WO1982002714A1

WO1982002714A1 - Fungicides

Info

Publication number: WO1982002714A1
Application number: PCT/EP1982/000018
Authority: WO
Inventors: Ag Sandoz; Patent Gmbh Sandoz
Original assignee: Sandoz AG; Sandoz Patent GmbH
Current assignee: Sandoz AG; Sandoz Patent GmbH
Priority date: 1981-02-09
Filing date: 1982-01-30
Publication date: 1982-08-19
Anticipated expiration: 1983-08-09
Also published as: IT8219496A0; IT1151507B; DE3231606A1; FR2499568A1

Abstract

Compounds of formula$(10,)$their preparation and fungicidal compositions containing them.

Description

FUNGICIDES

The present invention provides compounds useful in the combatting of phytopathogenic fungi.

More specifically the present invention provides compounds of formula I,

wherein R₁ is

wherein R₇ and R₈, independently, are C_1-4alkyl, halogen or C_1-4alkoxy, and R₉ is hydrogen, C_1-4alkyl or halogen, R₂ is CO-CH₂-A-R₁₀ wherein A is O or S, and

R₁₀ is hydrogen, -COR₁₁, COOR₁₁,

CONR₁₁R₁₂, -SO₂R₁₁, SO₂NR₁₁R₁₂, CSR₁₁, CSNR₁₁R₁₂ or CSOR₁₁, R₁₁ is C_1-6alkyl, C_2-6alkenyl, C_2-6alkinyl, C_3-6cycloalkyl, unsubstituted or substituted by one or more substituents selected from the group consisting of halogen, alkoxy, aikylthio, CN or SCN; or phenyl unsubstituted or substituted by one or more substituents selected from the group consisting of halogen, alkyl, alkoxy or NO₂,

R₁₂ is hydrogen or has a R₁₁ significance, R₃, R₄, R₅ and R₆ are independently hydrogen or C_1-4alkyl. When any of R₃, R₄, R₅, R₆, R₇, R₈, R₉, R₁₁ or R₁₂ is or includes an alkyl group (e.g. alkoxy), this is preferably C_1-3alkyl, i.e. methyl, ethyl, n-propyl or i-propyl.

When either of R₇ or R₈ is halogen, this is F, Cl, Br or I, preferably F, Cl or Br, more preferably Cl or Br, particularly Cl.

When any of R₉, R₁₁ or R₁₂ is or includes halogen this is F, Cl, Br or I, preferably F, Cl or Br, particularly Cl or Br. R₇ and R₈ are preferably in the 2- and the 6-position of the phenyl group to which they are bound. They are preferably identical.

When one of R₃ and R₄ is C_1-4alkyl, the other is preferably hydrogen. When one of R₅ and R₆ is C_1-4alkyl, the other is preferably hydrogen.

When R₁₂ is other than H, it is preferably identical to R₁₁. When R₁₁ and/or R₁₂ are C_1-6alkyl, C_2-6alkenyl, C_2-6alkinyl, C_3-6cycloalkyl, substituted by one or more substituents selected from the group consisting of halogen, alkoxy, alkylthio, CN or SCN they are preferably mono-substituted. Preferred C_2-6alkenyl or C_2-6alkinyl significances of R₁₁ and/or R₁₂ are C_2-4alkenyl. or C_2-4alkinyl.

When R₁₁ and/or R₁₂ are phenyl substituted by one or more substituents selected from the group consisting of halogen, alkyl, alkoxy or NO₂ they are preferably mono- or di-substituted.

A is preferably 0.

R₁₀ is preferably COR₁₁, SO₂R₁₁, SO₂NR₁₁R₁₂ or H.

Thus, a preferred group of compounds are the compounds of formula la,

wherein R₂' is -COCH₂OH, -COCH₂OCOCH₃, -COCH₂OSO₂CH₃,

-COCH₂OSO₂N(CH₃)₂ R₇' and R₈' indeoendently are CH₃, Cl or Br and R₉' is H, Cl, Br or methyl.

