1,3,4-THIADIAZOLES HAVING A HERBICIDAL ACTIVITY, THEIR AGRONOMICAL COMPOSITIONS AND RELATIVE USE

Abstract

The present invention relates to new thiadiazoles having general formula (I):

##STR00001##

and their use as herbicides.

Claims

1. Thiadiazoles having general formula (I), in racemic form, isomerically pure, or mixtures thereof: ##STR00010## wherein: R represents a, halogen atom, a C.sub.1-C.sub.4 alkyl, a C.sub.3-C.sub.6 cycloalkyl or a C.sub.4-C.sub.7 cycloalkylalkyl; A represents a group CR.sub.1R.sub.2, wherein R.sub.1 and R.sub.2, the same or different, represent a hydrogen atom, a C.sub.1-C.sub.4 alkyl, a C.sub.3-C.sub.6 cycloalkyl; Y represents a phenyl, a naphthyl, or an aromatic heterocyclic group, these groups being optionally substituted with at least one substituent selected from: halogen atoms, C.sub.1-C.sub.4 alkyl, C.sub.1-C.sub.4 haloalkyl, C.sub.1-C.sub.4 alkoxy, C.sub.1-C.sub.4 haloalkoxy, C.sub.3-C.sub.6 cycloalkoxy, C.sub.4-C.sub.7 cycloalkylalkoxy, phenoxy, C.sub.1-C.sub.4 alkylthio, C.sub.1-C.sub.4 haloalkylthio, C.sub.1-C.sub.4 alkylsulfinyl, C.sub.1-C.sub.4 alkylsulfonyl, C.sub.1-C.sub.4 alkylamino, C.sub.2-C.sub.8 dialkylamino, cyano, C.sub.2-C.sub.5 alkoxycarbonyl, benzyloxycarbonyls, phenoxycarbonyls, or two substituents together represent a C.sub.1-C.sub.4 alkylenedioxy group; in the case of the aromatic heterocyclic group, said at least one substituent also being selected from nitro and carboxyl; n represents an integer from 1 to 2; m represents an integer from 1 to 6.

2. The thiadiazoles according to claim 1, wherein said aromatic heterocyclic group is selected from: pentatomic ring compounds, hexatomic ring compounds, benzocondensed compounds or hetero-bicyclic compounds, containing at least one heteroatom selected from nitrogen, oxygen and sulfur.

