Cyclohexenon derivatives, process for their preparation and their use in combating the growth of undesirable plants.

The invention relates to new cyclohexenone derivatives, processes for their preparation, herbicides which contain these compounds as an active ingredient, and a process for controlling unwanted vegetation.

It is known from DE-A-2 439 1O4 to use cyclohexenone derivatives to combat unwanted grasses in broadleaved crops. Furthermore, DE-A-3 121 355, DE-A-3 123 312 and DE-A-3 239 O71 describe heterocyclically substituted derivatives.

There have now been new cyclohexenone derivatives of the formula I.<chemistry id="chem0001" num="0001"><img file="EP0218233A2_D0001.tif" /></chemistry> in the R¹ 2-fluoroethyl, 2-chloroethyl, but-2-en-2-yl, methoxymethyl or methoxyethyl, R² C₁-C₄-alkyl, preferably C₂- or C₃-alkyl, R³ 2-isopropyl-1,3-dioxepan-5-yl, tetrahydrothiopyran-3-yl, tetrahydropyran-3-yl, tetrahydropyran-4-yl, 3-methyltetrahydropyran-4-yl, pyrid-3-yl, tetrahydrofuran-3 -yl, or 4a, 7,8,8a-tetrahydro-2H, 5H-pyrano [4,3-b] pyran-3-yl, and R₄ is hydrogen, C₁-C₂₀-alkylcarbonyl, C₂-C₂₀-alkenylcarbonyl, which preferably each has a CC double bond, benzoyl, which is optionally substituted by C₁-C₈-alkyl, C₁-C₄-trialkylsilyl, C₁-C₄-alkylsulfonyl, phenylsulfonyl which is optionally substituted by C₁-C₄-alkyl, means C₁-C₄-dialkylphosphono or C₁-C₄-dialkylthiophosphono, such as Salts of these compounds were found.

The new cyclohexenone derivatives show a good herbicidal activity, preferably against species from the family or grasses (Gramineae).

The compounds of formula I can occur in several tautomeric forms, all of which are encompassed by the claim. For example, the compounds with R⁴ = hydrogen can occur, inter alia, in the following tautomeric forms:<chemistry id="chem0002" num="0002"><img file="EP0218233A2_D0002.tif" /></chemistry>

In the event that R 1 is but-2-en-2-yl, this includes both the E and the Z isomers.

R² in formula I is, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl or tert-butyl.

R⁴ in formula I is, for example, hydrogen; Acetyl, propionyl, acroyl, butyryl, isobutyryl, pivaloyl, valeroyl, caproyl, caprinoyl, lauroyl, palmitoyl, stearoyl, oleoyl; Benzoyl, 4-methylbenzoyl, 4-hexylbenzoyl; Trimethylsilyl, triethlsilyl; Methylsulfonyl, ethylsulfonyl; Benzoylsulfonyl, 4-methylphenylsulfonyl; Diethylphosphono or Diethylthiophosphono.

Suitable salts of the compounds of the formula I are agriculturally useful salts, for example the alkali metal salts, in particular the potassium or sodium salts, alkaline earth metal salts, in particular calcium and magnesium salts, manganese, copper, zinc or iron salts and ammonium, sulfonium and phosphonium salts Consideration.

The new compounds of formula I can by reacting tricarbonyl compounds of formula II<chemistry id="chem0003" num="0003"><img file="EP0218233A2_D0003.tif" /></chemistry> in which R² and R³ each have the abovementioned meaning, first with an ammonium compound of the formula R¹O-NH₃Y, in which R¹ has the abovementioned meaning and Y for an anion, for example for a halide, such as fluoride, chloride, bromide or iodide, for carbonate or represents sulfate, and then, in the event that R⁴ is not hydrogen, by reaction with a compound R⁴X in which R⁴, with the exception of hydrogen, has the abovementioned meaning and X represents a leaving group, optionally in the presence of an inert solvent.

