WO1996010566A1

WO1996010566A1 - Substituted phenylaminosulphonyl ureas as herbicides

Info

Publication number: WO1996010566A1
Application number: PCT/EP1995/003709
Authority: WO
Inventors: Johannes R. Jansen; Mark Wilhelm Drewes; Ernst R. F. Gesing; Hans-Jochem Riebel; Markus Dollinger; Hans-Joachim Santel
Original assignee: Bayer Aktiengesellschaft
Priority date: 1994-10-04
Filing date: 1995-09-21
Publication date: 1996-04-11
Also published as: AU3608595A; DE4435470A1

Abstract

The invention relates to novel substituted phenylaminosulphonyl ureas of the formula (I) in which A may be N or CH, Q may be O or S, R?1 and R2¿ are mutually independently e.g. C¿1?-C4 alkyl or C1-C4 alkoxy, R?3¿ may be H, halogen, C¿1?-C4 alkyl or C1-C4 alkoxy, R?4 and R5¿ may be individually C¿1?-C6 alkyl or together C2-C5 alkanediyl, and R?6¿ may be C¿1?-C6 alkyl, and salts of compounds of formula (I), a process for producing the novel compounds and their use as herbicides.

Description

SUBSTITUTED PHENYLAMINOSULFONYL HARVES AS HERBICIDES

The invention relates to novel substituted phenylaminosulfonylureas, to a process for their preparation and to their use as herbicides.

It is already known that certain substituted phenylaminosulfonylureas such as e.g. the compounds 1- [2- (1,1-dimethoxyethyl) phenylsulfamoyl] -3- (4-methyl-6-methoxy-1,3,5-triazin-2-yl) urea and 1- [ 2- (1,3-dioxolan-2-yl-methyl) -phenylsulfamoyl] -3- (4-methyl-6-methoxy-1,3,5-triazin-2-yl) -urea, have herbicidal properties (see EP-A 184122). However, these compounds have not gained any significant importance. There have now been the new substituted phenylaminosulfonylureas of the general formula (I),

in which

A is nitrogen, CH or C-halogen, Q is oxygen, sulfur, SO or SO ₂ ,

R ^{1 is} hydrogen, halogen or each optionally substituted by halogen or C ₁ -C ₄ alkoxy-substituted alkyl, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino or dialkylamino each having 1 to 4 carbon atoms in the individual alkyl groups, R ^{2 is} halogen or represents in each case optionally halogen or C ₁ -C ₄ -alkoxy-substituted alkyl, alkoxy, alkylthio, alkylsulfinyl, alkyl- is sulfonyl, alkylamino or dialkylamino having in each case 1 to 4 carbon atoms in the individual alkyl groups,

R ^{3 represents} hydrogen, halogen or represents in each case optionally halogen or C ₁ -C ₄ -alkoxy-substituted alkyl, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl or alkoxycarbonyl having in each case 1 to 4 carbon atoms in the individual alkyl groups,

R ^{4 is} individually alkyl which is optionally substituted by halogen or C ₁ -C ₄ -alkoxy and has 1 to 6 carbon atoms,

R ^{5 is} individually alkyl optionally substituted by halogen or C ₁ -C ₄ alkoxy having 1 to 6 carbon atoms, or together with R ^{4 is} alkanediyl having 2 to 5 carbon atoms, and

R ^{6 is} hydrogen or optionally halogen, C, -C ₄ alkoxy, C, -

C ₄ alkylthio, C ₁ -C ₄ alkylsulfinyl or C ₁ -C ₄ alkylsulfonyl substituted alkyl having 1 to 6 carbon atoms, and salts of compounds of formula (I) found, wherein the compounds

1- [2- (1,1-Dimethoxy-ethyl) -phenylsulfamoyl] -3- (4-methyl-6-methoxy-1,3,5-triazin-2-yl) -urea and 1- [2- (2- 1,3-dioxolan-2-ylmethyl) -phenylsulfamoyl] -3- (4-methyl-6-methoxy-1,3,5-triazin-2-yl) urea (both known from EP-A 184122) are excluded by disclaimer. The novel substituted phenylaminosulfonylureas of the general formula (I) are obtained when aminoazines of the general formula (II)

in which

A, R ¹ and R ^{2 have} the abovementioned meaning, with chlorosulfonyl isocyanate, if appropriate in the presence of a diluent, and the chlorosulfonylureas of the general formula (III) formed in this reaction are reacted.

