IE57672B1 - Cyclohexanedionecarboxylic acid derivatives with herbicid and plant growth regulating properties - Google Patents

Description

The present invention relates to novel cyclohexanedionecarboxylic acid derivatives with herbicidal and. plantgrowth-regulating properties, to compositions which contain ; those cyclohexanedionecarboxylic acid derivatives, and to the use of said derivatives for selective and total weed t. control and for regulating plant growth.

The novel cyclohexanedionecarboxylic acid derivatives have the formula I A-C 3 'J Lr / \ I tf ® I I . φ A is an -OR2 or -NR3R4 radical, B is hydroxyl or an -NHOR^^ radical, R is C^-Cgalkyl or C^-Cgcycloalkyl, each unsubstituted or substituted by halogen, Cj-C^alkoxv or Cq-C4alkylthio, Rx is C^-Cgalkvl, C1-C5haloalkyl, C3-C6alkenyl, C3-C5- % haloalkenyl or C3-Cgalkynyl, R2, R3 and R4 are each independently hydrogen, C^-Cgalkyl, Cy-Cghaloalkyl, C2-CjQalkoxyalkyl, C2-Cigalkylthioalkyl; C3-Cgalkenyl which is unsubstituted or substituted by halogen, CH-C^alkoxv or C^-C^alkylthio; C3-Cgalkynyl; phenyl or Cj-Cgaralkyl, wherein the phenyl nucleus is unsubstituted or substituted by halogen, C^-C^alkyl, Cj-C4alkoxy, C-j-C4haloalkyl, nitro or cyano, and r3 and R4, together with the nitrogen atom to which they are bonded, also form a 5- or 6-membered heterocyclic ring system which may also contain an oxygen or sulfur atom in the ring, or a metal or ammonium salt of such a cyclohexanedionecarboxylic acid derivative.

In the above definitions the alkyl radicals comprise both straight chain and branched radicals, e.g. methylt, ethyl, propyl, isopropyl, butyl, isobutvl, sec-butyl, tart-butyl, as well as all stereoisomers of the higher homologues. Alkenyl and alkynyl also comprise straight chain and branched radicals, e.g. vinyl, allyl, methallyl, butenyl, methylbutenyl and dimethylbutenyl, efchynyl, propvnyl, butynyl, methylbutynyl and dimethylbutynyl.

Halogen is fluorine, chlorine, bromine or iodine.

The 5- or β-membered heterocyclic ring systems which are formed by R3 and R- together with the nitrogen atom and may also contain an oxygen or sulfur atom in the ring are pyrrole, pyrrolidine, piperidine, morpholine or also thiomorpholine. These rings may be substituted by methyl groups.

The salts of these compounds are obtained with bases. Suitable bases are preferably alkali metal hydroxides, alkaline earth metal hydroxides, iron, copper, nickel and zinc hvroxides, and also ammonia or quaternary Ci-C4alkylammonium or Ci-C^hydroxyalkylammonium bases.

The cyclohexanedionecarboxylic acid derivatives of the formula I are characterised by good herbicidal and plantgrowth-regulating properties. Particularly effective compounds comprise the following groups: - cyclohexane derivatives of the formula la Θ OH SI! 6 wherein A and R are as defined above, and the metal or ammonium salts thereof; the derivatives of the formula la wherein A is an -OR2 radical and R and R2 are as defined above, and the metal and ammonium salts thereof; - the derivatives of the formula la wherein A is an -NR3R4 radical and R, R3 and ΪΑ are as defined above, and the metal and ammonium salts thereof; - the derivatives of the formula la wherein A is as defined above and R is a C3-Cgcycloalkyl radical, and the metal and ammonium salts thereof» Further particularly effective compounds are the cyclohexanediones of the formula lb h’HOR1 I --R A-CII It (lb) wherein A, R and R3 are as defined above, and the metal and ammonium salts thereof; - the derivatives of the formula lb wherein A is an -OR2 radical and R, and R2 are as defined above, and the metal and ammonium salts thereof; - the derivatives of the formula lb wherein A is an -NR3R4 radical and R, rx, r3 and R4 are as defined above, and the metal and ammonium salts thereof.

Preferred individual compounds are: ethyl 4-(l~hydroxybutylidene)-3,5-cyclohexanedionecar· boxylate, isobutyl 4-(1-hydroxybutylidene)-3f5-cyclohexanedicar5 boxy1ates ethyl 4-(1-ethoxyarainobutylidene) 3,5-cyclohexanedionecarboxylate, ethyl 4-(1-allyloxyaminobutylidene) 3,5-cyclohexanedionecarboxylate, ethyl 4—(cyclopropylhydroxymethvlidene)-3,5-cyclohexanedionecarboxvlate, dimethyl 4-(l-ethoxyaminofoutylidene)-3,5-cyclohexanedionecarboxamide, dimethyl 4-(l-allyloxyaminobutylidene)-3,5-cyclohexane15 dionecarboxamide, and the sodium, ammonium and tetramethvTammonium salts thereof.

The cyclohexanedionecarboxylic acid derivatives of the formula I can be obtained in different tautomeric forms.

For example, methyl 4-(1-ethoxyaminofoutvlidene)-3,5-cyclohexanedionecarboxylate exists in the following forms: HSOC.H, II I 2 5 o Ό Some 2-(1-hydroxyalkylidene)-3,5-cyclohexanedione~4carboxylic acids and esters having herbicidal and plantgrowth-regulating properties have already been described in published Japanese Patent Application JP-A-164 5*3/83, The salts of such acids# esters and thioesters and the preparation thereof have since been discussed in greater detail in EP-A-123 001.