The reaction with the ammonium compound is advantageously carried out in a heterogeneous phase in an inert diluent at a temperature between 0 and 80 ° C. or between 0 ° C. and the boiling point of the reaction mixture in the presence of a base. Suitable bases are, for example, the carbonates, hydrogen carbonates, acetates, alkanolates, hydroxides or oxides of alkali or alkaline earth metals, in particular of sodium, potassium, magnesium, calcium. Organic bases such as pyridine or tertiary amines can also be used.

Inert diluents for this reaction step are, for example, dimethyl sulfoxide, alcohols, such as methanol, ethanol or isopropanol, benzene, optionally chlorinated hydrocarbons, such as chloroform, dichloroethane, hexane or cyclohexane; Carboxylic acid esters, such as ethyl acetate; or ethers, such as dioxane or tetrahydrofuran.

The implementation is finished after a few hours. The reaction product can then be isolated by concentrating the mixture, adding water and extracting with a non-polar solvent such as methylene chloride and distilling off the solvent under reduced pressure.

Instead of with an ammonium compound, the tricarbonyl compounds of the formula II can also initially with a hydroxylamine of the formula R¹O-NH₂, in which R¹ has the meaning given above, in inert diluents at a temperature between 0 ° C and the boiling point of the reaction mixture, in particular between 15 and 7O ° C. If appropriate, the hydroxylamine can be used as an aqueous solution.

Suitable solvents for this reaction are, for example, alcohols, such as methanol, ethanol, isopropanol or cyclohexanol; optionally chlorinated hydrocarbons, such as hexane, cyclohexane, methylene chloride, toluene or dichloroethane; Carboxylic acid esters, such as ethyl acetate, nitriles, such as acetonitrile; or cyclic ethers such as tetrahydrofuran.

In the event that R⁴ in formula I is hydrogen, gelan already after the reaction with the ammonium compound or with the hydroxylamine to the target product.

In the event, however, that R⁴ in formula I has a meaning other than hydrogen, a further reaction with a compound of the formula R⁴ X follows, in which R⁴, with the exception of hydrogen, has the meaning given above and X for a Leaving group (for example chlorine, bromine or hydroxyl).

This reaction step is a known esterification or silylation reaction. Such reactions are generally carried out at a temperature of from 0 to 150 ° C., if appropriate in the presence of an inert solvent (for example toluene or chlorobenzene) and if appropriate in the presence of an auxiliary base (for example potassium carbonate).

The above-mentioned alkali metal salts of the cyclohexenone derivatives of the formula I can be obtained by treating these compounds with sodium or potassium hydroxide in aqueous solution or in an organic solvent such as methanol, ethanol or acetone. Sodium and potassium alkanolates can also serve as bases.

The other metal salts, e.g. B. the manganese, copper, zinc, iron, calcium and magnesium salts can be prepared from the sodium salts by reaction with the corresponding metal chlorides in aqueous solution. The ammonium, sulfonium and phosphonium salts can be prepared from the new compounds of the formula I using ammonium or phosphonium hydroxides, if appropriate in aqueous solution.

The tricarbonyl compounds of the formula II can be obtained from cyclohexenones of the formula III, which may also be in the tautomeric form IIIa.<chemistry id="chem0004" num="0004"><img file="EP0218233A2_D0004.tif" /></chemistry> by methods known from the literature by reaction with carboxylic anhydrides (tetrahedron letters, <u style="single">29</u>, 2491 (1975).

It is also possible to prepare the tricarbonyl compounds of the formula II via the intermediate stage of the enol esters. These occur during the reaction of the cyclohexenones of the formula III (possibly as mixtures of isomers) and can be rearranged in the presence of imidazole or pyridine derivatives (JP-A-36O52 / 1979).

The compounds of the formula III are also obtained by processes known from the literature, as can be seen from the following scheme:<chemistry id="chem0005" num="0005"><img file="EP0218233A2_D0005.tif" /></chemistry>

The aldehydes of the general formula R³-CHO listed in the above scheme can be obtained by processes known from the literature, for example by oxidation of the corresponding alcohols, reduction of carboxylic acid derivatives or hydroformylation of olefins.

