5-(N-3,4,5,6-tetrahydrophthalimido)benzoic acid thiol esters as selective herbicides

Abstract

The novel 5-(N-3,4,5,6-tetrahydrophthalimido)benzoic acid thiol esters of formula I below have good selective herbicidal properties pre- and postemergence and also influence or inhibit plant growth.The novel compound are of formula I ##STR1## wherein n is 0, 1 or 2,R.sub.1 is C.sub.1 -C.sub.3 alkyl,R.sub.2 is hydrogen or halogen,R.sub.3 is halogen,A-Q taken together is hydrogen or a radical --CH(COCH.sub.3)COOR.sub.4A is a straight chain or branched C.sub.1 -C.sub.4 alkylene bridge, which is unsubstituted or mono- or polysubstituted by C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 alkylthio or cyano.Q is hydroxyl or a radical as defined in the disclosure.

Description

The present invention relates to novel 5-(N-3,4,5,6-tetrahydrophthalimido)benzoic acid thiol esters of formula I with herbicidal and plant growth regulating properties, and to the preparation of these novel esters. The invention also relates to compositions which contain said novel compounds and to the use thereof for selectively controlling weeds or for regulating plant growth.

The novel 5-(N-3,4,5,6-tetrahydrophthalimido)benzoic acid thiol esters are of formula I ##STR2## wherein n is 0, 1 or 2,

R.sub.1 is C.sub.1 -C.sub.3 alkyl, R.sub.2 is hydrogen or halogen, R.sub.3 is halogen, A-Q taken together is hydrogen or a radical --CH(COCH.sub.3)COOR.sub.4, A is a straight chain or branched C.sub.1 -C.sub.4 alkylene bridge, which is unsubstituted or mono- or polysubstituted by C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 alkylthio or cyano, Q is hydroxyl, halogen, cyano, thiocyanato (--SCN), C.sub.2 -C.sub.6 alkenyl, C.sub.2 -C.sub.6 haloalkenyl, C.sub.2 -C.sub.6 cyanoalkenyl, C.sub.2 -C.sub.4 alkynyl, or a radical --C(R.sub.4).dbd.CH--COOR.sub.5, --CH[N(R.sub.4).sub.2 ]COOR.sub.4, --NR.sub.6 R.sub.7, --COR.sub.8, --CON (R.sub.6)SO.sub.2 CH.sub.3, --N(R.sub.4)CH.sub.2 CN, diallylcarbamoyl, --Si(R.sub.11).sub.3, --COOCH.sub.2 Si(CH.sub.3).sub.2 C.sub.1 -C.sub.6 -alkyl, --COON.dbd.C(R.sub.9).sub.2, --PO(OR.sub.12)--(O).sub.m R.sub.12, --CON(R.sub.4)SO.sub.2 C.sub.1 -C.sub.6 alkyl, --CON(R.sub.4)SO.sub.2 C.sub.1 -C.sub.4 haloalkyl, C.sub.1 -C.sub.6 alkylcarbonyl, C.sub.1 -C.sub.6 alkoxycarbonyl, a radical benzoyl or benzylcarbonyl whose phenyl ring is unsubstituted, mono- or polysubstituted by halogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 haloalkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 haloalkoxy, cyano or nitro, Q is further a radical COOR.sub.13, --COOCH(CH.sub.3)CH.sub.2 SR.sub.4, --CON(R.sub.4)CH.sub.2 C(OC.sub.1 -C.sub.6 alkyl).sub.2, --COO(CH.sub.2).sub.n+1 OC.sub.3 -C.sub.7 alkenyl, --COOC.sub.1 -C.sub.4 cyanoalkyl, --COO--C.sub.1 -C.sub.4 alkylen-N(R.sub.4).sub.2 or C.sub.1 -C.sub.8 alkanoyloxy, R.sub.4 is hydrogen, C.sub.1 -C.sub.6 alkyl or C.sub.2 -C.sub.6 alkoxyalkyl, R.sub.5 is C.sub.1 -C.sub.6 alkyl or C.sub.1 -C.sub.6 hydroxyalkyl, R.sub.6 and R.sub.7 are independently of each other hydrogen, C.sub.1 -C.sub.6 alkyl, C.sub.2 -C.sub.6 alkoxyalkyl, C.sub.3 -C.sub.6 alkenyl, C.sub.3 -C.sub.6 alkynyl or C.sub.3 -C.sub.6 cycloalkyl, 2-furanylmethyl, 2-tetrahydrofuranylmethyl, 2-(5-methyl)-tetrahydrofuranylmethyl or 2-thienylmethyl R.sub.8 is a radical pyrrolidino, piperidino, morpholino, thiomorpholino, 4-methylpiperazino, pyrazolidino, imidazolidino or 1,2,4-triazol, which is unsubstituted or mono- or disubstituted by C.sub.1 -C.sub.4 alkyl, R.sub.9 is C.sub.1 -C.sub.6 alkyl or two adjacent R.sub.9 can form a C.sub.2 -C.sub.6 alkylene bridge, R.sub.10 is C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 haloalkyl or two adjacent R.sub.10 from a 1,2-ethylene-, 1,3-propylene- or 1,2-cyclohexylene bridge, R.sub.11 is C.sub.1 -C.sub.6 alkyl or C.sub.1 -C.sub.6 alkoxy, R.sub.12 is hydrogen, C.sub.1 -C.sub.6 alkyl, C.sub.2 -C.sub.6 alkenyl or C.sub.3 -C.sub.6 alkynyl or C.sub.3 -C.sub.7 cycloalkyl, R.sub.13 is C.sub.1 -C.sub.12 alkyl, C.sub.2 -C.sub.6 alkoxyalkyl, C.sub.3 -C.sub.7 alkenyl, C.sub.1'-C.sub.6 alkynyl or C.sub.3 -C.sub.7 cycloalkyl and m is zero or one.

Similar tetrahydrophthalimido-N-benzoic acid esters are described in the published European Patent applications EP-A 207,894 and 233,151. The thiolesters of this invention are structurally different and are distinguished from those by a more specific selective-herbicidal activity against grasses and weeds in cultures of cultivated plants.

Particularly active compounds are those of formula Ia ##STR3## wherein n is zero, 1 or 2, R.sub.1 is C.sub.1 -C.sub.3 alkyl, R.sub.2 is fluorine, R.sub.3 is chlorine or bromine and R.sub.8 is pyrrolidino, piperidino, morpholino, thiomorpholino, 4-methylpiperazino, pyrazolino, imidazolidino or 1,2,4-triazol radical, which is unsubstituted or mono- or disubstituted by C.sub.1 -C.sub.4 alkyl, especially N-[4-chloro-2-fluoro-5-(2-methylmorpholinocarbonyl-eth-1-yl -thiocarbonyl)phenyl]-3,4,5,6-tetrahydrophthalimide, N-[4-chloro-2-fluoro-5-(2-pyrrolidinocarbonyl-eth-1-yl-thiocarbonyl)phenyl]-3,4,5,6-tetrahydrophthalimide, N-(4-chloro-2-fluoro-5-piperidinocarbonyl-eth-1-yl-thiocarbonylphenyl)3,4,5,6-tetrahydrophthalimide.

Equally active compounds are those of the formula Ib ##STR4## wherein n is zero, 1 or 2, R.sub.1 is C.sub.1 -C.sub.3 alkyl, R.sub.2 is fluorine, R.sub.3 is chlorine or bromine, A is a C.sub.1 -C.sub.4 alkylene bridge and the R.sub.a are independently of each other C.sub.1 -C.sub.6 alkyl or together a C.sub.2 -C.sub.6 alkylene bridge, especially N-[(acetoximecarbonyl-eth-1-ylthiolcarbonyl)-2-fluoro-4-chloro)phenyl]-3,4,5,6-tetrahydrophthalimide.

Good activity showed further the compounds of the formula Ic ##STR5## wherein n is zero, 1 or 2, R.sub.1 is C.sub.1 -C.sub.3 alkyl, R.sub.2 is fluorine, R.sub.3 is chlorine or bromine, A is a C.sub.1 -C.sub.4 alkylene bridge, R.sub.4 is hydrogen, C.sub.1 -C.sub.6 alkyl or C.sub.2 -C.sub.6 alkoxyalkyl and R.sub.10 are independently of each other C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 haloalkyl, or together form a 1,2-ethylene, 1,3-propylene or 1,2-cyclohexylene bridge, especially N-[4-chloro-5-(1,3-dioxolan-2-ylmethylthiocarbonyl) -2-fluorophenyl]-3,4,5,6-tetrahydrophthalimide.

Equally good activity showed the compounds of the formula Id ##STR6## wherein n is zero, 1 or 2, R.sub.1 is C.sub.1 -C.sub.3 alkyl, R.sub.2 is fluorine, R.sub.3 is chlorine or bromine, A is a C.sub.1 -C.sub.4 alkylene bridge and the R.sub.11 are independently of each other C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 alkoxy, especially N-[4-chloro-2-fluoro-5-(triethoxysilylethylthiocarbonyl)phenyl]-3,4,5,6-tetrahydrophthalimide.

