JPS6222981B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention provides N ¹ -methoxycarbonyl-N ⁴ -[2-
(2-Methyl-4-chlorophenoxy)propionyl]sulfanilamide, ^N1 -methoxycarbonyl- ^N4- (3,5-dichlorophenoxy)acetylsulfanilamide, ^N1 -methoxycarbonyl- ^N4- (3,5-dimethylphenoxy)acetylsulfanilamide, ^N1 -methoxycarbonyl- ^N4- (4-nitrophenoxy)acetylsulfanilamide, ^N1 -methoxycarbonyl- ^N4- (3-nitrophenoxy) Acetyl sulfanilamide, N ¹ -methoxycarbonyl-N ⁴ -
(2,4-dinitrophenoxy)acetylsulfanilamide and ^N1 -acetyl- ^N4- (2-methyl-4-chlorophenoxy)acetylsulfur
^N4 -phenoxyalkanoylsulfanilamides selected from the group consisting of nilamides (),
The present invention also relates to a herbicide containing at least one of these ^N4 -phenoxyalkanoylsulfanilamides or water-soluble metal salts thereof as an active ingredient. Compounds of the above formula are, for example, the corresponding phenoxyalkanoyl derivatives ()
When X is a halogen, the reaction is carried out in an inert organic solvent with a salt forming agent or a hydrogen halide scavenger, specifically an inorganic or hydrogen halide scavenger. It proceeds by contacting in the presence of an organic base. Examples of the phenoxyalkanoyl halides in () include 3-nitrophenoxyacetic acid, 4-nitrophenoxyacetic acid, and
-Nitrophenoxyacetic acid, 2,4-dinitrophenoxyacetic acid, 3,5-dichlorophenoxyacetic acid,
3,5-dimethylphenoxyacetic acid, 2-methyl-
Examples include chloride or bromide of 4-chlorophenoxyacetic acid and 2-methyl-4-chlorophenoxypropionic acid. Examples of the sulfanilamide () include N ¹ -methoxycarbonylsulfanilamide and N ¹ -acetylsulfanilamide. Examples of salt forming agents include sodium hydride, potassium hydride, sodium hydroxide, potassium hydroxide, sodium amide, sodium alkoxide, and the like; examples of hydrogen chloride scavengers include pyridine and triethylamine. Examples of the inert organic solvent include aromatic hydrocarbons such as benzene and toluene, dioxane, tetrahydrofuran, diethyl ether, pyridine, dimethylformamide, and dimethyl sulfoxide. The use of a solvent that also functions as the hydrogen chloride scavenger, such as pyridine, is convenient for simplifying the manufacturing process. The reaction is usually carried out at room temperature or slightly warmed, but in some cases, the mixture of the sulfanilamide and the solvent in () is cooled, and the acid halide in () is added to it or the solution thereof is added. A method such as dripping may also be used. Thereafter, the reaction is allowed to proceed under desired conditions, and the liquid properties are adjusted to obtain the optimum yield to complete the reaction. In addition, if the physical properties of the starting material and the product are acceptable, for example, if the melting point of the product is sufficiently higher than the melting points of both starting materials and both are highly stable against heat, phenoxyacetic acid, phenoxypropionyl The target substance can also be directly obtained by melting the free carboxylic acid together with the sulfanilamide under reduced pressure without converting the acid into a halide. The compound () obtained by the above method is recrystallized from a suitable solvent, such as aqueous methanol, or purified by chromatography. Alternatively, the obtained compound can be dissolved in water and treated with an alkali metal hydroxide or an alkaline earth metal to form a metal salt thereof. When the compounds () of the present invention are used as herbicides, they are usually diluted with a liquid or solid carrier that is inert to these compounds, and if necessary, a suitable auxiliary agent such as a surfactant is added thereto. emulsion,
It is used in the form of powder, wettable powder, granules, etc. Further, if necessary, other active ingredients may be mixed in for use. Liquid carriers used in the present invention include various organic solvents such as hydrocarbons such as kerosene, benzene, and xylene, halogenated hydrocarbons such as chlorobenzene and dichloroethylene, alcohols, and ketones such as acetone. Solid carriers include bentonite, kaolin, clay, talc, acid clay, diatomaceous earth,
Examples include silica sand, finely powdered silica, and calcium carbonate. Examples of the surfactant include alkylbenzenesulfonates, ligninsulfonates, higher alcohol sulfates, polyoxyethylene sorbitan fatty acid esters, dialkylsulfosuccinates, alkyltrimethylammonium chlorides, and the like. The amount of the compound of the present invention to be used as a herbicide is usually 1.0 to 20.0 g per are as the active ingredient, but it is not necessarily limited to this range, and as described below, the use situation, application method, timing, etc. It can be used in an appropriate amount depending on the crop to which it is applied and other conditions. 〓〓〓〓〓
The herbicidal action of the compounds of the present invention is not only more powerful than existing drugs, but also very unique. That is, at least in fields, these act only during the germination of weed seeds and strongly suppress the germination, but they do not act at all on weeds after germination. This is safe for seeds of useful crops that have different germination depths, and it is possible to kill only weeds.Furthermore, by performing treatment after transplanting crops, it is possible to selectively prevent the emergence of only weeds. Can be suppressed. The structure of the compound of the present invention has parts similar to existing known phenoxycarboxylic acid herbicides and N ¹ -acylsulfanilamide or sulfanylylurea herbicides, but their herbicidal properties are different from those of these herbicides. It has a completely different taste. This fact was confirmed as a very significant difference in properties by the test examples described below in which these existing herbicides were used as controls. The compounds of the present invention have strong herbicidal activity, and therefore, sufficient effects can be expected with low chemical damage even when applied in small amounts. In this way, this compound can be used not only as a non-selective herbicide for non-agricultural land and forests, but also as a selective herbicide for agricultural land, for soil treatment before or after sowing useful crops, before or after transplantation. For use, its herbicidal activity can be exerted arbitrarily in upland fields or paddy fields. When using the compound of the present invention as a herbicide, the optimum compound should be selected depending on the purpose of use, especially the type of weeds to be removed, and the planting, cultivation, and cropping type of useful crops in the fields or paddy fields to which it will be applied. or combinations are made. The selection or combination of optimal compounds can be carried out as appropriate, taking into consideration the detailed disclosure in the Examples below. Hereinafter, the present invention will be explained in more detail using compound synthesis examples, formulation examples, and test examples. Synthesis Example 1 A mixture of 1-(2-methyl-4-chlorophenoxy)propionic acid (4.0 g, 0.018 mol) and thionyl chloride (4.4 g, 0.037 mol) was mixed at 90-110°C with 3
After refluxing for a while, leave it overnight. Excess thionyl chloride was distilled off under reduced pressure from this reaction solution, and in the solution,
A solution of N ¹ -methoxycarbonylsulfanilamide (4.0 g, 0.032 mol) in pyridine (26.0 ml) is added dropwise over about 3 minutes while maintaining the temperature at 15-20°C. The reaction mixture was stirred at 20-30°C for about 1.5 hours, and then a mixture of 35% hydrochloric acid (31.6 g) and water (32 ml) was added to adjust the pH to about 2. As a result, the viscous substance produced in the mixture is separated by decantation, dissolved in a dilute aqueous sodium hydroxide solution, and then about 20% hydrochloric acid is added to remove the precipitated crude crystals. This crude crystal is recrystallized from benzene to give N ¹ −
Methoxycarbonyl-N ⁴ -[2-(2-methyl-
4-Chlorphenoxy)propionyl]sulfanilamide (compound No. 1) is obtained (powder, yield
5.7g, yield 71.6%). Melting point 86-87℃. Similarly, Compound No. 3 listed in Table 1 below
I got a score of 7. These N ¹ -salts can be easily obtained by reacting these with sodium hydroxide or potassium hydroxide in an aqueous solution. Synthesis Example 2 (2-Methyl-4-chlorophenoxy)acetic acid chloride (10.98 g, 0.048 mol) was added dropwise to a solution of N ¹ -acetylsulfanilamide (9.64 g, 0.048 mol) in pyridine (95 ml) to give a solution of 50 to 75 After reacting at ℃ for about 30 minutes with stirring, pyridine was distilled off under reduced pressure. Pour 100ml of water into the residue to make a slurry,
Adjust the pH to 2 with % hydrochloric acid and collect the precipitated crude crystals. Add this crude crystal to acetone (300ml) and water (140ml).
10% sodium hydroxide was added dropwise to dissolve it, and a small amount of decolorizing charcoal was added.The filtered mother liquor was neutralized with 35% hydrochloric acid, the precipitated crystals were removed, and N ¹ -acetyl-N ⁴ -(2-methyl-4-
Chlorphenoxy) acetylsulfanilamide (compound No. 2) was obtained (yield: 11.84 g, yield: 60.24
%, lobular). Melting point 253-255℃. 〓〓〓〓〓

