GB2287465A - Heterocyclic difluoro-butenyl ethers - Google Patents

Abstract

A compound of formula (1): ROCH2CH2CH=CF2 (I) wherein: R is a 1,2,4-oxadiazolyl, 1,2,4-thiadiazolyl, 1,3,4-oxadiazolyl, 1,3,4-thiadiazolyl, tetrazolyl, pyridazinyl, 1,2,4-triazinyl, 1,3,5-triazinyl, quinazolyl, or quinoxalyl group, each R group being optionally substituted by an R1 group selected from halogen, C1-6 alkyl, C1-6 haloalkyl, C1-6 alkoxy, C1-6 alkoxymethyl, C1-6 fluoroalkoxy, (e.g. -OCHF2 and -OCH2CH2F), amino, and mono- or di- C1-6 alkylamino (e.g. -NMe2), cyanomethyl, aryl, arylalkyl in which the alkyl moiety has from 1 to 6 carbon atoms, carboxy, alkoxycarbonyl of 2 to 6 carbon atoms, sulphamoyl, mono- or di- C1-6 alkylsulphamoyl, cyano, carbamoyl, mono- or di- C1-6 alkylcarbamoyl, thiocarbamoyl, alkylcarbonyl of 2 to 4 carbon atoms, or alkanesulphonamido of 1 to 6 carbon atoms, has nematicidal, insecticidal or acaricidal activity.

Description

HETEROCYCLIC COMPOUNDS This invention relates to novel heterocyclic derivatives having nematicidal, insecticidal, and acaricidal activity, to processes for their preparation, to compositions containing them, and to methods for killing or controlling nematode, insect, and acarid pests using them.

According to the present invention there is provided a compound of the formula (I): ROCH2CH2CH=CF2 (I) wherein R is a 1,2,4-oxadiazolyl, 1,2,4-thiadiazolyl, 1,3,4-oxadiazolyl, 1,3,4-thiadiazolyl, tetrazolyl, pyridazinyl, 1,2,4-triazinyl, 1,3,5-triazinyl, quinazolyl, or quinoxalyl group, each R group being optionally substituted by an R1 group selected from halogen, C1-6 alkyl, C1-6 haloalkyl, C16 alkoxy,C1-6 alkoxymethyl, C1 6 fluoroalkoxy (e.g. -OCHF2 and -OCH2CH2F), amino, and mono- or di- C16 alkylamino (e.g. -NMe2), cyanomethyl, aryl, arylalkyl in which the alkyl moiety has from 1 to 6 carbon atoms, carboxy, alkoxycarbonyl of 2 to 6 carbon atoms, sulphamoyl, mono- or di- C1-6 alkylsulphamoyl, cyano, carbamoyl, mono- or di- C1-6 alkylcarbamoyl, thiocarbamoyl, alkylcarbonyl of 2 to 4 carbon atoms, or alkanesulphonamido of 1 to 6 carbon atoms.

Examples of alkyl groups include methyl and ethyl. Halogen includes bromine, chlorine, and fluorine. Examples of haloalkyl groups include trifluoromethyl, 2-fluoroethyl and 2,2,2-trifluoroethyl. Examples of C16 alkoxy groups include methoxy. Examples of aryl groups include phenyl, optionally substituted in the 4-position by any of the R1 groups listed above.

When R is a 1,2,4-oxadiazol-5-yl or 1,2,4-thiadiazol-5-yl group, the R1 substituent, which will be in the 3-position, is preferably selected from CF3, alkoxycarbonyl of 2 to 6 carbon atoms, carboxy, sulphamoyl, monoor di-C1-6 alkyl sulphamoyl, cyano, or thiocarbamoyl.

When R is a 1,2,4-oxadiazol-3-yl or 1,2,4-thiadiazol-3-yl group, the R1 group, which will be in the 5-position, is preferably selected from CF3, sulphamoyl, mono- or di- C1-6 lower alkylsulphamoyl, cyano, or thiocarbamoyl.

When R is a 1,3,4-oxadiazol-2-yl or 1,3,4-thiadiazol-2-yl group, the R1 group, which will be in the 5-position, is preferably selected from CF3, sulphamoyl, mono- or di- C1-6 lower alkylsulphamoyl, cyano, or thiocarbamoyl.

When R is a tetrazol-5-yl group, the R1 group is preferably in the 1-position of the tetrazole ring, and is preferably selected from 2,2,2-trifluoroethyl, cyano, trifluoromethyl, or an optionally 4-substituted phenyl radical, wherein the 4-substituent is preferably selected from C1-6 alkyl, arylalkyl (eg benzyl), aryl (eg optionally substituted phenyl), cyanomethyl, alkoxymethyl, halogen, carbamoyl, monoand di- C1-6 alkylcarbamoyl, carboxy, alkoxycarbonyl of 2 to 6 carbon atoms, alkylcarbonyl of 2 to 6 carbon atoms, cyano, thiocarbamoyl, sulphamoyl, or mono- and di-C1-6 alkylsulphamoyl.

