DK162216B - (R) -2- (4- (5-CHLOR-3-FLUORPYRIDIN-2-YLOXY) -PHENOXY) -PROPIONIC ACID PROPINYLESTER AND ITS PREPARATION AND USE AS HERBICID AND PLANT ANTIFICANT - Google Patents

Description

in

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The present invention relates to the novel (R) -2- [4- (5-chloro-3-fluoropyridin-2-yloxy) phenoxy] propionic acid propynyl ester with herbicidal activity, its preparation, herbicide and plant growth inhibitors containing the ester in question as an active substance together with inert additives, and the use of the ester or agents as a selective herbicide in crops and, in particular, to control weeds 10 in crops such as cereals, rice, maize, soy and beet.

(R) -2- [4- (5-Chloro-3-fluoropyridin-2-yloxy) -phenoxy] -propionic acid propynyl ester has the formula. y * ~ * v ci ~ y \ -qS; - and -co-and2csch (i) \ = / S. = / * (R) (R) - 2- [4- (5-Chloro-3-fluoropyridine) The 2-yloxy-phenoxy] propionic acid propynyl ester of the invention is characterized by an exceptionally good effect against monocotyls and single dicotyl weeds, above all in the post-emergence process against difficult to control weeds and weeds in cultures such as corn, maize , rice, soy and sugar beet. The ester is particularly useful for controlling weeds that are otherwise difficult to come to life, such as. Avena fatua, Avena sterilis, Alopecurus myosuroides, Lolium perenne, Phalaris sp., Bromis 25 tectorum, various Setaria and Panicum species. The effect occurs under field conditions already at low application rates of less than 1 kg per day. ha, by which the cultures are not harmed or only insignificantly damaged.

Halogenpyridyloxy-α-phenoxy-propionic acid derivatives have been described in numerous publications, see e.g. DE-A No. 2,546,251, No. 2,649,706, No. 2,714,622, No. 2,715,284, and EP-A No. 483, No. 1473, No. 83,556, and No. 97460.

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2 α- [4- (3-Fluoro-halogenopyridyl-2-oxy) -phenoxy] -propionic acid esters are also disclosed therein. The optically active ester of the invention differs from the known halogenpyridyloxy-α-phenoxypropionic acid esters by a stronger effect, allowing it to be used in smaller amounts.

Surprisingly, it has been found that the optically active ester of the invention has an unexpectedly high average activity against a wide variety of grass species relative to the corresponding racemate, and especially an unexpectedly more potent effect on avian oats (Avena fatua) than the racemate at small applications.

The use can take place both in the post-emergence and in the pre-emergence process. Quantities of use can be varied within wide limits, e.g. between 0.01 and 2 kg of active substance per day. ha.

Also, the compound of formula I has favorable growth regulating effects (growth inhibition). In particular, it inhibits away-20 rocks of grass species.

The novel ester of formula I can be prepared by various methods.

The process of the invention is characterized in that a) 5-chloro-2,3-difluoropyridine of the formula

T

In an inert solvent or diluent, in the presence of the equimolar amount of a base, is reacted with the 4-hydroxyphenoxy-α-propionic acid ester of formula

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3ΪΗ3Η0 · (; -OCH-CO-OCH2-CsCH (III) * = · * (R) or b) an (R) -enantiomer 2- [4- (5-chloro-3-fluoropyridin-2-yl) -5 oxy) -phenoxy] -propionic acid halide of the formula? • - · y · "” · «. CH3

Cl - / - -0 - f OCH-COHal (VI) N = / * (R) wherein Hal represents fluorine, chlorine or bromine, in an inert solvent or diluent in the presence of the equimolar amount of a base, is reacted with propynol , H0CH2-C = CH.

Another method of preparing the ester of the invention consists in the fact that 4- (5-chloro-3-fluoropyridin-2-yloxy) -phenol of the formula? <IV)

Cl - (; · - <> ”</" ° H

15 in an inert solvent or diluent in the presence of the equimolar amount of a base is reacted with a (S) -enantiomer α-halogenopropionic acid propynyl ester of the formula CH 3 Hal-CH-CO-OCH 2 = CH (V) wherein Hal · means chlorine, bromine or iodine.

Also, the ester of formula I can be prepared by the (R) -enantiomeric 2- [4- (5-chloro-3-fluoropyridin-2-yloxy) -phenoxy] -propionic acid of the formula

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4

J H

Cl- / O- f O ^ H -COOH (VII) \ = / \ = / * (R) in an inert solvent or diluent and in the presence of the equimolar amount of a base is reacted with a propynyl halide of the formula

Hal-CH 2 -C = CH (VIII) wherein Hal represents halogen.

