DD240494A5 - PESTICIDE COMPOSITION - Google Patents

Abstract

The invention relates to pesticidal compositions in which new 2-cyanobenzimidazoles are included as active ingredients and which are useful in agriculture. The invention provides novel pesticidal compositions having antifungal properties. The object of the invention is to provide new pesticidal compositions available. According to the invention, the object is achieved in that pesticidal compositions contain as active material new derivatives of 2-cyanobenzimidazole of the general formula wherein the substituents which have the meaning given in the description and an inert carrier and / or a surface-active agent. formula

Description

Field of application of the invention

The present invention relates to novel pesticidal compositions, in particular antifungal compositions, useful in agriculture containing as active ingredient novel derivatives of 2-cyanobenzimidazole, as well as the pesticidal treatments, and in particular the antifungal treatments, which are effected with these compounds.

Characteristic of the known technical solutions

In US-PS 3576818 are derivatives of 2-cyanobenzimidazole of the formula (I)

(I)

in which Ri and R _{2 are} selected from the group comprising hydrogen, chlorine, bromine, NO ₂ and the alkyl and alkoxy radicals having at most 4 carbon atoms. This US patent states that these compounds (I) are useful as bactericides and antiseptic agents, in Example 1 the 2-cyanobenzimidazole is described, ie the compound of formula (I) where Ri and R _{2 are} hydrogen atoms.

In the French patent application 2051493 derivatives of 2-cyanobenzimidazole are described, wherein the nitrogen atom in the 1-position on the benzimidazole ring may be substituted by a hydrogen atom or an alkyl or alkoxycarbonyl. It is stated that these compounds have biocidal activity and are useful as fungicides, anthelmintics, insecticides and herbicides. Example 4 of this French patent application describes the above-mentioned 2-cyanobenzimidazole.

In the French patent application 2070090 derivatives of 2-cyanobenzimidazole are described, wherein the nitrogen atom in the 1-position on the benzimidazole ring by a hydrogen atom or an alkyl, alkoxyalkyl, alkenyl, CarboxyalkyhAlkanoyl-, aminoalkyl, hydroxy, alkoxy, carboxy alkoxy- , Sulfoalkoxy and aminoalkoxy groups, and it is stated that these compounds are useful as anthelmintic agents, anti-coccidial agents and pesticides, for example, herbicides and bactericides.

Object of the invention

The invention provides novel pesticidal compositions which have significant antifungal properties and which are useful in agriculture, in particular for controlling phytopathogenic fungi.

Explanation of the essence of the invention

The object of the invention is to provide novel pestitzide compositions which possess significant fungicidal activity.

The novel derivatives of 2-cyanobenzimidazole, which differ from those described in the above-mentioned publications, are characterized by having the general formula II

NO). - ^CN

where n, R and R 'are as defined below, the term "lower" or "lower" applied to an organic radical, unless otherwise stated, indicating that this radical is at most six carbon atoms carries atoms.

In formula (II) mean:

η denotes an integer which can be equal to O, 1 or 2,

m is an integer equal to 1 or 2,

R represents a halogen atom or a lower alkyl optionally substituted by one or more halogen atoms; niederesAlkoxygegebenenfallssubstituiertdurcheinodermehrereHalogenatome; lower alkylthio optionally substituted by one or more halogen atoms; nitro; cyano; when η is 2, the substituents R may be either identical or different;

R 'represents a lower alkyl or cycloalkyl radical optionally substituted by one or more halogen atoms (such as methyl, ethyl, isopropyltrichloromethyl, trifluoromethyl, etc.); or an amino radical which is optionally substituted by one or two lower identical or different alkyl radicals, which in turn are optionally substituted (for example by one or more halogens or lower alkoxy or alkylthio radicals); or a nitrogen atom substituted by two radicals which form with this nitrogen a heterocycle which is in turn optionally substituted, bearing four to six chain members and one to three heteroatoms in the ring (such as the morpholino radical, the pyrrolidino radical, etc.).

