WO1995032193A1

WO1995032193A1 - Substituted thiadiazolines used as herbicides

Info

Publication number: WO1995032193A1
Application number: PCT/EP1995/001789
Authority: WO
Inventors: Andreas Lender; Markus Dollinger; Hans-Joachim Santel
Original assignee: Bayer Aktiengesellschaft
Priority date: 1994-05-24
Filing date: 1995-05-11
Publication date: 1995-11-30
Also published as: AU2526995A; DE4418066A1

Abstract

The invention relates to novel substituted thiadiazolines of general formula (I) in which R?1, R2 and R3¿ have the meanings given in the description, process for producing them and their use as herbicides.

Description

HERBICIDE SUBSTITUTED THIADIAZOLINE

The invention relates to new substituted thiadiazolines, processes for their preparation and their use as herbicides.

It is already known that certain thiadiazolines, such as, for example, the compound 2-methylimino-3-benzyl-5- (3-chlorophenyl) -Δ ⁴ -l, 3,4-thiadiazoline, have herbicidal properties (cf. DE -A 2717742 / US-P 4020078; see also DE-A 4218157 / WO-A 93/24474). However, the effectiveness of the previously known compounds is not entirely satisfactory in all areas of application, in particular in the case of low amounts and concentrations.

The new substituted thiadiazolines of the general formula (I) have now been found

in which

R ¹ for hydrogen, cyano, nitro, halogen or for a radical of the series C ₁ -C ₆ -alkyl, C _j -C ₈ -alkoxy, Ci-C ₆ -alkylthio, C _r C ₆ -alkylsulfionyl, optionally substituted by halogen or C _r C ₆ alkylsulfonyl, R ^{2 represents} C _r C ₆ alkyl and

Substituted R ³ represents hydrogen or represents a respectively optionally halogen, cyano, C _j -C ₈ -alkyl-carbonyl, C _r C ₆ alkoxy-carbonyl or di- (C ₁ -C ₄ alkyl) amino carbonyl radical the series is C _r C ₆ alkyl, C ₂ -C ₆ alkenyl or C ₂ - C ₆ alkynyl,

R ³ furthermore represents an optionally substituted by halogen radical from the series C, -C ₆ -alkyl carbonyl, C ₂ -C ₆ -alkenyl-carbonyl, -C-C ₆ -alkoxy-carbonyl, -C-C ₆ -alkylthio-carbonyl , Di- (C ₁ -C ₄ -alkyl) -amino-carbonyl or C, -C ₆ -alkyl-sulfonyl,

R ³ furthermore represents C ₃ -C ₆ cycloalkyl, C ₃ -C ₆ cycloalkyl-C ₁ -C ₄ -al - yl or C ₅ -C each optionally substituted by halogen or C ₁ -C ₄ alkyl ₆ -cycloalkenyl, or

R continues for an in each case optionally substituted by nitro, cyano, halogen, C - ₄ alkoxy or Cι-C ₄ haloalkoxy sub-substituted C ₄ alkyl, C ₁ -C ₄ haloalkyl, _C] -C radical from the series phenyl, Phenyl carbonyl, phenoxycarbonyl, phenylsulfonyl or phenyl-C ₁ -C ₄ -alkyl,

where the compounds 2-methylimino-3- (4-benzyloxy-benzyl) -5- (3-methyl-phenyl) - Δ ⁴ - 1, 3,4-thiadiazoline and 2-methylimino-3- (4-benzyloxy-benzyl) - 5- (3-chlorophenyl) - Δ ⁴ -l, 3,4-thiadiazoline - known from DE-OS 2717742 US-P 4020078 - and the compounds 2-methylimino-3- (4-methoxy-benzyl) -5- (3-trifluoromethyl-phenyl) -Δ ⁴ - l, 3,4-thiadiazoline, 2-methylimino-3- (3-methoxy-benzyl) -5- (4-fluorophenyl) -Δ ⁴ -l , 3,4-thiadiazoline and 2-methylimino-3- (4-memoxy-benzyl) -5- (4-fluorophenyl) -Δ ⁴ -l, 3,4-thiadiazoline - known from DE-A 4218157 WO- A 93/24474 - are excluded by disclaimer.

The new substituted thiadiazolines of the general formula (I) are obtained if

(a) thiadiazoles of the general formula (II)

in which

1

R and R have the meanings given above,

with substituted benzyl halides of the general formula (HI)

in which

R ^{3 has} the meaning given above and

X represents halogen,

if appropriate in the presence of a diluent and if appropriate in the presence of a reaction auxiliary,

or if you

(b) thiadiazolines of the general formula (I) in which R and R have the meanings given above and R is hydrogen,

with electrophilic compounds of the general formula (IV)

X-R- (IV)

in which R and X have the meanings given above,

if appropriate in the presence of a diluent and if appropriate in the presence of a reaction auxiliary.

