JPS6045635B2 - Diphenylamine derivatives, their production methods and selective herbicides - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel compound, a method for producing the same, and a use thereof, and specifically, the compound of the present invention having the general formula [1] is extremely effective against weeds of the family Weeds such as barnyard grass, crabgrass, oat, and sycamore. It exhibits excellent selective herbicidal action and is almost harmless to broad-leaved crops such as rice, adzuki beans, soybeans, and heat.

The compound of the present invention exhibits excellent herbicidal efficacy against weeds when treated at any growth period, including before and after germination, but in general, when the same dosage is used, the efficacy is higher when treated after germination. You can expect it to be active. The compound of the present invention has almost no effect on broad-leaved crops such as daikon radish, adzuki beans, soybeans, peas, spinach, and heat, even when applied to leaves and foliage at a dose that completely kills the grasshopper weed. In addition, in pre-emergence soil treatment for weeds, even at doses that completely inhibit the germination of crabgrass, there is almost no effect on the seeds of broad-leaved crops, indicating that herbicides are extremely safe against chemical damage to broad-leaved crops. The range of application, such as application period, application location, and application concentration, is also extremely wide. In addition, since the compound of the present invention can be used at low concentrations, there is little concern about acute toxicity to livestock and fish, and it can be used safely. In addition, the compound of the present invention has particularly strong efficacy against Noviidae under both paddy field conditions and upland conditions, has a wide range of selectivity for rice, and is a drug that completely kills Noviidae before and after germination. No matter the amount, there is almost no effect on rice growth.

Furthermore, it has the excellent feature of having high activity against highly grown barnyard grass, which is relatively difficult to kill with conventional herbicides. The compounds of the present invention also have analgesic, hypotensive, anti-inflammatory, and antibacterial activities, and are useful as medicines.

The compound of the present invention is produced by the following reaction formula.

However, in the following formula, X represents a halogen atom, and R''3 represents a lower alkyl group, a lower alkenyl group, or a benzyl group.The above reaction is usually performed in the presence of an acid binder in an inert solvent. This is done by heating under reflux for an hour.

Inert solvents include acetone, methyl ethyl ketone,
General inert solvents such as acetonitrile and dichloromethane are used, and potassium carbonate, sodium carbonate, sodium methylate, etc. are used as acid binders. In the above formula, X
As the halogen represented by, chlorine or bromine is usually used. Pour the reaction solution into cold water, extract with a suitable organic solvent, wash the organic solvent layer with water, dry it, and then distill off the solvent.
Substantially pure compounds of the invention are obtained. Among the compounds of the present invention, compounds in which R3 is a hydrogen atom are usually produced by the above reaction formula (1), and R3 is a lower alkyl group,
A compound having a lower alkenyl group or a benzyl group is usually produced by the above reaction formula (2).

The raw material compound represented by the general formula [■] can be obtained by reacting p-aminophenol and a corresponding substituted benzene in the presence of an acid binder in a polar solvent, or by reacting p-anisidine and a corresponding substituted benzene. It can also be obtained by reduction after reaction.

As the acid binder used in the reaction between p-aminophenol and benzene, inorganic bases such as soda carbonate and sodium hydroxide, or organic bases such as pyridine, trimethylamine, tributylamine, and p-aminophenol are used, but organic bases are used. It is preferable to use Next, the method for producing the compound of the present invention will be explained in more detail with reference to Examples.

Example 1 Ethyl 2-(4-(2-nitro-4-trifluoromethylanilino)phenoxy)butyrate (Compound 1) 4-(2-
Nitro (4-trifluoromethylanilino)phenol 6f was dissolved in 60 ml of methyl ethyl ketone, 2.8 y of anhydrous potassium carbonate and 3.9 y of ethyl 2-bromobutyrate were added, and the mixture was heated under reflux for 5 hours.

