WO2025114013A1

WO2025114013A1 - Herbicidal compounds

Info

Publication number: WO2025114013A1
Application number: PCT/EP2024/082288
Authority: WO
Inventors: Joseph Andrew TATE; Suzanna DALE
Original assignee: Syngenta Crop Protection AG Switzerland
Current assignee: Syngenta Crop Protection AG Switzerland
Priority date: 2023-11-27
Filing date: 2024-11-14
Publication date: 2025-06-05
Anticipated expiration: 2026-05-27

Abstract

The application relates to compounds of Formula (I), or an agronomically acceptable salt of said compounds, 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

HERBICIDAL COMPOUNDS

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.

Herbicidal 3-isoxazolidinones are known from US 4,405,357. Herbicidal isoxazolidine-3, 5-diones are known from US 4,302,238. W02023/020274 describes the 3- isoxazolidinone compound Broclozone and its use as a herbicide.

The present invention relates to novel 3-isoxazolidinone and isoxazolidine-3, 5-dione compounds. Thus, according to the present invention there is provided a compound of Formula (I):

or an agronomically acceptable salt thereof, wherein:

A¹ is CHR¹ or C(O); A² is selected from the group consisting of CR⁹R¹⁰, C(O), O, S(O)_P and N(R¹³); A³ is selected from the group consisting of CR¹¹R¹², C(O), O, S(O)_P and N(R¹³⁾; X¹ is O or S; X² is bromo or fluoro; R¹ is selected from the group consisting of hydrogen, halogen, hydroxy, C1-C6alkoxy, C1-C6alkoxy-C1-C6alkoxy-, C1-C3alkyl-C(O)O-, HOC(O)Ci- Cealkoxy-, C1-C6alkoxy-C(O)- C1-C6alkoxy-, C1-C3alkyl-S(O)_p- and C1-C3alkyl-S(O)_pC1- Cealkoxy-; R³ is C1-C3alkyl; R⁴ is C1-C3alkyl; R⁵ is selected from the group consisting of hydrogen, halogen, C1-C6alkyl, C1-C6haloalkyl, C3-C6cycloalkyl and C1-C6alkoxy-; and R⁶ is selected from the group consisting of hydrogen, halogen, C1-C6alkyl, C1-C6haloalkyl, C3- Cecycloalkyl and C1-C6alkoxy-; or R⁵ and R⁶ together are =0 or -(CH2)n-; and R⁷ is selected from the group consisting of hydrogen, halogen, C1-C6alkyl, C1-C6haloalkyl, C3-C6cycloalkyl and C1-C6alkoxy-; R⁸ is selected from the group consisting of hydrogen, halogen, C1- C6alkyl, C1-C6haloalkyl, C3-C6cycloalkyl and C1-C6alkoxy-; or R⁷ and R⁸ together are =0 or - (CH₂)n-; and R⁹ is selected from the group consisting of hydrogen, halogen, C1-C6alkyl, C1-C6haloalkyl, C3-C6cycloalkyl and C1-C6alkoxy-; R¹⁰ is selected from the group consisting of hydrogen, halogen, C1-C6alkyl, C1-C6haloalkyl, C3-C6cycloalkyl and C1-C6alkoxy-; or R⁹ and R¹⁰ together are -(CH2)n-; and R¹¹ is selected from the group consisting of hydrogen, halogen, C1-C6alkyl, C1-C6haloalkyl, C3-C6cycloalkyl and C1-C6alkoxy-; R¹² is selected from the group consisting of hydrogen, halogen, C1-C6alkyl, C1-C6haloalkyl, C3-C6cycloalkyl and C1-C6alkoxy-; or R¹¹ and R¹² together are -(CH2)n-; R¹³ is hydrogen or C1-C3alkyl; n is independently 2, 3, 4 ,5 or 6; and p is independently 0, 1 or 2.

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.

In a third aspect the invention provides the use of a compound of Formula (I) or a composition of the invention as a herbcide.

In a third aspect, the invention provides a method of controlling plants, comprising applying to the plants or to the locus of the plants, a herbicidally effective amount of a compound or composition of the invention.

In a fourth aspect, the invention provides a method of inhibiting plant growth, comprising applying to the plants or to the locus thereof, a herbicidally effective amount of a compound or composition of the invention.

In a fifth aspect, the invention provides a method of controlling weeds in crops of useful plants, comprising applying to the weeds or to the locus of the weeds, or to the useful plants or to the locus of the useful plants, a herbicidally effective amount of a compound or composition of the invention.

