GB2182329A

GB2182329A - Benzoylphenylureas

Info

Publication number: GB2182329A
Application number: GB08624335A
Authority: GB
Inventors: Jozef Drabek
Original assignee: Ciba Geigy AG
Current assignee: Novartis AG
Priority date: 1985-10-14
Filing date: 1986-10-10
Publication date: 1987-05-13
Anticipated expiration: 2006-10-10
Also published as: DE3679024D1; GB2217323A; CY1683A; AU597278B2; AU6383386A; KR870003975A; GB2217324B; EG17946A; EP0219460A2; EP0219460B1; CN1014110B; GB8624335D0; HK33893A; GB8910035D0; GB2217324A; DK111692A; JPS6293268A; GB2182329B; SG117592G; IL80271A0

Abstract

Substituted N-benzoyl-N'-3,5-dichloro-hexafluoropropyloxyphenylureas of the formula <IMAGE> wherein R1 is hydrogen or fluorine and R2 is fluorine or chlorine, and salts thereof are useful for controlling insects, representatives of the order Acarina, slugs and snails, particularly plant-destructive insects. Intermediates for these compounds having the formulae <IMAGE> are also disclosed.

Description

SPECIFICATION Benzoylphenylureas The present invention relates to novel substituted N-benzoyl-N'-3,5-dichloro-4 hexafluoropropyloxyphenylureas, to processes and to intermediatesforthe preparation thereof, and tothe use of the novel compounds in pest control.

The invention relates to compounds of formula I

wherein R1 is hydrogen orfluorine and R2 is fluorine orchlorine, and to salts thereof.

Compoundsofformula I meriting particularinterestarethosewherein R1 isfluorineand R2isfluorineor chlorine.

Further preferred compounds offormula I those wherein R1 is hydrogen and R2 is fluorine orchlorine.

The compounds offormula I can be prepared by methods analogous to ones known perse (q.v. e.g.

German Offenlegungsschrift specifications 2 123236,2061 780 and 3240975).

Thus, for example, a compound of formula I can be obtained by reacting a) the compound offormula 11

with a compound of formula lil

or b) the compound offormula IV

with a compound of formula V

or c) the compound offormula II with a compound offormula VI

In formulae III,V and VI above, the radicals R1 and R2 are as definedforformula I, and R is a C-C8alkyi radical which is unsubstituted or substituted by halogen, preferably chlorine.

The above processes a), b) and c) can preferably be carried out under normal pressure and in the presence of an organic solvent ordiluent. Examples of suitable solvents or diluents are: ethers and ethereal compounds such as diethyl ether, dipropyl ether, dibutyl ether, dioxane, dimethoxyethane and tetrahydrofuran; N,N-dialkylated carboxamides; aliphatic, aromatic and halogenated hydrocarbons, especially benzene,toluene, xylene, chloroform, methylene chloride, carbon tetrachloride and chlorobenzene; nitriles such as acetonitrile or propionitrile; di methyl sulfoxide; and ketones, e.g. acetone, methyl ethyl ketone, methyl isopropyl ketone and methyl isobutyl ketone.Process a) is normally carried out in the temperature range from - 1 00to +200 C, preferably from 0 to 100 C, e.g at room temperature, and, if desired in the presence of an organic base, e.g. triethylamine. Process b) is carried out in thetemperature range from 0'to 150"C, preferably at the boiling point of the solvent employed and, if desired, in the presence of an organic base such as pyridine, and/or with the addition of an alkali metal or alkaline earth metal, preferably sodium.For process c), i.e. for the reaction of the urethane offormula VI with an aniline offormula II, a temperature range from about 60" to the boiling point of the reaction mixture is preferred, and the solvent employed is preferably an aromatic hydrocarbon such as toluene, xylene, chlorobenzene and the like.

The starting materials of formulae III and V are known and can be prepared by methods analogousto known ones. The starting aniline offormula II is a novel compound which likewise constitutes an object ofthe present invention. The compound offormula II can be prepared in a manner known per se by hydrogenating the suitably substituted nitrobenzene offormula VII

by a process analogous to that described in J. Org. Chem. 29(1964), 1, (q.v. also the literature cited therein).

