WO1997030047A1

WO1997030047A1 - Fungicidal 1,2,4-oxadiazoles and analogues

Info

Publication number: WO1997030047A1
Application number: PCT/GB1997/000388
Authority: WO
Inventors: Brian Anthony Moloney; Peter Dominic Riordan; Russel George Hunt
Original assignee: Agrevo Uk Limited
Priority date: 1996-02-17
Filing date: 1997-02-13
Publication date: 1997-08-21
Also published as: AU1730497A

Abstract

Compounds of formula (I), where W is H or halogen, and R is alkyl or trifluoromethyl and compounds of formula (II), where X is O or S; Y is alkyl, cycloalkyl, cycloalkenyl, alkenyl or alkynyl, each of which is optionally substituted, hydrogen or acyl; R1 is a phenyl or a 5- or 6-membered heterocyclyl group, each of which is optionally substituted; R?2 and R3¿ are hydrogen or alkyl or together with the nitrogen to which they are attached can form an optionally substituted ring which can contain 0 to 3 extra hetero atoms selected from nitrogen, oxygen or sulfur; and R4 is hydrogen or acyl; have activity as fungicides.

Description

FUNGICIDAL 1 ,2,4-OXADIAZOLES AND ANALOGUES

This invention relates to compounds having fungicidal activity.

In WO 95/25723, we have claimed compounds of formula

where

A is a 6 membered heteroaryl group comprising at least one nitrogen atom, which is optionally substituted by one or more of the group R^;

R¹ is alkyl, cycloalkyi, cycloalkenyl, alkenyl, alkynyl, or ammo, (each of which is optionally substituted), γ1 -X-, halogen, cyano, nitro, acyl, acyloxy, optionally substituted heterocyclyl or optionally substituted phenyl; or two adjacent groups together with the carbon atoms to which they are attached can form an optionally substituted benzo ring; R2 has the same meaning as R ^ or two adjacent groups together with the carbon atoms to which they are attached can form an optionally substituted heterocyclic ring;

Y is alkyl, cycloalkyi, cycloalkenyl, alkenyl or alkynyl, each of which is optionally substituted, hydrogen or acyl; γ1 has the same meaning as Y or is optionally substituted phenyl or optionally substituted heterocyclyl; Z is C( = X ¹ )-X²-R3, cyano, nitro, ammo, acyl, optionally substituted heterocyclyl,

-C(R⁵) = N-OR⁶ or -C{R⁵ ) = N-NR6R⁷;

R3 IS alkyl, cycloalkyi, cycloalkenyl, alkenyl, alkynyl, phenyl or heterocyclyl, each of which is optionally substituted, hydrogen or an inorganic or organic cationic group; X ¹ and X², which may be the same or different, are O or S; R5 , R6 and R⁷, which may be the same or different, are alkyl, cycloalkyi, cycloalkenyl, alkenyl, alkynyl, phenyl or heterocyclyl, each of which is optionally substituted or hydrogen or R§ and R⁷ together with the atom(s) to which they are attached can form a ring; and n is 0 to 4, as fungicides.

We have now found that a selected group of compounds where Z is an oxadiazole group have particularly valuable properties.

Accordingly, in one aspect the invention provides the compounds of formula I:

where W is H or halogen, and R is alkyl or trifluoromethyl, and complexes thereof.

The closest compound in WO 95/25723 is No 177, which is a compound where Z is 5-methyl-1 ,3,4-thiadiazol-2-yl and A is 6-methoxy-3-pyridyl. In the compounds of the present invention, not only is the sulfur of the thiadiazole replaced by oxygen but the oxadiazole of the present invention is attached to the phenyl from the 3-position compared with the 2-position in the prior art compound. Also in the prior art diazole ring, the nitrogens are adjacent to each other whereas they are separated by a carbon in the oxadiazole of the invention. We have also found that the oxadiazole analogue of the present invention has improved activity compared with said prior art compound.