In a sixth aspect, the invention provides a method of selectively controlling grasses and/or weeds in crops of useful plants which comprises applying to the useful plants or locus thereof or to the area of cultivation a herbicidally effective amount of a compound or composition of the invention.

As used herein the term C1-C6alkyl- includes, for example, 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). C1-C3alkyl includes methyl (Me, CH3), ethyl (Et, C2H5) and propyl (Pr e.g /so-propyl and n-propyl).

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. C1-C6haloalkyl- 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. C1-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. C1-C6alkoxy includes methoxy, ethoxy and iso-propoxy-. C1-C6haloalkoxy- 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. C1-C6alkoxy-C1-C6alkoxy- includes for example methoxym ethoxy- and ethoxymethoxy-. C1-C3alkyl-C(O)O- includes methyl-C(O)O- and ethyl-C(O)O-. C1-C6alkoxy-C(O)-C1-C6alkoxy- includes methoxy-C(O)-methoxy- and ethoxy-C(O)- m ethoxy-. C1-C3alkyl-S(O)_p C1-C6alkoxy- includes methyl-S(O)_pmethoxy- and ethyl- S(O)_pmethoxy-. C3-C6cycloalkyl includes cyclopropyl, cyclopentyl and cyclohexyl.

Ci-C4alkyl-S- (alkylthio) includes, for example, methylthio, ethylthio, propylthio, isopropylthio, n-butylthio, isobutylthio, sec-butylthio or tert-butylthio, preferably methylthio or ethylthio.

Ci-C4alkyl-S(O)- (alkylsulfinyl) includes, for example, methylsulfinyl, ethylsulfinyl, propylsulfinyl, isopropylsulfinyl, n-butylsulfinyl, isobutylsulfinyl, sec-butylsulfinyl or tert- butylsulfinyl, preferably methylsulfinyl or ethylsulfinyl.

Ci-C4alkyl-S(O)2- (alkylsulfonyl) includes, for example, methylsulfonyl, ethylsulfonyl, propylsulfonyl, isopropylsulfonyl, n-butylsulfonyl, isobutylsulfonyl, sec-butylsulfonyl or tert- butylsulfonyl, preferably methylsulfonyl or ethylsulfonyl.

Preferred values of A¹, A², A³, X¹, X², R³, R⁴, R⁵, R⁶, R⁷, R⁸, as well as of the substituents comprised within these moieties (i.e. R¹, R⁹, R¹⁰, R¹¹, R¹², R¹³, p and n) are given below and 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 for any specified set of embodiments may combined with values for any other set of embodiments where such combinations are not mutually exclusive.

As stated herein, X¹ may be O or S, however in one set of embodiments it is preferred that X¹ is O.

Preferably X² is bromo.

A¹ is defined as CHR¹ or C(O). In embodiments where A¹ is CHR¹, it is preferred that R¹ is is hydrogen, hydroxy, or C1-C6alkoxy. Such embodiments may be referred to as compounds of Formula (la)

wherein R³, R⁴, X¹, X², A², A³, R⁵, R⁶, R⁷, and

R⁸ are as defined herein. In one set of such embodiments it is preferred that R¹ is hydrogen whilst in a further set of such embodiments it is preferred that R¹ is OH or C1-C6alkoxy.

In alternative embodiments A¹ is C(O), and such embodiments may be referred to as compounds of Formula (lb)

wherein R³, R⁴, X¹, X², A², A³, R⁵, R⁶, R⁷, and

R⁸ are as defined herein.

Preferably R³ is methyl or ethyl, more preferably methyl.

Preferably R⁴ is methyl or ethyl, more preferably methyl. In ones set of embodiments both R³ and R⁴ are methyl.

A² is selected from the group consisting of CR⁹R¹⁰, C(O), O, S(O)_P and N(R¹³). Preferably A² is selected from the group consisting of CH2, C(O), O, S and NH. More preferably A² is O.

A³ is selected from the group consisting of CR¹¹R¹², C(O), O, S(O)_P and N(R¹³). Preferably A³ is selected from the group consisting of CH2, C(O), O, S and NH. More preferably A³ is CH2, C(O) or O, and most preferably A³ is O.

In one set of preferred embodiments A² is O, and A³ is selected from CR¹¹R¹² (preferably CH2), C(O), and O. In a further set of preferred embodiments A² and A³ are both O.

Preferably R⁵, R⁶, R⁷ and R⁸ are independently selected from the group consisting of hydrogen, halogen and Ci-Cealkyl. In a more preferred embodiment, R⁵, R⁶, R⁷ and R⁸ are independently selected from the group consisting of hydrogen, methyl and fluoro. In another embodiment, R⁵ and R⁶ are halogen, preferably fluoro and R⁷ and R⁸ are hydrogen. 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.

