CH626776A5 - Crop protection product and a process for its preparation - Google Patents

Description

The invention relates to new crop protection agents and a method for their production. With one exception, the active ingredients of these agents are new nitroalkanol derivatives which have not yet been described. Even in the case of the known active ingredient, the method of production according to the invention is new.

The only known compound among the active ingredients is the threo-l-phenyl-2-nitro-l, 3-propanediol diacetate, the intermediate product of a chloramphenicol-X synthesis, which is achieved by the reaction of cinnamon alcohol acetate with sodium nitrite and the reaction of this Were obtained DL-erythro-1-phenyl-nitroso-2-nitro-3-acetoxy-propane with sulfuric acid acetic anhydride. No effect generally in amounts of 96 to 0.01%, preferably 90 to 0.5% by weight. In the formula, R represents a C1-20 alkyl group or a phenyl or phenyl-20C ^ alkylene group optionally substituted with one or more C 1-4 alkyl groups or with halogen. As a result of the C (1) C (2) asymmetry center, there are 4 isomeric modifications of the compounds of the formula (I) which are related to one another in relation to the diastereometry or the optical isomerism. The two diastereomes, the threo and the erythro isomer, thus form a Race-25 mat that can be split into optical isomers that rotate to the right and left. The known compound mentioned is the threo isomer, where R represents a methyl group.

The agent according to the invention can, in addition to the nitroalkanol derivative of the general formula (I) - in accordance with the specific objective 30 - also contain another known active ingredient in crop protection agents. In addition, the agent contains the usual solubilizing carrier, dilution and / or dispersing and / or surface-active and / or regulating the duration of action and / or promoting adhesion and / or a stabilizer in the 100% necessary amount.

The active compounds of the formula (I) are converted into the customary formulations, such as solutions, emulsions, suspensions, powders, wettable powders, soluble powders, dusts, 40 foams, pastes, granules, aerosols, suspension emulsion concentrates, seed powders, etc. expedient Forms are, for example the 50 WP (emulsifiable powder with 50% active ingredient content), the EC (emulsifiable concentrate), Col. (colloidal suspension concentrate), microgranules, spray etc. 45 These formulations are prepared in a manner known per se, e.g. by mixing the active ingredients with extenders, that is to say liquid solvents, pressurized liquefied gases and / or carriers, if appropriate using surface-active agents, that is to say emulsifiers and / or dispersants and / or foam-generating agents. If water is used as an extender, organic solvents can be used as auxiliary solvents.

As liquid solvents e.g. the following come into question: aromatics, such as xylene, toluene or alkylnaphthalenes, chlorinated aromatics, such as chlorobenzenes, chlorinated aliphatic hydrocarbons, such as methylene chloride or ethylene chloride, aliphatic hydrocarbons, such as paraffins, alicyclic hydrocarbons, such as cyclohexane, alcohols, such as 60 butanol or glycol and their ethers and esters, ketones, such as acetone, methyl ethyl ketone or dyclohexanone, polar solvents, such as dimethylformamide or dimethyl sulfoxide, and water.

Liquefied gaseous extenders or carrier substances mean those liquids which are gaseous at normal temperature and under normal pressure, e.g. Aerosol propellants, such as halogenated hydrocarbons, as well as butane, propane, nitrogen and carbon dioxide. As a fixed carrier

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626 776

Materials can be used natural rock flour, such as kaolins, clays, talc, chalk, quartz, montmorillonite or diatomaceous earth, and synthetic gastein flours, such as highly disperse silica, aluminum oxide and silicates. Solid carrier materials for granules are essentially: broken and fractionated natural rocks such as calcite, marble, pumice, sepiolite, dolomite and synthetic granules from inorganic and organic flours as well as granules from organic material such as sawdust, coconut shells, corn cobs and tobacco stalks. Non-ionogenic and anionic emulsifiers such as polyoxyethylene fatty acid esters, polyoxyethylene fatty alcohol ethers, e.g. Alkylaryl polyglycol ethers, alkyl sulfates, alkyl sulfonates, aryl sulfonates and protein hydrolyzates are used. As dispersants e.g. Lignin, sulfite liquor and methyl cellulose may be mentioned.

