IL102075A - N-[(1,3,5-triazin-2-YL)aminocarbonyl] benzenesulfonamides their manufacture and their use as herbicides - Google Patents

Description

,D7T»n -nai?io-iT-i--[i'm-npi-i QK(i»,'K-2- T o-5,3,1)] -N N- [(1 ,3,5-Triazin-2-yl ) ami nocarbonyl] benzenensulfonamides , their manufacture and their use as herbicides BASF Aktiengesellschaft C. 86439 The present invention relates to N-[ (1,3,5-triazin-2-yl) -aminocarbonyl ] -benzenesulfona ides of the general formula I where R1 is methyl or ethyl, R2 is halogen, C,-C3-alkyl-sulfonyl, trifluoromethyl or 2-methoxyethoxy and R3 is hydrogen, methyl, ethyl, methoxy, ethoxy, fluorine or chlorine, and agriculturally useful salts thereof.

The present invention furthermore relates to a process for the preparation of the compounds I and their use, as herbicides.

U.S; .Patents 4,120,691 and 4,127,405 and ΞΡ-Α 44807 which corresponds to IL 63324 and 79463, relate to sulfonylureas which have a herbicidal action and whose general formula embraces the compounds of the general formula I which are defined at the outset.

U.S. Patent 4,120,691 describes the triazine compound A being the most closely related structure EP-A 44 807 describes two sulfonylureas C having ho allyloxy group.

R = CH3 or C2H5 - 2 - O.Z. 0050/42042 EP 44808 which corresponds to IL 63324 and 79463 describes two sulfonylureas D having a 2-chloroethoxy substituent in the aromatic moiety.

Z =» CH or N EP 48143 which corresponds to IL 55683, mentions two N-methylated sulfonylureas E without characterizing them further.

Z * CH or N EP 388,873 which corresponds to IL 93707 relates to benzoates having the structure F.

U.S. Patent 4,127,405 discloses sulfonylurea derivatives having chlorine or trifluoromethyl substitution in the ortho position of the phenyl ring and CH3/OCH3 substitution in the triazine ring The compound G is known under the name chloro- sulfuron (Glean*) .

It is an object of the present invention to synthesize sulfonylureas which have improved properties . compared with the known members of this herbicide class and are distinguished in particular by high selectivity in sensitive crops, such as rice or com.

We have found that this object is achieved by the N- [ ( 1 , 3 , 5-triazin-2-yl ) -aminocarbonyl ] -benzenesulfon- amides of the formula I which are defined at the outset.

In the formula I, Cj-C3-alkylsulfonyl is methyl, -ethyl-, propyl- or isopropylsulfonyl and halogen is fluorine, chlorine, bromine or iodine, in particular fluorine or chlorine. Benzenesulfonamides in which R2 is chlorine are particularly preferred.

The novel sulfonylureas of the formula I are obtainable by various methods which are described in the literature. Particularly advantageous methods (A-D) are described in detail below by way of example.

A: A sulfonyl isocyanate II is reacted in a conventional manner (EP-A-162 723) with about the stoichiometric amount of a 2-amino-l,3,5-triazine derivative III at from 0 to 120°C, preferably from 10 to 100eC. The reaction can be carried out continuously or batchwise - 4 0050/42042 under atmospheric or superatmospherlc pressure (up to 50 bar), preferably at from 1 to 5 bar.

Solvents and diluents which are inert under the particular reaction conditions are advantageously used for the reactions. Examples of suitable solvents are halohydrocarbons , in particular chlorohydrocarbons , eg. tetrachloroethylene, 1,1,2,2- or 1, 1, 1, 2-tetrachloro-ethane, dichloropropane, methylene chloride, dichloro-butane, chloroform, chloronaphthalene, dichloronaph-thalene, carbon tetrachloride, 1,1,1- or 1, 1,2-trichloro-ethane, trichloroethylene, pentachloroethane, o-, m- and p-difluorobenzene, 1,2-diehloroethane, 1, 1-dichloro-ethane, 1,2-cis-dichloroethylene, chlorobenzene, fluorobenzene, bromobenzene, iodobenzene, o-, m- and p-dichlorobenzene, o-, p- and m-dibromobenzene, o-, m- and p-chlorotoluene, and 1,2,4-trichlorobenzene; ethers, eg. ethyl propyl ether, methyl tert-butyl ether, n-butyl ethyl ether, di-n-butyl ether, diisobutyl ether, diiso-amyl ether, diisopropyl ether, anisole, phenetol, cyclo-hexyl methyl ether, diethyl ether, ethylene glycol dimethyl ether, tetrahydrofuran, dioxane, thioanisole and β ,β ' -dichlorodiethyl ether; nitrohydrocarbons , such as nitromethane, nitroethane, nitrobenzene, o-, m- and p-chloronitrobenzene and o-nitrotoluene; nitriles, such as acetonitrile, butyronitrile, isobutyronitrile, benzo-nitrile and m-chlorobenzonitrile; aliphatic or cyclo-aliphatic hydrocarbons, eg. heptane, pinane, nonane, o-, m- and p-cymene, gasoline fractions boiling within a range of from 70 to 190°C, cyclohexane, methylcyclohexane, decalin, petroleum ether, hexane, naphtha, 2,2,4-trimethylpentane, 2,2,3-trimethylpentane, 2 , 3 , 3-tri-methylpentane and octane; esters, eg. ethyl acetate, ethyl acetoacetate and isobutyl acetate; amides, eg. formamide, methylformamide and dimethylformamide; ketones, eg. acetone and methyl ethyl ketone, and corresponding mixtures. The solvent is advantageously used in an amount of from 100 to 2,000, preferably from 200 to - 5 - O.Z. 0050/42042 700, % by weight, based on the starting material II.

