GB2257970A - 4 - oxo - quinazolines and benzotriazines as herbicides - Google Patents

Abstract

A compound of formula: <IMAGE> in which Ar is an optionally substituted aryl or heterocyclic ring system; W is 0 or NR<1>; where R<1> is hydrogen or lower alkyl; <IMAGE> E is CR<3>R<3>XR<5>; X is (CH2)n, CH=CH, CH(OR6)CH2, COCH2; where n is 0, 1 or 2; R<2> is H, alkyl, haloalkyl, CN, halo or CO2R<7>; R<3> and R<4> are independently selected from H, optionally substituted alkyl, alkenyl or alkynyl, halogen, NR<8>R9, CR<10>R<11>C00R<12> or R<3> and R<4> together with the carbon to which they are attached form an optionally substituted alkenyl or cycloalkyl group; R<5> is CO2R<13>, CN, COR<13>, CH2OR<13>, CH(OH)R<13>, CH(OR<13>)R<14>, CSNH2, C0SR<13>, CSOR<13>, CONHSO2R<13>, C0NR<15>R<16>, CONHNR<13>R<16>, CONHN<+>R<13>R<15>R<16>R<x->, CO2-R<17+> or COON=CR<15>R<16>; R<6>, R<13> and R<14> are independently selected from H or an optionally substituted alkyl, aryl, alkenyl or alkynyl group; R<8>, R<9>, R<15>, R<16>, are independently selected from H or an optionally substituted alkyl, alkenyl, aryl or alkynyl group or any twos of R<8>, R<9>, R<15> and R<16> together with the atom to which they are attracted form a cycloalkyl or heterocyclic ring; R<7>, R<10> and R<11> are independently selected from is H or lower alkyl; and R<17+> is an agriculturally acceptable cation; and R<x-> is an agriculturally acceptable anion.

Description

HETEROCYCLIC COMPOUNDS The present invention relates to novel substituted fused ring systems, processes for their preparation, their use as herbicides and herbicidal compositions containing them.

UK Patent Application No 2189238 A describes certain benzheterocyclyl-phenyl ether derivatives which have herbicidal activity.

According to the present invention there is provided a compound of formula (I) in which Ar is an optionally substituted aryl or heterocyclic ring system; W is O or NR1; where R1 is hydogen or lower alkyl;

E is CR R4XR5; X is (CH2)n, CH=CH, CH(OR6)CH2, COCH2; where n is 0, 1 or 2; R is H, alkyl, haloalkyl, CN, halo or CO2R7 R3 and R4 are independently selected from H, optionally substituted alkyl, alkenyl or alkynyl, halogen, NR8R9, CR10RCOOR or R3 and R4 together with the carbon to which they are attached form an optionally substituted alkenyl or cycloalkyl group; R5 is CO2R , CN, COR , CH2OR , CH(OH)R , CH(OR )R14, CSNH2, COSR , CSOR , CONHSO2R , CONR14R16, CONHNR15R16, CONHN+R R15R16Rx-, CO2-R17+or COON=CR15R16; 6 12 13 14 R6, R12, R13 and R14 are independently selected from H or an optionally substituted alkyl, aryl, alkenyl or alkynyl group; R8, R9, R15 R16 are independently selected from H or an optionally substituted alkyl, alkenyl, aryl or alkynyl group or any two of R8, R9, R15 and R16 together with the atom to which they are attached form a cycloalkyl or heterocyclic ring; R7, R10 and R11 are independently selected from is H or lower alkyl; and R17+ is an agriculturally acceptable cation; and RX is an agriculturally acceptable anion.

As used herein the term "alkyl" includes straight or branched chains containing up to 10 carbon atoms preferably from 1 to 6 carbon atoms. The term "lower" used in relation to alkyl, alkenyl or alkynyl groups means that the group contains up to 3 carbon atoms. The terms "alkenyl and "alkynyl" refer to unsaturated straight or branched chains having from 2 to 10 and preferably from 2 to 6 carbon atoms. The term "cycloalkyl" includes rings containing from 3 to 9 carbon atoms, preferably from 3 to 6 carbon atoms. The term "alkoxy" includes straight or branched chains containing up to 10 carbon atoms preferably from 1 to 6 carbon atoms.

The term "haloalkyl" and "haloalkoxy" refer to alkyl and alkoxy groups respectively substituted by at least one halogen atom such as fluorine, chlorine or bromine. A particular haloalkyl group is trifluoromethyl. The term "aryl" includes phenyl and naphthyl. The term "heterocyclic" includes rings of up to 10 atoms, preferably up to 6 atoms up to 3 of which are selected from oxygen, nitrogen or sulphur. The term halogen includes fluorine, chlorine, bromine and iodine.

A suitable aryl ring system is phenyl.

Suitable heterocyclic ring systems for Ar are rings of up to 10 atoms, up to 3 of which are selected from oxygen, nitrogen or sulphur, preferably aromatic rings such as pyridine and pyrazole.

Suitable optional substitutents for the aryl or heterocyclic ring systems Ar and aryl groups R6, R8, R9, R, R , R14, R15 and R16 are up to 5 preferably up to 3 members selected from halogen (fluoro, chloro, bromo or iodo), lower alkyl, haloalkyl (for example CF3), haloalkoxy (for example OCF3), nitro, cyano, lower alkoxy (for example methoxy) or thioalkyl (for example thiomethyl, sulphinylmethyl and sulphonylmethyl).

Preferred positions of substitution when the aryl ring is a phenyl ring are the 2, 4 and 6 positions, particularly 2,4,6-tri- substituted rings with a trifluoromethyl group at the 4-position.

Preferred groups Ar are groups of sub-formula (i): where R20 is hydrogen or halo; J is N or CR where R is halo or cyano.

21 Preferably J is a group CR 21 Suitably halo groups tor R and R are fluorine and chlorine. Most preferably one of R20 or R is fluorine and the other is chlorine.