Good activity was further experienced with the compounds of the formulae Ie to Ir.

Compounds of formula Ie ##STR7## wherein n is zero, 1 or 2, R.sub.1 is C.sub.1 -C.sub.3 alkyl, R.sub.2 is fluorine, R.sub.3 is chlorine or fluorine, m is zero or 1, A is a C.sub.1 -C.sub.4 alkylene chain and the R.sub.12 are independently of each other hydrogen, C.sub.1 -C.sub.6 alkyl, C.sub.1 -C.sub.6 haloalkyl, C.sub.1 -C.sub.6 cyanoalkyl, C.sub.1'-C.sub.6 alkenyl or C.sub.3 -C.sub.6 alkinyl especially N-[4-chloro5-(deithoxyphosphonic-acid-eth-1-ylthiocarbonyl)-2-fluoro-phenyl]-3,4,5,6-tetrahydrophthalimide;

Compounds of the formula If ##STR8## wherein n is zero, 1 or 2, R.sub.1 is C.sub.1 -C.sub.3 alkyl, R.sub.2 is fluorine, R.sub.3 is chlorine or bromine, A is a C.sub.1 -C.sub.4 alkylene bridge, and Q.sub.1 is hydroxyl or cyano, especially N-[4-chloro-2-fluoro-5-(1-cyano-eth-1-ylthio-carbonyl)phenyl]-3,4,5,6-tetrahydrophthalimide and N-(4-chloro-2-fluoro-5-hydroxyethylthiocarbonylphenyl)-3,4,5,6-tetrahydrophthalimide.

Compounds of the formula Ig ##STR9## wherein n, A, R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 have the meaning given above.

Compounds of the formula Ih ##STR10## wherein A, R, R.sub.1, R.sub.2, R.sub.3 and the R.sub.4 independently of each other have the meaning given above.

Compounds of the formula Ii ##STR11## wherein n is zero, 1 or 2, R.sub.1 is C.sub.1 -C.sub.3 alkyl, R.sub.2 is fluorine, R.sub.3 is chlorine or bromine, A is a C.sub.1 -C.sub.4 alkylene bridge and R.sub.6 and R.sub.7 are independently of each other hydrogen, C.sub.1 -C.sub.6 alkyl, C.sub.2 -C.sub.6 alkoxyalkyl, C.sub.3 -C.sub.6 alkenyl, C.sub.3 -C.sub.6 alkynyl or C.sub.3 -C.sub.6 cycloalkyl, 2-furanylmethyl, 2-tetrahydrofuranylmethyl, 2-(5-methyl)-tetrahydrofuranylmethyl or 2-thienylmethyl, especially N-(4-chloro-5-dimethylaminoethylthiocarbonyl-2-fluorophenyl)-3,4,5,6-tetrahydrophthalimide.

Compounds of the formula Ij ##STR12## wherein n is zero, 1 or 2, R.sub.1 is C.sub.1 -C.sub.3 alkyl, R.sub.2 is fluorine, R.sub.3 is bromine or fluorine and A is a C.sub.1 -C.sub.4 alkylene bridge, especially N-(4-chloro-2-fluoro-5-trimethylsilylmethylthiocarbonylphenyl)-3,4,5,6-tetrahydrophthalimide.

Compounds of the formula Ik ##STR13## wherein A, n, R.sub.1, R.sub.2 and R.sub.3 have the meaning given above.

Compounds of the formula Il ##STR14## wherein n is zero, 1 or 2, R.sub.1 is C.sub.1 -C.sub.3 alkyl, R.sub.2 is fluorine, R.sub.3 is chlorine or bromine, A is a C.sub.1 -C.sub.4 alkylene bridge and R.sub.4 is C.sub.1 -C.sub.6 alkyl or C.sub.2 -C.sub.6 alkoxyalkyl, especially N-[allylthiprop-2-yloxycarbonyleth-1-ylthiocarbonyl)-4-chloro-2-fluorophenyl]-3,4,5,6-tetrahydrophthalimide.

Compounds of formula Im ##STR15## wherein A, n, R.sub.1, R.sub.2 and R.sub.3 have the meaning given above.

Compounds of formula In ##STR16## wherein n is zero, R.sub.2 is fluorine, R.sub.3 is chlorine or bromine and R.sub.13 is C.sub.1 -C.sub.12 alkyl, C.sub.2 -C.sub.6 alkoxyalkyl, C.sub.3 -C.sub.7 alkenyl, C.sub.6 -C.sub.6 cycloalkyl, especially N-[4-chloro-2-fluoro-5-(1'-methoxycarbonyl-1'-methoxy-methylthiocarbonyl) phenyl]-3,4,5,6-tetrahydrophthalimide and N-[4-chloro-2-fluoro-5-(1'-methoxycarbonyl-2'-methoxymethyl-ethylthio-carbonyl)phenyl]3,4,5,6-tetrahydrophthalimide.

Compounds of the formula Io ##STR17## wherein A, n, R.sub.1, R.sub.2 and R.sub.3 have the meaning given above.

Compounds of the formula Ip ##STR18## wherein A, n, R.sub.1, R.sub.2 and R.sub.3 have the meaning given above.

Compounds of the formula Iq ##STR19## wherein A, n, R.sub.1, R.sub.2, R.sub.3 and the R.sub.4 independently of each other have the meaning given above.

Compounds of the formula Ir ##STR20## wherein A, n, R.sub.1, R.sub.2 and R.sub.3 have the meaning given above.

The invention comprises also the possible optically active isomers, diastereomers and enantiomers and their mixtures, in which the 5-(N-3,4,5,6-tetrahydrophthalimido)benzoic-acid-thiol-esters of formula I may occur.

In the above definitions the expression halogen includes fluorine, chlorine, bromine or fluorine, especially fluorine, chlorine and bromine.

The expression alkyl, taken by itself or as part of a substituent includes straight-chained or branched radicals. Examples therefore are methyl, ethyl, n-propyl, isopropyl, n-butyl, sec. butyl, tert. butyl, isobutyl as well as the higher homologs thereof, pentyl, hexyl, heptyl, octyl etc. together with their isomers. Cyanoalkyl radicals contains accordingly an additional carbon atom.

The C.sub.2 -C.sub.6 alkenyl- or C.sub.2 -C.sub.6 alkynyl radicals mentioned in the above definition include also straight-chained and branched radicals. Alkenyl includes especially 2-propenyl (allyl), 2-methyl-2-propenyl (methallyl), 1-methyl-2-propenyl, 2-butenyl and 3-butenyl, and alkynyl are preferably 2-propinyl (propargyl), 2-butinyl and 3-butinyl radicals. The alkenyl radicals of the definitions of Q, R.sub.6 and R.sub.7 are preferably allyl, methallyl or 2-butenyl and preferred alkynyl radicals are propargyl and 2-butynyl. If these unsaturated radicals are bound via an oxygen atom to the rest of the molecule, the radical is bound preferably via a saturated carbon atom to the oxygen.

The definition A includes methylene, 1,2-ethylene and 1,3-propylen as well as radicals which can be derived therefrom by substitution of one to two hydrogen atoms, such as ethylidene, isopropylidene (2,2-propylidene), benzylidene, 1-phenylethylidene, diphenylmethylene, 1,2-propylene, 2,3-butylene, 1,1-dimethyl-1,2-ethylene, 1,1-diphenyl-1,2-ethylene, 1,2-diphenyl-1,2-ethylene, 1-methyl-1-phenyl-1,2-ethylene, 1,2-butylene, 1,3-butylene, 1,1-dimethyl-1,3-propylene, 1-methyl-1-phenyl-1,3-propylene, 1,2-diphenyl-1,3-propylene and 1,3-diphenyl-1,3-propylene. Preferred radicals A are methylene, 1,2-ethylene, 1,2-propylene, 2,3-butylene and 2,2-dimethyl-1,3-propylene.

The generic definitions given in other substituents of the compounds of formula I comprise e.g. the following single radicals, which enumeration is not limiting the invention:

Haloalkyls are alkyl radicals which are partly or completely halogenated with identical or different halogen atoms and which correspond to the given range of the definition, such as e.g. trifluoromethyl, trichloromethyl, difluoromethyl, dichloromethyl, 2.2.2-trifluoroethyl and 1,1,1,3,3,3-hexafluoroprop-2-yl.

Alkoxy are to be understood radicals in the given range of the definition, such as preferably methoxy and ethoxy. C.sub.1 -C.sub.4 Alkoxy-C.sub.2 -C.sub.4 alkyl and C.sub.1 -C.sub.4 haloalkoxy in the given range of the definition are also to be understood as alkoxy radicals, such as e.g. methoxymethyl, methoxyethyl, difluoromethoxy, dichloromethoxy, trifluoromethoxy, chlorodifluoromethoxy and trichloromethoxy.