We have also found that intermediates to the compounds of formula I and their analogues have fungicidal activity and accordingly the invention provides compounds of formula II

where X is 0 or S;

Y is alkyl, cycloalkyi, cycloalkenyl, alkenyl or alkynyl, each of which is optionally substituted, hydrogen or acyl; R¹ is a phenyl or a 5 or 6 membered heterocyclyl group, each of which is optionally substituted

R² and R^ are hydrogen or alkyl or together with the nitrogen to which they are attached can form an optionally substituted ring which can contain 0 to 3 extra hetero atoms selected from nitrogen, oxygen or sulfur; and R⁴ is hydrogen or acyl; together with complexes with metal salts, as well as salts with bases of compounds which are acids and salts with acids of compounds which are bases.

In the compounds of formula I, R is preferably an alkyl group of 1 to 6, especially 1 to 4 carbon atoms, and preferably methyl.

W is preferably hydrogen or chlorine and especially hydrogen.

A particularly preferred specific compound is 6-methoxy-2'-(5-methyl-1 ,2,4-oxadiazol- 3-yl)nicotinanilide.

In the compounds of formula II

Optional substituents on R ^*l are alkyl, cycloalkyi, cycloalkenyl, alkenyl, alkynyl, or amino, (each of which is optionally substituted), Y¹ -X-, halogen, cyano, nitro, acyl, optionally substituted heterocyclyl or optionally substituted phenyl; or two adjacent groups together with the carbon atoms to which they are attached can form an optionally substituted benzo or heterocyclic ring.

Y ¹ has the same meaning as Y or is optionally substituted phenyl or optionally substituted heterocyclyl.

Alkyl groups are preferably of 1 to 20, e.g. 1 to 6, carbon atoms. Alkenyl and alkynyl groups are generally of 3 to 6 carbon atoms. Cycloalkyi or cycloalkenyl groups are preferably of 3 to 8 carbon atoms. Substituents, when present on any alkyl, cycloalkyi, cycloalkenyl, alkenyl or alkynyl moiety include halogen, azido, cyano, optionally substituted alkoxy, optionally substituted alkylthio, hydroxy, nitro, optionally substituted amino, acyl, acyloxy, optionally substituted phenyl, optionally substituted heterocyclyl, optionally substituted phenoxy and optionally substituted heterocyclyloxy. Cycloalkyi or cycloalkenyl groups may also be substituted by alkyl.

Substituents when present on any phenyl or heterocyclyl group are usually one or more of the same groups as defined for R ¹ .

The term heterocyclyl includes both aromatic and non-aromatic heterocyclyl groups. Heterocyclyl groups are generally 5, 6 or 7-membered rings containing up to 4 hetero atoms selected from nitrogen, oxygen and sulfur. Examples of heterocyclyl groups are furyl, thienyl, pyrrolyl, pyrrolinyl, pyrrolidinyl, imidazolyl, dioxolanyl, oxazolyl, thiazoiyi, imidazolyl, imidazolinyl, imidazolidinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl, isoxazolyl, isothiazolyl, oxadiazolyl, triazolyl, thiadiazolyl, pyranyl, pyridyl, piperidinyl, dioxanyl, morpholino, dithianyl, thiomorpholino, pyridazinyl, pyrimidinyl, pyrazinyl, piperazinyl, triazinyl, thiazolinyl, benzimidazolyl, tetrazolyl, benzoxazolyl, imidazopyridinyl, 1 ,3-benzoxazinyl, 1 ,3-benzothiazinyl, oxazolopyndinyl, benzofuranyl, quinolinyl, quinazolinyl, quinoxalinyl, sulfolanyl, dihydroquinazoiinyl, benzothiazolyl, phthalimido, benzofuranyl, azepinyl, oxazepinyl, thiazepinyl, diazepinyl and benzodiazepinyl.

Amino groups may be substituted for example by one or two optionally substituted alkyl or acyl, or two substituents can form a ring, preferably a 5 to 7- membered ring, which may be substituted and may contain other heteroatoms, for example morpholine, thiomorpholine, or piperidine. When R² and R^ form a ring it is generally also a 5 to 7 membered ring. These rings can be substituted as for heterocyclyl.

