Benzoxazole derivatives as herbicides

Abstract

The present invention relates to compounds of Formula (I) or an agronomically acceptable salt of said compounds wherein A1, A2, A3, X1, R1, R2, R3, R4, R5, are as defined herein. The invention further relates to herbicidal compositions which comprise a compound of Formula (I) and to the use of compounds of Formula (I) for controlling weeds, in particular in crops of useful plants.

Description

[0001] BENZOXAZOLE DERIVATIVES AS HERBICIDES

[0002] The present invention relates to herbicidal compounds, to processes for their preparation, to herbicidal compositions which comprise the herbicidal compounds, and to their use for controlling weeds, in particular in crops of useful plants, or for inhibiting plant growth.

[0003] The present invention relates to novel methyl hydroxy amino oxo-propionate compounds, which demonstrate herbicidal activity. Thus, according to the present invention there is provided a compound of Formula (I): or an agronomically acceptable salt thereof, wherein:

[0004] A1is selected from the group consisting of C(R4), N(R5)n, S and O; A2is selected from the group consisting of C(R4), N(R5)n, S and O; A3is selected from the group consisting of C(R4), N(R5)n, S and O; X1is a halogen; R1is hydrogen or Ci-C4alkyl; R2and R3are both Ci-Csalkyl; R4is selected from the group consisting of hydrogen, halogen, Ci-Csalkyl, aryl, Ci-Cshaloalkyl, Ci-Cshaloalkoxy-, Ci-Csalkoxy- and Cs-Cecycloalkyl; R5is selected from the group consisting of hydrogen, Ci-Csalkyl-, Cs-Cecycloalkyl- and Ci-Cshaloalkyl; and n is 0 or 1.

[0005] In a second aspect there is provided a herbicidal composition comprising a compound of Formula (I) as described herein, and an agriculturally acceptable formulation adjuvant.

[0006] In a third aspect the invention provides the use of a compound of Formula (I) or a composition of the invention as a herbicide.

[0007] In a fourth aspect the invention provides a method of controlling weeds at a locus comprising applying to the locus a weed controlling amount of a compound of or composition as described herein.

[0008] Ci-Csalkyl includes methyl (Me, CH3), ethyl (Et, C2H5) and propyl (Pr e.g isopropyl and n-propyl). Ci-C4alkyl includes methyl (Me, CH3), ethyl (Et, C2H5), n-propyl (n- Pr), isopropyl ( / -Pr), n-butyl (n-Bu), isobutyl ( / -Bu), sec-butyl and tert-butyl (t-Bu).

[0009] Halogen (or halo) includes, for example, fluorine, chlorine, bromine or iodine. The same correspondingly applies to halogen in the context of other definitions, such as haloalkyl. Ci-Cehaloalkyl- includes, for example, fluoromethyl, difluoromethyl, trifluoromethyl, chloromethyl, dichloromethyl, trichloromethyl, 2,2,2-trifluoroethyl, 2- fluoroethyl, 2-chloroethyl, pentafluoroethyl, 1 , 1-difluoro-2,2,2-trichloroethyl, 2, 2,3,3- tetrafluoropropyl and 2,2,2-trichloroethyl and heptafluoro-n-propyl. Ci-C2haloalkyl is, for example, fluoromethyl, difluoromethyl, trifluoromethyl, chloromethyl, dichloromethyl, trichloromethyl, 2,2,2-trifluoroethyl, 2-fluoroethyl, 2-chloroethyl, pentafluoroethyl, or 1 ,1- difluoro-2,2,2-trichloroethyl.

[0010] Ci-Csalkoxy includes methoxy, ethoxy and iso-propoxy-.

[0011] Ci-Cshaloalkoxy- includes, for example, fluoromethoxy, difluoromethoxy, trifluoromethoxy, 2,2,2-trifluoroethoxy, 1 ,1 ,2,2-tetrafluoroethoxy, 2-fluoroethoxy, 2- chloroethoxy, 2,2-difluoroethoxy or 2,2,2-trichloroethoxy, preferably difluoromethoxy, 2- chloroethoxy or trifluoromethoxy.

[0012] Cs-Cecycloalkyl includes cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl.

[0013] Preferred values of A1, A2, A3, X1, R1, R2, and R3, as well as of the substituents comprised within these moieties (i.e. R4, and R5) are described below. A compound of Formula (I) according to, and for use in, the invention may comprise any combination of said values. The skilled man will appreciate that values of any specified set of embodiments may be combined with values of any other set of embodiments where such combinations are not mutually exclusive.

[0014] In one embodiment of the present invention, there is provided a compound of Formula (I) wherein X1is bromo, chloro or fluoro. Preferably X1is bromo or chloro.

[0015] In a preferred embodiment X1is preferably chloro.

[0016] In one preferred embodiment of the present invention, there is provided a compound of Formula (I) wherein R1is hydrogen.

[0017] In the present invention, there is provided a compound of Formula (I) wherein R2and R3are both methyl.

[0018] In another embodiment of the present invention, there is provided a compound of Formula (I) wherein R4is selected from the group consisting of hydrogen, Ci-Csalkyl, aryl, Ci-Cshaloalkyl, Ci-Cshaloalkoxy- Ci-Csalkoxy- and Cs-Cecycloalkyl. More preferably in such compounds, R4is selected from the group consisting of hydrogen, methyl, cyclopropyl and difluoromethyl.

[0019] In another embodiment of the present invention, there is provided a compound of Formula (I) wherein R5is methyl.

[0020] In the present invention, there is provided a compound of Formula (I) wherein A1is N(R5)n, A2is O and A3is C(R4). In the present invention, there is provided a compound of Formula (I) wherein A1is N(R5)n, A2is N(R5)nand A3is N(R5)n.

[0021] Compounds of Formula (I) may contain asymmetric centres and may be present as a single enantiomer, pairs of enantiomers in any proportion or, where more than one asymmetric centre are present, contain diastereoisomers in all possible ratios. Typically, one of the enantiomers has enhanced biological activity compared to the other possibilities.

[0022] The present invention also provides agronomically acceptable salts of compounds of Formula (I), and in one embodiment, it is preferred that compounds of Formula (I) are in salt form. Salts that the compounds of Formula (I) may form with amines, including primary, secondary and tertiary amines (for example ammonia, dimethylamine and triethylamine), alkali metal and alkaline earth metal bases, transition metals or quaternary ammonium bases are preferred. Salts of alkali metal and alkaline earth metal bases are particularly preferred.