In the substituents, which consist of several basic elements, the parts can be chosen freely within the given range of the definition.

In accordance with the present invention, the novel 5-(N-3,4,5,6-tetrahydrophthalimido)benzoic acid thiol esters of formula I are prepared by reacting the anhydride of a 3,4,5,6-tetrahydrophthalic acid of formula II ##STR21## wherein R.sub.1 and n are as defined for formula I, with the equimolar amount of a derivative of a 3-aminobenzoic acid ester of formula III ##STR22## wherein A, R.sub.2, R.sub.3 and Q are as defined for formula I, in an inert organic solvent or diluent and in the absence or presence of a minor amount of a dehydrating agent.

Suitable solvents or diluents for this reaction are higher boiling hydrocarbons, lower alkane acids and the esters thereof, higher boiling ketones and ethers. Examples of such solvents and diluents are toluene, xylene, acetic acid, ethyl acetate, isopropyl ether, tetrahydrofuran, methyl ethyl ketone and dimethylformamide.

The reaction takes place at a temperature in the range from 0.degree. C. to 200.degree. C.

In order to speed up the reaction, a minor amount of a dehydrating or water-absorbing agent may be added, e.g. of sulfuric acid or of an organic sulfonic acid, of a salt such as sodium acetate or of an anhydride such as phosphorus pentoxide.

The 3-aminobenzoic acid derivative of formula III can e.g. be prepared by the following synthesis route: ##STR23## In the above formulae, R.sub.2, R.sub.3, A and Q are as defined for formula I.

A benzoic acid suitably substituted in the phenyl nucleus is nitrated with a nitric acid mixture and the resultant 3-nitrobenzoic acid is subsequently converted into the acid halide, e.g. with phosphoroxy chloride or bromide, thionyl chloride or bromide or sulfuryl chloride or bromide.

The acid halide thus obtained is then reacted with a mercaptane of the formula HS-A-Q, in which A and Q are as defined for formula I, in the presence of the molar amount of a base.

However, the 3-nitrobenzoic thiol acid may also be condensed direct with an alkyl halide Hal-A-Q, in which A, X and Q are as defined for formula I and Hal is a halogen atom, preferably chlorine or bromine, in the presence of a base. ##STR24## The resultant 3-nitrobenzoic acid thiol ester is then reduced with hydrogen, e.g. in the presence of Raney nickel, to give the 3-aminobenzoic acid ester. The amine is subsequently condensed with a 3,4,5,6-tetrahydrophthalic anhydride in accordance with the process of this invention. ##STR25## Arylthiocarbonic acids respectively thiolbenzoic acid are known (c.f. Beilstein Vol. 9 419 I, 169; Org. Synthesis 37, p. 101) and can be synthetized e.g. by condensation of an optically substituted benzoyl chloride with sodium hydrogensulfide.

Thiolbenzoic acid can be produced e.g. by introducing benzoyl chloride into a cooled alcoholic solution of potassium hydroxyde, that has been saturated by hydrogen sulfide, then filtering off the potassium chloride and evaporating the filtrate to dryness. The remaining sodium salt can be dissoziated with hydrochloric acid, whereby oily thiolbenzoic acid is liberated, which can in turn be condensed with chloroacetamide whereby benzoyl-thioglykol acid amid is obtained. ##STR26## Another synthesis for the production of thiolbenzoic acid esters is disclosed in Tetrahedron Letters Vol. 27 (32) p. 3791-3794 (1986). According to this method, a benzoic acid halide is condensed in presence of a catalytic amount of anhydrous cobalt chloride Co.sup.II Cl.sub.2 with a mercaptan.

In accordance with a further process of the present invention, the 5-(N-3,4,5,6-tetrahydrophthalimido)benzoic acid thiol esters of formula I according to claim 1 are obtained by reacting a 5-(N-3,4,5,6-tetrahydrophthalimido)benzoyl halide of formula V ##STR27## wherein n, R.sub.1, R.sub.2 and R.sub.3 are as defined for formula I and Hal is a halogen atom, preferably chlorine or bromine, with a reactive compound of formula VI

X--A--Q (VI) wherein A, and Q are as defined for formula I, and X is an electronegative abassion group and hydrogen sulfide, in an inert organic solvent or diluent and in the presence of a base.

Higher boiling hydrocarbons, lower esters of alkane acids, higher boiling ketones and ethers are suitable solvents or diluents for this reaction too. Examples of such solvents and diluents are hexane, benzene, toluene, xylene, ethyl acetate, isoproyl ether, dioxane and methyl ethyl ketone.

The reaction takes place at a temperature in the range from 0.degree. C. to the boiling point of the reaction mixture.

Suitable bases are tertiary amines, for example, triethylamine, pyridine, collidine, further the hydroxides, carbonates, bicarbonates of alkali metals.

The 5-(N-3,4,5,6-tetrahydrophthalimido)benzoyl halide of formula V is prepared by condensing a 3,4,5,6-tetrahydro-phthalic anhydride of formula II with a 3-aminobenzoic acid suitably substituted by R.sub.2 and R.sub.3 and effecting subsequent halogenation in accordance with the described process.

A further process for the preparation of the 5-(N-3,4,5,6-tetrahydrophthalimido)benzoic acid fluid esters of formula I comprises reacting a 5-(N-3,4,5,6-tetrahydrophthalimido)benzoic acid, halide formula VI ##STR28## wherein n, R.sub.1, R.sub.2 and R.sub.3 are as defined for formula I, with a mercaptan of formula VIII

HS--A--Q (VIII) wherein A and Q are as defined in claim 1 and Hal is a halogen atom, preferably chlorine or bromine, in an inert organic solvent or diluent and in the presence of the molar amount of a base.

Suitable solvents or diluents are those listed under the first or second process.

The reaction takes place at a temperature in the range from 0.degree. C. to the boiling point of the reaction mixture.

The above-mentioned or tertiary amines, hydroxides, carbonates or bicarbonates of alkali metals may be employed as bases for this reaction too.

The reaction conditions in all described variants are similar.

The compounds of formula I are usually successfully applied at concentrations of 0.05 to 4 kg/ha, in particular 0.1 to 1 kg/ha.

When used at low rates of application, the compounds of formula I have good selective growth inhibiting and selective herbicidal properties which make them most suitable for use in crops of useful plants, preferably in cereals, cotton, maize and rice, especially however in soybeans. In some cases damage is also caused to weeds which have only been controlled up to now with total herbicides.

The mode of action of these compounds is unusual. Many are translocatable, i.e. they are absorbed by the plant and transported to other parts of it where they then exert their action. Thus, for example, it is possible to damage perennial weeds to the roots by surface treatment.

Compared with other herbicides and growth regulators, the novel compounds of formula I are effective even when used at very low rates of application.

The compounds of formula I have in addition pronounced plant growth inhibiting properties. The growth of both monocots and dicots is inhibited.

Thus, for example, the compounds of formula I selectively inhibit the growth of leguminosae which are frequently planted as cover crops in tropical regions, so that, while soil erosion between cultivated plants is prevented, the cover crops cannot compete with the cultivated plants.

Inhibition of the vegetative growth of many cultivated plants permits more plants to be sown in a crop area, so that a higher yield may be obtained per unit of area. A further mechanism of yield increase using growth inhibitors resides in the fact that nutrients are able increasingly to promote flower formation and fruiting, whereas vegetative growth is inhibited.

The compounds of formula I can also be used for defoliating and desiccating crops of cotton and potatoes. By treating the crops at the moment of ripening, the harvesting of the cotton capsules or of the tubers is greatly facilitated when the leaves fall off and/or shrivel up or when the shrubs shrivel up.

At higher rates of application of compounds of formula I, all tested plants are so severely damaged in their development that they die.

The invention also relates to herbicidal and plant growth regulating compositions which contain a novel compound of formula I, and also to methods of controlling weeds pre- and postemergence and of inhibiting the growth of monocots and dicots, especially grasses, tropical cover crops and tobacco plant suckers.

The compounds of formula I are used in unmodified form or, preferably, together with the adjuvants conventionally employed in the art of formulation, and are therefore formulated in known manner e.g. to 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, surface-active 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 materials such as 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.

Suitable anionic surfactants can be both water-soluble soaps and water-soluble synthetic surface-active compounds.

Suitable soaps are the alkali metal salts, alkaline earth metal salts or unsubstituted or substituted ammonium salts of higher fatty acids (C.sub.10 -C.sub.22), 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 unsubstitued or substituted ammonium salts and contain a C.sub.8 -C.sub.22 alkyl 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 sulfuric acid esters and sulfonic acids of 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 naphthalenesulfonic acid/formaldehyde condensation product.

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 glycol 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, such as polyoxyethylene sorbitan trioleate, are also suitable non-ionic surfactants.

