IE903474A1 - Novel herbicidal compounds - Google Patents

Abstract

The compounds of the formula I in which R<1> is hydrogen or (C1-C8)-alkyl; R<2> is hydrogen or (C1-C8-alkyl; or R<1> and R<2> together form a -(CH2)4-bridge which is optionally up to disubstituted by (C1-C4)-alkyl; R<3> and R<4> independently of one another are hydrogen or (C1-C4)-alkyl; or one of the radicals R<3> or R<4> is hydrogen and the other is a phenyl radical which is optionally up to trisubstituted by identical or different radicals from the series halogen, (C1-C4)-alkyl or (C1-C4)-alkoxy; or R<3> and R<4> together are a -(CH2)n bridge with n = 2, 3, 4, 5 or 6, which can optionally be up to trisubstituted by (C1-C4)-alkyl; R<5> is hydrogen or fluorine; R<6> is halogen; A is a straight-chain or branched (C1-C4)-alkylene chain; B is a radical -O-A-S(O)m-Q or -S-A-Q<1>; m is zero, 1 or 2; Q is (C1-C12)-alkyl; (C2-C8)-alkoxyalkyl; (C3-C7)-alkenyl; (C3-C7)-alkynyl; (C3-C7)-cycloalkyl; phenyl or benzyl, it being possible for the phenyl ring to be unsubstituted or mono- to trisubstituted by (C1-C4)-alkyl, halogen or (C1-C4)-alkoxy, Q<1> is -COOR<7>; R<7> is hydrogen; (C1-C12)-alkyl; (C2-C8)-alkoxyalkyl; (C3-C7)-alkenyl; (C3-C7)-alkynyl; (C3-C7)-cycloalkyl; (C3-C7)-alkenyloxy-(C1-C7)-alkyl; (C2-C8)-alkylthioalkyl; di-(C1-C4)-alkylamino-(C1-C4)-alkyl; phenyl or benzyl, it being possible for the phenyl ring to be unsubstituted or mono- to trisubstituted by (C1-C4)-alkyl, halogen or (C1-C4)-alkoxy, are herbicidal and plant-growth-regulating active substances. The invention relates to compounds of the formula I, processes for their preparation, novel intermediates and novel herbicidal and growth-regulating agents, and to their use for controlling undesired plant growth, or for influencing the growth of crop plants.

Description

The invention relates to compounds of formula I, to processes for the preparation thereof, » to novel intermediates and to novel herbicidal and growth regulating compositions and to their use for controlling undesired plant growth or for influencing the growth of cultivated plants. s I ΙΌ PUBLIC ΙΝδΡΕΟΊΊΟί j UNDER SECTION 69 AND RULE 117 JNL. NO. J6:53> OF 10¼ i4i ’4s - AG, a body corporate zer’and, of Klybecks* j ' ~° t/j Of -lflPS/5-17765/= Novel herbicidal compounds The invention relates to novel herbicidally active 1-phenyl-substituted 5-exo-methylenepyrrolidin-2-ones and 2-phenyl-substituted 3-exo-methylene-4,5,6,7-tetrahydroisoindol(2H)-l-ones of formula I, to processes for the preparation thereof, to herbicidal compositions and their use, and to novel intermediates.

US Patent Specification US 3,992,189 and published Japanese Patent Application JP-A 63.039.858 disclose herbicidally active 3-exo-methylene-4,5,6,7-tetrahydroisoindol(2H)-l-ones which carry in the 2-position of the isoindole system a phenyl radical that is substituted up to three times in the ortho- and para-position. These compounds known from the prior art are not always satisfactory as regards action and selectivity.

In contrast, the invention relates to compounds of formula I O wherein R1 is hydrogen or (Cj-CgJalkyl; R2 is hydrogen or (Ci-Cg)alkyl; or R1 and R2 together form a -(CH2)4- bridge that is unsubstituted or mono- or di-substituted by (C1-C4)alkyl; R3 and R4 independently of one another are hydrogen or (CrC4)alkyl; or one of the radicals R3 and R4 is hydrogen and the other is a phenyl radical that is unsubstituted or mono- to tri-substituted by identical or different substituents selected from halogen, -2(Cj-C^alkyl and (C4-C4)alkoxy; or R3 and R4 together form a -(CH2)n- bridge, in which n = 2, 3, 4, 5 or 6, which, if desired, may be mono- to tri-substituted by (CrC4)alkyl; R5 is hydrogen or fluorine; R6 is halogen; A is a straight-chained or branched (Q-C^alkylene chain; B is a radical -O-A-S(O)m-Q or -S-A-Q1; m is 0,1 or 2; Q is (Cj-C^lalkyl; (C2-C8)alkoxyalkyl; (C3-C7)alkenyl; (C3-C7)alkynyl; (C3-C7)cycloalkyl; phenyl or benzyl, the phenyl ring being unsubstituted or mono- to tri-substituted by (C1-C4)alkyl, halogen or by (CpC^alkoxy; Q1 is -COOR7; R7 is hydrogen; (CpC^alkyl; (C2-C8)alkoxyalkyl; (C3-C7)alkenyl; (C3-C7)alkynyl; (C3-C7)cycloalkyl; (C3-C7)alkenyloxy-(C1-C4)alkyl; (C2-C8)alkylthioalkyl; di(CpQlalkylamino-CCj-C^alkyl; phenyl or benzyl, the phenyl ring being unsubstituted or mono- to tri-substituted by (CrC4)alkyl, halogen or by (Cj-C4)alkoxy.

In the above definition, the generic terms given, and the substituents that are obtainable by combining individual subsidiary terms, include, for example, the following specific individual substituents; this list does not constitute a limitation of the invention.

Alkyl: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec.-butyl, tert.-butyl, n-pentyl and sec.-pentyl, preferably methyl, ethyl and isopropyl.

Halogen: fluorine, chlorine, bromine and iodine, preferably fluorine, chlorine and bromine.

Alkoxy: methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, isobutoxy, sec.-butoxy and tert.-butoxy, etc., preferably methoxy or ethoxy.

Haloalkyl: fluoromethyl, difluoromethyl, trifluoromethyl, chloromethyl, dichloromethyl, trichloromethyl, 2,2,2-trifluoroethyl, 2-fluoroethyl, 2-chloroethyl and 2,2,2-trichloroethyl, preferably chloromethyl, 2-chloroethyl and trifluoromethyl.

Alkoxyalkyl: methoxymethyl, ethoxymethyl, propoxymethyl, 2-methoxyethyl, 1-methoxy -3ethyl, ethoxyethyl, propoxyethyl, methoxypropyl, ethoxypropyl, propoxypropyl, etc..

Alkylthio: methylthio, ethylthio, propylthio, isopropylthio, (n)-butylthio, isobutylthio, sec.-butylthio, tert.-butylthio, etc..

Dialkylamino: dimethylamino or diethylamino.

Cycloalkyl: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl or cycloheptyl. Cyclopropyl, cyclopentyl or cyclohexyl are preferred.