Examples of optional substituents for alkyl, alkenyl, alkynyl groups R6, R7 R9 R12 R13 R14 R15 and R16 include one or more groups selected from halo such as fluoro, chloro or bromo; nitro; nitrile; aryl such as phenyl; CO2R, NHCOR' or NHCH2CO2R Wherein R is hydrogen, C1-6 alkyl or an agriculturally acceptable cation and R' is hydrogen or C1-6 alkyl; C1-6 alkoxy; oxo; S(O) p R25 where p is 0, 1 or 2 and R25 is alkyl (fol example thiomethyl, sulphinylmethyl and sulphonylmethyl); amino; mono- or di- C alkylamino;CONR R24 wherein R and R24 are independently 22 selected from hydrogen,C1-6 alkyl,C2-6 alkenyl or C2-6 alkynyl or R and R23 are joined together to form a heterocyclic ring having up to 7 ring atoms 3 of which may be selected from oxygen, nitrogen or sulphur. An example of a heterocyclic substitutent is tetrahydrofuranyl.

Examples of agriculturally acceptable cations R17+ and R22 include sodium, potassium or calcium ions, sulphonium or sulphoxonium ions such as those of formula S(O)mR R15R16 where m is 0 or 1, or ammonium or tertiary ammonium ions of formula N+R R15R16R26 where R , R15 and R16 are as herein before defined and R26 is a group as defined for R .

Suitable substituents for alkyl, alkenyl or alkynyl groups R , R15, 16 26 R16 and R26in these cation include hydroxy and aryl. Suitably where any of are optionally substituted alkyl, they contain from 1 to 4 carbon atoms.

Particular examples of R13, R15, R16 and R26, in these cations are hydrogen, ethyl, isopropyl 2-hydroxyethyl and benzyl.

Examples of agriculturally acceptable anions Rx- include halide ions and sulphate ions.

Suitable halo groups R3, and R4 include fluorine, chlorine and bromine.

Suitable heterocyclic rings formed from two of R8, R9, R15 and R16 and the atom to which they are attached are pyrrolidine, piperidine and morpholine.

Preferably B is N or CH.

Preferably R is H.

Preferably R4 is H or is C1-3 alkyl, in particular methyl, or is CHRCOOR.

5 13 13 Preferably R5 is CO@R@@, CN or CONH@' especially CO2R13.

Preferred examples of R and R1 are optionally substituted C1-6 alkyl, especially methyl or ethyl.

R11 is preferably H or methyl, Ar is preferably optionally substituted phenyl.

W is preferably oxygen.

Preferably X is (CH2)n where n is zero or 1, especially zero.

The formula (I) given above is intended to include tautomeric forms of the structure drawn, as well as physically distinguishable modifications of the compounds which may arise, for example, from different ways in which the molecules are arranged in a crystal lattice, or from the inability of parts of the molecule to rotate freely in relation to other parts, or from geometrical isomerism, or from intra-molelcular or inter-molecular hydrogen bonding, or otherwise.

Some of the compounds of the invention can exist in enantiomeric forms. The invention includes both individual enantiomers and mixtures of the two in all proportions.

Particular examples of compounds according to the invention are set out in Table I below where RO, B and E relate to formula IA: TABLE 1 IA Compound RO B E No 1 F N CH2COOH 2 F N CH2COOCH3 3 F N CH2COOC2H5 4 F N CH(CH3)COOH 5 F N CH(CH3)COOCH3 6 F N CH(CH3)COOC2H5 7 F N CH(CH2COOH)COOH 8 F N CH(CH2COOCH3)COOCH3 9 F N CH(CH2COOC2H5)COOC2H5 10 H N CH2COOH 11 H N CH2COOCH3 12 H N CH2COOC2H5 13 H N CH(CH3)COOH 14 H N CH(CH3)COOCH3 15 H N CH(CH3)COOC2H5 16 H N CH(CH2COOH)COOH 17 H N CH(CH2COOCH3)COOCH3 18 H N CH(CH2COOC2H5)COOC2H5 19 F CH CH2COOH 20 F CH CH2COOCH3 21 F CH CH2COOC2H5 TABLE 1 (continued) Compound RO B E No 22 F CH CH(CH3)COOH 23 F CH CH(CH3)COOCH3 24 F CH CH(CH3)COOC2H5 25 F CH CH(CH2COOH)COOH 26 F CH CH(CH2COOCH3)COOCH3 27 F CH CH(CH2COOC2H5)COOC2H5 28 H CH CH2COOH 29 H CH CH2COOCH3 30 H CH CH2COOC2H5 31 H CH CH(CH3)COOH 32 H CH CH(CH3)COOCH3 33 H CH CH(CH3)COOC2H5 34 H CH CH(CH2COOH)COOH 35 H CH CH(CH2COOCH3)COOCH3 36 H CH CH(CH2COOC2H5)COOC2H5 37 H C-CH3 CH(CH3)COOCH3 38 H C-CF3 CH(CH3)COOCH3 39 H C-CF3 CH2COOC2H5 Compounds of formula (I) can be prepared by cyclisation of compounds of formula (II) wherein Ar, W and E are as defined in relation to formula (I) using a nitrite ion, provided for example by a nitrite salt such as sodium nitrite, in the presence of an acid such as a mineral acid, for example hydrochloric acid.

The reaction is suitably carried out in an aqueous solution at reduced temperature, for example of from 0 to 100C. Conveniently the reaction may be carried out at 3 to 50C and then allowed to warm to ambient temperature.

Compounds of formula (II) are prepared by reduction of the corresponding nitro compound of formula (III). A wide variety of reducing agents may be used and may be selected from the chemical literature by the skilled worker in the art. The reduction may be carried out for example by using sodium dithionite or tin and hydrochloric acid, iron and hydrochloric acid, or hydrogen with a palladium on charcoal catalyst. The reaction is preferably effected in an organic solvent such as a lower alcohol optionally mixed with water at temperatures of from 60 to 1000C.

Compounds of formula (III) are prepared from compounds of formula (IV): wherein Ar and W are as defined in relation to formula (I) by reaction with an amino acid or a lower alkyl ester therefore, which may be in the form of a salt, at 10 to 250C, conveniently at 20 C, in a suitable solvent such as DMF in the presence of a base such as triethylamine.

Compounds of formula (IV) are prepared from the corresponding carboxylic acid (V) by reaction with thionyl chloride at 60 to 800C.