[Table] Formulation Example 1 Wettable powder: 50 parts of the compound of the present invention, 5 parts of Solpol (Toho Chemical Industries, trade name), 3 parts of Lunox (Toho Chemical Industries, trade name), Carplex #80 (Shionogi Pharmaceuticals, trade name) 15 parts and 27 parts of kaolin are ground and mixed to obtain a wettable powder containing 50% of the active ingredient. 2 Granules: 5 parts of the compound of the present invention, 5 parts of calcium lignosulfonate, 30 parts of bentonite, and 60 parts of clay
After pulverizing, mixing, adding water and kneading to granulate, the mixture is dried to obtain granules containing 5% of the active ingredient. Test Example (Field Condition) Pre-germination and post-germination treatments in Examples 1 to 3 below were carried out in accordance with the following methods. (1) Pre-germination treatment (germination inhibitory activity) test and its evaluation: 25 seeds of test plants were sown according to type into polyethylene cups 9 cm in diameter filled with sandy loam. After seeding, an aqueous suspension of the test compound (compound acetone solution, Tween 20 as a spreading agent, 100 ppm
It was applied to the soil surface using a sprayer and immediately covered with soil to a thickness of about 5 mm. The amount of dilution water was adjusted to 10 per are. Control was carried out in a greenhouse with natural sunlight at a temperature of 25°C, and the results observed 3 weeks after treatment were expressed using the following 6-level evaluation (common to the following tests). 5: Dead or non-germinated 4: On the verge of withering 3: Large effect 2: Small effect 1: Slightly affected 0: No effect (2) Post-emergence treatment (growth inhibition activity) test: 10 days after sowing of test plants The seedlings were treated with the test compound in the same manner as the pre-germination treatment.
Management, observation and evaluation 3 weeks after treatment were performed in the same manner. Example 1 The results are summarized in Table 2. These results demonstrate that the compound of the present invention has the activity of strongly inhibiting weed germination. This has been shown to be in sharp contrast to the post-emergence growth inhibitory activity against the same weed. More specifically, by using the compounds of the present invention before transplanting or during the growing of useful crops, it is possible to control only weeds that will germinate later on without affecting the growth of the crops. Obviously〓〓〓〓〓
It became.