The term acyl includes the residue of sulfur and phosphorus-containing acids as well as carboxylic acids. Examples of acyl groups are thus -COR^, -COOR^, -CXNR⁵R⁶, -CON(R )OR⁶, -COONR⁵R⁶, -CON(R⁵)NR⁶R⁷, -COSR⁵ , -CSSR⁵, -S(0)_pR⁵, -S(0)₂OR⁵ , -S(0)_pNR⁵R⁶, -P( = X)(OR⁵)(OR⁶), -CO-COOR⁵ , where R⁵, R6 and R⁷ are as defined previously, or R^ and R⁷ together with the atom(s) to which they are attached can form a ring, p is 1 or 2 and X is 0 or S.

Complexes are usually formed from a salt of formula MAn2, in which M is a divalent metal cation, e.g. copper, manganese, cobalt, nickel, iron or zinc and An is an anion, e.g. chloride, nitrate or sulfate.

The invention also includes tautomers of compounds of formula II, where one or both of R² and R^ is hydrogen.

In the compounds of formula II: X is preferably O;

Y, R² and R3 are preferably hydrogen;

R¹ is preferably phenyl or pyridyl, preferably substituted by one or two groups selected from halogen, especially chlorine, and methoxy, or by methylenedioxy; and R⁴ is preferably hydrogen, acetyl, propionyl or methoxyacetyl.

The compounds of the invention have activity against other pathogens of Deuteromycete, Ascomycete, Phycomycete and Basidiomycete origin, especially against fungal diseases of plants, e.g. mildews and particularly cereal powdery mildew (Erysiphe graminis), cucumber powdery mildew (Erysiphe cichoracaerum) , vine downy mildew (Plasmopara viticola) and vine powdery mildew (Uncinula necator), rice blast (Pyricυlaria oryzae), cereal eyespot (Pseudocercosporella herpotrichoides) , rice sheath blight {Pellicularia sasak/i), grey mould (Botrytis cinerea), wheat brown rust (Puccinia recondita), late tomato or potato blight (Phytophthora infestans), apple scab (Veπturia inaequalis) and glume blotch (Leptosphaeria nodorum). Some compounds may be active against only a few pathogens whereas others may have a broader spectrum of activity.

The compounds of the invention have particularly advantageous activity against fungal pathogens of plants and particularly those pathogens of Ascomycete origin, especially against mildew diseases of plants, particularly cereal powdery mildew (Erysiphe graminis), cucumber powdery mildew (Erysiphe cichoracearum) , vine downy mildew (Uncinula necator), and apple powdery mildew (Podosphaera leuchotricha). However some compounds may be active against other pathogens of Deuteromycete, Ascomycete, Phycomycete and Basidiomycete origin, e.g. rice blast (Pyricularia oryzae). cereal eyespot (Pseudocercosporella herpotrichoides), rice sheath blight (Pellicularia sasakii), grey mould (Botrytis cinerea), wheat brown rust (Puccinia recondita), late tomato or potato blight (Phytophthora infestans), apple scab (Venturia inaeqυalis) and glume blotch (Leptosphaeria nodorum). Some compounds may be active against only a few pathogens whereas others may have a broader spectrum of activity.

The compounds of the invention are generally formulated in conventional compositions used for fungicides. These compositions can contain one or more additional pesticides, for example compounds known to possess herbicidal, fungicidal, insecticidal, acaricidal or nematicidal properties.

