GB2118941A

GB2118941A - Benzoylphenylurea derivatives, their preparation and use as pesticides

Info

Publication number: GB2118941A
Application number: GB08310803A
Authority: GB
Inventors: Martin Anderson
Original assignee: SHELL INT RESEARCH; Shell Internationale Research Maatschappij BV
Current assignee: SHELL INT RESEARCH; Shell Internationale Research Maatschappij BV
Priority date: 1982-04-23
Filing date: 1983-04-21
Publication date: 1983-11-09
Also published as: GB2118941B; GB8310803D0

Abstract

Pesticidally active benzoylphenylurea derivatives of formula:- <IMAGE> wherein Hal is a halogen atom; B is a hydrogen or halogen atom; X is halogen, cyano, haloalkyl, haloalkoxy, or phenoxy substituted by one or more substituents selected from the group consisting of nitro, cyano, halogen, haloalkyl and haloalkoxy; n is 1, 2 or 3; and R is a haloalkyl group or a phenyl group optionally-substituted by one or more substituents selected from the group consisting of nitro, alkyl and halogen, have, in particular, insecticidal and ovicidal activity.

Description

SPECIFICATION Benzoylphenylurea derivatives, their preparation and use as pesticides The present invention relates to benzoyiphenylurea derivatives, their preparation, compositions containing such derivatives and their use as insecticides.

It is known from "Chemie der Pflanzenschutz und Schadlings-bekampfungsmittel", 1981, Band 6 pages 423 to 470 that benzoylphenylurea derivatives are a group of insecticides which was discovered around 1 970 as having a unique mode of action; when the insect larvae ingest a treated leaf or plant, the natural process of insect moulting is severely disru.pted thereby causing death of the insect. This group of compounds is characterised by being high melting point solids which are poorly soluble both in water and in solvents used for formulations. It has been found that the particle size of the active material has a considerable influence over biological activity and that the effectiveness increases with decreasing particle size.Accordingly, considerable efforts have been made to design formulations which produce a deposit on the leaf or plant which is in the finest particulate form. Clearly the finest deposit would result from a solution, for example an emulsifiable concentrate, of the benzoylphenylurea but because of the intractable nature of these compounds, this has hitherto been difficult. Although some of these benzoylphenylurea compounds are soluble in certain organic solvents the active ingredient is so water-insoluble that, as soon as the farmer dilutes such a formulation with water for application to his crops, the active ingredient precipitates out and the advantages of the active ingredient in solution are lost.

The Applicant has discovered a new group of benzoylphenylureas which possess the same order of pesticidal activity as the known examples but possess an increased solubility in organic formulation solvents and, when thus formulation, are less prone to precipitation on dilution with water.

Accordingly the present invention provides benzoylphenylurea derivatives of formula:

wherein Hal represents a halogen atom; B is a hydrogen or halogen atom; X is halogen, cyano, haloalkyl, haloalkoxy, a phenoxy group substituted by one or more substituents selected from the group consisting of nitro, cyano, halogen, haloalkyl, and haloalkoxy; n is 1, 2 or 3; and R is a haloalkyl group or a phenyl group optionally-substituted by one or more substituents selected from the group consisting of nitro, alkyl and halogen.

The halogen atom represented by "Hal" or by B may be fluorine, chlorine or bromine but is preferably chlorine or fluorine.

The X substituent or one of the X substituents in the compounds of formula I is preferably in the 4 position on the anilino phenyl group as this provides increased activity in the molecule.

The haloalkyl or haloalkoxy groups which X may represent preferably contain 1 to 6 carbon atoms and 1 to 3 halogen atoms, for example fluorine, chlorine or bromine; particular examples of such groups are being trifluoromethyl and trifluoromethoxy.

The phenoxy group which X can represent is preferably a nitrophenoxy group, a haloalkylphenoxy group, a haloalkoxyphenoxy group, or a haloalkyl-halophenoxy group, in which the halogen atoms are fluorine, chlorine, or bromine and the alkyl and alkoxy groups contain 1 to 4 carbon atoms. Particular examples are 2 chloro-4-trifluoromethylphenoxy and 4-nitrophenoxy.