[Table] Table 2 shows that although the compound of the present invention contains a part of its structure that is similar to that of the control compound, there is a significant difference in herbicidal activity when used. It is shown that there is. For this reason, although there are restrictions on the time when the compounds of the present invention can be treated, as far as farmland is concerned,
It proves to be extremely useful for the treatment of crops after transplantation or post-emergence. Furthermore, whereas the control compound acts after germination or is effective only against broad-leaved weeds, the compound of the present invention has been shown to be effective against both grass and broad-leaved weeds only before germination. . Example 2 In accordance with the post-emergence treatment method described in (2) above, the effects on useful crops after sowing and the germination-suppressing activity of symbiotic weeds were compared, and the results summarized in Table 3 on the next page were obtained. In other words, all of the compounds of the present invention exhibit strong germination-suppressing or herbicidal effects against major weed species occurring in fields through post-sowing treatment, and all have no effect on corn and soybean. Nakatsuta. Of these, compounds Nos. 1, 2, 5 and 6 had no effect on wheat, Nos. 1, 2, 3, 5 and 6 had no effect on cucumber, and No. 5 had no effect on rapeseed. On the other hand, among the control compounds A and B, herbicidal or germination inhibiting activity was observed, but they had a significant effect on all useful crops, and the others (C, D, and E) had no effect on both. It was inactive. 〓〓〓〓〓

[Table] Example 3 According to Example 1, the effects of the compounds of the present invention on useful crops were tested by pre-emergence and post-emergence treatments, and the results are summarized in Table 4 below.