The cyclohexanedionecarboxylic acid derivatives of the formula I are prepared in conventional manner by reacting a 3,5-cyclohexanedionecarboxylic acid derivative of the formula II (ΪΪ) A-i wherein A is an ester or amide radical as defined above, with an acid halide of the formula III Hal - COR (III) wherein R is as defined above, in an inert organic solvent and in the presence of a base as acid acceptor, isolating the product so obtained and, if desired, reacting it further with a hydroxylamine of the formula IV HONHRi (IV) wherein R^ is as defined above, in an inert waterimmiscible solvent at boiling temperature under condensation conditions, and isolating the resultant product.

Suitable solvents for these reactions are in particular aromatic hydrocarbons such as benzene, toluene and xylene, and also halogenated hydrocarbons such as chloroform, dichloroethane and carbon tetrachloride.

The reaction temperatures are in the range from room temperature to the boiling point of the reaction mixture. During the addition of acid chloride it may be necessary to cool the reaction vessel.

Suitable acid acceptors are organic and inorganic bases, e.g. pyridine, 4-aminopyridine, collidine, triethylamine, and ammonium, sodium, potassium or calcium carbonate, or the corresponding bicarbonates.

Suitable acid halides of the formula III are mainly acetyl chloride, propionyl chloride, butyryl chloride, valeryl chloride, 3-methoxypropionyl chloride, 2-chloropropionyl chloride, cyclopropanoyl chloride or cyclohexanoyl chloride, and also the corresponding bromides.

Suitable hydroxylamines of the formula IV are mainly the methyl-, ethyl-, chloroethyl-, propyl-, isopropyl-, butyl-, isobutvl-, allyl-, cycloallyl-, methallyl- and propynylhydroxylamines, which may also be used in salt form, e.g. as hydrochloride.

The starting cvclohexanedionecarboxylic acid derivatives of the formula II are obtained on the one hand by hydrogenating 3,5-dihvdroxybenzoic acid with hydrogen and Raney nickel and subsequently esterifving or amidating the acid radical in accordance with the following reaction scheme: OH /\ HO-C-χ J--OH II V O Raney Hi Λ, E HOC-» l‘ li <ϊ» OR esterifi cation or amidation *' i; / \ In the above reaction the keto group may have to be protected, e.g. as enol ether or enamine, q.v. J. Am- Chem. Soc. 78 . 4405 (1956).

However, it is also possible to hydrogenate a 3,5dihydroxybenzoic acid derivative with hydrogen and Raney nickel in accordance with the reaction scheme: A-C II OH I A «Β % -OH Z Z Raney-Hi II a z \ e AC-* ».

II \ZS 0 q,v, Arch. Pharm. 307, 577 (1974).

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, especially in sugar cane, cereals, cotton, soybeans, maize and rice. 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 the formula I are effective at very low rates of application.

In addition, the compounds of formula I have pronounced plant--growth-regulating properties, which can result in an increase in the yield of cultivated plants or harvest crops. Further,, many compounds of formula I have a growthinhibiting action which is dependent on the concentration. The growth of both monocots and dicots is inhibited.

Thus, for example, the growth of leguminosae which are frequently planted as cover crops in tropical regions can be selectively inhibited by the compounds of formula I so that, while soil erosion between the 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 to promote flower formation and fruiting to a greater extent, whilst vegetative growth is inhibited.

Inhibition of the vegetative growth of monocot plants, e.g. grasses or also cultivated plants such as cereals, is sometimes desirable and advantageous. Such a growth inhibition is of economic interest in respect of grasses, inter alia, as, for example, the frequency of cutting in flower gardens, parks, sports fields or road shoulders can thereby be reduced. Of importance too is the inhibition of growth of herbaceous and ligneous plants on road shoulders and near transmission lines, or quite generally in areas in Ο which strong growth is undesirable! The use of growth regulators for inhibiting the growth in height of cereals is also important, as shortening of the stalks reduces or completely eliminates the danger of lodging before harvesting. In addition, growth regulators are able to bring about a strengthening of the stalks in crops of cereals, and this too counteracts lodging.

Further, the compounds of formula I are suitable for preventing stored potatoes from seeding. During winter storage, potatoes often develop sprouts, which result in shrinkage, weight loss and rot.

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

The invention also relates to herbicidal and plant-growthregulating compositions which contain a novel compound of the 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 the formula I are used in unmodified form or, preferably, as compositions together with the adjuvants conventionally employed in the art of formulation, and are therefore formulated in known manner into e.g. 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. 1 The formulations, i.e. the compositions, preparations or mixtures containing the compound (active ingredient) of the formula I and, where appropriate, a solid or liquid adjuvant, are prepared in known manner, e.g. hy homogen5 eously 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, dimethylsulfoxide or dimethylformamide, as well as vegetable oils and 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 the formula I to i 2 be formulated, suitable surface-active conpounds are nonionic, cationic and/or anionic surfactants having good emulsifying, dispersing and wetting properties. The term surfactants” will also be understood, as comprising mixtures of surfactants.

Both 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 , 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 Ce”C22al&yi 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 ox fatty aleohol/ethvlene 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 dodecyIbenzene sulfonic 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-monylphenol with 4 to 14 moles of ethylene oxide, and phospholipids.

Non-ionic surfactants are especially polyglycol ether derivatives of aliphatic or cycloaliphatic alcohols, or saturated or unsaturatad fatty acids and alkylphenols, said derivatives containing 3 to 30 glycol ether groups and 8 to carbon atoms in the (aliphatic) hydrocarbon moiety and 5 to IS carbon atoms in the alkyl moiety of the alkylphenols.

Further suitable non-ionic surfactants are the watersoluble adducts of polyethylene oxide with polypropylene glycol, ethylenediaminopolypropylene glycol and alkylI5 polypropylene 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 nonylphenolpolyethoxvethanols, castor oil polyglycol ethers, polypropvlene/polyethylene oxide adducts, tributylphenoxypolyethanol, polyethylene glycol and octylphenoxvpolyethoxvethanol.