The diluent or carrier in the composition of the invention can be a solid or a liquid optionally in association with a surface-active agent, for example a dispersing agent, emulsifying agent or wetting agent. Suitable surface-active agents include anionic compounds such as a carboxylate, for example a metal carboxylate of a long chain fatty acid; an N-acylsarcosinate; mono- or di-esters of phosphoric acid with fatty alcohol ethoxylates or salts of such esters; fatty alcohol sulfates such as sodium dodecyl sulfate, sodium octadecyl sulfate or sodium cetyl sulfate; ethoxylated fatty alcohol sulfates; ethoxylated alkylphenol sulfates; lignin sulfonates; petroleum sulfonates; alkyl-aryl sulfonates such as alkyl-benzene sulfonates or lower alkylnaphthalene sulfonates, e.g. butyl-naphthalene sulfonate; salts of sulfonated naphthalene-formaldehyde condensates; salts of sulfonated phenol-formaldehyde condensates; or more complex sulfonates such as the amide sulfonates, e.g. the sulfonated condensation product of oleic acid and N-methyl taurine or the dialkyl sulfosuccinates, e.g. the sodium sulfonate of dioctyl succinate. Nonionic agents include condensation products of fatty acid esters, fatty alcohols, fatty acid amides or fatty-alkyl- or alkenyl-substituted phenols with ethylene oxide, fatty esters of polyhydric alcohol ethers, e.g. sorbitan fatty acid esters, condensation products of such esters with ethylene oxide, e.g. polyoxyethylene sorbitan fatty acid esters, block copolymers of ethylene oxide and propylene oxide, acetylenic glycols such as 2,4,7,9-tetramethyl-5-decyne-4,7-diol, or ethoxylated acetylenic glycols. Examples of a cationic surface-active agent include, for instance, an aliphatic mono-, di-, or polyamine as an acetate, naphthenate or oleate; an oxygen-containing amine such as an amine oxide or polyoxyethylene alkylamine; an amide-linked amine prepared by the condensation of a carboxylic acid with a di- or polyamine; or a quaternary ammonium salt.

The compositions of the invention can take any form known in the art for the formulation of agrochemicals, for example, a solution, a dispersion, an aqueous emulsion, a dusting powder, a seed dressing, a fumigant, a smoke, a dispersible powder, an emulsifiable concentrate or granules. Moreover it can be in a suitable form for direct application or as a concentrate or primary composition which requires dilution with a suitable quantity of water or other diluent before application.

As a dispersion, the composition comprises a compound of the invention dispersed in a liquid medium, preferably water. It is often convenient to supply the consumer with a primary composition which can be diluted with water to form a dispersion having the desired concentration. The primary composition can be provided in any one of the following forms. It can be a dispersible solution which comprises a compound of the invention dissolved in a water-miscible solvent with the addition of a dispersing agent. A further alternative comprises a compound of the invention in the form of a finely ground powder in association with a dispersing agent and intimately mixed with water to give a paste or cream which can if desired be added to an emulsion of oil in water to give a dispersion of active ingredient in an aqueous oil emulsion.

An emulsifiable concentrate comprises a compound of the invention dissolved in a water-immiscible solvent together with an emulsifying agent and which is formed into an emulsion on mixing with water.

A dusting powder comprises a compound of the invention intimately mixed with a solid pulverulent diluent, for example, kaolin.

A granular solid comprises a compound of the invention associated with similar diluents to those which may be employed in dusting powders, but the mixture is granulated by known methods. Alternatively it comprises the active ingredient adsorbed or absorbed on a pre-granular diluent, for example, Fuller's earth, attapulgite or limestone grit.

A wettabie powder usually comprises the active ingredient in admixture with a suitable surfactant and an inert powder diluent such as china clay.

Another suitable concentrate, particularly when the product is a solid, is a flowable suspension concentrate which is formed by grinding the compound with water, a wetting agent and a suspending agent.

The concentration of the active ingredient in the composition of the present invention is preferably within the range of 1 to 30 per cent by weight, especially 5 to 30 per cent by weight. In a primary composition the amount of active ingredient can vary widely and can be, for example, from 5 to 95 per cent by weight of the composition.

