EP0000359B1 - Phenoxy-phenylsulfinyl-and-sulfonylalkanecarboxylic acid derivatives, method for their preparation and their use as herbicides and plant growth regulators. - Google Patents

Description

The present invention relates to novel phenoxy-phenyl-sulfinyl and -sulfonyl-alkanecarboxylic acid derivatives which show herbicidal and plant growth-regulating activity, processes for the preparation of these derivatives, herbicidal and plant growth-regulating agent which contain these derivatives as active compounds and the use the new phenoxy-phenyl-sulfinyl- and -sulfonyl-alkane carboxylic acid derivatives or compositions containing them as herbicides and / or for regulating plant growth.

worin

• B einen Rest -OR₁, -SR₂ oder -NR₃R₄,
• C Wasserstoff, Halogen Nitro, C₁-C₄ Alkyl oder C₁-C₄ Alkoxy,
• D Halogen, Cyan, Nitro oder Trifluormethyl,
• E Wasserstoff, Halogen, Cyan oder Nitro,
• p die Zahl 1 oder 2,
• Q eine unverzweigte oder verzweigte C₁-C₄ Alkylenbrücke,
• R₁ Wasserstoff oder das Kation eines Alkali- oder Erdalkalimetalles, einen C₁-C₄ Alkylammonio-Rest, der im Alkylteil durch Hydroxyl, Cyan oder C₁-C₄ Alkoxy substituiert sein kann,
• -C₁-C₁₈ Alkyl, unsubstituiert oder substituiert durch Halogen, Nitro, Cyan, C₁-C₈ Alkoxy, Bis (C₁-C₄ alkyl)-amino,
• -C₃-C₁₈ Alkenyl, gegebenenfalls Halogen substituiert,
• - C₃-C₈ Alkinyl
• -C₃-C₁₂ Cycloalkyl,
• - Phenyl oder Benzyl, unsubstituiert oder substituiert durch Halogen, C₁-C₄ Alkyl, C₁-C₄ Alkoxy, C₁-C₄ Alkylthio, Nitro, Cyan oder Trifluormethyl;
• R₂ C₁-C₁₈ Alkyl,
• - Phenyl- oder Benzyl, unsubstituiert oder substituiert durch Halogen, C₁-C₄ Alkyl, C₁-C₄ Alkoxy, C₁-C₄ Alkylthio, Nitro, Cyan oder Trifluormethyl;
• R₃ und R₄ Wasserstoff, C,-C₄ Alkyl oder 2-Methoxyethyl bedeuten.

The new phenoxy-phenyl-sulfinyl and -sulfonyl-alkane carboxylic acid derivatives correspond to the formula I.

wherein

• B is a radical -OR ₁ , -SR ₂ or -NR ₃ R ₄ ,
• C hydrogen, halogen nitro, C ₁ -C ₄ alkyl or C ₁ -C ₄ alkoxy,
• D halogen, cyan, nitro or trifluoromethyl,
• E hydrogen, halogen, cyan or nitro,
• p is the number 1 or 2,
• Q is an unbranched or branched C ₁ -C ₄ alkylene bridge,
• R _{1 is} hydrogen or the cation of an alkali or alkaline earth metal, a C ₁ -C ₄ alkylammonio radical which can be substituted in the alkyl part by hydroxyl, cyano or C ₁ -C ₄ alkoxy,
• -C ₁ -C ₁₈ alkyl, unsubstituted or substituted by halogen, nitro, cyano, C ₁ -C ₈ alkoxy, bis (C ₁ -C ₄ alkyl) amino,
• -C ₃ -C ₁₈ alkenyl, optionally halogen-substituted,
• - C ₃ -C ₈ alkynyl
• -C ₃ -C ₁₂ cycloalkyl,
• - Phenyl or benzyl, unsubstituted or substituted by halogen, C ₁ -C ₄ alkyl, C ₁ -C ₄ alkoxy, C ₁ -C ₄ alkylthio, nitro, cyano or trifluoromethyl;
• R ₂ C ₁ -C ₁₈ alkyl,
• - Phenyl- or benzyl, unsubstituted or substituted by halogen, C ₁ -C ₄ alkyl, C ₁ -C ₄ alkoxy, C ₁ -C ₄ alkylthio, nitro, cyano or trifluoromethyl;
• R ₃ and R _{4 are} hydrogen, C, -C ₄ alkyl or 2-methoxyethyl.