The compound II required for the reaction is generally used in about an eguimolar amount (for example in an amount of from 80 to 120%, based on the particular starting material III, of the stoichiometric amount). The starting material III may be initially taken in one of the abovementioned diluents and the starting material II added.

Advantageously, however, the process for the preparation of the novel compounds is carried out by a method in which the starting material II, if necessary in one of the abovementioned diluents, is initially taken and the starting material III is then added.

To complete the reaction, stirring is carried out for a further 20 minutes to 24 hours at from 0 to 120°C, preferably from 10 to 100°C, after the addition of the components .

A tertiary amine, eg. pyridine, a,0,7-picoline, 2,4- and 2,6-lutidine, 2,4,6-collidine, p-dimethylamino-pyridine, trimethylamine, triethylamine, tri-n-propyl-amine, l,4-diazabicyclo[2.2.2]octane [DABCO] or 1,8-diazabicyclo[5.4.0]undec-7-ene, can advantageously be used as a reaction accelerator in an amount of from 0.01 to 1 mol per mole of starting material II.

The end product I is isolated from the reaction mixture in a -conventional manner, for example after distilling off the solvent or directly by filtration under suction. The remaining residue may furthermore be washed with water or dilute acid to remove basic impurities. However, the residue can also be dissolved in a water-immiscible solvent and washed in the manner described. The desired end products are obtained here in pure form; if necessary, they can be purified by re-crystallization, stirring in an organic solvent which takes up the impurities or chromatography.

This reaction is preferably carried out in aceto-nitrile, methyl tert-butyl ether, toluene or methylene - 6 O.Z. 0050/42042 chloride in the presence of from 0 to 100, preferably from 0 to 50 mol equivalents of a tertiary amine, such as l,4-diazabicyclo[2.2.2]octane or triethylamine .

Bt A corresponding sulfonylcarbamate of the formula IV is reacted in a conventional manner (EP-A-120 814, EP-A-101 407) with a 2-amino-l, 3,5-triazine derivative III in an inert organic solvent at from 0 to 120°C, preferably from 10 to 100°C. Bases, such as tertiary amines, may be added here, with the result that the reaction is accelerated and the quality improved.

Suitable bases for this ur f^ are, for example, tertiary amines as stated under A, in particular triethylamine or l,4-diazabicyclo[2.2.2]octane, in an amount of from 0.01 to 1 mol per mole of starting material IV.

Advantageously used solvents are those stated under A.

The solvent is used in an amount of from 100 to 2,000, preferably from 200 to 700, % by weight, based on the starting material IV.

The compound IV required for the reaction is generally used in about an equimolar amount (for example in an amount of from 80 to 120%, based on the particular starting material III, of the stoichiometric amount). The starting material IV may be initially taken in one of the abovementioned diluents and the starting material III then added. , However, it is also possible initially to take the starting material III in one of the stated solvents or diluents and to add the sulfonylcarbamate IV.

In both cases, a base may be added as a catalyst before or during the reaction.

.The end product I can be obtained from the reaction mixture in a conventional manner, as stated under A.

C: A sulfonamide of the formula V is reacted in a conventional manner (EP-A-141 777 and EP-A-101 670) with about the stoichiometric amount of a phenyl carbamate VI O.Z. 0050/42042 in an inert organic solvent at from 0 to 120°C, preferably from 20 to 100°C. The reaction is carried out continuously or batchwise at atmospheric or super-atmospheric pressure (up to SO bar) , preferably at from 1 to 5 bar.

Bases such as tertiary amines, which accelerate the reaction and improve the product quality, may be added here. Suitable bases for this purpose are those stated under A, in particular triethy1amine, 2,4,6-collidine, l,4-diazabicyclo[2.2.2]octane [DABCO] or 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), in an amount of from 0.01 to 1 mol per mole of starting material V.

Advantageously used solvents or diluents are those stated under A.

The solvent is used in an amount of from 100 to 2,000, preferably from 200 to 700, % by weight, based on the educt V.

The compound V required for the reaction is generally used in about an equimolar amount ( for example in an amount of 80 to 120%, based on the particular starting materials VI, of the stoichiometric amount). The starting material VI may be initially taken in one of the abovementioned diluents and the starting material V then added.

However, it is also possible initially to take the starting material V in one of the stated solvents and then to add the carbamate VI. In both cases, one of the stated bases may be added as a catalyst before or during the reaction.

To complete the reaction, stirring is carried out for a further 20 minutes to 24 hours at from 0 to 120°C, preferably from 10 to 100°C, in particular from 20 to 80°C, after the addition of the components.

The sulfonylureas of the formula I are isolated from the reaction mixture by the conventional methods, as described under A.