Adhesives, such as carboxymethyl cellulose, natural and synthetic powdery, granular or latex-shaped polymers, such as gum arabic, polyvinyl alcohol or polyvinyl acetate, can be used in the formulations.

Dyes such as inorganic pigments and trace nutrients such as salts of boron, iron, copper, cobalt, manganese, molybdenum and zinc can also be used.

The active compounds are used in the form of their commercially available formulations and / or the use forms prepared from these formulations.

The active substance content of the use forms prepared from the commercially available formulations can vary within wide ranges. The active substance concentration of the use forms can be from 0.000001 to almost 100% by weight of active substance, preferably between 0.01 and 10% by weight. The application takes place in a customary manner adapted to the application forms.

The agent according to the invention is obtained by reacting nitroalkanol derivatives of the formula I by reacting 1-phenyl-2-nitro-1,3-propanediol of the formula (II)

or preparing its alkali metal salt with an acylating agent under mild conditions and mixing it with a formulation agent.

Despite its apparent simplicity, the acylation of the diol of formula (II) is not an easy task, which results from the “aldol” character of the molecule and from the presence of the nitro group. As a result of the presence of the latter group, the use of basic acid-binding agents in acylation is ruled out in advance, since under their action the nitro group is tautomerized to nitric acid, and this leads to epimerization; on the other hand, it develops under the action of the basic agents an aldol balance, the "retroaldol" component of which causes the molecule to dissociate. The l-phenyl-2-nitro-1,3-propanediol is otherwise - unlike the other nitro alcohols - so unstable that no base is necessary for the cleavage (cleavage of the loose proton of the carbon atom C (2)) because the basicity of the solvent, e.g. of alcohol-water, is sufficient, and after a few hours a high degree of cleavage is detectable even at room temperature. At higher temperatures, this division increases rapidly. It is therefore not surprising that in the course of testing the formation and cleavage reactions of l-phenyl-2-nitroethane-l-ol, which is very similar to this molecule, it was found that these nitro alcohols cannot be acylated at all (Gazzetta Chimica Italiana 79, 192-201 [1949]).

Because of the above, it’s not surprising

that no method is known for the acylation of the nitro alcohol of the formula (II), although this has long been known as a synthetic intermediate.

It has now surprisingly been found that the acyl derivatives of the general formula (I) can be prepared without difficulty and without side reactions if the 1-phenyl-2-nitro-1,3-propanediol of the formula (II) - either in threo - or in the erythro isomer form - or an alkali metal salt thereof is reacted with an acylating agent under mild conditions. Acid halide and / or acid anhydride is expediently used as the acylating agent. The reaction is carried out in solvent or without using a solvent.

Starting from the alkali salt of l-phenyl-2-nitro-1,3-propanediol, it is particularly advantageous to use the alkali metal salt of propanediol of the formula (II), preferably its sodium salt, in a solvent, e.g. in acetic acid, at about 40 ° C with an acid halide. In the course of this reaction, which takes about 8 hours, the product obtained in good yield contains the threo and erythro isomers in an approximately 1: 1 ratio, which can be separated by crystallization.

The process variant in which the reaction is carried out without a solvent is also advantageous. In this case, the pure threo or erythro diastereomer can also be converted into the corresponding threo or ery-thro derivative in good yield.

A further advantageous embodiment of the process according to the invention is that the reaction is also carried out without a solvent using an acid anhydride as the acylating agent in the presence of a catalytic amount of a mineral acid or an acid chloride. The reaction can of course also be carried out with a mixture of an acid anhydride and an acid chloride.

As already mentioned, the starting compound, the propanediol of the formula (II), is a known and easily accessible compound. If one starts from the sodium salt, it can be prepared in a known manner (J.A.C.S. 1949, p. 2465). If the threo or erythro isomer is used as the starting compound of the formula (II), the preparation can expediently take place from the sodium salt (DE Patent No. 1,064,937) or advantageously directly in one step from benzalhehydrate and nitroethanol with alkali metal hydroxide as catalyst .