Compounds of formula (V) are known compounds or can be prepared from known compounds by known methods.

Alternatively compounds of formula (I) may be prepared from compounds of formula (VI) where Ar, B and W are as defined in relation to formula (I) by reaction with a compound of formula (VII): where E is as defined in relation to formula (I) and Z is a leaving group optionally in the presence of a base.

Suitable leaving groups Z include halides, such as bromide and chloride, iodide and sulphonates such as methanesulphonate and p-toluenesulphonate.

Suitable bases for use in the reaction include alkali metal hydrides such as sodium hydride, and alkali metal carbonates and hydroxides such as potassium carbonate or sodium hydroxide.

The reaction is preferably carried out in an suitable organic solvent such as dimethylformamide, toluene, dimethylsulphoxide, a lower alkanol such as methanol or ethanol, or a lower alkyl ketone such as acetone.

Moderate temperatures, for example of from 20 to 700C are suitably employed. Conveniently the reaction is carried out at ambient temperature.

This reaction will produce a product consisting of a mixture of compounds of formula (I). These products can be separated by conventional techniques such as chromatography.

Compounds of formula (VI) can be prepared by cyclisation of compounds of formula (VIII) using the Borshe reaction.

Compounds of formula (VII) and (VIII) are known compounds or can be produced from known compounds by known methods.

If desired one or more of the following steps may be carried out to convert a compound of formula (I) to another such compound: i) when R5 is alkoxycarbonyl hydrolysing to the corresponding acid.

ii) when R5 is COOH esterifying or forming a salt, amide, sulphonamide, hydrazide or hydrazinium derivative.

iii) when R5 is an alcohol, oxidation to COOH, CHO.

iv) when R5 is alkoxycarbonyl, reduction to an alcohol.

v) when R5 is an amide, dehydration to the corresponding nitrile.

The compounds of formula (I) are active as herbicides and therefore, in a further aspect the invention provides a process for severely damaging or killing unwanted plants which process comprises applying to the plants, or to the growth medium of the plants, an effective amount of a compound of formula (I) as hereinbefore defined.

The compounds of formula (I) are active against a broad range of weed species including monocotyledenous and dicotyledonous species. They may show some selectivity towards certain species; they may be used as selective herbicides in rice and wheat crops.

The compounds of formula (I) may be applied directly to the plant (post-emergence application) or to the soil before the emergence of the plant (pre-emergence application). They are particularly useful when applied post-emergence.

The compounds of formula (I) may be used on their own to inhibit the growth of, severely damage, or kill plants but are preferbly used in the form of a composition comprising a compound of the invention in admixture with a carrier comprising a solid or liquid diluent.

Therefore, in yet a further aspect, the invention provides plant growth inhibiting, plant damaging, or plant killing compositions comprising a compound of formula (I) as hereinbefore defined and an inert carrier or diluent.

Compositions containing compounds of formula (I) include both dilute compositions, which are ready for immediate use, and concentrated compositions, which require to be diluted before use, usually with water.

Preferably the compositions contain from 0.01% to 90% by weight of the active ingredient. Dilute compositions ready for use preferably contain from 0.01% to 2% of active ingredient, while concentrated compositions may contain from 20% to 90% of active ingredient, although from 20% to 70% is usually preferred.

The solid compositions may be in the form of granules, or dusting powders wherein the active ingredient is mixed with a finely divided solid diluent, e.g. kaolin, bentonite, kieselguhr, dolomite, calcium carbonate, talc, powdered magnesia, Fuller's earth and gypsum. They may also be in the form of dispersible powders or grains, comprising a wetting agent to facilitate the dispersion of the powder or grains in liquid. Solid compositions in the form of a powder may be applied as foliar dusts.

Liquid compositions may comprise a solution or dispersion of an active ingredient in water optionally containing a surface-active agent, or may comprise a solution or dispersion of an active ingredient in a water-immiscible organic solvent which is dispersed as droplets in water.

Surface-active agents may be of the cationic, anionic, or non-ionic type or mixtures thereof. The cationic agents are, for example, quaternary ammonium compounds (e.g. cetyltrimethylammonium bromide). Suitable anionic agents are soaps; salts of aliphatic mono esters of sulphuric acid, for example sodium lauryl sulphate; and salts of sulphonated aromatic compounds, for example sodium dodecylbenzenesulphonate, sodium, calcium, and ammonium lignosulphonate, butylnaphthalene sulphonate, and a mixture of the sodium salts of diisopropyl and triisopropylnaphthalenesulphonic aid.

Suitable non-ionic agents are the condensation products of ethylene oxide with fatty alcohols such as oleyl alcohol and cetyl alcohol, or with alkylphenols such as octyl- or nonyl-phenol (e.g. Agral 90) or octyl-cresol. Other non-ionic agents are the partial esters derived from long chain fatty cids and hexitol anhydrides, for example sorbitan monolaurate; the condensation products of the partial ester with ethylene oxide; and the lecithins; silicone surface active agents (water soluble surface active agents having a skeleton which comprises a siloxane chain e.g. Silwet L77). A suitable mixture in mineral oil is Atplus 411F.

The aqueous solutions or dispersions may be prepared by dissolving the active ingredient in water or an organic solvent optionally containing wetting or dispersing agent(s) and then, when organic solvents are used, adding the mixture so obtained to water optionally containing wetting or dispersing agent(s). Suitable organic solvents include, for example, ethylene di-chloride, isopropyl alcohol, propylene glycol, diacetone alcohol, toluene, kerosene, methylnaphthalene, the xylenes and trichloroethylene.

The compositions for use in the form of aqueous solutions or dispersions are generally supplied in the form of a conentrate containing a high proportion of the active ingredient, and the concentrate is then diluted with water before use. The concentrates are usually required to withstand storage for prolonged periods and after such storage, to be capable of dilution with water to form aqueous preparations which remain homogenous for a sufficient time to enable them to be applied by conventional spray equipment. Concentrates conveniently contain 20-90%, preferably 20-70%, by weight of the active ingredient(s). Dilute preparations ready for use may contain varying amounts of the active ingredients(s) depending upon the intended purpose; amounts of 0.01% to 10.0% and preferably 0.1% to 2%, by weight of active ingredient(s) are normally used.

