SK2795A3 - Benzimidazolesulfone acid derivatives, method of their preparation and agents containing these derivatives - Google Patents

Abstract

Compounds of formula (I) in which R1 is CN or -CS(=O)nNH2, R2 is C1-C4alkyl, C3-C6cycloalkyl or -N(R')2, in which R' radicals are different or identical C1-C3alkyl radicals and n is 0 or 1, are suitable for controlling and preventing infestation of plants by microorganisms. They can be used in the form of commercially available formulations.

Description

Benzimidazolesulfonic acid derivatives, processes for their preparation and compositions containing these derivatives

Technical field

The invention relates to novel benzimidazolesulfonic acid derivatives of the general formula below. The invention further relates to the preparation of these substances and agricultural chemical compositions containing at least one of these compounds as an active ingredient. The invention also relates to the preparation of the aforementioned compositions and to the use of said active ingredients or compositions for controlling or preventing the infestation of plants by phytopathogenic microorganisms, preferably fungi.

SUMMARY OF THE INVENTION

The compounds of the invention have the general formula I

in which R ^SO SO is located in position 1 or 3 a causes formation net or commingled positioning isomers

with respect to the substituents CF3,

R is CN or -CS (= O) NH, □ _ ΓΊ 2

R is C 1 -C 4 alkyl, C 3 -C 6 cycloalkyl, or -N (R ') - in which R' is different or identical C 1 -C 3 alkyl, and n is 0 or 1.

The term alkyl or alkyl as part of another substituent herein refers to the following straight or branched groups depending on the number of carbon atoms defining the alkyl group: methyl, ethyl, propyl, butyl and isomeric isopropyl derivatives thereof, isobutyl, sec-butyl and tert-butyl.

The compounds of formula I are stable solids at ambient temperature and have valuable microbicidal properties. Their particularly advantageous activity is mainly based on the specific substitution structure in the fused benzene ring. These compounds can be used preventively or curatively in agriculture or adjacent areas to control phytopathogenic microorganisms. When used at low concentrations, the compounds of formula I are not only characterized by excellent microbicidal, in particular fungicidal activity, but also by the fact that they are well tolerated by plants.

Important compounds of the invention are those compounds of formula I wherein R is C 1 -C 2 alkyl, cyclopropyl or N (R '), R' is methyl or ethyl and n is 0 or 1.

One particularly important group of compounds of the invention is a group of compounds of formula I wherein R 1 is methyl or N (R ') ₂ , R 1 is methyl and n is 0 or 1. Particularly preferred compounds of this group are wherein R is dimethylamino and n is 0 or

First

A group of preferred compounds of formula I includes those wherein the R ₂ SO ₂ groups are in the 1 or 3 position and cause the formation of pure or mixed positional isomers relative to the CF ₃ substituents and wherein -C 2 H 4 and R 6 are alkyl containing C 1-4 alkyl, C 3-6 cycloalkyl, or -N (R ') ₂ wherein R' is different or the same C 1-3 alkyl. R ₂ particularly preferred features is methyl or N _{(CH3) 2} ·

Preferred individual groups are:

1 (3) -dimethylaminosulfonyl-2-carbothioamide-4,6 bistrifluoromethylbenzimidazole,

1- (3) -Dimethylaminosulfonyl-2-carbothioamido-4,6-bistrifluoromethylbenzimidazole-S-oxide; and

1 (3) -dimethylaminosulfonyl-2-cyano-4,6-bistrifluoromethylbenzimidazole.

When n is 0 (Ib), compounds of formula I wherein R _x is -CS (= O) _n NH _{2 can be} prepared by reacting H ₂ S with a compound of formula Ia

N

(Ia) wherein R ₂ is as defined for formula (I). The reaction leading to the thioamide is carried out in the presence of inorganic or organic bases. Organic bases such as secondary amines such as dimethylamine / K are preferred. Kindler, Ann. 431, 187 (1923) / or diethylamine, or tertiary amines such as triethanolamine or triethylamine (JF Olin and TB Johnson, R. 50, 72 (1931), DW McCorquodale and TB Johnson, R 511, 833 (1932)). Preferably an equimolar amount or a slight excess of bases is used. As solvents, polar solvents such as alcohols (methanol, ethanol, isopropanol, etc.) are used, but acid amides such as dimethylformamide are preferred, or ethers such as diethyl ether, tetrahydrofuran, dioxane, etc. may be used.

