LU82699A1 - HERBICIDE COMPOSITIONS CONTAINING DIPHENYL ETHER AS ACTIVE INGREDIENT - Google Patents

Description

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B. 73.929 DP - AM

The present invention relates to certain substituted diphenyl ethers which have herbicidal activity. The invention also relates to the preparation of these compounds, as also the fight against weeds using the abovementioned ethers.

The invention relates, more particularly, to substituted diphenyl ethers which, according to one of the embodiments of the invention, are represented by the general structural formula

0 O

Il 11 -t X, C — 0 —R — C — Z — R1

CF3 ^ (oVo - <^ Oy-A

in which: A represents a nitro radical; X represents a hydrogen atom or a halogen atom; Y represents a hydrogen atom, a halogen atom, a cyano, trifluoromethyl or alkyl group containing from 1 to 4 carbon atoms; Z represents an oxygen or sulfur atom; R represents a mono-substituted alkylidene or alkylidene group containing from 1 to 3 carbon atoms, in which: the substituent is chosen from alkyl, oxoalkyl or hydroxyalkyl radicals containing from 1 to 4 carbon atoms, and

AT

R is chosen from agronomically acceptable ions, 1 * hydrogen atom, alkyl or alkoxy radicals containing from 1 to 10 carbon atoms, cycloalkyl containing from 3 to 8 carbon atoms, phenyl or phenyl mono- , di- or tri-substituted, where the substituent (s) are chosen from halogens, alkyl and alkoxy radicals containing from 1 to 10 carbon atoms, cyano, nitro or trifluo-romethyl.

The invention also relates to the substituted diphenyl ethers which, according to another embodiment of the invention, are represented by the formula

AT

cited above, in which X, Y, Z, R and R have the meanings indicated above, but in which A represents a halogen atom or a cyano radical.

Examples of halogens which are suitable for the purposes of the present invention include, for example, bromine, chlorine, iodine and fluorine, preferably bromine or chlorine. By way of illustrative examples of alkyl and cycloalkyl radicals which are suitable for the purposes of the present invention, mention may be made, for example, of methyl, ethyl, isobutyl, n-butyl, t-butyl, n-amyl, heptyl, octyl groups. , iso-octyl, nonyl, decyl, cyclopropyl, cyclopentyl, cyclohexyl, cyclo-octyl and the like. Suitable alkoxy, oxoalkyl and hydroxyalkyl groups include, for example! Methoxy, ethoxy, butoxy, octoxy, oxoethyl, oxopropyl, oxobutyl, hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl and the like radicals. The methylidene, ethylidene and propylidene groups constitute! examples of suitable alkylidene radicals. As examples of agronomically acceptable ions, mention may be made of those of alkali metals such as sodium, potassium and lithium; those of alkaline earth metals, such as barium and calcium; ammonium, alkylammonium and alkanolammonium ions containing from 1 to 4 carbon atoms.

The preferred compounds according to the invention are those in which Z represents an oxygen atom, t ^ Λ A represents a nitro group, R represents an alkyl group of up to 4 carbon atoms, X represents a hydrogen atom and Y represents a halogen atom.

The compounds of the above formula are believed to exert herbicidal activity in accordance with the invention. As specific examples of compounds which correspond to the above formula and which, in accordance with the present invention, constitute preferred substances, there may be mentioned the following: 5- (2-chloro-4-trifluoromethylphenoxy) -2-nitro 1'- (ethoxycarbonyl) ethyl benzoate; 5- (2-chloro-4-trifluoromethylphenoxy) -2-nitrobenzoate - (ethoxy-carbonylmethyl) ethyl; 5- (2-chloro-4-trifluoromethyl-phenoxy) -2'-ethoxycarbonyl nitrobenzoate; 2- (2-chloro-4-trifluoromethylphenoxy) -2-nitrobenzoate - (ethoxycarbonyl) -ethyl; 5- (2-chloro-4-trifluoromethyl- -5- phenoxy) -2-nitrobenzoate - (ethoxycarbonyl) -methyl; 5- (2-chloro-4-trifluorinated thylphenoxy) -2-nitrobenzoate of I ’-ethoxycarbonyl-2-oxopropyl; 5- (2-chloro-4-trifluoro-methylphenoxy) -2-nitrobenzoate from 11 - (ethoxycarbonyl) -butyl; 5- (2-chloro-4-trifluoromethylphenoxy) -2-nitro-benzoate from 1 '- (phenoxycarbonyl) ethyl; 5- (2-chloro-4-trifluoromethylphenoxy) -2-nitrobenzoate from 1 (- (ethoxycarbonyl) propyl; 5- (2-chloro-4-trifluoromethylphenoxy) - 1 * -ethoxycarbonyl-3 ′ -methylbutyl 2-nitrobenzoate; 5- (2-chloro-4-trif luoromethylphenoxy) -2-bromobenzoate from 1 ‘- (ethoxycarbonyl) ethyl; 5- (2-chloro-4-trifluorome thylphenoxy) -2-nitrobenzoate 1r- (ethoxycarbonyl) -2’-hydroxypropyl; 5- (2-chloro-4-trifluoromethylphenoxy) - 2-cyanobenzoate from 1 ‘- (ethoxycarbonyl) ethyl; 5- (2,6-dichloro-4-trifuoromé thylphenoxy) -2-nitrobenzoate of II - (ethoxycarbonyl) ethyl; 5- (2-chloro-6-bromo-4-trifluoro-methylphenoxy) -2-cyanobenzoate 1 - - (ethoxycarbonyl) ethyl and 5- (2-chloro-4-trifluoromethylphenoxy) -2-nitrobenzoate - (thioethylcarbonyl) ethyl.