The new substituted thiadiazolines of the general formula (I) are notable for strong and selective herbicidal activity.

Surprisingly, the compounds of the formula (I) according to the invention, with very good tolerance to crop plants, such as, for example, maize, have a considerably stronger action against a number of problem weeds than the known compound 2-methylimino-3-benzyl-5- (3-chlorophenyl) - Δ ⁴ -l, 3,4-thiadiazoline, which is a similar active ingredient with the same direction of action.

The invention preferably relates to compounds of the formula (I) in which

R ¹ represents hydrogen, cyano, nitro, fluorine, chlorine, bromine or represents in each case if appropriate substituted by fluorine and / or chlorine-substituted C ₁ -C ₄ alkyl, C ^ - alkoxy, C, -C ₄ alkylthio, C _{r is} C ₄ alkylsulfonyl or C _r C ₄ alkylsulfonyl,

R ^{2 represents} C _r C ₄ alkyl and

R ^{3 is} hydrogen or is optionally substituted by fluorine, chlorine, cyano, C ₁ -C ₄ alkylcarbonyl, C, -C ₄ alkoxycarbonyl or di (C ₁ -C ₃ alkyl) aminocarbonyl substituted radical of the series C ₁ -C ₅ alkyl, C ₂ -C ₅ alkenyl or C ₃ -C ₅ alkynyl,

R ³ furthermore sub¬ stituted for an in each case optionally substituted by fluorine / or chlorine, and the rest of the series of C, -C ₅ alkyl-carbonyl, C ₂ -C ₅ -alkenyl-carbonyl, CC ₅ -alkoxy-carbonyl, Cι-C ₅ -Alkylthio-carbonyl, di- (C _r C ₃ -alkyl) -amino-carbonyl or C _] -C ₅ -alkyl-sulfonyl, R ³ furthermore represents a respectively optionally substituted by fluorine, chlorine or Cι-C ₃ - alkyl-substituted radical from the group C ₃ -C ₆ cycloalkyl, C ₃ -C ₆ cycloalkyl C ₁ - C ₃ alkyl or C ₅ -C ₆ -cycloalkenyl, or

R ³ furthermore represents a respectively optionally substituted by nitro, cyano, fluorine, chlorine, bromine, C _j -C ₃ alkyl, trifluoromethyl, C, -C ₃ alkoxy, difluoromethoxy or trifluoromethoxy-substituted radical from the series phenyl, phenylcarbonyl, phenoxy - carbonyl, phenylsulfonyl or phenyl-C _j -C ₃ -alkyl,

where the compounds 2-methylimino-3- (4-benzyloxy-ben__yl) -5- (3-methyl-phenyl) - Δ ⁴ - 1, 3,4-thiadiazoline and 2-methylimino-3- (4-benzyloxy-benzyl) - 5- (3-chlorophenyl) - Δ ⁴ -l, 3,4-thiadi__zolin - known from DE-OS 2717742 / US-P 4020078 - and the compounds 2-methylimino-3- (4-methoxy-benzyl ) -5- (3-trifluoromethyl-phenyl) -Δ ⁴ - l, 3,4-thiadiazoline, 2-methylimino-3- (3-methoxy-benzyl) -5- (4-fluorophenyl) -Δ ⁴ - l, 3,4-thiadiazoline and 2-methylimino-3- (4-methoxy-benzyl) -5- (4-fluorophenyl) -Δ ⁴ -l, 3,4-thiadiazoline - known from DE-A 4218157 / WO-A 93/24474 - are excluded by disclaimers.

The hydrocarbon radicals listed in the radical definitions, such as alkyl, alkenyl and alkynyl, are - also in combination with other atoms or groups of atoms, e.g. in alkoxy or in phenylalkyl, in each case straight-chain or branched, even if this is not expressly mentioned.

The invention relates in particular to the compounds of the formula (Ia) and of the formula (Ib)

(la)

in which each

R ^{1 represents} hydrogen, cyano, nitro, fluorine, chlorine, bromine or methyl, ethyl, n- or i-propyl optionally substituted by fluorine and / or chlorine,

R represents methyl, ethyl, n- or i-propyl and

R ^{3 represents} hydrogen or methyl, ethyl, n- or i-propyl, n-, i- or s-butyl, propenyl, which is optionally substituted by fluorine, chlorine, cyano, acetyl, propionyl, methoxycarbonyl, ethoxycarbonyl or dimethylaminocarbonyl, Butenyl, propynyl or butynyl,

R ³ also for each optionally substituted by fluorine and / or chlorine

Acetyl, propionyl, methoxycarbonyl, ethoxycarbonyl, ethenylcarbonyl,

Propenylcarbonyl, butenylcarbonyl, methylsulfonyl, ethylsulfonyl, n- or i-

Propylsulfonyl, n-, i-, s- or t-butylsulfonyl or dimethylaminocarbonyl,

R ³ furthermore represents cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, cyclobutylmethyl, cyclopentylmethyl, cyclohexylmethyl, cyclopentenyl or cyclohexenyl, each optionally substituted by fluorine, chlorine, bromine, methyl or ethyl, or

