JPS6363541B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to novel diphenyl ether derivatives and their uses. For details, see the general formula () (In the formula, R is -NHNHCOCH ₂ OCH ₂ COOR ₁ or

[Formula], R ₁ represents a hydrogen atom or a lower alkyl group, respectively. The present invention relates to a herbicide characterized by containing a novel diphenyl ether derivative represented by the following formula and at least one of these compounds as an active ingredient. In the past, many diphenyl ether compounds have been considered for practical use as herbicides, but these compounds have little difference in chemical structure such as the type, number, or position of substituents. The presence or absence of herbicidal activity, mode of expression, selectivity, and duration of efficacy often differ significantly, and it is extremely difficult to predict the herbicidal activity of these compounds based on similarities in their chemical structures. be. It is a well-known fact that certain types of diphenyl ether compounds have excellent herbicidal activity. For example, 2,4,6-trichloro-4'-nitrodiphenyl ether and 2,4-dichloro-3'-methoxy-4'-nitrodiphenyl ether are widely used as herbicides for initial use in paddy fields. On the other hand, 2,4-dichloro-4'-nitrodiphenyl ether is widely used as a field herbicide, and a number of other diphenyl ether compounds are also known. However, these compounds have insufficient residual efficacy and are insufficiently effective against some types of weeds. There was a desire to develop a herbicide with this property. The present inventors synthesized various diphenyl ether compounds and examined their residual efficacy, herbicidal activity, and herbicidal spectrum. As a result, the novel diphenyl ether compound of the present invention was found to be one of the known diphenyl ether compounds. It was discovered that it has extremely superior herbicidal activity, high selectivity, sufficient residual effect, and excellent herbicidal activity that can even control difficult-to-control perennial weeds, and based on these facts, the present invention was completed. Next, typical synthesis examples of the compounds of the present invention will be explained below. Note that the compound numbers match those in Table 1 below. Synthesis Example 1 N-[2-nitro-5-(2-chloro-4-trifluoromethylphenoxy)phenyl]-N'-
Synthesis of diglycolic acid hydrazide (compound 1) 2-chloro-4-trifluoromethylphenyl-3-hydrazino-4-nitrophenyl ether
5.1g (0.015mol) and 1.7g diglycolic anhydride
(0.015 mol) and acetic acid 50ml mixture 110-120
The mixture was stirred and reacted at ℃ for 3 hours. After cooling, the reaction solution was discharged into cold water, and the precipitated oil was extracted by shaking with methyl acetate. The extract was thoroughly washed with water, dehydrated, and ethyl acetate was distilled off under reduced pressure to obtain 6.8 g (yield 97.8%) of the target compound 1. Synthesis Example 2 N-[2-nitro-5-(2-chloro-4-trifluoromethylpheenoxy)phenyl]-
Synthesis of N'-diglycolic acid methyl hydrazide (compound 2) 12.3 g of the compound obtained in Synthesis Example 1 was placed in a reaction flask.
(0.005 mol) methanol 50 ml and concentrated sulfuric acid 0.5 g
was charged and stirred under reflux for 1 hour. After cooling,
The reaction solution was concentrated, and the residue was dissolved in benzene. The benzene solution was thoroughly washed with water, dehydrated, and benzene was distilled off under reduced pressure to obtain a crude product of Compound 2. It was isolated and purified by silica gel column chromatography (developing solution: benzene/ethyl acetate = 3/2) to obtain 1.5 g of highly pure compound 2 (yield 62.8%).
Obtained. Compounds 3 and 4 were also synthesized according to Synthesis Example 2. Synthesis Example 3 2-chloro-4-trifluoromethylphenyl-3-(2,6-dioxomorpholinoamino)-
Synthesis of 4-nitrophenyl ether (compound 5) Compounds 1 and 2.3 obtained in Synthesis Example 1 were placed in a reaction flask.
g (0.005 mol) and p-toluenesulfonic acid 0.2 g
and 100 ml of toluene were charged and stirred under reflux for 3 hours to perform a dehydration ring closure reaction. After cooling, the reaction solution was thoroughly washed with water and dehydrated, and then toluene was distilled off under pressure. The residue was subjected to silica gel column chromatography (developing solution: benzene/ethyl acetate = 3/
1.3g of high purity compound 5 isolated and purified in 2)
(yield 58.4%). Next, representative rows of the compounds of the present invention and their physical properties are summarized and illustrated in Table 1 below.

