Herbicidal Compounds

The present invention relates to herbicidally active isoxazoline derivatives, as well as to processes and intermediates used for the preparation of such derivatives. The invention further extends to herbicidal compositions comprising such derivatives, as well as to the use of such compounds and compositions for controlling undesirable plant growth: in particular the use for controlling weeds, in crops of useful plants.

The present invention is based on the finding that isoxazoline derivatives of formula (I) as defined herein, exhibit surprisingly good herbicidal activity. Thus, according to the present invention there is provided a compound of formula (I) or an agronomically acceptable salt thereof: wherein

R ¹ is selected from the group consisting of hydrogen and Ci-C6alkyl;

R ² is selected from the group consisting of hydrogen, amino, Ci-C6alkyl, C3-C6alkenyl and C3- C6alkynyl;

R ³ is selected from the group consisting of hydrogen, halogen, Ci-C ₄ alkyl, Ci-C ₄ haloalkyl, Ci- C ₄ alkoxy, Ci-C ₄ haloalkoxy and Ci-C ₄ alkylsulfonyl;

R ⁴ is selected from the group consisting of hydrogen, halogen, cyano, aminocarbonyl, aminothiocarbonyl, Ci-C ₄ alkyl, Ci-C ₄ haloalkyl, Ci-C ₄ alkoxy, Ci-C ₄ haloalkoxy and Ci-C ₄ alkylsulfonyl; each R ⁵ and R ⁶ is independently selected from the group consisting of hydrogen, cyano, Ci-C6alkyl, Ci-Cehaloalkyl, Ci-C ₄ alkylsulfonyl, CO2R ⁹ , CONR ¹⁰ R ¹¹ and CH2OR ¹² ; each R ⁷ and R ⁸ is independently selected from the group consisting of hydrogen, cyano, Ci-C6alkyl, Ci-Cehaloalkyl, Ci-C ₄ alkoxy, Ci-C ₄ alkylsulfonyl, C(=Z)R ¹⁵ , CO2R ⁹ , CONR ¹⁰ R ¹¹ and CH2OR ¹² ;

Z is selected from the group consisting of oxygen, NOR ¹⁶ and NN(R ¹⁶ )2;

R ⁹ is selected from the group consisting of hydrogen, Ci-Cioalkyl, Ci-Ciohaloalkyl, C3-C6alkenyl, C3- C6haloalkenyl, C3-C6alkynyl, Ci-C ₄ alkoxyCi-C6alkyl, Ci-C ₄ haloalkoxyCi-C6alkyl, C6-CioarylCi-C3alkyl, C6-CioarylCi-C3alkyl substituted by 1-4 groups R ¹³ , heteroarylCi-C3alkyl and heteroarylCi-C3alkyl substituted by 1-3 groups R ¹³ ;

R ¹⁰ is selected from the group consisting of hydrogen, Ci-C6alkyl and SO2R ¹⁴ ;

R ¹¹ is selected from the group consisting of hydrogen and Ci-C6alkyl; or

R ¹⁰ and R ¹¹ together with the nitrogen to which they are attached form a 3- to 6-membered heterocyclyl ring, which optionally contains an oxygen atom; R ¹² is selected from the group consisting of hydrogen, Ci-C ₄ alkyl, Ci-C ₄ haloalkyl, Ci-C ₄ alkylsulfonyl, Ci-C ₄ haloalkylsulfonyl, phenylsulphonyl, phenylsulfonyl substituted by 1-2 groups R ¹³ ; Ci- C ₄ alkylcarbonyl, Ci-C ₄ haloalkylcarbonyl, C6-Cioarylcarbonyl, C6-Cioarylcarbonyl substituted by 1-4 groups R ¹³ , heteroarylcarbonyl, heteroarylcarbonyl substituted by 1-3 groups R ¹³ , C6-CioarylCi- C3alkylcarbonyl, C6-CioarylCi-C3alkylcarbonyl substituted by 1-4 groups R ¹³ , heteroarylCi- C3alkylcarbonyl and heteroarylCi-C3alkylcarbonyl substituted by 1-3 groups R ¹³ ; each R ¹³ is independently selected from the group consisting of halogen, Ci-C ₄ alkyl, Ci-C ₄ haloalkyl, Ci-C ₄ alkoxy, Ci-C ₄ haloalkoxy, cyano and Ci-C ₄ alkylsulfonyl;

R ¹⁴ is selected from the group consisting of Ci-C ₄ alkyl, Ci-C ₄ haloalkyl, and Ci-C ₄ alkyl(Ci- C ₄ alkyl)amino;

R ¹⁵ is selected from the group consisting of hydrogen, Ci-C ₄ alkyl and Ci-C ₄ haloalkyl; each R ¹⁶ is independently selected from the group consisting of hydrogen, Ci-C ₄ alkyl, Ci-C ₄ haloalkyl and Ci-C ₄ alkoxycarbonylCi-C ₄ alkyl;

R ¹⁷ is selected from the group consisting of hydrogen, Ci-C ₄ alkyl and Ci-C ₄ haloalkyl.

According to a second aspect of the invention, there is provided an agrochemical composition comprising a herbicidally effective amount of a compound of formula (I) and an agrochemically- acceptable diluent or carrier. Such an agricultural composition may further comprise at least one additional active ingredient.

According to a third aspect of the invention, there is provided a method of controlling or preventing undesirable plant growth, wherein a herbicidally effective amount of a compound of formula (I), or a composition comprising this compound as active ingredient, is applied to the plants, to parts thereof or the locus thereof.

According to a fourth aspect of the invention, there is provided the use of a compound of formula (I) as a herbicide.

According to a fifth aspect of the invention, there is provided a process for the preparation of compounds of formula (I).

As used herein, the term "halogen" or “halo” refers to fluorine (fluoro), chlorine (chloro), bromine (bromo) or iodine (iodo), preferably fluorine, chlorine or bromine.

As used herein, cyano means a -CN group.

As used herein, hydroxy means an -OH group.

As used herein, nitro means an -NO2 group.

As used herein, the term "Ci-C6alkyl" refers to a straight or branched hydrocarbon chain radical consisting solely of carbon and hydrogen atoms, containing no unsaturation, having from one to six carbon atoms, and which is attached to the rest of the molecule by a single bond. Ci-C ₄ alkyl and Ci- C2alkyl are to be construed accordingly. Examples of Ci-C6alkyl include, but are not limited to, methyl (Me), ethyl (Et), n-propyl, 1-methylethyl (iso-propyl), n-butyl, and 1-dimethylethyl (f-butyl). As used herein, the term "Ci-C6alkoxy" refers to a radical of the formula -OR _a where R _a is a Ci- C6alkyl radical as generally defined above. Ci-C ₄ alkoxy is to be construed accordingly. Examples of Ci- ₄ alkoxy include, but are not limited to, methoxy, ethoxy, propoxy, iso-propoxy and f-butoxy.

As used herein, the term "Ci-C6haloalkyl" refers to a Ci-C6alkyl radical as generally defined above substituted by one or more of the same or different halogen atoms. Ci-C ₄ haloalkyl is to be construed accordingly. Examples of Ci-C6haloalkyl include, but are not limited to chloromethyl, fluoromethyl, fluoroethyl, difluoromethyl, trifluoromethyl and 2,2,2-trifluoroethyl.

As used herein, the term "C2-C6alkenyl" refers to a straight or branched hydrocarbon chain radical group consisting solely of carbon and hydrogen atoms, containing at least one double bond that can be of either the (E)- or (^-configuration, having from two to six carbon atoms, which is attached to the rest of the molecule by a single bond. C ₂ -C ₄ alkenyl is to be construed accordingly. Examples of C2-C6alkenyl include, but are not limited to, prop-1 -enyl, allyl (prop-2-enyl) and but-1-enyl.

As used herein, the term “C2-C6haloalkenyl” refers to a C2-C6alkenyl radical as generally defined above substituted by one or more of the same or different halogen atoms. Examples of C2-C6haloalkenyl include, but are not limited to chloroethylene, fluoroethylene, 1 ,1-difluoroethylene, 1 ,1-dichloroethylene and 1 ,1 ,2-trichloroethylene.

