DE2830066A1 - Benzoxazole, benzothiazole and benzimidazole derivs. - useful as selective herbicides - Google Patents

Abstract

Benzazole derivs. of formula (I) are new. In (I) R is halo, CF3, NO2, CN, 1-4C alkyl, 1-4C alkoxy or 1-4C alkylthio; n = 0-3; A is O, S, NH or NR1, where R1 = 1-4C alkyl; R1 is halo, Me or CF3; m = 0-2; R2 is H or 1-4C alkyl; X is COOR3, COSR4, CONR5R6, CONHNR7-R8, CSNH2, CN, CH2OH, CH2OCOR9 or CH2OCONR5R6; R3 is (i) H, (ii) 1-12c alkyl opt. substd. by halogen and/or by OH, alkoxy, alkylthio, alkoxyalkoxy, haloalkoxy, methoxyethoxyethoxy, alkylamino, dialkylamino, Ph, oxiranyl, PhO, halophenoxy or alkylphenoxy; (iii) 5-6C cycloalkyl opt. substd. by halogen or Me; (iv) 3-6C alkenyl or haloalkenyl; (v) 5-6C cycloalkenyl; (vi) 3-4C alkynyl opt. substd. by alkyl, Ph, halogen or alkoxy; (vii) phenyl opt. substd. by alkyl, alkoxy, halogen, NO2 or CF3; (viii) furfuryl or tetrahydrofurfuryl; or (ix) an equiv. of a cation. R4 is 1-6C alkyl, Ar-methyl, Ar-ethyl, 3-6C alkenyl or Ar, where Ar is phenyl opt. mono- or disubstd. by 1-4C alkyl and/or ahlo; R5 and R6 are H, 1-6C alkyl, 1-6C hydroxyalkyl, 5-6C cycloalkyl, or phenyl opt. substd. by 1-4C alkyl, 1-4C alkoxy, halogen or CF3, provided that R5 and R6 are not both phenyl, or R5 + R6 forms a 2-, 4- or 5-membered methylene chain in which one CH2 gp. is opt. replaced by O, NH or NMe; R7 and R8 are H, Me, or Et, and R8 can also be Ph; R9 is 1-6C alkyl, 1-6C haloalkyl, cyclopropyl, 3-6C alkenyl, Ph, alkylphenyl, alkoxyphenyl, halophenyl, CF3-phenyl or nitrophenyl. (I) are selective herbicides useful for pre- and post-emergence control of annual and perennial weed grasses in broad-leaved and certain cereal crops.

