HERBICIDAL COMPOUNDS

Abstract

The present invention relates to compounds of Formula (I), or an agronomically acceptable salt of said compounds wherein Q, R.sup.1, R.sup.2, R.sup.4 and n are as defined herein. The invention further relates to herbicidal compositions which comprise a compound of Formula (I) and to the use of compounds of Formula (I) for controlling weeds, in particular in crops of useful plants.

##STR00001##

Claims

1. A compound of Formula (I): ##STR00061## or an agronomically acceptable salt thereof, wherein Q is selected from the group consisting of C.sub.1-C.sub.6haloalkyl, C.sub.1-C.sub.6haloalkyl-C(O)—, C.sub.1-C.sub.6haloalkoxy-, C.sub.1-C.sub.6haloalkoxyC(O)— and a 5-membered aromatic heterocyclic ring which is optionally substituted by 1 or 2 R.sup.3 substituents independently selected from the group consisting of C.sub.1-C.sub.4alkyl, C.sub.2-C.sub.4alkenyl, C.sub.2-C.sub.4alkynyl, cyclopropyl, C.sub.1-C.sub.4haloalkyl, C.sub.1-C.sub.2alkoxy-, C.sub.1-C.sub.2haloalkoxy-, halogen, —C(O)C.sub.1-C.sub.4alkyl, NO.sub.2, —CH.sub.2CN, —CN and —S(O).sub.pC.sub.1-C.sub.4alkyl; each R.sup.1 is independently selected from the group consisting of halogen, —CN, nitro, C.sub.1-C.sub.4alkyl, C.sub.2-C.sub.4alkenyl, C.sub.2-C.sub.4alkynyl, C.sub.1-C.sub.4haloalkyl, C.sub.1-C.sub.4alkoxy-, C.sub.1-C.sub.4haloalkoxy- and —S(O).sub.pC.sub.1-C.sub.4alkyl; R.sup.2 is selected from the group consisting of hydrogen, halogen, C.sub.1-C.sub.4alkyl, —NR.sup.5R.sup.6, C.sub.1-C.sub.4haloalkyl and C.sub.1-C.sub.4alkoxy; R.sup.4 is selected from the group consisting of hydrogen, halogen, —OCF.sub.3, —OCF.sub.2H and —CN; R.sup.5 is hydrogen or C.sub.1-C.sub.4alkyl; R.sup.6 is hydrogen or C.sub.1-C.sub.4alkyl; n=0, 1 or 2; and p=0, 1 or 2.

2. A compound according to claim 1, wherein Q is C.sub.1-C.sub.6fluoroalkyl.

3. A compound according to claim 1, wherein Q is C.sub.1-C.sub.6fluoroalkyl-C(O)—.

4. A compound of Formula (I) according to claim 1, wherein Q is a 5-membered aromatic heterocyclic ring selected from the group consisting of: ##STR00062## wherein R.sup.3 is selected from the group consisting of hydrogen, C.sub.1-C.sub.4alkyl, C.sub.2-C.sub.4alkenyl, C.sub.2-C.sub.4alkynyl, cyclopropyl, C.sub.1-C.sub.2haloalkyl, C.sub.1-C.sub.2alkoxy-, C.sub.1-C.sub.2haloalkoxy-, halogen, —C(O)C.sub.1-C.sub.4alkyl, NO.sub.2, —CH.sub.2CN, —CN and —S(O).sub.pC.sub.1-C.sub.4alkyl.

5. A compound of Formula (I) according to claim 4, wherein Q is selected from the group consisting of Q1, Q2 and Q5.

6. A compound of Formula (I) according to claim 4, wherein Q is Q2.

7. A compound according to claim 1, wherein n is 1 and R.sup.1 is fluorine.

8. A compound according to claim 7, wherein R.sup.1 is 3-fluoro.

9. A compound according to claim 1, wherein R.sup.2 is methyl or methoxy.

10. A compound according to claim 1, wherein R.sup.4 is selected from the group consisting of hydrogen, fluorine and chlorine.

11. A herbicidal composition comprising a compound according to claim 1 and an agriculturally acceptable formulation adjuvant.