The present invention also provides agronomically acceptable salts of compounds of Formula (I). 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.

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.

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.

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 micro-emulsion (ME), an oil dispersion (CD), 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).

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).

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).

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).

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).

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-Cio 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.

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.

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.

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.

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. 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).

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

Suitable SAAs of the cationic type include quaternary ammonium compounds (for example cetyltrimethyl ammonium bromide), imidazolines and amine salts.

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.

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.

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

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, Sixteenth Edition, British Crop Protection Council, 2012.

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.

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

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).

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.

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

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, 16^th Edition (BCPC), 2012. 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.

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.

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.

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.

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.

Crop plants are to be understood as also including those crop plants that have been rendered tolerant to other herbicides or classes of herbicides (e.g. ALS-, GS-, EPSPS-, PPO-, 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®.

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.

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).

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, Brom us, Cenchrus, Cyperus, 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.

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.

Processes for preparation of compounds, e.g. a compound of Formula (I) (which optionally can be an agrochemically acceptable salt thereof), are now described, and form further aspects of the present invention. SCHEME 1

In embodiments where A¹ is -CHR¹- and X¹ is O, compounds of formula (1) may be prepared from compounds of formula (2), where LG¹ represents a suitable leaving group (for example Br or Cl), and compounds of formula (3).

Compounds of formula (2) are treated with compounds of formula (3), a carbonate base, for example potassium carbonate, and optionally a suitable additive, for example sodium iodide, in a suitable solvent, for example acetone.

SCHEME 2

Compounds of formula (2) may be prepared from compounds of formula (4).

For example, where LG¹ is Cl, compounds of formula (4) are treated with a chlorinating agent, for example thionyl chloride, either neat or in a suitable solvent, for example dichloromethane.

SCHEME 3

In an alternative approach, in embodiments where A¹ is -CHR¹- and X¹ is O, compounds of formula (1) may be prepared from compounds of formula (4).

Compounds of formula (4) are treated with isoxazolidinones of formula (3), triphenylphosphine and a suitable azodicarboxylate reagent, for example diisopropyl azodicarboxylate, in a suitable solvent, for example 2-methyltetrahydrofuran.

SCHEME 4

Compounds of formula (4) may be prepared from compounds of formula (5), where Z is H or O-alkyl.

(5) (4) For example, where Z is H, compounds of formula (5) are treated with a reducing agent, for example sodium borohydride, in a suitable solvent, for example a tetrahydrofuran/methanol mixture.

SCHEME 5 The synthesis routes used to access compounds of formula (5) will vary depending on the nature of Z, X², A², A³, R⁵, R⁶, R⁷ and R⁸. For example, compounds of formula (6) may be prepared from compounds of formula (7).

(7) (6) Compounds of formula (7) are reacted under suitable formylation conditions, for example by treatment with titanium tetrachloride and dichloro(methoxy)methane, in a suitable solvent, for example dichloromethane.

SCHEME 6

In an alternative approach, compounds of formula (8) may be prepared from compounds of formula (9).

Compounds of formula (9) are treated with a brominating agent, for example /V- bromosuccinimide, in a suitable solvent, for example acetonitrile.

SCHEME 7

Compounds of formula (9) may be prepared from compounds of formula (10), where

Z is H or O-alkyl.

For example, where Z is H, compounds of formula (10) are treated with a reducing agent, for example sodium borohydride, in a suitable solvent, for example water.

SCHEME 8

In a further alternative approach, compounds of formula (4) may be prepared from compounds of formula (11).

(11) (4)

Compounds of formula (11) are treated with tributylstannylmethanol in the presence of a suitable (pre-)catalyst/ligand combination, for example (2-dicyclohexylphosphino- 2',4',6'-triisopropyl-1 ,T-biphenyl)[2-(2'-amino-1 ,1'-biphenyl)]palladium(ll) methanesulfonate, in a suitable solvent, for example 1 ,4-dioxane.

SCHEME 9

Compounds of formula (11) may be prepared from compounds of formula (7).

Compounds of formula (7) are treated with a brominating agent, for example /V- bromosuccinimide, in a suitable solvent, for example acetonitrile.

SCHEME 10

Compounds of formula (5), formula (7), formula (9), formula (10) and formula (11) may be commercially available. Alternatively, they may be prepared synthetically, for example by utilising ring synthesis strategies known in the literature. The synthetic route adopted will vary depending on the nature of Z, X², A², A³, R⁵, R⁶, R⁷ and R⁸. For example, compounds of formula (12) may be prepared from compounds of formula (13) according to the following scheme. Compounds of formula (13) and formula (14) are available from commercial sources or may be prepared according to strategies known in the literature.