It should of course be understood that the scope of the present invention also extends to stereoisomers and optical isomers of the compounds represented by the above formula.

The compounds according to the invention are typically synthesized by reacting, for example, a suitably substituted benzoyl halide with an alcohol or an appropriately substituted α-hydroxycarboxylic ester or by reacting a substituted benzoic acid. suitably on an ester 1-6-oc-halo carboxyli that substituted appropriately by implementing techniques well known to specialists · The substituted benzoyl halides (or the corresponding acids) and the esters cc-hydroxy (or a substituted halo) carboxyls can be obtained from commercial sources or can be prepared according to known techniques. More particularly, at least a stoichiometric amount of benzoyl halide substituted with the substituted cc-hydroxy-carboxylic acid is added, with stirring, preferably in the presence of an acid acceptor, such as, for example, triethylamine, pyridine, N, N-dimethyl-aniline and the like. Since the reaction is typically exothermic, the substituted benzoyl halide is added in successive fractions, so that the temperature of the reaction mixture does not appreciably exceed about 35 ° C. · When preparing the compounds according to the invention by reacting a substituted benzoic acid on an a-halocarboxylic ester, the latter is preferably added to the first in the presence of an azo compound such as, for example, 1,5-diazo-bicyclo (5.4.0 ) undec-5-ene (DBU). Whatever the synthesis process, the reaction can, if desired, be carried out in the presence of an inert solvent such as, for example, benzene, methylene chloride, chloroform, ethyl acetate, tetrahydrofuran and the like. After completion of the addition of substituted benzoyl halide to the α-hydroxycarboxylic ester (or after completion of the addition of the α-halocarboxylic ester to substituted benzoic acid), -7 - The reaction mixture is heated to reflux and maintained at reflux until the reaction reaches the desired degree of completion. The reaction mixture is then cooled to room temperature and is typically washed successively with dilute acid, dilute base and water and then phase separation is allowed to take place. The substituted diphenyl ether is recovered from the organic phase by the use of any known technique, such as, for example, evaporation, crystallization, drying under vacuum and the like. If desired, the product, namely the substituted diphenyl ether, can be further purified, for example by recrystallization.

Examples I to XII which follow illustrate the synthesis of certain specific substituted diphenyl ethers, in accordance with the present invention.

In these examples, NMR = nuclear magnetic resonance spectrum.

f

EXAMPLE I

5- (2-Chloro-4-trif luoromethylphenoxy) -2- nitrobenzoate of 1 * - (ethoxycarbonyl) ethyl -a-

In a three-necked flask, with a capacity of 100 milliliters, equipped with an addition funnel, a reflux condenser and a magnetic stir bar, 1.18 g (0, 01 mol) of ethyl lactate— ". and 0.79 g (0.01 mole) of pyridine in 30 milliliters of benzene. 3.79 g (0.01 mole) dechlorurqâ.e5- (2-chloro-4-trifluoro-methylphenoxy) were added to the stirred solution at room temperature (about 20 ° C.) 2-nitrobenzoyl in 20 milliliters of benzene. The course of an exothermic reaction has been observed. After the addition was complete, the reaction mixture was heated to reflux and kept at reflux for 6 hours. The reaction mixture was then cooled, transferred to a separatory funnel and washed successively with fractions of 30 milliliters of 1 Normal hydrochloric acid, water, 1 Normal sodium hydroxide and d 'water. The washed organic phase was dried over magnesium sulfate and concentrated in a rotary evaporator at 55 ° C, so as to obtain 2.89 g of a light yellow oil, identified as 5- (2 -4-chloro-trifluoromethyl-phenoxy) -2- 1 'nitrobenzoate - (ethoxycarbonyl) -ethyl: NMR (acetone, Dg) 7.3 - 8.3δ (complex multiplet, 6H' 5 »35δ (quartet, H) ; 4.280 (quartet, 2H); 1.62δ (doublet, 3H); 1.256 (triplet, 3H).