Preferably the group R in the general formula is a haloalkyl group containing 1 to 6 carbon atoms and 1 to 3 fluorine, chlorine or bromine atoms, or a phenyl group optionally substituted by one or more (suitably 1 or 2) substitutents selected from the group consisting of nitro, alkyl containing 1 to 6 carbon atoms, fluorine, chlorine and bromine. Particularly useful compounds according to the invention are those in which R is a phenyl group bearing at least one nitro group preferably in the 2-position.

Preferred compounds according to the invention may be defined as those having the general formula I in which Hal represents, fluorine, chlorine or bromine; B is hydrogen, fluorine, chlorine or bromine; X is fluorine, chlorine, bromine, a haloalkyl or haloalkoxy group containing 1 to 4 carbon atoms and 1 to 3 fluorine, chlorine or bromine atoms, a nitrophenoxy group, a haloalkylphenoxy, haloalkoxyphenoxy or haloalkyl-halophenoxy group in which the halogen can be fluorine, chlorine or bromine and the alkyl and the alkoxy group contains 1 to 4 carbon atoms; n is 1, 2 or 3; and R is haloalkyl containing 1 to 6 carbon atoms and 1 to 3 fluorine, chlorine or bromine atoms or a phenyl group optionally-substituted by one or more substituents selected from the group consisting of nitro, alkyl containing 1 to 4 carbon aotms, fluorine, chlorine and bromine.

Because of improved formulation characteristics and good pesticidal activity, the most preferred compound of the general formula I are those in which Hal is fluorine or chlorine; B is hydrogen, fluorine, or chlorine; X is chlorine, trifluoromethoxy, trifluoromethyl, 2-chloro-4-trifluoromethylphenoxy, or 4 nitrophenoxy, wherein X or one of X is in the 4-position on the anilino phenyl ring; n is 1,2 or 3; R is 2nitrophenyl or 2,4-dinitrophenyl.

Having conceived that the compounds of the general formula I might possess an interesting level of insecticidal activity, the Applicant then devised a new route to the desired compounds which route forms a further aspect of the present invention.

Accordingly the compounds of the general formula I may be prepared by a process which comprises reacting under anhydrous conditions a benzoylisocyanate of formula

in which B and Hal have the meanings hereinbefore defined with a sulphenamide of formula

in which X, n and R have the meanings hereinbefore defined.

Preferably the reaction is carried out in the presence of an aprotic solvent. Suitable solvents are aromatic solvents such as benzene, toluene, xylene, or chlorobenzene, hydrocarbons such as petroleum (b.p. 400--600C), chlorinated hydrocarbons such as chloroform, methylene chloride or ethylene chloride, ethers such as diethylether, dibutylether, or dioxan.

Preferably the reaction is carried out at a temperature in the range 0 to 1 000C suitably in the range 10 to 500C. Preferably the molar ratio of isocyanate to amine is from 1:1 to 2:1. The product may be worked up by the usual techniques. The starting materials of formulae ill and IV are known compounds and may be prepared by methods analogous to those known in the art.

The compounds of the present invention have been found to have high pesticidal, for example insecticidal, activity. Accordingly the present invention also provides pesticidal, particularly insecticidal, compositions comprising a compound of formula I as defined above together with a carrier. Such a composition may contain a single compound or a mixture of several compounds of the invention. The invention further provides a method of combating pests, particularly insect pests, at a locus, which comprises applying an insecticidally effective amount of a compound or composition according to the present invention to a locus infested by or liable to infestation by pests.

A composition according to the invention comprises one or more carriers. A carrier is any material with which the active ingredients are formulated to facilitate application to the locus to be treated, or to facilitate storage, transport or handling. A carrier may be a solid or a liquid, including a material which is normally gaseous but which has been compressed to form a liquid, and any of the carriers normally used in formulating pesticidal compositions may be used.