When R is a pyridazin-4-yl group, the R1 substituènt may be in the 3-, 5-, or 6-position, and is preferably in the 3-position. The R1 substituent is preferably selected from chlorine, bromine, carbamoyl, monoor di- C1-6 alkylcarbamoyl, alkoxycarbonyl of 2 to 6 carbon atoms, alkylcarbonyl of 2 to 6 carbon atoms, trifluoromethyl, sulphamoyl, mono- or di- C1-6 alkyl sulphamoyl, cyano, or thiocarbamoyl.

When R is a pyridazin-3-yl group, the R1 substituent is preferably in the 6-position, and is preferably selected from alkoxycarbonyl of 2 to 4 carbon atoms, alkylcarbonyl of 2 to 4 carbon atoms, trifluoromethyl, sulphamoyl, mono- or di- C1-6 alkyl sulphamoyl, cyano, or thiocarbamoyl.

When R is a 1,3,5-triazin-2-yl group, the R1 substituent is in the 2-position and is preferably selected from chlorine, bromine, fluorine, carbamoyl, mono- or di- C1-6 alkylcarbamoyl, alkoxycarbonyl of 2 to 6 carbon atoms, alkylcarbonyl of 2 to 6 carbon atoms, trifluoromethyl, sulphamoyl, mono- or di- C1-6 alkyl sulphamoyl, cyano, or thiocarbamoyl.

When R is a 1,2,4-triazin-3-yl group, the R1 substituent is preferably in the 5-position, although it may instead be in the 6-position, and it is preferably selected from CF3, sulphamoyl, mono- or di- C1-6 alkylsulphamoyl, cyano, or thiocarbamoyl.

When R is a 1,2,4-triazin-5-yl group, the R1 substituent is preferably in the 3-position, although it may instead be in the 6-position, and it is preferably selected from halogen, C1-6 alkyl, C1-6 haloalkyl, C1-6 alkoxymethyl, cyanomethyl, aryl, arylalkyl in which the alkyl moiety has from 1 to 6 carbon atoms, carboxy, alkoxycarbonyl of 2 to 6 carbon atoms, sulphamoyl, mono- or di- C1-6 alkylsulphamoyl, cyano, carbamoyl, mono- or di- C1-6 alkylcarbamoyl, thiocarbamoyl, alkylcarbonyl of 2 to 4 carbon atoms, or alkanesulphonamido of 1 to 6 carbon atoms.

When R is a 1,2,4-triazin-6-yl group, the R1 substituent is preferably in the 3-position, although it may instead be in the 5-position, and it is preferably selected from CF3, sulphamoyl, mono- or di- C1-6 alkylsulphamoyl, cyano, or thiocarbamoyl.

When R is a quinoxalin-2-yl group, the R1 group is preferably in the 3-position, and is preferably selected from C16 alkyl (e.g. Me), C16 alkoxy (e.g. OMe), C1-6 fluoroalkyl (e.g. -CH2CH2F), C1 6 fluoroalkoxy (e.g. -OCHF2, -OCH2CH2F), amino, or mono- or di- C16 alkylamino.

When R is a quinazolinyl group, the R1 group is preferably selected from C16 alkyl (e.g. Me), C1-6 alkoxy (e.g. OMe), C1-6 fluoroalkyl (e.g.

-CH2CH2F), C1-6 fluoroalkoxy (e.g. -OCHF2, -OCH2CH2F), amino, or mono- or di- C16 alkylamino.

Particular examples of compounds of the imvention are listed in Table I below.

TABLE I COMPOUND R SUBSTITUENTS No 1 112,4-thiadiazolyl 5-OCH2CH2CH=CF2 3-CF3 2 " " 3-CN 3 1,2,4-oxadiazolyl 3-OCH2CH2CH=CF2 5-CF3 4 " " 5-CN 5 1,3,4-thiadiazolyl 2-OCH2CH2CH=CF2 5-CF3 6 " 2-OCH2CH2CH=CF2 5-CN 7 1,3,4-oxadiazolyl " 5-CF3 8 " " II 5-CN 9 tetrazolyl 5-OCH2CH2CH=CF2 1-(C6H4Clp) 10 " II 1- (C6H4Fa) 11 " " 1-(C6H4CF3D) 12 pyridazinyl 4-OCH2CH2CH=CF2 6-CN 13 " "II 6-CF3 14 " 3-OCH2CH2CH=CF2 6-CN 15 II " 6-CF3 16 1,2,4-triazinyl 17 " " 5-Cl 18 " " 5-CN 19 " " 5-CF3 20 " 5-OCH2CH2CH=CF2 21 " " II 5-Cl 22 " " II 5-Me 23 " " II 5-CF3 TABLE I (continued) COMPOUND R SUBSTITUENTS No 24 II " 5-CN 25 " " 5-CONH2 26 " II 5-C02Me 27 " " II 5-C02H 28 " 6-OCH2CH2CH=CF2 3-CN 29 1,3,5-triazinyl 2-OCH2CH2CH=CF2 30 " I, 4-Cl 31 " " II 4-CN 32 quinoxalinyl 2-OCH2CH2CH=CF2 3-CN 33 " II 3-CF3 34 quinazolinyl 4-OCH2CH2CH=CF2 2-CN 35 II II 2-CF3 Compounds of formula (I) may be prepared by a variety of methods.

