KR810001999B1 - Process for the preparation of new n.n-disubstituted benzene sulfonamide derivatives - Google Patents

Abstract

Title compd.[I; Ro = cyano or lower alkoxy substituted alkyl, lower alkenyl, lower alkynyl; R1,R2,R3 = H, halogen, lower alkynyl, lower alkoxy; R4,R5,R6,R7,R8 = H, halogen, lower alkynyl, lower alkoxy; Y = >C=O, Ia(R9,R10 = H, lower alkyl); X4 = halogen; M = H, alkaline metals , useful as herbicide, were prepd. by reaction of compd.(II) and (III). Thus, the mixt. of N-(α,α-dimethylbenzyl)benzene sulfonamide 27.5 g, N,N-dimethylformamide anhydride 200 ml and 50 % sodium hydride 5.8 g was stirred for 30 min and then methyl bromide 16.1 g was added. The intermediate was stirred at 60≰C for 1 hr, filtered and then recrystallized with methanol to give N-methyl-N-(α,α-dimethylbenzyl)benzene sulfonamide.

Description

Method for preparing new N, N-disubstituted benzenesulfonamide derivatives

The present invention relates to a process for the preparation of novel benzenesulfonamide derivatives, more particularly novel N, N-disubstituted benzenesolfonamide derivatives.

Many benzene sulfonamide derivatives are known. For example, Swiss Federal Patent No. 224,856 describes that N-methyl-N-benzoyl-3,4-dichlorobenzenesulfonamide is useful as a pesticide. Japanese Patent Publication No. 74-7216 proposes the use of N-methyl-N-benzoyl-3,5-dibromo-6-acetobenzoylbenzene sulfonamide as a herbicide.

In addition, Zh, org. chim., 7, 363 (1971), reported N-halogenated ethyl-N-substituted benzoyl-4-methyl-4-methylbenzenesulfonamide as a known compound, Ukrain. Khim. Zhur., 26, 496 (1960), reports that N-isopropyl-N-benzoyl-p-chlorobenzene amide is known.

According to the present invention some of the novel N, N-disubstituted benzenesulfonamide derivatives are useful as herbicides and have no blood (especially Echinochlocus galli buube) without adversely affecting rice crops. -galli Beauv.) has been found to have an excellent selective herbicidal action. This is surprising in view of the fact that the most harmful weeds in the rice fields are poop grass weeds, and it has been thought that it is impossible to selectively remove blood without damaging the rice.

An object of the present invention is to provide a method for preparing a novel N, N-disubstituted benzenesulfonamide derivative having excellent selective herbicidal action.

Other objects and effects of the present invention will become apparent from the following description.

According to the present invention, a compound of the structure

Where

R ₀ represents an alkyl group, a lower alkenyl group and a lower alkynyl group which may have a substituent selected from the group consisting of a cyno group, a lower alkoxy group and a di- (lower alkyl) amino group,

R ₁ , R ₂ and R ₃ each represent a hydrogen atom, a halogen atom, a lower alkyl group or a lower alkoxy group, and R ₄ , R ₅ , R ₆ , R ₇ and R ₈ each represent a hydrogen atom, a halogen atom, a lower alkyl group or a lower group An alkoxy group,

의 기 또는 구조식

(여기서, R₉및 R₁₀중 하나는 저급알킬기이고 나머지는 수소원자 또는 저급알킬기임)를 나타내는데, Y가

기이고, R₁₀는 미치환 알킬기일 때 R₄, R₅, R₆, R₇및 R₈은 동시에 수소원자를 나타내지 않는다.Y is structural formula

Group or structural formula

Wherein one of R ₉ and R ₁₀ is a lower alkyl group and the other is a hydrogen atom or a lower alkyl group, wherein Y is

R ₄ , R ₅ , R ₆ , R ₇ and R ₈ do not represent a hydrogen atom at the same time when R ₁₀ is an unsubstituted alkyl group.

In this specification and in the claims, the term “lower grade” means that a group or group of atoms modified by this term contains up to six carbon atoms, preferably one to four carbon atoms.

In the present specification and claims, the term “alkyl group” refers to a saturated or aliphatic saturated aliphatic hydrocarbon group, and usually contains 20, preferably 15, more preferably up to 12 carbon atoms. Examples of alkyl groups include methyl, ethyl, n- or iso-propyl, n-butyl, sec-butyl or tert-butyl, n-pentyl or neo-pentyl, n-hexyl, n-heptyl, n-optyl, n-nonyl , n-undecyl and n-dodecyl. When R ₀ represents an alkyl group in formula (I), the alkyl group may contain a substituent. The substituent is selected from lower alkoxy groups such as cyano groups (CN), methoxy or ethoxy groups and di (lower alkyl) amino groups such as dimethyl amino or diethylamino groups. When any of R1 to R8 represents a lower alkyl group, methyl or ethyl group is preferable.

The term "lower alkenyl group" refers to a lower aliphatic hydrocarbon group containing one carbon-carbon double bond, which may be straight or branched. Examples are vinyl, allyl and butenyl groups, with the allyl group being most preferred.

The term "lower alkynyl group" is a lower aliphatic hydrocarbon group with one carbon-carbon triple bond. Representative examples of lower alkynyl groups include propargyl groups.