R "represents a lower alkenylthio, lower alkenyloxy, lower alkynylthio, lower alkynyloxy, aralkylthio radical, these radicals being in turn optionally substituted, where, if m is equal to two, the substituents R" may be either identical or different

 Preferably, the following meanings are:

η is equal to Ooderi,

R represents a halogen atom or the cyano, nitro, trifluoromethyl, trifluoromethoxy or trifluoromethylthio radical, R 'represents the dimethylamino radical or an optionally halogenated C 1 -C 8 -alkyl radical, m is 1,

R "represents the propargylthio radical or a benzylthio radical.

For the purposes of the above text, it is understood that the alkyl radicals or moieties may be either straight or branched.

This also applies to the alkenyl and alkynyl radicals.

The invention further relates to a process for the preparation of the compounds of the formula (II). , '

This process is characterized in that it consists of a 2-cyanobenzimidazole of the formula (III)

Ν- '« ^(III)

in which R, R ", m and η have the same meaning as in formula (II), or an alkali metal or ammonium salt of this 2-cyanobenzimidazole (Mi) to a halide of the formula (IV)

X-SO ₂ R ¹ (IV)

wherein R 'has the same meaning as in formula (II) and X represents a halogen atom, preferably a chlorine atom, to act.

The reaction of 2-cyanobenzimidazole (III) with the halide (IV) is advantageously carried out in the presence of an acid acceptor in an anhydrous or non-anhydrous medium in a solvent inert under the reaction conditions generally at the boiling temperature of the solvent. As acid acceptors may be mentioned mineral bases such as sodium or potassium hydroxide, alkali metal or alkaline earth metal carbonates, nitrogen bases such as triethylamine. The solvents used are advantageously polar aprotic solvents, for example dimethylformamide, dimethylacetamide, dimethylsulfoxide, acetone, methyl ethyl ketone, acetonitrile, N-methylpyrrolidone. If desired, this reaction may take place in the presence of a suitable catalyst. As a useful catalyst may be mentioned phase transfer catalysts, such as quaternary ammonium derivatives.

The reaction of the alkali metal or ammonium salt of 2-cyanobenzimidazole (III) with the halide (IV) does not require the presence of an acid acceptor. It is carried out in an anhydrous or non-anhydrous medium in a solvent which is inert under the reaction conditions, generally at the boiling point of the solvent. The above-mentioned polar aprotic solvents can be advantageously used in this reaction.

If desired, this reaction may be carried out in the presence of a suitable catalyst, such as a phase transfer catalyst (for example, a quaternary ammonium derivative).

The alkali metal or ammonium salt of compound (III) is prepared in a previous step, optionally in situ, by the action of a suitable base (e.g. sodium, potassium hydroxide, ammonia) or an alkali metal carbonates or alkali metal alcoholates (e.g. sodium methylate or sodium or potassium ethylate). to this compound (III).

At the end of the reaction, whichever method has been used, the compound formed is isolated from the reaction medium by any means known per se, for example by distilling off the solvent or by crystallizing the product from the reaction medium or by filtration, and then this compound becomes necessary , purified by conventional methods, such as recrystallization from a suitable solvent.

The starting 2-cyanobenzimidazole of the formula (III) can be prepared by one or the other of the following methods A, B and C:

Method A

Exposure of ammonia to a 2-trihalomethylbenzimidazole using the method described in the above-mentioned US Pat. No. 3,577,818.

Method B

Action of phosphorus trichloride on a 2-cyano-1-hydroxybenzimidazole of the formula (V)

/ v ^ Nv CN

(R) (T If "V ^- (V)

ⁿ ^ N-OH

wherein R, R ", m and η have the same meaning as in formula (II), wherein in acetone, which is heated to reflux temperature, worked.

The 2-cyano-1-hydroxbenzimidazole (V) can be prepared starting from 2- (2-nitrophenyl) amino-acetonitrile of the formula (VI)

(VI)

wherein R, R ", m and η have the same meaning as above, by heating in the presence of potassium carbonate according to dervon

L. KONOPSKI and B.SERAFIN in Rocz. Chem.51 1783 (1977).

The compound (VI) can be obtained from the corresponding 2-nitroaniline by following the procedure described by K. DIMROTH and H.CAURICH in Chem. Ber. 98 3902 (1965) method is described.