As used herein, the term "C2-C6alkynyl" refers to a straight or branched hydrocarbon chain radical group consisting solely of carbon and hydrogen atoms, containing at least one triple bond, having from two to six carbon atoms, and which is attached to the rest of the molecule by a single bond. C ₂ -C ₄ alkynyl is to be construed accordingly. Examples of C2-C6alkynyl include, but are not limited to, prop-1-ynyl, propargyl (prop-2-ynyl) and but-1-ynyl.

As used herein, the term "Ci-C6haloalkoxy" refers to a Ci-C6alkoxy group as defined above substituted by one or more of the same or different halogen atoms. Ci-C ₄ haloalkoxy is to be construed accordingly. Examples of Ci-C6haloalkoxy include, but are not limited to, fluoromethoxy, difluoro methoxy, fluoroethoxy, trifluoromethoxy and trifluoroethoxy.

As used herein, the term "Ci-C3haloalkoxyCi-C3alkyl" refers to a radical of the formula Rb-0-R _a - where Rb is a Ci-C3haloalkyl radical as generally defined above, and R _a is a Ci-C3alkylene radical as generally defined above.

As used herein, the term "Ci-C3alkoxyCi-C3alkyl" refers to a radical of the formula Rb-0-R _a - where Rb is a Ci-C3alkyl radical as generally defined above, and R _a is a Ci-C3alkylene radical as generally defined above.

As used herein, the term " Ci-C3alkoxyCi-C3alkoxy-" refers to a radical of the formula Rb-0-R _a - O- where Rb is a Ci-C3alkyl radical as generally defined above, and R _a is a Ci-C3alkylene radical as generally defined above.

As used herein, the term "C3-C6alkenyloxy" refers to a radical of the formula -OR _a where R _a is a C3-C6alkenyl radical as generally defined above.

As used herein, the term "C3-C6alkynyloxy" refers to a radical of the formula -OR _a where R _a is a C3-C6alkynyl radical as generally defined above. As used herein, the term “hydroxyCi-Cealkyl” refers to a Ci-C6alkyl radical as generally defined above substituted by one or more hydroxy groups.

As used herein, the term "Ci-C6alkylcarbonyl" refers to a radical of the formula -C(0)R _a where R _a is a Ci-C6alkyl radical as generally defined above.

As used herein, the term "Ci-C6alkoxycarbonyl" refers to a radical of the formula -C(0)0R _a where R _a is a Ci-C6alkyl radical as generally defined above.

As used herein, the term “aminocarbonyl” refers to a radical of the formula -C(0)NH ₂ .

As used herein, the term “aminothiocarbonyl” refers to a radical of the formula -C(S)NH2.

As used herein, the term "C3-C6cycloalkyl" refers to a stable, monocyclic ring radical which is saturated or partially unsaturated and contains 3 to 6 carbon atoms. C3-C ₄ cycloalkyl is to be construed accordingly. Examples of C3-C6cycloalkyl include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl.

As used herein, the term "C3-C6halocycloalkyl" refers to a C3-C6cycloalkyl radical as generally defined above substituted by one or more of the same or different halogen atoms. C3-C ₄ halocycloalkyl is to be construed accordingly.

As used herein, the term "C3-C6cycloalkoxy" refers to a radical of the formula -OR _a where R _a is a C3-C6cycloalkyl radical as generally defined above.

As used herein, the term “N-C3-C6cycloalkylamino” refers to a radical of the formula -NHR _a where R _a is a C3-C6cycloalkyl radical as generally defined above.

As used herein, except where explicitly stated otherwise, the term "heteroaryl" refers to a 5- or 6- membered monocyclic aromatic ring which comprises 1 , 2, 3 or 4 heteroatoms individually selected from nitrogen, oxygen and sulfur. The heteroaryl radical may be bonded to the rest of the molecule via a carbon atom or heteroatom. Examples of heteroaryl include, furyl, pyrrolyl, imidazolyl, thienyl, pyrazolyl, thiazolyl, isothiazolyl, oxazolyl, isoxazolyl, triazolyl, tetrazolyl, pyrazinyl, pyridazinyl, pyrimidyl or pyridyl.

As used herein, except where explicitly stated otherwise, the term "heterocyclyl" or "heterocyclic" refers to a stable 4- to 6-membered non-aromatic monocyclic ring radical which comprises 1 , 2, or 3 heteroatoms individually selected from nitrogen, oxygen and sulfur. The heterocyclyl radical may be bonded to the rest of the molecule via a carbon atom or heteroatom. Examples of heterocyclyl include, but are not limited to, pyrrolinyl, pyrrolidyl, tetrahydrofuryl, tetrahydrothienyl, tetrahydrothiopyranyl, piperidyl, piperazinyl, tetrahydropyranyl, dihydroisoxazolyl, dioxolanyl, morpholinyl or d-lactamyl.

The presence of one or more possible asymmetric carbon atoms in a compound of formula (I) means that the compounds may occur in chiral isomeric forms, i.e. , enantiomeric or diastereomeric forms. Also atropisomers may occur as a result of restricted rotation about a single bond. Formula (I) is intended to include all those possible isomeric forms and mixtures thereof. The present invention includes all those possible isomeric forms and mixtures thereof for a compound of formula (I). Likewise, formula (I) is intended to include all possible tautomers (including lactam-lactim tautomerism and keto- enol tautomerism) where present. The present invention includes all possible tautomeric forms for a compound of formula (I). Similarly, where there are di-substituted alkenes, these may be present in E or Z form or as mixtures of both in any proportion. The present invention includes all these possible isomeric forms and mixtures thereof for a compound of formula (I).

The compounds of formula (I) will typically be provided in the form of an agronomically acceptable salt, a zwitterion or an agronomically acceptable salt of a zwitterion. This invention covers all such agronomically acceptable salts, zwitterions and mixtures thereof in all proportions.

Suitable agronomically acceptable salts of the present invention can be with cations that include but are not limited to, metals, conjugate acids of amines and organic cations. Examples of suitable metals include aluminium, calcium, cesium, copper, lithium, magnesium, manganese, potassium, sodium, iron and zinc. Examples of suitable amines include allylamine, ammonia, amylamine, arginine, benethamine, benzathine, butenyl-2-amine, butylamine, butylethanolamine, cyclohexylamine, decylamine, diamylamine, dibutylamine, diethanolamine, diethylamine, diethylenetriamine, diheptylamine, dihexylamine, diisoamylamine, diisopropylamine, dimethylamine, dioctylamine, dipropanolamine, dipropargylamine, dipropylamine, dodecylamine, ethanolamine, ethylamine, ethylbutylamine, ethylenediamine, ethylheptylamine, ethyloctylamine, ethylpropanolamine, heptadecylamine, heptylamine, hexadecylamine, hexenyl-2-amine, hexylamine, hexylheptylamine, hexyloctylamine, histidine, indoline, isoamylamine, isobutanolamine, isobutylamine, isopropanolamine, isopropylamine, lysine, meglumine, methoxyethylamine, methylamine, methylbutylamine, methylethylamine, methylhexylamine, methylisopropylamine, methylnonylamine, methyloctadecylamine, methylpentadecylamine, morpholine, N,N-diethylethanolamine, N- methylpiperazine, nonylamine, octadecylamine, octylamine, oleylamine, pentadecylamine, pentenyl-2- amine, phenoxyethylamine, picoline, piperazine, piperidine, propanolamine, propylamine, propylenediamine, pyridine, pyrrolidine, sec-butylamine, stearylamine, tallowamine, tetradecylamine, tributylamine, tridecylamine, trimethylamine, triheptylamine, trihexylamine, triisobutylamine, triisodecylamine, triisopropylamine, trimethylamine, tripentylamine, tripropylamine, tris(hydroxymethyl)aminomethane, and undecylamine. Examples of suitable organic cations include benzyltributylammonium, benzyltrimethylammonium, benzyltriphenylphosphonium, choline, tetrabutylammonium, tetrabutylphosphonium, tetraethylammonium, tetraethylphosphonium, tetramethylammonium, tetramethylphosphonium, tetrapropylammonium, tetrapropylphosphonium, tributylsulfonium, tributylsulfoxonium, triethylsulfonium, triethylsulfoxonium, trimethylsulfonium, trimethylsulfoxonium, tripropylsulfonium and tripropylsulfoxonium.