The compound compounds are generally applied to seeds, plants or their habitat. Thus, the compound can be applied directly to the soil before, at or after drilling so that the presence of active compound in the soil can control the growth of fungi which may attack seeds. When the soil is treated directly the active compound can be applied in any manner which allows it to be intimately mixed with the soil such as by spraying, by broadcasting a solid form of granules, or by applying the active ingredient at the same time as drilling by inserting it in the same drill as the seeds. A suitable application rate is within the range of from 5 to 1000 g per hectare, more preferably from 10 to 500 g per hectare.

Alternatively the active compound can be applied directly to the plant by, for example, spraying or dusting either at the time when the fungus has begun to appear on the plant or before the appearance of fungus as a protective measure. In both such cases the preferred mode of application is by foliar spraying. It is generally important to obtain good control of fungi in the early stages of plant growth as this is the time when the plant can be most severely damaged. The spray or dust can conveniently contain a pre- or post-emergence herbicide if this is thought necessary. Sometimes, it is practicable to treat the roots of a plant before or during planting, for example, by dipping the roots in a suitable liquid or solid composition. When the active compound is applied directly to the plant a suitable rate of application is from 0.025 to 5 kg per hectare, preferably from 0.05 to 1 kg per hectare.

The compounds of formula II may be prepared in known manner, for example by reacting a compound of formula III

with a hydroxylamine salt, preferably hydroxylamine hydrochloride, to give a compound where R², R^ and R⁴ are hydrogen.

The R groups can be modified in known manner. For instance the compound can be reacted with a compound, R⁴Q, where Q is a leaving group such as halogen.

Compounds of formula III are either known or can be prepared in known manner (e.g. as described in our WO 95/25723).

Alternatively anthranilamide oxime

can be reacted with a compound

R¹ CO-Q where Q is as defined above to give a compound of formula II where X is oxygen, and Y is hydrogen and R⁴ is -COR ¹ .

If desired compounds can be modified in known manner to give other compounds where X and/or Y have other desired values, and if desired modifying compounds of formula I in known manner to give compounds where the R groups have other values.

Thio groups may be oxidised using a suitable oxidising agent, e.g. rn-chloro- perbenzoic acid, to give sulfinyl and sulfonyl groups.

Compounds where X is 0 can be converted to compounds where X is S by sulfurising the carbonyl group in known manner, e.g. using Lawesson's reagent or phosphorus pentasulfide.

Compounds of formula I may be prepared from the corresponding compound of formula II where X is O; R^, R⁴, R5 and Y are hydrogen and R ¹ is

where W is as previously defined, by heating with an acylating agent, e.g. an acid anhydride of formula (RCO)2θ, where R is as previously defined, to give the desired compound.

The invention is illustrated in the following Examples. Structures of isolated novel compounds were confirmed by nmr and/or other appropriate analyses.

Example 1

A mixture of N-(2-cγanophenyl)-6-methoxynicotinamide (31 g), hydroxylamine hydrochloride (17 g), potassium carbonate (17 g), water (250 ml) and methanol (250 ml) was heated under reflux for 24 hours. The mixture was cooled to room temperature, diluted with water and extracted with ether. The extract was dried and evaporated under reduced pressure to give N-{2-[amino(hydroxyimino)methyl]- phenyl}-6-methσxynicotinamide, m.p. 1 62-4° C (Compound l a)

In similar manner N-(2-cyanophenyl)-4-fluorobenzamide gave N-{2-[amino- (hydroxyimino)methyl]phenyl}-4-fiuorobenzamide, m.p. 1 90-1 ° C (Compound 1 b) Example 2

A mixture of compound 1 a (28.6 g) in dry tetrahydrofuran (500 ml) was treated with acetic anhydride ( 100 ml). The mixture was stirred and heated slowly to reflux. It was then heated under reflux for 2 hours, cooled to room temperature and evaporated under reduced pressure. The residue was added to water (1 I), stirred for one hour at room temperature. Ethyl acetate was added and the insoluble white solid was collected and dried to give N-{2-[amino(acetoxyimino)- methyllphenyl}-6-methoxynicotinamide, m.p. 1 77-80° C (Compound 2).