The compounds of formula (I) and their mixtures have a strong fungicidal and acaricidal action, without any harmful phytotoxic action. A significant “antifeedent” effect is also perceptible with certain insect species; so consume e.g. the locusts do not spray the plants sprayed with the agent according to the invention. The aphicidal effect of the agents according to the invention is also considerable. In addition, they stimulate germination in some crops and also have a stimulating effect on dry substance accumulation. The agents according to the invention, used in the doses used preemergent in the course of the experiments, increase the dry substance accumulation and also the willingness to germinate in the case of individually treated plants and at the same time show neither positive nor negative phytotoxic effects in the case of the postemergent treatment.

The compounds of the formula I have proven to be effective in the course of the trials in combating the following fungal strains:

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Alternaria tenuis Fusarium graminearum Trichotecium roseum Aspergillus flavus Pénicillium species Rhisopus nigricans Phytophtora infestans

Monilia fructigena Gladosporium herbarum Fusarium oxisporum Aspergillus oryzae Mucor mucedo Bothrytis cinerea Endostigme pirina.

Table 1

The biological effect of the agents according to the invention was mainly investigated on the following crop plants:

Wheat, corn, millet, mustard, sunflower, potato and pea.

The method used was to sow an appropriate amount of the plant to be grown (e.g. wheat, maize, millet, sunflower seeds, mustard or straw 100 grains) in breeding vessels or soil cultures, and by ensuring optimal conditions for germination were checked, the germination percentages in the treated and untreated vessels, as well as the height, the green weight and the dry weight of the 14-day seedling. The treatment was carried out with a 6 kg / ha dose of the corresponding active ingredient of the formula I, preemergent or with the agent postemergent.

The treatment with the mixture of the threo- and erythro-1-phenyl-2-nitro-1, 3-propanediol diacetate prepared according to Example 14, which was ground to a grain size of 1-20%, was preemergent or with that from the Example Performing 15 or 16 preparations prepared post-emergently, the results summarized in Table 1 (control = 100%) were obtained.

With the 0.1-1% solution of erythro-1-phenyl-2-nitro-1,3-propanediol diacetate obtained by dissolving in acetone and diluting with water, which is prepared according to the method of Examples 1, 6 and 7 different types of mushrooms were examined using the "disc method". The degree of inhibition of the colony diameter was determined in the case of treatment with 0.1% delan (2,3-dicyano-1,4-dithiaan-thrachinone) and 0.1% difolpet [N- (1,1,2 2, -Tetrachlor-äthylthio) -4-cyclohexen-l, 2-dicarboximid] and tested in an untreated control test. The activity indexes obtained are given in Table 2. Activity index means the toxic effect on the fungus

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treatment

plant

Germination percentages

height

%

Green weight,

%

Preemergent

wheat

63

105.5

105

Corn

108

99

107

millet

111

110

120

mustard

116

104

121

Sunflower

108

98

120

pea

100

118

131

Post-solvent

wheat

-

-

130

Corn

-

-

125

flax

-

-

130

paprika

-

-

130

tomato

-

-

120

Ratio of the effect 20 exercised on the untreated control with visual evaluation (1 = complete inhibition; 2 = partial coating; 3 = full coating, but different biological effects (e.g. morphological transformation) in relation to the control; 4 = no difference in relation to the Control).

Table 2

Mushroom type erythro-diacetate

0.1% 0.3% 0.5% 1.0%

Delan Difolpet Kon-0.1% 0.1% troll

Bothrytis

30 cinerea

1 1 1

1

3rd

1 4

Cladosporium

herbarum

1 1 1

1

3rd

4th

Fusarium

oxisporum

2 1 1

1

4th

1 4

35 Penicillium

species

2 1 1

1

3rd

4th

Aspergillus

oryzae

2 1 1

1

3rd

4th

Alternaria

40 tenuis

2 2 1

1

-

1 4

These are in Tables 3-7

Results of other economies

compilation of examinations.