Method C

Exposure of a dehydrating agent such as POCl ₃ or SOCl 2 to 2-hydroxyiminomethylbenzimidazole of the formula (VII)

NH-CH - CN

( ^R > n <"">"

wherein R, R ", m and η have the same meaning as in formula (II).

The compounds of the formulas (III), (V) and (VI) are within the scope of the invention insofar as they are included for carrying out the production process described above.

The following non-limiting examples illustrate the preparation of the compounds of the invention and their use as fungicides. The structures of the compounds described in these examples were confirmed by nuclear magnetic resonance (NMR) spectrometry and / or by infrared spectrometry.

applications example 1

Preparation of 2-cyano-1-dimethylsulfamoyl-5- (propyn-2-yl-thio) -benzimidazole (Compound 1A) in a mixture with 2-cyano-1-dimethylsulfamoyl-6- (propyn-2-yl-thio) -benzimidazole (Compound 1 B).

1.85 g of potassium hydroxide in platelets are added to a suspension of 6.2 g (0.029 mol) of 2-cyano-5- (propyn-2-yl-thio) -benzimidazole in 60 ml of acetone dried over K ₂ CO ₃ .

After about 30 minutes, the potassium hydroxide is dissolved and the reaction mixture has become almost homogeneous.

Then 3.12 ml (0.029 mol) of dimethylsulfamoyl chloride are added in one portion, and the reaction mixture is stirred for 12 hours at ordinary temperature. It turns white and heats up slightly.

The reaction mixture is then concentrated in vacuo, then taken up in 2 × 100 ml of CH ₂ Cl ₂ , filtered and chromatographed on 200 g of silica with CH ₂ Cl ₂ .

This gives an oily yellow solid which is recrystallized from 200 ml of pentane. Are thus obtained 5.2 g (yield 56%) of a yellowish solid, F = 87 ⁰ C. By NMR and IR spectrography, this compound as a mixture of substantially equal amounts of 2-cyano-1-dimethylsulfamoyl-5- ( propyn-1-yl-thio) benzimidazole (Compound 1 A). and 2-cyano-1-dimethylsulfamoyl-6- (propyn-2-yl-thio) benzimidazole (Compound 1 B).

Example 2

Using the method described in the previous example, the following mixture was prepared: 2-Cyano-5-benzylthio-1-dimethylsulfamoylbenzimidazole (Compound 2A) and 2-cyano-6-benzylthio-1-dimethylsulfamoylbenzimidazole (Compound 2B) in the form of a 50/50 mixture, F = 96 ° C.

Example 3 Test in glasshouse at the mildew of tomato

Tomato plants (Lycopersicum esculentum), variety Marmande, are grown in pots. When these plants are one month old (stage 5 to 6 leaves, height 12 to 15 cm) they are sprayed by means of an aqueous suspension or solution of the material to be tested in the desired concentration, and containing 0.02% of a condensate of sorbitan monoleate with 20 Mole treated ethylene oxide. Each tomato plant receives about 5 ml of the solution or dispersion. For each concentration of active substance to be tested, treatment is effected on eight plants. Plants used as controls are treated with a solution containing no active material but containing 0.02% of the same condensate of sorbitan monooleate and ethylene oxide.

After drying for four hours, each plant is sprayed by spraying it with an aqueous suspension of Phytophthora festa spores responsible for tomato mildew in an amount of about 1 ml per plant (ie, about 2 x 10 ⁵ spores per plant).

After this infestation, the tomato plants are incubated for two to three days at about 17 ° C in a moisture saturated atmosphere, then for four days at about 22 ° C under 70 to 80% relative humidity.

Seven days after the infection, the results obtained in the case of the plants treated with the active material to be tested are compared with those obtained in the case of the control plants and the minimum inhibitory concentration is determined, which indicates a 95 to 100% inhibition of the development of the caused fungus (CMI 95-100).