Cationic surfactants are preferably quaternary ammonium salts which contain, as N-substituent, at least one C.sub.8 -C.sub.22 alkyl 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, methylsulfates or ethylsulfates, e.g. stearyltrimethylammonium chloride or benzyldi(2-chloroethyl)ethylammonium bromide.

The surfactants customarily employed in the art of formulation are described e.g. in the following publications:

"McCutcheon's Detergents and Emulsifiers Annual", MC Publishing Corp., Ridgewood, N.J. 1981; H. Stache, "Tensid-Taschenbuch" (Handbook of Surfactants), C. Hanser Verlag, Munich & Vienna, 1981.

The pesticidal preparations usually contain 0.1 to 95%, preferably 0.1 to 80%, of a compound of formula I, 1 to 99.9% of a solid or liquid adjuvant, and 0 to 25%, preferably 0.1 to 25%, of a surfactant.

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

______________________________________Emulsifiable concentratescompound of formula I: 1 to 20%, preferably 5 to 10%surfactant: 5 to 30%, preferably 10 to 20%liquid carrier: 50 to 94%, preferably 70 to 85%Dustscompound of formula I: 0.1 to 10%, preferably 0.1 to 1%solid carrier: 99.9 to 90%, preferably 99.9 to 99%Suspension concentratescompound of formula I: 5 to 75%, preferably 10 to 50%water: 94 to 25%, preferably 90 to 30%surfactant: 1 to 40%, preferably 2 to 30%Wettable powderscompound of formula I: 0.5 to 90%, preferably 1 to 80%surfactant: 0.5 to 20%, preferably 1 to 15%solid carrier: 5 to 95%, preferably 15 to 90%Granulatescompound of formula I: 0.5 to 30%, preferably 3 to 15%solid carrier: 99.5 to 70%, preferably 97 to 85%______________________________________

Whereas commercial products will be preferably formulated as concentrates, the end user will normally employ dilute formulations. The formulations can be diluted to a concentration as low as 0.001% of active ingredient. The rates of application are usually from 0.005 to 5 kg a.i./ha.

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

The following Examples illustrate the preparation of compounds of the formula I. Further compounds prepared in corresponding manner are listed in the subsequent Tables. Temperatures are given in degrees centigrade, pressures in millibar (mbar).

EXAMPLE 1

Preparation of N-[4-chloro-5-(1-cyanoeth-1-ylthiocarbonyl)-2-fluoro-phenyl]-3,4,5,6-tetrahydrophthal imide. ##STR29##

To 60 g of pyridin, which is cooled to -5.degree. C., stirred and to which is simultaneously introduced gaseous hydrogen sulfide under the surface, is added in small portions during 1/2 hour 6,8 g N-(4-chloro-5-chloro carbonyl-2-fluorophenyl)-3,4,5,6-phthalimide. When the addition is completed the cooling bath is removed and the reaction mixture is stirred for another 2 hours at room temperature. The reaction mixture is then condensed in vacuo. The residue is taken up in 50 ml of toluene, then added first with 6 ml of triethylamine then with 2,7 g of 2-bromopropionylnitrile and stirred for 21/2 hours at 50.degree. C. A precipitation forms, which is filtered off. The filtrate is concentrated and taken up in water and ethyl acetate. The aqueous phase is discorded, the organic phase is dried over sodium sulfate and concentrated the residue is purified by chromatography with ethyl acetate/hexane 2:7 over a silicagel column. After evaporating the eluate there one obtains 5,3 g of the title product as colourless oil with a refractory index n.sub.D.sup.20 1,5709.

EXAMPLE 2

Preparation of N-[4-chloro-2-fluoro-5-(triethoxysilylethylthiocarbonyl)phenyl]-3,4,5,6-tetrahydrophthalimide ##STR30##

A solution of 6,8 g of N-(4-chloro-5-chlorocarbonyl-2-fluorophenyl)3,4,5,6-tetrahydrophthalimide is added dropwise, while stirring to a solution, cooled to 0.degree.-5.degree. C. of 5 ml of mercaptoethyltriethoxysilan and 4 ml of triethylamine in 150 ml toluene. After everything is added, the reaction mixture is stirred for 12 hours at room temperature and then poured into 500 ml of water. The organic layer is separated, dried over magnesium sulfate and concentrated in vacuo. The remaining brown oil is purified by chromatography by means of ethyl acetate/hexane 2:7 over a silicagel column.

After evaporation of the solvent there remains 8,6 g of the title product as clear oil with a refractory index n.sub.D.sup.21 1.5358.

In analogy to these examples the compounds listed in Tables 1 and 2 are prepared.

