GB2287464A - Herbicidal composition - Google Patents

Abstract

A herbicidal composition comprises a compound of formula (I): <IMAGE> or a salt thereof; where R<1> is hydrogen or a group of sub-formula (i> <IMAGE> where Z is hydrogen and R<4> is as defined below, or Z and R<4> together with the nitrogen atom and carbon atom to which they are respectively attached form an optionally substituted heterocyclic ring optionally containing further heteroatoms; R<2> is hydrogen or R<5)<CO)n; R<3> is hydrogen or R<6)<CO)m; where m and n are independently selected from 0 or 1 and R<5> and R<6> are as defined below or R<5> and R<6> together form an optionally substituted heterocyclic ring optionally containing further heteroatoms; Y is hydrogen, NR<7>R<8>, NR<9>NR<7>R<8>, N(OR<7>)R<8>, halo, cyano, OR<10>, COOH or salts thereof, COOR<10>, CONR<7>R<8>, S(O)pR<11> or R<12>; X is hydrogen, halo, cyano, NR<13>R<14>, N(OR<13>)R<14>, NR<15>NR<13>R<14>, OR<16>, COOH or salts thereof, COOR<16>, CONR<13>R<14>, S(O)qR<17>, R<18>; where p and q are independently selected from 0, 1 or 2, and 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>, R<17> and R<18> are either the same or different and are independently selected from hydrogen, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted aryl, or optionally substituted heterocyclyl; provided that when X is chloro and Y is amino, R<1>, R<2> and R<3> are not all hydrogen. Certain of the compounds are novel.

Description

HERBICIDAL COMPOSITION The present invention relates to herbicidal compositions, to processes for their preparation and to novel compounds.

DE-OS-4215738 describes a herbicidal compound, 5'-0-sulphamoyl-2chloroadenosine, which is produced by Streptomvces albus R2376.

According to the present invention there is provided a herbicidal composition comprising a compound of formula (I) or a salt thereof: where R1 is hydrogen or a group of sub-formula (i) where Z is hydrogen and R4 is as defined below, or Z and R4 together with the nitrogen atom and carbon atom to which they are respectively attached form an optionally substitued heterocyclic ring optionally containing further heteroatoms; 5 R2 is hydrogen or R5(CO)n; R3 is hydrogen or R6(CO)m; where m and n are independently selected from 0 or 1 and R5 and R6 are as defined below or R5 and R6 together form an optionally substitued heterocyclic ring optionally containing further heteroatoms; Y 7 is hydrogen, NR7R8, NR9NR7R8, N(OR7)R8, halo, cyano, OR10, COOH or salts thereof, COOR10, CONR7R8, 5(0) R11 or R12; X is hydrogen, halo, cyano, NR1R14, N(oR13)R14 NR15NR13R14 OR16 COOH or salts thereof, COOR C0NR13R14, S(O)qR17, R ; where p and q are independently selected from O, 1 or 2, and R , R , R6, R7 R8, R9 R10, R11, R12 R13 R14 R15 R16 R17 and R18 are either the same or different and are independently selected from hydrogen, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted aryl or optionally substituted heterocyclyl; provided that when X is chloro and Y is amino, R1, R2 and R3 are not all hydrogen.

As used herein the term "alkyl" includes straight or branched alkyl chains, suitably containing up to 10 carbon atoms, preferably from 1 to 6 carbon atoms. The terms "alkenyl" and "alkynyl" includes unsaturated straight or branched chains containing up to 10 carbon atoms, preferably from 2 to 6 carbon atoms. The term "alkoxy" relates to such an alkyl group linked with an oxygen atom. The term "aryl" includes phenyl and naphthyl.

The term "heterocyclic" includes rings containing up to 10, preferably up to 7 atoms, up to three of which are selected from oxygen, sulphur or nitrogen. The term "halo" or "halogen" includes chlorine, fluorine, bromine and iodine.

Suitable optional substituents for alkyl, alkenyl or alkynyl groups R4 to R18 include one or more groups selected from halogen such as chloro; nitro; cyano; hydroxy, alkoxy optionally substituted with for example halo, cyano, amino, aryl or carboxylate or salts thereof; optionally substituted aryl; thioalkyl; or COR19 or SO2R20 where R19 and R20 are independently selected from OR21 or NR22 where R21, R22 and R23 are independently selected from hydrogen or alkyl; or P(O)OR240R25 or P(O)R24R25 where R24 and R25 are alkyl.