The following examples are intended to explain the preparation of the new cyclohexenone derivatives in more detail. In the examples, parts by weight to parts by volume behave like kilograms to liters.

The 1 H-NMR spectra were recorded in deuterochloroform as a solvent with tetramethylsilane as the internal standard. The ¹H chemical shifts are given in δ [ppm]. The following abbreviations were used for the signal structure: s = singlet, d = doublet, t = triplet, q = quartet, m = multiplet, strongest signal.

In the examples, the but-2-en-2-yl radical is abbreviated as "2-butenyl". The isomer form is indicated in each case.

example 1

7.3 parts by weight of 2-acetyl-5- (3-tetrahydrothiopyranyl) cyclohexane-1,3-dione, 3.6 parts by weight of 2-butenyloxyammonium chloride and 2.4 parts by weight of sodium hydrogen carbonate were stirred in 100 parts by volume of methanol for 16 hours at room temperature. The solvent was distilled off under reduced pressure, the residue was stirred with a mixture of 50 parts by volume of water and dichloromethane and the aqueous phase was extracted once with 50 parts by volume of dichloromethane. The combined organic phases were washed with water, dried over sodium sulfate and the solvent was distilled off under reduced pressure. 2-1- [2-butenyloxyimino) ethyl] -3-hydroxy-5- (3-tetrahydrothiopyranyl) cyclohex-2-en-1-one was obtained as a solid with a melting point of 65 ° C. (compound no. 2).

Example 2

86 Parts by weight of 2-butyryl-5- (3-tetrahydrothiopyranyl) cyclohexane-1,3-dione and 2.6 parts by weight of 2-butenyloxyamine were stirred in dichloromethane at room temperature for 16 hours. The solution is washed with 5% by weight hydrochloric acid and water, dried over sodium sulfate and the solvent is distilled off under reduced pressure. 2-? 1- (2-butenyloxyimino) butyl®-3-hydroxy-5- (3-tetrahydro-thiopyranyl) cyclohex-2-en-1-one was obtained as an oil (compound no. 14).

Example 3

5 Parts by weight of 2-butyryl-5- (tetrahydrothiopyran-3-yl) cyclohexan-1,3-dione, 2.31 parts by weight of 2-fluoroethyloxyammonium chloride and 1.68 parts by weight of sodium hydrogen carbonate were stirred in 100 parts by volume of methanol at room temperature for 16 hours. The solvent was distilled off under reduced pressure, the residue was taken up in dichloromethane and water was added in a ratio of 1: 1. The aqueous phase was separated and extracted with dichloromethane. The combined organic phases were dried over sodium sulfate and concentrated under reduced pressure. 5.3 parts (85%) of 2-? 1- (2-fluoroethyloxyimino) butyl®-3-hydroxy-5- (tetrahydrothiopyran-3-yl) cyclohex-2-en-1-one were obtained as slightly yellow in color Oil (compound No. 13).

Further cyclohexenone derivatives are listed in Tables 1 and 2. They are manufactured in an analogous manner.

In Table 1, the rest R Rest is hydrogen.<tables id="tabl0001" num="0001"><img file="EP0218233A2_D0006.tif" /></tables><tables id="tabl0002" num="0002"><img file="EP0218233A2_D0007.tif" /></tables><tables id="tabl0003" num="0003"><img file="EP0218233A2_D0008.tif" /></tables><tables id="tabl0004" num="0004"><img file="EP0218233A2_D0009.tif" /></tables><tables id="tabl0005" num="0005"><img file="EP0218233A2_D0010.tif" /></tables><tables id="tabl0006" num="0006"><img file="EP0218233A2_D0011.tif" /></tables><tables id="tabl0007" num="0007"><img file="EP0218233A2_D0012.tif" /></tables><tables id="tabl0008" num="0008"><img file="EP0218233A2_D0013.tif" /></tables>

The cyclohexenone derivatives of the formula I can be, for example, in the form of directly sprayable solutions, powders, suspensions, including high-strength aqueous, oily or other suspensions or dispersions, emulsions, oil dispersions, pastes, dusts, sprinkles or granules by spraying, atomizing, dusting, scattering or pouring be applied. The application forms depend entirely on the purposes; in any case, they should ensure the finest possible distribution of the active compounds according to the invention.