12. A herbicidal composition according to claim 11, further comprising at least one additional pesticide.

13. A herbicidal composition according to claim 12, wherein the additional pesticide is a herbicide or herbicide safener.

14. A method of controlling weeds at a locus comprising application to the locus of a weed controlling amount of a composition according to claim 1.

15. Use of a compound of Formula (I) as defined in claim 1 as a herbicide.

Description

EXAMPLE 1

Synthesis of 3-(difluoromethyl)-5-[2-fluoro-6-(6-methoxypyrimidin-4-yl)oxy-phenyl]isoxazole

[0092] ##STR00011##

[0093] To a solution of 2-[3-(difluoromethyl)isoxazol-5-yl]-3-fluoro-phenol (0.60 g, 2.6 mmol) stirred and dissolved in N,N-dimethylformamide (26 mL) was added potassium carbonate (1.8 g, 13 mmol) and 4-chloro-6-methoxy-pyrimidine (1.1 g, 7.9 mmol). The mixture was heated at 75° C. for 40 h. The reaction mixture was then allowed to cool and concentrated to remove the bulk of DMF. The residual material was diluted with water (15 mL) and extracted with ether (3×20 mL). The organic extracts were combined, washed with water (2×10 mL) and separated. The collected organics were adsorbed onto granular celite and purified by chromatography, gradient elution with EtOAc/cyclohexane to afford the desired product (400 mg, 45%).

[0094] .sup.1H NMR: (400 MHz, CDCl.sub.3) δ 8.38 (d, 1H), 7.53 (dt, 1H), 7.18 (ddd, 1H), 7.09 (dt, 1H), 6.90-6.63 (t, 1H), 6.82 (d, 1H), 6.31 (d, 1H), 3.99 (s, 3H).

EXAMPLE 2

Synthesis of 3-[2-(6-bromopyrimidin-4-yl)oxy-6-fluoro-phenyl]-5-(trifluoromethyl)isoxazole

[0095] ##STR00012##

[0096] To a solution of 3-fluoro-2-[5-(trifluoromethyl)isoxazol-3-yl]phenol (0.10 g, 0.40 mmol) stirred and dissolved in N,N-dimethylformamide (4.0 mL) was added potassium carbonate (0.28 g, 2.0 mmol) and 4,6-dibromopyrimidine (0.14 g, 0.61 mmol) and the light orange-brown mixture was stirred at for 42 h at ambient temperature. The reaction mixture was then diluted with water (8 mL) and extracted with Et.sub.2O (3×8 mL). The organic extracts were combined, washed with water (2×10 mL) and separated. The collected organics were adsorbed onto granular celite and purified by chromatography, gradient elution with EtOAc/cyclohexane to afford the desired product (7 mg, 4%).

[0097] .sup.1H NMR: (400 MHz, CDCl.sub.3) δ 8.46 (d, 1H), 7.58 (dt, 1H), 7.26-7.21 (m, 1H), 7.20 (d, 1H), 7.12 (dt, 1H), 7.03-6.96 (m, 1H)

EXAMPLE 3

3-(6-methoxypyrimidin-4-yl)oxy-2-[4-(trifluoromethyl)pyrazol-1-yl]benzonitrile

[0098] ##STR00013##

[0099] To a solution of 3-hydroxy-2-[4-(trifluoromethyl)pyrazol-1-yl]benzonitrile (0.200 g, 0.790 mmol) and 4-chloro-6-methoxy-pyrimidine (0.171 g, 1.18 mmol) in N,N-dimethylformamide (7.90 mL) in a microwave vial was added potassium carbonate (0.546 g, 3.95 mmol). The solution was heated at 130° C. for 2 hours under microwave irradiation. The reaction mixture was poured into water and diluted with ethyl acetate resulting in formation of a yellow mixture. The aqueous phase was acidified to pH 1 (2M HCl). The phases were separated and the aqueous phase was extracted into ethyl acetate (2×10 mL). The combined organic extracts were washed with brine, dried over magnesium sulfate, filtered and concentrated to afford a brown liquid. Purification by RPHPLC afforded the desired product as a white solid (0.108 g, 38%).