3. The thiadiazoles according to claim 1, selected from compounds having general formula (I) wherein R, R.sub.1, R.sub.2, Y, n and m have the meanings specified hereunder: TABLE-US-00009 No R R.sub.1 R.sub.2 Y n m 1 CH.sub.3 H H 2,6-diCl-phenyl 1 1 2 CH.sub.3 H H 2,6-diCl-phenyl 2 1 3 CH.sub.3 H H 2,6-diF-phenyl 1 1 4 CH.sub.3 H H 2,6-diF-phenyl 2 1 5 CH.sub.3 H H 2-Cl-6-F-phenyl 1 1 6 CH.sub.3 H H 2-Cl-6-F-phenyl 2 1 7 CH.sub.3 H H 2,4-diCl-phenyl 1 1 8 CH.sub.3 H H 2,4-diCl-phenyl 2 1 9 CH.sub.3 H H 1-CH.sub.3-3-CF.sub.3-5-OCH.sub.2CF.sub.3- 1 1 pyrazol-4-yl 10 CH.sub.3 H H 1-CH.sub.3-3-CF.sub.3-5-OCH.sub.2CF.sub.3- 2 1 pyrazol-4-yl 11 CH.sub.3 H H 2-Cl-4,5-methyl-endioxy- 1 1 phenyl 12 CH.sub.3 H H 2-Cl-4,5-methyl-endioxy- 2 1 phenyl 13 CH.sub.3 H H 2,5-diCl-4-OEt-phenyl 1 1 14 CH.sub.3 H H 2,5-diCl-4-OEt-phenyl 2 1 15 CH.sub.3 H H 2-NO.sub.2-phenyl 1 1 16 CH.sub.3 H H 2-NO.sub.2-phenyl 2 1 17 CH.sub.3 H H 2-CH.sub.3-phenyl 1 1 18 CH.sub.3 H H 2-CH.sub.3-phenyl 2 1 19 CH.sub.3 H H 2,5-diCl-4-OMe-phenyl 1 1 20 CH.sub.3 H H 2,5-diCl-4-OCF.sub.2CF.sub.2H-phenyl 2 1 21 CH.sub.3 H H 2,5-diCl-4-OCF.sub.2CF.sub.2H-phenyl 1 1 22 CH.sub.3 H H 2,5-diCl-4-OMe-phenyl 2 1 23 CH.sub.3 H H 2,5-diCH.sub.3-phenyl 1 1 24 CH.sub.3 H H 2,5-diCH.sub.3-phenyl 2 1 25 CH.sub.3 H H 2,6-diOCH.sub.3-phenyl 1 1 26 CH.sub.3 H H 2,6-diOCH.sub.3-phenyl 2 1 27 CH.sub.3 H H 3-CF.sub.3-phenyl 1 1 28 CH.sub.3 H H 2-CF.sub.3-phenyl 2 1 29 CH.sub.3 H H 2,3,4,5,6-pentaF-phenyl 1 1 30 CH.sub.3 H H 2,3,4,5,6-pentaF-phenyl 2 1 31 CH.sub.3 H H 2-SO.sub.2Me-5-COCH.sub.3-6-Cl- 1 1 phenyl 32 CH.sub.3 H H 2-SO.sub.2Me-5-COCH.sub.3-6-Cl- 2 1 phenyl 33 CH.sub.3 H H 2,6-diCl-5-COCH.sub.3-phenyl 1 1 34 CH.sub.3 H H 2,6-diCl-5-COCH.sub.3-phenyl 2 1 35 CH.sub.3 H H 2-CH.sub.3-5-Br-thiazol-2-yl 1 1 36 CH.sub.3 H H 2-CH.sub.3-5-Br-thiazol-2-yl 2 1 37 CH.sub.3 H H 3-COOEt-furan-2-yl 1 1 38 CH.sub.3 H H 3-COOEt-furan-2-yl 2 1 39 CH.sub.3 H H 3-tBu-isoxazol-2-yl 1 1 40 CH.sub.3 H H 3-tBu-isoxazol-2-yl 2 1 41 CH.sub.3 H H 6-Cl-pyiridin-3-yl 1 1 42 CH.sub.3 H H 6-Cl-pyridin-3-yl-N-oxide 2 1 43 CH.sub.3 H H 6-Cl-pyridin-2-yl 1 1 44 CH.sub.3 H H 6-Cl-pyridin-2-yl-N-oxide 2 1 45 CH.sub.3 H H pyridin-3-yl 1 1 46 CH.sub.3 H H pyridin-3-yl-N-oxide 2 1 47 CH.sub.3 H H pyridin-2-yl 1 1 48 CH.sub.3 H H pyridin-2-yl-N-oxide 2 1 49 CH.sub.3 H CH.sub.3 2,4-diCl-phenyl 1 1 50 CH.sub.3 H CH.sub.3 2,4-diCl-phenyl 2 1 51 CH.sub.3 H H 1-CH.sub.3-3-CF.sub.3-5-OCF.sub.2H- 1 1 pyrazol-4-yl 52 CH.sub.3 H H 1-CH.sub.3-3-CF.sub.3-5-OCF.sub.2H- 2 1 pyrazol-4-yl 53 CH.sub.3 H H 1-CH.sub.3-3-CF.sub.2H-pyrazol-4-yl 1 1 54 CH.sub.3 H H 1-CH.sub.3-3-CF.sub.2H-pyrazol-4-yl 2 1 55 CH.sub.3 H H 4-F-phenyl 1 1 56 CH.sub.3 H H 4-F-phenyl 2 1 57 CH.sub.3 H H 1-CH.sub.3-3-CF.sub.3-5-OCF.sub.2H- 1 2 pyrazol-4-yl 58 CH.sub.3 H H 1-CH.sub.3-3-CF.sub.3-5-OCF.sub.2H- 2 2 pyrazol-4-yl 59 CH.sub.3 H H 1-CH.sub.3-3-CF.sub.3-5-OCF.sub.2H- 1 3 pyrazol-4-yl 60 CH.sub.3 H H 1-CH.sub.3-3-CF.sub.3-5-OCF.sub.2H- 2 3 pyrazol-4-yl 63 CH.sub.3 H CH.sub.3 1-CH.sub.3-3-CF.sub.3-5-OCF.sub.2H- 1 1 pyrazol-4-yl 64 CH.sub.3 H CH.sub.3 1-CH.sub.3-3-CF.sub.3-5-OCF.sub.2H- 2 1 pyrazol-4-yl 65 CH.sub.3 H CH.sub.3 1-CH.sub.3-3-CF.sub.3-5-OCF.sub.2H- 1 2 pyrazol-4-yl 66 CH.sub.3 H CH.sub.3 1-CH.sub.3-3-CF.sub.3-5-OCF.sub.2H- 