The term "lower alkoxy group" is a lower alkylether group, examples of which are methoxy, ethoxy, n-propoxy or iso-propoxy, n-butoxy, iso-butoxy, sec-butoxy or tert- Butoxy. Of course, a methoxy group and an ethoxy group are good among these.

The term “halogen atom” means fluorine, chlorine, cancelled and oxo atoms, most preferably chlorine atoms, followed by fluorine atoms.

Therefore, the preferred substituent R ₀ is an alkyl group having less than 15 carbon atoms, a lower alkenyl group or a propargyl group which may have a substituent selected from the group consisting of a cyano group, a lower alkoxy group and a di- (lower alkyl) amino group.

Among them, lower alkenyl, allyl, and propargyl groups are particularly preferred. Preferred types of R ₁ , R ₂ and R ₃ include a hydrogen atom, a halogen atom, a methyl group, an ethyl group, a methoxytoxy group and an ethoxy group. At least one of R ₁ , R ₂ and R ₃ is a hydrogen atom, moreover among these groups It is preferable that at least one is located at the fourth position of the benzene ring to which they are bonded.

)일때, R₄내지 R₈기는 모두 동시에 수소 원자인 것이 가장 유리하다.Preferred atoms or groups represented by R ₄ , R ₅ , R ₆ , R ₇ and R ₈ are hydrogen atoms, halogen atoms, methyl groups, ethyl groups, metho groups and ethoxy groups, with hydrogen atoms or halogen atoms being particularly preferred. When R ₄ to R ₈ represent the aforementioned groups other than at least one hydrogen, one or two of them are preferably located at the second position and / or the fourth position of the benzene ring. Y is a carbonyl group (

, R ₄ to R ₈ groups are all advantageously hydrogen atoms at the same time.

Among the compounds of the structural formula (I), preferred compound groups are those represented by the following structural formulas.

Where

R ₁ is an alkyl group, lower alkenyl group or propargyl group which may have a substituent selected from the group consisting of a cyno group, a lower alkoxy group and a di- (lower alkyl) amino group,

R ₁ and R ₁₁ are each a hydrogen atom, a halogen atom, a methyl group or a methoxy group,

기(여기서, R₉₁및 R₁₀₁중의 하나는 메틸 또는 에틸기이고 다른 하나는 메틸 또는 에틸기이고 다른 하나는 수소원자 또는 메틸 또는 에틸기임)인데, Y₁이 CO기이고, R₁이 미치환 알킬기인 경우에는, R₄₁, R₅₁, R₆₁, R₇₁및 R₈₁은 동시에 수소원자를 나타내지 않는다.Y ₁ is

Wherein one of R ₉₁ and R ₁₀₁ is a methyl or ethyl group, the other is a methyl or ethyl group and the other is a hydrogen atom or a methyl or ethyl group, wherein Y ₁ is a CO group and R ₁ is an unsubstituted alkyl group In the case, R ₄₁ , R ₅₁ , R ₆₁ , R ₇₁ and R ₈₁ do not represent a hydrogen atom at the same time.

기를 나타내는 것들이다. Y₁으로서

기와 R₁으로서 알릴기 또는 프로파르길기의 조합과 Y₁으로서

기와, R₁으로서 알릴기와의 조합이 특히 유익하다.Most preferred group of compounds of formula (Ia) are those in which R ₀₁ is an allyl group or a propargyl group, and Y ₁ is

These are the ones that represent the flag. As Y ₁

Combination of an allyl group or propargyl group as a group with R ₁ and Y ₁ as

The combination of a group and an allyl group as R <_1> is especially advantageous.

기, R₁₄는 할로겐원자, 그리고, R₅₁, R₆₁, R₇₁및 R₈₁중 어느 하나, 특히 R₆₁은 수소 또는 할로겐 원자이고, 나머지가 수소원자인 화합물들이다. 이 경우, R₁₁및 R₁₂가 각각 수소원자 또는 메틸기, 특히 수소 원자인 것이 좋다.Thus, particularly preferred among compounds of formula (la) are those in which R ₁ is an allyl or propargyl group and Y is

The group R ₁₄ is a halogen atom and any one of R ₅₁ , R ₆₁ , R ₇₁ and R ₈₁ , in particular R _61, is hydrogen or a halogen atom and the others are hydrogen atoms. In this case, R ₁₁ and R ₁₂ are each preferably a hydrogen atom or a methyl group, in particular a hydrogen atom.

기이고, R₁₁이 수소원자, 할로겐원자 또는 메틸 또는 메톡시기, R₂₁이 수소원자, R₄₁및 R₆₁이 각각 수소원자, 할로겐원자 또는 메틸기이고, R₅₁, R₇₁및 R₈₁이 모두 수소원자인 화합물들이다.In particular, another example of a compound of formula (Ia) wherein R ₁ is an allyl group, Y ₁ is

R ₁₁ is a hydrogen atom, a halogen atom or a methyl or methoxy group, R ₂₁ is a hydrogen atom, R ₄₁ and R ₆₁ are each a hydrogen atom, a halogen atom or a methyl group, and R ₅₁ , R ₇₁ and R ₈₁ are all hydrogen Compounds that are atoms.

As explained below, the compounds of formula (I) prepared by the process of the present invention have good selective herbicidal action. In view of herbicidal action, the most preferred of the compounds of formula (I) are the compounds of the following formula.