[0100] .sup.1H NMR (400 MHz, CDCl.sub.3) δ 8.32 (d, 1H), 7.95 (s, 1H), 7.90 (s, 1H), 7.75 (dd, H), 7.64 (t, 1H), 7.59-7.56 (m, 1H), 6.20 (d, 1H), 3.98 (s, 3H)

Synthesis of 3-hydroxy-2-[4-(trifluoromethyl)pyrazol-1-yl]benzonitrile

[0101] ##STR00014##

[0102] To a solution of 2-fluoro-3-hydroxy-benzonitrile (1.0 g, 7.3 mmol) and 4-(trifluoromethyl)-1H-pyrazole (1.1 g, 8.0 mmol) in N,N-dimethylacetamide (15 mL) under a nitrogen atmosphere was added powdered K.sub.2CO.sub.3 (3.1 g, 22 mmol). The resultant mixture was heated at 150° C. for 22 hours. The reaction mixture was allowed to cool to RT, diluted with water and extracted with EtOAc (×4). The combined organic extracts were washed with brine, dried over MgSO.sub.4 and evaporated to dryness to give an orange liquid. The crude product was purified by flash chromatography on silica gel using a gradient of 20 to 40% ethyl acetate in cyclohexane as eluent to give the desired product (594 mg, 32%) as a yellow solid.

[0103] .sup.1H NMR (400 MHz, CDCl.sub.3) δ 8.64 (s, 1H), 8.07 (s, 1H), 7.42-7.35 (m, 3H).

EXAMPLE 4

Synthesis of 5-[2-(6-chloro-5-fluoro-pyrimidin-4-yl)oxy-6-fluoro-phenyl]-3-(difluoromethyl)isoxazole

[0104] ##STR00015##

[0105] To a solution of 2-[3-(difluoromethyl)isoxazol-5-yl]-3-fluoro-phenol (0.1 g, 0.44 mmol) stirred and dissolved in N,N-dimethylformamide (4.5 mL) was added potassium carbonate (0.3 g, 2.2 mmol) and 4,6-dichloro-5-fluoro-pyrimidine (0.11 g, 0.65 mmol). After 4 h, the mixture was diluted with water (3 mL) and extracted with ether (3×8 mL). The organic extracts were combined, washed with water (2×10 mL) and separated. The collected organics were adsorbed onto granular celite and purified by chromatography, gradient elution with EtOAc/cyclohexane to afford the desired product (115 mg, 74%).

[0106] .sup.1H NMR: (400 MHz, CDCl.sub.3) δ 8.24 (s, 1H), 7.59 (dt, 1H), 7.27 (dt, J=1.0, 9.2 Hz, 1H), 7.17 (td, 1H), 6.91 (s, 1H), 6.90-6.64 (t, 1H)

EXAMPLE 5

Synthesis of 3-(difluoromethyl)-5-[2-fluoro-6-(5-fluoro-6-methoxy-pyrimidin-4-yl)oxy-phenyl]isoxazole

[0107] ##STR00016##

[0108] To a solution of 5-[2-(6-chloro-5-fluoro-pyrimidin-4-yl)oxy-6-fluoro-phenyl]-3-(difluoromethyl)isoxazole (0.050 g, 0.14 mmol) in methanol (5 mL) stirred and cooled to 0-5° C. in an ice bath was added sodium methoxide (0.50M in MeOH) (0.8 mL, 0.42 mmol). The colourless solution was stirred at room temp for 3 hours, then left to stand for 48 h. The reaction mixture was concentrated to remove the bulk of solvent, and the residue quenched by the addition of water then acidified with dil HCl. A white precipitate was filtered off, washing through with water then drying under suction giving a white powder. Purification by RPHPLC afforded the desired product (2.3 mg, 4.7%).

[0109] .sup.1H NMR: (400 MHz, CDCl.sub.3) δ 8.07 (s, 1H), 7.55 (dt, 1H), 7.21 (ddd, 1H), 7.15-7.11 (m, 1H), 6.93-6.62 (t, 1H), 6.87 (d, 1H), 4.09 (s, 3H).