Thus for example, they may be prepared by reacting a hydroxy- substituted heterocycle of formula R-OH, wherein R is as defined above, with a difluorobutenyl derivative of formula F2C=CHCH2CH2L (II) wherein L is a leaving group. The leaving group may be, for example, a halogen atom, (e.g. bromine), or a sulphonate ester, for example an optionally substituted benzenesulphonyloxy group (e.g. e-toluenesulphonyloxy).

The reaction may be carried out by reacting the hydroxy-compound R-OH with the difluorobutenyl derivative CF2=CH-CH2CH2L (II) in an inert solvent in the presence of a base. The reaction may be accelerated by heating (e.g. to a temperature in the range from 50 to 1500C). Examples of inert solvents include dimethyl formamide, acetonitrile, acetone, and liquid hydrocarbons (e.g. toluene). Examples of bases include inorganic bases (e.g. sodium hydride, potassium carbonate, and silver carbonate) and tertiary amines (e.g. ethyl diisopropylamine). The use of silver carbonate as the base in conjuntion with toluene may tend to reduce the side reaction (N-alkylation) in which the difluorobutenyl group becomes attached to a neighbouring nitrogen atom of the heterocycle instead of to the oxygen atom of the heterocyclic - OH group. In an alternative procedure, the hydroxysubstituted heterocycle of formula R-OH may be reacted with the difluorobutenyl derivative CF2=CHCH2CH2L (II) in an inert, water-immiscible solvent (e.g. toluene or methylene chloride) in the presence of a concentrated aqueous solution of a base (e.g. a 40-50% aqueous solution of sodium hydroxide) in the presence of a phase-transfer catalyst (e.g. tetra butlylammonium bromide or sulphate, or a tetraphenylphosphonium salt. This two phase system is stirred to facilitate contact between the two phases.

In an alternative method for preparing the compounds of the invention, the hydroxy- substituted heterocycle R-OH may be reacted with a 1-bromo-1,1,2-trifluoro butyl derivative of formula F2BrCCHFCH2CH2L (III) wherein L is a leaving group (e.g. bromo or D-toluenesulphonyloxy) as defined above, under conditions simular to those described above for the analogous reaction with the difluorobutenyl derivative CF2=CHCH2CH2L (II).

The product of the reaction, having the formula ROCH2CH2CHFCF2Br (IV), is then treated with a debromofluorinating agent (e.g. zinc) to give the compound of formula (I).

In a further alternative method for preparing compounds of formula (I), the appropriate heterocyclic derivative of formula R-X, wherein R is as defined above, and X is a halogen atom (e.g. bromine, chlorine, or fluorine) or a sulphonate ester residue (e.g. methanesulphonyloxy or optionally substituted benzenesulphonyloxy) is reacted with 4,,4-difluorobut-3-enyl alcohol, CF2=CHCH2CH20H (V) in an inert solvent (for example an ether, e.g. tetrahydrofuran) in the presence of a base (e.g. sodium hydride, or potassium carbonate) to give the required compound of formula (I).

In a variation of the latter procedure, an ester of 4,4-difluorobut-3-enyl alcohol, having the formula CF2=CHCH2CH2OCOR2 (VI); wherein R2 is hydrogen, C14 alkyl (e.g. methyl) or C14 halo alkyl (e.g.

CF3) may be used. Preferably R2 is hydrogen. In this variation, the ester (VI) is reacted in an inert, water-immiscible solvent, with the heterocyclic derivative R-X (wherein X is preferably halogen) in the presence of a concentrated aqueous solution of a base (e.g. a 40-50% solution of sodium hydroxide) and in the presence of a phase transfer catalyst (e.g. a tetrabutylammonium salt or a tetraphenylphosphonium salt, usually a halide or a sulphate). In this procedure, the ester (VI) is hydrolysed in the reaction mixture to form 4,4-difluorobut-3-enyl alcohol (V) which then reacts with the heterocyclic derivative R-X to give the compound of formula (I).

The ester (VI) required as a reactant in the above procedure may itself be prepared by reaction of 4,4-difluoro-3-butenyl bromide (11, L=Br) with a salt of the appropriate acid (e.g. an alkali metal salt) in an inert solvent (e.g. acetone). Thus the formate ester (VI, R2=H) may be prepared by reacting 4,4-difluoro-but-3-enyl bromide with potassium formate in acetone. Alternatively the ester (VI) may be prepared by reacting 4,4-difluoro-but-3-enyl bromide with an alkali metal salt of the appropriate acid in the absence of a solvent, but in the presence of a phase transfer catalyst (e.g. a tetrabutylammonium salt or a tetraphenylphosphonium salt).

