CS214751B2 - Fungicide means and method of making the active component - Google Patents

Abstract

1. 1-(2,4-Dichlorophenyl)-1-(2,6-dihalogenobenzyl- mercapto)-2-(1,2,4-triazol-1-yl)-ethanes of the general formula see diagramm : EP0022531,P12,F1 in which X and Y are identical or different and represent halogen, and physiologically acceptable acid addition salts thereof.

Description

The present invention relates to a fuingicidal composition comprising as active ingredient the novel 1- (2,4-dichlorophenyl) -1- (2,6-dichlorobenzylmercapto) -2- (1,2,6-dichloro-ethane) ethane. The invention further relates to processes for the preparation of the novel active ingredient and to its use as a fungicide.

It is already known that certain substituted 1-benzylmercapto-1-phenyl-2- (1,2,4-triazol-1-yl) ethanes such as 1- (2,4-dichlorophenyl) -1- ( 2,4-dibromobenzylmercapto) -2- (1,2,4-triazol-1-yl) ethane, have good fungicidal properties (cf. DOS 2,724,684). However, their effect is not always sufficient in certain areas of indication, especially at low application rates and concentrations.

We have now found the novel 1- (2,4-dichlorophenyl) -1- (2,6-dichloro-benzylamino) -2- (1,2,4-1-triazol-1-yl) ethane of formula I

H1) and its physiologically acceptable acid addition salts.

Accordingly, the present invention provides a fungicidal composition which comprises 1- (2,4-dichlorophenyl) -1- (2,6-dichlorobenzylmercapto) -2 - (1,2,4-triazo-M-) as the active ingredient. yl) ethane or a physiologically acceptable acid addition salt thereof.

According 'to the invention is l- (2,4-dichlorophenyl) -l- (2,6-1-ИсЫо <гЬепгу ^llne'Γkap: a) -2- (1,2,4-triazol-yl) -ethane of the formula I is prepared by producing 1- (2,4-dichlorophenyl) -1-halo-2- (1,2,4-triazol-1-yl) ethanes of the formula II

in which

Hal is a halogen atom, according to reaction III with mercaptan

Cl in which H-S-CH 2 -; Z is halogen or groups -0-SO2-R ¹ ct (lil) or

at a temperature of 20 to 150 ° C, optionally in the presence of a diluent and an acid-binding agent, the mercaptan of formula III preferably being used in situ.

This process of the invention will hereinafter be referred to as process a).

The compound of formula (I) may be further produced by:

b) 1- (2,4-dichlorophenyl) -2- (1,2,4-triazol-1-yl) ethane-1-thiol of formula IV

(IV) reacts with a 2,6-dichlorobenzyl derivative of formula (V)

-N (R ²⁾ with ^(+), wherein

R ¹ represents an alkyl group or an optionally substituted phenyl group and

R ² represents an alkyl SKU-pin, in the presence of a diluent and in the presence of a base.

The acid of the compounds of formula I thus obtained may optionally be added thereafter.

The novel 1- (2,4-dichlorophenyl) -1- (2,6-dichlorobenzylmercapto) -2- (1,2,4-triazol-1-yl) ethane according to the invention has potent fungicidal properties. Surprisingly, the compound according to the invention exhibits a considerably higher effect than the known 1- (2,4-dichlorophenyl) -1-

- (2,4-dichlorobenzylmercapto) -2- (1,2,4-triazol-1-yl) ethane, which is the closest chemical compound and is related to action. Thus, the compounds of the invention (including salt) are enriched in the art.

When 1-chloro-1-

- (2,4-dichlorophenyl) -2- (1,2,4-triazol-1-yl) ethane and 2,6-dichlorobenzyl mercaptan, the reaction according to the invention can be illustrated by the following reaction scheme [process a)]:

If, for example, 1-chloro-1- (2,4-dichlorophenyl) -2- (1,2,4-triazol-1-yl) ethane, 2,6-dichlorobenzyl chloride and thiourea are used as starting materials, the The reaction scheme is represented by the following reaction scheme [process a) without isolation of the intermediate]:

+

-Na.OH

NaCl, -O2ClNH4

If, for example, 1- (2,4-dichlorophenyl) -2- (1,2,4-triazol-1-yl) ethan-1-thiol and 2,6-dichlorobenzyl chloride are used as starting materials, then the reaction may proceed illustrated by the following reaction scheme [process b)]:

