JPH053444B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a herbicidal composition characterized by mixing starch with N-substituted chloroacetanilide. [Problems to be solved by the prior art and the invention] Properties essentially required for herbicide preparations include:
There are four matters below. That is, firstly, it must be safe for crops, and secondly, it must exhibit an even and stable weeding effect against weeds. The third reason is that the herbicide's effectiveness lasts for a long period of time, and the fourth reason is that the herbicide has a more effective herbicidal effect with a lower content of active ingredients due to environmental issues, cost, etc. The present inventors have conducted extensive research with the aim of developing a formulation represented by the following general formula as an excellent herbicide. The following general formula [], (However, in the formula, R ₁ , R ₂ and R ₃ represent the same or different hydrogen atoms, halogen atoms, alkyl groups, alkoxy groups, alkylthio groups, alkoxyalkyl groups or alkylthioalkyl groups, and R ₄ represents a hydrogen atom or an alkyl R ₅ , R ₆ and R ₇ are the same or different hydrogen atoms, halogen atoms, alkyl groups, alkenyl groups, alkynyl groups, alkoxy groups, or alkylthio groups. Acetanilide has already been proposed (Patent Application No. 111077/1984 and others). Naturally, the role of formulations in the expression of herbicide effects is very important. In other words, it is almost impossible to expect a sufficient herbicidal effect unless the physical or chemical properties of the drug substance are carefully considered and the optimal formulation is formulated. The present inventors have discovered that N represented by the above general formula []
-Substituted-chloroacetanilide as a herbicide,
With the aim of using it more effectively, we have continued intensive research on its formulation, and have found that weed control can be obtained by mixing starch with N-substituted chloroacetanilide represented by the above general formula []. It has been discovered that the drug composition exhibits a synergistic effect that could not be predicted from the properties of each agent alone, that is, it has a stable herbicidal effect at a low dose. The present inventors have proposed the present invention based on these new findings. [Means for solving the problems] The present invention is based on the following general formula [], (However, in the formula, R ₁ , R ₂ and R ₃ represent the same or different hydrogen atoms, halogen atoms, alkyl groups, alkoxy groups, alkylthio groups, alkoxyalkyl groups or alkylthioalkyl groups, and R ₄ represents a hydrogen atom or an alkyl R ₅ , R ₆ and R ₇ are the same or different hydrogen atoms, halogen atoms, alkyl groups, alkenyl groups, alkynyl groups, alkoxy groups, or alkylthio groups. This is a herbicidal composition characterized by mixing acetanilide and starch, that is, one selected from starches such as potato, wheat, corn, rice, sweet potato, etc., or a mixture thereof. The component of the herbicidal composition of the present invention is an N-substituted-chloroacetanilide represented by the following general formula []. Among the N-substituted-chloroacetanilides represented by the above general formula [], the 2-position of the thiophene ring