The reaction solution was poured into water, extracted with ethyl acetate, washed with water, dried over anhydrous magnesium sulfate, and the solvent was distilled off to obtain the desired product 7.8.
I got g. M. p. 6O-67C Example 2 Ethyl 4-(4-(2-nitro-4-trifluoromethylanilino)phenoxy)valerate (Compound 2) 4-(2
- Nitro (4-trifluoromethylanilino)phenol 6y was dissolved in 60ml of dimethylformamide, 2.8y of anhydrous potassium carbonate and 3.3y of 4-chlorovaleric acid were added, and the mixture was heated to 120-130°C for 5 hours with stirring. .

The reaction solution was poured into water, extracted with ethyl acetate, washed with water, dried over anhydrous magnesium sulfate, and the solvent was distilled off to obtain the desired product (7.7y).
I got it. M. p. 6O-67C Example 3 Ethyl 2-(4-(N-methyl-2-nitro-4-trifluoromethylanilino)phenoxy)propionate
(Compound 4) 3.1 g of 4-(N-methyl-2-nitro-4-trifluoromethylanilino)phenol was dissolved in 30 ml of methyl ethyl ketone, and 1.1 g of anhydrous potassium carbonate was dissolved.
4f, then ethyl 2-bromopropionate 1
．． 8f was added and heated under reflux for 5 hours.

The reaction solution was poured into water, extracted with ethyl acetate, washed with water, dried over anhydrous magnesium sulfate, and the solvent was distilled off to obtain the desired product 3.8.
I got y. M. p. 88-9.

C Example 4 Ethyl 2-(4-(N-allyl-2-nitro-4-trifluoromethylanilino)phenoxy)propionate
(Compound 6) Ethyl 2-(4-(2-nitro-4-trifluoromethylanilino)phenoxy)propionate 2
y was dissolved in 50 ml of dimethylformamide, cooled using a cryogen, and 0.26 g of sodium hydride (50% oily) was added little by little at below 0° C. while stirring.

Allyl bromide at the same temperature after hydrogen evolution stopped 0.61
After dropping y and continuing cooling for 1 hour, it was left at room temperature overnight. After the reaction, the crude product obtained by pouring into water and extracting with ethyl acetate was purified by silica gel chromatography to obtain 1.2 da of the desired product as a red oil. n ■. 511.5550 Table 1 shows representative examples of the compounds of the present invention.

The herbicide of the present invention is one of the compounds represented by the above general formula [1].
Alternatively, two or more suitable amounts can be mixed with a carrier and used in the form of a conventional agricultural chemical, such as a wettable powder, an emulsion, or a granule.

Examples of solid carriers include talc, bentonite, clay, diatomaceous earth, etc., and examples of liquid carriers include water, alcohol, benzene, xylene, kerosene, mineral oil, cyclohexane, cyclohexanone, dimethylformamide, and the like. If necessary, a surfactant may be added in order to obtain a uniform and stable form in these preparations. The preparation method is similar to the usual method for preparing pesticides, but for example, for wettable powders, the active ingredient and solid carrier are added in appropriate amounts, and if necessary, a surfactant is added and mixed uniformly. Obtained by finely pulverizing.

The active ingredient content in the wettable powder is about 5-80%, preferably 1
0 to 60% is appropriate. The emulsion is obtained by sufficiently dissolving an appropriate amount of the active ingredient in the above-mentioned liquid carrier by adding or adding a surfactant, and the active ingredient content is approximately 5.
~70%, especially 20-60% is preferred. In the case of granules, appropriate amounts of active ingredients and a solid carrier are uniformly mixed with a surfactant if necessary, finely ground, and then granulated with a diameter of 0.1 to 1.5 wn1, preferably in a granulator. 0.5
~1.0m! A method of forming n granules is carried out. The amount of active ingredient in the granules is approximately 0.5 to 30%, preferably 1 to 10%. The hydrating agent obtained in this way,
The emulsion is diluted with water to a predetermined concentration to form a suspension or emulsion, and the granule is used as it is for soil surface treatment or soil mixing treatment before weed germination, or for foliage spraying after weed germination.