The following list provides definitions, including preferred definitions, for substituents Z, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ with reference to the compounds of formula (I) according to the invention. For any one of these substituents, any of the definitions given below may be combined with any definition of any other substituent given below or elsewhere in this document.

Preferably R ¹ is selected from the group consisting of hydrogen and Ci-C ₄ alkyl, more preferably hydrogen and methyl, most preferably hydrogen.

Preferably R ² is selected from the group consisting of hydrogen, Ci-C ₄ alkyl and C3-C ₄ alkynyl, more preferably Ci-C2alkyl, most preferably methyl. Preferably R ³ is selected from the group consisting of hydrogen, chlorine and fluorine, more preferably chlorine and fluorine.

Preferably R ⁴ is selected from the group consisting of hydrogen, chlorine, cyano and aminothiocarbonyl, more preferably chlorine, cyano and aminothiocarbonyl, most preferably chlorine.

Preferably each R ⁵ and R ⁶ is independently selected from the group consisting of hydrogen, Ci- C ₄ alkyl, CO2R ⁹ and CH2OR ¹² , more preferably hydrogen and Ci-C2alkyl, most preferably hydrogen.

Preferably each R ⁷ and R ⁸ is independently selected from the group consisting of hydrogen, Ci- C ₄ alkyl, Ci-C6haloalkyl, CO2R ⁹ , CONR ¹⁰ R ¹¹ and CH2OR ¹² . More preferably R ⁷ is selected from the group consisting of CO2R ⁹ , CONR ¹⁰ R ¹¹ and CH2OR ¹² , most preferably CO2R ⁹ . More preferably R ⁸ is selected from the group consisting of hydrogen and Ci-C ₄ alkyl, most preferably methyl.

Preferably R ⁹ is selected from the group consisting of hydrogen, Ci-C ₄ alkyl, Ci-C ₄ haloalkyl, Ci- C2alkoxyCi-C2alkyl, phenylCi-C2alkyl and phenylCi-C2alkyl substituted by 1-2 groups R ¹³ , more preferably hydrogen, Ci-C ₄ alkyl, Ci-C2alkoxyCi-C2alkyl and phenylCi-C2alkyl, most preferably hydrogen, Ci-C ₄ alkyl and phenylCi-C2alkyl.

Preferably R ¹⁰ is selected from the group consisting of hydrogen and SO2R ¹⁴ , more preferably SO2R ¹⁴ .

Preferably R ¹¹ is hydrogen.

Preferably R ¹² is selected from the group consisting of hydrogen, Ci-C2alkyl, Ci-C2alkylsulfonyl, Ci-C2haloalkylsulfonyl, Ci-C ₄ alkylcarbonyl, phenylcarbonyl, phenylcarbonyl substituted by 1-2 groups R ¹³ , phenylCi-C2alkylcarbonyl and phenylCi-C2alkylcarbonyl substituted by 1-2 groups R ¹³ more preferably Ci-C2alkylsulfonyl, Ci-C2haloalkylsulfonyl and Ci-C ₄ alkylcarbonyl.

Preferably R ¹³ is selected from the group consisting of halogen, Ci-C ₄ alkyl, Ci-C ₄ haloalkyl, Ci- C ₄ alkoxy, Ci-C ₄ haloalkoxy, cyano and Ci-C ₄ alkylsulfonyl.

Preferably R ¹⁴ is selected from the group consisting of Ci-C ₄ alkyl and Ci-C ₄ alkyl(Ci- C ₄ alkyl)amino, more preferably methyl and isopropyl(methyl)amino.

Preferably R ¹⁷ is selected from the group consisting of Ci-C2alkyl and Ci-C2haloalkyl, more preferably halomethyl, most preferably trifluoromethyl.

A preferred subset of compounds is one in which;

R ¹ is selected from the group consisting of hydrogen or methyl;

R ² is Ci-C ₂ alkyl;

R ³ is selected from the group consisting of hydrogen, chlorine and fluorine;

R ⁴ is selected from the group consisting of chlorine, cyano and aminothiocarbonyl; each R ⁵ and R ⁶ is independently selected from the group consisting of hydrogen and Ci-C2alkyl;

R ⁷ is selected from the group consisting of CO2R ⁹ , CONR ¹⁰ R ¹¹ and CH2OR ¹² ;

R ⁸ is selected from the group consisting of hydrogen and Ci-C ₄ alkyl; R ⁹ is selected from the group consisting of hydrogen, Ci-C ₄ alkyl, Ci-C2alkoxyCi-C2alkyl and phenylCi- C2alkyl;

R ¹⁰ is SO2R ¹⁴ ;

R ¹¹ is hydrogen. R ¹² is selected from the group consisting of Ci-C2alkylsulfonyl, Ci-C2haloalkylsulfonyl and Ci- C ₄ alkylcarbonyl;

R ¹⁴ is selected from the group consisting of methyl and isopropyl(methyl)amino;

R ¹⁷ is selected from the group consisting of methyl and trifluoromethyl A more preferred subset of compounds is one in which; R ¹ is hydrogen;

R ² is methyl;

R ³ is selected from the group consisting of chlorine and fluorine;

R ⁴ is chlorine; each R ⁵ and R ⁶ is hydrogen; R ⁷ is CO2R ⁹ ;

R ⁸ is methyl;

R ⁹ is selected from the group consisting of hydrogen, Ci-C ₄ alkyl and phenylCi-C2alkyl;

R ¹⁷ is trifluoromethyl.

Table of Examples This table discloses specific compounds of formula (I), wherein R ¹ is hydrogen, R ² is methyl and R ¹⁷ is trifluoromethyl.

Of these, Compound 14 is most preferred.

Compounds of the invention may be prepared by techniques known to the person skilled in the art of organic chemistry. General methods for the production of compounds of formula (I) are described below. Unless otherwise stated in the text, the substituents Z, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ are as defined hereinbefore. The starting materials used for the preparation of the compounds of the invention may be purchased from usual commercial suppliers or may be prepared by known methods. The starting materials as well as the intermediates may be purified before use in the next step by state of the art methodologies such as chromatography, crystallization, distillation and filtration.

Compounds of formula (I) may be prepared from compounds of formula (A) as shown in reaction scheme 1 .

Reaction scheme 1 For example, a compound of formula (A) may be treated with a base, such as potassium carbonate, and an alkylating agent, such as methyl iodide, in a suitable solvent such as methylpentanone.

Compounds of formula (A) may be prepared from compounds of formula (B) and amines of formula (C) as shown in reaction scheme 2. Reaction scheme 2

For example, a compound of formula (C) may be treated with an oxazinone of formula (B), in a suitable solvent, such as acetic acid. Amines of formula (C) may be prepared from nitro compounds of formula (D) as shown in reaction scheme 3.

Reaction scheme 3

For example, a compound of formula (D) can be treated with a reducing agent, such as iron and ammonium chloride, in a suitable solvent, such as a mixture of water and ethanol.

Nitro compounds of formula (D) may be prepared from oximes of formula (E) and alkenes of formula (F) as shown in reaction scheme 4.

Reaction scheme 4 For example, an oxime of formula (E) may be treated with N-chlorosuccinimide in a suitable solvent, such as dimethylformamide, and the resulting intermediate then treated with an alkene of formula (F) in the presence of a base, such as triethylamine, in a suitable solvent such as dichloromethane.

Alkenes of formula (F) are available or may be prepared by methods well known in the literature.

Oximes of formula (E) may be prepared from aldehydes of formula (G) as shown in reaction scheme 5. Reaction scheme 5

For example, an aldehyde of formula (G) may be treated with hydroxylamine hydrochloride in a suitable solvent, such as a mixture of water and ethanol. Aldehydes of formula (G) are available or can be prepared by methods known in the literature.