[Formula] is bonded, R ₁ is a hydrogen atom or an alkyl group, R ₂ , R ₃ and R ₄ are hydrogen atoms,
R ₅ is an alkyl group, R ₆ is a hydrogen atom, an alkyl group, or an alkoxy group, R ₇ is a hydrogen atom,
A compound that is an alkyl group or a halogen atom is
It is known from US Pat. No. 3,901,917. but,
Most of the others are new compounds. In the general formula [], specific examples of the halogen atoms represented by R ₁ , R ₂ , R ₃ , R ₅ , R ₆ and R ₇ include:
Examples include chlorine, bromine, fluorine, and iodine atoms. Furthermore, in the general formula, R ₁ , R ₂ , R ₃ , R ₄ ,
The alkyl groups represented by R ₅ , R ₆ and R ₇ are linear,
It may be in any branched form, and the number of carbon atoms is not particularly limited. However, from the viewpoint of easy availability of raw materials, the number of carbon atoms is preferably 1 to 6. Specific examples of the alkyl group include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, t-butyl group, n-pentyl group, n-hexyl group. etc. In the general formula [], the alkoxy groups represented by R ₁ , R ₂ , R ₃ , R ₅ , R ₆ and R ₇ are not particularly limited, but are generally linear or branched groups having 1 to 6 carbon atoms. Branched saturated or unsaturated groups are preferred. Specific examples of the alkoxy group that are generally preferably used include methoxy group, ethoxy group, n-propoxy group, t-butoxy group, n-pentoxy group, n-hexoxy group, allyloxy group, and the like. In the general formula [], the alkylthio groups represented by R ₁ , R ₂ , R ₃ , R ₅ , R ₆ and R ₇ are not particularly limited and any known alkylthio group can be used, but they generally have 1 to 1 carbon atoms. Six straight-chain or branched saturated or unsaturated groups are preferred. Specific examples of the alkylthio group suitably used include methylthio group, ethylthio group, n-propylthio group, t-butylthio group, n-pentylthio group, n-hexylthio group, and allylthio group. In addition, the alkoxyalkyl group represented by R ₁ , R ₂ and R ₃ in the above general formula is not particularly limited in the number of carbon atoms, but may be a linear or branched saturated or unsaturated group having 2 to 6 carbon atoms. Specific examples of suitable alkoxylalkyl groups include methoxymethyl group, methoxyethyl group, ethoxymethyl group, n-propoxymethyl group, t-butoxyethyl group, and allyloxyethyl group. Furthermore, in the general formula, the alkylthioalkyl group represented by R ₁ , R ₂ and R ₃ is not particularly limited in the number of carbon atoms, but may be a linear or branched saturated or unsaturated group having 2 to 6 carbon atoms. Examples of the alkylthioalkyl group include methylthiomethyl group,
Methylthioethyl group, ethylthiomethyl group, n-
Examples include propylthiomethyl group, t-butylthioethyl group, and allylthioethyl group. Also,
In the general formula, the alkenyl groups represented by R ₅ , R ₆ and R ₇ may be linear or branched, and the number of carbon atoms is not particularly limited. However, from the viewpoint of easy availability of raw materials, the number of carbon atoms is preferably 2 to 4. Specific examples of the alkenyl group include vinyl group, allyl group, iso-propenyl group, 2-butenyl group,
Examples include 3-butenyl group. Furthermore, in the general formula, the alkynyl groups represented by R ₅ , R ₆ and R ₇ are:
The number of carbon atoms is not particularly limited, regardless of whether it is linear or branched, but it is preferable that the number of carbon atoms is 2 to 4 as described above. Specific examples of the alkynyl group include ethynyl group, 2-propynyl group, and the like. In the above N-substituted-chloroacetanilide, R ₁ is the same or different halogen atom, alkoxy group, alkylthio group, alkoxyalkyl group, or an alkylthio group, alkoxyalkyl group, or alkylthioalkyl group, and R ₂ and R ₃ is the same or different hydrogen atom, halogen atom,
an alkyl group, an alkoxy group, an alkylthio group, an alkoxyalkyl group, or an alkylthioalkyl group, R ₄ is a hydrogen atom or an alkyl group,
Compounds in which R ₅ , R ₆ and R ₇ are the same or different hydrogen atoms, halogen atoms, alkyl groups, alkenyl groups, alkynyl groups, alkoxy groups or alkylthio groups may be used at a low concentration of 15 g/10a or less. However, it not only has an excellent weeding effect that completely kills annual weeds such as field weeds and perennial weeds such as water cypress, but also has an excellent weeding effect of 500 g/
Since it is completely harmless to rice even when used at a high concentration of 10a, it is suitably used in the present invention. In particular, at least one of R ₁ to _{R 3} is a substituent other than a hydrogen atom, and this substituent is bonded to the thiophene ring.