Alkenyl: is especially the allyl, 2-butenyl, 3-butenyl or methallyl radicals bonded via a saturated carbon atom.

Alkynyl: is especially the propargyl, 2-butynyl or 3-butynyl radicals bonded via a saturated carbon atom.

Phenyl, also as part of a larger substituent such as benzyl, can generally be unsubstituted or substituted by further substituents. The substituents can be in the ortho-, meta- or para-position. Preferred positions for substituents are the ortho- and para-position with respect to the ring linkage position. Preferred substituents are halogen atoms.

When the substituents R3 and R4 together form a -(CH^- bridge, they form, together with the carbon atom to which they are bonded, a carbocyclic 3- to 7-membered ring. 3-, 5and 6-membered rings are preferred. The carbocyclic ring so formed may itself be substituted by up to three (C1-C4)alkyl groups.

In the further substituents composed of several basic elements, the subsidiary elements have the meanings given by way of example above. In these cases too, the lists do not constitute a limitation of the invention: they are given by way of illustration.

Depending on the nature of the substitution, the compounds of formula I can have one or more asymmetric centres. The invention includes the racemate and also the optically pure isomers and the mixtures enriched with one or more optically active forms.

The isomers can in general be prepared by known methods, such as fractional crystallisation or separation by means of special chromatographic processes. In addition, -4the desired enantiomeric product can in many cases be prepared by the use of chiral educts.

The invention relates especially to compounds of formula I wherein B is the radical -O-A-S(O)mQ; R3 and R4 independently of one another are hydrogen or (CrC4)alkyl; and R1, R2, R5, R6, A, m and Q are as defined above.

The invention relates also to compounds of formula I wherein B is the radical -S-A-Q1; R3 and R4 independently of one another are hydrogen or (Cj-C^alkyl; and R1, R2, R5, R6, A and Q1 are as defined above.

Preference is given to compounds of formula I wherein R1 and R2 together form the -(CH2)4-alkylene bridge; each of R3 and R4 is hydrogen; R5 is fluorine; R6 is chlorine; and B is the radical -OCH(CH3)CH2-S-Q, in which Q is as defined under formula I.

Preference is given also to those compounds of formula I wherein R1 and R2 together form the -(CH2)4-alkylene bridge; each of R3 and R4 is hydrogen; R5 is fluorine; R6 is chlorine; and B is the radical -S-A-CO-O-R7, in which A and R7 are as defined under formula I.

Furthermore, the compounds of formula I wherein R1 and R2 together form the -(CH2)4alkylene bridge; each of R3 and R4 is hydrogen; R5 is fluorine; R6 is chlorine; and B is the radical -O-CH(CH3)-S-Q, in which Q is as defined under formula I, exhibit good activity.

Likewise, the compounds of formula I wherein R1 and R2 together form the -(CH2)4alkylene bridge; each of R3 and R4 is hydrogen; R5 is fluorine; R6 is chlorine; and B is the radical -O-CH(CH3)CH2-SO2-Q, in which Q is as defined under formula I, also exhibit good activity.

Finally, those compounds of formula I wherein R1 and R2 together form the -(CH2)4alkylene bridge; each of R3 and R4 is hydrogen; R5 is fluorine; R6 is chlorine; and B is the radical -S-A-CO-OR7, in which A and R7 are as defined under formula I, are distinguished by good activity.

The following may be mentioned specifically: 2-[4-chloro-2-fluoro-5-(2-methoxycarbonylethylthio)-carbonylphenyl]-3-methyIene4,5,6,7-tetrahydroisoindol-(2H)-l-one (compound 2.08), -52-[4-chloro-2-fluoro-5-(l-ethoxycarbonylethylthio)-carbonylphenyl]-3-methylene4,5,6,7-tetrahydroisoindol-(2H)-l-one (compound 2.04), 2-[4-chloro-2-fluoro-5-(l-propoxycarbonylethylthiocarbonyl)-phenyl]-3-methylene4,5,6,7-tetrahydroisoindol-(2H)-l-one (compound 2.09), 2-[4-chloro-2-fluoro-5-(l-isopropoxycarbonylethylthiocarbonyl)-phenyl]-3-methylene4,5,6,7-tetrahydroisoindol-(2H)-l-one (compound 2.10), 2-[4-chloro-2-fluoro-5-(methoxycarbonylmethylthiocarbonyl)-phenyl]-3-methylene4,5,6,7-tetrahydroisoindol-(2H)-l-one (compound 2.02), 2-[4-chloro-2-fluoro-5-(ethoxycarbonylmethylthiocarbonyl)-phenyl]-3-methylene4,5,6,7-tetrahydroisoindol-(2H)-l-one (compound 2.03), 2-[4-chloro-2-fluoro-5-(l-tert.-butoxycarbonylethylthiocarbonyl)-phenyl]-3-methylene4,5,6,7-tetrahydroisoindol-(2H)-l-one (compound 2.06), 2-[4-chloro-2-fluoro-5-(2-methoxycarbonyl-2-methylethylthiocarbonyl)-phenyl]-3methylene-4,5,6,7-tetrahydroisoindol-(2H)-I-one (compound 2.07), 2-[4-chloro-2-fluoro-5-(l-methoxycarbonylethylthiocarbonyl)-phenyl]-3-methylene4,5,6,7-tetrahydroisoindol-(2H)-l-one (compound 2.01), 2-[4-chloro-2-fluoro-5-(2-methylthio-l-methylethoxycarbonyl)-phenyl]-3-methylene4,5,6,7-tetrahydroisoindol-(2H)-l-one (compound 1.01), 2-[4-chloro-2-fluoro-5-(2-ethylthio-l-methylethoxycarbonyl)-phenyl]-3-methylene4,5,6,7-tetrahydroisoindol-(2H)-l-one (compound 1.02), 2-[4-chloro-2-fluoro-5-(2-propylthio-l-methylethoxycarbonyl)-phenyl]-3-methylene4,5,6,7-tetrahydroisoindol-(2H)-l-one (compound 1.03), 2-[4-chloro-2-fluoro-5-(2-isopropylthio-l-methylethoxy)-phenyl]-3-methylene-4,5,6,7tetrahydroisoindol-(2H)-l-one (compound 1.04), 2-[4-chloro-2-fluoro-5-(2-n-butylthio-l-methylethoxycarbonyl)-phenyl]-3-methylene4,5,6,7-tetrahydroisoindol-(2H)-l-one (compound 1.05), 2-[4-chloro-2-fluoro-5-(2-sec.-butylthio-l-methylethoxycarbonyl)-phenyl]-3-methylene4,5,6,7-tetrahydroisoindol-(2H)-l-one (compound 1.06), 2-[4-chloro-2-fluoro-5-(2-tert.-butylthio-l-methylethoxycarbonyl)-phenyl]-3-methylene4,5,6,7-tetrahydroisoindol-(2H)-l-one (compound 1.08) and 2-[4-chloro-2-fluoro-5-(2-pentylthio-l-methylethoxycarbonyl)-phenyl]-3-methylene4,5,6,7-tetrahydroisoindol-(2H)-l-one (compound 1.09).

