IL43840A

IL43840A - Derivatives of 2-substituted 1,3,4-oxadiazole-5-thiol and fungicidal compositions containing them

Info

Publication number: IL43840A
Application number: IL43840A
Authority: IL
Original assignee: Pepro
Priority date: 1972-12-18
Filing date: 1973-12-17
Publication date: 1977-03-31
Also published as: DE2361613A1; BE808734A; DD110274A5; GB1429725A; IL43840A0; JPS4986546A; IT1048162B; FR2211008A5; CH587602A5

Description

43840/2 noma .¾IK:»II-5-VI»K*IRPPIK-4»3,1 ^ mtnn nn in jniK o^ 'Dan m *"IBB »Vt>ip ο »β3ηι 2 maps New derivatives 2-substitujed 1 ,3,4'*oxadiazole- 5- hiol and fungicidal compositions containing them PEPRO, J30CIESE POUR LB· -BBVBLOPPBMBME B!E LA VENTE DE SPECIALISES CHIMIAU S C: 41946 43840/2 This i vention relates to new derivatives of 1 , 3,4-oxadiazole and to a process for their production.

The invention also relates to compositions whic contain these derivatives and which are suitable for use in controlling, fungus disease in plants, especially in agriculture, viticulture, arboriculture, market gardening and horticulture.

The derivatives according to the invention correspond to the general formula: in which R is a phenyl radical optionally substituted by one or more halogen, a nitro, alkyl , alkoxy or alkylthio radical, the alkyl portion of these radicals containing from 1 to 5 carbon atoms; a phenylalkyl radical, the alkyl portion of which containing from 1 to 3 carbon atoms ; or a thienyl, trichlorothienyl or pyridyl radical, attached to the carbon atom of the oxadiazole ring either directly or through an aliphatic chain containing from 1 to 3 carbon atoms, and R' is a halogen-alkylthio , thiocyanatoalkyl , cyano , alkenyl or alkynyl , alkanoyl , alkoxycarbonyl , haloalkoxycarbonyl 43840/2 cyclohexyloxycarbonyl , ( alkylthio) carbonyl , carbamoyl or monoalkyl carbamoyl radical, the alkyl portion of these radicals containing from 1 to 3 carbon atoms.

These compounds can be obtained by reacting a sodium salt of a 2-mercapto-l , 3-oxadiazole , substituted in the 5-position, with a derivative containing a labile halogen atom, in accordance with the following scheme: The sodium salt .is preferably in solution or suspension in the methanol or te rahydrofuran into vzhich the halogenate derivative is introduced. The mixture is boiled for 1 to 2 hours. Following evaporation of the solvent, the crude product is washed with water and dried. Crude crystalline product can be recrystallised from a suitable solvent such as ethanol , acetone, benzene, cyclohexane , etc., either individually or in admixture with one another.

The crude liauid comoounds are extracted V7ith a solvent and then distilled under reduced pressure.

The follov7ing compounds have been prepared by this process: 43840/2 EXAMPLE 1 2-Thiocyanatoethylthio-5-phenyl-l , 3 , 4-oxadiazole 16.6 g (0.1 mole) of thiocyanatoethyl bromide are poured into a solution of 20 g (0. ".01.2) of \ 3 sodium EX iPLE 2 2-Metho:cycarbony1thίo-5-paenv1- , 3,4-o adiazo1e 9.5 g (0.1 mole) of methyl chloroformate are poured into a solution of 20 g (0.1 mole) of the sodiura salt of 2-mercapto~5-pher.yi- ,3, -oxadiazole in tetrahydrofuran. The procedure is then as described in Example 1.

EXAMPLE 3 2- (N-methylcarbamoy1) thio-5-phenyl-l , 3 , 4-oxadiazole 9.4 g (0.1 mole) of N-methylcarbamoyl chloride are reacted with a solution of 20 g (0.1 mole) of the sodium salt of 2-mercapto-5-phany1- , 3, 4-oxadiazole in tetrahydrofuran. The procedure is then as described in Exam le 1, except that the solvent used for recrystallisation is ethanol.

EXAMPLE 4 2-Thiocyanato-5-phenyl-l , 3 , 4-oxadiazole 5.3 g (0.05 mole) of cyanogen bromide are reacted at room temperature with an aqueous solution of 10 g (0.05 mole) of the sodium salt of 2-mercapto-5-pheny1- , 3, 4-oxadiazole. The product is separated and worked up i the same way as described in* Example' 1,' except ' that the solvent used for recrystallisaticn is carbon tetrachloride.