Cf bážó

Cl

The 2 (2,4-dichlorophenyl) -thaloyl-2- (1,2,4-triazol-1-yl) ethanes which are used as starting materials in carrying out process (a) of the invention are generally defined by the formula

II. In this formula. means Ha! preferably chlorine or bromine.

1- (2,4-Dichlorophenyl) -1-halo-2- (1,2,4-triazol-1-yl) ethanes of formula II are known [cf. DOS No. 2,547,954). These compounds are obtained by:. reacting the corresponding known 1- (2,4-dichlorophenyl) -1-hydropyloxy-2- (1,2,4-glyphol-1-yl) ethanethane (cf. DOS 2 431407) is reacted with a hydrogen halide cleaving agent, for example with thionyl chloride, optionally in the presence of a diluent, such as chloroform, at temperatures between 20 and 100 ° C.

The mercaptan further used as starting material for the process of the invention is defined by the formula. III.

The mercaptan of formula (III) is a generally known compound of organic chemistry and is obtained in a generally conventional manner by the addition of. known 2,6-dichlorobenzyl halides of the general formula VI in which

Hal is as hereinbefore defined, reacting with thiourea in the presence of a strong base, such as sodium hydroxide in particular, and in the presence of a solvent such as ethanol with heating. The resulting mercaptan can be reacted directly with the compounds of the formula II without isolation in a single reaction step (cf. also the examples).

The preparation of 1- (2,4-dichlorophenyl) -2- [1,2,4-riazolyl-yl] ethaneththiol of formula IV, which is used as starting material in process b), is described in the Examples.

The 2,6-di-benzobenzyl derivatives which are further used as starting materials for process b) are generally defined by formula V. In this formula, Z is preferably chlorine, bromine, iodine, as well as the groups -O-SO2-R1 and -N (R ² ) 3 ⁽ +), wherein R 1 is preferably C 1 -C 4 alkyl or optionally C 1 -C 2 alkyl, chlorine, bromine, C 1 -C 2 alkoxy or nitro substituted and R 2 is preferably C 1 -C 2 alkyl.

Formula V are generally known compounds of organic chemistry.

All physiologically acceptable acids are suitable for the preparation of acid addition salts of the compound of formula (I). These preferably include hydrohalic acids such as hydrochloric acid and hydrobromic acid, in particular hydrochloric acid, further phosphoric acid, nitric acid, sulfuric acid, mono- and dibasic carboxylic acids and hydroxycarboxylic acids such as acetic acid, maleic acid, succinic acid fumaric acid, tartaric acid, citric acid, sorbic acid, lactic acid, as well as sulfonic acids such as p-toluenesulfonic acid and 1,5-naphthalenedisulfonic acid.

Salts of the compound of formula (I) may be obtained in a simple manner according to conventional salt-forming methods, for example by dissolving the compound of formula (I) in a suitable inert solvent and adding an acid such as hydrochloric acid and isolated in a known manner, for example by filtration and optionally purified by an inert organic wash solvent.

Suitable diluents for the reaction according to the invention [process a)] are preferably inert organic solvents or aprotic solvents. These preferably include ketones, such as diethyl ketones, in particular acetone and methyl ethyl ketone; alcohols such as ethanol or isopropanol; nitriles, such as propyl, especially acetonitrile; hydrocarbons such as ligroin, petroleum ether, benzene, toluene, xylene; as well as formamides, in particular dimethylformamide.

The reaction according to the invention [according to process a) ·] is carried out in the presence of an acid binding agent. Any customary inorganic or organic acid binding agent such as an alkali metal carbonate such as sodium carbonate, potassium carbonate and sodium hydrogen carbonate, or lower tertiary alkylamines, cycloalkylamines or aralkylamine such as triethylamine, dimethylbenzylamine or dimethylcyclohexylamine may be added; or pyridine and diazabicyclooctane as well as alkali metal alkoxides such as sodium methoxide, potassium ethoxide or alkali metal hydroxides such as sodium hydroxide and potassium hydroxide.

The reaction temperatures can be varied within a wide range when carrying out the process according to the invention [process a)]. In general, the reaction is carried out at temperatures between 20 and 150 ° C, preferably at the boiling point of the solvent, for example between 60 and 100 degrees Celsius.