R ³ furthermore represents phenyl, phenylcarbonyl, in each case optionally substituted by nitro, cyano, fluorine, chlorine, bromine, methyl, ethyl, n- or i-propyl, trifluoromethyl, methoxy, ethoxy, n- or i-propoxy, difluoromethoxy or trifluoromethoxy , Phenoxycarbonyl or benzyl, where the compounds 2-methylimino-3- (4-benzyloxy-benzyl) -5- (3-methyl-phenyl) - Δ ⁴ - 1, 3, 4-thiadiazoline and 2-methylimino-3- (4-benzyloxy-benzyl) - 5- (3-chlorophenyl) - Δ ⁴ -l, 3,4-thiadiazoline - known from DE-OS 2717742 US-P 4020078 - and the compound £ ___- methylimino-3- (4-methoxy-ben__yl ) -5- (3-trifluoromethyl-phenyl) -Δ ⁴ -l, 3,4-thiadiazoline, 2-methylimino-3 - (3-methoxy-benzyl) -5- (4-fluorophenyl) -Δ ⁴ - 1, 3, 4-thia-diazoline and 2-methylimino-3 - (4-methoxy-benzyl) -5- (4-fluorophenyl) -Δ ⁴ - 1, 3, 4-thia-diazoline - known from DE -A 4218157 / WO-A 93/24474 - are excluded by disclaimers.

The general definitions given above or those specified in preferred ranges 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 radical definitions can be combined with one another as desired, that is to say also between the specified ranges of preferred compounds.

If, for example, 2- (3-chlorophenyl) -5-methylamino-l, 3,4-thiadiazole and 3-ethoxy-benzyl chloride are used as starting materials, the course of the reaction in the process according to the invention can be outlined using the following formula:

Formula (II) provides a general definition of the thiadiazoles to be used as starting materials in process (a) according to the invention for the preparation of the compounds of the general formula (I). In the formula (II), R ¹ and R ² preferably or in particular have those meanings which have already been mentioned above in connection with the description of the compounds of the formula (I) as preferred or as particularly preferred for R ¹ and R ^{2 were} specified. The starting materials of the formula (II) are known and / or can be prepared by processes known per se (cf. US-P 3522267, DE-A 1816696, DE-A 2100057, DE-A 2231664, DE-A 2247330, DE-A 2440922, DE-A 2541115, DE-A 2545142, US-P 4028090, US-P 4092148, US-P 4283543, US-P 4686294, EP-A 296864, WO-A 93/24474).

Formula (III) provides a general definition of the substituted benzyl halides to be used as starting materials in process (a) according to the invention for the preparation of the compounds of the general formula (I). In the formula (DI), R ³ preferably or in particular has the meaning which has already been given above in connection with the description of the compounds of the formula (I) as preferred or as particularly preferred for R ³ ; X preferably represents fluorine, chlorine, bromine or iodine, in particular chlorine, bromine or iodine.

The starting materials of the formula (III) are known and / or can be prepared by processes known per se (cf. J. Org. Chem. 46 (1981), 3029-3035; DE-OS 2556474; US-P 4221919) .

Formula (IV) provides a general definition of the electrophilic compounds to be used as starting materials in process (b) according to the invention for the preparation of the compounds of the general formula (I). In the formula (IV), R ³ preferably or in particular has the meaning which has already been given above in connection with the description of the compounds of the formula (I) as preferred or as particularly preferred for R ³ ; X preferably represents fluorine, chlorine, bromine or iodine, in particular chlorine, bromine or iodine.

The starting materials of the formula (IV) are known synthetic chemicals.

Suitable diluents for carrying out processes (a) and (b) according to the invention are the customary organic solvents. These include in particular aliphatic, alicyclic or aromatic, optionally halogenated hydrocarbons, such as, for example, gasoline, benzene, toluene, xylene, chlorobenzene, dichlorobenzene, petroleum ether, hexane, cyclohexane, dichloromethane, chloroform, tetrachloromethane; Ethers such as diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran or ethylene glycol dimethyl or diethyl ether; Ketones such as acetone, butanone or Methyl isobutyl ketone; Nitriles such as acetonitrile, propionitrile or benzonitrile; Amides, likeN _. N-dimethylformamide, N, N-dimethylacetamide, N-methylformanilide, N-methylpyrrolidone or hexamethylphosphoric triamide; Esters such as methyl acetate or ethyl acetate, sulfoxides such as dimethyl sulfoxide, alcohols such as methanol, ethanol, n- or i-propanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, their mixtures with water or pure water.

