WO1997045408A1 - Herbicidal indolines - Google Patents

Abstract

Compounds of formula (I) are useful as herbicides: wherein R?1 and R2¿ independently represent hydrogen or C¿1-4? alkyl; R?3¿ is hydrogen or a C¿1-10? aliphatic radical optionally substituted with one or more halogen atoms; W1 and W2 independently represent O or S; Y is O or NR4, wherein R?4¿ is hydrogen, C¿1-4? alkoxy or a C1-6 aliphatic radical optionally substituted with one or more halogen atoms or C1-4 alkoxy groups; Z is NR?5 or CR6R7¿; or, when Y is NR4 and Z is NR?5, R4 and R5¿ together may represent -CH¿2?CH2-, -CH=CH-, -C(O)C(O)- or -CH2C(O)-; or, when Y is NR4 and Z is CR?6R7, R4¿ and one of R?6 and R7¿ may represent -CH¿2?- or -CH2CH2-; or, when Z is CR?6R7, R3¿ may be a C¿1-6? alkoxycarbonyl group; X is C1-10 alkyl, halo-C1-10 alkyl, C1-10 alkoxy, halo-C1-10 alkoxy, cyano, -SF5, SO2CF3, -SCF3, nitro or halo; and n is 0, 1, 2, 3 or 4.

Description

HERBICIDAL INDOLINES

This invention relates to indoline derivatives useful as herbicides, processes for preparing them, and herbicidal processes and herbicidal compositions utilising them.

Heterocyclic compounds which are active as herbicides are known from, for example, WO 94/13652 and WO 95/33719.

Proc. Am. Pept. Symp., 5th, 559-61 , Editors Goodman et al, Wiley: New York, N.Y. 1977, discloses the compound A/-[2-oxo-2-(5-bromo-7-nitroindolin-l-yl)ethyl]acetamide. No utility is suggested for this compound.

We have now found a group of novel indoline derivatives which exhibit herbicidal activity.

According to the invention there is provided a compound of formula I:

I wherein R¹ and R² independently represent hydrogen or C_M alkyl;

R³ is hydrogen or a C_M0 aliphatic radical optionally substituted with one or more halogen atoms;

W| and W₂ independently represent O or S;

Y is O or NR⁴, wherein R⁴ is hydrogen, C _M alkoxy or a C,.₆ aliphatic radical optionally substituted with one or more halogen atoms or C_M alkoxy groups;

Z is NR⁵, wherein R⁵ is hydrogen or a C _M aliphatic radical; or CR⁶R⁷, wherein R⁶ and R⁷ independently represent hydrogen or a C _M aliphatic radical optionally substituted with one or more halogen atoms, or R⁶ and R⁷ together with the carbon atom to which they are attached form a 3- to 6-membered carbocyclic ring; or, when Y is NR⁴ and Z is NR³, R⁴ and R⁵ together may represent -CH₂CH₂-,

-CH=CH-, -C(0)C(0)- or -CH₂C(0)- in which the -CH₂- group is linked to Y and the -C(O)- group is linked to Z to form an imidazolidinedione ring; or, when Y is NR⁴ and Z is CR⁶R⁷, R⁴ and one of R⁶ and R⁷ may represent -CH₂- or -CH₂CH₂-, while the remaining R⁶ or R⁷ group is hydrogen or a Cι_-4 aliphatic radical; or, when Z is CR⁶R⁷, R¹ may be a d ₆ alkoxycarbonyl group,

X is Cι ιo alkyl, halo-Ci |₀ alkyl, C| ιo alkoxy, halo-Ci ι₀ alkoxy, cyano, -SF₅, S0₂CF^, -SCFi, nitro or halo; and

provided that the compound is not Λ/-[2-oxo-2-(5-bromo-7-nιtroιndolιn- 1 - yl)ethyl]acetamιde

When there is more than one group X they may be the same or different

The term halogen includes fluorine, chlorine, bromine and iodine When an aliphatic radical is substituted by more than one halogen atom they may be the same or different The aliphatic radical R¹ may be an alkyl radical, an alkenyl radical or an alkynyl radical

When it is an alkyl radical it may be a Cι ι₍₎ alkyl radical, e.g a C_{t 6} or C _M alkyl radical Examples of alkyl radicals include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl and its isomers and n-hexyl and its isomers. When the aliphatic radical R¹ is an alkenyl radical it may be a C₂ ιo alkenyl radical, e g. a C_{2 6} or C_{2 4} alkenyl radical Examples of alkenyl radicals include vinyl, allyl and butenyl When R¹ is an alkynyl radical it may be a C₂.ιo alkynyl radical, e.g. a C_{2 6} or C_{2 4} alkynyl radical. Examples of alkynyl radicals include ethynyl, propynyl and butynyl

R¹ is preferably a Cι ₆ alkyl radical optionally substituted with one or more halogen atoms Examples of values for R^ include methyl, chloromethyl, dichloromethyl and tert-butyl

When R⁴ is an aliphatic radical it may be an alkyl radical, an alkenyl radical or an alkynyl radical as described above for R\ for example a C_M alkyl radical, a C_{2 4} alkenyl radical, or a C₂.4 alkynyl radical. When R⁴ is substituted by more than one halogen atom, they may be the same or different. When R⁵, R⁶ or R ⁷ is an aliphatic radical, it may be for example a Cno alkyl, C_{2 10} alkenyl or C₂ in alkynyl radical, as described above for R¹, e.g. methyl, ethyl, propyl or butyl

When X is an alkyl, haloalkyl, alkoxy or haloalkoxy group, it preferably has from 1 to 6 carbon atoms, and more preferably from 1 to 4 carbon atoms.

X is preferably halo-Ci ι₀ alkyl, halo-d.io alkoxy, nitro or halo Examples of values for X include tπchloromethyl, tπfluoromethyl, tπfluoroethyl, difluoromethoxy, tπfluoromethoxy, bromo, chloro and nitro n is preferably 1 or 2.

W| and W₂ preferably represent O.

R¹ and R² preferably represent hydrogen. In particular when Z is NR⁵, R¹ and R² preferably represent hydrogen. Particular groups of compounds which may be mentioned include a) those in which Y is

NR⁴, Z is NR⁵, and R⁴ and R⁵ together represent -CH₂C(0)- in which the -CH₂- group is linked to Y and the -C(O)- group is linked to Z to form an imidazolidinedione ring; and b) those in which Y is O or NR⁴, and R⁴ is d-₄ alkoxy or a C|.₆ aliphatic radical optionally substituted with one or more halogen atoms or C_M alkoxy groups. Particular examples of compounds of formula I are listed in Table 1 below:

TABLE 1

The structural formula of the compound of Example 1 is:

A variety of methods are available for preparing the compounds of formula I and these form a further aspect of the invention.

Compounds of formula I wherein Y is an NR⁴ group (other than those in which Y is NR⁴, Z is NR⁵ and R⁴ and R⁵ represent -CH₂CH₂-, -CH=CH-, -C(0)C(0)- or -CH₂C(0)-) may be prepared from an amino compound of formula II:

II wherein R¹, R², R⁴, X and n are as defined for formula I.

The compounds of formula II may be prepared by various routes, for example those illustrated in Schemes A, B and C.

In Step a) of Scheme A, the indoline III is reacted with an acid chloride of formula ClCOC(R'R²)Hal, wherein Hal is halogen, preferably chlorine or bromine, in the presence of a base, and preferably in a solvent, to give the acyl derivative IV. The reaction may be carried out under the usual conditions for the acylation of an amine, i.e. at low temperature, e.g. from 0-15°C. The base is preferably a tertiary amine e.g. triethylamine, and the solvent may be a halogenated hydrocarbon, e.g. dichloromethane. When the acylation reaction is complete, the acyl derivative IV may be isolated by standard procedures. In Step b) of Scheme A, the acyl derivative IV is reacted with an amine R⁴NH₂ in the presence of a base, and preferably in an inert solvent, to give the compound of formula II. The base may be a tertiary amine or an inorganic base e.g. sodium carbonate or potassium carbonate, or the base may be provided by using a molar excess of the amine R⁴NH₂. The reaction may be carried out at ambient or somewhat elevated temperature, e.g. from 15- 100°C, preferably from 20-70°C. The solvent may be for example a halogenated hydrocarbon or an ether, e.g. tetrahydrofuran (THF). The compound of formula II may be isolated by conventional procedures, for example by diluting the reaction mixture with water, extracting II with a water-immiscible organic solvent, separating, drying and evaporating the organic extracts to obtain the crude product, which may be further purified if desired.

Scheme B outlines an alternative process for making compounds of formula II wherein R¹ and R² are both hydrogen. In Step a) of Scheme B, an indoline III is reacted with benzyloxyacetyl chloride to give the acyl compound V. The reaction may be carried out under the usual conditions for an acylation reaction in which a carboxylic acid chloride is used, as described for Step a) of Scheme A. The solvent may be for example a halogenated hydrocarbon e.g. dichloromethane. In Step b), the acyl compound V is treated with hydrogen in the presence of a catalyst e.g. a 5% palladium on carbon catalyst, to give the hydroxy compound VI. A wide variety of solvents may be used for the hydrogenation reaction. The hydroxy compound VI may be recovered by filtering off the catalyst and evaporating the filtrate.

In the process of Scheme B, the hydroxy group of compound VI is introduced in a protected form as a benzyloxy group. The benzyl group is subsequently removed by hydrogenation. Scheme B may be varied by using other hydroxy protecting groups.

