CS200510B2 - Herbicide and process for preparing effective compounds - Google Patents

Abstract

The present invention provides herbicidally active carbanilic acid esters of the general formula I (I) in which R represents an aliphatic or cycloaliphatic hydrocarbon group, x represents an alkyl or alkoxy group or a halogen atom and n represents 0 or 1.

Description

The present invention relates to a novel herbicidal composition comprising a carbanilic acid ester as an active ingredient and a process for the preparation of these compounds.

It is already known that certain carbanilic acid esters, such as, for example, isopropyl ester of carbanilic acid and isopropyl ester of 3-chlorocarbanilic acid, are herbicidally active. (DT-PS 833 274). However, these compounds do not act satisfactorily against dicotyledonous weeds in the lower amounts used and, moreover, have the disadvantage of limited selectivity.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a composition of the aforementioned species which also exhibits a strong herbicidal activity against dicotyledonous weeds and, at the same time, a low selectivity.

This object is achieved by the preparation of a herbicidal composition which comprises at least one compound of the formula I,

CN Nl · ^X! - CO-OR (where in which R

R is (C1-C3) -alkyl or allyl,

X is methyl or chloro and n is 0 or 1.

The compounds according to the invention are distinguished by a remarkable herbicidal activity against dicotyledons and also monocotyledonous weeds such as Stellaria media, Senecio vulgaris, Matricaria chamomilla, Lamium amplexicaule, Centaurea cyanus, Amaranthus tetroflexus, Galium aparine, Chrysantemium segeturi, Chrysantemum segetur, Fatua, Alopecurus myosuroides, Echinochloa crus galii, Setaria italica, Digitaria sanguinalis, Poa annua and others.

Due to their excellent selective properties, these compounds can be used in agricultural crops such as alfalfa, bush beans, cotton, soybeans, peanuts and wheat or other cultures.

In addition, it has been found that the compounds of the invention exhibit defoliant effects and growth-regulating properties in the strict sense.

The compounds according to the invention act satisfactorily already in amounts of - 0.5 kg / hectare. and can be used, depending on the purpose of application, without damaging the cultivated cultures in amounts of up to 5 kg / ha and more, both before and after emergence of the plant.

The compounds of the invention may be applied either alone or together in admixture or in admixture with other active substances.

Depending on the purpose of use, for example, the following herbicidal substances are available which may also be added immediately before application of the compounds according to the invention: substituted aniline, substituted alkocarboxylic acids and their salts, esters and amides, substituted ether, substituted arsonic acids, salts, esters and amides, substituted benzimidazoles, .............

substituted benzisothiazoles, substituted benzthiadiazine dioxides,; substituted benzoxazines, substituted benzoxazinones, substituted benzthiazoles, substituted benzthladiazoles, substituted biurets, substituted quinolines, substituted carbamates, substituted aliphatic carboxylic acids, as well as their salts, esters and amides,. substituted aromatic carboxylic acids and their salts, esters and amides, substituted carbamoylalkylthio or dithiophosphates, substituted quinazolines, substituted cycloalkylamidocarboxythiol acids, and their salts, esters and amides.

substituted cycloalkylcarboxyamidothiazoles; ....

substituted dicarboxylic acids as well as their esters and amides; substituted dihydrobenzofuranylsulfonates,. .

substituted disulfides, substituted. - dipyridyl salts, ...

substituted dithiocaramates, substituted dithiophosphoric acids, and the like. i. there are salts, esters and nmides thereof;

substituted - urea,. . ..

substituted hexahydro-1H-carbothioates, substituted hydantoins, substituted hydrazides.

substituted hydrazonium salts, substituted isoxazolpyrimidones, substituted imidazoles, substituted isothiazolopyrimidones, substituted ketones, substituted-naphthoquinones, substituted aliphatic nitriles, substituted aromatic nitriles, substituted axadiazoles, substituted dioxadiazones, substituted oxadiazolidinediones, substituted oxadiazolidinediones, substituted oxadiazolidinediones, their salts and esters, substituted phosphonic acids, and their salts, esters and amides, substituted phosphonium chlorides, substituted phosphonalkylglycines, substituted phosphites, substituted phosphoric acids, and their salts, esters and amines, substituted piperidines, substituted pyrazoles, substituted pyrazolalkylcarboxylic. acids, as well as their salts, esters or amides, substituted pyrazolium salts, substituted pyrazolium alkyl sulfates, substituted nyridazines.