2 2 pyrazol-4-yl 67 CH.sub.3 H C.sub.3H.sub.5 1-CH.sub.3-3-CF.sub.3-5-OCF.sub.2H- 1 1 pyrazol-4-yl 68 CH.sub.3 H C.sub.3H.sub.5 1-CH.sub.3-3-CF.sub.3-5-OCF.sub.2H- 2 1 pyrazol-4-yl 69 CH.sub.3 H H 2,6-diCl-phenyl 1 3 70 CH.sub.3 H H 2,6-diCl-phenyl 2 3 71 CH.sub.3 H H 2,6-diCl-phenyl 1 2 72 CH.sub.3 H H 2,6-diCl-phenyl 2 2 75 CH.sub.3 H CH.sub.3 2,6-diCl-phenyl 1 1 76 CH.sub.3 H CH.sub.3 2,6-diCl-phenyl 2 1 77 CH.sub.3 H CH.sub.3 2,6-diCl-phenyl 1 2 78 CH.sub.3 H CH.sub.3 2,6-diCl-phenyl 2 2 79 CH.sub.3 CH.sub.3 CH.sub.3 2,6-diCl-phenyl 1 1 80 CH.sub.3 CH.sub.3 CH.sub.3 2,6-diCl-phenyl 2 1 81 CH.sub.3 H C.sub.3H.sub.5 2,6-diCl-phenyl 1 1 82 CH.sub.3 H C.sub.3H.sub.5 2,6-diCl-phenyl 2 1 83 C.sub.2H.sub.5 H H 2,6-diCl-phenyl 1 1 84 C.sub.2H.sub.5 H H 2,6-diCl-phenyl 2 1 85 C.sub.3H.sub.5 H H 2,6-diCl-phenyl 1 1 86 C.sub.3H.sub.5 H H 2,6-diCl-phenyl 2 1 87 C.sub.6H.sub.11 H H 2,6-diCl-phenyl 1 1 88 C.sub.6H.sub.11 H H 2,6-diCl-phenyl 2 1 89 C.sub.6H.sub.11CH.sub.2 H H 2,6-diCl-phenyl 1 1 90 C.sub.6H.sub.11CH.sub.2 H H 2,6-diCl-phenyl 2 1 91 C.sub.3H.sub.5CH.sub.2 H H 2,6-diCl-phenyl 1 1 92 C.sub.3H.sub.5CH.sub.2 H H 2,6-diCl-phenyl 2 1 93 CH.sub.3 CH.sub.3 CH.sub.3 1-CH.sub.3-3-CF.sub.3-5-OCF.sub.2H- 1 1 pyrazol-4-yl 94 CH.sub.3 CH.sub.3 CH.sub.3 1-CH.sub.3-3-CF.sub.3-5-OCF.sub.2H- 2 1 pyrazol-4-yl 95 C.sub.2H.sub.5 H H 1-CH.sub.3-3-CF.sub.3-5-OCF.sub.2H- 1 1 pyrazol-4-yl 96 C.sub.2H.sub.5 H H 1-CH.sub.3-3-CF.sub.3-5-OCF.sub.2H- 2 1 pyrazol-4-yl 97 C.sub.3H.sub.5 H H 1-CH.sub.3-3-CF.sub.3-5-OCF.sub.2H- 1 1 pyrazol-4-yl 98 C.sub.3H.sub.5 H H 1-CH.sub.3-3-CF.sub.3-5-OCF.sub.2H- 2 1 pyrazol-4-yl 99 C.sub.6H.sub.11 H H 1-CH.sub.3-3-CF.sub.3-5-OCF.sub.2H- 1 1 pyrazol-4-yl 100 C.sub.6H.sub.11 H H 1-CH.sub.3-3-CF.sub.3-5-OCF.sub.2H- 2 1 pyrazol-4-yl 101 C.sub.6H.sub.11CH.sub.2 H H 1-CH.sub.3-3-CF.sub.3-5-OCF.sub.2H- 1 1 pyrazol-4-yl 102 C.sub.6H.sub.11CH.sub.2 H H 1-CH.sub.3-3-CF.sub.3-5-OCF.sub.2H- 2 1 pyrazol-4-yl 103 C.sub.3H.sub.5CH.sub.2 H H 1-CH.sub.3-3-CF.sub.3-5-OCF.sub.2H- 1 1 pyrazol-4-yl 104 C.sub.3H.sub.5CH.sub.2 H H 1-CH.sub.3-3-CF.sub.3-5-OCF.sub.2H- 2 1 pyrazol-4-yl 105 CH.sub.3 H H 2-CF.sub.3-4-F-phenyl 1 1 106 CH.sub.3 H H 2-CF.sub.3-4-F-phenyl 2 1 107 CH.sub.3 H H 2-CF.sub.3-5-F-phenyl 1 1 108 CH.sub.3 H H 2-CF.sub.3-5-F-phenyl 2 1 109 CH.sub.3 H H 2-CF.sub.3-6-F-phenyl 1 1 110 CH.sub.3 H H 2-CF.sub.3-6-F-phenyl 2 1 111 CH.sub.3 H H 5-CH.sub.3-1,3,4-thiadiazol-4-yl 1 1 112 CH.sub.3 H H 5-CH.sub.3-1,3,4-thiadiazol-4-yl 2 1 113 CH.sub.3 H H 2-CH.sub.3-4-CF.sub.3-1,3-thiazol-5-yl 1 1 114 CH.sub.3 H H 2-CH.sub.3-4-CF.sub.3-1,3-thiazol-5-yl 2 1 115 CH.sub.3 H H 1-CH.sub.3-3-CF.sub.3-5-Cl-pyrazol-4-yl 1 1 116 CH.sub.3 H H 1-CH.sub.3-3-CF.sub.3-5-Cl-pyrazol-4-yl 2 1 117 .sub.iC.sub.3H.sub.7 H H 2,6-diCl-phenyl 1 1 118 .sub.iC.sub.3H.sub.7 H H 2,6-diCl-phenyl 2 1 119 .sub.iC.sub.3H.sub.7 H H 2,5-diCl-4-OEt-phenyl 1 1 120 .sub.iC.sub.3H.sub.7 H H 2,5-diCl-4-OEt-phenyl 2 1 121 C.sub.2H.sub.5 H H 1-CH.sub.3-3-CF.sub.3-5-OCH.sub.2CF.sub.3- 1 1 pyrazol-4-yl 122 C.sub.2H.sub.5 H H 1-CH.sub.3-3-CF.sub.3-5-OCH.sub.2CF.sub.3- 2 1 pyrazol-4-yl 123 Cl H H 1-CH.sub.3-3-CF.sub.3-5-OCH.sub.2CF.sub.3- 1 1 pyrazol-4-yl 124 Cl H H 1-CH.sub.3-3-CF.sub.3-5-OCH.sub.2CF.sub.3- 2 1 pyrazol-4-yl

