DE3807532A1 - Pyrimidine-carboxylic acids, their preparation, and their use as herbicides - Google Patents

Abstract

Compounds of the formula I or salts thereof <IMAGE> in which R<1> is haloalkyl, R<2> is hydrogen, halogen, cyano, (substituted) alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylsulphonyl, (substituted) cycloalkyl, (substituted) phenoxy; R3 is hydrogen, alkyl, alkoxy, halogen or cyano; R4 is hydrogen, alkyl or alkoxy; X is O, S or NR5; and Y is a radical -NR5R6 or -OR8, have advantageous herbicidal properties; they are outstandingly suitable for combating weeds in crops of useful plants.

Description

EP-A 2 12 969 describes pyrimidinyloxyalkanamides herbicidal properties known.

It has now been found that pyrimidine carboxylic acid derivatives, which carry special haloalkyl radicals in the pyrimidine part, one have high selectivity in your application, and therefore especially for use as herbicides in agriculture are suitable.

The present invention therefore relates to Compounds of the formula I or their salts,

wherein
R₁ (C₁-C₈) haloalkyl;
R₂ is hydrogen, halogen, cyano, (C₁-C₄) alkyl which can be substituted one or more times by halogen, nitro, cyano, (C₁-C₄) alkoxy, (C₁-C₄) alkylthio or -NR₅R₆; (C₂-C₄) alkenyl, (C₂-C₄) alkynyl, (C₁-C₄) alkoxy, (C₁-C₄) alkylthio, (C₁-C₄) alkylsulfonyl, (C₃-C₈) cycloalkyl, by (C₁-C₄) alkyl can be mono- or polysubstituted; Phenoxy which is optionally substituted one or more times by halogen, NO₂ (C₁-C₄-alkyl, (C₁-C₄) -haloalkyl or (C₁-C₄) -alkoxy;
R₃ is hydrogen, (C₁-C₄) alkyl, (C₁-C₄) alkoxy, halogen or cyano;
R₄ is hydrogen, (C₁-C₄) alkyl or (C₁-C₄) alkoxy;
XO, S or NR₅;
Y is a residue -NR₅R₆ or -OR₈;
R₅ is hydrogen or (C₁-C₄) alkyl;
R₆ (C₁-C₄) alkyl, CH₂R₇, phenyl or naphthyl, both optionally one or more times by halogen, NO₂, (C₁-C₄) alkyl, (C₁-C₄) alkoxy, cyano or (C₁-C₄) -Alkylthio can be substituted;
R₇ phenyl, which is optionally mono- or polysubstituted by halogen, NO₂, (C₁-C₄) alkyl, (C₁-C₄) haloalkyl, (C₁-C₄) alkoxy, (C₁-C₄) alkylthio or cyano, (C₃-C₈) -cycloalkyl, which may optionally be substituted one or more times by (C₁-C₄) alkyl, furyl, thienyl, pyridyl or pyrimidinyl, these radicals each optionally by halogen, (C₁-C₄) - haloalkyl or (C₁-C₄) alkyl may be substituted; and
R₈ is hydrogen or (C₁-C₄) alkyl
mean, with the proviso that those compounds of formula I, wherein R₁ CF₃, X is oxygen and R₆ -CH₂R₇, are excluded.

Those compounds of the formula I in which Y is hydroxy can form salts in which the hydrogen is replaced by a cation which is suitable for agriculture. These salts are generally metal, especially alkali, alkaline earth, optionally alkylated ammonium or amine salts. Halogen means in particular fluorine, chlorine or bromine. The prefix "halo" in the designation of a substituent means here and below that this substituent can occur one or more times with the same or different meaning. The prefix halo contains fluorine, chlorine, bromine and iodine, especially fluorine, chlorine or bromine. Examples of haloalkyl are:
CCl₃, CHCl₂, CH₂Cl, CBr₃, CF₂Cl, CClF₂, CF₂CHF₂, CF₂CF₃, CF₂CHFCF₃, CF₂CHClF, CF₂CHCl₂, CCl₂CCl₃, n-C₃F₇, -CH (CF₃) ₂, n-C₄F₉, n-C₅-F₁₁₁, n- -C₇F₁₅ and n-C₈F₁₇.

