NZ236968A - 1-chloro-2-fluoro-3-iodo-5-trifluoromethyl benzene, 1-nitro-2,3-dibromo-5-trifluoromethyl benzene and 1-amino-2-fluoro-3-chloro-5-trifluoromethyl benzene - Google Patents

Description

New Zealand Paient Spedficaiion for Paient Number £36968 23 6 9 Priority Dst ids):.. ."X-d~< •'• UP-• ■ { Under the provisic lation 23 (1) the .<C$.Wt Filed: (s|^xcacas./ouT oorr .c:ao.. s ,/J .> r - Specification has been tLe,-daife"ff to Z P.O. J, 'W- ••■■'• 3?- Js^ JTOT3RS Initials NEW ZEALAND DIVIDED OUT OP APPLICATION No.: 228782 Date: 18 April 1989 PATENTS ACT, ] 953 COMPLETE SPECIFICATION NOVEL COMPOUNDS ^31 JAN199lS| f, fi ^/We, IMPERIAL CHEMICAL INDUSTRIES PLC a British Company of Imperial Chemical House, Millbank, London, SW1P 3JF, England hereby declare the invention for which "J?/ we pray that a patent may be granted to ipe/us, and the method by which it is to be performed, to be particularly described in and by the following statement: - - 1 - (followed by page la) a 236968 •? - la - OThe present invention relates to intermediates to phenyl pyrimidinone derivatives . New Zealand Patent Specification No. 228782 discloses phenyl pyrimidinone derivatives which have insecticidal activity, processes for their preparation and discloses their use as insecticides.

D Canadian Patent No. 888730 discloses certain herbicidal compounds of formula: (A) CF3yNY'RC Where Ra is inter alia halo or nitro; R° is inter alia optionally substituted phenyl and Rc is ■ inter alia hydrogen. However no specific examples of 10 substituted phenyl groups Rb are disclosed.

According to the invention of New Zealand Patent Specification No. 228782 there is provided a compound of formula (I) (I) wherein R1 and R2 are independently selected from halogen or nitro; R3 and R4 are independently 15 selected from hydrogen or halogen; R5 is hydrogen, halogen or cyano; and R^ is halogen or haloalkyl; provided that R1, R2' *3 and r4 are "ot a11 «uorine-Suitable halogen groups for R^-, R2, R^/ rS R 236 96 8 and R6 include fluoro, chloro, bromo or iodo.

Preferably at least one of or R2 is halo. In particular R1 and R2 are both fluoro or chloro.

Suitably R3 and R4 are hydrogen.

In preferred embodiments R^, R2, R^ and R^ are not all halo.

Suitably R5 is hydrogen or halogen. Most preferably R5 is hydrogen, chlorine, or bromine.

Suitable haloalkyl groups R^ contain straight or branched chain alkyl groups suitably having from 1 to 6 carbon atoms. Particular haloalkyl groups are di-or trihalomethyl groups, such as trifluoromethyl or difluoromethyl or pentahaloethyl groups such as pentafluoroethyl.

A preferred sub-groups of compounds of formula (I) are compounds of formula (IA) . CFo—(\ /> N M R (IA) where one of R^' or R2' is halo and the other is halo in particular fluorine, chlorine or bromine or nitro; R^1 is hydrogen or halogen in particular chlorine or bromine; and R®' is trifluoromethyl or pentafluoroethyl. 236 96 8 Examples of compounds of formula (I) are set out in Table I below.

TABLE I COMPOUND NO.

R1 R2 CO R4 R5 R6 1 CI Cl H H H cf3 2 CI no2 H H H cf3 3 no2 NO 2 H H H cf3 4 F Cl H H H cf3 Br Cl H H H cf3 6 Br Br H H H cf3 7 CI NO 2 H H F cf3 8 CI no2 H H Br cf3 9 CI Cl H H Br cf3 . 10 CI I H H H cf3 11 F F H H H cf3 12 CL no2 H H Cl cf3 13 CI Cl H H Cl cf3 14 CI no2 H H I cf3 no2 NO 2 H H Br cf3 16 no2 no2 Cl H H cf3 17 CI NO 2 H H H c2f5 18 CI Cl H H H C2F5 19 F Cl H H Br cf3 F no2 H H H cf3 21 no2 Br H H H cf3 22 F Cl H H Cl cf3 23 F F H H Br cf3 236 96 8 o TABLE I (contd.) COMPOUND NO.

R1 R2 R3 R4 R5 R6 24 no2 no2 H H Cl cf3 Br no2 H H Cl cf3 26 Br no2 H H Br cf3 27 Cl no2 H H CN CF3 28 Cl Cl H H CN cf3 29 Cl no2 H H Br c2f5 Cl Br H H Br cf3 31 Br Br H H Cl cf3 32 Br Br H H Br cf3 33 Cl Cl H H Br c2f5 34 Cl Br H H Cl cf3 * Cl Cl H H H Cl 36 Cl no2 H H H Cl 37 Cl no2 H H Cl c2f5 00 ro i F Cl H H H C2F5 39 F F H H Cl cf3 40 F Cl H H Br C2F5 41 Cl no2 H H H cf2h 42 Cl Br H H H c2f5 43 Cl Br H H Br C2F5 44 Br no2 H H H C2F5 45 Br Br H H H C2F5 46 Cl Cl H H Cl C2F5 47 Br Br H H Br c2f5 Compounds of formula (I) can be prepared by reacting a compound of formula (II) wherein R1, R2, R3 and R4 are as defined in relation to formula (I) and r'' is a leaving group; with a compound of formula (III) wherein R-* and R® are as defined in relation to formula (I); and thereafter if desired carrying out one or more of the following steps: (i) converting the group R^ where it is hydrogen, to different group R-*; or (ii) converting a group R-*-, R2, R3 or R4 to a different such group.

The reaction is suitably carried out in the presence of a solvent and a base. The base may be for example an alkali metal hydride, an alkali metal alkoxide or an alkali metal carbonate, and the solvent may be a hydrocarbon solvent, such as petroleum ether, an alcohol or an aprotic polar solvent such as dimethylformamide or dimethylacetamide.

Suitable leaving groups R-? include halo groups such as fluoro, chloro, bromo or iodo. r> 236 96 8 f"") If necessary an appropriate catalyst such as a 'Vr"' crown ether or copper can be added depending upon the precise nature of R^. Further details of the processes for preparation of the compounds may be 5 ascertaned from the Examples set out hereinafter.

Conversion of the group R5 from hydrogen into a halogen group such as bromine or chloro as in optional step (i) above can be carried out by reacting the compound of formula (I) where R^ is 10 hydrogen with a halogen such as bromine in the presence of a base such as sodium acetate. The reaction is suitably carried out in an organic solvent such as acetic acid at moderate temperatures of from 0 - 50°C, conveniently at ambient 15 temperature.

Alternatively the conversion can be carried out using other known halocjenat ing agents such as N-bromosuccinimide or N-chlorosuccinimide in an organic solvent such as acetonitrile or dimethylformamide. 20 Suitably elevated temperatures of from 60 to 100 °C are employed.