[0023] The compounds of Formula (I) according to the invention can be used as herbicides by themselves, but they are generally formulated into herbicidal compositions using formulation adjuvants, such as carriers, solvents and surface-active agents (SAA). Thus, the present invention further provides a herbicidal composition comprising a herbicidal compound according to any one of the previous claims and an agriculturally acceptable formulation adjuvant. The composition can be in the form of concentrates which are diluted prior to use, although ready-to-use compositions can also be made. The final dilution is usually made with water, but can be made instead of, or in addition to, water, with, for example, liquid fertilisers, micronutrients, biological organisms, oil or solvents.

[0024] The herbicidal compositions generally comprise from 0.1 to 99 % by weight, especially from 0.1 to 95 % by weight, compounds of Formula I and from 1 to 99.9 % by weight of a formulation adjuvant which preferably includes from 0 to 25 % by weight of a surface-active substance.

[0025] The compositions can be chosen from a number of formulation types. These include an emulsion concentrate (EC), a suspension concentrate (SC), a suspo-emulsion (SE), a capsule suspension (CS), a water dispersible granule (WG), an emulsifiable granule (EG), an emulsion, water in oil (EG), an emulsion, oil in water (EW), a microemulsion (ME), an oil dispersion (OD), an oil miscible flowable (OF), an oil miscible liquid (OL), a soluble concentrate (SL), an ultra-low volume suspension (Sil), an ultra-low volume liquid (UL), a technical concentrate (TK), a dispersible concentrate (DC), a soluble powder (SP), a wettable powder (WP) and a soluble granule (SG). The formulation type chosen in any instance will depend upon the particular purpose envisaged and the physical, chemical and biological properties of the compound of Formula (I).

[0026] Soluble powders (SP) may be prepared by mixing a compound of Formula (I) with one or more water-soluble inorganic salts (such as sodium bicarbonate, sodium carbonate or magnesium sulphate) or one or more water-soluble organic solids (such as a polysaccharide) and, optionally, one or more wetting agents, one or more dispersing agents or a mixture of said agents to improve water dispersibility / solubility. The mixture is then ground to a fine powder. Similar compositions may also be granulated to form water soluble granules (SG).

[0027] Wettable powders (WP) may be prepared by mixing a compound of Formula (I) with one or more solid diluents or carriers, one or more wetting agents and, preferably, one or more dispersing agents and, optionally, one or more suspending agents to facilitate the dispersion in liquids. The mixture is then ground to a fine powder. Similar compositions may also be granulated to form water dispersible granules (WG).

[0028] Granules (GR) may be formed either by granulating a mixture of a compound of Formula (I) and one or more powdered solid diluents or carriers, or from pre-formed blank granules by absorbing a compound of Formula (I) (or a solution thereof, in a suitable agent) in a porous granular material (such as pumice, attapulgite clays, fuller's earth, kieselguhr, diatomaceous earths or ground corn cobs) or by adsorbing a compound of Formula (I) (or a solution thereof, in a suitable agent) on to a hard core material (such as sands, silicates, mineral carbonates, sulphates or phosphates) and drying if necessary. Agents which are commonly used to aid absorption or adsorption include solvents (such as aliphatic and aromatic petroleum solvents, alcohols, ethers, ketones and esters) and sticking agents (such as polyvinyl acetates, polyvinyl alcohols, dextrins, sugars and vegetable oils). One or more other additives may also be included in granules (for example an emulsifying agent, wetting agent or dispersing agent).

[0029] Dispersible Concentrates (DC) may be prepared by dissolving a compound of Formula (I) in water or an organic solvent, such as a ketone, alcohol or glycol ether. These solutions may contain a surface-active agent (for example to improve water dilution or prevent crystallisation in a spray tank).

[0030] Emulsifiable concentrates (EC) or oil-in-water emulsions (EW) may be prepared by dissolving a compound of Formula (I) in an organic solvent (optionally containing one or more wetting agents, one or more emulsifying agents or a mixture of said agents). Suitable organic solvents for use in ECs include aromatic hydrocarbons (such as alkylbenzenes or alkylnaphthalenes, exemplified by SOLVESSO 100, SOLVESSO 150 and SOLVESSO 200; SOLVESSO is a Registered Trade Mark), ketones (such as cyclohexanone or methylcyclohexanone) and alcohols (such as benzyl alcohol, furfuryl alcohol or butanol), N-alkylpyrrolidones (such as N-methylpyrrolidone or N- octylpyrrolidone), dimethyl amides of fatty acids (such as Cs-C fatty acid dimethylamide) and chlorinated hydrocarbons. An EC product may spontaneously emulsify on addition to water, to produce an emulsion with sufficient stability to allow spray application through appropriate equipment.

[0031] Preparation of an EW involves obtaining a compound of Formula (I) either as a liquid (if it is not a liquid at room temperature, it may be melted at a reasonable temperature, typically below 70°C) or in solution (by dissolving it in an appropriate solvent) and then emulsifying the resultant liquid or solution into water containing one or more SAAs, under high shear, to produce an emulsion. Suitable solvents for use in EWs include vegetable oils, chlorinated hydrocarbons (such as chlorobenzenes), aromatic solvents (such as alkylbenzenes or alkylnaphthalenes) and other appropriate organic solvents which have a low solubility in water.

[0032] Microemulsions (ME) may be prepared by mixing water with a blend of one or more solvents with one or more SAAs, to produce spontaneously a thermodynamically stable isotropic liquid formulation. A compound of Formula (I) is present initially in either the water or the solvent / SAA blend. Suitable solvents for use in MEs include those hereinbefore described for use in in ECs or in EWs. An ME may be either an oil-in-water or a water-in-oil system (which system is present may be determined by conductivity measurements) and may be suitable for mixing water-soluble and oil-soluble pesticides in the same formulation. An ME is suitable for dilution into water, either remaining as a microemulsion or forming a conventional oil-in-water emulsion.

[0033] Suspension concentrates (SC) may comprise aqueous or non-aqueous suspensions of finely divided insoluble solid particles of a compound of Formula (I). SCs may be prepared by ball or bead milling the solid compound of Formula (I) in a suitable medium, optionally with one or more dispersing agents, to produce a fine particle suspension of the compound. One or more wetting agents may be included in the composition and a suspending agent may be included to reduce the rate at which the particles settle. Alternatively, a compound of Formula (I) may be dry milled and added to water, containing agents hereinbefore described, to produce the desired end product.

[0034] Aerosol formulations comprise a compound of Formula (I) and a suitable propellant (for example n-butane). A compound of Formula (I) may also be dissolved or dispersed in a suitable medium (for example water or a water miscible liquid, such as n- propanol) to provide compositions for use in non-pressurised, hand-actuated spray pumps. Capsule suspensions (CS) may be prepared in a manner similar to the preparation of EW formulations but with an additional polymerisation stage such that an aqueous dispersion of oil droplets is obtained, in which each oil droplet is encapsulated by a polymeric shell and contains a compound of Formula (I) and, optionally, a carrier or diluent therefor. The polymeric shell may be produced by either an interfacial polycondensation reaction or by a coacervation procedure. The compositions may provide for controlled release of the compound of Formula (I) and they may be used for seed treatment. A compound of Formula (I) may also be formulated in a biodegradable polymeric matrix to provide a slow, controlled release of the compound.