[Table] Here, Compound No. 1 had a considerable effect on corn, sorghum, wheat, and beet in the pre-germination treatment, and Compound No. 4 had a considerable effect on wheat, but Compound No. 3 had a considerable effect on wheat. It was confirmed that there was no effect to the extent that it would be a practical problem either before or after germination, and it was confirmed that none of the compounds had any effect on the crops after germination. Linyuron (F), which was used as a control, inhibited the growth of all the tested crops, except for the pre-emergence treatment of maize. Example 4 This example was conducted according to the following test method. (3) Soil mixing treatment test: A vat (40 m x 40 m) was filled with sandy loam soil, a predetermined amount of the test compound was mixed in to a mixing depth of 5 cm, and then the test plants were sown. Management, observation (3 weeks after treatment), and evaluation were performed according to (1) and (2) above, and the results are summarized in Table 5 on the next page. 〓〓〓〓〓

[Table] Table 5 shows that even when the compound of the present invention is used in soil mixing treatment to expand the depth of the treatment layer, it has the characteristic that high selectivity between weeds and beneficial effects can be maintained. I can see that you are doing it. Regarding the herbicidal spectrum, Compound No. 1 affected all tested weeds, including Japanese grasshopper, while Compounds No. 3, 4, and 6 had a considerable effect on Japanese grasshopper, Japanese knotweed, and Japanese knotweed.
If the dose is sufficient, it can cause complete or near-killing effects. Regarding the effects on useful crops, none of the compounds showed any phytotoxicity to corn except for Compound No. 1. None of the compounds showed any toxicity to soybean. Compound No. 6 was completely harmless to wheat, and Compounds No. 3, 4, and 6 did not cause any practical damage to tomatoes. From the above results, compound No. 6 is corn,
Compound No. 1 is found in wheat, soybeans, tomatoes, and cucumbers.
Compound No. 3 and 4 were found to be useful for corn and soybeans, and Compound No. 1 was found to be useful for soybeans. Example 5 This example was conducted according to the following test method. (4) Rice test (pot) method: Fill a/5000 Wagner pot with paddy soil,
Pre-flooded weed seeds were sown, and a predetermined amount of an aqueous suspension of the test compound was added dropwise to the weeds before germination. Immediately thereafter, two rice plants per pot were planted. Management was carried out according to (1) to (3) above, and the weight of the plants was measured one month after the treatment and expressed as a percentage (%) of the untreated plant weight, and the results shown in Table 6 below were obtained. .

[Table] 〓〓〓〓〓

[Table] As is clear from the previous table, under flooded conditions, all the test compounds suppressed the emergence of major weeds in paddy fields such as Japanese millet, Cyperus japonica, and other broad-leaved weeds at dosages of 5 g/a and 10 g/a. do.
In particular, Compound No. 1 completely inhibits the growth of almost all important weeds in paddy fields at a dosage of 5 g/a. Regarding the safety of the test compounds on rice, a slight effect was observed on Compound No. 1, but no effects were observed on the other compounds. Example 5 (5) Paddy rice test (field) method: Pre-germination treatment A 50 x 50 x 50 cm concrete pot set up in an outdoor field is filled with paddy soil (sandy loam) and 5 cm
The area was flooded. Four rice plants (2.5 leaf stage) per pot were planted there, underground stems or tubers of important perennial weeds in paddy fields were embedded, and annual paddy weeds were sown. Immediately thereafter, a predetermined amount of an aqueous suspension of the test compound was added dropwise for treatment. After being left for 30 days under natural sunlight conditions at an average temperature of 17-28℃, rice and annual weeds (naturally occurring)
We pulled out and perennial weeds, separated them, and weighed them to observe and evaluate the weed control effect and impact on rice under paddy field conditions, and obtained the results summarized in Table 7 below in comparison with the untreated plot. (represents grass amount%).

