DE2812571C2 - 2- [4- (5-trifluoromethyl-2-pyridyloxy) phenoxy] propionic acid derivatives and herbicides containing these compounds - Google Patents

Description

2. Ethyl ^ -H-i.S-trifluoromethyl ^ -pyridyloxyH'hcnoxyl-propionat.

3. 2- [4- (5-Trifluoromethyl-2-pyridyIoxy) -phenoxyl-propionic acid c.

4.2- [4- (3-chloro-5-trifluoromethyl-2-pyridyloxy) -phynoxy] -propionic acid.

5. Herbicidal agent containing a compound according to claim I and customary additives.

The invention relates to new 2- [4- (5-trifluoromethyl-2-pyridyloxy) -phynoxy | -propioiisäurcderivatc, which are suitable as herbicides in agriculture and in horticulture, and herbicidal compositions which contain these and a method for controlling weeds using the same. A number of herbicides have recently been developed and tried in practice. This herbicide .laben contributed significantly to saving labor costs and increasing agricultural production. But there is still a need for improvement and for new chemicals, crops only They do little harm but have a strong herbicidal effect on undesirable plants and are safe in terms of environmental pollution. An example of this are phenoxyalkanecarboxylic acids, for example 2,4-dichlorophenoxyacetic acid, which has been known for a long time and has a very good effect in terms of Broadleaf weed control has and is used to a considerable extent. There however, phenoxyalkanecarboxylic acids have little activity against gruesome weeds, which are the major noxious weeds and are phytotoxic to broad-leaved plants, too which also include cultivated plants and cultivated trees, these chemicals have only limited applicability

In recent years, 4-phenoxy-phynoxy-alkanecarboxylic acids, which have a control effect on grass-like weeds and which are not phytotoxic to broad-leaved crops, have been described as herbicides, for example in DE-OS 22 23 894 (US 39 54 442). Improvements to these herbicidal compounds have been described in DH-OS 24 33 067 and DE-OS 25 46 251 (corresponding to US Pat. No. 4,046,553), but these improvements are not yet sufficient.

The present invention relates to compounds of the general formula (1)

(D

where mean: 55

Y is a hydrogen atom or a chlorine atom,

Z ^{1 is} a hydroxy group, cine (C,.,) - alkoxy group, cine (C,.,) - alkunyloxy group, cine (C,,,) - cycloalkoxy group, or an -O-cation.

The invention also relates to herbicidal compositions composed of a herbicidally effective amount of at least one of the compounds of the aforementioned formula (I) in addition to an agriculturally suitable adjuvant.

The invention also relates to a method for controlling weeds using a herbicidally effective amount of the aforementioned herbicidal composition.

The compounds of the formula (I) which are herbicides (hereinafter referred to as “herbicidal compounds”) new compounds and have exceptional herbicidal activity different from the herbicidal activities of the known species of herbicidal compounds. Dk herbicidal compounds according to Invention have the following three important properties:

(1) The compounds of the formula (1) have a strong selective herbicidal activity against grasses. Since, on the other hand, they affect broad-leaved plants only to a small extent, especially those that are too have already grown to a certain extent, they can with great certainty in broad-leaved crops or useful trees. In other words, the compounds according to the invention have an inverse selectivity and a much higher selectivity than the known phenoxyalkarboxylic acids.

(2) The compounds of the formula (I) have a great ability to translocate in plant structures. the Compounds are absorbed by the leaves and roots of plants and mainly cause damage to the meristemic cells in the nodes, resulting in withering, falling off and death of the Plants leads. Even if they are only applied to a very limited area of the plant structure, they show strong herbicidal activity there and weeds that have already grown considerably wither and die due to the activity of the compounds according to the invention.

(3) The compounds of the formula (I) have an excellent control effect on the regrowth of perennial grassy weeds and are safe against cotton as compared with the known 4-phenoxy- or 4- (2-pyridyloxy) -phenoxyalkanecarboxylic acids. With regard to the wilting and killing of perennial grassy weeds, which are very difficult to control, the compounds of the form.! (I) a higher ability to translocate than 4-phenoxy- or 4- (2-pyridyloxy) -phenoxyalkanecarboxylic acids atifanä they also have a sufficient effect on the part of the plant to which it translocates, so that the plant, including the Roots wilts and dies and controls the regrowth of plants). As a result, the compounds of formula (I) are very useful for killing undesirable plants with only a small number of uses.

Suitable cations for the -O-potassium ion are alkali ions, such as the sodium ion and the potassium ion, and alkaline earth ions, such as the calcium ion and the magnesium ion, an ammonium ion, an organic ammonium ion, such as Dimethylammonium ion and diethanoiammonium ion.

The herbicidal compounds of formula (I) can be used as active ingredients in herbicidal compositions, as will be apparent from the experimental examples below. The compounds of the general formula (I)

CH ₃

in which Y is a hydrogen atom or a chlorine atom and Z 'is a hydroxyl group or a are particularly preferred. Typical examples of compounds of formula (I) are given below.

