IE48760B1 - Pesticidal imidazoline derivatives - Google Patents

Abstract

Pesticidal imidazolines are provided of formula wherein X is O or NH; and Y is Br, F, I, -NO2, -OR,-CO2R, -CONR1R2 or -SO2NR1R2, ?, when X is NH, Y may also be chosen from Cl, CN or alkyl of from 1 to 4 carbon atoms, in which R is an alkyl group of from 1 to 18 carbon atoms, and each of R1 and R2, which may be the same or different, is hydrogen or an alkyl group of from 1 to 18 carbon atoms. Pesticidal acid additions salts of the imidazolines are also provided. Methods are described for preparing the pesticides, together with intermediates formed in the preparative methods. Pesticidal formulations containing the pesticides and their use are also described. The pesticides may be used against Arthropods, e.g. against Acarina.

Description

This invention relates to imidazolines, their preparation pesticidal formulations containing the imidazolines, and to their use as pesticides. In particular, the invention relates to an improvement in or modification of the invention described in our Patent Specification No. 46119.

We have discovered that the compounds of formula (1) below and their acid addition salts have activity against Arthropods, for example against members of the Order Acarina.

Compounds of formula (1) are:- wherein X is 0 or NH, and Y is -COjR, -C0NR3R^ or -SOjNR^R^; when X is NH, Y may also be chosen from Cl, CN.methyl and Br; and when X is 0, Y may also be chosen from Br, OMe, NO2 and F in which R is an alkyl group of from 1 to 18 carbon atoms, preferably of from 1 to 4 or of from 12 to 18 1 2 carbon atoms, and each of R and R , which may be the same or different, is hydrogen or an alkyl - 3 group of from 1 to 18 carbon atoms, preferably of from 1 to carbon atoms or of from 12 to 18 carbon atoms, preferably 1 2 only one of R and R being of from 12 to 18 carbon atoms.

Preferred compounds of the formula (1) may be represented 5 by the formula (la) wherein X is 0 and Y1 is F, Br, -NO,,CH,O-, or -CO_C„Hc, λ j 2 2 5 or X is NH and Y1 is Cl, Br or CO„CnHc. 2 5 Certain compounds of formula (1) may exist in their solvated 10 forms.

Preferred compounds of formula (1) are:1-(N-(4-methoxyphenyl)carbamoyl)-2-(2,3-dimethylphenoxymethyl) -2-imidazoline,1-(N-(4-chlorophenyl)carbamoyl)-2-(2,3-dimethylanilinomethyl) 15 -2-imidazoline; 1-(N-(4-bromophenyl)carbamoyl)-2-(2,3-dimethylphenoxymethyl) -2-imidazoline; 8 7 6 0 - 4 1-(N—(4-nitrophenyl)carbamoyl)-2-(2,3-dimethylphenoxymethyl) -2-imidazoline, 1-(N-(4-fluorophenyl)carbamoyl)-2-(2,3-dimethylphenoxymethyl) -2-imidazoline, and 1-(N-(4-bromophenyl)carbamoyl)-2-(2,3-dimethylanilinomethyl) -2-imidazoline.

The compounds of formula (1) and their acid addition salts have activity against Arthropods. The compounds of formula (1) may be used to control pests such as Rhipicephalus appendic10 ulatus, Boophilus decoloratus, Boophilus microplus, Rhipicephalus evertsi, Amblyomma hebraeum, Psoroptes ovis.and Hyaloma species on animals and Tetranychus species on plants.

The compounds of the formula (1) have improved stability in aqueous media, relative to known imidazolines.

The compounds of formula (1) may be prepared by ;any known method for the preparation of compounds of an analogous structure.

In particular the compounds of formula (1) may be prepared from 2-substituted imidazolines of formula (11) or an acid 8 7 6 0 - 5 wherein X is as defined above, either by a direct addition reaction with (4-y-phenyl)isacyanate (to give the N-substituted carbamoyl compound) or by a substitution reaction with a compound of formula (111) :- wherein Y is as defined above and is a leaving group such as halo, acyl, alkoxy (e.g. carbamates) or sulphonyloxy.