Where

R ₂ is allyl or propargyl and X ₁ is hydrogen or chlorine atom. Moreover, it is a compound of the following structural formula.

Where

이고,Y ₂ is

ego,

X2 is a hydrogen atom or a chlorine atom.

Representative examples of the compounds of the formula (I) prepared by the present invention are as follows except for those described in the following Examples.

N-allyl-N- (4-chlorobenzoyl) benzenesulfonamide,

N-allyl-N- (3,4-dichlorobenzoyl) benzenesulfonamide,

N-allyl-N- (2,5-dichlorobenzoyl) benzenesulfonamide,

N-allyl-N- (3,5-dichlorobenzoyl) benzenesulfonamide,

N-allyl-N- (pentachlorobenzoyl) benzenesulfonamide, and

N-allyl-benzoylbenzenesulfonamide.

Specific examples of the most preferred compounds in the present invention are as follows.

N-allyl-N-N- (2-chlorobenzoyl) benzenesulfonamide,

N-allyl-N- (2,4-dichlorobenzoyl) benzenesulfonamide,

N-propargyl-N- (2-chlorobenzoyl) benzenesulfonamide,

N-allyl-N- (α, α-dichlorobenzoyl) benzenesulfonamide,

N-allyl-N- (α-methylbenzyl) benzenesulfonamide,

N-allyl-N- (α-methyl-4-chlorobenzyl) benzenesulfonamide, and

N-allyl-N- (α, α-dimethyl-4-chlorobenzyl) benzenesulfonamide.

The compound of formula (I) according to the present invention,

(a) reacting a benzenesulfonami derivative of the general formula (II) with a compound of the general formula (III)

(b) reacting the benzenesulfonyl halide of general formula (IV) with the compound of general formula (V)

(c) can be prepared by reacting a compound of the general formula (VI) with a compound of the general formula (VII).

In the above various formulas,

M is hydrogen or an alkali metal atom,

R ₀ , R ₁ , R ₂ and R ₃ are as defined above, X ₃ and X ₄ are halogen atoms,

R ₄ , R ₅ , R ₆ , R ₇ , R ₈ and Y are also as defined above.

In the method (a), the reaction of the benzenesulfonamide derivative of formula (II) with the compound of formula (III) can be carried out in the absence of solvent.

In general, however, it is preferable to carry out in an inert solvent. Examples of solvents that can be used include water, ethers such as diethyl ether, dioxane or tetrahydrofuran, aromatic hydrocarbons such as benzene, toluene or xylene, N, N-dimethylformamide, dimethyl sulfoxide and pyridine. have. For some kinds of starting materials, alcohols such as methanol or ethanol, ketones such as acetone or methyl ethyl ketone, or halogenated hydrocarbons such as methylene chloride, chloroform or carbon tetrachloride may also be used as the solvent. These solvents are used individually or in mixture of 2 or more types.

There is no restriction | limiting in reaction temperature, For example, it can change widely with the kind of starting material and the kind of solvent. The reaction temperature is usually in the range of about 0 ° C. to the reflux temperature of the reaction mixture, preferably at room temperature, at the reflux temperature of the reaction mixture. Atmospheric pressure is sufficient but the pressure may be reduced or elevated if necessary. Under these conditions, the reaction can be completed in about 0.5 to 5 hours.

The ratio between the compound of formula (II) and the compound of formula (III) to be reacted is not limited and can be varied widely. The compound of formula (III) is generally used in an amount of 1 mole or more, preferably 1.1 to 2 moles, per 1 mole of the compound of formula (II).

If M is a compound of the hydrogen atom structure II as starting material, the reaction is advantageously carried out in the presence of an acid binder. Examples of acid binders that can be used are basic materials such as alkali metal hydroxides such as sodium or potassium hydroxide and organic bases such as pyridine or triethylamine.

Examples of preferred alkali metal atoms for M in structural formula (II) are lithium, potassium and sodium. Compounds of formula (II) wherein M is an alkali metal are prepared in advance from compounds of formula (II) wherein M is a hydrogen atom and an alkali metal hydride such as sodium hydrogen or potassium hydride, or an alkali metal such as sodium or potassium And the compound of formula (III). Or it may be produced by itself by the presence of an alkali metal in the reaction system.

Therefore, in the reaction between the compound of formula (II) and the compound of formula (III), a mixture of sodium hydroxide or potassium hydroxide and water, a pyridine and an ether or an aromatic hydrocarbon, or an alkali metal hydride and N, N-dimethylform It is advantageous to use a reaction solvent consisting of a mixture of amide or dimethyl sulfoxide.

Each amount of the alkali metal hydroxide, the organic base, the alkali metal hydride and the like may be 1 mole or more and 1.1 mole to 3 moles with respect to 1 mole of the compound of formula (II).

In the compound of the formula (III), the chlorine atom is particularly preferred as the halogen atom represented by X ₃ .

인 구조식(I)의 화합물 제조에도 특히 유익하게 적용할 수 있다.Method (a) is Y

The present invention can also be particularly advantageously applied to the preparation of compounds of phosphorus structural formula (I).