/ / Il O / I l'liysikulischc consensus CF ₃ - ^, > —Ο- -Cl - <> - OCHCZ ¹ X-N -Il Oll Ip 97-H) O ⁰ C CH ₃ -Oll Mp 107-109 ⁰ C link γ -Cl -OCII, Mp 72-74 ° C No. -Il Bp 175-177 ° C / 2 milligrams I. -OCII, Mp 55-57 ° C 2 -Cl -OCII ₅ Mp 63-65 ° C 3 II Bp 182-185 ° C73mmHg Il -O-C.IMn) Bp 205-207 ° C72mmHg 4th Il OCIi, cn - cn. Kp l98-202 ° C / 3 milligrams 5 Cl - <> - <· ■> ' Kp 207-210 ⁰ CVI mmllg O "Na" ¹ Ip 70 75 ° C 6th O "Nu" ¹ ' l ^; o 100 I0.VC 7th K 9 IO

The compounds of the formula (I) according to the invention can be prepared by one of the procedures Λ or B. procedure A is preferred.

Procedure A

A 2-halo-5-trifluonomethylpyridine of the formula (II) Y

CF ₃

Shark

(H)

where Hai denotes a halogen atom and Y has the meaning given above, and a substituted Phe-IS nol of formula (III)

HO-

(HI)

wherein Q is a hydroxyl group, a C | -C ₄ ) -Alkor.ygruppe or a CH ₃ O

• ¹ L

- OCH - CZT group

denotes in which Z ⁴ denotes a hydroxyl group, a (C | -C ₄ ) -alkoxy group or an amino group, are first condensed, for example using equimolar amounts of the compound of the formula (II) and the compound of the formula (III), and although in the presence of an alkaline material in a 1- to 1.2-fold molar amount of the compound of the formula (III) with the formation of a substituted pyridylphenyl ether of the formula (IV)

CF ₃

(IV)

where Y u ^ d Q o \ <i have the meaning given above. Does Q mean a

CH ₃ Ö - OCH - CZ * group,

45 this gives a compound with formula (V) γ CH ₃

a ^ A ^.

_CFj ^ f \ -Of VOCH-CZ ⁴

(V)

-N

wherein Y and Z ^{4 have} the meaning given above. In any case, the resulting product of the formula (V) can be treated in the usual manner in order to convert Z ⁴ into Z ', whereby a herbicidal compound of the formula (I) is then obtained.

If Q is a (C | _{-C 4} ) -alkoxy group or a hydroxy group, the resulting substituted pyridyl-p-hydroxyphynyluethcr of the formula (VI)

OH

(VI)

in which Y has the meaning given above, and a haloalkanecarboxylic acid or a derivative thereof of the formula IVII)

CH ₃

Hal —CH-

in which Hal and Z ' ^{1 have} the meaning given above, condensed, for example using equimolar amounts of the compound of the formula (VI) and the compound of the formula (VI) in the presence of an alkaline material, in a molar I- up to 1.2 times the amount of the compound of the formula (VI) with or without prior alkylation (ie to remove the alkyl radical of the (C _{1 -C 4} ) alkoxy group) with formation of a compound of the formula (V) or a salt of it as previously described.

Procedure B

Trifluoromethyl iodide is combined with a compound of the formula (VIII)

CH ₃

(VIII)

in which T is a bromine atom or an Jodalom and Y and Z ⁴ have the previously given meaning, in the presence of Kupierstaub and a polar aprotic solvent such as pyridine, sulfolane, dimethylformamide or Dimelhylsulfoxid, at a temperature of 100 to 200 ⁰ CI 24 Reacted hours, using a compound of the formula (IX)

receives, in which Y and Z ^{4 have} the meaning given above. If desired, the substituent Z ^{4 of} the formula (IX) can be converted into Z ¹ in the customary manner, a herbicidal compound of the formula (I) being obtained.

The mentioned processes for the preparation of the compounds of the formula (1) or the intermediates used therein are described in more detail below.
[AI] The compound of the formula (V)

in which Y and Z ^{4 have} the meaning given above, can be prepared by adding a substituted pyridine of the formula (II)

■ 40

CF ₃ -

Shark

50

in which Hai and Y have the meaning given above, with a parahydroxyphenoxyalkanecarboxylic acid or a derivative thereof of the formula (X)

CH ₃

HO-

OCH —CZ ⁴

(X)

60

in which Z ^{4 have} the meaning given above, condensed, the compound of the formula (II) being used in an equimolar amount to the amount of the compound of the formula (X) and the condensation in the presence of an alkali material in an amount ranging from i to i, 2 may correspond to the moiarcn amount of the compound uut formula (X), at a temperature of at least 50 ⁰ C, preferably 70 to 180 ⁰ C, and a pressure of preferably atmospheric pressure for 1 to 20 hours, preferably 1 to 10 hours.

65

izy / \

| A-2 | The relationship between the formula (V)

CH,

CF, - <f y — o— <f \ - och — cz ⁴

(V)

in which Y and Z ^{4 have} the meaning given above, or a salt thereof can be prepared by adding a substituted pyridine of the formula (II)

Ihil

(N)

in which Hai and Y have the meaning given above, condensed with a hydroquinone and the connection of the form! (ii) in cinC'i / u uCiVi üyürocninon äQüiiTioiürcn amount arigeveridei vv: rd u "dd: e Kc" -2n densation in the presence of an alkaline material in an amount corresponding to 1 to 1.2 times the molar amount of the hydroquinone, preferably at a temperature of at least 50 ⁰ C. 70 to 18O ⁰ C, under an inert atmosphere, for example Stickstof ', for 1 to 20 hours to form a substituted pyridyl-p-hydroxyphenyläthers of formula (Vl) is carried out!:

OH

(VI)

.ii Formula (Vl), Y has the meaning given above. Then the compound of formula (VI) with a Halognaikancarbonsäurc or a derivative thereof of the formula (VII)

CH ₃

(VH)

in which Hal and Z ^{4 have} the meaning given above, condensed, the compound of the formula (VI) being used in an equimolar amount to the amount of the compound of the formula (VII) and the condensation in the presence of an alkaline material in an amount which corresponds to I to 1.2 times the molar amount of the compound of the formula (VI) is carried out at a temperature of 40 to 200 ^° C. and a pressure which is preferably atmospheric pressure for 0.5 to 10 hours.

