NO149207B - HERBICIDE SUBSTITUTED DIFENYLETERS - Google Patents

Description

The present invention relates to certain substituted diphenyl-

ethers with herbicidal action.

Substituted diphenyl ethers, as a class, are known to have

herbicidal properties and is extensively described in the prior art, e.g. in US-PS 3,928,416, 4,093,446 and 4,134,753,

as well as in DE-OS 2 628 384. For the most part, they differ

diphenyl ethers differ from each other in terms of the nature of the substituent in the one-position of the ring.

The previously known diphenyl ethers do not suggest the same substituent as the present invention, namely COOR-COOR^.

The present invention thus relates to substituted diphenyl-

ethers with the formula:

there:

A is nitro or halogen;

Y is halogen;

R is alkylene or monosubstituted alkylene with 1-3 carbon

atoms, in which the substituent is selected from alkyl, oxoalkyl or hydroxyalkyl, containing 1-4 carbon atoms; and R"*" is lower alkyl or phenyl. Examples of agronomically acceptable ions are alkali metals such as sodium, potassium or lithium; alkaline earth metals such as barium or calcium; ammonium; ;or alkylammonium or alkanolammonium containing 1-4 carbon atoms. Preferred compounds according to the invention are those where A is nitro and R"<*>" is alkyl of up to 4 carbon atoms.

It is of course clear that stereo- and optical isomers of compounds represented by the above formula are within the scope of the invention.

The compounds according to the invention are characteristically synthesized, e.g. by reacting suitable substituted benzoyl halides with an alcohol or an appropriately substituted α-hydroxycarboxylic acid ester, or by reacting a suitable substituted benzoic acid with a suitable substituted α-halocarboxylic acid ester using techniques known per se. The substituted benzoyl halides (or acids) and the substituted α-hydroxy (or α-halogen) carboxylic acid esters can be obtained from commercial sources or prepared by known techniques. More particularly, an at least stoichiometric amount of a substituted benzoyl halide is added with stirring to the substituted α-hydroxycarboxylic acid, preferably in the presence of an acid acceptor, such as triethylamine, pyridine, N,N-dimethylaniline or the like. Because the reaction is typically exothermic, the substituted benzoyl halide is added in portions, so that the temperature in the reaction mixture does not exceed approx. 35°C. When the compounds according to the invention are prepared by reacting a substituted benzoic acid with an α-halocarboxylic acid ester, the latter is preferably added to the former in the presence of an azo compound, such as e.g. 1,5-diazobicyclo(5,4,0)undec-5-ene (DBU). Regardless of the synthesis method, the reaction can, if desired, be carried out in the presence of an inert solvent, such as e.g. benzene, methylene chloride, chloroform, ethyl acetate, tetrahydrofuran or the like. Upon complete addition of substituted benzoyl halide to α-hydroxycarboxylic acid esters (or complete addition of α-halocarboxylic acid esters to the substituted benzoic acid), the mixture is heated to reflux and kept under reflux until the reaction is completed to the desired extent. The reaction mixture is then cooled to room temperature and characteristically washed successively with dilute acid, dilute base and water, and phase separation allowed. Substituted diphenyl ether is recovered from the organic phase by any known technique, such as e.g. evaporation, crystallization, vacuum drying or the like. If desired, the product, substituted diphenyl ether, can be further purified, e.g. by recrystallization.

The following examples I - XII are illustrative of the syntheses of certain specific substituted diphenyl ether compounds according to the invention.

Example I

1'-( Ethoxycarbonyl) ethyl- 5-( 2- chloro- 4- trifluoromethylphenoxy)-2- nitrobenzoate

A 100 mL, 3-necked flask equipped with an addition funnel, reflux condenser, and a magnetic stirrer was charged with 1.18 g (0.01 mol) ethyl lactate and 0.79 g (0.01 mol) pyridine in 30 mL benzene. To the stirred solution, 3.79 g (0.01 mol) of 5-(2-chloro-4-trifluoromethylphenoxy)-2-nitro-benzoyl chloride in 20 ml of benzene were added dropwise at ambient temperature (approx. 20°C). An exothermic heating was noted. After the addition was complete, the reaction mixture was heated to reflux and kept under reflux for 6 hours. The reaction mixture was then cooled, transferred to a separatory funnel and washed successively with 30 ml portions of 1N hydrochloric acid, water, 1N sodium hydroxide and water. The washed organic phase was dried over magnesium sulfate and concentrated in a rotary evaporator at 55°C to give 2.89 g of a light oil which was identified as 1'-(ethoxycarbonyl)ethyl-5-(2-chloro-4-trifluoromethylphenoxy) )-2-nitrobenzoate with an NMR spectrum (acetone, Dg): 7.3 - 8.36 (complex multiplet, 6H);