Description

4-oxyphenoxyalkanoic acid derivatives and herbicides containing them

Zide Mittcl The present application relates to new heterocyclically substituted 4-oxyphenoxyalkanoic acid derivatives of the general formula I. where R: halogen, CF3, NO2, CN, (C1-C4) -alkyl, (C1-C4) -alkyl, (C1-C4) -alkylthio, A: O, S, NH or N- (C1-C4) -Alkyl, R1:: halogen, methyl, CF5, R2; H, (C1-C4) -alkyl, n: 0-3, m: 0-2, Z: a group of the formula R5: H, (Cl-Ci2) -alkyl, which is optionally replaced by 1-6 halogen, preferably F, C1, Br and / or by OH, (C1-C6) -alkoxy, (C1-C4) -alkylthio, (C1 -C6) -Alkoxy- (C2-C6) -alkoxy, halogen- (C1-C2) -alkoxy, methoxy-ethoxy-ethoxy, (C1-C4) -alkylamino, di- (C1-C4) -alkylamino, phenyl, Oxiranyl and / or phenoxy, where the latter can also be substituted one to two times by halogen or (C1-C4) -alkyl, (C5-C6) -cycloalkyl, which is optionally substituted by halogen or methyl, tC3-C6) -Alkenyl, halogen- (C3-C6) -alkenyl or (C5-C6) -cycloalkenyl, (C3-C4) -alkynyl, which is optionally substituted once or twice by (C1-C6) -alkyl, phenyl, halogen or ( C1-C2) -alkoxy, phenyl which is optionally substituted one to three times by (C1-C4) -alkyl, (C1-C4) -alkoxy, halogen, NO2 or CF3, furfuryl, tetrahydrofurfuryl or a cation equivalent of an organic one or inorganic base; R4: (C1-C6) -alkyl, phenyl- (C1-C2) -alkyl, where the phenyl radical can be substituted once or twice by (C1-C4) -alkyl and / or halogen, (C5-C6-alkenyl or phenyl, which can also be substituted once or twice by (C1-C4) -alkyl and / or halogen, R5 and R6 are identical or different and H, (C1-C6) -alkyl, hydroxy- (C1-C6) -alkyl, (C5-C6) -cycloalkyl or phenyl, which is optionally substituted one to three times by (C1-C4) -alkyl, (C1-C4) -alkoxy, halogen or CF5, with the proviso that R5 and R6 are not together phenyl, mean or together form a methylene chain with 2, 4 or 5 members in which a CH2 group can optionally be replaced by 0, NH or N (CH3), R7: H, CH3 or C2H5, R8: H , CH3, C2H5 or phenyl, Rg: (C1-C6) -alkyl, which is optionally mono- to trisubstituted by halogen, cyclopropyl, (C5-C6) -alkenyl, phenyl, (C -C4) -alkylphenyl , (C1-C4) -alkoxyphenyl, halophenyl, trifluoromethylphenyl or nitrophenyl mean those in the The alkyl, alkenyl and alkynyl radicals listed for R2 to R6 and R9 can be either straight-chain or branched.

Preferred compounds of general formula I are those in which R: halogen, CF5, NO2, CH3, methoxy, CN, A: O, S R2: CH3 m: O, n: 0-2 and Z: has the meanings given.

Halogen preferably represents fluorine, chlorine or bromine.

Particularly preferred among the groups mentioned for Z are: Due to the biological effectiveness, however, most preferred are those compounds in which the group z: and R is halogen in the 5- or 6-position.

The radical R5 then preferably represents H, (C1-C4) -alkyl, if appropriate monosubstituted by chlorine, (C1-C4) -alkoxyethyl; or Kat, where Kai is a sodium or Potassium cation, ammonium, (C1-C4) -xono-, -di- or -trialkylammonium or mono-, di- or Trihydroxyäthyiammonium means.

The compounds of the general formula I can be derived from per se known or prepared by known methods of starting materials.

These processes are characterized in that a) compounds of the formula II with compounds of the formula III converts, b) compounds of the formula IV 1) with compounds of the formula V. where B represents halogen or a sulfoester group, for example the mesyl or tosyl radical, represents, reacts, or 2) reacts with compounds of the formula VI, c) Compounds of the formula I in which Z represents the -COOR2 group, hydrogenated and the alcohols obtained (Z = CH2OH), if desired by reaction with carboxylic acids, carboxylic acid halides or anhydrides, into the corresponding carboxylic acid esters (Z = -CH2-OC (O)) -) ) respectively.

by reaction with carbamic acid halides or isocyanates to form carbamic acid esters or d) the compounds obtained by processes a) and b) are converted into other compounds of the formula I according to the invention by saponification, salt formation, acid chloride formation, esterification, transesterification, amidation, elimination or addition of water or addition of hydrogen sulfide.

To a) and bl) The implementation of compounds II and III and IV and V is preferably carried out in inert aprotic solvents such as aliphatic or aromatic hydrocarbons (such as benzene, toluene, xylene), acid nitriles such as acetonitrile or propionitrile, ketones such as acetone, methyl ethyl ketone or methyl isobutyl ketone, acid amides such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone or hexamethylphosphoric triamide or in dimethyl sulfoxide at temperatures between 300 and 2500C or the boiling point of the solvent, preferably between 600 and 160 ° C, in the presence of inorganic or organic Bases such as

Metal alcoholates, tertiary amines, alkali or brodalkali carbonates and alkalis (NaOH, KOH).