The alkyl and alkenyl radicals in this definition can be branched or unbranched.

The present phenoxy-phenylsulfinyl and sulfonyl alkane carboxylic acid derivatives are new compounds. Phenoxyphenylthio-alkane carboxylic acid derivatives with a similar structure, which can be used as starting materials for the preparation of the present compounds, are known. The FR-PS 285 861 describes compounds which show pharmacological activity, the DOS 2 223 894 those with herbicidal activity. Furthermore, herbicidal diphenyl ethers with alkyl and alkenylsulfinyl or sulfonyl radicals have been described in DT-OS 2 130 919 and 2 333 848. The compounds of the formula I have a herbicidal action which does not act equally strongly against all types of plants. This creates valuable selectivities that make it possible to specifically combat weeds in crops without noticeably damaging the crops. The best effect is achieved in the post-emergence process in cereal and rice crops against broad-leaved weeds.

• - die Reduktion des veregativen Wachstums bei Soja und ähnlichen Leguminosen, was zu einer Ertragssteigerung dieser Kultur führt;
• - die Hemmung des unerwünschten Wachstums von Geiztrieben bie Tabak, dessen Haupttrieb man geschnitten hat, was der Ausbildung grösserer und schönerer Blätter zugute kommt;
• - die Hemmung des Wachstums von Gras und dikotyledonen Pflanzen, wie Obstbäume,Zierbäume, Gebüsche und Hecken, zwecks Einsparung an Schnittarbeit.

The active ingredients of the formula also have favorable growth-regulating effects (growth inhibition). In particular, they inhibit the washing of dicotyledonous plants. Examples of the beneficial use of the compound according to the invention are, for example

• - the reduction of the negative growth in soy and similar legumes, which leads to an increase in the yield of this culture;
• - the inhibition of the undesirable growth of stinging shoots in tobacco, the main shoot of which has been cut, which benefits the formation of larger and more beautiful leaves;
• - inhibiting the growth of grass and dicot plants, such as fruit trees, ornamental trees, bushes and hedges, in order to save on cutting work.

The compounds of the present invention are not very toxic to warm-blooded animals and their application poses no problems. The application rate is between 0.1 and 5 kg per hectare.

The new compounds of the formula I are prepared by methods known per se and can be seen from the following formula scheme:

In these formulas, B, C, D, E, Q and p have the meaning given under formula and Hal means a halogen atom, preferably chlorine or bromine.

One starts, for example, from an optionally substituted halogenobenzene of the formula III and condenses it with an optionally further substituted methylthiophenol of the formula IV in the presence of an acid-binding agent in an aprotic solvent at elevated temperature to give the phenoxy-methylthio compound of the formula V. This can then reacted further with an α-haloalkanecarboxylic acid derivative of the formula VI at elevated temperature, whereupon the phenoxy-phenyl-thioalkanecarboxylic acid of the formula II is obtained. The preparation of such phenoxy-phenylthioalkanecarboxylic acid derivatives is also described, inter alia, in DOS 2 223 894.

Another way to get to these phenoxy-phenylthio-alkane carboxylic acid derivatives of the formula II also starts from the optionally substituted halogenobenzenes of the formula III, which are e.g. condensed with an optionally further substituted hydroxyphenylthio-alkane carboxylic acid of formula VII in the presence of an acid-binding agent such as e.g. an inorganic base, in an aprotic solvent at elevated temperature. ,

The process according to the invention for the preparation of the new phenoxyphenylsulfinyl and sulfonyl alkane carboxylic acid derivatives is characterized in that a phenoxy phenylthio alkane carboxylic acid derivative of the formula II (see formula scheme), in which B, C, D, E and Q have the meaning given under formula, treated with an oxidizing agent until the sulfide bridge to the sulfinyl - (- SO) or sulfonyl bridge (-S0 ₂ ) is oxidized.