r EXAMPLE II

! ---! 5- (2-Chloro-4-trifluoromethylphenoxy) -2- 1 ’nitrobenzoate - (ethoxycarbonylmethyl) ethyl

In a 3-necked flask, with a capacity of 100 milliliters, equipped with an addition funnel, a reflux condenser and a magnetic stir bar, 1.32 g (0, 01 mole) of ethyl 3-hydroxybutyrate and 1.1 g (0.01 mole) of triethylamine in 30 milliliters of benzene. To the stirred solution and at ambient temperature (approximately 20 ° C.), 3.69 g (0.01 mole) of 5- (2-chloro-4-trifluoromethylphenoxy) -2 chloride were added dropwise. -nitrobenzoyl in 20 milliliters of benzene. After the addition was complete, the reaction mixture was heated to reflux and kept at reflux for 6 hours. The reaction mixture was then cooled, transferred to a separatory funnel and allowed to cool. washed successively with fractions of 30 milliliters of 1 Normal hydrochloric acid, water, 1 Normal sodium hydroxide and water.

The washed organic phase was dried over magnesium sulfate and concentrated on a rotary evaporator at 55 ° C, so as to obtain 3.75 g of a brown oil identified as 5- (2-chloro -4 ~ trifluoromethyl-phenoxy) -2-nitrobenzoate 1 '- (ethoxycarbonylmethyl) -ethyl: NMR (acetone d / -) 7.2 - 8.36 (complex multiplet, EH); 5.56 (quartet, 1H); 4.156 (quartet, 2H); 2.756 (doublet, 2H); 1.36 (overlapping doublet triplet, 6H).

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EXAMPLE III

5- (2-Chloro-4-trif luor omethylphenoxy) -2- 2'-ethoxycarbonyl nitrobenzoate

2.70 g (0.03 mole) of 3-hydroxypropionic acid and 2.38 g (0.03 mole) of pyridine in 100 milliliters of methylene chloride were introduced into a 3-necked flask, containing 250 milliliters, equipped with an addition funnel, a reflux condenser and a magnetic stir bar. To the stirred solution, 11.37 g (0.03 mole of 5- (2-chloro-4-trifluoromethylphenoxy) -2-nitrobenzoyl chloride was added at room temperature (about 20 ° C) and dropwise. 30 milliliters of methylene chloride, the course of an exothermic reaction was observed, and once the addition was complete, the reaction mixture was brought to reflux and kept at reflux for 22 hours. reaction mixture, transferred to a separator funnel and washed twice with fractions of 100 milliliters of Normal 1 hydrochloric acid and once with 100 milliliters of water The washed organic phase was dried on magnesium sulphate and it was concentrated in a rotary evaporator at 55 ° C, so as to obtain 11.8 g of a viscous yellow oil identified as being 5- (2-chloro-4-trifluoromethylphenoxy) - 2'-ethoxycarbonyl 2-nitrobenzoate: NMR (acetone dg) 7 "2 - 8.4δ (complex multiplet, 6H) 4.3δ (triplet, 2H); 2.67δ (tri plet, 2H).

! \

EXAMPLE IV

5- (2-C hlor o-4-trif luor omethylphenoxy) -2-nitro-benzoate of 2 '- (ethoxycarbonvl) ethyl_ -11-

In a 3-necked flask, with a capacity of 100 milliliters, equipped with an addition funnel, a reflux condenser and a magnetic stir bar, 20 milliliters of ethanol and 5 milliliters of pyridine in 30 milliliters of methylene chloride. 2.26 g (0.005 mole) of 5- (2-chloro-4-trifluoromethyl-phenoxy) -2-nitrobenzoate 2 was added dropwise to the stirred solution and at room temperature (about 20 ° C.) '- (chlorocarbonyl) ethyl in 15 milliliters of methylene chloride. After the addition was complete, the reaction mixture was heated to reflux and kept at reflux for 42.5 hours. The reaction mixture was then cooled and concentrated in a rotary evaporator at 55oC. The concentrated residue was taken up in 100 milliliters of methylene chloride, transferred to a separating funnel and washed successively with fractions of 30 milliliters of normal 1 hydrochloric acid, water, a 7 percent aqueous solution of ammonium hydroxide and water. The washed organic phase was dried over magnesium sulfate and concentrated in a rotary evaporator at 55 ° C, so as to obtain 1.3 g of a yellow oil identified as 5- (2-chloro -4-trifluoromethylphenoxy) -2-nitrobenzoate of 2 '- (ethoxycarbonyl) ethyl: j il -12- NMR (chloroform) 7.0 - 8.1 δ (multiplet, 6H); 4.3δ (multiplet, 4H); 2.656 (triplet, 2H); 1.3δ (triplet, 3H).