A further possibility of addition to H ₂ S consists in the use of heterocyclic bases as a solvent such as pyridine in the presence of a tertiary amine such as trialkylamine (e.g. triethylamine (AES Fairfull, JL Lowe and DA Peak, Soc.1952, 742). The H ₂ S may be introduced continuously or the reaction may be carried out under pressure.

The S-oxide compounds (n = 1, formula Ic) are prepared from thioamides (n = 0, formula Ib) by oxidation with organic peroxides or hydrogen peroxide (preferably in the form of a 30% aqueous solution). Preferably, approximately equimolar amounts of oxidizing agents are used. The solvents used are polar solvents, for example alcohols (methanol, isopropanol), acid amides (N-methylpyrrolidone), ketones (acetone), pyridine or aliphatic carboxylic acids. A preferred substance is acetic acid (glacial acetic acid) with or without addition of a base such as sodium acetate. The reaction temperature is between -20 and 60 ° C, preferably between 0 and 30 ° C.

(Ib, n = 0)

(Ic, n = 1)

The invention also relates to 2-cyano-4,6-bistrifluoromethylbenzimidazole of formula III and its preparation. This material is prepared from 1,2-diamino-3,5-bistrifluoromethylbenzene or its salts by known methods:

CF, A NH ₂ R C-Challa, -nh ₄ y (a) 1 1 HN ^Z ^ ΝΗ ₂ (.ΗΥ) Trihalogenimidát -THE CORNER

(Y = acid anion, Hal = halogen, preferably Cl, R = C ₁ -C ₃ -alkyl)

+ xNH ₃

(ΙΠ)

HY is an inorganic or organic acid, preferably hydrohalic acid or sulfuric acid. However, o-phenylenediamine derivatives can also be used in the form of the free base when reaction step a) is carried out in glacial acetic acid. Preferred solvents other than acetic acid are ethers such as diethyl ether, dioxane, 1,2-dimethoxyethane, esters such as ethyl acetate, or alcohols such as methanol and ethanol.

The trihalimidate (e.g., trichloromethylimidate or chlorodifluoromethylimidate) is preferably added to the dissolved or suspended o-phenylenediamine derivative at a temperature of -20 to 100 ° C. In reaction step b), the obtained 2-trihalomethylbenzimidazole derivative is preferably added to a concentrated aqueous solution of ).

The 2-cyano-4,6-bistrifluoromethylbenzimidazole) of formula III can also be prepared using the corresponding 2-nitro-4,6-bistrifluoromethylaniline in place of the o-phenylenediamine derivative by reaction with formaldehyde and KCN in glacial acetic acid with the addition of zinc chloride (or other Lewis) base) as a catalyst to give a compound of formula

NH - CH ₂ - CN no ₂ / K. Dimroth et al., Ber.98,3902 (1965)], which is cyclized by reaction with K ₂ CO ₃ to give the 1-hydroxy-2-cyanobenzimidazole derivative (B). Serafinowa et al. Rocz.Chem. 51, 1783 (1977)], which may be reacted with PCl ₃ to give a compound of formula III. This method variant is also an object of the invention.

The products of formula Ia may be prepared by reacting a compound of formula III or one of its salts with an alkali metal, preferably a sodium, potassium or lithium salt, with a compound of formula IV

Q-SO ₂ -R ₂ (IV) wherein R 1 is as defined above for formula (I) and Q represents a halogen atom, preferably a chlorine or bromine atom, or an O-SO ₂ -R _{2 group} , in an inert solvent, in the presence or absence of a base and at a temperature of -30 to 180 ° C, preferably at a temperature of -10 to 80 ° C.