EXAMPLE 6

Synthesis of 5-(difluoromethyl)-2-[2-fluoro-6-(6-methoxypyrimidin-4-yl)oxy-phenyl]oxazole

[0110] ##STR00017##

[0111] To a solution of 2-[5-(difluoromethyl)isoxazol-3-yl]-3-fluoro-phenol (0.100 g, 0.436 mmol) stirred and dissolved in N,N-dimethylformamide (4.5 mL) was added potassium carbonate (0.091 g, 0.655 mmol) and 4-chloro-6-methoxy-pyrimidine (0.095 g, 0.655 mmol), the mixture being stirred and heated to 70° C. for 40 h. The reaction mixture was allowed to cool and was diluted with water (5 mL) and was extracted with Et2O (3×8 mL). The organic extracts were combined, washed with water (2×10 mL) and separated and the collected organics were concentrated to give crude material as a brown gum. This was dissolved in 1 mL 10% MeOH in DMSO and purified by RPHPLC to afford the product as a pale-yellow solid (46.7 mg, 32%).

[0112] .sup.1H NMR: (400 MHz, CDCl.sub.3) δ 8.35 (s, 1H), 7.55 (dt, 1H), 7.40 (t, 1H), 7.22-7.14 (m, 1H), 7.11 (d, 1H), 6.79-6.52 (t, 1H), 6.26 (d, 1H), 3.98 (s, 3H).

EXAMPLE 7

[0113] Synthesis of 4-[3-bromo-2-(5,5,5-trifluoropentyl)phenoxy]-6-methoxy-pyrimidine

##STR00018##

[0114] 4-Chloro-6-methoxypyrimidine (0.046 g, 0.32 mmol) and potassium carbonate (0.073 g, 0.53 mmol) were stirred in N,N-dimethylformamide (4 mL) at ambient temperature to which 3-bromo-2-(5,5,5-trifluoropentyl)phenol (0.078 g, 0.26 mmol) was added in one portion. The reaction was stirred at 80° C. until completion. The reaction mixture was concentrated onto celite and purified by column chromatography on silica gel using a gradient of 0-10% EtOAc/cyclohexane afforded 4-[3-bromo-2-(5,5,5-trifluoropentyl)phenoxy]-6-methoxy-pyrimidine (0.100 g, 94%) as a colourless gum.

[0115] .sup.1H NMR: (400 MHz, CDCl.sub.3) δ 8.45 (s, 1H), 7.48 (dd, 1H), 7.13 (t, 1H), 7.01 (dd, 1H), 6.16 (d, 1H), 3.99 (s, 3H), 2.71 (br t, 2H), 2.13-1.99 (m, 2H), 1.62-1.57 (m, 4H).

EXAMPLE 8

Synthesis of 3-bromo-2-(5,5,5-trifluoropentyl)phenol

[0116] ##STR00019##

[0117] 3-Bromo-2-(5,5,5-trifluoropentyl)phenol was prepared according to procedures described in WO2016/196606. Phenols with alternative R1 substituents can be prepared by analogous methods.