Optional step (ii) above may also be carried out by conventional means. For example compounds of formula (I) wherein R-*- and/or R2 is nitro can be 25 converted to the corresponding compound of formula (I) wherein R1 and/or R2 is halo by reduction of the nitro groups to an amino group to form a compound of formula (IV): (IV) n O o o wherein R3, R4, R^ and R^ are as defined in relation to formula (I) and R® and R^ are amino or a group R^ or R2 as defined in relation to formula (I) provided that at least one of R® or R^ is amino; and 5 thereafter converting the amino group R® and/or R^ to halo.

Compounds of formula (IV) are novel and as such form a further aspect of the invention of New Zealand Patent Specification No. 228782.

Reduction of the nitro groups to form a compound 10 of formula (IV) can be carried out by reacting the compound with a reducing agent such as stannous chloride in acid conditions, for example in a solution in concentrated hydrochloride acid.

Moderate temperatures of from 2 to 45 °C are 15 suitably employed.

Subsequent halogenation may be carried out by reaction with t-butylnitrite and a copper halide salt such as copper (I)iodide. This step is suitably carried out in an organic solvent such as 20 acetonitrile at low temperatures of from -20° to +20°C preferably at about 0°C.

Compounds of formula (III) can be prepared by reacting a compound of formula (V) (V) wherein R^® is hydrogen or C^_4 alkyl such as ethyl 25 with Raney Nickel in an appropriate solvent such as aqueous ammonia. 1/,A, 23 6 9 Compounds of formula (V) are either known compounds or they can be prepared from known compounds by known methods (see for example A Giner-Sorolla, A Bendick: J. Am. Chem, Soc, 1958, 5 80, 5744).

Some compounds of formula (II), (III) and (V) are novel and these form a further aspect of the invention of New Zealand Patent Specification No. 228782. According to the present invention there is provided a compound of 10 formula (IIA) (IIA) wherein R^ is chlorine, R-1-2 is fluorine and R13 is iodine, or R-^ is nitro, R12 is bromo and R"'"3 is bromo.

The compound of formula (IIA) where R^ is 15 chlorine, R^-2 is fluorine and R13 is iodine can be prepared from the compound of formula (II) where R-*-is chlorine, R2 is nitro, R^ is fluorine and R3 and R4 are hydrogen by reduction of the group R2 to amino and subsequent halogenating to the desired compound of formula IIA using methods analogous to those 20 described above in relation to optional step (ii) for the preparation of the compounds of formula (I).

The intermediate compound of formula (VI): CF- (VI) n 236 9 6 8 is novel and forms a further aspect of the invention of f) New Zealand Patent Specification No. 228782. • •wf Novel compounds of formula (III) are compounds of formula (IIIA) O H N ) Ra* (IIIA) wherein R13 is hydrogen, halogen or cyano and R14 is 5 halo or haloalkyl with the proviso that (a) when R^3 is cyano, R^4 is other than chlorine; (b) R^3 and R^4 are not both halo; (c) when 3 is halo, R^4 is other than monof luoromethyl; and (d) when R^3 is hydrogen, R14 is not halo or a halomethyl group. 10 A particular example of R^4 is pentafluoroethyl.

Compounds of formula (IIIA) can be prepared by various routes including preparation from the ^ appropriate compound of formula (V) as described above. Alternatively the compound of formula (IIIA) can be prepared from the appropriate compound of formula (III) where R^ is hydrogen by halogenation using for example conditions similar to those ^ C described above in relation to the conversion of R 20 from hydrogen to halogen. Compounds of formula (IIIA) where R13 is cyano can be prepared by reacting a compound of formula (III) where R^ is bromine with a cyanide salt such as copper (I) cyanide in an organic solvent such as quinoline at elevated 25 temperature of from 200 to 250 °C.

Novel compouds of formula (V) are compounds of formula (VA): n 236 9 6 8 O (VA) wherein is as defined in relation to formula (V), R15 is cyano and R16 is as defined in relation to formula (V) or is hydrogen or halogen other than fluorine and R16 is pentafluoroethyl or difluoromethyl.

Compounds of formula (VA) can be prepared by reacting a compound of formula (VII): R16 | OR17 (VII) r!5 wherein R^ and R^® are as defined in relation to formula (VA) and R17 is a C1_6 alkyl group with thiourea or an appropriate alkylated derivative thereof in the presence of a strong base such as an alkali metal alkoxide such as sodium methoxide. Elevated temperatures of from 60 °C to 90 °C are suitably employed.

Other compounds of formula (II), (III) and (V) and compounds of formula (VII) are either known compounds or they can be prepared from known compounds by conventional methods.

The compounds of formula (I) may be used to combat and control infestations of insect pests and o o 0 3 • ...-yvy, 236 9 - li - also other invertebrate pests, for example, acarine pests. The insect and acarine pests which may be combatted and controlled by the use of the invention compounds include those pests associated with 5 agriculture (which term includes the growing of crops for food and fibre products), horticulture and animal husbandry, forestry, the storage ?f products of vegetable origin, such as fruit, grain and timber, and also those pests associated with the transmission 10 of diseases of man and animals.

Compounds of formula (I) are particularly useful against public health pests such as cockroaches and houseflies.

In order to apply the compounds to the locus of 15 the pests they are usually formulated into compositions which include in addition to the insecticidally active ingredient or ingredients of formula I suitable inert -diluent or carrier materials, and/or surface active agents. The 20 compositions may also comprise another pesticidal material, for example another insecticide or acaricide, or a fungicide, or may also comprise an insecticide synergist, such as for example dodecyl imidazole, safroxan, or piperonyl butoxide. 25 The compositions may be in the form of dusting powders wherein the active ingredient is mixed with a solid diluent or carrier, for example kaolin, bentonite, kieselguhr, or talc, or they may be in the form of granules, wherein the active ingredient is 30 absorbed in a porous granular material for example pumice.

Alternatively the compositions may be in the form of liquid preparations to be used as dips or 236 96 8 O sprays, which are generally aqueous dispersions or . emulsions of the active ingredient in the presence of one or-more known wetting agents, dispersing agents or emulsifying agents (surface active agents).

Wetting agents, dispersing agents and emulsifying agents may be of the cationic, anionic or non-ionic type. Suitable agents of the cationic type include, for example, quaternary ammonium compounds, for example cetyltrimethyl ammonium bromide. 10 Suitable agents of the anionic type include, for example, soaps, salts of aliphatic monoesters of sulphuric acid, for example sodium lauryl sulphate, salts of sulphonated aromatic compounds, for example sodium dodecylbenzenesulphonate, sodium, calcium or 15 ammonium lignosulphonate, or butylnaphthalene sulphonate, and a mixture of the sodium salts of diisopropyl- and triisopropylnaphthalene sulphonates. Suitable agents of the non-ionic type include, for example, the condensation products of ethylene oxide 20 with fatty alcohols such as oleyl alcohol or cetyl alcohol, or with alkyl phenols such as octyl phenol, nonyl phenol and octyl cresol. Other non-ionic agents are the partial esters derived from long chain fatty acids and hexitol anhydrides, the condensation 25 products of the said partial esters with ethylene oxide, and the lecithins.

The compositions may be prepared by dissolving the active ingredient in a suitable solvent, for example, a ketonic solvent such as diacetone alcohol, 30 or an aromatic solvent such as trimethylbenzene and adding the mixture so obtained to water which may contain one or more known wetting, dispersing or emulsifying agents.