TABLE 1__________________________________________________________________________ ##STR31##No. (R).sub.n AQ phys. data__________________________________________________________________________1.001 -- CH(CH.sub.3)CH.sub.2 OH1.002 -- CH(CH.sub.3)CN n.sub.D.sup.20 1.5709 (example 1)1.003 -- C.sub.2 H.sub.4 OH m.p. 98-99.degree.1.004 -- CH(CH.sub.3)CH.sub.2 Cl1.005 -- C.sub.2 H.sub.4 Cl1.006 -- CH.sub.2 CN1.007 -- CH.sub.2 C(CH.sub.3).sub.2 OH1.008 -- CH.sub.2 SCN1.009 -- C.sub.2 H.sub.4 CN1.010 -- CH(CH.sub.3)CH.sub.2 CN1.011 -- CH(CH.sub.2 OCH.sub.3 )COOCH.sub.3 n.sub.D.sup.24 1.53721.012 -- CH.sub.2 CH(OCH.sub.3)COOCH.sub.31.013 -- CH(CH.sub.3)COOC.sub.2 H.sub.4 OCH.sub.2 CHCH.sub.21.014 -- CH(CN)CH.sub.2 OCH.sub.31.015 -- CH.sub.2 CH(SCH.sub.3)COOCH.sub.31.016 -- CH.sub.2 CHCH.sub.21.017 -- CH.sub.2 CHCHCl1.018 -- CH.sub.2 CClCH.sub.21.019 -- CH.sub.2 CHCHCN1.020 -- CH.sub.2 CCH1.021 -- CH.sub.2 C(CH.sub.3)CHCOOCH.sub.31.022 -- C.sub.2 H.sub.4 N(CH.sub.3).sub.2 m.p. 76-78.degree.1.023 -- C.sub.2 H.sub.4 -pyrrolidino1.024 -- C.sub.2 H.sub.4 -piperidino1.025 -- C.sub.2 H.sub.4 -morpholino1.026 -- CH[N(CH.sub.3).sub.2 ]COOCH.sub.31.027 -- CH(CH.sub.3)CH.sub.2 N(CH.sub.3).sub.21.028 -- CH(CH.sub.3)CO-piperidino resin1.029 -- CH(CH.sub.3)CO-pyrrolidino m.p. 57-60.degree.1.030 -- CH(CH.sub.3)CO-4-methylpiperazino1.031 -- CH(CH.sub.3)CO-morpholino1.032 -- CH(CH.sub.3)CO-2-methylmorpholino n.sub.D.sup.20 1.53421.033 -- CH(CH.sub.3)CO-2,6-dimethylmorpholino1.034 -- CH(CH.sub.3)CO-2-methylpiperidino1.035 -- CH(CH.sub.3)CO-3-methylpiperidino1.036 -- CH(CH.sub.3)CO-4-methylpiperidino1.037 -- CH(CH.sub.3)CON(CH.sub.3)CH.sub.2 CN1.038 -- CH(CH.sub.3)CON(CH.sub.2 CHCH.sub.2).sub.21.039 -- CH(CH.sub.3)COOCH.sub.2 Si(CH.sub.3).sub.31.040 -- CH(CH.sub.3)COOC.sub.2 H.sub.4 Si(CH.sub.3).sub.31.041 -- (CH.sub.3)COONC(CH.sub.3).sub.21.042 -- CH(CH.sub.3)COONcyclopentyl1.043 -- CH(CH.sub.3)COONcyclohexyl1.044 --1,3-dioxolan-2-yleth-1-yl1.045 --1,3-dioxolan-2-ylmethyl m.p. 99-100.degree.1.046 --4-methyl-1,3-dioxolan-2-ylmethyl1.047 --1,3-dioxolan-2-ylpropyl1.048 --2-methyl-1,3-dioxolan-2-ylpropyl1.049 -- C.sub.2 H.sub.4 C(OCH.sub.3).sub.21.050 -- C.sub.2 H.sub.4 C(OC.sub.2 H.sub.5).sub.21.051 -- CH(CH.sub.3)C(OC.sub.2 H.sub.5).sub.21.052 -- CH(CH.sub.3)C(OCH.sub.3).sub.21.053 --2-methyl-1,3-dioxolan-2-ylmethyl1.054 -- C.sub.2 H.sub.4 Si(OC.sub.2 H.sub.5).sub.3 n.sub.D.sup.21 1.5358 (example 2)1.055 -- CH.sub.2 Si(CH.sub.3).sub.3 n.sub.D.sup.22 1.56381.056 -- CH(CH.sub.3)Si(CH.sub.3).sub.31.057 -- C.sub.2 H.sub.4 Si(CH.sub.3).sub.31.058 -- CH(CH.sub.3)CH.sub.2 Si(CH.sub.3).sub.31.059 -- CH(CH.sub.3)PO(OC.sub.2 H.sub.5).sub.21.060 -- CH(CH.sub.3)PO(CH.sub.3)OC.sub.2 H.sub.51.061 -- CH(CH.sub.3)CON(CH.sub.3)SO.sub.2 CH.sub.31.062 -- CH(CH.sub.3)CON(CH.sub.3)SO.sub.2 CH.sub.2 Cl1.063 -- CH.sub.2 CON(CH.sub.3)SO.sub.2 CH.sub.31.064 -- CH(CH.sub.3)CON(CH.sub.2 CHCH.sub.2)SO.sub.2 CH.sub.31.065 -- CH(CH.sub.3)CON(cyclopropyl)SO.sub.2 CH.sub.31.066 -- CH(CH.sub.3)CON[CH(CH.sub.3).sub.2 ]SO.sub.2 CH.sub.31.067 -- CH.sub.2 COCH.sub.31.068 -- CH.sub.2 CO benzyl1.069 -- CH.sub.2 CO phenyl1.070 -- CH.sub.2 COCH.sub.2 OCH.sub.31.071 -- CH(CH.sub.3)COCH.sub.31.072 -- CH(CH.sub.3)COCH.sub.2 COOCH.sub.31.073 -- CH(COCH.sub.3)COOC.sub.2 H.sub.51.074 -- CH(CH.sub.3)COOCH(CH.sub.3)CH.sub.2 SCH.sub.31.075 -- CH(CH.sub.3)COOCH(CH.sub.3)CH.sub.2 SC.sub.2 H.sub.5 n.sub.D.sup.21 1.56201.076 -- CH(CH.sub.3)COOCH(CH.sub.3)CH.sub.2 SC.sub.3 H.sub.7 -n1.077 -- CH(CH.sub.3)COOCH(CH.sub.3)CH.sub.2 SCH(CH.sub.3).sub.21.078 -- CH(CH.sub.3)COOCH(CH.sub.3)CH.sub.2 SC.sub.4 H.sub.9 -n1.079 -- CH(CH.sub.3)COOCH(CH.sub.3)CH.sub.2 SC(CH.sub.3).sub.31.080 -- CH(CH.sub.3)COOCH(CH.sub.3)CH.sub.2 SCH(CH.sub.3)C.sub.2 H.sub.51.081 -- CH(CH.sub.3)CON(CH.sub.3)CH.sub.2 CH(OCH.sub.3).sub.21.082 -- CH(CH.sub.3)CON(CH.sub.3)CH.sub.2 CH(OC.sub.2 H.sub.5).sub.21.083 -- CH(CH.sub.3)COOC.sub.2 H.sub.4 OCH.sub.2 CHCH.sub.21.084 -- CH(COCH.sub.3).sub.21.085 -- CH(CN)COOCH.sub. 31.086 -- CH(OCH.sub.3)COOCH.sub.3 resin__________________________________________________________________________ TABLE 2______________________________________ ##STR32## phys.No. (R).sub.n AQ data______________________________________2.001 -- CH(CH.sub.3)CH.sub.2 OH2.002 -- CH(CH.sub.3)CN2.003 -- C.sub.2 H.sub.4 OH2.004 -- CH(CH.sub.3)CH.sub.2 Cl2.005 -- C.sub.2 H.sub.4 Cl2.006 -- CH.sub.2 CN2.007 -- CH.sub.2 C(CH.sub.3).sub.2 OH2.008 -- CH.sub.2 SCN2.009 -- C.sub.2 H.sub.4 CN2.010 -- CH(CH.sub.3)CH.sub.2 CN2.011 -- CH(CH.sub.2 OCH.sub.3)COOCH.sub.32.012 -- CH.sub.2 CH(OCH.sub. 3)COOCH.sub.32.013 -- CH(CH.sub.3)COOC.sub.2 H.sub.4 OCH.sub.2 CHCH.sub.22.014 -- CH(CN)CH.sub.2 OCH.sub.32.015 -- CH.sub.2 CH(SCH.sub.3)COOCH.sub.32.016 -- CH.sub.2 CHCH.sub.22.017 -- CH.sub.2 CHCHCl2.018 -- CH.sub.2 CClCH.sub.22.019 -- CH.sub.2 CHCHCN2.020 -- CH.sub.2 CCH2.021 -- CH.sub.2 C(CH.sub.3)CHCOOCH.sub.32.022 -- C.sub.2 H.sub.4 N(CH.sub.3).sub.22.023 -- C.sub.2 H.sub.4 -pyrrolidino2.024 -- C.sub.2 H.sub.4 -piperidino2.025 -- C.sub.2 H.sub.4 -morpholino2.026 -- CH[N(CH.sub.3).sub.2 ]COOCH.sub.32.027 -- CH(CH.sub.3)CH.sub.2 N(CH.sub.3).sub.22.028 -- CH(CH.sub.3)CO-piperidino2.029 -- CH(CH.sub.3)CO-pyrrolidino2.030 -- CH(CH.sub.3)CO-4-methylpiperazino2.031 -- CH(CH.sub.3)CO-morpholino2.032 -- CH(CH.sub.3)CO-2-methylmorpholino2.033 -- CH(CH.sub.3)CO-2,6-dimethylmorpholino2.034 -- CH(CH.sub.3)CO-2-methylpiperidino2.035 -- CH(CH.sub.3)CO-3-methylpiperidino2.036 -- CH(CH.sub.3)CO-4-methylpiperidino2.037 -- CH(CH.sub.3)CON(CH.sub.3)CH.sub.2 CN2.038 -- CH(CH.sub.3)CON(CH.sub.2 CHCH.sub.2).sub.22.039 -- CH(CH.sub.3)COOCH.sub.2 Si(CH.sub.3).sub.32.040 -- CH(CH.sub.3)COOC.sub.2 H.sub.4 Si(CH.sub.3).sub.32.041 -- CH(CH.sub.3)COONC(CH.sub.3).sub.22.042 -- CH(CH.sub.3)COONcyclopentyl2.043 -- CH(CH.sub.3)COONcyclohexyl2.044 --1,3-dioxolan-2-yleth-1-yl2.045 --1,3-dioxolan-2-ylmethyl2.046 --4-methyl-1,3-dioxolan-2-ylmethyl2.047 --1,3-dioxolan-2-ylpropyl2.048 --2-methyl-1,3-dioxolan-2-ylpropyl2.049 -- C.sub.2 H.sub.4 C(OCH.sub.3).sub.22.050 -- C.sub.2 H.sub.4 C(OC.sub.2 H.sub.5).sub.22.051 -- CH(CH.sub.3)C(OC.sub.2 H.sub.5).sub.22.052 -- CH(CH.sub.3)C(OCH.sub.3).sub.22.053 --2-methyl-1,3-dioxolan-2-ylmethyl2.054 -- C.sub.2 H.sub.4 Si(OC.sub.2 H.sub.5).sub.32.055 -- CH.sub.2 Si(OH.sub.3).sub.32.056 -- CH(CH.sub.3)Si(CH.sub.3).sub.32.057 -- C.sub.2 H.sub.4 Si(CH.sub.3).sub.32.058 -- CH(CH.sub.3)CH.sub.2 Si(CH.sub.3).sub.32.059 -- CH(CH.sub.3)PO(OC.sub.2 H.sub.5).sub.22.060 -- CH(CH.sub.3)PO(CH.sub.3)OC.sub.2 H.sub.52.061 -- CH(CH.sub.3)CON(CH.sub.3)SO.sub.2 CH.sub.32.062 -- CH(CH.sub.3)CON(CH.sub.3)SO.sub.2 CH.sub.2 Cl2.063 -- CH.sub.2 CON(CH.sub.3)SO.sub.2 CH.sub.32.064 -- CH(CH.sub.3)CON(CH.sub.2 CHCH.sub.2)SO.sub.2 CH.sub.32.065 -- CH(CH.sub.3)CON(cyclopropyl)SO.sub.2 CH.sub.32.066 -- CH(CH.sub.3)CON[CH(CH.sub.3).sub.2 ]SO.sub.2 CH.sub.32.067 -- CH.sub.2 COCH.sub.32.068 -- CH.sub.2 CO benzyl2.069 -- CH.sub.2 CO phenyl2.070 -- CH.sub.2 COCH.sub.2 OCH.sub.32.071 -- CH(CH.sub.3)COCH.sub.32.072 -- CH(CH.sub.3)COCH.sub.2 COOCH.sub.32.073 -- CH(COCH.sub.3)COOC.sub.2 H.sub.52.074 -- CH(CH.sub.3)COOCH(CH.sub.3)CH.sub.2 SCH.sub.32.075 -- CH(CH.sub.3)COOCH(CH.sub.3)CH.sub.2 SC.sub.2 H.sub.52.076 -- CH(CH.sub.3)COOCH(CH.sub.3)CH.sub.2 SC.sub.3 H.sub.7 -n2.077 -- CH(CH.sub.3)COOCH(CH.sub.3)CH.sub.2 SCH(CH.sub.3).sub.22.078 -- CH(CH.sub.3)COOCH(CH.sub.3)CH.sub.2 SC.sub.4 H.sub.9 -n2.079 -- CH(CH.sub.3)COOCH(CH.sub.3)CH.sub.2 SC(CH.sub.3).sub.32.080 -- CH(CH.sub.3)COOCH(CH.sub.3)CH.sub.2 SCH(CH.sub.3)C.sub.2 H.sub.52.081 -- CH(CH.sub.3)CON(CH.sub.3)CH.sub.2 CH(OCH.sub.3).sub.22.082 -- CH(CH.sub.3)CON(CH.sub.3)CH.sub.2 CH(OC.sub.2 H.sub.5).sub.22.083 -- CH(CH.sub.3)COOC.sub.2 H.sub.4 OCH.sub.2 CHCH.sub.22.084 -- CH(COCH.sub.3).sub.22.085 -- CH(CN)COOCH.sub.32.086 -- CH(CH.sub.3)COOCH.sub.3______________________________________