Suitable optional substituents for aryl and heterocyclic groups R4 to R18 and for aryl substituents on said groups include halo, haloalkyl, cyano, nitro, hydroxy, alkoxy optionally substituted with for example halo, cyano, amino1 aryl or carboxylate or salts or esters thereof, or thioalkoxy optionally substituted with for example halo, cyano, amino, aryl or carboxylate or salts or esters thereof.

Compounds of formula (I) are amphoteric, i.e they contain both acid and basic functionality and can therefore be either the acid or the base component of a salt. The invention includes both such salts and these are preferably agriculturally acceptable.

Examples of acid salts of formula (I) are those formed with alkali metals, alkaline earth metals, ammonium, organic ammonium, trialkylsulphonium, trialkylsulphoxonium, phosphonium, and amidinium cations. The term organic ammonium cation is intended to include ammonium cations prepared from low molecular weight amines, that is to say those having a molecular weight below about 300. Examples of such amines include alkylamines, alkenylamines, and alkanolamines containing not more than two amino groups, such as methyl amine, ethyl amine, n-propylamine, isopropyl-amine, n-butylamine, isobutylamine, sec-butylamine, n-amylamine, isoamylamine, dimethylamine, diethylamine, di n-propylamine, diisoDropylamine, trimethylamine, triethylamine, tri-n-propylamine, triisopropylamine, tri-n-butylamine, ethanolamine, n-propanolamine, isopropanolamine, diethanolamine, dipropanolamine, N,N-diethylethanolamine, allylamine, methoxyethylamine, oleylamine, cyclohexylamine, tallowamine, ethylenediamine, propylene-diamine, aniline, o, m and - methoxy-substituted aniline, o, m and p-toluidine and heterocyclic amines, for example pyridine, morpholine, piperidine and pyrrolidine.

Tetra-substituted ammonium cations are also included, for example tetra-methylammonium, tetra-butylammonium, and benzyl trimethyl ammoni um cations.

Trialkylsulphonium cations include those, for example, in which each of the three alkyl groups,, which are not necessarily all the same, may contain from 1 to 6 carbon atoms. Trialkylsulphoxonium cations likewise include those in which each of the three alkyl groups, which may be the same or different, may contain from 1 to 6 carbon atoms. Particular examples are trimethylsulphonium and trimethylsulphoxonium cations respectively.

Phosphonium cations include, for example, cations in which the phosphorus atom bears four substituents, each of which may be an alkyl group of 1 to 10 carbon atoms or a phenyl group, for example the tetramethylphosphonium, tetrabutylphosphonium, and tetraphenylphosphonium cations.

Amidinium cations include, for example, straight-chain amidinium cations of formula RhC(NH2)NH2+ wherein Rh is an alkyl radical of, for example, from 1 to 10 carbon atoms, and cyclic amidinium cations such as the protonated form of 1,8-diazabicyclo[5,4,0]undec-7-ene (DBU). Alkali metal cations include lithium, sodium, and potassium; and alkaline earth metal cations include magnesium, calcium, strontium and barium.

Alternatively examples of such salts are inorganic acid addition salts such as hydrochloride, sulphate or hydrobromide salts, and organic acid salts such as acetate or tosic acid salts.

Salts or esters of carboxylate groups described above as potential optional substituents are suitably agriculturally acceptable. Examples of such salts include acid salts described above for formula (I). Suitable esters include optionally substituted alkyl, alkenyl alkynyl or aralkyl such as benzyl esters. Suitable optional substituents are those described above in relation of R4-R18.

Suitably R1 is hydrogen.

When R1 is a group of sub-formula (i), R4 and Z may be selected so that the group of sub-formula (i) forms an acylamino residue of an amino acid. Examples of such amino acid includes isoleucine and alanine.

Suitable Z is hydrogen and R4 is hydrogen or alkyl such as methyl or but-2-yl.

Suitably R2 and R3 are hydrogen.

Suitably X is hydrogen or halogen such as chlorine.

Examples of groups Y include amino and hydroxy.

Compounds of formula (I) may assume various stereochemical configurations both around the substituted tetrahydrofuryl ring and the group of sub-formula (i). The invention includes all stereochemical forms of the compound of formula (I) and mixtures of such forms in any proportions. Preferably the substitued tetrahydrofuryl ring assumes the configuration of p-D-ribofuranosyl ring. The stereochemistry at the group of sub-formula (i) is preferably that of an 'L' or '2S' amino acid.