[0035] The composition may include one or more additives to improve the biological performance of the composition, for example by improving wetting, retention or distribution on surfaces; resistance to rain on treated surfaces; or uptake or mobility of a compound of Formula (I). Such additives include surface active agents (SAAs), spray additives based on oils, for example certain mineral oils or natural plant oils (such as soy bean and rape seed oil), modified plant oils such as methylated rape seed oil (MRSO), and blends of these with other bio-enhancing adjuvants (ingredients which may aid or modify the action of a compound of Formula (I).

[0036] Wetting agents, dispersing agents and emulsifying agents may be SAAs of the cationic, anionic, amphoteric or non-ionic type.

[0037] Suitable SAAs of the cationic type include quaternary ammonium compounds (for example cetyltri methyl ammonium bromide), imidazolines and amine salts.

[0038] Suitable anionic SAAs include alkali metals salts of fatty acids, salts of aliphatic monoesters of sulphuric acid (for example sodium lauryl sulphate), salts of sulphonated aromatic compounds (for example sodium dodecylbenzenesulphonate, calcium dodecylbenzenesulphonate, butylnaphthalene sulphonate and mixtures of sodium di- / sopropyl- and tri- / sopropyl-naphthalene sulphonates), ether sulphates, alcohol ether sulphates (for example sodium laureth-3-sulphate), ether carboxylates (for example sodium laureth-3-carboxylate), phosphate esters (products from the reaction between one or more fatty alcohols and phosphoric acid (predominately mono-esters) or phosphorus pentoxide (predominately di-esters), for example the reaction between lauryl alcohol and tetraphosphoric acid; additionally these products may be ethoxylated), sulphosuccinamates, paraffin or olefine sulphonates, taurates, lignosulphonates and phosphates I sulphates of tristyrylphenols.

[0039] Suitable SAAs of the amphoteric type include betaines, propionates and glycinates. Suitable SAAs of the non-ionic type include condensation products of alkylene oxides, such as ethylene oxide, propylene oxide, butylene oxide or mixtures thereof, with fatty alcohols (such as oleyl alcohol or cetyl alcohol) or with alkylphenols (such as octylphenol, nonylphenol or octylcresol); partial esters derived from long chain fatty acids or hexitol anhydrides; condensation products of said partial esters with ethylene oxide; block polymers (comprising ethylene oxide and propylene oxide); alkanolamides; simple esters (for example fatty acid polyethylene glycol esters); amine oxides (for example lauryl dimethyl amine oxide); lecithins and sorbitans and esters thereof, alkyl polyglycosides and tristyrylphenols.

[0040] Suitable suspending agents include hydrophilic colloids (such as polysaccharides, polyvinylpyrrolidone or sodium carboxymethylcellulose) and swelling clays (such as bentonite or attapulgite).

[0041] The compounds of present invention can also be used in mixture with one or more additional herbicides and / or plant growth regulators. Examples of such additional herbicides or plant growth regulators include acetochlor, acifluorfen (including acifluorfen- sodium), aclonifen, ametryn, amicarbazone, aminopyralid, aminotriazole, atrazine, beflubutamid-M, benquitrione, bensulfuron (including bensulfuron-methyl), bentazone, bicyclopyrone, bilanafos, bipyrazone, bispyribac-sodium, bixlozone, broclozone, bromacil, bromoxynil, butachlor, butafenacil, carfentrazone (including carfentrazone-ethyl), cloransulam (including cloransulam-methyl), chlorimuron (including chlorimuron-ethyl), chlorotoluron, chlorsulfuron, cinmethylin, clacyfos, clethodim, clodinafop (including clodinafop-propargyl), clomazone, clopyralid, cyclopyranil, cyclopyrimorate, cyclosulfamuron, cyhalofop (including cyhalofop-butyl), 2,4-D (including the choline salt and 2-ethylhexyl ester thereof), 2,4-DB, desmedipham, dicamba (including the aluminium, aminopropyl, bis-aminopropylmethyl, choline, dichloroprop, diglycolamine, dimethylamine, dimethylammonium, potassium and sodium salts thereof) diclosulam, diflufenican, diflufenzopyr, dimethachlor, dimethenamid-P, dioxopyritrione, diquat dibromide, diuron, epyrifenacil, ethalfluralin, ethofumesate, fenoxaprop (including fenoxaprop-P-ethyl), fenoxasulfone, fenpyrazone, fenquinotrione, fentrazamide, flazasulfuron, florasulam, florpyrauxifen (including florpyrauxifen-benzyl), fluazifop (including fluazifop-P-butyl), flucarbazone (including flucarbazone-sodium), fluchloraminopyr (including fluchloramino-tefuryl), flufenacet, flufenoximacil, flumetsulam, flumioxazin, fluometuron, fomesafen flupyrsulfuron (including flupyrsulfuron-methyl- sodium), fluroxypyr (including fluroxypyr-meptyl), flusulfinam, fomesafen, foramsulfuron, glufosinate (including L-glufosinate and the ammonium salts of both), glyphosate (including the diammonium, isopropylammonium and potassium salts thereof), halauxifen (including halauxifen-methyl), haloxyfop (including haloxyfop-methyl), hexazinone, hydantocidin, icafolin (including icafolin-methyl), imazamox (including R-imazamox), imazapic, imazapyr, imazethapyr, indaziflam, indolauxipyr (including indolauxipyr- cyanomethyl), iodosulfuron (including iodosulfuron-methyl-sodium), iofensulfuron (including iofensulfuron-sodium), ioxynil, iptriazopyrid, isoproturon, isoxaflutole, lancotrione, MCPA, MCPB, mecoprop-P, mesosulfuron (including mesosulfuron-methyl), mesotrione, metamitron, metazachlor, methiozolin, metolachlor, metosulam, metribuzin, metsulfuron, napropamide, nicosulfuron, norflurazon, oxadiazon, oxasulfuron, oxyfluorfen, paraquat dichloride, pendimethalin, penoxsulam, phenmedipham, picloram, pinoxaden, pretilachlor, primisulfuron-methyl, prometryne, propanil, propaquizafop, propyrisulfuron, propyzamide, prosulfocarb, prosulfuron, pyraclonil, pyraflufen (including pyraflufen-ethyl), pyraquinate, pyrasulfotole, pyridate, pyriftalid, pyriflu benzoxi m, pyrimisulfan, pyroxasulfone, pyroxsulam, quinclorac, quinmerac, quizalofop (including quizalofop-P-ethyl and quizalofop-P-tefuryl), rimisoxafen, rimsulfuron, saflufenacil, sethoxydim, simazine, S-metalochlor, sulfentrazone, sulfosulfuron, tebuthiuron, tefuryltrione, tembotrione, terbuthylazine, terbutryn, tetflupyrolimet, thiencarbazone, thifensulfuron, tiafenacil, tolpyralate, topramezone, tralkoxydim, triafamone, triallate, triasulfuron, tribenuron (including tribenuron-methyl), triclopyr, trifloxysulfuron (including trifloxysulfuron-sodium), trifludimoxazin, trifluralin, triflusulfuron, tripyrasulfone, 3-(2- chloro-4-fluoro-5-(3-methyl-2,6-dioxo-4-trifluoromethyl-3,6-dihydropyrimidin-1(2H)- yl)phenyl)-5-methyl-4,5-dihydroisoxazole-5-carboxylic acid ethyl ester, 4-hydroxy-1- methoxy-5-methyl-3-[4-(trifluoromethyl)-2-pyridyl]imidazolidin-2-one, 4-hydroxy-1,5- dimethyl-3-[4-(trifluoromethyl)-2-pyridyl]imidazolidin-2-one, 5-ethoxy-4-hydroxy-1-methyl- 3-[4-(trifluoromethyl)-2-pyridyl]imidazolidin-2-one, 4-hydroxy-1-methyl-3-[4-

