CA2373429A1 - Substituted n-cyano amidines - Google Patents

Abstract

The invention relates to novel substituted N-cyano amidines of general formula (I) in which: R1 represents hydrogen or optionally substituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, aryl or alkyl aryl, and; R2 represents benzo-anellated, pyrido-anellated or thieno-anellated cycloalk(en)yl, oxacycloalk(en)yl or thiacycloalk(en)yl, whereby all cyclic and heterocyclic groupings can be substituted. The invention also relates to a method for producing the substituted N-cyano amidines and to their use as herbicides.

Description

Le A 33 707-Foreign Countries Hor/klu /NT

Substituted N-cyano-amidines The invention relates to novel substituted N-cyano-amidines, to a process for their preparation and to their use as herbicides.
It is already known that certain substituted N-cyano-guanidines have herbicidal prop-erties (cf. DE-A-2505301, US-A-4661520, US-A-4684398, US-A-4689348, J. Agric.
Food Chem. 37 (1989), 809-814). However, various aspects of the properties of the substituted N-cyano-guanidines of the prior art do not meet the high requirements for modern crop treatment agents.
This invention now provides the novel substituted N-cyano-amidines of the general formula (I), R' N ~
H
N (I) RCN
in which R' represents hydrogen or represents in each case optionally substituted alkyl, alkenyl, alkinyl, cycloalkyl, cycloalkylalkyl, aryl or arylalkyl and RZ represents in each case benzo-fused, pyrido-fused or t:hieno-fused cyclo-alk(en)yl, oxacycloalk(en)yl or thiacycloalk(en)yl, where all cyclic and hetero-cyclic groupings may be substituted.
The general formula (I) includes the E and Z configuration isomers which are possible in each case.
In the definitions, the hydrocarbon chains, such as alkyl, alkenyl or alkinyl, are in each case straight-chain or branched.

Le A 33 707-Foreign Countries Preferred substituents of the radicals listed in the formulae mentioned above and be-low are illustrated below.
Rl preferably represents hydrogen, represents optionally cyano-, halogen-, C1-C4-alkoxy-, C1-C4-alkylthio-, C1-C4-alkylsulphinyl- or C1-C4-alkyl-sulphonyl-substituted alkyl having 1 to 6 carbon atoms, represents in each case optionally halogen-substituted alkenyl or alkinyl having in each case 2 to 6 carbon atoms, represents in each case optionally cyano-, halogen- or C1-C4-alkyl-substituted cycloalkyl or cycloalkylalkyl having in each case 3 to 6 carbon atoms in the cycloalkyl groups and optionally 1 to 4 carbon atoms in the alkyl moiety, or represents in each case optionally nitro-, cyano-, halogen-, CI-C4-alkyl-, C1-C4-halogenoalkyl-, C~-C4-alkoxy- or C1-C:4-halogenoalkoxy-substituted aryl or arylalkyl having in each case 6 or 10 carbon atoms in the aryl groups and optionally 1 to 4 carbon atoms in the alkyl moiety.
R2 preferably represents in each case benzo-fused, pyrido-fused or thieno-fused cycloalk(en)yl, oxacycloalk(en)yl or thiacycloalk(en)yl from the list below, / /
O ~ S N~
I/ I/ I/ I/
,v Le A 33 707-Foreign Countries \
\ / / \ / ~
s. \ s s s ~ \ /
where all cyclic and heterocyclic groupings may preferably be substituted by one of the groupings listed below:
nitro, hydroxyl, amino, cyano, carbamoyl, thiocarbamoyl, formylamino, halo-gen, C1-CQ-alkyl, C1-C4-halogenoalkyl, C1-CQ-alkoxy, C~-C4-halogenoalkoxy, C,-C4-alkylthio, C,-C4-halogenoalkylthio, C1-C4-alkylsulphinyl, C1-CQ-halo-genoalkylsulphinyl, C1-C4-alkylsulphonyl, C~-C4-halogenoalkylsulphonyl, Cl-C4-alkylamino, di-(C,-C4-alkyl)-amino, C1-C4-alkyl-carbonyl, C1-C4-alkoxy-carbonyl, C~-C4-alkylamino-carbonyl, di-(C1-C4-alkyl)-amino-carbonyl, CI-C4-alkyl-carbonyl-amino, C1-C4-alkoxy-carbonyl-amino, CI-C4-alkyl-amino-carbonyl-amino, C~-C4-alkyl-sulphonyl-amino.
R' particularly preferably represents hydrogen, represents in each case optionally cyano-, fluorine, chlorine-, bromine-, methoxy-, ethoxy-., n- or i-propoxy-, methylthio-, ethylthio-, n- or i-propylthio-, methylsulphinyl-, ethylsulphinyl-, n- or i-propylsulphinyl-, methylsulphonyl-, ethylsulphonyl-, n- or i-propyl-sulphonyl-substituted methyl, ethyl, n- or i-propyl, n-, i-, s- or t-butyl, repre-sents in each case optionally fluorine-, chlorine- or bromine-substituted ethenyl, propenyl, butenyl, ethinyl, propinyl or butinyl, represents in each case optionally cyano-, fluorine-, chlorine-, bromine-, methyl-, ethyl-, n- or i-propyl-substituted cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclo-propylmethyl, cyclobutylmethyl, cyclopentylmethyl or cyclohexylmethyl, or represents in each case optionally nitro-, cyano-, fluorine-, chlorine-, bro-Le A 33 707-Foreign Countries mine-, methyl-, ethyl-, n- or i-propyl-, n-, i-, s- or t-butyl-, trifluoromethyl-, methoxy-, ethoxy-, n- or i-propoxy-, difluoromethoxy- or trifluoromethoxy-substituted phenyl or benzyl.
S R2 particularly preferably represents one of the cyclic and hete;rocyclic groupings mentioned above, where the substituents may be selected from one of the groupings listed below:
nitro, hydroxyl, amino, cyano, carbomoyl, thiocarbomoyl, formylamino, fluo-rine, chlorine, bromine, methyl, ethyl, n- or i-propyl, n-, i-, s- or t-butyl, di-fluoromethyl, dichloromethyl, trifluoromethyl, trichloromethyl, chlorodi-fluoromethyl, fluorodichloromethyl, methoxy, ethoxy, n- o:r i-propoxy, difluo-romethoxy, trifluoromethoxy, chlorodifluoromethoxy, fluorodichloromethoxy, methylthio, ethylthio, n- or i-propylthio, difluoromethylt:hio, trifluorometh-ylthio, chlorodifluoromethylthio, fluorodichloromethylthio, methylsulphinyl, ethylsulphinyl, trifluoromethylsulphinyl, methylsulphonyl, ethylsulphonyl, tri-fluoromethylsulphonyl, methylamino, ethylamino, n- or i-propylamino, di-methylamino, diethylamino, acetyl, propionyl, n- or i-butyroyl, methoxy-carbonyl, ethoxycarbonyl, n- or i-propoxycarbonyl, methylaminocarbonyl, ethylaminocarbonyl, n- or i-propylaminocarbonyl, dimethylaminocarbonyl, diethylaminocarbonyl, acetylamino, propionylamino, n- or i-butyroylamino, methoxycarbonylamino, ethoxycarbonylamino n- or i-propoxycarbonylamino, methylaminocarbonylamino, ethylaminocarbonylamino, n- or i-propylamino-carbonylamino, methylsulphonylamino, ethylsulphonylarr~ino, n-or i-propyl-sulphonylamino.
R' very particularly preferably represents hydrogen and represents in each case optionally cyano-, fluorine-, chlorine-, methoxy-, ethoxy-, n- or i-propoxy-, methylthio-, ethylthio-, methylsulphinyl-, ethylsulphinyl-, methylsulphonyl-, ethylsulphonyl-substituted methyl, ethyl, n- or i-propyl.