However, the aniline offormula II can also be obtained by chemical reduction (e.g.with Sn(ll) chloride/HCI) of the nitro compound offormula VII (q.v. Houben-Weyl, "Methoden d. org. Chemie" 11/1.422). The nitro compound offormula VII itself can be prepared by fluoroalkylating 3,5-dichloro-4-nitrophenol. Afurther process forthe preparation of the aniline of formula il comprises fluoroalkylating in corresponding manner the acylated 2,6-dichloro-4-hydroxyaniline and then removing the acyl group, e.g. by acid hydrolysis, or effecting the fluoroalkylation with a salt of 3,5-dichloro-4-hydroxyaniline, e.g. the chlorohydrate.

Benzoylisocyanates offormula Ill can be obtained, inter alia, as follows (q.v. J. Agr. Food Chem.21,348and 993; 1973):

The 4-(hexafluoropropyloxy)phenylisocyanate offormula IV (b.p. 950C/0.01 torr), which is novel per se, can be prepared e.g. by phosgenating the aniline offormula II by methods which are commonly employed in the art and also comprises an object of this invention. The benzamides offormula Vwhich are further used as starting materials are known (q.v. for example Beilstein "Handbuch der organischen Chemie", Vol.9, p.336).

Urethanes offormula VI can be obtained in a manner known per se by reacting a benzoylisocyanate of formula III with a suitable alcohol or by reacting a benzamide offormula V, in the presence of a base, with a corresponding ester of chloroformic acid CI-COOR.

In accordance with the present invention, the novel compounds of formula I also comprise the salts thereof which not only exhibit high insecticidal activity, but are also readily soluble in solvents and diluents, in particular in organic solvents, and can also be formulated more easily.

To be singled out for special mention are the metal salts of the compounds offormula I of the invention, in particularthe alkali metal and alkaline earth metal salts thereof, preferablythe sodium salts and potassium salts. These salts are prepared in a manner known peruse, e.g. by reacting a compound offormula I with a metal alkanolate such as sodium ethylate or potassium methylate. A given salt can be converted into a desired salt of another metal by salt-interchange, e.g. with anotheralkanolate.

Of particular importance are the salts of compounds offormula I with organic bases, an essential feature of which is the presence of a quaternary nitrogen atom. Such salts are offormula la

wherein R1 and R2 are as defined above and XO is the cation of an organic base. XO is preferably one ofthe following organic cations: (CH3)4 N0+, (C2H5)4 N0+, (n-C3H7)4 N0+, (i-C3H7)4 N0+, (n-C4H9)4 NO, (CII3) N , (C2Ss)4 N , (n-C3H7)4 N , C3H7)4 N

whereby n is an integer from 8 to 12.The salts offormula la also comprise mixtures of these salts with different cations. The saits of formula la can be prepared in a manner known perse by reacting a compound of formula I with corresponding ammonium hydroxides ofthe formula XO (OH)O, wherein XO is as defined above.

N-Benzoyl-N'-2,5-dichlorophenylureas with a haloalkoxy substituent in the 4position ofthe phenyl ring are already known as insecticides (q.v. US patent specification 4518804 and German Offenlegungsschirft 2848 794). Insecticidal N-halobenzoyl-N'-(3,5-dichloro-4-haloalkenyloxyphenyl)ureas are described in US Patent specification 4162330. Insecticidal N-halobenzoyl-N'-(3,5-dichloro-4-haloalkoxyphenyl)ureas are the subject matter of US patent specification 4468405.Furthermore, compounds of similar structure are known from US patent specification 4529819 and British patent applications 2 106499,2 106500,2 106501 and 2 113679. The feature which essentially distinguishes the novel benzoylphenylureas of formula I according to the present invention from the compounds described in these references is that the novel compounds ofthis invention carry in the 4-position ofthe phenyl ring a 1,1 ,2,3,3,3-hexafluoropropyloxy group.

Surprisingly, it has been found that the compounds of this invention and the salts thereof have excellent properties as pesticides while being well tolerated by plants and having low toxicity to warm-blooded animals. They are particularly suitable for controlling insects and representatives of the orderAcarina that attack plants and animals.

In particular, the compounds of formula I are suitable for controlling insects of the orders: Lepidoptera, Coleoptera, Homoptera, Heteroptera, Diptera, Thysanoptera, Orthoptera, Anoplura, Siphonaptera, Mallophaga, Thysanura, Isoptera, Psocoptera and Hymenoptera, as well as representatives of the order Acarina of the families: Ixodidae, Argasidae, Tetranychidae and Dermanyssidae.