5.35 6 (quartet, H);

4.286 (quartet, 2H);

1.626 (doublet, 3H);

1.256 (triplet, 3H).

Example II

1'-( ethoxycarbonylmethyl) ethyl- 5-( 2- chloro- 4- trifluoromethyl-phenoxy)- 2- nitrobenzoate

A 100 mL, 3-necked flask equipped with an addition funnel, reflux condenser, and magnetic stirrer was charged with 1.32 g (0.01 mol) ethyl 1-3-hydroxybutyrate and 1.1 g (0.01

mol) of triethylamine in 30 ml of benzene. To the stirred solution, at approx. 20°C dropwise added 3.69 g (0.01

mol) 5-(2-chloro-4-trifluoromethylphenoxy)-2-nitrobenzoyl chloride in 20 ml of benzene. After the addition was complete,

the reaction mixture was heated to reflux and kept under reflux for 6 hours. The reaction mixture was then cooled, transferred to a separatory funnel and washed successively with 30 ml portions of 1N hydrochloric acid, water, 1N sodium hydroxide and water. The washed organic phase was dried over magnesium sulfate and concentrated in a rotary evaporator at 55°C to give 3.75 g of a brown oil which was identified as 1'-(ethoxycarbonylmethyl)ethyl-5-(2-chloro-4-trifluoromethylphenoxy) )-2-nitrobenzoate with an NMR spectrum (acetone dg): 7.2 - 8.36 (complex multiplet, 6H);

5.5 6 (quartet, 1H);

4.156 (quartet, 2H) ;

2.75 6 (doublet, 2H) ;

1.36 (doublet overlapping a triplet, 6H).

Example III

2'-ethoxycarbonyl-5-(2-chloro-4-trifluoromethylphenoxy)-2-nitrobenzoate

A 250 mL, 3-necked flask equipped with an addition funnel, reflux condenser, and magnetic stirrer was charged with 2.70 g (0.03 mol) of 3-hydroxypropionic acid and 2.38 g (0.03 mol) of pyridine in 110 mL of methylene chloride . To the stirred solution, at approx. 20°C added dropwise 11.37 g (0.03 mol) 5-(2-chloro-4-trifluoromethylphenoxy)-2-nitrobenzoyl chloride in 30 ml methylene chloride. An exothermic reaction occurred. After the addition was complete, the reaction mixture was heated to reflux temperature and kept under reflux

ran for 22 hours. The reaction mixture was then cooled,

transferred to a separatory funnel and washed twice with 100

ml portions of IN hydrochloric acid and once with 100 ml of water. The washed organic phase was dried over magnesium sulfate and concentrated on a rotary evaporator to 55°C, whereby 11.8 g of a viscous yellow oil was obtained which was identified

serted as 2'-ethoxy-carbonyl-5-(2-chloro-4-trifluoromethyl-phenoxy)-2-nitrobenzoate by an NMR spectrum (acetone dg): 7.2 - 8.4 6 (complex multiplet, 6H);

4.3 6 (triplet, 2H);

2.676 (triplet, 2H).

