HERBICIDAL PHENYLETHERS

Abstract

The present invention relates to phenylethers of formula (I)

##STR00001##

or their agriculturally acceptable salts or derivatives, wherein the variables are defined according to the description, processes and intermediates for preparing the phenylethers of formula (I), compositions comprising them and their use as herbicides, i.e. for controlling harmful plants, and also a method for controlling unwanted vegetation which comprises allowing a herbicidal effective amount of at least one phenylether of formula (I) to act on plants, their seed and/or their habitat.

Claims

1. A phenylether of formula (I) ##STR00103## wherein the variables have the following meanings: R.sup.1 H or halogen; R.sup.2 halogen; R.sup.3 H; R.sup.4 H; R.sup.5 OR.sup.6, wherein R.sup.6 is hydrogen or C.sub.1-C.sub.6-alkyl; n 1; Q O; W O; X O; Y is a heterocycle selected from the group consisting of Y2, Y13, Y20, Y31, Y37, Y38, Y39, Y67 and Y69 ##STR00104## wherein A.sup.1, A.sup.3 are oxygen or sulfur; A.sup.2 is oxygen; A.sup.4 is sulphur; R.sup.19, R.sup.23, R.sup.24 are hydrogen, C.sub.1-C.sub.6-alkyl, C.sub.1-C.sub.6-haloalkyl or C.sub.1-C.sub.6-haloalkoxy; R.sup.21 and R.sup.22 together with the atoms to which they are attached, form a five- to six-membered cycle, which is saturated or partial unsaturated, and which for its part may be partially halogenated or substituted by two C.sub.1-C.sub.6-alkylradicals; R.sup.26 and R.sup.27 are C.sub.1-C.sub.6-alkyl; R.sup.28 is halogen or C.sub.1-C.sub.6-alkyl; R.sup.32 and R.sup.33 are hydrogen; R.sup.35 and R.sup.36 are C.sub.1-C.sub.6-alkyl; Z is Z-1 or Z-7, ##STR00105## wherein * denotes the point of attachment of Z to X; ** denotes the point of attachment of Z to Q; and R.sup.a, R.sup.b, R.sup.c and R.sup.d are H; including their agriculturally acceptable salts or amides, esters and thioesters, provided the compounds of formula (I) have a carboxyl group.

2. The phenylether of formula (I) according to claim 1 wherein R.sup.1 is H or F, and R.sup.2 is F or Cl.

3. The phenylether of formula (I) according to claim 1 wherein Y is selected from the group consisting of Y.sup.2, Y.sup.13, Y.sup.20 and Y.sup.67.

4. The phenylether of formula (I) according to claim 1 wherein Y is selected from the group consisting of Y.sup.2, Y.sup.20, Y.sup.37 and Y.sup.67.

5. The phenylether of formula (I) according to claim 1 wherein Y is Y.sup.67.

6. A herbicidal composition comprising an herbicidally active amount of at least one phenylether of formula (I) as claimed in claim 1 and at least one inert liquid and/or solid carrier.

7. A herbicidal composition according to claim 6, further comprising at least one surface-active substance.

8. A process for the preparation of herbicidal active compositions, which comprises mixing an herbicidally active amount of at least one phenylether of formula (I) as claimed in claim 1 and at least one inert liquid and/or solid carrier.

9. A process according to claim 8, wherein at least one surface-active substance is mixed with the herbicidally active amount of at least one phenylether of formula (I) and the at least one inert liquid and/or solid carrier.

10. A method of controlling undesired vegetation, which comprises allowing an herbicidally active amount of at least one phenylether of formula (I) as claimed in claim 1 to act on plants, their environment or on seed.

Description

A PREPARATION EXAMPLES

Example 1: ethyl 2-[[3-[2-chloro-5-[4-chloro-5-(difluoromethoxy)-1-methyl-pyrazol-3-yl]-4-fluoro-phenoxy]-2-pyridyl]oxy]acetate

[0794] ##STR00061##

Example 1 Step 1: 3-(2-chloro-4-fluoro-5-iodo-phenoxy)-2-nitro-pyridine

[0795] ##STR00062##

[0796] To a solution of 5.5 g (20.4 mmol) of 2-chloro-4-fluoro-5-iodophenol (CAS 148254-33-5) in 40 mL acetonitrile was added 3.4 g (24.5 mmol) potassium carbonate and 3.2 g (22.4 mmol) of 3-fluoro-2-nitropyridine (CAS 54231-35-5) at 0° C. under nitrogen atmosphere. The mixture was stirred for 1 hour at 0° C., and then for 14 hours at 80° C. The mixture was diluted with water and extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous MgSO.sub.4, filtered and the solvent was removed under reduced pressure. The crude product was purified by column chromatography on silica (petrol ether/ethyl acetate) to give 5.1 g (14.1 mmol, 69%) of the desired compound 1 step 1.