[0042] (trifluoromethyl)-2-pyridyl]imidazolidin-2-one, 4-hydroxy-1,5-dimethyl-3-[1-methyl-5- (trifluoromethyl)pyrazol-3-yl]imidazolidin-2-one, (4R)1-(5-tert-butylisoxazol-3-yl)-4- ethoxy-5-hydroxy-3-methyl-imidazolidin-2-one, (1RS,5SR)-3-[2-methoxy-4-(prop-1-yn-1- yl)phenyl]-4-oxobicyclo[3.2.1]oct-2-en-2-yl methyl carbonate, ethyl-2-[[3-[[3-chloro-5- fluoro-6-[3-methyl-2,6-dioxo-4-(trifluoromethyl)pyrimidin-1-yl]-2- pyridyl]oxy]acetate, methyl 2-[2-[2-bromo-4-fluoro-5-[3-methyl-2,6-dioxo-4- (trifluoromethyl)pyrimidin-1-yl]phenoxy]phenoxy]-2-methoxy-acetate, 6-chloro-4-(2,7- dimethyl-1-naphthyl)-5-hydroxy-2-methyl-pyridazin-3-one, (2-fluorophenyl)methyl 6- amino-5-chloro-2-(4-chloro-2-fluoro-3-methoxy-phenyl)pyrimidine-4-carboxylate, 6- amino-5-chloro-2-(4-chloro-2-fluoro-3-methoxy-phenyl)pyrimidine-4-carboxylic acid, and methyl 3-[2-chloro-5-[3,6-dihydro-3-methyl-2,6-dioxo-4-(trifluoromethyl)-1(2H)- pyrimidinyl]-4-fluorophenyl]-3a,4,5,6-tetrahydro-6-methyl-6aH-cyclopent[d]isoxazole-6a- carboxylate.

[0043] The mixing partners of the compound of Formula (I) may also be in the form of esters or salts, as mentioned e.g. in The Pesticide Manual, Nineteenth Edition, British Crop Protection Council, 2021.

[0044] The compound of Formula (I) can also be used in mixtures with other agrochemicals such as fungicides, nematicides or insecticides, examples of which are given in The Pesticide Manual.

[0045] The mixing ratio of the compound of Formula (I) to the mixing partner is preferably from 1 : 100 to 1000:1.

[0046] The mixtures can advantageously be used in the above-mentioned formulations (in which case "active ingredient" relates to the respective mixture of compound of Formula (I) with the mixing partner).

[0047] The compounds or mixtures of the present invention can also be used in combination with one or more herbicide safeners. Examples of such safeners include benoxacor, cloquintocet (including cloquintocet-mexyl), cyprosulfamide, dichlormid, fenchlorazole (including fenchlorazole-ethyl), fenclorim, fluxofenim, furilazole, isoxadifen (including isoxadifen-ethyl), mefenpyr (including mefenpyr-diethyl), metcamifen and oxabetrinil.

[0048] Particularly preferred are mixtures of a compound of Formula (I) with cyprosulfamide, isoxadifen-ethyl, cloquintocet-mexyl and / or metcamifen.

[0049] The safeners of the compound of Formula (I) may also be in the form of esters or salts, as mentioned e.g. in The Pesticide Manual, Nineteenth Edition, British Crop Protection Council, 2021.

[0050] The reference to cloquintocet-mexyl also applies to a lithium, sodium, potassium, calcium, magnesium, aluminium, iron, ammonium, quaternary ammonium, sulfonium or phosphonium salt thereof as disclosed in WO 02 / 34048.

[0051] Preferably the mixing ratio of compound of Formula (I) to safener is from 100:1 to 1 :10, especially from 20: 1 to 1 : 1.

[0052] The present invention still further provides a method of controlling weeds at a locus said method comprising applying to the locus a weed controlling amount of a composition comprising a compound of Formula (I). Moreover, the present invention may further provide a method of selectively controlling weeds at a locus comprising crop plants and weeds, wherein the method comprises application to the locus of a weed controlling amount of a composition according to the present invention. ‘Controlling’ means killing, reducing or retarding growth or preventing or reducing germination. It is noted that the compounds of the present invention show a much-improved selectivity compared to know, structurally similar compounds. Generally the plants to be controlled are unwanted plants (weeds). ‘Locus’ means the area in which the plants are growing or will grow. The application may be applied to the locus pre-emergence and / or postemergence of the crop plant. Some crop plants may be inherently tolerant to herbicidal effects of compounds of Formula (I). Preferred crop plants include maize, wheat, barley soybean and rice.

[0053] The rates of application of compounds of Formula I may vary within wide limits and depend on the nature of the soil, the method of application (pre- or post-emergence; seed dressing; application to the seed furrow; no tillage application etc.), the crop plant, the weed(s) to be controlled, the prevailing climatic conditions, and other factors governed by the method of application, the time of application and the target crop. The compounds of Formula I according to the invention are generally applied at a rate of from 10 to 2500 g / ha, especially from 25 to 1000 g / ha, more especially from 25 to 250 g / ha.

[0054] The application is generally made by spraying the composition, typically by tractor mounted sprayer for large areas, but other methods such as dusting (for powders), drip or drench can also be used.

