JPS5995271A - Pyridine-n-oxide derivative, preparation thereof and herbicide containing the same as active constituent - Google Patents

Abstract

NEW MATERIAL:A compound of formula I (X is Cl or Br; Y is sulfinyl or sulfonyl). EXAMPLE:5-Chloro-2-(2-chloro-6-fluorobenzylsulfinyl)pyridine-N-oxide. USE:A herbicide. PROCESS:A benzylthiopyridine-N-oxide of formula II is oxidized with an oxidizing agent, e.g. hydrogen peroxide, sodium metaperiodate, peracetic acid or metachloroperbenzoic acid, to give the aimed compound of formula I .

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is based on the general formula [where X represents a chlorine atom or a bromine atom and Y represents a sulfinyl group or a sulfonyl group]. ] The present invention relates to a pyridine-N-oxide derivative represented by the following, a method for producing the same, and a herbicide containing the same as an active ingredient.

Certain yuzu pyridine-N-oxide derivatives, such as 2-
(2,6-cyclopenzylsulfinyl)pyridine-
U.S. Patent No. 40 discloses that N-oxide, 5-bromo-2-(2,6-cyclobenzylsulfonyl)pyridine N-oxide, etc. are useful as active ingredients of herbicides.
19898 Specification and European Patent No. 8668
It is described in Specification No. 8. However, these compounds are not necessarily or always sufficient as herbicides.

The compound of the present invention can be applied to various weeds in paddy fields, such as
Quinubie, azalea, and Kikashigusa have sex.

The compounds of the present invention can be used as herbicides in paddy fields, fields, orchards, lawns, pastures, forests, non-agricultural lands, and the like.

The compound of the present invention has the general formula [wherein, X represents the same meaning as described above]. ] The pencylthiopyridine-N-oxide derivative represented by It can be produced by oxidation with a group peracid or the like. Is it necessary or not necessary to use a solvent?
When used, it depends on the type of oxidizing agent. For example, hydrogen peroxide can be used with water, glacial acetic acid, acetone, etc., and aromatic peracids can be used with chloroform, halogenated hydrocarbons such as methylene chloride, or ethers such as diethyl ether, dioxane, etc. preferable. In the case of aliphatic peracids, it is preferable to use the oxidizing agent itself in excess.

or 0.95 to 1.2 equivalents in the case of a compound in which Y is a sulfinyl group in general formula [I], and 1.95 in the case of a compound in which Y is a sulfonyl group in general formula III.
~2.4 equivalents are used.

The reaction temperature is from the freezing point to the boiling point of the solvent, preferably from ()°C to the boiling point of the solvent, and the reaction time is about 30 minutes to 10 hours.

After the reaction is completed, post-treatment is carried out according to a conventional method. If necessary, purify by recrystallization or column chromatography.

Benzylthiopyridine-N-oxide derivatives represented by the general formula
It can be obtained according to the method described in the specification.

Next, production examples of the compounds of the present invention will be shown.

Production Example 1 Production of Compound (1) of the Present Invention 2.0 y of 5-chloro-2-(2-chloro-6-fluorobenzylthio)pyridine-N-oxide was dissolved in 50 d of chloroform, and metachloroperbenzoic acid (containing 70 %)
A solution of 1.6y dissolved in 29 me of chloroform is
Drop for 10 minutes at ~1°C, then add 5~1°C.
After stirring at C for 2 hours, the mixture was washed twice with an aqueous potassium carbonate solution, dried over magnesium sulfate, chloroform was distilled off, and the residue was recrystallized from benzene-hexane (1:1).
5-chloro-2-(2-chloro-6-fluoropencilsulfinyl)pyridine-N-oxide (present compound t+) 2. I got Oy. Yield 95%, melting point 17
5.5-176.5'c Pro1-one NMR spectrum (delta value in deuterated chloroform, based on tetramethylsilane) Production Example 2 Production of Compound (4) of the Present Invention 5-furomo-2-(2-chloro-6 -fluoropencylthio)pyridine-N-oxide 2,1y was dissolved in 150 me of chloroborum,
70%) 8.8y was added over 5 minutes at 5 to 10°C, and after further stirring at room temperature for 8 hours, the mixture was washed twice with an aqueous potassium carbonate solution, dried over magnesium sulfate, and the chloroform was distilled off. The residue was recrystallized from benzene,
-bromo-2-(2-chloro-6=fluorobenzylsulfonyl)pyridine-N-oxide (compound of the present invention +4
1) 2.2 y was obtained. Yield 95%, melting point 195~
196°C proton NMR spectrum (shown as δ value in deuterated chloroform, based on tetramethylsilane)
8.4 (m, L H), 7.8-6.9 (
m, 5H), 5.8 (d, 2H) The compound of the present invention that can be produced by such a production method,
Shown in Table 1.