R₇' and R₈' are preferably identical. The invention also provides processes for the production of the compounds of formula I comprising

a) obtaining compounds of formula lb

wherein R'₁₀ has the significance of R₁₀, defined _ above, except that R'₁₀ is not H, and R₁, R₃, R₄, R₅ and R₆ are as defined above,

by subjecting compounds of formula II

wherein R₁, R₃, R₄, R₅, R₆ and A are as defined above, R₁₀' is as defined above and Y is halogen to an intramolecular condensation or b) obtaining compounds of formula lb as defined above by reacting a compound of the formula III

wherein R₁, R₃, R₄, R₅ and R₆ have the same meaning as defined above, and W is a leaving group with a compound of formula IV

B - A - R₁₀' IV wherein B is H or a metal equivalent and A and R₁₀' are as defined above,

c) obtaining compounds of formula Ic

wherein R₁, R₃, R₄, R₅ and R₆ and A are as defined above by alcoholysis of corresponding compounds of formula Id

wherein R"₁₀ is COR₁₁ or SO₂R₁₁, R₁₁ being as defined above and R₁, R₃, R₄, R₅, R₆ and A are as defined above. The above intramolecular condensation according to process a) can be carried out in a conventional manner. The reaction is exothermic. It can e.g. be carried out in a water-free medium using as solvent an ether such as dimethoxyethane, an hydrocarbon such as toluene or another solvent which is inert under the reaction conditions. The reaction temperature is not critical and can lie between about 0° and 100°C. Since the reaction is exothermic one starts the reaction conveniently at room temperature and allows the reaction temperature to rise gradually.

Y is preferably chlorine or bromine, particularly chlorine.

The reaction is conveniently carried out in the presence of an acid binding agent such as sodium hydride, sodium amide or a sodium alcoholate e.g. sodium ethylate. The intramolecular condensation can also be carried out in an aqueous/organic two-phase system in the presence of an anorganic base e.g. sodium hydroxide and optionally a catalytic amount of a phase transfer catalyst.

The organic phase may comprise any appropriate inert water immiscible solvent such as hydrocarbons or halogenated carbons, e.g. xylene, toluene, α-dichloro benzene or dichloromethane. Appropriate phase transfer catalysts are quaternary ammonium compounds such as benzyltrimethyl ammonium bromide, quaternary phosphonium compounds such as benzyltripheny.l phosphonium chloride and crown ethers such as 18-crown-6.

In process b) W is preferably halogen, or the sulphonyloxy moiety of an organic sulphonic acid e.g. an C_1-5alkyl-SO₂-O group such as mesyloxy or a phenylSO₂O group wherein the phenyl is optionally substituted e.g. by C_1-5alkyl, NO₂, CN or halogen, such as p-tosyloxy. The reaction is conveniently carried out in an organic solvent which is inert under the reaction condition, such as e.g. alcohols, hydrocarbons, halogenated hydrocarbons, nitriles such as acetonitrile, or amides such as dimethylformamide. The reaction temperature is not critical, and may be between room temperature and the boiling point of the solvent used. The exact reaction conditions vary with the choice of W and R'₁₀-A-B, as is known to the art. B is preferably a metal equivalent e.g. Na, K or ½ Ca.

The compounds of formula Ic are suitably obtained by base catalysed alcoholysis of the corresponding compounds of formula Id. Such an alcoholysis is conveniently carried out under mild conditions, e.g. at ambient temperature, preferably in a large excess of an alcohol e.g. methanol and in the presence of a catalytic amount of a sodium alcoholate, e.g. sodium methanolate.

As will be appreciated, interconversion of one compound of formula I to another compound of formula I may be carried out in conventional manner.

The compounds of formula I, wherein R₁₀ is other than H may for example also be prepared by acylating the corresponding compounds of formula I wherein R₁₀ is H with an acylating agent e.g. with the acid halide (preferably acid chloride or acid bromide) or acid anhydride of R₁₀' (R₁₀' being as defined above) or with R₁₁NCO in conventional manner.

The compounds of formula II are novel. They may be obtained by acylation of compounds of formula V

wherein R₁, R₃, R₄, R₅, R ₆ and Y are as defined above, with a compound of formula VI

wherein and A are as defined above

and Z is halogen, particularly Cl, or

wherein A and 1 are as defined

above. Suitable solvents for this acylation reaction are hydrocarbons such as toluene or halogenated hydrocarbons such as chlorobenzene. The reaction is conveniently effected at a temperature of from about 20° to about 120°C, e.g. 80°C.