Compounds of formula (l-A), which are compounds of formula (I) in which R ⁷ is a carboxylic acid group, may be prepared from compounds of formula (l-B), which are compounds of formula (I) in which R ⁷ is CO2R ⁹ , as shown in reaction scheme 6.

Reaction scheme 6

For example, a compound of formula (l-B) may be treated with sodium hydroxide in a suitable solvent, such as a mixture of water and ethanol.

Compounds of formula (l-C), which are compounds of formula (I) in which R ⁷ is a hydroxymethyl group, may be prepared from compounds of formula (l-A or l-B), as shown in reaction scheme 7. Reaction scheme 7

For example, a compound of formula (l-A) or (l-B) may be treated with a suitable reducing agent, for example a metal hydride reagent, such as sodium borohydride or borane, in a suitable solvent, such as tetrahydrofuran. Compounds of formula (l-D), which are compounds of formula (I) in which R ⁷ is CH2OR ¹² , may be prepared from compounds of formula (l-C) as shown in reaction scheme 8.

Reaction scheme 8 For example, a compound of formula (l-C) may be treated with a reagent R ¹² -LG, wherein LG is a leaving group such as a halogen, such as an alkylating agent, acylating agent or sulfonylating agent, in the presence of a base, such as sodium hydride or triethylamine, in a suitable solvent, such as tetrahydrofuran.

Compounds of formula (l-E), which are compounds of formula (I) in which R ⁷ is CONR ¹⁰ R ¹¹ , may be prepared from compounds of formula (l-A) as shown in reaction scheme 9.

Reaction scheme 9

For example, a compound of formual (l-A) may be treated with a halogenating reagent, such as oxalyl chloride, in a suitable solvent, such as dichloromethane, to form an acyl halide which may be treated with a reagent HNR ¹⁰ R ¹¹ in the presence of a base, such as triethylamine, in a suitable solvent, such as dichloromethane.

Compounds of formula (l-G), which are compounds of formula (I) in which R ⁷ is an oxime group, may be prepared from compounds of formula (l-F), which are compounds of formula (I) in which R ⁷ is a ketone group, as shown in reaction scheme 10. Reaction scheme 10

For example, a compound of formula (l-F) may be treated a hydroxylamine FhNOR ¹⁶ , or a salt thereof, optionally in the presence of a base, such as triethylamine, in a suitable solvent, such as ethanol.

Compounds of formula (l-H), which are compounds of formula (I) in which R ⁷ is a hydrazone group, may be prepared from compounds of formula (l-F), which are compounds of formula (I) in which R ⁷ is a ketone group, as shown in reaction scheme 11 .

Reaction scheme 11

For example, a compound of formula (l-F) may be treated a hydrazine H2NN(R ¹⁶ )2, or a salt thereof, optionally in the presence of a base, such as triethylamine, in a suitable solvent, such as ethanol.

One skilled in the art will realise that it is often possible to alter the order in which the transformations described above are conducted, or to combine them in alternative ways to prepare a wide range of compounds of formula (I). Multiple steps may also be combined in a single reaction. All such variations are contemplated within the scope of the invention.

The skilled person will also be aware that some reagents will be incompatible with certain values or combinations of the substituents Z, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ as defined herein, and any additional steps, such as protection and/or deprotection steps, which are necessary to achieve the desired transformation will be clear to the skilled person.

The compounds according to the invention can be used as herbicidal agents in unmodified form, but they are generally formulated into compositions in various ways using formulation adjuvants, such as carriers, solvents and surface-active substances. The formulations can be in various physical forms, e.g. in the form of dusting powders, gels, wettable powders, water-dispersible granules, water- dispersible tablets, effervescent pellets, emulsifiable concentrates, microemulsifiable concentrates, oil- in-water emulsions, oil-flowables, aqueous dispersions, oily dispersions, suspo-emulsions, capsule suspensions, emulsifiable granules, soluble liquids, water-soluble concentrates (with water or a water- miscible organic solvent as carrier), impregnated polymer films or in other forms known e.g. from the Manual on Development and Use of FAO and WHO Specifications for Pesticides, United Nations, First Edition, Second Revision (2010). For water-soluble compounds, soluble liquids, water-soluble concentrates or water soluble granules are preferred. Such formulations can either be used directly or diluted prior to use. The dilutions can be made, for example, with water, liquid fertilisers, micronutrients, biological organisms, oil or solvents.

The formulations can be prepared e.g. by mixing the active ingredient with the formulation adjuvants in order to obtain compositions in the form of finely divided solids, granules, solutions, dispersions or emulsions. The active ingredients can also be formulated with other adjuvants, such as finely divided solids, mineral oils, oils of vegetable or animal origin, modified oils of vegetable or animal origin, organic solvents, water, surface-active substances or combinations thereof.

The active ingredients can also be contained in very fine microcapsules. Microcapsules contain the active ingredients in a porous carrier. This enables the active ingredients to be released into the environment in controlled amounts (e.g. slow-release). Microcapsules usually have a diameter of from 0.1 to 500 microns. They contain active ingredients in an amount of about from 25 to 95 % by weight of the capsule weight. The active ingredients can be in the form of a monolithic solid, in the form of fine particles in solid or liquid dispersion or in the form of a suitable solution. The encapsulating membranes can comprise, for example, natural or synthetic rubbers, cellulose, styrene/butadiene copolymers, polyacrylonitrile, polyacrylate, polyesters, polyamides, polyureas, polyurethane or chemically modified polymers and starch xanthates or other polymers that are known to the person skilled in the art. Alternatively, very fine microcapsules can be formed in which the active ingredient is contained in the form of finely divided particles in a solid matrix of base substance, but the microcapsules are not themselves encapsulated.

The formulation adjuvants that are suitable for the preparation of the compositions according to the invention are known perse. As liquid carriers there may be used: water, toluene, xylene, petroleum ether, vegetable oils, acetone, methyl ethyl ketone, cyclohexanone, acid anhydrides, acetonitrile, acetophenone, amyl acetate, 2-butanone, butylene carbonate, chlorobenzene, cyclohexane, cyclohexanol, alkyl esters of acetic acid, diacetone alcohol, 1 ,2-dichloropropane, diethanolamine, p- diethylbenzene, diethylene glycol, diethylene glycol abietate, diethylene glycol butyl ether, diethylene glycol ethyl ether, diethylene glycol methyl ether, A/,A/-dimethylformamide, dimethyl sulfoxide, 1 ,4- dioxane, dipropylene glycol, dipropylene glycol methyl ether, dipropylene glycol dibenzoate, diproxitol, alkylpyrrolidone, ethyl acetate, 2-ethylhexanol, ethylene carbonate, 1 ,1 ,1 -trichloroethane, 2-heptanone, alpha-pinene, d-limonene, ethyl lactate, ethylene glycol, ethylene glycol butyl ether, ethylene glycol methyl ether, gamma-butyrolactone, glycerol, glycerol acetate, glycerol diacetate, glycerol triacetate, hexadecane, hexylene glycol, isoamyl acetate, isobornyl acetate, isooctane, isophorone, isopropylbenzene, isopropyl myristate, lactic acid, laurylamine, mesityl oxide, methoxypropanol, methyl isoamyl ketone, methyl isobutyl ketone, methyl laurate, methyl octanoate, methyl oleate, methylene chloride, m-xylene, n-hexane, n-octylamine, octadecanoic acid, octylamine acetate, oleic acid, oleylamine, o-xylene, phenol, polyethylene glycol, propionic acid, propyl lactate, propylene carbonate, propylene glycol, propylene glycol methyl ether, p-xylene, toluene, triethyl phosphate, triethylene glycol, xylenesulfonic acid, paraffin, mineral oil, trichloroethylene, perchloroethylene, ethyl acetate, amyl acetate, butyl acetate, propylene glycol methyl ether, diethylene glycol methyl ether, methanol, ethanol, isopropanol, and alcohols of higher molecular weight, such as amyl alcohol, tetrahydrofurfuryl alcohol, hexanol, octanol, ethylene glycol, propylene glycol, glycerol, A/-methyl-2-pyrrolidone and the like.