In Step c) the hydroxy compound VI is reacted with a sulfonyl chloride R⁸S0₂CI, wherein R⁸ may be an alkyl group, e.g. methyl, or an aryl group, e.g. phenyl, or p-tolyl. The reaction is preferably carried out in an inert solvent and in the presence of a base to neutralise the hydrogen chloride formed. The base may be a tertiary amine, e.g. triethylamine, pyridine or 4-dimethylaminopyridine, or an inorganic base, e.g. sodium or potassium carbonate. Preferably the reaction is performed at a temperature below ambient, e.g. at 0-10°C, although once the sulfonyl chloride and the hydroxy compound VI have been mixed and the initial reaction is over, the mixture may be allowed to warm to ambient temperature or heated to complete the reaction. The sulfonate VII may be isolated from the reaction mixture by standard procedures.

In Step d) the sulfonate VII is reacted with an amine R⁴NH₂ to give the compound of formula II. The reaction is preferably performed in the presence of a base and an inert solvent, for example an ether, e.g. THF, and may be carried out at ambient or moderately elevated temperatures for example from 15-100°C, e.g. at 25-50°C. The compound of formula II may be isolated if desired by standard methods, but is often pure enough to be used without further purification in the preparation of compounds of formula I.

A further process for making compounds of formula II in which R¹ and R² are both hydrogen is outlined in Scheme C. In Step a) of Scheme C, an indoline III is treated with an N(R⁴) substituted glycine protected as the /V-terf-butoxycarbonyl derivative, in the presence of a molar amount of dicyclohexylcarbodiimide (DCC) and a catalytic amount of 4- dimethylaminopyridine (DMAP) to give the acyl derivative VIII. The reaction takes place at ambient temperatures, e.g. 15-40°C. The solvent may be an ether or a halogenated hydrocarbon, e.g. dichloromethane. The acyl derivative VIII may be isolated by filtering the reaction mixture to remove the dicyclohexylurea formed in the reaction and evaporating the filtrate to leave the acyl derivative VIII as the residue.

In Step b) of Scheme C, the acyl derivative VIII is treated with an excess of trifluoroacetic acid to give the compound of formula II. The reaction is preferably carried out in an inert solvent, for example an ether or a halogenated hydrocarbon, e.g. dichloromethane. The reaction may be carried out at ambient temperature, e.g.15-40°C. The amino compound II may be isolated by standard methods; for example, the reaction mixture may be evaporated to leave the crude trifluoroacetate salt of the compound of formula II. This may then be agitated with an aqueous solution of a base, e.g. a saturated solution of sodium bicarbonate, and a water-immiscible organic solvent, e.g. dichloromethane, and the organic solvent separated. The aqueous solution may be further extracted with the organic solvent and the combined portions dried and evaporated to give the compound of formula II.

Scheme A

UI IV

Scheme B

HI a₎

VI

VII

Scheme C

VIII Compounds of formula I wherein Y is NR⁴ and Z is NH may be prepared as outlined in Scheme D. According to Scheme D, a compound of formula II is reacted with an isocyanate R³NCO in the presence of a catalytic amount of a base. The base is preferably a tertiary amine e.g. triethylamine. The reaction is preferably carried out in an inert solvent, for example an ether or a halogenated hydrocarbon, e.g. dichloromethane. The reaction may be carried out at ambient temperatures, e.g.l5-40°C. The product of formula IX, i.e. I; Y = NR⁴, Z = NH, may be isolated from the reaction mixture by standard methods; for example, the mixture may be agitated with an aqueous solution of a dilute acid, e.g. hydrochloric acid, to remove the catalytic base, and the organic solvent separated, washed, dried and evaporated to give the compound of formula X, which may be further purified if desired. Scheme D

IX Compounds of formula I wherein Y is NR⁴ and Z is CR⁶R⁷ may be prepared as outlined in Scheme E. According to Scheme E, a compound of formula II is reacted with an acid chloride C1C0CR⁶R⁷R¹ in the presence of a base to form a compound of formula X. The base may be an organic base, such as a tertiary amine, e.g. triethylamine, or an inorganic base, e.g. sodium or potassium carbonate. The reaction is preferably carried out in a solvent, the choice of solvent is not critical, provided it is inert towards the reactants. Suitable solvents include ethers and halogenated hydrocarbons, e.g. dichloromethane. The reaction may be carried out at below ambient temperature, e.g. 0-10°C, although once the acid chloride and compound of formula II have been mixed and the initial reaction is over, the mixture may be allowed to warm to ambient temperature, e.g. 20-30°C, to complete the reaction. The compound of formula X, i.e. I, Y = NR⁴ , Z = CR⁶R⁷, may be isolated by standard methods e.g. as described for Step a) of Scheme A. Scheme E

II

Compounds of formula I wherein Y is O and Z is NH may be prepared as outlined in Scheme F. According to Scheme F, the hydroxy compound VI is reacted with an isocyanate R³NCO in the presence of a catalytic amount of base. The base is preferably a tertiary amine, e.g. triethylamine. The reaction mixture is preferably cooled to below ambient temperature, e.g. to 0-10°C, until the isocyanate and the hydroxy compound have been completely mixed and the initial reaction is over, and then allowed to warm to ambient temperature, e.g. 20- 30°C, or if necessary heated, e.g. to 30-100°C, to complete the reaction. The reaction is preferably carried out in an inert solvent, for example an ether or a halogenated hydrocarbon, e.g. dichloromethane. The product of formula XI, i.e. I, Y=0, Z = NH, may be isolated as described for Scheme D. Scheme F

XI

Compounds of formula I wherein R¹ and R² are both hydrogen, Y is NR⁴, Z is NR⁵ and R⁴ and R⁵ represent -CH₂C(0)- in which the -CH₂- group is linked to Y and the -C(O)- group is linked to Z to form an imidazolidinedione ring, i.e. compounds of formula XV, may be prepared as outlined in Scheme G. According to Step a) of Scheme G, diethyliminodiacetate is reacted with an isocyanate R³NCO in the presence of a base to give the urea derivative XII. The reaction is preferably carried out in a solvent inert towards the reactants, for example an ether or halogenated hydrocarbon, e.g. dichloromethane. The base is preferably a tertiary amine, e.g. triethylamine, and is preferably present in at least a molar amount in relation to the reactants. The reaction takes place at ambient temperature, e.g. 15-40°C, and the urea derivative may be isolated by evaporation of the solvent and the triethylamine. In Step b), the urea derivative XII is cyclised to the imidazolidinedione by treatment with an alkali metal alkoxide. The reaction is performed in a solvent, preferably an alkanol, e.g. ethanol. The alkali metal alkoxide may conveniently be generated in the reaction mixture by adding sodium hydride in the required molar proportion to the reaction mixture comprising an alcohol solution of the diethyl iminodiacetate. The cyclisation reaction takes place at ambient temperature, e.g.l5-40°C, but the reaction mixture may be heated to accelerate or complete the reaction. The imidazolidinedione acetic ester may be isolated by standard methods for example by diluting the reaction mixture with water and extracting with a water-immiscible organic solvent. The organic extracts are then dried and evaporated to give the crude 3-R - substituted ethyl 2,4-dioxoimidazolidine-l -acetate. This may be purified further if desired, e.g. by chromatography on a silica column. The ester is then subjected to alkaline hydrolysis to obtain the carboxylic acid XIII. The ester may be hydrolysed by heating it under reflux with a solution of a mild base, e.g. potassium carbonate, in aqueous alcohol as solvent. The carboxylic acid XIII may be isolated by acidifying the reaction mixture with a dilute acid, e.g. molar hydrochloric acid, extracting the acidified mixture with a water-immiscible organic solvent, drying and evaporating the organic extracts.

In Step c), the carboxylic acid XIII is converted to the corresponding acid chloride by treatment with a chlorinating agent, e.g. oxalyl chloride. A catalyst for the reaction may be present, e.g. dimethylformamide (DMF). The reaction is preferably conducted in a solvent, for example a halogenated hydrocarbon, e.g. chloroform. The reaction may be carried out at ambient temperatures, e.g. 15-40°C. The acid chloride XIV may be isolated by evaporating the solvent from the reaction mixture.

In Step d), the acid chloride XIV is reacted with the indoline III in the presence of a base, for example a tertiary amine, e.g. triethylamine. The reaction may be conducted at a temperature below ambient, e.g. 0-10°C. Preferably the reaction is carried out in an inert solvent, for example an ether or a halogenated hydrocarbon, e.g. dichloromethane. When the reaction has been completed, the product may be isolated from the reaction mixture by mixing it with an aqueous solution of a mild base, e.g. a saturated solution of sodium bicarbonate, and then separating the organic layer. The aqueous solution is then extracted with a water- immiscible organic solvent, and the organic extracts combined with the original layer, dried and evaporated to give the crude product XV. This may be further purified if desired, e.g. by chromatography on silica gel.