The heterocyclic derivatives R-OH and R-X required for use in the above preparative procedures may be made by processes known to those skilled in the art.

The preparation of the difluorobutenyl derivatives F2C=CHCH2CH2L (II) wherein L is Br or e-toluenesulphonyloxy, is described below.

Preparation of 4.4-difluorobut-3-envl 4-methvl-benzenesulphonate Step 1: Preparation of 1,4-dibromo-1,1,2-trifluorobutane.

A solution of 4-bromo-1,1,2-trifluorobut-1-ene (2.59) in dry dichloromethane (25cm ) at 0 C was treated with hydrogen bromide gas for 45 minutes. The reaction mixture was then stirred at OOC for 1 hour. The reaction mixture was made alkaline with 5% sodium bicarbonate solution and extracted twice with dichloromethane. The combined dichloromethane extracts were dried over magnesium sulfate, filtered and concentrated under reduced pressure to give a pale yellow liquid (2.849). The material was shown by gc analysis to be greater than 99% pure. 1H NMR (CDCl3): s 2.15-2.59 (2H,m); 3.42-3.69(2H,m); 4.75-5.07(1H,m).

Step 2: Preparation of 4-bromo-3.4.4-trifluorobutvl 4-methvl-benzenesulfonate.

The product from Step 1 (1g) was added dropwise to a stirred suspension of silver tosylate (1.039) in acetonitrile (1Ocm3) at ambient temperature, protected from the light. The reaction was then heated under reflux for 24 hours after which gc analysis indicated complete consumption of starting material. The reaction mixture was cooled to the ambient temperature and the precipitate was filtered off and washed with ethyl acetate. The filtrate and ethyl acetate washings were combined and washed with water and the aqueous layer extracted with ethyl acetate. The combined ethyl acetate layers were washed with water and brine, dried over magnesium sulfate and evaporated under reduced pressure to give a brown oil (1.21g). GC analysis showed this material to be > 99% pure. 1H NMR (CDCl3): 8 2.20(2H,m); 2.46(3,s); 4.19(2H,m); 4.74(1H,m); 7.38(2H,d); 7.80(2H,d).

Step 3: Preparation of 4.4-difluorobut-3-envl 4-methvl-benzenesulfonate.

To a stirred suspension of powdered zinc (1.419) and iodine (one grain, catalytic) in methanol (3cm3) was added a solution of 4-bromo-3,4,4difluorobutyl p-tolysulfonate (0.719) in methanol (2cm3). The reaction mixture was heated under reflux for 2 hours after which gc analysis indicated complete consumption of starting material. The organic phase was pipetted from the zinc suspension and the zinc was washed with 3 portions of ethyl acetate. The combined ethyl acetate portions were washed with 2M hydrochloric acid, dried over magnesium sulphate and evaporated under reduced pressure to give a brown liquid (0.479). GC analysis showed this material to be > 99% pure. 1H NMR (CDCl3): b 2.35(2H,m); 2.46(3H,s); 4.01(2H,m); 4.15(1H,m); 7.38(2H,d); 7.79(2H,d).

As an alternative to the 4,4-difluorobut-3-enyl ester of a sulphonic acid, the preparation and use of which is described above, 4-bromo-1,1-difluorobut-1-ene may be used. This compound may be prepared in two steps from the commercially available compound 4-bromo-1,1,2-trifluorobut-1-ene, as follows: Step 1: Preparation of 1.4-dibromo-1.1 .2-trifluorobutane 4-bromo-1,1,2-trifluorobut-1-ene (240g) was washed with water (300cm3) and then with brine (300cm3) and dried (magnesium sulfate) before use.

Benzoyl peroxide (ca. 0.7g) was added in one portion, and hydrogen bromide gas was bubbled through the mixture at such a rate that the reaction temperature was maintained 30 to 4O0C. After 2 hours, gas chromatography of a sample of the reaction mixture showed that little starting material remained. The reaction mixture was washed with water (300cm ), then with saturated sodium bicarbonate solution and then again with water (300cm3), dried over magnesium sulfate and filtered to give a pale yellow oil (296.79) identified as 1,4-dibromo-1,1,2-trifluorobutane. The material was shown by gc analysis to be greater than 98% pure. 1H NMR (CDCl3): 8 2.38(2H,m); 3.57(2H,m); 4.90(1H,m).