Le A 33 707-Foreign Countries RZ very particularly preferably represents benzo-fused cycloalk(en)yl from the list above \ ~\ ~\
/ / / i~
where all cyclic groupings may be substituted by one of the groupings listed below:
[lacuna]
R' most preferably represents hydrogen, methyl, ethyl of n- or i-propyl.
RZ most preferably represents one of the groupings below:
NHZ
~ , ~ ~ ~ , off Preference according to the invention is given to the compounds of the formula (I) which contain a combination of the meanings listed above as being preferred.
Particular preference according to the invention is given to the compounds of the formula (I) which contain a combination of the meanings listed above as being par-ticularly preferred.

Le A 33 707-Foreign Countries Very particular preference according to the invention is given to the compounds of the formula (I) which contain a combination of the meanings listed at>ove as being very particularly preferred.
Most preference according to the invention is given to the compounds of the formula (I) which contain a combination of the meanings listed above as being most preferred.
The abovementioned general or preferred radical definitions apply both to the end products of the formula (I) and, correspondingly, to the starting materials or interme-diates required in each case for the preparation. These radical definitions can be com-bined with one another as desired, i.e. including combinations between the given preferred ranges.
The novel substituted N-cyano-amidines of the general formula (I) have interesting biological properties. In particular, they have strong herbicidal activities.
The novel substituted N-cyano-amidines of the general formula (I) are obtained when N-cyano-imidates of the general formula (II) R' R' O
(II) N~CN
in which R' is as defined above and R' represents alkyl are reacted with amino compunds of the general formula (III) Le A 33 707-Foreign Countries _7_ (III) H'N~H
in which R2 is as defined above, if appropriate in the presence of a reaction auxiliary and if appropriate in the presence of a diluent.
Using, for example, ethyl N-cyano-propaneimidate and indan-2-yl-amine as starting materials, the course of the reaction in the process according to the invention can be illustrated by the formula scheme below:
CZHS

