IE48061B1 - Herbicidally active phenylurea derivatives,a process for their manufacture and their use - Google Patents

Abstract

Novel phenylurea derivatives of the general formula (wherein R1 represents H, C1-C4- alkyl, C2-C4-alkenyl, C2-C4-alkynyl or OCH3, R2 and R3 each represents H or C1-C4-alkyl, R4 and R5 each represents halogen, each X represents H, C1-C4-alkyl, halogen or OCH3 and n represents 1 or 2) have a herbicidal action and accordingly may be made up with suitable carriers into herbicidal preparations and may be used for protecting living plants, crop areas and waste lands against weeds.

Description

The present invention is concerned with new phenylurea derivatives, with a process for the manufacture of these compounds and also with their use.

Phenylurea derivatives having a herbicidal action are already known, 5 for example 1-(3,4-dichlorophenyl)-3,3-dimethylurea according to United States Patent Specification No. 2,655,445. These have, however, only a vetynarrow range of selectivity with respect to cultivated plants.

The problem upon which the present invention is based has therefore 10 been to provide a herbicide which, in addition to an outstanding herbicidal action against weeds, has a broad range of selectivity with respect to cultivated plants.

This problem is solved according to the present invention by the compounds of the general formula I, as defined below.

The present invention accordingly provides compounds of the general formula I in which R-| represents a hydrogen atom or a C^-C^-alkyl, Cg-C^-al kenyl, Cg-C^alkynyl or methoxy group, Rg represents a hydrogen atom or a C-j-C^-alkyl group, Rg represents a hydrogen atom or a C^-C^-alkyl group, R^ represents a halogen atom, R5 represents a halogen atom, each of the symbols X represents a hydrogen atom, a Cj-C^-alkyl 10 group, a halogen atom or a methoxy group, and n represents 1 or 2.

The compounds of the present invention are distinguished both by an outstanding soil-herbicidal and leaf-herbicidal action and also by a broad range of selectivity with respect to cultivated plants. They are, therefore, advantageously used to control monocotyledonous and dicotyledonous weeds, in particular in cultivated plants.

When the compounds are used by the pre-emergence method and also by the post-emergence method, they contol, for example, agricultural weeds, for example Sinapis sp., Stellaria media, Senecio vulgaris, - 4 Matricaria chamomina, Ipomoea purpurea, Chrysanthemum segetum, Lamium amplexicaule, Centaurea cyanus, Amaranthus retroflexus, Alopecurus myosuroides, Echinochloa crus galli, Setaria italica and Lolium perenne.

For the control of seed weeds application quantities within the range of from 1 kg of active substance per hectare up to 5 kg of active substance per hectare are generally used. In so doing, the active compounds of the present invention are found to be selective in useful plant crops, for example, French bean, ground-nut, potato, rice, sorghum, maize, winter cereal and also soya crops. When two or more compounds of the qeneral formula I are used the range of 1 to 5 kg refers of course to the total amount applied of these compounds.

In larger aoplicatioi quantities these compounds are also suitable as total herbicides for destroying or suppressing waste land flora during a vegetation period.

The present invention accordingly also provides a herbicidal preparation which comprises a compound of the general formula I, in admixture or conjunction with a suitable carrier. The preparation may of course contain one or more compounds of the general formula I.

The present invention further provides a method of protecting a living plant against weeds, wherein the area in the vicinity of the living plant is treated with a compound of the general formula I.

The present invention further provides a method of protecting a crop - 5 area against weeds, wherein the crop area is treated with a compound of the general formula I.

The present invention further provides a method of protecting a waste land against weeds, wherein the waste land is treated with one or more compounds of the general formula I, the compound(s) being used in a total amount of more than 5 kg per hectare.

The present invention further provides a pack which comprises a compound of the general formula I together with instructions for its use as a herbicide.

The compounds of the present invention may be used either alone, or in admixture with one another or with other active substances. If desired, other defoliants, plant-protecting agents and/or pesticides may be added, depending on the desired purpose.

