CH623202A5 - Herbicide containing N,N-disubstituted alanine derivatives - Google Patents

Description

623 202

2nd

PATENT CLAIMS 1. Herbicidal agent, characterized in that it is an N, N-disubstituted alanine derivative of the general formula as active ingredient

COY

(I)

CHC00N = CR1R2

The invention relates to a herbicidal composition comprising N, N-disubstituted alanine derivatives and a process for their preparation.

The compound group contained in the agent according to the invention is of particular interest insofar as the alanine derivatives in question have selective herbicide properties.

These N, N-disubstituted alanine derivatives correspond to the general formula:

10 GOY

(X),

contains

where X, Y, Z, n and Rj and R2 have the following meaning:

each individual X corresponds to a hydrogen, fluorine, chlorine, bromine or iodine atom and n is an integer from 1 to 5;

Y corresponds to an optionally substituted aryl group;

Z corresponds to an alkyl group;

Ri corresponds to an acyl, a carboxyl, an alkoxy-carbonyl, an aminocarbonyl, a mono- or dialkyl-aminocarbonyl or mono- or diarylaminocarbonyl group and

R2 corresponds to an optionally substituted alkyl, alkenyl, aryl, aralkyl, heterocyclyl, alkoxy, alkylthio or acyl group.

2. Composition according to claim 1, characterized in that in formula I X corresponds to a chlorine or fluorine atom and n is 1 or 2, while Y corresponds to a phenyl and Z to a methyl group.

3. Composition according to claim 2, characterized in that Rj is an acyl or alkoxycarbonyl group having 1 to 6 carbon atoms, an aminocarbonyl group, a mono- or dialkyl-substituted aminocarbonyl group in which each alkyl group contains 1 to 4 carbon atoms, a monoaryl-aminocarbonyl group or a dihalophenylaminocar- bonyl group corresponds to, while R2 corresponds to an alkyl group having 1 to 4 carbon atoms, an acyl group having 1 to 6 carbon atoms, a phenyl group, a benzyl group or an alkoxy, alkylthio or cyanoalkylthio group having 1 to 4 carbon atoms.

4. A process for the preparation of the compound according to claim 1 or 2, characterized in that a compound of the general formula:

(II)

CHCOOH

z reacts with a compound of the general formula

R

1

B0N = C

(III)

35

45

50

(I)

CHCOON = CR1R2

20 wherein each individual X represents a hydrogen, fluorine, chlorine, bromine or iodine atom and n represents an integer from 1 to 5;

Y represents an optionally substituted aryl group; Z represents an alkyl group;

25 Ri represents an acyl, a carboxyl, an alkoxycarbonyl, an aminocarbonyl, a mono- or dialkylaminocarbonyl or a mono- or diarylaminocarbonyl group and

R2 represents an optionally substituted alkyl, alkenyl, aryl, alkaryl, heterocyclyl, alkoxy, alkylthio or acyl-30 group.

Preferred among them are those compounds according to the general formula I in which X represents a chlorine or fluorine atom, n is 1 or 2, while Y represents a phenyl group and Z represents a methyl group.

Among these preferred compounds, the 3,4-di-chloro, the 3-chloro-4-fluoro, the 4-chloro and the 4-fluoro derivatives are of particular interest.

Also preferred are compounds in which I X in the general formula represents a chlorine or a fluorine atom; n is 1 or 2; Y stands for a phenyl and Z for a methyl group, while Rj one of the following groups: an acyl or alkoxycarbonyl group with 1 to 6 C atoms, an aminocarbonyl group, a mono- or dialkyl-substituted aminocarbonyl group, in which each alkyl group 1 to Contains 4 carbon atoms, a monoarylaminocarbonyl group or a dihalophenylaminocarbonyl group; and R2 represents an alkyl group with 1 to 4 carbon atoms, an acyl group with 1 to 6 carbon atoms, a phenyl group, a benzyl group or an alkoxy, an alkylthio or a cyanoalkylthio group with 1 to 4 carbon atoms.