FORMULATION EXAMPLES

EXAMPLE 2

Formulation Examples for compounds of formula I (percentages are by weight)

______________________________________(a) Wettable powders (a) (b) (c)______________________________________compound of Tables 1 and 2 20% 60% 0.5%sodium lignosulfonate 5% 5% 5%sodium laurylsulfate 3% -- --sodium diisobutylnaphthalenesulfonate -- 6% 6%octylphenol polyethylene glycol ether -- 2% 2%(7-8 moles of ethylene oxide)highly dispersed silicic acid 5% 27% 27%kaolin 67% -- --sodium chloride -- -- 59.5%______________________________________ 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. ______________________________________(b) Emulsifiable concentrates (a) (b)______________________________________compound of Tables 1 and 2 10% 1%octylphenol polyethylene glycol ether 3% 3%(4-5 moles of ethylene oxide)calcium dodecylbenzenesulfonate 3% 3%castor oil polyglycol ether 4% 4%(36 moles of ethylene oxide)cyclohexanone 30% 10%xylene mixture 50% 79%______________________________________ Emulsions of any required concentration can be obtained from this concentrate by dilution with water. ______________________________________(c) Dusts (a) (b)______________________________________compound of Tables 1 and 2 0.1% 1%talcum 99.9% --kaolin -- 99%______________________________________ Dusts which are ready for use are obtained by mixing the active ingredient with the carrier, and grinding the mixture in a suitable mill. ______________________________________(d) Extruder granulates (a) (b)______________________________________compound of Tables 1 and 2 10% 1%sodium lignosulfonate 2% 2%carboxymethylcellulose 1% 1%kaolin 87% 96%______________________________________ The active ingredient is mixed and ground with the adjuvants, and the mixture is subsequently moistened with water. The mixture is extruded and then dried in a stream of air. ______________________________________(e) Coated granulate______________________________________compound of Tables 1 and 2 3%polyethylene glycol (mol. wt. 200) 2%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. ______________________________________(f) Suspension concentrates (a) (b)______________________________________compound of Tables 1 and 2 40% 5%ethylene glycol 10% 10%nonylphenol polyethylene glycol ether 6% 1%(15 moles of ethylene oxide)sodium lignosulfonate 10% 5%carboxymethylcellulose 1% 1%37% aqueous formaldehyde solution 0.2% 0.2%silicone oil in the form of a 75% 0.8% 0.8%aqueous emulsionwater 32% 77%______________________________________ 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. ______________________________________(g) Salt solution______________________________________compound of Tables 1 and 2 5%isopropylamine 1%octylphenol polyethylene glycol ether 3%(78 moles of ethylene oxide)water 91%______________________________________

BIOLOGICAL EXAMPLES

EXAMPLE 3

Preemergence herbicidal action

In a greenhouse, immediately after sowing the test plants in seed dishes, 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 of test compound per hectare are applied. The seed dishes are kept in the greenhouse at 22.degree.-25.degree. C. and 50-70% relative humidity and the test is evaluated 3 weeks later. The state of the plants is assessed in accordance with the following rating:

______________________________________1 plant has died or it has not germinated2-4 severe damage (the higher the grade, the less severe the damage)5 moderate damage6-8 slight damage (the higher the grade, the slighter the damage)9 normal growth, as untreated plants______________________________________ The results are shown in Table 3. TABLE 3______________________________________Compoundapplication rate 1.055 1.086g/ha 2000 1000 2000 1000______________________________________PlantBarley 9 9 9 9Wheat 9 9 9 9Maize 9 9 9 9Sorghum 9 9 9 9Soybean 9 9 9 9Cotton 9 9 9 9Sunflower 9 9 9 9Amaranthus retroflexus 1 2 4 4Chenopodum album 1 4 1 4Solanum nigrum 1 1 3 4Chrysanthemum leucom 1 1 1 1Viola tricolor 1 2 2 4Veronic sp 1 1 1 1______________________________________

EXAMPLE 4

Postemergence herbicidal action (contact herbicide)

A number of weeds, both mono- and dicotyledonous, are sprayed postemergence in the 4- to 6-leaf stage with an aqueous active ingredient dispersion at a rate of 4 kg of test compound per hectare and kept at 24.degree.-26.degree. C. and 45-60% relative humidity. The test is evaluated 15 days later in accordance with the rating indicated above. The results are shown in Table 4.

TABLE 4__________________________________________________________________________Compoundapplication rate 1.002 1.003 1.011 1.032 1.045 1.054 1.055 1.086g/ha 1000 500 1000 500 1000 500 1000 500 1000 500 1000 500 1000 500 1000 500__________________________________________________________________________PlantBarley 6 8 9 9 6 7 8 8 7 7 8 8 7 8 8 8Wheat 6 7 8 9 7 8 8 8 8 9 8 8 8 8 8 8Maize 6 7 8 8 7 8 6 7 6 7 7 8 9 9 5 6Sorghum 5 7 8 8 6 7 7 8 7 7 8 8 8 8 8 8Abutilon 1 1 3 4 1 1 1 4 1 1 1 2 1 3 2 2Xanthium 1 1 2 4 1 1 4 4 1 2 1 3 4 4 4 4Solanum nigrum 1 1 2 3 3 4 1 1 1 3 1 1 4 4 2 2Ipumuea purpurea 1 1 3 4 1 1 4 4 1 2 1 1 2 4 4 4Viola tricolor 1 1 4 4 1 1 1 2 1 1 1 2 2 2 3 4__________________________________________________________________________

EXAMPLE 5

Selective herbicidal action in soybeans

Soybeans, grasses and dicotyledoneous weeds are reared in the greenhouse until they have reached after about 2 weeks the 4-leaf-stage. Then they are sprayed with a diluted broth of active substance. The treated plants are then kept in the greenhouse under optimal conditions for growth i.e. 26.degree.-28.degree. C. temperature, 43-60% relative humidity and regular watering. The test is evaluated 21 days after the treatment and the condition of the plants is assessed according to the rating given in example 3. Results are given in Table 5.

TABLE 5__________________________________________________________________________Compoundapplication rate 1.002 1.032 1.045 1.054g/ha 1000 500 250 1000 500 250 1000 500 250 1000 500 250__________________________________________________________________________PlantSoybean 6 6 7 6 7 8 7 7 8 8 8 8Abutilon 1 1 2 1 1 4 1 1 1 1 2 4Sida spinosa 1 1 2 3 4 4 1 4 4 3 4 4Xanthium sp 1 1 1 4 4 4 4 4 4 1 3 4Chenopodium album 2 3 4 4 4 4 l 2 4 2 2 4Solanum nigrum 1 1 1 1 1 1 1 3 4 1 1 1Ipomoea purpurea 1 1 1 4 4 4 1 2 4 1 1 4Sinapis alba 1 3 4 3 4 4 1 3 4 1 4 4Viola tricolor 1 1 1 1 1 2 1 1 1 1 2 4Veronica sp 1 1 1 4 4 4 2 2 4 2 4 4__________________________________________________________________________

EXAMPLE 6

Preemergence herbicidal action

Plastic pots are filled with expanded vermiculite (density: 0.135 g/cm.sup.3 ; water-absorbing capacity: 0.565 l/l). After the non-adsorptive vermiculite has been saturated with an aqueous emulsion in deionised water which contains the test compound in a concentration of 70.8 ppm, seeds of the following plants are sown on the surface: Nasturtium officinalis, Agrostis tenuis, Stellaria media and Digitaria sanguinalis. The pots are then kept in a climatic chamber at 20.degree. C., an illumination of about 20 klux and a relative humidity of 70%. During the germinating phase of 4 to 6 days, the pots are covered with lightpermeable material and watered with deionised water to increase the local humidity. After the 5th day, 0.5% of a commercial liquid fertiliser (Greenzit.RTM.) is added to the water. The test is evaluated 12 days after sowing and the action on the test plants is assessed. The test compounds of Tables 1 and 2 exhibit good to very good herbicidal activity in this test.