EXAMPLE V

5- (2-Chloro-4-trifluoromethylphenoxy) -2- nitrobenzoate 1 '- (ethoxycarbonyl) methyl

1.25 g (0.012 mole) of ethyl glycolate and 0.80 g (0.01 mole) of pyridine were introduced into 35 ml of methylene chloride in a 3-necked flask, containing 100 ml , equipped with an addition funnel, a reflux condenser and a magnetic stir bar. 3.79 g (0.01 mole) of 5- (2-chloro-4-trifluoromethylphenoxy) -2- chloride were added dropwise to the stirred solution and at room temperature (about 20 ° C.) nitrobenzoyl in 20 milliliters of methylene chloride. Exothermic heating was observed. After the addition was complete, the reaction mixture was heated to reflux and kept at reflux for 42.5 hours. The reaction mixture was then cooled, transferred to a dropping funnel and washed successively with fractions of 30 milliliters of Normal 1 hydrochloric acid, water, 7 percent aqueous solution ammonium hydroxide and water. The washed organic phase was dried over magnesium sulfate and concentrated in a rotary evaporator at 55 ° C, so as to obtain 3.5 g of a yellow oil identified as 5- (2 -4-chloro-trifluoromethylphenoxy) ~ 1 '2-nitrobenzoate - (ethoxy-carbonyl) methyl: -13- NMR (chloroform) 7.0 - 8.4 δ (multiplet, 6H); 4.82 6 (singlet, 2H); 4.25 δ (quartet, 2H); 1.31 δ (triplet, 3H).

EXAMPLE VI

5- (2-Chloro-4 ~ trifluoromethylphenoxy) -2- 1 * nitrohenzoate -ethoxycarbonvl-2’-oxopropyle

In a 3-necked flask, d, with a capacity of 100 milliliters, equipped with an addition funnel, a reflux condenser and a magnetic stirring bar, 3.61 g (0, 01 mole) of 5- (2-chloro-4-trifluoromethylphenoxy) -2-nitrobenzoic acid and 1.53 g (0.01 mole) of 1,5-diazobicyclo (5.4.0.) Undec-5-ene ( DBU) in 50 milliliters of benzene. To the stirred solution and at room temperature (about 20 ° C), 1.65 g (0.01 mole) of ethyl 2-chloroacetoacetate was added. The reaction mixture was then heated to reflux and kept at reflux for 20.5 hours. The reaction mixture was then cooled, transferred to a separating funnel and washed successively with fractions of 30 milliliters of Normal 1 hydrochloric acid, water, 7 percent aqueous solution of ammonium hydroxide and water. The washed organic phase was dried over magnesium sulfate and concentrated in a rotary evaporator at 55 ° C so as to obtain 3.1 g of a brown oil identified as 5- (2-chloro- 4-trifluoromethylphenoxy) -2-nitrobenzoate of 1 * -ethoxycarbonyl-2 '-oxopropyl: -14- NMR (acetone, dg) 7> 2 - 8.2 δ (multiplet, 6H); 5.8 δ (singlet, 1H); 4.2 δ (quartet, 2H); 2.5 δ (singlet, 3H).

EXAMPLE VII

5- (2-Chloro-4-trifluoromethylphenoxy) -2- 1 'nitrobenzoate - (ethoxycarbonyl) butvle

3.61 g was placed in a 5-necked flask, containing 100 milliliters, equipped with an addition funnel, a reflux condenser and a magnetic stir bar. (0.01 mole) 5- (2-chloro-4-trifluoromethylphenoxy) -2-nitrobenzoic acid and 1.53 g (0.01 mole) of DBU in 50 milliliters of benzene. To the stirred solution and at room temperature, j. 2.19 g (0.01 mole) of ethyl 2-bromovalerate. The reaction mixture was then heated to reflux and kept at reflux for 22 hours. The reaction mixture was then cooled, transferred to a separating funnel and washed successively with fractions of 30 milliliters of Normal 1 hydrochloric acid, water, 7 percent aqueous solution of ammonium hydroxide and water. The washed organic phase was dried over magnesium sulfate and concentrated in a rotary evaporator at 55 ° C so as to collect 2.2 g of a brown oil identified as 5- (2-chloro- 1 '- (ethoxycarbonyl) butyl 4-triflu oromethyl) -2-nitro-benzoate: NMR (acetone dg) 7.2 - 8.2 Ô (multiplet, 6H); 5.25 δ (triplet, 1H); 4.28 δ (quartet, 2H); 0.8 - 1.9 δ (multiplet, 10H).