Halogen is especially chlorine and fluorine.

Preferred compounds of formula I are those in which
R₁ (C₁-C₈) haloalkyl, in particular the radicals -CCl₃, -CF₂CHF₂ or -CF₂CF₃;
R₂ (C₁-C₄) alkyl, (C₁-C₄) haloalkyl or (C₃-C₈) cycloalkyl;
R₃ is hydrogen, (C₁-C₄) alkyl or halogen;
R₄ is hydrogen, (C₁-C₄) alkyl or (C₁-C₄) alkoxy;
XO or S;
Y NR₅R₆ or OR₈;
R₅ is hydrogen or (C₁-C₄) alkyl;
R₆-CH₂R₇, phenyl which can be substituted one or more times by halogen, NO₂, (C₁-C₄) alkyl, (C₁-C₄) haloalkyl, (C₁-C₄) alkoxy or (C₁-C₄) alkylthio ;
R₇ phenyl which can be substituted one or more times by halogen, NO₂, (C₁-C₄) alkyl, (C₁-C₄) haloalkyl, (C₁-C₄) alkoxy, (C₁-C₄) alkylthio or cyano;
R₈ is hydrogen or (C₁-C₄) alkyl
mean, with the proviso that those compounds of formula I, wherein R₁ CF₃, X is oxygen and R₆ CH₂R₇, are excluded.

The present invention also relates to a method for the preparation of the compounds of formula I, thereby characterized in that a compound of formula II in Presence of a base with a compound

Formula III implements.  

The substituents R₁, R₂, R₃, R₄ and Y have the meanings as in formula I, V and W stand for halogen, hydroxy, a group NHR₅ or SH, where W for Halogen is, V hydroxyl, a group NHR₅ or SH must and in the event that V stands for halogen, W hydroxy, a group must mean NHR₅ or SH. The rest R₅ has that meaning given in formula I. Represents halogen here fluorine, chlorine, bromine or iodine, especially chlorine or bromine.

The compounds of the formula II and III are reacted preferably in inert aprotic solvents such as. B. Acetonitrile, dichloromethane, toluene, xylene, tetrahydrofuran, Dioxane, dialkyl ethers such as diethylene glycol dialkyl ether, in particular diethylene glycol dimethyl ether, or Dimethylformamide at temperatures between -10 ° C and the Boiling point of the solvent. Are suitable as bases the bases customary for this type of reaction, for example Carbonates and bicarbonates of alkali or Alkaline earth metals, alkali hydroxides, alkali alcoholates such as e.g. B. K-tert-butoxide, tert-amines, pyridine or substituted pyridine bases (e.g. 4-dimethylaminopyridine).

In the implementation of the compounds of formulas II and III has the use of phase transfer catalysts as proven very beneficial. Especially in the event that V for hydroxy, a group NHR₅ or SH and W for halogen is in the presence of a phase transfer catalyst the reaction time is greatly reduced and the yields significantly improved. As phase transfer catalysts quaternary ammonium and Phosphonium salts, crown ethers and cryptands as in W.E. Keller, Phase Transfer Reactions, Vol. I, II; 1985, 1986; Georg-Thieme-Verlag Stuttgart are described.  

The compounds of formula II can be synthesize basically known methods (cf. US-PS 43 43 803, DOS 36 44 799). The compounds of formula III are largely known and using customary methods easily accessible (see J. Am. Chem. Soc. 70, 677; Chem. Reports 70, 1836; Chem. Reports 87, 537; Chem. Reports 31, 3236).