Suitable solid carriers are, for example, talc, titanium dioxide, pyrophyllite clay, silica, attapulgite clay, kieselguhr, limestone, calcium carbonate, bentonite, calcium montmorillonite, cottonseed husks, wheat flour, soybean flour, pumice, wood flour, ground walnut shells, lignin and similar substances.

A large number of surface-active substances can advantageously be used in both solid and liquid formulations, especially in those formulations which can be diluted with a carrier prior to use. Surface-active substances may be anionic, cationic, non-ionic or polymeric and they can be used as emulsifiers, wetting agents or suspending agents or for other purposes. Typical surface-active substances include, for example, salts of alkyl sulfates, such as diethanolammonium lauryl sulfate; salts of alkylarylsulfonates, such as calcium dodecylbenzenesulfonate; alkylphenol/alkylene oxide addition products, such as nonylphenol ethoxylate; alcohol/alkylene oxide addition products, such as tridecylalcohol ethoxylate; soaps, such as sodium stearate; salts of alkylnaphthalenesulfonates, such as sodium dibutylnaphthalenesulfonate; dialkyl esters of sulfosu coin ate salts, such as sodium di(2- ethylhexyl)sulfosuccinate; sorbitol esters, such as sorbitol oleate; quaternary amines, such as lauryltrimethylammonium chloride, polyethylene glycol esters of fatty acids, such as polyethylene glycol stearate; block copolymers of ethylene oxide and propylene oxide; and salts of mono- and di- alkylphosphate esters; and also further substances described e.g. in McCutcheon's Detergents and Emulsifiers Annual, MC Publishing Corp., Ridgewood New Jersey (1981).

Further adjuvants that can be used in pesticidal formulations include crystallisation inhibitors, viscosity modifiers, suspending agents, dyes, anti-oxidants, foaming agents, light absorbers, mixing auxiliaries, antifoams, complexing agents, neutralising or pH-modifying substances and buffers, corrosion inhibitors, fragrances, wetting agents, take-up enhancers, micronutrients, plasticisers, glidants, lubricants, dispersants, thickeners, antifreezes, microbicides, and liquid and solid fertilisers.

The compositions according to the invention can include an additive comprising an oil of vegetable or animal origin, a mineral oil, alkyl esters of such oils or mixtures of such oils and oil derivatives. The amount of oil additive in the composition according to the invention is generally from 0.01 to 10 %, based on the mixture to be applied. For example, the oil additive can be added to a spray tank in the desired concentration after a spray mixture has been prepared. Preferred oil additives comprise mineral oils or an oil of vegetable origin, for example rapeseed oil, olive oil or sunflower oil, emulsified vegetable oil, alkyl esters of oils of vegetable origin, for example the methyl derivatives, or an oil of animal origin, such as fish oil or beef tallow. Preferred oil additives comprise alkyl esters of C8-C22 fatty acids, especially the methyl derivatives of C12-C18 fatty acids, for example the methyl esters of lauric acid, palmitic acid and oleic acid (methyl laurate, methyl palmitate and methyl oleate, respectively). Many oil derivatives are known from the Compendium of Herbicide Adjuvants, 10 ^th Edition, Southern Illinois University, 2010. 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 inventive compositions generally comprise from 0.1 to 99 % by weight, especially from 0.1 to 95 % by weight, of compounds of the present invention 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. Whereas commercial products may preferably be formulated as concentrates, the end user will normally employ dilute formulations.

The rates of application vary within wide limits and depend on the nature of the soil, the method of application, the crop plant, the pest to be controlled, the prevailing climatic conditions, and other factors governed by the method of application, the time of application and the target crop. As a general guideline compounds may be applied at a rate of from 1 to 2000 l/ha, especially from 10 to 1000 l/ha.

Preferred formulations can have the following compositions (weight %):

Emulsifiable concentrates: active ingredient: 1 to 95 %, preferably 60 to 90 % surface-active agent: 1 to 30 %, preferably 5 to 20 % liquid carrier: 1 to 80 %, preferably 1 to 35 %

Dusts: active ingredient: 0.1 to 10 %, preferably 0.1 to 5 % solid carrier: 99.9 to 90 %, preferably 99.9 to 99 %

Suspension concentrates: active ingredient: 5 to 75 %, preferably 10 to 50 % water: 94 to 24 %, preferably 88 to 30 % surface-active agent: 1 to 40 %, preferably 2 to 30 % Wettable powders: active ingredient: 0.5 to 90 %, preferably 1 to 80 % surface-active agent: 0.5 to 20 %, preferably 1 to 15 % solid carrier: 5 to 95 %, preferably 15 to 90 %

Granules: active ingredient: 0.1 to 30 %, preferably 0.1 to 15 % solid carrier: 99.5 to 70 %, preferably 97 to 85 %

The composition of the present may further comprise at least one additional pesticide. For example, the compounds according to the invention can also be used in combination with other herbicides or plant growth regulators. In a preferred embodiment the additional pesticide is a herbicide and/or herbicide safener.