Suitable solid carriers include natural and synthetic clays and silicates, for example natural silicas such as diatomaceous earths; magnesium silicates, for example talcs; magnesium aluminium silicates, for example attapulgites and vermiculites; aluminium silicates, for example kaolinites, montmorillonites and micas; calcium carbonate; calcium sulphate; synthetic hydrated silicon oxides and synthetic calcium or aluminium silicates; elements, for example carbon and sulphur; natural and synthetic resins, for example coumarone resins, polyvinyl chloride, and styrene polymers and copolymers; solid polychlorophenols; bitumen; waxes, for example beeswax, paraffin wax, and chlorinated mineral waxes; and solid fertilisers, for example superphosphates.

Suitable liquid carriers include water; ketones, for example acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; ethers; aromatic or araliphatic hydrocarbons, for example benzene, toluene and xylene; petroleum fractions, for example kerosine and light mineral oils; chlorinated hydrocarbons, for example carbon tetrachloride, perchloroethylene and trichloroethane.

Mixtures of different liquids are often suitable.

Agricultural compositions are often formulated and transported in a concentrated form which is subsequently diluted by the user before application. The presence of small amounts of a carrier which is a surface-active agent facilitates this process of dilution.

A surface-active agent may be an emulsifying agent, a dispersing agent or a wetting agent; it may be nonionic or ionic. Examples of suitable surface-active agents include the sodium or calcium salts of polyacrylic acids and lignin sulphonic acids; the condensation products of fatty acids or aliphatic amines or amides containing at least 12 carbon atoms in the molecule with ethylene oxide and/or propylene oxide; fatty acid esters of glycerol, sorbitan, sucrose or pentaerythritol; condensates of these with ethylene oxide and/or propylene oxide; condensation products of fatty alcohol or alkyl phenols, for example p-octylphenol orp-octylcresol, with ethylene oxide and/or propylene oxide; sulphates or sulphonates of these condensation products; alkali or alkaline earth metal salts, preferably sodium salts, of sulphuric or sulphonic acid esters containing at least 10 carbon atoms in the molecule, for example sodium lauryl sulphate, sodium secondary alkyl sulphates, sodium salts of sulphonated castor oil, and sodium alkylaryl sulphonates such as sodium dodecylbenzene sulphonate; and polymers of ethylene oxide and copolymers of ethylene oxide and propylene oxide.

The compositions of the invention may for example be formulated as wettable powders, dusts, granules, solutions, emulsifable concentrates, emulsions, suspension concentrates and aerosols.

Wettable powders usually contain 25, 50 and 75% w of active ingredient and usually contain, in addition to solid inert carrier, 3-10% w of a dispersing agent and, where necessary, 0-1 0% w of stabiliser(s) and/or other additives such as penetrants or stickers. Dusts are usually formulated as a dust concentrate having a similar compositions to that of a wettable powder but without a dispersant, and are diluted in the field with further solid carrier to give a composition usually containing ; 10% w of active ingredient. Granules are usually prepared to have a size between 10 and 100 BS mesh (1.676-0.152 mm), and may be manufactured by agglomeration or impregnation techniques.

Generally, granules will contain 21 25% w active ingredient and 0-10% w of additives such as stabilisers, slow release modifiers and binding agents. Emulsifiable concentrates usually contain, in addition to a solvent and, when necessary, co-solvent, 10-50% w/v active ingredient, 2-20% w/v emulsifiers and 0-20% w/v of other additives such as stabilisers, penetrants and corrosion inhibitors.

Suspension concentrates are usually compounded so as to obtain a stable, non-sedimenting flowable product and usually contain 1075% w active ingredient, 0.5-15% w of dispersing agents, 0.1- 10% w of suspending agents such as protective colloids and thixotropic agents, 0-1 0% w of other additives such as defoamers, corrosion inhibitors, stabilisers, penetrants and stickers, and water or an organic liquid in which the active ingredient is substantially insoluble; certain organic solids or inorganic salts may be present dissolved in the formulation to assist in preventing sedimentation or as anti-freeze agents for water.

Aqueous dispersions and emulsions, for example compositions obtained by diluting a wettable powder or a concentrate according to the invention with water, also lie within the scope of the present invention. The said emulsions may be of the water-in-oil or of the oil-in-water type, and may have a thick 'mayonnaise'-like consistency.