The reaction may be effected optionally in water or an organic solvent, such as chloroform or methylene chloride, preferably in the presence of a base such as an alkali metal hydroxide, an alkali metal carbonate, or a tertiary organic base, such as triethylamine, pyridine or substituted pyridines or piperidines, e.g. pentamethylpiperidine or tetramethylpiperidine, and generally at temperatures of -70°C to 120°C, preferably at temperatures of -10°C to 40°C.

Compounds of formula (1), in particular those in which the group is not strongly electron withdrawing, may be prepared by 20 reacting an ethylenediamine of formula (IV) or salt thereof:4 8 7 6 0 H2N.CH2CH2NH. CO.NH Y (IV) wherein Y is as defined hereinabove, with an appropriate, 2, 3-dimethylphenoxyalkyl or 2,3-dimethylanilinoalkyl carboxylic acid or a reactive derivative thereof such as an imidate, thioimidate, imidohalide, ester, amidine, thioamide, nitrile or carboxyalkylthioamide. These reactants may be conveniently represented by formula (V); Me Me (V) wherein X is as hereinbefore defined and Q is a carboxyl 10 group or a reactive derivative thereof which produces the imidazoline ring structure of formula (1) when reacted with a compound of formula (IV).

Suitable derivatives include:NH (imidate) OAlk OAlk I —C-OAlk (orthoester), OAlk -NH NH (thioimidate) -C (imido halide) SAlk Hal 0 -C (ester) OAlk NH NH. (amidine) -C.' (thioamide) -C=N (Nitrile) , and NH.

S (N-alkoxycarbonylthioamide) -C NHC02Alk -C (thioester) X BAlk wherein 'Aik1 is an alkyl group having from 1 to 6 carbon atoms, and one of A and B is S and the other is S or 0.

The conditions under which this reaction may be carried out of course depend upon the nature of the starting materials used, and a liquid medium may be present or absent, high and low temperatures may be used, and various pressures employed. 8 7 6 Ο - 8 When the carboxylic acid derivative is an imidate, this is preferably in the form of an acid addition salt such as a hydrogen halide salt, and may be prepared from the nitrile and a suitable anhydrous alkanol such as ethanol or methanol in the presence of dry diethyl ether or chlorofrom and hydrogen chloride at a low temperature. The reaction may be carried out at a temperature in the range of -20°C to ambient temperature.

The reaction with an ethylenediamine of formula (IV) may be conducted in an inert anhydrous medium, such as chloroform, methylene chloride or ether. The reactants are preferably heated under reflux until reaction is complete.

The thioimidate intermediates in the form of acid addition salts may be prepared from the corresponding nitrile by reaction with an alkyl mercaptan and a hydrogen halide gas at low temperatures about 0°C, in the presence of dry diethyl ether.

The thioimidate may then be reacted with an ethylenediamine of formula (IV) the reaction being effected at the reflux temperature of the reaction mixture.

The ester intermediates may be conveniently prepared from the 2o corresponding acid by known methods, and the acid itself may be prepared from the corresponding nitrile. They may then be reacted with an ethylenediamine of formula (IV), preferably in the presence of a liquid medium which may be polar or nonpolar. The reaction is preferably carried out at an elevated temperature.

The compounds of formula (1) may be prepared from the imidohalide 8 7 6 0 - 9 intermediates by reaction with an ethylenediamine of formula (IV), under anhydrous conditions in the presence or absence of an acid acceptor and optionally at an elevated temperature. The reaction mixture may include a polar or non-polar liquid medium such as a lower alkanol or an ether.

The amidine intermediate in the form of the base or acid addition salts thereof, is preferably converted to a compound of formula (1) by heating under reflux with an ethylene diamine of formula (IV) in the presence of a polar or non-polar liquid medium, for example a lower alkanol, until ammonia ceases to be evolved. The amidine intermediates themselves may be prepared by any known method, but conveniently from the corresponding imidates by reaction with ammonia.

The thioamide and amide intermediates may be prepared from the corresponding nitriles or by any other convenient method and may be converted into compounds of formula (1) by heating with an ethylenediamine of formula (IV), at a reflux or higher temperature, in the presence or absence of a polar or non-polar solvent. Conveniently the reactions are partly effected under reduced pressure to induce the removal of ammonia and/or hydrogen sulphide from the reaction mixture.