Particularly suitable solvents are polar reaction media, such as ketones (acetone, methyl ethyl ketone or tert-butyl methyl ketone), ethers (such as diethyl ether, dioxane, tetrahydrofuran or 1,2-dimethoxyethane), amides (e.g. dimethylformamide) or dimethylsulfoxide or, if appropriate, suitable mixtures of such solvents. The benzimidazole derivative III is preferably reacted in the presence of a strong base (such as KOH or NaOH).

Surprisingly, it has been found that compounds having a specific structure of formula I have a biocidal spectrum of activity, which is particularly desirable from a practical point of view in the control of phytopathogenic microorganisms, especially fungi. These compounds have very advantageous curative and preventive properties and are useful for protecting a large number of crops. The active compounds of the formula I permit the control of diseases on plants or parts of plants (fruits, flowers, leaves, stalks, tubers and roots), whereby even parts of the plants which are produced after application of the active substance are already free of phytopathogenic fungi. .

The novel active compounds of the formula I have been shown to be active against specific genus fungi imperfecti (e.g. Cercospora), Basidiomycetes (e.g. Puccinia) and Ascomycetes (e.g. Erysiphe and Venturia), but in particular against Oomycetes (e.g. Plasmopara, Peronospora, Pythium, Bremia and Phytophthora). These compounds are also a valuable adjunct to compositions used in plant protection to control phytopathogenic fungi. In practical application, these compounds have both a preventive and a curative effect and can also be used to protect a large number of crops. By using these active substances, pests found on plants or plant parts (fruits, flowers, leaves, stalks, tubers and roots) of a wide range of useful plants can be controlled or destroyed, even those parts of the plants which are formed later remain free of from phytopathogenic fungi. The compounds of the formula I can furthermore be used as agents for the treatment of seeds (fruit, tubers, grain) and plant debris in order to protect them against fungal infection and soil phytopathogenic fungi.

The invention also relates to compositions which contain the compounds of the formula I as active substances and their use in the field of agriculture or in adjacent areas.

In addition, the invention also encompasses the preparation of such compositions, the principle of which is to admix the active compound perfectly with one or more of the substances or groups of substances described herein. The invention also encompasses a method of treating plants which comprises applying new compounds of formula I or novel compositions.

Plants which can be treated for protection in the context of the invention are, for example, the following plant species: cereals (wheat, barley, rye, Triticale, oats, rice, maize, sorghum and the like), beets (sugar beet and fodder beet), palm fruits, stone fruits and soft fruits (apples, pears, plums, peaches, almonds, cherries, strawberries, raspberries and blueberries), legumes (beans, lentils, peas, soybeans), oilseeds (rape, mustard, poppy, olives, coconuts, castor oil plants, cocoa, groundnuts, cucumbers (cucumbers, cucumbers, pumpkins), fiber (cotton, flax, hemp, jute), citrus fruits (oranges, lemons, grapefruit, mandarins), vegetable crops (spinach) , lettuce, asparagus, tusk, carrot, onion, tomato, potato, pepper), Lauraceae (avocado, cinnamon, camphor) or other fruit, such as tobacco, nuts, coffee, sugar cane, tea and other flavoring ras herbs, vines, hops, Musaceae and latex plants, as well as ornamental plants.

The active compounds of the formula I are generally used in the form of compositions and can be applied to areas or plants either simultaneously with the other active substances or after or before the application of the other active substances. These other active substances may be fertilizers, trace element mediators or other preparations which affect the growth of plants. Similarly, selective herbicides as well as insecticides, fungicides, bactericides, nematicides, molluscicides, or mixtures of several of these agents can be used, together with or without the carriers customarily used in these types of formulations, surfactants or other additives which improve the effectiveness of the applied substances.

Suitable carriers or additives may be solid or liquid and are substances which are commonly used in these types of formulations, for example natural or regenerated minerals, solvents, dispersants, wetting agents, thickeners, binders or fertilizers.

A preferred method of administering an active ingredient of the formula I or an agrochemical composition comprising at least one such active ingredient is foliar application. The frequency and rate of application depend on the risk of infestation by the pathogen. The compounds of the formula I can also be applied to seeds (coating application), either by impregnating the grain in a liquid preparation containing the active substance or by coating the grain with a solid preparation.