The reaction mixture containing the resulting compound of formula (I) can be recovered according to known methods. For example, water is added to the reaction mixture, and when the final product precipitates as a solid, it can be separated by filtration, centrifugation or homogeneous methods. When the final product is precipitated in the oil state, it can be separated by solvent extraction, decantation, etc. In the case of the solvent extraction method, benzene, ethyl acetate and chloroform can be suitably used as the solvent.

According to the process (b) according to the present invention, the benzenesulfonyl halide of formula (IV) is reacted with the amine of formula (V). This reaction can be carried out in the absence of a solvent, but it is usually preferable to carry out the reaction in an inert solvent. Examples of useful inert solvents include aromatic hydrocarbons such as water, benzene, toluene or xylene, ethers such as diethyl ether, tetrahydrofuran or dioxane, ketones such as acetone or methyl ethyl ketone, methylene chloride, chloroform or carbon tetrachloride and the like. Halogenated hydrocarbons. Of these, water benzene and carbon tetrachloride are particularly preferred.

There is no restriction on the reaction temperature, but may vary widely depending on the kind of starting material and / or solvent used. The reaction temperature is generally advantageously in the range of about 0 ° C. to the reflux temperature of the reaction mixture, preferably from room temperature to about 80 ° C. The reaction pressure is usually at atmospheric pressure, but if necessary, elevated or reduced pressure may be used.

If necessary, the reaction in process (b) may be carried out in the presence of a catalyst. Useful catalysts include, for example, alkali metal hydroxides such as sodium hydroxide and organic bases such as pyridine or triethylamine. The amount of the compound of formula (IV) is advantageously about 1 to 2 moles per 1 mole of the compound of formula (IV).

There is no restriction on the ratio between the compound of formula (IV) and the compound of formula (V) and can vary widely. In general, the compound of formula (IV) is preferably used in an amount of 1 mole or more, preferably 1.1 to 2 moles, per 1 mole of the compound of formula (V).

Under the above reaction conditions, the reaction is usually finished within about 1 hour to 6 hours. The separation of the final product from the reaction mixture and its purification can be carried out in the same manner as described above with respect to process (a).

In process (c) of the present invention, the compound of formula (VI) is treated with an alkylating agent, an alkenylating agent or an alkynylating agent [compound of formula (VI)] so that the R ₀ group is an N-atom of the compound of formula (VI). To be introduced.

Examples of the compound of formula (VII) include substitution of alkyl halides such as methyl bromide, ethyl chloride, methyl iodide, n-butyl iodide, n-decyl bromide, cyanomethyl bromide, methoxypropyl iodide and brominated dimethylaminopropyl. Alkenyl halides, such as an alkyl halide and allyl chloride, and alkynyl halides, such as a propargyl chloride, are mentioned.

The reaction between the compound of formula (VI) and the compound of formula (VII) is generally preferred to proceed in an inert solvent. Examples of useful solvents include ethers such as diethyl ether, tetrahydrofuran or dioxane, aromatic hydrocarbons such as benzene, toluene or xylene, alcohols such as methanol or ethanol, ketones such as acetone or methyl ethyl ketone, and methylene chloride Or halogenated hydrocarbons such as chloroform, N, N-dimethylformamide, dimethylsulfoxide, pyridine and water.

The reaction between the compound of formula (VI) and M of hydrogen and the compound of formula (VII) is a basic catalyst such as alkali metal hydroxides such as sodium hydroxide or potassium hydroxide, organic bases such as pyridine or triethylamine, sodium hydroxide or potassium hydroxide It can advance in presence of alkali metal hydrides, such as these, or alkali metals, such as metal sodium or potassium. The amount of this catalyst can be used in an amount of 1 to 2 moles with respect to 1 mole of the compound of the formula (VI). Compounds in which M is an alkali metal atom in formula (VI) can be prepared by reacting a compound in which M is hydrogen in formula (VI) with an alkali metal hydride or an alkali metal. It may also be originally produced in the reaction system.

There is no restriction | limiting in reaction temperature, For example, it can fluctuate widely according to the kind of starting material or the kind of solvent. Generally the reaction temperature is in the range from about 0 ° C. to the reflux temperature of the reaction mixture, preferably from room temperature to the reflux temperature of the reaction mixture.

The ratio between the compound of formula (VI) and the compound of formula (VII) is unlimited and can vary widely. The compound of formula (VII) is used in an amount of at least 1 mole, usually 1.2 to 3 moles, per 1 mole of the compound of formula (VI).

Under these aforementioned reaction conditions, the reaction can be terminated in about 1 hour to 10 hours. The final product of formula (I) can be obtained in good yield from the final reaction mixture in the same manner as described above.

인 화합물들은 신규의 화합물이며, 예컨대 대응하는 치환 벤질 아민류를 수산화나트륨 등의 촉매 존재중에 대응하는 벤질술포닐 할로겐화물과 반응시킴으로서 제조될 수 있다.Among the compounds of formula (VI) used in process (c) in the present invention, several species, in particular Y,

Phosphorus compounds are novel compounds and can be prepared, for example, by reacting corresponding substituted benzyl amines with the corresponding benzylsulfonyl halides in the presence of a catalyst such as sodium hydroxide.

Processes for the preparation of compounds of formula (I) of the present invention are illustrated in detail in the following examples.