+ --N~CN
H~N~H HSCZ~N~H
INI~CN
The formula (II) provides a general definition of the N-cyano-imidates to be used as starting materials in the process according to the invention for preparing compounds of the general formula (I). In the general formula (II), Rl preferably has the meaning which has already been mentioned above, in connection with the; description of the compounds of the general formula (I) according to the invention, as being preferred, particularly preferred, very particularly preferred or most preferred for Rl;
R' prefer-ably represents alkyl having 1 to 4 carbon atoms, in particular methyl or ethyl.
The N-cyano-imidates of the general formula (II) are known and/or can be prepared by processes known per se (cf. J. Am. Chem. Soc. 104 (1982), 235-239; loc. cit.

Le A 33 707-Foreign Countries _g_ (1984), 2805-2811; J. Org. Chem. 28 (1963), 1816-1821; loc. cit. 46 (1981), 1465; Synthesis 1983, 402-404; Tetrahedron Lett. 21 (1980), 909-912).
The formula (III) provides a general definition of the amino compounds further to be used as starting materials in the process according to the invention for preparing com-pounds of the general formula (I). In the general formula (III), RZ preferably has that meaning which has already been mentioned above, in connection with the description of the compounds of the general formula (I) according to the invention, as being pre-ferred, particularly preferred, very particularly preferred or most preferred for R2.
The amino compounds of the general formula (III) are known ancL'or can be prepared by processes known per se (cf. J. Am. Chem. Soc. 88 (1966), 2233-2240; loc.
cit. 95 (1973), 4083-4084); J. Chem. Soc. C 1966, 717-722; Synthesis 1980, 695-697;
Tetra-hedron 24 (1968), 3681-3696; loc. cit. 50 (1994), 3627-3638).
The process according to the prevention for preparing compounds of the general for-mula (I) is, if appropriate, carried out using a reaction auxiliary. Reaction auxiliaries suitable for the process according to the invention are, in general, the customary inor-ganic or organic bases or acidic acceptors. These preferably include alkali metal or alkaline earth metal acetates, amides, carbonates, bicarbonates, hydrides, hydroxides or alkoxides, such as, for example, sodium acetate, potassium acetate or calcium ace-tate, lithium amide, sodium amide, potassium amide or calcium amide, sodium car-bonate, potassium carbonate or calcium carbonate, sodium bicarbonate, potassium bicarbonate or calcium bicarbonate, lithium hydride, sodium hydride, potassium hy-Bride or calcium hydride, lithium hydroxide, sodium hydroxide, potassium hydroxide or calcium hydroxide, sodium methoxide, ethoxide, n- or i-propoxide, n-, i-, s-or t-butoxide or potassium methoxide, ethoxide, n- or i-propoxide, n-, i-, s- or t-butoxide;
furthermore also basic organic nitrogen compounds, such as, for example, trimethyl-amine, triethylamine, tripropylamine, tributylamine, ethyl-diisopropylamine, N,N-dimethyl-cyclohexylamine, dicyclohexylamine, ethyl-dicyclohexylamine, N,N-di-methyl-aniline, N,N-dimethyl-benzylamine, pyridine, 2-methyl-, 3-methyl-, 4-methyl-Le A 33 707-Foreign Countries 2,4-dimethyl-, 2,6-dimethyl-, 3,4-dimethyl- and 3,5-dimethyl-pyridine, 5-ethyl-methyl-pyridine, 4-dimethylamino-pyridine, N-methyl-piperidine, 1,4-diazabi-cyclo[2,2,2]-octane (DABCO), 1,5-diazabicyclo[4,3,0]-non-5-ene (DBN), or 1,8-diazabicyclo[5,4,0]-undec-7-ene (DBL..
In most cases, the use of one of the reaction auxiliaries mentioned above can be dis-pensed with.
The process according to the invention for preparing compounds of the general formula (I) is preferably carned out using a diluent. Suitable diluents are, in addition to water, especially inert organic solvents. These include, in particular, aliphatic, ali-cyclic or aromatic, optionally halogenated hydrocarbons, such as, for example, benz-ine, benzene, toluene, xylene, chlorobenzene, dichlorobenzene, petroleum ether, hex-ane, cyclohexane, dichloromethane, chloroform, carbon tetrachloride; ethers, such as 1 S diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran or ethylene glycol dimethyl ether or ethylene glycol diethyl ether; ketones, such as acetone, butanone or methyl isobutyl ketone, nitrites, such as acetonitrile, propionitrile or butyronitrile; amides, such as N,N-dimethylformamide, N-dimethylacetamide, N-methyl-formanilide, N-methyl-pyrrolidone or hexamethylphosphorie triamide; esters such as methyl acetate or ethyl acetate, sulphoxides such as dimethylsulphoxide, alcohols, such as methanol, ethanol, n- or i-propanol, ethylene glycol monomethyl ether, ethylene glycol mono-ethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, mixtures thereof with water or pure water.
When carrying out the process according to the invention, the reaction temperatures can be varied within a relatively wide range. In general, the process is carned out at temperatures between 0°C and 150°C, preferably between 10°C and 120°C.
The process according to the invention is generally carned out under atmospheric pressure. However, it is also possible to carry out the process according to the inven-tion under elevated or reduced pressure - in general between 0.1 bar and 10 bar.