[0055] Crop plants are to be understood as also including those crop plants which have been rendered tolerant to other herbicides or classes of herbicides (e.g. ALS, GS, EPSPS, PPG, HPPD, PDS, SDPS and ACCase inhibitors) by conventional methods of breeding or by genetic engineering. An example of a crop that has been rendered tolerant to imidazolinones, e.g. imazamox, by conventional methods of breeding is Clearfield® summer rape (canola). Examples of crops that have been rendered tolerant to herbicides by genetic engineering methods include e.g. glyphosate- and glufosinate-resistant maize varieties commercially available under the trade names RoundupReady® and LibertyLink®.

[0056] Crop plants are also to be understood as being those which have been rendered resistant to harmful insects by genetic engineering methods, for example Bt maize (resistant to European corn borer), Bt cotton (resistant to cotton boll weevil) and also Bt potatoes (resistant to Colorado beetle). Examples of Bt maize are the Bt 176 maize hybrids of NK® (Syngenta Seeds). The Bt toxin is a protein that is formed naturally by Bacillus thuringiensis soil bacteria. Examples of toxins, or transgenic plants able to synthesise such toxins, are described in EP-A-451 878, EP-A-374 753, WO 93 / 07278, WO 95 / 34656, WO 03 / 052073 and EP-A-427 529. Examples of transgenic plants comprising one or more genes that code for an insecticidal resistance and express one or more toxins are KnockOut® (maize), Yield Gard® (maize), NuCOTIN33B® (cotton), Bollgard® (cotton), NewLeaf® (potatoes), NatureGard® and Protexcta®. Plant crops or seed material thereof can be both resistant to herbicides and, at the same time, resistant to insect feeding (“stacked” transgenic events). For example, seed can have the ability to express an insecticidal Cry3 protein while at the same time being tolerant to glyphosate.

[0057] Crop plants are also to be understood to include those which are obtained by conventional methods of breeding or genetic engineering and contain so-called output traits (e.g. improved storage stability, higher nutritional value and improved flavour).

[0058] The compositions can be used to control unwanted plants (collectively, ‘weeds’). The weeds to be controlled may be both monocotyledonous species, for example Agrostis, Alopecurus, Avena, Brachia ria, Bromus, Cenchrus, Cy perus, Digitaria, Echinochloa, Eleusine, Lolium, Monochoria, Rottboellia, Sagittaria, Scirpus, Setaria and Sorghum, and dicotyledonous species, for example Abutilon, Amaranthus, Ambrosia, Chenopodium, Chrysanthemum, Conyza, Galium, Ipomoea, Nasturtium, Sida, Sinapis, Solanum, Stellaria, Veronica, Viola and Xanthium.

[0059] In a further aspect of the present invention there is provided the use of a compound of Formula (I) as defined herein as a herbicide.

[0060] PROCESSES FOR PREPARATION OF COMPOUNDS OF FORMULA (I)

[0061] Processes for preparation of compounds, e.g. a compound of formula (I) (which optionally can be an agronomically acceptable salt thereof), are now described, and form further aspects of the present invention. The compounds of the present invention can be prepared according to the following schemes.

[0062] SCHEME 1

[0063] Compounds of formula (1) (or an agronomically acceptable salt thereof) may be prepared from compounds of formula (2).

[0064] Compounds of formula (2) are treated with a suitable base, for example sodium hydroxide, in a suitable solvent, for example a water / methanol / 2-methyltetrahydrofuran mixture. SCHEME 2

[0065] Compounds of formula (2) may be prepared from compounds of formula (3).

[0066] For example, R2and R3are methyl, compounds of formula (3) are treated with 2,2- dimethylmalonyl chloride and a suitable base, for example pyridine, in a suitable solvent, for example dichloromethane.

[0067] SCHEME 3

[0068] Compounds of formula (3) may be prepared from compounds of formula (4).

[0069] Compounds of formula (4) are treated with a suitable source of hydroxylamine, for example hydroxylamine hydrochloride, and optionally a suitable base, for example sodium acetate, in a suitable solvent, for example ethanol, to give compounds of formula (5). Compounds of formula (5) are treated with a suitable reducing agent, for example sodium cyanoborohydride, and a suitable acid, for example 4 M hydrochloric acid in 1 ,4-dioxane, in a suitable solvent, for example methanol, to give compounds of formula (3).

[0070] SCHEME 4

[0071] In an alternative approach, compounds of formula (3) may be prepared from compounds of formula (6), where LG represents a suitable leaving group (for example Br or Cl), according to the following scheme.

[0072] Acid

[0073] Solvent

[0074] Compounds of formula (6) are treated with (terf-butoxycarbonylamino) terf-butyl carbonate (7), a suitable base, for example potassium carbonate, and optionally a suitable additive, for example 18-crown-6, in a suitable solvent, for example acetonitrile, to give compounds of formula (8). Compounds of formula (8) are treated with a suitable acid, for example hydrochloric acid, in a suitable solvent, for example 1 ,4-dioxane, to give compounds of formula (3).

[0075] SCHEME 5 In a further alternative approach, compounds of formula (2) may be prepared from compounds of formula (9).

[0076] Compounds of formula (9) are treated with a suitable oxidant system, for example a mixture of trichloroisocyanuric acid and a catalytic quantity of TEMPO in a suitable solvent, for example dichloromethane.

[0077] SCHEME 6

[0078] Compounds of formula (9) may be prepared from compounds of formula (10), where PG1represents a suitable protecting group, for example -CH2CH2(Si(CH3)3).

[0079] Compounds of formula (10) are reacted under suitable deprotection conditions. For example, where PG1is -CH2CH2(Si(CH3)3) compounds of formula (10) are treated with a suitable Lewis acid source, for example boron trifluoride diethyl etherate, in a suitable solvent, for example dichloromethane.

[0080] SCHEME 7

[0081] Compounds of formula (10) may be prepared from compounds of formula (6), where LG represents a suitable leaving group (for example Br or Cl), and compounds of formula (11), where PG1represents a suitable protecting group, for example -

[0082] CH2CH2(Si(CH3)3).

[0083] Compounds of formula (6) are treated with compounds of formula (11), a carbonate base, for example potassium carbonate, and optionally a suitable additive, for example sodium iodide, in a suitable solvent, for example acetone.

[0084] SCHEME 8

[0085] Compounds of formula (11) may be prepared from compounds of formula (12) according to the following scheme.

[0086] 3,3-Dichloro-2,2-dimethylpropanoic acid (12) is treated with a suitable chlorinating agent, for example thionyl chloride, to give 3,3-dichloro-2,2-dimethylpropanoyl chloride (13). 3,3-Dichloro-2,2-dimethylpropanoyl chloride (13) is treated with a suitable source of hydroxylamine, for example hydroxylamine (50% in H2O), to give 3,3-dichloro-2,2- dimethyl-propanehydroxamic acid (14). 3,3-Dichloro-2,2-dimethyl-propanehydroxamic acid (14) is treated with compounds of formula (15), where PG1represents a suitable protecting group, for example -CH2CH2(Si(CH3)3), and a suitable base, for example 1 ,8- diazabicyclo(5.4.0)undec-7-ene, to give compounds of formula (11).