45 [A-3] The compound of the formula (V)

CF ₃

CH ₃

OCH-CZ ⁴

(V)

in which Y and Z ^{4 have} the meaning given above or a salt thereof can be prepared by adding a substituted pyridine of the formula (II)

CF ₃ -cf> -Hal

in which Hai and Y have the meaning given above, with a hydroquinone monoaikyl ether of the formula (Xl)

HO- ey- O-alkyl (XD

in which "alkyl" means a (C, -C ₄ ) -alkyl group, condenses, the compound of the formula (II) in

an iiqui molar amount / u of the compound of the formula (Xl) is applied and the condensation in the presence of an alkaline material in an amount corresponding to I to 1.2 times the molar amount of the compound of the formula I (Xl), at a temperature of at least 5UE ° C, preferably 7Cbis 180 ⁰ C, is carried out at a pressure of preferably atmospheric pressure for I to 20 hours, preferably I to 10 hours, to form <? ines substituted pyridyl-p-alkoxyphcnyläthcrs of formula (XII)

_{| 0}

in which Y and "alkyl" have the meaning given above. In dialkylation of the compound of the formula (XII) one obtains a substituted pyridyl-p-hydroxyphynyl ether of the form! (VI)

is

where Y has the meaning given above. Then the compound of the formula (VI) with a haloalkanecarboxylic acid or a derivative thereof of the formula (VII)

¹ L

Shark - CH - CT

in which Hal and Z ^{4 have} the meaning given above, condensed, the compound of the formula (VI) being used in an amount which is equimolar to the amount of the compound of the formula (VIl) and the condensation in the presence of an alkaline material in an amount which corresponds to 1 to 1.2 times the molar amount of the compound of the formula (VI) is carried out at a temperature of 40 to 200 ^° C. and a pressure of preferably atmospheric pressure for 0.5 to 10 hours.

Examples of suitable alkaline materials which can be used in all condensation reactions of the type described above are alkali hydroxides such as sodium hydroxide or potassium hydroxide, and alkali carbonates such as sodium carbonate or potassium carbonate. In the first condensation, a suitable reaction temperature is at least 50 ° C, preferably 70 to 180 ⁰ C, and the reaction time is generally 1 to 20 hours, preferably I to 10 hours. A ketone such as methyl ethyl ketone or methyl isobutyl ketone or a polar aprotic solvent such as dimethylformamide, dimethyl acetamide, dimethylsulfoxH, N-methylpyrrolidone, methylphosphoramide or sulfolane can be used as the solvent in this reaction. A suitable reaction temperature for the second condensation is from 40 to 200 ^° C. and the reaction time is generally from 0.5 to 10 hours. In this second condensation, a ketone such as methyl ethyl ketone or methyl isobutyl ketone or toluene can be used as the solvent.

In dealkylation, a dealkylation agent is used in a molar amount which is 1.5 to 2 times that of Amount of the compound of the formula (Xl) is used.

Pyridine hydrochloride is used as Deaikylierungsmittel in ücalkylierung, the reaction temperature is preferably 50 to 250 ° C, in particular 130 to 200 ⁰ C and the pressure is preferably atmospheric pressure and the reaction time is generally from 1 to 10 hours. If a hydrohalic acid with a concentration of 40 to 60% by weight, such as hydrobromic acid or hydriodic acid, is used as the dealkylation agent, the dealkylation reaction is preferably carried out in the presence of a (C ₁ -Q) -FeU acid as a solvent, such as acetic acid or lissetic anhydride an amount that makes up the I- 50fachc to the volume of the compound of formula (VI), while I to IO hours and preferably Almosphärendruck at a temperature of 90 to LSO performed ^0C.

Procedure for transferring /. ' the form! (V) in /. ' of the formula (!) are described below:

A compound of the formula (Va) Y

(I) formation of salts

OCH - COH

where Y has the meaning given above is treated with an alkaline material (e.g. sodium hydroxide, K-'Iiumhydroxid, ammonia and the like) neutralized with the formation of a compound of Formula (Ic)

jo

40 45 50

60

65

CH,

CF,

-O

y v

ii

OCH-C-O cation

(Ic)

in which Y has the meaning given above.

(2) Formation of stone nuclei

(2-1) A compound of the formula (Va) or an acid halide (I d) thereof is esterified with an alcohol of the formula Z - M (in which /., 'A (C' | -C,) alkoxy group, a ( C \ -C ₄ ) -Alkenyl <) xy group or a (Ci-C ,,) - Cycloa! Koxygruppe), whereby a compound of the formula (Ig)

CF,

CII,

OCH - CZ!