A preferred form of concentrated composition comprises the active ingredient which has been finely divided and which has been dispersed in water in the presence of a surface-active agent and a suspending agent.

Suitable suspending agents are hydrophilic colloids and include, for example, polyvinylpyrrolidone and sodium carboxymethylcellulose, and the vegetable gums, for example gum acacia and gum tragacanth. Preferred suspending agents are those which impart thixotropic properties to, and increase the viscosity of the concentrate. Examples of preferred suspending agents include hydrated colloidal mineral silicates, such as montmorillonite, beidellite, nontronite, hectorite, saponite, and suacorite. Bentonite is especially preferred. Other suspending agents include cellulose derivatives and polyvinyl alcohol.

The rate of application of the compounds of the invention will depend on a number of factors including, for example, the compound chosen for use, the identity of the plants whose growth is to be inhibited, the formulations selected for use and whether the compound is to be applied for foliage or root uptake. As a general guide, however, an application rate of from 0.01 to 20 kilograms per hectare is suitable while from 0.025 to 10 kilograms per hectare may be preferred.

The compositions of the invention may comprise, in addition to one or more compounds of the invention, one or more compounds not of the invention but which possess biological activity. Accordingly in yet a still further embodiment the invention provides a herbicidal composition comprising a mixture of at least one herbicidal compound of formula (I) as hereinbefore defined with at least one other herbicide.

The other herbicide may be any herbicide not having the formula (I).

It will generally be a herbicide having complementary action in the particular application.

Examples of useful complementary herbicides include: A. benzo-2,1,3-thiadiazin-4-one-2,2-dioxides such as bentazone; B. hormone herbicides, particularly the phenoxy alkanoic acids such as MCPA, MCPA-thioethyl, dichlorprop, 2,4,5-T, MCPB, 2,4-D, 2,4-DB, mecoprop, trichlopyr, clopyralid, and their derivatives (eg. salts, esters and amides); C. 1,3 dimethylpyrazole derivatives such as pyrazoxyfen, pyrazolate and benzofenap; D.Dinitrophenols and their derivatives (eg. acetates) such as dinoterb, dinoseb and its ester, dinoseb acetate; E. dinitroaniline herbicides such as dinitramine, trifluralin, ethalflurolin, pendimethalin, oryzalin; F. arylurea herbicides such as diuron, flumeturon, metoxuron, neburon, isoproturon, chlorotoluron, chloroxuron, linuron, monolinuron, chlorobromuron, daimuron, methabenzthiazuron; G. phenylcarbamoyloxyphenylcarbamates such as phenmedipham and desmedipham; H. 2-phenylpyridazin-3-ones such as chloridazon and norflurazon; I. uracil herbicides such as lenacil, bromacil and terbacil; J. triazine herbicides such as atrazine, simazine, aziprotryne, cyanazine, prometryn, dimethametryn, simetryne, and terbutryn; K. phosphorothioate herbicides such as piperophos, bensulide, and butamifos; ; L. thiolcarbamate herbicides such as cycloate, vernolate, molinate, * * thiobencarb, butylate , EPTC , tri-allate, di-allate, esprocarb, tiocarbazil, pyridate, and dimepiperate; M. 1,2,4-triazin-5-one herbicides such as metamitron and metribuzin; N. benzoic acid herbicides such as 2,3,6-TBA, dicamba and chloramben; 0. anilide herbicides such as pretilachlor, butachlor, alachlor, propachlor, propanil, metazachlor, metolachlor, acetochlor, and dimethachlor; P. dihalobenzonitrile herbicides such as dichlobenil, bromoxynil and ioxynil; Q. haloalkanoic herbicides such as dalapon, TCA and salts thereof; R. diphenylether herbicides such as lactofen, fluroglycofen or salts or ester thereof, nitrofen, bifenox, aciflurofen and salts and esters thereof, oxyfluorfen, fomesafen, chlornitrofen and chlomethoxyfen; S. (hetero)aryloxyphenoxypropionate herbicides such as diclofop and esters thereof such as the methyl ester, fluazifop and esters thereof, haloxyfop and esters thereof, quizalofop and esters thereof and fenoxaprop and esters thereof such as the ethyl ester; T. cyclohexanedione herbicides such as alloxydim and salts thereof, sethoxydim, cycloxyidim, tralkoxydim, and clethodim;; U. sulfonyl urea herbicides such as chlorosulfuron, sulfometuron, metsulfuron and esters thereof; benzsulfuron and esters thereof such as DPX-M6313, chlorimuron and esters such as the ethyl ester thereof pirimisulfuron and esters such as the methyl ester thereof, 2-[3-(4-methoxy-6-methyl-1,3,5- triazin-zyl)-3-methylureidosulphonyl) benzoic acid esters such as the methyl ester thereof (DPX-LS300) and pyrazosulfuron; V. imidazolidinone herbicides such as imazaquin, imazamethabenz, imazapyr and isopropylammonium salts thereof, imazethapyr; W. arylanilide herbicides such as flamprop and esters thereof, benzoylprop-ethyl, diflufenican; X. amino acid herbicides such as glyphosate and glufosinate and their salts and esters, sulphosate and bialaphos; Y. organoarsenical herbicides such as monosodium methanearsonate (MSMA);; Z. herbicidal amide derivative such as napropamide, propyzamide, carbetamide, tebutam, bromobutide, isoxaben, naproanilide and naptalam; AA. miscellaneous herbicides including ethofumesate, cinmethylin, difenzoquat and salts thereof such as the methyl sulphate salt, clomazone, oxadiazon, bromofenoxim, barban, tridiphane, flurochloridone, quinchlorac and mefanacet; BB. Examples of useful contact herbicides include: bipyridylium herbicides such as those in whichthe active entity is paraquat and those in which the active entity is diquat; * These compounds are preferably employed in combination with a safener such as dichlormid.