The compounds of formula V may be obtained by reacting compounds of formula VII

R₁ - NH - NH₂ VII wherein R₁ is as defined above, with a compound of formula VIII

wherein R₃, R₄, R₅, R₆ and Y are as defined above, and X is halogen, particularly Cl. This conversion may be effected at a temperature of from about 0° to about 10°C in water or in an organic solvent which is inert under the reaction conditions, conveniently in the presence of a base e.g. an organic amine or sodium hydrogen carbonate.

The compounds of formula III can be obtained by intramolecular condensation analogous to process a).

The starting materials and reagents employed in the processes described above are either known or, insofar as they are not known, they may be produced in analogous manner to the processes described herein or to known processes.

The compounds of formula I have useful fungicidal activity, particularly against phytopathogenic fungi, especailly against fungi of the class Oomycetes as indicated by a significant effect in the following tests. Test A : Fungicidal effect against Phytophthora infestans

Young potted potato plants (3-5 leaf stage) are sprayed with an aqueous spray suspension containing 0.003% (weight/volume) of a compound of formula I, e.g. 2-methylsulphonyloxy-N-(2,6-dimethylphenyl)-N-(2-oxo-3- oxazolidinyl)-acetamide (formulated in accordance with

Formulation Example I). Two hours later, the treated plants are inoculated with a spore suspension of Phytophthora infestans and the plants are then transferred to a tent providing 100% relative atmospheric humidity at an ambient temperature of 15°C and a day length of 16 hours. Disease control is evaluated 4-5 days later by comparing the treated plants with untreated, similarly inoculated pla s. With the above test compound, substantial control of the fungal infestation is observed without any sign of phytotoxicity on the host plants.

Test B : Fungicidal effect against Plasmopara viticola

Young potted plants of grape vine (3-6 leaf stage) are sprayed with an aqueous spray suspension containing 0.0008% (weight/volume) of a compound of formula I, e.g. 2-methylsulphonyloxy-N-(2,6-dimethylphenyl)-N-(2-oxo-3-oxazolidinyl)-acetamide (formulated in accordance with Formulation Example I). Two hours later, the treated plants are inoculated with a spore suspension of Plasmopara viticola and the plants are then transferred to a tent providing 100% relative atmospheric humidity at an ambient temperature of 15-22°C (fluctuating over a 24hr-period) and a day length of 16 hours. Disease control is evaluated 6 days after inoculation by comparing the treated plants with untreated, similarly inoculated plants. With the test compound, substantial control of the fungal infection is observed without significant sign of phytotoxicity on the host plants. Test C : Curative fungicidal effsct against Plasmopara viticola

Young potted plants of grape vine {3-6 leaf stage) are inoculated in the same way as determined in Test B, but the application of the compound, e.g. 2-methylsulphonyloxy-N-(2,6-dimethylphenyl)-N-(2-oxo-3-oxazolidinyl)-acetamide (formulated in accordance with Formulation Example I), follows only after 3 days after inoculation: the incubation conditions are the same as described in Test B. Disease control is evaluated as stated in Test B. With the test compound, substantial control of the fungal infection is observed. Test D : Sradicative fungicidal effect against Plasmopara viticola

The procedure to evaluate this kind of activity is evaluated as described in Test C, with the exception that the treatment is carried out only 6 days after inoculation, when sporulation on the lower leaf surface is already evident. Disease control evaluated 7 days after application of, e.g., 0.012% of the compound 2-methylsulphonyloxy-N-(2,6-dimethylphenyl)-N-(2-oxo-3- oxazolidinyl)-acetamide (formulated in accordance with Formulation Example I), reveals a stopping effect on already sporuiating zones. Test E : Translation in treated leaves of grape vines