EXAMPLE 7

Herbicidal action in rice (paddy rice)

Rice and the weeds Scirpus sp. and Monocharia vag., which occur in water, are sown in plastic beakers (surface: 60 cm.sup.2 ; 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. The rate of application corresponds to a concentration of 0.5 kg of active ingredient per hectare (concentration of the spray mixture=550 l/ha). The beakers are then kept in the greenhouse under optimum growth conditions for rice weeds, i.e. at 25.degree.-30.degree. C. and at high humidity. The evaluation of the tests takes place 3 weeks after application. The state of the plants is assessed in accordance with the rating indicated above. The results are given in Table 6.

TABLE 6______________________________________Plant Scirpus Monochariaapplication Rice sp vaginalisrate g/ha 2000 1000 2000 1000 2000 1000______________________________________Compound1.011 6 8 1 4 1 11.045 6 7 1 1 1 11.054 7 9 1 3 1 11.055 8 9 2 4 1 2______________________________________

EXAMPLE 8

Desiccation and defoliation action

Cotton plants of the Deltapine variety are reared in earthen-ware pots in a greenhouse. After the capsules have formed, the plants are sprayed with an aqueous formulation of compound No. 1 at rates of application corresponding to 1.2, 0.6 and 0.3 kg/ha in field application. Untreated plants act as controls. Evaluation of the test is made 3, 7 and 14 days after application of the active ingredient by determining the degree of defoliation (percentage of fallen leaves) and of desiccation (drying out of the leaves remaining on the plant).

In this test, plants treated with compounds of Tables 1 and 2 at rates of application of 0.6 and 1.2 kg/ha are left after 7 days with only a few dried out leaves (>80% defoliation and dessication).

EXAMPLE 9

Growth inhibition of tropical leguminous cover crops

The test plants (Centrosema plumieri and Centrosema pubescens) are reared until fully grown and then cut back to a height of 60 cm. The plants are sprayed 7 days later with an aqueous emulsion of the test compound. The test plants are kept at 70% relative humidity and 6000 lux artificial light for 14 hours per day, at day temperatures of 27.degree. C. and night temperatures of 21.degree. C. The test is evaluated 4 weeks after application by assessing and weighing the new growth compared with controls and by determining the phytotoxicity.

In this test, a marked reduction in new growth of the plants treated with compounds of Tables 1 and 2 at concentrations of 50 to 3000 g/ha is observed (less than 20% of the new growth of untreated control plants), without damage being caused to the test plants.

EXAMPLE 10

Growth regulation and yield increase of soybeans

Soybeans of the "Hark" variety are sown in plastic containers in an earth/peat/sand mixture (6:3:1). The containers are put into a climatic chamber and the plants develop to the 5-6 trefoil leaf stage after about 5 weeks by optimum control of temperature, light, fertiliser addition, and watering. The plants are then sprayed with an aqueous mixture of a compound of formula I until thoroughly wetted. The concentration corresponds to up to 100 g a.i. per hectare. Evaluation is made about 5 weeks after application. Compared with untreated controls, the compounds of Tables 1 and 2 of the invention markedly increase the number and weight of the harvested siliquae on the leading shoot.

EXAMPLE 11

Growth inhibition of cereals

Summer barley (Hordeum vulgare) and summer rye (Secale) are sown in sterilised soil in plastic beakers in a greenhouse and watered as required. The cereal shoots are treated about 21 days after sowing with an aqueous spray mixture of a compound of Tables 1 and 2. The concentration corresponds to up to 100 g of active ingredient per hectare. Evaluation of the growth of the cereals is made 21 days after application. A comparison with untreated controls shows that the new growth of treated cereal plants is reduced (60-90% of the controls) and that the diameter of the stalks has in some cases increased.

EXAMPLE 12

Growth inhibition of grasses

Seeds of the grasses Lolium perenne, Poa pratensis, Festuca ovina, Dactylis glomerate and Cynodon dactylon are sown in plastic dishes filled with an earth/peat/sand mixture (6:3:1), in a greenhouse, and watered as required. The emergent grasses are cut back weekly to a height of 4 cm, and about 50 days after sowing and 1 day after the last cut are sprayed with an aqueous spray mixture of a compound of Tables 1 and 2. The concentration of test compound corresponds to a rate of application of up to 500 g a.i. per hectare. The growth of the grasses is evaluated 21 days after application. The test compounds of Tables 1 and 2 effect a reduction in new growth in the range of 10-30% in comparison with untreated controls.

Claims

1. A 5-(N-3,4,5,6-tetrahydrophthalimido)benzoic acid thiol ester of formula I ##STR33## wherein n is 0, 1 or 2,

R.sub.1 is C.sub.1 -C.sub.3 alkyl,

R.sub.2 is hydrogen or halogen,

R.sub.3 is halogen,

A is a C.sub.1 -C.sub.4 alkylene bridge, which is unsubstituted or mono- or polysubstituted by C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 alkylthio or cyano,

Q is hydroxyl, halogen, cyano, thiocyanato, C.sub.2 -C.sub.6 alkenyl, C.sub.2 -C.sub.6 haloalkenyl, C.sub.2 -C.sub.6 cyanoalkenyl, C.sub.2 -C.sub.14 alkynyl, or a radical --C(R.sub.4).dbd.CH--COOR.sub.5, --CH(N(R.sub.4) .sub.2)COOR.sub.4, --NR.sub.6 R.sub.7, --COR.sub.8, --CON(R.sub.6)SO.sub.2 CH.sub.3, --N(R.sub.4)CH.sub.2 CN, diallylaminocarbonyl, --Si (R.sub.11).sub.3, --COOCH.sub.2 Si(CH.sub.3).sub.2 C.sub.1 -C.sub.6 alkyl, --COON.dbd.C(R.sub.9).sub.2, --PO(OR.sub.12)--(O).sub.m R.sub.12, --CON(R.sub.4)SO.sub.2 C.sub.1 -C.sub.6 alkyl, --CON(R.sub.4)SO.sub.2 C.sub.1 -C.sub.4 haloalkyl, C.sub.1 -C.sub.6 alkylcarbonyl, a benzoyl or benzylcarbonyl radical whose phenyl ring is unsubstituted, mono- or polysubstituted by halogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 haloalkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 haloalkoxy, cyano or nitro, --COOCH(CH.sub.3)CH.sub.2 SR.sub.4, --CON(R.sub.4)CH.sub.2 C(OC.sub.1 -C.sub.6 alkyl).sub.2, --COO(CH.sub.2).sub.n+1 OC.sub.3 -C.sub.7 alkenyl, --COOC.sub.1 -C.sub.4 cyanoalkyl, --COO--C.sub.1 -C.sub.4 alkylene-N(R.sub.4).sub.2 or C.sub.1 -C.sub.8 alkanoyloxy,

A is a C.sub.1 -C.sub.4 alkylene bridge, which is mono- or polysubstituted by C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 alkylthio or cyano, Q also is COOR.sub.13,

R.sub.4 is hydrogen, C.sub.1 -C.sub.6 alkyl or C.sub.2 -C.sub.6 alkoxyalkyl,

R.sub.5 is C.sub.1 -C.sub.6 alkyl or C.sub.1 -C.sub.6 hydroxyalkyl,

R.sub.6 and R.sub.7 are independently of each other hydrogen, C.sub.1 -C.sub.6 alkyl, C.sub.2 -C.sub.6 alkoxyalkyl, C.sub.3 -C.sub.6 alkenyl, C.sub.3 -C.sub.6 alkenyl, C.sub.3 -C.sub.6 alkynyl or C.sub.3 -C.sub.6 cycloalkyl, 2-furanylmethyl, 2-tetrahydrofuranylmethyl, 2-(5-methyl)-tetrahydrofuranylmethyl or 2-thienylmethyl,

R.sub.8 is a pyrrolidino, piperidino, morpholino, thiomorpholino, 4-methylpiperazino, pyrazolidino, imidazolidino or 1,2,4-triazol radical, which radical is unsubstituted or mono- or disubstituted by C.sub.1 -C.sub.4 alkyl,

R.sub.9 is C.sub.1 -C.sub.6 alkyl or two adjacent R.sub.9 can form a C.sub.2 -C.sub.6 alkylene bridge,

R.sub.11 is C.sub.1 -C.sub.6 alkyl or C.sub.1 -C.sub.6 alkoxy,

R.sub.12 is hydrogen, C.sub.1 -C.sub.6 alkyl, C.sub.2 -C.sub.6 alkenyl, C.sub.3 -C.sub.6 alkynyl C.sub.3 -C.sub.7 cycloalkyl, and

m is zero or 1.