It should be noted that many of the compounds of the formula I exhibit geometric or optical isomerism and that the individual isomers of these compounds and their isomeric mixtures can be used in the agent according to the invention.

The process for the preparation of the compounds of the formula I, which also forms part of the invention, is characterized in that a compound of the formula:

60

65

GOY

CHCOOH

(II)

R,

3rd

623 202

reacted with a compound of the formula:

where X, Y, Z, n, Rt and R2 have the above meaning.

Since the reaction is a condensation process with elimination of water, the reaction is preferably carried out in the presence of a dehydrating agent which absorbs this by-product; an example of a suitable means of dehydration is dicyclohexylcarbodi-imide. The reaction proceeds at room temperature and is preferably carried out in an inert liquid medium in which both the reactants and the dehydrating agent are soluble. A preferred solvent is methylene chloride. During the reaction, the dicyclo-hexylcarbodiimide is converted into dicyclohexylurea, which is filtered off; the remaining mixture is worked up in the usual way.

The compounds of formula I can be used as herbicides in a manner known per se, i. H. they can be used with a suitable carrier and / or a surfactant.

The compounds have been found to be of particular interest in the selective control of wind oats in cereal fields, particularly in wheat and barley fields; the herbicide according to the invention, in which it is contained as an active ingredient, is applied to the affected area in a manner known per se.

The term "carrier" here means a solid or liquid material, which can be inorganic or organic and of synthetic or natural origin and with which the active ingredient is mixed or prepared in such a way that its application to the plant, the seeds, the soil or a other object to be treated or their storage, transport or handling is facilitated. The carrier can be a solid or a liquid, all substances being suitable which are suitable for the preparation of agents for controlling plant growth or pests.

Suitable solid carriers are natural and synthetic clays and silicates, e.g. B. natural silica such as diatomaceous earth; Magnesium silicates, e.g. B. Talk; Magnesium aluminum silicates, e.g. Attapulgite and vermiculite; Aluminum silicates, e.g. B. kaolinites, montmorillinites and mica; Calcium carbonates; Calcium sulfate; synthetic hydrated silicon oxides and synthetic calcium or aluminum silicates; Elements such as carbon or sulfur; Natural and synthetic resins, e.g. B. coumarone resins, polyvinyl chloride and styrene polymers and copolymers; solid polychlorophenols; Bitumen; Waxes, e.g. Bees or paraffin wax and chlorinated mineral waxes; as well as solid fertilizers, e.g. B. Superphosphates.

Examples of suitable liquid carriers are water, alcohols, such as isopropanol or a glycol; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; Ether; aromatic hydrocarbons such as benzene, toluene and xylene; Petroleum fractions such as kerosene or light oils; chlorinated hydrocarbons such as carbon tetrachloride, perchlorethylene or trichloroethane including the liquefied, normally vapor or gaseous compounds. Mixtures of different liquids are often also suitable.

An emulsifying or dispersing or wetting agent, which can be non-ionic or ionic, can serve as the surface-active agent. All surfactants commonly used for herbicides or insecticides are suitable. Examples of suitable surface-active agents are: the sodium or calcium salts of polyacrylic acids and lignin sulfonic acids; the condensation products of fatty acids or aliphatic amines or amides with at least 12 carbon atoms in the molecule with ethylene oxide and / or propylene oxide; Fatty acid esters of glycerol, sorbitol, sucrose or pentaerythritol and their condensates with ethylene oxide and / or propylene oxide; Condensation products of fatty alcohols or alkylphenols, e.g. B. p-octylphenol or p-octyl-cresol, with ethylene oxide and / or propylene oxide; Sulfates or sulfonates of these condensation products; Alkali or alkaline earth metal salts, preferably sodium salts of sulfur or sulphonic acid esters with at least 10 carbon atoms in the molecule, e.g. B. sodium lauryl sulfate, sodium sec-alkyl sulfates, sodium salts of sulfonated castor oil and sodium alkyl aryl sulfonates, such as sodium dodecylbenzenesulfonate, and polymers of ethylene oxide and copolymers of ethylene and propylene oxide.