The compounds of formula I according to the invention have a excellent herbicidal activity against a broad Spectrum of economically important mono- and dicotylers Harmful plants. Also difficult to fight perennials Weeds made from rhizomes, rootstocks or others Drive out permanent organs, the active ingredients are good detected. It does not matter whether the substances in the Pre-sowing, pre-emergence or post-emergence procedures applied will. Some representatives are examples of the monocotyledonous and dicotyledonous weed flora caused by the compounds of the invention are controlled can, without being limited by the name certain types should be done.

On the side of the monocot weed species, e.g. B. Avena, Kolium, Alopecurus, Phalaris, Echinochloa, Digitaria, Setaria etc. as well as Cyperus species from the annual group and on the part of the perennial species Agropyron, Cynodon, Imperata as well as sorghum etc. and also Persistent cyperus species well recorded.

This extends to dicotyledon weed species Spectrum of action on Sinapis, Ipomoea, Matricaria, Abutilon, Sida etc. on the annual side as well Convolvulus, Cirsium, Rumex, Artemisia etc. in the perennial weeds.

Under the specific culture conditions in the rice occurring weeds such as. B. Sagittaria, Alisma, Eleocharis, Scirpus, Cyperus etc. are from the  Active substances according to the invention are also outstanding fought.

Are the compounds of the invention before germination applied to the earth's surface, so either Leakage of weed seedlings completely prevented, or the weeds grow up to the cotyledon stage, but then stop growing and die finally complete after three to four weeks from.

When applying the active ingredients to the green parts of the plant the post-emergence procedure also occurs very quickly after the Treatment a drastic growth stop, and the Weed plants remain in that at the time of application existing growth stage stand or die after one certain time more or less quickly, so that on this way is harmful to crops Weed competition very early and sustainably through the Use of the new agents according to the invention can be eliminated can.

Although the compounds of the invention are one excellent herbicidal activity against mono- and dicotyledon weeds are cultivated plants economically important cultures such as B. wheat, Barley, rye, rice, corn, sugar beet, cotton and soy only slightly or not at all damaged. The The present compounds are suitable for these reasons very good for selective control of unwanted Plant growth in agricultural crops.

The agents according to the invention can be used as wettable powder, emulsifiable concentrates, emulsions, sprayable solutions, Dusts, mordants, dispersions, granules, Microgranules or ULV formulations in the usual Preparations are applied.  

The biological and / or chemical-physical parameters of the respective active ingredient determines the preferred one Type of formulation to use.

Spray powders are evenly dispersible in water Preparations in addition to the active ingredient except where appropriate a diluent or inert wetting agent, e.g. B. polyoxethylated alkylphenols, polyoxethylated Fatty alcohols, alkyl or alkylphenyl sulfonates and Dispersants, e.g. B. sodium lignosulfonic acid, 2,2′-dinaphthylmethane-6,6′-disulfonic acid sodium, dibutylnaphthalenesulfonic acid sodium or also Contain oleoylmethyl tauric acid sodium. The production takes place in the usual way, e.g. B. by grinding and mixing of the components.

Emulsifiable concentrates can e.g. B. by dissolving the Active ingredient in an inert organic solvent, e.g. As butanol, cyclohexanone, dimethylformamide, xylene or also higher-boiling aromatics or hydrocarbons Addition of one or more emulsifiers produced will. In the case of liquid active ingredients, the Part or all of the solvent content is eliminated. As For example, emulsifiers can be used: Alkylarylsulfonic acid calcium salts such as Ca-dodecylbenzenesulfonate or nonionic emulsifiers such as Fatty acid polyglycol esters, alkyl aryl polyglycol ethers, Fatty alcohol polyglycol ether, propylene oxide-ethylene oxide Condensation products, fatty alcohol propylene oxide ethylene oxide Condensation products, alkyl polyglycol ethers, Sorbitan fatty acid esters, polyoxethylene sorbitan fatty acid esters or polyoxethylene sorbitol ester.

Dusts can be obtained by grinding the active ingredient with finely divided, solid substances e.g. B. talc, natural Clays such as kaolin, bentonite, pyrophillite or diatomaceous earth receive.  