Compounds of formula (13) are treated with compounds of formula (14), where LG² represents a suitable leaving group (for example Br or Cl), and a carbonate base, for example potassium carbonate, in a suitable solvent, for example acetonitrile, to give compounds of formula (15). Compounds of formula (15) are treated with a suitable reducing agent, for example sodium borohydride, in a suitable solvent, for example methanol, to give compounds of formula (16). Compounds of formula (16) are treated with of a suitable (pre- )catalyst/ligand combination, for example copper(l) iodide and 1 ,10-phenanthroline, and a suitable base, for example cesium carbonate, in a suitable solvent, for example toluene, to give compounds of formula (12).

SCHEME 11

In embodiments where A¹ is -C(O)-, compounds of formula (17) may be prepared from compounds of formula (18).

For example, where R³ and R⁴ are methyl, compounds of formula (18) are treated with 2,2-dimethylmalonyl chloride and a suitable base, for example pyridine, in a suitable solvent, for example dichloromethane. SCHEME 12

Compounds of formula (18) may be prepared from compounds of formula (6) according to the following scheme.

(6) (19) (18)

Compounds of formula (6) 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 (19). Compounds of formula (19) 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 (18).

SCHEME 13

Compounds of formula (3) may be commercially available. For example, the compound of formula (3) where R³ and R⁴ are methyl and R¹ is hydrogen is commercially available (CAS no 81778-07-6). Alternatively, compounds of formula (3) may be prepared synthetically. For example, where R³ and R⁴ are methyl and R¹ is C1-C6alkoxy, C1-C6alkoxy- C1-C6alkoxy-, HOC(O)C1-C6alkoxy-, C1-C6alkoxy-C(O)-C1-C6alkoxy- or C1-C3alkyl-S(O)_pC1- Cealkoxy-, compounds of formula (3) may be prepared from 3,3-dichloro-2,2- dimethylpropanoic acid (20) according to the following scheme.

3,3-Dichloro-2,2-dimethylpropanoic acid (20) is treated with a suitable chlorinating agent, for example thionyl chloride, to give 3,3-dichloro-2,2-dimethylpropanoyl chloride (21). 3,3-Dichloro-2,2-dimethylpropanoyl chloride (21) is treated with a suitable source of hydroxylamine, for example hydroxylamine (50% in H2O), to give 3,3-dichloro-2,2-dimethyl- propanehydroxamic acid (22). 3,3-Dichloro-2,2-dimethyl-propanehydroxamic acid (22) is treated with an alcohol and a suitable base, for example 1 ,8-diazabicyclo(5.4.0)undec-7- ene, to give compounds of formula (3).

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

Example 1 : Preparation of Compound 1.001

Step 1 : Preparation of methyl 3-(2-hydroxypropoxy)-4-iodo-benzoate

To a mixture of methyl 3-hydroxy-4-iodo-benzoate (4.4 g, 16 mmol) and potassium carbonate (8.8 g, 64 mmol) in acetonitrile (32 mL) was added 1 -chloropropanone (1.5 mL, 19 mmol). The reaction was heated at 80 °C for 1 h. The reaction mixture was concentrated then partitioned between water and ethyl acetate. The organic portions were washed with brine, dried over MgSO4,, filtered and concentrated. The resulting residue was dissolved in methanol (100 mL) and sodium borohydride (1.2 g, 30 mmol) was added portion wise at 0 °C. The reaction was stirred at 0 °C for 10 min then quenched with saturated aqueous ammonium chloride. The mixture was concentrated then partitioned between water and ethyl acetate. The organic portions were washed with brine, diluted with dimethyl sulfoxide (5 mL) and concentrated to afford a crude dimethyl sulfoxide solution. Purification by reverse phase flash column chromatography (50-80 % acetonitrile in water, both modified with 0.1 % formic acid) afforded methyl 3-(2-hydroxypropoxy)-4-iodo-benzoate (4.04 g, 11.4 mmol, 72%). ¹H NMR (400 MHz, DMSO-d₆) δ ppm 7.94 (d, 1 H), 7.41 (d, 1 H), 7.31 (dd, 1 H), 4.87 (d, 1 H), 4.04 - 3.96 (m, 2H), 3.92 - 3.82 (m, 4H), 1.23 (d, 3H).

