INSECTICIDAL USE OF A BENZOYLUREA

Abstract: A method for controlling selected household pests by contacting them or their environment with N-(2,6-difluorobenzoyl)N'-(2-fluoro-4-[2-chloro-4-(trifluoromethyl)phe noxy]phenylurea).

Description: I SECTICIDAL USE OF A BENZOYLUREA BACKGROUND OF THE INVENTION U.S. 4,666,942 and U.S. 4,698,365 disclose the compound of Formula I and its use as an insecticide. EP 275,132 discloses the compound of Formula I for use against termites. U.S. 4,005,223 discloses analogs of Formula I as insecticides. No disclosure is known that teaches or suggests use of the compound of Formula I against cockroaches and the other household pests disclosed herein. SUMMARY OF THE INVENTION This invention concerns a method for using the following compound to control cockroaches and certain other household pest species: by applying an insecticidally effective amount of the compound to the pest, its food or to its environment. The compound of this invention has been found to have a mode of action as a growth regulant and chitin growth inhibitor in cockroaches and other household pest species. Other household pests against which this compound is particularly effective include flies, ants and carpet beetles. DETAILS OF THE INVENTION The compound of Formula I can be prepared by reacting a compound of the formula with a compound of the formula in which R represents, independently, NH 2 or NCO. The reaction can be carried out in the presence of a solvent. Suitable solvents are aromatic solvents such as benzene, toluene, xylene, or chlorobenzene, hydrocarbons such as petroleum fractions, chlorinated hydrocarbons such as chloroform, methylene chloride or dichloroethane, and ethers such as diethyl ether, dibutyl ether, or dioxan. Mixtures of solvents are also suitable. Preferably, the reaction is carried out at a temperature from 0°C to 100°C. Preferably, the molar ratio of isocyanate to amine is from about 1:1 to 2:1. Preferably, the reaction is carried out under anhydrous conditions. Compounds of Formula II can be prepared by reacting a compound of the formula with a compund of the formula to produce a compound of Formula II in which R is NH 2 . For further details pertaining to the preparation of compound I, see U.S. Patent No. 4,698,365. The following Examples illustrate the invention. PREPARATION OF FORMULA I COMPOUND Step A: Preparation of 2-fluoro-4-(2-chloro-4- rtrifluoromethylTphenoxy)aniline A solution of 2-fluoro-4-hydroxyaniline (7.1 g) and potassium hydroxide (3.7 g, 85% pure) in dimethyl¬ suifoxide (25 ml) was heated to 80°C and treated with a solution of l,2-dichloro-4-(trifluoromethyl)benzene (10.9 g) in dimethylsuifoxide (10 ml). The mixture was stirred at 90 to 95°C for 20 hours, after which time it was diluted with a mixture of water and dichloromethaneT The organic phase was dried over sodium sulfate and evaporated down to give 3.6 g of the intermediate amine as a brown oil. Chromatography over silica gel using toluene/petroleum ether (4:1 ratio) gave 1.1 g of the pure amine as a yellow oil. Elemental Analysis: Calculated: C; 51.1% H; 2.6% N; 4.6% Found: C; 50.3% H; 2.7% N; 4.3% Step B: Preparation of N-(2.6-difluorobenzoyl)-N'- (2-fluoro-4-r2-chloro-4-(trifluoromethyl)- phenoxylphenylurea (Compound of Formula I) A solution of the compound of Step A (0.9 g) in dry toluene (5 ml) was treated with 2,6-difluoro- benzoylisocyanate (0.56 g) and the mixture was stirred at room temperature overnight. The precipitated product was then separated, washed with cold methanol and dried in an oven at 60°C to give 1.15 g of the desired product, melting point 173 to 175°C. Elemental Analysis: Calculated: C; 51.6% H; 2.3% N; 5.7% Found: C; 51.7% H; 2.1% N; 5.7 _. Formulation and Use The compound of this invention will typically be used in formulation with a pesticidally suitable carrier comprising a liquid or solid diluent or an organic solvent. Useful formulations of Formula I compound can be prepared in conventional ways. They include dusts, granules, baits, pellets, solutions, suspensions, emulsions, wettable powders, aerosols, emulsifiable concentrates, dry flowables and the like. Many of these can be applied directly. Sprayable formulations can be extended in suitable media and used at various spray volumes. High strength compositions are primarily used as intermediates for further formulation. The formulations, broadly, contain about 0.01% to 99% by weight of active ingredien (s) and at least one of a) about 0.1% to 20% surfactant(s) and b) about 5% to 99% solid or liquid diluent(s). More specifically, they will contain effective amounts of these ingredients in the following approximate proportions: Percent by Weight Active Ingredient Diluent(s) Surfactant(s) Wettable Powders 25-90 0-74 1-10 Oil Suspensions, 5-50 40-95 0-15 Emulsions, Solutions, (including Emulsi- fiable Concentrates) Dusts 1-25 70-99 0-5 Granules, Baits and 0.01-95 5-99.9 0-15 Pellets High Strength 90-99 0-10 0-2 Compositions Lower or higher levels of active ingredient can, of course, be present depending