The agents produced with the active substances mentioned can be wettable powders, dusts, granules, solutions, emulsifiable concentrates, emulsions, suspension concentrates or aerosols which, generally speaking, 0.5 to 95% by weight, preferably 0.5 to 75% by weight Contain active ingredient. Wettable powders are usually prepared so that they contain 25, 50 or 75% active ingredient and usually also a solid carrier, 3 to 10% by weight of dispersant and, if necessary, up to 10% by weight of stabilizers and / or other additives, such as agents included to facilitate penetration or sticking. Dusts are usually concentrates, the composition of which corresponds to that of the wettable powders, but the dispersant has been omitted. They are diluted on the spot with further solid carrier, so that an agent is obtained which generally contains 0.5 to 10% by weight of active ingredient. Granules usually have a grain diameter of approximately 0.15 to 1.7 mm and can be produced using agglomeration or impregnation methods. They usually contain 0.5 to 25% by weight of active ingredient and up to 10% by weight of additives such as stabilizers, retarders and binders. In addition to the solvent and optionally an auxiliary solvent, emulsifiable concentrates usually contain 10 to 50% w / v. Active ingredients, 2 to 20% w / v. Emulsifiers and up to 20% w / v. suitable additives, such as stabilizers or agents to facilitate penetration or to prevent corrosion. Suspension concentrates are prepared in such a way that a stable, non-settling, flowable product is obtained; they usually contain 10 to 75% by weight of active ingredient, 0.5 to 15% by weight of dispersant, 0.1 to 10% by weight of suspending agent, such as protective colloids or thixotropic agents, and up to 10% by weight of suitable additives, such as Defoamers, corrosion inhibitors, stabilizers or agents to facilitate penetration or adhesion; water or an organic liquid in which the active substance is practically insoluble is present as the carrier, it being possible for certain organic solids or inorganic salts which may prevent settling or, if water is present, freezing to be dissolved in the carrier.

The aqueous dispersions and emulsions, e.g. B. those obtained by diluting a wettable powder or concentrate according to the invention also fall under the invention. The emulsions can be of the water-in-oil or oil-in-water type and have a thick, mayonnaise-like consistency. The examples serve to explain the invention in more detail.

5

10th

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20th

25th

30th

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65

623 202

4th

example 1

Preparation of N-benzoyl-N- (3-chloro-4-fluorophenyl) alanine-2,3-pentadione-2-monoxime ester N-benzoyl-N- (3-chloro-4-fluorophenyl) alanine (6.4 g, 0.02 mol) was dissolved in methylene chloride (60 ml) containing 2,3-pentanedione-2-monoxime (2.3 g, 0.02 mol). 4.4 g of dicyclohexylcarbodiimide in 40 ml of methylene chloride were added to the reaction mixture with stirring. The course of the reaction was monitored by means of thin layer chromatography (silica plates), the eluent being methylene chloride.

The reaction was completed within 8 hours, after which the N, N'-dicyclohexylurea was filtered off. To

The residue was recrystallized from ethyl acetate / petroleum ether (bp. 60 to 80 ° C.). The product obtained in a yield of 21% / c melted at 15M to 161 ° C.

Analysis: C21H20N2O4Fa calc .: found:

C 60.2 C 59.9

H 4.8 N H 5.0 N

6.7% 6.7%

Examples 2 to 6 10 Using the method used in Example 1, a number of related compounds were prepared, the structure and physical properties of which are listed in Table 1.

Table 1

"? ° R

- N-CH-C00IT = C

I \

ch3 r £

Bei- X

game

No.