In addition to their action against flies, e.g. Musca domestica, and mosquito larvae, the compounds of formula I are also suitable for controlling plant-destructive feeding insects in ornamentals and crops of useful plants, especially in cotton (e.g. against Spodoptera littoralis and Heliothis virescens) and in fruit and vegetables (e.g. against Laspeyresia pomonella, Leptinotarsa decemlineata and Epilachna varivestis). The compounds offormula I have a pronounced ovicidal and, in particular, larvicidal action against insects, especially against larvae of noxious feeding insects. If compounds offormula I are ingested by adult insect stages with the feed, then a diminished oviposition and/or reduced hatching rate is observed in many insects, especially in Coleopterae, e.g. Anthonomus grandis.

The compounds offormula I can also be used for controlling ectoparasites such as Lucilia sericata, in domestic animals and productive livestock, e.g. by treating animals, cowsheds, barns, stables etc., and pastures.

The compounds offormula I are also suitableforcontrolling thefollowing species of mites which attack crops of fruit and vegetables: Tetranychus urticae, Tetranychus cinnabarinus, Panonychus ulmi, Broybia rubrioculus, Panonychus citri, Eriophyes piri, Eriophyes ribis, Eriophyes vitis, Tarsonemus pallidus, Phyllocoptesvitis and Phyllocoptruta oleivora.

Moreover, the benzoylureas offormula I have properties enabling them to be used for controlling slugs and snails. The repellant and feed inhibiting action of these compounds is frequently very difficult to ascertain in laboratory tests. However, in field trials even at very low concentrations good activity is observed in agricultural and horticultural crops. In particular, sensitive crops of lettuce, vegetables and fruit (such as strawberries) and ornamentals and flowers are afforded protection against feeding damage caused by slugs and snails. The compounds offormula I ofthis invention are effective against all slugs and snails, most of which occur as polyphagic pests in agricultural and horticultural crops. In addition to exhibiting feed inhibiting action, the compounds of formula I can also effect mortality.Numbering among terrestrial slugs are several pests which cause damage of great economic significance, for example the slugs Arion rufus (red slug), Arion ater and other Arionidae, Limax species and field slugs, e.g. Deroceras reticulatum and D. agreste of the family Limacidae, and also species of thefamily Milacidae. Damage is aiso caused by snails, interalia, ofthe genera Bradybaena, Cepea, Cochlodina, Discus, Euomphalia, Galba, Helicigona, Helix, Helicella, Helicodiscus, Lymnaea, Opeas, Vallonia and Zonitoides.

The good pesticidal activity of the compounds offormula I of the invention corresponds to a mortality of at least 50-60 % ofthe above pests.

The activity ofthe compounds of formula I and of the compositions containing them can besubstantially broadened and adapted to prevailing circumstances by addition of other insecticides and/oracaricides.

Examples of suitable additives include: organophosphorus compounds, nitrophenols and derivatives thereof,formamidines, ureas, carbamates, pyrethroids, chlorinated hydrocarbons, and Bacillus thuringiensis preparations.

The compounds offormula I are used in unmodified form, or preferably together with the adjuvants conventionally employed in the art offormulation, and are therefore formulated in known mannerto emulsifiable concentrates, directly sprayable ordilutable solutions, dilute emulsions, wettable powders, soluble powders, dusts, granulates, and also encapsulations in e.g. polymer substances. As with the nature ofthe compositions, the methods of application such as spraying, atomising, dusting, scattering or pouring, are chosen in accordance with the intended objectives and the prevailing circumstances.

The formulations, i.e. the compositions, preparations or mixtures containing the compound (active ingredient) offormula I or combinations thereof with other insecticides or acaricides, and, where appropriate, a solid or liquid adjuvant, are prepared in known manner, e.g. by homogeneously mixing and/or grinding the active ingredients with extenders, e.g. solvents, solid carriers and, in some cases, surface-active compounds (surfactants).

Suitable solvents are: aromatic hydrocarbons, preferably the fractions containing 8to 12 carbon atoms, e.g. xylene mixtures or substituted naphthalenes, phthalates such as dibutyl phthalate or dioctyl phthalate, aliphatic hydrocarbons such as cyclohexane or paraffins, alcohols and glycols and their ethers and esters, such as ethanol, ethylene glycol, ethylene glycol monomethyl or monoethyl ether, ketones such as cyclohexanone, strongly polarsolvents such as N-methyl-2-pyrrolidone, dimethyl sulfoxide or dimethylformamide, as well as vegetable oils or epoxidised vegetable oils such as epoxidised coconut oil or soybean oil; or water.