Finally, a further process consists of the (R) -enantiomeric 2- [4- (3-amino-5-chloropyridin-2-yloxy) -phenoxy] -propionic acid propynyl ester of the formula NH 2 ._o- / (ix).

according to known methods, it is converted to a diazonium salt and this is further converted to the fluorine compound.

According to another process, the (R) -enantio-15 ester of formula I is also prepared by reacting in 4- (5-chloro-3-fluoropyridin-2-yloxy) in an inert organic solvent and in the presence of a base. ) -phenol of the formula

Cl - () - 0 - (> -0H UV) with an (S) -enantiomeric lactic acid propynyl ester sulfonate of the formula

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Wherein R is a straight or branched C1-6 alkyl group which is unsubstituted or substituted by halogen, cyano, C1-4 alkoxycarbonyl or a phenyl group which is a R3 SO2OCH-CO-OCH2SCH (X) * (S) unsubstituted or substituted by halogen, C 1-4 alkyl, C 1-4 alkoxy, nitro, cyano or C 1-4 alkoxycarbonyl, then the (R) -2- [4- (5-chloro-3-fluoropyridin-2-yloxy)] -phenoxy] -propionic acid propynyl ester is isolated from the reaction mixture.

The starting compound of formula II, 5-chloro-2,3-difluoro-pyridine, can be prepared by fluorinating the corresponding 2,3,5-trichloropyridine in the presence of cesium fluoride. The product is distilled off from the reaction mixture and purified by fractional distillation. 5-Chloro-2,3-difluoropyridine is also prepared from 2,5-dichloro-3-nitro-pyridine, which is reduced to 3-amino-2,5-dichloro by means of hydrogen in the presence of Raney nickel catalyst. pyridine. The product is then converted with sodium nitrite in hydrogen fluoric acid to 2,5-dichloro-3-fluoropyridine. This compound can be fluorinated with good yield in the presence of potassium fluoride to 5-chloro-2,3-difluoropyridine.

4- (5-Chloro-3-fluoropyridyl-2-oxy) -phenol, the starting product of formula IV, is prepared by condensation of 5-chloro-2,3-difluoropyridine with hydroquinone, in an inert organic solvent in the presence of a base.

The starting compound of formula IX can be prepared by reducing the (R) -2- [4- (5-chloro-3-nitropyridin-2-yloxy) phenoxypropionic acid propynyl ester.

The other starting compounds are either known or known

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6 are readily prepared by commonly known synthetic methods. Part of these reactions is advantageously carried out in an organic solvent or diluent which is inert to the reactants such as e.g. an alcohol, an ester, an ether, a ketone, dimethylformamide, dimethylsulfoxide, acetonitrile, aromatic compounds such as benzene, toluene, etc.

The reaction temperatures are between -10 and 150 ° C, but usually between room temperature and the boiling point of the solvent. The reaction time, depending on the starting compound used, is the solvent and the temperature, from 1 hour to approx. 1 day.

If a halogen atom is decomposed by the reaction, the 15 equimolar amount of an acid binding agent should be used. As such, in principle, any inorganic or organic base, e.g. · NaOH, KOH, NaHCO 3, K 2 CO 3, K-tert-butanolate and amines such as trimethylamine, triethylamine, pyridine, 4-dimethylaminopyridine, etc.

The novel active substance of formula I is a stable compound which is soluble in conventional organic solvents such as alcohols, ethers, ketones, dimethylformamide, dimethylsulfoxide, etc.

The ester of formula I is used in unchanged form or preferably with the aids common to the formulation technique and is then processed in a known manner, e.g. for emulsion concentrates, directly sprayable or dilute solutions, diluted emulsions, spray powders, soluble powders, powder preparations, granules, and enclosures in e.g. polymeric substances. The methods of application, such as spraying, misting, spraying, spraying or pouring, as well as the nature of the agent are selected, taking into account the desired effects and conditions.

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The preparations, ie. the agents containing the active compound of formula I and optionally a solid or liquid additive, the preparations or compositions are prepared in known manner, e.g. by thoroughly mixing and / or grinding the active compounds with excipients such as e.g. solvents, solid carriers and optionally surfactants (surfactants).