EXAMPLE VIII

5- (2-Chloro-4-trifluoromethylphenoxy) -2- 1 ’nitrobenzoate - (phenoxycarbonyl) ethyl -15-

In a 3-necked flask, with a capacity of 100 milliliters, equipped with an addition funnel, a reflux condenser and a magnetic stirring bar, 3.61 g (0, 01 mole) of 5- (2-chloro-4-trifluoromethylphenoxy) -2-nitrobenzoic acid and 1.53 g (0.01 mole) of DBU in 50 milliliters of benzene, With the solution stirred and at room temperature ( about 20 ° C), 2.29 g (0.01 mole) of phenyl 2-bromoacetate was added. The reaction mixture was then heated to reflux and maintained at reflux for 22.5 hours. The reaction mixture was then cooled, transferred to a dropping funnel and washed successively with fractions of 30 milliliters of hydrochloric acid 1 Normal, water, sodium hydroxide 1 Normal and water. The washed organic phase was dried over magnesium sulfate and concentrated. in a rotary evaporator at 55 ° C, so as to obtain 2.58 g of a light green syrupy liquid, identified as being 5- (2-chloro-4-trifluoromethylphenoxy) -2-nitro-benzoate (phenoxycarbonyl) ethyl: NMR (acetone, dg) 7.0 - 8.25 to (multiplet, 11H); 5.5 δ (quartet, 1H) î 1.68 Ô (doublet, 3H).

EXAMPLE IX

5- (2-Chloro-4-trif luoromethylphenoxy) -2-nitrobenzoate from 1 * - (ethoxvcarbonyl) propvle

3.61 g was introduced into a 3-necked flask, containing 100 milliliters, equipped with an addition funnel, a reflux condenser and a magnetic stir bar. (0.01 mole) 5- (2-chloro-4-trifluoromethylphenoxy) -2-nitrobenzoic acid and 1.53 g (0.01 mole) of DBU in 35 milliliters of benzene. 1.95 g (0.01 mole) of ethyl 2-bromobutyrate in 15 milliliters of benzene were added dropwise to the stirred solution at room temperature (about 20 ° C). The course of an exothermic reaction was observed. After the addition was complete, the reaction mixture was heated to reflux and kept at reflux for 24 hours. The reaction mixture was then cooled, transferred to a dropping funnel and washed successively with fractions of 30 milliliters of Normal 1 hydrochloric acid, water, 7 percent aqueous solution ammonium hydroxide and water. The washed organic phase was dried over magnesium sulfate, concentrated in a rotary evaporator at 55 ° C, so as to obtain 1.2 g of a light brown syrupy liquid identified as 5- (2 -4-chloro-trifluoromethylphenoxy) -2-nitrobenzoate 1 '- (ethoxycarbonyl) propyl: NMR (acetone, dg) 7.2 - 8.2 δ (multiplet, 6ü); 5.15 δ (triplet, H); 4.2 to (quartet, 2H); 1.9 δ (quartet, 2H); 0.8 - 1.3 ô (overlapping triplets, 6H).

EXAMPLE X

5- (2-Chloro-4-trifluoromethylphenoxy) -2-nitro-benzoate of 1 ’-ethoxvcarbonyl-3 * -methvrbutvle -17-

In a 3-necked flask, with a capacity of 100 milliliters, equipped with an addition funnel, a reflux condenser and a magnetic stir bar, 1.60 g (0, 01 mole) of ethyl α-hydroxyisocaproate and 0.79 g (0.01 mole) of pyridine in 40 ml of methylene chloride. 3.79 g (0.01 mole) of 5- (2-chloro-4 - trifluoromethylphenoxy) -2- chloride was added dropwise to the stirred solution at room temperature (about 20 ° C). nitrobenzoyl in 10 milliliters of methylene chloride. The course of an exothermic reaction has been observed. After the addition was complete, the reaction mixture was heated to reflux and kept at reflux for 46.5 hours. The reaction mixture was then cooled, transferred to a separatory funnel and washed successively with fractions of 25 milliliters of Normal 1 hydrochloric acid, water, 3.5% aqueous solution percent ammonium hydroxide and water.