Table 1 When using the compound of the present invention with the general formula as an active ingredient of a herbicide,
It is usually mixed with solid carriers, liquid carriers, surfactants, and other formulation auxiliaries to formulate emulsions, wettable powders, suspensions, granules, powders, etc. The content of the compound of the present invention as an active ingredient in the formulation is 1 to 90%, preferably 2 to 8.0%.

Examples of solid carriers include kaolin, hentonite,
Examples of liquid carriers include aromatic hydrocarbons such as xylene and methylnaphthalene, ketones such as cyclohexanone and isopolone, and halogenated carbons such as chlorobenzene and dichloroethane. Hydrogens, dimethylformamide, cellosolve, Nkericol manufactured by Echire, water, etc. Surfactants used for emulsification, dispersion, and spreading include polyoxyethylene alkyl ether, polyoxyethylene alkylaryl ether, polyoxyethylene styryl aryl ether, polyoxyethylene fatty acid ester, and HoIJ. Nonionic surfactants such as oxyethylene sorbicun fatty acid esters and oxyethylene oxypropylene polymers, anionic surfactants such as alkyl sulfate ester salts, alkyl sulfonates, dialkyl sulfosuccinates, alkylaryl sulfonates, etc. be.

As formulation aids, lignin sulfonate, alkinate, polyhinyl alcohol, cellulose, PA,
P (isopropyl acid phosphate), HHT (2,6-
di-t-butyl-4-methylphenol).

Next, a formulation example will be shown.
Thoroughly grind and mix the two parts to obtain a wettable powder.

Formulation Example 2 The compound of the present invention (+) 8*, 10 parts of polyoxyethylene alkylaryl ether, 5 parts of alkylaryl sulfonate and 82 parts of 0.isopolone are thoroughly mixed to obtain an emulsion.

Formulation Example 8 1 part of the compound of the present invention (1), 1 part of synthetic hydrous silicon oxide, 5 parts of sodium ligninsulfonate, and 93 parts of kaolin were thoroughly ground and mixed, water was added, the mixture was sieved, and then granulated. Dry to obtain a powder.

Formulation Example 4 Compound of the present invention (213 parts, inpropyl acid phosphate 0.
5 g, 66.5 parts of kaolin, and 80 parts of talc were thoroughly ground and mixed to obtain a powder.

Formulation Example 5 The compound of the present invention (1120 parts) was mixed with 60 parts of an aqueous solution containing 3% by weight of polyoxyethylene sorbitan monooleate, wet-pulverized until the particle size of the active ingredient became 3μ or less, and a dispersion stabilizer was added to the mixture. Sodium alginate as 3
A suspension is obtained by mixing 20 parts of an aqueous solution containing % by weight.

It can be applied as is, sprayed on foliage, or mixed into the soil. In addition, the compound of the present invention has the ability to enhance its efficacy as a herbicide.
It can be applied simultaneously with or without mixing with other herbicides, and in some cases a synergistic effect can be expected. Furthermore, it can be used in combination with insecticides, acaricides, nematicides, fungicides, plant growth regulators, fertilizers, soil conditioners, and the like.

When using the compound of the present invention for either foliage treatment or soil treatment, the application amount can be varied over a fairly wide range, but usually the amount of active ingredient is 0.1 y or 0.2 y/are.
-1002, and the application concentration is 0.02-2% for water diluents of emulsions, wettable powders, and suspensions. These application amounts and concentrations can be increased or decreased depending on the type of preparation, application location, method, timing, crop, type of weed, degree of weed damage, weather conditions, etc. without deviating from the above range.

Next, a trial example will be shown to demonstrate that the compound of the present invention is useful as an active ingredient of a herbicide. To determine chemical damage to crops and herbicidal efficacy against weeds, the fresh weight of the stems and leaves of the plants that remained withered during the survey was measured, and the ratio (%) to that of the untreated area was determined.
They were evaluated from 0 to 5 according to Section 5 in Table 2 and shown as numerical values.

Table 2 Regarding the test compounds, the compounds of the present invention are shown by the compound numbers in Table 1, and the compounds used for comparison are shown by the compound symbols in Table 3.

Table 8 Test Example 1 Soil Treatment Test before Germination in Paddy Fields In a plastic pot with an inner diameter of 8 cm and a height of 10 cm, seeds of paddy field top 13 were sown on 8-1 scales, and seeds of quince, broad-leaved weeds (Azaena, Kikashigusa), and Hokurui were sown and covered with soil. Ice was then poured until the water depth was 3 ax. Place the emulsion in a greenhouse for 1 day, and add 50% of the prepared emulsion according to Formulation Example 2I.
The diluted solution was diluted with 7 liters of water and added dropwise to 1 liter of water. The mixture was kept in a greenhouse for an additional 20 days, and its potency was examined. The results are shown in Table 4.