on the intended use and the physical properties of the compound. Higher ratios of surfactant to active ingredient are some¬ times desirable, and are achieved by incorporation into the formulation or by tank mixing. Typical solid diluents are described in Watkins, et al., "Handbook of Insecticide Dust Diluents and Carriers", 2nd Ed., Dorland Books, Caldwell, New Jersey. The more absorptive diluents are preferred for wettable powders and the denser ones for dusts. Typical liquid diluents and solvents are described in Marsden, "Solvents Guide," 2nd Ed., Interscience, New York, 1950. Solubility under 0.1% is preferred for suspension concentrates; solution concentrates are preferably stable against phase separation at 0°C. "McCutcheon"s Detergents and Emulsifiers Annual", Allured Publ. Corp., Ridgewood, New Jersey, as well as Sisely and Wood, "Encyclopedia of Surface Active Agents", Chemical Publ. Co., Inc., New York, 1964, list surfactants and recommended uses. All formula¬ tions can contain minor amounts of additives to reduce foam, caking, corrosion, microbiological growth, etc. Preferably, ingredients should be approved by the U.S. Environmental Protection Agency for the use intended. The methods of making such compositions are well known. Solutions are prepared by simply mixing the ingredients. Fine solid compositions are made by blending and, usually, grinding as in a hammer or fluid energy mill. Suspensions are prepared by wet milling (see, for example, Littler, U.S. Patent 3,060,084). Granules and pellets may be made by spraying the active material upon preformed granular carriers or by agglomeration techniques. See J. E. Browning, "Agglomeration", Chemical Engineering. December 4, 1967, pages 147 and following, and "Perry's Chemical Engineer's Handbook", 4th Ed., McGraw-Hill, New York, 1963, pages 8 to 59 and following. Examples of useful formulations of the active compound are as follows: EXAMPLE A Emulsifiable Concentrate N-(2,6-difluorobenzoyl)-N'-(2-fluoro-4-[2-chloro- 4-(trifluoromethyl)phenoxy]phenylurea 5% blend of oil soluble sulfonates and polyoxyethylene ethers 4% xylene 91% The ingredients are combined and stirred with gentle warming to speed solution. A fine screen filter is included in packaging operation to insure the absence of any extraneous undissolved material in the product. EXAMPLE B Wettable Powder N-(2,6-difluorobenzoyl)-N'-(2-fluoro-4-[2-chloro- 4-(trifluoromethyl)phenoxy]phenylurea 30% sodium alkylnaphthalenesulfonate 2% sodium ligninsulfonate 2% synthetic amorphous silica 3% kaolinite 63% The active ingredient, warmed to reduce visco¬ sity, is sprayed onto the inert materials in a blender. After grinding in a hammer-mill, the material is re- blended and sifted through a 50 mesh screen. EXAMPLE C Dust Wettable powder of Example B . ιo% pyrophyllite (powder) 90% The wettable powder and the pyrophyllite diluent are thoroughly blended and then packaged. The product is suitable for use as a dust. EXAMPLE D Granule N-(2,6-difluorobenzoyl)-N'-(2-fluoro-4-[2-chloro- 4-(trifluoromethyl)phenoxy]phenylurea ιo% attapulgite granules (low volative matter, 0.71/0.30 mm; U.S.S. No. 25-50 sieves) 90% The active ingredient is dissolved in a suitable solvent and sprayed onto dedusted attapulgite granules in a double cone blender. The granules are warmed to drive off solvent, cooled and packaged. EXAMPLE E Granule Wettable powder of Example D 15% gypsum 69% potassium sulfate 16% The ingredients are blended in a rotating mixer and water sprayed on to accomplish granulation. When most of the material has reached the desired range of 1.0 to 0.42 mm (U.S.S. No. 18 to 40 sieves), the gran¬ ules are removed, dried, and screened. Oversize material is crushed to produce additional material in the desired range. These granules contain 4.5% active ingredient. EXAMPLE F Solution N-(2,6-difluorobenzoyl)-N'-(2-fluoro-4-[2-chloro- 4-(trifluoromethyl)phenoxy]phenylurea 10% isophorone 90% The ingredients are combined and stirred to produce a solution suitable for direct, low volume application. EXAMPLE G Bait N-(2,6-difluorobenzoyl)-N'-(2-fluoro-4-[2-chloro- 4-(trifluoromethyl)phenoxy]ρhenylurea 0.25% Muscalure (Fly attractant) 0.10% Tartrazine 0.20% Sucrose 99.45% The ingredients are mixed in a blender. The ingredients are then ground together in an airmill and compacted in a roll compactor. The sheets are then broken up and sifted. The material that is the proper size is packaged (about 0.15 to 2.0 mm). EXAMPLE H Bait N-(2,6-difluorobenzoyl)-N'-(2-fluoro-4-[2-chloro- 4-(trifluoromethyl) henoxy]phenylurea 0.50% Gum Arabic 10.0% High Molecular Weight Polyethylene Oxide 13.0% Cornstarch 76.5% The ingredients are mixed together in a blender and ground in a hammer-mill. The mixture is then extruded in a ring type extruder to produce pellets. The pellets are then screened to remove fines and . packaged. The polymer acts as a framework that encompasses the toxicant and holds it for ingestion by the insect. The compound of Formula I can also be mixed with one or more other insecticides, acaricides, or