Scheme G

(EtOCOCH,),NH a)

XIII

XIV

XV

Compounds of formula I in which Y is NR⁴, Z is NR⁵ and R⁴ and R⁵ represent -C(0)C(0)-, i.e. compounds of formula XVI, may be prepared by reaction of oxalyl chloride with a compound of formula I wherein Y and Z each represent an NH group, as outlined in Scheme H. The reaction is preferably carried out in an inert solvent, e.g. a liquid hydrocarbon or a chlorinated hydrocarbon. The reaction proceeds at moderately elevated temperature, e.g. 40-100°C. Scheme H

XVI

Compounds of formula I in which Y is NR⁴, Z is NR⁵ and R⁴ and R⁵ represent -CH₂CH₂-, i.e. compounds of formula XVIII, may be prepared by reaction of a compound of formula IV with an R³-substituted imidazolidinone XVII in the presence of a base, as outlined in Scheme I. The process is preferably carried out in an inert solvent. The base may be an alkali metal carbonate, e.g. potassium carbonate, and the solvent may be a ketone, e.g. acetone or methyl ethyl ketone. The reaction may be carried out at a moderately elevated temperature, e.g. 50-100°C. Alternatively, compounds of formula XVIII may be prepared by hydrogenation of compounds of formula XX in the presence of a hydrogenation catalyst, e.g. 5% palladium on charcoal, under the usual conditions for hydrogenation of a -CH=CH- group to a -CH₂CH₂- group. Scheme I

XVII _χvπι

Compounds of formula I in which Y is NR⁴, Z is NR⁵ and R⁴ and R⁵ represent -CH=CH-, i.e. compounds of formula XX, may be prepared for example by reaction of a compound of formula IV with an R³ substituted imidazolinone XIX, as outlined in Scheme J. The process may be carried out as described for Scheme I. Scheme J

XIX ^

Alternatively, compounds of formula XX may be prepared as outlined in Scheme K. According to Step a) of Scheme K, the halogeno compound IV is reacted with an amine of formula NH₂CH₂CH(OR)₂ in which R is a C_MO aliphatic radical (preferably a C_μ4 alkyl radical) under the conditions described for Step b) of Scheme A to give the amino acetal XXI.

In Step b) of Scheme K, the aminoacetal XXI is reacted with an isocyanate R³NCO to give the urea XXTI, under the conditions described for Step b) of Scheme D.

In Step c) of Scheme K, the urea XXII is treated with an acid, e.g. hydrochloric acid, whereby the acetal group -CH(OR)₂ is converted into an aldehyde group. The aldehyde compound then undergoes cyclisation to form the required compound of formula XX. Scheme K

Compounds of formula I in which Y is NR⁴, Z is CR⁶R⁷, and R⁴ and one of R⁶ and R⁷ represent -CH₂- and the remaining R⁶ or R⁷ group is a C|.₄ aliphatic radical, i.e. compounds of formula XXIV, may be prepared as outlined in Scheme L. According to Step a) of Scheme L, a compound of formula II, R = H, is reacted in the presence of an acid acceptor with an acid chloride of formula ClCOCR³R^6/7CH₂(CH₂)_mCl, wherein m is 0, and R^6/7 is a C_M aliphatic radical, under the usual conditions for an acylation of a primary amine with an acid chloride, e.g. as described for Step a) of Scheme A, to give the amide XXIII, m=0. In Step b) of Scheme L, the amide XXIII, m=0, is treated with a strong base, e.g. sodium hydride, in an inert solvent, e.g. THF, DMF or dimethylsulfoxide. The reaction takes place at moderate temperatures, e.g. l5-40°C, for example ambient temperature, i.e.15-25°C. The reaction product XXIV, m = 0, may be isolated by conventional procedures, e.g. by diluting the reaction mixture with water, extracting the mixture with a water-immisicible organic solvent, and drying and evaporating the organic extracts to obtain the product XXIV, m=0. Another base which may be used in place of sodium hydride in the reaction of Step b) is caesium fluoride, in conjunction with a tetraalkyl ammonium salt, e.g. benzyltriethyl ammonium chloride, as a phase transfer catalyst. Scheme L

XXIV

Compounds of formula I in which Y is NR⁴, Z is CR⁶R⁷, and R⁴ and one of R^ft and R⁷ represent -CH₂CH₂-, while the remaining R⁶ or R⁷ group is hydrogen or a C|.₄ aliphatic radical may be prepared by the process of Scheme L, using an acid chloride of formula ClCOCR³R^6/7CH₂(CH₂)_mCl, wherein m is 1.

Compounds of formula XXV wherein Wi is S may be prepared by reaction of the corresponding compound XXV, W| = O, with a thiating reagent. Examples of thiating agents include phosphorus pentasulfide and Lawesson's reagent.

Compounds of formula XXVI wherein W₂ is S, Y is O or NR⁴ and R¹, R² and R⁵ arc hydrogen, may be prepared by reaction of a compound of formula VI with an isothiocyanate of formula R³NCS.

Compounds in which Wi and W₂ are both S may be prepared by reaction of the corresponding compounds in which W₍ and W₂ are O with phosphorus pentasulfide or with Lawesson's reagent at higher temperatures and for a longer period than when preparing compounds of formula XXV wherein W[ is S.

XXV XXVI The indolines III required as starting materials for the above mentioned processes are in many cases known compounds, or may be prepared by processes well known to those skilled in the art. In general, indolines may be prepared by reduction of the corresponding indoles, a suitable reducing agent is sodium cyanoborohydride in acetic acid. The indoles used in the preparation of the indolines are also in many cases known compounds, or may be prepared by processes well known to those skilled in the art. A method for preparing indoles is outlined in Scheme M. In Scheme M, an X-substituted o- nitro-phenylacetonitrile is hydrogenated in the presence of a catalyst, e.g. 5% palladium on carbon, to give an X-substituted indole. The process is illustrated in the examples below. Scheme M

The compounds of formula 1 are active as herbicides. Therefore, according to a further aspect of the invention, there is provided a process for severely damaging or killing unwanted plants, which process comprises applying to the plants, or to the growth medium of the plants, a herbicidally effective amount of a compound of formula I as hereinbefore defined, but without the proviso.

The compounds of formula I are active against a broad range of weed species including monocotyledonous and dicotyledonous species. They also show some selectivity towards certain species, and may be used, for example, as selective herbicides in rice (upland or paddy), soya, and maize crops. The compounds of formula I may be applied directly to unwanted plants (post-emergence application) but they are preferably applied to the soil before the unwanted plants emerge (pre-emergence application).

The compounds of formula I may be used on their own to kill or severely damage plants, but are preferably used in the form of a composition. Therefore, according to a further aspect of the invention, there is provided a herbicidal composition comprising a compound of formula I, but without the proviso, in admixture with a carrier comprising a solid or liquid diluent. Compositions containing compounds of formula I as active ingredient include both dilute compositions, which are ready for immediate use, and concentrated compositions, which require dilution before use, usually with water. Preferably the compositions contain from 0.01% to 90% by weight of the active ingredient. Dilute compositions may contain varying amounts of the active ingredient depending upon the intended purpose, amounts of 0.01% to 10.0% and preferably 0.01% to 2%, by weight of active ingredient are normally used. Concentrated compositions may conveniently contain 20-90%, preferably 20-70%, by weight of the active ingredient.

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 or 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 the active ingredient in water optionally containing a surface-active agent, or may comprise a solution or dispersion of the active ingredient in a water-immiscible organic solvent which is dispersed as droplets in water. Surface-active agents may be of the cationic, anionic or non-ionic types or mixtures thereof. Suitable cationic agents include quaternary ammonium compounds e.g. cetyltrimethylammonium bromide. Suitable anionic agents include soaps; salts of aliphatic mono esters of sulfuric acid, e.g. sodium lauryl sulfate; and salts of sulfonated aromatic compounds, e.g. sodium dodecylbenzenesulfonate, sodium, calcium and ammonium lignosulfonate, butylnaphthalene sulfoate, and a mixture of the sodium salts of diisopropyl and triisopropylnaphthalenesulphonic acid. Suitable non-ionic agents include 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, e.g. 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™. Aqueous solutions or dispersions may be prepared by dissolving the active ingredient in water or an organic solvent optionally containing wetting or dispersing agent(s) and then, when organic solvents are used, adding the mixture so obtained to water optionally containing wetting or dispersing agent(s). Suitable organic solvents include ethylene di-chloride, isopropyl alcohol, propylene glycol, diacetone alcohol, toluene, kerosene, methylnaphthalene, the xylenes and trichloroethylene.

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.

A preferred form of concentrated composition comprises the active ingredient which has been finely divided and which has been dispersed in water in the presence of a surface-active agent and a suspending agent. Suitable suspending agents are hydrophilic colloids and include 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 rate of application of the compounds of formula I will depend on a number of factors including, for example, the compound chosen for use, the identity of the plants whose growth is to be inhibited, the composition selected for use and whether the compound is to be applied for foliage or root uptake. As a general guide, an application rate of from 0.001 to 20 kg per hectare is suitable, while from 0.025 to 10 kg per hectare may be preferred. The compositions of the invention may comprise, in addition to one or more compounds of formula I, one or more compounds not of the invention but which possess biological activity. According to a further aspect of the invention, there is provided a herbicidal composition comprising a mixture of at least one compound of formula I as hereinbefore defined, but without the proviso, 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 and derivatives thereof e.g. salts, esters and amides, such as 2,4,5-T, 2,4-D, 2,4-DB, clopyralid, dichlorprop, dichlorprop-p, fluroxypyr, MCPA, MCPA-thioethyl, MCPB, mecoprop, mecoprop-p, picloram, thiazopyr, and trichlopyr;

C. 1,3-dimethylpyrazole derivatives such as benzofenap, pyrazolate and pyrazoxyfen;

D. dinitrophenols and their derivatives, e.g. acetates, such as dinoterb and DNOC;

E. dinitroanilines such as dinitramine, ethalflurolin, fluchloralin, oryzalin, pendimethalin, prodiamine and trifluralin;

F. arylureas such as chlorobromuron, chlorotoluron, daimuron, dimefuron, diuron, fenuron, flumeturon, isoproturon, isourn, linuron, methabenzthiazuron, methyldymron, metobromuron, metoxuron, monolinuron, neburon and tebuthiuron; G. phenylcarbamoyloxyphenylcarbamates such as desmedipham and phenmedipham; H. phenylpyrazoles such as ET-751 ;

I. 2-phenylpyridazin-3-ones such as chloridazon and norflurazon;

J. pyridones such as fluridone; K. pyrimidinyloxybenzoic herbicides such as DPX-PE350 (pyrithiobac-sodium) and

KIH-2023 (bispyribac-sodium); L. uracil herbicides such as bromacil, lenacil and terbacil;