Granules can either by spraying the active ingredient on adsorbable, granulated inert material be produced or by applying Active substance concentrations by means of binders, e.g. B. Polyvinyl alcohol, sodium polyacrylic acid or also Mineral oils on the surface of carriers such as sand, Kaolinite or granulated inert material. Can too suitable active substances in the for the production of Fertilizer granules in the usual way, if desired in Mix with fertilizers, granulated.

The active ingredient concentration in wettable powders is e.g. B. about 10 to 90 wt .-%, the rest of 100 wt .-% consists of usual formulation components. With emulsifiable Concentrates can have the active ingredient concentration about 5 to 80 % By weight. Contain dusty formulations usually 5 to 20 wt .-%, sprayable solutions about 2 to 20% by weight. In the case of granules, the active ingredient content depends on Part of whether the active compound is liquid or solid and which granulation aids, fillers etc. be used.

In addition, the active ingredient formulations mentioned contain where applicable, the usual liability, network, Dispersing, emulsifying, penetrating, solvent, filling or carriers.

For example, these types of formulation above described in: Winnacker-Küchler, "Chemical Technology", Volume 7, C. Hauser Verlag Munich, 4th ed. 1986; van Falkenberg, "Pesticides Formulations", Marcel Dekker N.Y., 2nd Ed. 1972-73; K. Martens, "Spray Drying Handbook", 3rd Ed. 1979, G. Goodwin Ltd. London.

The ones to be used for these formulations Formulation aids (inert materials, emulsifiers,  Wetting agents, surfactants, solvents etc.) are for example in Marschen, "Solvents Guide", 2nd Ed., Interscience, N.Y. 1950; McCutcheon's, "Detergents and Emulsifiers Annual", MC Publ. Corp., Ridgewood N.J .; Sisley and Wood or "Encyclopedia of Surface Active Agents", Chem. Publ. Co. Inc., N.Y. 1964.

To be used in the commercial form existing concentrates, if necessary, in a customary manner diluted, e.g. B. with wettable powders, emulsifiable Concentrates, dispersions and sometimes also at Microgranules using water. Dusty and granulated preparations and sprayable solutions are usually no longer used before other inert substances diluted.

With the external conditions such as temperature, humidity i.a. the required application rate varies. she can fluctuate within wide limits, e.g. B. between 0.005 and 10.0 kg / ha or more of active substance, preferably it is however between 0.01 and 5 kg / ha.

Mixtures or mixed formulations with others Active ingredients, such as B. insecticides, acaricides, herbicides, Fertilizers, growth regulators or fungicides possibly possible.

The invention is illustrated by the following examples explained.  

Formulation examples

A. A dust is obtained by adding 10 parts by weight Active ingredient and 90 parts by weight talc or inert mixes and crushed in a hammer mill.

B. A water-dispersible, wettable powder is obtained by adding 25 parts by weight of active ingredient, 64 Parts by weight of quartz containing inert material, 10 Parts by weight of lignosulfonic acid potassium and 1 Part by weight of oleoylmethyl tauric acid sodium as a and dispersant mixes and grinds in a pin mill.

C. An easily dispersible in water Dispersion concentrate is obtained by 20 Parts by weight of active ingredient with 6 parts by weight Alkylphenol polyglycol ether (®Triton X 207), 3 Parts by weight of isotridecanol polyglycol ether (8 EO) and 71 parts by weight of paraffinic mineral oil (boiling range e.g. B. mixes about 255 to over 377 ° C) and in one Grinding ball mill to a fineness of less than 5 microns married.

D. An emulsifiable concentrate is obtained from 15 Parts by weight of active ingredients, 75 parts by weight of cyclohexanone as a solvent and 10 parts by weight of ethoxylated Nonylphenol (10 EO) as an emulsifier.