The compounds of the invention are used either as pure active ingredients or preferably in combination with excipients usually used in these types of formulations. For this purpose, these compounds are preferably processed in a known manner to give, for example, emulsion concentrates, spreadable pastes, directly sprayable or dilutable solutions, dilute emulsions, wetting powders, soluble powders, dusts, granules or encapsulated formulations in which polymeric substances are used as the coating agent. . Depending on the circumstances and objectives pursued, the nature of the applied formulation is selected and the formulation is applied by spraying, dusting, dispersing, brushing or brushing or in the form of an impregnating bath.

Favorable application rates are generally 5 g to 2 kg of active ingredient (A.I.) per hectare (ha), preferably 10 g to 1 kg of A.I./ha, in particular 20 g to 600 g of A.I./ha.

The formulations, i. compositions, preparations or compositions containing the active compound of the formula I, with or without a solid or liquid additive, are prepared in a known manner, for example by intimately mixing and / or grinding the active compound with extenders such as solvents, solid carriers and optionally surfactants .

Aromatic hydrocarbons, preferably fractions containing 8 to 12 carbon atoms, such as xylene mixtures or substituted naphthalenes, phthalic acid esters such as dibutyl phthalate or dioctyl phthalate, aliphatic hydrocarbons such as cyclohexane or paraffins, alcohols and glycols, as well as their ethers, may be used as solvents. and esters such as ethanol, ethylene glycol, ethylene glycol monomethyl ether and ethylene glycol monoethyl ether, ketones such as cyclohexanone, strongly polar solvents such as N-methyl-2-pyrrolidone, dimethylsulfoxide or dimethylformamide, and epoxidized or non-epoxidized soybean oil, such as epoxidized or coconut oil; Water.

Solid carriers which are generally used, for example, for the preparation of dusts and dispersible powders are ground natural minerals such as calcite, talc, kaolin, montmorillonite or attapulgite. Highly dispersed essential oil or high absorbent polymers may also be added to improve physical properties. Possible particulate adsorbent carriers for granular compositions are porous type materials such as pumice, clay, sepiolite or bentonite, while possible non-adsorbent carrier materials are, for example, calcite or sand. In addition, a large number of pre-granulated substances of an inorganic or organic nature, such as dolomite or ground plant residues, may be used.

Suitable surfactants are nonionic, cationic and / or anionic surfactants having good emulsifying, dispersing and wetting properties, the choice of which depends on the active compound of the formula I to be formulated. Surfactants are also understood as meaning mixtures of surfactants.

Possible anionic surfactants can be so-called water-soluble soaps as well as water-soluble synthetic surfactants.

Examples of nonionic surfactants are nonylphenolpolyethoxyethanols, castor oil polyglycol ethers, polypropylene oxide and polyethylene oxide adducts, tributylphenoxypolyethylethanol, polyethylene glycol and octylphenoxypolyethoxyethanol.

Fatty acid esters of polyoxyethylene sorbitan, such as polyoxyethylene sorbitan trioleate, are also suitable.

Cationic surfactants are in particular quaternary ammonium salts which contain an alkyl group having 8 to 22 carbon atoms as N-substituents and a lower halogenated or free alkyl group, a benzyl group or a lower hydroxyalkyl group as further substituents.

Other surfactants commonly used in this type of formulation are known to those skilled in the art or can be found in the corresponding literature.

Agrochemical preparations generally contain from 0.1 to 99% by weight, in particular from 0.1 to 95% by weight, of active compound of the formula I, from 99.9 to 1% by weight, in particular from 99.8 to 5% by weight of solid or liquid additives and % by weight, in particular 0.1 to 25% by weight, of a surfactant.

While a concentrate is preferred as a commercially available form of said formulations, the consumer generally uses the agrochemical formulation in diluted form.

Said compositions may also contain other additives such as stabilizers, antifoams, viscosity regulators, binders or thickeners, as well as fertilizers or other active substances, the choice of such additives being chosen to achieve the desired specific effects.

In the following, the invention will be explained in more detail by way of examples or specific embodiments, these examples being for the purpose of illustration only and are not intended to limit the scope of the invention as defined by the claims.