[0087] SCHEME 9

[0088] Compounds of formula (6) may be prepared from compounds of formula (16).

[0089] For example, where LG is Cl, compounds of formula (16) are treated with a chlorinating agent, for example thionyl chloride, either neat or in a suitable solvent, for example dichloromethane.

[0090] SCHEME 10

[0091] Compounds of formula (16) may be prepared from compounds of formula (17), where Z is H or O-alkyl.

[0092] For example, where Z is H, compounds of formula (17) are treated with a reducing agent, for example sodium borohydride, in a suitable solvent, for example a tetra hy d rof u ra n / m eth an ol m ixtu re .

[0093] SCHEME 11

[0094] The synthesis routes used to access compounds of formula (17) will vary depending on the nature of Z, X1, A1, A2and A3. For example, compounds of formula (4) may be prepared from compounds of formula (18).

[0095] (18) (4)

[0096] Compounds of formula (18) are reacted under suitable formylation conditions, for example by treatment with titanium tetrachloride and dichloro(methoxy)methane in a suitable solvent, for example dichloromethane.

[0097] SCHEME 12

[0098] In an alternative approach, compounds of formula (16) may be prepared from compounds of formula (19).

[0099] Compounds of formula (19) are treated with a suitable halogenating agent, for example / V-chlorosuccinimide, in a suitable solvent, for example acetonitrile. SCHEME 13

[0100] Compounds of formula (19) may be prepared from compounds of formula (20), where Z is H or O-alkyl.

[0101] For example, where Z is H, compounds of formula (20) are treated with a reducing agent, for example sodium borohydride, in a suitable solvent, for example water.

[0102] SCHEME 14

[0103] In a further alternative approach, compounds of formula (16) may be prepared from compounds of formula (21) and compounds of formula (22) where PG2represents a suitable protecting group, for example -CH2CH2(Si(CH3)3), according to the following scheme. Compounds of formula (22) are available from commercial sources.

[0104] Compounds of formula (21) are reacted with compounds of formula (22) in the presence of a suitable catalyst system and a suitable base in a suitable solvent to give compounds of formula (23). For example, where PG2is -CH2CH2(Si(CH3)3), compounds of formula (21) are reacted with potassium trifluoro(2- trimethylsilylethoxymethyl)boranuide in the presence of a suitable (pre-)catalyst / ligand combination, for example palladium^ I) acetate and RuPhos, and a suitable base, for example cesium carbonate, in a suitable solvent, for example a 1 ,4-dioxane / water mixture. Compounds of formula (23) are reacted under suitable deprotection conditions to give compounds of formula (16). For example, compounds of formula (23) where PG2is -CH2CH2(Si(CH3)3) are treated with boron trifluoride diethyl etherate in a suitable solvent, for example dichloromethane. SCHEME 15

[0105] Compounds of formula (21) may be prepared from compounds of formula (18).

[0106] (18) (21)

[0107] Compounds of formula (18) are treated with a suitable brominating agent, for example / V-bromosuccinimide, in a suitable solvent, for example acetonitrile.

[0108] SCHEME 16

[0109] Compounds of formula (17), formula (18), formula (19), formula (20) and formula (21) may be commercially available. Alternatively, they may be prepared utilising ring synthesis strategies known in the literature. The synthetic route adopted will vary depending on the nature of Z, X1, A1, A2and A3. For example, compounds of formula (24) may be prepared from compounds of formula (25) according to the following scheme. Compounds of formula (25) are available from commercial sources or may be prepared according to strategies known in the literature.

[0110] Compounds of formula (25) are treated with a suitable acylation agent, for example acetic anhydride, and a suitable base, for example triethylamine, in a suitable solvent, for example dichloromethane, to give compounds of formula (26). Compounds of formula (26) are treated with a suitable acid, for example para-toluenesulfonic acid, in a suitable solvent, for example toluene, to give compounds of formula (24).

[0111] SCHEME 17

[0112] Compounds of formula (27) where R1is Ci-C4alkyl may be prepared from compounds of formula (2).

[0113] Compounds of formula (2) are treated with a metal alkoxide, for example sodium methoxide, in a suitable solvent, for example methanol.

[0114] SCHEME 18

[0115] In an alternative approach, compounds of formula (27) where R1is Ci-C4alkyl may be prepared from compounds of formula (3) and compounds of formula (28). Compounds of formula (28) are available from commercial sources.

[0116] Compounds of formula (28) are activated by converting the -OH of the carboxylic acid into a good leaving group such as -Cl, for example by treatment with a suitable chlorinating agent, for example thionyl chloride, and optionally a suitable base, for example triethylamine, either neat or in a suitable solvent, for example dichloromethane. The activated intermediates derived from compounds of formula (28) are then treated with compounds of formula (3) and a suitable base, for example triethylamine, in a suitable solvent, for example dichloromethane. Alternatively, compounds of formula (28) are reacted with compounds of formula (3) under suitable amide coupling conditions, for example by treatment with a carboxylic acid activating agent, for example 2,4,6-tripropyl- 1 ,3,5,2A5,4A5,6A5-trioxatriphosphinane 2,4,6-trioxide, and a suitable base, for example triethylamine, in a suitable solvent, for example dichloromethane.

[0117] The following non-limiting examples provide specific synthesis methods for representative compounds of the present invention, as referred to in Table 1 below. PREPARATION EXAMPLES

[0118] Example 1 : Preparation of Compound 1.001

[0119] 1.1 Preparation of 4,4-dimethyl-5-(2-trimethylsilylethoxy)isoxazolidin-3-one

[0120] Step 1: Preparation of 3,3-dichloro-2,2-dimethyl-propanoyl chloride

[0121] 3,3-Dichloro-2,2-dimethyl-propanoic acid (88.0 g, 514 mmol) was added to a stirred solution of thionyl chloride (148 mL) at room temperature. The mixture was heated to 70 °C for 5 h. Excess thionyl chloride was removed by crude distillation (75 °C). The residue was then purified by distillation (40 °C at 5 mbar) to afford 3,3-dichloro-2,2- dimethyl-propanoyl chloride (87.0 g, 459 mmol, 89%).1H NMR (400 MHz, CDCI3) 6 ppm 6.17 (s, 1 H), 1.50 (s, 6H).