4. The thiadiazoles according to claim 1, selected from compounds having general formula (I) wherein: R represents a C.sub.1-C.sub.4 alkyl, R.sub.1 and R.sub.2, the same or different, represent a hydrogen atom or a C.sub.1-C.sub.4 alkyl, Y represents a phenyl, optionally substituted, or a penta-atomic heterocyclic ring containing at least one heteroatom selected from nitrogen, oxygen and sulfur.

5. The thiadiazoles according to claim 1, selected from compounds having general formula (I) wherein: R represents a methyl or ethyl, R.sub.1 and R.sub.2 are hydrogen, Y represents a group selected from 2,6-dichloro-phenyl, 2,5-dichloro-4-ethoxy-phenyl, 1-methyl-3-trifluoromethyl-5-difluoromethoxy-pyrazol-4-yl, 1-methyl-3-trifluoro-methyl-5-(2,2,2-trifluoroethoxy)-pyrazol-4-yl, 2,5-dichloro-phenyl, n and m are equal to 1.

6. The thiadiazoles according to claim 1, selected from compounds having general formula (I), wherein: TABLE-US-00010 No R R.sub.1 R.sub.2 Y n m 1 CH.sub.3 H H 2,6-diCl-phenyl 1 1 51 CH.sub.3 H H 1-CH.sub.3-3-CF.sub.3-5-OCF.sub.2H- 1 1 pyrazol-4-yl 9 CH.sub.3 H H 1-CH.sub.3-3-CF.sub.3-5-OCH.sub.2CF.sub.3- 1 1 pyrazol-4-yl 83 C.sub.2H.sub.5 H H 2,6-diCl-phenyl 1 1 95 C.sub.2H.sub.5 H H 1-CH.sub.3-3-CF.sub.3-5-OCF.sub.2H- 1 1 pyrazol-4-yl 121 C.sub.2H.sub.5 H H 1-CH.sub.3-3-CF.sub.3-5-OCH.sub.2CF.sub.3- 1 1 pyrazol-4-yl

7. Herbicidal compositions comprising at least one compound having formula (I) according to claim 1, at least one solvent and/or diluent, possibly one or more agronomically acceptable excipients selected from: surfactant, dispersant, stabilizer and mixtures thereof.

8. The herbicidal compositions according to claim 7 also comprising at least one active ingredient compatible with the compounds having general formula (I) selected from: herbicides different from those having general formula (I), fungicides, insecticides, acaricides, fertilizers and mixtures thereof.

9. The herbicidal compositions according to claim 7, wherein said compound having general formula (I) has a concentration ranging from 1% to 90% by weight with respect to the total weight of the composition.

10. Use of thiadiazoles having the general formula (I) according to claim 1, as herbicides for the control of at least one weed in an agricultural crop.

11. Use according to claim 10 for the control of at least one weed in pre-emergence or post-emergence.

12. Use according to claim 10, wherein said weed is selected from: Abutilon theofrasti, Alisma plantago, Amaranthus spp., Amni maius, Capsella bursa pastoris, Chenopodium album, Convolvulus sepium, Galium aparine, Geranium dissectum, Heteranthera spp., Ipomea spp., Matricaria spp., Papaver rhoaes, Phaseolus aureus, Polygonum persicaria, Portulaca oleracea, Setaria viridis, Sida spinosa, Sinapsis arvensis, Solanum nigrum, Stellaria media, Veronica spp., Viola spp., Xanthium spp., Alopecurus myosuroides, Anisanta spp., Apera spica-venti, Avena spp., Cyperus spp., Digitaria sanguinalis, Eleusine spp. Echinochloa spp., Eleocharis avicularis, Lolium spp., Panicum spp., Poa spp., Scirpus spp., Sorghum spp.