The washed organic phase was dried over magnesium sulfate and concentrated in a rotary evaporator at 55 ° C, so as to obtain 3.99 g of a brown and viscous oil, identified as 5- ( 2-chloro-4-trifluoromethylphenoxy) -2-nitrobenzoate of-ethoxy-carbonyl-3'-methylbutyl: il -18- NMR (acetone, dg) 7.2 - 8.3 δ (multiplet, 6Η); 5.2 δ (triplet, 1H); 4.2 δ (quartet, 2H); 1.8 δ (multiplet, 3H); 0.8 - 1.4 δ (multiplet, 9Η).

EXAMPLE XI

5- (2-Chloro-4-trif luoromethylphenoxy) -2-nitro-benzoate of 1 '-ethoxycarbonvl-2'-hvdroxvpropvle

19.56 g (0.04 mole) was introduced into a 3-necked flask, with a capacity of 500 milliliters, equipped with an addition funnel, a reflux condenser and a magnetic stir bar. ) of 5- (2-chloro-4-trifluoromethylphenoxy) -2-nitrobenzoate of 1 * -ethoxy-carbonyl-2'-oxopropyl (prepared as described in Example VI) in 100 milliliters of methanol. To the stirred solution and at ambient temperature (approximately 20 ° C., 3.14 g (0.05 mol) of sodium cyanoborohydride and a few drops of a methyl orange-based indicator were added. drop and at a rate sufficient to maintain the color of the indicator a solution of 2N hydrochloric acid and methanol 75:25 v / v.

The reaction mixture was then heated to reflux and kept at reflux for 20 hours, then the reaction mixture was cooled and concentrated in a rotary evaporator to 55 ° C. The residue from the concentration in 200 milliliters of diethyl ether, the solution was transferred to a dropping funnel and washed successively with fractions of 100 milliliters of hydrochloric acid 1 Normal, water, sodium hydroxide 1 Normal and water. The washed organic phase was then dried over magnesium sulfate! -19- and concentrated in a rotary evaporator at 55 ° C, so as to obtain 18.1 g of a yellow syrupy liquid, identified as being 5- (2-chloro-4-trifluoromethyl-phenoxy ) -2-nitrobenzoate 1'-ethoxycarbonyl-2'-hydroxy-propyl: NMR (acetone, dg) 7.2 - 8.3 δ (multiplet, 6H) î 4.2 Ô (multiplet, 3H); 3.2 Ô (quartet, 2H); 1.3 δ (overlapping doublet triplet, 5H).

EXAMPLE XII

5- (2-C chloro-4-trifluoromethylphenoxy) -2-bromobenzoate from 1 * - (ethoxycarbonyl) ethyl

1.18 g (0.01 mole) of ethyl lactate and 0.79 g (0.01 mole) of pyridine were introduced into 50 milliliters of methylene chloride into a 3-necked flask, containing 100 milliliters, equipped with an addition funnel, a reflux condenser and a magnetic stir bar. 2.07 g (0.005 mole) of 5- (2-chloro-4-tri-fluoromethylphenoxy) -2-bromobenzoyl chloride was added dropwise to the stirred solution and at ambient temperature (approximately 20 ° C.) in 10 milliliters of methylene chloride. The course of an exothermic reaction has been observed. After the addition was complete, the reaction mixture was refluxed and kept at reflux temperature for 66 hours. The reaction mixture was then cooled, transferred to a dropping funnel and washed successively with fractions of 30 milliliters of Normal 1 hydrochloric acid, water, 7 percent aqueous solution ammonium hydroxide and water.

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The washed organic phase was dried over magnesium sulfate and concentrated in a rotary evaporator at 55 ° C, so as to collect 2.2 g of a yellow viscous syrupy liquid, identified as 3e 5- (2- 1 * - (ethoxycarbonyl) ethyl chloro-4-trifluoromethylphenoxy) -2-bromobenzoate: NMR (acetone, dg) 7.0 - 8.0 δ (multiplet, 6H); 5.25 δ (quartet, 1H); 4.18 δ (doublet, 3H); 1.68 δ (doublet, 5H); 1.18 δ (triplet, 6H).

Although syntheses of the compounds according to the present invention have been illustrated above, with a certain detail in the examples I to XII above, it should be understood that any compound according to the invention can be prepared by those skilled in the art by simply varying the choice of starting materials and using the illustrated techniques or other suitable techniques.

