JPS58208273A - Benzylsulfinylpyridine-n-oxide derivative, its preparation, and herbicide comprising it as active ingredient - Google Patents

Abstract

NEW MATERIAL:A benzylsulfinylpyridine-N-oxide derivative shown by the formula I (X is Cr or Br). EXAMPLE:5-Chloro-2-(2,6-dichlorobenzylsulfinyl)pyridine-N-oxide. USE:Useful as a herbicide. Having herbicidal effect on various kinds of weeds in paddy fields, such as Echinochloa oryzicola Vasing, false pimpernel, toothcup, etc., having no phytotoxicity to rice plants. Showing herbicidal activity against plowed fields by soil incorporation before germination, and used effectively in paddy fields, plowed fields, orchards, lawns, etc. PROCESS:A benzylthiopyridine-N-oxide derivative shown by the formula II is oxidized to give a compound shown by the formula I . Hydrogen peroxide, metachloropercarboxylic acid, etc. are used as the oxidizing agent, and its amount used is usually 0.5-1.5 equivalent, preferably 0.95-1.2 equivalent based on the benzylthiopyridine-N-oxide derivative.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a benzyl sulfinyl pyridine-N-oxide derivative represented by the general formula (1), a method for producing the same, and a herbicide containing the same as an active ingredient. Species of pyridine-N-oxide derivatives, such as 2-(,2,4-dichlorobenzylsulfinyl)pyridine-N-oxide,! -Promo, 2-(J, A-dikuG3E)benzylsulfonyl)pyridine-N-oxide, etc. are useful as active ingredients of herbicides, as disclosed in US Patent No. 9.3.
However, it cannot be said that these compounds are always sufficient as herbicides. , for example, Japanese cabbage, azalea, japonica, pine cabbage, firefly,
It has a herbicidal effect on rice plants, etc., and does not cause any harmful effects on rice. The compound of the present invention also has herbicidal activity in fields by pre-emergence soil mixing treatment. Therefore, the compound of the present invention can be used in paddy fields, fields, orchards, lawns, etc.
It can be used as a herbicide in pastures, forests, non-agricultural lands, etc.

The compound of the present invention can be prepared by treating a benzylthiopyridine-N-oxide derivative represented by the general formula (wherein, X is as defined above) with an oxidizing agent such as hydrogen peroxide, sodium metaperiodate, etc. K can be oxidized with inorganic peracids, aliphatic peracids such as peracetic acid, aromatic peracids such as metachloroperbenzoic acid, etc.
It can be easily manufactured. Solvents do not necessarily have to be layered, but depending on the type of oxidizing agent used, for example, water, glacial acetic acid, acetone, etc. are used for hydrogen peroxide, and chloroform, methylene chloride, etc. are used for aromatic peracids. ethers such as halogenated hydrocarbons, diethyl ether, dioxane, etc. are preferred, and when aliphatic peracids are used, it is preferred to use an excess of the oxidizing agent itself. The oxidizing agent is usually used in an amount of 3 equivalents, preferably 2 equivalents, preferably 2 equivalents, based on the benzylthiopyridine-N-oxide derivative. The reaction temperature is from the freezing point to the boiling point of the solvent, preferably from 0°C to the boiling point of the solvent, and the reaction time is 30°C.
The time range is from about 70 minutes to about 7θ hours. The reaction aid is treated in a conventional manner and, if necessary, purified by recrystallization or column chromatography.

The benzylthiopyridine-N-oxide derivative represented by the general formula [■] can be used, for example, in Mieroppa Patent No. 3463.
The compound of the present invention can be obtained by the method described in Specification No. 1. Next, production examples of the compound of the present invention will be shown. Thio)
Pyridine-N-oxide3. ．． 2y in chloroform SO
-Metachloroperbenzoic acid (content 70%), 2
．． A solution of sy dissolved in 30ml of chloroform is added to
Dropwise at 0°C for 76 minutes, and further
After stirring for two hours at
j-chloro-λ-(ko.