in which

A, R ¹ and R ^{2 have} the abovementioned meaning, with substituted anilines of the general formula (IV)

in which Q, R ³ , R ⁴ , R ⁵ and R ^{6 have} the abovementioned meaning, if appropriate in the presence of an acid acceptor and if appropriate in the presence of a diluent and optionally converting the thus obtained compounds of formula (I) by conventional methods into salts ,

The novel substituted phenylaminosulfonylureas of the general formula (I) are distinguished by strong and selective herbicidal activity.

The invention preferably compounds of formula (I), in which

A is nitrogen, CH or C-halogen,

Q is oxygen, sulfur, SO or SO ₂ , R ^{1 is} hydrogen, fluorine, chlorine, bromine or in each case optionally substituted by fluorine, chlorine, methoxy or ethoxy alkyl, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino or dialkylamino each having 1 to 3 carbon atoms in the individual alkyl groups, R ² for fluorine, chlorine, bromine, or in each case optionally by fluorine, chlorine,

Methoxy or ethoxy is substituted alkyl, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino or dialkylamino having in each case 1 to 3 carbon atoms in the individual alkyl groups,

R ^{3 represents} hydrogen, fluorine, chlorine, bromine, or represents in each case optionally fluorine, chlorine, methoxy or ethoxy-substituted alkyl, alkoxy, alkylthio,

Alkylsulfinyl, alkylsulfonyl or alkoxycarbonyl having in each case 1 to 3 carbon atoms in the individual alkyl groups,

R ^{4 is} individually alkyl optionally substituted by fluorine, chlorine, methoxy or ethoxy having 1 to 4 carbon atoms, R ^{5 is} individually optionally substituted by fluorine, chlorine, methoxy or ethoxy substituted alkyl having 1 to 4 carbon atoms, or together with R ^{4 is} Alkandiyl having 2 to 4 carbon atoms, and R ^{6 is} hydrogen or optionally fluoro, chloro, C ₁ -C ₃ alkoxy, C ₁ -C ₃ alkylthio, C ₁ -C ₃ alkylsulfinyl or C ₁ -C ₃ AlkylsulfonyI is substituted alkyl having 1 to 4 carbon atoms, wherein the compounds 1- [2- (1,1-dimethoxy-ethyl) phenylsulfamoyl] -3- (4-methyl-6-methoxy-1,3,5-triazine -2-yl) urea and 1 - [2- (1,3-dioxolan-2-ylmethyl) phenylsulfamoyl] -3- (4-methyl-6-methoxy-1,3,5-triazine-2 -yl) urea (both known from EP-A 184122) are excluded by disclaimer. The invention further preferably sodium, potassium,

Magnesium, calcium, ammonium, C ₁ -C ₄ -alkylammonium, di- (C ₁ -C ₄ -alkyl) -ammonium, tri- (C ₁ -C ₄ -alkyl) -ammonium, C ₅ - or C ₆ -cycloalkyl-ammonium and di- (C ₁ -C ₂ -alkyl) -benzyl-ammonium salts of compounds of the formula (I) in which A, Q, R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ^{6 have} the meaning given above preferably. The invention relates in particular to compounds of the formula (I) in which

A is nitrogen or CH,

Q is oxygen or sulfur, R ^{1 is} hydrogen, chlorine or optionally in each case by fluorine, chlorine,

Methoxy or ethoxy is substituted methyl, ethyl, methoxy, ethoxy, methylthio, ethylthio, methylamino, ethylamino or dimethylamino,

R represents chlorine or represents in each case optionally fluorine, chlorine, methoxy or ethoxy-substituted methyl, ethyl, methoxy, ethoxy, methylthio, ethylthio, methylamino, ethylamino or dimethylamino,