Chemical examples Example 123 (see Table 1) 1- (5-chloro-2-trichloromethyl-pyrimidin-4-yloxy) - ethyl propanoate

24.15 g (0.175 mol) are added to a solution of 9.33 g (0.035 mol) of 4,5-dichloro-2-trichloromethyl-pyrimidine and 4.13 g (0.035 mol) of ethyl 2-hydroxypropanoate in 150 ml of toluene. K₂CO₃ and a spatula tip of triethylbenzylammonium chloride. The mixture is heated to reflux for 6 hours. After cooling, the insoluble constituents are suctioned off and the filtrate is evaporated in vacuo. The substance is obtained as a viscous oil.
Yield: 11.37 g93.3% of theory. Th.
NMR (CDCl₃): δ 8.6 (s, 1H); 5.4 (q, 7 = 7 Hz, 1H); 4.2 (q, 7 = 7 Hz, 2H); 1.8 (d, 7 = 7 Hz, 3H); 1.3 (t, 7 = 7 Hz, 3H).

Example 308 (see Table 1) 2- [5-chloro-2- (1,1,2,3,3,3-hexafluoropropyl) pyrimidine-4- yloxy] butanoic acid benzylamide

To a solution of 5.61 g (0.02 mol) of 5-chloro-2- (1,1,2,3,3,3-hexafluoropropyl) -4-hydroxy-pyrimidine and 5.12 g (0.02 mol) 2-bromobutanoic acid benzylamide in 80 ml acetonitrile, 4.14 g (0.03 mol) potassium carbonate and a spatula tip of triethylbenzylammonium chloride are added. The mixture is heated to reflux for 10 h. The mixture is then allowed to cool to room temperature, the solid constituents are filtered off with suction and the filtrate is evaporated in vacuo. The resulting solid is recrystallized from diisopropyl ether.
Yield: 7.6 g83% of theory. Th.
Mp: 118-120 ° C

Example 240 (see Table 1) 2- [4-methyl-2- (1,1,2,2-tetrafluoroethyl) pyrimidin-6-yloxy] - acetic acid-N-methyl-N-phenyl-amide

To a solution of 4.2 g (0.02 mol) of 4-hydroxy-6-methyl-2- (1,1,2,2-tetrafluoroethyl) pyrimidine and 4.6 g (0.02 mol) of bromoacetic acid. N-methyl-N-phenyl-amide in 90 mol of acetonitrile is added 4.14 g (0.03 mol) of K₂CO₃ and a spatula tip of triethylbenzylammonium chloride and the reaction mixture is heated at reflux for 6 h. After cooling, all solid components are suctioned off and the filtrate is evaporated in vacuo. The solid obtained is recrystallized from ethanol.
Yield: 6.3 g 88% of theory. Th.
M.p .: 70-71 ° C.

Example 302 (see Table 1) S- [5-chloro-2-trifluoromethyl-pyrimidin-4-yl] - mercaptoacetic acid ethyl ester

6.51 g (0.03 mol) of 4,5-dichloro-2-trifluoromethyl-pyrimidine and 3.6 g (0.03 mol) of ethyl thioglycolate are dissolved in 150 ml of ethanol. 2.96 g (0.03 mol) of sodium acetate are added and the mixture is stirred at room temperature for 5 h. The solid constituents are then suctioned off and the filtrate is evaporated in vacuo. The resulting solid is recrystallized from diisopropyl ether.
Yield: 6.67 g74% of theory. Th.
M.p .: 88-89 ° C.

Example 139 (see Table 1) N- (5-bromo-2-trichloromethyl-pyrimidin-4-yl) amino ethyl acetate

7.8 g (0.025 mol) of 5-bromo-4-chloro-2-trichloromethyl-pyrimidine and 3.91 g (0.028 mol) of glycine ethyl ester hydrochloride  dissolved in 90 ml of acetonitrile. 5.29 g (0.063 mol) are added NaHCO₃ added and heated to reflux for 3 h. After cooling all solid components are suctioned off and the filtrate evaporated in vacuo. The resulting solid is made Recrystallized ethanol.

Yield: 8.8 g93% of theory. Th.
Mp: 95 ° C.

