NO750266L - - Google Patents

Description

"Herbicide containing a pyrazolium salt"

The present invention relates to new valuable pyrazolium salts, herbicides containing these compounds, and methods of combating unwanted plant growth with the help of these compounds.

It is known to use pyrazolium salts, especially 1,2-dimethyl-3,5-diphenylpyrazolium methylsulphate, as herbicide (DT-OS 2 260 485). However, their herbicidal effect is not always satisfactory.

It was now found that pyrazolium salts of the formula

where z means a phenyl radical substituted by the radical R, X means an anion, R means hydrogen, lower alkyl, lower alkoxy or halogen, and D means the same or different lower alkyl radicals and

a) c means hydrogen, lower alkyl, halogen or lower alkoxy when

A and B have the meaning z, or

b) B means lower alkyl, halogen or lower alkoxy when A and C have the meaning z, or c) C and A or C and B means the residue R when B or A has the meaning

Z, or

d) A, B and C simultaneously mean the same or different halogen residues, have a strong herbicidal effect, especially a selective herbicidal effect.

Lower alkyl groups are, for example, methyl, ethyl, n-propyl, isopropyl and tert.-butyl, and lower alkoxy substituents are, for example, methoxy, ethoxy, n-prboxy, isopropoxy and tert.-butoxy.

Halogens are, for example, chlorine, bromine and iodine.

Anions are, for example, the anions in the following salts: halides, for example chlorides or bromides; sulfates, hydrogen sulfates; perchlorates, lower alkyl sulfates, for example methyl sulfate, lower alkane sulfonates, substituted benzene sulfonates, amino sulfonates and alkyl amino sulfates.

The pyrazoles that serve as starting compounds for the production of the pyrazolium salts can be prepared by following the following scheme

either condenses a 1,2-dicarbonyl compound with alkylhydrazine or, after reaction with hydrazine hydrate, alkylates to the corresponding 1-alkylpyrazole by reaction with an alkylating agent, for example dialkyl sulfate or alkyl halide, where A, B, C and D have the same meaning as above, with the exception that A, C and advantageously also B do not mean halogen or alkoxy substituents. In the case of 1-H or 1-alkyl pyrazoles, the replacement of hydrogen with halogen in A or B, respectively A and B or also in A, B and C, can take place by the addition of elementary halogen, for example chlorine, bromine or iodine, possibly in the presence of catalytic amounts of Lewis acids, for example iron (III) bromide or aluminum (III) chloride, or by the action of halogenating agents, for example sulphuryl chloride.

The halogenation reactions are carried out in common solvents,

for example methylene chloride, chloroform, carbon tetrachloride, ether or

lower organic carboxylic acids.

The quaternization of the alkyl pyrazoles is carried out by reaction with at least one mol equivalent of an alkylation agent 1 in a known manner at temperatures between 30 and 150°C. The usual reagents can be suitably used as alkyl starting agents, for example lower alkyl halides, for example methyl iodide, or lower alkyl sulphates,

in, for example, diethyl sulfate. The reaction can also be carried out in aprotic solvents, for example chlorinated, aliphatic or aromatic hydrocarbons or ketones.

The quaternized pyrazolium salts are most often obtained in crystalline form. In reactions with alkylating agents in the absence of solvents, it is occasionally advantageous to bring the crude products to complete crystallization by stirring with lower ketones or with suitable mixtures of lower alcohols or ethers.

If a different anion is to be used in the pyrazolium salt than that provided by the alkylating agent, this can conveniently be achieved by anion exchange using ion exchange resins.