Example 1 Step 2: 3-(2-chloro-4-fluoro-5-iodo-phenoxy)pyridin-2-amine

[0797] ##STR00063##

[0798] To a solution of 6.6 g (18.2 mmol) of compound 1 step 1 in 15 mL THF at 0° C. was added 5.1 g (91 mmol) iron and 50 mL aq. NH.sub.4Cl dropwise. The mixture was stirred for 3 hours at 0° C., filtered and the filter cake was washed with ethyl acetate. The filtrate was diluted with water and extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous MgSO.sub.4, filtered and the solvent was removed under reduced pressure to give the desired compound 1 step 2 (5.6 g) which was used without further purification in the next step.

Example 1 Step 3: 3-(2-chloro-4-fluoro-5-iodo-phenoxy)pyridin-2-ol

[0799] ##STR00064##

[0800] To a solution of 3.1 g (45.0 mmol) of sodium nitrite in 59 mL water at 0° C. was added 59 mL of hydrosulfuric acid dropwise. A solution of 5.5 g (15.0 mmol) of compound 1 step 2 in 59 mL acetic acid was added dropwise. The mixture was stirred for 1 hour at 0° C. The mixture was diluted with water, filtered and the filter cake was washed with ethyl acetate. the solvent was removed under reduced pressure to give the desired compound 1 step 3 (4.9 g) which was used without further purification in the next step.

Example 1 Step 4: ethyl 2-[[3-(5-bromo-2,4-dichloro-phenoxy)-2-pyridyl]oxy]acetate

[0801] ##STR00065##

[0802] To a solution of 17.5 g (47.9 mmol) of compound 1 step 3 in 200 mL 1,2-dichloroethane at 85° C. was added 1.7 mL of boron trifluoride diethyl etherate dropwise, followed by a solution of 25 g (192 mmol) of ethyl diazoacetate in 30 mL 1,2-dichloroethane dropwise. The mixture was stirred for 12 hours at 85° C. The mixture was diluted with water and extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous Na.sub.2SO.sub.4, filtered and the solvent was removed under reduced pressure to give the desired compound 1 step 4 (16.0 g) which was used without further purification in the next step.

[0803] .sup.1H NMR (CDCl.sub.3, ppm): 7.94 (d, J=3.76 Hz, 1H); 7.31 (d, J=5.77 Hz, 1H); 7.13-7.24 (m, 2H); 6.93 (dd, J=7.65, 4.89 Hz, 1H); 4.95 (s, 2H); 4.17-4.30 (m, 2H); 1.27 (t, J=7.03 Hz, 3H).

Example 1 Step 5

[0804] ##STR00066##

[0805] To a solution of 2.0 g (4.4 mmol) of compound 1 step 4 in 20 mL 1,4-dioxane at 0° C. under nitrogen atmosphere was added 3.3 g (13.3 mmol) of bis(pinacolato)diboron, 26 g (26.6 mmol) of potassium acetate and 0.4 g (0.5 mmol) of 1,1′-bis(diphenylphosphino)ferrocene dichloropalladium(II). The mixture was stirred for 24 hours at 90° C. The mixture was diluted with water and extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous Na.sub.2SO.sub.4, filtered and the solvent was removed under reduced pressure. The crude product was purified by column chromatography on silica (petrol ether/ethyl acetate) to give 1.8 g (4.0 mmol, 90%) of the desired compound 1 step 5.

Example 1 Step 6: 4-chloro-5-(difluoromethoxy)-3-iodo-1-methyl-pyrazole

[0806] ##STR00067##

[0807] To a solution of 7.7 g (30.4 mmol) of iodine in 40 mL acetonitrile was added 3.1 g (30.4 mmol) of tert-butyl nitrite at 0° C. under argon atmosphere. The mixture was stirred for 1 hour at 0° C. and then 4.0 g of 4-chloro-5-(difluoromethoxy)-1-methyl-1H-pyrazol-3-amine (CAS 149978-51-8) was added at 0° C. The mixture was stirred for 2 hours at 25° C. The mixture was diluted with water and extracted with ethyl acetate. The combined organic layer was washed with aq. Na.sub.2S.sub.2O.sub.3, dried over anhydrous MgSO.sub.4, filtered and the solvent was removed under reduced pressure. The crude product was purified by column chromatography on silica (petrol ether/ethyl acetate) to give 4.5 g (22.8 mmol, 73%) of the desired compound 1 step 6.