The compounds of formula I can be prepared by reacting an anhydride of formula II, wherein R1 and R2 are as defined under formula I, with an aniline of formula III, wherein the radicals R3 and R4 are as defined under formula I, with heating in an inert organic -6solvent.

The resulting 2,5-dihydro-N-phenylpyrrole-2,5-dione of formula IV, wherein R1, R2, R5 and R6 are as defined under formula I, is then reacted in ethereal solution in a Grignard reaction with an alkylmagnesium halide of formula V to give the 1 -phenyl-3-hydroxy-3methylpyrrol-(lH)-2-one of formula VI, wherein R3 and R4 are as defined under formula I and X is halogen, especially iodine.

O IV VI This process step can be carried out analogously to processes known in the literature (R. Scheffold and P. Dubs, Helv. Chim. Acta 50 (1967) 798 and the literature listed therein).

The compound of formula VI, wherein R1 to R6 are as defined under formula I, is then reacted by boiling in an inert organic solvent, for example in toluene, under conditions removing the elements of water, in the presence of a small amount of sulfuric acid or of an organic sulfonic acid, e.g. para-toluenesulfonic acid, to give l-phenyl-3-methylenepyrrol(lH)-2-one of formula VII, wherein R1 to R6 are as defined under formula I.

VI VII To convert the tert.-butyl ester of formula VII, wherein R1 to R6 are as defined under formula I, into a compound of formula I, the ester is hydrolysed by heating in the presence of a strong mineral acid or an organic acid. Trifluoroacetic acid, for example, has proved very suitable for that purpose. The resulting free acid of formula VIII, wherein R1 to R6 are as defined under formula I, is then reacted with a halogenating agent, for example thionyl chloride or bromide, phosphorus oxychloride or oxybromide or, preferably, oxalyl chloride, to give the acid halide of formula IX, wherein R1 to R6 are as defined under formula I and Hal is a halogen atom, preferably chlorine or bromine, in accordance with the reaction scheme: IX -8The process according to the invention for the preparation of the compounds of formula I comprises reacting an acid halide of formula Di, wherein R1 to R6 are as defined under formula I, in an inert organic solvent, in the presence of at least the equimolar amount of a base, with an alcohol or thiol of the formula HB, wherein B is a radical -O-A-S(O)mQ or -S-A-Q1, in which A, m, Q and Q1 are as defined under formula I, in accordance with the reaction scheme O O Di I In the Grignard reaction, the Grignard reagent of formula V can react with the two carbonyl groups of the imide IV, which, in the case of asymmetric substitution of IV (R1 # R2), results in two different products.

In general, the action of the Grignard reagent will begin at the side having least sterical hindrance (kinetically controlled reaction). The desired product can be obtained in enriched or pure form from the mixture of primary products that forms in the case of asymmetric substitution using separation processes (extraction, chromatography, crystallisation, etc.). The separation processes can be carried out both at the stage of the primary adduct VI and at the stage of the exo-methylene compound VII or I.

In cases where the radicals R3 and R4 in the compound of formula I have different meanings, the removal of the elements of water from compounds of formula V likewise produces a mixture of isomeric compounds, in accordance with the following reaction scheme: O Vila O Vllb The mixture of compounds of formulae Vila and Vllb can be worked up by means of generally customary separation processes (see above) and separated into the different pure or enriched geometric components.

Although the syntheses of the compounds of formula I outlined as reactions describe processes which can in principle be used to prepare all the compounds covered by formula I, it may for reasons of economy or process technology be advantageous to convert particular compounds of formula I into different derivatives also covered by formula I.

Advantageously, the above reactions are carried out in an inert solvent. Suitable inert solvents are hydrocarbons, such as benzene, toluene or xylene; ethers, such as diethyl ether, methyl isopropyl ether, glyme, diglyme; cyclic ethers, such as tetrahydrofuran and dioxane; ketones, such as acetone, methyl ethyl ketone; amides, such as dimethylformamide, N-methylpyrrolidone; sulfoxides, such as dimethyl sulfoxide; or chlorinated hydrocarbons, such as dichloromethane, trichloromethane, tetrachloromethane or tetrachloroethane. - 10The reaction temperature can be varied within wide limits. Suitable reaction temperatures are, for example, from -20°C to the reflux temperature of the reaction mixture. Preferably, the reaction is carried out at a temperature of from 0°C to 100°C.

The reaction of the acid halide is advantageously carried out with the addition of a base. Suitable bases are, inter alia, alkali metal and alkaline earth metal carbonates, tertiary amines, such as, for example, triethylamine, or heterocycles, such as pyridine or DABCO.

The reaction of the compound of formula VI to give the compound of formula VII may advantageously also be carried out under phase transfer conditions. Reactions of that type are known to the person skilled in the art (for example, as described in Dehmlow, Phase Transfer Catalysis, Verlag Chemie, Weinheim 1983; W.E. Keller, Phase Transfer Reactions Vol. 1 and Vol. 2, G. Thieme Verlag, Stuttgart 1986, 1987).

The addition of the organomagnesium compound of formula V is known as a Grignard reaction (Krauch Kunz; Reaktionen der Organischen Chemie (Reactions of Organic Chemistry), A. Hiithig Verlag, Heidelberg; 5th edition 1976, pp. 572-574; and the references mentioned therein). The reaction conditions for Grignard reactions (process steps, solvents, temperatures, etc.) are generally known and do not need to be explained further here.

The compounds of formula I are highly active plant active ingredients which, when used at suitable rates of application, are excellently suitable as selective herbicides for controlling weeds in crops of useful plants. That is to say, when used at those rates of application, the compounds of formula I are distinguished by good selective herbicidal properties against weeds. Cultivated plants, such as rye, barley, oats, wheat, maize, millet, rice, cotton and soybeans, remain virtually undamaged at low rates of application. At higher rates of application, the growth of cultivated plants is affected to only a slight degree. When applied at very high rates of application, the compounds of formula I have total herbicidal properties.

The selective herbicidal activity of the compounds of the invention is observed both on preemergence and on postemergence application. These compounds can therefore be used with equal success for selective weed control both preemergence and postemergence.

The compounds according to the invention act on the metabolism of the plants and can - 11 therefore also be used as growth regulators.

As regards the mode of action of plant growth regulators, previous experience has shown that it is possible for an active ingredient to exert several different types of action on plants. The actions of the substances depend essentially on the time of application relative to the stage of development of the plant and on the amounts of active ingredient applied to the plants or their locus and on the method of application. In every case, growth regulators should affect the cultivated plants in a particular desired manner.

Under the influence of growth regulators, it is possible to control the foliage of the plants in such a manner that defoliation of the plants is achieved at a desired time. Defoliation of that kind plays an important part in the mechanical harvesting of cotton, but is also of value in other crops, for example in viniculture, for facilitating the harvest. Defoliation of the plants can also be carried out in order to reduce transpiration of the plants before transplantation.