Preparation of the output compounds

A) 1-methyl-3,4-(4,5)-diphenylpyrazole:

To 183 parts (parts by weight) of α-formyldesoxybenzoin in 1000 parts of isopropanol, 84 parts of methylhydrazine were added dropwise at 25°C under nitrogen, after which the mixture was stirred for 2 hours at 25°C and boiled for 1 hour under reflux. After evaporation of the solvent in vacuo, the residue was distilled. At 182-186°c/ 0.3 Torr, 127 parts of the product l-methyl-3,3-(4,5)-diphenylpyrazole were obtained.B) l-methyl-4-bromo-3,5-diphenylpyrazole:

To a solution of 150 parts of 1-methyl-3,5-diphenylpyrazole i

A solution of 103 parts of bromine in 100 parts of chloroform was added dropwise at room temperature over the course of 3 hours to 900 parts of chloroform, followed by stirring for 2 hours. After the solvent had been removed in vacuo, 160 parts of the product 1-methyl-4-bromo-3,5-diphenylpyrazole with a melting point of 111-112°C were obtained by recrystallization from ethanol.

C) 1,4-dimethyl-3,5-diphenylpyrazole:

To a solution of 23 parts of 1,1-dibenzoylethane in 100 parts of isopropanol, 9 parts of methylhydrazine were added dropwise at 80-85°C, after which the mixture was heated for 2 hours under reflux. After cooling, 21 parts of the product 1,4-dimethyl-3,5-diphenylpyrazole with melting point 108-109°C were obtained.

D) 1-methyl-3,4,5-tribromopyrazole:

45.5 parts of 3,4,5-tribromopyrazole was added to 26.3 parts of a 30% (wt%) solution of sodium methylate in methanol, and 17 parts of methanol were added. 27.6 parts of methyl iodide were then added, and the reaction mixture was stirred at 50°C until it reacted neutrally. The precipitated sodium iodide was filtered off, the filtrate evaporated in vacuo, filtered and the product washed with water. 42 parts of the product 1-methyl-3,4,5-tribromopyrazole with melting point 86-87°C were obtained.

Example 1

1,2-dimethyl-3,4-diphenylpyrazolium methyl sulfate:

90 parts of 1-methyl-3,4-(4,5)-diphenylpyrazole were dissolved in 400 parts of dry xylene under heating, after which 50.7 parts of dimethyl sulfate were added dropwise and the mixture stirred for 8 hours at 105-110°C. After decanting the xylene phase, the residue was stirred with dry acetone until complete crystallization was achieved. After filtering off and drying, 82 parts of the product 1,2-dimethyl-3,4-diphenyl-pyrazolium methylsulphate with a melting point of 153-154°C were obtained.

Example 2

1,2-dimethyl-4-bromo-3,5-diphenylpyrazolium methyl sulfate:

63 parts of 1-methyl-4-bromo-3,5-diphenylpyrazole were stirred with

33.6 parts dimethyl sulfate for 2 hours at 150°C. After cooling, the crude product was treated with dry acetone and the mixture filtered.

After dissolution in ethanol and precipitation with ether, 60 parts were obtained

of the product 1,2-dimethyl-4-bromo-3,5-diphenylpyrazolium methylsulfate with melting point 164-165°c.

Example 3

1,2,4-trimethyl-3,5-diphenylpyrazolium methyl sulfate:

20.4 parts of 1,4-dimethyl-3,5-diphenylpyrazole were dissolved at 60-65°C in 100 parts of dry xylene, 10.8 parts of dimethyl sulfate in 15 parts of dry xylene were added, and the mixture was stirred for 8 hours at 105-110°C. After cooling, the upper xylene phase was separated, and the residue was stirred with dry acetone. After filtration, 14.2 parts of 1,2,4-trimethyl-3,5-diphenylephazolium methylsulfate with a melting point of 86-88°C were obtained.

Example 4

1,2-dimethyl-3,4,5-tribromopyrazolium methyl sulfate:

20 parts of 1-methyl-3,4,5-tribromopyrazole were mixed with 10.4 parts of dimethyl sulfate and stirred for 3 hours at 105-110°C. After cooling, the crystalline residue was stirred with 150 parts of dry acetone. After filtration, 19 parts of 1,2-dimethyl-3,4,5-tribromopyrazolium methylsulphate were obtained with a melting point of 210°C.