DETAILED DESCRIPTION OF THE INVENTION

Example 1

preparation

1- (3) -Dimethylsulfamoyl-2-cyano-4,6-bistrifluoromethylbenzimidazole (compound 0.3) of formula

Dissolve 10.0 g (36 mmol) of 2-cyano-4,6-bistrifluoromethylbenzimidazole in 100 ml of acetone, then add 2.6 g of potassium hydroxide (85%, powder) to the obtained solution and stir the mixture for one hours at 25 c. The solution will now turn orange. 5.8 ml of Ν, Ν-dimethylsulfamoyl chloride are slowly added dropwise to the solution. The ongoing reaction is slightly exothermic. The mixture is stirred for 22 hours at ambient temperature and finally filtered, the filtrate is concentrated to dryness in a rotary evaporator and the residue is dissolved in methylene chloride, then silica gel is added to the solution. After stirring the mixture for 2 hours, the mixture is filtered, the filtrate is concentrated and digested with ether, and then the product is finally filtered off and dried.

Yield: 4.6 g, melting point: 166-168 C.

Example 2

Preparation 1 (3) -Dimethylsulfamoyl-2-carbothioamido-4,6-bistrifluoromethylbenzimidazole (compound 1,3) of formula

140 g (0.36 mol) of 1 (3) -dimethylsulfamoyl-2-cyano-4,6-bistrifluoromethylbenzimidazole are dissolved in 1500 ml of dioxane at ambient temperature and with stirring, then 490 ml of tetrahydrofuran are added to the obtained solution and then 53 ml. ml triethylamine. The hydrogen sulfide was slowly introduced into the mixture for 2 hours at ambient temperature. When the reaction is complete, the reaction mixture is concentrated in a rotary evaporator to about half the volume and then poured into a mixture of ice and water while stirring, the precipitate formed being filtered off under vacuum and washed with water. After drying, crystals are obtained which melt on decomposition at 212 to 213 ° C.

Example 3

Preparation 1 (3) -Dimethylsulfamoyl-2-carbothioamido-4,6-bistrifluoromethylbenzimidazole-S-oxide (compound 2,2) of formula

2.0 g (5 mmol) of 1 (3) -dimethylsulfamoyl-2-carbothioamido-4,6-bistrifluoromethylbenzimidazole are suspended in 30 ml of glacial acetic acid. To the suspension obtained was added 1.87 g of anhydrous sodium acetate. A dense yellow suspension is formed. 0.5 ml of hydrogen peroxide (30% in water) is slowly added to this suspension with vigorous stirring, and the mixture is stirred for 3 hours at 20 ° C. The reaction mixture is then poured into ice-water, and the solid is filtered off. and the filtrate is washed with water until neutral and dried at temperature

C in the oven.

Yield: 1.85 g (88.9% of theory);

Preparation of intermediates

(a) 2-Cyano-4,6-bistrifluoromethylbenzimidazole

12.2 g (50 moles) of 1,2-diamino-3,5-bistrifluoromethylbenzene are dissolved in 50 ml of glacial acetic acid, then 13.3 g (83 mmol) of methyl- 2,2,2-trichloroacetamides. The reaction mixture is stirred until the adduct disappears. Using tetrahydrofuran, the reaction mixture is then transferred to a dropping funnel and 290 ml of concentrated ammonia are added dropwise to the reaction solution under ice-cooling. After stirring the reaction mixture at 25-30 ° C for 1 hour, the mixture was concentrated on a rotary evaporator, water was added to the oily residue and the mixture was acidified with concentrated hydrochloric acid. The product was extracted with ethyl acetate, washed with water, dried over sodium sulfate and concentrated. The remaining oil is chromatographed on silica gel using ethyl acetate as eluent. This gives about 15 g of an oil which is sufficiently pure in the next step.

b) 1,2-Diamino-3,5-bistrifluoromethylbenzene

13.8 g (50 mmol) of 2-nitro-4,6-bistrifluoromethylaniline are dissolved in 140 ml of tetrahydrofuran, then 6 g of Raney nickel are added to the obtained solution and the mixture is hydrogenated at atmospheric pressure and at 20-25 ° C. the hydrogen uptake ceased, the hydrogenation catalyst was removed by filtration, and the solvent was distilled off in a rotary evaporator.