D: A sulfonamide of the formula V is reacted in a - 8 - 0050/42042 conventional manner (EP-A-234 352) with about the stoichiometric amount of an isocyanate VII in an inert organic solvent at from 0 to 150°C, preferably from 10 to 100°C. The reaction can be carried out continuously or batchwise at atmospheric or superatmospheric pressure (up to 50 bar), preferably at from 1 to 5 bar.

Bases such as tertiary amines, which accelerate the reaction and improve the product quality, may be added before or during the reaction. Suitable bases for this purpose are those stated under A, in particular triethylamine or 2,4,6-collidine, in an amount of from 0.01 to 1 mol per mole of starting material V.

Advantageously used solvents are those stated under A. The solvent is used in an amount of from 100 to 2,000, preferably from 200 to 700, % by weight, based on the educt V.

The compound V required for the reaction is generally used in about the equimolar amount ( for example in an amount of from 80 to 120%, based on the educts VII, of the stoichiometric amount) . The starting material VII can be initially taken in one of the stated diluents and the starting material V then added. However, it is also possible initially to take the sulfonamide and then to add the isocyanate VII.

To complete the reaction, stirring is carried out for a further 2Ό minutes to 24 hours at from 0 to 120°C, preferably from 10 to 100°C, in particular from 20 to 80°C, after the addition of the components. The end product I can be obtained from the reaction mixture in a conventional manner, as described under A.

The sulfonyl isocyanates of the formula II which are required as starting materials can be obtained in a conventional manner from the corresponding sulfonamides by phosgenation (Houben- eyl, 11/2 (1985) 1106 and U.S. Patent 4,379,769) or by reaction of the sulfonamides with chlorosulfonyl isocyanate (German Laid-Open Application DOS 3,132,944). 9 - 0050/42042 The sulfonylcarbamates of the formula IV were prepared by, or similarly to, conventional reactions (eg. EP-A 120 814). However, the sulfonyl isocyanates of the formula II can also be converted into the carbamates of the formula IV in a smooth reaction in an inert solvent, such as ether or dichloromethane .

Carbamates of the formula VI are obtainable by, or similarly to, known reactions (eg. EP-A 101 670), but they can also be prepared from the corresponding iso-cyanates VII by reaction with phenol.

The isocyanates of the formula VII are obtained from the amines of the formula III by treatment with oxalyl chloride or phosgene (by a method similar to that described in Angew. Chem. £1 (1971), 407 or EP-A 388 873) .

The sulfonamides can be obtained by reacting the corresponding sulfonyl chlorides with ammonia (Houben-Weyl, Methoden der organischen Chemie, Volume 9 (1955), 605). The sulfonyl chlorides are obtained either by a Meerwein reaction (diazotization of suitable amines and sulfochlorination under catalysis with a copper salt) or by chlorosulfonation of suitable aromatics, for example 2 , 5-dichlorobenzenesulfonyl chloride from p- dichlorobenzene (Houben-Weyl, Methoden der organischen Chemie, Volume 9 (1955), 557 et seq. ) . 2-Amino-4-methoxy-6-trifluoromethyl-1 , 3,5- triazine and 2-amino-4-ethoxy-6-trifluoromethyl-1, 3 , 5- triazine are known from the literature (Takugaku Zasshi H (1975), 499).

The salts of the compounds I are obtainable in a conventional manner (EP-A 304 282, US-A 4,599,412). They are obtained by deprotonation of the corresponding sulfonylureas I in water or in an inert organic solvent at from -80 to 120°C, preferably from 0 to 60°C, in the presence of a base.

Examples of suitable bases are alkali metal or alkaline earth metal hydroxides, hydrides, oxides or - 10 - 0050/42042 alcoholates, such as sodium, potassium and lithium hydroxide, sodium methylate, ethylate or tert-butylate, sodium and calcium hydride and calcium oxide.

Examples of suitable solvents in addition to water are also alcohols, such as methanol, ethanol and tert-butanol, ethers, such as tetrahydrofuran and diox-ane, acetonitrile, dimethylformamide, ketones, such as acetone and methyl ethyl ketone, and halgenated hydrocarbons .

The deprotonation can be carried out under atmospheric pressure or at up to 50 bar, preferably at from atmospheric pressure to a superatmospherlc pressure of 5 bar. 11 O.Z. 0050/42042 The compounds I, or herbicidal agents containing them, and environmentally friendly alkali metal and alkaline earth metal salts, provide excellent control of injurious plants in crops such as wheat, rice and Indian corn without damaging the crop plants, an effect which occurs particularly at low application rates. The compounds may be applied for instance in the form of directly sprayable solutions, powders, suspensions (including high-percentage aqueous, oily or other suspensions), dispersions, emulsions, oil dispersions, pastes, dusts, broadcasting agents, or granules by spraying, atomizing, dusting, broadcasting or watering. The forms of application depend entirely on the purpose for which the agents are being used, but they must ensure as fine a distribution of the active ingredients according to the invention as possible.

The compounds I are suitable for the preparation of solutions, emulsions, pastes and oil dispersions to be sprayed direct. Examples of inert additives are mineral oil fractions of medium to high boiling point, such as kerosene or diesel oil, further coal-tar oils, and oils of vegetable or animal origin, aliphatic, cyclic and aromatic hydrocarbons such as toluene, xylene, paraffin, tetrahydronaphthalene, alkylated naphthalenes and their derivatives, methanol, ethanol, propanol, butanol, cyclohexanol, cyclohexanone, chlorobenzene, isophorone, etc., and strongly polar solvents such as N, -dimethylformamide, dimethyl sulfoxide, N-methyl-pyrrolidone, water, etc.