As solvents, aromatic hydrocarbons may be used, preferably fractions C C₂i, such as xylene mixtures or substituted naphthalene, phthalic acid esters such as dibutyl or dioctyl phthalate, aliphatic hydrocarbons such as cyclohexane, or paraffins, alcohols and glycols, ether, , ethylene glycol monomethyl or ethyl ether, ketones such as cyclohexanone, highly polar solvents such as N-methyl-2-pyrrolidone, dimethylsulfoxide or dimethylformamide, and optionally epoxidized plant oils such as epoxidized coconut oil or soybean oil, or water.

As solid carriers, e.g. For powdering agents and dispersible powders, natural stone flour types such as calcite, talc, kaolin, mont-morillonite or attapulgite are usually used. To improve the physical properties, high-dispersion silicic acid or high-dispersion, suction-resistant polymerisates can also be added. Porous types, such as pumice, bricks, sepiolite or bentonite, can be used as granular adsorptive granular carriers, and as non-sorptive carriers, e.g. calcite or sand is used. In addition, a large number of pre-granulated materials of inorganic or organic nature can be used, e.g. especially dolomite or finely divided plant residues.

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As surfactants, depending on the nature of the active compound of formula I to be formulated, nonionic, cationic and / or anionic surfactants having good emulsifying, dispersing and wetting properties can be used. Surfactants also mean surfactant mixtures.

Suitable anionic surfactants may be so-called water-soluble soaps as well as water-soluble synthetic surfactants.

As soaps, the alkali metal, alkaline earth metal or optionally substituted ammonium salts of higher fatty acids (Cio-22) can be used, for example. The Na or K salts of oil or stearic acid, or of natural fatty acid mixtures, such as e.g. can be prepared from coconut oil or tallow oil. Also mentioned are the fatty acid methyltaurine salts.

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

The fatty sulfonates or sulphates are usually present as alkali metal, alkaline earth metal or optionally substituted ammonium salts, and they contain an alkyl group of 8-22 carbon atoms, the alkyl also comprising the alkyl portion 25 in acyl groups, e.g. The Na or Ca salt of lignin sulfonic acid, dodecyl sulfuric acid ester or a fatty alcohol sulfate mixture prepared from natural fatty acids. These include the salts of the sulfuric acid esters and sulfonic acids of fatty alcohol ethylene oxide addition products. The sulfonated benzimidazole derivatives preferably contain two sulfonic acid groups and a fatty acid residue of 8-22 carbon atoms. Examples of alkylarylsulfonates are the Na, Ga or triethanolamine salts of dodecylbenzenesulfonic acid, dibutylnaphthalenesulfonic acid or a naphthalenesulfonic acid.

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9 formaldehyde condensation product.

Further, similar phosphates can also be used, such as salts of the phosphoric acid ester of a p-nonylphenol-5 (4-14) ethylene oxide addition product.

As nonionic surfactants, polyglycol ether derivatives of aliphatic or cycloaliphatic alcohols, saturated or unsaturated fatty acids and alkyl phenols containing 3-30 glycol ether groups 10 and 8-20 carbon atoms in the (aliphatic) hydrocarbon group and 6-18 carbon atoms are used primarily. in the alkyl group of the alkyl phenols.

Other suitable nonionic surfactants are the water-soluble 20-250 ethylene glycol ether groups and 10-100 propylene glycol ether groups containing polyethylene oxide adducts of polypropylene glycol, ethylene diaminopolypropylene glycol and alkyl polypropylene glycol having 1-10 carbon atoms in the alkyl chains. The said compounds usually contain from 1 to 5 ethylene glycol units per liter. propylene glycol unit.

Examples of nonionic surfactants include nonylphenol polyethoxyethanols, castor oil polyglycol ethers, polypropylene-polyethylene oxide adducts, tribylphenoxypolyethoxyethanol, polyethylene glycol and octylphenoxypolyethoxyethanol.

Furthermore, fatty acid esters of polyoxyethylene sorbitan such as polyoxyethylene sorbitan trioleate can also be used.

Among the cationic surfactants, first of all, quaternary ammonium salts are used which contain as N substituents at least one alkyl group of 8-22 carbon atoms and which further substituents contain lower, optionally halogenated alkyl, benzyl or low hydroxyalkyl groups.

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The salts are preferably present as halides, methyl sulfates or ethyl sulphates, e.g. the stearyltrimethylammonium chloride or the benzyldi (2-chloroethyl) ethylammonium bromide.

The surfactants commonly used in the formulation technique include: described in the following publications: "McCutcheon's Detergents and Emulsifiers Annual" MC Publishing Corp., Ringwood, New Jersey, USA, 1979.