In a similar way, the following compounds can be prepared: 1,2-dimethyl-3-phenyl-4-bromo-5-chloropyrazolium methylsulphate (m.p. 200-201°).

1,2-dimethyl-4-bromo-3-phenyl-5-p-chlorophenylpyrazolium methyl sulfate. 1,2-dimethyl-3-bromo-4,5-diphenylpyrazolium methyl sulfate. (m.p. 128-130°C).

1,2-dimethyl-4-methoxy-3,5-diphenylpyrazolium methyl sulfate, characteristic UR bands 2850, 1230, 1060, 1010 cm"1.

1,2-dimethyl-3,4-dichloro-5-phenylpyrazolium methyl sulfate,

1,2-dimethyl-4-chloro-3,5-diphenylpyrazolium methyl sulfate (m.p. 135-136°C).

1,2,4-trimethyl-3,5-diphenylpyrazolium trifluoromethylsulfonate (m.p. 128-130°C).

1,2-dimethyl-4-ethyl-3,5-diphenylpyrazolium methyl sulfate (m.p. 130-132°C). 1,2-dimethyl-4-n-propyl-3,5-diphenylpyrazolium methyl sulfate (m.p. 122-124°C).

The active substances have a strong herbicidal effect and can therefore be used as a weedkiller or to combat unwanted plant growth. Whether the agents act as total or selective agents mainly depends on the amount of active substance used per surface unit.

By weeds or unwanted plant growth is meant all monocots

and dicots that grow in places where they are not wanted.

Thus, for example, the following plants can be combated with the agents according to the invention:

Plants of the grass family, such as

The funds according to? the invention can be used before planting, after planting, before sowing, before the plants emerge from the soil,

after the plants have emerged from the soil or while the cultivated plants or the unwanted plants [are about to emerge from the soil'' and the means can be used one or more times.

The application takes place, for example, in the form of directly sprayable solutions, powders, suspensions of varying consistency (for example, flowable suspensions) or dispersions, emulsions, oil dispersions, pastes, dusty agents, streamers, granules,

by spraying, dusting, spreading or pouring. The forms of application depend entirely on the purpose of application; the aim is always to achieve the best possible distribution of the active substances.

In the production of directly sprayable solutions, emulsions, pastes and oil dispersions, you can use mineral oil fractions with high boiling points, such as kerosene or diesel oil, also coal tar oils etc., as well as oils of vegetable or animal origin, aliphatic, cyclic and aromatic hydrocarbons, for example benzene, toluene, xylene, paraffin, tetrahydronaphthalene, alkylated naphthalenes or their derivatives, for example methanol, ethanol, propanol, butanol, chloroform, carbon tetrachloride, cyclohexanol, cyclohexanone, chlorobenzene, isophorone, etc., strongly polar solvents, such as for example, dimethylformamide, dimethylsulfoxide, N-methylpyrrolidone, water, etc.

Aqueous forms of use can be prepared from emulsion concentrates, pastes or wettable powders (spray powders), oil dispersions, by adding water. in the production of emulsions, pastes or oil dispersions, the substances as such or dissolved in oil or solvent can be homogenised in water using wetting, adhesive, dispersing or emulsifying agents. However, it is also possible to prepare concentrates consisting of active substance, wetting, adhesive, dispersing or emulsifying agent and any solvent or oil, which concentrates are suitable for diluting with water.