13. Use according to claim 10, wherein said agricultural crop is selected from wheat (Triticum sp.), barley (Hordeum vulgare), corn (Zea mays), soya (Glycine max).

14. A method for controlling at least one weed in an agricultural crop which comprises applying to the agricultural crop at least one effective dose of at least one compound having general formula (I) according to claim 1.

15. The method according to claim 14, wherein said compound having general formula (I) or said herbicidal composition is applied to the agricultural crop in a dosage of said compound having general formula (I) within the range of 1-1,000 g/ha.

16. A process for preparing thiadiazoles having general formula (I) comprising the phase of oxidizing a compound having general formula (II) with at least one oxidizing agent in at least one solvent, according to the scheme ##STR00011## wherein R, R.sub.1, R.sub.2, Y, n and m have the meanings defined in claim 1.

17. The process according to claim 16, wherein said oxidizing agent is selected from an organic peroxide, such as 4-chloro-perbenzoic acid, peracetic acid or an inorganic peroxide, such as hydrogen peroxide, potassium permanganate, sodium periodate.

18. Use of thiadiazoles according to the compositions according to claim 7, as herbicides for the control of at least one weed in an agricultural crop.

19. A method for controlling at least one weed in an agricultural crop which comprises applying to the agricultural crop at least one effective dose of at least one herbicidal composition according to claim 7.

Description

EXPERIMENTAL PART

Example 1

Preparation of 2-[(2,6-dichlorobenzyl)-sulfinyl]-5-methyl-1,3,4-thiadiazole [Compound Nr. 1]

a) Preparation of (2-[(2,6-dichlorobenzyl)thio]-5-methyl-1,3,4-thiadiazole [thioether having general formula (II)]

[0063] 10.5 ml (75.6 mmoles) of triethylamine were added dropwise at room temperature to a suspension under nitrogen atmosphere of 10 g (75.6 mmoles) of 5-methyl-1,3,4-thiadiazole-2-thiol in 40 ml of chloroform; 14.8 g (75.6 mmoles) of 1,3-dichloro-2-(chloromethyl)benzene, dissolved in 10 ml of chloroform were then added. Finally, additional 15.7 ml (0.11 moles) of triethylamine were added dropwise.

[0064] The mixture was left under stirring at room temperature for a night. After control in GC-MS and LC-MS, the mixture was diluted with water and the phases were then separated; the aqueous phase was re-extracted twice with dichloromethane. The organic phases joined together, were washed with water and a saturated solution of sodium chloride.

[0065] After anhydrification on sodium sulfate, filtration and evaporation of the solvent at reduced pressure, 19.8 g (68.0 mmoles) of the desired product were obtained, as a yellow oil. Yield 90.0% LC-MS [M+H]=292.

b) Preparation of 2-[(2,6-dichlorobenzyl)-sulfinyl]-5-methyl-1,3,4-thiadiazole [Compound Nr. 1]

[0066] 4.2 g (18.92 mmoles) of 4-Cl-perbenzoic acid at 77% were added to 5 g (17.2 mmoles) of 2-[(2,6-dichlorobenzyl)thio]-5-methyl-1,3,4-thiadiazole, dissolved in 85 ml of chloroform, maintaining a temperature of about 4-5° C. with an ice bath, the mixture was then left under stirring at room temperature for a night.

[0067] After control in LC-MS, the mixture was diluted with water and the phases were then separated; the aqueous phase was re-extracted twice with dichloromethane. The organic phases joined together, were washed with an aqueous solution at 5% of NaHSO.sub.3, a saturated solution of NaHCO.sub.3, water and a saturated solution of NaCl.

[0068] After anhydrification on sodium sulfate, filtration and evaporation of the solvent at reduced pressure, 4.9 g (15.9 mmoles) of the desired product were obtained, as a yellow oil. The raw product thus obtained was crushed with ethyl ether, filtered and dried in the air, obtaining 4.2 g (13.7 mmoles) of the desired product as a white solid. Yield 79.4%.

[0069] M.P.=115-118° C.

[0070] LC-MS [M+H]=308.

Example 2

Preparation of 2-[(2,6-dichlorobenzyl)-sulfonyl]-5-methyl-1,3,4-thiadiazole [Compound Nr. 2]

[0071] 11.6 g (51.6 mmoles) of 4-Cl-perbenzoic acid at 77% were added to 5 g (17.2 mmoles) of 2-[(2,6-dichlorobenzyl)thio]-5-methyl-1,3,4-thiadiazole, dissolved in 85 ml of chloroform, maintaining a temperature of about 4-5° C. with an ice bath. The mixture was then left under magnetic stirring at room temperature for a night.