Thus, compounds of formula (I) can be used in combination with one or more other herbicides to provide various herbicidal mixtures. Specific examples of such mixtures include (wherein “I” represents a compound of formula (I)):- 1 + acetochlor; I + acifluorfen (including acifluorfen-sodium); I + aclonifen; I + alachlor; I + alloxydim; I + ametryn; I + amicarbazone; I + amidosulfuron; I + aminocyclopyrachlor ; I + aminopyralid; I + amitrole; I + asulam; I + atrazine; I + bensulfuron (including bensulfuron-methyl); I + bentazone; I + bicyclopyrone; I + bilanafos; I + bifenox; I + bispyribac-sodium; I + bixlozone; I + bromacil; I + bromoxynil; I + butachlor; I + butafenacil; I + cafenstrole; I + carfentrazone (including carfentrazone-ethyl); cloransulam (including cloransulam-methyl); I + chlorimuron (including chlorimuron-ethyl); I + chlorotoluron; I + cinosulfuron; I + chlorsulfuron; I + cinmethylin; I + clacyfos; I + clethodim; I + clodinafop (including clodinafop-propargyl); I + clomazone; I + clopyralid; I + cyclopyranil; I + cyclopyrimorate; I + cyclosulfamuron; I + cyhalofop (including cyhalofop-butyl); I + 2,4-D (including the choline salt and 2-ethylhexyl ester thereof); I + 2,4-DB; I + daimuron; I + desmedipham; I + dicamba (including the aluminum, aminopropyl, bis-aminopropylmethyl, choline, dichloroprop, diglycolamine, dimethylamine, dimethylammonium, potassium and sodium salts thereof); I + diclofop-methyl; I + diclosulam; I + diflufenican; I + difenzoquat; I + diflufenican; I + diflufenzopyr; I + dimethachlor; I + dimethenamid-P; I + diquat dibromide; I + diuron; I + esprocarb; I + ethalfluralin; I + ethofumesate; I + fenoxaprop (including fenoxaprop-P-ethyl); I + fenoxasulfone; I + fenquinotrione; I + fentrazamide; I + flazasulfuron; I + florasulam; I + florpyrauxifen; I + fluazifop (including fluazifop-P-butyl); I + flucarbazone (including flucarbazone-sodium);; I + flufenacet; I + flumetralin; I + flumetsulam; I + flumioxazin; I + flupyrsulfuron (including flupyrsulfuron-methyl-sodium);; I + fluroxypyr (including fluroxypyr-meptyl);; I + fluthiacet-methyl; I + fomesafen; I + foramsulfuron; I + glufosinate (including the ammonium salt thereof); I + glyphosate (including the diammonium, isopropylammonium and potassium salts thereof); I + halauxifen (including halauxifen-methyl); I + halosulfuron-methyl; I + haloxyfop (including haloxyfop- methyl); I + hexazinone; I + hydantocidin; I + imazamox; I + imazapic; I + imazapyr; I + imazaquin; I + imazethapyr; I + indaziflam; I + iodosulfuron (including iodosulfuron-methyl-sodium); I + iofensulfuron; I + iofensulfuron-sodium; I + ioxynil; I + ipfencarbazone; I + isoproturon; I + isoxaben; I + isoxaflutole; I + lactofen; I + lancotrione; I + linuron; I + MCPA; I + MCPB; I + mecoprop-P; I + mefenacet; I + mesosulfuron; I + mesosulfuron-methyl; I + mesotrione; I + metamitron; I + metazachlor; I + methiozolin; I + metobromuron; I + metolachlor; I + metosulam; I + metoxuron; I + metribuzin; I + metsulfuron; I + molinate; I + napropamide; I + nicosulfuron; I + norflurazon; I + orthosulfamuron; I + oxadiargyl; I + oxadiazon; I + oxasulfuron; I + oxyfluorfen; I + paraquat dichloride; I + pendimethalin; I + penoxsulam; I + phenmedipham; I + picloram; I + picolinafen; I + pinoxaden; I + pretilachlor; I + primisulfuron-methyl; I + prodiamine; I + prometryn; I + propachlor; I + propanil; I + propaquizafop; I + propham; I + propyrisulfuron, I + propyzamide; I + prosulfocarb; I + prosulfuron; I + pyraclonil; I + pyraflufen (including pyraflufen-ethyl): I + pyrasulfotole; I + pyrazolynate, I + pyrazosulfuron-ethyl; I + pyribenzoxim; I + pyridate; I + pyriftalid; I + pyrimisulfan, I + pyrithiobac-sodium; I + pyroxasulfone; I + pyroxsulam ; I + quinclorac; I + quinmerac; I + quizalofop (including quizalofop-P-ethyl and quizalofop-P-tefuryl),; I + rimsulfuron; I + saflufenacil; I + sethoxydim; I + simazine; I + S-metolachlor; I + sulcotrione; I + sulfentrazone; I + sulfosulfuron; I + tebuthiuron; I + tefuryltrione; I + tembotrione; I + terbuthylazine; I + terbutryn; I + thiencarbazone; I + thifensulfuron; I + tiafenacil; I + tolpyralate; I + topramezone; I + tralkoxydim; I + triafamone; I + triallate; I + triasulfuron; I + tribenuron (including tribenuron-methyl); I + triclopyr; I + trifloxysulfuron (including trifloxysulfuron-sodium); I + trifludimoxazin; I + trifluralin; I + triflusulfu ron; I + tritosulfuron; I + 4-hydroxy-1-methoxy-5-methyl-3-[4-(trifluoromethyl)-2- pyridyl]imidazolidin-2-one; I + 4-hydroxy-1 ,5-dimethyl-3-[4-(trifluoromethyl)-2-pyridyl]imidazolidin-2- one; I + 5-ethoxy-4-hydroxy-1-methyl-3-[4-(trifluoromethyl)-2-pyridyl ]imidazolidin-2-one; I + 4-hydroxy-1- methyl-3-[4-(trifluoromethyl)-2-pyridyl]imidazolidin-2-one; I + 4-hydroxy-1 ,5-dimethyl-3-[1-methyl-5- (trifluoromethyl)pyrazol-3-yl]imidazolidin-2-one; I + (4R)1-(5-tert-butylisoxazol-3-yl)-4-ethoxy-5-hydroxy-

3-methyl-imidazolidin-2-one; I + 3-[2-(3,4-dimethoxyphenyl)-6-methyl-3-oxo-pyridazine-4- carbonyl]bicyclo[3.2.1]octane-2,4-dione; I + 2-[2-(3,4-dimethoxyphenyl)-6-methyl-3-oxo-pyridazine-4- carbonyl]-5-methyl-cyclohexane-1 ,3-dione; I + 2-[2-(3,4-dimethoxyphenyl)-6-methyl-3-oxo-pyridazine-

4-carbonyl]cyclohexane-1 ,3-dione; I + 2-[2-(3,4-dimethoxyphenyl)-6-methyl-3-oxo-pyridazine-4- carbonyl]-5,5-dimethyl-cyclohexane-1 ,3-dione; I + 6-[2-(3,4-dimethoxyphenyl)-6-methyl-3-oxo- pyridazine-4-carbonyl]-2,2,4,4-tetramethyl-cyclohexane-1 ,3,5-trione; I + 2-[2-(3,4-dimethoxyphenyl)-6- methyl-3-oxo-pyridazine-4-carbonyl]-5-ethyl-cyclohexane-1 ,3-dione; I + 2-[2-(3,4-dimethoxyphenyl)-6- methyl-3-oxo-pyridazine-4-carbonyl]-4,4,6,6-tetramethyl-cycl ohexane-1 ,3-dione; I + 2-[6-cyclopropyl-2- (3, 4-dimethoxyphenyl)-3-oxo-pyridazine-4-carbonyl]-5-methyl-cyc lohexane-1 ,3-dione; I + 3-[6- cyclopropyl-2-(3,4-dimethoxyphenyl)-3-oxo-pyridazine-4-carbo nyl]bicyclo[3.2.1]octane-2,4-dione; I + 2- [6-cyclopropyl-2-(3,4-dimethoxyphenyl)-3-oxo-pyridazine-4-ca rbonyl]-5,5-dimethyl-cyclohexane-1 ,3- dione; I + 6-[6-cyclopropyl-2-(3,4-dimethoxyphenyl)-3-oxo-pyridazine-4- carbonyl]-2,2,4,4-tetramethyl- cyclohexane-1 ,3,5-trione; I + 2-[6-cyclopropyl-2-(3,4-dimethoxyphenyl)-3-oxo-pyridazine-4- carbonyl]cyclohexane-1 ,3-dione; I + 4-[2-(3,4-dimethoxyphenyl)-6-methyl-3-oxo-pyridazine-4-carbo nyl]- 2,2,6,6-tetramethyl-tetrahydropyran-3,5-dione and I + 4-[6-cyclopropyl-2-(3,4-dimethoxyphenyl)-3-oxo- pyridazine-4-carbonyl]-2,2,6,6-tetramethyl-tetrahydropyran-3 ,5-dione.

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, Fourteenth Edition, British Crop Protection Council, 2006.

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).

Compounds of formula (I) of the present invention may also be combined with herbicide safeners. Preferred combinations (wherein Ί” represents a compound of formula (I)) include:- I + benoxacor, I + cloquintocet (including cloquintocet-mexyl); I + cyprosulfamide; I + dichlormid; I + fenchlorazole (including fenchlorazole-ethyl); I + fenclorim; I + fluxofenim; l+ furilazole I + isoxadifen (including isoxadifen-ethyl); I + mefenpyr (including mefenpyr-diethyl); I + metcamifen; I + N-(2- methoxybenzoyl)-4-[(methylaminocarbonyl)amino] benzenesulfonamide and I + oxabetrinil. Particularly preferred are mixtures of a compound of formula (I) with cyprosulfamide, isoxadifen (including isoxadifen-ethyl), cloquintocet (including cloquintocet-mexyl) and/or N-(2-methoxybenzoyl)-4- [(methyl-aminocarbonyl)amino]benzenesulfonamide.

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, 14 ^th Edition (BCPC), 2006. 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, and the reference to fenchlorazole-ethyl also applies to fenchlorazole, etc.

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 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 safener).

The compounds of formula (I) of this invention are useful as herbicides. The present invention therefore further comprises a method for controlling unwanted plants comprising applying to the said plants or a locus comprising them, an effective amount of a compound of the invention or a herbicidal composition containing said compound. ‘Controlling’ means killing, reducing or retarding growth or preventing or reducing germination. Generally the plants to be controlled are unwanted plants (weeds). ‘Locus’ means the area in which the plants are growing or will grow.

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-emergence; post-emergence; 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 2000 g/ha, especially from 50 to 1000 g/ha. A preferred range is 10-200g/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.

Useful plants in which the composition according to the invention can be used include crops such as cereals, for example barley and wheat, cotton, oilseed rape, sunflower, maize, rice, soybeans, sugar beet, sugar cane and turf.

Crop plants can also include trees, such as fruit trees, palm trees, coconut trees or other nuts. Also included are vines such as grapes, fruit bushes, fruit plants and vegetables.