M. triazines such as amytryn, atrazine, cyanazine, dimethametryn, prometon, prometryn, propazine, simazine, simetryne terbuthylazine, terbutryn and trietazine;

N. triazoles such as amitrole; O. triazolinones such as carfentrazone (F-8426) and sulfentrazone (F-6285); P. phosphorothioates such as bensulide, butamifos and piperophos;

Q. phthalamides such as flumioxazin;

R. thiocarbamates such as butylate*, cycloate, dimepiperate, EPTC*, esprocarb, molinate, orbencarb, pebulate, prosulfocarb, thiobencarb, tiocarbazil, tri-allate and vernolate; S. l,2,4-triazin-5-ones such as metamitron and metribuzin;

T. benzoic acid herbicides such as 2,3,6-TBA, chloramben and dicamba;

U. chloroacetanilides such as acetochlor, alachlor, butachlor, dimethachlor, dimethanamid, metazachlor, metolachlor, prctilachlor, propachlor, propanil and thenylchlor (NSK-850); V. dihalobenzonitriles such as bromoxynil, dichlobenil, ioxynil and the dihalobenzonitrile herbicide precursor bromofenoxim; W. haloalkanoic herbicides such as TCA and salts thereof and dalapon; X. diphenylethers such as aciflurofen and salts and esters thereof, aclonifen, bifenox, chlomethoxyfen, chlomitrofen, fluroglycofen and salts and esters thereof, fomesafen and lactofen; Y. diphenylureas such as oxyfluorfen;

Z. phenoxyphenoxypropionates such as clodinafop-propargyl, cyhalofop-butyl (DEH-1 12), diclofop and esters thereof e.g. the methyl ester, fenoxaprop and esters thereof e.g. the ethyl ester, fluazifop and esters thereof, haloxyfop and esters thereof, propaquizafop, quizalofop and esters thereof and quizalofop-p- tefuryl; AA. cyclohexanediones such as alloxydim and salts thereof, butroxydim, clethodim, cycloxydim, sethoxydim and tralkoxydim;

BB. sulfonyl ureas such as amidosulfuron, azimsulfuron, benzsulfuron and esters thereof such as DPX-M6313, chlorimuron and esters thereof such as the ethyl ester, chlorosulfuron, cinosulfuron, ethametsulfuron-methyl, flazasulfuron, halosulfuron, HOE-95404, imazosulfuron, metsulfuron and esters thereof, nicosulfuron, pirimisulfuron and esters thereof such as the methyl ester. prosulfuron, pyrazosulfuron, rimsulfuron, sulfometuron, thifensulfuron, triasulfuron, tribenuron, tribenuron-methyl and triflusulfuron-methyl; CC. imidazolinones such as imazamethabenz, imazapyr and isopropyiammonium salts thereof, imazaquin and imazethapyr; DD. methyl isothiocyanate herbicide precursors such as dazomet;

EE. arylanilides such as diflufenican, flamprop, flamprop-M and esters thereof;

FF. quinolinecarboxylic acids such as quimerac and quinclorac;

GG. amino acid herbicides such as bialaphos, glyphosate and glufosinate and their salts and esters and sulfosate; HH. organoarsenical herbicides such as DSMA and monosodium methanearsonate

(MSMA); II. organophosphorus herbicides such as anilofos and fosamine-ammonium; JJ. herbicidal amide derivatives such as bromobutide, carbetamide, FOE-5043, isoxaben, napropamide, naproanilide, naptalam, propyzamide and tebutam; KK. sulfamoylureas such as AC-322,140 (cyclosulfamuron);

LL. sulfonanilides such as chloransulam-methyl, DE-51 1 (metosulam) and flumetsulan; MM. carbamates such as chlorpropham; NN. triketones such as sulcotrione; OO. miscellaneous herbicides such as ammonium sulfamate, asulam, benazolin, cinmethylin, clomazone, difenzoquat and salts thereof e.g. the methyl sulfate salt, dimethipin, diphenamid, dithiopyr, ethofumesate, fumiclorac, flupoxam, flurenol -butyl, flurochloridone, flurtamone, hexazinone, HW-32, KIH-9201

(fluthiacet-methyl), KPP-314, mefenacet, oxadiazon, pyridate, RPA-201772 (isoxaflutole), sodium chlorate and thidiazimin; and

PP. contact herbicides including bipyridylium herbicides such as diquat and paraquat; * These compounds are preferably employed in combination with a safener such as:

AD-67, benoxacor, cloquintocet-methyl, dichlormid, fenchlorazole-ethyl, fenclorim, fluxofenim, furilazole, MG-191, naphthalic anhydride, oxabentrinil or

R-29148. The invention is illustrated by the following Examples. The abbreviations used in the Examples have the following meanings:

NMR: nuclear magnetic resonance spectrum recorded at 270 or 400 MHz. (This refers to the proton magnetic resonance spectrum recorded in CDC1₃ unless otherwise stated). Example 1

a) Λ/-tgrr-Butylaminocarbonyl diethyl iminodiacetate

A stirred solution of diethyl iminodiacetate (3.78 g) and triethylamine (4.77 ml) in dichloromethane (5 ml) was treated with tert-butyl isocyanate (2.51 ml) and the mixture stirred for 16 hours. Evaporation under reduced pressure gave the sub-title compound as a white crystalline solid.

NMR δ: 1.29 (6H,t), 1.34 (9H,s), 4.00 (4H,s), 4.21 (4H,q), 5.12 (lH.brs). b) Ethyl 2.4-dioxo-3-fgrt-butylimidazolidine- 1 -acetate

The compound of step a) was dissolved in dry ethanol (60 ml) and a 60% dispersion of sodium hydride in mineral oil (30 mg) added. The resultant solution was stirred for 2 hours then poμred into water. The mixture was extracted with dichloromethane (x2), the combined extracts dried (Na₂S0₄) and evaporated under reduced pressure. The residue was chromatographed on silica-gel, eluting with 30% ethyl acetate/hexane, to give the sub-title compound as a colourless oil (3.75 g). NMR 6: 1.28 (3H,t), 1.59 (9H,s), 3.87 (2H,s), 4.09 (2H,s), 4.20 (2H,q). c) 2.4-Dioxo-3-i'err-butylimidazolidine- 1 -acetic acid

The compound of step b) was dissolved in a 4: 1 mixture of ethanol and water ( 180 ml) and potassium carbonate (2.57 g) added. The reaction mixture was heated under reflux for 3 hours then cooled and poured into 1M hydrochloric acid (300 ml). The mixture was extracted with dichloromethane (x3), the combined extracts dried (Na₂S0₄) and evaporated under reduced pressure to leave an oil which slowly crystallised. Trituration with ethyl acetate/hexane gave the sub-title compound as a colourless crystalline solid. NMR δ: 1.60 (9H,s), 3.89 (2H,s), 4.17 (2H,s), 6.81 (lH,brs). d) 2.4-Dioxo-3-rerr-butylimidazolidine-l-acetyl chloride A stirred suspension of the compound of step c) (0.85 g) in chloroform ( 10 ml) containing 1 drop of DMF was treated dropwise with oxalyl chloride (0.38 ml). Stirring was continued for 3 hours after which the effervescence had ceased. The solvent was removed under reduced pressure to give the sub-title compound as a pale yellow oil which was used directly in step f). e) 6-Chloroindoline A stirred solution of 6-chloroindole (0.50 g) in glacial acetic acid ( 10 ml) was treated with sodium cyanoborohydride (0.63 g) in one portion at 15°C under a nitrogen atmosphere. The mixture was stirred for 20 min then poured into water (50 ml). The resultant mixture was cooled to ca 0°C then made strongly alkaline by the slow addition of sodium hydroxide flakes. The mixture was extracted with diethyl ether (x4) and the combined extracts washed with water (x2) and brine (x2) then dried (K₂CO,). Evaporation of the solvent under reduced pressure gave the sub-title compound which was used directly in step f). f) 3-(tert-But\D- 1 -r2-(6-chloro-2.3-dihydro- 1 H- 1 -indolvn-2-oxoethyll-2.4- imidazolinedione

A stirred solution of the the compound of step d) in dichloromethane (10 ml) was cooled to ca. 0°C and treated with a solution of the compound of step e) in dichloromethane (5 ml), followed by triethylamine (0.91 ml). The mixture was stirred with cooling for 30 min then poured into saturated aqueous sodium bicarbonate solution. The organic layer was separated and the aqueous layer extracted with dichloromethane. The combined dichloromethane extracts were washed with water and brine, then dried (Na₂S0₄). The solvent was evaporated under reduced pressure and the product purified by chromatography on silica-gel, eluting with 50% ethyl acetate/hexane, to give the title compound as a white solid ( 1.01 g), m.p. 212-214°C.

NMR δ: 1.66 (9Η,s), 3.21 (2H,t), 3.97 (2H,s), 4.10 (2H,t), 4.19 (2H,s), 7.02 ( lH,dd), 7.10 (lH,d), 8.19 (lH,d). Example 2

The following compounds were prepared according to the method of Example 1 : 2a) 3-(/grr-ButvD- l-r2-(4-chloro-2.3-dihvdro- 1H- 1 -indolvn-2-oxoethvn-2.4- imidazolinedione m.p.l89-191°C; NMR δ: 1.65 (9Η,s), 3.28 (2H,t), 3.98 (2H,s), 4.10 (2H,t), 4.19 (2H,t), 7.04 (lH,d),

7.15 (lH,t), 8.03 (lH,d). 2b) 3-⁽ _< ^Jgrr-ButvI⁾-l-r2-⁽6-trifluoromethyl-2.3-dihvdro-lH-l-indolyl)-2-oxoethvn-2.4- imidazolinedione m.p. 174- 177°C;

NMR δ: 1.61 (9Η,s), 3.30 (2H,t), 3.97 (2H,s), 4.14 (2H,t), 4.21 (2H,s), 7.25-7.34 (2H,m), 8.43 (lH,s).