To produce directly sprayable solutions, emulsions, pastes or oil dispersions, mineral oil fractions from medium to high boiling points, such as kerosene or diesel oil, furthermore coal tar oils as well as oils of vegetable or animal origin, aliphatic, cyclic and aromatic hydrocarbons, e.g. Toluene, xylene, paraffin, tetrahydronaphthalene, alkylated naphthalenes or their derivatives, methanol, ethanol, propanol, butanol, cyclohexanol, cyclohexanone, chlorobenzene, isophorone or strongly polar solvents, such as N, N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone or water .

Aqueous use forms can be prepared from emulsion concentrates, dispersions, pastes, wettable powders or water-dispersible granules by adding water. To prepare emulsions, pastes or oil dispersions, the substrates as such or dissolved in an oil or solvent can be homogenized in water by means of wetting agents, adhesives, dispersants or emulsifiers. However, it is also possible to prepare concentrates composed of an active substance, wetting agents, adhesives, dispersants or emulsifiers and possibly solvents or oil, which are suitable for dilution with water.

Suitable surfactants are alkali metal, alkaline earth metal and ammonium salts of lignosulfonic acid, naphthalenesulfonic acid, phenolsulfonic acid, alkylarylsulfonates, alkyl sulfates, alkyl sulfonates, alkali metal and alkaline earth metal salts of dibutylnaphthalenesulfonic acid, lauryl ether sulfate, fatty alcohol sulfates, fatty acid alkali and alkaline earth metal salts, salts of sulfated hexadecanols, heptadecanols, and octadecanols, salts of sulfated fatty alcohol glycol ether, Condensation products of sulfonated naphthalene and naphthalene derivatives with formaldehyde, condensation products of naphthalene or the naphthalenesulfonic acids with phenol and formaldehyde, polyoxyethylene octylphenol ether, ethoxylated isooctylphenol, octylphenol or nonylphenol, alkylphenol polyglycol ether, tributylphenylpolyglycol ether, alkylarylpolyether alcohols, isotridecyl alcohol, fatty alcohol ethylene oxide condensate oil, ethoxylated ethoxylated ethoxylated ethoxylated ethoxylated ethoxylated ethoxylated ethoxylated ethoxylated ethoxylated ethoxylated ethoxylated ethoxylated ethoxylated ethoxylated ethoxylated ethoxylated ethoxylated ethoxylated ethoxylated ether

Powders, materials for broadcasting and dusts can be prepared by mixing or grinding the active substances together with a solid carrier.

Granules, for example coated granules, impregnated granules and homogeneous granules, can be prepared by binding the active ingredients to solid carriers. Solid carriers are mineral earths such as silica gel, silicas, silica gels, silicates, talc, kaolin, limestone, lime, chalk, bolus, loess, clay, dolomite, diatomaceous earth, calcium and magnesium sulfate, magnesium oxide, ground plastics, fertilizers such as ammonium sulfate, ammonium phosphate, Ammonium nitrate, ureas and vegetable products such as corn flour, tree bark, wood and nutshell flour, cellulose powder or other solid carriers.

The formulations contain between 0.1 and 95% by weight, preferably between 0.5 and 90% by weight, of active ingredient.