The following Examples illustrate the invention EXAMPLE 1 This Example illustrates the preparation of Compound Nos 3 and 9 in Table I: Step A 2-Amino-5-(2-chloro-6-fluoro-4-trifluoromethylphenoxy)benzamide (0.85g) was suspended in glacial acetic acid (5cm3), concentrated hydrochloric acid (1.5cm3) and water (3cm3) added to the mixture stirred and cooled to 30C. Sodium nitrite (0.3g) in water (1cm3) was added dropwise, keeping the temperature at 3 to 50C to give a clear yellow solution. lOM sodium hydroxide (2cm3) was added slowly followed by concentrated hydrochloric acid until the pH was 2. The mixture was extracted with chloroform, the chloroform solution washed with water, dried (MgSO4) and filtered.The filtrate was evaporated under vacuum to give a pale yellow solid (0.6g). The solid was purified by preparative plate chromatography (SiO2, ether) to give 6-(2-chloro-6-fluoro-4-trifluoromethylphenoxy)-1,2,3-benzotriazin-4(3H)-one (0.35g) as a yellow solid M = 359. NMR (CDC13) S: 7.5(d)lH, 7.55(m)lH, 7.65(s)1H, 7.70(dm)1H, 8. 25(d)1H.

Step B 6-(2-Chloro-6-fluoro-4-trifluoromethylphenoxy)-1,2,3-benzotriazin4(3H)-one (1.1g) was dissolved in dry DMF (6cm ) and added slowly to a stirred suspension of sodium hydride (0.16g of 50%) in dry DMF (15cm3) with ice cooling. A solution of ethyl iodoacetate (0.5cm3) in DMF (3cm3) was then added slowly. The mixture was stirred at room temperature for 2.5 hours, poured into a solution of 1M hydrochloric acid and extracted with ether. The ethereal extract was washed with water, dried (MgS04) filtered and the filtrate evaported under vacuum to give a pale yellow oil (1.2g).

Purification by preparative plate chromatography (SiO2; ether: hexane: acetic acid, 12:8:1), followed by replating (SiO2; dichloromethane), gave, as the faster component compound 3, ethyl 6-(2-chloro-6-fluoro-4 -trifluoromethylphenoxy)-3,4-dihydro-4-oxo-l, 2, 3-benzotriazin-3-ylacetate (0.2g) as a pale yellow oil which crystallised on standing. MP = 90-920C.

M+ = 445. NMR (CDC13) 8: 1.3(t)3H, 4.25(q)2H, 5.15(s)2H, 7.45(dm)lH, 7.5(s)1H, 7.65(s)1H, 7.7(dm)1H, 8.25(d)1H.

The slower component was plated again (SiO2, dichloromethane) to give compound 9, diethyl 2-[6-(2-chloro-6-fluoro-4-trifluoromethylphenoxy)-3,4 -dihydro-4-oxo-1,2,3-benzotriazin-3-yl] succinate (0.13g) as an oil. NMR (CDCl3) 8: 1.25(m)6H, 3.4(dd)2H, 4.12(m)2H, 4.22(m)2H, 6.1(m)1H, 7.45(d)1H, 7.50(s)1H, 7.65(s)lH, 7.7(dm)lH, 8.25(d)1H. Compound No. 14 (m.p.

105-1060C) was prepared by an analogous method using appropriate reactants.

EXAMPLE 2 This Example illustrates the preparation of compound No. 11 in Table I.

Step A 5-(2-Chloro-4-trifluoromethylphenoxy)-2-nitrobenzoic acid (5g) was stirred and heated under reflux with thionyl chloride (50cm3) for 3 hours.

The solution was evaporated under reduced pressure to yield a brown oil which was dissolved in toluene and evaporated to give crude 5-(2-chloro -4-trifluoromethylphenoxy)-2-nitrobenzoylchloride. This was dissolved in dry DMF (40cm3) and methylglycinate hydrochloride (2.6g) added with stirring. Triethylamine (5cm3) was added dropwise and the mixture stirred overnight. The mixture was filtered to remove triethylamine hydrochloride and the filtrate added to water, extracted with ether and the ethereal extracts washed with water, dried (MgSO4) and filtered. The filtrate was evaporated under reduced pressure to give methyl N-[5-(2-chloro-4 -trifluoromethylphenoxy)-2-nitrobenzoyl] glycinate (2.6g) as a yellow solid.NMR (CDC13): 6 8.15(d)lH, 7.82(d)lH, 7.63(dd)lH, 7.25(d)1H, 7.05(d)1H, 7.0(dd)1H, 6.6(t)1H, 4.25(d)2H, 3.8(s)3H.

Step B Methyl N-[5-(2-chloro-4-trifluoromethylphenoxy)-2-nitrobenzoyl] glycinate, (lug), was dissolved in warm isopropanol (20cm3). Water (5cm3), then reduced iron powder (5g) were added followed by concentrated hydrochloric acid (10 drops). The mixture was stirred under reflux for 4 hours, filtered and the filtrate concentrated under reduced pressure.

The residue was dissolved in ethyl acetate, the solution washed with water, and the organic phase dried (MgSO4), filtered and evaporated under reduced pressure to give methyl N-[5-(2-chloro-4-trifluoromethylphenoxy) -2-aminobenzoyl] glycinate, 0.73g, as a gum which crystallised on standing.

MP = 110-1120C. M+ = 402. NMR (CDCl3): 6 7.7(d)1H, 7.4(dd)1H, 7.2(d)1H, 7.0(dd)1H, 6.9(t)1H, 6.8(d)1H, 6.7(d)1H, 4.15(d)2H, 3.75(s)3H.

Step C Methyl N-[5-(2-chloro-4-trifluoromethylphenoxy)-2-aminobenzoyl] glycinate (0.9g) was stirred in a mixture of acetic acid (lem3), concentrated hydrochloric acid (2cm3) and water (3cm3) with ice bath cooling. A solution of sodium nitrite (0.3g) in water (1cm3) was added dropwise. After 0.5 hours 2N sodium hydroxide solution was added slowly until the mixture was alkaline. The mixture was filtered and the solid air dried, purified by preparative plate chromatography (SiO2, dichloromethane) to give methyl 6-(2-chloro-4-trifluoromethylphenoxy)-3,4-dihdro-4-oxo- 1,2,3-benzotriazin-3-yl acetate (0.33g) MP = 111-113 . M+ = 413. NMR (CDC13): 88.2(d)1H, 7.8(d)1H, 7.65(dd)1H, 7.6(dd)1H, 7.55(d)1H, 7.3(d)1H, 5.2(s)2H, 3.8(s)3H.