2c) 3-(/grr-Butvn-l-r2-(6-difluoromethoxy-2.3-dihvdro-lH-l-indolvn-2-oxoethyll-2.4- imidazolinedione m.p. 155-157°C;

NMR δ: 1.60 (9Η,s), 3.22 (2H,t), 3.97 (2H,s), 4.1 1 (2H,t), 4.22 (2H,s), 6.49 ( lH,t), 6.82 ( lH,dd), 7.15 ( lH,d), 7.98 (lH,d).

2d) 3-(tgrr-Butyl)-l-f2-⁽6-nitro-2.3-dihvdro-lH-l-indolyl)-2-oxoethyll-2.4- imidazolinedione m.p. 270-273°C;

NMR δ: 1.63 (9Η,s), 3.35 (2H,t), 3.98 (2H,s), 4.20 (2H,t), 4.22 (2H,s), 7.32 (lH,m), 7.95 (lH,m), 8.94 (lH,m).

2e) 3-(rgrt-Butvn-l -r2-(2.3-dihvdro-lH-l-indolyl)-2-oxoethyll-2.4-imidazolinedione 2f) 3-(tgrr-Butyl)- l-r2-(5.6-dichloro-2.3-dihvdro-lH-l-indolvn-2-oxoethvn-2.4- imidazolinedione m.p. 213-216°C. Example 3

3.3-Dimethyl-yV-12-oxo-2-(6-chloroindolin-l-yl)ethyll-yV-methylbutanamide a) 6-Chloro-A^r-(/V'-methyl-/v"-fgrr-butoxycarbonylamino)acetyl indoline

A stirred solution of 6-chloroindoline (prepared from 6-chloroindole (0.70 g) as described in Example le)), 4-dimethyIaminopyridine (0.02 g) and N-te rr-butyloxycarbonyl sarcosine (0.92 g) in dichloromethane (10 ml) was treated with dicyclohexylcarbodiimide (1.00 g) whereupon a thick white precipitate formed. The slurry was stirred for a further 15 min then filtered through Ηyflo™, washing through with a little dichloromethane. The filtrate was evaporated under reduced pressure and the residue purified by chromatography on silica- gel, eluting with 50% ethyl acetate/hexane, to give the sub-title compound as a solid (1.20 g), m.p. 141-143°C. b) 6-Chloro-/V-(N'-methylamino)acetyl indoline A solution of the compound of step a) (0.75 g) in dichloromethane (10 ml) was treated with trifluoroacetic acid (2 ml) and left to stand for 2 hours. The solvent was evaporated under reduced pressure and the residue triturated with diethyl ether/hexane to give the crude trifluoroacetate salt of the amine. This was partitioned between dichloromethane and saturated aqueous sodium bicarbonate solution and the layers separated. The aqueous layer was extracted with dichloromethane and the combined dichloromethane layers washed with brine and dried (Na₂S0₄). Evaporation of the solvent gave the sub-title compound as a colourless solid (0.48 g), m.p. 98.5-99.5°C. c) 3.3-Dimethyl-/V-f2-oxo-2-(6-chloroindolin-l-yl)ethyll-/V-methylbutanamide A stirred solution of the compound of step b) (180 mg) and triethylamine (0.2 ml) in dichloromethane (5 ml) was cooled to ca 0°C and treated with 3,3-dimethylbutanoyl chloride (0.10 ml). The mixture was stirred with cooling for 1 hour then poured into saturated aqueous sodium bicarbonate solution. The mixture was extracted with dichloromethane (x3) and the combined extracts dried (Na₂S0₄). The solvent was removed under reduced pressure and the residue purified by chromatography on silica-gel, eluting with 60-80% ethyl acetate/hexane mixtures, to give the title compound as a solid (0.24 g), m.p. 110-1 13°C.

NMR δ: 1.1 1 (9H,s), 2.36 (2H,s), 3.15 (2H,t), 3.18 (3H,s), 4.1 1 (2H,t), 4.22 (2H,t), 6.97 (lH,dd), 7.07 ( l H,d), 8.22 (lH.d). Example 4 2.2-Dimethyl-N-12-oxo-2-f6-chloroindolin-l-yl)ethyll-N-methylpropanamide The title compound was prepared according to the method of Example 3. m.p.l27-129°C;

NMR δ: 1.33 (9H,s), 3.18 (2H,t), 3.31 (3H,s), 4.14 (2H,t), 4.15 (2H,s), 6.96 (lH,dd), 7.06 (lH,d), 8.23 (lH,d). Example 5

3.3-Dimethyl-N-[2-oxo-2-(6-trifluoromethylindolin-l-yl)ethyll-/V-propylbutanamide a) Ethyl 4-trifluoromethyl-2-nitrophenyl-α-cyanoacetate

A stirred suspension of potassium carbonate (5.58 g) in dimethyl formamide (30 ml) was heated to 1 10°C, and treated with ethyl cyanoacetate (6.76 g) followed by l-chloro-4- trifluoromethyl-2-nitrobenzene (9.00 g). After heating for 15 min the mixture was cooled, poured onto water and acidified using 2M sulfuric acid. This mixture was extracted with ethyl acetate (x3), the combined extracts washed with water and brine and dried (MgS0₄). The solvent was removed under reduced pressure and the residual oil chromatographed on silica-gel, eluting with 25% ethyl acetate/hexane, to yield a solid, which was recrystallised from methanol/hexane to give the sub-title compound as a white crystalline solid (1 1.73 g), m.p. 57.5-59°C.

NMR δ: 1.35 (3H,t), 4.34 (2H,q), 5.76 ( lH,s), 7.98 ( lH,d), 8.03 ( lH,dd), 8.48 ( lH,d). b) 4-Trifluoromethyl-2-nitrophenylacetonitrile

A mixture of the compound of step a) (1 1.73 g), 50% aqueous acetic acid (40 ml) and concentrated sulfuric acid (0.6 ml) was heated under reflux for 18 hours when tic analysis showed that little reaction had taken place. A further quantity of acetic acid (10 ml) and concentrated sulfuric acid (0.6 ml) was added and the mixture heated under reflux for 42 hours. The cooled mixture was extracted with diethyl ether (x3) and the combined extracts washed with water (x3) and brine, then dried (MgS0₄). The solvent was evaporated under reduced pressure and the residue purified by silica-gel chromatography, eluting with 15% ethyl acetate/hexane, to give the sub-title compound as an oil (6.31 g). NMR δ: 4.30 (2H,s), 7.95 (lH,d), 7.99 ( lH,dd), 8.47 (lH,d). c) 6-Trifluoromethyl indole

A solution of the compound of step b) (6.00 g) and acetic acid (0.5 ml) in ethanol (50 ml) was hydrogenated over a 5% palladium on carbon catalyst for 24 hours. The reaction mixture was filtered through Hyflo™ washing through with a little ethanol and the filtrate evaporated to dryness under reduced pressure. The residue was purified by silica-gel chromatography, eluting with 20% ethyl acetate/hexane, to give the sub-title compound as a solid (2.44 g).

NMR δ: 6.62 (lH,m), 7.30-7.41 (2H,m), 7.66-7.77 (2H,m), 8.41 (lH,brs). d) 6-Trifluoromethylindoline

By a procedure similar to that described in Example le) but using the compound of step c) (0.50 g), sodium cyanoborohydride (0.63 g) and acetic acid (10 ml), the sub-title compound was obtained as a yellow solid (0.472 g).

NMR δ: 3.08 (2H,t), 3.63 (2H,t), 3.90 (lH,brs), 6.89 (lH,s), 6.93 (lH,d), 7.16 ( lH,d). e) N-Chloroacetyl-6-trifluoromethyl indoline A stirred solution of the compound of step d) (472 mg) and triethylamine (0.87 ml) in dichloromethane (15 ml) was cooled to ca 0°C and treated with chloroacetyl chloride (0.30 ml). The mixture was stirred with cooling for 1 hour then poured into water. The mixture was extracted with dichloromethane (x3) and the combined extracts dried (Na₂S04). The solvent was removed under reduced pressure and the residue purified by flash chromatography on silica-gel, eluting with 30% ethyl acetate/hexane, to give the sub-title compound as a solid (593 mg).

NMR δ: 3.31 (2H,t), 4.17 (2H,s), 4.22 (2H,t), 7.25-7.38 (2H,m), 8.49 ( l H,s). 0 6-Trifluoromethyl-/V-(N'-n-propylamino)acetyl indoline A stirred solution of the compound of step e) (200 mg) in tetrahydrofuran ( 10 ml) was treated with a solution of n-propylamine (0.16 ml) in tetrahydrofuran (5 ml). The mixture was stirred at room temperature for 3 hours then heated to 60°C for a further 4 hours. The cooled solution was evaporated to dryness under reduced pressure and the residue partitioned between ethyl acetate and water. The ethyl acetate layer was separated, dried (Na₂S0₄) and evaporated under reduced pressure to leave an oily solid. This was purified by chromatography on silica-gel, eluting with 20% methanol/ethyl acetate, to give the sub-title compound as a solid ( 128 mg), m.p. 87-88°C.