Le A 33 707-Foreign Countries For carrying out the process according to the invention, the starting materials are generally employed in approximately equimolar amounts. However, it is also possible to use a relatively large excess of in each case one of the components. The reaction is generally carried out in a suitable diluent in the presence of a reaction auxiliary, if appropriate, and the reaction mixture is generally stirred at the required temperature for a plurality of hours. Work-up is carried out by customary methods (cf. the Prepa-ration Examples).
The active compounds according to the invention can be used as defoliants, desic-cants, haulm killers and, especially, as weed killers. By weeds in the broadest sense there are to be understood all plants which grow in locations where they are undesired.
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 in-vention can be used, for example, in connection with the following plants:
Dicotyledonous weeds of the genera: Sinapis, Lepidium, Galium, Stellaria, Matricaria, Anthemis, Galinsoga, Chenopodium, Urtica, Senecio, Amaranthus, Portulaca, Xan-thium, Convolvulus, Ipomoea, Polygonum, Sesbania, Ambrosia, Cirsium, Carduus, Sonchus, Solanum, Rorippa, Rotala, Lindernia, Lamium, Veronica, Abutilon, Emex, Datum, Viola, Galeopsis, Papaver, Centaurea, Trifolium, Ranunculus, Taraxacum.
Dicotyledonous crops 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, Sagittaria, Eleocharis, Scir-pus, Paspalum, Ischaemum, Sphenoclea, Dactyloctenium, Agrostis, Alopecurus, Apera, Aegilops, Phalaris.

Le A 33 707-Foreign Countries Monocotyledonous crops of the genera: Oryza, Zea, Triticum, Ho:rdeum, Avena, Se-cafe, Sorghum, Panicum, Saccharum, Ananas, Asparagus, Allium.
However, the use of the active compounds according to the invention is in no way restricted to these genera, but also extends in the same manner to other plants.
Depending on the concentration, the active compounds according to the invention are suitable for total weed control, for example on industrial terrain and railway tracks and on paths and areas with or without tree growth. Equally, the active compounds ac-cording to the invention can be employed for controlling weeds in perennial crops, for example forests, ornamental tree plantings, orchards, vineyards, citrus groves, nut orchards, banana plantations, coffee plantations, tea plantations, rubber plantations, oil palm plantations, cocoa plantations, soft fruit plantings and hop fields, on lawns and turf and pastures and for selective weed control in annual crops.
The compounds of the formula (I) according to the invention have strong herbicidal activity and a broad activity spectrum when used on the soil and on rough-ground parts of plants. To a certain extent, they are also suitable for selective control of monocotyledonous and dicotyledonous weeds in monocotyledonous and dicotyle-donous crops, both by the pre-emergence and by the post-emergence method.
The active compounds can be converted into the customary formulations, such as solutions, emulsions, wettable powders, suspensions, powders, dusts, pastes, soluble powders, granules, suspo-emulsion concentrates, natural and synthetic substances impregnated with active compound, and microencapsulations in polymeric substances.
These formulations are produced in a known manner, for example by mixing the ac-tive compounds with extenders, that is to say liquid solvents and/or solid earners, optionally with the use of surfactants, that is to say emulsifiers and/or dispersants and/or foam formers.

Le A 33 707-Foreign Countries If the extender used is water, it is also possible to use, for example, organic solvents as auxiliary solvents. Liquid solvents which are suitable are mainly: aromatics, such as xylene, toluene or alkylnaphthalenes, chlorinated aromatics and chlorinated aliphatic hydrocarbons, such as chlorobenzenes, chloroethylenes or methylene chloride, ali-phatic hydrocarbons, such as cyclohexane or paraffins, for example petroleum frac tions, mineral and vegetable oils, alcohols, such as butanol or glycol, and also their ethers and esters, ketones, such as acetone, methyl ethyl ketone, methyl isobutyl ke tone or cyclohexanone, strongly polar solvents, such as dimethylformamide and di methyl sulphoxide, and water.
Suitable solid carriers are for example ammonium salts and ground natural minerals, such as kaolins, clays, talc, chalk, quartz, attapulgite, montmorillonite or diato-maceous earth, and ground synthetic minerals, such as finely divided silica, alumina 1 S and silicates; suitable solid Garners for granules are for example crashed and fraction-ated natural rocks, such as calcite, marble, pumice, sepiolite, dolomite and synthetic granules of inorganic and organic meals, and granules of organic material, such as sawdust, coconut shells, maize cobs and tobacco stalks; suitable emulsifiers and/or foam formers are for example nonionic and anionic emulsifiers, such as polyoxyethyl-ene fatty acid esters, polyoxyethylene fatty alcohol ethers, for example alkylaryl poly-glycol ethers, alkylsulphonates, alkyl sulphates, arylsulphonates and protein hydroly-sates; suitable dispersants are for example lignosulphite waste liquors and methylcel-lulose.
Tackifiers, such as carboxymethylcellulose, natural and synthetic polymers in the form of powders, granules or latices, such as gum arabic, polyvinyl alcohol and polyvinyl acetate, and also natural phospholipids, such as cephalins and lecithins and synthetic phospholipids can be used in the formulations. Other possible additives are mineral and vegetable oils.