Growth regulators can also be used to control fruit fall. On the one hand, premature fruit fall can be prevented. On the other hand, however, fruit fall or even the fall of the blossoms can be promoted to a desired extent (thinning) in order to break the altemance. Alternance shall be understood as being the property of some types of fruit to produce very different yields from year to year for endogenous reasons. Finally, by means of growth regulators it is possible to reduce the force required to remove the fruits at the time of harvesting, in order to permit mechanical harvesting or to facilitate manual harvesting.

The invention relates also to herbicidal and growth regulating compositions that contain a novel compound of formula I, and to methods of controlling weeds pre- and postemergence and of regulating the growth of cultivated plants.

Advantageously, the compounds or compositions according to the invention can also be applied to the propagation material of the cultivated plant. Special mention may be made here of seed dressing. Propagation material is seeds, cuttings or other parts of the plant from which the cultivated plant can be grown. The invention relates also to propagation material treated with a compound of formula I in an amount having herbicidal or growth regulating effect.

The compounds of formula I are used in unmodified form or, preferably, as compositions - 12together with the adjuvants conventionally employed in the art of formulation, and are therefore formulated in known manner e.g. into emulsifiable concentrates, directly sprayable or dilutable solutions, dilute emulsions, wettable powders, soluble powders, dusts, granulates, and also encapsulations in e.g. polymer substances. As with the nature of the compositions, the methods of application, such as spraying, atomising, dusting, scattering or pouring, are chosen in accordance with the intended objectives and the prevailing circumstances.

The formulations, i.e. the compositions, preparations or mixtures containing the compound (active ingredient) of formula I and, where appropriate, a solid or liquid adjuvant, are prepared in known manner, e.g. by homogeneously mixing and/or grinding the active ingredients with extenders, e.g. solvents, solid carriers and, where appropriate, surfaceactive compounds (surfactants).

Suitable solvents are: aromatic hydrocarbons, preferably the fractions containing 8 to 12 carbon atoms, e.g. xylene mixtures or substituted naphthalenes, phthalates such as dibutyl phthalate or dioctyl phthalate, aliphatic hydrocarbons such as cyclohexane or paraffins, alcohols and glycols and their ethers and esters, such as ethanol, ethylene glycol, ethylene glycol monomethyl or monoethyl ether, ketones such as cyclohexanone, strongly polar solvents such as N-methyl-2-pyrrolidone, dimethyl sulfoxide or dimethylformamide, as well as vegetable oils or epoxidised vegetable oils, such as epoxidised coconut oil or soybean oil; or water.

The solid carriers used, e.g. for dusts and dispersible powders, are normally natural mineral fillers such as calcite, talcum, kaolin, montmorillonite or attapulgite. In order to improve the physical properties it is also possible to add highly dispersed silicic acid or highly dispersed absorbent polymers. Suitable granulated adsorptive carriers are porous types, for example pumice, broken brick, sepiolite or bentonite; and suitable nonsorbent carriers are, for example, calcite or sand. In addition, a great number of pregranulated materials of inorganic or organic nature can be used, e.g. especially dolomite or pulverised plant residues.

Depending on the nature of the compound of formula I to be formulated, suitable surface-active compounds are non-ionic, cationic and/or anionic surfactants having good emulsifying, dispersing and wetting properties. The term surfactants will also be understood as comprising mixtures of surfactants. - 13Both so-called water-soluble soaps and water-soluble synthetic surface-active compounds are suitable anionic surfactants.

Suitable soaps are the alkali metal salts, alkaline earth metal salts or unsubstituted or substituted ammonium salts of higher fatty acids (C10-C22), e.g. the sodium or potassium salts of oleic or stearic acid or of natural fatty acid mixtures which can be obtained e.g. from coconut oil or tallow oil. Mention may also be made of fatty acid methyltaurin salts.

More frequently, however, so-called synthetic surfactants are used, especially fatty sulfonates, fatty sulfates, sulfonated benzimidazole derivatives or alkylarylsulfonates.

The fatty sulfonates or sulfates are usually in the form of alkali metal salts, alkaline earth metal salts or unsubstituted or substituted ammonium salts and contain a Cg-C22alkyl radical, which also includes the alkyl moiety of acyl radicals, e.g. the sodium or calcium salt of lignosulfonic acid, of dodecylsulfate or of a mixture of fatty alcohol sulfates obtained from natural fatty acids.

These compounds also comprise the salts of sulfated and sulfonated fatty alcohol/ethylene oxide adducts. The sulfonated benzimidazole derivatives preferably contain 2 sulfonic acid groups and one fatty acid radical containing 8 to 22 carbon atoms. Examples of alkylarylsulfonates are the sodium, calcium or triethanolamine salts of dodecylbenzenesulfonic acid, dibutylnaphthalenesulfonic acid, or of a condensate of naphthalenesulfonic acid and formaldehyde.

Also suitable are corresponding phosphates, e.g. salts of the phosphoric acid ester of an adduct of p-nonylphenol with 4 to 14 moles of ethylene oxide, or phospholipids.

Non-ionic surfactants are preferably polyglycol ether derivatives of aliphatic or cycloaliphatic alcohols, or saturated or unsaturated fatty acids and alkylphenols, said derivatives containing 3 to 10 glycol ether groups and 8 to 20 carbon atoms in the (aliphatic) hydrocarbon moiety and 6 to 18 carbon atoms in the alkyl moiety of the alkylphenols.

Further suitable non-ionic surfactants are the water-soluble adducts of polyethylene oxide with polypropylene glycol, ethylenediaminopolypropylene glycol and alkylpolypropylene - 14glycol containing 1 to 10 carbon atoms in the alkyl chain, which adducts contain 20 to 250 ethylene glycol ether groups and 10 to 100 propylene glycol ether groups. These compounds usually contain 1 to 5 ethylene glycol units per propylene glycol unit.

Representative examples of non-ionic surfactants are nonylphenolpolyethoxyethanols, castor oil polyglycol ethers, polypropylene/polyethylene oxide adducts, tributylphenoxypolyethoxyethanol, polyethylene glycol and octylphenoxypolyethoxyethanol.

Fatty acid esters of polyoxyethylene sorbitan, e.g. polyoxyethylene sorbitan trioleate, are also suitable non-ionic surfactants.

Cationic surfactants are preferably quaternary ammonium salts which contain, as N-substituent, at least one C8-C22alkyl radical and, as further substituents, unsubstituted or halogenated lower alkyl, benzyl or hydroxy-lower alkyl radicals. The salts are preferably in the form of halides, methyl sulfates or ethyl sulfates, e.g. stearyltrimethylammonium chloride or benzyldi(2-chloroethyl)ethylammonium bromide.

The surfactants customarily employed in the art of formulation are described inter alia in the following publications: 1986 International McCutcheon’s Emulsifiers & Detergents, Glen Rock, N.J., USA, 1986; H. Stache, Tensid-Taschenbuch, 2nd edition, C. Hanser Verlag, Munich, Vienna, 1981; M. and J. Ash, Encyclopedia of Surfactants, Vol. I-III, Chemical Publishing Co., New York, 1980-1981.