substituted, pyridazones, substituted pyridine carboxylic acids, as well as their salts, esters and amides, substituted pyridines, ...........

substituted pyridine carboxylates, substituted pyridinones, substituted pyrimidones, substituted pyrrolidine carboxylic acids, as well as their salts, esters or amides, substituted pyrrolidines, substituted arylsulfonic acids, as well as their salts, esters and amides, substituted styrols, substituted tetrahydrooxazindiones, substituted tetrahydromethanoindenes tetrahydrodiazolithiones, substituted tetrahydrothiadiazinthiones, substituted tetrahydrothiadiazoldiones, substituted thiadiazoles, substituted aromatic amides of thiocarboxylic acids, .......

substituted thiocarboxylic acids as well as their salts, esters and amides;

substituted thiolcarbamates, substituted thiophosphoric acids, i. and their salts, esters and amides, substituted triazines, substituted trlazoles, substituted uracils and substituted uretldindiones.

In addition to this, other additives, for example non-phytotoxic additives, can also be used. u - herbicides cause a synergistic increase in efficacy, such as. - are-. wetting agents, emulsifying agents, solvents and oily additives · · .. ·

The active compounds or mixtures thereof are expediently used in the form of preparations, such as powders, dusts, granules, solutions, emulsions or suspensions, with the addition of liquid and / or solid carriers, diluents and, if appropriate, wetting agents. , emulsifying and / or dispersing excipients.

Suitable liquid carriers are, for example, water, aliphatic and aromatic hydrocarbons such as benzene, toluene, xylene, caclohexanoc, isophorone, dimethylsulfoxide, dimethylformamaid, and mineral oil fractions.

As solid carriers, minerals such as tonsil, silica gel, talc, kaolin, limestone, silicic acid, or pulp clay are used, and plant products such as flour.

Surfactants include, for example, calcium lignin sulfonate, polyoxyethylene alkylphenyl ether, naphthalenesulfonic acid and its salts, phenolsulfonic acids and their salts, formaldehyde condensates, fatty alcohol sulfates, and substituted benzenesulfonic acids and their salts.

Proportion of active substance (s); it can vary within wide limits in different preparations. For example, the compositions comprise from 10 to 80% by weight of active ingredient, from about 90 to 20% by weight of a liquid or solid carrier, optionally up to 20% by weight of a surfactant.

The spreading of the composition may be carried out in a conventional manner, for example by means of water as a wearer with an amount of spray liquid of about 100 to 1000 liters per hectare. The use of the compositions in the so-called low-volume and ultra-low-volume processes is also possible as applications in the form of so-called microgranules.

The isopropyl ester of 3-cyanocarbanilic acid occupies a prominent place among the compounds according to the invention with regard to herbicidally selective properties.

The hitherto unknown compounds according to the invention can be prepared, for example, by preparing them

a) reacting the 3-aminobenzonitrile of formula II,

in which they have

X and n as defined above, with the chloroformic acid ester of formula III,

Cl-CO-OR (III) in which it has

R is as defined above, or is

b) reacting the 3-cyanophenyl isocyanate of formula IV

with an alcohol of formula V,

R — ОН (V) wherein

X, n and R are as defined above.

The following examples illustrate the preparation of the compounds of the present invention.

3-Cyanocarbanilic acid isopropyl ester

A mixture of 11.8 g (0.1 mol) of 3-aminobenzonitrile, 140 ml of ethyl acetate, 90 ml of water and 2.5 g (0.063 mol) of magnesium oxide is mixed dropwise with stirring with 13.5 g (0.11) mol) of isopropyl chloroformate. The reaction mixture is stirred for 3 hours at room temperature, the aqueous phase is then acidified with dilute hydrochloric acid and the organic phase is washed with water until neutral. The acetate phase was separated, dried over magnesium sulfate and filtered. The crude product was recrystallized from ethyl acetate / hexane.