10 Sisley and Wood, "Encyclopedia of Surface Active Agents", Chemical Publishing Co., Inc. New York, USA, 1964.

The compositions usually contain 0.1-99%, especially 0.1-95%, active substance of formula I, 1-99% of a solid or liquid additive and 0-25%, especially 0.1-25%, surfactant. .

15 While, as a commodity, concentrated funds are rather preferred, the end consumer usually uses diluted funds.

The agents may also contain additional additives such as stabilizers, anti-foaming agents, viscosity regulators, binders, adhesives, and fertilizers or other active compounds to achieve special effects.

The following examples describe in detail the preparation of the (R) -2- [4- (5-chloro-3-fluoropyridin-2-yloxy) -phenoxy] -propionic acid propynyl ester of formula I, as well as agents containing this ester as the active agent. connection. Percentages are calculated on a weight basis.

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Example 1

Preparation of (R) -2- [4- (5-Chloro-3-fluoropyridin-2-yloxy) -phenoxy] -propionic acid propynyl ester J CH3 c1.1 / N-O- and Cooch2-csch N- '* (*>

A solution of 24.2 g (0.11 mol) of (R) -2- (4-hydroxyphenoxy) propionic acid propynyl ester in 80 ml of dimethylformamide is slowly added dropwise at 10 ° C to a stirred suspension of 4.9 g (0). Sodium hydride suspension (55%) in dimethylformamide. When everything is added, stir for an additional 1 hour at the same temperature. Then a solution of 16.4 g (0.10 mol) of 5-chloro-2,3-difluoropyridine in 40 ml of dimethylformamide is added dropwise to the reaction mixture and stirred for 24 hours at room temperature. The reaction mixture is then poured into ice / water and the organic material is extracted three times with ether. The ether phases are collected, washed with water and NaCl solution, dried with magnesium silicate and filtered over silica gel. After evaporation of the ether filtrate, a clear oil is left which is crystallized out of ethanol. There is thus obtained 25 g (72% of theoretical yield) of the (R) propynyl ester. Melting point 55-56 ° C.

The 5-chloro-2,3-difluoropyridine used as the starting material is prepared as follows: a) 3-Amino-2,5-dichloropyridine To a solution of 129.2 g (0.69 mol) of 2, 5-dichloro -3-nitropyridine in 1300 ml of dioxane is added 26 g of Raney nickel, which is first washed with ethanol. The mixture is now hydrogenated with hydrogen at 20-35 ° C at normal pressure. When 20% of the theoretical amount of hydrogen is taken up, 30 g of Raney nickel, which is washed with ethanol, are added again.

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The hydrogenation is carried out for another 22 hours, then the catalyst is filtered off, the solvent is evaporated and the residue is crystallized by hexane / ethyl acetate. There is thus obtained 84.9 g of 3-amino-2,5-dichloropyridine, which melts at 129-132 ° C. Yield: 78% of theory.

b) 2,5-Dichloro-3-fluoropyridine In a steel autoclave, 450 ml (22.5 mol) of hydrogen fluoride is placed. To this is added 163 g (1.0 mole) of 3-amino-2,5-dichloropyridine with stirring at a temperature of -1 ° C. Then 82.8 g (1.2 moles) of sodium nitrite are slowly added to the solution at the same temperature. When all is added, stir for an additional 1.5 hours at a temperature of -5 to -1 ° C, and the reaction mixture is gradually heated to 60 ° C. When gas evolution has ceased, the hydrogen fluoride is distilled off and the residue is taken up in methylene chloride. Then ice and water are added to the mixture and neutralized with concentrated ammonia. The organic phase is separated and the aqueous phase is washed three times with methylene chloride. The combined organic phases are washed with water, dried over magnesium sulfate, filtered through silica gel and evaporated.

In this way 141.5 g (85% of theoretical yield) of 2,5-dichloro-3-fluoropyridine is obtained.

C) 5-Chloro-2,3-difluoropyridine

A suspension of 64.6 g (1.1 mole) of potassium fluoride and 11.25 g (0.075 mole) of cesium fluoride in 240 ml of sulfolane (1,1-dioxo-tetrahydrothiophene) is prepared. When heated under reduced pressure, 50 ml of sulfolane is distilled off. To the remaining suspension is added, with stirring, a solution of 61.4 g (0.37 mol) of 2,5-dichloro-3-fluoropyridine in 20 ml of sulfolane. The mixture is then stirred for 35 hours at 140 ° C. After cooling, the mixture is poured onto ice / water and the organic matter is extracted with ether. The ether phase 35 is washed with water, dried with magnesium sulfate, filtered and evaporated. 48.7 g are obtained

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13 5-Chloro-2,3-difluoropyridine as a colorless liquid boiling at 65-69 ° C / 133 mbar. Yield: 88% of theory.