Le A 33 707-Foreign Countries It is possible to use colorants, such as inorganic pigments, for example iron oxide, titanium oxide, Prussian blue, and organic dyestuffs, such as alizarin dyestuffs, azo dyestuffs and metal phthalocyanine dyestuffs, and trace nutrients, such as salts of iron, manganese, boron, copper, cobalt, molybdenum and zinc.
The formulations generally comprise between 0.1 and 95 per cent by weight of active compound, preferably between 0.5 and 90%.
For controlling weeds, the active compounds according to the invention, as such or in the form of their formulations, can also be used as mixtures with known herbicides, finished formulations or tank mixes being possible.
Possible components for the mixtures are known herbicides, for example acetochlor, acifluorfen(-sodium), aclonifen, alachlor, alloxydim(-sodium), ametryne, amidochlor, amidosulphuron, anilofos, asulam, atrazine, azafenidin, azimsulphuron, benazolin(-ethyl), benfuresate, bensulphuron(-methyl), bentazone, benzobicyclon, benzofenap, benzoylprop(-ethyl), bialaphos, bifenox, bispyribac(-sodium), bromo-butide, bromofenoxim, bromoxynil, butachlor, butroxydim, butylate, cafenstrole, caloxydim, carbetamide, carfentrazone(-ethyl), chlomethoxyfen, chloramben, chlor-idazon, chlorimuron(-ethyl), chlornitrofen, chlorsulphuron, chlorotoluron, cinidon-(-ethyl), cinmethylin, cinosulphuron, clefoxydim, clethodim, clodinafop(-propargyl), clomazone, clomeprop, clopyralid, clopyrasulphuron(-methyl), cloransulam(-methyl), cumyluron, cyanazine, cybutryne, cycloate, cyclosulphamuron, cycloxydim, cyhalo-fop(-butyl), 2,4-D, 2,4-DB, 2,4-DP, desmedipham, diallate, dicamba, diclofop(-methyl), diclosulam, diethatyl(-ethyl), difenzoquat, diflufenican, diflufenzopyr, dime-furon, dimepiperate, dimethachlor, dimethametryn, dimethenamid, dimexyflam, dinitramine, diphenamid, diquat, dithiopyr, diuron, dymron, epropodan, EPTC, espro-carb, ethalfluralin, ethametsulphuron(-methyl), ethofumesate, ethoxyfen, ethoxysul-phuron, etobenzanid, fenoxaprop(-P-ethyl), fentrazamide, flamprop(-isopropyl), flam-prop(-isopropyl-L), flamprop(-methyl), flazasulphuron, florasulam, fluazi-fop(-P-butyl), fluazolate, flucarbazone, flufenacet, flumetsulam, flumiclorac(-pentyl), Le A 33 707-Foreign Countries flumioxazin, flumipropyn, flumetsulam, fluometuron, fluorochloridone, fluoroglyco-fen(-ethyl), flupoxam, flupropacil, flurpyrsulphuron(-methyl, -sodium), flurenol(-butyl), fluridone, fluroxypyr(-methyl), flurprimidol, flurtamone, fluthi-acet(-methyl), fluthiamide, fomesafen, glufosinate(-ammonium), glypho-sate(-isopropylammonium), halosafen, haloxyfop(-ethoxyethyl), haloxy-fop(-P-methyl), hexazinone, imazamethabenz-(-methyl), imazamethapyr, imazamox, imazapic, imazapyr, imazaquin, imazethapyr, imazosulphuron, iodosulphuron(-methyl, -sodium), ioxynil, isopropalin, isoproturon, isouron, isoxaben, isoxachlortole, isoxaflutole, isoxapyrifop, lactofen, lenacil, linuron, MCPA, MCPP, mefenacet, mesotrione, metamitron, metazachlor, methabenzthiazuron, metobenzuron, meto-bromuron, (alpha-)metolachlor, metosulam, metoxuron, metribuzin, metsul-phuron(-methyl), molinate, monolinuron, naproanilide, napropamide, neburon, nico-sulphuron, norflurazon, orbencarb, oryzalin, oxadiargyl, oxadiazon, oxasulphuron, oxaziclomefone, oxyfluorfen, paraquat, pelargonic acid, pendimethalin, pendralin, pentoxazone, phenmedipham, piperophos, pretilachlor, primisulphuron(-methyl), prometryn, propachlor, propanil, propaquizafop, propisochlor, propyzamide, prosul-phocarb, prosulphuron, pyraflufen(-ethyl), pyrazolate, pyrazosulphuron(-ethyl), pyrazoxyfen, pyribenzoxim, pyributicarb, pyridate, pyriminobac(-methyl), pyrithio-bac(-sodium), quinchlorac, quinmerac, quinoclamine, quizalofop(-P-ethyl), quizalo-fop(-P-tefuryl), rimsulphuron, sethoxydim, simazine, simetryn, sulcotrione, sulphen trazone, sulphometuron(-methyl), sulphosate, sulphosulphuron, tebutam, tebuthiuron, tepraloxydim, terbuthylazine, terbutryn, thenylchlor, thiafluamide, thiazopyr, thidi azimin, thifensulphuron(-methyl), thiobencarb, tiocarbazil, tralkoxydim, triallate, triasulphuron, tribenuron(-methyl), triclopyr, tridiphane, trifluralin and tri flusulphuron.
A mixture with other known active compounds, such as fungicides, insecticides, acar-icides, nematicides, bird repellents, plant nutrients and agents which improve soil structure, is also possible.