[Table] 〓〓〓〓〓

[Table] As is clear from the previous table, compounds No. 1 and 4
At each dose, germination of the annual weeds tested was completely suppressed. Furthermore, No. 1 is less effective against perennial weeds that are difficult to control than the control drug H, which is a perennial weed herbicide currently on the market, against Japanese black grubs. It was highly effective. In this case, the effect on rice was significantly lower than that of H. On the other hand, a control drug widely used as an initial herbicide for paddy fields in Japan had no effect on perennial weeds. Comparative drug H, which is a mixture, shows strong phytotoxicity to rice at this treatment stage, whereas Compound No. 1, although a single agent, has only slight phytotoxicity and has excellent properties as a herbicide for paddy fields. It was recognized that Example 6 (6) Rice test (pot) method (growth inhibition effect by post-germination treatment): Pack paddy soil into a/5000 Wagner pot,
Before flooding, seeds of annual weeds were sown and tubers of perennial weeds were planted. Immediately thereafter, two rice plants per pot were planted and flooded. Thereafter, when the rice and weeds reached the following leaf stage (leaf stage), a predetermined amount of the test compound was applied and treated. Rice: 3.8 leaves Cyperus japonica: 3 leaves (15cm) Black-capped cypress: 5 leaves (5cm) Urikawa: 4 leaves (5cm) Japanese millet: 1.5 leaves (8cm) Management was carried out in the same manner as in (4) above, and the effect on rice after 1 month of treatment The effects on weeds were also measured, and the results shown in Table 8 below were obtained.

[Table] As is clear from the previous table, compound No. 1 is
At a dosage of 10 g/a, it completely suppressed annual broad-leaved weeds and showed a moderate suppressive effect on perennial weeds such as pine snail and cypress. In contrast, control drugs A' and E' had little effect on both annual and perennial weeds. In this way, under flooded conditions, Compound No. 1 is effective against broad-leaved weeds and perennial weeds with considerably advanced leaf stages.
It was also found that it is effective against herbicides and has excellent properties as a paddy herbicide. 〓〓〓〓〓

Claims (1)

[Claims] 1 N ¹ -methoxycarbonyl-N ⁴ -[2-(2-
Methyl-4-chlorophenoxy)propionyl]
Sulfanilamide, ^N1 -methoxycarbonyl- ^N4- (3,5-dichlorophenoxy)acetylsulfanilamide, ^N1 -methoxycarbonyl- ^N4- (3,5-dimethylphenoxy)acetyl Sulfanilamide, ^N1 -methoxycarbonyl- ^N4- (4-nitrophenoxy)acetylsulfanilamide, ^N1 -methoxycarbonyl- ^N4-
(3-nitrophenoxy)acetylsulfanilamide, ^N1 -methoxycarbonyl- ^N4- (2.4
-dinitrophenoxy)acetylsulfanilamide and ^N1 -acetyl- ^N4- (2-methyl-4
^-N4 -phenoxyalkanoylsulfanilamide selected from the group consisting of -chlorophenoxy)acetylsulfanilamide. 2 N ¹ -Methoxycarbonyl-N ⁴ -[2-(2-
Methyl-4-chlorophenoxy)propionyl]
Sulfanilamide, ^N1 -methoxycarbonyl- ^N4- (3,5-dichlorophenoxy)acetylsulfanilamide, ^N1 -methoxycarbonyl- ^N4- (3,5-dimethylphenoxy)acetyl Sulfanilamide, ^N1 -methoxycarbonyl- ^N4- (4-nitrophenoxy)acetylsulfanilamide, ^N1 -methoxycarbonyl- ^N4-
(3-nitrophenoxy)acetylsulfanilamide, ^N1 -methoxycarbonyl- ^N4- (2.4
-dinitrophenoxy)acetylsulfanilamide and ^N1 -acetyl- ^N4- (2-methyl-4
A herbicide containing as an active ingredient at least one N ⁴ -phenoxyalkanoylsulfanilamide or a water-soluble metal salt thereof selected from the group consisting of -chlorophenoxy)acetylsulfanilamide.