O-dichlorobenzylsulfinyl) pyridine-N-oxide (compound (1) of the present invention) j,,2F was obtained ◇Yield 5%, melting point /76 J~/77,,,f''Ct proton NMR spectrum ( In deuterated chloroform, 0) 5.2 (multiplet, /H), 7.6-7..2 (multiplet, 6H) 1.!r, / (quartet) expressed as δ value based on tetramethyllerane , -H) Production Example - Production of Compound (2) of the Present Invention! -Promoco-(-,≦-dicaobenzylthio)pyridine-N-oxide-13y was dissolved in 30d of chloroform', and metachloroperbenzoic acid (content 70%) was dissolved in 30d of chloroform. )/, A
A solution of P dissolved in chloroform 3θd was added dropwise over 76 minutes at 3 to 70°C, and then stirred for 2 hours at 1 to 70°C. was distilled off, and the residue was recrystallized from benzene to give j-bromo-,2-(,2,A-dichlorobenzylsulfinyl)pyridine-N-oxido (compound of the present invention (P2')), 2.01. 90 yield g
3%, melting point /r7, S~/KI J''C Proton NMR spectrum (in deuterochloroform, expressed as a value with reference to tetramethylsilane) iJ (multibullet, /H).

7.6 to 7.7 (multiplet, sH), s, θ (quartet, -H) When the compound of the present invention is used as an active ingredient of a herbicide, 1
It is usually mixed with a carrier, a liquid carrier, a surfactant, and other formulation auxiliaries to formulate an emulsion, a wettable powder, a suspension, a granule, a powder, etc. - The present invention as an active ingredient in a preparation The content of the compound is 7 to 9θ, preferably 1 to 10.Solid carriers include, for example, kaolin, bentonite, talc, diatomaceous earth, gicrite, and synthetic hydrous silicon oxide. Examples of liquid carriers include aromatic hydrocarbons such as kyrelene and methylnaphthalene, ketones such as leclohexanone and isophorone, halogenated hydrocarbons such as chlorobenzene and dichloroethane, dimethylformamide,
Cellosolve, ethylene keglycol.

There is water power. Surfactants used for emulsification, dispersion, and spreading include polyoxyethylene alkyl ether, polyoxyethylene alkylaryl ether, polyoxyethylene styryl 7-ryl ether, polyoxyethylene fatty acid ester, and polyoxyethylene sorbitan. Nonionic surfactants such as fatty acid esters and oxyethylene oxylebrobylene polymers.

Examples include anionic surfactants such as alkyl sulfates, alkyl sulfonates, dialkyl sulfonosuccinates, and furkylaryl sulfonates.

As formulation aids, lignin sulfonate, alginic acid, W, polyvinyl alcohol, cellulose, PEP
(J) isopropyl phosphate), B) IT (j, A-di-t-butyl-methylpheno(7)yl), and the like.

Examples of formulations are shown below.

Formulation Example / 10% Irrigation Agent 0 parts of the present compound (to), 5 parts of polyoxyethylene furkylaryl ether, and synthetic hydrated silicon oxide/S part are thoroughly ground and mixed to obtain an irrigation agent. Formulation Example -/θ Emulsion 3 parts of the compound of the present invention (/), 5 parts of polyoxyethylene alkyl 7-aryl ether/θ part, 5 parts of alkylaryl sulfonate and 2 parts of isophorone are thoroughly mixed to obtain an emulsion.

Formulation Example 37 Granules Compound of the Invention (1)/Part 1 7 parts of synthetic hydrous silicon oxide, 5 parts of sodium ligninsulfonate and 93 parts of kaolin were thoroughly ground and mixed, water was added and the mixture was thoroughly kneaded. Granules are obtained by drying @ Formulation Example 41 J% powder 3 parts of the present compound C2), 0.5 part of 11 isopro(8) cynic acid pill, 66.5 parts of kaolin and 3θ parts of talc are thoroughly ground. Mix to obtain a powder.

Formulation Example 6.20 Suspension Agent 430 parts of the compound of the present invention (430 parts) was mixed with 40 parts of an aqueous solution containing 3 parts by weight of polyethylene sorbitan monooleate, and wet-pulverized until the particle size of the active ingredient became 3 μm or less. Then, a suspension is obtained by mixing 0 part of an aqueous solution containing 3% by weight of sodium alginate as a dispersion stabilizer.Emulsions, water preparations, suspensions, etc. prepared in this way are 1
Usually, the compound of the present invention can be applied as a single granule after diluting with water, or as a powder, sprayed on foliage, or mixed into the soil, or mixed with other herbicides or mixed with other herbicides to enhance its effectiveness as a herbicide. In addition, insecticides can be applied simultaneously, and in some cases a synergistic effect may be expected.
It can also be used in combination with acaricides, nematicides, fungicides, plant growth regulators, fertilizers, ring-locking improvers, and the like.

