compound of the present invention is effective against the various weeds listed in L at extremely low concentrations during the weed growth period and during pre-emergence treatment, has a long-lasting effect in soil, and is not toxic to humans, livestock, or fish. It has a low quality.

Furthermore, the characteristics of the compound of the present invention as a herbicide are that when it is used in paddy fields, there is no phytotoxicity to transplanted paddy rice, and it is effective against grasshoppers, azaleas, cypress grasses, cypress grasses, and the perennial weeds urikawa and bulrushes. It is also active against.

The excellent properties of the compounds of the present invention as herbicides for paddy rice are similar to conventional urea-based herbicides, such as diu.
ron (N-N-dimethylN'-3-4-dichlorophenylurea), DS-5328 (cis2.5
-dimethyl-1-pyrrolidinecarboxyanilide) etc.

In other words, the compound has a strong phytotoxicity to rice, so it could not be used as a herbicide for paddy rice, even though it has a strong effect on weeds.

The present inventors have developed an extremely safe herbicide for paddy rice that eliminates the drawbacks of conventional urea-based herbicides and maintains its activity against weeds while causing no chemical damage to rice. was discovered in the compound of the present invention.

In addition, the compound of the present invention is safe when used in upland rice, wheat, soybeans, corn, etc. in addition to paddy rice, and is also used in a wide variety of crops, including various grains, vegetables, orchards, lawns, pastures, non-agricultural lands, etc. It can be used as a herbicide with various application situations.

Furthermore, one of the remarkable features of the compounds of the present invention is that in order for the compounds of the present invention to exhibit selectivity for rice, a very limited structure is required.

That is, it has a pyrrolidine ring while having a phenyl urea structure, and it has a p-halogen-substituted penzyloxy group at the p-position of the phenyl group.

The compound of the present invention is a new compound, and the following four methods can be cited for its synthesis.

The first method can be carried out in good yield by reacting p-halogen-substituted penzyloxyphenyl isocyanate [■] and substituted pyrrolidine (II) in an inert organic solvent.

(In each formula, X, R1 and R2 represent the same meanings as above.

) For example, an equimolar amount of substituted pyrrolidine is added dropwise to a benzene solution containing p-halogen-substituted penzyloxyphenylisocyanate [■] at room temperature.

After stirring for about 30 minutes, the solvent is distilled off to obtain the desired urea compound CI,l.

The second method is to combine p-halogen-substituted penzyloxyphenyl rubamyl chloride (IV) with substituted hyrolidine (■
) in an inert organic solvent.

In this case, the desired product can be obtained in good yield by using a dehydrochlorination agent.

(In each formula, X, R1 and R2 represent the same meanings as above.

) For example, a mixed solution of equimolar amounts of substituted pyrrolidine and triethylamine prepared in advance is added dropwise to a benzene solution in which p-halogen-substituted penzyloxyphenylcarbamyl chloride is dissolved.

After that, the mixture was left under reflux for 2 hours, and after returning to room temperature, water was added to remove triethylamine hydrochloride.

By distilling off the solvent, the desired urea compound (I) is obtained.

The third method is p-halogen-substituted penzyloxoaniline [V] and substituted pyrrolidine-substituted lupoxychloride (■).
The reaction is carried out by reacting these in an inert organic solvent.

In this case, the desired product can be obtained in good yield by using a dehydrochlorination agent.

(In each formula, X, R1 and R2 represent the same meanings as above.

) For example, to a toluene solution in which p-halogen-substituted penzyloxyaniline was dissolved, equimolar amounts of substituted pyrrolidine-substituted lupoxychloride and triethylamine were added, and the mixture was refluxed for 8 hours. After returning to room temperature, water was added to dissolve triethylamine hydrochloride. except.

When the solvent is distilled off, the desired urea compound CI) is obtained.

The fourth method is carried out by reacting substituted pyrrolidine carboxy p-hydroxyanilide [■] with p-halogen-substituted penzyl halide [food] in an inert organic solvent.

In this case, the desired product can be obtained in good yield by using a dehydrochlorination agent.

(In each formula, R1, R2 and X represent the same meanings as above, and Y represents a halogen atom.

) For example, an equimolar amount of p-halogen-substituted penzyl chloride is added to a benzene solution of substituted pyrrolidine-substituted carboxy p-hydroxyanilide, and then 50% of the equimolar amount is added.
A caustic soda aqueous solution is added and heated under reflux, washed with water and the solvent is distilled off to obtain the desired urea compound [I].

Next, examples of the compounds of the present invention represented by the general formula CI) are shown in Table 1, but the compounds of the present invention are not limited to these.