The active ingredient formulations usually contain 0.1 to 95 %, preferably 0.1 to 80 %, of a compound of formula I, 1 to 99.9 % of one or more solid or liquid additives, and 0 to 25 % of a surfactant.

Preferred formulations are composed in particular of the following constituents (% = percentage by weight).

Emulsifiable concentrates: active ingredient: surfactant: to 20 %, preferably 5 to 10 % 5 to 30 %, preferably 10 to 20 % liquid carrier: Dusts: active ingredient: solid carrier: - 15 50 to 94 %, preferably 70 to 85 % 0.1 to 10 %, preferably 0.1 to 1 % 99.9 to 90 %, preferably 99.9 to 99 % Suspension concentrates: active ingredient: water: surfactant: Wettable powder: active ingredient: surfactant: solid carrier: Granulates: active ingredient: solid carrier: to 75 %, preferably 10 to 50 % 94 to 25 %, preferably 88 to 30 % to 40 %, preferably 2 to 30 % 0.5 to 90 %, preferably 1 to 80 % 0.5 to 20 %, preferably 1 to 15 % to 95 %, preferably 15 to 90 % 0.5 to 30 %, preferably 3 to 15 % 99.5 to 70 %, preferably 97 to 85 %.

Whereas commercial products will preferably be formulated as concentrates, the end user will normally employ dilute formulations. The forms of application can be diluted down to 0.001 % active ingredient. The rates of application are generally from 0.001 to 4 kg a.i./ha, preferably from 0.005 to 1 kg a.i./ha.

The compositions may also contain further auxiliaries such as stabilisers, antifoams, viscosity regulators, binders, tackifiers as well as fertilisers or other active ingredients for obtaining special effects.

The following Examples illustrate the invention. - 16Example 1: Preparation of2-(4-chloro-2-fluoro-5-tert.-butoxycarbonyl)-phenyl-3methylene-4,5,6,7-tetrahydroisoindol- (2H)-1 -one 160 ml of methyl iodide are added dropwise to 60 g of magnesium turnings in 1500 ml of anhydrous diethyl ether in such a manner that the ether boils. When all the magnesium has gone into solution, the mixture is heated at boiling point for a further 20 minutes. The methylmagnesium iodide solution so obtained is then cooled and added dropwise at 10°C with stirring to a solution of 395 g of 2-(4-chloro-2-fluoro-5-tert.-butoxycarbonylphenyl)4,5,6,7-tetrahydroisoindol-(2H)-l,3-dione in 1500 ml of diethyl ester. When the dropwise addition is complete, the mixture is heated at boiling point for one hour. When the reaction mixture has cooled, it is poured into 2000 ml of aqueous saturated ammonium chloride solution and the organic phase is separated off. After drying over magnesium sulfate, the product is concentrated in vacuo and the residue is taken up in toluene. 2 g of para-toluenesulfonic acid are added to the toluene solution, and the mixture is heated under reflux at boiling point for 2 hours. After 2 hours, the mixture is concentrated. The residue crystallises, and filtering with suction and drying yield 350 g of crystalline title compound which has a melting point of 101 °C.

Example 2: Preparation of 2-(4-chloro-2-fluoro-5-carboxyphenvl)-3-methylene-4,5,6,7tetrahydroisoindol-(2H)-1 -one O -1793 g of 2-(4-chloro-2-fluoro-5-tert.-butoxycarbonylphenyl)-4,5,6,7-tetrahydroisoindol(2H)-l-one are added in portions with stirring to a solution, cooled to 0°C, of 500 ml of trifluoroacetic acid and 500 ml of water, and the mixture is stirred further first at 0°C and then overnight at room temperature. The resulting solution is then poured into ice-water and the organic material is extracted with ethyl acetate. The organic phases are dried over magnesium sulfate and concentrated. The residue crystallises. Filtering with suction and drying yield 62 g of title product having a melting point of 236-237°C.

Example 3: Preparation of 2-[4-chloro-2-fluoro-5-(inethoxycarbonyleth-l-ylthio)carbonvlphenyll-3-methylene-4,5,6,7-tetrahvdroisoindol-(2H)-l-one O C - S — CH- COOCH3 II I O CH3 3.6 ml of oxalyl chloride are added dropwise to a suspension, stirred at room temperature, of 10 g of 2-(4-chloro-2-fluoro-5-carboxyphenyl)-3-methylene-4,5,6,7-tetrahydroisoindol-(2H)-l-one in 150 ml of toluene. The reaction mixture is then slowly brought to boiling point and boiled further under reflux. The reaction is complete after two hours. The mixture is concentrated in vacuo, yielding the acid chloride in the form of a brown residue. The residue is taken up in 100 ml of ethyl acetate and added dropwise with stirring at 0°C to a solution of 5.1 g of thiolactic acid methyl ester and 6.5 ml of triethylamine in 100 ml of ethyl acetate. When the addition is complete, the reaction mixture is stirred at room temperature for a further one hour and then the precipitated triethylamine chloride is filtered off. The filtrate is concentrated by evaporation, yielding .4 g of the title compound in the form of an oil having a refractive index of n10D 1.5774. - 18Example 4: 2-r4-chloro-2-fluoro-5-(2-methvlthio-l-methylethoxvcarbonyl)-phenvll-3methylene-4,5,6,7-tetrahydroisoindole .1 g of a solution of 2-(4-chloro-2-fluoro-5-chlorocarbonylphenyl)-3-methylene-4,5,6,7tetrahydroisoindol-(2H)-l-one in 50 ml of toluene are added dropwise at room temperature to a solution of 1.6 g of l-methylthiopropan-2-ol and 2.1 ml of triethylamine in 50 ml of toluene. The reaction mixture is stirred at room temperature for 2 hours and then the precipitated triethylammonium chloride is filtered off. The filtrate is concentrated and 3.0 g of the title compound (compound no. 1.01) are isolated in the form of an oil having a refractive index of n20D 1.5729.