[Formula] is substituted at the ortho position, R ₄ is a hydrogen atom, and furthermore, at least two of R ₅ to _{R 7} are substituents other than hydrogen atoms,
N-substituted chloroacetanilide in which these substituents are substituted at the 2- and 6-positions of the phenyl group is particularly preferably used because the above-mentioned properties are stronger. The structure of the N-substituted chloroacetanilide represented by the general formula [] can be confirmed by the following means. (b) By measuring the infrared absorption spectrum (IR), it is possible to observe an absorption based on the CH bond in the vicinity of 3150 to 2800 cm ^-1 and a characteristic absorption based on the carbonyl bond of the amide group in the vicinity of 1680 to 1660 cm ^-1 . I can do it. (b) Measure the mass spectrum (MS) and calculate the composition formula corresponding to each observed peak (generally a value expressed as m/e, which is the ion mass number m divided by the ion charge number e). By this method, it is possible to know the molecular weight of the compound subjected to measurement and the bonding mode of each atomic group within the molecule. In other words, the sample subjected to measurement is expressed by the general formula [] When expressed as The molecular weight of can be determined. Furthermore, regarding the N-substituted-chloroacetanilide represented by the general formula [], M -Cl, M -
_COCH2Cl and

〔effect〕

The herbicidal composition of the present invention described above exhibits a herbicidal effect that cannot be expected from the properties of each component alone. That is, by adding starch to a specific N-substituted-chloroacetanilide, the content of the N-substituted-chloroacetanilide, which is an active ingredient of the herbicide, is reduced. As shown in the examples, it exhibits the same herbicidal effect as the N-substituted chloroacetanilide alone. Furthermore, it is extremely safe for crops. Therefore, the herbicidal composition of the present invention fully satisfies the properties required of a herbicide and is extremely useful. EXAMPLES The herbicidal composition of the present invention will be specifically explained below using Examples, but the present invention is not limited to these Examples. Synthesis of N-substituted-chloroacetanilide (Synthesis Example 1) N-[2'-(5'-bromo)-thienylmethyl]-
2,6-dimethylaniline 1.81g (6.14×10 ^-3
mole) was dissolved in 40 ml of benzene, 0.81 g (7.98 x 10 ^-3 mole) of triethylamine was added, and the mixture was placed in ice water. Then 0.83g of chloroacetyl chloride
(7.37×10 ⁻³ mole) in benzene solution (15 ml) was gradually added. After stirring for 3 hours, the mixture was heated at 50°C for 1 hour. After cooling the reaction mixture to room temperature,
It was washed successively with 50 ml of water, 50 ml of 2N hydrochloric acid, and then 50 ml of water, and the benzene layer was dried over anhydrous sodium sulfate. Thereafter, it was purified by column chromatography to obtain 1.13 g of a yellow solid. As a result of measuring the infrared absorption spectrum of this product, it showed an absorption based on the C-H bond at 3110 to 2900 cm ^-1 and a strong absorption based on the carbonyl bond of the amide group at 1670 cm ^-1 . Its elemental analysis values are C48.3%, H4.05%, N3.99%, and _C15
This is the calculated value for H ₁₅ NSOB _r Cl (372.71)
It matched well with C48.20%, H4.32%, and N3.75%. In addition, when mass spectra were measured, m/
Molecular ion peak corresponding to molecular weight (M
), a peak corresponding to M-Cl at m/e336,
A peak corresponding to M-COCH ₂ Cl at m/e293,
m/e143 (100%) The corresponding peaks are shown. Furthermore, ^{the 1} H-nuclear magnetic resonance spectrum is as shown as a specific example in the specification. From the above results, it is clear that the isolated product is N-[2'-(5'-
bromo)-thienylmethyl]-N-chloroaceto-
It became clear that it was 2,6-dimethylanilide (hereinafter abbreviated as compound (1)). The yield is N
-[2'-(5'-bromo)-thienylmethyl]-2,6
−49.5% (3.04×10 ^-3 for dimethylaniline)
mole). (Synthesis Example 2) The properties, physical properties (boiling point), characteristic absorption values in the infrared spectrum, and elemental analysis results of N-substituted-chloroacetanilide synthesized in the same manner as in Synthesis Example 1 are summarized in Table 1. Furthermore, the general formula in Table 1 is the general formula [] Corresponding to, A is

[Formula], B is R ₄ , D is

[Formula] means.