Aqueous formulations may be prepared from emulsion concentrates, pastes, oil dispersions, wettable powders or water-dispersible granules by adding water. To prepare emulsions, pastes and oil dispersions the ingredients as such or dissolved in an oil or solvent may be homogenized in water by means of wetting or dispersing agents, adherents or emulsifiers. Concen-trates which are suitable for dilution with water may be prepared from active ingredient, wetting agent, adherent, emulsifying or dispersing agent and possibly solvent or oil.

Examples of surfactants are: alkali metal, alkaline earth metal and ammonium salts of aromatic sulfonic acids, e.g., 1 igninsulfonic acid, phenolsulfonic acid, naphthalenesulfonic acid and dibutylnaphthalene-sulfonic acid, and of fatty acids, alkyl and alkylaryl sulfonates, and alkyl, lauryl ether and fatty alcohol sulfates, and salts of sulfated hexadecanols, heptadecanols, and octadecanols, salts of fatty alcohol glycol ethers, condensation products of sulfonated naphthalene and naphthalene derivatives with formaldehyde, condensation products of naphthalene or naphthalenesulfonic acids with phenol and formaldehyde, polyoxyethylene octylphenol ethers, ethoxylated isooctylphenol, ethoxyl-ated octylphenol and ethoxylated nonylphenol, alkylphenol polyglycol ethers, tributylphenyl polyglycol ethers, alkylaryl polyether alcohols, isotridecyl alcohol, fatty alcohol ethylene oxide condensates, ethoxylated 12 O.Z. 0050/42042 castor oil, polyoxyethylene alk I ethers, ethoxylated polyoxyprop lene, lauryl alcohol polyglycol ether acetal, sorbitol esters, lignin-sulf ite waste liquors and methyl cellulose.

Powders, dusts and broadcasting agents may be prepared by mixing or grinding the active ingredients with a solid carrier.

Granules, e.g., coated, impregnated or homogeneous granules, may be prepared by bonding the active ingredients to solid carriers. Examples of solid carriers are mineral earths such as silicic acids, silica gels, silicates, talc, kaolin, attapulgus clay, limestone, lime, chalk, bole, loess, clay, dolomite, diatomaceous earth, calcium sulfate, magnesium sulfate, magnesium oxide, ground plastics, fertilizers such as ammonium sulfate, ammonium phosphate, ammonium nitrate, and ureas, and vegetable products such as grain meals, bark meal, wood meal, and nutshell meal, cellulosic powders, etc.

The formulations contain from 0.1 to 95, and preferably 0.5 to 90, % by weight of active ingredient.

Examples of formulations are as follows: I. 90 parts by weight of compound no. 1 is mixed with 10 parts by weight of N-methyl-alpha-pyrrolidone. A mixture is obtained which is suitable for application in the form of very fine drops.

II. 20 parts by weight of compound no. 1 is dissolved in a mixture consisting of 80 parts by weight of xylene, 10 parts by weight of the adduct of 8 to 10 moles o*f ethylene oxide and 1 mole of oleic acid-N-monoethanolamide, 5 parts by weight of the calcium salt of dodecy Ibenzene-sulfonic acid, and 5 parts by weight of the adduct of 40 moles of ethylene oxide and 1 mole of castor oil. By pouring the solution into 100,000 parts by weight of water and uniformly distributing it therein, an aqueous dispersion is obtained containing 0.02% by weight of the active ingredient.

III. 20 parts by weight of compound no. 1 is dissolved in a mixture consisting of 40 parts by weight of cyclohexanone, 30 parts by weight of isobutanol, 20 parts by weight of the adduct of 7 moles of ethylene oxide and 1 mole of isooctylphenol, and 10 parts by weight of the adduct of 40 moles of ethylene oxide and 1 mole of castor oil. By pouring the solution into 100,000 parts by weight of water and finely distributing it therein, an aqueous dispersion is obtained containing 0.02% by weight of the active ingredient. 13 O.Z. 0050/42042 IV. 20 parts by weight of compound no. 1 is dissolved in a mixture consisting of 25 parts by weight of cyclohexanone, 65 parts by weight of a mineral oil fraction having a boiling point between 210 and 280°C, and 10 parts by weight of the adduct of 40 moles of ethylene oxide and 1 mole of castor oil. By pouring the solution into 100,000 parts b weight of water and uniformly distributing it therein, an aqueous dispersion is obtained containing 0.02% by weight of the active ingredient.

V. 20 parts by weight of compound no. 1 is well mixed with 3 parts by weight of the sodium salt of di isobutylnaphthalene-alpha-sulfonic acid, 17 parts by weight of the sodium salt of a 1 ignin-sulfonic acid obtained from a sulfite waste liquor, and 60 parts by weight of powdered silica gel, and triturated in a hammer mill. By uniformly distributing the mixture in 20,000 parts by weight of water, a spray liquor is obtained containing 0.1% by weight of the active ingredient.

VI. 3 parts by weight of compound no. 1 is intimately mixed with 97 parts by weight of particulate kaolin. A dust is obtained containing 3% by w ight of the active ingredient.