Step 2: Preparation of methyl 2-methyl-2,3-dihydro-1 ,4-benzodioxine-6-carboxylate

Under an atmosphere of nitrogen, a mixture of methyl 3-(2-hydroxypropoxy)-4-iodo- benzoate (2.14 g, 6.0 mmol), cesium carbonate (4.0 g, 12 mmol), copper(l) iodide (0.12 g, 0.6 mmol), 1,10-phenanthroline (0.11 g, 0.6 mmol) and toluene (24 mL) were heated to reflux overnight. The reaction mixture was partitioned between ethyl acetate and dilute (0.2 M) hydrochloric acid, then the organics were washed with brine, dried over MgSO4, filtered and concentrated. Purification by reverse phase flash column chromatography (50-80 % acetonitrile in water, both modified with 0.1 % formic acid) afforded methyl 2-methyl-2,3- dihydro-1 ,4-benzodioxine-6-carboxylate (0.55 g, 2.5 mmol, 42%). ¹H NMR (400 MHz, DMSO-d₆) δ ppm 7.46 (dd, 1 H), 7.41 (d, 1 H), 6.96 (d, 1 H), 4.40 - 4.32 (m, 2H), 3.88 - 3.81 (m, 1 H), 3.80 (s, 3H), 1.31 (d, 3H). Step 3: Preparation of methyl 6-bromo-3-methyl-2,3-dihydro-1 ,4-benzodioxine-7- carboxylate

To a solution of methyl 2-methyl-2,3-dihydro-1 ,4-benzodioxine-6-carboxylate (0.55 g, 2.5 mmol) in methanol (4 mL) was added bromine (0.3 mL, 5.8 mmol) drop wise, at 0 °C. The reaction was stirred at 0 °C for 10 min then at room temperature for 1 h. The reaction mixture was quenched by the addition of aqueous sodium thiosulfate solution then purified by reverse phase flash column chromatography (50-80 % acetonitrile in water, both modified with 0.1 % formic acid) to afford methyl 6-bromo-3-methyl-2,3-dihydro-1 ,4- benzodioxine-7-carboxylate (0.362 g, 1.2 mmol, 48%). ¹H NMR (400 MHz, DMSO-de) 5 ppm 7.35 (s, 1 H), 7.22 (s, 1 H), 4.42 - 4.33 (m, 2H), 3.90 - 3.83 (m, 1 H), 3.80 (s, 3H), 1.30 (d, 3H).

Step 4: Preparation of (6-bromo-3-methyl-2,3-dihydro-1,4-benzodioxin-7-yl)methanol

Under an atmosphere of nitrogen, a solution of methyl 6-bromo-3-methyl-2,3- dihydro-1 ,4-benzodioxine-7-carboxylate (0.362 g, 1.3 mmol) in 2-methyltetrahydrofuran (5.4 mL) had diisobutylaluminium hydride (1.0 M solution in hexanes, 4.2 mL, 4.2 mmol) added dropwise whilst maintaining the temperature below 10 °C. The reaction was stirred at 0 °C for 30 min then quenched by the addition of ethyl acetate (3 mL) followed by a 10% aqueous solution of Rochelle salt. The mixture was stirred at room temperature for an additional 30 min then extracted with ethyl acetate. The organics were washed with water and brine, then dried over MgSO4, and concentrated. Purification by flash column chromatography (0-30% ethyl acetate in cyclohexane) afforded (6-bromo-3-methyl-2,3- dihydro-1 ,4-benzodioxin-7-yl)methanol (0.284 g, 1.1 mmol, 87%). ¹H NMR (400 MHz, DMSO-de) δ ppm 7.03 (s, 1 H), 6.98 (s, 1 H), 5.29 (br, 1 H), 4.39 - 4.35 (m, 2H), 4.31 - 4.21 (m, 2H), 3.82 - 3.78 (m, 1 H), 1.27 (d, 3H).

Step 5: Preparation of 2-[(6-bromo-3-methyl-2,3-dihydro-1 ,4-benzodioxin-7-yl)methyl]-4,4- dimethyl-isoxazolidin-3-one