Example 1

Preparation of N-methyl-N- (α, α-dimethylbenzyl) benzenesulfonamide

27.5 g (0.1 mol) of N- (α, α-dimethylbenzyl) benzenesulfonamide was added to a mixture of 200 ml of anhydrous N, N-dimethylformamide and 5.8 g (0.12 mol) of 50% sodium hydride. The mixture was stirred at room temperature for 30 minutes to react. 16.1 g (0.17 mol) of methyl bromide was added to the sodium salt of obtained N-methyl-N-((alpha), (alpha)-dimethylbenzyl) benzenesulfonamide, it heated to 60 degreeC and stirred for 1 hour. N-methyl-N- (α, α-dimethylbenzyl) benzenesulfonamide was obtained by recrystallizing the white solid obtained by depressurizing N, N- dimethylformamide and adding cold water to methanol (yield 87%). This mixture was indicated as compound number 61 in Table 2 by its melting point and elemental analysis.

N- (α, α-dimethylbenzylben) zensulfonamide used as the starting compound in the above process can be prepared by the following method. That is, two kinds of mixtures consisting of 33.8 g (0.25 mol) of α, α-dimethylbenzylamine and 120 ml of a 10% aqueous sodium hydroxide solution are stirred at a temperature below 40 ° C, and 44.1 g of benzenesulfonyl chloride is added dropwise thereto. The mixture was stirred for another 1.5 hours to obtain a white precipitate, which was filtered off and recrystallized from methanol to obtain N-(?,?-Dimethylbenzyl) benzenesulfonamide (melting point: 114 to 115 ° C) (yield 67%).

The same is true except for using α-methylbenzylamine or the corresponding substituted α, α-dimethylbenzylamine instead of the above-mentioned α, α-dimethylbenzylamine, and also using the corresponding substituted benzenesulfonylchloride instead of benzylsulfonyl chloride. The procedure was repeated to obtain starting compounds shown in FIG.

TABLE 1

Compound Nos. 65 to 102 of Table 2 are prepared by the same method as Example 1 using the starting compound Nos. 2 to 15.

Example 2

Preparation of N-alkyl-N- (2-chlorobenzoyl) benzenesulfonamide

3.0 g (0,01 mol) of N-2-chlorobenzoylbenzenesulfonamide prepared from benzenesulfonamide and 2-chlorobenzoyl chloride were added to a mixture of 15 ml of anhydrous tetrahydrofuran and 0.58 g (0.012 mol) of 50% sodium hydrogen. After stirring at room temperature for 30 minutes, 1.48 g (0.012 mol) of allyl bromide was added, and the mixture was reacted for 2 hours under the same conditions. Tetrahydrofuran was distilled off under reduced pressure and cold water was added. The obtained oil layer was extracted with benzene, the benzene layer was separated and concentrated to dryness over anhydrous magnesium sulfate to obtain a white solid, which was recrystallized in methanol to obtain the compound number 27 of the second table in a yield of 35%.

Compound Nos. 16 to 26 and 28 to 63 in Table 2 can be prepared in the same manner as in Example 4.

TABLE 2

The compound of formula (I) according to the present invention has an excellent herbicidal effect and is effective as an active ingredient of herbicide for controlling various weeds in crops. Examples of weeds controlled by the compound of formula (I) according to the present invention include various blood species (e.g., echinochlora cruis-galibeau, echinochlora cruis galiva, orchicola owi, and echinoclaw Acrus-Gali Subspie, Jenuna Bar, Echinata Honda, Spkerus (Eleo Charis Pelusida Prestle), Cedji S.P. (Cyprus Hakonensis Sciart), Umbrella Prent (Sea) Perus Deformis L.), Piper Wort (Erio Cowlon Sibold Tianum Sieve), Water Bort (Elatinine Triandra), Redstem Esp. (Rotali Indaka Jeanne), Reed (Ski) Lupus Juncoides Roxv) Redstem Sp. (Ammaniania Phylogen Roxv), Pulse Pimpernel (Lindernia Pixidaria L.) and Slender Spikerush (Eleo Charis Asicularis Roem). Esalt Barr, Longjitheta Svensson). The structural formula (I) compound according to the present invention, not show a herbicidal effect for the other types of weeds.

Structural formula (I) compounds according to the present invention have a remarkable effect on the control of weeds occurring in soils containing water such as muddy rather than in dry soil.

Thus, the compound of formula (I) is a very harmful weed in various blood species, especially in hydrangea, and has an excellent control effect on blood which is recognized as one of the five weeds in the world. These weeds grow in paddy fields throughout the world, especially in mud soil underwater. Compound (I) had the ability to inhibit blood growth and inhibit growth in mud soil.

Moreover, compound (I) is very characteristic in that it has a good selective herbicidal activity which is not actually phytotoxic to be useful for crops such as rice.

Many herbicides have been proposed for use in the field, and some have been used. However, none of them showed selective herbicidal activity between blood and rice. The conventional method for removing blood from the answer is to process the answer in the rice growing stage (including the transplant stage) to control the blood sprouting.

This is due to the fact that their resistance to herbicides differs between blood and rice depending on their growth stage, or by the principle of chemical absorption in the upper layers of the soil (artificial selectivity), so that their roots are placed under the herbicide treatment layer. It is based on the same method that transplanted rice plants are protected from herbicides and the upper layer of blood is removed.