VII. 30 parts by weight of compound no. 1 is intimately mixed with a mixture consisting of 92 parts by weight of powdered silica gel and 8 parts by weight of paraffin oil which has been sprayed onto the surface of this silica gel. A formulation of the active ingredient is obtained having good adherence.

VIII. 20 parts by weight of compound no. 1 is intimately mixed with 2 parts of the calcium salt of dodecylbenzenesulfonic acid, 8 parts of a fatty alcohol polyglycol 'ether, 2 parts of the sodium salt of a phenol-sulfonic acid-urea-formaldehyde condensate and 68 parts of a paraffinic mineral oil. A stable oily dispersion is obtained.

The active ingredients or the herbicidal agents containing them may be applied pre- or postemergence. If certain crop plants tolerate the active ingredients less well, application techniques may be used in which the herbicidal agents are sprayed from suitable equipment in such a manner that the leaves of sensitive crop plants are if possible not touched, and the agents reach the soil or the unwanted plants growing beneath the crop plants (post-directed, lay-by treatment).

The application rates depend on the objective to be achieved, the time of the year, the plants to be combated and their growth stage, and are from 0.001 to 1.0, preferably 0.001 to 0.5, kg of active ingredient per hectare. 14 O.Z. 0050/42042 In view of the numerous application methods possible, the compounds according to the invention may be used in a large number of crops. Those which follow are given by way of example: Botanical name Common name Allium cepa onions Ananas comosus pineapples Arachis hypogaea peanuts (groundnu Asparagus officinalis asparagus Beta vulgaris spp. altissima sugarbeets Beta vulgaris spp. rapa fodder beets Brassica napus var. napus rapeseed Brassica napus var. napobrassica swedes Brassica rapa var. silvestris Camellia sinensis tea plants Carthamus tinctorius safflower Citrus limon lemons Citrus sinensis orange trees Coffea arabica (Coffea canephora, Coffea liberica) coffee plants Cucumis sativus cucumbers Cynodon dact lon Bermudagrass Daucus carota carrots Elais guineensis oil palms Fragaria vesca strawberries Glycine max soybeans Gossypium hirsutum (Gossypium arboreum, Gossypium herbaceum, Gossypium viti folium) cotton Helianthus annuus " sunflowers Hevea brasiliensis rubber plants Hordeum vulgare barley Humulus lupulus hops Ipomoea batatas sweet potatoes Juglans regia walnut trees Lens culinaris lentils Linum usitatissimum flax Lycopersicon lycopersicum tomatoes Malus spp. apple trees Manihot esculent cassava Medicago sativa alfalfa (lucerne) Mentha piperita peppermint Musa spp. banana plants Nicotiana tabacum (N. rustica) tobacco Olea europaea olive trees 15 O.Z. 0050/42042 Botanical name Common name Oryza sativa rice Phaseolus lunatus 1 imabeans Phaseolus vulgaris snapbeans, green beans, dry beans Picea abies Norway spruce Pinus spp. pine trees Pi sum sativum English peas Prunus avium cherry trees Prunus dulcis almond trees Prunus persica peach trees Pyrus communis pear trees ibes sylvestre redcurrants Ribes uva-crispa gooseberries Ricinus communis castor-oil plants Saccharum o ficinarum sugar cane Secale cereale rye Solanum tuberosum Irish potatoes Sorghum bicolor (s. vulgare) sorghum Theobroma cacao cacao plants Tri folium pretense red clover Triticum aestivum wheat Triticum durum durum wheat icia faba tick beans Vitis vinifera grapes Zea mays Indian corn, sweet corn, maize To increase the spectrumOf action and to achieve synergistic effects, the triazin l-substituted sulfonylureas of the formula I may be mixed with each other, or mixed and applied together with numerous representatives of other herbicidal or growth-regulating active ingredient groups. Examples of suitable components are diazines, 4H-3, 1-benzoxazine derivatives, benzothi adiazinones, 2, 6-dinitroani 1 ines, N-phenylcarbamates, thiolcarbam-ates, halocarboxylic acids, triazines, amides, ureas, diphenyl ethers, triazinones, uracils, benzofuran derivatives, cyclohexane-1, 3-dione derivatives, quinol inecarboxyl ic acids, (hetero)-aryloxyphenoxypropionic acids and salts, esters, amides thereof, etc.