[0072] After control in LC-MS, the mixture was diluted with water and the phases were then separated; the aqueous phase was re-extracted twice with dichloromethane. The organic phases joined together, were washed with an aqueous solution at 5% of NaHSO.sub.3, a saturated solution of NaHCO.sub.3, water and a saturated solution of NaCl.

[0073] After anhydrification on sodium sulfate, filtration and evaporation of the solvent at reduced pressure, 5.1 g of yellow oil (15.8 mmoles) were obtained. The raw product thus obtained was crushed with ethyl ether, filtered and dried in the air, obtaining 4.7 g (14.7 mmoles) of the desired product as a white solid.

[0074] Yield 85.7%.

[0075] M.P.=180-183° C.

[0076] LC-MS [M+H]=324

[0077] .sup.1H-NMR (δ-ppm, CDCl.sub.3)=2.89 (s, 3H); 5.24 (s, 2H); 7.25-7.38 (m, 3H).

Example 3

Preparation of 2-[(1-CH.SUB.3.-3-CF.SUB.3.-5-OCF.SUB.2.H-pyrazol-4-yl)sulfinyl]-5-methyl-1,3,4-thiadiazole [Compound Nr. 51]

a) Preparation of (4-(bromomethyl)-5-(difluoromethoxy)-1-methyl-3-(trifluoromethyl)-1H-pyrazole [compound having general formula (IV)]

[0078] 3.40 g (19.14 mmoles) of N-bromo-succinimide and a catalytic quantity of azaisobutyrronitrile were added at room temperature to a solution under nitrogen of 4 g (17.4 mmoles) of 5-(difluoromethoxy)-1,4-dimethyl-3-(trifluoromethyl-1H-pyrazole in 17 ml of carbon tetrachloride.

[0079] The mixture was left under stirring and reflux temperature, irradiated with a 300 W lamp for 5 hours.

[0080] After control in LC-MS, the mixture was poured into water and extracted three times with chloroform. The organic phases joined together were washed with water and a saturated solution of sodium chloride.

[0081] After anhydrification on sodium sulfate, filtration and evaporation of the solvent at reduced pressure, 4.78 g (15.5 mmoles) of the desired product were obtained, as a yellow oil. Yield 89.0% LC-MS [M+H]=309.

b) Preparation of 2-[5-difluoromethoxy-1-methyl-3-trifluoromethyl-1H-pyrazol-4-yl]methylthio-5-methyl-1,3,4-thiadiazole [thioether having general formula (II)]

[0082] 2.10 ml (15.2 mmoles) of triethylamine were added dropwise at room temperature to a suspension under nitrogen of 2 g (15.2 mmoles) of 5-methyl-1,3,4-thiadiazole-2-thiol in 10 ml of chloroform; 4.70 g (15.2 mmoles) of (4-(bromomethyl)-5-(difluoromethoxy)-1-methyl-3-(trifluoromethyl)-1H-pyrazole, dissolved in 4 ml of chloroform were then added. Finally 3.15 ml (22.8 mmoles) of triethylamine were added dropwise.

[0083] The mixture was left under magnetic stirring at room temperature for a night.

[0084] After control in GC-MS and LC-MS, the mixture was diluted with water and the phases were then separated; the aqueous phase was re-extracted twice with dichloromethane. The organic phases joined together, were washed with water and a saturated solution of sodium chloride.

[0085] After anhydrification on sodium sulfate, filtration and evaporation of the solvent at reduced pressure, 4.57 g (68.0 mmoles) of the desired product were obtained, as a brown oil. Yield 83.5% LC-MS [M+H]=361.

c) Preparation of 2-[(1-CH.SUB.3.-3-CF.SUB.3.-5-OCF.SUB.2.H-pyrazol-4-yl)sulfinyl]-5-methyl-1,3,4-thiadiazole [Compound No 51]

[0086] 3.08 g (13.75 mmoles) of 4-Cl-perbenzoic acid at 77% were added to 4.5 g (12.5 mmoles) of 2-({[5-(difluoromethoxy)-1-methyl-3-(trifluoromethyl)-1H-pyrazol-4-yl]methyl}thio-5-methyl-1,3,4-thiadiazole, dissolved in 50 ml of chloroform, maintaining a temperature of about 4-5° C. with an ice bath; the mixture was then left under magnetic stirring at room temperature for a night.

[0087] After control in LC-MS, the mixture was diluted with water and the phases were then separated; the aqueous phase was re-extracted twice with dichloromethane. The organic phases joined together, were washed with an aqueous solution at 5% of NaHSO.sub.3, a saturated solution of NaHCO.sub.3, water and a saturated solution of NaCl.

[0088] After anhydrification on sodium sulfate, filtration and evaporation of the solvent at reduced pressure, 4.1 g (15.9 mmoles) of the desired product were obtained, as a yellow oil. The raw product thus obtained was crushed with ethyl ether, filtered and dried in the air, obtaining 3.7 g (9.87 mmoles) of the desired product as a white solid. Yield 79.0%.