When actually applying the herbicide of the present invention, an appropriate amount of the active ingredient is applied in an amount of 10 V or more, preferably 25 Y or more per 10 are. The herbicide of the present invention can also be used in combination with known bactericides, insecticides, acaricides, herbicides, plant growth regulators, and the like. In particular, when used in combination with a herbicide, not only the amount of chemicals used can be reduced and labor savings can be achieved, but even higher effects can be expected due to the synergistic action of both chemicals. Known herbicides suitable for use in combination with the herbicide of the present invention include triazine herbicides such as simazine, propazine, and promethrin, carbamate herbicides such as petanal, and urea herbicides such as linyuron and tribunyl. Examples include phenoxyalkanecarboxylic acid herbicides such as agents, 2,4-D agents, and heterocyclic herbicides such as pyrazone agents and renacil agents. Next, some examples regarding the herbicide of the present invention will be shown, but the active ingredient compounds, additives, and addition ratios are not limited to these examples and can be varied within a wide range.

Example 5 Emulsion compound 325 parts dimethylformamide 47 parts xylene
2? At least 8 parts of polyoxyethylene phenyl ether were mixed and dissolved to obtain an emulsion containing 25% of the active ingredient.

Example 6 Wettable powder compound 23 Diatomaceous earth 56 parts Higher alcohol sulfate ester 8 parts White carbon
At least 6 parts were mixed uniformly and finely ground to obtain a wettable powder containing 30% of the active ingredient.

Example 7 Granule compound 53 parts pennite 8 parts talc
85 parts polyoxyethylene alkyl phenyl ether sulfate
Mix and pulverize 4 or more parts uniformly, and use a granulator to reduce the diameter to 0.
．． Granules were granulated to 5 to 1.07 T$t to obtain granules containing 3% of the active ingredient.

Next, test examples will be shown to demonstrate the effectiveness of the herbicide of the present invention.
Test Example 1 Soil treatment test A 250 cIt pot was filled with soil, and seeds of crabgrass, oat, pigweed, goldenrod, garland chrysanthemum, and soybean were sown, and the pot was covered with soil to the extent that each seed could not be seen.

A chemical solution with a predetermined concentration prepared by diluting an emulsion of each test compound with water was sprayed onto the soil surface at a ratio of 100e/101. Three weeks later, the growth status of each weed was investigated.

The growth status was expressed in 11 stages from 0 to 10, with O indicating the same level of growth as without treatment and 10 indicating withering or non-germination, and the results shown in Table 2 were obtained. Test Example 2 Stalk and Leaf Treatment Test A 200 cIt pot was filled with soil, and seeds of crabgrass, oat, pigweed, and dogweed were sown, lightly covered with soil, and grown in a greenhouse.

When weeds have grown to the 2-4 leaf stage, a chemical solution with a predetermined concentration prepared by diluting an emulsion of each test compound with water is added to IOOe/I.
The foliage was sprayed at a rate of Oll. After 3 weeks, the growth status of each weed was investigated, and the growth status was expressed according to the same criteria as Test Example 1, and the results shown in Table 3 were obtained.

Claims (1)

[Claims] 1 General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R_1 and R_2 are lower alkyl groups, R_3
represents a hydrogen atom, a lower alkyl group, a lower alkenyl group or a benzyl group, and n represents 0, 1 or 2. However, at the same time, R_1 is a methyl group, R_3 is a hydrogen atom,
Except when n is 0. ). 2. The compound according to claim 1, wherein R_3 is a hydrogen atom. 3. The compound according to claim 1, wherein R_3 is a lower alkyl group, a lower alkenyl group, or a benzyl group. 4 Compounds represented by the formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ and general formulas ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, X is a halogen atom, R_1 and R_2 are lower alkyl groups, n represents 0, 1 or 2. However, at the same time, R_1 is a methyl group, R_3 is a hydrogen atom,
Except when n is 0. ) A method for producing a compound represented by the general formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼. 5 Formula▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R_1 and R_2 are lower alkyl groups, n is 0
, 1 or 2. ) is reacted with a compound represented by the general formula A method for producing a compound represented by the general formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼. 6 General formula▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R_1 and R_2 are lower alkyl groups, R_3
represents a hydrogen atom, a lower alkyl group, a lower alkenyl group or a benzyl group. However, at the same time, R_1 is a methyl group, R_3 is a hydrogen atom,
Except when n is 0. A herbicide characterized by containing a compound represented by ) as an active ingredient.