Other suitable organic solvents are dimethyl O <« n 23696 O formamide, ethylene dichloride, isopropyl alcohol, propylene glycol and other glycols, diacetone alcohol, toluene, kerosene, white oil, methylnaphthalene, xylenes and trichloroethylene, 5 N-methyl-2-pyrrolidone and tetrahydrofurfury1 alcohol Q (THFA)- The compositions which are to be used in the form of aqueous dispersions or emulsions are generally supplied in the form of a concentrate 10 containing a high proportion of the active ingredient or ingredients, the said concentrate to be diluted with water before use. These concentrates are often required to withstand storage for prolonged periods and after such storage, to be capable of dilution 15 with water to form aqueous preparations which remain homogenous for a sufficient time to enable them to be applied by conventional spray equipment. The concentrates may contain 10-85% by weight of the active ingredient or ingredients. When diluted to 20 form_aqueous preparations such preparations may contain varying amounts of the active ingredient depending upon the purpose for which they are to be . used. For agricultural or horticultural purposes, an aqueous preparation containing between 0.0001% and 25 0.1% by weight of the active ingredient (approximately equivalent to from 5-2000g/ha) is particularly useful.

In use the compositions are applied to the pests, to the locus of the pests, to the habitat of 30 the pests, or to growing plants liable to infestation by the pests, by any of the known means of applying pesticidal compositions, for example, by dusting or spraying.

The compounds of the invention may be the sole . +sa*r*> - v 236 9 o active ingredient of the composition or they may be admixed with one or more additional active ingredients such as insecticides, insecticide synergists, herbicides, fungicides or plant growth 5 regulators where appropriate.

Suitable additional active ingredients for inclusion in admixture with the compounds of the invention may be compounds which will broaden the spectrum of activity of the compounds of the invention or 10 increase their persistence in the location of the pest. They may synergise the activity of the compound of the invention or complement the activity for example by increasing the speed of effect, improving knockdown or overcoming repellency. 15 Additionally multi-component mixtures of this type may help to overcome or prevent the development of resistance to individual components.

The particular insecticide, herbicide or fungicide included in the mixture will depend upon its intended 20 utility and the type of complementary action required. Examples of suitable insecticides include the following: a) Pyrethroids such as permethrin, esfenvalerate, deltamethrin, cyhalothrin in particular lamda-25 cyhalothrin, biphenthrin, fenpropathrin, cyfluthrin, tefluthrin, fish safe pyrethroids for example etofenprox, natural pyrethrin, tetramethrin, s-bioallethrin, fenfluthrin, prallethrin and 5-benzyl-3-furylmethyl-(E) 30 -(lR,3S)-2,2-dimethyl-3-(2-oxothiolan-3- ylidenemet'hyl) cyclopropane carboxylate; b) Organophosphates such as profenofos, sulprofos, n o 236968 methyl parathion, azinphos-methyl, demeton-s-methyl, heptenophos, thiometon, fenamiphos, monocrotophos, profenophos, triazophos, methamidophos, dimethoate, 5 phosphamidon, malathion, chloropyrifos, /O) phosalone, fensulfothion, fonofos, phorate, phoxim, pyrimiphos-methyl, fenitrothion or diazionon; c) Carbamates (including aryl carbamates) such as 10 pirimicarb, cloethocarb, carbofuran, ethiofencarb, aldicarb, thiofurox, carbosulfan, beniocarb, fenobucarb, propoxur or oxamyl; d) Benzoyl ureas such as triflumeron, or chlorofluazuron; e) Organic tin compounds such as cyhexatin, fenbutatin oxide, azocyclotin; f) Macrolides such as avermectins or milbemyins, for example such as avamectin, avermectin, and milbemycin; g) Hormones such as pheromones; h) Organochlorine compounds such as benzene hexachloride, DDT, chlordane or dieldrin. i) Amidines, such as chlordimeform or amitraz.

In addition to the major chemical classes of 25 insecticide listed above, other insecticides having particular targets may be employed in the mixture if 236 9 6 -Inappropriate for the intended utility of the mixture. For instance selective insecticides for particular crops, for example stemborer specific insecticides for use in rice such as cartap or buprofezin can be 5 employed. Alternatively insecticides specific for particular insect species/stages for example ovo-larvicides such as clofentezine, flubenzimine, hexythiazox and tetradifon, moltilicides such as dicofol or propargite, acaricides such as 10 bromopropylate, chlorobenzilate, or growth regulators such as hydramethylon, cyromazin, methoprene, chlorofluazuron and diflubenzuron may also be included in the compositions.

Examples of suitable insecticide synergists for 15 use in the compositions include piperonyl butoxide, sesamax, and dodecyl imidazole.

Suitable herbicides', fungicides and plant-growth regulators for inclusion in the compositions will depend upon the intended target and the effect 20 required.

An example of a rice selective herbicides which can be included is propanil, an example of a plant growth regulator for use in cotton is "Pix", and examples of fungicides for use in rice include blasticides such 25 as blasticidin-S.

The ratio of the compound of the invention of New Zealand Patent Specification No. 228782 to the other active ingredient in the composition will depend upon a number of factors including type of target, effect required from the mixture etc.

However in general, the additional active ingredient of the composition will be applied at about the rate as it is usually employed, or at a slightly lower rate if synergism occurs.

The compounds of formula I and compositions O o o Q 2 36 9 comprising them have shown themselves active against a variety of insect and other invertebrate pests.

They are particularly useful in controlling public health pests such as flies and cockroaches. They may 5 also be active against organophosphate and pyrethroid resistant strains of pests such as houseflies (Musca domestica). They may be effective in combating both susceptible and resistant strains of the pests in their adult, larval and intermediate stages of 10 growth, and may be applied to the infested host animal by topical, oral or parenteral administration.

The following Preparations and Examples are given by way of illustration.

Preparation 1 This description illustrates the preparation of 4-pentafluoroethyl-2-thiouraci1.

Thiourea (3g) was added to a solution of sodium methoxide in methanol (previously prepared by adding 20 sodium metal (1.089g) to dry methanol (20ml)). This was followed by ethyl pentafluoropropionyl acetate (9.61g) and the reaction mixture was heated under reflux for 3 days. After cooling the solvent was evaporated, i_n vacuo, to give a brown solid, which 25 was acidified with dilute aqueous hydrochloric acid and extracted with diethyl ether. The combined organic extracts were dried, and removal of the solvent by evaporation, under reduced pressure, gave 4-pentafluoroethyl-2-thiouracil (4.14g), which was 30 immediately carried to the next stage; ■H NMR£(CDCl3) 12.3 (1H, brs), 11.65 (1H, brs) and 6.2(lH,s). o 8 n K£NU"Si" o Preparation 2 This description illustrates the preparation of 4-pentafluoroethylpyr imidin-6-one.

Raney Nickel (0.83g, of a 50% dispersion in 0 5 water) was added to a suspension of 4-pentafluoroethyl-2-thiouracil (0.5g) in a mixture of concentrated aqueous ammonia (0.23ml) in water (6ml). The reaction mixture was heated to reflux for 5.5 hours, cooled, stood overnight, and filtered hot 10 through hyflo. The filterate was concentrated by evaporation of the solvent under reduced pressure to give the desired compound as a pale green solid. Sublimation (100°C, 0.1 mbar) gave 4-pentafluoroethylpyrimidin-6-one as a white solid mpt 15 122-126 °C; •H NMR S" (CDCI3) 13.05 (1H, brs) 8.30 (lH,s) and 6.94 (1H,s ) .