The nitrile intermediates may be reacted in the presence or absence of a liquid medium with an ethylenediamine of formula (IV) or a salt thereof: the reaction may be carried out in the presence of hydrogen sulphide. A liquid medium such as a lower alkanol may be included in the reaction mixture 8 ι 6 Ο - 10 which may be heated to reflux temperature, or to a higher temperature in a closed vessel, optionally in the presence of an inert gas such as nitrogen.

It will of course be understood that where the intermediate 5 is the carboxylic acid, the ester or thioamide, there may be isolated as an intermediate the acylethylenediamines of formula (VI): wherein X and Y are as defined above and W is oxygen or sulphur and these compounds may themselves be converted in situ to a compound of formula (1), either by separate treatment with a dehydrating agent such as calcium oxide or by continuing the reaction to completion under the original conditions giving rise to a compound of formula (1).

The compounds of formula (1) may be prepared by the reaction of a phenol or amine of formula (Vll), or an 0- or N-metal compound thereof; (Vll) -X-H - 11 wherein X is as defined for formula (1) with a compound of formula (Vlll): wherein Y is as defined for formula (1), and V is a leaving group derived from a suitable inorganic or organic acid.

Suitable derivatives are halo, such as chloro, iodo or bromo, alkylsulphonyloxy or arylsulphonyloxy, such as p-toluenesulphonyloxy.

The compounds of formula (Vlll) may be in the form of their bases or acid addition salts thereof.

The reaction may be carried out in an inert liquid medium which is preferably a polar liquid such as acetonitrile or isopropanol, or may be dimethylsulphoxide, sulpholane, methyl ethyl ketone, dimethylformamide, acetone, dimethylacetamide, N-methyl-2-pyrrolidone, or mixtures of the foregoing. In the cases where V is chloro in a compound of formula (Vlll), then a small catalytic of an iodide salt, for example sodium iodide, or a phase transfer catalyst, such as a quaternary ammonium salt, such as benzyltrimethylammonium chloride, may advantageously be included in the reaction 8 7 6 0 - 12 mixture. The reactants may be heated together under an inert atmosphere, such as nitrogen, at the reflux temperature of the reaction mixture.

The compounds a compound of of formula (1) may also be prepared by reacting formula (IX): (IX) in which X is as defined above and P is a leaving group (such as halo, acyl, alkoxy, alkylthio, S , SH, sulphonyloxy or carbalkoxy) with a suitably active amine for formula (X): nh2 (X) wherein Y is as defined for fonnula (1).

The compounds of formula (1) may be isolated from the reaction mixtures as the free base or in the form of an acid addition salt. The bases may be converted into acid addition salts 8 7 6 0 - 13 thereof by known techniques with the aid of the appropriate acid, and salts of the compound may also be converted into the free bases or into other acid addition salts.

For use as a pesticide, the compounds of formula (1) may be presented in the form of their acid addition salts, or more preferably, as their free bases. Suitable salts of compounds of formula (1) include hydrohalide, sulphate, nitrate, phosphate, thiocyanate, acetate, propionate, stearate, naphthenate, perchlorate, benzoate, methanesulphonate, ethanesulphonate, tosylate and benzenesulphonate acid addition salts thereof.

The compounds of formula (1) may be used as pesticides to combat insects, ticks, mites and other arthropods including free living arthropods and those which are ectoparasites of plants, mammals and birds and may be used alone or in combination with an additive, which may take the form of one or more of the carriers used in the formulation art, such as wetting, diluting, stabilising, thickening, emulsifying, dispersing or surface active agents or other standard carrier ingredients.

A formulation may be an aqueous solition of an acid addition salt of a compound of formula (1), or a suspension of a compound of formula (1) in water, and may be used alone or in combination with suitable surface active agents. The formulation per se may be used alone or diluted with water for application to the pests or their immediate environment by at) (ου - 14 way of spraying or dipping, A formulation may be in the form of a miscible oil comprising a compound of formula (1) in the form of its free base or with equimolar quantity of a suitable organic acid, such as oleic acid or naphthenic acid, to provide a salt soluble in organic solvents, and emulsifiers, and may be applied as an emulsion by way of spraying or dipping.