If it is intended to broaden the range of action, other herbicides may be added. As suitable herbicidally-active co-components there may be mentioned, for example, active substances from the groups of triazines, aminotriazoles, anilides, diazines, uracils, aliphatic carboxylic acids and halocarboxylic acids, substituted benzoic acids and aryloxycarboxylic acids, hydrazides, amides, nitriles, esters of such carboxylic acids, carbamic acid esters and thiocarbamic acid esters, ureas, 2,3,6-trichlorobenzyloxypropanil and thiocyanatecontaining agents.

Among other additives there are also to be understood, for example - 6 non-phytotoxic additives which can give a synergistic increase in action with herbicides, for example inter alia wetting agents, emulsifiers, solvents and oily addives.

The active compounds of the present invention or mixtures thereof are advantageously used in the form of herbicidal preparations, for example powders, strewable preparations, granules, solutions, emulsions or suspensions, with the addition of liquid and/or solid vehicles or diluents and if desired of surface-active agents, for example wetting, adhesive, emulsifying and/or dispersing agents.

Suitable liquid carriers are for example, water, aliphatic hydrocarbons, aromatic hydrocarbons, for example benzene, toluene and xylene, cyclohexanone, isophorone, dimethyl sulphoxide and dimethylformamide, and also mineral oil fractions.

Suitable solid carriers are, for example, mineral earths, for 15 example tonsil, silica gel, talcum, kaolin, attaclay, limestone and silicic acid, and vegetable products, for example meals.

As surface-active agents there may be mentioned, for example, calcium lignin sulphonate, polyoxyethylenealkylphenol ethers, naphthalenesulphonic acids and salts thereof, phenolsulphonic acids and salts thereof, formaldehyde condensates, fatty alcohol sulphates and also substituted benzenesulphonic acids and salts thereof.

The total amount of the active substance or substances in the various herbicidal preparations may vary within wide limits. For - 7 example, the preparations may contain approximately 10 to 80% by weight of active substance(s), approximately 90 to 20% by weight of liquid or solid carrier and also, if desired, up to 20% by weight of surface-active agent(s).

The active substances may be applied in the usual manner, for example with water as carrier in quantities of spray liquor of approximately 100 to 1000 litres per hectare. It is also possible to apply the active substances by the so-called low-volume method and ultra-lowvolume method and it is also possible to apply them in the form of so-called microgranules.

The symbol R^ in the general formula I representing the compounds of the present invention may represent, for example, apart from a hydrogen atom, a methyl, ethyl, n-propyl, isopropyl, n-butyl, sec.-butyl, isobutyl, tert.-butyl, allyl, propenyl, propynyl, butenyl, butynyl or methoxy group and the symbols and R3 may each represent, apart from a hydrogen atom, a methyl, ethyl, n-propyl, isopropyl, n-butyl, sec.-butyl, isobutyl or tert.-butyl group.

The symbols R4 and Rg may each represent a fluorine, chlorine or bromine atom.

When n represents 2, X may represent two substituents which may be the same or different. Each of the symbols X may represent, for example, a hydrogen atom, a methyl, ethyl, n-propyl, isopropyl, nbutyl, sec.-butyl, isobutyl or tert.-butyl group, a fluorine, chlorine, bromine or iodine atom or a methoxy group. 4806 1 - 8 Among the compounds of the present invention that are distinguished by an outstanding herbicidal action are especially those of the general formula I given above in which represents a methyl or methoxy group, R2 represents a hydrogen atom or a methyl group, Rg represents a hydrogen atom or a methyl group, represents a chlorine or bromine atom, Rg represents a chlorine or bromine atom, each of the symbols X represents a hydrogen atom, a methyl group, a chlorine atom or a methoxy group and n represents the number 1 or 2.

The new compounds of the present invention may be manufactured, for example, by the process of the present invention, as defined below.

The present invention accordingly further provides a process for the manufacture of a compound of the general formula I, wherein A) a compound of the general formula in which R2, R3> R4> Rg, X and n have the meanings given above, is (a) reacted in the presenceof an acid-binding agent with a carbamic acid halide of the general formula R-j—-N—CO—Hal, ch3 - 9 in which R-j has the meaning given above and Hal represents a halogen atom, or (b) when R-j represents a hydrogen atom, reacted in the presence of a catalyst with methyl isocyanate of the formula ch3—N= C=0, or B) a compound of the general formula in which R2> R3> R^, Rg, X and n have the meanings given above, is 10 reacted in the presence of a catalyst with an amine of the general formula ch3 in which Rj has the meaning given above, or C) a compound of the general formula - 10 in which Rg, Rg, R^, Rg, X and n have the meanings given above, is reacted with an amine of the general formula R1 — NH, CHg in which R-| has the meaning given above, or 5 D) a compound of the general formula in which R-|, X and π havethe meanings given above, is reacted in a solvent and in the presence of an acid-binding agent with a halide of the general formula V5 c Hal-CHg-C-CH in which Rg, Rg, R^ and Rg have the meanings given above and Hal represents a halogen atom.