The compositions of the invention may also contain other ingredients, for example, other compounds possessing pesticidal, herbicidal or fungicidai properties. Further insecticidal compounds may be included, particularly such compounds having a different mode of activity, such as more rapid knock down than the compounds of the present invention. Examples are pyrethrum or pyrethroid compounds such as permethrin, cypermethrin, deltamethrin and fenvalerate.

The invention is further illustrated by the following examples. The sulphenamide starting materials were prepared by a method based essentially on that of J. H. Billman, J. Garrison, R. Anderson, B. Wolnak, J. Amer. Chem. Soc. 1941 , 63, p. 1 920.

Example 1 2-Chloro-N-[[[4-(trifluoromethoxy)phenyl] [(2-nitrophenyl)thio]amino]carbonyl]benza mide A solution of 2-chlorobenzoyl isocyanate (50 g, 0.28 mole) in dry toluene (50 ml) was added to a stirred solution of N-[4-(trifluoromethoxy)phenyl]-2-nitrobenzenesulphenamide (60 g, 0.1 8 mole) in the same solvent (100 ml).The reaction was slightly exothermic, reaching a maximum temperature of 35cC. After 4 days at room temperature, the reaction mixture was cooled to -50C and the crystalline cake of product was broken up under cold toluene, filtered, washing with toluene followed by cold light petroleum (b.p. 40--600C) and dried at 400C under vacuum, yielding the pure product as pale yellow crystals (89.3 g).

m.p. 1 55-1 580C with decomposition.

Analysis C21H,3CIF3N30sS Calc. 49.3% C 2.6% H 8.2% N Found 49.4% C 2.5% H 8.3% N Example 2 2-Chloro-N-[[[4-(trifluoromethoxy)phenoxyl] [(2.4-dinitrophenyl)thio]amino]carbonyl] benzam ide A solution of 2-chlorobenzoyl isocyanate (3.6 g; 0.02 moles) in dry toluene (20 ml) was added to a stirred solution of N-[4-(trifluoromethoxy)phenyl]-2,4-dinitrobenzenesulphenamide (3.75 g; 0.01 mole) in the same solvent (30 ml) at room temperature. After 6 days, the reaction mixture was cooled to -50C and filtered, washing with cold toluene and finally with cold light petroleum (b.p. 40-600C).

The pure product was obtained as pale yellow crystals (5.25 g).

m.p. 184-1 860C with decomposition.

Analysis C21H12CIF3N407S: Calc. 45.3% C 2.2% H 10.1%N Found 45.1%C 2.0% H 10.0% N Example 3 N-[[[4-[(2-chloro-4-(trifluoromethyl)phenoxy]phenyl][(2-nitrophenyl)thio]amino]carbonyl]-2,6difluorobenzamide Asolution of 2,6-difluorobenzyl isocyanate (1.0 g;0.0055 mole) in dry methylene chloride (10 ml) was added over five minutes to a stirred solution of N-[4-t2-chloro-4-(trifluoromethyl)phenoxy]- phenyl]-2-nitrobenzenesulphenamide (2.2 g; 0.005 mole) in the same solvent (35 ml) at room temperature. After 24 hours, the reaction mixture was diluted with dry light petroleum (b.p. 40--600C) and the resulting precipitate of crude product was separated. Recrystallisation of this material from ether/light petroleum gave the pure product as pale yellow crystals (2.8 g).

m.p. 149-1520C.

Analysis C27H,5CIF5N305S: Calc. 52.0% C 2.4% H 6.7% N Found 52.1%C 2.3% H 6.8% N Example 4 2-Chloro-N-[[[4-(trifluoromethoxy)phenyl] [(2-methylphenyl)thio]amino]carbonyl]benzamide A solution of 2-chlorobenzoyl isocyanate (2.0 g; 0.011 mole) in dry toluene (5 ml) was added to a stirred suspension of N-[4-(trifluoromethoxy)phenyl]-2-methyl-benzenesulphenamide (3.0 g; 0.01 mole) in dry light petroleum (b.p..40-600C, 40 ml) at room temperature. After a few minutes, the reaction mixture became clear and subsequently the product came out of solution as an oil which eventually recrystallised. After 24 hours the reaction mixture was cooled to -50C and filtered, washing the pale purple product with cold light petroleum.Recrystallisation from ether/light petroleum afforded colourless crystals of pure material (3.3 g).

m.p. 79--800C.