Certain compounds of formula (I) are novel and these form a further aspect of the invention. In particular there is provided a salt of a compound of formula (I) as defined above; or a compound of formula (I), where X, Y, R2 and R3 are as defined above and R1 is a group of subformula (i) but is other than glycyl, alanyl, prolyl or phenylalanyl.

Other examples of novel compounds of formula (I) which form as aspect of the invention are those where R1 is a group of subformula (i) where R4 and Z are selected so that the group of subformula (i) forms a glycyl, alanyl, prolyl or phenylalanyl residue, X, Y, R2 and R3 are as defined above provided that when Y is amino, X is other than hydrogen or chloro.

Particular examples of compounds of formula (I) are listed in Table I. TABLE I

Compound No. X Y R3 R2 RI 1 H NH2 H H H 2 H NH2 H H CH3CH(NH2)CO 3 H NH2 H H CH3CH2CH(CH3)CH(NH2)CO 4 Cl NH2 H H CH3CH(NH2)CO 5 Cl NH2 H H CH3CH2CH(CH3)CH(NH2)CO 6 H NH2 H H (CH3)2CHCH2CH(NH2)CO 7 H NH2 H H CH3S(CH2)2CH(NH2)CO 8 H NH2 H H H2N(CH2)4CH(NH2)CO 9 H NH2 H H C6H5CH2CH(NH2)CO 10 H NH2 H H (CH3)2CHCH(NH2)CO 11 H NH2 H H H2NCHCO 12 H NH2 H H t iĭCH2CH (NH2) CO L H 13 H NH2 H H HO2C(CH2)2CH(NH2)CO 14 H NH2 H H CH3OCH(CH3)CH2CH(NH2)CO 15 H NH2 H H HSCH2CH(NH2)CO 16 H NH2 H H 4-HOC6H4CH2CH(NH2)CO 17 H NH2 H H HO2CCH2CH(NH2)CO TABLE II Compound Characterising Data No.

1 NMR bH (d6DMSO): 4.06-4.30(4H,m); 4.58(1H,t); 5.90(1H,d); 7.27(2H,brs); (D20 exchangeable); 7.55(2H,brs); (D20 exchangeable); 8.12(1H,s); 8.25(1H,s)ppm.

2 NMR 3H (d6DMSO+D20): 1.23(3H,d); 3.41(1H,q); 3.95-4.13(4H,m); 4.51(1H,t); 5.85(1H d); 8.09(1H,s); 8.31(1H,s)ppm.

3 NMR EH (d6DMSO+D20): 0.80(3H,t); 0.85(3H,d); 1.16(1H,m); 1.45(1H,m); 1.78(1H,m); 3.28(1H,d); 3.98-4.17(4H,m); 4.55(1H,t); 5.88(1H,d); 8.10(1H,s); 8.34(1H,s)ppm.

4 NMR bH (d6DMSO+D2O) 1.25(3H,d); 3.42(1H,q); 3.98-4.13(4H,m); 4.46(1H,t); 5.80(1H,d); 8.37(1H,s)ppm.

5 NMR bH (d6DMSO+D20): 0.79(3H,t); 0.85(3H,d); 1.15(1H,m); 1.45(1H,m); 1.78(1H,m); 3.28(1H,m); 3.98-4.15(4H,m); 4.48(1H,t); 5.80(1H,d); 8.37(1H,s)ppm.

Compounds of formula (I) where R2 and R3 are hydrogen may be prepared by the acid catalysed removal of protecting groups from a compound of formula (II) where Z, X and Y are as defined in relation to formula (I) and R1a is a group R1 or a protected form thereof, and R26 and R27 are protecting groups. Where Rla is a group of sub-formula (i), the amino group may be protected so that the compound of formula (II) is a compound of formula (IIA) where R28 is an amino protecting group. Typical acids are either mineral acids for example hydrochloric acid, or organic acids, for example trifluoroacetic acid. The reaction may be undertaken in either non-aqueous solvents at temperatures of from -300C to 1000C, or in aqueous solvents such as trifluoroacetic acid in water, at a temperature between 5"C to 1000C, typically at room temperature.