The following Table shows, for each product obtained, the formula of the reactants (for the 1·, 3, -oxadiazole derivative corresponding to the formula N N only the meaning of R is shown), the physical constants (me point in the case of a crystallised product accompanied una neath by the type of solvent used for recrystallisation, for their action on the germination of spores of the following fungi: Altemaria solani, responsible for altemariosis ; Botrytis cinerea, responsible for grey rot; Monilia fructigena, responsible for moniliosis; Piricularia oryzae, responsible for piriculariosis in rice; Uromyces appendiculatus, responsible for bean blight. The following procedure is adopted for each test: a 0.1 g/1 acetone solution of the material to be tested is sprayed onto plates of glass. Following evaporation -of the acetone, an aqueous suspension containing approximately 80,000 spores/cc of the fungus is applied.

If the material to be tested is insoluble in acetone a mixture of 1 volume of the above aqueous suspension and 1 volume of an aqueous suspension containing 0.1 g/1 of the material to be tested of a we able powder of the following composition is applied to the glass plates: active material to be tested 20 % deflocculant (calcium lignosulphate) 5 % - wetting agent (sodium alkylaryl sulphonate) 1 % filler (aluminium silicate) 74 % Thiswettable powder is then mixed with a quantity of water calculated for application in the required dose.

This is followed by incubation for 24 hours at 20°C in an atmosphere of 00 % relative humidity.

The number of germinated spores is then checked, being expressed as percentage germination in relation to an untreated control.

Under these circumstances, the following results are obtained (with a dose of 0.05 g/1): Altemaria solani: compounds 2,3, 5, 6, 7, 8, 9, 11, 12, 13, 14, 16, 17, 19, 20, 24, 26, 28, 30, 31, 34 and 36, upon germination of this fungus.

Botrytis cinerea: compounds 1, 4, 7, 11, 12, 13, 14, 16, 18, 19, 22, 23, 25, 27, 29, 30, 31 and 33 completely inhibit germination of this fungus, whilst compounds 2, 3, 5, 6, 15, 21 have a marked inhibiting effect upon germination of this fungus.

Monilia fructigena: compounds 1, 2, 3, 4, 5, 6, 7, 8, 10, 11, 12, 13, 14, 15, 16, 18, 19, 21, 23, 25, 26, 27, 28, 29, 30, 31, 33 and 35 completely inhibit germination of this fungus, whilst compounds 9, 22 and 24 have a marked inhibiting effect upon germination of this fungus.

Piricularia oryzae: compounds 1, 2, 3, , 5, 6, 7, 8, 10, 11, 12, 13, 14, 15, 16, 18, 19, 20, 21, 23, 25, 26, 27, 28, 29, 30, 31, 33, 34 and 35 completely inhibit germination of this fungus, whilst compounds 9, 22 and 24 have a marked inhibiting effect upon the germination of this fungus.

Uromyces appendiculatus ; compounds 1, 2, 3, 5, 6, 7, 8, 9, 10 11, 12, 13, 14, 16, 18, 19, 21, 22, 23, 24, 27, 33 and 35 completely inhibit germination of this fungus.

EXAMPLE 6 In vitro test on mycelian growth The products according to the invention are tested for their effect on the mycelian growth of the following fungi: Fusarium oxysporum, responsible for tracheom cosis; - Rhizoctonia solani, responsible for canker of the neck? - Pythium de Baryanum, responsible for damping-off of seediin The following procedure is adopted for each test: a suspension in gelcse (agar-agar), containing around 70,000 spores/cc of the fungus, is poured into a Petri dish ata temperature of around 50°C. This suspension is left to harden, after which discs of paper impregnated with a suspension of the material to be tested in various concentra ions are placed onto it. The material to be tested is in the form of a wettable powder prepared as described in Example 5.

. A Petri dish containing discs impregnated with distilled water is used as the control- After 4 days at 20°C, the concentrations for which an inhibition zone is obtained are noted.

Under these conditions, an inhibition zone is observed (dose: 0.2 g/1) on Fusarium oxysporum with compounds 1, 2, 4, 5, 13, 14, 16, 18, 19, 30 and 31; on Rhizoctonia solani with compounds 2, 3, 5, 12, 13, , 16, 18, 19, 30 and 31; on Pythium de Baryanum with compounds 2,5, 13, 14, 16, 17, 18, 19, 21, 23, 27, 30 and 31.