Preparation 3 This description illustrates the preparation of 20 5-bromo-4-trifluoromethylpyrimidin-6-one.

Bromine (4.62g) was added in one portion to a stirred solution of 4-trifluoromethylpyrimidin-6-one (4.3g) and sodium acetate (10.53g) in acetic acid (43ml). After stirring for 2 hours, the reaction 25 mixture was left to stand for a period of 3 days, after which time it was heated to 80°C for 1 hour. After cooling to the ambient temperature (ca 22°C), the solvent was evaporated under reduced pressure. The resultant orange solid was dissolved in ethyl o o o 0 0 ..... 236968 acetate, and washed several times with water. The combined aqueous washings were extracted with ethylacetate, and the combined organic layers were washed with aqueous sodium thiosulphate 5 solution, followed by aqueous sodium bicarbonate solution and brine. After drying over magnesium sulphate, evaporation of the solvent under reduced pressure gave 5-bromo-4-trifluoromethylpyrimidin-6-one as a white solid (4.8g, mpt 226-227°C); 'H NMR£(CDC13 ) , 8 . 0 5(S); 19F NMR S(CDCI3), -67.4(s).

Preparation 4 \ This description illustrates the preparation of -iodo-4-trifluoromethylpyrimidin-6-one.

N-Iodosuccinimide (2.75g) was added to a stirred suspension of 4-trifluoromethylpyrimidin-6-one (lg) in dry acetonitrile (13ml). The reaction mixture was stirred at the ambient temperature for 2 hours, and then heated under reflux for 10 hours. After : cooling, removal of the solvent .under reduced 20 pressure gave a brown solid which was recrystallised from water to give 5-iodo-4-trifluoromethylpyrimidin- 6-one as a pale orange solid (150mg); j •H NMR5(CDCl3 + 3 drops DMSO) 13.5 (1H, brs) and j 8.00 (lH,s). j Preparation 5 I __ ^ s» T 3 This description illustrates the preparation of f -chloro-4-t r if luoromethylpyr imidin-6-one . ■> N-chlorosuccinimide (6.56g) was added to a ? stirred suspension of 4-trifluoromethylpyrimidin-6- I H \ one (4g) in dry acetonitrile (50ml), and the mixture heated under reflux for 17 hours. After cooling, the the solvent was removed by evaporation under reduced pressure to give a white solid which was recrystallised from water (twice) to give 5-chloro-4-trifluoromethylpyrimidin-6-one as a white solid (1.06g, mpt 191-192°C) 'fl NMR £(CDC13 + 1 drop DMSO) 13.5 (1H, brs) and 8.05 (1H, d).

Preparation 6 This description illustrates the preparation of 5-cyano-4-trifluoromethylpyrimidin-6-one.

Copper(I)cyanide (80mg) was added to a solution of 5-bromo-4-trifluoromethylpyrimidin-6-one (150mg) in quinoline (5ml). The reaction mixture was then heated to the reflux temperature for a period of 3 hours. After cooling to the ambient temperature, the-reaction mixture was pured into dilute aqueous acetic acid, and extracted into ethyl acetate. After drying, evaporation of the solvent under reduced pressure gave a brown oil, which was subjected to chromatography on silica gel plates using ethylacetate containing acetic acid and water (250:5:1 by volume) as eluent. The desired fraction was collected, and the brown solid thus isolated was identified as a phenolic salt. This material was dissolved in ethanol, and acidified with ethanolic hydrogen chloride. Evaporation of the solvent under reduced pressure gave a brown solid which was dissolved in diethyl ether and filtered. Evaporation of the solvent under reduced pressure gave 5-cyano-4-trifluoromethyl-pyrimidin-6-one as a brown solid. n 2369 ^ IR (Nujol mall) 3100, 2920, 2235, 1730, 1700, 1680, 1600, 1440, 1330, 1210, 1160, 1130 and 958 cm"'; o 3 'H NMR^(DMSO) 8.70 (lH,s), 3.45 (1H, brs). Preparation 7 - This description illustrates the preparation of 3,4-difluoro-5-nitrotrifluoromethylbenzene.

A mixture of 4-chloro-3,5-dinitrotrifluoromethylbenzene (lOg) and dry potassium fluoride (4.3g) in dry dimethylformamide (25ml) was stirred 10 vigorously and heated to 100°C for 16 hours. After cooling to ambient temperature, further potassium fluoride (2.15g) was added, and the mixture was heated to 130°C for 2 days. After cooling, the reaction mixture was poured into water, and extracted 15 with diethyl ether. The organic layer was dried, filtered, and the solvent removed by evaporation, under reduced pressure. The residual oil was subjected to kugelrohr distillation under reduced pressure to give 3,4-difluoro-5-20 nitrotrifluoromethylbenzene containing dimethyl- formamide as a yellow oil, as the first distilling component (0.18g); 'H NMR (CDCI3) 8.2 (1H, m) and 7.83 (1H, m) . Preparation 8 This description illustrates the preparation of 3-amino-5-chloro-4-fluorotri fluoromethylbenzene.

-Chloro-4-fluoro-3-nitrotrifluoromethylbenzene (5Og) was added to a cooled (5°C) solution of o 23 6 9 6 stannous chloride (140g) in concentrated aqueous hydrochloric acid (187ml). After stirring for several hours at the ambient temperature (ca 22°C), the reaction mixture was stood overnight. After 5 basification by the addition of sodium hydroxide, the reaction mixture was extracted with ethyl acetate. The organic layer was washed with water, dried, and the solvent removed by evaporation under reduced pressure. The residual yellow oil was kugelrohr 10 distilled under reduced pressure to give 3-amino-5~ chloro-4-fluorotrifluoromethylbenzene (32g):bp. 105°C/11 mm Hg; 'H NMR S"(CDC13) 7.03 (1H, dq), 6.90 (1H, dq) . Preparation 9 This description illustrates the preparation of 3-chloro-4-fluoro-5-iodotrifluoromethylbenzene. 3-Amino-5-chloro-4-fluorotrifluoromethylbenzene (lOg) was added dropwise to a stirred suspension of t-butylnitrite (25g) and copper (I) 20 iodide (9g) in dry acetonitrile (185ml) whilst the temperature was maintained at 0°C. After the addition was complete the stirred reaction mixture was kept at 0°C for a further 2 hours, after which it was allowed to warm to ambient temperature. After the addition 25 of dilute aqueous hydrochloric acid, the reaction mixture was extracted into ether, the organic layer throughly washed with aqueous sodium metabisulphite solution, and dried over anhydrous magnesium sulphate. Removal of the solvent by evaporation 30 under reduced pressure gave a brown oil, which was 23 6 9 6 purified by chromotography on silica gel with a mixture of 5% ethyl acetate (by volume) in n-hexane as eluent. The first eluting component was collected to give 3-chloro-4-fluoro-5-5 iodotrifluoromethylbenzene as a pale yellow oil (5.6 6g); 'H NMRS(CDC13) 7.8 (1H , m) and 7.65 (1H, m); 19F NMR S(CDC13) -63.96 (3F, s) and -89.48 (IF, s).

Preparation 10 The following compound was prepared according to the general method of Preparation 3 from appropriate compounds of formula (III).