Each of the reactions according to variants A(a), A(b), B and C may >48061 - η if desired, be carried out with the use of a solvent. The reaction according to variant D may, if desired, be carried out in the presence of a catalyst.

The reaction products may be isolated in a manner known per se.

Suitable solvents with respect to the reactants in the case of all reactions are inert aliphatic and aromatic hydrocarbons, for example hexane, benzene and toluene, chlorohydrocarbons, for example methylene chloride, chloroform, carbon tetrachloride and dichlorethane, ethers, for example diethyl ether, tetrahydrofuran and dioxan, ketones, for example acetone and butanone, nitriles, for example acetonitrile, and amides, for example dimethylformamide and hexamethyl phosphoric acid triamide.

Suitable acid-binding agents in all the appropriate reactions are organic bases, for example tertiary amines, for example triethylamine, pyridine and dimethylaniline, or inorganic bases, for example oxides, hydroxides or carbonates of alkali metals and alkaline earth metals.

Suitable catalysts for the reactions with isocyanates are tertiary amines, for example triethylamine, and suitable catalysts for the reaction of the phenol with the halide are metal iodides, for 2o example sodium iodide.

In the case of all reactions the reactants are reacted at temperatures between 0 and 150°C. - 12 The aniline derivatives used as starting materials may be obtained by etherifying corresponding nitrophenols and then reducing the nitro group according to processes known per se.

Conversely, it is possible first to acylate aminophenols 5 regioselectively at the nitrogen and to select etherification as the last step.

Some of the dihalocyclopropane derivatives used for the etherification are already known per se and can be prepared according to processes known per se.

A process has now been found which makes it possible to produce these compounds more easily and in higher yields using cheap starting materials. According to this new process an allyl halide of the general formula R, —CH == C — CH,Hal, ( R3 in which R^ and R3 have the meanings given above and Hal represents a halogen atom, is reacted in the presence of a catalyst in a two -phase system consisting of a haloform of the general formula CHR^RgHal, in which R^ and Rg have the meanings given above and Hal represents a halogen atom, if desired diluted by an inert solvent, and an alkali metal hydroxide, in solid form or as an aqueous solution, Surprisingly, the allyl halides used in this way are not - 13 saponified by the alkali metal hydroxides or are saponified to only a slight degree.

Of the haloforms, chloroform and bromoform are preferred and, of the hydroxides, sodium hydroxide, preferably as a 50% aqueous solution, is preferred.

Suitable catalysts are onium compounds, for example quaternary ammonium, phosphonium and arsonium compounds and also sulphonium compounds.

Polyglycol ethers are also suitable, especially cyclic ethers, for 10 example 18-crown-compounds-6, and tertiary amines, for example tributyl amine. Preferred compounds are quaternary ammonium compounds, for example benzyltriethylammonium chloride and tetrabutylammonium bromide.

The quantitative ratios of the reactants may be varied within wide 15 limits. The reactions are preferably carried out with once the excess tocten times the excess, in each case, of haloform and of hydroxide, 0.02 Equivalents of catalyst are sufficient.

The reaction takes place at between 20 and 100°C but generally, however, between 20 and 60°C. The reaction lasts for 1 to 72 hours.

Thorough mixing is necessary throughout the entire duration of the reaction. 4806 1 - 14 The di halocyclopropane derivatives required as starting materials are surprisingly formed in this manner in a higher yield and by a technically simpler method than according to known processes.

The phenylurea derivatives of the present invention are colourless and odourless crystalline substances that are readily soluble in ethyl acetate, acetone and alcohol. Some of them are only moderately soluble in benzene and are practically insoluble in saturated hydrocarbons and water.