The blood is a plant and weed like rice, and they are very physiological. Therefore, eliminating blood with herbicide chemicals often causes phytotoxicity to rice, so it is extremely difficult to selectively remove this weed from rice fields. Therefore, eradicating blood from rice fields is considered difficult and there is a strong demand for the emergence of herbicides capable of selectively removing blood.

Compound (III) of the present invention fulfills this need in agriculture. They have good selectivity for blood seeds and seedlings to strongly inhibit sprouting, but do not actually cause plant toxicity in rice. This property makes compound (I) very suitable as a component of herbicides used in rice fields.

The excellent herbicidal activity of the compound (I) of the present invention is that the germination of blood when N-allyl-N- (2-chlorobenzoyl) benzenesulfonamide is used in rice and blood planted rice paddies at a rate of 62.5 g per 10 ars. While completely inhibited, the fact that rice shows normal germination and growth without any phytotoxicity, and even when used with increased compound ratios up to 1000 g per 10 ar, rice shows normal germination and growth without phytotoxicity. This is demonstrated by experimental facts. Therefore, the compound of the present invention does not substantially affect the germination or growth of rice even when it is used at about 20 times the amount necessary to completely inhibit blood.

The high selectivity between blood and rice in the compounds of the invention is presumably attributed to the specific physiological activity of the blood and rice of the compounds of the invention. This excellent selectivity cannot be expected with conventional herbicides that can be used in rice fields.

Compound (I) of the present invention can be used directly as a herbicide. Generally, however, it is formulated into a herbicide composition by mixing with an inert liquid or solid carrier or diluent commonly used in herbicide formulations.

In the present invention, known inert liquid or solid carriers or diluents can be used. Examples of inert solid carriers or diluents include materials such as kaolin, diatomaceous earth, talc, bentonite, silica and silica. Examples of inert liquid carriers or diluents include liquefied gases such as water, xylene, toluene, benzene, N, N-dimethylformamide, dimethylsulfoxide and tetrafluoroethane.

In addition to an inert liquid or solid carrier or diluent, the herbicide composition may, if desired, contain a surface active agent, such as polyoxyethylene monolaurate or polyethylene sorbitol, in an amount usually selected according to the type of herbicide composition.

The herbicide composition may contain the active compound of formula (I) in an amount of at least 0.5% by weight, preferably 1 to 99% by weight, more preferably 2 to 80% by weight, based on the weight of the composition itself. have.

The herbicide composition can be used in any conventional form, such as powder, granules, hydrating agents, solutions, emulsified functional concentrates, depending on the method of use. Any known formulation method may be used for this purpose. For example, when making powders, granules or hydrates, one or more compounds (I) are mixed with one or more inert solid carriers or diluents. The mixture is ground and mixed uniformly with the appropriate amount of surfactant. Solutions or emulsifiable concentrates may be prepared by dissolving or dispersing one or more active compounds (I) in one or more inert liquid carriers or diluents, if desired, by adding a surfactant.

Conveniently, the amount of active compound (I) is 3 to 20% by weight for powders and granules, 20 to 75% by weight for hydrated powders and 20 to 50% by weight for solutions and emulsifiable concentrates, all of which result It is based on the weight of.

Herbicide compositions may also contain agrochemicals commonly used to grow agricultural crops such as fungicides, insecticides, nematicides and fertilizers. Representative fungicides include, but are not limited to, benoyl [methyl-1- (n-butylaminocarbonyl) -1H-benzimidazol-2-yl-carbamate], himexazole (5-methyl-3-isoxazolol), Captans [3a, 4, 7, 7a, -tetrahydro-N- (trichloromethanesulphenyl) phthalimide], genep [zinc ethylenebis (dithiocarbamate)], and the like.

Examples of pesticides include Disulfoton (0,0-diethyl S-2-ethylthiophosphorodithioate) and Propoxur (2-isopropoxyphenyl methylcarbamate).

Examples of nematicides include methomyl [S-methyl-N- (methylcarbamoyloxy) thioacetamide] and alidicarb [2-methyl-2- (methylthio) propionaldehyde -0-methylcarbamoyl oxime].

In addition, one or more other herbicidal active ingredients used in the known art may be distributed to the herbicide composition of the present invention. This often results in a high herbicidal effect on a wide range of weed varieties. Examples of other herbicidal active compounds include MCP (2-methyl-4-chlorophenoxy acetic acid), TOK (2,4-dichlorophenyl-4'-nitrophenyl ether), bentiocarb (4-chlorobenzyl- N, N-diethylthiocarbamate), molinate (S-ethyl-N, N-hexamethylenethiocarbamate), oxadiazone [2-tert-butyl-4- (2,4-dichloro -5-isopropoxyphenyl-5-oxo-1,3,4-oxadiazoline] and butachloro [2-chloro-2 ', 6'-diethyl-N- (butoxymethyl) acetanilide] Etc. It is to be understood that these examples are not limiting, and other effective compounds may be formulated equivalent to the herbicide compositions of the present invention, if desired.

The herbicide compositions of the present invention containing such other herbicidal active ingredients are particularly useful for use in paddy rice paddies, for example transplanted rice paddies.

Herbicides containing compound (I) as an active ingredient can be used to remove various weeds in areas where agricultural products are grown.