Step 2: Preparation of 4-bromo-1.1-difluorobut-1-ene Zinc powder (0.88g) was added to a stirred solution of the product from Step 1 (1.38g) in acetone (6cm3) containing water (one drop), under an atmosphere of nitrogen. After 45 minutes, gc analysis showed that a large proportion of the starting material had been consumed. The mixture was then added to more zinc powder (39) in stirred acetone containing a trace of water, which had been preheated to 550C. After a further 20 minutes at this temperature, gc analysis indicated that all of the starting material had been consumed, showing that the de-bromofluorination reaction had initiated. More starting material (12.34g) was then added to the reaction over a period of 75 minutes while the reaction mixture was kept at 55"C.

Heating was then continued for a further 95 minutes. Gc analysis of a sample indicated that about 3% of the starting dibromo compound remained unchanged. Further zinc powder (0.169) was added and heating continued until gc analysis showed all the starting material had been consumed. The acetone solution was decanted from the zinc residues to give a solution of 4-bromo-1,1-difluorobut-1-ene suitable for use in further chemical reactions.

The compounds of formula (I) are nematicidal and can be used to control nematodes in crop plants. Therefore, in a further aspect of the invention, there is provided a method for killing or controlling nematodes which comprises applying to the locus of the pests or to a plant susceptible to attack by the pest an effective amount of a compound of formula (I) as defined herein.

The term "controlling" extends to non-lethal effects which result in the prevention of damage to the host plant and the limitation of nematode population increase. These effects may be the result of chemically induced disorientation, immobilisation, or hatch prevention or induction. The chemical treatment may also have deleterious effects on nematode development or reproduction.

The compounds of the invention can be used against both plantparasitic nematodes and nematodes living freely in the soil. Examples of plant-parasitic nematodes are: ectoparasites, for example Xiphinema spp., Longidorus spp. and Trichodorous spp.; semi-endoparasites, for example, Tvlenchulus spp.; migratory endoparasites, for example, Pratvlenchus spp., Radonholus spp. and Scutellonema spp.; sedentary endoparasites, for example, Heterodera spp., Globodera SDD. and Meloidogvne spp.; and stem and leaf endoparasites, for example, Ditvlenchus spp., Aphelenchoides spp. and Hirshmaniella spp..

The compounds of formula (I) may also be used to combat and control infestations of insect pests such as Lepidoptera, Diptera, Homoptera and Coleoptera (including Diabrotica i.e. corn rootworms) and also other invertebrate pests, for example, acarine pests. The insect and acarine pests which may be combated and controlled by the use of the invention compounds include those pests associated with agriculture (which term includes the growing of crops for food and fibre products), horticulture and animal husbandry, forestry, the storage of products of vegetable origin, such as fruit, grain and timber, and also those pests associated with the transmission of diseases of man and animals. Examples of insect and acarine pest species which may be controlled by the compounds of Formula (I) include: Mvzus persicae (aphid) Aphis oossynii (aphid) Aphis fabae (aphid) Meqoura viceae (aphid) Aedes aegvnti (mosquito) Anopheles spp. (mosquitos) Culex spp. (mosquitos) Dvsdercus fasciatus (capsid) Musca domestica (housefly) Pieris brassicae (white butterfly) Plutella xvlostella (diamond back moth) Phaedon cochleariae (mustard beetle) Aonidiella spp. (scale insects) Trialeurodes spp. (white flies) Bemisia tabaci (white fly) Blattella oermanica (cockroach) Periplaneta americana (cockroach) Blatta oriental is (cockroach) Spodoptera littoralis (cotton leafworm) Heliothis virescens (tobacco budworm) Chortiocetes terminifera (locust) Diabrotica spp. (rootworms) Aarotis spp. (cutworms) Chilo oartellus (maize stem borer) Nilanarvata luaens (planthopper) Nephotettix cincticeps (leafhopper) Panonvchus ulmi (European red mite) Panonvchus citri (citrus red mite) Tetranvchus urticae (two-spotted spider mite) Tetranvchus cinnabarinus (carmine spider mite) Phyllcoptruta oleivora (citrus rust mite) PolvDhaootarsonemus latus (broad mite) Brevipalpus spp. (mites) In order to apply the compound to the locus of the nematode, insect or acarid pest, or to a plant susceptible to attack by the nematode, insect or acarid pest, the compound is usually formulated into a composition which includes in addition to the compound of formula (I) suitable inert diluent or carrier materials, and/or surface active agents. Thus in two further aspects of the invention there is provided a nematicidal, insecticidal or acaricidal composition comprising an effective amount of a compound of formula (I) as defined herein and an inert diluent or carrier material and optionally a surface active agent.

The amount of composition generally applied for the control of nematode pests gives a rate of active ingredient from 0.01 to 10 kg per hectare, preferably from 0.1 to 6 kg per hectare.

The compositions can be applied to the soil, plant or seed, to the locus of the pests, or to the habitat of the pests, in the form of dusting powders, wettable powders, granules (slow or fast release), emulsion or suspension concentrates, liquid solutions, emulsions, seed dressings, fogging/smoke formulations or controlled release compositions, such as microencapsulated granules or suspensions.