2. 5-(N-3,4,5,6-tetrahydrophthalimido)benzoic acid thiolester according to claim 1 of formula Ia ##STR34## wherein n is zero, 1 or 2, R.sub.1 is C.sub.1 -C.sub.3 alkyl, R.sub.2 is fluorine, R.sub.3 is chlorine or bromine and R.sub.8 is pyrrolidino, piperidino, morpholino, thiomorpholino, 4-methylpiperazino, pyrazolino, imidazolidino or 1,2,4-triazol radical, which is unsubstituted or mono- or disubstituted by C.sub.1 -C.sub.4 alkyl.

3. N-[4-chloro-2-fluoro-5-(2-methylmorpholinocarbonyl-eth-1-yl-thiocarbonyl)phenyl]-3,4,5,6-tetrahydrophthalimide according to claim 1.

4. N-[4-chloro-2-fluoro-5-(2-pyrrolidinocarbonyl-eth-1-yl-thiocarbonyl)phenyl]-3,4,5,6-tetrahydrophthalimide according to claim 1.

5. N-(4-chloro-2-fluoro-5-piperidinocarbonyl-eth-1-yl-thiocarbonyl)phenyl]-3,4,5,6-tetrahydrophthalimide according to claim 1.

6. 5-(N-3,4,5,6-tetrahydrophthalimido)benzoic acid thiolester according to claim 1 of formula Ib ##STR35## wherein n is zero, 1 or 2, R.sub.1 is C.sub.1 -C.sub.3 alkyl, R.sub.2 is fluorine, R.sub.3 is chlorine or bromine, A is a C.sub.1 -C.sub.4 alkylene bridge and the R.sub.a are independently of each other C.sub.1 -C.sub.6 alkyl or together a C.sub.2 -C.sub.6 alkylene bridge.

7. N-[(acetoximecarbonyl-eth-1-ylthiolcarbonyl)-2-fluoro-4-chloro)phenyl]-3,4,5,6-tetrahydrophthalimide according to claim 1.

8. 5-(N-3,4,5,6-tetrahydrophthalimido)benzoic acid thiol ester of formula Ic ##STR36## wherein n is zero, 1 or 2, R.sub.1 is C.sub.1 -C.sub.3 alkyl, R.sub.2 is fluorine, R.sub.3 is chlorine or bromine, A is a C.sub.1 -C.sub.4 alkylene bridge, R.sub.4 is hydrogen, C.sub.1 -C.sub.6 alkyl or C.sub.2 -C.sub.6 alkoxyalkyl and R.sub.10 are independently of each other C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 haloalkyl, or together form a 1,2-ethylene, 1,3-propylene or 1,2-cyclohexane bridge.

9. N-[4-chloro-5-(1,3-dioxolan-2-ylmethylthiocarbonyl)-2-fluorophenyl]3,4,5,6-tetrahydrophthalimide according to claim 8.

10. 5-(N-3,4,5,6-tetrahydrophthalimido)benzoic acid thiolester according to claim 1 of formula Id ##STR37## wherein n is zero, 1 or 2, R.sub.1 is C.sub.1 -C.sub.3 alkyl, R.sub.2 is fluorine, R.sub.3 is chlorine or bromine, A is a C.sub.1 -C.sub.4 alkylene bridge and R.sub.11 are independently of each other C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 alkoxy.

11. N-[4-chloro-2-fluoro-5-(triethoxysilylethylthiocarbonyl)phenyl]-3,4,5,6-tetrahydrophthalimide according to claim 1.

12. N-[4-chloro-2-fluoro-5-(trimethylsilylmethylthiocarbonyl)phenyl]-3,4,5,6-tetrahydrophthalimide according to claim 1.

13. 5-(N-3,4,5,6-tetrahydrophthalimido)benzoic acid thiolester according to claim 1 of formula If ##STR38## wherein n is zero, 1 or 2, R.sub.1 is C.sub.1 -C.sub.3 alkyl, R.sub.2 is fluorine, R.sub.3 is chlorine or bromine, A is a C.sub.1 -C.sub.4 alkylene bridge, and Q.sub.1 is hydroxyl or cyano.

14. N-[4-chloro-5-(1-cyanoeth-1-ylthiocarbonyl)-2-fluorophenyl]-3,4,5,6-tetrahydrophthalimide according to claim 11.

15. N-[4-chloro-2-fluoro-5-(hydroxyethylthiocarbonyl)phenyl]-3,4,5,6-tetrahydrophthalimide according to claim 11.

16. 5-(N-3,4,5,6-tetrahydrophthalimido)-benzoic acid thiolester according to claim 1 of formula Ii ##STR39## wherein n is zero, 1 or 2, R.sub.1 is C.sub.1 -C.sub.3 alkyl, R.sub.2 is fluorine, R.sub.3 is chlorine or bromine, A is a C.sub.1 -C.sub.4 alkylene bridge and R.sub.6 and R.sub.7 are independently of each other hydrogen, C.sub.1 -C.sub.6 alkyl, C.sub.2 -C.sub.6 alkoxyalkyl, C.sub.3 -C.sub.6 alkenyl, C.sub.3 -C.sub.6 alkynyl or C.sub.3 -C.sub.6 cycloalkyl, 2-furanylmethyl, 2-tetrahydrofuranylmethyl, 2-(5-methyl)-tetrahydrofuranylmethyl or 2-thienylmethyl.

17. N-[4-chloro-5(dimethylaminoethylthiocarbonyl)-2-fluorophenyl]-3,4,5,6-tetrahydrophthalimide according to claim 16.

18. 5-(N-3,4,5,6-tetrahydrophthalimido)benzoic acid thiolester according to claim 1 of formula Il ##STR40## wherein n is zero, 1 or 2, R.sub.1 is C.sub.1 -C.sub.3 alkyl, R.sub.2 is fluorine, R.sub.3 is chlorine or bromine, A is a C.sub.1 -C.sub.4 alkylene bridge and R.sub.4 is C.sub.1 -C.sub.6 alkyl or C.sub.2 -C.sub.6 alkoxyalkyl.

19. N-[5-allylthiprop-2-yloxycarbonyleth-1-ylthiocarbonyl)-4-chloro-2-fluorophenyl]-3,4,5,6-tetrahydrophthalimide according to claim 1.

20. 5-(N-3,4,5,6-tetrahydrophthalimido)benzoic acid thiolester according to claim 1 of formula In ##STR41## wherein n is zero, R.sub.2 is fluorine, R.sub.3 is chlorine or bromine and R.sub.13 is C.sub.1 -C.sub.12 alkyl, C.sub.2 -C.sub.6 alkoxyalkyl, C.sub.3 -C.sub.7 alkenyl, C.sub.6 -C.sub.6 cycloalkyl.

21. N-[4-chloro-2-fluoro-5-(1'-methoxycarbonyl-1'-methoxy-methylthiocarbonyl) phenyl]-3,4,5,6-tetrahydrophthalimide according to claim 1.

22. N-[4-chloro-2-fluoro-5-(1'-methoxycarbonyl-2'-methoxymethyl-ethylthio-carbonyl)phenyl]-3,4,5,6-tetrahydrophthalimide according to claim 1.

23. A herbicidal or plant growth regulating composition which contains, as active ingredient, an effective amount of a 5-(N-3,4,5,6-tetrahydrophthalimido)benzoic acid thiol ester of formula I according to claim 1, together with inert carriers or other adjuvants.

24. A method of selectively controlling weeds pre- or postemergence in crops of useful plants, which method comprises treating said useful plants or the crop area thereof with an effective amount of a compound of formula I according to claim 1, or of a composition containing such a compound as the active ingredient.

25. A method of suppressing plant growth beyond the 2-leaf stage, which method comprises treating the plants during their growth with an effective amount of a compound of formula I according to claim 1, or of a composition containing such a compound as the active ingredient.

26. A method of defoliating or desiccating crops of cotton and potatoes in order to facilitate the harvesting thereof, which method comprises treating the crop, shortly before harvesting, with an effective amount of a compound of formula I according to claim 1, or of a composition containing such a compound as the active ingredient.

27. A herbicidal or plant growth regulating composition which contains, as active ingredient, an effective amount of a 5-(N-3,4,5,6-tetrahydrophthalimido)benzoic acid thiol ester of formula Ic according to claim 8 and a carrier.

28. A method of selectively controlling weeds pre- or postemergence in crops of useful plants, which method comprises treating said useful plants or the crop area thereof with an effective amount of a compound of formula Ic according to claim 8.

29. A method of suppressing plant growth beyond the 2-leaf stage, which method comprises treating the plants during their growth with an effective amount of a compound of formula Ic according to claim 8.

30. A method of defoliating or desiccating crops of cotton or potatoes in order to facilitate the harvesting thereof, which method comprises treating said crops, shortly before harvesting, with an effective amount of a compound of formula Ic according to claim 8.