Processes (a) and (b) according to the invention are optionally carried out in the presence of a suitable reaction auxiliary. All conventional inorganic or organic bases are suitable as such. These include, for example, alkaline earth metal or alkali metal hydrides, hydroxides, amides, alcoholates, acetates, carbonates or hydrogen carbonates, such as, for example, sodium hydride, sodium amide, sodium methylate, sodium ethylate, potassium tert-butoxide, sodium hydroxide, potassium hydroxide, ammonium hydroxide , Sodium acetate, potassium acetate, calcium acetate, ammonium acetate, sodium carbonate, potassium carbonate, potassium hydrogen carbonate, sodium hydrogen carbonate or ammonium carbonate and basic organic nitrogen compounds, such as trimethylamine, triethylamine, tributylamine, N, N-dimethylaniline, pyridine, N-methylpiperidine, N, N -Dimethylaminopyridine, diazabicyclooctane (DABCO), diazabicyclonones (DBN) or diazabicycloundecene (DBU).

The reaction temperatures can be varied within a substantial range when carrying out processes (a) and (b) according to the invention. In general, temperatures between 0 ° C and 150 ° C, preferably at temperatures between 10 ° C and 120 ° C.

Processes (a) and (b) according to the invention are generally carried out under atmospheric pressure. However, it is also possible to work under increased or reduced pressure - generally between 0.1 bar and 10 bar.

To carry out processes (a) and (b) according to the invention, the starting materials required in each case 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, if appropriate in the presence of a Reaction auxiliary carried out, and the reaction mixture is stirred for several hours at the required temperature. Working up is carried out in the method according to the invention in each case by customary methods (cf. the production examples).

The active compounds according to the invention can be used as defoliants, desiccants, haulm killers and in particular as weed killers. Weeds in the broadest sense are understood to mean all plants that grow up in places where they are undesirable. Whether the substances according to the invention act as total or selective herbicides depends essentially on the amount used.

The active compounds according to the invention can e.g. can be used in the following plants:

Dicotyledon weeds of the genera: Sinapis, Lepidium, Galium, Stellaria, Matricaria, Anthemis, Galinsoga, Chenopodium, Urtica, Senecio, Amaranthus, Portulaca, Xanthium, Convolvulus, Ipomoea, Polygonum, Sesbania, Ambrosia, Cirsium, Sonusum, Carduus , Rorippa, Rotala, Lindernia, Lamium, Veronica, Abutilon, Emex, Datura, Viola, Galeopsis, Papaver, Centaurea, Trifolium, Ranunculus, Taraxacum.

Dicotyledon 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, Sor¬ ghum, Agropyron, Cynodon, Monochoria, Fimbristylis, Sagittirpum, Eleocharis, Pas , Ischaemum, Sphenoclea, Dactyloctenium, Agrostis, Alopecurus, Apera.

Monocot 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.

Depending on the concentration, the compounds are suitable for total weed control, e.g. on industrial and track systems and on paths and squares with and without tree cover. The compounds for weed control in permanent crops, e.g. Forest, ornamental wood, fruit, wine, citrus, nut, banana, coffee, tea, rubber, oil palm, cocoa, berry fruit and hop plants, on ornamental and sports turf and pasture land and for selective weed control in annual crops.

The compounds of formula (I) according to the invention are particularly suitable for the selective control of monocotyledon and dicotyledon weeds in monocotyledon crops such as cereals and maize, especially in the post-emergence process.

The active ingredients 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-impregnated natural and synthetic substances and very fine encapsulations in polymeric fabrics.

These formulations are prepared in a known manner, e.g. B. by mixing the active ingredients with extenders, that is to say liquid solvents and / or solid carriers, optionally using surface-active agents, that is to say emulsifiers and / or dispersants and / or foam-generating agents.

If water is used as an extender, organic solvents can, for example, also be used as auxiliary solvents. The following are essentially suitable as liquid solvents: aromatics, such as xylene, toluene, or alkylnaphthalenes, chlorinated aromatics and chlorinated aliphatic hydrocarbons, such as chlorobenzenes, chlorethylenes or methylene chloride, aliphatic hydrocarbons, such as cyclohexane or paraffins, for example 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. The following are suitable as solid carriers:

e.g. Ammonium salts and natural rock meals, such as kaolins, clays, talc, chalk, quartz, attapulgite, montmorillonite or diatomaceous earth and synthetic rock meals, such as highly disperse silica, aluminum oxide and silicates, are suitable as solid carriers for granules: e.g. broken and fractionated natural rocks such as calcite, marble, pumice, sepiolite, dolomite and synthetic granules from inorganic and organic flours as well as granules from organic material such as sawdust, coconut shells, corn cobs and tobacco stems; as emulsifying and / or foaming agents are possible: e.g. non-ionic and anionic emulsifiers, such as polyoxyethylene fatty acid esters, polyoxyethylene fatty alcohol ethers, e.g. Alkylaryl polyglycol ethers, alkyl sulfonates, alkyl sulfates, aryl sulfonates and protein hydrolyzates; Possible dispersants are: e.g. Ligin sulfite waste liquor and methyl cellulose.