It has been found that the compounds according to the invention are suitable for regulating the growth of a certain number of undesirable plants, that is to say the; weeds, when applied in a herbicide-effective amount to the growing medium, before weeds emerge or to weeds after they emerge from the growing medium. The term "herbicide-effective amount" defines the amount of compound or mixture of compounds that is necessary to harm or damage the weeds to the point of rendering the weeds unable to recover after application. The amount of a particular compound or a particular mixture of compounds applied in order to demonstrate a satisfactory herbicidal effect can vary between wide limits and depends on a whole series of factors, such as, for example, the resistance of '' a particular weed species, the extent of weed infestation, climatic conditions, the nature of the soil or soil, the method of application and the like. Typically, as little as about 225 g to 11.2 kg of compound or mixture of compounds is used per hectare. Obviously, the effectiveness of a particular compound vis-à-vis a particular species of weed can be easily determined by a relatively direct field or laboratory test, as those skilled in the art know perfectly well. good.

The compounds according to the present invention can be used as such or in combination with agronomically acceptable adjuvants, inert vehicles, other herbicides or other commonly used agricultural compounds, for example pesticides, stabilizers, safety agents , fertilizers and the like. The compounds according to the present invention, whether or not in combination with other agronomically acceptable materials, are typically applied in the form of dust, granules, wettable powders, solutions, suspensions, aerosols , emulsions, dispersions and the like, in a manner well known to those skilled in the art

When the compounds according to the present invention are combined with other agronomically acceptable materials, typically used, the amount of the compound (s) according to the present invention present in the combination composition can vary within wide limits, for example d about 0.05 to about 95 percent by weight of the weight of the composition. Typically, such compositions contain from about 5 to about 75 percent by weight of the compound (s) according to the invention.

The compounds according to the present invention have been found to be effective in controlling a wide variety of broad-leaved, vegetative weeds at application rates of 2.24 kg / hectare or less before or after emergence , without significantly damaging desirable food crops, such as corn, wheat, rice and soybeans. As examples of weeds which can be effectively combated by the application of the compounds in accordance with the present invention, the following may be mentioned: Brassica kaber, Setaria glauca, Digitaria san-guinalis, Sesbania spp., Abutilon theophrasti, Sorghum halepense, Echinochloa crusgalli, Datura stramonium, Sids spinosa, Ipomoea purpurea (Roth), etc.

Some of the compounds prepared in accordance with the methods described in Examples I to XII were tested for their herbicidal activity against certain weed species, under controlled laboratory conditions of light, temperature and humidity. The seeds of the selected weeds were planted in flower beds. .For the pre-emergence tests, the beds were treated with the chosen compound immediately after planting. For the tests relating to post-emergence, the beds were treated with the chosen compound after a germination period of two weeks. The compound was applied to the beds by spraying a solution of the compound in a solvent at the indicated application rate.

Weeds were observed for growth and the toxic effect of the compound was evaluated periodically after application.

The weeds (identified by their Latin names) and the applied compounds (indicated by an "X" and identified by reference to the example in which the preparation has been described) have been summarized in tabular form below. to the weed species. In each case, the compound was applied prior to emergence at the dose of 2.24 kg of compound per hectare.

| -24- Γ "........

Compound Weed

I II IV V VI VII VIII IX X

AIDS spinosa X X X X _ i '

Datura stramonium XX xjxx X X X X

Brassica kaber X xjXX X X X X

Setaria glauca X X X X X X X X

| - I —— Ι ·· Ι »· Ι II 1 '1 1' 'f

. Digitaria sanguinalis X X X X X X X X

Sorghum halepense X X X X X X X

Sesbania spp. . X X J X X X _; | -

Abutilon theophrasti X X X! X X

. |

: Ipomoea purpurea X X X I X j X

; j; i

; Avena fatua j X X j X

• Echinochloa crusgalli X X X; X X X

In each of the above tests, it was observed that all of the weeds tested were killed or had suffered damage such that they had not yet recovered within 21 to 22 days of application of the particular compound.

In the following table, the compound specified after emergence was applied to the indicated weed species at the rate of 2.24 kg of compound per hectare.

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Weed j Compound

I II III IV V VI VII [VIII IX X

j _

AIDS spinosa X X X! j X

Datura stramonium i X X X XX X .. I X XX

2!

Brassica kaber j X X X X X j X X X X X X

Sétaria glauca X X X d X X XXX

i _. j

Digitaria sanguinalis X; j

Sorghum halepense X XXX

Sesbania spp. XXX XXXX X XX

Abutilon theophrasti X XXX XX

.Ipomoea purpurea X XXXXXX XX

Avena fatua X X X X

I î

Echinochloa crusgalli X ‘X X!

Xanthium pennsylvanicum X X; X X

; __i ___J_ _ ____

In each of the above tests, it was observed that all of the weeds had been killed or had suffered damage such that they had not yet recovered within 21 to 22 days of application of the particular compound.