The compounds of Tables 1 to 5 are prepared analogously to the above preparation processes. tl ' O ch3 No. Q1 Phys, data 1.01 ch3 ng° 1.5729 1.02 c2h5 ng5 1.5714 1.03 c3h7 ng° 1.5502 1.04 C3H7(i) ng° 1.5664 1.05 c4h9 ng° 1.5573 1.06 C4H9(s) ng° 1.5570 1.07 C4H9(i) 1.08 C4H9(t) resin 1.09 -C5Hn ng° 1.5569 1.10 -C5Hh(s) 1.11 -ch2-ch2-och3 1.12 -ch2-ch=ch2 1.13 -ch2-cci=ch2 1.14 -ch2-ch=chci 1.15 -ch2-och 1.16 Benzyl 1.17 Phenyl 1.18 ch2ch2och2ch3 II II ο ο No. A R8 Phys, data 2.01 CH(CH3) CH3 ng9 1.5774 2.02 ch2 ch3 ng9 1.5886 2.03 ch2 c2h5 m.p. 82-84° 2.04 CH(CH3) c2h5 ng° 1.5621 2.05 ch2 C3H7(i) ng° 1.5586 2.06 CH(CH3) C4H9(t) ng° 1.5449 2.07 CH2CH(CH3) ch3 ng° 1.5468 2.08 ch2ch2 ch3 ng° 1.5828 2.09 CH(CH3) c3h7 ng4 1.5733 2.10 CH(CH3) C3H7(i) - 21 Table 3 Compounds of formula No. Q1 3.1 CH3 3.2 C2H5 3.3 c3h7 3.4 C3H7(i) 3.5 C4H9(s) 3.6 c4h9 3.7 C4H9(i) 3.8 C4H9(t) 3.9 C5H„ 3.10 ch2ch=ch. 3.11 ch2c=ch Phys, data Ο ιι CH- CH2-S-Q I Ά ch3 o No. Q 4.01 ch3 4.02 c2h5 4.03 C3H7 4.04 C3H7(i) 4.05 c4h9 4.06 C4H9(s) 4.07 C4H9(i) 4.08 C4H9(t) 4.09 -C5H11 4.10 -C5Hn(s) 4.11 -ch2-ch2-och 4.12 -CH2-CII=CH2 4.13 -ch2och No. A R8 5.1 CH(CH3) ch3 5.2 ch2 ch3 5.3 ch2 c2h5 5.4 CH(CH3) c2h5 5.5 ch2 C3H7(i) 5.6 CH(CH3) C3H7(i) 5.7 ch2 c3h7 5.8 CH(CH3) c3h7 5.9 ch2 C4H9(t) 5.10 CH(CH3) C4H9(t) 5.11 CH(CH3) C4H9(s) 5.12 ch2 C4H9(S) 5.13 CH2CH(CH3) ch3 5.14 CH2CH(CH3) C2H5 5.15 ch2 C4H9(i) 5.16 CH(CH3) C5Hh Formulation Examples Example 5: Formulation Examples for active ingredients of formula I (throughout, percentages are by weight) a) Emulsifiable concentrates a compound of Tables 1 to 5 a) b) c) % 40 % 50 % -24calcium dodecylbenzenesulfonate castor oil polyethylene glycol ether (36 moles of ethylene oxide) tributylphenol polyethylene glycol ether (30 moles of ethylene oxide) cyclohexanone xylene mixture % 8 % 5.8 % % % 4.2 % % 20 % % 25 % 20 % Emulsions of any desired concentration can be produced from such concentrates by dilution with water. b) Solutions a) b) c) a compound of Tables 1 to 5 80% 10% 5 % ethylene glycol monomethyl ether 20% - - polyethylene glycol (mol. wt. 400) - 70% - N-methyl-2-pyrrolidone - 20% 5 % epoxidised coconut oil - - 90% These solutions are suitable for application in the form of micro-drops. c) Granulates a) b) a compound of Tables 1 to 5 5 % 10% kaolin 94% - highly dispersed silicic acid 1 % - attapulgite - 90% The active ingredient is dissolved, the solution is sprayed onto the carrier, and the is subsequently evaporated off in vacuo. d) Dusts a) b) c) a compound of Tables 1 to 5 2% 5 % 8 % highly dispersed silicic acid 1 % 5 % 5 % talcum 97 % - 10% kaolin - 90% 77 % Ready-for-use dusts are obtained by intimately mixing the carriers with the active -25ingredient. e) Wettable powders a) b) a compound of Tables 1 to 5 20 % 60 % sodium lignosulfonate 5 % 5 % sodium laurylsulfate 3 % 6 % octylphenol polyethylene glycol ether (7-8 moles of ethylene oxide) - 2 % highly dispersed silicic acid 5 % 27 % kaolin 67 % The active ingredient is thoroughly mixed with the adjuvants and the mixture is thoroughly ground in a suitable mill, affording wettable powders which can be diluted with water to give suspensions of the desired concentration. f) Extruder granulate a compound of Tables 1 to 5 10 % sodium lignosulfonate 2 % carboxymethylcellulose 1 % kaolin 87 % The active ingredient is mixed and ground with the adjuvants, and the mixture is moistened with water. The mixture is extruded and then dried in a stream of air. g) Coated granulate a compound of Tables 1 to 5 3 % polyethylene glycol (mol. wt. 200) 3 % kaolin 94 % The finely ground active ingredient is uniformly applied, in a mixer, to the kaolin moistened with polyethylene glycol. Non-dusty coated granulates are obtained in this manner. h) Suspension concentrate a compound of Tables 1 to 5 ethylene glycol 40% % -26nonylphenol polyethylene glycol ether (15 moles of ethylene oxide) sodium lignosulfonate carboxymethylcellulose 37 % aqueous formaldehyde solution silicone oil in the form of a 75 % aqueous emulsion water 6% 10% 1 % 0.2% 0.8% 32% The finely ground active ingredient is intimately mixed with the adjuvants, giving a suspension concentrate from which suspensions of any desired concentration can be obtained by dilution with water.

Biological Examples Example 6: Preemergence herbicidal action In a greenhouse, immediately after the test plants have been sown in seed trays, the surface of the soil is treated with an aqueous dispersion of the test compounds obtained from a 25 % emulsifiable concentrate. Concentrations of 4 kg active ingredient/hectare are applied. The seed trays are kept in the greenhouse at 22-25°C and 50-70 % relative humidity and the test is evaluated after 3 weeks.

In this test, the compounds of Tables 1 to 5 exhibit good herbicidal activity.

Example 7: Postemergence herbicidal action A number of weeds, both mono- and dicotyledonous, are sprayed postemergence (in the 4to 6-leaf stage) with an aqueous active ingredient dispersion at a rate of from 60 g to 1 kg of test compound per hectare and kept at 24-26°C and 45-60 % relative humidity. The test is evaluated 15 days after the treatment. In this test too, the compounds of Tables 1 to 5 exhibit good to very good herbicidal activity.

The condition of the plants is assessed according to the following scale of ratings: plant has died or has not germinated 2-8 decreasing degrees of damage no damage, the plant is growing like untreated control plants. -27The tested compounds of Tables 1-5 exhibit good activity against dicotyledonous weeds, while monocotyledonous crops, such as cereals, are protected. Some results are summarised in Table 6. <<§ - ο ε Ρ» n 3.° » o CO O ? O Oo 0-5*3.