other biologically active compounds to form a multi-component pesticide giving broad protection against household pests. Representative of the insecticides with which the compound of Formula I can be used are: chloropyrifos, methoprene, hydramethylnon, abamectin, fenoxycarb, dichlorvos, diazinon, propetamphos, propoxur, bendiocarb and natural and synthetic pyrethroids. Utility The compound described herein exhibits activity against several species of household pests although those skilled in the art will recognize that it may not be equally effective against all such pests. Household pests are undesirable insect species normally found to inhabit the household environment. The specific species for which control is exemplified hereafter is Blattella germanica . Application Insects are controlled and human health is protected by applying the Formula I compound, in an effective amount, to the locus of infestation, to the area to be protected, to a food source or directly on the pests to be controlled. A preferred method of application is by spraying the compound in the environment of the pests. The compound can be incorporated into baits which are consumed or in devices such as traps and the like which entice the insects to ingest or otherwise contact the toxicant. The compound can be applied in its pure state, but most often application will be of a formulation comprising the compound in a suitable entraining carrier or diluent, possibly in combination with a food. A most preferred method of application involves a bait formulation or spraying a water dispersion of a formulation of the compound. The rate of application required for effective control will depend on such factors as the species of insect to be controlled, the pest's life stage, its size, its location, time of year of application, ambient moisture, temperature conditions, and the like. In general, application rates of 0.1 to 1 mg of active ingredient per square foot are sufficient to provide effective control under normal circumstances, but as little as 0.05 mg/sq ft may be sufficient or as much as 4 mg/sq ft may be required, depending upon the factors listed above. A second method of application is to incorporate the compound into a bait that will be ingested by the pest. In general, application rates of about 2 to 5 ppm of active ingredient, by total weight, are sufficient to provide effective control under normal circumstances, but as little as 0.1 ppm may be sufficient or as much as 20 ppm may be required depending upon the factors listed. The following Examples demonstrate the control efficacy of the compound of Formula I on cockroaches. EXAMPLE 1 Aluminum foil-covered panels (6" x 6") were treated with acetone solution of compound I at the rate of 0.7 mg/sq ft (active ingredient). This was replicated three times. Each was placed in a two gallon glass jar with twenty-five third instar Blattella germanica. Two pieces of lab chow (Wayne Rodent Blox®) was placed in each jar. Mortality was assessed after two weeks. Rate % mα/sα ft (active) Replication Mortality 0.7 1 96 2 92 3 96 EXAMPLE 2 Samples of compound I were incorporated into portions of lab chow in varying amounts. These were fed to third instar nymphs of Blattella germanica in two gallon glass jars, twenty-five insects per jar. Three replicates were used at each concentration level. Mortality was assessed after twelve days. 10 Rates % (PPM) Mortality 2 100 1 100 1 " L 5 :> Con °tr ' o 1 l 2 1 Example 3 Samples of compound I were incorporated into portions of lab chow in varying amounts. These were fed to fifth instar Blatella germanica nymphs which had fasted for twenty-four hours. Mortality was determined seven days after post molting. 25 30 35

Claims: CLAIMS What is claimed is: 1. A method for controlling pests selected from flies, cockroaches, ants and carpet beetles comprising applying to the pests, their food or to their environment a pesticidally effective amount of a compound of the formula: in a carrier or diluent. 2. A method according to Claim 1 that comprises controlling flies. 3. A method according to Claim 1 that comprises controlling cockroaches. 4. A method according to Claim 1 that comprises controlling ants. 5. A method according to Claim 1 that comprises controlling carpet beetles. 6. A method according to Claim 1 that comprises applying the compound together with an insect attractant. 7. A method according to Claim 6 wherein the attractant is a sex attractant. 8. A method according to Claim 6 wherein the attractant is food. 9. A method according to Claim 6 wherein the compound and attractant are contained in a bait. 10. A method according to any one of Claims 6 to 9 wherein the compound and attractant are contained in a polymeric framework. 11. A method according to any one of Claims 6 to 9 wherein the compound and attractant are contained in a trap.

Inventors: ROBERTS CLYDE ALLEN, ROBERTS, CLYDE, ALLEN
Applicants: DU PONT, E.I. DU PONT DE NEMOURS AND COMPANY
Application year: 1989
Main classification: A01N47
IPC codes: A01N47, C07C275