Under an atmosphere of nitrogen, a solution of (6-bromo-3-methyl-2,3-dihydro-1 ,4- benzodioxin-7-yl)methanol (0.284 g, 1.1 mmol), 4,4-dimethyl-1 ,2-oxazolidin-3-one (0.151 g, 1.3 mmol) and triphenylphosphine (0.352 g, 1.3 mmol) in 2-methyltetrahydrofuran (3.3 mL) had diisopropyl azodicarboxylate (0.24 mL, 1.2 mmol) added drop wise at 0 °C. The reaction was stirred at room temperature for 30 min then quenched by the addition of a few drops of water and concentrated onto diatomaceous earth. Purification by reverse phase flash column chromatography (50-80 % acetonitrile in water, both modified with 0.1 % formic acid) afforded 2-[(6-bromo-3-methyl-2,3-dihydro-1 ,4-benzodioxin-7-yl)methyl]-4,4- dimethyl-isoxazolidin-3-one. ¹H NMR (400 MHz, CDCI₃) δ ppm 7.07 (s, 1H), 6.85 (s, 1 H), 4.71 (s, 2H), 4.29 - 4.18 (m, 2H), 4.02 (s, 2H), 3.84 - 3.77 (m, 1 H), 1.35 (d, 3H), 1.27 (s, 6H).

Example 2: Preparation of Compounds 1.002 and 1.003

Step 1 : Preparation of methyl 2-bromo-4,5-dihydroxy-benzoate

To a solution of 2-bromo-4,5-dimethoxybenzoic acid (10.0 g, 38.3 mmol) in dry dichloromethane (80 mL) was added tri bromoborane (1 M solution in dichloromethane, 95.7 mL, 95.7 mmol) dropwise at 0 °C under an atmosphere of nitrogen. The reaction was stirred at room temperature for 2 h then methanol (50 mL) was added dropwise. The mixture was stirred at room temperature for 2 days then quenched with ice water. Volatile organics were removed under reduced pressure resulting in the formation of a precipitate which was collected by filtration and washed with water to give methyl 2-bromo-4,5-dihydroxybenzoate (90 % purity, 7.60 g, 27.7 mmol, 72%). ¹H NMR (400 MHz, DMSO-d₆) δ ppm 7.30 (s, 1 H), 7.03 (s, 1 H), 3.77 (s, 3H).

Step 2: Preparation of methyl 6-bromo-3,3-difluoro-2H -1 ,4-benzodioxine-7-carboxylate and methyl 6-bromo-2,2-difluoro-3/7-1,4-benzodioxine-7-carboxylate

To a solution of methyl 2-bromo-4,5-dihydroxybenzoate (3.00 g, 10.9 mmol) in /V,/V- dimethylformamide (30 mL) was added 1 ,2-dibromo-1 ,1-difluoroethane (2.72 g, 12.1 mmol) and potassium carbonate (6.71 g, 48.6 mmol) under an atmosphere of nitrogen. The reaction was heated at 80 °C for 16 h then diluted with water and extracted with ethyl acetate (x3). The combined organic layers were washed with brine, dried over sodium sulfate, and concentrated. Purification by reverse phase preparative HPLC afforded a mixture of methyl 6-bromo-3,3-difluoro-2H -1,4-benzodioxine-7-carboxylate and methyl 6- bromo-2,2-difluoro-3H -1 ,4-benzodioxine-7-carboxylate (1.18 g, 3.82 mmol, 35%). ¹H NMR (400 MHz, DMSO-d₆) δ ppm 7.67 (s, 1 H), 7.64 (s, 1 H), 7.59 (s, 1 H), 7.57 (s, 1 H), 4.74 - 4.67 (m, 4H), 3.84 (s, 6H).

Step 3: Preparation of (6-bromo-3,3-difluoro-2H -1 ,4-benzodioxin-7-yl)methanol and (6- bromo-2, 2-difluoro-3H -1 , 4- benzodioxi n-7-yl)methanol

A mixture of methyl 6-bromo-3,3-difluoro-2/7-1 ,4-benzodioxine-7-carboxylate and methyl 6-bromo-2,2-difluoro-3H -1 ,4-benzodioxine-7-carboxylate (1.18 g, 3.82 mmol) in tetrahydrofuran (6 mL) had lithium borohydride (2 M solution in tetrahydrofuran, 9.5 mL, 19 mmol) added under an atmosphere of nitrogen. The reaction was heated at 50 °C for 4 h then quenched with water and extracted with ethyl acetate (x3). The combined organic layers were washed with brine, dried over sodium sulfate, and concentrated. Purification by flash column chromatography (0-40% ethyl acetate in petroleum ether) afforded a mixture of (6-bromo-3,3-difluoro-2/7-1 ,4-benzodioxin-7-yl)methanol and (6-bromo-2,2-difluoro-3/7-

1.4-benzodioxin-7-yl)methanol (1.00 g, 3.56 mmol, 93%). ¹H NMR (400 MHz, DMSO-d₆) δ ppm 7.46 (s, 1 H), 7.40 (s, 1 H), 7.23 (s, 1 H), 7.21 (s, 1 H), 5.47 (br s, 2H), 4.62 - 4.59 (m, 4H), 4.45 - 4.41 (m, 4H).