Compound No. 8 (m.p. 95-960C) was prepared in an analogous manner using appropriate reactants, as was compound 17 (NMR (CDCl3) : 3.4(m)2H, 3.7(s)3H, 3.75(s)3H, 6.1(m)1H, 7.3(d)lH, 7.6(d)1H, 7.65(d)1H, 7.7(dd)1H, 7.8(s)1H, 8.25(d)lH).

EXAMPLE 3 This Example illustrates the preparation of compound No. 20 in Table I: Methyl N-[5-(2-chloro-6-fluoro-4-trifluoromethyl-phenoxy)-2- -aminobenzoyl]glycinate (0.5g, prepared as in step B of Example 2) was dissolved in formic acid (15cm3) and stirred at 90 C for 4 hours.

Concentration under vacuum gave a brown oil which was purified by preparative plate chromatography (SiO2; ether: hexane: acetic acid, 12:8:1) to give methyl 6-(2-chloro-6-fluoro-4-trifluoromethyl-phenoxy)-3,4- -dihydro-4-oxo-quinazolin-3-yl acetate (0.17g), compound 20, as a beige solid. Melting point: 157-80C. NMR(CDC13) 6: 3.8(s)3H, 4.7(s)2H, 7.42(dd)lH, 7.5(d)lH, 7.55(dd)lH, 7.6(s)1H, 7.8(d)lH, 7.95(s)1H.

Compounds made in an analogous manner using appropriate reactants were: 26 NMR(CDCl3) 6: 3.35(m)2H, 3.65(s)3H, 3.75(s)3H, 5.15(m)lH, 7.42(m)2H, 7.60(m)2H, 7.8(d)lH, 8.2(s)lH.

29 NMR(CDC13) 6: 3.8(s)3H, 4.7(s)2H, 7.1(d)1H, 7.52(m)2H, 7.7(d)lH, 7.75(s)lH, 7.8(d)lH, 7.95(s)1H.

32 NMR(CDC13) 6: 1.7(d)3H, 3.7(s)3H, 5.3(q)lH, 7.0(d)1H, 7.4(m)2H, 7.6(d)1H, 7.7(s)lH, 7.75(d)lH, 8.0(s) 1H.

35 NMR(CDCl3) 6: 3.35(m)2H, 3.7(s)3H, 3.8(s)3H, 3.8(s)3H, 5.15(m)1H, 7.1(d)1H, 7.53(m)2H, 7.62(d)1H, 7.8(m)2H, 8.15(s)lH EXAMPLE 4 This Example illustrates the preparation of compound No. 37 in Table I.

Step A Methyl N-[5-(2-chloro-4-trifluoromethylphenoxy)-2-aminobenzoyl alaninate (2g, prepared by a method analogous to that of Example 2 step B) was dissolved in toluene (25cm ). Acetyl chloride (2cm ) was added dropwise with stirring. After 0.5 hours triethylamine (3cm ) was added dropwise and after 0.5 hours the mixture was filtered to remove triethylamine hydrochloride. The orange filtrate was evaporated under reduced pressure to give a sticky solid (3.5g). Part of this (lg) was purified by preparative plate chromatography (SiO2,ether) to give methyl N-[5-(2-chloro-4-trifluoromethylphenoxy)-2-acetamidobenzoyl]alaninate (0.2g) as a pale yellow solid. Melting point 129-13O0C. NMR(CDCl3) 6: 1.55(d)3H, 2.2(s)3H, 3.8(s)3H, 4.75(m)1H, 6.9(d)1H, 7.1(m)1H, 7.15(dd)1H, 7.35(dd)1H, 7.5(d)1H, 7.8(s)1H, 8.6(d)1H.

Step B Methyl N-[5-(2-chloro-4-trifluoromethylphenoxy)-2-acetamidobenzoyl] alaninate (lug) was dissolved in dry toluene (50cm3). Sodium hydride (O.lg of 60%) was added with stirring giving effervescence. The solution was concentrated to small volume under reduced pressure. The resulting brown oil was heated to 18O0C for 4 hours the oil was dissolved in ether and the solution washed with water and brine then dried (MgS04), filtered and evaporated under reduced pressure to give a brown oil (0.9g). Purification by preparative plate chromatogarphy (SiO2; ether) gave methyl 6-(2-chloro-4-trifluoromethylphenoxy)-3,4-dihydro-2-methyl-4-oXo- -quinazolin-3-yl alaninate (0.3g) compound 37 as a brown oil.NMR(CDCl3) 8: 1.7(d)3H, 2.68(s)3H, 3.75(s)3H, 4.95(s)1H, 7.1(d)1H, 7.5(m)2H, 7.6(d)1H, 7.7(d)1H, 7.78(d)1H.

EXAMPLE 5 This Example illustrates the preparation of compound No. 39 in Table I: Step A 2-Amino-5-(2-chloro-4-trifluoromethylphenoxy) benzamide (3g) was treated with trifluoroacetic anhydride (10cm ). The stirred solution gave a white precipitate after 5 minutes. This was filtered off and washed with petrol. The solid was purified by preparative plate chromatography (SiO2, ether). The faster component gave 6-(2-chloro-4-trifluoromethylphenoxy) -3,4-dihydro-4-oxo-2-trifluoromethylquinazoline (O.lg) as a pale yellow solid. Melting point 135-60C. NMR(CDC13) 6: 7.15(d)1H, 7.25(m)2H, 7.55(d)1H, 7.8(s)lH, 8.3(d)1H.

The slower component gave 5-(2-chloro-4-trifluoromethylphenoxy)-2 -trifluoroacetamidobenzamide (O.2g) as a pale yellow solid melting point 160-1610C.