Example 1 Step 7: ethyl 2-[[3-[2-chloro-5-[4-chloro-5-(difluoromethoxy)-1-methyl-pyrazol-3-yl]-4-fluoro-phenoxy]-2-pyridyl]oxy]acetate

[0808] ##STR00068##

[0809] To a solution of 1.3 g (4.1 mmol) of compound 1 step 6 in 20 mL 1,4-dioxane/acetonitrile/water (3:3:1) at 0° C. under nitrogen atmosphere was added 1.8 g (4.0 mmol) of compound 1.5, 1.7 g (12.2 mmol) of potassium carbonate and 0.9 g (1.2 mmol) of 1,1′-bis(diphenylphosphino)-ferrocene dichloropalladium(II). The mixture was stirred for 14 hours at 90° C. The mixture was diluted with water and extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous Na.sub.2SO.sub.4, filtered and the solvent was removed under reduced pressure. The crude product was purified by column chromatography on silica (petrol ether/ethyl acetate) to give 1.2 g (2.4 mmol, 59%) of the desired compound 1.

[0810] .sup.1H NMR (CDCl.sub.3, ppm): 7.89 (d, J=4.02 Hz, 1H); 7.33 (d, J=9.03 Hz, 1H); 7.17 (dd, J=13.80, 7.03 Hz, 2H); 6.91 (br. s., 1H); 6.88 (dd, J=8.03, 2.76 Hz, 1H); 6.69 (s, 1H); 6.51 (s, 1H); 4.96 (s, 2H); 4.19 (q, J=7.03 Hz, 2H); 3.81 (s, 3H); 1.22 (t, J=7.03 Hz, 3H).

Example 2: ethyl 2-[[3-[2,4-dichloro-5-(3-oxo-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyridin-2-yl)phenoxy]-2-pyridyl]oxy]acetate

[0811] ##STR00069##

Example 2 Step 1: ethyl 2-[[3-[5-(2-tert-butoxycarbonylhydrazino)-2,4-dichloro-phenoxy]-2-pyridyl]oxy]acetate

[0812] ##STR00070##

[0813] To a solution of 3.2 g (7.6 mmol) of ethyl 2-[[3-(5-bromo-2,4-dichloro-phenoxy)-2-pyridyl]oxy]acetate (synthesized from 5-bromo-2,4-dichlorophenol (CAS 183803-12-5) in analogy to compound 1 step 4 described above) and 3.0 g (CAS 870-46-2, 22.8 mmol) of tert-butyl hydrazinecarboxylate in 50 mL 1,4-dioxane was added 5.0 g (15.2 mmol) of caesium carbonate, 0.5 g (0.9 mmol) of Xantphos and 0.3 g (0.4 mmol) of tris(dibenzylideneacetone)dipalladium(0). The mixture was stirred under nitrogen atmosphere for 12 hours at 105° C. The volatiles were evaporated and the residue was purified by column chromatography on silica (petrol ether/ethyl acetate) to give 1.2 g (2.6 mmol, 34%) of the desired compound 2 step 1.

[0814] .sup.1H NMR (CDCl.sub.3, ppm): 7.77 (d, J=7.03 Hz, 1H); 7.15-7.27 (m, 3H); 7.07-7.13 (m, 1H); 6.24 (s, 1H); 5.40 (d, J=8.53 Hz, 1H); 3.70 (s, 3H); 1.34 (s, 9H); 1.29 (t, J=7.21 Hz, 3H).

Example 2 Step 2: ethyl 2-[[3-(2,4-dichloro-5-hydrazino-phenoxy)-2-pyridyl]oxy]acetate

[0815] ##STR00071##

[0816] To a solution 1.2 g (2.5 mmol) of compound 1 step 5 in 50 mL ethyl acetate was added 30 mL of a 1 M solution of hydrochloric acid in ethyl acetate dropwise. The mixture was stirred for 12 hours at 20° C. The volatiles were evaporated to give the desired product 2 step 1 (0.9 g) which was used without further purification in the next step.

Example 2 Step 3: ethyl 2-[[3-[2,4-dichloro-5-[(2Z)-2-(2-piperidylidene)hydrazino]phenoxy]-2-pyridyl]oxy]acetate

[0817] ##STR00072##

[0818] To a solution 0.9 g (2.4 mmol) of compound 2 step 1 in 5 mL acetic acid was added a solution of 0.6 g (4.8 mmol) of 6-methoxy-2,3,4,5-tetrahydropyridine (CAS 5693-62-9) in 5 mL acetic acid. The mixture was stirred for 16 hours at 25° C. The volatiles were evaporated and the residue was purified by column chromatography on silica (dichloromethane/methanol) to give 0.7 g (1.5 mmol, 64%) of the desired compound 2 step 3.