[0089] LC-MS [M+H]=377

Example 4

Preparation of 2-[(1-CH.SUB.3.-3-CF.SUB.3.-5-OCF.SUB.2.H-pyrazol-4-yl)sulfonyl]-5-methyl-1,3,4-thiadiazole [Compound Nr. 52]

[0090] 8.40 g (37.5 mmoles) of 4-chloro-perbenzoic acid at 77% were added to 4.5 g (12.5 mmoles) of 2-({[5-(difluoromethoxy)-1-methyl-3-(trifluoromethyl)-1H-pyrazol-4-yl]methyl}thio)-5-methyl-1,3,4-thiadiazole, dissolved in 50 ml of chloroform, maintaining a temperature of about 4-5° C. with an ice bath; the mixture was then left under magnetic stirring at room temperature for a night.

[0091] After control in LC-MS, the mixture was diluted with water and the phases were then separated; the aqueous phase was re-extracted twice with dichloromethane. The organic phases joined together, were washed with an aqueous solution at 5% of NaHSO.sub.3, a saturated solution of NaHCO.sub.3, water and a saturated solution of NaCl.

[0092] After anhydrification on sodium sulfate, filtration and evaporation of the solvent at reduced pressure, 4.7 g (15.9 mmoles) of the desired product were obtained, as an orange oil. The raw product thus obtained was purified by flash chromatography, obtaining 3.47 g (8.87 mmoles) of the desired product as a white solid.

[0093] Yield 71.0%.

[0094] LC-MS [M+H]=393

[0095] .sup.1H-NMR (δ-ppm, CDCl.sub.3)=2.91 (s, 3H); 3.86 (s, 3H); 4.75 (s, 2H); 6.81 (t, 1H).

Example 5

Preparation of Compounds Nr. 3-50, 53-124

[0096] Operating analogously to what is described in the previous examples, the compounds having general formula (I) were obtained, corresponding to compounds Nr. 3-50 and 53-124, listed in Table 1.

[0097] Table 2 indicates the results of the GC-MS and/or LC-MS analyses carried out on the synthesized compounds.

TABLE-US-00003 TABLE 2 Nr. GC-MS LC-MS [M + H.sup.+] 1 — 308 2 323 324 3 — 275 4 290 291 5 — 291 6 306 307 7 — 308 8 323 324 9 — 409 10 424 425 11 — 318 12 333 334 13 — 351 14 366 367 15 — 284 16 299 300 17 — 253 18 268 269 19 — 337 20 352 353 21 — 423 22 438 439 23 — 267 24 282 283 25 — 299 26 314 315 27 — 307 28 322 323 29 — 329 30 344 345 31 — 393 32 408 409 33 — 349 34 364 365 35 — 339 36 354 355 37 — 301 38 316 317 39 — 286 40 301 302 41 — 274 42 305 306 43 — 274 44 305 306 45 — 240 46 271 272 47 — 240 48 271 272 49 — 321 50 336 337 51 — 377 52 392 393 53 — 293 54 308 309 55 — 257 56 272 273 57 — 391 58 406 407 59 — 405 60 420 421 61 — 363 62 378 379 63 — 391 64 406 407 65 — 419 66 434 435 67 — 417 68 432 433 69 — 335 70 350 351 71 — 321 72 336 337 73 — 293 74 308 309 75 — 321 76 336 337 77 — 349 78 364 365 79 — 335 80 350 351 81 — 347 82 362 363 83 — 321 84 336 337 85 — 333 86 348 349 87 — 375 88 390 391 89 — 389 90 404 405 91 — 347 92 362 363 93 — 405 94 420 421 95 — 391 96 406 407 97 — 403 98 418 419 99 — 445 100 460 461 101 — 459 102 474 475 103 — 417 104 432 433 105 — 425 106 440 441 107 — 425 108 440 441 109 — 425 110 440 441 111 — 261 112 276 277 113 — 328 114 343 344 115 — 345 116 360 361 117 — 335 118 350 351 119 — 379 120 394 395 121 — 423 122 438 439 123 — 429 124 444 445

Example 6

Determination of the Herbicidal Activity and Phytotoxicity in Pre-Emergence.

[0098] The herbicidal activity in pre-emergence of the compounds of the invention was evaluated according to the following operating procedures.

[0099] The plant species of interest (weeds or crops) were seeded in vases having an upper diameter of 10 cm, a height of 10 cm and containing sandy earth. 10 vases were used for each plant species.

[0100] Water was added to each vase in a suitable quantity for the germination of the seeds. The vases were then divided into two groups, each containing 5 vases for each weed or crop.

[0101] One day after seeding, the first group of vases was treated with a dispersion having the following composition:

TABLE-US-00004 Compound having general formula (I) 50 mg Water 56 ml Acetone 14 ml Tween 20 0.5%

[0102] Said dispersion was prepared by adding a compound of the present invention at the desired concentration to a hydroacetonic solution containing acetone at 20% by volume and Tween 20 at 0.5% by weight, with respect to the total weight of the dispersion.