Example 3

A solution of acetyl chloride (0.14 g) in dry tetrahydrofuran (2 ml) was added dropwise over 10 minutes to a stirred solution of compound 1 b (0.5 g) in dry tetrahydrofuran (20 ml) having cooled to a temperature of 0-5° C. The mixture was stirred for 48 hours at room temperature. It was then evaporated under reduced pressure and the residue was partitioned between water and dichloromethane. The aqueous layer was extracted twice more with dichloromethane and the combined organic extracts were washed with brine, dried and evaporated under reduced pressure. The residue was re-crystallised from toluene to give gave N-{2-[amino(acetoxyimino)methyl]phenyl}-4-fluorobenzamide, m.p. 182-4° C (Compound 3a).

In a similar manner, anthranilamide oxime was treated with 3,4-dimethoxybenzoyl chloride to give N-{2-[amino(3,4-dimethoxybenzoγloxyimino)methyl]phenyl}- 3,4-dimethoxybenzamide, m.p. 1 83-183.5° C (Compound 3b).

Example 4

In a similar manner to one of the processes disclosed in the previous Examples, the following compounds of formula II where X is 0 and Y, R² and R^ are H, were obtained:

Compound Rl R⁴ m.p.rC)

4 5-CI-6-Me0-3-pyridyl benzoyl 188-90

5 5-CI-6-MeO-3-pyridyl propionyl 127-8

6 5-Br-2-furyl H 156-8

7 3,4-OCH₂CH₂0-phenyl propionyl 156-8

8 3,4-(MeO)2-phenyl H 198-200

9 3,4-(MeO)2-phenyl propionyl off-white solid

10 3,4-(MeO)2-phenyl acetyl 148-50

11 6-MeO-3-pyridyl COCH₂OMe 160-1

12 6-MeO-3-pγridyl propionyl 173-4

13 3,4-OCH₂0-phenyl H 187-8

14 3,4-OCH2θ-phenyl acetyl 206-7

15 3,4-{MeO)2"Phenyl COBu* 156-62

16 3,4-(MeO)2-phenγl 169-72 s

17 3,4-(MeO)2-phenyl COPr' 138-41

18 3,4-(MeO)2-phenyl COCH₂Bu^t 163-8

19 3,4-(MeO)2-phenyl COcyclohexyl 145-55

20 3,4-(MeO)2-phenyl COPr 150-5

21 3,4-(MeO)2-phenyl COBu' 139-44 Compound R 1 R⁴ m.p.(° C)

22 3,4-(MeO>2-phenyl CObenzyl 1 1 9-30

23 3,4-(MeO)2-phenyl COcyclopropyl 1 52-9

24 3,4-(MeO)2"phenyl COCH₂OMe 1 22-6

25 3,4-(MeO>2-phenyl COCH = C(Me)₂ 137-45

26 3,4-(MeO)2-phenyl COpentyl 128-9

27 2-CF3-phenyl acetyl 1 67-8

28 2-Me-phenyl acetyl 1 55-6

29 4-Ph-phenyl acetyl 1 86-7

30 4-Bu^t-phenyl acetyl 1 72-3

31 1 -naphthyl acetyl 142-3

32 3-CI-phenyl acetyl 1 64-6

33 3-CI-phenyl H 1 52-4

34 2-Me-phenyl H 101 -2

35 1 -naphthyl H 94-6

36 2-CF3-phenyl H 1 61 .5-3

Example 5

A mixture of the Compound 1a (2g) and acetic anhydride (50 ml) was heated under reflux for 2 hours, after which it was poured into water, stirred for 1 hour, and extracted into ethyl acetate. The extract was washed and dried over magnesium sulfate. Removal of the solvent gave a brown solid which was recrystallised from acetonitrile to give 6-methoxy-2'-(5-methyl-1 ,2,4-oxadiazol-3-yl)nicotinanilide, m.p. 1 25-6° C. (Compound 50) In a similar manner, the following compounds of formula I were obtained:

Compound W R m.p.(° C)