In particular, the herbicides of the present invention are more effective at removing moist weeds than dry paddy fields, and include Ekicloak-Gali Beauv. Very powerful selective herbicidal effect on the same blood.

As active ingredients, 2,4,6-trichlorophenyl-4-nitrophenylether (CNP), S- (4-chlorobenzyl) -N, N-diethylthiocarbamate (benzyl) widely accepted in rice fields Thiocarb), 2-chloro-2 ', 6'-diethyl-N- (butoxymethyl) acetanilide (butachloro), and S-ethyl-N, N-hexamethylenethiocarbamate (molinate Herbicides containing) do not show selectivity between rice and blood at the germination stage and are not absolutely safe for transplanted rice at the early stage of growth. Such conventional herbicides include, for example, when rice is transplanted shallowly on the soil surface, when the soil is sand, when water leaks, when root growth is abnormal, or when the temperature is unusually high. As environmental conditions change, the risks of plant toxicity are inevitable.

Since the herbicides provided by the present invention are based on physiological selectivity, they can be used at all stages of growth from germination to maturation, and can actually free rice from plant toxicity as environmental conditions change. have.

To date, 3 ', 4'-dichloroprocyionanilide (propanyl) has been widely used as a substance having selective activity for the blood of the rice paddy. However, propanyl is a suitable material for use in leaves and has no effect on inhibiting germination. On the contrary, since the herbicide of the present invention has a much higher selective action than propanyl during germination of blood and rice, it is not an exaggeration to say that the herbicide of the present invention has achieved an epoch of herbicide that a known herbicide cannot match.

The most effective and most preferred herbicides of the present invention are N-allyl-N- (2-chlorobenzoyl) benzenesulfonamide and N-allyl-N- as active ingredients. (2,4-dichlorobenzoyl) benzenesulfonamide, N-propazyl-N- (2-chlorobenzoyl) benzenesulfonamide, N-allyl-N- (α, α-dimethylbenzyl) benzenesulfonamide, and N- Herbicide containing allyl-N- (α-methylbenzyl) benzenesulfonamide. These effective compounds usually have the property of strongly inhibiting the germination of blood without affecting the germination of rice. However, there are some differences between these compounds. For example, herbicides containing benzoyl active compounds are long lasting in the soil and inhibit weed growth for a long time. On the other hand, the herbicide containing a benzyl active compound has a very high range of selectivity between blood and rice immediately after germination.

In use, the herbicides of the invention containing the active ingredient of formula (I) are used in areas to be protected from weeds. Therefore, according to another aspect of the present invention, there is provided a method for inhibiting weeds in a crop, characterized by the use of the compounds of the general formula (I) described so far in areas to be protected from blood.

The number of uses of compound (I) is not strictly limited and depends on the crop to be suppressed or weeds and crops. In general, in order for the active compounds of the present invention to exhibit the best herbicidal action, the weeds to be suppressed are best used just before sprouting or during the germination stage. Of course, it is also possible to use in weeds after germination, which brings about some inhibitory effect.

There is no particular limitation on the place where the active compound of the present invention can be used. It can be used on various types of crops as in the case of conventional herbicides. However, it is best used in wet paddy fields, especially in flooded waters, and when used in high altitudes with low water content, the active compounds of the invention tend to exhibit somewhat reduced herbicidal effects.

In order for the herbicide of the present invention to have the best herbicidal effect, the herbicide of the present invention is used in rice paddy conditions before or during weed germination.

The effective compound (I) of the present invention exhibits herbicidal action against various weeds as described above, but various types of blood associated with rice, in particular, Echinoloclus cruce-Gali Beauv. It is excellent in the effect of suppressing germination of rice without actually giving phytotoxicity to rice. Therefore, the effective compounds of formula (I) can be effectively used to selectively inhibit blood and protect rice from them.

The rate of use of the effective compound of formula (I) is not limited, and may vary widely depending on the type, time of use, method of use, and the like of the active compound. The use rate of the effective compound (I) is generally 25 g or more, preferably 50 to 1000 g, more preferably 100 to 500 g per 10 ars.

The method of use may be any conventional method. For example, the herbicide compositions of the present invention may be sprayed from the ground or from air on areas to be protected from weeds. Alternatively, it may be sprayed with the seed of the crop at the time of seeding of the crop.

In addition, according to the present invention, the seed of the crop may be buried before spraying an aqueous solution containing the active compound of the present invention in order to suppress germination of the weed seed.

The effective compound (I) of the present invention is very suitable as a herbicide because of its low toxicity to useful crops and low toxicity to mammals.

The following examples further illustrate the formulation of the herbicides provided by the present invention, as well as their selective herbicidal action.

In these examples, all parts and percentages are by weight. The numbers of the compounds indicate those listed in Table 2.

Example A (Wet Powder)

40 parts of compound number 27, 55 parts of a 2: 1 mixture of Zeeklite and Kunilite (registered trademark of Kunimine Co., Ltd.) and Sorpol 800 (Toho Chemical Co., Ltd.) as a surfactant (Trademark) was mixed and ground to form a 40% wet powder.

Example B (Emulsified Concentrate)

25 parts of compound number 85, 65 parts of benzene, and 10 parts of Sorpol 800 as a surfactant were mixed and dissolved to form a 25% emulsion concentrate.