Adhesives such as carboxymethyl cellulose, natural and synthetic powdery, granular or latex-shaped polymers, such as gum arabic, polyvinyl alcohol, polyvinyl acetate, and natural phospholipids, such as cephalins and lecithins and synthetic phospholipids, can be used in the formulations. Other additives can 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 0.1 and 95 percent by weight of active compound, preferably between 0.5 and 90%.

The active compounds according to the invention, as such or in their formulations, can also be used for combating weeds, in a mixture with known herbicides, finished formulations or tank mixes being possible.

Known herbicides are suitable for the mixtures, for example anilides, such as, for example, diflufenican and propanil; Aryl carboxylic acids, such as dichloropicolinic acid, di- camba and picloram; Aryloxyalkanoic acids, such as, for example, 2.4 D, 2.4 DB, 2.4 DP, fluroxypyr, MCPA, MCPP and triclopyr; Aryloxy-phenoxy-alkanoic acid esters, such as, for example, diclofop-methyl, fenoxaprop-ethyl, fluazifop-butyl, haloxyfop-methyl and quizalofop-ethyl; Azinones such as chloridazon and norflurazon; Carbamates such as chloropropham, desmedipham, phenmedipham and propham; Chloroacetanilides, such as, for example, alachlor, acetochlor, butachlor, metazachlor, metolachlor, pretilachlor and propa-chlorine; Dinitroanilines such as oryzalin, pendimethalin and trifluralin; Diphenyl ethers such as acifluorfen, bifenox, fluoroglycofen, fomesafen, halosafen, lactofen and oxyfluorfen; Ureas such as chlorotoluron, diuron, fluometuron, isoproturon, linuron and methabenzthiazuron; Hydroxylamines such as 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, primi sulfuron, pyrazosulfuron-ethyl, thifensulfuron-methyl, triasulfuron and tribenuron-methyl; Thiol carbamates such as butylates, cycloates, dialallates, EPTC, esprocarb, molinates, prosulfocarb, thiobencarb and triallates; Triazines such as atrazine, cyanazine, simazin, simetryne, terbutryne and terbutylazine; Triazinones such as hexazinone, metamitron and metribuzin; Others such as aminotriazole, benfuresate, bentazone, cinmethylin, clomazone, clopyralid, difenzoquat, dithiopyr, ethofumesate, fluorochloridone, glufosinate, glyphosate, isoxaben, pyridate, quinchlorac, quinmerac, sulphosate and tridiphane.

A mixture with other known active compounds, such as fungicides, insecticides, acaricides, nematicides, bird repellants, plant nutrients and agents which improve soil structure, is also possible.

The active compounds can be used as such, in the form of their formulations or in the use forms prepared therefrom by further dilution, such as ready-to-use solutions, suspensions, emulsions, powders, pastes and granules. They are used in the customary manner, for example by watering, spraying, spraying or scattering. The active compounds according to the invention can be applied both before and after the plants emerge. They can also be worked into the soil before sowing.

The amount of active ingredient used can vary over a wide range. It essentially depends 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, preferably between 50 g and 5 kg per ha.

The preparation and use of the active compounds according to the invention can be seen from the examples below.

Manufacturing examples:

example 1

A mixture of 3.0 g (13 mmol) of 5- (3-chlorophenyl) -2-methylamino-l, 3,4-thiadiazole, 4.5 g (26 mmol) of 4-ethoxybenzyl chloride and 100 ml of dioxane becomes 14 Heated under reflux for hours. After cooling, it is diluted with 200 ml of hexane and filtered off. The filter cake is washed twice with 50 ml of diethyl ether and stirred for 2 hours in 25 ml of 10% methanolic potassium hydroxide solution. The product obtained in crystalline form is isolated by filtration, washed with water and dried.

2.8 g (59% of theory) of 5- (3-chlorophenyl) -3- (4-ethoxybenzyl) -2-methylimino-Δ ^4- l, 3,4-thiadiazoline of melting point 82 ° C. are obtained.

Analogously to Example 1 and in accordance with the general description of the production process according to the invention, it is also possible, for example, to prepare the compounds of the formula (I) or of the formulas (Ia) or (Ib) listed in Table 1 below.