-Bromo-4-pentafluoroethylpyrimidin-6-one (mp. 165-166.5°C); 'H NMR £(CDC13) 13.6 (1H, brs) and 8.35 (1H, s).

Preparation 11 This description illustrates the preparation of 5-chloro-4-pentafluoroethylpyrimidin-6-one.

A solution of 4-pentafluoroethylpyrimidin-6-one 20 (0.4g) and N-chlorosuccinimide (0.27g) in dry dimethylformamide (5ml) was heated to 80°C for 3 hours. After cooling to ambient temperature, the reaction mixture was poured into water, and extracted into ethyl acetate. The organic layer was dried, 25 over anhydrous magnesium sulphate, filtered, and evaporation of the solvent under reduced pressure gave a brown oil. Recrystallisation from water gave 5-chloro-4-pentafluoroethylpyrimidin-6-one o 236 9 'H NMR S(CDCI3) 8.22 (s).

Preparation 12 This description illustrated the preparation of 4~di fluoromethylpyrimidin-6-one.

Thiourea was reacted with chloro-difluoro acetoacetate in the presence of sodium methoxide according to the manner illustrated in Preparation 1. The crude material so formed was then reacted with Raney nickel according to the manner illustrated in 10 Preparation 2. The orange product so formed was identified as a mixture of components, containing 75% (by G.L.C. analysis) of 4-difluoromethylpyrimidin-6-one.

"H NMR£(CDCl3 + 1 drop DMSO) 8.10 (1H, s), 6.70 15 (1H, s) and 6.38 (1H, t).

This material was used without further purification.

Preparation 13 This description illustrated the preparation of 20 3,4-dibromo-5-nitrotrifluoromethylbenzene. 4-Amino-3-bromo-5-nitrotrifluoromethylbenzene (lOg) in acetonitrile (7ml) was added dropwise to a stirred suspension of t-butylnitrite (18.6g) and copper (II) bromide (lOg) in dry acetonitrile (138 25 ml) whilst the temperature was maintained at 0°C.

After the addition was complete the stirred reaction mixture was kept at 0°C for a further 2 hours, after which time it was allowed to warm to ambient 23 6 9 6 temperature. The reaction mixture was poured into dilute aqueous hydrochloric acid and extracted into diethyl' ether. The organic layer was throughly washed with water and brine and dried over anhydrous magnesium sulphate. Filtration and evaporation of the solvent under reduced pressure gave a yellow oil which was subjected to kugelrohr distillation to give 3/4-dibromo-5-nitrotrifluoromethylbenzene as a yellow oil/ which solidified on cooling. B.p. 140°C at 15mm Hg).

•H NMR«g (CDC13) 8.10 (1H, d) and 7.90 (1H, d).

EXAMPLE 1 This Example illustrates the preparation of 1-(2,6-dichloro-4-trifluoromethyl)-4-trifluoromethylpyr imidin-6-one (Compound 1 in Table I).

A dry reaction flask was purged with nitrogen and charged with a 50% suspension of sodium hydride (1.6 g). The sodium hydride was washed with pentane and suspended in dimethylformamide (DMF, 20 ml). A solution of 6-trifluoromethylpyrimidin-4-one (5g) in DMF (30 ml) was added dropwise. When the addition was complete the reaction was stirred for a further fifteen minutes, then 3,5-dichloro-4-fluorobenzo-trifluoride (28 g) was added in one portion and the mixture heated at 100°C for six hours. The reaction mixture was allowed to cool, poured into brine, and extracted with ethyl acetate. The organic layer was washed with brine, dried over magnesium sulphate and evaporated in vacuo to give a brown residue which was purified by chromotography on silica gel using 20% diethyl ether/petrol as eluent to give (compound 1 in Table I) (812 mg). 236 9 'H NMRcT(CDC13) 8.0 (lH,s), 7.8 (2H,s)/ 7.0 (lH,s).

EXAMPLE 2 The following compounds were prepared according to the general method of Example 1 from appropriate 5 compounds of formula II and formula III. (a) 1-(2-Chloro-6-ni tro-4-trifluoromethylphenyl)-4-trifluoromethylpyrimidin-6-one (Compound 2 in Table I) mp. 149-150°C? "H NMR: T(CDCI3) 8.4 (lH,m), 8.2 (lH,m), 8.1 10 (1H,S), 7.0 (1H,s). (b) 1~(2-Fluoro-6-chloro-4-trifluoromethylphenyl) - 4-trifluoromethylpyrimidin-6-one (Compound 4 in" Table I).

•H NMR: ST (CDCI3) 8.08 (1H, s), 7.74 (1H, s), 15 " 7.55 (1H, d) , 6.98 (1H, s). (c) 1-(2-Bromo-6-chloro-4-trifluoromethylphenyl)-4-trifluoromethylpyrimidin-6-one (Compound 5 in Table I) mp. 172-174.8°C; 'H NMR: £(CDCI3) 8.03 (1H, s), 7.99 (1H, s), 20 7.84 (1H, s), 7.00 (1H, s). (d) 1-(2,6-Dibromo-4-trifluromethylphenyl)-4-trifluoromethylpyrimidin-6-one (Compound 6 in Table I) mp. 177.6-179.8°C 23 6 9 6 NMR: (CDCI3) 8*08 (2H' s)' 7,98 (1H' s) 7'00 (1H, s). (e) l-(2-Chloro-4-trifluoromethyl-6-nitrophenyl)-4-pentafluoroethylpyrimidin-6-one (Compound no 5 17 in Table I); except that the reaction was heated to 100°C for 4 hours. The compound showed a mp. 145-146.5°C; •H NMR(T(CDC13) 8.45 (1H, s), 8.21 (1H, s), 8.11 (1H, s) and 7.02 (1H, s). (f) 1—(2,6-Dichloro-4-trifluoromethylphenyl)-4- pentafluoroethylpyrimidin-6-one (Compound 18 in Table I); except that the reaction was heated to 100°C for 16 hours. The compound showed mp. 168.7-169.8°C; 'H NMRcT(CDCl3) 8.00 (1H, s), 7.82 (2H, s) and 7.05 (1H, s). (g) l-(2,6-Difluoro-4-trifluoromethylphenyl)-4- trifluoromethylpyrimidin-6-one (Compound 11 in Table I); except that a four fold excess of aryl 20 fluoride was used, and the reaction mixture was heated at 90°C for 36 hours.

•H NMR£~(CDC13) 8.12 (1H, s), 7.48 (2H, d) and 6.98 (1H,s). (h) l-(2-Chloro-6-iodo-4-trifluoromethylphenyl) 25 4-trifluoromethylpyrimidin-6-one (Compound 10 in Table I); except that the reaction was heated to 90°C for 16 hours. . , 23 6 9 6 n 'H NMR^(CDC13) 8.15 (s, 1H), 7.95 (s, 1H), 7.85 ** (S, 1H) and 7.0 (s, 1H); 19F NMR?(CDC13) -63.6 (3F/ s) and -72.0 (3F, s). (i) 1-(2-Fluoro-6-ni tro-4-trifluoromethylphenyl) 5 -4-trifluoromethylpyrimidin-6-one (Compound 20 in Table I); except that the reaction mixture was maintained at the ambient temperature for 2 hours. The compound showed mp. 147-151°C.