Among surfactants can be mentioned: alkali, alkaline earth, ammonium salts of ligninsulfonic acid, naphthalene sulfonic acids, phenolsulfonic acids, alkylarylsulfonates, alkyl sulfates, alkylsulfonates, alkali and alkaline earth salts of dibutyl naphthalene sulfonic acid, lauryl ether sulfate, fatty alcohol sulfates, fatty acid alkali and alkaline earth salts, salts of sulfated hexadecanols, heptadecanols, octadecaihols, salts of sulfated fatty alcohol glycol ethers, condensation products of sulfonated naphthalene and naphthalene derivatives with formaldehyde, condensation products of naphthalene or naphthalene sulfonic acids with phenol and formaldehyde, polyoxyethylene octylphenol ether, etdk^ sylated isooctylphenol, octylphenol, nonylphenol, alkylphenol polyglycol ethers, tributylphenyl polyglycol ethers, alkylaryl polyether alcohols , isotridecyl alcohol, fatty alcohol ethylene oxide condensates, ethoxylated castor oil, polyoxyethylene alkyl ether, ethoxylated polyoxypropylene, lauryl alcohol polyglycol ether acetal, sorbitol ether, ligniripsulfite deluter and methyl cellulose see.

Powders, sprinkles and dust-like agents can be produced by grinding together the active substances with a solid carrier material.

Granules, for example encasing, impregnation and homogenous granules, can be produced by binding the active substances to solid carrier materials. Solid carrier materials are, for example, mineral materials such as silica gel, silicic acids, silica gels, silicates, talc, kaolin, attaclay, limestone, lime, chalk, bolus,

loess, clay, dolomite, diatomaceous earth, calcium and magnesium sulphate, magnesium oxide, ground resins, fertilizers, for example ammonium sulphate, ammonium phosphate, ammonium nitrate, urea and vegetable products such as flour from grain, bark, wood and nut shells , cellulose powder and other solid carrier materials.

The preparations contain between 0.1 and 95% by weight of active ingredients

substance, preferably between 0.5 and 90% by weight.

Oils of various types, herbicides, fungicides, nematocides, insecticides, bactericides, trace elements, fertilisers, anti-foaming agents (for example silicones), growth regulators can be added to the mixtures or the individual active substances, possibly only immediately before use (tank mixture). , antivenoms or other herbicidally active compounds, such as

substituted anilines

substituted aryloxycarboxylic acids and their salts, esters and amides

substituted arsonic acids and their salts, esters and amides substituted benzimidazoles

substituted benzisothiazoles

substituted benzthiadiazine dioxides

substituted benzoxazines

substituted benzoxazinones

substituted benzthiadiazoles

substituted biurets

substituted quinolines

substituted carbamates substituted aliphatic carboxylic acids and their salts, esters and amides,

substituted aromatic carboxylic acids and their salts, esters and amides

substituted carbamdylalkylthiol or \rdithio phosphates

substituted quinazolines

substituted cycloalkylamidocarboxylic acids and their salts,

esters and amides

substituted cycloalkyltfarbonamidothiazoles

substituted carboxylic acids and their salts, esters and amides substituted dihydrobenzofuranyl sulphonates

substituted disulfides

substituted dipyridylium salts substituted dithiocarbamates

substituted dithiophosphoric acids and their salts, esters and amides substituted ureas

substituted hexahydro-1-H-carbothioates substituted hydante ions

substituted hydrazides

substituted hydrazonium salts substituted isoxazolepyrimidones substituted imidazoles

substituted isothiazole pyri<midones substituted ketones

substituted naphthoquinones

substituted aliphatic nitriles substituted aromatic nitriles substituted oxadiazoles

substituted oxadiazinones

substituted oxadiazolidinediones substituted oxadiazinediones

substituted phenols and 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 amides substituted piperidines

substituted pyrazoles substituted pyrazoloTalkylcarboxylic acids and their salts, esters and amides

substituted pyrazolium salts substituted pyrazolium alkyl sulfates substituted pyridazines

substituted pyridazones

substituted pyridine carboxylic acids and their salts, esters and amides

substituted pyridines

substituted pyridine carboxylates substituted pyridinones

substituted pyrimidines

substituted pyrimidones

substituted pyrrolidine carboxylic acid and its salts, esters and amides

substituted pyrrolidines

substituted pyrrolidones

substituted arylsulfonic acids and their salts, esters and amides substituted styrenes

substituted tetrahydrooxadiazindiones

substituted tetrahydrooxadiazolediones

substituted tetrahydromethanoindenes

substituted tetrahydrodiazole ions

substituted tetrahydrothiadiazine ions

substituted tetrahydrothiadiazolediones substituted aromatic thiocarboxylic acid amides

substituted thiocarboxylic acids and their salts, esters and amides substituted thiol carbamates

substituted thioureas

substituted thiophosphoric acids and their salts, esters and amides substituted triazines

substituted triazoles

substituted uracils

substituted uretidine diones.'