TABLE-US-00001 TABLE 1 Examples of herbicidal compounds of the present invention. COMPOUND STRUCTURE .sup.1H NMR (400 MHz, CDCl.sub.3) 1.001 [00020] 8.38 (s, 1H), 7.52 (dt, 1H), 7.17 (ddd, 1H), 7.08 (d, 1H), 6.81 (d, 1H), 6.88-6.62 (t, 1H), 6.22 (d, 1H), 3.98 (s, 3H) 1.002 [00021] 8.67 (s, 1H), 7.56 (dt, 1H), 7.22 (ddd, 1H), 7.10 (d, 1H), 6.88-6.62 (t, 1H), 6.87 (s, 1H), 6.86-6.83 (m, 1H), 5.40 (br s, 2H), 2.58 (s, 3H) 1.003 [00022] 8.46 (d, 1H), 7.58 (dt, 1H), 7.26- 7.21 (m, 1H), 7.20 (d, 1H), 7.12 (dt, 1H), 7.03-6.96 (m, 1H) 1.004 [00023] 8.75 (s, 1H), 7.59 (dt, 1H), 7.26-7.21 (m, 2H), 7.18-7.10 (m, 1H), 7.03- 6.97 (m, 1H), 6.77-6.36 (t, 1H) 1.005 [00024] 8.81 (s, 1H), 7.60 (dt, 1H), 7.33 (d, 1H), 7.29-7.23 (m, 1H), 7.15 (td, 1H), 7.04-7.00 (m, 1H) 1.006 [00025] 8.51 (d, 1H), 7.58 (dt, 1H), 7.25- 7.20 (m, 1H), 7.12 (dt, 1H), 7.01 (d, 1H), 7.00 (dd, 1H) 1.007 [00026] 8.38 (s, 1H), 7.54 (dt, 1H), 7.2-7.15 (m, 1H), 7.09 (d, 1H), 6.95 (br. d, 1H), 6.24 (d, 1H), 3.99 (s, 3H)