NMR δ: 0.95 (3H,t), 2.59 (2H,m), 2.25 (lH,brs), 2.69 (2H,t), 3.25 (2H,t), 3.56 (2H,s), 4.08 (2H,s), 7.22-7.31 (2H,m), 8.49 ( lH,s). g) 3.3-Dimethyl-N-[2-oxo-2-(6-trifluoromethylindolin- l-yl)ethyll-N-propylbutanamide

By a procedure similar to that described in Example 3c) but using the compound of step f) (256 mg), triethylamine (0.25 ml), dichloromethane (5 ml) and 3,3-dimethylbutanoyl chloride (0.19 ml) and conducting the reaction at room temperature rather than at ca 0°C, the title compound was obtained ( 181 mg), m.p 92-95°C. m/z 384 (M⁺) (ei).

Example 6

The following compounds were prepared according to the method of Example 5: 6a) l-(^"5-/grt-Butyl-3-(prop-2-ynyl)hydantoyl)-6-trifluoromethylindoline

NMR δ: 1.37 (9H,s), 2.38 ( lH,t), 3.27 (2H,t), 4.05-4.23 (4H,m), 4.25 (2H,s), 7.23- 7.32 (2H,m), 8.48 ( lH,s).

6b) 2.2-Dimethyl-/V-r2-oxo-2-(6-(trifluoromethyl)indolin-l-yl)ethyll-N-ethylpropanamide 6c) 2-Dichloromethyl-2-methyl-/V-r2-oxo-2-(6-(trifluoromethynindolin-l-ynethyH-/V- ethylpropanamide

6d) l-(5-rgrr-Butyl-3-ethylhydantoyl)-6-trifluoromethylindoline

6e) 2-Chloromethyl-2-methyl-N-r2-oxo-2-(6-(trifluoromethyl)indolin-l-vnethyll-N- ethylpropanamide

6f) 2.2-Dimethyl-N-r2-oxo-2-(6-(trifluoromethvnindolin-l-vnethyll-N-(prop-2- ynyDpropanamide

6g) 2-Dichloromethyl-2-methyl-/V-r2-oxo-2-⁽6-(trifluoromethyl)indolin-l-yπethyn-N-(prop-

2-ynyl)propanamide NMR δ: 1.60 (6H,s), 2.38 ( lH,t), 3.30 (2H,t), 4.18 (2H,t), 4.29 (2H,s), 4.42 (2H,d),

6.39 (lH,s), 7.25-7.31 (2H,m), 8.44 (lH,s).

6h) 2-Chloromethyl-2-methyl-N-r2-oxo-2-(6-(trifluoromethylMndolin-l-yl)ethvn-/V-(prop-2- ynyDpropanamide

NMR δ: 1.50 (6H,s), 2.33 (lH,t), 3.30 (2H,t), 3.76 (2H,s), 4.19 (2H,t), 4.30 (2H,s), 4.45 (2H,d), 7.25-7.30 (2H,m), 8.44 ( lH,s).

6i) 2,2-Dimethyl-N-r2-oxo-2-(^'6-(trifluoromethvnindolin-l-yl)ethyll-N-('2-methoxyethyl)- propan amide

6j) 2-Dichloromethyl-2-methyl-N-r2-oxo-2-(6-(trifluoromethvnindolin-l-yl)ethyll-iV-(2- methoxyethyDpropanamide 6k) l -(5-fe^Butyl-3-(2-methoxyethy0hydantoyl)-6-trifluoromethylindoline

61) 2-Chloromethyl-2-methyl-/V-r2-oxo-2-(6-(trifluoromethvnindolin-l-vnethyll-N-(2- methoxyethyDpropanamide

6m) 2.2-Dimethyl-N-r2-oxo-2-(6-(trifluoromethyl)indolin-l-yl)ethyll-N-propyl-propanamide

6n) 2-Dichloromethyl-2-methyl-N-[2-oxo-2-(6-(trifluoromethyl)indolin-l-yl)ethyll-/v^'- propylpropanamide

6o) l-(5-rgrr-Butyl-3-propylhydantoyl)-6-trifluoromethylindoline

6p) 2-Chloromethyl-2-methyl-N-12-oxo-2-(6-(trifluoromethyl)indolin-l-yl)ethyl1-Λ^r- propylpropanamide

Example 7 3.3-Dimethyl-iV-f 1 -oxo- 1 -(6-trifluoromethylindolin- 1 -yl)propan-2-yll-N-propylbutanamide a) Λ^r-(2-Bromopropanoyl)-6-trifluoromethyl indoline By a procedure similar to that described in Example 5e) but using 6-trifluoromethy- lindoline (2.5 g), triethylamine (4.64 ml), dichloromethane (75 ml) and 2-bromopropanoyl chloride (2.02 ml), the sub-title compound was obtained as a solid, (1.46 g), m.p. 92-94°C.

NMR δ: 1.92 (3H,d), 3.30 (2H,m), 4.12 (lH,m), 4.42 ( IH,m), 4.55 (lH,q), 7.35-7.45 (2H,m), 8.55 (lH,s). b) 6-Trifluoromethyl-N-2-(iV'-n-propylamino)propanoyl indoline

By a procedure similar to that described in Example 5f) but using the compound of step b) (200 mg), tetrahydrofuran (10 ml) and n-propylamine (0.127 ml), the sub-title compound was obtained as an oil (204 mg). NMR δ: 0.91 (3H,t), 1.32 (3H,d), 1.78 ( lH,brs), 2.39-2.62 (2H,m), 3.29 (2H,t), 3.53

(lH,q), 4.08-4.33 (2H,m), 7.25-7.38 (2H,m), 8.57 (lH,s). c) 3.3-Dimethyl-N-r 1 -oxo- 1 -(6-trifluoromethylindolin- 1 -yl)propan-2-yll-N- propylbutanamide

By a procedure similar to that described in Example 5g), but using the compound of step b) (204 mg), triethylamine (0.17 ml), dichloromethane (5 ml) and 3,3-dimethylbutanoyl chloride (0.13 ml), the title compound was obtained (138 mg), m.p 102-104°C. m/z 398 (M⁺) (ei). Example 8

2-Dichloromethyl-2-methyl-N-[ 1 -oxo- 1 -(6-trifluoromethylindolin- 1 -yl)propan-2-yn-N- ethylpropanamide

The title compound was prepared according to the method of Example 7. Example 9 l-(5-te^Butyl-3-methoxyhydantoyl)-6-chloroindoline a) 6-Chloro-;V-chloroacetyl indoline By a procedure similar to that described in Example 5e), but using 6-chloromethyl- indoline (2.00 g), triethylamine (4.53 ml), dichloromethane (35 ml) and chloroacetyl chloride (1.55 ml), the sub-title compound was obtained as a solid (1.41 g).

NMR δ: 3.20 (2H,t), 4.17 (2H,s), 4.29 (2H,t), 7.03 (lH,dd), 7.10 (lH,d), 8.22 (lH,d). b) 6-Chloro-N-(N'-methoxyamino)acetyl indoline A slurry of 0-methyl hydroxylamine hydrochloride (0.45 g) and sodium carbonate (0.75 g) in dimethylsulfoxide ( 10 ml) was stirred for 15 min then a solution of the compound of step a) (0.50 g) in dimethylsulfoxide (30 ml) was added. The mixture was stirred at room temperature for 2 hours, at 60°C for 4 hours, then cooled and left to stand for 16 hours. The mixture was poured into water and extracted with ethyl acetate. The ethyl acetate extract was dried (Na₂SO₄), evaporated under reduced pressure and the residue purified by chromatography on silica-gel, eluting with 20-50% ethyl acetate/hexane mixtures, to give the sub-title compound as a solid (0.296 g), m.p. 89-91°C.

NMR δ: 3.19 (2H,t), 3.57 (3H,s), 3.74 (2H,s), 4.09 (2H,t), 6.54 ( lH,brs), 6.98 (dd), 7.07 ( lH,d), 8.29 ( lH,d). c) l-(5-rgr/-Butyl-3-methoxyhydantoyl)-6-chloroindoline

A stirred solution of the compound of step b) (0.10 g) and triethylamine (0.1 16 ml) in dichloromethane was cooled to 0°C and treated with t-butyl isocyanate (0.07 ml). The solution was slowly warmed to room temperature and left to stand for 16 hours. The mixture was poured into water and extracted with dichloromethane (x3). The combined dichloromethane extracts were dried (Na₂S0₄), evaporated to dryness under reduced pressure and the residue purified by silica-gel chromatography, eluting with 50-70% ethyl acetate/hexane mixtures, to give the title compound (0.155 g).

NMR δ: 1.41 (9H,s), 3.15 (2H,t), 3.71 (3H,s), 4.05 (2H,t), 4.34 (2H,s), 5.94 ( lH,brs), 6.94 ( lH,dd), 7.04 ( lH,d), 8.20 ( l H,d).

Example 10

3.3-Dimethyl-N-r2-oxo-2-(6-trifluoromethylindolin-l-yl)ethyn-N-methoxylbutanamide By a procedure similar to that described in Example 5d), but using 6-chloro-/V-(/V"- methoxyamino)acetyl indoline (Example 5b), 100 mg), triethylamine (0.144 ml), dichloromethane (10 ml) and 3,3-dimethylbutanoyl chloride (0.06 ml) the title compound was obtained as a solid (85 mg).

NMR δ: 1.1 1 (9H,s), 2.49 (2H,s), 3.20 (2H,t), 3.78 (3H,s), 4.1 1 (2H,t), 4.45 (2H,s),

6.97 (lH,dd), 7.05 (lH,d), 8.24 (lH,d).