The latter herbicidal compounds can also be used before the active single substances or mixtures according to the invention.

The addition of these agents to the herbicides according to the invention can take place in a weight ratio of 1:10 to 10:<r>1;. The same applies to oils, fungicides, nematicides, insecticides, bactericides, antivenoms and growth regulators. The amounts used of the agents according to the invention may vary. The amount used depends mainly on the nature of the desired effect.

The amount used is usually between 0.1 and 15

or more, preferably 0.2 and 6, kg of active substance per hectares.

The agents according to the invention can be used in grain cultures,

so like

and in cultures of dicots, such as

Example 5

In a greenhouse, the plants listed in the following tabe11" with a growth height of 74^[18 cm were treated with

In 1,2-dimethyl-4-bromo-3,5-diphenylpyrazolium methyl sulfate

II 1,2,4-trimethyl-3,5-diphenylpyrazolium methyl sulfate

IV 1,2-dimethyl-3,5-diphenyl-4-bromopyrazolium perchlorate,

with the amount in each case being 1.0 and 2.0 kg/ha of active substance, dispersed or emulsified in 500 1 water per hectares. In the same way, it became a known active substance

III 1,2-dimethyl-3,5-diphenylpyrazolium methyl sulfate

used.

.After 3-4 weeks, it was established that the active substances I, II and IV showed a better compatibility with the cultivated plants through a stronger herbicidal effect, especially against Avena fatua, than substance III.

The test result will appear in the following table.

Correspondingly biologically active are the compounds: 1,2-dimethyl-3,4-diphenylpyrazolium methylsulphate

1,2-dimethyl-3,5-diphenyl-4-chiorpyrazolium methyl sulfate 1,2-dimethyl-3,4,5-tribromopyrazolium methyl sulfate.

Example 6

90 parts by weight of the compound from Example 1 are mixed with

10 parts by weight of N-methyl-a-pyrrolidone and obtain a solution which is suitable for use in the form of very fine droplets.

Example 7

20 parts by weight of the compound from Example 2 are dissolved in a mixture consisting of 80 parts by weight of xylene, 10 parts by weight of the addition product of 8-10 mol of ethylene oxide and 1 mol of oleic acid-N-monoethanolamide, 5 parts by weight of the calcium salt of dodecylbenzenesulfonic acid and 5 parts by weight of the addition product of 40 mol of ethylene oxide and 1 mol of castor oil. By pouring and finely distributing the solution in 100,000 parts by weight of water, an aqueous dispersion containing 0.02% by weight is obtained

of the active substance.

Example 8

20 parts by weight of the compound from Example 3 are dissolved in a mixture consisting of 40 parts by weight cyclohexanone, 30 parts by weight iso-butanol, 20 parts by weight of the addition product of 7 mol ethylene oxide and 1 mol isooctylphenbl and 10 parts by weight of the addition product of 20 mol ethylene oxide and 1 mol castor oil. The solution is diluted in 100,000 parts by weight of water, whereby an aqueous dispersion containing 0.02% by weight of the active substance is obtained.

Example 9

20 parts by weight of compound I are dissolved in a mixture consisting of 25 parts by weight of cyclohexanol, 65 parts by weight of a mineral oil fraction boiling between 210 and 280°C, and 10 parts by weight of an addition product of 40 mol of ethylene oxide and 1 mol of castor oil. The solution is diluted in 100,000 parts by weight of water, whereby a solid dispersion containing 0.02% by weight of the active substance is obtained.