Dusting powders are formulated by mixing the active ingredient with one or more finely divided solid carriers and/or diluents, for example natural clays, kaolin, pyrophyllite, bentonite, alumina, montmorillonite, kieselguhr, chalk, diatomaceous earths, calcium phosphates, calcium and magnesium carbonates, sulphur, lime, flours, talc and other organic and inorganic solid carriers.

Granules are formed either by absorbing the active ingredient in a porous granular material for example pumice, attapulgite clays, fuller's earth, kieselguhr, diatomaceous earths, ground corn cobs, and the like, or on to hard core materials such as sands, silicates, mineral carbonates, sulphates, phosphates, or the like. Agents which are commonly used to aid in impregnation, binding or coating the solid carriers include aliphatic and aromatic petroleum solvents, alcohols, polyvinyl acetates, polyvinyl alcohols, ethers, ketones, esters, dextrins, sugars and vegetable oils.

with the active ingredient. Other additives may also be included, such as emulsifying agents, wetting agents or dispersing agents.

Microencapsulated formulations (microcapsule suspensions CS) or other controlled release formulations may also be used, particularly for slow release over a period of time, and for seed treatment.

Alternatively the compositions may be in the form of liquid preparations to be used as dips, irrigation additives or sprays, which are generally aqueous dispersions or emulsions of the active ingredient in the presence of one or more known wetting agents, dispersing agents or emulsifying agents (surface active agents). The compositions which are to be used in the form of aqueous dispersions or emulsions are generally supplied in the form of an emulsifiable concentrate (EC) or a suspension concentrate (SC) containing a high proportion of the active ingredient or ingredients. An EC is a homogeneous liquid composition, usually containing the active ingredient dissolved in a substantially non-volatile organic solvent. An SC is a fine particle size dispersion of solid active ingredient in water. To apply the concentrates they are diluted in water and are usually applied by means of a spray to the area to be treated.

Suitable liquid solvents for ECs include methyl ketone, methyl isobutyl ketone, cyclohexanone, xylenes, toluene, chlorobenzene, paraffins, kerosene, white oil, alcohols, (for example, butanol) methylnaphthalene, trimethylbenzene, trichloroethylene, N-methyl-2-pyrrolidone and tetrahydrofurfuryl alcohol (THFA).

Wetting agents, dispersing agents and emulsifying agents may be of the cationic, anionic or non-ionic type. Suitable agents of the cationic type include, for example, quaternary ammonium compounds, for example cetyltrimethyl ammonium bromide. Suitable agents of the anionic type include, for example, soaps, salts of aliphatic monoesters of sulphuric acid, for example sodium lauryl sulphate, salts of sulphonated aromatic compounds, for example sodium dodecylbenzenesulphonate, sodium, calcium or ammonium lignosulphonate, or butylnaphthalene sulphonate, and a mixture of the sodium salts of diisopropyl- and triisopropylnaphthalene sulphonates.

Suitable agents of the non-ionic type include, for example, the condensation products of ethylene oxide with fatty alcohols such as oleyl alcohol or cetyl alcohol, or with alkyl phenols such as octyl phenol, nonyl phenol and octyl cresol. Other non-ionic agents are the partial esters derived from long chain fatty acids and hexitol anhydrides, the condensation products of the said partial esters with ethylene oxide, and the lecithins.

These concentrates are often required to withstand storage for prolonged periods and after such storage, to be capable of dilution with water to form aqueous preparations which remain homogeneous for a sufficient time to enable them to be applied by conventional spray equipment. The concentrates may contain 10-85% by weight of the active ingredient or ingredients. When diluted to form aqueous preparations such preparations may contain varying amounts of the active ingredient depending upon the purpose for which they are to be used.

The compounds of formula (I) may also be formulated as powders (dry seed treatment DS or water dispersible powder WS) or liquids (flowable concentrate FS, liquid seed treatment LS, or microcapsule suspension CS) for use in seed treatments. In use the compositions are applied to the nematodes, to the locus of the nematodes, to the habitat of the nematodes, or to growing plants liable to infestation by the nematodes, by any of the known means of applying pesticidal compositions, for example, by dusting, spraying, or incorporation of granules.

The compounds of the invention may be the sole active ingredient of the composition or they may be admixed with one or more additional active ingredients such as nematicides or agents which modify the behaviour of nematodes such as hatching factors, insecticides, synergists, herbicides, fungicides or plant growth regulators where appropriate.

Suitable additional active ingredients for inclusion in admixture with the compounds of the invention may be compounds which will broaden the spectrum of activity of the compounds of the invention or increase their persistence in the location of the pest. They may synergise the activity of the compound of the invention or complement the activity for example by increasing the speed of effect or overcoming repellency. Additionally multi-component mixtures of this type may help to overcome or prevent the development of resistance to individual components.