Example 1 1 2-(6-Chloroindolin- 1 -yl)-2-oxoethyl-ι'grr-butylcarbamate a) 6-Chloro-N-(Q-benzyloxy)acetyl indoline A stirred solution of 6-chloroindoline (prepared from 6-chloroindole (0.50 g) as described in Example le)) in dichloromethane (15ml) was treated with benzyloxyacetyl chloride (0.87 g) and triethylamine (0.50 ml). Stirring was continued for 60 min then the mixture was diluted with dichloromethane and washed with 2M hydrochloric acid (x2), saturated sodium bicarbonate, water and brine, then dried (MgSO₄). The solvent was removed under reduced pressure and the residue purified by silica-gel chromatography, eluting with 35% ethyl acetate/hexane, to give the sub-title compound (0.944 g), m.p.107- 110°C.

NMR δ: 3.12 (2H,t), 4.05 (2H,t), 4.21 (2H,s), 4.70 (2H,s), 7.00 (lH,dd), 7.09 ( lH,d), 7.23-7.41 (5H,m). 8.29 (lH,d). b) 6-Chloro-/V-hydroxyacetyl indoline

A solution of the compound of step a) (0.670 g) in ethyl acetate (10 ml) was hydrogenated over a 5% palladium on carbon catalyst for 60 min. The reaction mixture was filtered through Hyflo™ washing through with a little ethyl acetate and the filtrate evaporated to dryness under reduced pressure. The residue was purified by silica-gel chromatography, eluting with 70% ethyl acetate/hexane, to give the sub-title compound as a solid (0.432 g), m.p. 159- 160°C.

NMR δ: 3.21 (2H,t), 3.49 ( lH,brs), 3.94 (2H,t), 4.21 (2H,d), 7.03 (lH,dd), 7.12 ( lH,d), 8.22 (lH,d). c) 2-(6-Chloroindolin- 1 -yl)-2-oxoethyl-rgrr-butylcarbamate

A stirred solution of the compound of step b) (0.19 g) in dichloromethane (5 ml) was cooled and treated with /gr/-butyl isocyanate (0.15 ml) followed by triethylamine (0.12 ml). The mixture was warmed to room temperature and stirred for 2 hours then left to stand for 72 hours when tic analysis showed that some starting materials remained. More tgrt-butyl isocyanate (0.5 ml) was added and the mixture heated under reflux for 7 hours, then cooled and left to stand overnight. The mixture was diluted with dichloromethane, washed with 2M hydrochloric acid (x2) and brine, then dried (MgS0₄). The solvent was removed under reduced pressure and the residue purified by silica-gel chromatography, eluting with 47% ethyl acetate/hexane, to give the title compound (0.20 g), m.p. 1 12-1 14°C. NMR δ (CDC1₃): 1.36 (9H,s), 3.19 (2H,t), 4.15 (2H,t), 4.78 (2H,s), 5.03 (lH,brs), 6.99

(lH,dd), 7.08 (lH,d), 8.22 (lH,d). Example 12 l-(5-tgrt-Butyl-3-methylhydantoyl)-6-trifluoromethylindoline a) 6-Chloro-N-(0-methanesulfonyloxy)acetyl indoline

A stirred solution of 6-chloro-N-hydroxyacetyl indoline (0.190 g) and triethylamine (0.14 ml) in dichloromethane (5 ml) was cooled to ca 0°C and treated with methanesulfonyl chloride (0.113 g). Stirring was continued with cooling for 30 min, then the mixture was warmed to room temperature and stirred for a further 45 min. Water was added, the mixture extracted with dichloromethane (x2) and the combined extracts washed with water (x2) and brine, then dried (MgS0₄). Evaporation of the solvent under reduced pressure gave the sub- title compound (0.310 g), which was used in the next step without further purification.

NMR δ: inter alia 3.21 (2H,t), 3.31 (3H,s), 4.02 (2H,t), 4.90 (2H,s), 7.02 ( l H,dd), 7.10 ( lH,d), 8.19 ( lH,d). b) 6-Chloro-N-(ΛT-methylamino)acetyl indoline

Methylamine gas was bubbled through a stirred solution of the compound of step a) (0.310 g) in tetrahydrofuran (10 ml) for 10 min and the mixture stirred for a further 10 min. The mixture was evaporated to dryness to leave an off-white solid which was shown to contain the desired product by comparative tic analysis using an authentic sample (Example 3b)) which was used directly in the next step. c) l -(5-ι'gr/-Butyl-3-methylhydantoyl)-6-trifluoromethylindoline The compound of step b) was dissolved in dichloromethane and treated with triethylamine (0.12 ml) and tert-butyl isocyanate (0.31 ml). The mixture was stirred for 3 hours, then diluted with dichloromethane, washed with 2M hydrochloric acid (x2), water and brine, then dried (MgS0₄). The solvent was removed under reduced pressure and the residue purified by silica-gel chromatography, eluting with 70% ethyl acetate/hexane, to give the title compound (0.25 g), m.p. 173-175°C.

NMR δ: 1.37 (9H,s), 3.00 (3H,s), 3.17 (2H,t), 4.09 (2H,t), 4.20 (2H,s), 4.50 (lH.brs), 6.95 (lH,dd), 7.04 ( lH,d), 8.22 ( lH,d). Example 13 2-(6-Difluoromethoxyindolin- 1 -yl)-2-oxoethyl-_t'grr-butylcarbamate a) l-Chloro-4-difluoromethoxy-2-nitrobenzene A stream of chlorodifluoromethane was passed into a stirred solution of 4-chloro-3- nitrophenol (10.00 g) and tetra-n-butyl ammonium bromide (29.29 g) in dichloromethane, and a solution of sodium hydroxide (9.20 g ) in water (30 ml) added over 30 min. Chlorodifluoro¬ methane was passed through the mixture for a further 60 min then water was added and the mixture extracted with dichloromethane (x3). The combined extracts were washed with brine (x2), dried (MgS0₄) and evaporated to dryness under reduced pressure. The residue was filtered through a pad of silica-gel, eluting with 20% ethyl acetate/hexane, to give the sub-title compound as an oil (12.35 g).

NMR δ: 6.58 (lH,t), 7.33 (lH,dd), 7.57 (lH,d), 7.69 ( lH,d). b) 6-Difluoromethoxy indole

By a similar procedure to that described in Example la)-c), the compound of step a) was converted to the sub-title compound in 44% overall yield.

NMR δ: 6.50 (lH,t), 6.53 (lH,m), 6.92 (lH,dd), 7.15-7.23 (2H,m), 7.59 (lH,d), 8.23 (lH.brs). c) 2-(6-Difluoromethoxyindolin- 1 -yl)-2-oxoethyl-tgr/-butylcarbamate

Using procedures similar to those described in Example la) and Example 1 la) and b), 6-difluoromethoxy-iV-hydroxyacetyl indoline was prepared from the compound of step b). The compound of step b) (0.370 g) was dissolved in dichloromethane (10 ml) and treated with boron trifluoride etherate (0.019 ml) and tert-butyl isocyanate (0.21 ml) and the mixture stirred for 4 hours. The reaction was diluted with dichloromethane, washed with saturated sodium bicarbonate (x2) and brine, then dried (MgS0₄). The solvent was removed under reduced pressure and the residue was purified by silica-gel chromatography, eluting with 45% ethyl acetate/hexane, to give the title compound (0.409 g), m.p. 151-153°C.

NMR δ: 1.37 (9H,s), 3.20 (2H,t), 4.05 (2H,t), 4.69 (2H,s), 5.01 (lH.brs), 6.48 ( lH,t), 6.79 (lH.dd), 7.11 (lH,d), 8.02 (lH.d). Example 14 2-(6-Trifluoromethylindolin- 1 -yl)-2-oxoethyl-tgrt-butylcarbamate

The title compound was prepared according to the method of Example 13. m.p. 139-141T; NMR δ: 1.38 (9H,s), 3.28 (2H,t), 4.08 (2H,t). 4.70 (2H,s), 5.03 (lH,brs), 7.25-7.31

(2H,s), 8.49 (1H,S). Example 15 2-(5-Chloro-6-dιfluoromethoxyιndolιn-l-yl)-2-oxoethyl-tgrt-butylcarbamate

A stirred solution of the compound of Example 13 (200 mg) in dimethyl formamide (3 ml) was cooled and treated with N-chlorosuccιmmιde (0.094 g), the solution was allowed to warm to room temperature and left to stand for 24 hours The mixture was heated under reflux for 8 hours, cooled and left to stand for 16 hours, when gc analysis showed a significant amount of starting material remained. More N-chlorosuccinimide (0.100 g) was added and the mixture heated under reflux for 72 hours, cooled, poured onto water and extracted with diethyl ether (x3) The combined extracts were washed with water (x2) and brine, then dried (MgS0₄) The solvent was removed under reduced pressure and the residue purified by silica-gel chromatography, eluting with 45% ethyl acetate/hexane, to give the title compound (0.145 g), m.p. 130- 131.5°C.