Table 3

Compound concentration of test organism mortality

Spray solution%

%

Compounds of the 0.02 Tetranychus urticae • 4.6

Examples 1.6 and 7 0.2 76.0

(50 WP) 2.0 100.0

Connections of the 0.02 13.5

Examples 3 to 6 0.2 88.8

(50 WP) 2.0 97.3

Diazinon * -Fenkapton ** 0.2 100.0

* 0.0-Diethyl-0-2-isopropyl-4-methyl-6-pyrimidyl-thiophosphate ** S- (2,5-dichlorophenylthiomethyl) -0.0-diethyl-dithiophosphate

Connections of the 2.0 Megaurea vicae 88.0

Examples 1 to 8 2.0 70.0

Dimetoate (Dimethyl-S-2.0 100.0 (N-methyl-carbamyl-methyO-dithiophosphate)

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Table 3 (continued)

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connection

Concentration of

Spray solution

%

Test organism

Mortality after

24 48 hours,%

Compounds of Example 9, 1-20 ju

Methyl parathione

(0.0-dimethyl-0- [p-nitrophenyl] thiophosphate)

0.01 0.1 1.0 0.5

Acyrthosiphon (aphid)

35 '90

95 100

100 100

100 100

Table 4

connection

Concentration of

Spray solution

%

Test organism

Antifeedent effect

Compounds of Examples 1 to 8 (50 WP)

0.1 0.3 0.0

Indian walking grasshoppers

Table 5

remained unaffected remained unaffected eaten

connection

Concentration of

Spray solution

%

Test organism

Degree of inhibition of the

Spore germ

0.1% 1.0%

Product of example 2 (50 WP)

0.1 and 1.0

Alternaria tenuis Fusarium graminearum Trichotecium roseum Aspergillus flavus Pénicillium species Rhizopus nigricans Bothrytis cinerea Phytophtora infestans Endostigme pirina Monilia fructigena

Table 6

partially partially partially partially partially partially none partially partially none totally totally totally totally totally totally totally totally totally

connection

Concentration of

Spray solution

%

Test organism

Infection

%

Product of example 2

0.05

with Phytophtora infestans

5.0

(50 WP)

0.1

infected potato leaves

0.0

1.0

0.0

Zineb (zinc-ethylene-bis-

thiocarbamate)

0.3

20.0

(80 WP)

Untreated

-

100.0

Product of example 2

0.1

Phytophora, artificial

0.0

(50 WP)

Infection on potato slices

Product of example 2

0.01

infected with fusarium

26

(50 WP)

0.1

Potato leaves

0

1.0

0

Zineb (zinc-ethylene-bis-

thiocarbamate)

0.1

40

(80 WP)

Untreated

-

50

Connection of the

0.1

with Phytophtora infestans

0

Example 9

infected potato leaves

(50 WP)

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Table 6 (continued)

connection

Concentration of

Spray solution

%

Test organism

Infection

%

Orthocid

0.2

0

(N- [trichloromethylthio] -

4-cyclohexene-1,2-dicarboximide)

Untreated

-

60

Connection of example 9

0.1

Phytophtora, artificial

0

Table 7

Compound concentration of the test organism

Degree of inhibition of the

effect

Spray solution,%

i

Spore germ,%

%

0.1%

1.0%

0.1%

1.0%

Connection of 0.1 and 1.0

Alternaria tenuis totally total

111

333

Example 9

Fusarium

(50 WP)

graminearum totally total

300

833

Trichotecium

roseum totally total

90

300

Aspergillus

flavus totally total

150

466

Penicillium

species totally total

112

275

Bothrytis

cinerea totally total

166

316

Rhizopus

nigricans partially total

0

170

Mucor mucedo partially total

0

266

Comment on table 7:

The effect of Zineb (zinc ethylene bis-thiocarbamate) (80 WP) in 0.2% solution is considered to be 100%.

The invention is illustrated by the examples below.

example 1

Preparation of erythro-l-phenyl-2-nitro-1,3-propanediol diacetate 158 g of l-phenyl-2-nitro-l, 3-propanediol sodium salt are stirred, in 25 minutes, at a temperature below 20 ° C mixed to 700 ml of glacial acetic acid. Afterwards, 302 ml of acetyl chloride are added dropwise to the mixture in 35 minutes at a temperature likewise not exceeding 20 ° C. The reaction mixture is stirred at 40 ° C. for 14 hours, then the sodium chloride which has separated out is removed by filtration. 600 ml of petroleum ether are added to the filtrate. The mixture is stirred under ice-water cooling for 2 hours, whereupon a crystalline precipitate separates out which is filtered.