EXAMPLE 7 In vivo test on living organs Test on vine mildew (Plasmooara viticola) A drop of a mixture of a suspension of spores containing approximately 80,000 units/cc and of a suspension, in the required dilution, of a wettable powder identical in composition to that described in Example 5, in the case of an insoluble product, or of a solution in acetone, the concentration of active material being 0.05 g/1 in either case, is applied to freshly cut vine leaves.

The drop is then removed and the leaf exposed to light. An assessment is made after 10 days. Under these conditions, extremely good protection is provided by compounds 1, 4, 13, 14, 18, 19 and 23, and good protection by compound 12.

In vivo test on living tomatoes These tests re r ut n t e Bobr tls cinerea, responsible for grey rot.

A tomato plant aged 60 to 75 days is sprayed with an aqueous suspension containing the active material to be tested in the form of a wettable powder identical in composition to that of Example 5 in the corresponding dose.

After 24 hours, the leaves are cut and placed into Petri dishes whose bottom is covered with a disc of damp filter paper. A plug of filter paper impregnated with a nutritive suspension containing approximately 80,000 units/cc of- spores, is applied to the tomato leaves.

After 4 days at 20°C/100 % relative humidity, the results are assessed by counting the patches of rot.

Under these conditions, the following results are obtained: Alternaria solani: compounds 3, 14, 22 and 31 provide good protection at a dose of 2 g/1; compounds 4, 6 and 27 afford excellent protection at a dose of 2 g/1 and good protection at a dose of 1 g/1, compound 5 still affording good protection at a dose of only 0.05 g/1; compounds 21 and 23 afford excellent protection at a dose of 2 g/1.

Botrytis cinerea: ' compounds 4 and 14 afford good protection at a dose of 2 g/1 whilst compound 18 provides excellent protection at a dose of 2 g/1.

EXAMPLE 9 In vivo test on monllia fructigena in apples The fruit is sprayed with 10 ml of an aqueous suspension or acetone solution, prepared as described in Example 5, containing the active material to be tested in the required dose. After drying, each fruit is inoculated by scarificatior. with culture of t .2 fungus selected and placed into an atmosphere of 100 % relative humidity at a temperature of 20°C. Development In vivo test on plants The products according to the invention are tested for their action on the following fungi; Erysiphe gra inis, responsible for corn rot, Piricularia or/zas, responsible for piriculariosis in r Plasmopara viticola, responsible for vine mildew.

An aqueous suspension of the wettable powder described in Exam le 5, in the required dilution containing the active material to be tested in the required dose is applied by a spray gun to the underside of leaves of com plants, rice plants and vine plants grown in pots. Each test is repeated twice.

After 24 hours, the plants are contaminated by spraying onto the underside of the leaves an aqueous suspension containing approximately 80,000 units/cc of spores of the fungus selected.

The pots are then stored for 48 hours in an inc batio cell in 100 % relative humidity at a temperature of 20°C. The plants are checked 15 days after contamination.

Under these conditions, the following results are obtained: Erysiphe graminis; compound 19 affords good protection at a dose of 1 g/1; Piricularia orvzaa; compounds 5, 15, 20 and 29 afford excellent protection at a dose of 1 g/1, compound 5 still affording good protection at a dose of only 0.5 g/1; compounds 16, 24, 27 and 30 afford good protection at a dose of 1 g/1.

Plas opara viticola; compounds 1 and 4 afford excellent protection at a dose of 0.5 g/1 and good protection at a dose of 0.25 g/1; compounds 13, 18, 19, 23 and 31 affor exce ient proceccio at a cose of 1 g/1; compound 14 affords good protection at a cose of 1 g/1.

EXAMPLE 11 In vivo best on ground fungi The product according to the invention is tested for its effect on the following fungi: Fusarium oxysporum, responsible for trachecmyccsis Pythiutn de Baryanum, responsible for dam ing-off of seedlings.

The following procedure is adopted for each test: a medium containing a fungus culture is mixed with a sterilised earth and pots filled with the resulting mixture. After 8 days, the earth is contaminated.

It is then sprinkled with a suspension of the material to be tested in various concentrations. The material to be tested is in the form of a wet able powder prepared as described in Example 5.