It may also be useful to apply the compounds I, either alone or in combination with other herbicides, in admixture with other crop protection agents, e.g., agents for combating pests or phytopathogenic fungi or bacteria. The compounds may also be mixed with solutions of mineral salts used to remedy nutritional or trace element deficiencies. Non-phytotoxic oils and oil concentrates may also be added. 16 O.Z. 0050/42042 Some examples illustrating the synthesis of the compounds I are given below. 1) 2-Chloro-l-N-[4-methoxy-6-trifluoromethyl-l,3, 5-triazin-2-yl )-amino- carbony I ]-benzenesufonamide At 25°C, 4.5 g (21 mmol) of 2-chlorobenzenesulfonyl isocyanate was added to a solution of 4.0 g (21 mmol) of 2-amino-4-methoxy-6-tri- fluoromethyl-1, 3, 5-triazine in 20 ml of acetonitri le. The solution thus obtained was stirred for 21 hours at 25°C. The solvent was removed under reduced presssure at 40°C, and the solid residue was stirred vigorously for 3 hours with 1 liter of a 1:1 by volume mixture of diethyl ether and hexane. The product was suction filtered and dried under reduced pressure at 40°C. There was obtained 6.5 g (75% of theory) of the title compound; m.p. 166 - 168°C. 2) Sodium[2-chloro-l-N-[ (4-methoxy-6-trifluoromethyl-1, 3, 5-triazin-2- 1 )- aminocarbon l 3-benzenesul onamide] At 25°C, 0.66 g (3.6 mmol) of a solution of sodium methanolate (30wt%) in methanol was added to a suspension of 1.5 g (3.6 mmol) of 2-chloro- l-[ (4-methoxy-6-trifluoromethy1-1, 3-5-triazin-2- I) -aminocarbon l ]- benzenesulfonamide in 10 ml of methylene chloride. The homogeneous solution which formed was stirred for 1 hour at 25°C. After removal of the volatile portions' at 60°C under a water-pump vacuum the title compound was obtained in quantitative yield; decomposition point: 220 - 224°C.

The active ingredients given in Table 1 below are obtained analogously Rl R2 R3 mp [°C] CH3 CI H 166-168 CH3 0(CH2)2OCH3 H 108-110 CH3 CF3 H 164-169 CH3 CI H 220-224(decomp) Na salt CH3 0(CH2) 2OCH3 H 119 (decomp) Na salt CH3 0(CH2)2OCH3 H 139 (decomp) Ca salt CH3 CF3 H 165 (decomp) Na salt CH3 CI 6-Cl 168 CH3 CI H 160-163(decomp) Ca salt CH3 CI H 232 (decomp) salt CH3 CI 6-CH3 140-144 CH3 CI 5-C 151-156 CH3 F H 162-164 CH3 Br H CH3 I H CH3 F H >220 (decomp) Na salt CH3 F H >220 (decomp) salt CH3 F H >220 (decomp) Ca salt CH3 F 6-F 177-180 CH3 F 6-F 180-200 (decomp) Na salt CH3 F 6-F >220 (decomp) K salt CH3 F 6-F 155-159(decomp) Ca salt C2H5 C 3-C 155-157 CH3 C 3-C 175-177 C2H5 CI 3-Cl 197-200 (decomp) Na salt CH3 C 3-Cl 198-201 (decomp) Na salt CH3 C 6-CH3 175-178(decomp) Na salt CH3 C 6-CH3 180-183 K salt CH3 S02CH3 H 176-177 CH3 S02CH3 H 186-188 Na salt CH3 CI 3-Cl >220 (decomp) K salt C2H5 S02CH3 H 164-165 C2H5 CI H 149-151 CH3 CF3 6-CH3 149-150 CH3 CH3 6-CH3 200 (decomp) Na salt CH3 CF3 H 211 (decomp) Ca salt CH3 S02C2H5 H 152-155 CH3 S02-n-C3H7 H 181-182 CH3 S02-i-C3H7 H 173-177 CH3 Br H 183 (decomp) Na salt lt CH3 ■ S02C2H5 H 173 (decomp) sa CH3 S0,,-n-C,H7 H 180 (decomD) Na salt CH3 196 f decomp) w= salt S02-i-C3H7 H 18 O.Z. 0050/42042 The compounds listed below may be obtained analogously: or their Na salts, R3 having the following meanings: hydrogen, 3-methyl, 4-methyl, 5-methyl, 6-methyl, 3-ethyl, 4-eth l, 5-ethyl, 6-ethyl, 3-fluoro, 4-fluoro, 5-fluoro, 6-fluoro, 3-chloro, 4-chloro, 5-chloro, 6-chloro, 3-methoxy, 4-methoxy, 5-methoxy, 6-methoxy, 3-ethoxy, 4-ethoxy, 5-ethoxy, 6-ethoxy; or their Na salts, R3 having the following meanings: hydrogen, 3-methyl, 4-methyl, 5-methyl, 6-methyl, 3-ethyl, 4-ethyl, 5-ethyl, 6-ethyl, 3-fluoro, 4-fluoro, 5-fluoro, 6-fluoro, 3-chloro, 4-chloro, 5-chloro, 6-chloro, 3-methoxy, 4-methoxy, 5-methoxy, 6-methoxy, 3-ethoxy, 4-ethoxy, 5-ethoxy, 6-ethoxy; 3 or their Na salts, R3 having the following meanings: hydrogen, 3-methyl, 4-methyl, 5-methyl, 6-methyl, 3-ethyl, 4-ethyl, 5-ethyl, 6-ethyl, 3-fluoro, 4-fluoro, 5-fluoro, 6-fluoro, 3-chloro, 4-chloro, 5-chloro, 6-chloro, 3-methoxy, 4-methoxy, 5-methoxy, 6-methoxy, 3-ethoxy, 4-ethoxy, 5-ethoxy, 6-ethoxy; or their Na salts, R3 having the following meanings: hydrogen, 3-methyl, 4-methyl, 5-methyl, 6-methyl, 3-ethyl, 4-ethyl, 5-ethyl, 6-ethyl, 3-fluoro, 4-fluoro, 5-fluoro, 6-fluoro, 3-chloro, 19 O.Z. 0050/42042 4- chloro, 5-chloro, 6-chloro, 3-methoxy, 4-methoxy, 5-methoxy, 6-methoxy, 3- ethoxy, 4-ethoxy, 5-ethoxy, 6-ethoxy; or their Na salts, R3 having the following meanings: hydogen, 3-methyl, 4-methyl, 5-methyl, 6-methyl, 3-ethyl, 4-ethyl, 5- ethy , 6-ethyl, 3-fluoro, 4-fluoro, 5-fluoro, 6-fluoro, 3-chloro, 4- chloro, 5-chloro, 6-chloro, 3-methoxy, 4-methoxy, 5-methoxy, 6-methoxy, 3-ethoxy, 4-ethoxy, 5-ethoxy, 6-ethoxy; or their Na salts, R3 having the following meanings: hydrogen, 3-methyl, 4-methyl, 5-methyl, 6-methyl, 3-ethyl, 4-ethyl, 5- ethyl, 6-ethyl, 3-fluoro, 4-fluoro, 5-fluoro, 6-fluoro, 3-chloro, 4-chloro, 5-chloro, 6-chloro, 3-methoxy, 4-methoxy, 5-methoxy, 6-methoxy, 3- ethoxy, 4-ethoxy, 5-ethoxy, 6-ethoxy; or their Na salts, R3 having the following meanings: hydrogen, 3-methyl, 4-methyl, 5-methyl, 6-methyl, 3-ethyl, 4-ethyl, 5-ethyl, 6-ethyl, 3-fluoro, 4-fluoro, 5-fluoro, 6-fluoro, 3-chloro, 4- chloro, 5-chloro, 6-chloro, 3-methoxy, 4-methoxy, 5-methoxy, 6-methoxy, 3- ethoxy, 4-ethoxy, 5-ethoxy, 6-ethoxy; or their Na salts, R3 having the following meanings: hydrogen, 3-methyl, 4-methyl, 5-methyl, 6-methyl, 3-ethyl, 4-ethyl, 5- ethyl, 6-ethyl, 3-fluoro, 4-fluoro, 5-fluoro, 6-fluoro, 3-chloro, 4- chloro, 5-chloro, 6-chloro, 3-methoxy, 4-methoxy, 5-methoxy, 6-methoxy, 3-ethoxy, 4-ethoxy, 5-ethoxy, 6-ethoxy; 20 O.Z. 0050/42042 or their Na salts, R3 having the following meanings: hydrogen, 3-methyl, 4-methyl, 5-methyl, 6-methyl, 3-ethyl, 4-ethyl, 5-ethyl, 6-ethyl, 3-fluoro, 4-fluoro, 5-fluoro, 6-fluoro, 3-chloro, 5 4-chloro, 5-chloro, 6-chloro, 3-methoxy, 4-methoxy, 5-methoxy, 6-methoxy, 3-ethoxy, 4-ethoxy, 5-ethoxy, 6-ethoxy.