Suitable oxidizing agents for this reaction are, for example, hydrogen peroxide, oxygen or optionally also air which is blown through the reaction mixture. Furthermore, the phenoxy-phenylthio-alkane carboxylic acid derivative can be added to dilute sodium hydroxide solution and then slowly chlorine can be blown through the reaction mixture.

Furthermore, the compounds of the formula I can also be prepared by reducing an appropriately substituted diphenyl ether sulfochloride with sodium sulfite to give the sulfinic acid and then, or a salt thereof, with a radical Hal-Q-COB, in which B, Q and Hal have the meaning given under formula I.

The following examples illustrate the preparation of the active compounds of the formula 1. Further active compounds prepared in a corresponding manner are listed in the tables below. Temperatures refer to degrees Celsius. Pressure values are given in millibars (mbar).

Another table shows phenoxy-phenylthio-alkane carboxylic acids of the formula II obtained as intermediates.

example 1 3- (2 ', 4'-dichlorophenoxy) -6-iodo-phenylsulfinyl-acetic acid, methyl ester

• a) 12 g of 4-chloro-2-methylmerkapto-nitrobenzene are heated to 160 ° in 50 ml of dimethyl sulfoxide with 10 g of 2,4-dichlorophenol and 2.5 g of sodium hydroxide. After two hours, the mixture is poured onto ice and extracted with ethyl acetate. The organic solution is evaporated and the residue is recrystallized from toluene / hexane. 16 g of 2,4-dichloro-3'-methylmerkapto-4 "-nitrodiphenyl ether having a melting point of 120-122 ° are obtained. The catalytic reduction in dioxane with Raney nickel results in 2,4-dichloro-3'- in almost quantitative yield. methylmerkapto-4'-aminodiphenyl ether, mp 40-4.2 °.
• b) 65 g of this compound are concentrated with 300 ml of water and 144 ml. Mixed sulfuric acid and cooled to 0 °. By reacting with a 5% sodium nitrite solution at 0-5 °, a diazonium solution is prepared, into which a solution of 39.5 g of potassium iodide in 270 ml of water is added dropwise after one hour at 0 °. A sticky precipitate forms, which is dissolved after 2 hours by adding methylene chloride. The organic phase is separated off and evaporated. The residue is extracted several times with warm hexane and the combined hexane extracts are concentrated and cooled. Crystallization gives 2,4-dichloro-3'-methylmerkapto-4-iodo-diphenyl ether.
• c) 10 g of 2,4-dichloro-3'-methylmerkapto-4'-iodo-diphenyl ether were refluxed with 20 ml of methyl bromoacetate for 10 hours, the purification was carried out chromatographically on a column of silicic acid with eluent cyclohexane. After evaporation of the solvent, 7 g of methyl 3- (2 ', 4'-dichlorophenoxy) -6-iodophenylthioacetate with the refractive index Nß4 1.6528 is obtained.
• d) 5.4 g of this compound in 100 ml of methylene chloride are slowly mixed with 2.5 g of 86% 3-chloroperbenzoic acid. After two hours, the mixture is extracted with dilute sodium hydroxide solution, the organic phase is dried over sodium sulfate, evaporated and the residue is recrystallized from toluene / hexane. 3.5 g of the title compound are obtained. Mp 120-122 °.

Example 2 Methyl α- [3- (2'.4'-dichlorophenoxy) -6-chlorophenylsulfonyl] propionate.