Le A 33 707-Foreign Countries 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, sus-pensions, emulsions, powders, pastes and granules. They are used in the customary manner, for example by watering, spraying, atomizing, scattering.
S
The active compounds according to the invention can be applied both before and after the emergence of the plants. They can also be incorporated into the soil before sowing.
The amount of active compound used can vary within a relatively wide range. It de-pends essentially on the nature of the desired effect. In general, the amounts used are between 1 g and 10 kg of active compound per hectare of soil surface, preferably between 5 g and 5 kg per ha.
The preparation and the use of the active compounds according to the invention can be seen from the examples below.

Le A 33 707-Foreign Countries Preparation Examples:
Example 1 N~CN
S
A mixture of 0.98 g (10 mmol) of methyl N-cyano-ethaneimidate, 1.42 g (10 mmol) of 1,2,3,4-tetrahydro-1-naphthylamine and 20 ml of water is stirred at room temperature (about 20°C) for 12 hours. The resulting crystalline product is then isolated by filtra-tion with suction, washed with a little water and diethyl ether and dried on a disc made of clay.
This gives 1.3 g (62% of theory) of N'-cyano-N-(1,2,3,4-tetrahydro-1-naphthyl)-ethaneimideamide of melting point 113°C.
Analogously to Example 1, and in accordance with the general description of the preparation process according to the invention, it is also possible to prepare, for ex-ample, the compounds of the general formula (I) listed in Table 1 below.

(I) N~CN

Le A 33 707-Foreign Countries Table 1: Examples of compounds of the formula (I) Ex. No. R1 R Melting point (°C) 2 H NH2 162°C
3 H ~ 148 /

CH3 ...., 139 6 CH3 -,. 176 HO ~ ''' (1R,2S) 7 CH3 .-_ 173 HO ~ "
( 1 S,2R) Le A 33 707-Foreign Countries Ex. No. ~ Rl R Melting point (°C) 8 C2H5 ~ 117 I /

9 C3H7-n ~ 149 /

11 CZHS -,. 140 HO ~ "
(1R,2S) 12 CZHS ~ 141 HO ~ "
( 1 S,2R) 13 C3H7-n NH2 194 14 C3H7-n ~. (amorphous) HO ~ "
(1R,2S) Le A 33 707-Foreign Countries Ex. No. RI R2 Melting point (°C) 15 C3H7-n -.~ (amorphous ) /
HO ~ ''' (1 S,2R) 16 H H3C ...~ 223 /
17 H -,. 149 HO ~ "
(1R,2S) 18 H ~ 156 HO ~ "
( 1 S,2R) 19 H / \ 136 20 CH3 / ~ 206 Le A 33 707-Foreign Countries Ex. No. R1 R Melting point (°C) 21 CZHS / \ 150 22 C3H7-n / ' 126 23 H , 105 24 C2H5 .~ 133 25 C3H7-n -," 84 26 CH3 ~ ,,.'' 27 CH3 i H3 152 o Le A 33 707-Foreign Countries Ex. No. . R1 R Melting point (°C) / ,,,.

30 CH3 ~ ..~~~ 228 Br 31 CH3 B~ 205 \ ,,,,, /
32 CH3 Br 204 / CHs 34 CH3 -_ 3 5 H -, HsC ~ r Le A 33 707-Foreign Countries Use Examples:
Example A
S Pre-emergence Test Solvent: S 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.
Seeds of the test plants are sown in normal soil. After about 24 hours, the soil is sprayed with the preparation of active compound such that the particular amount of active compound desired is applied per unit area. The concentration of the spray liquor is chosen such that the particular amount of active compound desired is applied in 1000 litres of water per hectare.
After three weeks, the degree of damage to the plant is rated in% damage in compari-son to the development of the untreated control.
The figures denote:
0% - no effect (like untreated control) 100% - total destruction In this test, for example, the compound of Preparation Example 1 shows strong activ-ity against weeds.