(Ig)

forms, in which Y and '/.' have the meaning given above. (2-2) A compound of the formula (Vb)

ν CH3

CF ₃ - (^> - — <ζ J ^ -OCH - C— (C, - C ₄ ) alkoxy

(Vb)

in which Y has the meaning given above, is with an alcohol of the formula Z '- H, as it was before is transesterified in the presence of a Lewis acid catalyst (e.g., BF, and the like) with formation of a compound of the formula (Ig).

(3) Formation of acids

A compound of formula (Vb) is hydrolyzed (e.g., with an appropriate acidic oderalka-Ishe-n material) * ⁷ Ausbiidun a Verbindun ° the Porme! (Va). Of the starting compounds of the general formula (H), a compound of the formula (Ha)

CF ₃

// V

-Y '

(Ha)

in which Y has the meaning given above and Y 'denotes a fluorine atom or a chlorine atom, for example can be produced in the following way:

2-Amino-5-methyIpyridin (described for example in Chemical Abstracts, Vol. 42, 7050i, 1949) is with or diazotized without prior halogenation to form a compound of the formula (Hb)

CH

(Hb)

in which Y "denotes a hydrogen atom or a chlorine atom or a bromine atom and Y '" denotes a halogen atom, with a fluorine atom, a chlorine atom or a bromine atom being preferred. The compound of the formula (lib) is then chlorinated under irradiation with ultraviolet light to form a compound of Formula (lic)

CCl ₃

J'X

(Hc)

in which Y and Y '"is as defined above have, and this compound is then reacted with hydrogen fluoride at a temperature of 0 to 50 ^u C, or with a Melal'fluorid as Antimontriftuorid, at a temperature of 100 to 250 ⁰ C to form the compound of formula (Ha) implemented.

The other starting compounds, i.e. H. Hydroquinone, a hydroquinone monoalkyl ether of the formula (XI), a parahydroxypJvenoxyalkanecarboxylic acid of the formula (X) or a derivative thereof, a haloalkanecarboxylic acid of the formula (VII) or a derivative thereof, and a compound of the formula (VIII) are, for example, in US 40 46 553 described. Trifluoromethyl iodide, which is used as one of the starting compounds in the The present invention is described in Org. Reactions, Vol. 9, p. 358, for example.

Some specific examples for preparing the herbicidal compounds according to the invention are shown below. Unless otherwise noted, all parts, percentages, ratios, and the like are given based on weight.

Production example 1 Preparation of ethyl 2- [4- (5-trinuomethyl-2-pyridyloxy) phenoxy] propionate.

[A-I]

(a) 40 ml of dimethyl sulfoxide, 4.2 g of hydroquinone, 5.0 g of 2-chloro-5-trifluoromethylpyridine and 2.3 g of potassium hydroxide are allowed to react ^{at 150 ° C. for 2 hours in a nitrogen atmosphere with stirring.} The reaction product is allowed to cool and poured onto e ^; a reasonable amount of ice water. The mixture is then neutralized with 30% concentrated hydrochloric acid and extracted with methylene chloride. The extract is washed with water and dried over anhydrous sodium sulfate and the methylene chloride is removed by distillation, giving 2.5 g of 2- (4-hydroxyphenoxy) -5-trifluoromethylpyridine with a melting point of 82 to 84 ° C.

(b) 40 ml of dimethyl sulfoxide, 5.0 g of hydroquinone monomethyl ether, 5.0 g of 2-chloro-5-trifluoromethylpyridine and 23 g of potassium hydroxide are mixed with stirring at 150 ° C. for 3 hours. The reaction product is cooled and poured onto an appropriate amount of ice water. The mixture is then extracted with methylene chloride and the extract is washed with water and dried over anhydrous sodium sulfate, the methylene chloride is separated off by distillation and the residue obtained contains 2- (4-methoxyphenoxy) -5-trifluoromel.hylpyridine, is mixed with 5.0 3 pyridine hydrochloride. The mixture is allowed to ^{react at 140 to 160 °} C. for 2 hours with stirring. After the reaction mixture has cooled, it is poured onto a suitable amount of ice water and then it is rid extracted. The methylene chloride layer is then back extracted with a 5% aqueous solution of sodium hydroxide and the resulting aqueous extract is acidified with 30% concentrated hydrochloric acid to give a solid. The obtained product was collected by filtration and dried to obtain 2.1 g of 2- (4-hydroxyphenoxy) -5-trifluoromethyl pyridine.

5.1 g of 2- (4-hydroxyphenoxy) -5-trifluoromethylpyridine, which was prepared as above, and 3.6 g of ethyl 2-bromopropionate are dissolved in 50 ml of methyl ethyl ketone and the solution is left for 2 hours in the presence of 3, 3 g of anhydrous potassium carbonate at 150 ⁰ C under reflux to react. After the completion of the reaction, water is added to the reaction product to dissolve the remaining solid, and the mixture is then concentrated under reduced pressure to distill off the methyl ethyl ketone. The residue is then extracted with toluene and the extract is washed with water and dried over anhydrous sodium sulfate. The toluene is distilled off, an oily product being obtained. The oily product solidifies on cooling. It is washed with η-hexane and dried, 1.8 g of the desired product having a melting point of 63 to 65 ° C. being obtained.