The following compounds listed in Table 1 can be according to the procedures described above produce.

The following abbreviations are used in Table 1:
Et = ethyl
Me = methyl
Bu = n-butyl

Biological examples

The damage to the weed plants or the Crop tolerance was determined according to a key rated, in which the effectiveness by value numbers from 0-5 is expressed. Here means:

0 = without effect or damage
1 = 0-20% effect or damage
2 = 20-40% effect or damage
3 = 40-60% effect or damage
4 = 60-80% effect or damage
5 = 80-100% effect or damage

1. Pre-emergence weed action

Seeds or rhizome pieces of mono- and dikoytyls Weed plants were grown in sandy plastic pots Clay soil laid out and covered with earth. The in the form of wettable powders or emulsion concentrates Compounds according to the invention were then as aqueous Suspensions or emulsions with a water application rate from converted 600-800 l / ha in different Dosages applied to the surface of the earth. After the treatment, the pots were in the greenhouse set up and under good growth conditions for the Weeds kept. The visual rating of the plant or the accidental damage occurred after the emergence of the Trial plants after a trial period of 3-4 weeks in Comparison to untreated controls.

As the rating values in Table 2 show, the Compounds according to the invention a good herbicidal Pre-emergence effectiveness against a wide range of Grasses and weeds.

Table 2

Effect of the compounds according to the invention in pre-emergence

2. Post-emergence weed action

Seeds or rhizome pieces of mono- and dicotyledon weeds were laid out in plastic pots in sandy clay soil, covered with earth and in the greenhouse under good Growth conditions attracted. Three weeks after the The test plants were sown at the three-leaf stage treated.

The as wettable powder or as emulsion concentrates formulated compounds according to the invention were in different doses with a water application rate of  converted 600-800 l / ha on the green parts of the plant sprayed and after about 3-4 weeks of standing Trial plants in the greenhouse under optimal Growth conditions the effect of the preparations optically in Rating compared to untreated controls.

The agents according to the invention also have post-emergence good herbicidal activity against a broad spectrum economically important grasses and weeds (Table 3).

Table 3

Effect of the compounds of the invention in post-emergence

3. Crop tolerance

In further experiments in the greenhouse, seeds of one larger number of crops and weeds in sandy clay soil laid out and covered with earth. Part of the pots were immediately as described under 1. treated, the rest in the greenhouse until the Plants had developed two to three real leaves and then with the substances according to the invention in different dosages, as described under 2., sprayed.

Four to five weeks after application and standing time in the Greenhouse was determined by means of an optical rating, that the compounds according to the invention have two cotyledons Cultures such as B. soybeans, cotton, rapeseed, sugar beet and Pre-and post-emergence potatoes themselves high dosage of active ingredient undamaged. Some Substances also protect Gramineae crops such as B. barley, wheat, rye, sorghum, millet or Rice. The compounds of formula I thus have a high Selectivity when used to combat undesirable Plant growth in agricultural crops.

4. Herbicidal action when used in rice

Bulbs and rhizomes or young plants or seeds various rice weeds such as Cyperus species, Eleocharis, Scirpus and Echinochloa were closed in Plastic pots laid out in special rice soil or planted and with water up to a height of 1 cm above pent up the floor. The same procedure was followed with rice plants.

Pre-emergence, d. H. 3-4 days after transplanting the compounds of the invention became more aqueous Pouring suspensions or emulsions into the water or sprinkled into the water as granules.  

The herbicidal activity and a possible harmful effect vis-à-vis rice rated. The results showed that the Compounds according to the invention for selective Weed control.

Compared to previous rice herbicides, the Compounds according to the invention from that numerous weeds, especially difficult to control, which germinate from permanent organs, fight effectively and be tolerated by rice.