c) 2-Nitro-4,6-bistrifluoromethylaniline

19.6 g (58 mmol) of 2-nitro-4,6-bistrifluoromethyl bromobenzene are dissolved in 70 ml of ethanol, then 15 g of ammonia are injected into the autoclave and the mixture is heated to 125 C. After 6 hours, the autoclave is drained, the reaction mixture It is concentrated, stirred with water and filtered, and the collected solid is dried. Yield: 14.8 g, melting point: 72-73 ° C.

d) 2-Nitro-4,6-bistrifluoromethylbromobenzene

19.5 g (66 mmol) of 2,4-bistrifluoromethylbromobenzene are heated to about 95 DEG C. While stirring, 80 ml of a 1: 1 mixture of concentrated sulfuric acid and fuming nitric acid are added dropwise. When the reaction is complete, stirring is continued for 2 hours at 95-100 ° C. After cooling, the reaction mixture is poured into ice-water and the product is extracted with ethyl acetate and washed with water, dilute sodium hydroxide solution and brine, dried over sulfate. sodium and thicken. The remaining oil is chromatographed on a short column of silica gel, eluting with hexane.

Yield: 20.6 g of an oil.

Here and in the following the 1 (3) -dimethylsulfamoyl group may also be referred to as a 1 (3) -dimethylaminosulfonyl group.

The following are examples of other compounds that can be prepared by this method or by one of the above methods.

Table O

(Ia)

Compound No. R 2 temperature Heating: 0.1 CH 3 199-202 C 0.2 cyclopentyl 0.3 ⁿ < ^ch ₃ ) ₂ 166-168 C 0.4 cyclohexyl 0.5 C H -terc. 4 © 0.6 cyclopropyl 0.7 C H -sec. 0.8 C H -n 4 9 0.9 CH ³ N XCH 2 5 120-121 C 00:10 C H -i 3 7 00:11 N (C H) '2 S' 2 112-115 C 00:12 CH / ³ N XCH -1 37 00:13 C H -n 3 7 00:14 C H 2 5

Table 1

(Ib)

Compound No. R 2 temperature mp 1.1. CH 3 1.2 cyclopentyl 1.3 -N (CH) 212-213 C 1.4 cyclohexyl 1.5 -CH -terc. 4 & 1.6 cyclopropyl 1.7 -CH -sec. 4 θ 1.8 -CH -n 4 θ 1.9 CH ³ -N-CH 204-205 C 1.10 -CH -i 3 * 7 1.11 -N (C H) '2 S * 2 165-167 C 1.12 CH ² -N-CH 3 13 1.13 -CH -n 3 7 1.14 -C H

Table 2

(Ic)

Compound No. R 2 Melting point 2.1. CH 3 2.2 -N (CH) '3'2 162-164 C 2.3 CH ³ -N-H 2 5 162-163 C 2.4 -N (CH) ^x 25 * 2 149-150 C 2.5 CH / ³ -N, H-13V

Examples of formulations of the active compounds of the formula I (% = weight percent)

2.1. Soaking powders a) b) c)

Active substance from tables% 50% 75%

Sodium lignin sulphonate 5%

Sodium lauryl sulfate 3%

Sodium diisobutylnaphthalenesulfonate

Oktylfenolpolyetylénglykol20

ether (7-8 moles of ethylene oxide) - 2 % - Highly disperse silicas 5 % 10 % 10 kaolin 62 % 27 % -

The active ingredient is thoroughly mixed with the ingredients and the resulting mixture is thoroughly ground in a suitable mill. Thus, soaking powders are obtained which can be diluted with water to form suspensions of any desired concentration of active ingredient.

2.2 Emulsion concentrate

Active substance from tables 10% Oktylfenolpolyetylénglykoléter 3% (4-5 moles of ethylene oxide) Calcium dodecylbenzenesulfonate 3% Castor oil polyglycol ether 4% (35 moles of ethylene oxide) cyclohexanone 34% Xylene mixture 50%

By diluting this concentrate with water, emulsions of any desired concentration can be prepared.