Excised leaves of grape vine are treated with an aqueous spray suspension containing 0.012% of a compound of formula I, e.g. 2-methylsulphσnyloxy-N-(2,6-dimethylphenyl)-N-(2-oxo-3-oxazolidinyl)-acetamide (formulated in accordance with Formulation Example I) , in that only the lower half of such leaves is treated. Two hours after treatment, the whole leaf is inoculated with a spore suspension of Plasmopara viticola after which the leaves are incubated in a tent providing 100% atmospheric humidity at conditions as described in Test B. Although only the lower half of the leaves was treated as stated above, with the test compound substantial disease control on the entire leaf inoculated was observed. The same effect was also observed, when only the upper half of the leaves was treated. This Test thus shows, that the 2-methylsulρhonyloxy-N-(2,6-dimethylphenyl)-N-(2-oxo-3-oxazolidinyl)-acetamide (formulated in accordance with Formulation Example I), is distributed within a leaf both acropetally and basipetally. Test F : Soil Treatment In vivo, employing Pythium aphanidermaturn. The fungus is cultivated in a sterile mixture of same and forn meal (97:3 v/v); cultivation lasts for 4 days at 25°C. The fungus is then mixed into a semi-sterile mixture of peat and sand which then is treated with a suspension containing the formulated active ingredient to give concentration of 10 to 160 ppm (e.g. 10, 40 and 160 ppm) calculated per volume substrate). The substrate is transferred to pots of 5 cm diameter which are seeded with cucumber seeds. The planted pots are incubated at 24°C and 60 - 70% relative humidity in an incubation chamber for 7 days, after which disease attack is determined by comparing the number of healthy emerged plants with that in untreated, similarly inoculated check pots. The compound of Example 1, hereinafter, used in the wettable powder formulation given above provides significant disease control.

Tests analogous to Test F give similar results with peas and sugar beets.

Each of the compounds listed below in the following Examples is found to possess fungicidal properties indicating their usefulness as fungicides.

Particularly effective fungicidal activity is found in the above tests with the compound of formula la wherein R₇' and R₈' are CH₃; R₉' is H; and R₂' is COCH₂OH or -COCH₂OSO₂CH₃.

The invention therefore also provides a method of combatting phytopathogenic fungi, especially of the class Oomycetes, in plants, seeds or soil, which process comprises treating the plants, seeds or soil with a fungicidally effective amount of a compound of formula I. Fungi of the class Oomycetes, against which the method of the invention is particularly effective, are those of the genus Phytoohthora in plants such as potatoes, tomatoes, tobacco, citrus, cacao, rubber, apples, strawberries, vegetables and ornamentals, e.g. Phytophthora infestans in potatoes and tomatoes; of the genus Plasmopara viticola in grape vines; of the genus Peronospora in plants such as tobacco, e.g. Peronospora tabacina in tobacco; of the genus Pseudoperonospora in plants such as hops and cucumber, e.g. Pseudoperonospora humuli in hops; of the genus Bremia in plants such as lettuce, e.g. Bremia lactucae in lettuce; of the genus Pythium causing damping-off and root rots in a great number of plants, such as vegetables, sugar beets, ornamentals and conifers, e.g. Pythium aphanidermatum in sugar beets; of the genus Sclerospora in plants such as sorghum and corn, e.g. Sclerosoora sorghis in sorghum.

For use in the method of the invention, the amount of the preparation to be employed will vary depending on such factors as the species of fungi to be combated, the time and nature of application and the amount and nature of the compound of formula I employed in the preparation.

However, in general, satisfactory results are obtained when applied to a locus, e.g. on crops or to soil with a dosage rate in the range of frcm 0.05 to 5 kg, preferably from 0.1 to 3 kg of a compound of formula I/ha treated locus, the application being

repeated as required. When employed as a seed dressing, satisfactory results are obtained when applied at a rate of from about 0.05 to 0.5, preferably about 0.1 to 0.3 g compound of formula I/kg seed. Depending on the circumstances, the compounds of formula I may be used in association with other pesticides e.g. fungicides, bactericides, insecticides, acaricides, herbicides or plant growth regulating agents in order to enhance their activity or to widen their spectrum of activity.

A particularly preferred method of the invention comprises applying to the locus to be treated fungicidally effective aggregate amounts of a component a) comprising a compound of formula I and of one or more compounds selected from a copper fungicide, captan, folpefc, mancozeb.or maneb.