Example 2 Step 4: ethyl 2-[[3-[2,4-dichloro-5-(3-oxo-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyridin-2-yl)phenoxy]-2-pyridyl]oxy]acetate

[0819] ##STR00073##

[0820] To a solution of 0.65 g (1.43 mmol) of compound 2 step 3 in 10 mL dichloromethane was added 1 mL (7.1 mmol) of triethylamine, 17.5 mg (0.14 mmol) of DMAP and a solution of triphosgene (0.65 g, 2.15 mmol) in 5 mL dichloromethane. The mixture was stirred for 2 hours at −10° C. The mixture was diluted with water and extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous Na.sub.2SO.sub.4, filtered and the solvent was removed under reduced pressure. The crude product was purified by column chromatography on silica (petrol ether/ethyl acetate) to give 80 mg (0.68 mmol, 48%) of the desired compound 24.

[0821] .sup.1H NMR (CDCl.sub.3, ppm): 7.93 (d, J=4.03 Hz, 1H); 7.61 (s, 1H); 7.29 (d, J=4.03 Hz, 1H); 7.00 (s, 1H); 6.91 (t, J=3.80 Hz, 1H); 4.92 (s, 2H); 4.20 (t, 2H); 3.66 (t, J=5.80 Hz, 2H); 2.72 (t, J=6.20 Hz, 2H); 1.87-1.98 (m, 4H); 1.23 (t, 3H).

Example 3: ethyl 2-[[3-[2-chloro-4-fluoro-5-[(Z)-(3-oxo-5,6,7,8-tetrahydro-[1,3,4]thiadiazolo[3,4-a]pyridazin-1-ylidene)amino]phenoxy]-2-pyridyl]oxy]acetate

[0822] ##STR00074##

Example 3 Step 1: ethyl 2-[[3-(2-chloro-4-fluoro-phenoxy)-2-pyridyl]oxy]acetate

[0823] ##STR00075##

[0824] To a solution of 52.0 g (0.21 mol) of compound 3 step 3 in 400 mL 1,2-dichloroethane at 85° C. was added 5.2 mL of boron trifluoride diethyl etherate dropwise, followed by a solution of 84 g (0.74 mol) of ethyl diazoacetate in 400 mL 1,2-dichloroethane dropwise. The mixture was stirred for 12 hours at 85° C. The mixture was diluted with water and extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous Na.sub.2SO.sub.4, filtered and the solvent was removed under reduced pressure. The crude product was purified by column chromatography on silica (petrol ether/ethyl acetate) to give 46.0 g (0.14 mol, 66%) of the desired compound 3 step 1.

[0825] .sup.1H NMR (CDCl.sub.3, ppm): 7.89 (dd, J=4.89, 1.38 Hz, 1H); 7.22 (dd, J=7.91, 2.64 Hz, 1H); 7.09 (dd, J=7.65, 1.38 Hz, 1H); 6.92-7.02 (m, 2H); 6.88 (dd, J=7.78, 5.02 Hz, 1H); 4.94-5.00 (m, 2H); 4.23 (q, J=7.11 Hz, 2H); 1.27 (t, J=7.15 Hz, 3H).

Example 3 Step 2: ethyl 2-[[3-(2-chloro-4-fluoro-5-nitro-phenoxy)-2-pyridyl]oxy]acetate

[0826] ##STR00076##

[0827] To a solution of 46.0 g (0.14 mol) of ethyl 2-[[3-(2-chloro-4-fluoro-phenoxy)-2-pyridyl]oxy]acetate (synthesized from 2-chloro-4-fluorophenol (CAS 1996-41-4) in analogy to compound 1 step 4 described above) in 400 mL sulfuric acid at −10° C. was added 30 mL of a solution of fuming nitric acid and sulfuric acid (1:1). The mixture was stirred for 2 hours at −5° C. The mixture was poured into ice water, filtered and the filter cake was washed with water. The filter cake was dried to give 48.0 g of the desired compound 3 step 2 which was used without further purification in the next step.

[0828] .sup.1H NMR (CDCl.sub.3, ppm): 8.01-8.07 (m, 1H) 8.11 (s, 1H); 7.54 (d, J=6.62 Hz, 1H); 7.38-7.49 (m, 2H); 7.02 (dd, J=7.72, 5.07 Hz, 1H); 5.31 (s, 1H); 4.90 (s, 1H); 4.19 (q, J=7.06 Hz, 2H); 1.23 (t, J=7.06 Hz, 3H).

Example 3 Step 3: ethyl 2-[[3-(5-amino-2-chloro-4-fluoro-phenoxy)-2-pyridyl]oxy]acetate

[0829] ##STR00077##

[0830] To a solution of 48.0 g (0.13 mol) of compound 3 step 1 in 500 mL acetic acid was added 36.0 g (0.65 mol) of iron at 0° C. The mixture was stirred for 12 hours at 25° C., filtered and the filter cake was washed with ethyl acetate. The filtrate was diluted with water and extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous Na.sub.2SO.sub.4, filtered and the solvent was removed under reduced pressure to give the desired compound 3 step 3 (30.0 g) which was used without further purification in the next step.