Analysis C22H16CIF3N203S: Calc. 54.9% C 3.4% H 5.8% N Found 54.6% C 3.3% H 6.1% N Example 5 N-[[[4-Chlorophenyl][(2-nitrophenyl)thio]amino]carbonyl]-2,6-difluorobenzamide A solution of 2,6-difluorobenzoyl isocyanate (1.8 g; 0.01 mole) in dry toluene (15 ml) was added over 15 minutes to a stirred solution of N-(4-chlorophenyl)-2-nitrobenzenesulphenamide (2.8 g; 0.01 mole) in the same solvent (35 ml) at room temperature. After stirring overnight, the reaction was incomplete. A few drops of triethylamine were added, and after a further 24 hours, the reaction mixture was cooled to -50C and filtered, washing the pale yellow product with cold toluene. Traces of toluene were removed by drying under vacuum at about 400C for 3 days.

Yield: 3.1 g.

m.p. 176-1780C.

Analysis C20H12CIF2N304S: Calc: 51.8% C 2.6% H 9.1%N Found 51.8% C 2.5% H 9.1%N Example 6 2,6-DifluornN-[[[(trichlornmethyl)thio] [4-(trifluoromethyl)phenyl]amino]carbonyl] benzamide A solution of 2,6-difluorobenzoyl isocyanate (2.0 g; 0.011 mole) in dry methylene chloride (15 ml) was added to a stirred solution of 1,1,1-trichloro-N-[4-(trifluoromethyl)phenyl]-methanesulphen amide (3.1 g; 0.01 mole) in the same solvent (35 ml) at room temperature. After 2 days, only partial reaction had occurred and a further quantity of isocyanate (2.0 g) was added. After a total reaction time of 28 days, the reaction mixture was diluted with light petroleum (b.p. 40--600C, 400 ml) and filtered.Evaporation of the filtrate afforded a residue (4.0 9) from which the pure product was obtained as colourless crystals by chromatography on silica gel using methylene chloride as eluant.

Yield 1.3 9.

m.p. 129-1300C.

Analysis C16H8CI3FsN202S: Calc. 38.9% C 1.6% H 5.7% N Found 39.3% C 1.6% H 5.9% N Example 7 2-Chloro-N-[[[4-[2-chloro-4-(trifluoromethyl)phenoxy]phenyl][(trichloromethyl)thio]amino]carbonyl]benzamide A solution of 2-chlorobenzoyl isocyanate (3.6 g; 0.02 mole) in dry toluene (15 ml) was added over five minutes to a stirred solution of 1,1,1-trichloro-N-[4-[2-chloro-4-(trifluoromethyl)phenoxy]- phenyl]methanesulphenamide (4.0 g, 0.009 mole) in the same solvent (25 ml) at room temperature.

After 10 days, the reaction mixture was diluted with light petroleum (b.p. 40--600C, 500 ml) and filtered.Evaporation of the filtrate afforded a crude residue from which the pure product was obtained by rapid chromatography on silica gel using methylene chloride as eluant.

m.p. 68-71 OC.

Analysis C22H,2CI5F3N203S: Calc. 42.7% C 1.9% H 4.5% N Found 43.3%C 1.9% H 4.5% N .

Further compounds were prepared according to procedures similar to those described above. The melting points and analyses of these compounds are set out in Table 1 below.