Crops are to be understood as also including those crops which have been rendered tolerant to herbicides or classes of herbicides (e.g. ALS-, GS-, EPSPS-, PPO-, ACCase- and HPPD-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®.

Crops 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.

Crops 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).

Other useful plants include turf grass for example in golf-courses, lawns, parks and roadsides, or grown commercially for sod, and ornamental plants such as flowers or bushes.

The compounds of the present invention can be used in methods of controlling undesired vegetation in crop plants which are tolerant to protoporphyrinogen oxidase (PPO) inhibitors. Such plants can be obtained, for example, by transforming crop plants with nucleic acids which encode a suitable protoporphyrinogen oxidase, which may contain a mutation in order to make it more resistant to the PPO inhibitor. Examples of such nucleic acids and crop plants are disclosed in W095/34659, WO97/32011 , W02007/024739, WO2012/080975, WO2013/189984, WO2015/022636,

WO2015/022640, WO2015/092706, WO2016/099153, WO2017/023778, WO2017/039969, WO2017/217793, WO2017/217794, WO2018/114759, WO2019/117578, WO2019/117579 and WO2019/118726. Thus the present invention also provides a method for controlling undesired vegetation at a plant cultivation site, the method comprising the steps of: a) providing, at said site, a plant that comprises at least one nucleic acid comprising a nucleotide sequence encoding a protoporphyrinogen oxidase (PPO) polypeptide which is resistant or tolerant to a PPO inhibiting herbicide; b) applying to said site an effective amount of said herbicide, wherein the PPO inhibiting herbicide is a compound of formula (I) as herein defined.

Compounds of formula (I) and compositions of the invention can typically be used to control a wide variety of monocotyledonous and dicotyledonous weed species. Examples of monocotyledonous species that can typically be controlled include Alopecurus myosuroides, Avena fatua, Brachiaria plantaginea, Bromus tectorum, Cyperus esculentus, Digitaria sanguinalis, Echinochloa crus-galli, Lolium perenne, Lolium multiflorum, Panicum miliaceum, Poa annua, Setaria viridis, Setaria faberi and Sorghum bicolor. Examples of dicotyledonous species that can be controlled include Abutilon theophrasti, Amaranthus retroflexus, Bidens pilosa, Chenopodium album, Euphorbia heterophylla, Galium aparine, Ipomoea hederacea, Kochia scoparia, Polygonum convolvulus, Sida spinosa, Sinapis arvensis, Solanum nigrum, Stellaria media, Veronica persica and Xanthium strumarium. Unwanted plants are to be understood as also including those weeds that have been rendered tolerant to herbicides or classes of herbicides (e.g. ALS-, GS-, EPSPS-, PPO-, ACCase- and HPPD-inhibitors) by evolution, by conventional methods of breeding or by genetic engineering. Examples include Amaranthus palmeri that has evolved resistance to glyphosate and/or acetolactate synthase (ALS) inhibiting herbicides.

The compounds of the present invention can be used in methods of controlling unwanted plants or weeds which are resistant to protoporphyrinogen oxidase (PPO) inhibitors. For example, Amaranthus palmeri and Amaranthus tuberculatus populations have evolved as PPO-resistant weeds e.g. due to amino acid substitutions in PPX2L such as those occurring at amino acids R128 (also referred to as R98) and G399, or a codon (glycine) deletion in PPX2L at codon 210 (D210). The compounds of the present invention can be used in methods of controlling Amaranthus palmeri and/or Amaranthus tuberculatus with mutations or deletions at the previously mentioned codons, and it would be obvious to try the compounds to control unwanted plants or weeds with other mutations conferring tolerance or resistance to PPO inhibitors that may arise.

The compounds of formula (I) are also useful for pre-harvest desiccation in crops, for example, but not limited to, potatoes, soybean, sunflowers and cotton. Pre-harvest desiccation is used to desiccate crop foliage without significant damage to the crop itself to aid harvesting.

Compounds/compositions of the invention are particularly useful in non-selective burn-down applications, and as such may also be used to control volunteer or escape crop plants.

Various aspects and embodiments of the present invention will now be illustrated in more detail by way of example. It will be appreciated that modification of detail may be made without departing from the scope of the invention.

EXAMPLES

The Examples which follow serve to illustrate, but do not limit, the invention.

SYNTHESIS EXAMPLES

Example 1 Preparation of ethyl 3-[3-chloro-5-fluoro-6-[3-methyl-2,6-dioxo-4- (trifluoromethyl)pyrimidin-1-yl]-2-pyridyl]-5-methyl-4H-isox azole-5-carboxylate

(Compound 14)

Step 1 Synthesis of (3-chloro-5,6-difluoro-2-pyridyl)methanol Sodium borohydride (0.6 g, 20 mmol) was added to a stirred solution of ethyl 3-chloro-5,6-difluoro- pyridine-2-carboxylate (0.9 g, 4 mmol) in tetrahydrofuran (10 ml) and methanol (3 ml). The resulting mixture was stirred at ambient temperature for 2 hours, evaporated under reduced pressure and water (50 ml) added. The resulting mixture was extracted with ethyl acetate (150 ml) and the organic phase dried and evaporated under reduced pressure to leave an oil which was purifed by chromatography to provide (3-chloro-5,6-difluoro-2-pyridyl)methanol as an oil (520 mg).

Ή NMR (400 MHz, CDC ) d 7.65 (t,1 H), 4.7 (d,2H), 3.2 (t,1 H) ppm.

Step 2 Synthesis of (6-amino-3-chloro-5-fluoro-2-pyridyl)methanol

A mixture of (3-chloro-5,6-difluoro-2-pyridyl)methanol (1.8 g, 9.7 mmol) and saturated aqueous ammonia (5 ml, 260 mmol) was heated at 100 °C in a microwave oven for 2 hours, then allowed t ocool and evaporated under reduced pressure to provide (6-amino-3-chloro-5-fluoro-2- pyridyl)methanol (1.0 g).

Step 3 Synthesis of 3-[5-chloro-3-fluoro-6-(hydroxymethyl)-2-pyridyl]-6-(trifluo romethyl)-1 H- pyrimidine-2,4-dione

2-(Dimethylamino)-4-(trifluoromethyl)-1 ,3-oxazin-6-one (1 .9 g, 8.7 mmol) was added t oa stirred solution of (6-amino-3-chloro-5-fluoro-2-pyridyl)methanol (1 .4 g, 7.9 mmol) in acetic acid (2 ml). The resulting mixture was heated under reflux for 2 hours, allowed t ocool and evaporated under reduced pressure to leave a brown oil, which wa spurifed by chromatography to provide 3-[5-chloro-3-fluoro-6- (hydroxymethyl)-2-pyridyl]-6-(trifluoromethyl)-1 H-pyrimidine-2,4-dione as a brown oil (0.9 g).

Step 4 Synthesis of 3-[5-chloro-3-fluoro-6-(hydroxymethyl)-2-pyridyl]-1 -methyl-6- (trifluoromethyl)pyrimidine-2,4-dione

Potassium carbonate (0.42 g, 3 mmol) followed by iodomethane (0.065 ml, 1 mmol) were added to a solution of 3-[5-chloro-3-fluoro-6-(hydroxymethyl)-2-pyridyl]-6-(trifluo romethyl)-1 H-pyrimidine-2,4-dione (375 mg, 1 mmol) in acetonitrile (11 ml) and the resulting mixture stirred at ambient temperature for 17 hours. The mixture was evaporated under reduced pressure, water added the mixture extracted with dichloromethane (6 ml). The organic phase was dried and evaporated under reduced pressure. The residue was purified by chromatography to provide 3-[5-chloro-3-fluoro-6-(hydroxymethyl)-2-pyridyl]-1- methyl-6-(trifluoromethyl)pyrimidine-2,4-dione as a colourless oil (100 mg).