A formulation may be a non-aqueous solution or suspension of a compound of formula (1) in a suitable organic solvent for the direct application by the pour-on method. A formulation may also take the form of a wettable powder for dilution with water and application by dipping or spraying. Other solid formulations may also be used for direct application without dilution, such as dusts, powders and granules.

A further formulation may be a paste, grease or gel containing a compound of formula (1) and a suitable carrier, and may be applied by spreading the formulation over the infected area.

An acid addition salt or base of a compound of formula (1) is preferably present in a pesticidal formulation in an amount between 5 and 80%, calculated by weight of the base, and particularly preferred formulations containing about 20%, calculated by weight of the base. The concentration of a compound of formula (1) applied to the pests or their iimedlate environment may be in the range of 0.001% - 20%, calculated by 8 7 6 0 - 15 weight of the base.

It will be appreciated from the foregoing that the invention includes the following aspects: (a) A novel 2,3-dimethylphenoxymethyl or 2,3-dimethylanil5 inomethyl imidazoline compound of formula (1) and acid addition salts thereof; (b) A method of preparation of a novel compound of formula (1) and acid addition salts thereof; (c) A method of controlling arthropod pests, particularly 10 members of the Order Acarina, by applying to the pest or the pest1s environment a compound of formula (1); (d) A pesticidal formulation comprising a compound of formula (1) and a carrier thereof; and (e) A method of making a formulation comprising admixture 15 of a carrier and a ccmpound of formula (1); 8 7 6 Ο - 16 The following Examples are provided by way of illustration of the present invention and should not be construed as in any way constituting a limitation thereof.

Example 1 1- (N- (4-Chlorophenyl)carbamoyl)-2-(2,3-dimethylanilinomethyl) -2-imidazoline 2-(2,3-dimethylanilinomethyl)-2-imidazoline (4.20 g, 0.024 moles) was stirred in methylene chloride (90 ml), cooled to 0°C and a solution of 4-chlorophenyl isocyanate (3.66 g, 0.024 moles) in methylene chloride (10 ml) was then added dropwise. A white precipitate formed rapidly. Stirring was continued for 2 to 3 hours after the addition at 0°C, the reaction mixture then allowed to reach ambient temperature and stirring was continued overnight. The reaction mixture was then evaporated to dryness under reduced pressure and the solid residue so obtained recrystallised from propan-2-ol to yield white crystals of 1-(N-(4-chlorophenyl)carbamoyl) -2-(2,3-dimethylanilinomethyl)-2-imidazoline m.p. 153 - 155°C.

Examples 2 to 6 By methods analogous to that described in Example 1 above the compounds of Examples 2 to 6 below were also prepared.

Example 2 1-(N-(4-Bromophenyl)carbamoyl)-2-(2,3-dimethylphenoxymethyl) -2-imidazoline, monohydrate m.p. 150 - 151°C (white powder). 8 7 6 0 - 17 Example 3 1-(Ν-(4-Methoxyphenyl)carbamoyl)-2-(2,3-dimethylphenoxymethyl) -2-imidazoline, m.p. 126 - 127°C (white powder).

Example 4 1-(N-(4-Nitrophenyl)carbamoyl)-2-(2,3-dimethylphenoxymethyl) -2-imidazoline, monohydrate, m.p. 182 - 185°C (pale yellow powder).

Example 5 1-(N-(4-Carbethoxyphenyl)carbamoyl)-2-(2,3-dimethylphenoxy10 methyl)-2-imidazoline, m.p. 153°C (white powder).

Example 6 1-(N-(4-Fluorophenyl)carbamoyl)-2-(2,3-dimethylphenoxymethyl) -2-imidazoline, m.p. (about 5% impurity) 172 - 173°C.