NMR δ 1.35 (9H,s), 3 21 (2H,t), 4.08 (2H,t), 4 68 (2H,s), 5 00 ( lH.brs), 6 51 ( lH,t), 7.21 ( lH,d), 8 17 ( lH,d) Biological Data

The herbicidal activity of the compounds of the invention was tested as follows Sample Preparation

Each compound was dissolved in an appropriate amount, dependent on the final spray volume, of a solvent/surfactant blend comprising 16 7 g/litre of Tween 85 and 33 3 g/litre of Synperonic NPE-1800 dissolved in cyclohexanone [Tween 85 is a Trade Mark for a surface-active agent comprising 20 moles polyoxyethylene sorbitan tπoleate, Synperonic NPE-1800 is a Trade Mark for a surface-active agent comprising propoxylated and ethoxylated nonylphenol derivative]. If the chemical did not dissolve glass beads were added and the mixture was shaken to effect dissolution or suspension after which the beads were removed. In all cases, the mixture was then diluted to the required spray volume. The final spray volume was dependent on the species range and the application mode (I e. post- emergence, pre-emergence or both), typical spray volumes were in thr range of from 6 to 18 ml. The sprayed aqueous emulsion contained 4% of the initial solvent/surfactant mix and the test chemical at an appropriate concentration Test Methods a) Pre-emergence To detect pre-emergence herbicidal activity, crop seeds were sown at 2cm depth and weed seeds at 1cm depth beneath compost and sprayed with the test samples prepared as described above at a rate of 400 litres per hectare. 20 days after treatment (DAT), the seedlings in sprayed trays were compared with the seedlings in unsprayed control trays. Damage to plants was assessed on a scale of 0 to 9 where 0 is 0% damage, 1 is 1-5% damage, 2 is 6-15% damage, 3 is 16-25% damage, 4 is 26-35% damage, 5 is 36-59% damage, 6 is 60-69% damage, 7 is 70-79% damage, 8 is 80-89% damage and 9 is 90-100%

The results of the pre-emergence tests are given in Table 2 below, b) Post-flood, post-emeregnce in rice paddy To detect herbicidal activity in post-flood, post-emergence conditions in rice paddy, a paddy 'unit' test was used. Paddy 'unit' set-up was completed 2 days prior to treatment and involved the use of a 13cm x 13cm x 10cm plastic tub filled with soil to a depth of 5cm. Oryza saliva, Echinochloa crusgalli, Sagittaria pygmaea and Cyperus dijformis, each at 1 -2 leaf stage, were 'transplanted' into the soil. The paddy units were then flooded such that the water level is 1.5cm above the soil surface, this water depth was maintained throughout the experiment. Rates for the paddy test are based upon the surface area of the water in the paddy unit. Treatment involved pipetting a 0.7cm³ aliquot test sample, prepared as described above, into the water. Visual assessments were made 20 DAT by comparing treated to untreated plants and recording the observations using a scale of 0 to 100%, where 0 and 100 are equivalent to no phytotoxicity and complete kill, respectively.

The results of the flooded conditions tests are given in Table 3. Table 4 gives the meanings of the abbreviations.

TABLE 2 RESULTS OF PRE-EMERGENCE TEST

CO en

TABLE 2 RESULTS OF PRE-EMERGENCE TEST (continued)

CO

TABLE 3 RESULTS OF FLOODED CONDITIONS TEST

TABLE4 ABBREVIATIONSUSEDFORTESTPLANTS

Short Code Name

GM Soya bean

ZM Maize

OS Rice

CA Chenopodium album

AR Amaranthus retroflexus

IH Ipomoea hederacea ssp hederacea

AT Abutilon threophrasti

SH Sorghum halepense

SV Setaria viridis

BP Brachiaria platyphylla

PD Panicum dicotomiflorum

EC Echinochloa crus-galli

CE Cyperus esculentus

CD Cyperus difformis

SP Sagittaria pygmaea

Claims

A compound of formula I:

wherein R¹ and R² independently represent hydrogen or C_M alkyl;

R³ is hydrogen or a C_M0 aliphatic radical optionally substituted with one or more halogen atoms;

W| and W₂ independently represent O or S;

Y is O or NR⁴, wherein R⁴ is hydrogen, C_M alkoxy or a Cι_₆ aliphatic radical optionally substituted with one or more halogen atoms or C|.₄ alkoxy groups;

Z is NR⁵, wherein R⁵ is hydrogen or a C,.₄ aliphatic radical; or CR⁶R⁷, wherein R⁶ and

R⁷ independently represent hydrogen or a C_M aliphatic radical optionally substituted with one or more halogen atoms, or R⁶ and R⁷ together with the carbon atom to which they are attached form a 3- to 6-membered carbocyclic ring; or, when Y is NR⁴ and Z is NR⁵, R⁴ and R⁵ together may represent -CH₂CH₂-,

-CH=CH-, -C(0)C(0)- or -CH₂C(0)- in which the -CH₂- group is linked to Y and the

-C(O)- group is linked to Z to form an imidazolidinedione ring; or, when Y is NR⁴ and Z is CR⁶R⁷, R⁴ and one of R⁶ and R⁷ may represent -CH₂- or

-CH₂CH₂-, while the remaining R⁶ or R⁷ group is hydrogen or a C_M aliphatic radical; or, when Z is CR⁶R⁷, R³ may be a Cι.₆ alkoxycarbonyl group;

X is CLIO alkyl, halo-Ci-io alkyl, C|_ι₀ alkoxy, halo-C_M0 alkoxy, cyano, -SF₅, S0₂CF₃,

-SCF₃, nitro or halo; and n is O, 1,

2, 3 or 4; provided that the compound is not /V-[2-oxo-2-(5-bromo-7-nitroindolin-l- yl)ethyl]acetamide.

A compound according to claim 1 wherein Wi and W₂ represent O.

3. A compound according to claim 1 or claim 2 wherein R³ is a C|.₆ alkyl radical optionally substituted with one or more halogen atoms.

4. A compound according to any one of claims 1 to 3 wherein Y is NR⁴, Z is NR⁵, and R⁴ and R⁵ together represent -CH₂C(0)- in which the -CH₂- group is linked to Y and the -C(O)- group is linked to Z to form an imidazolidinedione ring.

5. A compound according to any one of claims 1 to 3 wherein Y is O or NR⁴, and R⁴ is C_M alkoxy or a C,.₆ aliphatic radical optionally substituted with one or more halogen atoms or C|.₄ alkoxy groups.

6. A compound according to any one of the preceding claims, wherein R¹ and R² are hydrogen.

7. A compound according to any one of the preceding claims, wherein X is halo-C_M0 alkyl, halo-C_M0 alkoxy, nitro or halo, and n is 1 or 2.

8. A herbicidal composition comprising a compound of formula I as defined in claim 1 , but without the proviso, in admixture with a carrier comprising a solid or liquid diluent.

9. A process for severely damaging or killing unwanted plants, which process comprises applying to the plants, or to the growth medium of the plants, a herbicidally effective amount of a compound of formula I as defined in claim 1, but without the proviso.

10. A process for the production of a compound of formula I as defined in claim 1 which comprises: a) for compounds of formula I in which Y is NR⁴ and Z is NH, reaction of a compound of formula II:

II wherein R¹, R², R⁴, X and n are as defined in claim 1, with an isocyanate of formula R³NCO, in which R³ is as defined in claim 1 , in the presence of a catalytic amount of a base; or

b) for compounds of formula I in which Y is NR⁴ and Z is CR⁶R⁷, reaction of a compound of formula II with an acid chloride of formula ClCOCR⁶R⁷R³, in which R³

R⁶ and R⁷ are as defined in claim 1, in the presence of a base; or

c) for compounds of formula I wherein Y is O and Z is NH, reaction of a compound of formula VI:

VI wherein X and n are as defined in claim 1, with an isocyanate of formula R³NCO, in which R³ is as defined in claim 1 , in the presence of a catalytic amount of a base; or

d) for compounds of formula I wherein R¹ and R² are both hydrogen, Y is NR⁴, Z is NR⁵ and R⁴ and R⁵ represent -CH₂C(0)- in which the -CH₂- group is linked to Y and the -C(O)- group is linked to Z to form an imidazolidinedione ring, reaction of a compound of formula III:

III wherein X and n are as defined in claim 1 ; with a compound of formula XIV:

XIV wherein R³ is as defined in claim 1, in the presence of a base; or

e) for compounds of formula I in which Y is NR⁴, Z is NR⁵ and R⁴ and R⁵ represent -C(0)C(0)-, reaction of oxalyl chloride with a compound of formula I wherein Y and Z each represent an NH group; or

f) for compounds of formula I in which Y is NR⁴, Z is NR⁵ and R⁴ and R⁵ represent -CH₂CH₂-, reaction of a compound of formula IV:

IV wherein R¹, R², X and n are as defined in claim 1, with a compound of formula XVII:

XVII wherein R³ is as defined in claim 1, in the presence of a base; or f) for compounds of formula I in which Y is NR⁴, Z is NR⁵ and R⁴ and R⁵ represent

-CH₂CH₂-, hydrogenation of the corresponding compound in which R⁴ and R⁵ represent -CH=CH-; or

h) for compounds of formula I in which Y is NR⁴, Z is NR⁵ and R⁴ and R⁵ represent -CH=CH-, reaction of a compound of formula IV with an imidazolinone of formula XIX:

H- ^■R^J

O XIX wherein R is as defined in claim 1 ; or

i) for compounds of formula I in which Y is NR⁴, Z is NR⁵ and R⁴ and R⁵ represent

-CH=CH-, reaction of a compound of formula XXII:

wherein R^l, R², R³, X and n are as defined in claim 1, and R is a C[._l0 aliphatic radical, with acid; or

j) for compounds of formula I in which Y is NR⁴, Z is CR⁶R⁷ and R⁴ and one of R⁶ and

R⁷ represent -CH₂- or -CH₂CH₂-, and the remaining R⁶ or R⁷ group is a Q_-4 aliphatic radical, reaction of a compound of formula XXIII:

XXIII wherein R¹, R², R³, R^6/7, X and n are as defined in claim 1, and m is 0 or 1 , with a strong base; or

k) for compounds of formula I wherein one or both of W, and W₂ is S, reaction of the corresponding compound in which one or both of W| and W₂ is O, with a thiating reagent; or

1) for compounds of formula I wherein W₂ is S, Y is O or NR⁴ and R¹, R² and R⁵ are hydrogen, reaction of a compound of formula VI with an isothiocyanate of formula

R³NCS, in which R³ is as defined in claim 1.