Use examples: 10 The herbicidal action of N-[ (1, 3, 5-triazin-2-yl)aminocarbonyl]benzene- sulfonamides of the formula I on the growth of test plants is demonstrated in the following greenhouse experiments.

The vessels employed are plastic flowerpots having a volume of 300 cm3 and 15 filled with a sandy loam containing about 3.0% humus. The seeds of the test plants are sown separately, according to species.

For the postemergence treatment, plants are used which have been sown in the pots and grown there, or they are grown separately as seedlings and 20 transplanted to the pots a few days before treatment. The plants are grown, depending on growth form, to a height of 3 to 15 cm before being treated with the compounds, suspended or emulsified in water. The application rates for postemergence treatment are 0.06 and 0.03 kg/ha of active ingredient. 25 The pots are set up in the greenhouse, heat-loving species at 20 to 35°C, and species from moderate climates at 10 to 20°C. The experiments are run for from 2 to 4 weeks. During this period the plants are tended and their reactions to the various treatments assessed. The assessment scale is 0 to 30 100, 100 denoting nonemergence or complete destruction of at least the visible plant parts, and 0 denoting no damage or normal growth.

The plants employed in the greenhouse experiments are Amaranthus retroflexus, Chenopodium album, Chrysanthemum, Galium aparine, Stellaria 35 media, Triticum aestivum and Zea mays. 21 O.Z. 0050/42042 Example no. 1, applied postemergence at 0.06 and 0.03 kg/ha, provides excellent control of unwanted broadleaved plants and proves to be outstandingly selective in the crop plants wheat and Indian corn.

The following table contains results of biological experiments in which the active . ingredient example no. 1 was compared with compound 8 disclosed in U.S. 4, 169,719. 3 Table 1: Comparison of the herbicidal action of Example no. 1 with that" of comparative compound B on postemergence application of 0.06 and 0.03 kg/ha in the greenhouse Test plants Damage [%] Appl. rate [kg/ha] Example 1 B 0.06 0.03 0.06 0.03 Amaranthus retroflexus 65 65 75 75 Galium aparine 98 98 90 85 Chenopodium album 75 70 75 70 Oryza sativa (rice) 20 0 90 80 In Tables 2 and 3 the compounds of Examples 1 and 3 according to the invention are compared with comparative "Substances G and H disclosed U.S. 22 O.Z. 0050/42042 The results clearly demonstrate the surprisingly high selectivity, The prior art compounds cause unacceptable damage to Indian corn (85 and 70%). By contrast, Examples 1 and 3 have the same good herbicidal action (or better) and only cause 10% damage to the crop plants.