Claims (6)

1. Compounds of the formula I or their salts, wherein
R₁ (C₁-C₈) haloalkyl;
R₂ is hydrogen, halogen, cyano, (C₁-C₄) alkyl which can be substituted one or more times by halogen, nitro, cyano, (C₁-C₄) alkoxy, (C₁-C₄) alkylthio or -NR₅R₆; (C₂-C₄) alkenyl, (C₂-C₄) alkynyl, (C₁-C₄) alkoxy, (C₁-C₄) alkylthio, (C₁-C₄) alkylsulfonyl, (C₃-C₈) cycloalkyl, by (C₁-C₄) alkyl can be mono- or polysubstituted; Phenoxy which is optionally substituted one or more times by halogen, NO₂ (C₁-C₄-alkyl, (C₁-C₄) -haloalkyl or (C₁-C₄) -alkoxy;
R₃ is hydrogen, (C₁-C₄) alkyl, (C₁-C₄) alkoxy, halogen or cyano;
R₄ is hydrogen, (C₁-C₄) alkyl or (C₁-C₄) alkoxy;
XO, S or NR₅;
Y is a residue -NR₅R₆ or -OR₈;
R₅ is hydrogen or (C₁-C₄) alkyl;
R₆ (C₁-C₄) alkyl, CH₂R₇, phenyl or naphthyl, both optionally one or more times by halogen, NO₂, (C₁-C₄) alkyl, (C₁-C₄) haloalkyl, (C₁-C₄) alkoxy , Cyano or (C₁-C₄) alkylthio may be substituted;
R₇ phenyl, which is optionally mono- or polysubstituted by halogen, NO₂, (C₁-C₄) alkyl, (C₁-C₄) haloalkyl, (C₁-C₄) alkoxy, (C₁-C₄) alkylthio or cyano, (C₃-C₈) -cycloalkyl, which may optionally be substituted one or more times by (C₁-C₄) alkyl, furyl, thienyl, pyridyl or pyrimidinyl, these radicals each optionally by halogen, (C₁-C₄) - haloalkyl or (C₁-C₄) alkyl may be substituted; and
R₈ is hydrogen or (C₁-C₄) alkyl
mean, with the proviso that those compounds of formula I, wherein R₁ CF₃, X is oxygen and R₆CH₂R₇, are excluded. 2. Compounds of formula I of claim 1, wherein
R₁ (C₁-C₈) haloalkyl, in particular the radicals -CCl₃, -CF₂CHF₂ or -CF₂CF₃;
R₂ (C₁-C₄) alkyl, (C₁-C₄) haloalkyl or (C₃-C₈) cycloalkyl;
R₃ is hydrogen, (C₁-C₄) alkyl or halogen;
R₄ is hydrogen, (C₁-C₄) alkyl or (C₁-C₄) alkoxy;
XO or S;
Y NR₅R₆ or OR₈;
R₅ is hydrogen, (C₁-C₄) alkyl;
R₆ -CH₂R₇, phenyl, which may be substituted one or more times by halogen, NO₂, (C₁-C₄) alkyl, (C₁-C₄) haloalkyl, (C₁-C₄) alkoxy or (C₁-C₄) alkylthio can;
R₇ phenyl, which can be substituted one or more times by halogen, NO₂, (C₁-C₄) alkyl, (C₁-C₄) haloalkyl, (C₁-C₄) alkoxy, (C₁-C₄) alkylthio or cyano ;
R₈ is hydrogen or (C₁-C₄) alkyl
mean, with the proviso that those compounds of formula I, wherein R₁ CF₃, X is oxygen and R₆ CH₂R₇, are excluded. 3. A process for the preparation of the compounds of formula I of claims 1 or 2, characterized in that a compound of formula II in the presence of a base with a compound Formula III implements. 4. Herbicidal agents, characterized in that they have a Compound of formula I of claims 1 or 2 or their Contain salts in addition to usual carriers. 5. Use of compounds of formula I of claim 1 or 2 or their salts as herbicides. 6. Procedure for controlling harmful plants, thereby characterized in that one on this or the cultivated soils effective amount of a compound of formula I of claim 1 or 2 or their salts applied.