All of the compounds of the present invention obtained as described above are new compounds, have strong herbicidal efficacy, and are said to cause no harm to useful plants such as rice, especially during the growing season. It has excellent properties as a drug.

When actually using the compound of the present invention, the active substance itself may be sprayed, or any formulation form such as powder, granule, fine granule, wettable powder, emulsion, etc. can be used.

In preparing these pharmaceutical products, examples of solid carriers include talc, bentonite, clay, kaolin, diatoms, vermiculite, and slaked lime, and examples of liquid carriers include benzene, alcohols, acetone, xylene, and methyl. Examples include naphthalene, dioxane, and cyclohexanone.

In actual use, it is necessary to mix surfactants such as spreading agents used in agriculture to improve and ensure efficacy, as well as fungicides, microbial pesticides, pyrethroid insecticides, and other insecticides. Mixed use with other pesticides, such as other herbicides, or fertilizers is also possible.

Examples of formulations of the composition of the present invention are shown below.

Formulation Example 1 5 parts by weight of compound (2) 2, 5 parts by weight of a polyoxyethylene alkylaryl ether surfactant, and 70 parts by weight of talc are thoroughly ground and mixed to obtain a wettable powder.

Formulation example 2 30 parts by weight of compound (3), 20 parts by weight of polyethylene glycol ether surfactant, and 5 parts by weight of cyclohexanone
0 parts by weight are thoroughly mixed to obtain an emulsion.

Formulation example 3 5 parts by weight of compound (5), 40 parts by weight of bentonite, 50 parts by weight of clay, and 5 parts by weight of sodium ligninsulfonate
Parts by weight are thoroughly ground and mixed, water is added and the mixture is thoroughly kneaded, followed by granulation and drying to obtain granules.

Formulation Example 4 3 parts by weight of compound (1) and 97 parts by weight of clay were ground and mixed to obtain granules.

Formulation Example 5 Add 5 parts by weight of compound (2), 4 parts by weight of sodium ligninsulfonate, 86 parts by weight of Fubasamiclay [trade name of Fubasamiclay Co., Ltd.], and 5 parts by weight of water, knead with a ribbon mixer, and dry to obtain fine granules. get.

The present invention will be explained in more detail below with reference to Examples.

The names of the compounds under efficacy testing are indicated by the compound numbers listed above.

In addition, compounds (i) to (iii) shown in Table 2 were used as control compounds in order to clarify the structure necessary to express the action characteristics of the compounds of the present invention.

Example 1 p-chlorobenzyloxyphenyl isocyanate 13
Dissolve g in 60 ml of benzene, and add 3. g of pyrrolidine to this.
A solution of 62 dissolved in benzene 50 mA was heated at 20 to 30°C.
Drip with.

After the dropwise addition, stirring was continued for an additional 30 minutes at the same temperature.

The solvent was distilled off under reduced pressure to obtain 16 g of crystals.

This was recrystallized twice from benzene to obtain 8.5 g of white needle-like crystals (1).

Melting point 162.5-1635°C Elemental analysis example 2 p-promobenzyloxyphenylcarbamyl chloride 17. Dissolve Og in 60ml of benzene.

A solution of pyrrolidine 782 dissolved in 50 mA of benzene was added dropwise to the mixture at 20 to 30°C, followed by refluxing for 2 hours.

Return to room temperature and add 50ml of 0.1N salt to the benceso layer.
Wash twice.

After repeated washing with water, the benzene layer was dried with Glauber's salt and the solvent was distilled off to obtain 15.8 g of pale yellow crystals.

Recrystallize twice in benzene to obtain white needle-like crystals (2)
Obtain 13.6 g.

Melting point: 183-185.5°C Elemental analysis Example 3: 11.0 g of p-fluoropenzyloxyaniline, 11.0 g of pyrrolidine, 67.0 g of lupoxychloride, 10 g of toluene.
0 ml, add 6.9 g of potassium carbonate, and reflux for 8 hours.

After returning to room temperature, washing with water was repeated three times, the toluene layer was dried with sodium sulfate, and the solvent was distilled off to give light brown crystals 23.3P.
get.

When this is recrystallized twice in benzene, it becomes 1.6.5? Obtain pale yellow needle-shaped crystals.

Melting point 148-153°C Elemental analysis Example 4 2,5-dimethyl 1-pyrrolidinecarboxy p-hydroxyanilide 23.4f and p-chloropenzyl chloride 1.6. IP and dimethylformamide 100ml
10.6 P of potassium carbonate was added to the solution, and heating under reflux was continued for 5 hours.

Return to room temperature, add to 300ml of water, and add benzene LOOm.
Extract twice with l.