Table 2: Comparison of the herbicidal action of example no. 1 with that of comparative compound G on postemergence application of 0.03 kg/ha of active ingredient in the greenhouse Test plants Damage [%] Example 1 Zea mays 10 85 Unwanted plants: Amaranthus retroflexus 90 90 Galium aparine 80 74 Table 3: Comparison of the herbicidal action of Example no. 3 with that of comparative compound H on postemergence application of 0.06 and 0.03 kg/ha of active ingredient in the greenhouse Test plants Damage [%] Appl. rate [kg/ha] Example 3 H 0.06 0.03 0.06 0.03 Zea mays 10 10 70 70 Unwanted plants: Amaranthus retroflexus 90 90 90 90 Galium. aparine 95 60 10 0 Chenopodium album 98 98 98 98 Sinapis alba 95 90 90 90 Compound no. 7 according to the invention provides excellent selectivity in the sensitive crops spring wheat and Indian corn, as is shown by the results in Tables 4 and 5 below. 23 O.Z. 0050/42042 Table 4: Control of unwanted broadleaved plants and tolerance by spring wheat and Indian corn on postemergence application of 0.015 kg/ha of compound no. 7 in the greenhouse Test plants Damage [ ] Triticum aestivum 10 Zea mays 15 Unwante plants: Amaranthus retroflexus 90 Chenopodium album 75 Stellaria media 100 Table 5 : Control of unwanted broadleaved plants and tolerance by rice on postemergence application of 0.015 kg/ha of compound no. 7 in the greenhouse Test plants Damage [¾] Oryza sativa 10 Unwanted plants: Amaranthus retroflexus 95 Sinapis alba 70 Stellaria media 100 In a further experiment, the sodium salt of comparative compound H was compared with Example 7. The results are given in Table 6.

Table 6: Comparison between the herbicidal action of Example no. that of the sodium salt of comparative compound H on postemergenc application of 0.06 and 9.03 kg/ha in the greenhouse Test plants Damage [%] Appl. rate [kg/ha] Example 7 Na salt of H 0.06 0.03 0.06 0.03 Zea mays 10 0 100 100 Unwanted plants: Amaranthus retroflexus 100 100 90 90 Galium aparine 98 98 70 60 Chenopodium album 100 100 100 100 These results clearly demonstrate the surprisingly high selectivity of the compound according to the invention and its excellent herbicidal action.

Claims (4)

24 O.Z. 0050/42042 We claim:

1. N-[ (1, 3, 5-Triazin-2-yl)aminocarbonyl]-benzenesulfonamides of the formula I where Rl is methyl or ethyl, R2 is halogen, Ci-C3-alkylsulfony1, trifluoromethyl or 2-methoxyethoxy and R3 is hydrogen, methyl, ethyl, methoxy, ethoxy, fluorine or chlorine, and agriculturally useful salts thereof.

2. N-[ (1, 3, 5-Triazin-2-yl)aminocarbonyl]-benzenesulfonamides of the formula I, R2 denoting chlorine.

3. A process for the manufacture of N-[(l,3,5-triazin-2-yl)amino- carbonyllbenzenesulfonamides of the formula I as set forth in claim 1, wherein a sulfonyl isocyanate II is reacted in conventional manner in an inert organic solvent with approximately the stoichiometric amount of a 2-amino-l, 3, 5-triazine derivative III

4. A process for the manufacture of N-[(l,3, 5-triazin-2-yl)amino- carbonyl]-benzenesulfonamides of the formula I as set forth in claim 1, wherein a carbamate of the formula IV is reacted in conventional manner in an inert organic solvent at from 0 to 120°C with approximately the stoichiometric amount of a 2-amino-l, 3, 5-triazine III. 102075/3 25 O . Z . 0050/42042 A process for the manufacture of N-[ ( 1 , 3 , 5-triazin-2-yl)amino-carbonyl ]-benzenesul fonamides of the formula I as set forth in claim 1 , wherein a corresponding sulfonamide of the formula V is reacted in conventional manner in an inert organic solvent with phenylcarbamate VI A process for the manufacture of N-[ ( 1 , 3 , 5-tr i azin-2-y 1 ) ami no carbonyl ]-benzenesul fonamides of the formula I as set forth i claim 1 , wherein a corresponding sulfonamide of the formula V is reacted in conventional manner in an inert organic solvent with an isocyanate of the formula VII A process for the manufacture of salts of compounds I as set forth in claim 1 , wherein a compound of the formula I as set forth in claim 1 is deprotonated in conventional manner in water or an inert organic solvent with a base. Herbicidal composition containing an N-[(l,3,5-triazin-2-yl)amino- carbony 1 ]-benzenesulfonamide of the formula I as set forth in claim 1 , or a salt thereof, and conventional carriers. A process for combating the growth of unwanted plants, wherein a herbicidally effective amount of an N— ( 1 , 3, 5-tr i azin-2-y I ) ami no- carbonyl ]-benzenesul fonamide of the formula I as set forth in claim 1 , or a salt thereof, is allowed to act on the plants and/or their habitat. For the Applicants „ ir_, OR. REINH0LD C0HN AND PARTNERS By: