JPS6021962B2 - Herbicide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is based on the general formula (wherein, X represents a halogen atom, Y represents a halogen atom or a trifluoromethyl group, and Z represents a hydrogen atom, a halogen atom, or a cyano group).

The present invention relates to a herbicide characterized by containing at least one of the novel diphenyl ether compounds represented by the following as an active ingredient. It is a well-known fact that some diphenyl ether compounds have excellent herbicidal activity.

For example, 2,4-dichlorophenyl-4 nitrophenyl ether (hereinafter abbreviated as NIP), 2,4,6
-Trichlorphenyl-4 nitrophenyl ether (
Hereinafter, it will be abbreviated as CNP. ) is widely used as a herbicide for paddy fields, but a number of other diphenylable compounds are also being investigated for their practicality as herbicides. These compounds differ in their herbicidal activity, degree, mode of expression, selectivity, and duration of efficacy due to slight differences in their chemical structure, such as the type, number, or position of substituents. They often differ markedly, and it is extremely difficult to predict the herbal activity of these compounds based on the similarity of their chemical structures. As a result of synthesizing various diphenyl ether compounds and examining their herbicidal activity, the present inventors found that the compound of the present invention represented by the general formula [1] has an extremely superior herbicidal activity compared to NIP and CNP. It was discovered that it has grass activity, and based on this fact, the present invention was completed.

That is, the compound represented by the general formula [1] is NI
Compared to P and CNP, it exhibits superior herbicidal activity against grasses and many weeds, has less activity decline due to concentration dilution, has a long-lasting effect, and is extremely phytotoxic to paddy rice. It has many excellent herbicide properties such as small size.

Next, the above general formula [1] which is an active ingredient of the herbicide of the present invention
An example of synthesis of the compound shown is shown below. Synthesis example 12.2.
Synthesis of 4'-trichloro-3'-(8-fluoroethoxy)diphenyl ether [Compound 1] Two parts of 35% hydrochloric acid were added to a reactor and dissolved while stirring at room temperature.
9 parts of 4-dichloro-3-(8-fluoroethoxy)-4'-aminodiphenyl ether were added thereto to prepare a fine suspension of the hydrochloride.

Next, this liquid was cooled to 0 to 5°C, and a solution consisting of 2.3 parts of sodium sulfite and 30 parts of water was added dropwise thereto and reacted at the same temperature for 1 hour. The resulting diazonium salt solution was cooled to 0°C, and while stirring, 8 parts of Daiichi Steel Chloride and 2 parts of 35% hydrochloric acid were placed in a bag at the same time, and then heated on a tin bath until the internal temperature reached 70°C. It was heated and reacted for 3G minutes.

The reaction-completed liquid was cooled to room temperature, and 100 parts of benzene was added thereto for shaking and extraction. The benzene extract layer was dehydrated with anhydrous sodium sulfate, and then benzene was removed under reduced pressure to obtain 8.3 parts of a solid containing a large amount of the target compound, which was further recrystallized from ethanol, with a melting point of 80.5 to 82.0. 6.1 parts of pale yellow crystals of Compound 1 were obtained.

Synthesis Example 2 Synthesis of 2,4-dichloro-3-(8-fluoroethoxy)-cyanodiphenyl ether [Compound 3] 35 parts of 15% sulfuric acid was placed in a bag and stirred to melt the 2,4-dichloro- 3'-(8-fluoroethoxy)-
Eaminodiphenyl ether12. Aphids were added to this to prepare a fine sulfate suspension.

Next, this liquid was cooled to 0 to 5°C, and a solution consisting of 3 parts of sodium nitrite and 15 parts of water was added dropwise thereto to carry out a diazotization reaction at the same temperature for 30 minutes. Separately, 15 parts of Daiichi Steel Cyanide, 1 part of sodium cyanide, and 4 parts of water were charged into a reaction vessel, and the mixture was flooded to 75-80 pm, and while stirring, added the diazonium salt solution prepared earlier. Approximately 20
It was added dropwise to this within minutes.