Suitable amino protecting groups R28 for use in compound (IIA) include carbamates, such as tert-butyloxycarbamate, where R28 is C02C(CH3)3, and amides, typically where R28 is acyl such as acetyl or trifluoroacetyl.

Suitable protecting groups R26 and R27 for the hydroxy functional 6 groups include groups of formula R5(CO) n or R (CO)m respectively in particular esters, typically acetates, and acetals, typically when R26 and R27 together are > CMe2 thus forming a cyclic isopropylidene acetal.

Where in the compound of formula (IIA), R26 and R27 are groups of formula R5(CO) n or R6(CO) respectively, partial deprotection by removing the group R28 only will yield compounds of formula (I) where R and R are other than hydrogen. Suitable conditions for partial deprotection when for example the amino protecting group R28 is a carbamate, in particular benzyloxycarbamate (R28 is C02CH2C6H5),include catalytic hydrogenolysis in the presence or absence of a solvent and acid catalyst. Suitable catalysts include 10% palladium on charcoal. Suitable solvents are alcohols in particular methanol or ethanol. A suitable acid catalyst is trace quantities of tosic acid.

Compounds of formula (IIA) are suitably prepared by coupling a suitably protected amino acid derivative of formula (III), where R4 and R28 are as hereinbefore defined and R29 is an activating group, with a protected ribosyl derivative of formula (II) where Rla is hydrogen shown as formula (IV), where X, Y, R26 and R27 are as hereinbefore defined.

Suitable activating groups R29 for the compound of formula (III) include halide such as chloride, mixed anhydride such as pivaloyl, esters, in particular the N-hydroxysuccinimide esters, and N-linked acyl imidazoles.

Compounds of formula (III) and (IV) may be coupled in a base mediated reaction in the presence or absence of solvent and optionally in the presence of a nucleophilic catalyst. The base may be either inorganic, for example alkali or alkaline earth carbonates or hydrides, or organic, for example triethylamine or 1,8-diazobicyclo[5,4,0]undec-7-ene (DBU). The solvent will suitably be non-aqueous, for example tetrahydrofuran or dimethylformamide. The reaction temperature will be typically between -30 C and 100 C, for example room temperature. Suitable nucleophillic catalysts include pyridine and 4-dimethylaminopyridine.

Alternatively a compound of formula (IIA) could be formed by the base mediated reaction of an amino protected amino acid of formula (V) where R1 and R28 are as hereinbefore defined with a compound of formula (IV) and a dehydrating agent in the presence or absence of a solvent, and optionally in the presence of a nucleophilic catalyst.

Typical dehydrating agents include carbodiimides, for example N,N'-dicyclohexylcarbodiimide. Typical solvents are non-aqueous, for example, tetrahydrofuran, dimethylformamide or methylene chloride.

Suitable bases are either inorganic bases, for example alkali or alkaline earth carbonates or hydrides, or organic bases for example triethylamine.

Typical nucleophilic catalysts are pyridine and 4-dimethylaminopyridine.

The reaction temperature will be suitably be between -30 C to 1000C, for example room temperature.

Compounds of formula (III) and (V) are known compounds or can be readily prepared by application of standard amino acid chemistry.

Compounds of formula (IV) may be prepared by the reaction of sulphamoyl chloride of formula (VI) with compound of formula (VII) where X and Y are as defined in relation to formula (I) and R26 and R27 are as defined hereinbefore. This reaction may be undertaken in a non-aqueous inert solvent, for example tetrahydrofuran, toluene or methylene chloride in the presence or absence of a base at a reaction temperature for example of from -30 C to 1000C, conveniently at room temperature in the presence or absence of a nucleophilic catalyst. Suitable bases include inorganic bases, for example alkali and alkaline earth carbonates and hydrides, and organic bases, for example pyridine, DBU and triethylamine. Suitable nucleophilic catalysts include pyridine and 4-dimethylaminopyridine.

Alternatively compounds of formula (VII) may be initially activated by prior treatment with a tin reagent, for example bis(tributyltin)oxide in an inert solvent, for example toluene, with removal of water, typically using a Dean and Stark apparatus, at elevated temperatures, for example 30"C to 150 C. A solution of sulphamoyl chloride of formula (VI) in an inert solvent, for example dioxane, is then added to a solution of the activated tin complex of compound of formula (VII) in an inert solvent such as toluene, at a reduced temperature for example of from -50 C to 100C, typically 0 C to 50C, achieved by cooling the reaction mixture.