Example 7 Preparation of 1-(N-(4-Bromophenyl)carbamoyl)-2-(2,3dimethylphenoxymethyl)-2-imidazoline A. A solution of 2-(2,3-dimethylphenoxymethyl)-2-imidazoline (20.4 g, 1.0 mol) in methylene chloride (300 ml) was cooled to -65°C and a solution of 4-bromophenylisocyanate (19.8 g, 1.0 mol) in methylene chloride (300 ml) added dropwise during minutes. The reaction mixture was then allowed to warm to ambient temperature and left to stand for 2 hours, when a precipitate had formed. The reaction mixture was evaporated under reduced pressure and the residue recrystallised from acetone to give 1-(N-(4-bromophenyl) 8 7 6 0 - 18 carbamoyl)-2-(2,3-dimethylphenoxymethyl)-2-imidazoline monohydrate, m.p. 150 - 151°C.

B. via the N-Chlorocarbamoyl adduct of 2-(2,3-dimethylphenoxymethyl)-2-imidazoline A 17% solution of phosgene in toluene (3.2 g containing 0.5521 g, 0.00549 moles COC^) in dry chloroform (15 ml) was added slowly with stirring at 0°C to a solution of 2(2,3-dimethylphenoxymethyl)-2-imidazoline (2.40 g, 0.0115 moles) in dry chloroform (£0 ml). When addition was complete 10 the reaction mixture was left at ambient temperature for hours, diluted with an equal volume of dry diethylether and rapidly filtered. The filtrate, which contained the Nchlorocarbamoyl adduct of 2-(2,3-dimethylphenoxymethyl)-2imidazoline, was treated with freshly distilled dry 435 bromoaniline (1.22 g, 0.00714 moles) and the mixture left at ambient temperature overnight at which time t.l.c shewed that the major compound was the desired product. The mixture was evaporated to dryness in vacuo and the residue taken up in a mixture of aqueous sodium carbonate and dichloromethane. organic layer was washed with water, dried over magnesium sulphate and evaporated to dryness to give a residue which was purified as described in (A) above to give l-(N-(4bromopheny1)carbamoyl-2-(2,3-dimethylphenoxymethyl)-2imidazoline, identical with that obtained in (A) above. 4-8760 - 19 Examples 8 to 10 By methods analogous to that described in Example 1, the following compounds were prepared: 1-(N-(4-methylphenyl)carbamoyl)-2-(2,3-dimethylanilinomethyl) -2-imidazoline (m.p. 154 - 155°C), 1-(N-(4-cyanophenyl)carbamoyl)-2-(2,3-dimethylanilinomethyl) -2-imidazoline, and l-(N-(4-bromophenyl)carbamoyl)-2-(2,3-dimethylanilinomethyl) -2-imidazoline (m.p. 161.6 - 162.2°C).

Example 11 Engorged female ticks of the Biarra Strain of Boophilus microplus are immersed, in groups of 20 ticks, per concentration in washes of a range of dilutions of the compound under test. The wash is prepared immediately prior to the test by dilution (with water) of the compound under test.

The constituents may be in the form of miscible oil or wettable powder formulations. The desired range of concentrations for the test is obtained by further dilution of the master solution or wash.

The ticks are removed from the wash after 10 minutes, dried, and stuck dorsal side down on double-sided adhesive tape.

They remain in this position for 14 days when the numbers laying viable eggs are determined. From this data a regression line is plotted (concentration against % inhibition of egg-production) and the IR99 (concentration at which 99% inhibition of egg-production occurs) is derived. 8 7 6 0 - 20 The results obtained are shown in Table 1 below Table 1 Compound Example No. IR99 5 1-(N-(4-Chlorophenyl)carbamoyl) -2-(2,3-dimethylanilinomethyl) -2-imidazoline 1 O.O29S 10 1-(N-(4-Bromophenyl)carbamoyl -2-(2,3-dimethylphenoxymethyl) -2-imidazoline 2 0.0095% 1- (N-(4-Methoxyphenyl)carbamoyl) -2-(2,3-dimethylphenoxymethyl)- 2- imidazoline 3 0.0038% 15 1-(N-(4-Nitrophenyl)carbamoyl) -2-(2,3-dimethylphenoxymethyl) -2-imidazoline hydrate 4 0.010% 1-(N-(4-Carbethoxyphenyl)carbamoyl) -2-(2,3-dimethylphenoxymethyl)-2- imidazoline 5 0.019% 8 7 6 0 - 21 The following formulations are given to illustrate the way in which the pesticidal compounds of the invention can be applied to pests or environments susceptable to pest attack.