When the compound of the present invention is used for either foliage treatment or soil treatment, the amount of application can be varied within a wide range, but the amount of active ingredient usually ranges from 77-1/P-100, preferably -y~/θθ Riadashi, application concentration is emulsion, irrigation agent,
The water diluent of the suspension is 0.02% to 2%. The amount and concentration of these applications can be increased or decreased depending on the type of preparation, place of application, time of method, crop, type of H. grass, degree of stagnation, weather conditions, etc. without being affected by the above range.

Next, test examples will be shown to show that the compound of the present invention is useful as an active ingredient in herbicides.The herbicidal efficacy against chemical damage to crops and fine leather is determined by calculating the fresh weight of the stems and leaves of plants that remain withered at the time of investigation. Calculate the ratio (a) with that of the non-treated area, evaluate each from θ to j according to the classification in Table 1, and indicate the numerical value. The compound number in the example and the compound used for comparison are indicated by the compound symbol in Table ◇ Test Example / Paddy field pre-emergence soil treatment test A plastic pot with inner diameter gem and height / θα was filled with paddy soil, After sowing the seeds of broad-leaved weeds (Azena, Kikashigusa) and firefly, and covering with soil, the water depth was 3 cm.
Pour water until it reaches tn. Place it in a greenhouse for 7 days, and then add the prescribed amount of the emulsion prepared according to Formulation Example 2! The herbicidal efficacy was investigated by diluting the solution in water and dropping it onto the water surface and keeping it in a greenhouse for another 10 days. The results are shown in Table 3.

5. / Pavilion 3 Table (/4t) Test example - Paddy stem and leaf and soil treatment test '4θθθR Wagner pot filled with paddy soil,
Japanese millet in the soil surface layer Jcrn.

Seeds of firefly, broad-leaved weeds (Azeena, Kikashigusa), and overwintering buds of Pinus japonica were mixed.

Furthermore, after adding water until the flooding method becomes da cmK,
Transplanted rice and weed tubers at the leaf stage were grown in a greenhouse for 3 days, and when these weeds germinated, a prescribed amount of the emulsion prepared according to Formulation Example 2 was diluted in /θd water and poured onto the water surface. dripped. Furthermore, after -0 days, we investigated herbicidal efficacy and phytotoxicity to rice. The results are shown in Table y. Fill a cylindrical plastic pot with field soil, and add seeds of millet, oat, mulva morning glory, and yelp and Oyperum 5saulent.
US ) tubers were sown, a fixed amount was diluted with water, and a small sprayer was used to spread the soil surface at a rate of 7 are/θ to a depth of 41 cm'! After thoroughly mixing the surface layer of the soil and growing it in a greenhouse for another 10 days, the herbicidal efficacy was investigated.The results are shown in Table 5.Q Table J (7g completed) Procedural amendment (voluntary) January 20, 1980 1 Indication of the case 1988 Patent Application No. 91929 2 Name of the invention Benzylsulfinylpyridine-N-oxide derivative,
The manufacturing method and the herbicide 3 containing the herbicide as an active ingredient, and its relationship with the case of the person making the amendment Column 6 of the detailed explanation of the invention in the patent applicant's specification, Self-answer of the amendment (Chapter 11 from the bottom of Part 8 of the Specification) In the second line, "lPI'IP (isopropyl phosphate)" is corrected to "rPAFl (isopropyl acid phosphate)".

(2) In the second line from the bottom of page 12, the words "Examples" are corrected to read "Manufacturing Examples."

Hereafter,

Claims (1)

[Scope of Claims] A benzylsulfinylpyridine-N-oxide derivative represented by the following. [In the formula, X represents a chlorine atom or a bromine atom. ] A general method for oxidizing a benzylthiopyridine-N-oxide derivative represented by the formula [wherein, X is as defined above]. ] A method for producing a benzylsulfinylpyridine-N-oxide derivative represented by the following. A herbicide characterized by containing as an active ingredient a benzylsulfinylpyridine-N-oxide derivative represented by [wherein X is replaced by 0 representing a chlorine atom or a bromine atom]