Yield: 55 g (25.6%).

M.p .: 81-82 ° C.

The crystal fractions obtained by repeated evaporation of the mother liquor consist of the mixture of the diacetates of the threo and erythro modifications.

Yield: 110.2 g (51%).

M.p .: 55-61 ° C.

The substances obtained in this way can be used together or separately for crop protection purposes.

Example 2

Preparation of threo-l-phenyl-2-nitro-1,3-propanediol diacetate 10 g of threo-l-phenyl-2-nitro-l, 3-propanediol are slowly mixed to 16 ml of acetyl chloride at room temperature. Strong hydrochloric acid development is perceptible when warming up. The cooling is regulated in such a way that the temperature does not exceed 40 ° C. After the release of the strong evolution of hydrochloric acid, the reaction mixture is kept at 40 ° C. for a further 3 hours, then it is left to stand at room temperature overnight.

After the addition of a large amount of petroleum ether and cooling to 45 ° C., the product which precipitates out in crystalline form is filtered, and then it is washed acid-free with petroleum ether.

Yield: 10.4 g (73%).

M.p .: 72-73 ° C.

Example 3

so production of threo-l-phenyl-2-nitro

1,3-propanediol diacetate 10 g of threo-l-phenyl-2-nitro-l, 3-propanedial are dissolved in 30 ml of glacial acetic acid and 16 ml of acetyl chloride are added to the solution at room temperature. The reaction mixture 55 is kept at 40 ° C. for 3 hours, then left to stand overnight. While cooling to 0 ° C, the product is precipitated with a lot of petroleum ether and left in the refrigerator for a few hours.

Yield: 11.5 g (80.5%).

60 m.p .: 70-72 ° C.

Example 4

Preparation of threo-l-phenyl-2-nitro-1,3-propanediol diacetate 35 g of threo-l-phenyl-2-nitro-l, 3-propanediol are dissolved in 65 49 ml of acetic anhydride and the solution slowly becomes 49 ml Acetyl chloride added in such a way that the temperature does not rise above 40 ° C. The mixture is kept at 40 ° C for 8 hours, then left overnight.

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The reaction mixture is poured into 200 g of ice with stirring, the diacetyl product separating out in the form of a dense oil, which then converts within a short time to crystals which are kept at 0 ° C. for 2 hours, then filtered and distilled Washes water acid-free.

Yield: 49.05 g (97.5%). M.p .: 71-72 ° C.

24.0 g of the above product are dissolved in 72 ml of isopropanol at about 85-90 ° C. and the solution is left to stand at room temperature. The product is eliminated within a few hours and washed out after filtration with cold petroleum ether.

Yield: 22.19 g (92%).

M.p .: 72-73 ° C.

Example 5

Preparation of threo-l-phenyl-2-nitro-1,3-propanediol diacetate 19.7 g of threo-l-phenyl-2-nitro-l, 3-propanediol are dissolved in 30 ml of acetic anhydride, the 0.2 ml Boron fluoride ether solution are added in such a way that the temperature does not rise above 20 ° C. The mixture is stirred for 1 hour at 40 ° C. and then poured onto ice. The crystals which separate out are filtered and washed with ice-cold distilled water Yield: 26.2 g (93.2%).

M.p .: 69-71 ° C.

21.0 g of product are recrystallized from 50 ml of ethanol. Yield: 16.8 g (80.0%).

Smg .: 70.5-72 ° C.

Example 6

Preparation of erythro-l-phenyl-2-nitro-1,3-propanediol diacetate 4.9 g of erythro-l-phenyl-2-nitro-l, 3-propanediol are dissolved in 14.7 ml of glacial acetic acid and the solution added 7.85 ml of acetyl chloride at room temperature. The mixture is kept at 40 ° C. for 6 hours and then left to stand at room temperature overnight. A lot of petroleum ether is added to the solution and it is left to stand in the refrigerator for 4 hours. The precipitated crystalline product is filtered and washed with petroleum ether.