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[Table] Formulation Example 1 (Granules) 1 part by weight of the compound shown in Table 1 No. 4, 1 part by weight of dioctyl succinate, 3 parts by weight of sodium ligninsulfonate
parts by weight, 15 parts by weight of bentonite, potato starch
40 parts by weight and 40 parts by weight of talc are thoroughly mixed and pulverized, water is added and kneaded, and then granulated and dried.
It was obtained by grading into mesh. Formulation Example 2 (Wettable powder) 10 parts by weight of the compound No. 6 in Table 1, 2 parts by weight of polyoxyethylene nonyl phenyl ether, 20 parts by weight of wheat starch, 20 parts by weight of fine clay, and 48 parts by weight of Siegrite. The mixture was ground and mixed in a hammer mill to obtain a wettable powder. Formulation Example 3 (Powder) 5 parts by weight of the compound No. 42 in Table 1, 30 parts by weight of corn starch, 1 part by weight of white carbon, and 64 parts by weight of clay were ground and mixed in a hammer mill to obtain a powder. Formulation example 4 (fine granules) 2 parts by weight of the compound No. 63 in Table 1, 5 parts of sweet potato starch
parts by weight, 5 parts by weight of rice starch, 87 parts of clay, and 1 part of polyvinyl alcohol were thoroughly stirred and mixed, and then granulated using a rotary granulator while adding 5 parts of water.
and dry. Fine granules were obtained by sieving into 48 to 150 mesh pieces. As a comparative example, preparations not containing starch were carried out in the same manner as in Formulation Examples 1, 2, 3, and 4, using various clay minerals instead of starch. Example 1 A 1/8850 are porcelain pot was filled with paddy soil (alluvial loam) that had been stirred with water, and after sowing wild grass seeds, water was added to make the pot submerged to a depth of 3 cm. After the wildflowers had grown to the 2.0 leaf stage, a predetermined amount of 3 kg/10a of granules of each compound prepared according to Formulation Example 1 was treated. After treatment, the plants were grown in a greenhouse at an average temperature of 25°C, and three weeks later, the herbicidal effects of each test granule were investigated. The results are shown in Table 2. however,
In the table, the results when no starch was included are also listed as a comparative example. Regarding the weeding effect, weed suppression rate (100-0%)
was converted into a numerical value from 10 to 0 and evaluated on the following 10 scale. 10: 100% (complete withering) 9: 90-99% 8: 80-89% 7: 70-79% 6: 60-69% 5: 50-59% 4: 40-49% 3: 20-39% 2:10-19% 1:1-9% 0:0% (No effect observed at all.) Example 2 Paddy soil (alluvial loam) prepared by adding water to a 1/8850 are porcelain pot and stirring After filling and sowing wildflower seeds, water was added to make it flooded to a depth of 3 cm. After the wildflowers have grown to the 2.0 leaf stage, apply 300g/10a of the hydrating agent of each compound produced according to Formulation Example 2.
A predetermined amount of the aqueous solution was treated. After treatment, the plants were grown in a greenhouse at an average temperature of 25°C, and three weeks later, the herbicidal effects of each test granule were investigated. The results are shown in Table 3. However, as a comparative example, the table also shows the results when no starch was included.
Note that the criteria for the herbicidal effect in the table are the same as in Example 1.

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【table】 [Brief explanation of the drawing]

FIG. 1 shows a ¹ H-NMR chart of N-substituted-chloroacetanilide obtained in Synthesis Example 1.

Claims (1)

[Claims] 1. The following general formula (However, in the formula, R ₁ , R ₂ and R ₃ are the same or different hydrogen atoms, halogen atoms, alkyl groups, alkoxy groups, alkylthio groups, alkoxyalkyl groups,
or represents an alkylthioalkyl group, R ₄ represents a hydrogen atom or an alkyl group, and R ₅ , R ₆ and R ₇ represent the same or different hydrogen atoms, halogen atoms, alkyl groups, alkenyl groups, alkynyl groups, alkoxy groups, or Indicates an alkylthio group. 1. A herbicidal composition characterized in that 0.5 to 500 times by weight of starch is mixed with N-substituted-chloroacetanilide represented by the following formula.