FORMULATION 1 Dusting Powders Active compound Talc FORMULATION 2 Wettable Powder Active Compound Sodium dioctyl sulphosuccinate Dispersal ACA Kaolin FORMULATION 3 Aqueous Dispersion Active compound Keltrol Sodium dioctyl sulphosuccinate 1.0 20.0 parts by weight 99.0 80.0 parts by weight 100.0 100.0 .0 parts by weight 1.0 parts by weight 2.0 parts by weight 72.0 parts by weight 100.0 .0 parts by weight 0.5 parts by weight 0.4 parts by weight „ 48760 - 22 FORMULATION 3 Water 79.1 parts by weight 100.0 FORMULATION 4 Pour-On Active compound .0 parts by weight Dimethyl formamide 85.0 parts by weight Castor Oil .0 parts by weight 100.0 FORMULATION 5 Grease Active compound 6.0 parts by weight Petroleum Jelly 94.0 parts by weight 100.0 FORMULATION 6 Miscible Oil Compound from Example 3 .0 parts by weight Aromasol H 70.0 parts by weight Nonyl phenol ethoxylate .0 parts by weight 100.0 - 23 STABILITY The compound of Example 1 had a half-life of greater than 6 months in an aqueous pH7 medium, while that of 2(2,3-dimethylphenoxy)-2-imidazoline was approximately 2 weeks.

EXAMPLE 12 Using the procedure of Example 1, except that no recrystallisation step was used, l-(N-(4-dimethylsulphonamidophenyl) carbamoyl-2-(2,3-dimethylanilinomethyl)-2-imidazoline (m.p. 151 - 153°C) was prepared.

Claims (29)

1. CLAIMS or an acid addition salt thereof wherein X is 0 or NH, and Y is -CO 2 R, -CONR 1 R 2 or -SO 2 NR 1 R 2 ; 5 when X is NH, Y may also be chosen from Cl, CN,methyl and Br; when X is 0, Y may also be chosen from Br, OMe, NC> 2 and P in which R is an alkyl group of 1 2 from 1 to 18 carbon atoms, and each of R and R which may be the same or different, is hydrogen or an alkyl group of from 10 1 to 18 carbon atoms.

2. A compound according to claim 1 wherein X is 0 and Y is -OMe or X is 0 or NH and Y is -C0 2 R wherein R is an alkyl group of from 1 to 4 or 12 to 18 carbon atoms. - 25 1 2 3.

3.A compound according to claim 1 wherein Y is —CONR R 12 12 or SO 2 NR R wherein each of R and R , which may be the same or different, is hydrogen or an alkyl group of from 1 to 4 or 12 to 18 carbon atoms. 54.

4.A compound according to claim 3 wherein not more than 1 2 one of R and R is an alkyl group of from 12 to 18 carbon atoms. or is or an acid addition salt thereof wherein F, Br, — N0 2' cii 3°— or — C0 2 C 2 6 * * * * Ii 5' or X is 0 and Y 1 X is NH and Y 1 is C3,Br 6.

5.A compound selected from 1-(N-(4-methoxyphenyl) carbamoyl-2-(2,3-dimethylphenoxymethyl)-2-imidazoline, 1-(N(4-chlorophenyl)-carbamoyl)-2-(2,3-dimethylanilinomethyl) 15 -2-imidazoline, l-(N-(4-bromophenyl)carbamoyl)-2-(2,3-dimethylphenoxymethyl) -2-imidazoline, 1-(N-(4-nitrophenyl)carbamoyl) -2-(2,3-dimethylphenoxymethyl)-2-imidazoline, 1-(N-(4fluorophenyl)carbamoyl)-2-(2,3-dimethylphenoxymethyl)-24 8 7

6.Ο - 26 imidazoline, and l-(N-(4-bromophenyl)carbamoyl)-2-(2,3dimethylanilinomethyl)-2-imidazoline, or an acid addition salt thereof.

7. 1-(N-4-chlorophenyl)carbamoyl)-2-(2,3-dimethylanilino 5 -methyl)-2-imidazoline or an acid addition salt thereof.