Regarding b2) The reaction of the compounds IV and VI takes place under basic conditions at temperatures between 1400 and 2400C, preferably between 1500 and 2200C, in the presence or absence of an organic solvent inert under these conditions according to the following scheme, the compounds of the formula I according to the invention with-Z = COOKat: I (where Z = COOKat) Basic compounds suitable for the reaction are, for example, sodium or potassium hydroxides, but also metallic sodium, the phenols of the formula IV preferably first being converted into the corresponding alkali metal salts.

The compounds obtained in this way can be according to those mentioned under d) Converting the process into further derivatives of the general formula I according to the invention.

Re c) The reduction of acids or esters to alcohols is preferred with complex metal hydrides such as LiAlH4 in ethereal, anhydrous solvents carried out. Since the reaction is usually exothermic, it is generally unnecessary a temperature supply from eyes, the subsequent esterification with acid anhydrides or acid halides takes place in inert solvents (as in a) at temperatures between OOC and the boiling point of the solvent with the addition of an organic or inorganic base, e.g. Na2CO3, CO3 pyridine or triethylamine. The esterification with carboxylic acids is done either by adding water-binding agents such as P205 or by azeotropic extractive distillation of the acidified components. Carbamic acid halides and isocyanates can be mixed with the alcohols in the presence of bases among similar React conditions such as carboxylic acid halides, with generally somewhat increased Temperatures are used, preferably between 400C and the boiling point of the solvent.

To d) For amidation of compounds of the formula I one can either start from esters and react them with amines, ammonia or hydrazides. Man preferably uses the same solvents as in a) and works at temperatures between 400C and reflux temperature. But you can also initially Convert acids of the formula I in a known manner into acid halides and then these react with ammonia, amines or hydrazines. For binding the released hydrogen halide an at least one molar excess of the base used is required. By Other esters can be used to react the acid chloride with alcohols or mercaptans or thioesters of formula I obtained.

The transesterification takes place through acidic or basic catalysis.

The alcohol to be introduced into the ester is expediently used in excess and distills the liberated, lower-boiling alcohol continuously to the extent to which it is formed during the transesterification.

The dehydration of amides to nitriles is preferred in aromatic hydrocarbons at temperatures from 500C to the boiling point. The subsequent addition of H2S is expediently carried out in the autoclave Presence of catalytic amounts of a base (preferably ethanolamine) at temperatures between 500 and 1500C.

The general for the preparation of the compounds according to the invention Formula I required heterocycles of the formula II are according to the definition of A for correspondingly substituted 2-halobenzoxazoles, 2-halobenzothiazoles, 2-halo-1-alkylbenzimidazoles or 2-halobenzimidazoles, which are obtained by known processes, for example from the corresponding 2-mercapto compounds or 2-oxo compounds are produced by halogenation can LC.A. 59, 396f; At the. Chem. J. 21, 111 (1899i7.

The corresponding phenols of the formulas III and IV can be e.g. through etherification of hydroquinone on the side (j. Org.

Chem. 9, p. 214 (1974); Soc. 1965: 954-73; EP 793.714).

For R1 i hydrogen, the compounds of the formula I have a center of asymmetry and are usually in racemic form. The racemates decrease Separate the usual methods into diastereomers. It is also possible according to procedure a) or b) optically active starting materials of the formulas III and V to be used.

The compounds of the general formula I according to the invention are im Pre- and post-emergence proceedings against a wide range of annual and perennial Harmful grasses are very effective, but at the same time they become dicotyledonous Cultivated plants and some types of cereals are excellently tolerated.

The compounds are therefore for the selective control of one and perennial weeds in cultivated plants.

Such harmful grasses are, for example, wild oathe (Avena), foxtail (Alopecurus spp.), Bluegrass (Poa spp.), Ryegrass (Lolium spp.), Annual and perennial Wild millet (Echinochloa spp., Setaria spp., Digitaria sp., Panicum spp., Sorghum sp.), Bermuda grass (Cynodon spp.) and couch grass (Agropyron spp.).