[Table] For the compound of the present invention, the active ingredient compound represented by the above general formula () may be used as it is, but generally, depending on the purpose of use, it is mixed with a suitable liquid carrier (for example, an organic solvent). They are used by being dissolved or dispersed, or mixed or adsorbed onto a suitable solid carrier (eg, diluent, filler). At that time, by appropriately adding various auxiliary agents (e.g. emulsifiers, stabilizers, dispersants, suspending agents, spreading agents, wetting agents, penetrants) as necessary, emulsions,
It can be used in various dosage forms such as wettable powders, granules, and powders. When the compound of the present invention is used as a herbicide, it is used in combination with one or more other herbicides, agricultural chemicals such as insecticides, fungicides, and plant growth regulators, soil conditioners, or fertilizing substances. Of course, mixed formulations with these are also possible, and synergistic effects can be expected in some cases. Next, formulation examples and herbicidal activity tests of herbicides containing the compound of the present invention as an active ingredient will be shown.
Of course, the present invention is not limited to these. In the examples, the active ingredient compounds represented by the general formula () are represented by the compound numbers in Table 1, and "parts" represent "parts by weight." Example 1 Granule Compound 2 5 parts, bentonite 72 parts, talc 20
1 part, 2 parts of sodium dodecylbenzenesulfonate, and 1 part of sodium ligninsulfonate, and after adding an appropriate amount of water and kneading, granulate using an extrusion granulator in a conventional manner to obtain 100 parts of granules. . Example 2 Wettable powder 50 parts of Compound 3, 40 parts of diatomaceous earth and 10 parts of sodium dodecylbenzenesulfonate are mixed and ground to obtain 100 parts of a wettable powder. Next, the herbicidal activity of the compounds of the present invention will be specifically explained using test examples. Test Example 1 Pre-emergence weeding test in a rice field Alpha/5000 Wagner pots were filled with soil, and seeds of Japanese millet, broad-leaved weeds (e.g., commonweed, azalea, japonica, etc.), bulrushes, snails, and cypress were sown in a flooded state. Two paddy rice seedlings (2-3 leaf stage) that had been raised in advance were used as one plant, and the two plants were transplanted and grown in a greenhouse.
Three days after rice transplantation, at the beginning of weed emergence, a predetermined amount of the test compound was submerged in water using a granule according to the method described in Example 1 above. Thirty days after the treatment, weed growth and chemical damage to paddy rice were investigated, and the results shown in Table 2 were obtained. In this table, the degree of chemical damage to crops and the herbicidal effect on weeds are expressed by comparing the state of emergence or growth of crops or weeds with the air dry weight of untreated plots according to the evaluation criteria below. The test compounds are indicated by compound numbers in Table 1 above (the same applies hereinafter). Evaluation standard 0: Survival rate shown by air dry weight ratio vs. untreated area
91-100% 1 〃 〃 71-90% 2 〃 〃 41-70% 3 〃 〃 11-40% 4 〃 〃 6-10% 5 〃 〃 0-5%

【table】

[Table] Lether test example 2 Weeding test during the rice field growing season α/5000 Wagner pots were filled with soil, and seeds of Japanese millet, broad-leaved weeds (such as staghorn grass, azalea, and japonica), scallops, snails, and cypress were sown in a flooded state. Two paddy rice seedlings (2 to 3 leaf stage) that had been raised in advance were transplanted to this as one plant 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 a granule according to the method described in Example 1 above. Thirty days after the treatment, weed growth conditions and chemical damage to paddy rice were investigated, and Table 3 was obtained. In this table, the degree of chemical damage to crops and the herbicidal effect on weeds are expressed according to the method shown in Test Example 1.

【table】

[Table] Lether test example 3 Pre-emergence weeding test for field crops Pack soil into α/1000 planters, and sow seeds of wheat, corn, soybean, crabgrass, foxtail grass, Japanese wildflower, Japanese apricot, whitewort, wild mustard, Japanese knotweed, Japanese fir, and Japanese morning glory. did. Three days after seeding, a predetermined amount of the test compound was diluted to 10 equivalent amounts of water per are using a wettable powder according to the method described in Example 2, and sprayed using a micro-pressure sprayer. This was grown in a greenhouse.
Thirty days after the treatment, the appearance and growth of crops and weeds was investigated, and the results shown in Table 4 were obtained. In this table, the degree of chemical damage to crops and the herbicidal effect on weeds are expressed using the method shown in the test example.

【table】

[Table] Test example 4 Field crop growing season weeding test α/1000 planters were filled with soil and seeds of wheat, corn, soybean, crabgrass, foxtail grass, Japanese wild grass, green grass, white grass, wild mustard, Japanese knotweed, Japanese fir, and Japanese morning glory were sown. and grown in a greenhouse. When the test plant has grown to the 2nd to 3rd leaf stage, a predetermined amount of the test compound is diluted to an amount of water equivalent to 10 per are using a hydrating agent according to the method described in Example 2, Sprayed with a micro-pressure sprayer. The growth status of crops and weeds was investigated 30 days after the treatment, and the results shown in Table 5 were obtained. In this table, the degree of chemical damage to crops and the herbicidal effect on weeds are expressed according to the method shown in the test example.

【table】

【table】

Claims (1)

[Claims] 1 General formula () (In the formula, R represents -NHNHCOCH ₂ OCH ₂ COOR ₁ or [Formula], and R ₁ represents a hydrogen atom or a lower alkyl group, respectively.) A novel diphenyl ether derivative represented by the following. 2 In the general formula (), R is -
The compound according to claim 1, wherein when NHNHCOCH ₂ OCH ₂ COOR ₁ , R ₁ is a methyl group, an ethyl group or an iso-propyl group. 3 General formula () (In the formula, R represents -NHNHCOCH ₂ OCH ₂ COOR ₁ or [Formula], and R ₁ represents a hydrogen atom or a lower alkyl group, respectively.) It is characterized by containing a novel diphenyl ether derivative represented by the following as an active ingredient. and herbicides.