Example 3 Step 4: ethyl 2-[[3-(2-chloro-4-fluoro-5-isothiocyanato-phenoxy)-2-pyridyl]oxy]acetate

[0831] ##STR00078##

[0832] To a solution of 2.0 g (6.0 mmol) of compound 3 step 2 in a 30 mL solution of chloroform and aq. NaHCO.sub.3 (1:1) was added 1.0 g (8.8 mmol) of thiophosgene over 2 hours at 0° C. The mixture was diluted with water and extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous Na.sub.2SO.sub.4, filtered and the solvent was removed under reduced pressure to give the desired compound 3 step 4 (1.5 g) which was used without further purification in the next step.

Example 3 Step 5: ethyl 2-[[3-[2-chloro-4-fluoro-5-(hexahydropyridazine-1-carbothioylamino)phenoxy]-2-pyridyl]oxy]acetate

[0833] ##STR00079##

[0834] To a solution of 1.5 g (3.9 mmol) of compound 3 step 3 in 15 mL dichloromethane under nitrogen atmosphere was added 1.2 g (11.9 mmol) of triethylamine and a solution of 0.7 g (4.4 mmol) of hexahydropyridazine dihydrochloride (CAS 124072-89-5) in 5 mL dichloromethane. The mixture was stirred for 1 hour at 27° C. The volatiles were removed under vacuum. The residue was triturated with water, filtered, the filter cake was washed with water. The filtrate was extracted with ethyl acetate, washed with brine, dried over anhydrous Na.sub.2SO.sub.4, filtered and the solvent was removed under reduced pressure to give the desired compound 3 step 5 (1.7 g) which was used without further purification in the next step.

Example 3 Step 6: ethyl 2-[[3-[2-chloro-4-fluoro-5-[(Z)-(3-oxo-5,6,7,8-tetrahydro-[1,3,4]thiadiazolo[3,4-a]pyridazin-1-ylidene)amino]phenoxy]-2-pyridyl]oxy]acetate

[0835] ##STR00080##

[0836] To a solution of 20% triphosgene in toluene at −5° C. was added a solution of 2.1 g (4.6 mmol) of compound 3 step 4 in 20 mL 1,2-dichloroethane at 0° C. The mixture was stirred for 2 hours at 27° C. The mixture was diluted with water and extracted with dichloromethane. The combined organic layer was washed with brine, dried over anhydrous Na.sub.2SO.sub.4, filtered and the solvent was removed under reduced pressure to give 1.6 g of the desired compound 3 (3.3 mmol, 72%).

[0837] .sup.1H NMR (CDCl.sub.3, ppm): 7.88 (dd, J=4.96, 1.21 Hz, 1H); 7.24 (d, J=9.48 Hz, 1H); 7.12 (dd, J=7.83, 1.21 Hz, 1H); 6.89 (dd, J=7.83, 4.96 Hz, 1H); 6.62 (d, J=7.50 Hz, 1H); 4.96 (s, 2H); 4.22 (q, J=7.06 Hz, 2H); 3.66-3.81 (m, 4H); 1.77-1.94 (m, 4H); 1.26 (t, J=7.17 Hz, 3H).

Example 4: Ethyl 2-[[3-[5-[3,5-dimethyl-2,6-dioxo-4-(trifluoromethyl)pyrimidin-1-yl]-4-fluoro-2-nitro-phenoxy]-2-pyridyl]oxy]acetate

[0838] ##STR00081##

Example 4 Step 1: ethyl (Z)-3-amino-4,4,4-trifluoro-2-methyl-but-2-enoate

[0839] ##STR00082##

[0840] To a solution of 36.8 g (186 mmol) of (CAS 344-00-3) in 75 mL ethanol and 3.8 mL water was added 42.9 g (186 mmol) of ammonium acetate. The mixture was stirred for 16 hours at 90° C. The mixture was diluted with water and extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous MgSO.sub.4, filtered and the solvent was removed under reduced pressure to give the desired compound 4 step 1 (17.0 g) which was used without further purification in the next step.

[0841] .sup.1H NMR (CDCl.sub.3, ppm): 6.45 (br s, 2H); 4.14-4.22 (m, 2H); 1.77-1.93 (m, 3H); 1.29 (t, J=7.09 Hz, 3H).