Examples of formulations are:<ul id="ul0001" list-style="none"><li>I. 90 parts by weight of compound no. 134 are mixed with 10 parts by weight of N-methyl-pyrrolidone and a solution is obtained which is suitable for use in the form of tiny drops.</li><li>II. 20 parts by weight of compound No. 5O are dissolved in a mixture consisting of 80 parts by weight of xylene, 10 parts by weight of the adduct of 8 to 10 mol of ethylene oxide and 1 mol of oleic acid-N-monoethanolamide, 5 parts by weight of calcium salt of dodecylbenzenesulfonic acid and 5 parts by weight of the adduct of 40 moles of ethylene oxide to 1 mole of castor oil. By pouring the solution into 100,000 parts by weight of water and finely distributing it therein, an aqueous dispersion is obtained which contains 0.02% by weight of the active ingredient.</li><li>III. 20 parts by weight of compound no. 2 are dissolved in a mixture consisting of 40 parts by weight of cyclohexanone, 30 parts by weight of isobutanol, 20 parts by weight of the adduct of 7 mol of ethylene oxide and 1 mol of isooctylphenol and 10 part by weight of the adduct of 4O mol of ethylene oxide and 1 mol of castor oil. By pouring the solution into 100,000 parts by weight of water and finely distributing it therein, an aqueous dispersion is obtained which contains 0.02% by weight of the active ingredient.</li><li>IV. 20 parts by weight of active ingredient No. 1O4 are dissolved in a mixture consisting of 25 parts by weight of cyclohexanone, 65 parts by weight of a mineral oil fraction from the boiling point 21O to 28O ° C and 10 parts by weight of the adduct of 40 moles of ethylene oxide and 1 mole of castor oil. By pouring the solution into 100,000 parts by weight of water and finely distributing it therein, an aqueous dispersion is obtained which contains 0.02% by weight of the active ingredient.</li><li>V. 20 parts by weight of active ingredient no. 14 are mixed well with 3 parts by weight of the sodium salt of diisobutylnaphthalene-α-sulfonic acid, 17 parts by weight of the sodium salt of lignosulfonic acid from a sulfite waste liquor and 60 parts by weight of powdered silica gel and ground in a hammer mill. By finely distributing the mixture in 20,000 parts by weight of water, a spray liquor is obtained which contains 0.1% by weight of the active ingredient.</li><li>VI. 3 parts by weight of active ingredient No. 122 are mixed with 97 parts by weight of finely divided kaolin. In this way, a dusting agent is obtained which contains 3% by weight of the active ingredient.</li><li>VII. 30 parts by weight of active ingredient no. 2 are intimately mixed with a mixture of 92 parts by weight of powdered silica gel and 8 parts by weight of paraffin oil which has been sprayed onto the surface of this silica gel. In this way, a preparation of the active ingredient with good adhesiveness is obtained.</li><li>VIII. 20 parts by weight of active ingredient No. 5O are intimately mixed with 2 parts by weight of calcium salt of dodecylbenzenesulfonic acid, 8 parts by weight of fatty alcohol polyglycol ether, 2 parts by weight of sodium salt of a phenol-urea-formaldehyde condensate and 68 parts by weight of a paraffinic mineral oil. A stable oily dispersion is obtained.</li><li>IX. 40 parts by weight of active ingredient No. 2 are dissolved in 60 parts by weight of a mixture consisting of 93% by weight of xylene and 7% by weight of the adduct of 8 moles of ethylene oxide and 1 mole of nonylphenol. A solution is obtained which contains 40% by weight of the active ingredient.</li></ul>

The new herbicides have a good herbicidal action, preferably against species from the grass family (gramineae). They are tolerated and therefore selective in broadleaved crops and in monocotyledonous plants, which are not among the Gramineae. There are also active ingredients which additionally have herbicidal activity against broad-leaved plants and also those which are suitable for the non-selective control or suppression of unwanted vegetation.

The funds can be applied pre-emergence or post-emergence. If the active ingredients are less compatible for certain crop plants, application techniques can also be used in which the herbicidal compositions are sprayed with the aid of sprayers in such a way that the leaves of the sensitive crop plants are not hit as far as possible, while the active ingredients are more undesirable on the leaves below them Plants or the uncovered floor area (postdirected, lay-by).

Depending on the season, the target plants and the growth stage, the application rates of active ingredient are 0.015 to 3 kg / ha, preferably 0.05 to 0.5 kg / ha.

The effect of the cyclohexenone derivatives of the formula I on plant growth can be shown by greenhouse experiments:

Plastic flower pots with 3OO cm³ content and loamy sand with about 3, 0 wt .-% humus serve as culture vessels. The seeds of the test plants are sown flat according to species. In pre-emergence treatment, the active ingredients are applied to the earth's surface immediately afterwards. They are suspended or emulsified in water as a distribution agent and sprayed using finely distributing nozzles. The application rates are 3.0 kg / ha.