Step B 6-(2-Chloro-4-trifluoromethylphenoxy)-3, 4-dihydro-4-oxo-2-trifluoro- methylquinazoline (lg) was dissolved in dry DMF (15cm3). Sodium hydride (0.2g of 60%) was added and stirred for 1 hour until effervescence ceased.

Ethyl iodoacetate (2cm3) was added dropwise. The mixture was stirred at room temperature for a further 3 hours. It was poured onto very dilute hydrochloric acid and the mixture extracted with ether. The ethereal extract was washed with water and brine, dried (MgSO4), filtered and evaporated under reduced pressure to give a yellow oil. Purification by preparative plate chromatography (SiO2; ether:hexane: acetic acid 12:8:1) gave ethyl 6-(2-chloro-4-trifluoromethylphenoxy)-3,4-dihydro-4 -oxo-2-trifluoromethylquinazolin-3-yl acetate (0.23g), compound 39, as a yellow solid. Melting point 80-810C. NMR(CDCl3) 6: 1.25(t)3H, 4.25(q)2H, 5.l(s)2H, 7.2(d)lH, 7.6(m)2H, 7.7(dd)1H, 7.8(s)1H, 8.15(d)1H.

Compound 38 (NMR(CDC13) 6: 1.75(d)3H, 3.75(s)3H, 4.9(q)1H, 7.2(d)lH, 7.6(m)3H, 7.8(s)lH, 7.9(d)lH) was made in an analagous manner using appropriate reactants.

Biological Data The herbicidal activity of the compounds was tested as follows: Each chemical was formulated by dissolving it in an appropriate amount, dependent on the final spray volume, of a solvent/surfactant blend which comprised 78.2 gm/litre of Tween 20 and 21.8 gm/litre of Span 80 adjusted to 1 litre using methylcyclohexanone. Tween 20 is a Trade Mark for a surface-active agent comprising a condensate of 20 molar proportions of ethylene oxide with sorbitan laurate. Span 80 is a Trade Mark for a surface-active agent comprising sorbitan mono-laurate. If the chemical did not dissolve, the volume was made up to 5cm with water, glass beads were added and this mixture was then shaken to effect dissolution or suspension of the chemical, after which the beads were removed. In all cases, the mixture was then diluted with water to the required spray volume. If sprayed independently, volumes of 25cm3 and 30cm3 were required for pre-emergence and post-emergence tests respectively; if sprayed together, 45cm3 was required. The sprayed aqueous emulsion contained 4% of the initial solvent/surfactant mix and the test chemical at an appropriate concentration.

The spray compositions so prepared were sprayed onto young pot plants (post-emergence test) at a spray volume equivalent to 1000 litres per hectare. Damage to plants was assessed 13 days after spraying by comparison with untreated plants, on a scale of O to 9 where 0 is 0% damage, 1 is 1-5% damage, 2 is 6-15% damage, 3 is 16-25% damage, 4 is 26-35% damage, 5 is 36-59% damage, 6 is 60-69% damage, 7 is 70-79% damage, 8 is 80-89% damage and 9 is 90-100% damage.

In a test carried out to detect pre-emergence herbicidal activity, crop seeds were sown at 2 cm depth (i.e. sugar beet, cotton, rape, winter wheat, maize, rice, soya) and weed seeds at 1 cm depth beneath compost and sprayed with the compositions at a spray volume equivalent to 1000 litres per hectare. 20 days after spraying, the seedlings in the sprayed plastic trays were compared with the seedlings in unsprayed control trays, the damage being assessed on the same scale of O to 9.

The results of the tests are given in Table II below.