The solid carriers used e.g. for dusts and dispersible powders are normally natural mineral fillers such as calcite,talcum, kaolin, montmorillonite orattapulgite. In order to improve the physical properties it is also possible to add highly dispersed silicic acids or highly dispersed absorbent polymers. Suitable granulated adsorptive carriers are porous types, for example pumice, broken brick, sepiolite or bentonite; and suitable nonsorbentcarriers are materials such as calcite orsand. In addition, a great number of pregranulated materials of inorganic or organic nature can be used, e.g. especially dolomite or pulverised plant residues.

Depending on the nature of the compound of formula I to be formulated, orof combinations thereofwith other insecticides oracaricides, suitable surface-active compounds are non-ionic, cationic and/oranionic surfactants having good emulsifying, dispersing and wetting properties. The term "surfactants" will also be understood as comprising mixtures of surfactants.

Suitable anionic surfactants can be both water-soluble soaps and water-soluble synthetic surface-active compounds.

Suitable soaps are the alkali metal salts, alkaline earth metal salts or unsubstituted orsubstituted ammonium salts of higher fatty acids (C 0-C22), e.g. the sodium or potassium salts of oleic orstearic acid, or of natural fatty acid mixtures which can be obtained, e.g. from coconut oil ortallow oil. Furthersuitable surfactants are also the fatty acid methyltaurin salts as well as modified and unmodified phospholipids.

More frequently, however, so-called synthetic surfactants are used, especially fatty sulfonates, fatty sulfates, sulfonated benzimidazole derivatives or alkylarylsulfonates.

Thefattysulfonates orsulfates are usually in the form of alkali metal salts,alkaline earth metal salts or unsubstituted or substituted ammonium salts and contain a C8-C22alkyl radical which also includes the alkyl moiety of acyl radicals, e.g. the sodium or calcium salt of lignosulfonic acid, ofdodecylsulfate, or of a mixture of fatty alcohol sulfates obtained from natural fatty acids.

These compounds also comprise the salts ofsulfuric acid esters and sulfonic acids of fatty alcohol/ethylene oxide adducts. The sulfonated benzimidazole derivatives preferably contain 2 sulfonic acid groups and one fatty acid radical containing 8 to 22 carbon atoms. Examples of alkylarylsulfonates are the sodium, calcium or triethanolamine salts of dodecylbenzenesulfonic acid, dibutylnaphthalenesulfonic acid, or of a naphthaienesulfonic acid/formaldehyde condensation product. Also suitable are corresponding phosphates, e.g. salts of the phosphoric acid ester of an adduct of p-nonylphenol with 4 to 14 moles of ethylene oxide.

Non-ionic surfactants are preferably polyglycol ether derivatives of aliphatic or cycloaliphatic alcohols, or saturated or unsaturated fatty acids and alkylphenols, said derivatives containing 3 to 30 glycol ether groups and 8to 20 carbon atoms in the (aliphatic) hydrocarbon moiety and 6to 18 carbon atoms in the alkyl moietyof the alkylphenols.

Further suitable non-ionic surfactants arethewater-soluble adducts of polyethylene oxidewith polypropylene glycol, ethylenediaminopolypropylene glycol and alkylpolypropylene glycol containing 1 to 10 carbon atoms in the alkyl chain, which adducts contain 20to 250 ethylene glycol ether groups and 10 to 100 propylene glycol ether groups. These compounds usually contain 1 to 5 ethylene glycol units per propylene glycol unit.

Representative examples of non-ionic surfactants are nonylphenolpolyethoxyethanols, castor oil polyglycol ethers, polypropylene/polyethylene oxide adducts, tributylphenoxypolyethoxyethanol, polyethylene glycol and octylphenoxypolyethoxyethanoi. Fatty acid esters of polyoxyethylene sorbitan, e.g.

polyoxyethylene sorbitan trioleate, are also suitable non-ionic surfactants.

Cationic surfactants are preferably quaternary ammonium salts which contain, as N-substituent, at least oneC8-C22alkyl radical and, as further substituents, unsubstituted or halogenated lower alkyl, benzyl or hydroxy-lower alkyl radicals. The salts are preferably in the form of halides, methylsulfates or ethylsulfates, e.g. stearyltrimethylammonium chloride or benzyldi(2-chloroethyl)ethylammonium bromide.