After the application of the agents, the vessels are lightly sprinkled to start germination and growth. Then cover the containers with transparent plastic covers until the plants have grown. This cover causes the test plants to germinate evenly, unless this is affected by the active ingredients.

For the purpose of post-emergence treatment, depending on the growth habit, the test plants are first grown to a height of 3 to 15 cm and then treated. The soybean plants are grown in a substrate enriched with peat. For post-emergence treatment, either plants that have been sown directly and grown in the same containers are selected, or they are first grown separately as seedlings and transplanted into the test containers a few days before the treatment. The application rate for post-emergence treatment is 0.015 to 3.0 kg of active ingredient / ha. There is no cover during post-emergence treatment.

The test vessels are set up in the greenhouse, warmer areas (2O to 35 ° C) being preferred for heat-loving species and 1O to 25 ° C for those with moderate climates. The trial period spans 2 to 4 weeks. During this time, the plants are cared for and their reaction to the individual treatments is evaluated. It is rated on a scale from 0 to 100. 100 means no emergence of the plants or complete destruction of at least the aerial parts.

The plants used in the greenhouse experiments are composed of the following species.<tables id="tabl0009" num="0009"><img file="EP0218233A2_D0014.tif" /></tables>

The herbicidal action of the active ingredients Nos. 134, 122, 50 and 104 selected by way of example against common grasses and crops is clearly superior to that of chemically closely related derivatives. Herbicides containing active substances which are known from DE-A-3 34O 265, DE-A-3 239 O71, DE-A-3 123 312 and DE-A-3 121 355 were used as comparative agents.

For example, at a rate of 3 kg / ha, active ingredients Nos. 2 and 14 are suitable for combating undesirable grass-like vegetation in broadleaved crops, for example soybeans and sugar beets, without significantly influencing them. They have a higher herbicidal activity than known comparative active ingredients which are known from DE-A-3 121 355.

The active ingredient no. 2 selected as an example shows the possibility of using the new compounds to suppress broad-leaf unwanted vegetation. In the pre- and post-emergence process, a significantly better herbicidal effect is achieved than with the known active ingredients.

In comparison with known compounds from GB 2 137 2OO and EP-125 O94, corresponding compounds, for example, the active ingredient no. 49 shows, at a low application rate against undesirable grasses and wheat, a significantly stronger herbicidal action with very good tolerance for soybeans.

Even at low application rates, active ingredients Nos. 8, 26 and 62 are suitable for controlling a wide range of undesirable grass-like plants without damaging the soybean crop.

In view of the detectable spectrum of activity for weed control, the tolerance for crop plants or the desired influence on the growth thereof, and in view of the variety of application methods, the compounds according to the invention can be used in a large number of crop plants. For example, the following crops can be considered:<tables id="tabl0010" num="0010"><img file="EP0218233A2_D0015.tif" /></tables><tables id="tabl0011" num="0011"><img file="EP0218233A2_D0016.tif" /></tables>

To broaden the spectrum of activity and to achieve synergistic effects, the cyclohexenone derivatives of the formula I can be mixed with numerous representatives of other herbicidal or growth-regulating active compound groups and applied together. For example, diazines, 4H-3,1-benzoazine derivatives, benzothiadiazinones, 2,6-dinitroanilines, N-phenyl carbamates, thiol carbamates, halocarboxylic acids, triazines, amides, ureas, diphenyl ethers, triazinones, uracils, benzofuran derivatives, quinoline carboxylic acids and other consideration come as mixing partners.

It may also be useful to apply the cyclohexenone derivatives of the formula I, alone or in combination with other herbicides, also mixed with other crop protection agents, for example with agents for controlling pests or phytopathogenic fungi or bacteria. Also of interest is the miscibility with mineral salt solutions, which are used to remedy nutritional and trace element deficiencies. Non-phytotoxic oils and oil concentrates can also be added.