Fatty acid esters of polyoxyethylene sorbitan, such as polyoxyethylene sorbitan trioleate, are also suitable nonionic surfactants.

Cationic surfactants are especially quaternary ammonium salts which contain, as N-substituent, at least one C8~c22 alkyl radical and, as further substituents, lower 4 unsubstituted or halogenated alkyl, benzyl or lower hydroxyalkyl radicals. The salts are preferably in the form of halides, methylsulfates or ethyIsuifates, e.g. stearyltrimethylammoniura chloride or benzyldi(2-chloroethyl )ethylammonium bromide.

The surfactants customarily employed in the art of formulation are described inter alia, in the following publications: McCutcheon’s Detergents and Emulsifiers Annual, MC Publishing Corp., Ridgewood, New Jersey, 1979? J. and M. Ash, ''Encyclopedia of Surfactants, Vol. I-III, Chemical Publishing Co., Inc. New York, 1980-81.

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

Preferred formulations are composed in particular of the following constituents (% = percentage by weight): Emulsifiable concentrates active ingredient: 1 to 20 preferably 5 to 10 % surfactant: 5 to 30 £ preferably 10 to 20 % liquid carrier: 50 to 94 preferably 70 to 85 % Dusts active ingredient: 0.1 to 10 %, preferably 0 .1 to 1 % solid carrier: 99.9 to 90 preferably 99 . 9 to ! 99 % Suspension concentrate active ingredient: 5 to 75 %, preferably 10 to 50 % water: 94 to 25 %, preferably 90 to 30 % surfactant: 1 to 40 preferably 2 to 30 % Wettable powders active ingredient: 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 % Granulates active ingredient: 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 normally from 0.01 to 10 kg/ha, preferably from 0.025 to 5 kg/ha.

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

In the following Examples, temperatures are given in degrees Celsius °C and pressures in millibar mb.

Preparatory Examples: Example 1- Preparation of isobutyl 4-buiyryl-3,5-cyclohexanedionecarboxylate is° II ti / \ ^ OH 2-C,H,n '3 7 compound 1.3 6 a) Isobutvl 3,5-cvclohexanedionecarboxylate A mixture of 50 g of 3,5-cyclohexanedionecarboxylic acid, 150 ml of isobutanol, 30 g of 85 % orthophosphoric acid and 400 ml of toluene is boiled overnight in a water separator. The solution is then concentrated in a rotary evaporator. The residue is taken up in 200 ml of tetrahydrofuran, and the solution is boiled for 2 hours after addition of 100 ml of IN hydrochloric acid. After cooling, ethyl acetate is added. The organic phase is separated, washed with a saturated solution of sodium chloride, dried and concentrated by evaporation. The wax-like residue is recrystallised from ether/hexane and melts at 74-76e. b) Isobutvl 4-butyryl~3,5-cyclohexanedionecarboxylate ml of butyryl chloride are added dropwise to a solution of 60 g of isobutyl 3,5-cyclohexanedionecarboxylate and 25 ml of pyridine in 400 ml of dichloroethane, and the mixture is stirred for a further 15 hours at room temperature. The reaction solution is then filtered and the filtrate is washed with IN hydrochloric acid, dried and concentrated. The O-acylated product so obtained is taken up in 200 ml of dichloroethane, 4 g of 4-dimethylaminopyridine are added, and the reaction mixture is refluxed for 4 hours. The cooled reaction solution is then washed with IN hydrochloric acid, dried and concentrated, and the residue is chromatographed over a small amount of silica gel, affording 51 g of isobutvl 4-butyryl-3,5-cyclohexanedionecarboxylate in the form of a pale oil with refractive index ηθ1 = 1.4907.

Example 2: Preparation of isobutyl 4-(1-allyloxyaminobutylidene)-3,5-cvclohexanedionecarboxylate 7 iso HftC,OC 9 i ii compound 2.5 A mixture of 14 g of isobutyl 4-butyryl-3t5-cyclohexanedionecarboxylate, 6.5 g of O~allylhydroxylamine hydrochloride, 6=5 g of potassium carbonate and 150 ml of chloroform is refluxed for 6 hours. The reaction solution is then washed with IN hydrochloric acid, dried and concentrated, and the residue is chromatographed over a small amount of silica gel with a 1:3 mixture of ethyl acetate/petroleum ether. After removal of the solvent by evaporation there are obtained 6.9 g of isobutyl 4-(1allvloxyaminobutylidene)-3,5-cvclohexanedionecarboxylate in the form of a pale oil with refractive index n^1 = 1.4989.

Example 3: Preparation of dimethyl 4-(1-ethoxyamino15 butylidene)-3,5-cyclohexanedionecarboxamide compound 2.72 (ch3)2ncz V ll a) 18.4 ml of dimethylcarbamoyl chloride are added dropwise, with stirring, to a solution of 15.6 g of cyclohexane-3,5-dione-carboxvlic acid, and the mixture is then stirred for a further 12 hours at room temperature and for 2 hours at boiling temperature under reflux. The cooled reaction mixture is then taken up in 400 ml of ethyl acetate and the organic phase is washed 4 times with 8 brine, dried over magnesium sulfate and concentrated. The residue consists of 13.2 g of crude dimethyl 3-(H,Ndimethylcarbamoyl) -5· oxocyclohex-(3)-ene-carboxamide.