Table 1

Example m.p. Analysis% No. (X)n- R Hal B C C H N 8 4-Cl- C6H5 F F 115-117 Calc. C20H13CIF2N2O2S 57.3 3.1 6.7 9 4-Cl- 2-CH3-C6H4- F F 125-128 Calc. C2,H15CIF2N2O2S 58.3 3.5 6.5 Found 58.1 3.3 6.6 10 4-Cl- 3-CH3-C6H4- F F 140-142 Calc. C21H15CIF2N2O2S 58.3 3.5 1.5 Found 58.5 3.3 6.6 11 4-Cl- 4-Ch3-C6H4- F F 130-133 Calc. C21H15CIF2N2O2S 68.3 3.5 6.5 Found 57.6 3.5 6.7 12 4-Cl- 4-Cl-C6H4- F F 86-88 Calc. C20H12Cl2F2N2O2S 53.0 2.6 6.2 13 4-Cl- 2,4(NO2)2-C6H3- F F 171-173 Calc. C20H11CIF2N4O6S 47.2 2.2 11.0 Found 47.2 2.2 10.9 14 4-Cl- Cl3C- F F 135-136 Calc. C15H8Cl4F2N2O2S 29.1 1.7 6.1 Found 40.1 1.8 6.2 15 4-CF3- C6H5 F F 127-130 Calc. C21H13F5N2O2S 55.8 2.9 6.2 Found 55.5 2.9 6.6 16 4-CF3- 2-CH3-C6H4- F F 120-123 Calc. C22H15F5N2O2S 56.6 3.2 6.0 Found 55.9 2.9 6.1 17 4-CF3- 3-Ch3-C6H4- F F 150-153 Calc.C22H15F5N2O2S 56.6 3.2 6.0 Found 56.6 3.1 6.3 18 4-CF3- 4-Ch3-C6H4- F F 142-145 Calc. C22H15F5N2O2S 56.6 3.2 6.0 Found 56.3 3.0 6.3 Table 1 (continued) Example m.p. Analysis % No. (X)n- R Hal B C C H N 19 4-CF3- 4-Br-C6H4- F F 135-137 Calc. C21H12BrF5N2O2S 47.5 2.2 5.3 Fund 47.5 2.1 5.5 20 4-CF3- 2-NO2-C6H4 F F 115-118 Calc. C21H12F6N3O4S 50.7 2.4 8.5 Found 51.1 2.4 8.4 21 4-Cf3- 4-NO2-C6H4 F F 109-112 Calc. C21H12F5N3O4S 50.7 2.4 8.5 Found 51.0 2.8 8.7 22 4-CF3- 2,4-(NO2)2-C6H3 F F 143-145 Calc. C21H11F5N4O6S 46.5 2.0 10.3 Found 46.4 2.0 10.3 23 4-CF3O- 4-CH3-C6H4- Cl H 124-126 Calc. C22H16CIF3N2O3S 54.9 3.4 5.8 Found 54.8 3.1 5.8 24 4-CF3O- 4-NO2-C6H4- Cl H 177-178 Calc. C21H13CIF3N3O5S 49.3 2.6 8.2 Found 49.1 2.4 7.8 25 4-CF3O- Cl3C- Cl H 97-99 Calc. C16H9Cl4F3N2O3S 37.8 1.8 5.5 Found 38.6 1.7 5.6 26 4-CF3 4-t-butyl-C6H4 F F 63-66 Calc.C25H21F5N2O2S 59.1 4.1 5.5 Found 59.3 4.3 5.4 27 4-Cf3 4-Cl-C6H4 F F 144-146 Calc. C21H12CIF5N2O2S 51.8 2.5 5.8 Found 51.7 2.2 6.1 28 4-Cl 4-NO2-C6H4 F F 110-113 Calc. C20H12CIF2N3O4S 51.8 2.6 9.1 Found 51.8 2.3 8.9 29 4-(2-Cl-4- C6H5 Cl H 55-58 Calc. C27H17Cl2F3N2O2S 56.2 2.9 4.9 CF3-C6H3O)- Found 55.4 2.9 4.8 30 " 4-Cl-C6H4 Cl H 93-95 Calc. C27H16Cl3F3N2O3S 53.0 2.6 4.6 Found 53.2 2.6 4.7 31 " 2-CH3-C6H4 Cl H 65-68 Calc. C29H19Cl2F3N2O3S 56.8 3.2 4.8 Table 1 (continued) Example m.p. Analysis % No. (X)n- R Hal B C C H N 32 4-CF3O 2-isopropyl-C6H4 Cl H 65-68 Calc. C24H20CIF3N2O3S 56.6 4.0 5.5 Found 56.6 4.4 5.4 33 4-CF3O 4-Cl-C6H4 Cl H 124-126 Calc. C21H13Cl2F3N2O3S 50.3 2.6 5.6 Found 50.4 2.6 6.0 34 4-(2-Cl-4- 4-Ch3-C6H4 Cl H 133-135 Calc. C26H19Cl2F3N2O3S 56.8 3.2 4.8 Cf3-C6H3O)- Found 56.6 3.2 4.7 Calc.C27H16Cl2F3N3O5S 52.1 2.6 6.7 35 " 2-NO2-C6H4 Cl H 136-138 Found 52.6 2.6 6.4 Calc. C24H21CIf2N2O2S 60.7 4.4 5.9 36 4-Cl 4-t-butyl-C6H4 F F 93-96 Found 59.6 4.2 5.6 Calc. C20H12BrClF2N2O2S 48.3 2.4 5.6 37 4-Cl 4-Br-C6H4 F F 110-121 Found 48.6 2.5 5.9 Calc. C26H14Cl2F2N4O7S 49.1 2.2 8.8 38 3,5-Cl2-4- 2-NO2-C6H4 F F 126-129 Found 49.1 2.2 8.3 (4-NO2-C6H4O)- Example 39 The insecticidal activity of the compounds of the invention was determined in the following tests Test 1 The insecticidal and ovicidal activities of the compounds of the invention were assessed employing the pests Spodoptera littoralis (S.l.),Aedes aegypti (A.a) and eggs of Spodoptera littoralis (S.l.ov.).