[A-21

9.1 g of 2-chloro-5-trifluoromethylpyridine and 21.0 g of ethyl 2- (4-hydroxyphenoxy) propionate are dissolved in 50 ml of dimethyl sulfoxide and the solution is heated for 2 hours in the presence of 13.8 g of anhydrous potassium carbonate while stirring at 150 ⁰ C react. The reaction product is cooled, poured into water and the solid obtained is extracted with toluene. The toluene layer is washed with water several times, dried over anhydrous sodium sulfate, and the toluene is removed by distillation to obtain 12.4 g of an oily substance, (i).

The aqueous layer obtained from the aforementioned toluene extraction was washed with toluene and then acidified with aqueous concentrated hydrochloric acid to obtain an oily substance. The obtained oily substance was extracted with methylene chloride, washed thoroughly with water and dried over anhydrous sodium sulfate. The Melhylenchloridschicht was then removed by distillation to obtain ¹ J ₁ Og of an oily substance obtained, which was mixed with an excess volume of methanol. 2 ml of a solution of boron trifluoride in Diäthyliilher were added to the mixture, followed by 2 hours at 8O ⁰ C was heated under reflux. A small amount of water was added to the mixture and the oil phase obtained after distilling off the ethanol was extracted with methylene chloride. The extract was washed with water and dried over anhydrous sodium sulfate, and the methyl chloride was distilled off to obtain 6.0 g of an oily substance (ii).

The oily substances (i) and (ii) obtained as described above were combined with each other and adsorbed on a silica gel column and eluted with toluene. The toluene was obtained from the

An eluate was distilled off to obtain 11.6 g of an oily substance, and this substance was removed by cooling solidified, washed with η-hexene and dried, 6.5 g of the desired product being obtained.

[Bl

4.1 g of ethyl 2- [4- (5-iodo-2-pyridyloxy) phenoxy | propional, 2.45 g of trihydric methyl iodide. 40 ml of pyridine and 1.62 g of copper powder was mixed in an autoclave and the mixture was stirred for 12 hours implemented at 120 to 130 ° C. After the completion of the reaction, the reaction mixture was cooled and the copper salt precipitated by the addition of ethyl ether was separated off by huricren The ethereal solution was washed successively with water, 15% hydrochloric acid and with water and then dried over anhydrous sodium sulfate. The ethereal solution was then concentrated and the obtained oily substance (5 g) was chromatographed on a silica gel column (solution with Methylene chloride) and distilled under reduced pressure, giving 1.9 g of the desired product with a boiling point of 182 to 185 ° C73 mmllg.

Setting example 2

Preparation of 2- [4- (5-trifluoromethyl-2-pyridyloxy) -phynoxy] -propionic acid 20th

IAl

16 g of 2- (4-hydroxyphenoxy) -5-trifluoromethylpyridine were dissolved in 100 ml of toluene and ^{7 g of sodium hydroxide were added to the solution at 60 °} C., followed by stirring for 30 minutes. 8.8 g of 2-chloropropionic acid were added to the mixture at 50 to 8O ⁰ C dropwise and then stirred for 1 hour and then 7.6 g of sodium hydroxide were added. The obtained mixture under reflux was allowed to react at 110 ⁰ C 1 to 1.5 hours. Water was added to the reaction product obtained and the mixture was made neutral with 10% sulfuric acid. The mixture was left to ^{stand at 70 to 80 °} C. with separation of an organic layer and an aqueous layer. Water and sodium hydroxide were added to the organic layer to adjust the solution to pH 9 to 10, and the mixture was stirred ^{at 70 to 80 ° C.} After removing toluene, the resulting aqueous solution was made acidic with 10% sulfuric acid. To the solution, 100 ml of toluene is added and the mixture is washed with water, dried over anhydrous sodium sulfate and nitrated. The Totuol is removed and the residue is washed with n-Hcxan to give g of the desired product having a melting point of 97-100 ⁰ C is 16.8.

[B]

3.55 g of ethyl 2- [4- (5-trifluoromethyl-2-pyridyloxy) phenoxy] propionate, obtained according to the preparation example 1 [B] were added to a mixture of 4 g of sodium hydroxide, 16 ml of water and 16 ml of ethanol and the obtained mixture was reacted for 2 hours with stirring at room temperature. After the Reaction, an appropriate amount of ice was added to the reaction mixture and the mixture was stirred 30% concentrated hydrochloric acid acidified. The precipitated crystals were filtered off with Washed with water and dried to give 2.5 g of the desired product.

Production example 3 Preparation of methyl 2- [4- (5-irifluoromethyl-2-pyridyloxy) -phenoxyi-propionate

[Λ |

255 g of 2-f4-llydroxyphynoxy) -5-trinuormethylpyridine, 199.1 g of methyl-2-bromopropiona! and 207g of anhydrous potassium carbonate are allowed in 1000 ml of methyl ethyl ketone under Rückflußcrhitzen at 80 ⁰ C for 2 hours RCA yaw. After the reaction mixture has cooled, the inorganic salts are separated off by filtration and the methyl ethyl ketone is distilled off. The residue is extracted with methyl chloride and the The extract is successively with water, a 5% aqueous dilute solution of sodium bicarbonate and Water washed. The extract is dried over anhydrous sodium sulfate and the methylene chloride becomes separated by distillation, 346 g of an oily substance being obtained, which rapidly evaporates on cooling

M) strengthens. The solid obtained was washed with η-hexane and recrystallized from ethanol, 1% g of the desired product having a melting point of 72 to 74 ^° C. being obtained.