The present invention therefore also relates to herbicidal agents which are characterized in that they contain a herbicidally effective amount of a compound of general formula I contain conventional additives and formulation auxiliaries.

The agents according to the invention contain the active ingredients of the formula I. generally 2-95 wt. They can be used as wettable powders, emulsifiable concentrates, sprayable solutions, dusts or granules in the usual preparations be applied.

Wettable powders are preparations that are uniformly dispersible in water, which in addition to the active ingredient besides a diluent or inert substance also wetting agents, e.g. polyoxyethylated alkylphenols, polyoxyethylated oleyl, stearylamines, alkyl or alkylphenyl sulfonates and dispersants, e.g. sodium lignin sulfonic acid, Sodium 2,2'-dinaphthylmethane-6,6'-disulfonic acid, or oleylinethyltauric acid Contain sodium.

Emulsifiable concentrates are made by dissolving the active ingredient in an organic solvent such as butanol, cyclohexanone, dimethylformamide, xylene or higher-boiling aromatics and the addition of a nonionic wetting agent, for example a polyoxyethylated alkylphenol or a polyoxyethylated oleyl or stearylawin, obtain.

Dust is obtained by grinding the active ingredient with finely divided, solid substances, e.g. talc, natural clays such as kaolin, bentonite, pyrophillite or diatomaceous earth.

Sprayable solutions, as they are often traded in spray cans, contain the active ingredient dissolved in an organic solvent, located next to it For example, a mixture of fluorocarbon gases can be used as the propellant.

Granules can either be sprayed onto adsorptive, Granulated inert material can be produced or by applying active ingredient concentrates by means of adhesives, e.g. polyvinyl alcohol, polyacrylic acid sodium, or else Diineral oils on the surface of carrier materials such as sand, kaolinite, or of granulated inert material.

Suitable active ingredients can also be used in the production of fertilizer granules the usual way - if desired in a mixture with fertilizers - are produced.

In the case of the herbicidal compositions, the concentrations of the active ingredients be different in the commercial formulations.

In wettable powders, the active ingredient concentration varies e.g. between about 10, and 95%, the remainder being the formulation additives given above. In the case of emulsifiable concentrates, the active ingredient concentration is around 10% to 80 .

Dust-like formulations usually contain 5 - 20 ß of active ingredient, sprayable solutions about 2 - 20 p. In the case of granules, the IYirl; substance content hfinOt partly on whether the active compound is liquid or solid and which one Granulating aids, fillers, etc. are used. will.

The commercially available concentrates are optionally used for use diluted in the usual way, e.g. in the case of wettable powders and emulsifiable concentrates by means of water. Stub-like and granulated preparations as well as sprayable solutions are no longer diluted with other inert substances before use. With the external conditions such as temperature, humidity, etc., the required varies Application rate. It can fluctuate within wide limits, e.g. between 0.05.

and 10.0 kg / ha or more of active ingredient, but it is preferably between 0.1 and 5 kg / ha.

The active compounds according to the invention can be used with other herbicides, insecticides and fungicides are combined.

I. Preparation Examples Examples 1: 4- [4- (6-chloro-2-benzthiazolyloxy) phenoxy] valeric acid 27.8 g of 4- (6-chloro-2-benzthiazolyloxy) phenol are placed in 150 ml of toluene and 4.8 g of sodium hydroxide, dissolved in 10 ml of water, are added dropwise at 80.degree. After the addition, the sodium salt formed is first azeotropic and then the solvent is completely distilled off.

At 180 ° C., 12 g of # -valerolactone are added dropwise.

The reaction mixture is kept at 180 ° -200 ° C. inuentemperature held until no phenol is found by thin-layer chromatography (the samples are added with Acidified hydrochloric acid) can be proven (approx. 10-12 hours). The reaction mixture is cooled, treated with 200 ml of water, with conc. Hydrochloric acid set to ptI 2, Sucked off, washed neutral with water, dried at 1000C in a vacuum.