TABLE-US-00002 TABLE 2 Examples of herbicidal compounds of the present invention. COMPOUND STRUCTURE .sup.1H NMR (400 MHz, CDCl.sub.3) 2.001 [00027] 8.58 (s, 1H), 7.61 (dt, 1H), 7.31 (ddd, 1H), 7.16 (dd, 1H), 6.95 (d, 1H), 6.92-6.63 (t, 1H) 2.002 [00028] 8.09 (s, 1H), 7.53 (dt, 1H), 7.17 (ddd, 1H), 7.12 (td, 1H), 6.92-6.62 (t, 1H), 6.87 (d, 1H), 5.47 (br d, 1H), 3.11 (d, 3H) 2.003 [00029] 8.39 (d, 1H), 7.64 (dd, 1H), 7.44 (t, 1H), 7.22 (dd, 1H), 6.91-6.62 (t, 1H), 6.60 (s, 1H), 6.15 (d, , 1H), 3.97 (s, 3H) 2.004 [00030] 8.39 (d, 1H), 7.51 (t, 1H), 7.46 (dd, 1H), 7.18 (dd, 1H), 6.92-6.60 (t, 1H), 6.65 (d, 1H), 6.17 (d, 1H), 3.98 (s, 3H) 2.005 [00031] 8.16 (s, 1H), 7.51 (dt, 1H), 7.14 (ddd, 1H), 7.10-7.06 (m, 1H), 6.93- 6.62 (t, 1H), 6.81 (d, 1H), 5.90 (s, 1H), 5.09 (brs, 1H), 2.95 (d, 3H) 2.006 [00032] 8.62 (s, 1H), 7.66 (dd, 1H), 7.46 (t, 1H), 7.24 (dd, 1H), 6.92-6.61 (t, 1H), 6.70 (s, 1H), 6.59 (s, 1H), 2.49 (s, 3H) 2.007 [00033] 8.61 (d, 1H), 7.53 (t, 1H), 7.48 (dd, 1H), 7.21 (dd, 1H), 6.89-6.62 (t, 1H), 6.73 (s, 1H), 6.64 (s, 1H), 2.50 (s, 3H) 2.008 [00034] 8.31 (s, 1H), 7.57 (dt, 1H), 7.26-7.20 (m, 1H), 7.16 (d, 1H), 6.88 (d, 1H), 6.92-6.61 (t, 1H), 2.57 (d, 3H) 2.009 [00035] 8.24 (s, 1H), 7.59 (dt, 1H), 7.27 (dt, 1H), 7.17 (td, 1H), 6.91 (s, 1H), 6.90-6.64 (t, 1H) 2.010 [00036] 8.54 (d, 1H), 8.45 (d, 1H), 7.59 (dt, 1H), 7.26 (dt, 1H), 7.19 (td, 1H), 6.89 (d, 1H), 6.88-6.61 (t, 1H) 2.011 [00037] 8.61 (d, 1H), 7.55 (dt, 1H), 7.23- 7.16 (m, 1H), 7.11 (d, 1H), 6.89-6.82 (t, 1H), 6.88 (s, 1H), 6.81 (d, 1H), 2.81 (q, 2H), 1.33 (t, 3H) 2.012 [00038] 8.38-8.34 (m, 1H), 7.77 (dd, 1H), 7.67 (t, 1H), 7.53 (dd, 1H), 6.94-6.63 (m, 1H), 6.91 (s, 1H), 6.31 (d, 1H), 4.00 (s, 3H) 2.013 [00039] 8.74 (s, 1H), 7.58 (dt, 1H), 7.34 (s, 1H), 7.25 (dt, 1H), 7.12 (dt, 1H), 6.89-6.62 (t, 1H), 6.85 (d, 1H), 6.71- 6.43 (t, 1H) 2.014 [00040] 8.46 (d, 1H), 7.57 (dt, 1H), 7.28 (d, 1H), 7.26-7.20 (m, 1H), 7.10 (d, 1H), 6.85 (d, 1H), 6.92-6.62 (t, 1H) 2.015 [00041] 8.81 (s, 1H), 7.59 (dt, 1H), 7.40 (d, 1H), 7.29-7.24 (m, 1H), 7.13 (d, 1H), 6.87 (d, 1H), 6.76 (t, 1H) 2.016 [00042] 8.50 (d, 1H), 7.57 (dt, 1H), 7.26-7.20 (m, 1H), 7.11 (dt, 1H), 7.09 (d, 1H), 6.85 (d, 1H), 6.77 (t, 1H) 2.017 [00043] 8.38 (d, 1H), 7.53 (dt, 1H), 7.18 (ddd, 1H), 7.09 (dt, 1H), 6.90-6.63 (t, 1H), 6.82 (d, 1H), 6.31 (d, 1H), 3.99 (s, 3H) 2.018 [00044] 8.59 (d, 1H), 7.55 (dt, 1H), 7.20 (ddd, 1H), 7.10 (dt, 1H), 6.90-6.61 (t, 1H), 6.88 (s, 1H), 6.81 (d, 1H), 2.54 (s, 3H) 2.019 [00045] 8.78-8.44 (m, 2H), 7.67-7.43 (m, 1H), 7.34-7.01 (m, 3H), 6.93-6.54 (m, 2H) 2.020 [00046] 8.07 (s, 1H), 7.55 (dt, 1H), 7.21 (ddd, 1H), 7.15-7.11 (m, 1H), 6.93- 6.62 (t, 1H), 6.87 (d, 1H), 4.09 (s, 3H) 2.021 [00047] 8.51 (d, 1H), 7.82 (dd, 1H), 7.72 (t, 1H), 7.56 (dd, 1H), 7.07 (d, 1H), 6.97 (s, 1H), 6.80 (t, 1H) 2.022 [00048] 8.61-8.57 (m, 1H), 7.79 (dd, 1H), 7.69 (t, 1H), 7.56 (dd, 1H), 6.91 (s, 1H), 6.86 (s, 1H), 6.79 (t, 1H), 2.55 (s, 3H) 2.023 [00049] 8.44 (s, 1H), 8.06 (dd, 1H), 7.58- 7.51 (m, 1H), 7.47-7.39 (m, 1H), 7.24 (dd, 1H), 6.89-6.62 (t, 1H), 6.78 (s, 1H), 6.26 (d, 1H), 4.00 (s, 3H) 2.024 [00050] 8.39 (s, 1H), 7.58 (dt, 1H), 7.30- 7.22 (m, 1H), 7.17-7.12 (m, 1H), 6.91 (d, 1H), 6.91-6.64 (t, 1H), 4.16 (s, 3H)