Example IV

2'-(ethoxycarbonyl)ethyl-5-(2-chloro-4-trifluoromethylphenoxy)-2-nitrobenzoate

A 100 ml 3-neck flask equipped with an addition funnel, reflux condenser and magnetic stirrer was charged with 20 ml ethanol and 5 ml pyridine in 30 ml methylene chloride. To the stirred solution, at ambient temperature,

about. 20°C, dropwise added 2.26 (0.005 mol) 2'-(chloro-carbonyl)-ethyl-5-(2-chloro-4-trifluoromethylphenoxy)-2-nitro-

benzoate in 15 ml of methylene chloride. After the addition was complete, the reaction mixture was heated to reflux and held under reflux for 42.5 hours. The reaction mixture was then cooled and concentrated in a rotary evaporator at 55°C. The concentrated residue was taken up in 100 ml of methylene chloride, transferred to a separatory funnel and washed after .

each other with 30 ml portions of IN hydrochloric acid, water, 7% water

ammonium hydroxide and water. The washed organic phase was dried over magnesium sulfate and concentrated in a rotary evaporator at 55°C to give 1.3 g of a yellow oil which was identified as 2'-(ethoxycarbonyl)ethyl-5-(2-chloro-4-trifluoromethylphenoxy) )-2-nitrobenzoate with an NMR spectrum (chloroform): 7.0 - 8.16 (multiplet, 6H);

4.36 (multiplet, 4H);

2.656 (triplet, 2H);

1.36 (triplet, 3H).

Example V

1'-( ethoxycarbonyl) methyl- 5-( 2- chloro- 4- trifluoromethyl-phenoxy)- 2- nitrobenzoate

A 100 ml 3-necked flask equipped with an addition funnel, reflux condenser and magnetic stirrer was charged with 1.25

g (0.012 mol) ethylene glycolate and 0.80 g (0.01 mol) pyridine in 35 ml methylene chloride. To the stirred solution, at approx. 20°C added dropwise 3.79 g (0.01 mol) 5-2(2-chloro-4-trifluoromethylphenoxy)-2-nitrobenzoyl chloride in 20 ml methylene chloride. An exothermic heating was noted. After the addition was complete, the reaction mixture was heated to reflux and kept under reflux for 42.5 hours. The reaction mixture was then cooled, transferred to a separatory funnel and washed successively with 30

ml portions of IN hydrochloric acid, water, 7% aqueous ammonium hydroxide and water. The washed organic phase was dried over magnesium sulfate and concentrated in a rotary evaporator at 55°C to give 3.5 g of a yellow oil which was identified as 1'-(ethoxycarbonyl)methyl-5-(2-chloro-4-trifluoromethyl) -phenoxy)-2-nitrobenzoate with an NMR spectrum (chloroform): 7.0 - 8.46 (multiplet, 6H);

4.86 (singlet, 2H);

4.256 (quartet, 2H) ;

1.316 (triplet, 3H).

Example VI

1'- ethoxycarbonyl- 2'- oxopropyl- 5-( 2- chloro- 4- trifluoro-methylphenoxy)- 2- nitrobenzoate

A 100 mL 3-necked flask equipped with an addition funnel, reflux condenser, and magnetic stirrer was charged with 3.61

g (0.01 mol) 5-(2-chloro-4-trifluoromethylphenoxy)-2-nitro-benzoic acid and 1.53 g (0.01 mol) 1,5-diazobicyclo(5,4,0)undec-4 -en (DBU) in 50 ml of benzene. To the stirred solution, at approx. 20°C added 1.65 g (0.01 mol) ethyl 2-chloro-acetoacetate. The reaction mixture was then heated to reflux and kept under reflux for 20.5 hours. The reaction mixture was then cooled, transferred to a

separatory funnel and washed successively with 30 ml portions of 1N hydrochloric acid, water, 7% aqueous ammonium hydroxide and water. The washed organic phase was dried over magnesium sulfate and concentrated in a rotary evaporator at 55°C to give 3.1 g of a brown oil, identified as 1<1->ethoxycarbonyl-2'-oxopropyl-5-(2-chloro -4-trifluoromethylphenoxy)-2-nitrobenzoate with an NMR spectrum (acetone, <d>6) <: >7.2 - 8.26 (multiplet, 6H);

5.86 (singlet, 1H);

4.26 (quartet, 2H);

2.36 (singlet, 3H).