After recrystallization from toluene, 25.8 g (68.3% of theory) are obtained.

Th.) Of 4- [4- (6-chloro-2-benzthiazolyloxy) phenoxy] valeric acid Example 2: Ethyl 4- [4- (6-chloro-2-benzthiazolyloxy) phenoxy] valerate a) 4- [4- (6-chloro-2-benzthiazolyloxy) phenoxy] valeric acid chloride 37.8 g of the acid obtained according to Example 1 in 200 ml of dry toluene are treated dropwise at 70 ° C. with 13.2 g of thionyl chloride. After the addition, the reaction mixture is slowly heated to the boil, the temperature is maintained until the evolution of gas has ended (approx. 6 hours). Then excess thionyl chloride and approx.

70 ml of toluene distilled off.

In this way, 4-F4- (6-chloro-2-benzthiazolyloxy) -phenoxy7-valeric acid chloride is obtained in an inquantitative manner, solved in approx.

130 ml of dry toluene.

b) 39.6 g of the acid chloride obtained according to a) in about 130 ml of dry Toluene is added dropwise with a mixture of 4.6 g ethanol and 11.1 g triethylamine, dissolved in 50 ml of toluene, added. After the addition, the mixture is stirred at 50 ° C. for 1 hour and washed three times at room temperature with 200 ml of water each time.

The toluene phase is dried over sodium sulfate and concentrated on a rotary evaporator. The remaining residue is distilled with an oil pump. After the distillation, 35.4 g (87.2 fo of theory) of ethyl 4-g - (6-chloro-2-benzthiazolyloxy) -phenoxz7-valerate with a boiling point of 0.05: 2250-2500 ° C. are obtained.

Example 3: Sodium 4-AW- (6-chloro-2-benzthiazolyloxy) -phenoxy7-valerate 37.8 g of the acid obtained according to Example 1 are suspended in 200 ml of water and at room temperature with 4.2 g of sodium hydroxide, dissolved in -20 ml water, added. After the addition, stirring is continued for 1 hour at 50 ° C. and then water is distilled off on a rotary evaporator. The residue is dried at 10,000 in vacuo. After drying, one obtains. 39 g (97.6% of theory of sodium 4- [4- (6-chloro-2-benzthiazolyloxy) phenoxy7-valerate.

Example 4 Dimethylammonium 4- [4- (6-chloro-2-benzthiazolyloxy) phenoxy] valerate 37.8 g of the acid obtained according to Example 1 in 200 ml of dry toluene are mixed with 4.7 g of dimethylamine in 50 ° C. ml of dry toluene are added. After the addition, stirring is continued for 2 hours at 900-950C, then toluene is completely distilled off and the remaining residue is dried at 800-900C in vacuo. After drying, 40.4 g (94.5% of theory) of dimethyl onium-4-Z4- (6-chloro-2-benzthiazolyloxy) phenoxy7-valerate are obtained.

Example 5: Isopropyl 4- [4- (6-chloro-2-benzoxazolyloxy) phenoxy] valerate 25.2 g of isopropyl 4- (4-hydroxyphenoxy) valerate are mixed with 16.6 g of potassium carbonate in 150 ml of acetonitrile held at 80 ° C. for 1 hour. Then 18.8 g of 2,6-dichlorobenzoxazole were added added dropwise in 70 ml of acetonitrile. After the addition, the mixture is heated to boiling for 18 hours, filtered off from the salt content and the filtrate concentrated on a rotary evaporator. Of the remaining residue is taken up in approx. 200 ml of toluene, once with 50 ml of 5 % sodium hydroxide solution and washed several times with water. After drying over sodium sulfate toluene is distilled off on a rotary evaporator. The remaining oily residue is dried at 700C in a vacuum. After drying, 29 g (72 d.

Th.) On isopropyl 4- [4- (6-chloro-2-benzoxazolyoxy) phenoxy] valerate as a viscous brownish oil.