Step 4: Preparation of 2-[(6-bromo-3,3-difluoro-2/7-1,4-benzodioxin-7-yl)methyl]-4,4- dimethyl-isoxazolidin-3-one and 2-[(6-bromo-2,2-difluoro-3/7-1,4-benzodioxin-7-yl)methyl]-

4.4-dimethyl-isoxazolidin-3-one

Under an atmosphere of nitrogen, a mixture of (6-bromo-3,3-difluoro-2H -1 ,4- benzodioxin-7-yl)methanol and (6-bromo-2,2-difluoro-3/7-1 ,4-benzodioxin-7-yl)methanol (1.00 g, 3.56 mmol) in tetrahydrofuran (10 mL) had 4,4-dimethylisoxazolidin-3-one (0.410 g, 3.56 mmol) and triphenylphosphine (1.40 g, 5.34 mmol) added. Diisopropyl azodicarboxylate (1.08 g, 5.34 mmol) was then added drop wise at 0 °C. The reaction mixture was stirred at room temperature for 3 h and was then quenched with water and extracted with ethyl acetate (x3). The combined organic layers were washed with brine, dried over sodium sulfate, concentrated and purified by flash column chromatography (0- 40% ethyl acetate in petroleum ether). The appropriate eluant fractions were combined and concentrated to afford 2-[(6-bromo-3,3-difluoro-2H -1,4-benzodioxin-7-yl)methyl]-4,4- dimethyl-isoxazolidin-3-one. ¹H NMR (400 MHz, DMSO-d6) δ ppm 7.48 (s, 1 H), 7.16 (s, 1 H), 4.68 - 4.61 (m, 4H), 4.05 (s, 2H), 1.14 (s, 6H).

Eluant fractions containing impure 2-[(6-bromo-2,2-difluoro-3H -1,4-benzodioxin-7- yl)methyl]-4,4-dimethyl-isoxazolidin-3-one were combined, concentrated and further purified by reverse phase preparative HPLC to afford 2-[(6-bromo-2,2-difluoro-3H -1 ,4- benzodioxin-7-yl)methyl]-4,4-dimethyl-isoxazolidin-3-one. ¹H NMR (400 MHz, DMSO-d6) δ ppm 7.55 (s, 1 H), 7.10 (s, 1 H), 4.68 - 4.58 (m, 4H), 4.05 (s, 2H), 1.14 (s, 6H).

Example 3: Preparation of Compound 1.004

Preparation of 2-[(6-bromo-2,3-dihydro-1 ,4-benzodioxin-7-yl)methyl]-4,4-dimethyl- isoxazolidin-3-one

Potassium carbonate (0.160 g, 1.14 mmol) and 4,4-dimethylisoxazolidin-3-one (0.105 g, 0.91 mmol) were added to a solution of 6-bromo-7-(chloromethyl)-2,3-dihydro-

1.4-benzodioxine (0.200 g, 0.75 mmol) and sodium iodide (11.4 mg, 0.076 mmol) in acetone (6 mL). The reaction mixture was stirred at room temperature for 3 days and was then quenched by the addition of water and extracted with ethyl acetate (x3). The combined organic extracts were washed with brine, dried over MgSCL, filtered and concentrated. Purification by flash column chromatography (0-40% ethyl acetate in cyclohexane) afforded 2-[(6-bromo-2,3-dihydro-1 ,4-benzodioxin-7-yl)methyl]-4,4-dimethyl-isoxazolidin-3-one. ¹H NMR (400 MHz, CDCI₃) δ ppm 7.07 (s, 1 H), 6.85 (s, 1 H), 4.70 (s, 2H), 4.23 (s, 4H), 4.02 (s, 2H), 1.27 (s, 6H).

Structures and characterising data for the Examples described above are shown in Table 1 below. Compounds 1.005, 1.006 and 1.007 were made in an analogous manner to those described in Examples 1 to 3 above.