Example VII

1'-( ethoxycarbonyl) buty1- 5-( 2- chloro- 4- trifluoromethyl-phenoxy)- 2- nitrobenzoate

A 100 mL 3-neck flask equipped with an addition funnel, reflux condenser, and magnetic stirrer was charged with 3.61 g (0.01 mol) of 5-{2-chloro-4-trifluoromethylphenoxy)-2-nitrobenzoic acid and 1.53 g (0.01 mol) DBU in 50 ml benzene. 2.19 g (0.01 mol) of ethyl 2-bromovalerate was added to the stirred solution at ambient temperature. The reaction mixture was then heated to reflux temperature and kept under reflux for 22 hours. The reaction mixture was then cooled, transferred to a separatory funnel and washed successively with 30 ml portions of 1N hydrochloric acid, water, 7%

aqueous ammonium hydroxide and water. The washed organic phase was dried over magnesium sulfate and concentrated in a rotary evaporator at 55°C to give 2.2 g of a brown oil, identified as 1'-(ethoxycarbonyl)butyl-5-(2-chloro-4-trifluoromethyl) -2-nitrobenzoate with an NMR spectrum (acetone dg): 7.2 - 8.26 multiplet, 6H);

5.256 (triplet, 1H);

4.286 (quartet, 2H);

0.8 - 1.96 (multiplet, 10H).

Example VIII

1'-(phenoxycarbonyl)ethyl-5-(2-chloro-4-trifluoroethyl-phenoxy)-2-nitrobenzoate

A 100 mL 3-neck flask equipped with an addition funnel, reflux condenser, and magnetic stirrer was charged with 3.61 g (0.01 mol) of 5-(2-chloro-4-trifluoromethylphenoxy)-2-nitrobenzoic acid and 1.53 g (0 .01 mol) of DBU in 50 ml of benzene.

2.29 g (0>01 mol) of phenyl-2-bromoacetate were added to the stirred solution at ambient temperature. The reaction mixture was then heated to reflux and kept under reflux for 22.5 hours. The reaction mixture was then cooled, transferred to a separatory funnel and washed successively with 30 ml portions of 1N hydrochloric acid, water,

IN sodium hydroxide and water. The washed organic phase

was dried over magnesium sulfate and concentrated in a rotary evaporator at 55°C to give 2.58 g of a light green syrup-like liquid which was identified as 1'-(phenoxycarbonyl)-5-(2-chloro-4-trifluoromethylphenoxy)-2 -nitrobenzoate with an NMR spectrum (acetone, dg): 7.0 - 8.256 (multiplet, 11H);

5.56 (quartet, 1H);

1.686 (doublet, 3H).

Example IX

1'-( ethoxycarbonyl) propyl- 5-( 2- chloro- 4- trifluoromethyl-phenoxy)- 2- nitrobenzoate

A 100 mL 3-neck flask equipped with an addition funnel, reflux condenser, and magnetic stirrer was charged with 3.61 g (0.01 mol) 5-(2-chloro-4-trifluoromethylphenoxy)-2-nitrobenzoic acid and 1.53 g (0.01 mole) of DBU in 35 ml of benzene. To the stirred solution, 1.95 g (0.01 mol) of ethyl 2-bromobutyrate to 15 ml of benzene was added dropwise at ambient temperature. The reaction was exothermic. After the addition was complete, the reaction mixture was heated to reflux and kept under reflux for 24 hours. The reaction mixture was then cooled, transferred to a separatory funnel and washed successively with 30 ml portions of 1N hydrochloric acid, water 7% aqueous ammonium hydroxide and water. The washed organic phase was dried over magnesium sulfate, concentrated in a rotary evaporator at 55°C and 1.2 g of a light brown syrup-like liquid was obtained which was identified as 1'-(ethoxycarbonyl)propyl-5-(2-chloro-4 -trifluoromethylphenoxy)-2-nitrobenzoate with an NMR spectrum (acetone, dg): 7.2 - 8.26 (multiplet, 6H);

5.156 (triplet, H);

4.26 (quartet, 2H);

1.9 6 (quartet, 2H);

0.8 - 1.36 (overlapping triplets, 6H).