The following Examples illustrate the invention. Example 1 illustrates the manufacture of the compounds of the present invention and Examples 2 and 3 illustrate the possible uses of the compounds of the present invention and their superior selective herbicidai action.

EXAMPLE 1 1-[4-(2,2-Di chiorocyclopropylmethoxy)-phenyl] -3,3-dimethylurea 2 g of benzyl triethyl ammonium chloride were added to 100 ml (1,16 mole) of 3-bromopropene in 600 ml of chloroform. 600 ml of a 50% sodium hydroxide solution were then added in the course of 30 minutes while stirring well. The temperature increased and was maintained between 56 and 60°C by cooling. Stirring was continued for 4 hours at this temperature and then 750 ml of chloroform and 750 ml of water were added. The organic phase was separated, dried, concentrated by evaporation and fractionated in vacuo.

Yield; 162 g of l-bromomethyl-2,2-dichlorocyclopropane - 15 B.p.13:63 - 70°C; ηθ° = 1.5096. g (0.5 mole) of 4-m'trophenol were dissolved in 250 ml of dimethylformamide and added, while stirring, to 108 g (0.53 mole) of l-bromomethyl-2,2~dichlorocyclopropane, 83 g of potassium carbonate and 1.5 g of sodium iodide. The whole was then stirred for 2 hours at 90°C. The mixture was allowed to cool poured on to water and extracted with ethyl acetate. The organic phases were washed with a dilute sodium hydroxide solution and then with water, dried and concentrated by evaporation.

The residue was crystallized with pentane.

Yield: 113 g of 4-(2,2-dichlorocyclopropylmethoxy)-nitrobenzene Melting point: 66 - 67°C. 108 g (1.73 mole) hydrazine hydrate were dissolved in 500 ml of ethanol and added to 10 g of a nickel catalyst. 113 g (0.43 mole) of the nitro compound identified above were added in small portions in the course of 45 minutes. During this addition, the temperature rose to 60°C. The mixture was stirred for a further hour, then filtered, and the filtrate was concentrated and poured into water.

The whole was extracted with ethyl acetate, dried and concentrated by evaporation. A yellowish oil remained behind which was used for the reaction described below without being purified.

Yield: 96 g of 4-(2,2-dichlorocyclopropylmethoxy)-aniline g (0.086 mole) of 4-(2,2-dichlorocyclopropylmethoxy)-aniline were dissolved in 100 ml of pyridine. 8.7 ml of dimethyl carbamoyl chloride were added dropwise in the course of 5 minutes while stirring and during this addition the temperature rose to 53°C.

The whole was stirred for 2 hours and was then concentrated extensively by evaporation at 50 torr. The residue was taken up in 8061 - 16 ethyl acetate, washed once with water and once with 5% hydrochloric acid, dried, concentrated by evaporation and crystallized from isopropyl ether.

Yield; 16 g of l-[4-(2,2-dichlorocyclopropylmethoxy)-phenyl]-3,3dimethylurea Melting point: 108-110°C.

Each of the following compounds of the present invention may be prepared in a manner analogous to that described in Example 1 above.