3.27 g of 2- [4- (5-Tril1uormelhyl-2-pyridyloxy) -phynoxy] -propion; iuri: obtained according to Ilcrsellungsbcispicl 2 [B] were dissolved in 33 ml of methanol and 0.5 g of a diethyl ether solution of boron trifluoride was added and then the mixture was reacted under reflux at (> 4 ° C. for 3 hours. After the end of the Reaction was given a small amount of water / um RcaktioiisgcmiM'h and the resulting mixture

Ki

was concentrated under reduced pressure and then extracted with methylene chloride. The extract was washed with water and dried over anhydrous sodium sulfate. The methylene chloride was removed by distillation and the residue evaporated under reduced pressure to give 2.3 g of the desired product in the form of an oily substance with a boiling point of 175 to 17 ° C / 2 mmHg received. The obtained oily substance solidified on standing to give a product having a melting point from 72 to 74 ° C crhicit.

Production example 4

Preparation of sodium 2- [4- (5-trifluoromethyl-2-pyridyloxy) phenoxy] propionate

3.27 g of 2- [4- (5-trinuomethyl-2-pyridyloxy) phenoxy [propionic acid were added to a small amount of ethanol dissolved and the solution was mixed with 0.8 g of a 50% strength aqueous solution of sodium hydroxide. the The mixture was reacted at room temperature with stirring for 30 minutes and the reaction mixture became concentrated under reduced pressure. The precipitated crystals were then dried, whereby 3.0 g of the desired product with a melting point of 70 to 75 ° C was obtained.

Production example 5

Production of methyl ^ - ^ - O-chloro-S-trifluoromethyW-pyridyloxyJ-phenoxyl-propionate

[A-I]

6 g of 2,3-dichloro-5-trifIuormcthylpyridin, 40 ml Dimcthylsulfoxid, 4.2 g hydroquinone and 2.3 g of potassium hydroxide were reacted for 2 hours with stirring under Slickstoffalmosphärc at 150 ⁰ C. The reaction mixture was then cooled and poured onto an appropriate amount of ice water. The mixture was neutralized with 30% concentrated hydrochloric acid and extracted with methylene chloride. The extract was washed with water, dried over anhydrous sodium sulfate and methylene chloride was distilled; separated off, 2.7 g of 2- {4-hydroxyphenoxy) -3-chloro-5-trifluoromethyl pyridine (melting point 70 ° to 72 ° C.) being obtained. 5.8 g of ents>"ndencn 2- (4-hydroxyphenoxy) -3-chloro-5-trinuormethylpyridins and 3.3 g of methyl 2-bromopropionate were dissolved in 50 ml methyl ethyl ketone and the resulting mixture was refluxed at 8O ⁰ C and reacted in the presence of anhydrous potassium carbonate for 2 hours. Water was added to the reaction mixture and the mixture was concentrated under reduced pressure to distill off methyl ethyl ketone. The residue was extracted with toluene, and the extract was washed with water, dried over anhydrous sodium sulfate, and the toluene was removed by distillation to obtain an oily substance. On cooling, the oily substance solidified, which was washed with η-hexane and dried, 2.2 g of the desired product having a melting point of 55 to 57 ° C. being obtained.

! Λ-2]

4.3 g of 2,3-dichloro-5-trilluormethylpyridine and 4 g of methyl 2- (4-hydroxyphenoxy) propionate were dissolved in 30 ml of dimethyl sulfoxide and the resulting solution was stirred for 2 hours in the presence of 3.3 g of anhydrous potassium carbonate implemented at 150 ⁰ C. After the reaction mixture was cooled, it was poured onto ice water and the solid substance obtained was extracted with toluene. The toluene layer was washed with water several times, dried over anhydrous sodium sulfate, and the toluene was removed by distillation to obtain 3.5 g of an oily substance (iii).

The aqueous layer was washed with toluene and acidified with 30% hydrochloric acid, whereby to crhicit an oily substance. The oily substance was extracted with methylene chloride and the extract was washed with water and dried over anhydrous sodium sulfate. The methylene chloride was removed from the extract to obtain 1.5 g of an oily substance. The obtained oily substance was with an excess volume of methanol and mixed with 2 ml of an Oiiithyläther solution of Given boron rifluoride and the solution was kept for 2 hours at 64 ° C under reflux. To the mix a small amount of water was added and the methanol was removed by distillation, whereby received an oily substance. The oily substance was extracted with methylene chloride and the extract was made with Washed with water and dried over anhydrous sodium sulfate. After removing methylene chloride by distillation, 1.2 g of an oily substance (iv) was obtained.

The combined oily substances (iii) and (iv) were chromatographed on a silica gel column and the Column was cluicrt with toluene. The toluene was removed from the eluate, leaving 2.5 g of an oily substance received. The obtained oily substance solidified on cooling and was washed with η-hexane and dried to give 2.1 g of the desired product.

! »I.

3.9 g methyl-2- [4- (3-ehl <> r-5-i < > d-2-p.vndyl (> xy) -phenoxy | -propi (> niit, 2.45 g of trillium methyl iodide, 40 ml of pyridine '■■ .j and 1.62g copper powder were mixed in an autoclave and the mixture was 2 hours

1Ά Il

reacted with stirring at 140 ^° C. and then at 160 to 170 ^{° C. for 1 hour.} After the reaction mixture had cooled, diethyl ether was added and the copper salts to be precipitated were removed by filtration. The ethereal filtrate was washed successively with water, 10% dilute hydrochloric acid and water and dried over anhydrous sodium sulfate. The ethereal solution was concentrated to give 1.5 g of an oily substance, which was purified by chromatography on a silica gel column (eluting with methylene chloride). After removing the solvent from 1 cm Elual by distillation, 500 mg of the desired product were obtained.