Example X

1'-ethoxycarbonyl-3'-methylbutyl-5-(2-chloro-4-trifluoro-methylphenoxy)-2-nitrobenzoate

A 100 ml 3-neck flask equipped with a separatory funnel, reflux condenser and magnetic stirrer was charged with 1.60 g (0.01 mol) ethyl α-hydroxyisocaproate and 0.79 g (0.01 mol) pyridine in 40 ml methylene chloride. . To the stirred solution, 3.79 g (0.01 mol) of 5-(2-chloro-4-trifluoromethylphenoxy)-2-nitrobenzoyl chloride in 10 ml of methylene chloride were added dropwise at ambient temperature. The reaction was exothermic. After the addition was complete, the reaction mixture was heated to reflux and kept under reflux for 46.5 hours. The reaction mixture was then cooled, transferred to a separatory funnel and washed successively with 25 ml portions of 1N hydrochloric acid, water, 3.5% aqueous ammonium hydroxide and water. The washed organic phase was dried over magnesium sulfate and concentrated in a rotary evaporator at 55°C, thereby obtaining 1<1->ethoxycarbonyl-3<1->methylbutyl-5-(2'chloro-4-trifluoromethylphenoxy)-2- nitrobenzoate with an NMR spectrum (acetone, dg): 7.2 -8.36 (multiplet, 6H);

5.26 (triplet, 1H);

4.26 (quartet, 2H);

1.86 (multiplet, 3H);

0.8 - 1.46 (multiplet, 9H) .

Example XI

1'-ethoxycarbonyl-2'-hydroxypropyl-5-(2-chloro-4-trifluoro-methylphenoxy)-2-nitrobenzoate

A 500 mL 3-neck flask equipped with an addition funnel, reflux condenser, and magnetic stirrer was charged with 19.56 g (0.04 mol) of 1'-ethoxycarbonyl-2'-oxopropyl-5-(2-chloro-4-trifluoromethylphenoxy) -2-nitrobenzoate (prepared according to Example VI) in 100 ml of methanol. To the stirred solution at ambient temperature, 3.14 g (0.05 mol) of sodium cyanoborohydride and a few drops of methyl orange indicator were added. A 75:25 v/v solution of 2N hydrochloric acid and methanol was added dropwise at a rate sufficient to maintain the indicator color. The reaction mixture was then heated to reflux and refluxed for 20 hours, after which the reaction mixture was cooled and concentrated in a rotary evaporator at 55°C. The concentrated residue was taken up in 200 ml of diethyl ether, transferred to a separatory funnel and washed successively with 100 ml portions of 1N hydrochloric acid, water 1N sodium hydroxide and water. The washed organic phase was then dried over magnesium sulfate and concentrated in a rotary evaporator at 55°C to give 18.1 g of yellow syrup-like liquid identified as 1'-ethoxycarbonyl-2'-hydroxypropyl-5-(2-chloro-4-tri -fluoromethylphenoxy)-2-nitrobenzoate with an NMR spectrum (acetone, dg): 7.2 - 8.36 (multiplet, 6H);

4,2.6 (multiplet, 3H);

3.26 (quartet, 2H) ;

1.36 (doublet overlapping triplet, 5H).

Example XII

1'-(ethoxycarbonyl)ethyl-5-(2-chloro-4-trifluoromethylphenoxy)-2-bromobenzoate

A 100 ml 3-neck flask equipped with an addition funnel, a reflux condenser and magnetic stirrer was charged with 1.18 g (0.01 mol) ethyl lactate and 0.79 g (0.01 mol) pyridine in 50 ml methylene chloride. To the stirred solution, 2.7 g (0.005 mol) of 5-(2-chloro-4-trifluoromethylphenoxy)-2-bromobenzoyl chloride in 10 ml of methylene chloride were added dropwise at ambient temperature. The reaction was exothermic. After the addition was complete, the reaction mixture was heated to reflux and kept under reflux for 66 hours. The reaction mixture was then cooled, transferred to a separatory funnel and washed successively with 30 ml portions of 1N hydrochloric acid, water, 7% aqueous ammonium hydroxide and water.

The washed organic phase was dried over magnesium sulfate and concentrated in a rotary evaporator at 55°C to give 2.2 g of a viscous, yellow, syrup-like liquid which was identified as 1'-(ethoxycarbonyl)ethyl-5-(2-chloro) -4-trifluoromethylphenoxy)-2-bromobenzoate with an NMR spectrum (acetone, d,):

O

7.0 - 8.06 (multiplet, 6H);

5.256 (quartet, 1H);

4.186 (doublet, 3H);

1.68 6 (doublet, 3H);

1.186 (triplet, 6H).