Name of the compound 1-[4-(2,2-Dichlorocyclopropylmethoxy)-3methoxyphenyl] -3,3-dimethylurea 1 -[4-(2,2-Di chiorocyclopropylmethoxy)-3methoxyphenyl] -3-methoxy-3-methylurea 1 -[3-Chloro-4-(2,2-d 5 c hlorocyclopropylmethoxy) -phenyl]-3,3-dimethylurea -[3-C h1oro-4-(2,2-d i chiorocyclopropylmethoxy) -phenyl]-3-methoxy-3-methylurea -[4-(2,2-D ichiorocyclopropylmethoxy)-phenyl] -3-methoxy-3-methylurea 1-Butyl-3-[4-(2,2-dichlorocyclopropylmethoxy)phenyl]-1-methyl urea -[4-(2,2-Di chiorocyclopropylmethoxy)-phenyl] -3-methyl-3-(1-methyl-2-propynyl)-urea 1 - [4-(2,2-D i c hlorocyc1opropy1methoxy)-3,525 dimethyl phenyl]-3,3-dimethylurea Physical constant M.p.: 163 - 164°C M.p.: 105 - 106°C M.P.: 130 - 13l°C M.p.: 79 - 80°C M.p.: 88 - 89°C M.p.: 87 - 88°C M.p.: Ill - 113°C M.p.: 135 - 136°C 480 61 - 17 1 - [4- (2,2-Dic hl orocycl opropyl methoxy) -3,5· dimethylphenyl]-3-methoxy-3-methylurea M.p.: 66 - 67°C 1- [4-(2,2-Di chiorocyclopropylmethoxy-3,5dichlorophenyl] -3,3-dimethylurea M.p.: 146 - 147°C 1-[4-(2,2-Dichlorocyclopropylmethoxy)-3methylphenyl]-3,3-dimethylurea M.p.: Ill - 113°C 1-[4-(2,2,-Dichioro-1-methyleye1opropylmethoxy)-phenyl] -3-methoxy-3-methylurea M.p.: 103 - 104°C 1 - [4-(2,2-Dichloro-1-methylcyclopropylmethoxy)-phenyl]-3,3-dimethyl urea M.p.: 127 - 128°C l-[4-(2,2,-Dibromocyclopropylmethoxy)phenyl]-3,3-dimethyl urea M.p.: 99 - 101°C 1-[4-(2,2-Dichloro-3-methylcyclopropylmethoxy)-phenyl]-3,3-dimethylurea M.p.: 140 - 142°C EXAMPLE 2 In a series of tests carried out in a greenhouse, the compounds of the present invention listed in the Table below were each sprayed in the form of an aqueous emulsion in an application quantity of 5 kg of active substance per hectare in 500 litres of water per hectare on to Sinapis sp. and Solanum sp. as test plants by the pre- and post-emergence methods. The results were assessed 3 weeks after the treatment and expressed by a numerical scale extending from 0 to 4, the value 0 representing no action and the value 4 representing destruction of the plant. As will be seen from the Table, destruction of the test plants was generally achieved. 1- [4-( 2,2-Dichlorocycl opropy!methoxy)-phenyl] 3,3-dimethylurea Xt - 20 EXAMPLE 3 In a series of tests carried out in a greenhouse, the plants listed in the following Table were treated after their emergence with the listed agents being tested in an application quantity of 1 kg of active substance per hectare. For this purpose the agents were in each case sprayed uniformly over the plants in the form of an aqueous emulsion using 500 litres of water per hectare. In this case, too, three weeks after the treatment the compounds of the present invention were tolerated extremely well by the cultivated plants while having an excellent action against the weeds. The agent used for comparison did not display this selectivity. The results of the treatment were assessed and expressed by a numerical scale extending from 0 to 10, the value 0 representing total destruction of the plant and the value 10 representing no damage. - 21 uini lojmqsdet uinuo6A|Od uinqaBas uinuaqquesAuqo bl l (.uiouieip B14B3U4.BH o ο Ιainuede iunL[C9 sapLOjnsoXui snunoadotv siouueo eoLB in 9ZLVW yfeiueg C O »r— •P c Φ > c Φ x: +j qo Ί3 CM o co to *d* CO Φ £Z Q. o ίο S >> o i•P (Λ Φ •o >> φ ε Φ Ό II o

Claims (52)

1. A phenylurea derivative of the general formula I in which R-| represents a hydrogen atom or a C-j-C^-alkyl, Cg-C^-al kenyl, Cg-C^-alkynyl or methoxy group, R? represents a hydrogen atom or a C-j-C^-alkyl group, R 3 represents a hydrogen atom or a C^-C^-alkyl group, R^ represents a halogen atom, Rg represents a halogen atom, each of the symbols X represents a hydrogen atom, a C-|-C 4 -alkyl group, a halogen atom or a methoxy group, and n represents 1 or 2.

2. A compound as claimed in claim 1, wherein 15 R-| represents a methyl or methoxy group, R 2 represents a hydrogen atom or a methyl group, R 3 represents a hydrogen atom or a methyl group, represents a chlorine or bromine atom, Rg represents a chlorine or bromine atom, 20 each of the symbols X represents a hydrogen atom, a methyl group, a chlorine atom or a methoxy group, and - 23 n represents 1 or 2.