This is dissolved in 300 ml of tetrahydrofuran, δ ml of concentrated hydrochloric acid are added and the solution is stirred for 2 hours at room temperature. The reaction mixture is then washed with brine, dried over magnesium sulfate and concentrated, affording 13.2 g of dimethyl 3,5cyclohexanedionecarboxamide in the form of a resinous substance. Purification by chromatography with hexane/ether over a column of silica gel yields crystals with a melting point of 152°-155C. b) The 13.2 g of dimethyl 3,5-cyclohexanedionecarboxamide are dissolved in 100 ml of ethylene chloride together with 6.9 ml of pyridine. 8.5 ml of butyryl chloride are then added dropwise to this solution with stirring. The ensuing reaction is slightly exothermic. The resultant yellow suspension is stirred for 14 hours at room temperature, then washed with IN hydrochloric acid and brine, dried over magnesium sulfate and concentrated. The residue is dissolved in 100 ml of dichloroethane and refluxed for 2 hours together with 0.5 g of 4-dimethylaminopyridine and 0.1 ml of butyryl chloride. The cooled reaction mixture is subsequently washed with 20 ml of IN hydrochloric acid saturated with sodium chloride, dried over magnesium sulfate and concentrated. The residue is purified by chromatography over a column of silica gel with ethyl acetate as eluant, affording 7.8 g of dimethyl 4-butyrvl3,5-cyclohexanedionecarboxamide in the form of a pale oil. c) A mixture of 4.3 g of the dimethyl 4-bufcyryl~3-cyclohexanedionecarboxamide obtained above, 1.9 g of ethoxvamine hydrochloride, 1.4 g of potassium carbonate in 50 ml of chloroform and 5 ml of methanol is stirred for 24 hours at room temperature. The reaction mixture is then washed with IN hydrochloric acid, dried over magnesium sulfate and concentrated. The residue is an oil which is purified by chromatography over a column of silica gel with ethyl acetate as eluant. Removal of the solvent by evaporation yields an oil which crystallises on standing. 2 g of the title compound with a melting point of 5W-58'C are thus obtained.

Example 4: Preparation of benzyl 3,5 4-(ethoxyaminobutylidene)-3,5-cyclohexanedionecarboxamide 0 NHOC,H ί - 3 compound 2.47 a) A solution of 107 g of 3,5-cyclohexanedionecarboxylic acid and 1 ml of concentrated sulfuric acid in 400 ml of methanol is stirred for 3 hours at room temperature. A crystalline solid precipitates during stirring. Then 400 ml of ether are added and crystals of 3-methoxy~5“Oxocyclohex-3-ene-carboxylic acid precipitate. The precipitate is isolated by filtration and dried in an exsiccator, affording 120 g of product. b) 34 g of 3-methoxy-5-oxo~cyclohex-3-ene-carboxylic acid, 33 g of Ν,N5-carbonyldiimidazole and 300 ml of dichloroethane are mixed and the resultant suspension is stirred for 1 hour at room temperature. Then 22 ml of benzylamine are added dropwise and stirring is continued for 14 hours (overnight) at room temperature. Then IN hydrochloric acid is added to the reaction mixture until the pH is between 3 and 4. The organic phase is separated, washed with brine, dried over magnesium sulfate and concentrated, affording 43.6 g of benzyl 3-methoxy-5-oxy-cvclohex-3-ene-carboxamide 0 in the form of a pale oil. c) 42 g of the above benzyl 3-methoxy-5-Qxy-cyclohex~3~ene~ carboxamide are dissolved in 500 ml of tetrahydrofuran.

Then 0.5 ml of concentrated hydrochloric acid and 10 ml of water are added and. the mixture is stirred for 5 hours at room temperature. The solution is dried over a molecular sieve, affording IS.6 g of crystalline benzyl 3,5-cyclohexanedionecarboxamide. A further 17.8 g of product could be obtained by concentrating the mother liquor. Yield: 34.4 g. Melting point: 178‘-181’. d) 29 g of benzyl 3,5-eyclohaxanedionecarboxamine are treated with butyryl chloride in ethylene chloride in the presence of a small amount of pyridine analogously to Example 3b. The reaction mixture is worked up and then benzyl 4-butyryl-3,5-cyclohexanedionecarboxamide is isolated in the form of a wax-like substance, which crystallises from ether/hexane. Yield: 15 g. Melting point: 126’-128’. e) S g of benzyl 4-butyryl-3,5-cvclohexanedionecarboxamide are reacted with ethoxyamine hydrochloride in chloroform in the presence of potassium carbonate in accordance with Example 3c. The reaction mixture is worked up, affording 2.3 g of crystalline benzyl 4-(l-ethoxyaminobutylidene)3,5-cyclohexanedionecarboxamide with a melting pont of 88’—90’.