• a) A solution of 400 g of di- (2 ', 4'-dichlorophenoxy) nitrobenzene, 64 g of 85% potassium hydroxide and 100 ml of dioxane is mixed with 45 g of methyl mercaptan at 50-70 °. After one hour the solvent is removed in vacuo and the residue is taken up in toluene. The solution freed from the resulting 2,4-dichlorophenol by washing the solution with dilute sodium hydroxide solution is concentrated to a boiling mixture of 500 g iron powder, 500 g ethanol and 50 ml. Dropped hydrochloric acid. After 15 hours of reflux, the mixture is cooled, made alkaline with 30% sodium hydroxide solution, suction filtered from the iron sludge and the filter cake is washed with toluene. The organic phase of the filtrate is evaporated and distilled off. 192.5 g of 4- (2 ', 4'-dichlorophenoxy-2-methylmerkaptoaniline are obtained. Bp. 170 ° / 0.1 mbar.
• b) 180 g of the compound Example 3a are dissolved in 1.5 liters of glacial acetic acid and concentrated with 153 ml. Hydrochloric acid added. A solution of 41.5 g of sodium nitrite in 100 ml of water at 5 ° is added dropwise to produce a diazo solution which, after destroying the excess nitrite with sulfamic acid at 75-90 ° in 2 liters of 18% hydrochloric acid and 118 g of copper (I) chloride is dropped. After 1 hour, the mixture is extracted with toluene, the organic phase is evaporated and the residue is distilled. 172 g of 3- (2'-4'-dichlorophenoxy) -6-chloromethylmercaptobenzene are obtained, bp 158 ° / 0.05 mbar.
• c) 140 g of the compound from Example 3b were refluxed for 16 hours with 105 ml of 2-bromo-propionic acid methyl ester and a crystal of potassium iodide. The subsequent distillation gives 150 g of methyl a- [3 (2 ', 4'-dichlorophenoxy) phenol-6-chlorophenylthio] propionate. Bp. 186 ° / 0.09 mbar.
• d) Treatment of 7 g of this compound with 8.2 g of 3-chloroperoxybenzoic acid in methylene chloride analogously to Example 1 d gives 6 g of the title compound in the form of an oil with a refractive index of ⁴ = 1.5890.

Example 3

α-[3(2'-Chlor-4'-trifluormethylphenoxy)-6-chlor-phenylsulfinyl]-propionsäuremethylester.

• a) 241 g 2-Chlor-5-methoxy-anilin werden unter starkem Rühren zu 310 ml Wasser und 385 ml konz. Salzsäure gegeben, gefolgt von 750 g Eis. Man kühlt die Mischung auf-10° und gibt auf einmal eine Lösung von 111 g Natriumnitrit in 150 ml Wasser dazu, dabei steigt die Temperatur auf 10° an. Nach 30 Minuten wird der Nitritüberschuss mit Sulfaminsäure entfernt und die Lösung durch Filtration geklärt. Diese Diazolösung wird bei 55-60° zu einer Lösung von 300 ml Wasser, 800 ml Toluol, 225 g Kaliummethylxanthogenat, 85 g Natriumbicarbonat und 75 ml 30%iger Natronlauge getropft.. Nach beendeter, sehr lebhafter Gasentwicklung trennt man die organische Phase ab. Diese wird mit Wasser gewaschen und nach dem Trocknen über Natriumsulfat in 100 ml Triäthylamin bei 70° getropft. 2 Stunden Rückfluss, dann abkühlen und Zugabe von 200 ml 30%iger Natronlauge. Die organische Phase wird abgetrennt und destilliert. Man erhält 160 g 4-chlor-3-methyl-merkaptoanisol. Sdp. 138-145°/11 mbar.
  152,2 g dieser Verbindung werden analog J.Am.Chem.Soc. 79, 720 zu 110 g 4-Chlor-3-methyl- merkaptophenol verseift. Sdp. 117-121°/0,03 mbar.
• b) 50 g 4-Chlor-3-methylmerkaptophenol, 62 g 3,4-Dichlorbenzotrifluorid und 12 g Natriumhydroxyd werden in 150 ml Dimethylsulfoxyd 6 Stunden bei 142° verrührt, dann giesst man das Reaktionsgemisch auf Eis, extrahiert mit Toluol und destilliert die organische Phase ab. Man erhält 81 g 3-(2'-Chlor-4-trifluormethyl-phenoxy)-6-chlor-thioanisol vom Sdp. 158°/0,4 mbar.
  20g dieser Verbindung werden mit 30 ml 2-Brompropionsäuremethylester bei 190° 20 Stunden verrührt; dann erfolgt Destillation im Kugelrohr. Man erhält 21 g 'a-[3-(2'-Chlor-4'-trifluormethyl- phenoxy)-6-chlorphenylthio]-propionsäure-methylester. Sdp. 200°/0,13 mbar.
• c) 10 g dieser Verbindung werden in Methylenchlorid (200 ml) analog Beispiel 1 mit 3-Chlorperbenzoesäure umgesetzt. Die Aufarbeitung ergibt 9,5 g eines viskosen Oels mit Brechungsindex n2³ = 1,3295.