Example 2

Preparation of (R) (+) - 2- [4- (5-Chloro-3-fluoropyridyl-2-oxy) -phenoxy] -propionic acid propynyl ester

Cl— (o — f o? H-cooch2-csch • ~ w χ · = · * (R)

A solution of 4.9 ml (0.035 mol) of triethylamine and 2 ml of 10 (0.035 mol) of propynol in 40 ml of toluene is prepared and cooled with ice / water. To the mixture is added dropwise 10.6 g (0.030 mol) of (R) -2- [4- (5-chloro-3-fluoropyridin-2-yloxy) phenoxy] propionyl chloride in 30 ml of toluene over 45 minutes.

Then stir for 3 hours at room temperature. The reaction mixture is then poured onto 150 ml of ice / water and extracted twice with acetic acid ethyl ester. The extracts are washed with NaCl solution, dried over magnesium sulfate, filtered and evaporated. The residue is taken up in hexane / ethyl acetate (2: 1) and chromatographed over a silica gel column for purification. After evaporation of the solvent, the residue crystallizes. The crystals melt at 54 ° C, [a] §0 + 45.4 ° (2% in acetone).

The (R) -2- [4- (5-chloro-3-fluoropyridin-2-yloxy) -phenoxy] -propionic acid chloride used as starting material is prepared as follows: a) 4- (5-Chloro-3-fluoropyridine) 2-yloxyphenol Under a nitrogen atmosphere, a mixture of 27.5 g (0.25 mole) of hydroguinone, 11.2 g (0.2 mole) of potassium hydroxide and 600 ml of dimethyl sulfoxide is stirred until dissolved. Then 30 drops dropwise with stirring a solution of 30 g (0.2 mol)

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14 5-Chloro-2,3-difluoropyridine in 200 ml of dimethyl sulfoxide. The reaction solution is then heated to 70 ° C and stirred for 4 hours at this temperature. The mixture is then poured onto 5 ice / water, acidified with concentrated hydrochloric acid and extracted with ethyl acetate. The organic phases are washed, dried with magnesium sulfate, filtered and evaporated to dryness. The residue is taken up in hexane / ethyl acetate and chromatographed over a silica gel column for purification. After evaporation of the solvent, the residue crystallizes. 33 g of 4- (5-chloro-3-fluoropyridin-2-yloxy) phenol are obtained as white crystals melting at 97-98 ° C.

b) (R) -2- [4- (5-Chloro-3-fluoropyridin-2-yloxy) -phenoxy] propionic acid methyl ester

To a suspension of 13.8 g (0.1 mole) of potassium carbonate in 50 ml of dimethyl sulfoxide is added dropwise with stirring a solution of 24.0 g (0.1 mole) of 4- (5-chloro-3-fluoropyridin-2-yloxy) ) -phenol in 80 ml of dimethyl sulfoxide, and the mixture is stirred for 2 hours at room temperature. To the mixture, a solution of 25.8 g (0.1 mole) of S (-) lactic acid methyl ester tosylate in 30 ml of dimethyl sulfoxide is added dropwise over 30 minutes. Then, the reaction mixture is stirred for 20 hours at 60 ° C. For work up, the mixture is poured onto ice / water and extracted three times with ether. The extracts are washed with water and NaCl solution, dried over. magnesium sulfate, filtered and evaporated. The crude product obtained is purified by chromatography on silica gel (solvent mixture: hexane / acetic acid ethyl ester 3: 1). Thus, 26.0 g of pure substance is obtained as an oil ([α] §0 = + 38.8 ί0.5 ° in acetone).

c) (R) (+) -2- [4- (5-Chloro-3-fluoropyridin-2-yloxy) -phenoxy 1-propionic acid 13.0 g (0.040 mol) (R) (+) - 2 - [4- (5-Chloro-3-fluoropyridin-2-35 yloxy) -phenoxy] -propionic acid methyl ester is dissolved in 65 ml of dioxane. Then 42 ml of 1 N sodium hydroxide solution is added

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The mixture is stirred and the mixture is heated to 35 ° C for 2.5 hours. Then the reaction mixture is poured onto ice / water and acidified with 22 ml of 2N hydrochloric acid. Then extract twice with ethyl acetate, wash the extracts with NaCl solution, dry with magnesium sulfate, filter and evaporate. The residue is crystallized by acetic acid ethyl ester / hexane. Thus, 10.2 g of white crystals are obtained, mp 95-96 ° C. Yield 81.8% of theory. [a] §0 +37.7 t0.5 ° in acetone.

d) (R) -2- [4- (5-Chloro-3-fluoropyridin-2-yloxy) -phenoxy] -propionic acid chloride 10.8 g (0.035 mol) (R) -2- [4- (5-chloro) Dissolve -3-fluoropyridin-2-yloxy-phenoxy] -propionic acid in 150 ml of toluene. At a bath temperature of 130 ° C, 50 ml of toluene is distilled off.