The following compounds are prepared by procedures analogous to those described in the foregoing Examples: 1 OH (Μ ) I .C-R '/ Υ \> II ο Table 1 No. Α a & Phys, data s 1 1 Δ β A. OCR, 3 C,H..n 3 / 1.2 oc2K5 C,H^n 3 / 27 t»D 1.5060 1.3 OC,Kn iso t® V Cyiyii n£' 1.4907 Ex. 1 1.4 OCH7SCH3 C3H?n 25 tip 1.5193 1.5 OC-H.SCH, κ & J C.H„n 3 / 1.6 OCH.OCH C,H,n 2 4 3 3 7 1.7OC3H7l C3H2n 25 tr 1.4998 D 1.8 °c3h6ci C_H,n 3 7 2.9 OCH —( C,H„rs 2 \ / erne 3 / 1.10 OCH--' θ C„H,n 2 \ / 3 7 \ OCH3 1.11 OCH,CH“CH2C3H7r 1.12 OCH2CC1=CH2 CjH^n 1.13 OCH2C«CH C3H?n 1.14 OCH, C-H,,n 3 6 13 nJ0 1.5330 1.15 oc2h5 Cyclopropyl 1.2 6 OCH3 Cyclohexyl 1.17OC6H23 ch3 1.18 OCH2SCH3C«3 1.19OC2H5 ch,sch3 tt»/ °C2H5 c,e.ock, I « j cere. CHC1CH. 3 nh7C3H7n nh2 f* w V» K(CH3), C «Η «,ία J / K(CH3), C3H.i iso W NHCJi^ isoC5S n(ch2-ch-ch,)? Cyclopropy nhch2-c=ch CH,0CH, ft —< « NHCH,-·; > CJUn KHCH / a / \θ„ C2H4C1 k(ch3)ch2~Y c2h4oc2h5 •2h4sc2h5 Piperidino Morpholino OC2H5 °c2h5 OCaH9 iso OC.H. iso 4 9 n(ch3)3 NH, °C2H5 oc2h5 OCH3 °c2h5C?9 iso C,K„ iso 3 / C,H _n o 13 c3H?n C3H?n C Η n C3»7n C3H7n c,h5 CH, Κι NH / · « Ms i 2a χ(αφ/ Na’ Cyclobutyl Cyclobutyl Cyclopentyl c Wo. Λ R Phys, data 1.46 OCH. 3 Cyclopetnyl 1.47 OC,S5 Cyclohexyl 1.68 OCH. i Cyclohexy1 j 1.69 W(CH3), Cyclopropyl m.p. Χ09-Π2'” (wax) l.SO φ —» flb ) Λ ΝΗΟΗ,-*ζ Ν» Cyclopropyl I m.p. 130-144'’ Φ wa α> wax E51 ι» “ Λ κΗ-*ς Cyclopropyl φ SK ® 1.52 «η -= ® Cyclopropyl \γ3 1.53 N(CH3)OCH3 C3H7n oi 1 1.56 N(CH3)OCH3C2H5 1.55 Φ·» ® Α ΝΗ-» · OJ cal Wi C3H7n m.p. 123-127* 1.56 Λί · ® Α ΝΗ-*ς ,* 1» R >·> ch3 1.57 ® · ® // ΝΗ-«ζ X ® Μ ι»C6H13n 1.58 IB ™ ‘Β ΚΗ-< > ® β Λ ο,Η,αΚαφ, ---~~ .mil 4 $o. A R Phys, data { i 1.74 3 Λ c,ks m.p. 82-83* Ϊ § 1.75 KHCEL 3 CJ3„n 1.75 H(CH3)C,H5 C,H,b 3 j 1 1.77 fi(CH3)C,B5 C Xi 3 / t! 1.78 w(ch3)c,h5 Cyclopropyl | 1.79 «Vz ρ H « IB A &β 5 il m.p. 70-72* 6 Table 2 hoR ,R1 R nor, II ' / \ 4 • i A-CZ V»Z S II 0 No Λ RR1 2.1 OCH3C2H5 2.2 °C2H5 C^^n.C2H5 2.3 oc2h5 CH,CH-CH, 2.4 OC.Hn iso CJLn J / SS 2.5 OC£H9 iso SV CH2CH«CH2 2.8 OCH,SCH3 C3Hyn SS 2.7 OCH2SCH3 C3H?n CH,-C»CH 2.8 OC3H? iso SV SS 2.9 OC3H? iso SV CH,-CH«CH? 2.10 OCjH? iso SS CHjCCl-CH, 2.11 OC.HSCH C-H n C-H- 2 4 3 3 7 2 5 2.12 oWch3 03Η?η CH2-CH-CH, 2.13 oc2h^sch3 C H?nC2H4Cl 2.15 oc,ha°ch3 SS SS 2.16 oc3h6ci SS SS 2.17 X*“’x OCH,-< > C,H,n C-H, 2 \ X 3 7 2 5 β W A β 2.18 X X 0CH2-< > C3H?n CH,-CH-CH, β TOW <5 —. Λ 2.19 X X OCH,-·' > C.H,n C.H.,n 2 X / 3 7 6 1 > ® rtf a X och3 2.20 OCH2CH=CH2 SSC6H13n Phys, data n, nD 1.5002 27 9 ι ςι ι Ί A · J A A A, 1.4929 1.4989 D 27 nD Example 2 1.5198 D D 1.5003 1.5088 7 No. ARl Phvs. data 2.21 OCH2-CH“CH, 3 /cx a 2.22OC2H4Cl CJiLn 3 l CH2-C-CH, 2.23 OCH2CC1-CH2 C,H,n 3 / C,K£C1 2.24 OCH,-C‘CH C,K,- iso 6 13 2.25 OCH, CzH,,n C„H, 3 6 13 2 5 2.26OC2H5 Cyclopropyl ch,~ch»ch2 2.27 OCFL· 3 Cyclohexyl C,Hr 2 5 Z.28 OC.H, _n CH.. 3 C/ΚαΉ & 13 2.29 och,sch3 % C^Hq sec 2.30 °c,h5 CK,SCH3C2H5 2.31 oc,h5 c2h4och3 CH,-C“CH 2.32 0C,Ho cere. chci-ch3 c,h5 2.33 NH2 C,H-.Si 3 /C2H5 2.34 NH, CH,-CH-CH, m.p. 127-129* 2.35 NH2C2H5C2H5 2.36 nh2C2H5 CH2-CC1-CH, 2.37 N(CH-.)-, J 4. C3H?aC2H5 m.p. 54-58“ 2.38 N(CH,), □ X C-H«n 3 I CH2-CH-CH, m.p. 59-65 2.39 n(ch3), ch3 2.40 κ<αψ2 C3H7iWr 2.41 NHC^HQ iso CjhyftC2H5 m.p. 88-90 2.4? NHC6H9 isoC3H7n CH3 2.43NHC4H9 iso C3H7n CH,CH-CH, H.p. 100-102* 2.44NHC4Ho isoCH3 CH,C»CH 2.45 N(CH^-CH-CH,), Cyclopropyl C2«5 2.46 NHCH -CH“CH 2 ch,och3C5HllSeC 2.47 NHCH,-»' <£ \ /C3H7a c,h5 m.p. 116-119* Example 14 2.48 I» j « NHCH -·* X 2 \ / W1 W X I • 8 .0 Phys. data v2 4 2 4 2 3 HHC,H^0Cl(, j C3H?n SS NHC_HfSCH« 1 2 m 3C?5 i5° CH, Piperidino C-H.I 3 1 CH,-CH-CH, Morpholino V3n SS oc?h5 C,H,n 3 7C2K5 Ks.OC2H5 C,H,n 3 7 CH,-CH-CH, X OC^H^ iso j C-H-n 3 Ί SS 1 — Cu 0C,H9 iso SV ch2-ch«ch2 XH, N(CH3)2 C.H.n 3 / ch,-ch-ch2 Na ™2 SS ch,-cci-ch2 Πρ° 1.5077 °c2h5 ch3 SS N(CH_)0CK, 3 3 C — H - tn 3 / SS 25 1.5122 N(CH3)OCH3 C3H?n CH,CH»CH2 N(CH,)0CK, 3 3 C,H,n 3 7 CH,CH»CHCl oi 1 k(c2h5), SV C H 2 5 wax n2h5)2 SV CH,CH-CH2 »3)2 Cyc Xo-C2H5 propyl NH—ζ Cyclo- CH2CH’C^ φ tw propyl N(CH3)OCH3 SS SS KHCH ,— X x» SSis£> SS » —· β ί > e bi a Cyclo- propyl CH,CH-CH, // \ z' CjHjR j I C,h5 9 Ko. AR © ir Phys, data 2.72 X ΜΗ-» '·' \ Z ty at 3 / j CH,CH-CH2 wax Example 3 2.73 z KH1—# ® \ Z ty SM $ CH, 3 CH,CH«CH, 2.74 Hl·» 1» 4 \ \ zcsH»a 2.75 C Η n J 7 C,K- V C‘3 2.76 90— ty ΝΗ-·ζ z “0CH3 «0ί·1 I<| CJLjs o 13C2H5 2.77 'li — «I if jiH-,Ζ X-CI «1Μ tyC6H13n CH,CH-CH? 2.78 ® — tH A N(CH3)-»^ tyse wC6H13a ch,ch»ch2 2.79 Cyclopropy latninoC6H13nC2H5 2.80 whc6h13« ch3 C^Jij 2.81 oh— co A ΝΗ-·ζ ty OR gp C3H?n CH^CH-CHCl 2.82 n(ch3)2C3K7n ch7ch»chci 2.83 tD·-* « ΝΗΟΗ,-*ζ C H 'Π 3 7 CH2CH-CHC1 2.84 nhc2h^sch3 CJM 3 /C2H5 61-67 2.85 nhWch3 C,H,n 3 / CH2CH«CH, 2.86 micjrscH. l k 3 C»&Ln 3 7 CH2CH“CHC1 Ο 1 iiso« 1R I ll ? a 1 1 i ,e ft ft Phys. data. 2.87| N(CH3>, ij Cyclopropyll ί CH,CH“CH7 2.8sj M(CK3), CJLsa j / !! ch7ch-ch7 oil 2.89 N(CH3>7 C ! a li, 3'7^ IS ii] SV m.p. 67-70* 5 2.90 N(CH3)o C ?