The herbicidal compounds according to the invention can be dispersed in water with formation an aqueous dispersion. The herbicidal compounds can be formulated in various ways,

z. B. as emulsifiable concentrates, wettable powders, water-miscible solutions, dusts or granules by adding conventional agricultural adjuvants, for example carriers such as diatomaceous earth, calcium hydroxide, calcium carbonate, talc, white carbon, kaolin, bentonite or kaolinite, solvents such as η-hexane, toluene , Xylene, solvent phthalate, ethanol, dioxane, acetone, isophorone, methyl isobutyl octone, dimethylformamide, dimethyl sulfoxide or water, or an anionic or nonionic surface-active agent, such as sodium alkyl sulfate, a sodium alkyl benzene sulfonate, a sodium alkyl benzene sulfonate, an alkyl ethylacetate, an alkyl ethylacetate, an alkyl ethylacetate, a polyoxyethylene lignin acid ester, a polyoxyethylene lignin acid ester, a polyoxyethylene lignin acid ester, a polyoxyethylene lignin acid ester, a polyoxyethylene lignin acid ester, a polyoxyethylene lignin . A suitable ratio of the compound according to the invention to the adjuvant (s) is in the range from about 1 to 90:99 to 10, preferably 1 to 70:99 to 30, based on weight. The herbicidal compositions according to the invention can also be mixed or applied together with suitable agricultural chemicals such as other herbicides, insecticides or fungicides or agricultural products such as fertilizers, Bodenverbesscrern, earth or << ηά, at the time of formulation or application. Sometimes such a combined use brings better effects.
Some typical examples of herbicidal formulations obtained with the compounds according to the invention are shown below:

Formulation example I

20 parts by weight of ethyl 2- [4- (5-trifluoromethyl-2-pyridyIoxy) phenoxy] propionate, 60 parts by weight of xylene and 20 parts of a mixture of polyoxyethylene phenylphenol derivative, a polyoxyethylene alkylaryl ether, polyoxyethylene sorbitan alkylate and an alkylarylsulfonate as a surface active agent Evenly mixed together to form an emulsifiable concentrate.

Formulation example 2

78 parts by weight kaolinite, 15 parts by weight black carbon, 2 parts by weight sodium naphthalenesulfonate-formaldehyde condensate and 5 parts by weight of sulfate of Polyoxyäthylcnalkylarylülhcr, were mixed and the obtained Mixture was then with methyl ^ - ^ - O-chloro-S-trifluoromethyl ^ -pyridyloxyJ-phenoxyJ-propionate in mixed in a weight ratio of 4: 1 to form a wettable powder.

Formulation example 3

20 parts by weight of sodium 2- [4- (5-trifluoromethylpyridyloxy) phenoxy | propionate, 5 parts by weight of polyethylene glycol octylphenyl ether, 2 parts by weight of sodium dodccylbenzene sulfonate and 73 parts by weight of Wg-.ser were mixed uniformly to form a water-miscible solution.

The somewhat common herbicidal activity of the herbicidal compounds of the present invention is shown below shown in detail.

(1) The compounds of the invention can be used to treat grassy weeds by a Soil treatment before emergence or by foliar treatment while the weeds are growing to destroy. In particular, the compounds of the invention can be used to produce grassy Destroying weeds that have grown to a height of about 1 m by treating them with leaves. There the connections according to the invention are extremely safe against broad-leaved agricultural ones Crops, like soybeans, peanuts and cotton, are the compounds used for weed control suitable in agricultural areas.

(2) With appropriate selection of the application, the dosage and the time of application, for example, when the weeds grow together with plants such as corn and the like, foliar treatment with a small amount (5 to 20 g / 100 m ² ) of the are subjected to active ingredient, the compounds of the present invention can be applied to fields in which grass-like crops are cultivated after the plants have grown to a certain extent. If the dosage of the compound according to the invention is increased very greatly or if the compounds according to the invention are used together with other herbicides, weeds other than grass-like weeds can be destroyed.

(3) The compounds according to the invention are not very toxic to fish and do not affect fishing areas.
The compounds according to the invention are particularly suitable for use on high soils, in particular soils on which broad-leaved crops are grown, and they can also be used in orchards, forests and in numerous non-agricultural areas. The compounds according to the invention can be used for soil treatment or for leaf binding in raised areas or in flooded areas. The most suitable level of application varies depending on the

various factors such as climatic conditions, soil conditions, the type of animal chemical, the time of application, the method of application, the type of crops to which the application is made and the main weeds that are to be influenced. If the compounds according to the invention are used in the form of solid preparations (ie dusts or granules), the amount of active ingredient is 0.1 to 1000 g / ar (100 m ^? ), Preferably 0.5 to 500 g and in particular 1 to 250 g / ar.

The test of the herbicidal activity of the compounds according to the invention and the results obtained are shown below.