In the process according to the invention, about 1 to 2 moles of mercaptan of formula (III) and about 1.5 to 2.5 moles of acid-binding agent are used per mole of the compounds of formula II. In order to isolate the compound of formula I, the reaction mixture is filtered, the filtrate is concentrated, and the residue is digested with an aqueous base. It is shaken into an organic solvent and the reaction product is isolated in the usual manner. The reaction products may optionally be purified by recrystallization.

In a preferred embodiment of the process of the invention, the process is carried out in a single step, i.e. without isolation of the mercaptan of formula III. In this case, preferably 1.2 to 2 moles of benzyl halide (IV), 1.2 to 2 moles of thiourea and 2 to 3 moles of base are used per mole of the compounds of the formula II. The isolation of the compound of formula I is carried out in a conventional manner.

Suitable solvents for the reaction according to variant b) are protic and aprotic solvents, in particular those in which the reactions S 1 _N 1 and S _N 2 are carried out. These include, for example, water, alcohols, carboxylic acids, acetone, acetonitrile, dimethylformamide, dimethylacetamide, dimethylsulfoxide, tetramethylurea or aromatic hydrocarbons such as toluene.

The reaction according to variant bj is carried out in the presence of a base. These include all customary organic and especially inorganic bases such as sodium hydroxide and potassium hydroxide or sodium carbonate or potassium carbonate.

In carrying out process b), the reaction temperatures can be varied within a wide range. In general, the reaction is carried out at temperatures between 20 and 150 ° C, preferably between 20 and 100 ° C, optionally at the boiling point of the solvent used.

In process b), preferably 1 to 3 mol of 2,6-dichlorobenzyl derivative of formula V is used per mole of compound of formula IV. In order to isolate the reaction products, the reaction mixture is freed from the solvent and the residue is mixed with water and an organic solvent. The organic phase is separated and worked up in the usual manner.

The active compounds according to the invention have a strong microbicidal action and can be used for combating undesirable microorganisms. The active compounds are suitable as plant protection agents.

Fungicidal compositions are used in plant protection to combat fungi of the class Plasmodiophoromycetes, Oomycetes, Chytridicimycetes, Zygomyceites, Ascomycetes, Basidiomycetes, Deuteromycetes.

The good purity of the active ingredients at the concentrations necessary to combat plant diseases by plants allows the treatment of aboveground parts of plants, seedlings and seeds, as well as the soil.

As plant protection agents, the active compounds according to the invention can be used with a particularly good result in combating powdery mildew species, such as cucumber powdery mildew (Erysiphe cichoacearum) and true powdery mildew (Podosphaera leucotricha).

The active substances can be converted into round formulations such as solutions, emulsions, suspensions, powders, foams, pastes, granules, aerosols, natural and synthetic substances impregnated with active substances, small particles coated with polymeric substances and coating materials for seeds, flammable additives such as smoke cartridges, smoke jars, smoke spirals and the like, as well as compositions in the form of active ingredient concentrates for cold or hot mist dispersion.

These compositions are prepared in a manner known per se, for example by mixing the active ingredient with fillers, i.e. liquid solvents, liquefied gases under pressure and / or solid carriers, optionally using surfactants, i.e. emulsifiers and / or dispersants. and / or foaming agents. If water is used as a filler, it is also possible to use, for example, organic solvents as co-solvents. Basically suitable liquid solvents are: aromatics, such as xylene, toluene or alkylnaphthalenes, chlorinated aromatics or chlorinated aliphatic hydrocarbons, such as chlorobenzenes, chlorethylenes or methylene chloride, aliphatic hydrocarbons, such as cyclohexane or paraffins, for example petroleum fractions, alcohols such as butanol or glycol, as well as their ethers and esters, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone, strongly polar solvents such as dimethylformamide and dimethylsulfoxide, and water. By liquefied gaseous fillers or carriers is meant liquids which are gaseous at normal temperature and pressure, for example aerosol propellants, such as halogenated hydrocarbons, as well as butane, propane, nitrogen and carbon dioxide. Suitable solid carriers are: natural stone meal, such as kaolins, alumina, talc, chalk, quartz, attapulgite, montmorillonite or diatomaceous earth, and synthetic stone meal, such as highly disperse silica, alumina and silicates. Suitable solid carriers for the preparation of the granules are crushed and fractionated natural stone materials such as limestone, marble, pumice, sepiolite and dolomite as well as synthetic granules of inorganic and organic flours and granules of organic material, such as sawdust, coconut shells, corn sticks and tobacco stems. Suitable emulsifiers and / or reinforcing agents are non-ionic and anionic emulsifiers, such as polyoxyethylene fatty acid esters, fatty alcohol polyoxyethylene ethers, e.g.