The mixture is then cooled to an internal temperature of 90 ° C and 3.8 ml of thionyl chloride is added dropwise slowly with stirring. The reaction mixture is stirred for 16 hours at the same temperature and then evaporated under vacuum.

The acid chloride thus obtained, having a melting point of 47-48 ° C, is used directly further.

Example 3

Preparation of a liquid active compound of formula I (% = wt%).

Emulsion Concentrate a) b) c) (R) -2- [4- (5-Chloro-3-fluoropyridin-2-yloxy) phenoxy] propionic acid propynyl ester 20% 40% 50%

Ca-Dodecylbenzenesulfonate 5% 8% 5.8% Castor oil polyethylene glycol ether (36 mol EO) 5% -

Tributylphenol-polyethylene glycol ether (30 moles EO) - 12% 4.2%

Cyclohexanone - 15% 20%

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Xylene blending 70% 25% 20%

From such concentrates, emulsions of any desired concentration can be prepared by dilution with water.

Solutions a) b) c) d)

Propynyl ester (as above) 80% 10% 5% 95%

Ethylene glycol monomethyl ether 20% - -

Polyethylene Glycol (Molecular Weight 400) - 70% N-Methyl-2-pyrrolidone - 20% -

Epoxidized Coconut Oil - - 1% 5%

Gasoline (boiling range 160-190 ° C) - - 94%

The solutions are suitable for use in the form of very small droplets.

Granules a) b) (R) -2- (5-Chloro-3-fluoropyridin-2-yloxy) phenoxy] propionic acid propynyl ester 5% 10%

Kaolin 94% High-dispersion silicic acid 1% 20 Attapulgite> - 90%

The active substance is dissolved in methylene chloride, sprayed onto the carrier and then the solvent is evaporated in vacuo.

Powder preparation a) b)

Propynyl ester 2% 5% 25 High-dispersion silicic acid 1% 5%

Talc 97%

Kaolin - 90%

To obtain a ready-to-use powder preparation, mix the active substance thoroughly with the carriers.

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Formulation Examples for Solids, Formulas of Formula I (% = wt%) a) Spray Tea Powder a) b) 5 Propynyl Ester 20% 60%

Na-lignin sulfonate 5% 5%

Na-Lauryl Sulfate 3%

Na-Diisobutylnaphthalenesulfonate - 6%

Octylphenol polyethylene glycol ether 10 (7-8 moles EO) 2% High-dispersion silicic acid 5% 27%

Kaolin 67%

The active substance is thoroughly mixed with the additives and the mixture is thoroughly ground on a suitable mill. A spray powder is obtained which, by dilution with water, can be made into suspensions of any desired concentration.

Emulsion Concentrate (R) -2- [4- (5-Chloro-3-fluoropyridin-2-yloxy) -phenoxy] -propionic acid propynyl ester 10%

Octylphenol polyethylene glycol ether (4-5 mol E0) 3%

Ca-Dodecylbenzenesulfonate 3%

Castor oil polyglycol ether (36 mol EO) 4% Cyclohexanone 30%

Xylene blending 50%

From this concentrate, emulsions of any desired concentration can be prepared by dilution with water. 1

Powder preparation a) b)

Propynyl ester 5% 8%

Talc 95% -

Kaolin - 92%

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To obtain a ready-to-use powder preparation, mix the active ingredient with the carrier and grind the mixture on a suitable mill.

Extruder granules

Propynyl ester 10%

Na-lignin sulfonate 2%

Carboxymethyl cellulose 1%

Kaolin 87% 10 The active substance is mixed with the additives and the mixture is ground and wetted with water. The moist mixture is extruded and then dried in an air stream.

Omhylningsgranulat

Propynyl ester 3% Polyethylene Glycol (Molecular Weight 200) 3%

Kaolin 94%

The finely ground active substance is uniformly applied in a mixer to the kaolin wetted with polyethylene glycol.

In this way, dust-free casing granules are obtained.