Yield: 15.3 g (75% of theory)

Mp: 94-96 ° C

The following compounds of the invention can be prepared in an analogous manner:

Name · Compounds Methyl ester

3-Cyanocarbanilic acid ethyl ester

3-Cyanocarlninilic allyl ester

3-cyanocarbanilic acid methyl ester

5-cyano-2-methylcarbanil ethyl ester propyl ester

5-Cyrno-2-methyl-pyrrolidinyl and ethyl ester

5-Cyano-2-methylcarbonyl-isopropyl ester

5-Cyrno-2-methyl-pyrrolidinyl-propyl ester

3-Cyanocarboxylic acid isopropyl ester Z-ceroro-k-cyanocarbanilic acid allyl ester

2-C0-5-3-cyanocarbanyl isopropyl ester

4-chloro-1-cyanocaraanil physical constant

mp: 93-95 ° C

mp: 48-50 ° C

mp: 67-68 ° C

mp: 100-101 ° C

mp: 96-97 ° C

Mp: 101-102 ° C

mp: 94-95 ° C

mp: 127-128 ° C

mp: 38-39 ° C

mp: · 127-129 ° C

mp: 84-85 ° C

mp: 95-96 ° C

The compounds of the invention are highly soluble in ethyl acetate, acetone and alcohol. In contrast, they are sparingly soluble in aenzene and are practically insoluble in saturated hydrocarbons and water.

The following examples serve to illustrate the possibilities of using the compounds of the invention.

Example 1 of the present invention is given in Table I in an amount of 5 kg of active ingredient per hectare suspended in 500 liters of water per hectare. Sugar beets and tomatoes were used as test plants in the post emergence process. Three weeks after treatment, the results were evaluated with = no effect and = plant destruction.

Beet compounds were sprayed in the greenhouse

290510 i and the name of the compound methyl ester of the acid

3-Cyanocarbanilic acid isopropyl ester

3-Cyanocarbanilic acid ethyl ester

5-Cyano-2-methylcarbanilic acid methyl ester

5-Cyano-2-methylcarbanilic acid propyl ester

5-Cyano-2-methylcarbanilic allyl ester

5-Cyano-2-methylcarbanilic acid isopropyl ester

2-methyl-5-cyanocarhamyl ethyl ester

3-cyanocarbanilic allyl ester

3-Cyanocarbanilic acid isopropyl ester

2-chloro-5-cyanocarbanyl propyl ester

3-cyanocarbanilic allyl ester

2-chloro-5-cyanocarbanilic acid

Table I mustard tomatoes

34 44

44

43

43 - —3

44

44

44

43

4 4

4 4

Example 2

In a greenhouse, the plants are treated with 1 kg of active ingredient per hectare prior to emergence by said compositions. For this purpose, the compositions are used as aqueous suspensions with 500 liters of water per hectare and are uniformly applied to the soil. The results after three weeks after treatment show that the compositions of the invention are superior to the comparative composition. The results obtained are shown in Table II, indicating = total destruction and = harmless.

Table II plant compound of the invention isopropyl acid isopropyl ester

3-Cyanocarbanilic Comparative 3-Chlorocarbanilic acid isopropyl ester.

cotton soybean

Stellaria media

Senecio vulgaris Lamium amplexicaule Centuarea cyanus Amaranthus retroflexus Galium aparine Chrysanthemum segetum Ipomoea purpurea

Ί «-» 4-V-> ₽1 ΐί,

A. Uiy gVJllUlll lupuiiliuiuiiuill Echinochloa crus galii Digitaria sanguinalis o o o o o

o π

Example 3

The plants are treated in a greenhouse (Table III) prior to emergence by the compositions in an amount of 1 kg of active ingredient per hectare. For this purpose, the composition is applied as an aqueous suspension in an amount of 500 liters per hectare evenly on the soil. The results after three weeks after application show that the composition of the invention is better and more selective than the comparative composition.

= total destruction, = harmless.

plant

Table III Compound of the Invention 3-Cyanocarbanilic acid isopropyl ester Comparative 3-Chlorocarbanilic acid isopropyl ester wheat

Alopecurus myosuroides

Claims (3)

A herbicidal composition, characterized in that the active ingredient comprises a carbanilic acid ester of the formula I, CN NW-CO-OR (II) R is (C1-C3) -alkyl or allyl, X is methyl or chloro and n is 0 or 1. 2. A composition according to claim 1, wherein the active ingredient is 3-cyanocarbanilic acid isopropyl ester. 3. A process according to claim 1, which comprises reacting a 3-aminobenzonitrile of the formula II in which: X and n as defined above, with the chloroformic acid ester of the formula ΠΙ, Cl-CO-OR (III) in which it has R is as defined above. severography, n. p., zAvod 7 »Most