3. l-[4-(2,2-Dichlorocyclopropylmethoxy)-phenyl]-3,3-dimethylurea.

4. 1-[4-(2,2-Dichlorocyclopropylmethoxy)-3-methoxyphenyl] -3,3dimethylurea.

5. 1-(4-(2,2-Dichlorocyclopropylmethoxy)-3-methoxyphenyl]-3-methoxy -3-methylurea.

6. 1- [3-Chloro-4-(2,2-dichlorocyclopropylmethoxy)-phenyl]-3,3dimethylurea.

7. 1 - [3-Chloro-4-(2,2-dichlorocyclopropylmethoxy)-phenyl] -3methoxy-3-roethylurea.

8. l~[4-(2,2-Dichlorocyclopropylmethoxy)-phenyl] -3-methoxy-3methylurea.

9. l-Butyl-3-[4-(2,2-dichlorocyclopropylmethoxy)-phenyl]-lmethylurea.

10. 1-[4-(2,2,-Di chiorocyclopropylmethoxy)-phenyl] -3-methyl-3(1-methyl-2-propynyl)-urea.

11. 1-[4-(2,2-D ichiorocyclopropylmethoxy)-3,5-d imethylphenyl]-3,3dimethylurea.

12. 1 - [4-(2,2-Dichiorocyclopropylmethoxy)-3,5-dimethylphenyl]-3methoxy-3-methylurea.

13. 1-(4-(2,2-Dichlorocyclopropylmethoxy)-3,5-dichlorophenyl]-3,3dimethylurea.

14. i-[4-(2,2-Dichlorocyclopropylmethoxy)-3-methylphenyl]-3,3dimethylurea.

15. 1 -(4-(2,2-Dichloro-l-methylcyclopropylmethoxy)-phenyl]-348061 - 24 methoxy-3-methylurea.

16. 1 - [4- (2,2-D ichioro-1-methylcyclopropy!methoxy)-phenyl]-3,3dimethylurea.

17. l-[4-(2,2-Dibromocyclopropylmethoxy)-phenyl]-3,3-dimethylurea. 5

18. 1-(4-(2,2-Di chioro-3-methylcyclopropylmethoxy)-phenyl]-3,3dimethylurea.

19. A process for the manufacture of a compound of the general formula I given in claim 1, in which Rp Rg, Rg, Rp Rg, X and n have the meanings given in claim 1, wherein 10 A) a compound of the general formula in which Rg, Rg, Rp Rg, X and n have the meanings given above, is (a) reacted in the presence of an acid-binding agent with a carbamic acid halide of the general formula 15 R,—N —CO—Hal, I CHg in which R-| has the meaning given above and Hal represents a halogen atom or (b) when R^ represents a hydrogen atom, reacted in the presence of a catalyst with methyl isocyanate of the formula CHg —N = C=O, - 25 or B) a compound of the general forrnula R 4 R 5 OCH,-C-CH I I R 2 R 3 in which R 2> Rg, R^, Rg, X and n have the meanings given above, is 5 reacted in the presence of a catalyst with an amine of the general formula R,— NH 1 I ch 3 in which R-j has the meanings given above, or C) a compound of the general formula in which R 2> Rg, R 4 , R fi , X and n have the meanings given above, is reacted with an amine of the general formula R, — NH 1 I ch 3 in which Rj has the meaning given above, or - 26 D) a compound of the general formula ch 3 in which Rp X and n have the meanings given above, is reacted in a solvent and in the presence of an acid-binding agent with a halide 5 of the general formula Hal-CH,-C-CH 2 I I R 2 R 3 in which R 2> R 3 > R 4 and Rg have the meanings given above and Hal represents a halogen atom.

20. A process as claimed in claim 19, wherein each of the reactions. 10 according to variant A(a), A(b), B and C is carried out in a solvent.

21. A process as claimed in claim 19, wherein the reaction according to variant 0 is carried out in the presence of a catalyst.

22. A process as claimed in claim 19, conducted substantially as described herein. 15

23. A process as claimed in claim 19, conducted substantially as described in Example 1 or 2 herein. - 27

24. A herbicidai preparation which comprises a compound of the general formula I given in claim 1, in which Rp Rg.Rg R^, Rg, X and n have the meanings given in claim 1, in admixture or conjunction with a suitable carrier. 5

25. A herbicidai preparation which comprises a compound as claimed in claim 2, in admixture or conjunction with a suitable carrier.