Table 4 Test Example 2 Paddy foliage and soil treatment test plant, firefly, seeds of broad-leaved weeds (Azaena, Kikashi I''su), and overwintering buds of Pinus cabbage were mixed. Furthermore, water was added until the water depth reached 4 sides, and then the three-leaf stage rice and Urikawa tubers were transplanted. The weeds were grown in a greenhouse for 5 days, and when the weeds germinated, a predetermined amount of the emulsion prepared according to Formulation Example 2 was diluted with 1 Q me of water and dropped onto the water surface.

Furthermore, after 20 days, the herbicidal efficacy and chemical damage to rice were investigated. The results are shown in Table 5.

Table 5 Trial parking example 3 Field field pre-germination soil mixing trial trial
Fill a cylindrical plastic pot with a height lOσ with field soil, and embed it with millet.

Then, sow the tubers of Malva Asakao, Iff f- glaze and Cypcrust esculent (S), and after coloring the soil, dilute a prescribed amount of the emulsion formulated according to Formulation Example 2 with ice, After spraying on the soil surface with a small sprayer at a rate of 10/spread per area, the depth is 4c! The soil surface layer up to rR was thoroughly mixed. After growing in a greenhouse for an additional 20 days, the herbicidal efficacy was investigated. The results are shown in Table 6.

Table 6 Test U) Example 4 Upland soil treatment test (133 x 28 cy 1. Upland seeds were seeded in an 11 cm vat and poured to a thickness of 1 to 2 cm. A predetermined amount of emulsion prepared according to Formulation Example 2) was diluted with water (7.5 liters per are) and sprayed on the soil surface using a small sprayer. After spraying, it was grown in a greenhouse for 20 days, and the herbicidal efficacy was examined. Shown in the table.

Table 7 Test Example 5 Upland Soil Treatment Test Upland soil was packed into a hunt with an area of 33 x 28 m and a depth of 11 cm, and barley, grass wheat, oat, black grass, and sycamore were sown and covered with soil to a thickness of 1 to 2 cTn. A predetermined amount of the emulsion prepared according to Formulation Example 2 was diluted with water and sprayed onto the soil surface using a small sprayer at a rate of 5 liters per ar. After spraying, growth and herbicidal efficacy were investigated in a greenhouse for 27 days. The results are shown in Table 7.

Table 8 Procedural Amendment 1. i' (spontaneous) 6゜March 31, 1939, special, t'1゛Chief of the Agency,! 11 Kazuo Sugi,
Display of the case 1981 Interpatent No. 206310 2, Title of the invention: Pyridine-N-oxide derivatives, their production method, and herbicides containing them as active ingredients, 3. Concave line between the person making the amendment and tenancy Patent applicant Address: 5-15'8 Kitahama, Higashi-ku, Osaka City
(209) Sumitomo Chemical Co., Ltd. Representative Sat
Takeshi 4, Agent/J: Address: Sumitomo Chemical Industry Co., Ltd., 5-15 Kitahama, IL-ku, Osaka 11, -2 Name: Patent attorney (8597) Mitsuteru Moroishi, ``''] Correction of the invention in the specification : 1lil explanation 1 ■ Contents of amendment fl + Specification Store Page 20 Table 6 Test compound section “(
t)) "Toal (IJ') woll (hl -17!
: its' f 1, 2) In the section of test compounds in Table 7 on page 21, replace ]-(I)lJ with r (hl-1
3) "Table 7" on page 22, line 10.
``Corrected to ``Table 8, Table 1.''

4) In the column of test compounds in Table 8 on page 22 [(bi J is corrected to f-(h)J).

”− -54:-

Claims (2)

[Claims] (1) A pyridine-N-oxide derivative represented by the general formula [wherein, X represents a chlorine atom or a bromine atom, and Y represents a sulfinyl group or a sulfonyl group]. (2) General formula [wherein, X represents a chlorine atom or a bromine atom]. [In the formula, Y represents a sulfinyl group or a sulfonyl group, and
has the same meaning as above. ] A method for producing a pyridine-N-oxide derivative represented by the following. 3) General formula [wherein, X represents a chlorine atom or a bromine atom, and Y represents a sulfinyl group or a sulfonyl group]. ] A herbicide characterized by containing a pyridine-N-oxide derivative represented by the following as an active ingredient.