R ^{3 represents} hydrogen, fluorine, chlorine, bromine, or represents in each case optionally fluorine, chlorine, methoxy or ethoxy-substituted methyl, ethyl, methoxy, ethoxy, methoxycarbonyl or ethoxycarbonyl,

R ^{4 is} individually methyl or ethyl which is optionally substituted by fluorine, chlorine, methoxy or ethoxy,

R individually is each methyl or ethyl which is optionally substituted by fluorine, chlorine, methoxy or ethoxy, or together with R ^{4 is} ethane-1,2-diyl (dimethylene) or propane-1,3-diyl (trimethylene), and R ^{6 is} hydrogen or optionally substituted by fluorine, chlorine, methoxy,

Ethoxy, methylthio, ethylthio, methylsulfinyl, ethylsulfinyl, methylsulfonyl or ethylsulfonyl substituted methyl, ethyl, n- or i-propyl, wherein the compounds 1- [2- (1, 1-dimethoxy-ethyl) -phenylsulfamoyl] -3 - (4-methyl-6-methoxy-1,3,5-triazin-2-yl) urea and 1- [2- (1,3-dioxolan-2-ylmethyl) phenylsulfamoyl] -3- ( 4-methyl-6-methoxy-1,3,5-triazin-2-yl) urea (both known from EP-A 184122) are excluded by disclaimer. Especially emphasized are the compounds of the following general formula (Ia), in which Q, R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ^{6 have} the meaning given above as being particularly preferred.

The general or preferred radical definitions given above apply both to the end products of the formula (I) and correspondingly to the starting materials or intermediates required in each case for the preparation. These remainder definitions can be combined with one another as desired, that is to say also between the stated ranges of preferred compounds.

If, for example, 2-amino-4-chloro-6-methoxy-pyrimidine, chlorosulfonyl isocyanate and 2- (1,1-dimethoxy-ethyl) -aniline are used as starting materials, the course of the reaction in the process according to the invention can be outlined by the following formula scheme:

The aminoazines to be used as starting materials in the process according to the invention for the preparation of the compounds of the general formula (I) are generally defined by the formula (II). In the formula (II), A, R ¹ and R ^{2 have} or, in particular, those meanings which have already been mentioned above in connection with the description of the compounds of the formula (I) as being preferred or as being particularly preferred for A, R ¹ and R ² .

The starting materials of formula (II) are known synthetic chemicals. The substituted anilines to be used further as starting materials in the process according to the invention are generally defined by the formula (IV). In the formula (IV), Q, R ³ , R ⁴ , R ⁵ and R ⁶ preferably or in particular have those meanings which have already been mentioned above in connection with the description of the compounds of formula (I) as being preferred or particularly preferred for Q, R ³ , R ⁴ , R ⁵ and R ^{6 were} given.

The starting materials of the formula (IV) are likewise known and / or can be prepared by processes known per se (cf .. EP-A 184122; US-P 4592776; Synthesis 1983, 203-205; Liebigs Ann. Chem. 1979, 1130- 1136; manufacturing examples). The inventive method for preparing the novel compounds of

Formula (I) is preferably carried out using diluents. Suitable diluents are virtually all inert organic solvents. These include, preferably, aliphatic and aromatic, optionally halogenated hydrocarbons, such as pentane, hexane, heptane, cyclohexane, petroleum ether, gasoline, ligroin, benzene, toluene, xylene, methylene chloride,

Ethylene chloride, chloroform, carbon tetrachloride, chlorobenzene and o-dichlorobenzene, ethers such as diethyl and dibutyl ether, glycol dimethyl ether and diglycol dimethyl ether, tetrahydrofuran and dioxane, ketones such as acetone, methyl ethyl, methyl isopropyl and methyl isobutyl ketone, esters such as methyl acetate and ethyl ester, nitriles such as Acetonitrile and propionitrile, amides, e.g. Dimethylform- amide, dimethylacetamide and N-methylpyrrolidone and dimethyl sulfoxide, tetramethylene sulfone and hexamethylphosphoric triamide.