2.3 dusts

a)

b)

Active substance from tables

talc

kaolin

Dustable applications are obtained by mixing the active ingredient with a carrier and grinding the resulting mixture in a suitable mill.

2.4 Granules obtained by extrusion

Active substance from tables

N-lignin

carboxymethylcellulose

kaolin

%

The active ingredient is mixed with the ingredients and the resulting mixture is ground and moistened with water. The mixture thus obtained is extruded in an extruder and then air-dried.

2.5. Coated granules

Active substance from tables

Polyethylene glycol (molecular weight 200)

kaolin

%

The finely divided active substance is uniformly applied in a mixer to kaolin which has been moistened with polyethylene glycol. In this way, dust-free coated granules are obtained.

2.6 Suspension concentrate

Active substance from tables

ethylene glycol

Nonylphenolpolyethylene glycol ether (15 moles of ethylene oxide)

Sodium lignin sulphonate 10%

Carboxymethylcellulose 1%

37% aqueous formaldehyde solution 0,2%

Silicone oil in the form of 75% aqueous emulsion 0.8%

Water 32%

The finely divided active ingredient is thoroughly mixed with the ingredients. A suspension concentrate is obtained from which a suspension can be prepared by diluting with water at any desired concentration of active ingredient.

Biological examples

Example 3.1

Action against Plasmopara viticola on vines

(a) Residual protective effect

Grape vine seedlings in the 4-5 leaf stage are sprayed with a spray mixture prepared from a soaking powder containing 0.02% active ingredient. After 24 hours, the treated plants are infected with the sporangium suspension of the fungus. The fungal infection is evaluated after a 6-day incubation at 20 ° C and 95-100% relative humidity.

b) Residual curative effect

Grapevine seedlings in the 4-5 leaf stage are infected with the sporangium suspension of the fungus. The infected plants are incubated in a humid chamber for 24 hours at 20 ° C and 95-100% relative atmospheric humidity, then dried and sprayed with a spray mixture prepared from a soaking powder containing 0.02% active ingredient. After the spray coating has dried, the treated plants are returned to the wet chamber. The fungal infestation is evaluated 6 days after infection.

Good to very good protection against Plasmopara viticola on grapevines is obtained using the compounds of Tables 0, 1 and 2 (fungal infestation reduced to 10 to 0%). In particular, active compounds 0,3, 1,3 and 2,2 cause complete control of the fungal infestation (residual infestation 0-5%). In contrast, infestation of untreated but infected plants with Plasmopara is 100%.

Example 3.2

Effect against Phytophthora on tomatoes

Residual protective effect

Tomato plants are grown for 3 weeks and then sprayed with a spray mixture prepared from a soaking powder containing 0.02% active ingredient. After 24 hours, the treated plants are infected with the sporangium suspension of the fungus. The fungal infestation is evaluated after the infected plants have been incubated for 5 days at 20 ° C and 90-100% relative atmospheric humidity.

The compounds of Tables 0, 1 and 2 show demonstrable efficacy (fungal infestation is less than 20%). Using compounds 0,3, 1,3, 2,2 and others, fungal infestation is prevented completely (0-5% infestation). In contrast, the infestation of untreated but infected plants with Phytophthora is 100%.

Example 3.3

Effect against Phytophthora on tomatoes

Residual protective effect

Tomato plants (age: 2 to 3 weeks, variety: Bintje) are grown for 3 weeks, then sprayed with a spray mixture prepared from a soaking powder containing 0.02% active ingredient. After 24 hours, the treated plants are infected with the sporangium suspension of the fungus. The fungal infestation is evaluated after the infected plants have been incubated for 5 days at 20 ° C and 90-100% relative atmospheric humidity.

The compounds of Tables 0, 1 and 2 show a demonstrable effect (fungal infestation is less than 20%). Using compounds 0,3, 1,3, 2,2 and others, fungal infestation is prevented completely (fungal infestation is 0 and 5%). In contrast, the infestation of untreated but infected plants with Phytophthora is 100%.