Le A 33 707-Foreign Countries Example B
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 b;y 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 of a height of 5 - 15 cm are sprayed with the preparation of active com-pound such that the particular amounts of active compound desired are applied per unit area. The concentration of the spray liquor is chosen such that the particular amounts of active compound desired are applied in 10001 of waterlha.
After three weeks, the degree of damage to the plants is rated in "/°
damage in com-parison to the development of the untreated control.
The figures denote:
0% = no effect (like untreated control) 100% = total destruction In this test, for example, the compound of Preparation Example 1 shows strong activ-ity against weeds.

Claims (8)

Claims

1. Subtituted N-cyano-amidines of the general formula (I), in which R1 represents hydrogen or represents in each case optionally substituted alkyl, alkenyl, alkinyl, cycloalkyl, cycloalkylalkyl, aryl or arylalkyl and R2 represents in each case benzo-fused, pyrido-fused or thieno-fused cycloalk(en)yl, oxacycloalk(en)yl or thiacycloalk(en)yl, where all cyclic and heterocyclic groupings may be substituted.

2. Compounds according to Claim 1, characterized in that R1 represents hydrogen, represents optionally cyano-, halogen-, C1-C4-alkoxy-, C1-C4-alkylthio-, C1-C4-alkylsulphinyl- or C1-C4-alkyl-sulphonyl-substituted alkyl having 1 to 6 carbon atoms, represents in each case optionally halogen-substituted alkenyl or alkinyl having in each case 2 to 6 carbon atoms, represents in each case optionally cyano-, halogen- or C1-C4-alkyl-substituted cycloalkyl or cycloalkyl-alkyl having in each case 3 to 6 carbon atoms in the cycloalkyl groups and optionally 1 to 4 carbon atoms in the alkyl moiety, or represents in each case optionally nitro-, cyano-, halogen-, C1-C4-alkyl-, C1-C4-halogenoalkyl-, C1-C4-alkoxy- or C1-C4-halogenoalkoxy-substituted aryl or arylalkyl having in each case 6 or 10 carbon atoms in the aryl groups and optionally 1 to 4 carbon atoms in the alkyl moiety, and R2 represents in each case benzo-fused, pyrido-fused or thieno-fused cycloalk(en)yl, oxacycloalk(en)yl or thiacycloalk(en)yl from the list below, where all cyclic and heterocyclic groupings may preferably be substi-tuted by one of the groupings listed below:
nitro, hydroxyl, amino, cyano, carbamoyl, thiocarbamoyl, formyl-amino, halogen, C1-C4-alkyl, C1-C4-halogenoalkyl, C1-C4-alkoxy, C1-C4-halogenoalkoxy, C1-C4-alkylthio, C1-C4-halogenoalkylthio, C1-C4-alkylsulphinyl, C1-C4-halogenoalkylsulphinyl, C1-C4-alkylsulphonyl, C1-C4-halogenoalkylsulphonyl, C1-C4-alkylamino, di-(C1-C4-alkyl)-amino, C1-C4-alkyl-carbonyl, C1-C4-alkoxy-carbonyl, C1-C4-alkyl-amino-carbonyl, di-(C1-C4-alkyl)-amino-carbonyl, C1-C4-alkyl-carb-onyl-amino, C1-C4-alkoxy-carbonyl-amino, C1-C4-alkyl-amino-carb-onyl-amino, C1-C4-alkyl-sulphonyl-amino.