Acid acceptors which can be used in the process according to the invention are all acid binders customarily used for such reactions. Preferably, alkali metal hydroxides such as e.g. Sodium and

Potassium hydroxide, alkaline earth metal hydroxides such as calcium hydroxide, alkali metal carbonates and alcoholates such as sodium and potassium carbonate, such as sodium and Potassium tert-butylate, further aliphatic, aromatic or heterocyclic amines, for example triethylamine, trimethylamine, dimethylaniline, dimethylbenzylamine, pyridine, 1,5-diazabicyclo [4,3,0] -non-5-ene (DBN), 1,8 Diazabicyclo [5,4,0] undec-7-ene (DBU) and 1,4-diazabicyclo [2,2,2] octane (DABCO). The reaction temperatures can be varied within a substantial range in the process according to the invention. In general, one works at temperatures between -30 ° C and + 80 ° C, preferably at temperatures between - 10 ° C and + 60 ° C.

The process according to the invention is generally carried out under normal pressure. However, it is also possible to work under elevated or reduced pressure.

To carry out the process according to the invention, the particular starting materials required are generally used in approximately equimolar amounts. However, it is also possible to use one of the two components used in each case in a larger excess. The reactions are generally carried out in a suitable diluent in the presence of an acid acceptor, and the reaction mixture is stirred for several hours at the temperature required in each case. The workup is carried out in the inventive method in each case by customary methods (see the preparation examples). Salts may optionally be prepared from the compounds of the general formula (I) according to the invention. Such salts are obtained in a simple manner by customary salt formation methods, for example by dissolving or dispersing a compound of formula (I) in a suitable solvent, e.g. Methylene chloride, acetone, tert-butyl methyl ether or toluene, and addition of a suitable base. The salts can then - be isolated by concentration or suction - optionally after prolonged stirring.

The active compounds of the invention may e.g. used in the following plants:

Dicotyledonous weeds of the genera: Sinapis, Lepidium, Galium, Stellaria, Matricaria, Anthemis, Galinsoga, Chenopodium, Urtica, Senecio, Amaranthus,

Portulaca, Xanthium, Convolvulus, Ipomoea, Polygonum, Sesbania, Ambrosia, Cirsium, Carduus, Sonchus, Solanum, Rorippa, Rotala, Lindernia, Lamium, Veronica, Abutilon, Emex, Datura, Viola, Galeopsis, Papaver, Centaurea, Trifolium, Ranunculus, Taraxacum.

Dicotyledonous cultures of the genera: Gossypium, Glycine, Beta, Daucus, Phaseolus, Pisum, Solanum, Linum, Ipomoea, Vicia, Nicotiana, Lycopersicon, Arachis,

Brassica, Lactuca, Cucumis, Cucurbita.

Monocotyledonous weeds of the genera: Echinochloa, Setaria, Panicum, Digitaria, Phleum, Poa, Festuca, Eleusine, Brachiaria, Lolium, Bromus, Avena, Cyperus, Sorghum, Agropyron, Cynodon, Monochoria, Fimbristylis, Sagittaria, Eleocharis, Scirpus, Paspalum, Ischaemum , Sphenoclea, Dactyloctenium, Agrostis,

Alopecurus, Apera.

Monocotyledonous cultures of the genera: Oryza, Zea, Triticum, Hordeum, Avena, Seeale, Sorghum, Panicum, Saccharum, Pineapple, Asparagus, Allium.

However, the use of the active compounds according to the invention is by no means restricted to these genera, but extends in the same way to other plants.

The compounds are useful depending on the concentration for total weed control e.g. on industrial and railway tracks and on paths and squares with and without tree cover. Similarly, the compounds for weed control in permanent crops, e.g. Forestry, ornamental, fruit, wine,

Citrus, nut, banana, coffee, tea, gum, oil palm, cocoa, berry fruit and hop plants, on ornamental and sports turf and pasture and for selective weed control in annual crops.

The compounds of the formula (I) according to the invention are particularly suitable for the selective control of dicotyledonous weeds in monocots and dicots

Cultures, both pre-emergence and post-emergence.