The compounds according to the invention have been found to be effective for

to regulate the growth of a number of unwanted plants, i.e. weeds, when they are added in herbicide-effective amounts to the growth medium before the weed germinates or to the weed after it has germinated from the growth medium-. The term "herbicidally effective amount" is the amount of compound or mixture of compounds necessary to injure or prevent weeds from being able to recover after application of the agent. The amount of a particular compound or a mixture of compounds that is applied to show satisfactory herbicidal action can vary within wide ranges and depends on a number of factors such as e.g. the robustness of a particular type of weed, the degree of weed growth, climatic conditions, soil conditions, method of application and the like. Characteristic is all the way down to 25 g or less per mole and up to 1.5 kg or more per mol, necessarie according as. Of course, the activity of a particular compound against a particular type of weed can be easily determined by relatively simple laboratory or field tests.

search in a manner well known to the person skilled in the art.

The compounds according to the invention can be used as such or in formulations with agronomically acceptable excipients, inert carriers, other herbicides or other commonly used agricultural compounds, e.g. pesticides, stabilizers, fertilizers and the like. The compounds according to the invention are typically used in the form of dust, granules, wettable powders, solutions, suspensions, aerosols, emulsions, dispersions or the like in a manner known per se. Formulated with other typical agronomically acceptable substances used, the amount of compound or compounds of the invention present in the formulation may vary within wide ranges, e.g. from approx. 0.05 to 95% by weight, calculated on the weight of the formulation. Typical such formulations will contain from approx. 5 to 75% by weight compound or compounds according to the invention.

The compounds according to the invention have been found effective with a view to regulating a number of broad-leaved and grass-shaped weeds at application quantities of approx. 250 g target or less before or after germination, while not significantly damaging the desired crops, such as e.g. corn, wheat, rice and soybeans. Examples of weeds that can be effectively controlled using the compounds according to the invention are wild mustard (Brassica kaber); yellow foxtail (Setaria glauca); crabgrass (Digitaria sangui-nalis); "coffeeweed" (Sesbania spp.); "velvetleaf" (Abu-tilon theophrasti); johnsongrass (Sorghum halepense); barnyard grass (Echinochloa crusgalli); "Jimsonweed"

(Datura stramonium); "teaweed" (Sida spinosa); great worm-swindle (Roth); and such.

Certain of the compounds prepared according to Examples I-XII were tested for herbicidal action against certain weeds under controlled laboratory conditions with regard to light, temperature and humidity. Seeds of selected weeds were planted on plots. For preventive samples, these were treated with selected compounds immediately after planting. Before post-treatment tests, the surfaces were treated with the selected compound after a 2-week germination period. The compounds were applied to the surfaces by spraying a solvent solution of the compound in the indicated amount and the growth condition of the weed was observed and the toxic effect of the compound was assessed periodically after the application.

The following tabulates the type of weed (identified by its Latin name) and the compound used (indicated by an "X" and identified by reference to the sample in which it was prepared. In each case, the compound was applied preventively in an amount of 250 g per measure.

) In each of the preceding tests it was observed that all the different weeds were either killed or injured without that

they recovered within 21-22 days after application of the special compound.

In the following table, the specified compounds were applied after a germination period to the indicated weed type in an amount of 250 g per goal..

In each of the preceding tests, it was noted that all the different types of weeds were either killed or injured beyond recovery within 21 to 22 days of application of the particular compound.

It is noted that the compound of the invention where the substituent A is different from nitro, e.g. halogen and especially bromine (the compound prepared according to Example XII), showed a somewhat better herbicidal effect applied after germination than before in amounts down to less than 600 g per goals, e.g. at 250 g per goals and less. The compounds according to the invention where the substituent A is nitro have generally been found to be effective both before and after germination in quantities of 250 g per goals and less.

Claims (1)

Herbicidal compound, characterized in that it is covered by the formula wherein: A is halogen or nitro; Y is halogen; R is alkylene or monosubstituted alkylene with 1-3 carbon atoms, in which the substituent is selected from alkyl, oxoalkyl or hydroxyalkyl containing 1-4 carbon atoms; and R"*" is lower alkyl or phenyl.