51 Cl Me 147-9

52 H Et 1 23-5

53 C! Pr' 133-5

54 H CF₃ 125-7

Example 6

To a solution of Compound 50 (0.5 g) in hot ethanol (20 ml) was added with stirring a solution of copper (II) chloride (0.1 1 g) in water (0.5 ml). The mixture was allowed to cool to room temperature and then stirred overnight. The solid was collected by filtration, washed with ethanol, water and acetone and dried in vacuo to give bis-[6-methoxy-2'-(5-methyl-1 ,2,4-oxadiazol-3-yl)nicotinanilide] copperODchloride complex, m.p. 213-4° C (dec.) (compound 60).

Test Example

Compounds are assessed for activity against one or more of the following:

Plasmopara vitico/a: vine downy mildew

Erysiphe graminis f. sp. hordei: barley powdery mildew Erysiphe graminis f. sp. tritici: wheat powdery mildew

Pyricularia oryzae: rice blast

Pellicularia sasakii: rice sheath blight

Botrytis cinerea: grey mould

Venturia inaequalis: apple scab Leptosphaeria nodorum: glume blotch

Aqueous solutions or dispersions of the compounds at the desired concentration, including a wetting agent, were applied by spray or by drenching the stem base of the test plants, as appropriate. Plants or plant parts were then inoculated with appropriate test pathogens and kept under controlled environment conditions suitable for maintaining plant growth and development of the disease. After an appropriate time, the degree of infection of the affected part of the plant was visually estimated. Compounds are assessed on a score of 1 to 3 where 1 is little or no control, 2 is moderate control and 3 is good to total control. At a concentration of 500 ppm (w/v) or less, the following compounds scored 2 or more against the fungi specified Plasmopara viticola

1 7, 18, 61

Erysiphe graminis f. SD. hordei 1 a, 50-52

Erysiphe graminis f. so. tritici 1 b, 2, 5, 9-14, 26, 50-54, 61 Pyricularia oryzae

18, 1 9 Pellicularia sasakii 7

Botrytis cinerea 5, 23, 24, 26 Venturia inaeαualis

1 a

Leptosphaeria nodorum

17

Comparison Test Example

Compounds of Examples 1 and 6-methoxy-2'-(5-methyl-1 ,3,4-thiadiazol-2- yDnicotinanilide (compound X) which is the prior art compound of closest structure were assessed for activity against the following:

Erysiphe graminis tritici: wheat powdery mildew

Erysiphe graminis hordei: barley powdery mildew. The compounds were tested as previously but at more rates and with more replicates.

Results obtained were as follows: (a blank means the compound was not tested at that rate)

Erysiphe graminis tritici

Rate % Control (g/ha) Compound 50 Compound X

80 100 86

10 99 82

0.63 90 NT

Erysiphe graminis hordei

Rate % Control (g/ha) Compound 50 Compound X

80 100 83

20 96 1 1

1 .25 87 NT

Claims

1. Compounds of formula I:

2. 6-Methoxy-2'-(5-methyl-1 ,2,4-oxadiazol-3-yl)nicotinanilide and complexes thereof.

3. Compounds of formula II

where X is 0 or S;

Y is alkyl, cycloalkyi, cycloalkenyl, alkenyl or alkynyl, each of which is optionally substituted, hydrogen or acyl;

R¹ is a phenyl or a 5 or 6 membered heterocyclyl group, each of which is optionally substituted

R² and R^ are hydrogen or alkyl or together with the nitrogen to which they are attached can form an optionally substituted ring which can contain 0 to 3 extra hetero atoms selected from nitrogen, oxygen or sulfur; and

R⁴ is hydrogen or acyl; together with complexes with metal salts, as well as salts with bases of compounds which are acids and salts with acids of compounds which are bases,

4. A fungicidal composition which comprises a compound according to claim 1 or 2 or a complex thereof in association with agriculturally acceptable diluents. 5 The use as a phytopathogenic fungicide of a compound according to any one of claims 1 to 3