The surfactants customarily employed in the artofformulation are described e.g. in "McCutcheon's Detergents and EmulsifiersAnnual", MC Publishing Corp., Ridgewood, NewJersey, 1979; Dr. Helmut Stache, "TensideTaschenbuch" (Handbook of Surfactants), Carl HanserVerlag, Munich/Vienna 1981 .

The pesticidal compositions usually contain 0.1 to 99%, preferably 0.1 to 95%, of a compound offormula I or combination thereofwith other insecticides or acaricides, 1 to 99.9% of a solid or liquid adjuvant, and Oto 25 %, preferably 0.1 to 20 %, of a surfactant.

Whereas commercial products are preferably formulated as concentrates, the end user will normally employ diluted formulations of substantially lower concentration.

The compositions may also contain further ingredients, such as stabilisers, antifoams, viscosity regulators, binders, tackifiers as well as fertiiisers or other active ingredients in order to obtain special effects.

Example 1: a) Preparation of 3,5-dichloro-4-/7, 1,2,3,3,3-hexafluoropropyloxy)aniline 47 g of 4-acetylamino-3,5-dichlorophenol togetherwith 154 g of 90 % potassium hydroxide solution and 130 ml of dimethylforma mide are stirred in an autoclave. 75.8 g of hexafl uoropropylene are then pressed into the closed autoclave. The mixture is stirred for 20 hours at 70"C underthe pressure developing in the autoclave. After cooling, the mixture is concentrated by rotary evaporation and the residue is dissolved in methylene chloride. The resultant solution iswashed with water, dried over Na2SO4 and concentrated.The crude product obtained as residue is chromatographed through a column of silica gel (length: m; diameter: 10cm) eluted with an 11:1 mixture oftoluene and acetone, affording 4-acetylamino-3,5-dichloro-1 -(1,1,2,3,3,3- hexafluoropropyloxy)benzene in the form of pale yellow crystals (m.p.: 1 13-1 1 5"C), 26 g of which are kept for 10 hours under reflux with 110 ml of ethanol and 35.6 ml of 37% hydrochloric acid. The reaction mixture is then concentrated, diluted with ice/water and made weakly alkaline. The product is extracted from the mixture with methylene chloride. The organic extract phase iswashed with water, dried over Na2SO4 and concentrated.The residue is purified bydistillation,thusaffordingthetitle compound oftheformula

as a colourless liquid with a boiling point of 91 -960C/0.001 torr.

b) Preparation ofN-(2, 6-difluornbenzoyl)-N'-[3, 5-dichloro-4-( 1,1,2,3,3, 3-hexafluoroprop yloxy)phenyl]urea 4.3 g of3,5-dichloro-4-(1 of 3,5-dichloro-4-(l,l ,2,3,3,3-hexafluoropropyloxy)aniline are dissolved with stirring in 50 ml of dry toluene and, with exclusion of moisture, a solution of 2.41 g of 2,6-difluorobenzoylisocyanate in 10 ml of dry toluene is added at room temperature. The batch is stirred for a further 13 hours at room temperature. About 75% ofthe solvent is then removed by rotary evaporation, the precipitated residue is filtered with suction, washed with a small amount of cold toluene and hexane and then dried in vacuo, affording the title compound oftheformula

in the form of a crystallinewhite powder with a meiting point of 171-1 720C (compound 1).

The following compounds offormula I have been prepared in a manner corresponding to that described above:

Compound mp.

oC1 /C1 2 &commat; CO-NH-CO-NH-* 178-1800C// 8 \C1 C1 C1 3 + CO-NH-CO-NH-^ -O-CF2CHFCF3 177-178"C Cl Cl /Cl 4 + #-CO-NH-CO-NH- j-O-CFZCHFCF3 156-158 C \C1 c) Preparation ofthe sodium salt of compound 1 9.58 g of N-(2,6-difluorobenzOyl)-N'-[3,5-dichloro-4-(1,1,2,3,3,3-hexafluoropropyloxy)phenyl]urea are suspended in 20 ml of absolute methanol. A solution of 0.43 g of sodium in 30 ml of absolute methanol is added dropwise with stirring tothis suspension. A clear solution forms which is then concentrated.The residual product is dried in vacuo at room temperature, affording the title compound oftheformula

as colourless crystals.