The active compounds can be converted into the customary formulations, such as solutions, emulsions, wettable powders, suspensions, powders, dusts, pastes, soluble powders, granules, suspension-emulsion concentrates, active ingredient Concerning natural and synthetic substances as well as the finest encapsulation in polymeric substances.

These formulations are prepared in a known manner, for. B .. by mixing the active compounds with extenders, ie liquid solvents and / or solid carriers, optionally using surface-active

Agents, ie emulsifiers and / or dispersants and / or foam-forming agents.

In the case of using water as an extender, e.g. also organic solvents can be used as auxiliary solvents. Suitable liquid solvents are essentially: aromatics, such as xylene, toluene, or alkylnaphthalenes, chlorinated aromatics and chlorinated aliphatic hydrocarbons, such as chlorobenzenes, chloroethylenes or methylene chloride, aliphatic hydrocarbons, such as cyclohexane or paraffins, e.g. Petroleum fractions, mineral and vegetable oils, alcohols such as butanol or glycol and their ethers and esters, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone, strongly polar solvents such as dimethylformamide and dimethyl sulfoxide, and water.

Suitable solid carriers are:

e.g. Ammonium salts and ground natural minerals, such as kaolins, clays, talc, chalk, quartz, attapulgite, montmorillonite or diatomaceous earth, and ground synthetic minerals, such as fumed silica, alumina and silicates, as solid carriers for granules are suitable: e.g. crushed and fractionated natural rocks such as calcite, marble, pumice, sepiolite, dolomite and synthetic granules of inorganic and organic flours and granules of organic material such as sawdust, coconut shells, corn cobs and tobacco stalks; suitable emulsifiers and / or foam formers are: e.g. nonionic and anionic emulsifiers, such as polyoxyethylene fatty acid esters, polyoxyethylene fatty alcohol ethers, e.g. Alkylaryl polyglycol ethers, alkylsulfonates, alkyl sulfates, arylsulfonates and protein hydrolysates; suitable dispersants are: e.g. Lignin-sulphite liquors and methylcellulose.

It can be used in the formulations adhesives such as carboxymethylcellulose, natural and synthetic powdery, granular or latex-like polymers, such as gum arabic, polyvinyl alcohol, polyvinyl acetate, and natural phospholipids such as cephalins and lecithins and synthetic phospholipids. Other additives may be mineral and vegetable oils.

Dyes such as inorganic pigments, e.g. Iron oxide, titanium oxide, ferrocyan blue and organic dyes such as alizarin, azo and metal phthalocyanine dyes and trace nutrients such as salts of iron, manganese, boron, copper,

Cobalt, molybdenum and zinc are used.

The formulations generally contain between 0 and 95% by weight of active ingredient, preferably between 0.5 and 90%.

The active compounds according to the invention can be used as such or in their formulations also in admixture with known herbicides for controlling weeds, ready-to-use formulations or tank mixes being possible.

For the mixtures, known herbicides are suitable, for example anilides, eg e. Diflufeni can and Propani l; Arylcarboxylic acids, such. Dichloro-picolinic acid, dicamba and picloram; Aryloxyalkanoic acids, e.g. 2,4-D,

2,4-DB, 2,4-DP, fluroxypyr, MCPA, MCPP and triclopyr; Aryloxyphenoxyalkanoic acid esters, e.g. Diclofop-methyl, fenoxaprop-ethyl, fluazifop-butyl, haloxy-pent-methyl and quizalofop-ethyl; Azinones, such as Chloridazon and norflurazon; Carbamates, such as e.g. Chlorpropham, Desmedipham, Phenmedipham and Propham; Chloroacetanilides, e.g. Alachlor, acetochlor, butachlor, metazochlor, metolachlor, pretilachlor and propachlor; Dinitroanilines, e.g. Oryzalin, pendimethalin and trifluralin; Diphenyl ethers, e.g. Acifluorfen, bifenox, fluoroglycofen, fomesafen, halosafen, lactofen and oxyfluorfen; Ureas, such as e.g. Chlortoluron, diuron, fluometuron, isoproturon, linuron and methabenzthiazuron; Hydroxylamines, such as e.g. Alloxydim, clethodim, cycloxydim,