Methyl α- [3 (2'-chloro-4'-trifluoromethylphenoxy) -6-chlorophenylsulfinyl] propionate.

• a) 241 g of 2-chloro-5-methoxy-aniline are concentrated to 310 ml of water and 385 ml of conc. Hydrochloric acid, followed by 750 g of ice. The mixture is cooled to -10 ° and suddenly a solution of 111 g of sodium nitrite in 150 ml of water is added, the temperature rising to 10 °. After 30 minutes, the excess nitrite is removed with sulfamic acid and the solution is clarified by filtration. This diazo solution is added dropwise at 55-60 ° to a solution of 300 ml of water, 800 ml of toluene, 225 g of potassium methylxanthate, 85 g of sodium bicarbonate and 75 ml of 30% sodium hydroxide solution. After the very vigorous evolution of gas has ended, the organic phase is separated off. This is washed with water and, after drying over sodium sulfate in 100 ml of triethylamine, added dropwise at 70 °. 2 hours reflux, then cool and add 200 ml of 30% sodium hydroxide solution. The organic phase is separated off and distilled. 160 g of 4-chloro-3-methyl-mercaptoanisole are obtained. Bp. 138-145 ° / 11 mbar.
  152.2 g of this compound are analogous to J.Am.Chem.Soc. 79, 720 saponified to 110 g of 4-chloro-3-methylmercapthenol. Bp 117-121 ° / 0.03 mbar.
• b) 50 g of 4-chloro-3-methylmercaptophenol, 62 g of 3,4-dichlorobenzotrifluoride and 12 g of sodium hydroxide are stirred in 150 ml of dimethyl sulfoxide for 6 hours at 142 °, then the reaction mixture is poured onto ice, extracted with toluene and the organic is distilled Phase. 81 g of 3- (2'-chloro-4-trifluoromethyl-phenoxy) -6-chloro-thioanisole are obtained, boiling at 158 ° / 0.4 mbar.
  20 g of this compound are stirred with 30 ml of 2-bromopropionic acid methyl ester at 190 ° for 20 hours; then distillation takes place in the Kugelrohr. 21 g of methyl [3- (2'-chloro-4'-trifluoromethylphenoxy) -6-chlorophenylthio] propionate are obtained. Bp 200 ° / 0.13 mbar.
• c) 10 g of this compound are reacted in methylene chloride (200 ml) analogously to Example 1 with 3-chloroperbenzoic acid. Working up gives 9.5 g of a viscous oil with refractive index n2 ³ = 1.3295.

The following compounds were prepared in an analogous manner to the examples:

Phenoxy-phenylthio-alkane carboxylic acid derivatives of the formula 11 required as intermediates

The phenoxy-phenylsulfinyl and - phenylsulfonylalkane-carboxylic acid derivatives of the formula are stable compounds which are soluble in common organic solvents, such as alcohols, ethers, ketones, dimethylformamide, dimethyl sulfoxide, etc.

The invention also relates to herbicidal and plant growth-regulating agents which receive a new active ingredient of the formula I, and to processes for pre- and post-emergent weed control and for inhibiting the growth of monocotyledonous and dicotyledonous plants, in particular grasses, cereals, soybeans and tobacco stems.

The agents according to the invention can be present in the usual formulations.