The following salt of compound 2 ofthe formula below can also be prepared by proceeding as described above:

d) Preparation ofthe tetrabutylammonium salt of compound 1 2.56 g of N-(2,6-difluorobenzoyl)-N'-[3,5-dichloro-4-(1 uoropropyloxy)phenyl] are suspended in 30 ml of methanol. With stirring, 5.2 g of a methanolic solution containing 1.3 g of tetra-n-butylammonium hydroxide are added to this suspension, whereupon a clear solution forms. This solution is concentrated and the residual crude product is suspended in hexane. The suspension is filtered with suction and the filter residue is washed with hexane and then dried, affording the title compound ofthe formula

as colourless crystals.

The following salts of formula la can also be prepared in accordance with this procedure:

Example2: Formulations foractive ingredients offormula according to Example 1 or combinations thereofwith other insecticides oracaricides (throughout, percentages are byweight) 1. Wettablepo wders a) b) c) compound offormula I orcombination 25% 50% 75% sodium lignosulfonate 5% 5% sodium laurylsulfate 3% - 5% sodium diisobutylnaphthalenesulfonate - 6% 10% octylphenol polyethylene glycol ether (7-8 moles of ethylene oxide) - 2% - highlydispersed silica acid 5% 10% 10% kaolin 62% 27% - The active ingredientor combination is thoroughly mixed with the adjuvants and the mixture isthoroughly ground in a suitable mill, affording wettable powders which can be diluted with water to give suspensions of the desired concentration.

2. Emulsifiable concentrate compound offormula I or combination 10% octylphenol polyethylene glycol ether (4-5 moles of ethylene oxide) 3% calcium dodecylbenzenesulfonate 3% castor toil poiygycol ether (36 moles of ethylene oxide) 4% cyclohexanone 30% xylene mixture 50% Emulsions of any required concentration can be obtained from this concentrate by dilution with water.

3. Dusts a) b) compound offormula I orcombination 5% 8% talcum 95% - kaolin - 92% Ready for use dusts are obtained by mixing the active ingredientwith the carrier, and grinding the mixture in a suitable mill.

4. Extrudergranulate compound offormula I orcombination 10% sodium lignosulfonate 2% carboxymethylcellulose 1% kaolin 87 % The active ingredient or combination is mixed and ground with the adjuvants, and the mixture is subsequently moistened with water. The mixture is extruded and then dried in a stream of air.

5. Coated granulate compound offormula I or combination 3% polyethylene glycol (mol.wt.200) 3% kaolin 94% The finely ground active ingredient or combination is uniformly applied, in a mixer, to the kaolin moistened with polyethylene glycol. Non-dusty coated granulates are obtained in this manner.

6. Suspension concentrate compound offormula I or combination 40 % ethylene glycol 10 % nonylphenol polyethylene glycol ether (15 moles of ethylene oxide) 6 % sodium lignosulfonate 10 % carboxymethylcellulose 1 37 % aqueous formaldehyde solution 0.2 % silicone oil in the form of a 75 % aqueous emulsion 0.8 % water 32 % The finely ground active ingredient or combination is intimately mixed with the adjuvants, giving a suspension concentrate from which suspensions of any desired concentration can be obtained by dilution with water.

Example 3: Action againstmusca domestica 50 g offreshly prepared nutrient substrate for maggots are charged into each of a number of beakers. A specific amount of a 1 % acetonic solution of the respective test compound is pipetted onto the nutrient substrate present in the beakers to give an active ingredient concentration of 800 ppm. The substrate is then thoroughly mixed and the acetone subsequently allowed to evaporate over a period of at least 20 hours.

Then 25 one-day-old maggots of Musca domestica are put into each of the beakers containing the treated nutrient substrate for testing with each active ingredient at the given concentration. After the maggots have pupated, the pupae are separated from the substrate by flushing them out with water and then deposited in containers closed with a perforated top.

Each batch offlushed out pupae is counted to determine the toxic effect ofthe test compound on the maggot development. A count is then made after 10 days of the number offiles which have hatched out ofthe pupae.

The compounds offormula I according to Example 1 exhibit good activity in this test.

Example 4: Action against lucilia sericata 1 ml ofan aqueous solution containing 0.5 % oftestcompound is added at 50"C to 9 ml of a culture medium.

Then about 30 freshly hatched Lucilia sericata larvae are added to the culture medium, and the insecticidal action is determined after 48 and 96 hours by evaluating the mortality rate.

In this test, compounds offormula I according to Example 1 exhibit good activity against Lucilia sericata.