[0122] Step 2: Preparation of 3,3-dichloro-2,2-dimethyl-propanehydroxamic acid

[0123] To hydroxylamine (50 mass%) in water (8.09 g, 7.5 mL, 122 mmol) was added 3,3-dichloro-2,2-dimethyl-propanoyl chloride (3.00 g, 15.8 mmol) dropwise. The reaction mixture was stirred for 10 mins at room temperature. The reaction mixture was extracted with dichloromethane, passed through a hydrophobic frit and concentrated to afford 3,3- dichloro-2,2-dimethyl-propanehydroxamic acid (1.94 g, 10.4 mmol, 66%).1H NMR (400 MHz, CDCh) 6 ppm 6.40 (br s, 1 H), 6.12 (s, 1 H), 1.40 (s, 6H).

[0124] Step 3: Preparation of 4,4-dimethyl-5-(2-trimethylsilylethoxy)isoxazolidin-3-one

[0125] A solution of 1 ,8-diazabicyclo(5.4.0)undec-7-ene (0.835 g, 0.82 mL, 5.38 mmol) and 3,3-dichloro-2,2-dimethyl-propanehydroxamic acid (0.500 g, 2.69 mmol) in 2- trimethylsilylethanol (5.0 mL) was heated at 75 °C overnight. The reaction mixture was diluted with ethyl acetate and washed with 2 M hydrochloric acid (x2) then brine. The organic portion was concentrated to afford crude 4,4-dimethyl-5-(2- trimethylsilylethoxy)isoxazolidin-3-one (0.308 g, 1.33 mmol, 50%). This material was used crude in the next step without further purification.

[0126] 1.2 Preparation of sodium 3-f(6-chloro-2-methyl-1 ,3-benzoxazol-5-yl)methyl-hydroxy- amino1-2,2-dimethyl-3-oxo-propanoate (compound 1.001)

[0127] Step 1: Preparation of (6-chloro-2-methyl-1 ,3-benzoxazol-5-yl)methanol

[0128] A solution of (2-methyl-1 ,3-benzoxazol-5-yl)methanol (0.500 g, 3.06 mmol) and N- chlorosuccinimide (0.430 g, 3.22 mmol) in acetonitrile (10.2 mL) was stirred at 70 °C for 1 h. The reaction mixture was concentrated onto diatomaceous earth and purified by flash column chromatography (0-70% ethyl acetate in cyclohexane) to afford (6-chloro-2- methyl-1 ,3-benzoxazol-5-yl)methanol (0.268 g, 1.36 mmol, 44%).1H NMR (400 MHz, CDCI3) 6 ppm 7.76 (s, 1 H), 7.52 (s, 1 H), 4.85 (s, 2H), 2.64 (s, 3H).

[0129] Step 2: Preparation of 5-(bromomethyl)-6-chloro-2-methyl-1 ,3-benzoxazole

[0130] To a solution of (6-chloro-2-methyl-1 ,3-benzoxazol-5-yl)methanol (0.268 g, 1.36 mmol) in dichloromethane (2.71 mL) was added carbon tetrabromide (0.540 g, 1.63 mmol) and the solution was cooled to 0 °C in an ice bath. Triphenylphosphine (0.534 g, 2.03 mmol) was added and the reaction allowed to warm to room temperature. The reaction mixture was stirred for 3 h then concentrated onto diatomaceous earth and purified via flash column chromatography (0-40% ethyl acetate in cyclohexane) to afford 5- (bromomethyl)-6-chloro-2-methyl-1 ,3-benzoxazole (0.213 g, 0.818 mmol, 60%).1H NMR (400 MHz, CDCI3) 5 ppm 7.71 (s, 1 H), 7.55 (s, 1 H), 4.70 (s, 2H), 2.64 (s, 3H).

[0131] Step 3: Preparation of 2-[(6-chloro-2-methyl-1,3-benzoxazol-5-yl)methyl]-4,4-dimethyl-5- (2-trimethylsilylethoxy)isoxazolidin-3-one

[0132] To a solution of 5-(bromomethyl)-6-chloro-2-methyl-1 ,3-benzoxazole (0.238 g, 0.914 mmol) in acetone (7.1 mL) was added potassium carbonate (0.256 g, 1.83 mmol) and 4,4-dimethyl-5-(2-trimethylsilylethoxy)isoxazolidin-3-one (0.317 g, 1.37 mmol). The reaction was stirred at room temperature overnight then diluted with acetone (10 mL), filtered through diatomaceous earth and concentrated onto diatomaceous earth. Purification via flash column chromatography (0-30% ethyl acetate in cyclohexane) afforded 2-[(6-chloro-2-methyl-1 ,3-benzoxazol-5-yl)methyl]-4,4-dimethyl-5-(2- trimethylsilylethoxy)isoxazolidin-3-one (0.106 g, 0.258 mmol, 28%).1H NMR (400 MHz, CDCI3) 5 ppm 7.68 (s, 1 H), 7.52 (s, 1 H), 4.99 (d, 1 H), 4.89 - 4.85 (m, 2H), 3.70 - 3.63 (m, 1 H), 3.47 - 3.40 (m, 1 H), 2.62 (s, 3H), 1.30 (s, 3H), 1.21 (s, 3H), 0.90 - 0.84 (m, 2H), -0.07 (s, 9H).

[0133] Step 4: Preparation of 2-[(6-chloro-2-methyl-1 ,3-benzoxazol-5-yl)methyl]-5-hydroxy-4,4- dimethyl-isoxazolidin-3-one

[0134] To a solution of 2-[(6-chloro-2-methyl-1 ,3-benzoxazol-5-yl)methyl]-4,4-dimethyl-5- (2-trimethylsilylethoxy)isoxazolidin-3-one (0.106 g, 0.258 mmol) in dichloromethane (2.6 mL) at 0 °C was added boron trifluoride diethyl etherate (0.183 g, 0.16 mL, 1.29 mmol) dropwise. The reaction mixture was stirred at room temperature under nitrogen for 48 h then further boron trifluoride diethyl etherate (0.183 g, 0.16 mL, 1.29 mmol) was added and the reaction was stirred at room temperature under nitrogen for 72 h. The reaction was quenched with sat. aq. NaHCOs and the product extracted with ethyl acetate (x3). The organic portions were combined, dried over MgSC>4, filtered and concentrated. Purification by flash column chromatography (0-80% ethyl acetate in cyclohexane) afforded 2-[(6-chloro-2-methyl-1 ,3-benzoxazol-5-yl)methyl]-5-hydroxy-4,4-dimethyl- isoxazolidin-3-one (38.0 mg, 0.122 mmol, 47%).1H NMR (400 MHz, CDCI3) 6 ppm 7.68 (s, 1 H), 7.50 (s, 1 H), 5.29 (d, 1 H), 5.01 - 4.97 (m, 1 H), 4.90 - 4.86 (m, 1 H), 3.82 (d, 1 H), 2.62 (s, 3H), 1.31 (s, 3H), 1.28 (s, 3H).