Example 4 Step 2: 2-(dimethylamino)-5-methyl-4-(trifluoromethyl)-1,3-oxazin-6-one

[0842] ##STR00083##

[0843] To a solution of 23.6 g (120 mmol) of compound 4 step 1 1 in 300 mL chloroform was added 19.5 g (120 mmol) of (dichloromethylene)dimethylammonium chloride (CAS 33842-02-3). The mixture was stirred for 16 hours at 25° C. The mixture was diluted with water and extracted with dichloromethane. The combined organic layer was washed with brine, dried over anhydrous MgSO.sub.4, filtered and the solvent was removed under reduced pressure. The crude product was purified by column chromatography on silica (petrol ether/ethyl acetate) to give 20.0 g (90 mmol, 75%) of the desired compound 4 step 2.

[0844] .sup.1H NMR (CDCl.sub.3, ppm): 3.18-3.07 (m, 6H); 2.02 (q, J=2.3 Hz, 3H).

Example 4 Step 3: 3-(2,5-difluorophenyl)-5-methyl-6-(trifluoromethyl)-1H-pyrimidine-2,4-dione

[0845] ##STR00084##

[0846] To a solution of 19.8 g (153 mmol) of 2,5-difluoroaniline (CAS 367-30-6) in 40 mL acetic acid was added 17.0 g (77.0 mmol) of compound 4 step 2. The mixture was stirred for 16 hours at 80° C. The mixture was quenched with a sat. aq. NH4Cl solution water and extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous Na.sub.2SO.sub.4, filtered and the solvent was removed under reduced pressure to give the desired compound 4 step 3 (33.0 g) which was used without further purification in the next step.

Example 4 Step 4: 3-(2,5-difluorophenyl)-1,5-dimethyl-6-(trifluoromethyl)pyrimidine-2,4-dione

[0847] ##STR00085##

[0848] To a solution of 33.0 g (110 mmol) of compound 4 step 3 in 40 mL dimethyl formamide was added 30.4 g (220 mmol) potassium carbonate and 30.0 g (211 mmol) methyl iodide. The mixture was stirred for 16 hours at 25° C. The mixture was diluted with water and extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous Na.sub.2SO.sub.4, filtered and the solvent was removed under reduced pressure. The crude product was purified by column chromatography on silica (petrol ether/ethyl acetate) to give 13.6 g (42.5 mmol, 39%) of the desired compound 4 step 4.

[0849] .sup.1H NMR (CDCl.sub.3, ppm): 7.24-7.12 (m, 2H); 7.00 (ddd, J=3.0, 5.5, 8.1 Hz, 1H); 3.56 (q, J=2.1 Hz, 3H); 2.25 (q, J=4.6 Hz, 3H).

Example 4 Step 5: 3-(2,5-difluoro-4-nitro-phenyl)-1,5-dimethyl-6-(trifluoromethyl)pyrimidine-2,4-dione

[0850] ##STR00086##

[0851] To a solution of 10.7 g (33.4 mol) of compound 4 step 4 in 40 mL sulfuric acid was added a solution of 3.6 mL of fuming nitric acid in 10.7 mL sulfuric acid dropwise at −5° C. The mixture was stirred for 1.5 hours at −5° C. The mixture was diluted with ice water and extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous Na.sub.2SO.sub.4, filtered and the solvent was removed under reduced pressure to give the desired compound 4 step 5 (13.7 g) which was used without further purification in the next step.

Example 4 Step 6: ethyl 2-[[3-[5-[3,5-dimethyl-2,6-dioxo-4-(trifluoromethyl)pyrimidin-1-yl]-4-fluoro-2-nitro-phenoxy]-2-pyridyl]oxy]acetate

[0852] ##STR00087##

[0853] To a solution of 13.7 g (37.5 mmol) of compound 4 step 5 in 100 mL dimethylformamide was added 1.3 g (80 mmol) of potassium carbonate and 9.7 g (49.0 mmol) of ethyl 2-((3-hydroxypyridin-2-yl)oxy)acetate (CAS 353292-81-6). The mixture was stirred for 16 hours at 25° C. The mixture was diluted with water and extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous Na.sub.2SO.sub.4, filtered and the solvent was removed under reduced pressure. The crude product was purified by column chromatography on silica (petrol ether/ethyl acetate) to give 5.6 g (10.3 mmol, 28%) of the desired compound 4.

[0854] .sup.1H NMR (CDCl.sub.3, ppm): 7.98 (d, J=4.9 Hz, 1H); 7.87 (d, J=8.7 Hz, 1H); 7.49 (d, J=7.8 Hz, 1H); 7.10 (d, J=6.0 Hz, 1H); 6.98 (dd, J=5.0, 7.7 Hz, 1H); 4.93-4.84 (m, 2H); 4.13-4.09 (m, 2H); 3.50 (d, J=1.9 Hz, 3H); 2.19 (q, J=4.6 Hz, 3H); 2.09-2.00 (m, 3H).