The compositions of the invention may include adhesives such as carboxymethylcellulose, natural and synthetic powdered, granular or Jexex polymers such as gum arabic, polyvinyl alcohol and polyvinyl acetate.

In addition, these compositions may contain coloring agents such as inorganic pigments, for example iron oxide, titanium dioxide and ferrocyanide blue, and organic dyes such as alizarin dyes and metallic azo-phthalocyanine dyes, as well as trace elements such as iron, manganese, boron, copper salts. , cobalt, molybdenum and zinc.

The concentrates generally contain between 0.1 and 95% by weight, preferably between 0.5 and 90% by weight, of active ingredient.

The active compounds according to the invention may be present in the formulations in admixture with other known active substances, such as fungicides, bactericides, insecticides, acaricides, nematocides, herbicides, avian ozone preservatives, growth agents, plant nutrients with plant-improving agents. soil structure.

The active compounds according to the invention can be applied as such, in the form of concentrates or from them. by diluting the ready-to-use dosage forms, such as ready-to-use solutions, emulsions, suspensions, powders, pastes and granules. Application is carried out in a conventional manner, for example by watering, dipping, spraying, evaporating mist, injection, suspension, coating, dusting, tossing, dry pickling, wet pickling, wet pickling or suspension or incrustation.

In the treatment of plant parts, the co-concentration of the active substance in the use forms can vary within wide limits. They are generally between 1 and 0.0001% by weight, preferably between 0.5 and 0.001% by weight.

In the treatment of seed, the active compound is generally required in an amount of from 0.001 to 50 g per kg of seed, preferably 0.01 to 10 g.

In soil treatment, active compound concentrations of from 0.00001 to 0.1% by weight, preferably from 0.0001 to 0.02% by weight, are required at the site where the effect is to be achieved.

Example A

Powdery mildew test (Erysiphej / protective effect (cucumbers)

Solvent: 4.7 parts by weight of acetone

Emulsifier: 0.3 part by weight of alkylaryl polyglycol ether

Water: 95.0 parts by weight

The amount of active ingredient required to achieve the desired active ingredient concentration in the liquid spray is mixed with the indicated amount of solvent and the concentrate is diluted with the specified amount of water containing the above ingredients.

Young cucumber plants having about 3 leaves are sprayed by liquid spray until dew. The plants are allowed to dry for 24 hours in a greenhouse and then inoculated by dusting with spores of Erysiphe cichoracearum (powdery mildew). The plants are then stored in a greenhouse at a temperature of 23-24 ° C and about 75% relative humidity.

After 12 days, cucumber plants were found to be infected. The values obtained are converted to infestation in%. 0% means no attack,

100% means complete infestation of plants.

Active substances, active substance concentrations and results are shown in the following table:

Table A

Powdery mildew test (Erysiphe) / protective effect (cucumbers)

Active substance

Infestation in% at active compound concentration of 0.0005%

(known)

^{5 C1} > \

Ct .2 HNOj (2)

Example В

Protective test for apple powdery mildew (Podosphaera)

Solvent: 4.7 parts by weight of acetone

Emulsifier: 0.3 part by weight of alkylaryl polyglycol ether

Water: 95.0 parts by weight

The amount of active ingredient required to achieve the desired concentration of active ingredient in the spray is mixed with the indicated amount of solvent and the concentrate is diluted with the specified amount of water containing the above ingredients.

By spraying, young apple seedlings having 4-6 leaves are sprayed until wet. The plants are kept for 24 hours in a greenhouse at 20 ° C and a relative air humidity of 70%, then inoculated by dusting with conidia of Podosphaera leucotricha (powdery mildew) and placed in a greenhouse at 21-23 ° C and a relative air humidity of about 70%.

infestation of the seedlings is observed on days after inoculation.

The values obtained are expressed in% of attack. 0% means that no infection occurred, 100% means that the plants are completely infected.