[0135] Step 5: Preparation of 2-[(6-chloro-2-methyl-1,3-benzoxazol-5-yl)methyl]-4,4-dimethyl- isoxazolidine-3, 5-dione

[0136] (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl (2.0 mg, 0.012 mmol) was added to a solution of 2-[(6-chloro-2-methyl-1 ,3-benzoxazol-5-yl)methyl]-5-hydroxy-4,4-dimethyl- isoxazolidin-3-one (38 mg, 0.12 mmol) and 1 ,3,5-trichloro-1 ,3,5-triazinane-2,4,6-trione (34 mg, 0.15 mmol) in dichloromethane (0.61 mL). The reaction mixture was stirred at room temperature for 1.5 h then diluted with dichloromethane (10 mL), filtered through diatomaceous earth and concentrated onto diatomaceous earth. Purification via flash column chromatography (0-60% ethyl acetate in cyclohexane afforded 2-[(6-chloro-2- methyl-1 ,3-benzoxazol-5-yl)methyl]-4,4-dimethyl-isoxazolidine-3, 5-dione (26 mg, 0.084 mmol, 69%).1H NMR (400 MHz, CDCI3) 6 ppm 7.65 (s, 1 H), 7.57 (s, 1 H), 5.15 (s, 2H), 2.65 (s, 3H), 1.47 (s, 6H).

[0137] Step 6: Preparation of sodium 3-[(6-chloro-2-methyl-1,3-benzoxazol-5-yl)methyl-hydroxy- amino]-2,2-dimethyl-3-oxo-propanoate

[0138] To a stirred solution of 2-[(6-chloro-2-methyl-1 ,3-benzoxazol-5-yl)methyl]-4,4- dimethyl-isoxazolidine-3, 5-dione (0.103 g, 0.343 mmol) in methanol (0.7 mL) and 2- methyltetrahydrofuran (0.7 mL) was added sodium hydroxide (2 M solution in water, 0.17 mL, 0.34 mmol). The reaction mixture was stirred at room temperature for 40 min then concentrated to dryness. The resulting residue was re-dissolved in water and again concentrated to dryness to afford sodium 3-[(6-chloro-2-methyl-1 ,3-benzoxazol-5- yl)methyl-hydroxy-amino]-2,2-dimethyl-3-oxo-propanoate.1H NMR (400 MHz, DMSO-de) 5 ppm 15.45 (br s, 1 H), 7.71 (s, 1 H), 7.55 (s, 1 H), 4.70 (s, 2H), 2.57 (s, 3H), 1.31 (s, 6H).

[0139] Structures and characterising data for the Examples described above are shown in Table 1 below. Table 1 Compounds of the present invention

[0140] BIOLOGICAL EXAMPLES

[0141] Seeds of a variety of test species are sown in standard soil in pots Amaranthus palmeri (AMAPA), Amaranthus retoflexus (AMARE), Setaria faberi (SETFA), Echinochloa crus-galli (ECHCG) and Ipomoea hederacea (IPOHE). After cultivation for one day (preemergence) or after 8 days cultivation (post-emergence) under controlled conditions in a glasshouse (at 24 / 16°C, day / night; 14 hours light; 65% humidity), the plants are sprayed with an aqueous spray solution derived from either i) the formulation of the technical active ingredient in acetone I water (50:50) solution containing 0.5% Tween™ 20 (polyoxyethelyene sorbitan monolaurate, CAS RN 9005-64-5) or ii) the dissolution of the technical active ingredient in a small amount of acetone and a special solvent and emulsifier mixture referred to as IF50 (11.12% Emulsogen™ EL360 TM + 44.44% N- methylpyrrolidone + 44.44% Dowanol™ DPM glycol ether), which was then diluted to required concentration using 0.2% Genapol™ XO80 (CAS No.9043-30-5) in water, as the diluent. Compounds are applied at 1000 g / ha. The test plants are then grown in a glasshouse under controlled conditions in a glasshouse (at 24 / 16°C, day / night; 14 hours light; 65% humidity) and watered twice daily. After 13 days for pre and post-emergence, the test is evaluated for the percentage damage caused to the plant. The biological activities are shown in the following tables on a five-point scale (5 = 81-100%; 4 = 61- 80%; 3=41-60%; 2=21-40%; 1=0-20%).

[0142] Table B1. Post-emergence Test

[0143] Table B2. Pre-emergence Test

Claims

CLAIMS1. A compound of Formula (I),or an agronomically acceptable salt thereof, wherein:A1is selected from the group consisting of C(R4), N(R5)n, S and O;A2is selected from the group consisting of C(R4), N(R5)n, S and O;A3is selected from the group consisting of C(R4), N(R5)n, S and O;X1is a halogen;R1is hydrogen or Ci-C4alkyl;R2and R3are both Ci-Csalkyl;R4is selected from the group consisting of hydrogen, halogen, Ci-Csalkyl, aryl, Ci- Cshaloalkyl, Ci-Cshaloalkoxy-, Ci-Csalkoxy-, and Cs-Cecycloalkyl;R5is selected from the group consisting of hydrogen, Ci-Csalkyl-, Cs-Cecycloalkyl and Ci-Cshaloalkyl; n is 0 or 1.

2. The compound of Formula (I) according to claim 1 , wherein X1is bromo, chloro or fluoro.

3. The compound of Formula (I) according to claim 2, wherein X1is chloro.

4. The compound of Formula (I) according to any one of the previous claims, wherein R2and R3are both methyl.

5. The compound according to any one of the previous claims wherein R4is selected from the group consisting of hydrogen, Ci-Csalkyl, Cs-Cecycloalkyl-, aryl, Ci- Cshaloalkyl, Ci-Cshaloalkoxy-, and Ci-Csalkoxy-.

6. The compound according to any one of the previous claims, wherein R4is selected from the group consisting of hydrogen, methyl, cyclopropyl and difluoromethyl.

7. The compound according to any one of the previous claims, wherein R4is methyl.

8. The compound according to any one of claims 1 to 7 wherein R5is selected from the group consisting of hydrogen, methyl and ethyl.

9. The compound according to claim 8, wherein R5is methyl.

10. A herbicidal composition comprising a compound of Formula (I) as defined in any one of the previous claims and an agriculturally acceptable formulation adjuvant.

11. A herbicidal composition according to claim 10, further comprising at least one additional pesticide.

12. A herbicidal composition according to claim 11 , wherein the additional pesticide is a herbicide or herbicide safener.

13. A method of controlling weeds at a locus comprising applying to the locus a weed controlling amount of a composition as defined in any one of claims 10 to 12.

14. Use of a compound of Formula (I) as defined in claim 1 as a herbicide.

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