% ί b 13 m.p. 65-68* 2.91 N(CH3)7 Π C 1« SS 2.92 H(CH3)2 C M u2 *5 CK2CH-CH, m.p. 82-83* 2.93 N(CH3)2 C.H, a 13 C H 2°5 2.94 N(CH3)2 CjH,., n CH,CH-CH2 m.p. 64-66* 10 2.95 < i β — ® SV SS m.p. (wax ) 77-85* 2.96 <.! W ch7-ck»ch7 2. 97 CH,-CHCHC1 2.98 NHCH3 SV C H 2 5 2.99 NHCH3 CH7CH-CH2 15 2.100 NHCU3 CH* 3 m.p. 13Q-141· ? a - a 2.101 N(CH3)-”^ C-H-a 3 z ch7ch-ch7 m.p. 52-56* 2.102 n(ch3>-·' y ene C M « w*£o^, M 3 /C2H5 m.p. 93-95* 2.103 N(CH,CH“CH,), SV SS 20 2.104 n(ch2ch-ch2)2 C.H^n 3 7 C«7CH»CH2 oil 2.105 N(CH.CH=CH_), Λ. Ζ Z C « n 3 7 CH-CH-CHCl 2 oil 2.106 N(CH,CH“CH2)2 C-H^n 3 7CS 1 Wo. A R,Λ1 c*5 -] Phys . data | 2.107 MHCK, CkriL 2.106 mien. j C„H„rsi 3 / F Β» / ®“λ 2. IOS HKCH, 3C5Hlln ch,ch-ch, 2.11C f*KCH. 3 ^6^13° 0, si — bji 4 9 i 2.113 nhc,h4sck3C2H5 ch,ch-ch, I 2.112 hhc^sc^x C-Eka 3 s CH,CH»CH, ft1 i 2.112 KHC.H, SC.lki 2 4 3 / Cta e»»* a 3 7 C,Hon » 2.114 N(CH3)C2H5 el ch,ch»ch, 2-115 w(ch3)c,h5cAa β», 3? 2. ne K(CH3)C7H5 CH./n 3 / CH,CH-CH,Cl 2.11/ N(CH3)2 ,nC2K5 2 gxampXe 5: Formulation Examples for active ingredients of the formula I ?% =-Percentage bv weight) a) wettable powders a) active ingredient 20 % sodium lignosulfonate 5 % sodium laurylsulfate 3 % sodium diisobutylnaphthalenesulfonate octylphenol polyethylene glycol ether (7-8 moles of ethylene oxide) highly dispersed silicic acid 5 % kaolin 67 % sodium chloride b) c) SO % 0.5 % % 5 % % 6 % % 2 % % 27 % 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 any desired concentration. b) Emulsifiable concentrates active ingredient octylphenol polyethylene glycol ether (4-5 moles of ethylene oxide) calcium dodecylbenzenesulfonate castor oil polyglycoi ether (36 moles of ethylene oxide) cyclohexanone xylene mixture a) b) % 1 % % 3 % % 3 % % 4 % % 10 % % 79 % Emulsions of any desired concentration can be obtained from this concentrate by dilution with water. 3 c) active ingredient talcum kaolin a) fo) 0.1 % 1 % 99.9 % % Dusts which are ready for use are obtained by nixing the active ingredient with the carrier and grinding the mixture in a suitable mill. d) Extruder granulate active ingredient sodium lignosulfonate carboxymethylcellulose kaolin a) % % % 87 % b) % 2 % 1 % % 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. e) Coated granulate active ingredient 3 % polyethylene glycol (MW 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. 4 active ingredient ethylene glycol nonylphenol polyethylene glycol ether (15 moles of ethylene oxide) sodium 1ignosulfonate carboxymethylcellulose 37 % aqueous formaldehyde solution silicone oil in the form of a 75 % agueous emulsion water a) % % % % 0.2 % 0.8 % 32 % b) % 10 % 0.2 % 0.8 % 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 active ingredient 5 % isopropylamine 1 % octylphenol polyethylene glycol ether (78 moles of ethylene oxide) 3 % water 91 % Example 6: Preemergence herbicidal activity Plant seeds are sown in flower pots (diameter 11 cm) in a greenhouse. Immediately afterwards the surface of the soil is treated with an aqueous emulsion of the test compound at a concentration of 4 kg of active ingredient per hectare. The pots are then kept in the greenhouse at a temperature of 22°~25°C and 50 to 70% relative humidity. The test is evaluated 3 weeks later and assessment of the action on the test plants is made in accordance with the following rating: : plant has not germinated or has totally withered 2-3 : very pronounced action 4-6 : medium action 7-8 : poor action : no action (as untreated control) The results are as follows: Pl ant: sativa Setaria ita1ica Sinapis alba Stellaria med i a Compound 2.37 1 1 c 0 X 2.47 1 1 9 9 2.61 1 1 9 9 2.63 3 X 9 9 2.64 1 2 8 8 Example 7: Herbicidal activity on postemerqence application of the active ingredients Various cultivated plants and weeds are reared from seeds in pots in a greenhouse until they have reached the 4- to 5-leaf stage. The plants are then sprayed with an aqueous emulsion of test compound (obtained from a 25% emulsifiable concentrate) at a concentration of 4 kg/ha. The treated plants are then kept under optimum conditions of light, regular watering, temperature (22‘-25’C), and relative humidity (50-70%). The test is evaluated 15 days after treatment in accordance with the above rating. The results are as follows: 6 Plant: Aven* saliva Setsris italiea Loiium perenns Solatium lycopet- sicura Sinspis elb& Stellasis media Fhaseolus vulgaris Compound 1 2.37 1 2 2 0 8 8 7 j 2.47 2 4 2 4 6 8 o 2.61 1 2 2 7 7 8 9 2.63 1 1 2 8 5 8 5 2.64 I 1 2 4 / 8 0 w i ! Example 8: Growth inhibition of tropical 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’ and night temperatures of 21°C. The test is evaluated 4 weeks after application by assessing and weighing the new growth compared with the control and by determining the phytotoxicity. In this test a marked reduction in new growth of the plants treated with compounds of the formula I is observed (less than 20 % of the new growth of untreated control plants), without damage being caused to the test plants.