Sethoxydim and tralkoxydim; Imidazolinones such as imazethapyr, imazamethabenz, imazapyr and imazaquin; Nitriles such as bromoxynil, dichlobenil and ioxynil; Oxyacetamides, such as mefenacet; Sulfonylureas such as amidosulfuron, bensulfuron-methyl, chlorimuron-ethyl, chlorosulfuron, cinosulfuron, metsulfuron-methyl, nicosulfuron, primisulfuron, pyrazosulfuron-ethyl, thif- forsulfuron-methyl, triasulfuron and tribenuron-methyl; Thiolcarbamates such as butylates, cycloates, dialkyls, EPTC, esprocarb, molinates, prosulfocarb, thiobencarb and triallates; Triazines such as atrazine, cyanazine, simazine, simetryne, terpene butryne and terbutylazine; Triazinones such as hexazinone, metamitron and metribuzin; Others such as aminotriazole, benfuresates, bentazones, cinmethylin, clomazones, clopyralid, difenzoquat, dithiopyr, ethofumesates, fluorochloridones, glufosinates, glyphosates, isoxaben, pyridates, quinchlorac, quinmerac, sulphosates and tridiphanes.

A mixture with other known active ingredients, such as fungicides, insecticides, acaricides, nematicides, bird repellents, plant nutrients and soil conditioners is also possible.

The active compounds can be used as such, in the form of their formulations or the use forms prepared therefrom by further dilution, such as ready-to-use solutions, suspensions, emulsions, powders, pastes and granules. The application is done in the usual way, e.g. by pouring, spraying, spraying, sprinkling.

The active compounds according to the invention can be applied both before and after emergence of the plants. They can also be incorporated into the soil before sowing.

The amount of active ingredient used can vary within a substantial range. It depends essentially on the type of effect desired. In general, the application rates are between 10 g and 10 kg of active ingredient per hectare of soil surface, preferably between 50 g and 5 kg per ha.

The preparation and the use of the active compounds according to the invention are evident from the following examples.

Preparation Examples: Example 1

0.6 g (3.8 mmol) of 2-amino-4,6-dimethoxy-pyrimidine are added with stirring to a cooled to 0 ° C solution of 0.5 g (3.5 mmol) of chlorosulfonyl isocyanate in 10 ml of methylene chloride and the mixture is stirred for 30 minutes at 20 ° C. Then, 0.73 g (3.5 mmol) of 2-methyl-2- (2-amino-3-ethyl-phenyl) -1,3-dioxolane and 0.53 g (5.25 mmol) of triethylamine, each in about 10 ml of methylene chloride - added to it and the reaction mixture is stirred for 15 hours at 20 ° C. It is then washed with 1N sodium dihydrogen phosphate solution and twice more with water, dried with sodium sulfate and filtered. The filtrate is concentrated in a water-jet vacuum, the residue digested with ethanol and the resulting crystalline product is isolated by suction.

This gives 0.7 g (43% of theory) of N- (4,6-dimethoxy-pyrimidin-2-yl) -N '- [2- (2-methyl-1,3-dioxolan-2-yl)] 6-ethyl-phenyl-amino-sulfonyl] -urea of melting point 165 ° C.

Example 2

0.51 g (3.3 mmol) of 2-amino-4,6-dimethoxy-pyrimidine are added with stirring to a cooled to 0 ° C solution of 0.43 g (3 mmol) of chlorosulfonyl isocyanate in

10 ml of methylene chloride and the mixture is 30 minutes at 20 ° C. touched. Then, 0.8 g (3 mmol) of 2-ethyl-2- (2-amino-3-ethyl-phenyl) -1,3-dithiane and 0.45 g (4.5 mmol) of triethylamine are added, each in approx. 10 ml of methylene chloride - added to it and the reaction mixture is stirred for 15 hours at 20 ° C. It is then washed with 1N sodium dihydrogen phosphate solution and with water, dried with sodium sulfate and filtered. The filtrate is concentrated in a water jet vacuum, the residue digested with petroleum ether and the resulting crystalline product is isolated by suction.