Examples of copper fungicides suitable for use in association with a compound of formula I are e.g. copper (II) carbonate, copper (II) calcium sulphate, copper (II) calcium oxychloride, tetracupric oxychloride, Bordeaux mixture, Burgundy mixture, cuprous oxide, cupric hydroxide, cooper (II) oxychloride or also copper complexes such as copper triethanolamine hydroxide of the formula [Cu N(CH₂CH₂OH)₃]- (OH)₂, commercially available under the Trademark K-Lox, or bis (ethylenediamine)-copper (II) sulphate of the formula [Cu(H₂NCH₂CH₂NH₂)₂]SO₄, commercially available under the Trademark Komeen, and mixtures thereof, particularly cuprous oxide, copper (II) oxychloride, cupric hydroxide and a mixture of copper (II) calcium sulphate and copper (II) oxychloride.

Captan, Folpet, Manoczeb and Maneb are the common n-ames for pretective fungicides effective against foliage diseases (Pesticide Manual, 5th Ed., by H. Martin and C.R. Worthing, page 76, 281, 328 and 329 resp.).

The compounds of formula I are conveniently employed as fungicidal compositions in association with agriculturally acceptable carriers or diluents. Such compositions also form part of the present invention. They may contain, aside from a compound of formula I as active agent, other active agents, such as fungicides. They may be employed in either solid or liquid application forms e.g. in the form of a wettable powder, an emulsion concentrate, a water dispersible suspension concentrate ("flowable"), a dusting powder, a granulate, a delayed release form, incorporating conventional carriers, diluents and/or adjuvants. Such compositions may be produced in conventional manner, e.g. by mixing the active ingredient with a carrier and other formulating ingredients.

Particularly formulations to be applied in spraying forms such as water dispersible concentrates or wettable powders may contain surfactants such as wetting and dispersing agents, e.g. the condensation product of formaldehyde with naphthalene sulphonate, an alkylarylsulphonate, a lignin sulphonate, a fatty alkyl sulphate, an ethoxylated alkylphenol and an ethoxylated fatty alcohol. In general, the formulations include from 0.01 to 90% by weight of active agent, said active agent consisting either of at least one compound of formula I or mixtures thereof with other active agents, such as fungicides. Concentrate forms of compositions generally containbetween about 2 and 80%, preferably between about 5 and 70% by weight of active agent.

Application forms of formulation may for example contain from 0.01 to 20% by weight, preferably from 0.01 to 5% by weight of active agent. The invention is illustrated by the following Examples wherein parts and percentages are by weight and temperatures are in °C.

Formulation Example I : Wettable Powder

50 Parts of 2-methylsulphonyloxy-N-(2,6-dimethylphenyl)-N-(2-oxo-3-oxazolidinyl)-acetamide are ground with 2 parts of lauryl sulphate, 3 parts sodium lignin sulphonate and 45 parts of finely divided kaolinite until the mean particle size is below 5 microns. The resulting wettable powder so obtained is diluted with water before use to a concentration of between 0.01% to 5% active agent. The resulting spray liquor may be applied by foliar spray as well as by root drench application. Formulation Example 2 : Granulate

Onto 94.5 parts by weight of quartz sand in a tumbler mixer is sprayed 0.5 parts by weight of a binder (non-ionic tenside) and the whole thoroughly mixed. 5 Parts by weight of powdered 2-methylsulphonyloxy-N-(2,6-dimethylρhenyl)-N-(2-oxo-3-oxazolidinyl)- acetamide are then added and thoroughly mixing continued to obtain a granulate formulation with a particle size in the range of from 0.3 to 0.7 mm. The granulate may be applied by incorporation into the soil adjacent the plants to be treated. Formulation Example 3 : Emulsion Concentrate

25 Parts of a compound of formula I, e.g. the compound of Example 8.1, hereinafter given, 65 parts of xylene, 10 parts of the mixed reaction product of an alkylphenol with xyleneoxide and calcium-dodecylbenzene sulphonate are thoroughly mixed until a homogeneous solution is obtained. The resulting emulsion concentrate is diluted with water before use.

Example 1 : 2-[(4-Methylphenyl)-sulphonyloxy]-N-(2,6- dimethylphenyl)-N-(2-oxo-3-oxazolidinyl)- acetamide

A slurry of 95.5 g (0.21 mol) 2-chloroethyl 2- (4-methylphenylsulphonyloxyacetyl)-2-(2,6-dimethylphenyl)-hydrazine carboxylate in 500 ml dry methanol are slowly added with stirring to a solution of 12.4 g (0.23 mol) sodium methanolate in 200 ml dry methanol. After the exothermic reaction is completed, the mixture is stirred for two hours at room temperature, then freed of the solvent in vacuo. The residue is dissolved in dichloromethane, washed twice with water, dried over MgSO₄ and evaporated.

The residue was chromatographed on silica gel using toluene/ethylacetate as eluant, yielding the title compound as a yellow oil, which solidified upon treatment with toluene to give a colourless solid, m.p. 122-5°. Example 2

Following the procedure of Example 1 but employing the appropriate starting material of formula II the following compounds of formula I are obtained (Table A : R₃, R₄, R₅ and R₆ being H).

Example 3 : 2-Acetoxv-N-(2,6-dimethylphenyl)-N-(2-oxo- 3-oxazolidinyl)-acetamide

A mixture of 70.6 g (0.25 mol) 2-chloro-N-(2,6-dimethylphenyl)-N-(2-oxo-3-oxazolidinyl)-acetamide and 49.2 g (0.6 mol) dry sodium acetate are heated with stirring in 500 ml dry dimethylformamide at 110°C for three hours. The cooled mixture is filtered with suction, the residue washed thoroughly with dimethylformamide, and the combined filtrates concentrated in vacuo. The residue is dissolved in dichloromethane, washed with water, dried and freed of the solvent and yielded after crystallization from ethanol the title compound as colourless crystals , m. p . 102-6 °C .

Example 4

Following the procedure of Example 3, but employing the appropriate starting material of formula III, wherein

W is Cl or p-tosyl, and of formula IV wherein B is Na, the following compounds of formula I are obtained

(Table B: R₃, R₄ , R₅ and R₆ being H).

Example 5 : 2-Hydroxy- N- ( 2, 6-di methy lphenyl) -N- ( 2-oxo- 3-oxazolidinyl) -acetamide

A solution. of 24.8 g (0.46 mol) sodium meth-anolate in 200 ml dry methanol is slowly added to a slurry of 258 g (0.843 mol) 2-acetoxy-N-(2,6-dimethylphenyl)-N- (2-oxo-3-oxazolidinyl)-acetamide, prepared as in Example 3, in 2.5ℓ dry methanol with stirring. The mixture, which becomes a clear solution after 30 minutes, is stirred for a total of two hours at room temperature, then freed of the solvent in vacuo. The resulting oil is poured into water and the pH adjusted to pH=2 with 2N aqueous HCl. The product is extracted with three portions of chloroform, the combined organic layers washed with water and dried over MgSO₄, and the solvent evaporated in vacuo to yield a colourless solid. The title compound is obtained as colourless crystals from ethanol, m.p. 138-9°. Example 6 :

Following the procedure of Example 5 , but alcoholizing the apropriate starting materials of formula I, wherein R₂ is COCH₂OCOCH₃, the following compounds of formula I, wherein R₂ is COCH₂OH are obtained (Table C:

R ₃, R₄, R₅ and R₆ being H) .

Example 7: 2-(Dimethylaminosulphonyloxy)-N-(2,6-di- methylphenyl)-N-(2-oxo-3-oxazolidinyl)- acetamide

13.2 g (0.05 mol) 2-hydroxy-N-(2,6-dimethylphenyl)- N-(2-oxo-3-oxazolidinyl)-acetamide is added in portions to a slurry of 2.2 g (appr. 0.05 mol) sodium hydride (as 55-60% dispersion in oil) in 100 ml dry dimethoxyethane with stirring at 10-15°C under a blanket of nitrogen. The mixture is stirred at room temperature for half an hour, and then are added 7.9 g (0.055 mol) dimethylsulphamic acid chloride. The mixture is heated to 50° and stirred overnight at this temperature. The mixture is filtered, after cooling, the filtrate concentrated in vacuo, the resulting oil dissolved in chloroform and washed thoroughly with water, dried over MgSO₄ and freed of the solvent in vacuo.

The title compound is obtained as a yellow, sticky oil after chromatography on silica gel, using a 1:1 mixture of toluene/ethyl acetate as eluant. Example 8 :

Following the procedure of Example 7, but employing the appropriate compounds of formula Ic and acid chlorides R₁₀Cl, the following compounds of formula I are obtained (Table D: R₃, R₄, R₅ and R₆ being H).

STARTING MATERIALS

The starting materials used in Example 1 can be prepared as follows: Example A : 2-Chloroethyl 2-(4-methvlphenylsulphonyloxy- acetyl)-2-(2,6-dimethylphenyl)-hydrazine-

A solution of 112 g (0.45 mol) 2-(4-methylphenylsulphonyloxy)-acetyl chloride in 100 ml toluene is slowly added with stirring at room temperature to a slurry of 2-chloroethyl 2-(2,6-dimethylphenyl)-hydrazine σarboxylate in 500 ml toluene, and the mixture stirred at room temperature for 4 hours. The reaction mixture is then subsequently washed with water, an aqueous NaHCO₃ solution and water, dried over MgSO₄ and evaporated in vacuo to yield a yellowish solid, which upon recrystallization from ethanol gives the title compound as colourless crystals, m.p. 125-7°. Example B : 2-Chloroethyl 2-(2,6-dimethylphenyl)- hydrazine carboxylate

A mixture of 17.7 g (0.1 mol) 2,6-dimethylphenyl. hydrazine hydrochloride and 21.2 (0.2 mol) sodium carbonate in 50 ml water/50 ml xylene are stirred for 30 minutes at room temperature, then cooled to 5°C. 14.3 g (0.1 mol) chloroformic acid 2-chloroethylester is then added over a period of 1 hour, the temperature being maintained at 5°C with external cooling. The mixture is stirred at 5°C for another hour, at the end of which 100 ml water are added, the precipitate thus formed filtered off, washed with water and dried, to yield the title compound as a slightly coloured solid, m.p. 69-70°. Recrystallization from diethyl ether/light petroleum raises the m.p. to 74-5°. Example C

Following the procedure of Example 1, but employing starting materials analogous to compounds of formula II, wherein AR₁₀ is, however, Cl or Br, the following compounds of formula III are obtained (Table E: R₃, R₄, R₅ and R₆ being H).

Claims

What we claim is

1. A compound of formula I

wherein R₁ is

R₁₀ is hydrogen, -COR₁₁, COOR₁₁,

CONR₁₁R₁₂, -SO₂R₁₁, SO₂NR₁₁R₁₂, CSR₁₁, CSNR₁₁R₁₂ or CSOR₁₁, R-, is C_1-6alkyl, C_2-6alkenyl, C_2-6alkinyl, C_3-6cycloalkyl, unsubstituted or substituted by one or more substituents selected from the group consisting of halogen, alkoxy, alkylthio, CN or SCN; or phenyl unsubstituted or substituted by one or more substituents selected from the group consisting of halogen, alkyl, alkoxy or NO₂, R₁₂ is hydrogen or has a R₁₁ significance, R₃, R₄, R₅ and R₆ are independently hydrogen or C_1-4alkyl.

2. A method of combatting phytopathogenic fungi in plants, seeds or soil, which comprises applying to the plants, seeds or soil a fungicidally effective amount of a compound of Claim 1.

3. A fungicidally composition comprising a compound of Claim 1 in association with an agriculturally acceptable carrier or diluent.

4. A process for the production of a compound of Claim 1, characterized by

a) obtaining compoxinds of formula lb

wherein R'₁₀ has the significance of R₁₀, defined in Claim 1, except that R'₁₀ is not H, and R₁, R₃, R₄, R₅ and R₆ are as defined in Claim 1

by subjecting compounds of formula II

wherein R₁, R₃, R₄, R₅, R₆ and A are as defined in Claim 1,

R'₁₀ is as defined in this Claim,

and Y is halogen, to an intramolecular condensation or b) obtaining compounds of formula Ib as defined in Claim 1, by reacting a compound of the formula III

wherein R₁, R₃, R₄, R₅ and R₆ have the same meaning as defined in Claim 1, and W is a leaving group with a compound of formula IV

B - A - R₁₀' IV wherein B is H or a metal equivalent and A and R₁₀' are as defined in Claims 1 and 4 resp.,

c) obtaining compounds of formula Ic

wherein R₁, R₃, R₄, R₅, R₆ and A are as defined in Claim 1, by alcoholysis of corresponding compounds of formula Id

wherein R"₁₀ is COR₁₁ or SO₂R₁₁, R₁₁ being as defined in Claim 1, and R₁, R₃, R₄, R₅, R₆ and A are as defined in Claim 1.