Example 5: ethyl 2-[[3-[2-amino-5-[3,5-dimethyl-2,6-dioxo-4-(trifluoromethyl)pyrimidin-1-yl]-4-fluoro-phenoxy]-2-pyridyl]oxy]acetate

[0855] ##STR00088##

[0856] To a solution of 5.6 g (10.3 mmol) of compound 4 in 200 mL ethanol was added 10 mL water, 2.9 g (50 mmol) iron and 2.7 g (50 mmol) ammonium chloride. The mixture was stirred for 16 hours at 25° C. The mixture was diluted with water and extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous Na.sub.2SO.sub.4, filtered and the solvent was removed under reduced pressure. The crude product was purified by column chromatography on silica (petrol ether/ethyl acetate) to give 4.0 g (7.8 mmol, 76%) of the desired compound 5.

[0857] .sup.1H NMR (CDCl.sub.3, ppm): 7.81 (d, J=4.8 Hz, 1H); 7.19 (d, J=7.9 Hz, 1H); 6.84 (dd, J=5.0, 7.8 Hz, 1H); 6.76 (d, J=6.8 Hz, 1H); 6.60 (d, J=10.9 Hz, 1H); 4.97 (s, 2H); 4.32-4.26 (m, 2H); 4.29 (q, 2H); 3.51 (d, J=1.9 Hz, 3H); 2.25-2.18 (m, 3H); 1.25 (d, J=1.4 Hz, 3H).

Example 6: ethyl 2-[[3-[2-chloro-5-[3,5-dimethyl-2,6-dioxo-4-(trifluoromethyl)pyrimidin-1-yl]-4-fluoro-phenoxy]-2-pyridyl]oxy]acetate

[0858] ##STR00089##

[0859] To a solution of 4.0 g (7.8 mmol) of compound 5 in 150 mL acetonitrile was added 1.6 g (15.6 mol) copper(I) chloride, 2.9 g (25 mmol) isoamyl nitrite and 2.1 g (15.6 mol) copper(II) chloride. The mixture was stirred for 1.5 hours at 25° C. The mixture was diluted with water and extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous Na.sub.2SO.sub.4, filtered and the solvent was removed under reduced pressure. The crude product was purified by reverse phase preparative HPLC (acetonitrile/water containing trifluoroacetic acid) to give 2.1 g (4.0 mmol, 51%) of the desired compound 6.

[0860] .sup.1H NMR (CDCl.sub.3, ppm): 7.91 (dd, J=1.5, 5.0 Hz, 1H); 7.37 (d, J=8.8 Hz, 1H); 7.29 (dd, J=1.5, 7.8 Hz, 1H); 6.96-6.88 (m, 2H); 4.93 (d, J=2.5 Hz, 2H); 4.17 (q, J=7.2 Hz, 2H); 3.55-3.48 (m, 3H); 2.20 (q, J=4.6 Hz, 3H); 1.25 (t, J=7.2 Hz, 3H).

[0861] The compounds listed below in tables 1 to 9 can be prepared similarly to the example mentioned above:

TABLE-US-00005 TABLE 1 (I) [00090] m/z Example no R.sup.1 R.sup.2 R.sup.3 R.sup.6 [M + H] R.sub.t [min] 7 Cl Cl OCH.sub.3 CH.sub.3 494.0 1.133

TABLE-US-00006 TABLE 2 (I) [00091] m/z Example no R.sup.1 R.sup.2 R.sup.3 R.sup.6 [M + H] R.sub.t [min] 8 Cl Cl H H 451.0 0.969 9 Cl Cl CH.sub.3 C.sub.2H.sub.5 493.0 1.185

TABLE-US-00007 TABLE 3 (I) [00092] Example no R.sup.1 R.sup.2 R.sup.6 m/z [M + H] R.sub.t [min] 10 F Cl H 478.0 1.159

TABLE-US-00008 TABLE 4 (I) [00093] Example no R.sup.1 R.sup.2 R.sup.6 m/z [M + H] R.sub.t [min] 11 F Cl C.sub.2H.sub.5 495.0 1.297 12 F Cl H 467.0 1.120

TABLE-US-00009 TABLE 5 (I) [00094] m/z Example no R.sup.1 R.sup.2 R.sup.6 A.sup.3 [M + H] R.sub.t [min] 13 F Cl C.sub.2H.sub.5 O 481.0 1.164 14 F Cl C.sub.2H.sub.5 S 497.0 3.839

TABLE-US-00010 TABLE 6 (I) [00095] Example no R.sup.1 R.sup.2 R.sup.6 m/z [M + H] R.sub.t [min] 15 F Cl Et 502.0 1.198