HfSS »83 t° 3* O Ο X EP > 2-? 3 g S. cr o 3 £7 c O 3:45 ~ *0 c 32.0 0333 Cl 3 0 C # £ □ 3 2223® 3 p 3- ς Q o' n g of ·-* O JX <<; O μ ό ET CT3 Cf 73 ^-o ~ O H—> fD ~ 0’ 0 O s G o’ K 3 ri Ό O c O. k—‘ )—» LU t—* 1—* to LU ‘ 1 k—5 —J -£*· L/ι '-J Os 0 0 O U O to to LU to h- to LU 1—* tO t—‘ 00 L/i Οι Ό OO to 0 ό ·—* pL LU LU -pL to LU Pl tO LU >—* 00 σι Ό lO 00 Ul 0 1—* LU 4L -fL (Ο LU pL LU LU 1— O0< O OO M Ui k—I k—* t— to 1—* t—* μ-k k—k >—1 μ—* t— O-JOi P=LA δ o Ui k—‘ I—* -Pl >—t »— to k—» μ-k μ_k t—* 00 Ό Ό Ό Oi 0 k—‘ 1— -Pl to — -PL ‘ LU *—1 >—* LC 00 00 00 00 bu Ui 0 0 to 0 >—k H- — Ul -P- LU -fL b4 LU 1—k— 0 00 00 0 00 M Ui ►—» >—‘ k— to 1— k—k μ—k »—» k—k k—k <01^00 0 0 i—= tO tO i—= 0 Ui to tO 1-= to μ-k μ- 1—‘ OOOlOiOOO 0 to >— to k—» I—* k—k to to to 1-= O< ~J OOC' 250 0 0 k—k Ui 1— to I—* k— to LU -pi LU μ-4 \D OO OO Ό O bu Ui k—k ►—* μ- to >—‘ k— »—k k—* k—k k—k k—k -~J -Pi. Jx -O O\ 0 0 K> 1— to k—‘ k— μ-* to to 1-= 1-= LO Ol Oi OO Ό 0 Ui to LU Η-» LU to 1—= to ts> N> N> ·—k OOffiO OC bo Ul 0 to O k—k -U to LU to — to -Pl 4l 4l to Ό 00 Ό IO OO bO Ul k—* to »— to to 1— *“* LU ·—1 k—‘ ·—* -J LA U OO Ό 0 Ui to LU t— to LU ·—* to LU tO 1— 1-- —J Ol Οι Ό OO δ 0 to -P^ -P- to LU P- 1— to LU bU »—1 00 00 Οι Ό 00 Ui 0 k—k Ol to LU -PL H- to -Pl LU LU tO VO OO 00 \o Ό bU Ui μ—i to to to >—» k— to ^L tO 1-= 1-= Ό Ol LZi 00 Ό LU LU to to H- to -Pl IO 1-- f- ~J Οι Ό IO 00 0 Ul O to LU to to H- to .p^ to ,— 00 =-J -o 10 00 bo Ul 0 0 Ui 0 Oi -Pl to LU μ- -pL Lh -Pl tO 1-= o-jccoo bu Ui k—* Η- μ- k—» μ- t—* k—k k—k k—k k—k Lzi Ln -P- -J 4^- 0 Ui bJ k— to 1—» >—1 k—* k—k k—* k—k •*4 OS Ov **4 Cs to δ O «-4 k—* k— to μ-* k—» >—L k—k k—k k—‘ k—» «J'JO'CO-U Ui 0 k—k k—1 k— to H-* k—-* f—1 1—· to 1—= 1—= 00 OO Ol 00 to Ul k—k to — to k— LU 1-= tO 1-= Ό —J Lzi OO Ό to to to to 1— H-k LU LU μ·* OO ~U Oi 00 Ό bu Ui 500 to 0 bU LU to to 1— k—k -px tO LU 1-= O«J 00 000 00 0 H- Pl -Pl LU -Pi —1 LU tO -P- ,-= 10 00 00 10 IO bu Ui -83Table 6 -29Example 8: Herbicidal action in wild rice (paddy) The weeds Echinochloa crus galli and Monocharia vag., which occur in water, are sown in plastic beakers (surface: 60 cm2; volume: 500 ml). After sowing, the beakers are filled with water up to the surface of the soil. 3 days after sowing, the water level is increased to slightly above the soil surface (3-5 mm). Application is effected 3 days after sowing by spraying the beakers with an aqueous emulsion of the test compounds at a rate of application of from 60 to 250 g a.i. per hectare. The beakers are then kept in the greenhouse under optimum growth conditions for rice weeds, i.e. at 25-30°C and at high humidity. The evaluation of the tests takes place 3 weeks after application. The compounds of Tables 1 to 5 damage the weeds but not the rice.

Claims (27)

1. A compound of formula I o (D II wherein R 1 is hydrogen or (Cj-Cgjalkyl; R 2 is hydrogen or (C r C 8 )alkyl; or R 1 and R 2 together form a -(CH^- bridge that is unsubstituted or mono- or di-substituted by (Cj-C^alkyl; R 3 and R 4 independently of one another are hydrogen or (CrC4)alkyl; or one of the radicals R 3 and R 4 is hydrogen and the other is a phenyl radical that is unsubstituted or mono- to tri-substituted by identical or different substituents selected from halogen, (Ci-C4)alkyl and (Ci-C 4 )alkoxy; or R 3 and R 4 together form a -(CH 2 ) n - bridge, in which n = 2, 3,4, 5 or 6, which, if desired, may be mono- to tri-substituted by (C r C 4 )alkyl; R 5 is hydrogen or fluorine; R 6 is halogen; A is a straight-chained or branched (CpC^alkylene chain; B is a radical -O-A-S(O) m -Q or -S-A-Q 1 ; m is 0, 1 or 2; Q is (CpC^jalkyl; (C 2 -C 8 )alkoxyalkyl; (C 3 -C 7 )alkenyl; (C 3 -C 7 )alkynyl; (C 3 -C 7 )cycloalkyl; phenyl or benzyl, the phenyl ring being unsubstituted or mono- to tri-substituted by (C r C 4 )aIkyl, halogen or by (C r C 4 )alkoxy; Q 1 is -COOR 7 ; R 7 is hydrogen; (C r C 12 )alkyl; (C 2 -C 8 )alkoxyalkyl; (C 3 -C 7 )alkenyl; (C 3 -C 7 )alkynyl; (C 3 -C 7 )cycloalkyl; (C 3 -C 7 )alkenyloxy-(C 1 -C 4 )alkyl; (C 2 -C 8 )alkylthioalkyl; di(C 1 -C 4 )alkylamino-(C 1 -C 4 )alkyl; phenyl or benzyl, the phenyl ring being -31 unsubstituted or mono- to tri-substituted by (C r C 4 )alkyl, halogen or by (Cj-C^)alkoxy.

2. A compound of formula I, wherein R 1 and R 2 together form the -(CH2)4-alkylene bridge; each of R 3 and R 4 is hydrogen; R 5 is fluorine; R 6 is chlorine; and B is the radical -OCH(CH3)CH 2 -S-Q, in which Q is as defined in claim 1.

3. A compound of formula I, wherein R 1 and R 2 together form the -(CH 2 ) 4 -alkylene bridge; each of R 3 and R 4 is hydrogen; R 5 is fluorine; R 6 is chlorine; and B is the radical -S-A-CO-O-R 7 , in which A and R 7 are as defined in claim 1.