The treated soils are then sown with melon seeds and cucumber seeds, respectively, depending on whether the fungus under examination is Fusarium oxysporum or Pythium ce Baryanum.

The results are assessed 20 and 15 days, respectively after sowing by counting the number of destroyed or sick plants in relation to an untreated control and an uncontaminated control.

Under these conditions, the following results are obtained: F s rium cx sporum: compound 25 affords good protection at a dose of 1 g/l; Pythium de Baryanum: compounds 14, 30 and 31 afford excellent protection at a dose of 2 g/l; compounds 13 and 21 afford excellent protection at a dose of 0.5 g/l.

The preceding Examples are merely intended to illustrate the process by which the compounds according to the invention are prepared, and their fungicidal properties. 43840/2 the invention are rarely used alone. They generally form part of formulations which , as a rule, comprise a carrier and/or a surfactant in addition to the active material according to the invention.

In the^ context of the invention, a "carrier" is an organic or mineral, natural or synthetic material with which the active material is associated to facilitate its application to the plant, to seeds or to the soil, or its transport or handling. The carrier can be solid (clays, natural or synthetic silicates, resins, waxes, solid fertilisers ....) or liquid (water, alcohols, ketones, petroleum fraction, chlorinated hydrocarbons, liquified gases).

The surfactant can be an ionic or non-ionic emulsifier, dispersant or wetting agent such as, for example, salts of polyacrylic acids, ligninsulphonic acids, condensates of ethylene oxide with fatty alcohols, fatty acids or fatty amines.

The compositions according to the invention can be prepared in the form of wettable powders, dusting powders., granulates, solutions, eroulsifiable concentrates emulsions, suspended concentrates and aerosols.

The wettable powders according to the invention can be prepared in such a way that they contain from 20 to 95 % by weight of active material- They normally contain, in addition to a said carrier, from 0 to 5 % of a wetting agent, from 3 to 10 % by weight of a dispersant and, when necessary, from 0 to 10 % by weight of 1 or more stabilisers and/or other additives, such aspenetration agents, adhesives or an ilumping agents, colorants, etc. · For example, a wettable powder can have the followin composition, the percentages being expressed in weight: * active material 50 % ant ilumping silica 5 % kaolin filler 39 % The powders for treating seed are normally prepared in the form of a dust- like concentrate similar in composi ion · to a we able powder, but without the dispersant. They can be diluted on site with a complementary quantity of liquid carrier to form a composition which can conveniently surround the seeds to be treated.

For example, powder for treating seed can have the following composition: active material 50 % anionic watting agent · 1 % antilumping silica 6 kaolin (filler) 43 % Aqueous dispersions and erauisions, for example compositions obtained by diluting a wettable powder or an emulsifiable concentrate according to the invention with water, are included within the general scope of the invention. These emulsions can be of the water-in-oil type. or of the oil- in- ater type, and can have a thick consistency resembling that of a "mayonnaise".

The compositions according to the invention can contain other ingredients, for example protective colloids, adhesives or thickeners, thixotropic agents, stabilisers or sequestrants , and other active materials known to show pesticidal properties, especially herbicides, insecticides or fungicides.

Accordingly, the products according to the invention can be used as preventive or curative agents for controlling the parasitic fungi encountered in agricultur arboriculture, viticulture, horticulture or market gardening and, more generally, against the parasitic

Claims

43840/2 CLAIMS :

1. Compounds of the general formula: N in which: R is a phenyl radical optionally substituted by one or | more halogen, a nitro, alkyl, alkpxy or alkylthio radical, the alkyl portion of these radicals containing from 1 to 5 carbon atoms; a phenylalkyl radical, the alkyl portion of which containing from 1 to 3 carbon atoms; or a thienyl , trichlorothienyl or pyridyl radical, attached to the carbon atom of the oxadiazole ring either directly or through an aliphatic chain containing from 1 to 3 carbon atoms, and R* is a halogen-alkylthio, thiocyanatoalkyl , cyano, alkenyl or alkynyl, alkanoyl, alkoxycarbonyl , haloalkoxycarbonyl , cyclohexyloxycarbonyl , (alkylthio) carbonyl , carbamoyl or monoalkyl carbamoyl radical, the alkyl portion of these radicals containing from 1 to 3 carbon atoms.

2. Fungicidal compositions for protecting plants against fungus disease, containing as active material at least one compound as claimed in Claim 1.