Active substances, active substance concentrations and results are shown in the following table:

Infestation in% at active substance concentration 01.0001%

Table В

Protective test for apple powdery mildew (Podosphaera)

Active substance

HNO ₃ (known)

S Cl. 's ₂ ~ <O /

Cl

HNO ₅ (2)

Examples illustrating the method of manufacture of the active ingredient:

Example 1

Cl

Ct, 2 HNO _b

606 g (3,1 mol) of 2,6-dichlorobenzyl chloride are dissolved in 2,5 l of ethanol and to this solution 258 g (3,4 mol) of thiourea in 1060 ml of ethanol are added. The reaction mixture was heated under reflux for 6 hours, distilled with 1.5 liters of ethanol, cooled to 45 ° C, and 173.6 g (4.34 mol) of sodium hydroxide dissolved in 342 g of water were added dropwise under a nitrogen atmosphere. , and it- during

1.5 hours. After the addition was complete, the reaction mixture was allowed to stir for 30 minutes at room temperature45. Then 600 g (2.1 mol) of 1-chloro-1- (2,4-dichlorophenyl) -2- (1,2,4-triazole-1) was added dropwise. -yl) ethane in 2 liters of ethanol over 3 hours. The mixture was subsequently stirred for 15 hours at 40- ^Q C, distilling off the 1,5 lit ru ethanol at 50 ° C under vacuum, the mixture was allowed to cool and then added 4 liters of water. The reaction mixture was extracted once with 4 L and 3 times with 2 L of methylene chloride each time; the combined methylene chloride phases are washed twice with 2 liters of water each time, dried over sodium sulphate and concentrated by distilling off the solvent in a water-jet vacuum. The oily residue is dissolved in 2.5 liters of ethanol and 3801 g of 1,5-naphthalenedisulfonic acid in 2 liters of ethanol are added. The precipitate formed is filtered off and carefully mixed into 3 liters of sodium bicarbonate solution. The free base was extracted with 18 L of methylene chloride. The organic phase is concentrated by distilling off methylene chloride, the residue is dissolved in 3 liters of chloroform and 66 ml (1.53 mol) of 6% nitric acid is added dropwise under ice-cooling. 1006 ml of diethyl ether are then added, the precipitate formed is filtered off and washed with 50 ml of diethyl ether. 661 g (61.3% of theory) of 1- (2,4-dichlorophenyl) -1- (2,6-dichlorobenzylmercaptoyl) -2- [1,2,4-triazol-1-yl] ethanenate are obtained. Mp 156-158 ° C.

The above compound was also prepared by reacting 1- (2,4-dichlorophenyl) -1-thiol-2- (1,2,4-triazol-1-yl) ethane (see below for its preparation) and 2,6-dichlorobenzyl chloride in the presence of a diluent (eg ethanol or acetone) and a base (eg potassium carbonate) pre-product:

1S

Cl

30 ml of ethereal hydrogen chloride are added. In this process, 13.8 g (87.6 percent of theory) of 1- (2,4-dichlorophenyl) -2- (1,2,4-triazol-1-yl) ethane-1-thiol hydrochloride crystallized, m.p. to 150 ° C.

The compound of formula:

> 16.05 (0.05 mol) of 1-bromo-1- (2,4-dichlorophenyl) -2 - (1,2,4-triazol-1-yl) ethane and 4.2. g of thiourea (0.055 mol) was heated to reflux in methanol (50 ml) for 3 hours. The reaction mixture was allowed to cool to 0 ° C and then 25 ml of 2 N sodium hydroxide solution was added dropwise under nitrogen for 3.0 min. The reaction mixture is then allowed to stir at room temperature for 2 hours, 100 ml of water are added and extraction is carried out three times with 50 ml of methylene chloride each time. The combined organic phases were dried over sodium sulfate.

n _D ²⁰ = 1.6158.

Claims (2)

A fungicidal composition, characterized in that it contains as active ingredient 1- (2,4-dichlorophenyl) -1- (N -dichlorobenzylmercapic) -2- (1,2,4-ζτ1βζο1-γ1-γ1) βΐΙιβη of the formula Or a physiologically acceptable acid addition salt thereof. 2. A process for the preparation of an active ingredient according to claim 1, wherein the 1- (2,4-dichlorophenyl) -1-halo-2- (1,2,4-triazol-1-yl) ethanes of formula II wherein Hal is halogen, in reaction with mercaptan of formula III Cl (III) at a temperature of 20 to 150 ° C, optionally in the presence of a diluent and an acid-binding agent, the mercaptan of formula III is preferably used in situ, and optionally the acid of the compound of formula I obtained.