4. A compound of formula I, wherein R 1 and R 2 together form the -(CH2)4-alkylene bridge; each of R 3 and R 4 is hydrogen; R 5 is fluorine; R 6 is chlorine; and B is the radical -O-CH(CH3)-S-Q, in which Q is as defined in claim 1.

5. A compound of formula I, wherein R 1 and R 2 together form the -(CH2)4-alkylene bridge; each of R 3 and R 4 is hydrogen; R 5 is fluorine; R 6 is chlorine; and B is the radical -O-CH(CH3)CH 2 -SO 2 -Q, in which Q is as defined in claim 1.

6. A compound of formula I according to claim 1 selected from 2-[4-chloro-2-fluoro-5-(2-methoxycarbonylethylthio)-carbonylphenyl]-3-methylene4,5,6,7-tetrahydroisoindol-(2H)-l-one, 2-[4-chloro-2-fluoro-5-(l-ethoxycarbonylethylthio)-carbonylphenyl]-3-methylene4,5,6,7-tetrahydroisoindol-(2H)-l-one, 2-[4-chloro-2-fluoro-5-(l-propoxycarbonylethylthiocarbonyl)-phenyl]-3-methylene4,5,6,7-tetrahydroisoindol-(2H)-l-one, 2-[4-chloro-2-fluoro-5-(l-isopropoxycarbonylethylthiocarbonyl)-phenyl]-3-methylene4.5.6.7- tetrahydroisoindol-(2H)-l-one, 2-[4-chloro-2-fluoro-5-(methoxycarbonylmethylthiocarbonyl)-phenyl]-3-methylene4.5.6.7- tetrahydroisoindol-(2H)-1-one, 2-[4-chloro-2-fluoro-5-(ethoxycarbonylmethylthiocarbonyl)-phenyl]-3-methylene4.5.6.7- tetrahydroisoindol-(2H)-1 -one, 2-[4-chloro-2-fluoro-5-(l-tert.-butoxycarbonylethylthiocarbonyl)-phenyl]-3-methylene4,5,6,7-tetrahydroisoindol-(2H)-1 -one, 2-[4-chloro-2-fluoro-5-(2-methoxycarbonyl-2-methylethylthiocarbonyl)-phenyl]-3methylene-4,5,6,7-tetrahydroisoindol-(2H)-1 -one, -322-[4-chloro-2-fluoro-5-(l-methoxycarbonylethylthiocarbonyI)-phenyI]-3-methyIene4,5,6,7-tetrahydroisoindol-(2H)-l-one, 2-[4-chloro-2-fluoro-5-(2-methylthio-l-methylethoxycarbonyl)-phenyl]-3-methylene4.5.6.7- tetrahydroisoindol-(2H)-l-one, 2-[4-chloro-2-fluoro-5-(2-ethylthio-l-methylethoxycarbonyl)-phenyl]-3-methylene4.5.6.7- tetrahydroisoindol-(2H)-1 -one, 2-[4-chloro-2-fluoro-5-(2-propylthio-l-methylethoxycarbonyl)-phenyl]-3-methylene4.5.6.7- tetrahydroisoindol-(2H)-1 -one, 2-[4-chloro-2-fluoro-5-(2-isopropylthio-l-methylethoxy)-phenyl]-3-methylene-4,5,6,7tetrahydroisoindol-(2H)-1 -one, 2-[4-chloro-2-fluoro-5-(2-n-butylthio-l-methylethoxycarbonyl)-phenyl]-3-methylene4.5.6.7- tetrahydroisoindol- (2H)-1 -one, 2-[4-chloro-2-fluoro-5-(2-sec.-butylthio-l-methylethoxycarbonyl)-phenyl]-3-methylene4.5.6.7- tetrahydroisoindol-(2H)-l-one, 2-[4-chloro-2-fluoro-5-(2-tert.-butylthio-l-methylethoxycarbonyl)-phenyl]-3-methylene4.5.6.7- tetrahydroisoindol-(2H)-l-one, and 2-[4-chloro-2-fluoro-5-(2-pentylthio-l-methylethoxycarbonyl)-phenyl]-3-methylene4.5.6.7- tetrahydroisoindol-(2H)-1 -one.

7. A process for the preparation of a compound of formula I according to claim 1, which comprises reacting an acid chloride of formula IX, wherein R 1 to R 6 are as defined under formula I, in an inert organic solvent, in the presence of at least the equimolar amount of a base, with an alcohol or thiol of the formula HB, wherein B is a radical -O-A-S(O) m Q or -S-A-Q 1 , in which A, m, Q and Q 1 are as defined under formula I, in accordance with the reaction scheme R 3 R 4 p3 R 4 d5 O C-B II O R' -Hal II IX VII

8. A compound of formula VIII Ο wherein R 1 to R 6 are as defined in claim 1, with the proviso that when R 1 and R 2 together form the -(CH 2 ) 4 -alkylene bridge, only one of R 3 and R 4 can be hydrogen.

9. 2-(4-chloro-2-fluoro-5-carboxyphenyl)-3-methylene-4,5,6,7-tetrahydroindol-(2H)-l-one according to claim 8.

10. A compound of formula IX (IX) O wherein R 1 to R 6 are as defined in claim 1 and Hal is halogen.

11. A tert.-butyl ester of formula VI wherein R 1 to R 6 are as defined in claim 1.

12. 2-(4-chloro-2-fluoro-5-tert.-butoxycarbonylphenyl)-3-methylene-4,5,6,7-tetrahydroindol-(2H)-l-one according to claim 11.

13. A herbicidal composition which contains as active ingredient a compound of formula I according to claim 1, together with inert adjuvants and/or carriers.

14. A method of controlling undesired plant growth, which comprises applying a compound of formula I according to claim 1 or a composition according to claim 13 to the plants or the locus thereof.

15. A method according to claim 14 for controlling weeds or grasses in crops of useful plants.

16. A method according to claim 14 for controlling weeds or grasses pre- or postemergence in crops of cereals, cotton, soybeans, maize, rice or sorghum.

17. Seeds of useful plants which have been treated with a compound of formula I according to claim 1 in an amount having herbicidal or growth regulating effect.

18. A plant growth regulating composition which contains as active ingredient a compound of formula I according to claim 1 in an amount having growth regulating effect, together with adjuvants and/or carriers.

19. A method of influencing the growth of cultivated plants, which comprises applying to the cultivated plant or the locus thereof a compound of formula I according to claim 1 or a -35composition according to claim 18 in an amount having growth regulating effect.

20. A method according to claim 19 of defoliating cotton.

21. A compound according to claim 1, substantially as hereinbefore described and exemplified.

22. A process for the preparation of a compound according to claim 1, substantially as hereinbefore described and exemplified.

23. A compound according to claim 1, whenever prepared by a process claimed in a preceding claim.

24. A compound according to claim 8, substantially as hereinbefore described and exemplified.

25. A compound according to claim 10, substantially as hereinbefore described and exemplified.

26. A compound according to claim 11, substantially as hereinbefore described and exemplified.

27. A herbicidal composition according to claim 13, substantially as hereinbefore described and exemplified.