Suspension Concentrate (R) - 2- [4- (5-Chloro-3-fluoropyridin-2-yloxy) phenoxy] propionic acid propynyl ester 40%

Ethylene glycol 10%

Nonylphenol polyethylene glycol ether (15 mol EO) 6%

Na-lignin sulfonate 10%

Carboxymethyl cellulose 1% 37% aqueous formaldehyde solution 0.2%

Silicone oil in the form of a 75% fs aqueous emulsion 0.8% 30 Water 32%

The finely ground, active substance is carefully mixed

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19 the additives. A suspension concentrate is obtained from which, by dilution with water, suspensions of any desired concentration can be prepared.

Example 5

Herbicidal action

Postemergic herbicide action (contact herbicide)

The grasses Zea maize, Sorghum hybridum, Oryza sativa,

Avena fatua, Bromus tectorum, Lolium perenne, Alopecurus 10 myosuroides, Digitaria sanguinalis, Echinochloa crus galli, Sorghum tailpipe and Rottboellia exaltata are grown in pots in a greenhouse and after the growth (in 4, - to 6th leaf stage), the plant is sprayed dispersion of the (R) enantiomer of the invention and the corresponding racemate in different dosages, expressed in active substance per ha and maintain a temperature of 24-26 ° C at a relative humidity of 45-60%, watering * regularly. The trial is evaluated 10 days after treatment. The damage done to the plants is assessed on a 9 scale.

20 Plant 9 corresponds to untreated control plants 1 total damage, plant gone 2-8 stages of damage

Bonus is determined for each amount of use on the 25 tested grass species and the average value is plotted on the drawing.

In the drawing, the average post-energy activity of both the tested active substances against the grasses is depicted. As can be seen from the figure, an amount of 86 g of active ingredient per gram must be used to obtain 30 of a goodness value of 3, which corresponds to a good herbicidal effect. ha of the breed food. Surprisingly, the same degree of control can already be obtained with 42 g of active substance per day.

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20 ha when the R-enantiomer is used. This shows an unexpected increase in activity by more than a factor of 2.

Example 6 5 In a greenhouse experiment, the herbicidal effect of the compound of the invention is compared to the formula

Cl - () -O- (0? IFC0-0CH2ChCH (i) • = r · = · * (r) with the herbicidal effect of the one from EP patent no.

83,556 known compound of the formula Y - ch 3 Cl - (). -O- () -OCH-C00CH 2 CsCH 2 • = w · = ·

The compounds are formulated as 10% emulsion concentrates with the following compositions, the percentages being by weight.

10% test compound 15 3% octylphenol polyethylene glycol ether with 4-5 moles of ethylene oxide 3% calcium dodecylbenzenesulfonate 4% castor oil polyglycol ether with 36 moles of ethylene oxide 30% cyclohexanone 30 30% xylene mixture

The finely ground test compound is thoroughly mixed with the additives and the mixture is ground in a ball mill. An emulsion concentrate is obtained which, upon dilution with water, gives a spray liquid containing the test compound at a concentration which per ha corresponds to the specified quantity and 500 l water.

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The experiment is carried out as follows:

Postemergent herbicidal action

Various grasses are grown in pots in a greenhouse, and 5 after emergence (in the 4th to 6th leaf stage), the plants are sprayed with an aqueous dispersion of the test compound in various dosages expressed in grams of test compound and 500 l water per day. ha. The plants are then kept at a temperature of 24-26 ° C at a relative humidity of 45-60% 10 and regular watering. The trial is evaluated 2 weeks after treatment. The resulting damage to the plants is expressed as a percentage as follows: 0% means no damage, the plant grows as an untreated control plant 15 100% means total damage, the plant has gone out.

The plant damage between them is assessed linearly.

The results are shown in the following table.

DK 162216 B

22

RTP

o m island i 'd

Λ 11 C

0 o 0 0 β M ø M ø 0 P 0 0 g -H p * ϋ · -P ø ø • h ø m u ø -p g

te O β »ø S

• η -p p »s ø β oø in« & se ^ & se «S'Sss ^ SfrS μ ω ø o Λ $ &

oce o od tn un co co n co d ^ -P 0 P

<djj o cn cn cn σ \ σ \ r- * o, β 0 β Η p β ø • U Η H Ό 0 - ft 0 0

• u «, ¾ β rP β Q H

o X P -H ft 0 β 0 ** ffl___8 Λ i — i 0 · tn

two -P P 0 g Ό ø -P

oh 0 0 Ti P, β tf HH „„ „> P 0 O ° ø \ ø æh S'Ss-ss'Se-s ^ M ^ p ø T3 m Pj tn 44 o ω o o o o o o o o 2 J? yeah _. .. _ Ϊ} - oooo o o o o · ΰ ^ Ή Ό -P O 0 • HW Η Η H, —I Hi — li — IH ø Λ 0 ø co β Æ 3 P P g g 0