R1

R2

Fp. Aus

(° C) loot

(%)

analysis

% C% H% N

o o

II II

2 F Cl -CN (Et) 2 -C-CH3 134-136 82 O O

QmHzsOsNsFCI calc .: 58.9 5.1 8.6 found: 59.3 5.3 8.2

3 F

4 F

Cl a

-c-ch, -c-oc2h,

82

Cl

Cl

O O

Il II

-C-CH3 -C-NH 154-155 52

C22H20O6N2FCl calc .: 57.1 4.3 6.0 found: 57.5 4.3 5.7

QsHziOsNgFCl calc .: 61.3 4.1 8.3 found: 61.2 4.3 8.3

165-166 47

C26H19OsN3FC13 calc .: 54.0 3.3 found: 54.1 3.0

O O

Il II

-c-nh -c-ch3

I.

ch3

172-174 39

C21H19OsN3FC1 calc .: 56.2 4.3 found: 55.9 4.7

7.3 7.2

9.4 9.2

Example 7

Attempts to determine the herbicide effect In order to determine their herbicid effect, the compounds according to the invention were tested on a representative number of plants. The test plants used were: maize, zea mays (M); Oats, Avena sativa (Ha); Raygrass, Lolium perenne (R); Chicken millet, Echinochloa crusgalli (Hi); Pea, risum stivum (E); Flax, linum usitatissimum (L); Mustard, sina

pis alba (S); Sugar beet, beta vulgaris (Z); and tomato, Solanum lycopersicum (T).

Two types of experiments were carried out, namely those before emergence and those after emergence. To test the agents before emergence of the plants, the soil, into which seeds of the above-mentioned test plants had been introduced shortly before, was treated with a liquid preparation of the compound in question

5

sprayed. The post-emergence experiments were carried out in two ways, namely by soaking the soil and spraying the plant leaves.

In the former case, the soil in which the above test plants had grown was treated with a liquid 5

Preparation of the compound to be tested according to the invention is impregnated, while in the second case the sprung plantlets themselves were sprayed with a liquid preparation of the agent.

10th

In these experiments, a steam-sterilized compost mixture according to John Innes was used as soil, in which half of the peat was replaced by vermiculite in bulk.

The preparations used for these experiments had been prepared in such a way that solutions of the compounds in question in acetone which additionally contained 0.4% by weight of a condensate of alkylphenol and ethylene oxide available under the protected trade name “Triton X-155” were also included Diluted water. In the experiments in which the soil was sprinkled before the leaves or the leaves of the emerged plants were sprayed, the acetone solutions were

623 202

solutions diluted with an equal volume of water and the preparations obtained in this way applied in two different dosages, each containing 5 to 1 kg of active ingredient per ha, the volume applied in both cases being 400 l / ha. In the experiments in which the soil was soaked around the raised plantlets, one volume of acetone solution was diluted with water to 155 volumes and the resulting preparation was used in a dosage which was about 30001 / ha or, in other words, 10 kg of active ingredient per ha corresponded.

The herbicide activity of the respective compound was determined visually in the tests after emergence 7 days after spraying the leaves (or after soaking the soil) and in the tests before emergence 11 days after spraying the soil and classified on a scale from 0 to 9. A rating of 0 corresponds to no effect on the treated plants, a rating of 2 corresponds to a reduction in the fresh weight of the stem and leaves of the plants of approximately 25%, a rating of 5 corresponds to a reduction of approximately 55%, and a rating of 9 shows one 95% reduction.

The test results are shown in Table 2.

Table 2

Compound Dosage After emergence (planting) Seeds of example kg / ha soil soaking Spray the leaves before emergence

No. MHaRHiELS ZT M Ha R Hi EL S ZT MHaRHiELS Z

1 10 045157620

5 47607760207703773

1 07307621 132230

2 10 266020000

5 16731430114763740

1 1662122 00041063

3 10 357056534

5 76767755426756786

1 06503520206200350

4 10 065046603

5 6674464221472378

1 25102010100201541

5 10 043023401

5 56664732102622462

1 052024100 02001 10

6 10 000026500

5 57627650105722672

1 07607640 2000530

s