It has been observed that the compounds according to the invention, in which the substituent "A" is other than a nitro group, for example your halogen atom and, more specifically, a bromine atom (as illustrated by the compound prepared according to the procedure -26- described in Example XII), exhibited somewhat better herbicidal activity when applied after emergence rather than before emergence, in doses of less than about 5.60 kg per hectare, for example at a rate of approximately 2.24 kg per hectare or even less · It has been found that the compounds according to the invention, in which the substituent "A" represents a nitro group, were generally effective, both in during the pre-emergence application than during the post-emergence application, in application doses of 2.24 kg / hectare or less.

Although the invention has been described above with considerable detail concerning its illustrative embodiments, it is understood that the scope of the invention is in no way limited thereto and that one can bring many modifications and variations to these details and these embodiments | without departing from the scope and spirit of the invention. ^

Claims (9)

1.- Compounds represented by the formula 0 O "I" A X yC — 0 —R — C — Z — R 'CF3 A> in which: A represents a halogen atom, a cyano or nitro group; X represents a hydrogen atom or a halogen atom; Y represents a hydrogen atom, a halogen atom, a cyano, trifluoromethyl or alkyl group containing from 1 to 4 carbon atoms; Z represents an oxygen atom or a sulfur atom; R represents a mono-substituted alkylidene or alkylidene group containing from 1 to 3 carbon atoms, where the substituent is chosen from alkyl, oxoalkyl or hydroxyalkyl radicals containing from 1 to 4 carbon atoms; and -j R is chosen from agronomically acceptable ions, hydrogen atom, alkyl or alkoxy radicals containing from 1 to 10 carbon atoms, cyclo-alkyl containing from 3 to 8 carbon atoms, phenyl or phenyl mono-, di- or tri-substituted, where the substituent (s) are chosen from halogens, alkyl and alkoxy radicals containing from 1 to 10 carbon atoms, cyano, nitro or trifluoromethyl. i -28- 2. Compounds according to claim 1, characterized in that Z represents an oxygen atom. 3. Compounds according to claim 1, characterized in that R represents an alkyl group containing up to 4 carbon atoms. 4. Compounds according to claim 1, characterized in that A represents a nitro radical. 5. Compounds according to claim 1, characterized in that A represents a halogen atom or a cyano group. 6. Compounds according to claim 1, characterized in that A represents a nitro radical, Z represents A has an oxygen atom, R represents an alkyl group having up to 4 carbon atoms, X represents a hydrogen atom and Y represents a halogen atom. 7. Compounds according to Claim 1, chosen from the following substances: 5- (2-chloro-4-trifluoro-methylphenoxy) -2-nitrobenzoate - (ethoxycarbonyl) ethyl; 1- (2-chloro-4-trifluoromethylphenoxy) -2-nitro-benzoate (ethoxycarbonylmethyl) -ethyl; 2- (2-chloro-4-trifluoromethylphenoxy) -2-nitrobenzoate 2- ethoxycarbonyl; 2- (2-chloro-4-trifluoromethylphenoxy-2-nitro-benzoate - 2 - (ethoxycarbonyl) ethyl; 5- (2-chloro-4-trifluoromethylphenoxy) -2-nitrobenzoate - (ethoxy-carbonyl) methyl ; 5- (2-chloro-4-trif luorornethylphenoxy) - 2-nitrobenzoate 1'-ethoxycarbonyl-2f-oxopropyl; 5- (2-chloro-4-trif luor decorated thylphenoxy) -2-nitrobenzoate 1'-ethoxycarbonyl ) butyl; 5- (2-chloro-4-trifluoromethyl-! J · l -29- phenoxy) -2-nitrobenzoate 1 '- (phenoxycarbonyl) ethyl; 5- (2-chloro-4-trifluoromethylphenoxy) -2-nitrobenzoate * * - (ethoxycarbonyl) propyl; 5- (2-chloro-4-trifluoromethylphenoxy) -2-nitrobenzoate 1′-ethoxycarbonyl-3’-methylbutyl; 5- (2-chloro-4-trifluoromethylphenoxy) -2-nitrobenzoate 1'-ethoxycarbonyl-2 * -hydroxypropyl, and 5- (2-chloro-4-trifluoromethylphenoxy) -2-bromobenzoate ethyl - (ethoxycarbonyl) ethyl . 8. Herbicidal compositions containing a herbicidally effective amount of a compound or mixture of compounds according to any of claims 1 to 7. * 9. A method for combating the growth of weeds, characterized in that a herbicidally effective amount of a compound or a mixture of compounds according to any one of claims 1 is applied. 7 ”either in the growth medium before the emergence of weeds, or on weeds after their emergence from their growth medium.