Table 1 Compounds of the present invention

BIOLOGICAL EXAMPLES

Seeds of a variety of test species are sown in standard soil in pots Leptochloa chinesis (LEFCH), Echinochloa crus-galli (ECHCG) and Cyperus esculentus (CYPES). After cultivation for one day (pre-emergence) or after 13 days cultivation (post-emergence) under controlled conditions in a glasshouse (at 30/20°C, day/night; 18 hours light; 75% humidity), the plants are sprayed with an aqueous spray solution derived from 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 500 g/ha. The test plants are then grown in a glasshouse under controlled conditions in a glasshouse (at 30/20°C, day/night; 18 hours light; 75% 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 table on a five-point scale (5 = 81-100%; 4 = 61-80%; 3=41-60%;

2=21-40%; 1=0-20%). Table B1 Post-emergence Test

Table B2 Pre-emergence Test

Claims

1. A compound of Formula (I),

wherein

A¹ is CHR¹ or C(O);

A² is selected from the group consisting of CR⁹R¹⁰, C(O), O, S(O)_P and N(R¹³);

A³ is selected from the group consisting of CR¹¹R¹², C(O), O, S(O)_P and N(R¹³⁾;

X¹ is O or S;

X² is bromo or fluoro,

R¹ is selected from the group consisting of hydrogen, halogen, hydroxy, C1- Cealkoxy, C1-C6alkoxy-C1-C6alkoxy-, C1-C3alkyl-C(O)O-, HOC(O)C1-C6alkoxy-, C1- C6alkoxy-C(O)-C1-C6alkoxy-, C1-C3alkyl-S(O)_p- and C1-C3alkyl-S(O)_pC1-C6alkoxy-;

R³ is C1-C3alkyl;

R⁴ is C1-C3alkyl;

R⁵ is selected from the group consisting of hydrogen, halogen, C1-C6alkyl, C1- Cehaloalkyl, C3-C6cycloalkyl and C1-C6alkoxy-; and

R⁶ is selected from the group consisting of hydrogen, halogen, C1-C6alkyl, C1- Cehaloalkyl, C3-C6cycloalkyl and C1-C6alkoxy-; or

R⁵ and R⁶ together are =0 or -(CH2)n-; and R⁷ is selected from the group consisting of hydrogen, halogen, C1-C6alkyl, C1-

Cehaloalkyl, C3-C6cycloalkyl and C1-C6alkoxy-;

R⁸ is selected from the group consisting of hydrogen, halogen, C1-C6alkyl, C1- Cehaloalkyl, C3-C6cycloalkyl and C1-C6alkoxy-; or

R⁷ and R⁸ together are =0 or -(CH2)n-; and

R⁹ is selected from the group consisting of hydrogen, halogen, C1-C6alkyl, C1- Cehaloalkyl, C3-C6cycloalkyl and C1-C6alkoxy-;

R¹⁰ is selected from the group consisting of hydrogen, halogen, C1-C6alkyl, C1- Cehaloalkyl, C3-C6cycloalkyl and C1-C6alkoxy-; or

R⁹ and R¹⁰ together are -(CH2)n-; and

R¹¹ is selected from the group consisting of hydrogen, halogen, C1-C6alkyl, C1- Cehaloalkyl, C3-C6cycloalkyl and C1-C6alkoxy-;

R¹² is selected from the group consisting of hydrogen, halogen, C1-C6alkyl, C1- Cehaloalkyl, C3-C6cycloalkyl and C1-C6alkoxy-; or

R¹¹ and R¹² together are -(CH2)n-;

R¹³ is hydrogen or C1-C3alkyl; n is independently 2, 3, 4 ,5 or 6; and p is independently 0, 1 or 2.

2. The compound of Formula (I) according to claim 1 wherein X¹ is O.

3. The compound of Formula (I) according to claim 1 or claim 2, wherein R³ and R⁴ are methyl.

4. The compound of Formula (I) accordingly to any one of the previous claims, wherein A¹ is CHR¹ and R¹ is hydrogen, hydroxy or C1-C6alkoxy.

5. The compound of Formula (I) according to any one of claims 1 to 3, wherein A¹ is C(O).

6. The compound of Formula (I) according to any one of the previous claims wherein X² is bromo.

7. The compound of Formula (I) according to any one of the previous claims, wherein A² is O.

8. The compound of Formula (I) according to claim 7, wherein A³ is CR¹¹R¹².

9. The compound of Formula (I) according to any one of claims 1 to 7, wherein A² and A³ are both O.

10. The compound of Formula (I) according to any of the previous claims, wherein R⁵, R⁶, R⁷ and R⁸ are each independently selected from the group consisting of hydrogen, methyl and fluoro.

11. A herbicidal composition comprising a compound of Formula (I) according to any one of the previous claims and an agriculturally acceptable formulation adjuvant.

12. The herbicidal composition according to claim 11 , further comprising at least one additional pesticide.

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

14. A method of controlling weeds at a locus comprising applying to the locus a weed controlling amount of a composition according to any one of claims 11 to 13.

15. Use of a compound of Formula (I) as defined in any one of claims 1 to 10 as a herbicide.