O U 0 o -P g «0 -P

M ° ___ 0 JP M β g ft 0 r ~ h oøø p

• H 0. +1 0 p ø TØL

β η «« o. Ό - h m ό m H Cd SS δί 5 «6? B-S & «B ·« & -S β p 4-1 0 tn

a h o od m m w m m m 'rfS ^' SR'SiS

jj3 o ^ ^ σ \ σ \ r · * r * Λ w £ j 0 ro ° (tf • h cd η P 0 P -H g β co s 0 t0 0 m -P 0 ft

Htd 4-1 p p ft 0 0 O

and w___0 tn β o P 0

- b> - +1 Ό. Η P

O- h ø m ø ø 0) 0 P P tn Ό t) te s «i« si δί & «bs & ·« b-s pø ^! H «.β

^ 3 S o co co co co tn co eo ιρ β -p li o t> O

P æo.OCT'O'O ovotvocn hspimho ^ o

P a> αΓ η Λ _3, ^ S

ø uh ΟΗΡ ø »· to ο co -Ρ ft 0 β Ό tn flj w —__ ø ø β β β £ - ^ Γ ~ Ι øøøøøø · ΗΡ Ο« ® Ό Ό S Η β0 o-a 0 ρ 0 0 ό λ:>

w η s? si ^ si • POtn'dPøPO

ο 2 ο co η co co ο ν co -Λ «Λε -> '§ OO Ρ g Ρ ° ø 0 0 η>, 0-pøOftPPtn h <s + j λ; ø m> øo m ø β Η p ø tn n · Ρ00Ό0β00 ø H ft ø -P ø> β

Eh BSB'SB ^ & s & SB'Sess'S PtJgSc!> 0 \ O co co tn eotn »o Increase, ^ g g oosotn cor-co M ^ ø ^ Dtiløo §5 +> β H 0 - tn«>.

> cd 0 0 P tn 0 <4-t 'OØHg-Søpoø - β g -P 0 0 P ft 0 g 4J β P -P β

»0 0 0 ø 0 P

b ^ s-5 b-s &? ^ s ^ s & ss ^ -P p ø pmm ø ω ø m Ό ø p Ό ε cg £ g £ S øHøøøtn 3C cno'i-o o co o co 0 &> βΗΗβββ> 0 tn 0 H 0 tø O Ϊ 0 0 ø > ri! g yes -P 0 <! ø - (-—-- m ø m o m øø icoQ) ØP-PPØØØØ

d 0 0 ø ro n o O © tn o © Ό. > P -Ρ Η H

ø ø tj>, p in cn o co in cnj o co P'PHØPfløø

Q | rice cm h ns h oø Ø ^ ØøtJ'd β 0 ft} tn & ι · »Οι ^ 40Ηββ ιβ g gtngpHft-HØ __ 0β0000Χ1> p -H ø tn + J p β Φ ιΡβΛ!> .- Ρ03θ ø in co AiøøOpm

μβΗ ^^ -P P -r-iøP-PO

0 -H 0 0 · Η P 0 Λ Λ ø 0 Q> 000pg>

Claims (4)

Herbicide and plant growth inhibitor, characterized in that it contains as the active substance (R) -2- [4- (5-chloro-3-fluoropyridin-2-yloxy) -phenoxy] -propionic acid propynyl ester of claim 1 together with inert 10 additives. Use of the (R) -2- [4- (5-chloro-3-fluoropyridin-2-yloxy) -phenoxy] -propionic acid propynyl ester of claim 1 or an agent containing it, as a selective herbicide in culture plantings. Process for preparing the (R) -2- [4- (5-chloro-3-fluoropyridin-2-yloxy) -phenoxy] -propionic acid prop-ynyl ester according to claim 1, characterized in that a) 5-chloro-2 , 3-difluoropyridine of the formula? an-inert solvent or diluent, in the presence of the equimolar amount of a base, is reacted with the 4-hydroxyphenoxy-α-propionic acid ester of formula 9Ha ho ·; and (b) an (R) -enantiomer 2- [4- (5-chloro-3-fluoropyridin-2-yl-oxy) - and phenoxy] -propionic acid halide of formula f Wherein Hal means fluorine, chlorine or bromine, in an inert solvent or diluent in the presence of the equimolar amount of a base, is reacted with propynol, HOCH2- C = CH.