Yield: 3.08 g (44%).

M.p .: 81 ° C.

Example 7

Preparation of erythro-l-phenyl-2-nitro-1,3-propanediol diacetate 8.0 g of erythro-l-phenyl-2-nitro-1,3-propanediol are dissolved in 11.2 ml of acetic anhydride and the solution 11.2 ml of acetyl chloride were slowly added dropwise at a temperature not exceeding 40 ° C. The mixture is kept at 40 ° C. for a further 8 hours. The reaction mixture is poured into 30 g of ice with stirring, whereupon the diacetate slowly separates out. It is kept at 0 ° C for 2 hours, then filtered and washed acid-free with distilled water at 0 ° C. 11.75 g of crude product are obtained, which is recrystallized from 66 ml of ethanol. The filtered crystals are washed with petroleum ether.

Yield: 4.7 g (41%).

M.p .: 79-80 ° C.

Example 8

Preparation of threo-1-phenyl-2-nitro-1,3-propanedial dipropionate In 40 ml of propionic anhydride containing 0.2 ml of boron fluoride etherate, 19.7 g of threo-1-phenyl-2-nitro- 1,3-propanediol mixed. The mixture is kept under stirring at 40 ° C for 2 hours, after which it is poured onto ice. The crystals which separate out are filtered and washed with ice-cold distilled water.

Yield of crude dipropionate: 28.6 g (92.6%).

Recrystallized from ethanol: 25.25 g (88.5%).

M.p .: 48-50 ° C.

Example 9

Preparation of threo-1-phenyl-2-nitro-1,3-propanediol dibenzoate 19.7 g of threo-l-phenyl-2-nitro-1,3-propanediol slowly become 28 g (24.1 ml ) Benzoyl chloride mixed so that the temperature does not exceed 20 ° C, then the temperature is raised to 85-90 ° C and the mixture is kept at this temperature for 7-8 hours. Allow to stand overnight, then drop the dibenzoate with diethyl ether. After filtering, the product is washed acid-free with petroleum ether. Yield of crude dibenzoate: 19.6 g (48.5%). Recrystallized from ethanol-tetrahydrofuran: 15.8 g

(80.5%).

M.p .: 130.5-132 ° C.

Example 10 Preparation of threo-1-phenyl-2-nitro-1,3-propanediol dipalmitate The mixture of 19 g of threo-1-phenyl-2-nitro-1, 3-propane-diol and 55.8 g of palmitoyl chloride is made Stirred at 80 ° C for 8 hours. After cooling, the reaction mixture is mixed with petroleum ether. The crude product which separates out is filtered after standing for a short time and washed with petroleum ether. Once recrystallized from ethanol, the yield is 9.95 g (29.3%).

M.p .: 51-53 ° C.

Example 11 Preparation of threo-l-phenyl-2-nitro-1,3-propanediol-diphenyl acetate The mixture of 4.0 g of threo-l-phenyl-2-nitro-l, 3-pro-pandiol and 9.4 g Phenylacetyl chloride is stirred at 70 ° C for 5 hours, then at 85 ° C for 10 hours. After cooling, the reaction mixture is cleaved with ice and left to stand overnight. The product separating in the form of a dense oil is separated from the aqueous part, dissolved in 15 ml of diethyl ether, dried with magnesium sulfate and filtered. 25 ml of petroleum ether are added to the solution obtained, and after standing for a few days, the crystalline product is filtered (5.6 g) and, triturated with 15 ml of ethanol, left to stand in the refrigerator. The next day the mixture is filtered and washed with cold ethanol. The crude product obtained in this way is recrystallized from 12.5 ml of ethanol and the filtered product is washed with cold ethanol and petroleum ether.

Yield: 4.1 g (46.6%).

M.p .: 63-64 ° C.