Example 5: Action againstaddes aegypti A concentration of 800 ppm is obtained by pipetting a specific amount of a 0.1 % solution ofthe test compound in acetone on tthe surface of 150 ml of water in a beaker. After the acetone has evaporated, 30 to40 two-day-old larvae of Andes aegypti are put into the beaker containing the test compound. Mortality counts are made after 1,2 and 5 days.

In this test, compounds offormula I according to Example 1 exhibit good activity against Aëdes aegypti.

Example 6: Insecticidal action against feeding insects a) Cotton plants about cm high, in pots, are sprayed with aqueous emulsions which contain the respective testcompound in concentrations of 3, 12.5 and 50 ppm. Afterthe spray coating has dried,the cotton plants are populated with Spodoptera littoral is and Heliothis virescens larvae in the L3-stage. The test is carried outat 24"C and 60% relative humidity. The percentage mortality ofthe test insects is determined after 2 days.

Compounds 1,2,3 and 4according to Example 1 effect 80-100% mortality againstSpodoptera larvae at3 ppm.80-100 mortality is effected against Heliothis larvae by compound 1 at 12.5 ppm and bycompounds2 and3at50ppm.

b) Comparative test The above test a) is repeated using compound 1 ofthis invention and two prior art compounds. In distinction to test a), the percentage mortality of the larvae is not determined until after7 days. The active ingredient concentrations, the compounds employed and the results obtained are indicated in thefollowing Table::

7 Hortality Compounds employed Spodoptera littoralis Heliothis virescens 0.4 ppm 0.8 ppm 0.8 ppm 1.5 ppm -co--co--.' v--O-CPz-CIIF - CF3 100 % 100 % 90 % 100 7. CO-NI1-COINB-~~/ compound 1 according to Example 1 of the present invention d P * < v--CO-NH-CO-NH-- < v--O-CFz-CHFz 67 Z 90 X 23 Z 70 Z h acc. to US Patent 4 468 405 (columns 7/8, compound 1) F1 \\/ /-CO-BH-CO-NH-. --0-CFz-CHFz 8 % 10 % 0 % 0 % 1 acc. to US Patent 4 518 804 (column 6, compound "A")

Example 7: Action against epilachna varivestis Phaseolus vulgaris plants (dwarf beans) about 15-20 cm in height are sprayed with aqueous emulsion formulations of the test compound in a concentration of 800 ppm. After the spray coating has dried, each plant is populated with 5 larvae of Epilachna varivestis (Mexican bean beetle) in the L4-stage. Aplastic cylinder is slipped overthe treated plants and covered with a copper gauze top. The test is carried out at28 C and 60% relative humidity. The percentage mortality is determined after 2 and 3 days. Evaluation offeeding damage (anti-feeding effect), and of inhibition of development and shedding, is made by observingthetest insectsforafurther3 days.

Example 8: Ovicidal action againstheliothis virescens Corresponding am6unts of a wettable powder formulation containing 25% by weight ofthe test compound are mixed with sufficientwaterto produce an aqueous emulsion with an active ingredient concentration of 800 ppm. One-day-old egg deposits of Heliothis on cellophane are immersed in these emulsions for3 minutes and then collected by suction on round filters. The treated deposits are placed in petri dishes and kept in the dark. The hatching rate in comparison with untreated controls is determined after6 to 8 days.

The compounds offormula I according to Example 1 exhibit good activity in thistest.

Example 9Action against laspeyresia pomonella (eggs): Egg deposits of Laspeyresia pomonella not more than 24 hours old are immersed on filter paper for 1 minute in an aqueous acetonic solution containing 800 ppm of the test compound.

Afterthe solution has dried, the eggs are placed in petri dishes and kept at a temperature of 280C. The percentage of larvae hatched from the treated eggs and the percentage mortality is evaluated after 6 days.

Example 10: Influence on the reproduction ofanthonomousgrandis Anthonomous grandis adults which are not more than 24 hours old after hatching are transferred in groups of 25 to barred cages. The cages are then immersed for 5to 10 seconds in an acetonic solution containing 400 ppm of the test compound. After the beetles have dried, they are placed in covered dishes containing feed and left for copulation and oviposition. Egg deposits are flushed outwith running watertwiceto threetimes weekly, counted, disinfected by putting them for 2 to 3 hours into an aqueous disinfectant, and then placed in dishes containing a suitable larval feed.A count is made after7 days to determine the percentage mortality of the eggs, i.e. the number of larvae which have developed from the eggs.