'H NMR/(CDC13) 8.38 (1H, s), 8.37 (1H, s); 7.97 10 1H, d) and 6.98 (1H, s) . (j) l-(2-Bromo-6-nitro-4-trifluoromethylphenyl) -4-trifluoromethylpyrimidin-6-one (Compound 21 in Table I); except that the reaction was heated at 75°C for 16 hours. The compound showed mp.' 15 128-130 °C.

'H NMRcT(CDCl3) 8.45 (1H, d), 8.35 (1H, d), 8.10_ (1H, s) and 6.95 (1H, s) . In this Example R7 in formula (II) represents bromine. (k) l-(2,6-Dichloro-4-trifluoromethylphenyl)-5-bromo-4-trifluoromethylpyrimidin-6-one (Compound 9 in Table I); except that the reaction mixture was heated 75°C for 6 hours, followed by heating at 90°C for 24 hours. The 25 compound showed mp. 167-168°C.

'H NMR cT(CDCl3) 7.95 (1H, 19F NMR f(CDC13) 67.45 (3F, s). s ) and 7.82 (2H, s); -63.80 (3F, s) and - o o 3 © 2 3 6 9 6 8 (1) 1-(2,6-Dinitro-4-trifluoromethylphenyl)-5-bromo-4-trifluoromethylpyrimidin-6-one (Compound 15 in Table I); except that the reaction mixture was maintained at ambient 5 temperature for 16 hours. The compound showed mp. 199.5-202°C.

'H NMR ^ (CDCI3) 8.8 (2H, s) and 8.45 (1H, s). (m) l-(2,Chloro-6-nitro-4-trifluoromethyl)-5-chloro-4-trifluoromethylpyrimidin-6-one (compound 12 10 in Table I); except that the reaction mixture was stirred at the ambient temperature for 2 hours. The compound showed mp 145-147°C.

'H NMR S(CDC13) 7.95 (1H, s) and 7.85 (2H, s).. (o) 1-(2-bromo-6-nitro-4-trifluoromethylphenyl)-5-chloro-4-trifluoromethylpyrimidin-6-one (compound 25 in Table I); except that the reaction mixture was heated to 90°C for 5 hours 25 The compound showed mp. 136.5-138°C.

*H NMRr(CDCl?) 8.5 (1H, s), 8.25 (1H, s) and I J I 8.2 (1H, s). | (n) l-(2,6-dichloro-4-trifluoromethyl)-5-chloro- | 4-trifluoromethylpyrimidin-6-one (Compound 13 } $ in Table I); except that the reaction mixture | f was heated at 85°C for a period of 20 hours. | I The compound showed mp. 166-168°C. - f 'H NMR^(CDC13) 8.50 (1H, s), 8.38 (1H, s) and 8.02 (1H, s). In this example R7 in formula (II) represents bromine. . 23 6 9 6 O (p) 1-(2-chloro-6-fluoro-4-trifluoromethylphenyl)-5-chloro-4-trifluoromethylpyrimidin-6-one (compound 22 in Table I); except that the reaction mixture was heated to 90°C for 40 5 hours.

■H NMR^(CDC13) 8.98 (1H, s), 7.74 (1H, s) and 5.57 (1H, d). (q) 1-(2-Bromo-6-chloro-4-t rifluoromethyl)-5-chloro-4-trifluoromethylpyrimidin-6-one (Compound 34 in 10 Table I).

•H NMRJ"(CDC13) 8.00 (1H, s), 7.93 (1H, s), 7.88 (1H, s). (r) 1-(2,6-Dibromo-4-trifluoromethyl)-5-chloro-4- " trifluoromethylpyrimidin-6-one (Compound 31 in 15 Table I); except that the reaction mixture was heated at 90°C for 16 hours. The compound -showed mp. 160-161°C.

'H NMR r(CDCl3) 8.03 (2H, s), 7.91 (1H, s). (s) 1- (2-Br omo-6-chloro-4-tr if luoromethyl )-5-brorno-20 4-trifluoromethylpyrimidin-6-one (Compound 30 in Table I); except that the reaction mixture was heated to 85°C for 16 hours. The compound showed mp. 166-168°C.

'H NMR T(CDC13) 7.98 (1H, s), 7.92 (1H, s), 7.88 (1H, s). o 23 6 9 6 (t) 1-(2-Chloro-6-nitro-4-tr ifluoromethyl)-5-cyano-4-trifluoromethylpyrimidin-6-one (Compound 27 in Table I); except that the reaction mixture was maintained at the ambient temperature for 18 5 hours. The compound showed mp. 168.7-169.2°C.

■H NMRS(CDC13) 8.50 (1H, d), 8.26 (1H, s), 8.24 (1H, d). (u) l-(2,6-Dichloro-4-trifluoromethyl)-5-cyano-4-trifluoromethylpyrimidin-6-one (Compound 28 in 10 Table I); except that the reaction mixture was heated to 100°C for 23 hours.

'H NMR5(CDC13) 8.19 (1H, s), 7.85 (2H, s). (v) 1-(2,6-dichloro-4-trimethylfluorophenyl)-4- chloropyrimidin-6-one (compound 35 in Table 1); 15 except that the reaction mixture was heated to 90°C for 27 hours. The compound showed mp. 119.1-122°C .

•H NMR S (CDC13} 7.84 (1H, s); 7.80 (2H, s) and 6.7 (1H, s). (w) l-(2-chloro-6-fluoro-4-trifluoromethylphenyl)-4-pentafluoroethylpyrimidin-6-one (compound 38 in Table I); except that the reaction was heated to 90°C for 23 hours and a four fold excess of the aryl fluoride was used. The compound showed mp. 121-122.8°C.

•H NMR S"(CDC13) 8.05 (1H, s), 7.75 (1H, s), 7.58 (1H, dd) and 7.06 (1H, s). ■ 23 6 9 6 m o o o (x) 1-(2,6-Difluoro-4-trifluoromethyl)-5-chloro-4-trifluoromethylpyrimidin-6-one (compound no 39 in Table 1), except that the reaction mixture was heated to 90°C for 48 hours.

'H NMR£(CDC13) 8.05 (1H, s) and 7.5 (2H, d). (y) 1- ( 2-Brorno-6-chloro-4-t r if luoromethyl) - 4- pentafluoromethylpyrimidin-6-one (compound no 42 in Table 1), except that the reaction mixture was heated to 90°C for 16 hours. The compound 10 showed m.p. 172-173°C.

'H NMR S(CDC13) 8.00 (2H, brs), 7.88 (1H, s) and 7.08 (1H, s). (z) 1-(2,6-dibromo-4-trifluoromethyl)-4- pentafluoroethylpyrimidin-6-one (compound no 45 15 in Table 1) except that the reaction mixture was heated to 90°C for 16 hours. The compound "showed m.p. 175.8-176.2°C.

'H NMRS(CDC13) 8.05 (2H, s), 7.98 (1H, s) and 7.06 (1H, s). (aa) l-(2,6-dichloro-4-trifluoromethyl)-5-chloro-4- pentafluoromethylpyrimidin-6-one (compound no 46 in Table 1) except that the reaction mixture was heated to 90°C for 16 hours.

'H NMR <5 (CDC13) 7.9 (1H, s) and 7.82 (1H, s).

The product was shown by G.L.C. analysis is to contain 10% of 1-(2,6-dichloro-4- 2 3 6 9 trifluoromethy1-4-pentafluoroethylpyrimidin-6- one as an impurity.