Experimental example 1

An area of 1/3000 ar (1/30 nv) was provided with soil. Predetermined amounts of seeds from edible barnyard grass, radish, and soybeans were sown and covered with soil, the seeds of grassy weeds, such as large grass (Digitariaadscendcns 11ENR.i, barnyard grass (Echinochloacrusgalli BEAUFV.), green Foxtail (Sctaria viridis BEAUFV.) And the like, covered to a thickness of about 1 cm. Two days after sowing, an aqueous dispersion of the herbicidal compounds shown in Table I became sprayed thereon and the growth of the weeds was visually assessed 30 days after the spraying. The achieved Results are shown in Table I. The degree of growth inhibition indicated in Table 1 is rated on a scale of IO degrees, IO means that the growth is completely inhibited and I indicates no inhibition.

Table 1 Connection no.

Amount of active ingredient (g / ar)

Degree of growth inhibition

edible radish

Harnyard grass Soybeans

grassy Weeds

2
3
4th
5
6th
7th
8th

50 25

50 25

50 25

50 25 50 25

50 25

50 25

50 25

10 1 1 10 10 1 1 10 10 1 1 10 10 1 t 10 10 1 1 10 10 I. 1 10 10 1 1 10 10 I. I. 10 10 1 1 10 10 I. 1 10 10 2 1 10 10 1 1 10 10 1 1 10 10 1 1 10 10 1 1 10 10 1 1 10 Experimental example 2

An area of ^{1/3000 acres (1/30 m 2} ) each was given away with soil, and predetermined amounts of seeds of edible barnyard grass and soybean were sown and covered with soil about 1 cm thick. When the edible barnyard grass reached a 2.5-leaf stage, an aqueous dispersion of the herbicidal compounds shown in Table 2 was put on the leaves in a predetermined amount. Twenty days after the treatment, the growth of barnyard grass and soybean was visually evaluated, and the degree of growth inhibition was evaluated using the same rating scale as in Example I. The results are shown in Table 2 below.

Table 2

Connection no.

concentration on active component (ppm)

Degree of growth inhibition

edible soybeans

Barnyard grass

10
10

13th

28 12 5/1 continuation link
No. Kon / en Ira ti
on active
component 2 400
200 in (the wheel of wax
inhirticration
elibaies soybeans
llarnyard grass 3 400
200 IO
IO 4th 400
200 K)
10 5 400
200 10
IO 6th 400
200 10
10 7th 400
200 10
10 8th 400
200 10
10 10
10 Experimental example 3

Predetermined amounts of cottonseed were sown on a plot of 1/5000 ar (1/50 m ^{2) each.} When the cotton reached the 5-leaf stage, a predetermined amount of an aqueous dispersion of each of the compounds shown in Table 3 was sprayed thereon. Twenty days after the treatment with the dispersion, the growth of the cotton was visually observed to evaluate the degree of phytotoxicity. The degree of phytotoxicity was evaluated for necrosis, wilting and growth inhibition, and the results obtained are shown in Table 3. The degree of phytotoxicity shown in Table 3 was rated on a scale of 10 degrees, with 10 indicating that the cotton was completely withered and 1 indicating no phylotoxicity and corresponding to the growth behavior in an untreated attachment.

Table 3

40 test connection

Amount of active Component (at all)

Phytotoxicity Necrosis withering growth

inhibition

⁴⁵ Compound No. 5

CH ₃

OCHCOCH ₃

(D

CH ₃

OCHCOC ₂ H ₅

10 20th

10
20th

5
10
20th

(2)

14th

continuation

Connection

Amount of iiklivem ingredient <g / ar)

l'hylotoxi / i'.iit

Necrnsis wilting growth

inhibition

(3)

CH ₃

OCHCOC ₂ H ₅

(1): Connection according to US 39 54 442 (2): Connection according to DE-OS 24 33 067 (3): Connection according to US 40 46 553

5 IO 20

Experimental example 4

Two underground roots (10 to 20 cm long) of Johnsongrass (Sorghum halepence (L.) Pers.), With 4-5 Nodes, were each trunsplanlierl on a cultivation area of 1/5000 ar (1/50 ην). When the johnson grass had achieved 4-5 sheet status, a predetermined amount of an aqueous dispersion became that shown in Table 5 The connections shown are sprayed on. 40 days after the treatment with the dispersion, the number of evaluating the growth of plants. The results obtained are shown in Table 4.

Table 4
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Compound No. 5

CH, O

OCHCOCH ₃ (I)

Amount of Select the active rewanted- Component beautiful plants (at all) 1.25 0 0 5 0 1.25 15th 2.5 13th 5 13th

CHj

-OCHCOCjH ₅ (2)

1.25

2.5

control

CH,

OCHCOC ₂ H ₅ (3)

1.25

2.5

3
1
0

13th

(I): Connection according to US 39 54 442 (2): Connection according to DIU) S 24 M 067 (3): Connection according to US 40 46 553

15th

Claims (1)

Patent claims: 1. 2- [4- (5-Trinuormethyl-2-pyridyloxy) -phenoxy] -propionic acid derivative of the general formula I. / O CF ₃ - <ζ> - Ο— \ y> - OCHCZ ¹ (I) ! O CH3 where mean: Y is a hydrogen atom or a chlorine atom, Z ^{1 is} a Hydroxygruppc, cine (C, ₄ ) alkoxy group, cine (C .. ₄ ) -Alkcnyloxygruppc, cine (Ci ,,) - Cycloalk- oxygruppc or an -O cation.