The duration of the reproduction inhibiting effect of thetest compounds is determined by monitoring the egg deposits further, i.e. over a period of about4weeks. Evaluation is made by assessing the reduction in the numberof deposited eggs and hatched larvae in comparison with untreated controls.

Compounds offormula I according to Example 1 exhibit good activity in this test.

Example 11: Action againstanthonomusgrandis (adults) Two cotton plants in the 6-leaf stage, pots, are each sprayed with a wettable aqueous emulsion formulation containing 400 ppm of the test compound. Afterthe spray coating has dried (about 1.5 hours), each plant is populated with 10 adult beetles (Anthonomous grandis). Plastic cylinders, covered at the top with gauze, are then slipped over the treated plants populated with the test insects to prevent the beetles from migrating from the plants. The treated plants are then kept at 250C and about 60% relative humidity. Evaluation is made after 2,3,4 and 5 days to determine the percentage mortality of the beetles (percentage in dorsal position) as well as the anti-feeding action as compared with untreated controls.

Compounds offormula I according to Example 1 exhibit good activity in thistest.

Example 12: Insecticidal stomach poison action againstplutellaxylostella Potted Chinese cabbage plants (pot size: 10cm diameter) in the 4-leaf stage are sprayed with aqueous emulsions which contain the test compound in a concentration of 0.8 ppm and which dry on the plants.

After 2 days, each of the treated Chinese cabbage plants is populated with 10 Plutella xylostella larvae in the L2-stage. The test is carried out at 240C and at 60% relative humidity in dim light. Evaluation of the percentage mortality of the larvae is made after 2 and 5 days.

Compound 1 according to Example 1 effects 100% mortality in this test Example 13: Feed inhibiting action againstslugs 5 red slugs (Arion rufus) are left for 17 hours under controlled test conditions in each of a number ofcages containing 4 fresh lettuce leaves. In these tests, each cage either only contains untreated leaves or only contains leaves which have been treated by spray application. The concentration of the test compound in the aqueous formulation applied is 0.5 by weight. The extent of the feeding damage is determined on the basis ofweight differences, photocopies of pictures ofthe feeding damage and on the basis of any evident assessable criteria in comparison with untreated controls.

The mortalityofthetest animals is also determined.

Compounds offormula I according to claim 1 exhibit good activity inthistest.

Claims

1. A compound of formula I

wherein R1 is hydrogen orfluorineand R2 is fluorine orchlorine, ora saltthereof.

2. Acompound offormula I according to claim 1,wherein R1 is fluorine and R2 is fluorine orchlorine.

3. Acompound offormula I according to claim 1,wherein R1 is hydrogen and R2 isfluorineorchlorine.

4. The compound according to claim 2 ofthe formula

5. The compound according to claim 3 of the formula

6. Thecompound accordingto claim 3 oftheformula

7. The compound according to claim 2 oftheformula

8. A metal salt of a compound offormula I according to any one of claims 1 to7.

9. Asaltofa compound offormula I according to anyone of claims 1 to 7 with an organic base.

10. A salt according to claim 9, wherein a quatenary nitrogen atom is present.

11. A process forthe preparation of a compound according to any one of claims 1 to 10, which process comprises reacting a) the compound of formula II

with a compound offormula III

or b)thecompoundofformula IV

with a compound of formula V

or c) the compound of formula II with a compound of formula VI

in which formulae lil, V and Vl,the radicals R1 and R2are as defined in any one of claims 1 to 3 and R isa C-C8alkyl radical which is unsubstituted or substituted by halogen, and, if desired, converting the resultant compound offormula I into a salt thereof.

12. Thecompound offormula II

13. The compound offormula IV

14. A pesticidal composition which contains as active ingredient a compound according to any one of claims 1 to 7, or a salt thereof, together with suitable carriers and/or other adjuvants.

15. Use of a compound according to any one of claims 1 to 7, or of a salt thereof, for controlling insects, representatives of the orderAcarina and slugs and snails.

16. Use according to claim 15 for controlling larval stages of plant-destructive insects.

17. Use according to claim 1Sforcontrolling insect eggs.

18. A method of controlling insects, representatives of the order Acarina and slugs and snails, which method comprises treating said pests, the various development stages or the locus thereof with a a pesticidally effective amount a compound offormula I according to anyone of claims 1 to 7, or of a saltthereof, orwith a composition which contains a pesticidally effective amount of such a compound,togetherwith adjuvants and carriers.