TABLE II Test Plants (see Table III) COMPOUND PRE-OR RATE OF NO. POST-EMERGENCE APPLN APPLICATION kg/ha BV BN GH GM ZM OS TA PA CA AR BP EH IH IL AT XT AF AM AE SH SV DS EC CE 3 Pre 1 7 8 0 0 0 0 0 - 9 9 0 9 - 0 0 0 0 0 - 0 5 - 0 0 Post 1 9 9 9 9 9 3 7 9 9 9 9 9 9 - 9 9 7 6 8 9 9 6 7 2 8 Pre 0.25 0 0 - 0 0 0 0 0 8 9 - 0 - 0 0 - 7 0 - 3 1 - 0 0 Post 0.25 9 9 - 8 8 5 6 9 9 9 9 9 9 - 9 - 6 9 7 9 9 - 9 2 9 Pre 1 9 9 2 0 2 0 2 - 9 9 6 9 - 2 9 0 0 0 - 0 9 - 0 0 Post 1 9 9 9 9 9 4 8 9 9 9 9 9 9 - 9 9 2 4 6 9 8 9 5 4 11 Pre 1 4 3 - 0 0 0 0 8 9 9 5 3 - 0 0 0 0 0 - 0 0 0 0 0 Post 1 9 9 - 9 8 5 3 9 9 9 9 9 9 - 9 9 5 5 7 6 8 9 5 7 14 Pre 0.25 0 0 - 0 0 2 0 5 4 3 - 3 0 - 0 0 0 0 - 0 0 - 0 0 Post 0.25 9 9 - 9 5 0 5 9 9 9 - 9 9 - 9 9 2 2 - 8 7 - 7 0 TABLE II Test Plants (see Table III) COMPOUND PRE-OR RATE OF NO.POST-EMERGENCE APPLN APPLICATION kg/ha BV BN GH GM ZM OS TA PA CA AR BP EH IH IL AT XT AF AM AE SH SV DS EC CE 17 Pre 0.25 0 0 - 0 0 0 0 0 5 9 - 0 0 - 0 0 0 0 - - 0 - 0 0 Post 0.25 7 9 - 8 6 2 2 9 9 9 - 9 9 - 8 9 2 2 - 7 9 - 6 1 20 Pre 0.25 0 0 - 0 0 0 0 0 0 0 0 2 - 0 0 0 0 0 - 1 0 0 0 1 Post 0.25 7 6 - 5 5 2 0 6 9 8 5 9 9 - 6 - 2 2 2 6 6 4 3 2 26 Pre 0.25 0 3 - 2 0 0 0 0 7 6 - 3 - 0 3 - 0 0 - 2 0 - 0 0 Post 0.25 6 9 - 9 5 4 3 9 9 9 9 9 9 - 7 - 4 2 3 9 9 9 5 4 29 Pre 0.25 0 0 - 0 0 3 0 0 0 0 0 0 - 0 0 - 0 0 - 0 2 0 0 0 Post 0.25 3 6 - 2 3 1 0 6 9 8 3 8 8 - 2 0 0 0 0 6 5 3 1 0 TABLE II Test Plants (see Table III) COMPOUND PRE-OR RATE OF NO.POST-EMERGENCE APPLN APPLICATION kg/ha BV BN GH GM ZM OS TA PA CA AR BP EH IH IL AT XT AF AM AE SH SV DS EC CE 32 Pre 0.25 0 0 - 0 0 0 0 3 2 2 - 0 0 - 0 0 0 0 - 0 0 - 0 0 Post 0.25 2 9 - 4 2 0 0 9 9 9 - 6 9 - 9 3 0 0 - 1 4 - 1 0 35 Pre 0.25 0 0 - 0 0 0 0 0 7 3 - 0 1 - 0 0 0 0 - - 0 - 0 0 Post 0.06 6 4 - 4 5 0 0 7 8 9 - 7 9 - 2 5 1 1 - 5 3 - 1 1 37 Pre 0.25 0 0 - 0 0 0 0 0 0 0 - 5 0 - 0 0 0 0 - - 0 - 0 0 Post 0.25 3 8 - 5 5 0 0 3 8 9 - 5 5 - 4 4 1 0 - 3 3 - 3 2 38 Pre 0.25 0 0 - 0 4 0 0 0 0 0 - 0 2 - 1 0 5 5 - - 1 - 0 0 Post 0.25 2 3 - 2 5 0 0 2 5 8 - 5 0 - 7 5 4 4 - 2 2 - 2 0 39 Pre 0.25 0 0 - 2 0 0 0 0 0 9 - - 0 - 2 0 0 0 - - 0 - 3 4 Post 0.25 7 8 - 5 7 0 0 9 9 9 - 8 7 - 9 7 0 2 - 5 9 - 6 2 TABLE III Abbreviations used for Test Plants BV - Sugar beet BN - Rape GH - Cotton GM - Soybean ZM - Maize OS - Rice TA - Winter wheat PA - Polygonum aviculare CA - Chenopodium album AR - Amaranthus retroflexus BP - Bidens pilosa EH - Euphorbia heterophylla IH - Ipomoea hederacea (post-emergence) IL - Ipomoea lacunosa (pre-emergence) AT - Abutilon theophrasti XT - Xanthium strumarium AF - Avena fatua AM - Alopecurus myosuroides AE - Agropyron repens SH - Sorghum halepense SV - Setaria viridis DS - Digitaria sanguinalis EC - Echinochloa crus-galli CE - Cyperus esculentus CHEMICAL FORMULAE (in description)

CHEMICAL FORMULAE (continued) (in description)

(IA) Table I

Claims (9)

1. CLAIMS 1. A compound of formula:

   in which Ar is an optionally substituted aryl or heterocyclic ring system; W is O or NR1 where R1 is hydogen or lower alkyl;

   E is CR3R4XR5; X is (CH2)n, CH=CH, CH(OR6)CH2, COCH2; where n is 0, 1 or 2; R is H, alkyl, haloalkyl, CN, halo or CO2R7 3 4 R3 and R4 are independently selected from H, optionally substituted alkyl, alkenyl or alkynyl, halogen, NR8R9, CR1ORllCOOR12 or R3 and R4 together with the carbon to which they are attached form an optionally substituted alkenyl or cycloalkyl group; R5 is CO2R , CN, COR , CH2OR , CH(OH)R , CH(OR )R14, CSNH2, COSR , CSOR , CONHSO2R , CONR15R16, CONHNR R16, CONHN+R R15R16Rx-, CO2-R17+ or COON=CR15R16;; R6, R and R14 are independently selected from H or an optionally substituted alkyl, aryl, alkenyl or alkynyl group; 8 9 15 16 R8, R9, R15, R16, are independently selected from H or an optionally substituted alkyl, alkenyl, aryl or alkynyl group or any two of R8, R9, R15 and R16 R , and R together with the atom to which they are attached form a cycloalkyl or heterocyclic ring; R7, R10 and R11 are independently selected from is H or lower alkyl; and R17+ is an agriculturally acceptable cation; and Rx is an agriculturally acceptable anion.
2. 2. A compound according to claim 1 wherein W is oxygen.
3. 3. A compound according to claim 1 or claim 2 wherein Ar is a group:

   where J is N or CR21 where R21 is halo or cyano and R20 is H or halo.
4. 4. A compound according to any of the preceding claims wherein CR3R4XR5 is -CH-R5, where R4' R4' is H or Cl-3 alkyl and R5' is CO2R
5. 5. A compound according to claim 4 in which R13 is C16 alkyl.
6. 6. A compound according to any one of the preceding claims wherein B is N or CH.
7. 7. A process for preparing a compound of formula (I) by a) cyclisation of a compound of formula (II):

   where Ar, E and W are as defined in relation to formula (I) in claim 1 or b) by reacting a compound of formula (VI)

   where Ar, B and W are as defined in relation to formula (I) in claim 1 with a compound of formula (VII) ZE (VII) where E is as defined in relation to formula (I) in claim 1 and Z is a leaving group in the presence of a base; and thereafter if desired carrying out one or more of the following steps: i) when R5 is alkoxycarbonyl hydrolysing to the corresponding acid.

   ii) when R5 is COOH esterifying or forming a salt, amide, sulphonamide, hydrazide or hydrazinium derivative.

   iii) when R5 is an alcohol, oxidation to COOH, CHO.

   iv) when R5 is alkoxycarbonyl, reduction to an alcohol.

   v) when R5 is an amide, dehydration to the corresponding nitrile.
8. 8. A herbicidal composition comprising a compound of formula (I) as defined in claim 1 in combination with a carrier or diluent.
9. 9. A method of killing or controlling the growth of unwanted plants which method comprises applying to the plants or to a locus thereof an effective amount of a compound of formula (I) as defined in claim 1.