Example 6: Methv1-4- / T- (5-chloro-2-benzoxazolzloxy) -phenoxL7-valerate 26.2 g of 4- (5-chloro-2-benzthiazolyloxy) phenol are mixed with 16.6 g of potassium carbonate in 150 ml of dimethylformamide held at 120 ° C. for 1.5 hours. Then one drips 16.5 g of methyl 4-chloro valerate are added at 80 ° C. and the mixture is heated for 20 hours 1200C.

The salt content is filtered off and the filtrate is concentrated on a rotary evaporator. The remaining residue is taken up in 200 ml of toluene, washed once with 50 ml of 5% sodium hydroxide solution and several times with water. After drying over sodium sulfate, toluene is distilled off on a rotary evaporator and the residue is distilled. After the distillation, 28.7 g (76.3 ffi of theory) of methyl 4- [4- (5-chlorobenzoxazolyloxy) phenoxy] valerate with a boiling point of 0.1: 218 ° -220 ° C. are obtained .

Example 7: 4- [4- (2-Benzthiazolyloxy) phenoxy] pentanol-1 35.7 g of methyl 4- [4- (2-benzthiazolyloxy) phenoxy] valerate (prepared analogously to Example 5) are in 200 ml of dry ether and so mixed with a stirred suspension of 2.2 g of lithium aluminum hydride in 150 ml of dry ether that the reaction mixture is kept at the boil. After the addition, the mixture is stirred under reflux for 1 hour. After cooling, first 200 ml of water and then 200 ml of 2N sulfuric acid are added. The phases are separated, the aqueous phase is extracted twice with 150 ml of ether each time, and the combined ether phases are washed with water until the wash water is neutral. It is then dried over sodium sulfate and the ether is distilled off. The remaining residue is distilled. After the distillation, 27.2 g (80.3% of theory) of 4- [4- (2-benzthiazolyloxy) phenox7-pentanol-1 are obtained.

Example 8: 1-Ethylcarbonyloxy-4- [4- (2-benzthiazolyloxy) phenoxy] pentane 33.9 g of the alcohol obtained in Example 7 and 12.1 g of triethylamine are dissolved in 200 ml of dry toluene and within 15 minutes a solution of 10 g of propionyl chloride in 50 ml of dry toluene is added. After the addition, stirring is continued for 1 hour at 60 ° C., triethylamine hydrochloride is separated off and the filtrate is extracted several times with 150 ml of water each time. After drying over sodium sulfate, toluene is distilled off and the residue that remains is dried at 100 ° C. in vacuo. After drying, 35.7 g (90.5% of theory) of 1-ethylcarbonyloxy-4- [4- (2-benzthiazolyloxy) -phenoxZ7-pentane are obtained.

The following compounds are prepared in an analogous manner according to Examples 1 - 6: Example R z No. 0 II 9 6-C1 S -CO-CH2-CH (CHs) 2 0 10 6-Cl 5 -CO CH2-CH2-OCH3 0 II 11 5-C1 S -CO-CH3 0 12 H S. -C-OH 0 13 HS -C-OCHz 0 II 14 6-C1 O -C -OH 0 15 6-Cl O -C-OK 0 Iv 16 6-C1 O -C-OCH, 0 II 17 5-C1 O -CO-CH2 -CH2 -Cl 0 18 6-C1 SO -C-NH2 0 19 6-C1 S -C "-N (CH5) 2 0 II 20 6-C1 S -CS-C2H6 and according to example 7 and 8: Example RAZ No . 22 6-C1 O -CH2, o °, E 0 II 23 6-C1 S -CH2-OC-CH3 0 24 6-C1 S -CH2-OC-CH2-CH2-C1 II. Formulation Examples Example A: An emulsifiable concentrate is obtained from 15 parts by weight of active ingredient, 75 parts by weight of cyclohexanone as solvent and 10 parts by weight of oxethylated nonylphenol (10 AeO) as emulsifier.