[0103] The desired concentration of a compound of the present invention corresponds to the concentration necessary for allowing the application of an effective dose of said compound equal to 250 g/ha to the plant species of interest.

[0104] The second group was only treated with a hydroacetonic solution containing acetone at 20% by volume and Tween 20 at 0.5% by weight, and was used as a comparison (control).

[0105] All the vases were kept under observation in a conditioned environment under the following environmental conditions: [0106] temperature: 24° C.; [0107] relative humidity: 60%; [0108] photo-period: 16 hours; [0109] light intensity: 12,000 lux.

[0110] Every two days the vases were uniformly watered to ensure a sufficient humidity degree for a good growth of the plants.

[0111] Fifteen days after treatment, the herbicidal activity was evaluated on the basis of the following scale of values which refers to the percentage of damage revealed on the treated plants with respect to the non-treated plants (control).

TABLE-US-00005 0 = 0-10% of damage; 1 = 11-30% of damage; 2 = 31-50% of damage; 3 = 51-70% of damage; 4 = 71-90% of damage; 5 = 91% of damage-death of the plant.

[0112] Table 3 shows the results obtained by treating the plant species indicated below with compounds Nr. 1, Nr. 9, Nr. 51 and Nr. 121, compared with a dispersion containing the compound CR1 described in DE 2533604, instead of the compound having general formula (I): CR1=2-(2,6-dichlorophenylsulfonyl)-5-(trifluoromethyl)-1,3,4-thiadiazole

TABLE-US-00006 TABLE 3 Herbicidal activity in pre-emergence at a dose of 250 g/ha Compounds Weeds Nr. 1 Nr. 9 Nr. 51 Nr. 121 CR1 Echinochloa crusgalli 4 5 5 5 0 Digitaria sanguinalis 5 5 5 5 0 Setaria viridis 4 5 5 5 0 Eleusine indica 5 5 5 5 0 Lolium rigidum 4 5 4 5 0 Poa Annua 5 5 5 5 0 Apera spica-venti 5 5 5 5 0 Alopecurus myosuroides 4 5 5 5 0

Example 7

Determination of the Herbicidal Activity and Phytotoxicity in Post-Emergence.

[0113] The herbicidal activity in post-emergence of the compounds of the invention was evaluated according to the following operating procedures.

[0114] The plant species of interest (weeds or crops) were seeded in vases having an upper diameter of 10 cm, a height of 10 cm and containing sandy earth. 10 vases were used for each plant species.

[0115] Water was added to each vase in a suitable quantity for the germination of the seeds. The vases were then divided into two groups, each containing 5 vases for each weed or crop.

[0116] Fifteen days after seeding (ten in the case of wheat), i.e. when the weeds and crops, depending on the species, had a height of 10-15 cm, the first group of vases was treated with the same hydroacetonic dispersion containing acetone at 20% by volume, the compound being evaluated at the desired concentration and Tween 20 at 0.5% by weight, indicated in Example 6.

[0117] The second group was only treated with a hydroacetonic solution containing acetone at 20% by volume and Tween 20 at 0.5% by weight, and was used as a comparison (control).

[0118] All the vases were kept under observation in a conditioned environment under the following environmental conditions: [0119] temperature: 24° C.; [0120] relative humidity: 60%; [0121] photo-period: 16 hours; [0122] light intensity: 12,000 lux.

[0123] Every two days the vases were uniformly watered to ensure a sufficient humidity degree for a good growth of the plants.

[0124] Fifteen days after treatment, the herbicidal activity was evaluated on the basis of the following scale of values which refers to the percentage of damage revealed on the treated plants with respect to the non-treated plants (control).

TABLE-US-00007 0 = 0-10% of damage; 1 = 11-30% of damage; 2 = 31-50% of damage; 3 = 51-70% of damage; 4 = 71-90% of damage; 5 = 91% of damage-death of the plant.

[0125] Table 4 shows the results obtained by treating the vegetable species indicated below with compounds Nr. 1, Nr. 9, Nr. 51 and Nr. 121 compared with a hydroacetonic dispersion containing the compound CR1 described in DE 2533604:

TABLE-US-00008 TABLE 4 Herbicidal activity in post-emergence at a dose of 250 g/ha Compounds Weeds Nr. 1 Nr. 9 Nr. 51 Nr. 121 CR1 Echinochloa crusgalli 4 5 5 5 0 Digitaria sanguinalis 5 5 5 5 0 Setaria viridis 4 4 4 4 0 Eleusine indica 5 5 5 5 0 Lolium rigidum 4 4 4 4 0 Poa Annua 5 5 5 5 0 Apera spica-venti 5 5 5 5 0 Alopecurus myosuroides 4 5 4 4 0

[0126] Compounds Nr. 2-8 and 10-124 tested under the same conditions of pre- and post-emergence showed a herbicidal activity of at least 50% with respect to the weeds indicated in Tables 3 and 4.