The reaction was completed by further stirring at the same temperature for 30 minutes, and after cooling to room temperature, 100% of benzene was added and extracted by shaking. Next, the benzene layer was thoroughly washed with water,
After dehydration over anhydrous sodium sulfate, benzene was distilled off under reduced pressure to obtain a base portion of an oil containing a large amount of the target product. Heat this oil.

After being brought into contact with activated carbon in a vacuum chamber, the filtrate is cooled and crystallized to obtain a melting point of 0.25%. 5.2 parts of white crystals of Compound 3 with 5 to 100 qC were obtained. Synthesis Example 3 Synthesis of 2,4-dichloro-3'-(8-chloroethoxy)diphenyl ether [Compound 5] 7 parts of 2,4-dichloro-3'-(8-chloroethoxy)-4'-aminodiphenyl ether , diazotization was performed in the same manner as in Synthesis Example 1.

While maintaining this diazotized solution at 0° C., 15 parts of a 50% hypophosphorous acid solution was added thereto, stirred at the same temperature for 1 hour, and then left in a refrigerator overnight. 8 parts of benzene was added to the reaction solution and extracted by shaking, and the extracted benzene layer was washed with water and dehydrated with sodium chloride sulfate, and then the benzene was removed under reduced pressure. 5.2 parts of the obtained brown oil was subjected to column chromatography (silica gel 200 mesh 60 tat was used, eluent: benzene/n-hexane = 3/2).
The product was purified in a single machine to obtain 3.2 parts of a pale yellow oil as Compound 5. Next, active ingredient compounds related to the present invention are illustrated in Table 1 along with their physical properties. For ships and ships, the herbicide of the present invention may use the active ingredient compound represented by the general formula [1] as it is, but generally it is mixed with a suitable liquid carrier (for example, an organic carrier) depending on the purpose of use. dissolved or dispersed in a suitable solid carrier (solvent) or a suitable solid carrier (
(e.g. diluent, filler) or adsorbed.

At that time, various auxiliary agents (e.g. emulsifiers, stabilizers, dispersants, suspending agents, spreading agents, wetting agents, penetrating agents) may be added as necessary.
By appropriately adding , it can be used in various dosage forms such as emulsions, wettable powders, granules, and powders. The herbicide of the present invention can be used in combination with one or more other herbicides, pesticides such as insecticides, fungicides, plant growth regulators, soil conditioners, or fertilizing substances. Mixed formulations with these are also possible. For example, the herbicides used in combination with the herbicide of the present invention include urea-based herbicides, thiol carbamate-based herbicides, organophosphorus herbicides, acid amide-based herbicides, and triazine-based herbicides. , allyloxy fatty acid herbicides, etc. The active ingredient content of the present invention is 1 to 10% in granules.
, 30 to 50% for wettable powders, and 10 to 50% for emulsions (both indicate fleas percentage).

Next, Examples of the herbicide of the present invention will be shown.

In the examples, "parts" represent "parts by weight." Further, the active ingredient compound is represented by the compound number in the first notation. Example 1 Granule compound 1 6 parts, bentonite 7 base, talc 21 parts,
2 parts of sodium dodecylbenzenesulfonate and 1 part of sodium ligninsulfonate were mixed, an appropriate amount of water was added and the mixture was exposed, and then granulated using an extrusion granulator in a conventional manner to obtain 10 parts of granules. get.

Example 2 Granule compound 2 5 parts, bentonite 7 parts, talc 22 parts,
After mixing 1 part of sodium lauryl sulfate and 2 parts of sodium nafrinsulfonate, an appropriate amount of water was added and kneaded.
Granules are granulated in a conventional manner using an extrusion granulator to obtain 10 granules.