Example 3.4

Action against Pythium on corn and sugar beet

(a) Effect after soil impregnation

The fungus is grown on oat grain and the infected grain is then added to the soil / sand mixture. The infected soil is then filled with pots and planted with sugar beet or corn. Immediately after sowing, a test preparation, which is formulated as a wetting powder and, if used, is in the form of an aqueous suspension (20 ppm of active ingredient, based on soil volume), is poured onto the soil. The pots are then stored in a greenhouse at 20-24 ° C for 2 to 3 weeks. The soil in the pots is kept evenly moist by constant spraying with a small amount of water. The evaluation of this test shall determine the rate of emergence of maize or sugar beet and the number of healthy and disease-affected plants.

(b) Effect after seed dressing

The fungus is grown on sterile oat grain, which is added to a mixture of soil and sand. The infected soil is filled with pots, which are then planted with corn or sugar beet, the seeds of which are pickled with a test preparation formulated as a seed treatment powder (1000 ppm of active ingredient, based on seed weight). The planted seed pots are then stored in a greenhouse at 20-24 ° C for 2 to 3 weeks. The soil in the pots is kept evenly moist by constant spraying with a small amount of water. The evaluation of this test shall determine the rate of emergence of maize or sugar beet and the number of healthy and disease-affected plants.

After treatment with Compound 1.3 of Table 1, 80% emergence of the plants is achieved, the emerging plants having a healthy appearance.

Claims (11)

PATENT CLAIMS 1. A compound of benzimidazol of formula I (I) wherein R ₂ ^S0 ₂ ^is in position 1 or 3, and causes the formation of pure or mixed positional isomers of the substituent CF _3, R is CN or -CS (= O) _n NH ₂ , R _a is C 1 -C 4 alkyl, C 3 -C 6 cycloalkyl or -N (R ') ₂ wherein R' is the same or different C 1 -C 3 alkyl, and n is 0 or 1, provided that R is -CS (= O) 4 NH 4 when R ₂ is dimethylamino. 2. A benzimidazolesulfonic acid derivative of the general formula (Ib) in which the group R @ 1 SO2 is in the 1-position or 3 and causes formation of pure or mixed positional isomers with respect to the substituents CF ₃ , R is -CSNH ₂ , R ₂ is C 1 -C 4 alkyl, C 3 -C 6 cycloalkyl or -N (R ') wherein R 'is the same or different alkyl groups having 1 to 3 carbon atoms. A compound according to claim 1, wherein R ₂ is C 1 -C 2 alkyl, cyclopropyl, or -N (R '), wherein R' is methyl or ethyl, and n is 0 or 1. A compound according to claim 3 wherein R ₂ is methyl or N (CH ₃ ) ₂ and n is 0 or 1. The compound of claim 2, wherein R ₂ is methyl or -N (CH ₃ ) ₂ . The compound of claim 3 consisting of 1 (3) -dimethylaminosulfonyl-2-carbothioamido-4,6-bistrifluoromethylbenzimidazole-S-oxide. The compound of claim 3 consisting of 1 (3) -dimethylaminosulfonyl-2-carbothioamido-4,6-bistrifluoromethylbenzimidazole. A compound according to claim 4, wherein R ₂ is a dimethylamino group and n is 0 or 1. 9. A composition for controlling and preventing infestation of plants by microorganisms, characterized in that it comprises an active compound of the formula I together with a suitable carrier material. 10. A method of controlling and preventing infestation of plants by microorganisms, characterized in that a compound of the formula I is applied as an active substance to plants, parts of plants or to the substrate forming the plant growth medium. 11th Use of a compound according to claim 1 as a microbicide. 12th A process for the preparation of a compound of the general formula Ib according to claim 1, characterized in that the compound of formula (I) Ia reacts with H, S in the presence of a base at a temperature of -20 to 80 ° C. A process for the preparation of a compound of formula Ic according to claim 1, characterized in that the compound of formula Ib is oxidized with an organic peroxide or hydrogen peroxide at a temperature of -20 to 60 ° C.