8. 1-(N-(4-chlorophenyl)carbamoyl)-2-(2,3-dimethylanilinomethy1)-2-imidazoline.

9. A process for the preparation of a compound defined in any of claims 1 to 8, which process comprises 10 (a) the reaction of a compound of the formula (11): N H (ID or an acid addition salt thereof, wherein X is as defined in claim 1, with (4-y-phenvl) isocyanate or with a compound of the formula (111): (ill) 4. 8 7 6 0 - 27 wherein Y is as defined in claim 1 and X 1 is a leaving group; (b) the reaction of a compound of the formula (IV): h 2 n.ch 2 ch 2 nh.co.nh- (IV) or a salt thereof, wherein Y is as defined in claim 1, with a 5 compound of the formula (V): (V) wherein X is as defined in claim 1 and Q is a carboxyl group or a reactive derivative thereof: (c) the cyclisation of a compound of the formula wherein X and Y are as defined in claim 1 and W is oxygen or sulphur; 4 8 7 6 0 - 28 (d) the reaction of a phenol or amine of the formula (Vll): Me Me -X-H (Vll) or an 0- or N-metal compound thereof, wherein X is as defined 5 in claim 1, with a compound of the formula (Vlll): Y (Vlll) or an acid addition slat thereof, wherein Y is as defined in claim 1 and V is a leaving group derived from an inorganic or organic acid; (e) the reaction of a compound of the formula (IX) Me Me (IX) wherein X is as defined in claim 1 and P is a leaving group with an amine of the formula (X): Y '2 NH. (X) wherein Y is as defined in claim 1, and thereafter if desired 5 converting a compound of the formula (1) to an acid addition salt or converting an acid addition salt of a compound of the formula (1) to the free base or an alternative acid addition salt.

10. A pesticidal composition comprising a compound as 10 defined in any one of claims 1 to 8 in association with a carrier therefor.

11. A composition according to claim 10 wherein the carrier is a surface active agent.

12. A composition according to claim 10 wherein the carrier 15 is a liquid.

13. A composition according to claim 12 wherein the carrier is a suspending agent.

14. A composition according to any of claims 10 to 13 in the form of an aqueous solution or suspension, miscible oil, 4 IS 7 © ii - 30 non-aqueous solution or suspension, paste, grease, gel, wettable powder, dust, powder or granules.

15. A composition according to any one of claims 10 to 14 comprising from 5 to 80% of the compound defined in claims 1 5. To 8 calculated by weight of the free base.

16. A composition according to any of claims 10 to 15 wherein the compound is 1-(N-(4-chlorophenyl)carbamoyl)-2(2,3-dimethylanilinomethyl)-2-imidazoline.

17. A composition according to claim 16 in the form of a 10 wettable powder.

18. A composition according to claim 16 in the form of a miscible oil.

19. A method of controlling arthropod pests comprising the application to the pests or their environment a compound as 15 defined in any of claims 1 to 8.

20. A method according to claim 19 wherein the pests are of the Order Acarina.

21. A method according to claim 19 or claim 20 wherein the pests are ectoparasites of mammals or birds. 20

22. A method according to any one of claims 19 to 21 wherein - 31 the compound is applied by spraying, dusting or dipping.

23. A method according to any one of claims 19 to 22 wherein concentration of the compound applied to the pests or their environment is from 0.001 to 20%, calculated by weight 5 of the free base.

24. A method according to any one of claims 19 to 23 wherein the compound is 1-(N-(4-chlorophenyl)carbamoyl)-2(2,3-dimethylanilinomethyl)-2-imidazoline.

25. A process for the preparation of a composition as 6. 10 defined in any of claims 10 to 18 comprising the admixture of a compound as defined in any of claims 1 to 8 and a carrier.

26. A compound according to claim 1 described in any of Examples 1 to 10 herein.

27. A process according to claim 9 substantially as 15 described in any of Examples 1 to 10 herein.

28. A compound according to claim 1 when prepared by the process of claim 9 or claim 27.

29. A composition according to any of claims 10 to 18 4876© - 32 substantially as described in any of formulations 1 to 6 herein.