Ή NMR (400 MHz, CDCb) d 7.7 (d,1 H), 6.0 (s, 1 H), 4.8 (br s,2H), 3.6 (s, 3H), 3.4 (m,1 H) ppm. Step 5 Synthesis of 3-chloro-5-fluoro-6-[3-methyl-2,6-dioxo-4-(trifluoromethyl)p yrimidin-1-yl]pyridine- 2-carbaldehyde

Pyridinium dichromate (100 mg, 0.6 mmol) was added to a solution of 3-[5-chloro-3-fluoro-6- (hydroxymethyl)-2-pyridyl]-1-methyl-6-(trifluoromethyl)pyrim idine-2,4-dione (72 mg, 0.2 mmol) in dichloromethane (5 ml) and the resulting mixture stirred at ambient temperature for 24 hours. The mixture was filtered and the filtrate purified by chromatography to provide 3-chloro-5-fluoro-6-[3- methyl-2,6-dioxo-4-(trifluoromethyl)pyrimidin-1-yl]pyridine- 2-carbaldehyde as an oil (41 mg).

Ή NMR (400 MHz, CDCb) d 10.3 (s, 1 H), 7.8 (d,1 H), 6.4 (s, 1 H), 3.6 (s, 3H) ppm.

Step 6 Synthesis of 3-chloro-5-fluoro-6-[3-methyl-2,6-dioxo-4-(trifluoromethyl)p yrimidin-1-yl]pyridine- 2-carbaldehyde oxime

Hydroxylamine hydrochloride (12 mg, 0.17 mmol) was added to a stirred solution of 3-chloro-5-fluoro- 6-[3-methyl-2,6-dioxo-4-(trifluoromethyl)pyrimidin-1-yl]pyri dine-2-carbaldehyde (40 mg, 0.11 mmol) in tetrahydrofuran (1 ml). Water (0.15 ml) was added and the resulting mixture stirred at ambient temperature for 1 hour then evaporated under reduced pressure to provide 3-chloro-5-fluoro-6-[3- methyl-2,6-dioxo-4-(trifluoromethyl)pyrimidin-1-yl]pyridine- 2-carbaldehyde oxime, which was used in Step 7 without further purification.

Step 7 Synthesis of ethyl 3-[3-chloro-5-fluoro-6-[3-methyl-2,6-dioxo-4-(trifluoromethy l)pyrimidin-1-yl]- 2-pyridyl]-5-methyl-4H-isoxazole-5-carboxylate (Compound 14)

/V-chlorosuccinimide (11.6 mg, 0.085 mmol) was added to a stirred solution of 3-chloro-5-fluoro-6-[3- methyl-2,6-dioxo-4-(trifluoromethyl)pyrimidin-1-yl]pyridine- 2-carbaldehyde oxime (26 mg, 0.07 mmol) in chloroform (5 ml) and the resulting solution stirred at 40 °C for 2 hours. The mixture was cooled to ambient temperature and a solution of ethyl 2-methylprop-2-enoate (12.3 mg, 0.11 mmol) and triethylamine (0.015 ml, 0.11 mmol) in dichloromethane (2 ml) added dropwise. The resulting mixture was stirred for 1 hour, then evaporated underreduced pressure to leave a yellow solid that was purified by chromatography to provide ethyl 3-[3-chloro-5-fluoro-6-[3-methyl-2,6-dioxo-4- (trifluoromethyl)pyrimidin-1-yl]-2-pyridyl]-5-methyl-4H-isox azole-5-carboxylate (Compound 14) as an oil (3 mg).

Ή NMR (400 MHz, CDCh) d 7.8 (d,1 H), 6.4 (s, 1 H), 4.25 (q, 2H), 4.0 (dd, 1 H), 3.6 (s, 3H), 3.4 (dd,

1 H), 1.7 (s, 3H), 1.3 (t, 3H) ppm.

FORMULATION EXAMPLES

Wettable powders a) b) c) active ingredients 25 % 50 % 75 % sodium lignosulfonate 5 % 5 % sodium lauryl sulfate 3 % - 5 % sodium diisobutylnaphthalenesulfonate 6 % 10 % phenol polyethylene glycol ether 2 %

(7-8 mol of ethylene oxide) highly dispersed silicic acid 5 % 10 % 10 %

Kaolin 62 % 27 %

The combination is thoroughly mixed with the adjuvants and the mixture is thoroughly ground in a suitable mill, affording wettable powders that can be diluted with water to give suspensions of the desired concentration.

Emulsifiable concentrate active ingredients 10 % octylphenol polyethylene glycol ether 3 %

(4-5 mol of ethylene oxide) calcium dodecylbenzenesulfonate 3 % castor oil polyglycol ether (35 mol of ethylene oxide) 4 %

Cyclohexanone 30 % xylene mixture 50 %

Emulsions of any required dilution, which can be used in plant protection, can be obtained from this concentrate by dilution with water.

Dusts a) b) c)

Active ingredients 5 % 6 % 4 %

Talcum 95 %

Kaolin 94 % mineral filler 96 %

Ready-for-use dusts are obtained by mixing the combination with the carrier and grinding the mixture in a suitable mill.

Extruder granules

Active ingredients 15 % sodium lignosulfonate 2 % carboxymethylcellulose 1 % Kaolin 82 %

The combination is mixed and ground with the adjuvants, and the mixture is moistened with water. The mixture is extruded and then dried in a stream of air.

Coated granules

Active ingredients 8 % polyethylene glycol (mol. wt. 200) 3 %

Kaolin 89 %

The finely ground combination is uniformly applied, in a mixer, to the kaolin moistened with polyethylene glycol. Non-dusty coated granules are obtained in this manner. Suspension concentrate active ingredients 40 % propylene glycol 10 % nonylphenol polyethylene glycol ether (15 mol of ethylene oxide) 6 %

Sodium lignosulfonate 10 % carboxymethylcellulose 1 % silicone oil (in the form of a 75 % emulsion in water) 1 %

Water 32 %

The finely ground combination is intimately mixed with the adjuvants, giving a suspension concentrate from which suspensions of any desired dilution can be obtained by dilution with water.

Slow Release Capsule Suspension

28 parts of the combination are mixed with 2 parts of an aromatic solvent and 7 parts of toluene diisocyanate/polymethylene-polyphenylisocyanate-mixture (8:1). This mixture is emulsified in a mixture of 1 .2 parts of polyvinylalcohol, 0.05 parts of a defoamer and 51 .6 parts of water until the desired particle size is achieved. To this emulsion a mixture of 2.8 parts 1 ,6-diaminohexane in 5.3 parts of water is added. The mixture is agitated until the polymerization reaction is completed.

The obtained capsule suspension is stabilized by adding 0.25 parts of a thickener and 3 parts of a dispersing agent. The capsule suspension formulation contains 28% of the active ingredients. The medium capsule diameter is 8-15 microns.

The resulting formulation is applied to seeds as an aqueous suspension in an apparatus suitable for that purpose.

BIOLOGICAL EXAMPLES Pre-emergence biological efficacy

Seeds of weeds and/or crops were sown in standard soil in pots. After cultivation for one day under controlled conditions in a glasshouse (at 24/19°C, day/night; 16 hours light), the plants were sprayed with an aqueous spray solution derived from the formulation 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), to create a 50g/l solution which was then diluted using 0.2% Genapol XO80 as diluent to give the desired final dose of test compound.

The test plants were then grown under controlled conditions in the glasshouse (at 24/18°C, day/night; 15 hours light; 50 % humidity) and watered twice daily. After 13 days the test was evaluated (100 = total damage to plant; 0 = no damage to plant). The results are shown in Table 2 below.

Table 2

Post-emergence biological efficacy

Seeds of weeds and/or crops were sown in standard soil in pots. After cultivation for 14 days under controlled conditions in a glasshouse (at 24/19°C, day/night; 16 hours light), the plants were sprayed with an aqueous spray solution derived from the formulation 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), to create a 50g/l solution which was then diluted using 0.2% Genapol XO80 as diluent to give the desired final dose of test compound.

The test plants were then grown under controlled conditions in the glasshouse (at 24/18°C, day/night; 15 hours light; 50 % humidity)and watered twice daily. After 13 days the test was evaluated (100 = total damage to plant; 0 = no damage to plant). The results are shown in Table 3 below.

Table 3