Compounds of formula (VII) where X is hydrogen and Y is amino and where X is chloro and Y is amino are commercially available. The sulphomoylchloride of formula (VI) may be prepared by the controlled hydrolysis of chloro- sulphonylisocyanate by a standard literature procedure.

Compounds of formula (VII) may be prepared from the corresponding diol compound of formula (VIII) where X and Y are as defined in relation to formula (I) by an acid catalysed reaction with acetone, in the presence or absence of a solvent for example toluene, and optionally in the presence of a dehydrating agent or with removal of water for example using a Dean & Stark apparatus. Suitable reactions temperatures are between 10 C to 1500C. Suitable acid catalysts include mineral acids1 for example hydrochloric acid or organic acids for example toluenesulphonic acid.

Alternatively compound of formula (VII) may be prepared from the reaction of compound of formula (IX), where R26 and R27 are as hereinbefore defined and R30 is an acyl group such as acetyl, with a compound of formula (X) where X and Y are as hereinbefore defined optionally in the presence of a solvent such as tetrahydrofuran, toluene or 1,2-dichlorobenzene and in the presence or absence of a catalyst. Suitable reaction temperatures are elevated temperatures for example of from 600C to 2000C.

Compounds of formula (IX) may be prepared by the reaction of compound of formula (XI) when R26, R27 and R30 are as hereinbefore defined with sulphamoylchloride of formula (VI) as hereinbefore defined in a manner analogous to that described for the reaction of the compound of formula (VII) with the compound of formula (VI).

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

The composition of the invention are active against a broad range of weed species including monocotyledonous and dicotyledonous species.

The composition suitably include carriers comprising a solid or liquid diluent.

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

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

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

Liquid compositions may comprise a solution or dispersion of an active ingredient in water optionally containing a surface-active agent.

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

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

The aqueous solutions or dispersions may be prepared by dissolving the active ingredient in water or an organic solvent optionally containing wetting or dispersing agent(s) and then1 when organic solvents are used, adding the mixture so obtained to water optionally containing wetting or dispersing agent(s). Suitable organic solvents include, for example, ethylene di-chloride, isopropyl alcohol, propylene glycol, diacetone alcohol, toluene, kerosene, methylnaphthalene, the xylenes and trichloroethylene including the compounds sold under the trade name "Solvesso".

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

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

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

The compositions of the invention may comprise, in addition to one or more compounds of the invention, one or more compounds not of the invention but which possess biological activity for example herbicides, fungicides, insecticides (optionally with an insecticide synergist) and plant growth regulators. Accordingly in yet a still further embodiment the invention provides a herbicidal composition comprising a mixture of at least one herbicidal compound of formula (I) as hereinbefore defined with at least one other herbicide.

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

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

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

The following examples illustrate the invention.

EXAMPLE 1 This example illustrates the preparation of compound 1 in Table 1.

Step A To a stirred, cooled (solid C02/acetone bath) solution of chlorosulphonyl isocyanate (5.529) in acetonitrile (20cm3), at -30 C was added dropwise a solution of water (0.72cm3) in acetonitrile (2.50cm3) at such a rate that the temperature did not rise above -20 C. After addition the reaction was allowed to warm to -50C over 30 minutes and then finally to 10 C. After stirring at this temperature for 15 minutes the reaction was concentrated under reduced pressure to give a cloudy oil (5.60g)containing some acetonitrile. This material was used crude in Step B.

SteD B 2',3'-0-isopropylideneadenosine (3.00g), bis(tributyltin)oxide (11.509) in toluene (200cm3) was heated in a Dean and Stark apparatus for 3 hours. After cooling and emptying the receiver of the Dean and Stark apparatus, the reaction was heated again for a further 3 hours (no more water collected), then cooled to 0-5"C. To this was added the sulphamoyl chloride from Step A of Example 1 in 1,4-dioxane (50cm3) over 20 minutes at such a rate that the temperature did not rise above 5"C. During the addition a white precipitate formed. After stirring for 1 hour at 0-50C the reaction was concentrated under reduced pressure. The residue was treated with hot hexane (3x10Ocm ), leaving a gelatinous solid. This was dissolved in methanol (50cm3) and the pH adjusted to 8-9 with concentrated aqueous ammonia, then concentrated under reduced pressure to give a pale yellow solid. The solid was column chromatographed (silica/chloroform-methanol, 9:1) to give 5'-0-sulphamoyl-2'3'-0-isopropylideneadenosine as a white solid (2.939, 78%). bH (d6DMSO): 1.27(3H,s); 1.50(3H,s); 4.08(1H,dd); 4.19(1H,dd); 4.34(1H,m); 5.03(1H,dd); 5.38(1H,dd); 6.20(1H,d); 7.32(2H,br.s) (exchangeable D20); 7.55(2H,br.s); (exchangeable D20); 8.11(1H,s); 8.25(1H,s)ppm.