Example C (particle)

5 parts of Compound No. 67, 50 parts of bentonite, 40 parts of gunnyrite and 5 parts of Sorpol 800 as a surfactant were mixed and ground, and 10 parts of water was added and stirred uniformly to form a paste. This arc-shaped material was extruded through a hole of 0.7 mm in diameter and cut into lengths of 1 to 2 mm to form 5% granules.

Example D

Paddy soil of muddy state is filled in pots (volume: 1/5000 aare), blood (Echinochloa crusgalli Beavu) and other broad-leaf weeds (weed, fightweed, umbrella, speaker rush, zinnia) , Redstem, horse pump funnel, etc.), bluedersk and slender speaker rush, sowing or transplanting, at the same time sowing 10 germinated rice seeds (variant: Nihonbare) and planted two 3-leaf rice seedlings as a share .

After 2 days, a predetermined amount of each herbicidal active compound according to the present invention, shown in Table 3, was diluted with 10 ml of water, applied to irrigated water on the surface of each pollen, and the treated pollen was placed in a greenhouse. Control effects and toxicity to rice plants were examined.

The results are presented in Table 3 by evaluating 10 steps with 0 as normal development and 10 as withering.

TABLE 3

Example E

Two sheets of paper were spread out in a Petri dish having a diameter of 9 cm, and 6 ml of the wet powder of each active compound according to the present invention shown in Table 4 was added dropwise to a predetermined concentration. Here, 10 seeds of bark and rice (variety: nihongbare) are sown directly, and the Petri dishes are placed in a thermostat room at 26 ° C. After 72 hours, the lengths of young root, young stems, and leaves are measured. It is measured and evaluated in 10 steps, with normal growth set to 0 and complete suppression set to 10, and presented in Table 4.

TABLE 4

Example F

The soil was filled with potted plants (1/5000 are) and the topsoil 1 cm deep and 30 seeds were mixed. Ten rice seeds (seeds: nihongbare) were sown on topsoil, two seedlings of single, bi- and 3.5-leafed plants were planted as a share, and each plant was filled with irrigation water 2 cm deep. After 1 day, a predetermined amount of each active compound according to the present invention shown in Table 5 was diluted in 10 ml of water and added dropwise to the surface of each pollen cultivation. After 20 days of treatment, the control effect and toxicity were examined in the same manner as in Example D and the results are shown in Table 5.

TABLE 5

Example G

In this example, the following tests were carried out under the same conditions as the actual site.

The muddy soil was filled with a concrete planter of 70 cm in width, 70 cm in width and 50 cm in height. Sixty seeds of Echinochloa crus-galli Beauv. Were sown, 20 cm deep watered and 20 seed germinated seedlings were planted in the soil. Four shares were transplanted with two shares of the same seedlings of the third leaf phase. One day later, each of the active compounds according to the present invention shown in Table 6, and the amounts shown in Table 6 of Benthiocarb and granules were sprayed by hand. Thus, two weeks after the treatment, the control effect on weeds (naturally occurring photoleaf species) and the toxicity to rice are examined and presented in Table 6.

TABLE 6

Example H

Fill the pollen (18.5% of clay) with slits of lumber (clay content 48.5) and sandy loam (clay content 15.4%), stirring them, and then answer them. The seedlings of subspecies and trifoliate seedlings were transplanted and the irrigation water was 3 cm deep. One day later, the wet powder of each active compound according to the present invention of Table 7 was applied, and two weeks after the treatment, the control effect was examined in the same manner as in Example D and presented in Table 7.

TABLE 7

Example 1

Three blades of rice seedlings were machined in the answer, and after 4 days, the answer was divided into 2 m x 2 m by vinyl resin plates. A predetermined amount of the wet powder of each active compound according to the present invention of Table 8 was diluted with 400 ml of each sugar per compartment and sprayed over the entire irrigation water. Three weeks after this treatment, weed control effects and toxicity to rice are examined and presented in Table 8.

Toxicity evaluation for rice should be expressed as follows.

- : normal

+: Slight disturbance

++: slight obstacle

+++: weak obstacles

TABLE 8

Claims (1)

A process for preparing a N'N-disubstituted benzenesulfonamide derivative of the following structure- (I) characterized by reacting a compound of the following formula (VI) with a compound of the following formula (VII).

In each formula above, R ₀ represents an alkyl group, a lower alkenyl group and a lower alkynyl group which may have a substituent selected from the group consisting of a cyano group, a lower alkoxy group and a di- (lower alkyl) amino group, R ₁ , R ₂ and R ₃ each represent a hydrogen atom, a halogen atom, a lower alkyl group or a lower alkoxy group, and R ₄ , R ₅ , R ₆ , R ₇ and R ₈ respectively represent a hydrogen atom, a halogen atom, a lower alkyl group or a lower group An alkoxy group, Y is structural formula

Group or structural formula

Wherein one of R ₉ and R ₁₀ is a lower alkyl group and the other is a hydrogen atom or a lower alkyl group, wherein Y is

When R ₀ is an unsubstituted alkyl group, R ₄ , R ₅ , R ₆ , R ₇ and R ₈ do not simultaneously represent a hydrogen atom, X ₄ is a halogen atom, and M represents a hydrogen atom or an alkali metal atom.