3. Compounds according to Claim 1 or 2, characterized in that R1 represents hydrogen, represents in each case optionally cyano-, fluo-rine-, chlorine-, bromine-, methoxy-, ethoxy-, n- or i-propoxy-, meth-ylthio-, ethylthio-, n- or i-propylthio-, methylsulphinyl-, ethylsul-phinyl-, n- or i-propylsulphinyl-, methylsulphonyl-, ethylsulphonyl-, n-or i-propylsulphonyl-substituted methyl, ethyl, n- or i-propyl, n-, i-, s-or t-butyl, represents in each case optionally fluorine-, chlorine- or bromine-substituted ethenyl, propenyl, butenyl, ethinyl, propinyl or butinyl, represents in each case optionally cyano-, fluorine-, chlorine-, bromine-, methyl-, ethyl-, n- or i-propyl-substituted cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, cyclobutyl-methyl, cyclopentylmethyl or cyclohexylmethyl, or represents in each case optionally nitro-, cyano-, fluorine-, chlorine-, bromine-, methyl-, ethyl-, n- or i-propyl-, n-, i-, s- or t-butyl-, trifluoromethyl-, methoxy-, ethoxy-, n- or i-propoxy-, difluoromethoxy- or trifluoromethoxy-sub-stituted phenyl or benzyl, and R2 represents one of the cyclic and heterocyclic groupings mentioned in Claim 1 or 2, where the substituents may be selected from one of the groupings listed below:
nitro, hydroxyl, amino, cyano, carbamoyl, thiocarbamoyl, formyl-amino, fluorine, chlorine, bromine, methyl, ethyl, n.- or i-propyl, n-, i-, s- or t-butyl, difluoromethyl, dichloromethyl, trifluoromethyl, tri-chloromethyl, chlorodifluoromethyl, fluorodichloromethyl, methoxy, ethoxy, n- or i-propoxy, difluoromethoxy, trifluoromethoxy, chlorodi-fluoromethoxy, fluorodichloromethoxy, methylthio, ethylthio, n- or i-propylthio, difluoromethylthio, trifluoromethylthio, chlorodifluo-romethylthio, fluorodichloromethylthio, methylsulphinyl, ethyl-sulphinyl, trifluoromethylsulphinyl, methylsulphonyl, ethylsulphonyl, trifluoromethylsulphonyl, methylamino, ethylamino, n- or i-propyl-amino, dimethylamino, diethylamino, acetyl, propionyl, n- or i-buty-royl, methoxycarbonyl, ethoxycarbonyl, n- or i-propoxycarbonyl, methylaminocarbonyl, ethylaminocarbonyl, n- or i-propylamino-carbonyl, dimethylaminocarbonyl, diethylaminocarbonyl, acetylamino, propionylamino, n- or i-butyroylamino, methoxycarbonylamino, eth-oxycarbonylamino, n- or i-propoxycarbonylamino, methylamino-carbonylamino, ethylaminocarbonylamino, n- or i-propylamino-carbonylamino, methylsulphonylamino, ethylsulphonylamino, n- or i-propylsulphonylamino.

4. Compounds according to any of Claims 1 to 3, characterized in that R1 represents hydrogen and represents in each case optionally cyano-, fluorine-, chlorine-, methoxy-, ethoxy-, n- or i-propoxy-, methylthio-, ethylthio-, methylsulphinyl-, ethylsulphinyl-, methylsulphonyl-, ethyl-sulphonyl-substituted methyl, ethyl, n- or i-propyl, and R2 represents benzo-fused cycloalk(en)yl from the list below where all cyclic groupings may be substituted by one of the groupings listed below:
nitro, hydroxyl, amino, cyano, carbamoyl, thiocarbamoyl, formylamino, fluo-rine, chlorine, bromine, methyl, ethyl, n- or i-propyl, n-, i-, s- or t-butyl, di-fluoromethyl, dichloromethyl, trifluoromethyl, trichloromethyl, chlorodifluo-romethyl, fluorodichloromethyl, methoxy, ethoxy, n- or i-propoxy, difluo-romethoxy, trifluoromethoxy, chlorodifluoromethoxy, fluorodichloromethoxy, methylthio, ethylthio, n- or i-propylthio, difluoromethylthio, trifluorometh-ylthio, chlorodifluoromethylthio, fluorodichloromethylthio, methylsulphinyl, ethylsulphinyl, trifluoromethylsulphinyl, methylsulphonyl, ethylsulphonyl, tri-fluoromethylsulphonyl, methylamino, ethylamino, n- or i-propylamino, di-methylamino, diethylamino, acetyl, propionyl, n- or i-butyroyl, methoxy-carbonyl, ethoxycarbonyl, n- or i-propoxycarbonyl, methylaminocarbonyl, ethylaminocarbonyl, n- or i-propylaminocarbonyl, dimethylaminocarbonyl, diethylaminocarbonyl, acetylamino, propionylamino, n- or i-butyroylamino, methoxycarbonylamino, ethoxycarbonylamino, n- or i-propoxycarbonylamino, methylaminocarbonylamino, ethylaminocarbonylamino, n- or i-propylamino-carbonylamino, methylsulphonylamino, ethylsulphonylamino, n- or i-propyl-sulphonylamino.

5. Compounds according to any of Claims 1 to 4, characterized in that R1 represents hydrogen , methyl, ethyl or n- or i-propyl, and R2 represents one of the groupings below.

6. Process for preparing compounds according to any of Claims 1 to 5, charac-terized in that N-cyano-imidates of the general formula (II) in which R1 is as defined in any of Claims 1 to 5 and R' represents alkyl, are reacted with amino compounds of the general formula (III) in which R2 is as defined in any of Claims 1 to 5, if appropriate in the presence of a reaction auxiliary and if appropriate in the presence of a diluent.

7. Herbicidal compositions, characterized in that they comprise at least one com-pound according to any of Claims 1 to 5 and customary extenders.

8. Use of at least one compound according to any of Claims 1 to 5 for controlling undesirable plants.