Step C 5'-0-sulphamoyl-2',3'-0-isopropylideneadenosine (1.86g) produced in Step A of Example 1 was dissolved in a mixture of trifluoroacetic acid water (5:2 21cm3) and stirred at room temperature for 2 hours. The reaction was then concentrated under high vacuum to give a colourless oil.

This was treated with ethanol (4x7cm ), each time concentrating under high vacuum to give a white foam (2.179). The foam was column chromatographed (silica/chloroform-methanol, 2:1) to give compound No. 1 as a white solid (1.519, 90%).

EXAMPLE 2 This Example illustrates the preparation of Compound No. 2 in Table 1.

Step A 5'-0-sulphamoyl-2',3'-0-isopropylideneadenosine (0.3869), as produced in Example 1, Step B was dissolved in N,N-dimethylformamide (6cm3). To the solution was added DBU (0.1529), N-BOC-L-alanine hydroxysuccinimide ester (0.2869), and the reaction was then stirred at room temperature for 1 hours. After concentration under high vacuum at 400C the residual yellow oil was column chromatographed twice: firstly; silica/chloroform-methanol, 6:1, isolating impure product; secondly, silica/chloroform-methanol, 9:1 to give 2' ,3'-O-isopropylidene-5'-O-[N-(Boc-L-alanyl)sulphamoyl]adenosine as a white solid (0.1369, 63%). bH (d6DMSO): 1.09(3H,d); 1.25(3H,s); 1.29(9H,s); 1.48(3H,s); 3.65(1H,m); 3.93(2H,m); 4.33(1H,m); 4.93(1H,dd); 5.30(1H,dd); 6.10(1H,d); 7.29(2H,br.s) exchangeable D20); 8.10(1H,s); 8.33(1H,s)ppm.

Step B 2',3'-0-isopropylidene-5'-0-[N-(Boc-b-alanyl)sulphamoyl]adenosine (0.599) was treated with aqueous trifluoroacetic acid as outlined in Step C of Example 1. Column chromatography (silica/chloroform-methanol, 2:1) gave compound No. 2 as a white solid (0.3759, 85%).

Compounds 3,4 and 5 were produced in an analogous manner using appropriate reagents and starting materials.

Compounds 1-5 have been tested in glasshouse trials and have shown herbicidal activity against a number of weed species including Chenopodium album, Amaranthus retroflexus, Avena fatua, Alopecurus mvosuroides, Setaria viridis and Echinochloa crus-oalli.

CHEMICAL FORMULAE (IN DESCRIPTION)

CHEMICAL FORMULAE (IN DESCRIPTION)

Claims (5)

1. CLAIMS 1. According to the present invention there is provided a herbicidal composition comprising a compound of formula (I):

   or a salt thereof; where R1 is hydrogen or a group of sub-formula (i)

   where Z is hydrogen and R4 is as defined below, or Z and R4 together with the nitrogen atom and carbon atom to which they are respectively attached form an optionally substitued heterocyclic ring optionally containing further heteroatoms; R2 is hydrogen or R5(CO)n; R3 is hydrogen or R5(CO)m; where m and n are independently selected from 0 or 1 and R5 and R6 are as defined below or R5 and R6 together form an optionally substitued heterocyclic ring optionally containing further heteroatoms; Y is hydrogen, NR7R8, NR9NR7R8, N(OR7)R8, halo, cyano, OR10, COOH or salts thereof, COOR10, CONR7R8, S(O)pR11 or R12; X is hydrogen, halo, cyano, NR13R14, N(OR13)R14, NR15NR13R14 OR16, COOH or salts thereof, COOR16, CONR13Rl4 5(0) R17, R18 where where p and q are independently selected from 0, 1 or 2, and R4, R5, R6, R7, R8 R9 R10, R11, R12 R13 R14 R15 R16, R17 and R18 are either the same or different and are independently selected from hydrogen, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted aryl or optionally substituted heterocyclyl; provided that when X is chloro and Y is amino1 R1, R2 and R3 are not all hydrogen.