The test methods used for each species appear below. In each case the tests were conducted under normal insectary conditions (280C+200C; fluctuating light and humidity).

In each test an LC50 for the compound was calculated from the mortality figures and compared with the corresponding LC50 for ethyl parathion in the same tests. The results are expressed as toxicity indices= LC (parthion) x100 LC50 (test compound) are set out in Table 2 below.

(i) Spodoptera littoralis Solutions or suspensions of the compound were made up over a range of concentrations in 10% acetone/water containing .025% Triton Xl 00 ("Triton" is a registered trade mark). These solutions were sprayed using a logarithmic spraying machine onto petri dishes containing a nutritious diet on which the Spodoptera littoralis larvae had been reared. When the spray deposit had dried each dish was infected with 10 2nd instar larvae. Mortality assessments were made 7 days after spraying.

(ii) Aedes aegypti Several solutions of the test compounds of varying concentration were prepared in acetone. 1 00 microlitre quantities were added to 100 ml of tap water, the acetone being allowed to evaporate off. 1 0 early 4th instar larvae were placed in the test solution; after 48 hours the (surviving) larvae were fed with animal feed pellets, and the final percentage mortality assessed when all the larvae had either pupated and emerged as adults or died.

(iii) Spodoptera littoralis (ovicide) Solutions as described in (i) above were prepared. Eggs less than 24 hours old were obtained as follows. Adult Spodoptera littoralis were held in large plastic cylinders containing blotting paper on which the moths laid their batches of eggs. Egg batches containing approximately 60-70 eggs were cut from the blotting paper with a 1 cm surround. These were placed eggs uppermost on filter paper in the deeper half of 5 cm disposable petri dishes and each batch of eggs was then sprayed with a different test solution or the control solution. The dishes were covered until the control eggs had hatched, approximately 5 days. The percentage ovicidal mortality was then calculated.

Table 2 Toxicity index Compound of Example S.l. A.a. S.l.ov.

1 750 220 210 2 150 82 3300 3 4500 0 4 110 77 2200 5 90 220 6 260 34 400 7 1800 55 0 8 16 22 480 9 43 31 1400 10 20 24 1400 11 23 25 680 12 17 14 13 35 100 1800 14 10 6 560 15 170 50 1800 16 550 - 2700 17 260 160 2800 18 300 170 2300 19 240 10 1500 Table 2 (continued) Toxicity index Compound of Example S.l. A.a. S.l.ov.