Example 12 Preparation of threo-l-phenyl-2-nitro-1,3-propanediol-di-p-chlorobenzoate The mixture of 1.95 g of threo-l-phenyl-2-nitro-l, 3-pro-pandiol and 5.35 g of p-chlorobenzoyl chloride is stirred at 85-90 ° C for 14 hours. Ice is added to the cooled reaction mixture; it is left to stand overnight, then it is filtered and washed with water and petroleum ether. The crude product obtained in this way is crystallized from 62 ml of ethanol.

Yield: 1.08 g (23.4%).

M.p .: 107-109 ° C.

Example 13 Production of WP preparation The compound of the general formula (I) is comminuted in a micronizing mill to at least 80% to 1-20 a grain size. The millbase is homogenized with 1-5% by weight of neutral or non-basic wetting agent and with 20-60% by weight of solid inert binder, such as kaolin or bentonite. The WP won in this way, i.e. wettable powder, contains about 82-60 wt .-% active ingredient (82 WP-60 WP).

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Example 14 Preparation of WP preparation The procedure described in Example 13 is followed, with the difference that in the course of grinding and homogenization, in addition to the inert binder, there is also an acid buffer substance which increases stability, e.g. Potassium or sodium dihydrophosphate, lactic acid or tartaric acid, is added in an amount of 10-20% by weight. The WP preparation obtained in this way contains about 76-54% by weight of active ingredient (76 WP-54 WP).

Example 15 Preparation of a spray preparation A compound of the general formula (I) is dissolved in benzene or in a benzene homolog (toluene, xylene) to a 0.1-1% solution. 1-3% of wetting agent and 1% of the auxiliary substance which increases the adhesion are added to the solution. The mixture is filled with a propellant gas (e.g. freon, propane-butane gas, carbon dioxide) in aerosol bottles, the nozzle of which secures a fine spray.

Example 16 Preparation of an EC preparation A compound of the general formula (I) is ground to at least 80% to 1-20 // grain size, then the 5 substance is mixed with the same weight of an inert organic solvent and also in the course of the homogenization 5-7% wetting agent added. The emulsifiable concentrate obtained in this way contains about 47-48% active ingredient, and can be diluted arbitrarily with the solvent used.

Example 17 Preparation of a Microgranulate A compound of the general formula (I) is dissolved in Chlo-15 roform or in another chlorinated hydrocarbon, whereby a solution is prepared, the concentration of which corresponds to the homogenizer to be used. This solution is processed in a homogenizer using the "wet" method, e.g. Coating pan, applied to a solid support of 20 0.1-1 mm grain size (e.g. perlite, coke powder), and the active ingredient content is adjusted to 10-30%.

s

Claims (2)

626 776 2nd PATENT CLAIMS 1. Plant protection product, characterized in that it contains one or more nitroalkanol derivatives of the formula I as active ingredient (I), / V CH - CH - CH 2 (II) OH OH or alkali metal salt of this compound is reacted with an acylating agent under mild ratios and the compounds obtained are mixed with a formulation agent. 3. The method according to claim 2, characterized in that one carries out the reaction in a solvent. 4. The method according to claim 2, characterized in that an acid halide and / or acid anhydride is used as the acylating agent. 5. The method according to claim 2, characterized in that reacting the alkali salt of the compound of formula II in a solvent at about 40 ° C with an acid halide as an acylating agent. 6. The method according to claim 2, characterized in that one carries out the reaction without solvent, with an acid anhydride as acylating agent, in the presence of a catalytic amount of a mineral acid or a chloride corresponding to the acid anhydride. This compound is known (C.A. 59, 1956, p. 6360). Due to its stereochemical conditions, this process only enables the production of the threo product. The crop protection agents according to the invention contain one or more nitroalkanol derivatives of the formula I as active ingredient NO, wherein R represents a C 1-4 alkyl group or a phenyl or phenyl-C 1-4 alkylene group optionally substituted with one or more C 1-4 alkyl groups or with halogen, and also contains a formulation agent. 2. A process for the preparation of an agent according to claim 1, characterized in that nitroalkanol derivatives of the formula I are prepared in which R has the meaning given above by using l-phenyl-2-nitro-1,3-propanediol of the formula II NO_ CH ~! o-co! R CH, O-Cü R (I)