The particular additional active ingredient included will depend upon the intended utility of the mixture and the type of complementary action required. Examples of suitable insecticides include the following: a) Pyrethroids such as permethrin, esfenvalerate, deltamethrin, cyhalothrin in particular lambda-cyhalothrin, biphenthrin, fenpropathrin, cyfluthrin, tefluthrin, fish safe pyrethroids for example ethofenprox, natural pyrethrin, tetramethrin, s-bioallethrin, fenfluthrin, prallethrin and 5-benzyl-3-furylmethyl-(E)-(lR,3S)-2,2-dimethyl- 3-(2-oxothiolan-3-ylidenemethyl) cyclopropane carboxylate; b) Organophosphates such as profenofos, sulprofos, methyl parathion, azinphos-methyl, demeton-s-methyl, heptenophos, thiometon, fenamiphos, monocrotophos, profenophos, triazophos, methamidophos, dimethoate, phosphamidon, malathion, chloropyrifos, phosalone, terbufos, fensulfothion, fonofos, phorate, phoxim, pyrimiphos-methyl, pyrimiphos-ethylr fenitrothion or diazinon; c) Carbamates (including aryl carbamates) such as pirimic abamectin, ivermectin, and milbemycin; g) Hormones and pheromones; h) Organochlorine compounds such as benzene hexachloride, DDT, chlordane or dieldrin; i) Amidines, such as chlordimeform or amitraz; j) Fumigant agents; k) Imidacloprid.

In addition to the major chemical classes of insecticide listed above, other insecticides having particular targets may be employed in the mixture if appropriate for the intended utility of the mixture. For instance selective insecticides for particular crops, for example stemborer specific insecticides for use in rice such as cartap or buprofezin can be employed.

Alternatively insecticides specific for particular insect species/stages for example ovo-larvicides such as chlofentezine, flubenzimine, hexythiazox and tetradifon, motilicides such as dicofol or propargite, acaricides such as bromopropylate, chlorobenzilate, or growth regulators such as hydramethylron, cyromazine, methoprene, chlorofluazuron and diflubenzuron may also be included in the compositions.

Examples of suitable synergists for use in the compositions include piperonyl butoxide, sesamax, safroxan and dodecyl imidazole.

Suitable herbicides, fungicides and plant-growth regulators for inclusion in the compositions will depend upon the intended target and the effect required.

An example of a rice selective herbicide which can be included is propanil, an example of a plant growth regulator for use in cotton is "Pix", and examples of fungicides for use in rice include blasticides such as blasticidin-S. The ratio of the compound of the invention to the other active ingredient in the composition will depend upon a number of factors including type of target, effect required from the mixture etc. However in general, the additional active ingredient of the composition will be applied at about the rate as it is usually employed, or at a slightly lower rate if synergism occurs.

The following Examples illustrate the invention. The compounds were identified and characterised by means of the melting points, nuclear magnetic resonance spectroscopy (1H NMR 5 (CDCl3)) or (1H d6 DMSO), infra red (IR) or mass (M+) spectroscopy.

EXAMPLE 1 This Example illustrates the preparation of 5-(4,4-difluorobut-3-enyloxy)-1-phenyltetrazole, a compound according to the invention.

Step (a): Preparation of 4.4-difluorobut-3-envlformate Anhydrous potassium formate (5.0g), tetrabutylammonium bromide (catalyst 0.59) and 4-bromo-1,1-difluorobut-1-ene (5.0g) were stirred under nitrogen and heated to reflux for 3F hours. The required 4,4-difluorobut-3-enyl formate was distilled from the reaction mixture, and obtained as a colourless liquid, (bp 112-3"C at 760mm Hg). 1H NMR (CDCl3): b 2.38(2H,m); 4.20(3H,m); 8.08(1H,s). M+ 136.

Step (b): PreDaration of 5-(4.4-difluorobut-3-envioxv)-1-phenvitetrazole The ester (0.2729) prepared in Step (a) was stirred and treated at ambient temperature with 50% aqueous sodium hydroxide (0.5cm3). After h hour the mixture was extracted with dichloromethane (2x1cm3). The dichloromethane solution containing 4,4-difluorobut-3-en-1-ol was treated with tetra n butyl ammonium bromide (lOmg; catalyst) and 5.chloro-1-phenyl tetrazole (0.369). To the stirred mixture was added 50% aqueous sodium hydroxide (lcm3) at ambient temperature. After 3F hours the organic phase was extracted with dimethyl ether and evaporated to give the required product as a colourless solid.

In a separate preparation, the procredures described in Steps (a) and (b) above were combined into a single sequence of operations, without isolating the ester or alcohol intermediates, to give the required compound as a colourless solid, m.p. 56.5-57.5 (recrystallised from hexane).

EXAMPLE 2 The activity of the compounds of formula (I) was determined using an acarine pest (Tetranvchus urticae). The pest was treated with a liquid composition containing 500 parts per million (ppm) by weight of the compound. The composition was made by dissolving the compound in acetone and ethanol (50:50) mixture and diluting the solution with water containing 0.05% by weight of a wetting agent sold under the trade name "SYNPERONIC" NP8 until the liquid composition contained the required concentration of the compound. "SYNPERONIC" is a Registered Trade Mark.