The benzene layer was washed twice with water and then dried with Glauber's salt.
When the solvent is distilled off, light brown crystals]. Obtain 5.3P.

This was recrystallized twice in benzene, and pale yellow crystals (5) 1
Obtain 0.0P.

Melting point: 119.5-123°C Elemental analysis value Example 5 Soil treatment test after sowing In a 3-inch unglazed flowerpot, a grasshopper was placed as a representative of grass weeds.
Seeds of common broad-leaved weeds, such as Japanese grasshopper and pigweed, and representative crops, such as soybean, wheat, and corn, were sown. After covering the soil, a chemical in the form of a wettable powder was diluted with water, and the soil was treated with a hand sprayer.

After that, it was grown in a greenhouse, and 20 days after treatment, the herbicidal effect was confirmed.
The drug damage was observed and the results are shown in Table 3.

Evaluation of herbicidal efficacy and phytotoxicity was expressed as a number from 0 to 5 as shown below.

0...Weed control rate 0% 1...20 2...40 3...Weed control rate 60% 4...80 5・・・・・・〃 100 Regarding chemical damage, the ratio of plant height, tiller number, and total weight (air dry weight) to the untreated plot was calculated, and the worst value of the three factors was taken and evaluated on a scale of 0 to 5. .

0...... Ratio to untreated area 100% 1...... 80 2... 60 3... 40 4... 20 5......〃0 Example 6 Field weeds, crop growth season spray treatment test In 3-inch unglazed flower pots, weed grass as a representative of the grass family weeds, silverweed as a representative of broad-leaved weeds, and pigweed as a representative of crop 1. Soybeans, wheat, and corn were sown and grown in a greenhouse, and on the 15th day after sowing, the leaves and foliage of each plant were treated with a predetermined concentration of a chemical (hydrating agent) using a hand sprayer.

The treatment was carried out using a practical amount of water of 10 l/a.

Thereafter, the plants were grown in a greenhouse, and the herbicidal efficacy and phytotoxicity were observed on the 20th day after treatment. The results are shown in Table 4.

Evaluation of herbicidal efficacy and phytotoxicity was performed in the same manner as in Example 5.

Example 7 A Wagner pot with a diameter of 14 cm filled with 1.5 kg of paddy soil was made into a paddy field, rice seedlings at the 3-leaf stage were transplanted, and millet seeds were sown, and a predetermined amount of chemicals were applied to the soil by flooding. did.

On the 25th day after the chemical treatment, the herbicidal efficacy and degree of chemical damage were investigated for the transplanted or sown plants and naturally occurring broad-leaved weeds such as Aspergillus japonica, Azena, and Kikashigusa.

The results are shown in Table 5.

Regarding the treatment method, a predetermined amount of the drug was treated in the form of a wettable powder at a rate of 1 5 cc per pot.

During the treatment, the solution was dropped using a pipette.

Evaluation of herbicidal efficacy and phytotoxicity was performed in the same manner as in Example 5.

Claims (1)

[Claims] 1 General formula (wherein, X represents a halogen atom, R1 and R2
are the same or different and represent a hydrogen atom or a methyl group. ) A herbicide characterized by containing one or more of the urea compounds represented by the following as an active ingredient. 2 p-halogen-substituted penzyloxyphenyl isocyanate represented by the general formula (wherein X represents a halogen atom) and general formula (wherein R1 and R2 are the same or different and represent a hydrogen atom or a methyl group A method for producing a herbicide, which comprises reacting a substituted pyrrolidine represented by .) to obtain a urea compound represented by the general formula according to claim 1. 3 p-halogen-substituted penzyloxyphenyl rubber chloride represented by the general formula (wherein, X represents a halogen atom) and general formula (wherein, R1 and R2 are the same or different, and a hydrogen atom or A method for producing a herbicide, which comprises reacting a substituted pyrrolidine represented by (representing a methyl group) to obtain a urea-based compound represented by the general formula according to claim 1. 4 p-halogen-substituted penzyloxyaniline represented by the general formula (wherein, X represents a halogen atom) and general formula (wherein, R1 and R2 are the same or different and represent a hydrogen atom or a methyl group. ) and a substituted pyrrolidine carboxychloride to obtain a urea-based compound represented by the general formula according to claim 1. 5 Substituted pyrrolidine carboxy p-hydroxyanilide represented by the general formula (wherein R1 and R2 are the same or different and represent a hydrogen atom or a methyl group) and the general formula (wherein X and Y are halogen atoms) ) is reacted with p-halogen-substituted penzyl halide to obtain a urea-based compound represented by the general formula set forth in claim 1, item 1. .