EXAMPLE 3 This Example illustrates an alternative 5 preparation of 1-(2-Chloro-6-nitro-4-trifluoromethylphenyl )-4-trifluoromethylpyrimidin-6-one (Compound 2 in Table I).

A dry reaction flask was purged with nitrogen and charged with a 50% suspension of sodium hydride 10 (640mg). The sodium hydride was suspended in DMF (20ml). Solid 6-trifluoromethylpyrimidin-6-one (2g, 12mmol) was added portionwise, the mixture stirred for a further 10 minutes, and then 3-chloro-4-fluoro-5-nitrobenzotrifluoride (3.3g) was added in one 15 portion. The deep-red reaction mixture was vigorously stirred for ten minutes and then poured into water and extracted rigorously with ether. The _ combined ethereal layers were washed with water, then brine, and dried over magnesium sulphate. The solvent 20 was removed under reduced pressure to afford a yellow residue which was recrystallised from a mixture of ethyl acetate and hexane to give 1-(2-chloro-6-• nitro-4-trifluoromethylphenyl)-4-trifluoromethylpyrimidin-6-one as yellow crystals 25 (2.3g), mp 149-150°C, and NMR spectrum as before.

EXAMPLE 4 The following compounds were prepared according 23 6 9 6 to the general method of Example 3 from appropriate compounds of formula II and formula III. (a) 1-(2,6-Dinitro-4-trifluoromethylphenyl)-4- trifluoromethylpyrimidin-6-one (Compound 3 in Table I) mp 194-197.6°C.

'H NMR£(CDCl3) 8.82 (2H, s), 8.60 (1H, s), 6.95 (1H, s). (b) 1-(2-Chloro-4-nitro-4-trifluoromethylphenyl)-5-fluoro-4-trifluoromethylpyr imidin-6-one (Compound 7 in Table I).

'H NMR£(CDC13): 8.48 (1H, s), 8.24 (1H, s), 7.92 (1H, s). (c) 1-(2-Chloro-6-nitro-4-trifluoromethylphenyl)-5-bromo-4-trifluoromethylpyr imidin-6-one (Compound 8 in Table I) mp. 141-142°C •H NMR: £(CDC13): 8.45 (1H, s), 8.20 (2H, s), 8.05 (1H, s). (d) l-(2,6-dinitro-4-trifluoromethylphenyl)-5-chloro -4-trifluoromethylpyrimidin-6-one (Compound 24 Table I); except that the reaction mixture was maintained at room temperature for 16 hours.

The compound showed mp. 190-193°C.

•H NMR £ (CDC13 + 3 drops DMSO) 8.85 (2H, s) and 8.60 (1H, s). (e) 1-(2-chloro-6-nitro-4-trifluoromethylphenyl)-5- 23 6 9 6 iodo-4-trifluoromethylpyrimidin-6-one (Compound 14 Table I); except that the reaction mixture was maintained at room temperature for 1 hour. The compound showed mp. 151-153°C.

■H NMR S(CDCI3) 8.44 (1H fine d), 8.20 (1H, fine d) and 7.98 (1H, s). ( f) 1-(2-chloro-6-nitro-4-trifluoromethylphenyl)-4-chloropyrimidin-6-one (compound 36 in Table I); except that the reaction mixture was maintained at ambient termperature for 2 hours. The compound showed mp. 170.5-172.1°C.

'H NMRS(CDC13) 8.40 (1H, s); 8.20 (1H, s), 7.95 (1H, s) and 6.68 (1H, s). (g) 1- (2-chloro-6-nitro-.4-tr if luoromethylphenyl) -5-chloro-4-pentafluoroethylpyrimidin-6-one (compound no 37 in Table I); except that the reaction mixture was maintained at room temperature for 2 hours. The compound showed mp. 170-171.2°C.

'H NMR 5"(CDC13) 8.46 (1H, d), 8.22 (1H, d), 8.00 (1H, S). (h) 1-(2-Chloro-6-nitro-4-trifluoromethylphenyl)-4-difluoromethylpyrimidin-6-one (compound no 41 in Table I); except that the reaction mixture was maintained at ambient temperature for 1.5 hours. The compound showed mp. 130-132°C.

'H NMR S"(CDC13) 8.41 (1H, d), 8.19 (1H, d), 8.05 (1H, s), 6.90 (1H, s) and 6.47 (1H, t). r,,..

'-T' ■ i » ^ 236 96 (i) 1-(2-Bromo-6-nitro-4-tr ifluoromethyl)-4- pentafluoroethylpyrimidin-6-one (compound no 44 in Table I); except that the reaction mixture was maintained at ambient temperature for 1 hour. The compound showed m.p. 138-139°C.

'H NMRS(CDC13) 8.48 (1H, d), 8.38 (1H, d), 8.10 (1H, s) and 7.02 (1H, s).

O EXAMPLE 5 This Example illustrates the preparation of 10 1-(3-chloro-2,6-dinitro-4-trifluoromethylphenyl)-4-trifluromethylpyrimidin-6-one (Compound 16 in Table I.).

A mixture of 4-trffluoromethylpyrimidin-6-one (0.48g), 2,4-dichloro-3,5-dinitrotrifluorobenzene 15 (0.9g) and potassium carbonate (0.41g) in dry dimethylformamide (10ml) was vigorously stirred at ambient temperature for a period of 15 minutes. The reaction mixture was then poured into water/and extracted into ethyl acetate. After drying and 20 evaporation of the solvent, under reduced pressure, the residue was subjected to chromatography on silica gel using 30% (by volume) ethylacetate in petroleum ether (boiling range 60-80°C) as eluent. The required fractions were combined, and the solvent 25 removed under reduced pressure to give a yellow solid, which was then triturated with petroleum ether (boiling range 60-80°C). The solid was dissolved in boiling ethanol, filtered, and the solvent removed under reduced pressure. The residue was again 30 triturated with petroleum ether (boiling range r\ n 236 9 6 8 60-80°C) and finally recrystallised from petroleum ether (boiling range 60-80°C) containing ethylacetate (9% by-volume) to give 1-(3-chloro-2,6-dinitro-4-tr ifluoromethylphenyl) - 4-trifluoromethylpyrimidin-6-one as a yellow solid: 'H NMR S(CDCI3) 8.8 (1H, s), 8.1 (1H, s) and 6.95 (1H, s) .

EXAMPLE 6 This Example illustrates the preparation of 10 1-(2-Chloro-6-fluoro-4-trifluoromethyl)-5-bromo-4- trifluoromethylpyrimidin-6-one (Compound 19 in Table I ) .

-Chioro-3,4-difluorotrifluoromethylbenzene was reacted with 5-bromo-4-trifluoromethylpyrimidin-6-one 15 according to the procedure given in Example 1. The resultant product was then reacted with a mixture of bromine (O.leg) and sodium acetate (0.3 eg) in acetic acid for 16 hours. The reaction mixture was then poured into water, and extracted with ethyl acetate. 20 The organic layer was washed with aqueous sodium bicarbonate solution, followed by aqueous sodium thiosulphate solution and finally brine. After drying and filtration, evaporation of the solvent under reduced pressure gave 1-(2-chloro-6-fluoro-4-25 trifluoromethyl)-5-bromo-4-trifluoromethylpyrimidin-6-one as a pale orange solid mp. 122-125°C.