• Example 10

20 parts by weight of the active ingredient II are mixed well with

3 parts by weight of the sodium salt of diisobutylnaphthalene-a-sulfonic acid,

17 parts by weight of the sodium salt of a lignin sulfonic acid from a sulphite liquor and 60 parts by weight of powdered silica gel, and the mixture is ground in a hammermill.

Example 11

3 parts by weight of compound I are mixed well with 97 parts by weight of finely divided kaolin. In this way, a dust-like agent containing 3% by weight of the active substance is obtained.

Example 12

30 parts by weight of compound II are mixed well with a mixture of 92 parts by weight of powdered silica gel and 8 parts by weight of paraffin oil which was sprayed over the surface of the silica gel. In this way, you get a preparation with good adhesion.

Example 13

In a greenhouse, different plants at a growth height of 4-18 cm were treated with the following active single substances and their mixtures as an emulsion:

In 1,2-dimethyl-4-bromo-3,5-diphenylpyrazolium methyl sulfate

II 1,2,4-trimethyl-3,5-diphenylpyrazolium methyl sulfate

IV Addition product of 6-7 mol ethylene oxide and 1 mol isooctylphenol

(wetting agent that improves the wetting of the plants),

I and II each used in an amount of 0.75 kg/ha, IV in an amount of

2 kg/ha,

I + IV and II + IV were used in quantities of 0.75 + 2 1 kg/ha respectively.

After 3-4 weeks, it was found that the mixtures of I and

II with the wetting agent IV showed a better herbicidal effect at the same compatibility with the cultivated plants than the widows I and II each separately.

The test result will appear in the following table.

Example 14

In a greenhouse, different plants were grown at a growth height of

6-20 cm treated with the following active substances

I 1,2-dimethyl-3,4-diphenyl-pyrazolium-methylsulfate + IV

II 1,2-dimethyl-4-methoxy-3,5-diphenyl-pyrazolium-methylsulphate + IV,

in each case 1.0 +1.0 kg/ha active substance.

IV Addition product of 6-7 mol ethylene oxide and 1 mol isooctylphenyl,

1.0 and 2.0 kg/ha active substance,

in each case emulsified in 500 ml of water per hectares.

After 2-3 weeks, it was established that the active substances

showed a good effect against field oats at the same compatibility with the cultivated plants.

The test result will appear in the following table.

Correspondingly biologically active are: 1,2-dimethyl-4-bromo-3,5-diphenylpyrazolium-trifluoromethylsulfate \T22-dimethyl-4-methyl-3,5-diphenylpyrazolium-trifluoromethylsulfate l-methoxy-2-methyl-3,5- diphenylpyrazolium methyl sulfate.

Example 15

Various plants were sprayed with the substances

I .1,2-Dimethyl-4-bromo-3,5-diphenylpyrazolium methyl sulfate

II 1,2,4-trimethyl-3,5-diphenylpyrazolium methyl sulfate

in comparison with the active substance

III 1,2-dimethyl-3,5-diphenylpyrazolium methylsulphate, in each case emulsified or dispersed in 500 ml/ha. In each case, 1.5 kg/ha of active substance was used. The growth height of the plants was 5-15 cm.

After 4 weeks, it was established that the herbicidal effect

of substances I' and II was better than the effect of substance III.

The test result will appear in the following table:

Claims (1)

H herbicide, characterized in that it contains a pyrazolium salt with the formula where Z is a phenyl radical substituted by the radical R, x is et anion, R .is hydrogen, lower alkyl, lower alkoxy or halogen, and D are the same or different lower alkyl residues, and a) C means hydrogen, lower alkyl, halogen or lower\ alkoxyj when A and B have the meaning Z, or b) B means lower alkyl, halogen or lower alkoxy when A and C have the meaning Z, or c) C and A or C and B means the remainder R when B or A has the meaning z, or d) A, B and C simultaneously mean the same or different halogen residues.