20 160 180 1800 21 96 13 22 220 51 2300 23 140 145 1500 24 54 31 11 25 140 28 1300 26 580 82 8 27 220 21 2200 28 54 6 720 29 930 330 0 30 670 220 0 31 960 240 0 32 88 28 2000 33 57 44 1300 34 1200 130 0 35 2500 82 0 36 42 22 0 37 51 26 850 38 330 30 0 Example 40 In order to illustrate the improved solubility in a common formulation solvent, xylene, of the compounds according to the invention, solubility tests were carried out with certain of these compounds and closely-related compounds known from the literature. The test method is described below.

The Compound (200 mg) was equilibrated with solvent (0.5 ml of o-xylene at 200C in the dark for 48 hr. After equilibration, the supernatant liquors were removed, centrifuged and then filtered. An aliquot portion of this (0.1 ml) was made up to volume (1 to 100 ml) with acetonitrile and then analysed against standards by means of liquid chromatography.

The results were as shown in the following table.

Solubility results Solubility in xylene Compound (gel) Example 1 3.7 1-(4-trifluoromethoxy-phenyl)-3-(2-chlorobenzoyl)urea (see German Patent Specification 2.601.780) 2.3 Example 3 18.8 1 -(4-(4-trifluoromethyl-2-chlorophenoxy)-phenyl)-3-(2,6 difluorobenzoyl)urea (see Belgian Patent 838.286) 5.7 It can be seen that the compounds according to the invention (which differ in structure from the known compounds in that they have the anilino nitrogen atom substituted by a 2-nitrophenylthio group) are more soluble in xylene than the known compounds and hence more readily converted into manageable formulations.

Claims

1. Benzoylphenylurea derivatives of formula.

wherein Hal is a halogen atom; B is a hydrogen or halogen atom; X is halogen, cyano, haloalkyl, haloalkoxy, or phenoxy substituted by one or more substituents selected from the group consisting of nitro, cyano, halogen, haloalkyl and haloalkoxy; n is 1,2 or 3; and R is a haloalkyl group or a phenyl group optionally-substituted by one or more substituents selected from the group consisting of nitro, alkyl and halogen.

2. Compounds according to claim 1 characterised in that Hal is fluorine, chlorine or bromine; B is hydrogen, fluorine, chlorine or bromine; X is fluorine, chlorine, bromine, a haloalkyl or haloalkoxy group containing 1 to 4 carbon atoms and 1 to 3 fluorine, chlorine or bromine atoms, a nitro-phenoxy group, a haloalkylphenoxy, haloalkoxyphenoxy or haloalkyl-halo-phenoxy group in which the halogen can be fluorine, chlorine or bromine and the alkyl and alkoxy group contains 1 to 4 carbon atoms; n is 1, 2 or 3; and R is haloalkyl containing 1 to 6 carbon atoms and 1 tq 3 fluorine, chlorine or bromine atoms or a phenyl group optionally-substituted by one or more substituents selected from the group consisting of nitro, alkyl containing 1 to 4 carbon atoms, fluorine, chlorine and bromine.

3. Compounds according to Claim 1 or 2 characterised in that Hal is fluorine or chlorine; B is hydrogen, fluorine or chlorine; X is chlorine, trifluoromethoxy, trifluoromethyl, 2-chloro-4 (trifluoromethyl)phenoxy or 4-nitrophenoxy wherein X or one of X is in the 4-position; n is 1, 2 or 3; R is 2-nitrophenyl or 2,4-dinitrophenyl.

4. Compounds according to claim 1 specifically named herein.

5. A process for the preparation of compounds of the general formula I specified in claim 1 characterised in that a benzoylisocyanate of formula:

in which B and Hal have the meanings specified in claim 1 is reacted under anhydrous conditions with a sulphenamide of formula:

in which X, n and R have the meanings defined in claim 1.

6. A process according to claim 5 substantially as hereinbefore described with reference to the Examples.

7. Compounds prepared by a process claimed in claim 5 or 6.

8. A pesticidal composition characterised in that as active ingredient it contains a compound as claimed in any one of claims 1 to 4 or 7.

9. A pesticidal composition according to claim 8 substantially as hereinbefore described with reference to the Examples.

10. A method of combating pests which comprises applying a pesticidally-effective amount of a compound according to anyone of claims 1 to 4 or 7 or a composition according to claim 8 or 9 to a locus infested by or liable to pest infestation.