The test procedure adopted with regard to the pest comprised supporting a number of the pest individuals on a French bean leaf and treating both the leaf and the pests with the composition. The mortality of the pests was then assessed three days after the treatment.

It was found that the treatment caused 99% mortality of the pests.

EXAMPLE 3 This example demonstrates granules suitable for soil application. The granules can be made by standard techniques such as impregnation, coating, extrusion or agglomeration.

%w/w Impregnated granule : Active ingredient 5 Wood Rosin 2.5 Gypsum granules 92.5 (20-40 mesh) Coated granule : Active ingredient 0.5 * 'Solvesso' 200 0.4 Calcium carbonate granules 99.1 (30-60 mesh) Slow release granule : Active ingredient 10 Polyvinylacetate/vinyl 5 chloride copolymer latex Attapulgus granules 85 EXAMPLE 4 This example demonstrates formulations for use as a spray. The compounds can be formulated as wettable powders, water dispersible granules, suspension concentrates, emulsifiable concentrates, emulsions or microcapsule suspensions for application diluted in water.

g/l Emulsifiable concentrate: Active ingredient 250 Calcium dodecyl- 50 benzene sulphonate Nonyl phenol ethoxylate 50 Alkylbenzene solvent to 1 litre %w/w Wettable powder : Liquid active ingredient 40 lignosulphonate dispersant 5 silica 25 sodium lauryl sulphate 3 china clay (kaolin) 27 Microcapsule suspension : Liquid active ingredient 250 toluene diisocyanate 10 polymethylene polyphenyl isocyanate 20 nonyl phenol ethoxylate 6 lignosulphonate dispersant 15 xanthan gum 1 bentonite 10 biocide 'Proxel' 0.1 sodium carbonate 5 water to 1 litre The microcapsule suspensions can be used as a spray, soil drench or as an intermediate to prepare slow release granules for application to the soil.

a/l Suspension concentrate : Solid active ingredient 400 lignosulphonate dispersant 50 sodium lauryl sulphate 30 xanthan gum 1 biocide 'Proxel' 0.1 bentonite 10 water to 1 litre EXAMPLE 5 This example demonstrates formulations suitable for use as seed treatments in conventional application machinery.

%w/w Dry seed treatment : Active ingredient 20 dodecyl benzene 3 Rubine Toner (dyestuff) 2.7 Talc 53.3 Silica to 100% The suspension concentrate and microcapsule suspension of Example 4 can be used as flowable concentrates for seed treatment.

EXAMPLE 6 This example demonstrates the formulation of the compounds for electrostatic spraying.

a/l Active ingredient 200 N-methylpyrrolidone 50 Soyabean oil 120 'Solvesso' 200 to 1 litre NUMBERING OF HETEROCYCUC GROUPS REFERRED TO IN THE SPECIFICATION

1,2,4-thiadiazole 1,3,4-thiadiazole 1,2,4-oxadizzole

1,3,4-oxadiazole tetrazole

pyrazine pyrldazine 1,2,4-triazine

1,3,5-triazine quinoxaline

quinazoline

Claims (3)

1. CLAIMS 1. A compound of formula (1): ROCH2CH2CH=CF2 (I) wherein: R is a 1,2,4-oxadiazolyl, 1,2,4-thiadiazolyl, 1,3,4-oxadiazolyl, 1,3,4-thiadiazolyl, tetrazolyl, pyridazinyl, 1,2,4-triazinyl, 1,3,5-triazinyl, quinazolyl, or quinoxalyl group, each R group being optionally substituted by an R1 group selected from halogen, C1-6 alkyl, C1-6 haloalkyl, C16 alkoxy,C1-6 alkoxymethyl, C16 fluoroalkoxy (e.g. -OCHF2 and -OCH2CH2F), amino, and mono- or di- C16 alkylamino (e.g. -NMe2), cyanomethyl, aryl, arylalkyl in which the alkyl moiety has from 1 to 6 carbon atoms, carboxy, alkoxycarbonyl of

   2 to 6 carbon atoms, sulphamoyl, mono- or di- C1-6 alkylsulphamoyl, cyano, carbamoyl, mono- or di- C1-6 alkylcarbamoyl, thiocarbamoyl, alkylcarbonyl of 2 to 4 carbon atoms, or alkanesulphonamido of 1 to 6 carbon atoms.
2. 2. A nematicidal, insecticidal, or acaricidal composition comprising an effective amount of a compound of formula (I) as defined in claim 1 and an inert diluent or carrier material and optionally a surface active agent.
3. 3. A method for killing or controlling nematode, insect, or acarid pests which comprises applying to the locus of the pests or to a plant susceptible to attack by the pest an effective amount of a compound of formula (I) as defined in claim 1.