26. A herbicidai preparation which comprises the compound claimed in any one of claims 3 to 18, in admixture or conjunction with a suitable carrier. 10

27. A preparation as claimed in any one of claims 24 to 26, which is in the form of a powder, a strewable preparation, granules, a solution, an emulsion or a suspension.

28. A preparation as claimed in any one of claims 24 to 27, containing a single compound of the general formula I. 15

29. A preparation as claimed in any one of claims 24 to 27, containing two or more compounds of the general formula I.

30. A preparation as claimed in any one of claims 24 to 29, which also contains one or more active substances selected from defoliants, plant protecting agents, pesticides and herbicides 20 other than compounds of the general formula I. - 28

31. A preparation as claimed in any one of claims 24 to 30, wherein the total amount present of active substance or substances is 10 to 80% by weight.

32. A preparation as claimed in any one of claims 24 to 31, 5 containing a single surface-active agent in an amount of up to 20% by weight.

33. A preparation as claimed in any one of claims 24 to 31, containing two or more surface-active agents in a total amount of up to 20% by weight. 10

34. Any one of the herbicidai preparations as claimed in claim 24 and substantially as described in Example 3 or 4 herein.

35. A method of protecting a living plant against weeds, wherein the area in the vicinity of the living plant is treated with a compound of the general formula I given in claim 1, in which Rp Rg» Rg» Rp Rg, 15 X and n have the meanings given in claim 1.

36. A method as claimed in claim 35, wherein the area is treated with a compound as claimed in claim 2.

37. A method as claimed in claim 35, wherein the area is treated with the compound claimed in any one of claims 3 to 18. 20

38. A method as claimed in claim 35, wherein the area is treated with a herbicidai preparation as claimed in any one of claims 24 to - 29 34.

39. A method as claimed in any one of claims 35 to 38, wherein a single compound of the general formula I is used for the treatment in an amount within the range of from 1 to 5 kg per hectare. 5

40. A method as claimed in any one of claims 35 to 38, wherein two or more compounds of the general formula I are used for the treatment in a total amount within the range of from 1 to 5 kg per hectare.

41. A method as claimed in claim 35, conducted substantially as described in Example 4 herein. 10

42. A method of protecting a crop area against weeds, wherein the crop area is treated with a compound of the general formula I given in claim 1, in which Rp Rg, Rg, Rp X and n have the meanings given in claim 1.

43. A method as claimed in claim 42, wherein the crop area is 15 treated with a compound as claimed in claim 2.

44. A method as claimed in claim 42, wherein the crop area is treated with the compound claimed in any one of claims 3 to 18.

45. A method as claimed in claim 42, wherein the crop area is treated with aherbicidal preparation as claimed in any one of 20 claims 24 to 34. - 30

46. A method as claimed in any one of claims 42 to 45, wherein a single compound of the general formula X is used for the treatment in an amount within the range of from 1 to 5 kg per hectare.

47. A method as claimed in any one of claims 42 to 45, wherein two 5 or more compounds of the general formula I are used for the treatment in a total amount within the range of from 1 to 5 kg per hectare.

48. A method as claimed in any one of claims 42 to 47, wherein the crop is a French bean, ground-nut, potato, rice, sorghum, maize, 10 winter cereal or soya crop.

49. A method of protecting a waste land against weeds, wherein the waste land is treated with one or more compounds of the general formula I given in claim 1, in which Rp Rg, Rg, Rp Rg, X and n have the meanings given in claim 1, the compound(s) being used in a 15 total amount of more than 5 kg per hectare.

50. A pack which comprises a compound of the general formula I given in claim 1, in which Rp Rg, Rg, Rp Rg, X and n have the meanings given in claim 1, together with instructions for its use as a herbicide.

51. A pack as claimed in claim 50, wherein the compound of the 20 general formula I is a compound as claimed in claim 2.

52. A pack as claimed in claim 50, wherein the compound of the general - 31 formula I is the compound claimed in any one of claims 3 to 18. Dated the 31st day of January, 1979.