Example 3 5 parts of granule compound 3, 5 parts of clay, 44 parts of bentonite,
After mixing 0.5 part of sodium alkylbenzene sulfonate and 0.5 part of polyvinyl alcohol, an appropriate amount of water was added and kneaded, and the mixture was granulated using an extrusion granulator in a conventional manner. Get the capital.

Example 4 Wettable powder compound 4 50 parts, diatomaceous powder ±30 parts, clay 10 parts,
and 10 parts of sodium lauryl sulfate were mixed and ground to obtain 10 parts of a wettable powder.

Example 5 Emulsion Compound 6 2 parts Anchor, Tween-80 5 parts, Span-8
0.05 parts and 70 parts of solvent naphtha were mixed to obtain 10 emulsions.

Next, the effects of the herbicide of the present invention will be specifically explained using test examples.

Test example 1 Field cultivation weed killing test by treatment of emerging knot soil Field air-dried fine soil (passed through a 14-mesh sieve) 3.
5 kg was placed in an A/5.000 Wagner pot, and 0.5 kg of each of N, P205, and K20 was applied to the entire layer with chemical fertilizers, and the soil moisture was adjusted to 60% of the maximum water amount.

A certain amount of seeds of test crops and weeds were sown on this, and after uniformly covering it, a predetermined amount of the test compound was added to it.
The soil was treated with an emulsion prepared according to the method described in , and grown in a greenhouse.

Thirty days after the treatment, the appearance and growth of crops and weeds were observed and investigated, and the results shown in Table 2 were obtained. In this table, the degree of chemical damage to crops and the effect of Kogusa on weeds are shown as "0" for crops or weeds whose emergence or growth is similar to that in the untreated area, and "5" for those that are almost completely suppressed.
It is divided into 6 levels and displayed. Table 2 Test Example 2 Paddy field initial weed killing test Paddy soil (14
(passed through a mesh fluorite) 3.3k9 to a/5.
000 into the Wagner pot, and add N, P2Q, and K2 to it.
After fertilizing the whole area with chemical fertilizer for 0.8 minutes each, add an appropriate amount of water and stir to create a hydrated state.

To this, three paddy rice seedlings (seedlings, mulberry age 3.0) grown in advance in a greenhouse were used as one plant, and two of the plants were transplanted and grown in the greenhouse. Five days after transplanting paddy rice, at the onset of weed emergence, a predetermined amount of the test compound was treated under swamping using granules prepared according to the method described in Examples 1 and 3 above.

One month after the treatment, the appearance of weeds and the degree of chemical damage to paddy rice were investigated by observation, and the results shown in Table 3 were obtained.

In this table, the herbicidal effect is classified into 6 levels as in Test Example 1, and the degree of chemical damage to paddy rice is classified as "Jinsho", "Daisho", "Nakakiichi", "Slight harm", and "Slight harm". and ``harmless''. During the test period, the water leakage depth in the pot was maintained at 3 skins per day. Table 3 Test Example 3 Initial Grass Killing in Paddy Fields Mysterious Sapping Three days after rice planting, the paddy field was divided into 1 section of 10 〆 sections, and a prescribed amount of the compound was applied according to the method described in Example 1 and 3 above. Using the granules prepared in this way, they were sprayed on the surface of the stagnant water.

One month after the treatment, the amount of weeds per unit area in the test plot was measured, and at the same time, phytotoxicity to paddy rice was observed and investigated.

The results are shown in Table 4. In this table, the classification of the degree of chemical damage to paddy rice is the same as in Test Example 2. As is clear from the test results in Table 4 and above, the herbicide of the present invention has a wide range of herbicidal spectrum, has essentially high herbicidal activity, and has low activity and low toxicity to crops due to concentration dilution. It has significantly superior herbicidal properties compared to conventional diphenyl ether herbicides.

[Brief explanation of the drawing]

FIG. 1 shows an infrared absorption spectrum diagram of Compound 5.

Claims (1)

[Claims] 1 General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, A herbicide characterized by containing at least one type of diphenyl ether compound represented by the following as an active ingredient.