Agents according to the invention are prepared in a manner known per se by intimately mixing and grinding active ingredients of the formula I with suitable carriers, optionally with the addition of dispersing agents or solvents which are inert to the active ingredients. The active ingredients can be present and used in the following forms:

The active ingredients are mixed with solid carriers to produce solid processing forms (dusts, scattering agents, granules). Carriers include, for example, kaolin, talc, bolus, loess, chalk, limestone, lime grits, ataclay, dolomite, diatomaceous earth, precipitated silica, alkaline earth metal silicates, sodium and potassium aluminum silicates (feldspar and mica), calcium and magnesium sulfates, magnesium oxide, ground Plastics, fertilizers, such as ammonium sulfate, ammonium phosphate, ammonium nitrate, urea, ground vegetable products, such as grain flour, tree bark flour, wood flour, nutshell flour, cellulose powder, residues from plant extracts, activated carbon, etc., each individually or as a mixture with one another in question.

The content of active ingredient in the agents described above is between 0.1 to 95%, preferably between 1 to 80%. Application forms can be diluted down to 0.001%. The application rates are generally 0.1 to 10 kg ai / ha, preferably 0.25 to 5 kg ai / ha.

The active substances contained in the agents according to the invention influence plant growth in various ways. In the first place, they inhibit, delay or prevent growth and germination. It is therefore both a pre- and post-emergent herbicide effect as well as growth inhibition.

Agents according to the invention which contain at least one compound of the formula I as active component are particularly suitable for inhibiting and controlling the plant growth of monocotyledonous and dicotyledonous plants, such as grasses, shrubs, trees, crops of cereals and legumes, sugar cane, tobacco, soybeans, Bulbs of onions and potatoes, ornamental plants, fruit trees and vines.

The herbicidal activity of known and structurally similar, known compounds according to the invention was tested in the greenhouse by the following experiments.

1. Tested connections

Verbindung 49 DOS 2 223 894

gemäss FR-PS 2 285 861 oder DOS 2 223 894

Verbindung 6 DOS 2 223 894The compounds according to the invention are identified by the number which they have in the tables above. The following known connections were tested:

Compound 49 DOS 2 223 894

according to FR-PS 2 285 861 or DOS 2 223 894

Compound 6 DOS 2 223 894

These compounds were worked up to a 25% emulsion concentrate of the composition described above, which was then diluted with water to the desired active ingredient concentration.

• Herbizide Wirkung bei Applikation der Wirkstoffe nach dem Auflaufen der Pflanzen (post-emergent).

The herbicidal activity was tested as follows:

• Herbicidal effect when the active ingredients are applied after the plants have emerged (post-emergent).

• 9 = Pflanze gedeiht normal wie unbehandelte Kontrollpflanze.
  • 8-2 linear, prozentual zunehmende Schädigung der Pflanzen
• 1 Pflanze abgestorben
  • - Pflanze nicht geprüft.

Various crops and weeds are grown from the seeds in pots in the greenhouse until they reach the 4 to 6 leaf stage. Then the plants are sprayed with aqueous active ingredient emulsions (obtained from the emulsion concentrate) in various doses. The treated plants are then kept under optimal conditions of light, watering, temperature (22-25 ° C) and air humidity (50-70% relative). The test was evaluated 15 days after treatment according to the following EWRC rating (European Weed Research Council):

• 9 = plant thrives normally like untreated control plant.
  • 8-2 linear, percentage increasing damage to the plants
• 1 plant died
  • - Plant not checked.

In a first run, all compounds were tested on 7 plants, mono- and dicotyledon, at a rate of 4 kg per hectare. The results are in the table below. merged.

Some of these compounds have been subjected to further scrutiny:

Some compounds have also been tested for their selective herbicidal activity in rice crops.

Selective herbicidal effect on rice in the post-emergence process

Rice plants that are 25 days old were transplanted into large rectangular eternit bowls in the greenhouse. Seeds of the weeds Echinochloa crus galli found in rice crops were then placed between the rows of rice plants. Cyperus difformis, Ammania and Rotala sown. The dishes were well watered and kept at a temperature of approx. 25 ° C and high humidity. After 12 days, when the weeds had emerged and reached the 2-3 leaf stage, the earth in the bowl was covered with a 2.5 cm high layer of water. The active substance was then applied as an emulsion concentrate by means of a pipette between the rows of plants, the emulsion concentrate being diluted and applied so that it corresponded to an application amount in the field of 4, 2, 1 and 1/2 kg of active ingredient per hectare. The experiment was evaluated after 4 weeks. The results are summarized in Table 3.