Table 1: Examples of the compounds of the formula (I)

CH ₃ CH ₃ CH ₃ CH ₃ CH ₃ CH ₃ CH ₃ CH ₃ CH ₃ CH ₃ CH ₃ CH ₃ CH ₃ CH ₃ CH ₃ CH ₃

CH,

Table 1 - Continuation

CH,

Cl

32 Ib Cl CH, cι 101

/

-CH ₂ -CH = C

\

Cl - left

Table 1 - Continuation

R ²

CH ₃ CH ₃ CH ₃ CH ₃ CH ₃ CH ₃ CH ₃ CH ₃ CH ₃ CH ₃ CH ₃ CH ₃ CH,

CH,

The compound listed in Table 1 as Example 35 can be produced, for example, as follows:

A mixture of 14.0 g (61 mmol) of 5- (3-chlorophenyl) -2-methylamino-l, 3,4-thiadiazole, 28.5 g (121 mmol) of 4-acetoxybenzyl bromide and 500 ml of dry dioxane Heated under reflux for 3 hours. After cooling, the mixture is diluted with 500 ml of hexane and filtered off. The filter cake is washed twice with 200 ml of diethyl ether and stirred for 2 hours in 100 ml of 10% methanolic potassium hydroxide solution. The solution is poured onto 300 ml of water and the product obtained in crystalline form is isolated by filtration, washed with water and pressed onto clay.

19.7 g (96% of theory) of 5- (3-chlorophenyl) -3- (4-hydroxybenzyl) -2-methylimino-Δ ^4- l, 3,4-thiadiazoline with a melting point of 135 ° C. are obtained.

The compound listed in Table 1 as Example 37 can be produced, for example, as follows:

A solution of 2.5 g (7.5 mmol) of 5- (3-chlorophenyl) -3- (4-hydroxybenzyl) -2-methylimino-A ⁴ -l, 3,4-thiadiazoline and 1.0 g (7.9 mmol) of ethyl diisopropylamine in 100 ml of dry dichloromethane is stirred at room temperature for 10 minutes. After addition of 0.62 g (7.9 mmol) of acetyl chloride, stirring is continued for 2 hours. The solution is washed twice with 100 ml of water, dried and concentrated. The residue is stirred with petroleum ether. The product obtained in crystalline form is isolated by filtration, washed with petroleum ether and dried.

2.0 g (73% of theory) of 5- (3-chlorophenyl) -3- (4-acetoxybenzyl) -2-methylimino-Δ ^4- l, 3,4-thiadiazoline of melting point 88 ° C. are obtained.

Example of use:

In the following application example, the following connection is used for comparison:

2-Methylimino-3-benzyl-5- (3-chlorophenyl) -A ⁴ -l, 3,4-thiadiazoline (known from DE-A 2717742 / US-P 4020078).

Example A

Post emergence test

Solvent: 5 parts by weight of acetone

Emulsifier: 1 part by weight of alkylaryl polyglycol ether

To produce a suitable preparation of active compound, 1 part by weight of active compound is mixed with the stated amount of solvent, the stated amount of emulsifier is added and the concentrate is diluted with water to the desired concentration.

Test plants with a height of 5-15 cm are sprayed with the active substance preparation in such a way that the desired amounts of active substance are applied per unit area. The concentration of the spray liquor is chosen so that the desired amounts of active compound are applied in 2000 l of water / ha. After three weeks, the degree of damage to the plants is rated in% damage compared to the development of the untreated control.

It means:

0% = no effect (like untreated control)

100% = total annihilation

In this test, for example, the compounds according to Production Examples 23 and 24 show at an application rate of 250 g / ha and with very good tolerance to crop plants, such as e.g. Corn (10%), strong against weeds such as Abutilon (100%), Chenopodium (90 - 95%), Matricaria (70 - 90%) and Veronica (100%).

Claims

1. Substituted thiadiazolines of the general formula (I),

in which

R ¹ for hydrogen, cyano, nitro, halogen or for a radical of the series C ₁ -C ₆ -alkyl, C ₁ -C ₆ -alkoxy, C _r C ₆ -alkylthio, C _r C ₆ -alkylsulfinyl which is optionally substituted by halogen or C _r C ₆ alkyl sulfonyl,

R ^{2 represents} C _r C ₆ alkyl and

R ³ represents hydrogen or an optionally by halogen, cyano, C ₁ -C ₆ -alkyl-carbonyl, C, -C ₆ alkoxy-carbonyl or di- (C _j -C ₄ - alkyl) -amino-carbonyl substituted radical the series Cι-C ₆ alkyl, C ₂ - C ₆ alkenyl or C ₂ -C ₆ alkynyl,

R ³ furthermore represents in each case optionally a substitu¬ ierten by halogen radical from the series C ₁ -C ₆ -alkyl-carbonyl, C ₂ -C ₆ -alkenyl-carbonyl, C, -C ₆ alkoxy-carbonyl, Cι-C ₆ - Alkylthio-carbonyl, di- (C _r C ₄ -alkyl) -amino-carbonyl or C ₁ -C ₆ -alkyl-sulfonyl,

R ³ furthermore represents respectively optionally halogen or C, -C ₄ - alkyl-substituted C ₃ -C ₆ cycloalkyl, C ₃ -C ₆ -cycloalkyl-C ₁ -C ₄ alkyl, or