   2. A process for severely damaging or killing unwanted plants which process comprises applying to the plants or to the locus thereof, a herbicidally effective amount of a compound of formula (I) as defined in claim 1.

   3. A process for preparing a compound of formula (I) as defined in claim 1 which process comprises coupling a compound of formula (VI) NH2S02Cl (VI) with a compound of formula (VII)

   where X and Y are as defined in claim 1 and R26 and R27 are protecting groups and thereafter if desired or necessary carrying out one or more of the following steps: i) reacting the product with a compound of formula (III):

   where R4 is as defined above, R28 is an amino protecting 1\ 5 an amino group1 and R is an activating group; ii) reacting the product with a compound of formula (V):

   where R4 and R28 are as defined above, in the presence of a dehydrating agent; iii) removing some or all of the protecting groups.

   A salt of a compound of formula (I) as defined in claim 1 or compound of formula (I) as defined in claim 1, provided that R1 is a group of subformula (i) as defined in claim 1 but is other than glycyl, alanyl, prolyl or phenylalanyl.

   A compound of formula (I) as defined in claim 1 provided that R1 is a group of subformula (i) as defined in claim I where R4 and Z are selected so that the group of subformula (i) forms a glycyl, alanyl, prolyl or phenylalanyl residue1 and further provided that when Y is amino1 X is other than hydrogen or chloro.

   Amendments to the claims have been filed as follows 1. According to the present invention there is provided a herbicidal composition comprising a compound of formula (I):

   or a salt thereof; where R1 is hydrogen or a group of sub-formula (i)

   where Z is hydrogen and R4 is as defined below, or Z and R4 together with the nitrogen atom and carbon atom to which they are respectively attached form an optionally substitued heterocyclic ring optionally containing further heteroatoms; R2 is hydrogen or R5(CO)n; R3 is hydrogen or R6(CO)m; where m and n are independently selected from 0 or 1 and R5 and R6 are as defined below or R5 and R6 together form an optionally substitued heterocyclic ring optionally containing further heteroatoms; Y is hydrogen, NR7R8, NR9NR7R8, N(OR7)R8, halo, cyano, OR10, COOH or salts thereof, COOR10, CONR7R8, S(O)pR11 or R12 X is hydrogen, halo, cyano, NR13R14, N(OR13)R14, NR15NR13R14, OR16, COOH or salts thereof, COOR16 CONR13Rl4 S(O) R17 R18 where where p and q are independently selected from 0, 1 or 2, and R4, R5, R6, R7, R81 R9, R10, R111 R12, R13, R14, R15, R16, R17 and R18 are either the same or different and are independently selected from hydrogen, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl1 optionally substituted aryl or optionally substituted heterocyclyl; provided that when X is chloro and Y is amino, R11 R2 and R3 are not all hydrogen.
2. 2. A process for severely damaging or killing unwanted plants which process comprises applying to the plants or to the locus thereof, a herbicidally effective amount of a compound of formula (I) as defined in claim 1.
3. 3. A process for preparing a compound of formula (I) as defined in claim 1 which process comprises coupling a compound of formula (VI) NH2S02Cl (VI) with a compound of formula (VII)

   where X and Y are as defined in claim 1 and R26 and R27 are protecting groups and thereafter if desired or necessary carrying out one or more of the following steps: i) reacting the product with a compound of formula (III):

   where R4 is as defined above, R28 is an amino protecting group, and R29 is an activating group; ii) reacting the product with a compound of formula (V):

   where R4 and R28 are as defined above, in the presence of a dehydrating agent; iii) removing some or all of the protecting groups.
4. 4. A salt of a compound of formula (I) as defined in claim 1 or compound of formula (I) as defined in claim 1, provided that R1 is a group of subformula (i) as defined in claim 1 but is other than glycyl, alanyl, prolyl or phenylalanyl.
5. 5. A compound of formula (I) as defined in claim 1 provided that R1 is a group of subformula (i) as defined in claim 1 where R4 and Z are selected so that the group of subformula (i) forms a glycyl, alanyl1 prolyl or phenylalanyl residue, and further provided that when Y is amino, X is other than hydrogen or chloro.