"H NMR S(CDC13)- 8.00 (1H, s); 7.74 (1H, s) and 7.55 (1H, d) . 2 3 6 9 6 8 EXAMPLE 7 This Example illustrates the preparation of l-(2,6-difluoro-4-tri fluoromethylphenyl)-5-bromo-4-trifluoromethylpyrimidin-6-one (compound 23 in Table 5 I) .

A solution of bromine (146mg) in acetic acid (lml) was added dropwise to a solution of compound 11 (in Table I) (285mg) and sodium acetate (204mg) in acetic acid (3ml). After stirring at the ambient 10 temperature for 16 hours, the solvent was removed by evaporation under reduced pressure and the residue dissolved in aqueous sodium bicarbonate solution. After extraction with ethyl acetate, the organic layer was washed with aqueous sodium thiosulphate 15 solution, dried and filtered, and concentrated under reduced pressure to give a pale yellow solid. Recrystallization from a mixture of ethyl acetate and petroleum ether (boiling range 60-80°C) gave l-(2,6-difluoro-4-trifluoromethylphenyl)-5-bromo-4-20 trifluoromethylpyrimidin-6-one; •H NMR £(CDCI3) 8.05 (1H, s) and 7.48 (2H, d).

EXAMPLE 8 The following compounds were prepared according to the general method of Example 7 from the 25 appropriate compounds of formula I. (a), l-(2-bromo-6-nitro-4-trifluoromethyl)-5-bromo-4-trifluoromethylpyrimidin-6-one (Compound 26 in Table I). The compound showed mp. 139-141°C. J r> 23 6 9 6 'H NMR S (CDC13) 8.50 (1H, m), 8.38 (1H, m) and 8.02 (1H, m). (b) 1-(2,6-Dichloro-4-trifluoromethyl)-5-bromo-4-pentafluoroethylpyrimidin-6-one (Compound 33 in O 5 Table I). The compound showed mp. 140.5- 141.5°C.

'H NMRS(CDC13) 7.92 (1H, s) and 7.83 (2H, s). (c) 1-(2-Chloro-6-fluoro-4-trifluoromethyl)-5-bromo-4-pentafluoroethylpyrimidin-6-one (compound no 40 in Table I). The compound showed mp. 94- 96 °C.

■H NMRS(CDC13) 8.00 (1H, s), 7.78 (1H, s) and 7.58 (1H, d). (d) 1-(2-Chloro-6-bromo-4-trifluoromethyl)-5-bromo-(2,) 15 . 4-pentaf luoroethylpyr imidin-6-one (compound no 43 in Table I). The compound showed mp. 148.5-149.5°C.

•H NMRS"(CDC13) 7.99 (1H, d), 7.90 (1H, s) and © 7.87 (1H, d). (e) 1-(2,6-dibromo-4-trifluoromethyl)-5-bromo-4- pentafluoroethylpyrimidin-6-one (compound no 47 in Table I). The compound showed mp. 158-159.5°C. 1 H NMRS'(CDC13) 8.02 (2H, s) and 7.90 (1H, s). (f) 1-(2,6-Dibromo-4-trifluoromethy1)-5-bromo-4- 23 6 9 trifluoromethylpyrimidin-6-one (compound 34 in Table I). The compound showed mp 163.5-164.5°C •H NMR S'(CDC13) 8.03 (2H, s), 7.92 (1H, s).

EXAMPLE 9 The following compound was prepared according to the general method of Example 6 from the appropriate compounds. (a) 1-(2-Chloro-6-nitro-4-tr i fluoromethyl)-5-bromo-4-pentafluoroethylpyrimidin-6-one (Compound 29 10 in Table I). The compound showed mp. 178-181°C.

'H NMR $ (CDCl^) 8.46 (1H, d), 8.21 (1H, d) and 8.02 (1H, s).

O EXAMPLE 10 This Example illustrates the insecticidal 15 properties of the compounds of formula (I).

The activity of the compounds was determined using a variety of insect pests. The compound was used in the form of liquid preparations containing 500 parts per million (ppm) by weight of the 20 compound. The preparations were made by dissolving ompound the cin acetone and diluting the solutions water with containing 0.01% by weight of a wetting sold agentunder the trade name "SYNPERONIC" NX until iquid the lpreparations contained the required 25 ntration of concethe Product. "SYNPERONIC" is a 2 3 6 9 Registered Trade Mark.

The test procedure adopted with regard to each pest was basically the same and comprised supporting a number of the pests on a medium which was usually a 5 host plant or a foodstuff on which the pests feed, and treating either or both the pests and the medium with the preparations. The mortality of the pests was then assessed at periods usually varying from one to three days after the treatment.

The results of the tests are given in Table II for the compounds, at the rate in parts per million given in the second column as a grading of mortality designated as 9, 5 or 0 wherein 9 indicates 80-100% mortality, 5 indicates 50-79% mortality and 0 indicates less than 50% mortality.

In Table III the pest organism used is designated by a letter code and the pest species, the support medium or food, and the type and duration of test is given.

In similar tests, certain compounds of formula (I) showed activity against Nephotettix Cincticeps (green leaf hopper-nymphs), Spodoptera exiqua (lesser army worm-larvae) and Heliothis virescens (tobacco budworm-larvae).

TABLE II COMPOUND RATE OF SPECIES APPLICATION MD BG PPm (see Table III) 1 500 9 9 2 500 9 9 4 500 9 9 500 9 9 6 500 9 9 8 500 0 5 9 500 9 500 9 9 11 500 9 9 12 500 0 9 13 500 9 9 14 500 9 9 500 0 17 500 9 9 18 500 9 9 19 500 9 9 500 9 9 21 500 9 9 22 500 9 9 23 500 0 9 500 9 26 500 9 5 27 500 9 9 28 500 9 9 29 500 0 5 fs ' ' '*'"■ ',* 236 9 6 8 43 - TABLE II (contd.) O COMPOUND RATE OF APPLICATION ppm SPECIES MD BG (see Table III) 500 0 9 31 500 0 9 32 500 0 9 33 500 0 9 34 500 0 9 37 500 9 9 38 500 9 9 39 500 9 9 40 500 9 9 41 500 9 0 42 500 9 9 43 500 9 9 44 500 9 9 45 500 9 9 46 500 9 9 47 500 9 9 A dash indicates not tested.

TABLE III CODE LETTERS (Table II) TEST SPECIES 1 SUPPORT MEDIUM/FOOD TYPE OF TEST DURATION (Days) BG Blattella gerraanica (Cockroach nymphs) Plastic pot Residual 3 MD Musca domestica (houseflies - adults) Cotton wool/ sugar Contact 1 "Contact" test indicates that both pests and medium were treated and "Residual" indicates that the medium was treated before infestation with the pests.

P34714MAIN CPR/VKM/OU 16/3/89 I 236968

Claims (2)

1. WHAT WE CLAIM IS: A compound of formula (IIA): wherein R^ is chlorine, R-*-2 is fluorine and R^3 is iodine? or R11 is nitro, R12 is bromo and R13 is bromo; or R11 is amino, R12 is fluoro and R^3 is chloro.
2. 2. A compound of formula (IIA) as defined in claim i substantially as hereinbefore described with reference to any example thereof. CH£fr\(O^L i fOTJUSrfcieS ?l£-.r.:s By fctfs/Their authorised Agent A.J. PARK & SON P6r;