Example 9: Growth regulation 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, lighting, fertiliser addition and watering. The plants are then sprayed with 7 an aqueous mixture of a compound of the formula I until thoroughly wetted» The concentration is up to 100 g a.i. per hectare. Evaluation is made about 5 weeks after application of the active ingredient. Compared with ’ untreated controls,, the compounds of the formula I bring about a marked increase in the number and weight of the harvested siliques on the leading shoot.

Example 10: Growth inhibition of cereals Summer barley (Hordeum vulgare) and summer rye (Secale) are 10 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 the formula I. The concentration is 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 growth of the treated plants is reduced (60-SO % of the controls) and that the diameter of the stalks has in some cases increased.

Example 11: 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 the formula I. The concentration of test compound corresponds to a rate of application of up to 100 g of active ingredient per hectare. The growth of the grasses is evaluated 21 days after application.

The test compounds effect a reduction in new growth of about 10-30 % in comparison with the untreated control.

Claims (32)

CLAIMS :

1. A cyclohexanedionecarboxylic acid derivative of the formula I A-C II β <® I a (X) wherein A is an -OR 2 or -NR3R4 radical, B is hydroxyl or an -NHORi radical, R is Cj-Cgalkyl or C 3 -C 6 cycloalkyl, each unsubstituted or substituted by halogen, Cj-C^alkoxy or Cj-C^alkylthio, Rj is Cj-C 6 alkyl, Ci-Cghaloalkyl, C 3 -C 6 alkenyl, C 3 -Cghaloalke.nyl or C 3 -Cgalkynvl, R 2 , R 3 and R4 are each independently hydrogen, Cj-Cgalkvl, Cj-Cghaloalkyl, C 2 -Ci O alkoxvalkyl, C 2 -C 10 alkylthioalkyl; C 3 -Cgalkenvl which is unsubstituted or substituted by halogen, Cj-C^alkoxv or Cj~C 4 alkylthio; C 3 -Cgalkynyl; phenyl or Ci-Cgaralkyl, wherein the phenyl nucleus is unsubstituted or substituted by halogen, CjC^alkyl, Cj-C^alkoxv, Ci -C^haloalkyl, nitro or cyano, and R 3 and R 4 , together with the nitrogen atom to which they are bonded, also form a 5~ or 6-membered heterocyclic ring system which may also contain an oxygen or sulfur atom in the ring, or a metal or ammonium salt of such a cyclohexanedionecarboxylic acid derivative.