Under these conditions, it is observed that for the compounds or compound mixtures described in the above examples, this concentration is as follows:

Compound or mixture CMI (95-100)

tested Phytphthora infestans

in mg / l

1A + 1B below125

Example 4 Test in hothouse at the mildew of tobacco

The procedure is as in the previous example, except that the plants are tobacco plants (Nicotina tabacum), variety Samson, and that these plants are contaminated with spores of Peronospora tabacina, which are responsible for the mildew of the tobacco.

Under these conditions, it has been observed that for the compounds or mixtures of compounds described in the previous examples, the minimum inhibitory concentrations causing 95 to 100% inhibition of the considered fungus (CMI 95-100) are the following:

Compounds or Mixture CMI (95-100)

tested Peronospora tabacina

in mg / l

1A + 1B below 500

The compounds according to the invention are advantageously used as antifungal agents in agriculture. They have a contact action and a systematic action and can be used for the prevention and / or cure in combating various phytopathogenic fungi such as numerous Phycomycetes and Basidiomycetes. Some of these compounds can also be used to advantage as anti-acarine agents especially against phytophagous acarines.

For their use in practice, the compounds according to the invention are generally not used alone. Most commonly, they are used in compositions which generally comprise, in addition to the active material, an inert carrier (or diluent) and / or a surfactant that is compatible with the active material.

These compositions also form part of the present invention. They usually contain from 0.001 to 95% by weight of active material. Their content of surfactant is generally between 0 and 20% by weight.

By the term "carrier" herein is meant an organic or mineral, natural or synthetic material with which the active material is associated to facilitate its application to the plant, to the grains or to the soil.

This carrier is therefore generally inert and is said to be acceptable in agriculture, especially by the treated plant. The carrier may be solid (clays, natural or synthetic silicates, silica, chalks, resins, waxes, solid fertilizers, etc.) or liquid (water, alcohols , Ketones, petroleum fractions, aromatic or paraffinic hydrocarbons, chlorinated hydrocarbons, liquified gases, etc.).

The surfactant may be an ionic or nonionic type emulsifying, dispersing or wetting agent. For example, polyacrylic acid salts may be mentioned; Salts of lignosulfonic acids, salts of phenolsulfonic or naphthalenesulfonic acids; Polycondensates of ethylene oxide with fatty alcohols or fatty acids or fatty amines or substituted phenols (especially alkylphenols or arylphenols or styrylphenol); Salts of sulfonic acid esters; Derivatives of taurine (especially alkyl taurates); Phosphoric acid esters of polyoxyethylated alcohols or phenols. The presence of at least one surface-active agent is generally essential, especially when the inert carrier is insoluble in water, and when the carrier of the application is water.

The compositions used according to the invention can be in very different solid or liquid forms.

Forms of solid compositions may be powder for dusting (containing up to 100% of active material).

As forms for liquid compositions or intended to form liquid compositions during use, there may be mentioned solutions, in particular water-soluble concentrates, emulsifiable concentrates, emulsions, concentrated suspensions, aerosols, wettable powders (or powders for spraying), pastes.

The emulsifiable or soluble concentrates often contain from 10 to 80% active material, with the emulsions or solutions used in turn containing from 0.001 to 20% active material. In addition to the solvent, the emulsifiable concentrates may, if necessary, contain a suitable co-solvent and 2 to 20% of suitable additives such as stabilizers, surfactants, particularly emulsifiers, penetrants, corrosion inhibitors, dyes, adhesives.

From these concentrates it is possible, by dilution with water, to obtain emulsions of any desired concentration, which are particularly suitable for use on crops.

The concentrated suspensions, which are also applicable by sputtering, are prepared such that a stable, non-settling fluid product is obtained, and usually contain 10 to 75% active material, 0.5 to 15% surfactant, 0 , 1 to 10% thixotropic agent, 0 to 10%, suitable additives such as anti-foaming agents, corrosion inhibitors, stabilizers, penetrating agents and adhesives and as a carrier water or an organic liquid, wherein the active material is little or not soluble: certain organic solids or Mineral salts may be dissolved in the carrier to help prevent sedimentation or as antigels to the water.