C ₅ -C ₆ cycloalkenyl, or

R ³ further for each optionally by nitro, cyano, halogen, C, -C ₄ alkyl, C _r C ₄ haloalkyl, C, -C ₄ alkoxy or C _r C ₄ -haloalkoxy-substituted radical from the series phenyl, phenylcarbonyl, phenoxycarbonyl, phenylsulfonyl or phenyl-C _] -C ₄ -alkyl,

where the compounds 2-methylimino-3- (4-benzyloxy-benzyl) -5- (3-methylphenyl) -Δ ⁴ -l, 3,4-thiadiazoline, 2-methylimino-3- (4-benzyloxy-benzyl ) -5- (3-chlorophenyl) -Δ ⁴ -l, 3,4-thiadiazoline, 2-methylimino-3- (4-methoxy-benzyl) -5- (3-trifluoromethyl-phenyl) -Δ ⁴ - 1, 3, 4-thiadiazoline ^ -Methylimino-3- (3-methoxy-benzyl) -5- (4-fluorophenyl) -Δ -l, 3,4-thiadiazoline and 2-methylimino-3- (4- methoxy-benzyl) -5- (4-fluorophenyl) -Δ ⁴ -l, 3,4-thiadiazoline are excluded.

Substituted thiadiazolines of the general formula (I) according to Claim 1, characterized in that

R ¹ for hydrogen, cyano, nitro, fluorine, chlorine, bromine or for C ₁ -C ₄ -alkyl optionally substituted by fluorine and / or chlorine, C _r C ₄ -alkoxy, C, -C ₄ -alkylthio, C _r C ₄ alkylsulfinyl or C, -C ₄ alkylsulfonyl,

R ^{2 represents} C _r C ₄ alkyl and

R represents hydrogen or a radical which is optionally substituted by fluorine, chlorine, cyano, C ₄ -C ₄ -alkyl carbonyl, C 1 -C ₄ -alkoxy-carbonyl or di- (C ₃ -C ₃ -alkyl) amino-carbonyl the series is C _j -C ^ alkyl, C ₂ -C ₅ alkenyl or C ₃ -C ₅ alkynyl,

• X •

R furthermore represents a radical of the series C _] -C ₅ alkylcarbonyl, C ₂ -C ₅ alkenylcarbonyl, C, -C ₅ alkoxycarbonyl, CC ₅ alkylthio which is optionally substituted by fluorine and / or chlorine -carbonyI, di- (C _j - C ₃ -alkyl) -amino-carbonyl or C, -C ₅ -alkyl-sulfonyl,

R ³ furthermore for one in each case optionally by fluorine, chlorine or Ci

C ₃ alkyl substituted radical of the series C ₃ -C ₆ cycloalkyl, C ₃ -C ₆ cycloalkyl-C _j -C ₃ alkyl or C ₅ -C ₆ cycloalkenyl, or R furthermore represents a radical of the series phenyl, phenylcarbonyl, phenoxycarbonyl, phenylsulfonyl or optionally substituted by nitro, cyano, fluorine, chlorine, bromine, C _r C ₃ alkyl, trifluoromethyl, C _r C ₃ alkoxy, difluoromethoxy or trifluoromethoxy Phenyl-C _] -C ₃ -alkyl,

where the compounds 2-methylimino-3- (4-benzyloxy-benzyl) -5- (3-methylphenyl) -Δ ⁴ -l, 3,4-thiadiazoline, 2-methylimino-3- (4-benzyloxy-benzyl ) -5- (3-chlorophenyl) -Δ ⁴ - 1, 3, 4-thiadiazoline, 2-methylimino-3- (4-methoxy-benzyl) -5- (3-trifluoromethyl-phenyl) -Δ ⁴ - l, 3,4-thiadiazolin_2-methylimino-3- (3-methoxy-benzyl) -5- (4-fluoro-phenyl) -Δ ⁴ - 1, 3,4-thiadiazoline and 2-methylimino-3- (4- methoxy-benzyl) -5- (4-fluorophenyl) -Δ ⁴ -l, 3,4-thiadiazoline are excluded.

Substituted thiadiazolines of the general formula (Ia)

characterized in that

R ^{1 represents} hydrogen, cyano, nitro, fluorine, chlorine, bromine or methyl, ethyl, n- or i-propyl which may be substituted by fluorine and / or chlorine,

R ^{2 represents} methyl, ethyl, n- or i-propyl and

R ^{3 represents} hydrogen or methyl, ethyl, n- or i-propyl, n-, i- or s-butyl, propenyl, which is optionally substituted by fluorine, chlorine, cyano, acetyl, propionyl, methoxycarbonyl, ethoxycarbonyl or dimethylaminocarbonyl, Butenyl, propynyl or butynyl, R ³ furthermore represents acetyl, propionyl, methoxycarbonyl, ethoxycarbonyl, ethenylcarbonyl, propenylcarbonyl, butenylcarbonyl, methylsulfonyl, ethylsulfonyl, n- or i-propylsulfonyl, n-, i-, n-, i-, s- or t-butylsulfonyl or dimethylaminocarbonyl,