Trial of rice

In these experiments, the compounds according to the invention generally show good herbicidal activity against dicotyledonous plants and some monocotyledon weeds. For example, they could be used for selective control, especially dicotyledonous weeds in rice and certain cereals.

The known compounds A, B and C showed no pronounced herbicidal action here, while the compound D acts differently and, above all, damages weeds which are monocotyledonous.

Claims (11)

1. A phenoxyphenylsulfinyl- or -sulfonylalkanecarboxylic acid derivative of the formula I

wherein

B is a radical -OR₁, -SR₂ or -NR₃R₄,

C is hydrogen, halogen, nitro, C₁-C₄alkyl or C₁-C₄alkoxy,

D is halogen, cyano, nitro or trifluoromethyl,

E is hydrogen, halogen, cyano or nitro,

p is 1 or 2,

Q is an unbranched or a branched C₁-C₄alkylene bridge,

R₁ is hydrogen or the cation of an alkali metal or alkaline earth metal; a C₁-C₄alkylammonium radical which can be substituted in the alkyl moiety by hydroxyl, cyano or C₁-C₄alkoxy; C₁-C₄alkyl which is unsubstituted or substituted by halogen, nitro, cyano, C₁-C₈alkoxy or bis(C₁-C₄alkyl)amino; C₃--C₁₈alkenyl which is unsubstituted or substituted by halogen; C₃-C₈alkynyl; C₃-C₁₂cycloalkyl; phenyl or benzyl, unsubstituted or substituted by halogen, C₁-C₄alkyl, C₁-C₄alkoxy, C₁-C₄alkylthio, nitro, cyano or trifluoromethyl;

R₂ is C₁-C₁₈alkyl; phenyl or benzyl, unsubstituted or substituted by halogen, C₁-C₄alkyl, C₁-C₄alkoxy, C₁-C₄alkylthio, nitro, cyano or trifluoromethyl; and

R₃ and R₄ are C_l-C₄alkyl or 2-methoxyethyl.

2. A phenoxyphenylsulfinylalkanecarboxylic acid derivative of the formula

wherein B, C, D, E and Q are as defined for formula I in claim 1.

3. A phenoxyphenylsulfonylalkanecarboxylic acid derivative of the formula

wherein B, C, D, E and Q are as defined for formula I in claim 1.

4. α-[3-(2'-Chloro-4'-trifluoromethylphenoxy)-6-nitrophenylsulfonyl]propionic acid methyl ester.

5. α-[3-(2',4'-Dichlorophenoxy)-6-chlorophenylsulfonyl]propionic acid methyl ester.

6. a-[3-(2'-Nitro-4'-trifluoromethylphenoxy)-6-chlorophenoxysulfinyl]propionic acid methyl ester.

7. α-[3-(2'-Nitro-4'-trifluoromethylphenoxy)-6-chlorophenoxysulfonyl)propionic acid methyl ester.

8. A process for the production of a phenoxyphenyl-sulfinyl- or -sulfonylalkanecarboxylic acid derivative according to claim 1, characterised in that a phenoxy-phenylthioalkanecarboxylic acid derivative of the formula II

wherein B, C, D, E and Q are as defined in claim 1, is treated with an oxidising agent until the sulfide bridge is oxidised to the sulfinyl (-SO-) or sulfonyl (-SO₂-) bridge.

9. A herbicidal and plant growth-regulating composition, characterised in that it contains, as active ingredient, at least one phenoxyphenylsulfinyl- or -sulfonylalkanecarboxylic acid derivative of the formula I according to claim 1, together with inert formulation adjuvants conventionally employed in agricultural chemistry.

10. The use of a phenoxyphenylsulfinyl- or -sulfonylalkanecarboxylic acid derivative of the formula I according to claim 1, or of a composition containing such a compound, for selectively controlling weeds in crops of useful plants.

11. The use of a phenoxyphenylsulfinyl- or -sulfonylalkanecarboxylic acid derivative of the formula I according to claim 1, or of a composition containing such a compound, for inhibiting plant growth.