0.9 g (57% of theory) of N- (4,6-dimethoxypyrimidin-2-yl) -N '- [2- (2-ethyl-1,3-dithian-2-yl)] are obtained. 6-ethyl-phenyl-amino-sulfonyl] -urea of melting point 179 ° C.

Analogously to Examples 1 and 2 and according to the general description of the preparation process according to the invention, it is also possible, for example, to prepare the compounds of the formula (I) listed in Table 1 below.

Starting materials of the formula (IV):

Example (IV-1)

2.3 g (14 mmol) of 2-acetyl-6-ethyl-aniline are dissolved in 40 ml of ethylene glycol and at 20 ° C with stirring 4J g (37 mmol) of chloro-trimethylsilane are added dropwise. The mixture is stirred for 20 hours at 20 ° C, then diluted with diethyl ether, washed twice with saturated sodium bicarbonate solution, dried with sodium sulfate and filtered. The filtrate is concentrated and the residue is purified by column chromatography (hexane / ethyl acetate, vol. 9: 1, silica gel).

1.1 g (38% of theory) of 2-methyl-2- (2-amino-3-ethylphenyl) -1,3-dioxolane are obtained as an amorphous product.

Example (IV-2)

3.0 g (17 mmol) of 2-ethyl-6-propionyl-aniline are dissolved in 30 ml of methylene chloride and, at 20 ° C., 5.5 g (51 mmol) of propane-1,3-dithiol and 9.6 g ( 68 mmol) of boron trifluoride etherate. The mixture is stirred for 20 hours at 20 ° C, then diluted with diethyl ether and stirred with 10% sodium hydroxide solution. The organic phase is then washed with water, with Dried sodium sulfate and filtered. The filtrate is concentrated and the residue is purified by column chromatography (methylene chloride / silica gel). This gives 2.0 g (44% of theory) of 2-ethyl-2- (2-amino-3-ethyl-phenyl) -1,3-dithiane as an amorphous product.

Application Examples: Example A

Post-emergence test

Solvent: 5 parts by weight of acetone

Emulsifier: 1 part by weight of alkylaryl polyglycol ether

To prepare a suitable preparation of active compound, 1 part by weight of active compound is mixed with the stated amount of solvent, the indicated amount of emulsifier is added and the concentrate is diluted with water to the desired concentration. With the preparation of active compound is injected test plants, which have a height of 5 - 15 cm, so that the particular desired amounts of active ingredient per unit area are applied. The concentration of the spray mixture is chosen so that in 2000 1 water / ha, the respective desired amounts of active ingredient are applied. After three weeks, the degree of damage of the plants is rated in% damage in comparison to the development of the untreated control.

It means:

0% = no effect (like untreated control)

100% = total annihilation

In this test, for example, the compound according to Preparation Example 3 exhibits very good compatibility with crop plants, such as e.g. Wheat, strong

Action against weeds. The same applies to the compounds according to Preparation Examples 1, 5, 7, 8J0, 15, 21, 22, 41, 47 and 48 (see Table A).

Example B

Pre-emergence test

Solvent: 5 parts by weight of acetone

Emulsifier: 1 part by weight of alkylaryl polyglycol ether To prepare a suitable preparation of active compound, 1

Part by weight of active compound with the stated amount of solvent, add the indicated amount of emulsifier and dilute the concentrate with water to the desired concentration.

Seeds of the test plants are sown in normal soil. After 24 hours, the soil is doused with the preparation of active ingredient. It is advisable to keep the amount of water per unit area expediently constant. The concentration of active ingredient in the preparation does not matter, only the application rate of the active ingredient per unit area is decisive. After three weeks, the degree of damage of the plants is rated in% damage in comparison to the development of the untreated control. It means:

0% = no effect (like untreated control)

100% = total annihilation

In this test, for example, the compound according to Preparation Example 3 exhibits very good compatibility with crop plants, such as e.g. Cotton, strong activity against weeds (see Table B-1). Further, e.g. the

Compounds according to Preparation Examples 5, 8, 10, 11, 13, 16, 18, 20 and 31 with excellent tolerance to soybean very good activity against weeds (see Table B-2).

Claims