R further for each optionally by nitro, cyano, fluorine, chlorine,

Bromine, methyl, ethyl, n- or i-propyl, trifluoromethyl, methoxy, ethoxy, n- or i-propoxy, difluoromethoxy or trifluoromethoxy substituted phenyl, phenylcarbonyl, phenoxy carbonyl or benzyl,

where the compounds 2-methylimino-3- (4-ben__yloxy-benzyl) -5- (3-methylphenyl) -Δ ⁴ - 1, 3, 4-thiadiazoline, 2-methylimino-3- (4-benzyloxy-benzyl ) -5- (3-chlorophenyl) -Δ ⁴ -l, 3,4-thiadiazoline, 2-methylimino-3- (4-methoxy-benzyl) -5- (3-trifluoromethyl-phenyl) -Δ ⁴ - l, 3,4-thiadiazolin2-methylimino-3- (3-methoxy-benzyl) -5- (4-fluorophenyl) -Δ ⁴ -l, 3,4-thiadiazoline and 2-methylimino-3- (4- methoxy-benzyl) -5- (4-fluorophenyl) -Δ ⁴ -l, 3,4-thiadiazoline are excluded by disclaimer.

Substituted thiadiazolines of the general formula (Ib)

characterized in that

R ^{2 represents} methyl, ethyl, n- or i-propyl and

R ^{3 represents} hydrogen or methyl, ethyl, n- or i-propyl, n- which is optionally substituted by fluorine, chlorine, cyano, acetyl, propionyl, methoxycarbonyl, ethoxycarbonyl or dimethylaminocarbonyl.

, i- or s-butyl, propenyl, butenyl, propynyl or butynyl,

R ³ furthermore represents acetyl, propionyl, methoxycarbonyl, ethoxycarbonyl, ethenylcarbonyl, propenylcarbonyl, butenylcarbonyl, methylsulfonyl, ethylsulfonyl, n- or i-propylsulfonyl, n-, i-, s-, each optionally substituted by fluorine and or chlorine - or t-butylsulfonyl or

Dimethylaminocarbonyl,

R ³ further for each optionally by nitro, cyano, fluorine, chlorine, bromine, methyl, ethyl, n- or i-propyl, trifluoromethyl, methoxy, ethoxy, n- or i-propoxy, difluoromethoxy or trifluoromethoxy substituted phenyl, phenylcarbonyl, phenoxycarbonyl or benzyl,

where the compounds 2-methylimino-3- (4-benzyloxy-benzyl) -5- (3-methylphenyl) -Δ ⁴ -l, 3,4-thiadiazoline, 2-methylimino-3- (4-benzyloxy-benzyl ) -5- (3-chlorophenyl) -Δ ⁴ - 1, 3,4-thiadiazoline, 2-methylimino-3- (4-methoxy-benzyl) -5- (3-trifluoromethyl-phenyl) -Δ ⁴ - l, 3,4-thiadiazoline ^ -Methyliπ_ino-3- (3-methoxy-benzyl) -5- (4-fluorophenyl) -Δ ⁴ -l, 3,4-thiadiazoline and 2-methylimino-3- (4th - methoxy-benzyl) -5- (4-fluorophenyl) -Δ ⁴ - 1, 3,4-thiadiazoline are excluded.

Process for the preparation of the substituted thiadiazolines of the general formula (I)

1 "3 in which R, R and R have the meanings given in claim 1,

characterized in that one

(a) thiadiazoles of the general formula (II)

in which

R and R have the meanings given above,

with substituted benzyl halides of the general formula (III)

in which

R ^{3 has} the meaning given above and

X represents halogen,

if appropriate in the presence of a diluent and, if appropriate, in the presence of a reaction auxiliary,

or that one

(b) thiadiazolines of the general formula (I) in which R ¹ and R ^{2 have} the meanings given above and R ^{3 represents} hydrogen,

with electrophilic compounds of the general formula (IV)

X-R- (IV)

in which

R> 3 and X have the meanings given above,

Process for controlling unwanted plants, characterized in that substituted thiadiazolines of the general formula (I) according to Claims 1 to 5 are allowed to act on undesired plants and / or their habitat. 7. Use of substituted thiadiazolines of the general formula (I) according to Claims 1 to 5 for combating undesirable plants.

8. A process for the preparation of herbicidal compositions, characterized in that substituted thiadiazolines of the general formula (I) according to Claims 1 to 5 are mixed with extenders and / or surface-active substances.

9. Herbicidal agents, characterized in that they contain at least one substituted thiadiazoline of the general formula (I) according to Claims 1 to 5.