TABLE-US-00003 TABLE 3 Examples of herbicidal compounds of the present invention. COMPOUND STRUCTURE .sup.1H NMR (400 MHz, CDCl.sub.3) 3.001 [00051] 8.47 (d, 1H), 7.97 (s, 1H), 7.88 (s, 1H), 7.80 (dd, 1H), 7.68 (t, 1H), 7.62-7.59 (m, 1H), 6.94 (d, 1H) 3.002 [00052] 8.32 (d, 1H), 7.95 (s, 1H), 7.90 (s, 1H), 7.75 (dd, 1H), 7.64 (t, 1H), 7.59-7.56 (m, 1H), 6.20 (d, 1H), 3.98 (s, 3H) 3.003 [00053] 8.57-8.53 (m, 1H), 7.94 (s, 1H), 7.88 (s, 1H), 7.77 (dd, 1H), 7.66 (t, 1H), 7.61-7.58 (m, 1H), 6.73 (s, 1H), 2.50 (s, 3H) 3.004 [00054] 8.60 (s, 1H), 7.58 (dt, 1H), 7.37 (t, 1H), 7.21 (ddd, 1H), 7.15-7.10 (m, 1H), 6.85 (s, 1H), 6.78-6.51 (t, 1H), 5.85 (br s, 1H), 2.55 (s, 3H) 3.005 [00055] 8.35 (s, 1H), 7.55 (dt, 1H), 7.40 (t, 1H), 7.22-7.14 (m, 1H), 7.11 (d, 1H), 6.79-6.52 (t, 1H), 6.26 (d, 1H), 3.98 (s, 3H) 3.006 [00056] 8.45 (s, 1H), 7.48 (dd, 1H), 7.13 (t, 1H), 7.01 (dd, 1H), 6.16 (d, 1H), 3.99 (s, 3H), 2.71 (br t, 2H), 2.13-1.99 (m, 2H), 1.62- 1.57 (m, 4H) 3.007 [00057] 8.42 (s, 1H), 7.56 (dd, 1H), 7.40- 7.34 (m, 1H), 7.32-7.27 (m, 1H), 6.26 (d, 1H), 4.01 (s, 3H), 2.85- 2.77 (m, 2H), 2.13-2.00 (m, 2H), 1.73-1.58 (m, 4H)

BIOLOGICAL EXAMPLES

[0118] Seeds of a variety of test species are sown in standard soil in pots Amaranthus retoflexus (AMARE), Echinochloa crus-galli (ECHCG), Setaria faberi (SETFA)). After cultivation for one day (pre-emergence) or after 8 days cultivation (post-emergence) under controlled conditions in a glasshouse (at 24/16° C., day/night; 14 hours light; 65% humidity), the plants are sprayed with an aqueous spray solution derived from the formulation of the technical active ingredient in acetone/water (50:50) solution containing 0.5% Tween 20 (polyoxyethelyene sorbitan monolaurate, CAS RN 9005-64-5). Compounds are applied at 250 g/ha unless otherwise stated. The test plants are then grown in a glasshouse under controlled conditions in a glasshouse (at 24/16° C., day/night; 14 hours light; 65% humidity) and watered twice daily. After 13 days for pre- and post-emergence, the test is evaluated for the percentage damage caused to the plant. The biological activities are shown in the following table on a five-point scale (5=81-100%; 4=61-80%; 3=41-60%; 2=21-40%; 1=0-20%).

TABLE-US-00004 TABLE B1 Post-emergence Test Compound AMARE ECHCG SETFA 2.002 2 1 1 2.003 3 4 4 2.004 4 4 4 2.005 2 2 2 2.006 1 3 3 2.007 2 4 4 2.008 3 1 1 2.017 4 4 4

TABLE-US-00005 TABLE B2 Pre-emergence Test Compound AMARE ECHCG SETFA 2.002 2 1 1 2.003 5 5 5 2.004 5 5 5 2.005 2 2 2 2.006 2 5 4 2.007 4 5 5 2.008 4 4 4 2.017 5 5 5

TABLE-US-00006 TABLE B3 Comparative Test (Post-Emergence) RATE % Phytotoxicity Compound g/ha AMARE ZEAMX [00058] 250  63  16 80 60 60 10 10  0 [00059] 250  63  16 20 10  0 20 10  0 [00060] 250  33  16  0  0  0  0  0  0

[0119] The results demonstrate that the 2,4-pyrimidine compounds of the present invention exhibit much improved herbicidal action vis-à-vis weed species e.g AMARE whilst conferring little if any damage to the crop (ZEAMX—corn).