2. A cyclohexanedionecarboxylic acid derivative according to claim 1 of the formula la 3. 9 0 OH ll ι wherein A and R are as defined in claim 1, or a metal or ammonium salt thereof.

3. A c yclohexanedionecarboxvlic acid derivative according to claim 2. wherein A is an -0R 2 radical and R and R 2 are as defined in claim 1, or a metal or ammonium salt thereof.

4. A cyclohexanedionecarboxylic acid derivative according to claim 2, wherein A is an -NRjR^ radical and R, R3 and R4 are as defined in claim 1, or a metal or ammonium salt thereof.

5. A cyclohexanedionecarboxylic acid derivative according to claim 2, wherein A is as defined in claim 1 and R is a C 3 -C 6 cycloalkyl radical, or a metal or ammonium salt thereof.

6. A cyclohexanedionecarboxylic acid derivative according to claim 1 of the formula lb A-CII (lb) wherein A, R and Ri are as defined in claim 1, or a metal or quaternary ammonium salt thereof.

7. A cyclohexanedionecarboxylic acid derivative according to claim 6, wherein A is an -or 2 radical and R, Rl and R 2 are as defined in claim 1. or a metal or quater4 0 nary ammonium salt thereof.

8. A cyclohexanedionecarboxylic acid derivative according to claim 6, wherein A is an -NR 3 R 4 radical and R, R x , R 3 and R 4 are as defined in claim 1, or a metal or quaternary ammonium salt thereof.

9. Ethyl 4-butyryl-3#5-cyclohexanedionecarboxylate according to claim 2.

10. Isobutyl 4-butvryl-3,5-cyclohexanedionecarboxylate according to claim 2.

11. Ethyl 4-(cyclopropylhydroxymethylidene)-3,5-cyclohexanedionecarboxylate according to claim 2.

12. Dimethyl 4-(1-ethoxyaminobutylidene)-3,5-cyclohexanedionecarboxamide according to claim 6.

13. Diethyl 4-(l-allyloxvaminobutylidene)-3,5-cyclohexanedionecarboxamide according to claim 6.

14. Benzyl 4-(l-ethoxyaminobutylidene) -3,5-cyclohexanedionecarboxamide according to claim 6.

15. Isobutyl 4-(1-allyloxyaminobutylidene)-3,5-cyclohexanedionecarboxylate according to claim 6.

16. A process for the preparation of a cyclohexanedionecarboxylic acid derivative of the formula I according to claim 1, which comprises reacting a 3,5-cyclohexanedionecarboxylic acid derivative of the formula II i ο II /\ (Ιϊ) wherein A is an ester or amide radical as defined in claim 1, with an acid halide of the formula III Hal - COR (III) wherein R is as defined in claim 1, in an inert organic solvent and in the presence of a base as acid acceptor, isolating the product so obtained and, if desired, reacting it further with a hydroxylamine of the formula IV HOWHR X (IV) wherein R^ is as defined above, in an inert organic solvent at boiling temperature under condensation conditions, and isolating the resultant product.

17. A herbicidal and plant-growth-regulating composition, which contains, as active ingredient, at least one cyclohexanedionecarboxylic acid derivative of the formula I according to claim 1, together with carriers and/or other adjuvants .

18. The use of the cyclohexanedionecarboxylic acid derivatives of the formula I according to claim 1, or of compositions containing such compounds, for controlling undesirable plant growth.

19. The use of the cyclohexanedionecarboxylic acid derivatives of the formula I according to claim 1, or of compositions containing such compounds, for regulating plant growth. 4 2 the cyclohexanedionecarboxylic acid formula I according to claim 1, or of ining such compounds, for inhibiting the

20. The use ox derivatives of the compositions conta growth of grasses.

21. » A method of selectively controlling weeds pre- or postemergence in crops of useful plants, which comprises treating the useful plants or the locus thereof with an effective amount of a cyclohexanedionecarboxylic acid derivative of the formula I according to claim 1, or of a composition containing such a derivative.

22. A method of selectively controlling weed grasses pre- and postemergence in crops of useful plants, which comprises treating the useful plants or the locus thereof with an effective amount of a cyclohexanedionecarboxylic acid derivative of the formula I according to claim 1, or of a composition containing such a derivative.

23. » A method of regulating plant growth, which comprises treating plants, parts of plants or seeds with an effective amount of a cyclohexanedionecarboxylic acid ester of the formula I according to claim 1, or of a composition containing such a derivative.

24. The use of the cyclohexanedionecarboxylic acid derivatives of the formula I, or of compositions containing such compounds, for inhibiting plant growth beyond the 2-leaf stage, wherein the active ingredients are applied pre-emergence.

25. The use according to claim 22 in crops of sugar cane, cereals, maize, soybeans, rice and cotton. 4 3

26. The use of the cyclohexanedionecarboxylic acid derivatives of the formula Ϊ according to claim 1, or of compositions containing such compounds, for regulating the growth of cultivated plants for the purpose of increasing yield.

27. The use according to claim 26 in crops of soybeans.

28. The use according to claim 24 in leguminous cover crops.

29. A compound according to Claim 1, substantially as hereinbefore described with particular reference to the accompanying Preparatory Examples.

30. A process for the preparation of a compound according to Claim 1, substantially as hereinbefore described with particular reference to the accompanying Preparatory Examples.

31. A compound according to Claim 1, whenever prepared by a process claimed in Claim 16 or 30.

32. A herbicidal and plant-growth-regulating composition according to Claim 17, substantially as hereinbefore described with particular reference to the accompanying Formulation Examples.