TABLE-US-00011 TABLE 7 (I) [00096] Example no R.sup.1 R.sup.2 R.sup.6 R.sup.37 m/z [M + H] R.sub.t [min] 16 F Cl C.sub.2H.sub.5 CH.sub.3 531.0 1.300

TABLE-US-00012 TABLE 8 (I) [00097] Example no R.sup.1 R.sup.2 R.sup.6 R.sup.13 m/z [M + H] R.sub.t [min] 17 F Cl C.sub.2H.sub.5 H 533.4 1.395

TABLE-US-00013 TABLE 9 (I) [00098] Example no R.sup.1 R.sup.2 R.sup.6 m/z [M + H] R.sub.t [min] 18 F Cl C.sub.2H.sub.5 505.0 1.404 19 F Cl H 476.9 1.231

B USE EXAMPLES

[0862] The herbicidal activity of the phenylethers of formula (I) was demonstrated by the following greenhouse experiments:

[0863] The culture containers used were plastic flowerpots containing loamy sand with approximately 3.0% of humus as the substrate. The seeds of the test plants were sown separately for each species.

[0864] For the pre-emergence treatment, the active ingredients, which had been suspended or emulsified in water, were applied directly after sowing by means of finely distributing nozzles.

[0865] The containers were irrigated gently to promote germination and growth and subsequently covered with transparent plastic hoods until the plants had rooted. This cover caused uniform germination of the test plants, unless this had been impaired by the active ingredients.

[0866] For the post-emergence treatment, the test plants were first grown to a height of 3 to 15 cm, depending on the plant habit, and only then treated with the active ingredients which had been suspended or emulsified in water. For this purpose, the test plants were either sown directly and grown in the same containers, or they were first grown separately as seedlings and transplanted into the test containers a few days prior to treatment.

[0867] Depending on the species, the plants were kept at 10-25° C. or 20-35° C., respectively.

[0868] The test period extended over 2 to 4 weeks. During this time, the plants were tended, and their response to the individual treatments was evaluated.

[0869] Evaluation was carried out using a scale from 0 to 100. 100 means no emergence of the plants, or complete destruction of at least the aerial moieties, and 0 means no damage, or normal course of growth. A good herbicidal activity is given at values of at least 70 and a very good herbicidal activity is given at values of at least 85.

[0870] The plants used in the greenhouse experiments were of the following species:

TABLE-US-00014 Bayer code Scientific name AMARE Amaranthus retroflexus CHEAL Chenopodium album ECHCG Echinocloa crus-galli SETVI Setaria viridis ZEAMX Zea mays

[0871] At an application rate of 16 g/ha, the compounds (examples) 1, 2, 4, 7, 8, 10, 11, 12, 15, 16, 17, 18 and 19 applied by the post-emergence method, showed very good herbicidal activity against AMARE, CHEAL, ECHCG and SETVI.

[0872] At an application rate of 16 g/ha, the compound (example) 9 applied by the post-emergence method, showed very good herbicidal activity against AMARE, CHEAL and ECHCG.

[0873] At an application rate of 31 g/ha, the compound (example) 13 applied by the post-emergence method, showed very good herbicidal activity against AMARE, CHEAL and ECHCG.

TABLE-US-00015 TABLE 10 Comparison of the herbicidal activity of example 16 of the present invention and compound no. a-9 known from WO 02/098227 example 16 [00099] compound a-9 [00100] post-emergence application, control 21 days after treatment (greenhouse): cmpd no. a-9 compound example 16 (WO 02/098227) application rate [g/ha] 2 2 damages unwanted plants 100 98 ECHCG crop plants 10 70 ZEAMX

[0874] The data clearly demonstrate the better herbicidal activity and the superior crop compatibility of the inventive compounds of formula (I) of the present invention over the compounds known from the prior art.

[0875] The replacement of the hydrogen by a methyl group within the uracil moiety leads not only to a better herbicidal activity, but also to a much better crop compatibility as achieved by the compound known from WO 02/098227.

TABLE-US-00016 TABLE 11 Comparison of the herbicidal activity of example 17 of the present invention and compound no. a-9 known from WO 02/098227 example 17 [00101] compound a-9 [00102] pre-emergence application, control 21 days after treatment (greenhouse): cmpd no. a-9 compound example 17 (WO 02/098227) application rate [g/ha]  32  32 damages unwanted plants 100 100 AMARE crop plants  0  40 ZEAMX

[0876] The data clearly demonstrate the superior crop compatibility of the inventive compounds of formula (I) of the present invention over the compounds known from the prior art.

[0877] The replacement of the uracil ring by an thiouracil ring leads not only to the same herbicidal activity, but also to a much better crop compatibility as achieved by the compound known from WO 02/098227.