The wettable powders (or powders for atomizing) are usually prepared to contain from 20 to 95% active material and usually contain, in addition to the solid support, 0 to 5% of a wetting agent, 3 to 10% of a dispersing agent and, if necessary , 0 to 10% of one or more stabilizers and / or other additives such as penetrants, adhesives or anti-caking agents, dyes, etc.

In order to obtain these powders for atomizing or wettable powders, the active material is intimately mixed in suitable mixing devices with the additional substances and ground in mills or other suitable comminuting devices. This gives sputtering powders whose wettability and suspensibility are advantageous; it can be suspended with water in any desired concentration, and this suspension is very useful particularly for application to foliage of plants.

As already mentioned, these aqueous dispersions and emulsions, for example, compositions obtained by diluting a wettable powder or an emulsifiable concentrate according to the invention by means of water, are included in the general range of compositions useful in the present invention.

The emulsions may be of the water-in-oil or oil-in-water type, and may have a tough consistency, such as that of a "mayonnaise".

The granules intended to be placed on the ground are usually made to have dimensions between 0.1 and 2 mm, and they can be produced by agglomeration or impregnation. In general, the granules or granules contain 0.5 to 25% active material and 0 to 10% additives such as stabilizers, slow release modifiers, binders and solvents.

The compounds of the formula (II) can also be used in the form of powders for dusting, it is thus possible to use a composition with 50 g of active material and 950 g of talc; it is also possible to use a composition containing 20 g of active material, 10 g of finely divided silica and 970 g of talc; Mix and grind these ingredients and bring the mixture by dusting.

The invention also relates to a method of treating plants against phytopathogenic fungi.

This method is characterized in that it consists in applying to these plants an effective amount of a composition containing as active material a compound according to formula (II). By "effective amount" is meant an amount sufficient to allow control and destruction of the fungi present on these plants, but application dosages may vary widely depending on the fungus to be controlled, the type of crop, the climatic conditions and conditions vary depending on the connection used.

In practice, dosages of from 5g / hl to 100g / hl, corresponding to substantially active material dosages per hectare, will range from 50g / ha to about 1000g / ha, generally good results.

Claims (3)

- ι - £ .t \ ß did claim for invention: 1. Pesticidal composition for use in agriculture, usable in particular for combating phytopathogenic fungi, characterized in that they contain as active material new derivatives of 2-cyanobenzimidazole of the general formula in which mean η is an integer equal to 0.1 or 2, m equalsnumbers equal to 1 or 2, R represents a halogen atom or a lower alkyl radical which is optionally substituted by one or more halogen atoms, lower alkoxy optionally substituted by one or more halogen atoms; lower alkylthio optionally substituted by one or more halogen atoms; nitro; Cyano, where, when η is 2, the substituents R may be either identical or different; R 'represents a lower alkyl or cycloalkyl radical optionally substituted by one or more halogen atoms; or an amino radical may optionally be substituted; or a nitrogen atom which is substituted by two radicals which form a heterocyclic with this nitrogen atom, which in turn is optionally substituted, and having four to six chain members and one to three antero atoms in the ring; R "represents a lower alkenylthio, lower alkenyloxy, lower alkynylthio, lower alkynyloxy or aralkylthio radical, these radicals themselves being optionally substituted, where, if m is 2, the substituents R" may be either identical or different, and hereinabove, the term "lower" as applied to an organic radical means that this radical bears at most six carbon atoms and contains an inert carrier and / or surface active agent useful in agriculture. 2. Composition according to item ↑, characterized in that it contains 0.001 to 95 wt .-% of active material and 0 to 20 wt .-% surfactant. 3. A method for the treatment of plants against phytopathogenic fungi, characterized in that an effective amount of a compound according to item 1 is applied to these plants.