Example B: A wettable powder that is easily dispersible in water is obtained by adding 25 parts by weight of active ingredient to 64 parts by weight of kaolin-containing quartz as an inert substance, 10 parts by weight of lignosulfonic acid potassium and 1 part by weight of oleylmethyltauric acid Mixes sodium as a wetting and dispersing agent and grinds it in a pin mill.

Example C: A dusting agent is obtained by adding 10 parts by weight Mixes active ingredient and 90 parts by weight of talc as inert and in a hammer mill crushed.

EXAMPLE D: A granulate consists e.g. of about 2-15 parts by weight of active ingredient 98-85 parts by weight inert to granulate materials, such as e.g.

Attapulgite, pumice stone and quartz sand.

III, biological examples Example I: Pre-run treatment seeds of the annual pollutant grass Lolium were sown in pots and used as wettable powder formulated preparations according to the invention sprayed onto the surface of the earth. Afterward the pots were placed in a greenhouse for 4 weeks and the result the treatment (as in the following examples) by rating recorded in the numerals 1-5 (see table).

The preparations according to the invention showed a good effect against Lolium. Some of the compounds were also effective against other weeds.

Example II: Post-emergence treatment seeds of the grass weeds Lolium and Echinochloa were sown in pots and grown in the greenhouse. 3 weeks after The preparations according to the invention, formulated as wettable powders, were sown sprayed on the plants and the effect after standing in the greenhouse for 4 weeks of the preparations rated.

The compounds according to the invention showed a good action against Lolium and Echinochloa. They were also effective against other weeds.

Example III: Compatibility with Crop Plants In further experiments seeds from a large number of cultivated plants, e.g. soybean, Sugar beet, rapeseed, French beans and cotton, laid out in pots. Part of the pots was treated immediately (pre-emergence), the rest were placed in the greenhouse, until the plants had developed 2 to 3 real leaves, and then with those according to the invention Substances sprayed (post-emergence).

The results, which were observed 4 to 5 weeks after application, show that the substances according to the invention dicotyledonous cultures before and post-emergence procedures even with 2.5 kg / ha completely or almost leave completely undamaged. Some substances also protect Gramineae cultures like barley, sorghum, corn, wise men or rice. The substances are thus related the weed effect described in the previous examples is highly selective.

Tabel: Damage effect in% Weeds crops value number 0-20 0-20 1 20-40 20-40 2 40-60 40-60 3 60-80 60-80 4 80-100 80-100 5

Claims (4)

claims 3 / i compounds of the formula I where R: halogen, CF3, NO2, CN, (Cl-C4) -alkyl, (C1-C4) -alkoxy, (C1-C4) -alkylthio, A: O, S, NH or N- (C1-C4) -Alkyl, R1: halogen, methyl, CF3, R2: H, (C1-C4) -alkyl, n: 0-3, m: 0-2, Z: a group of the form Alkenyl, phenyl, ((C1-C4) -alkyl-phenyl, (C1-C4) -alkoxyphenyl, halophenyl, trifluoromethylphenyl or nitrophenyl. 2. Process for the preparation of compounds of the formula I, characterized in that a) compounds of the formula II with compounds of the formula III converts, b) compounds of the formula IV 1) with compounds of the formula V. where B represents halogen or a sulfoester group, for example the mesyl or tosyl radical, or 2) with compounds of the formula VI reacts, c) compounds of the formula I in which Z represents the -COOR2 group, hydrogenated and the alcohols obtained (Z = CH20H), if desired by reaction with carboxylic acids, carboxylic acid halides or anhydrides, into the corresponding carboxylic acid esters (Z = -CH2-OC ( O) -R9) or by reaction with carbamic acid halides or isocyanates in carbamic acid esters, or d) the compounds obtained according to processes a) and b) are converted into other compounds of the formula I according to the invention by saponification, salification, acid chloride formation, esterification, transesterification, amidation, elimination or addition of water or addition of hydrogen sulfide. 3. Herbicidal agents, characterized in that they contain a compound of Formula 1. 4. Use of compounds of the formula I for combating weeds, in particular for combating grass weeds in crops of useful plants.