CH637920A5 - N-Formylphenylhydrazones, processes for their preparation, and their use as fungicides - Google Patents

Description

The invention relates to N-formyl-phenylhydra-i5 zone, which are suitable as agents for protecting plants against fungal attack.

The N-formylphenylhydrazones according to the invention correspond to the general formula:

R

C =

(I)

25th

R

30 in which R represents an optionally substituted phenyl, thienyl, furyl or pyridyl group and R1 represents an alkyl, phenyl or cycloalkyl group, X represents a hydrogen or halogen atom or an alkyl or alkoxy group and n is one of the numbers Ó, 1 or 2 represents.

Compounds according to formula (I) in which R represents a phenyl, thienyl or furyl group are preferred, each of these groups being substituted by an alkyl radical, preferably an alkyl radical having 1 to 4 carbon atoms and in particular the methyl radical, or a halogen atom (for example a 40 chlorine, fluorine or bromine atom) can be substituted, while R1 represents an alkyl group with 1 to 4 carbon atoms (e.g. a methyl, ethyl or tert-butyl group) or a phenyl or cyclopropyl group, X represents a hydrogen or a halogen atom ( preferably chlorine or fluorine) occurs and n is 0 or 1.

Examples of particularly preferred compounds according to the invention are:

2-thienylmethylketone-N-formyl-4-fluorophenylhydrazone 2-thienylmethylketone-N-formyl-4-chlorophenylhydrazone 2-thienylmethylketone-N-formylphenylhydrazone The N-formylphenylhydrazone according to the invention is prepared by reacting a ketone of the formula:

50

R

R1

G = 0

60 with a phenylhydrazine of the formula:

II

H, N -

. (X)

wherein R, R1, X and n have the above meanings, and subsequent reaction with a formylating agent.

The reaction can be carried out using the corresponding substituted hydrazine salt, preferably the hydrochloride, together with an appropriate base, e.g. B. sodium acetate, are carried out. The reaction is preferably carried out in a polar solvent at a temperature between ambient temperature and 100 ° C. Suitable solvents are e.g. Ethyl alcohol, diethyl ether and 50% aqueous acetic acid. However, the reaction can also be carried out in the absence of a dehydrating agent, in which case distillation is carried out with a liquid carrier in order to remove water under Dean-Stark conditions. Suitable water-immiscible liquids which form an azeotrope with water are e.g. Benzene, toluene and xylene.

The preferred formylating agent is a mixed anhydride of formic and acetic acid. Formylation is usually carried out on the isolated hydrazone compound. However, if a liquid carrier has been used to remove water, direct formylation of the liquid carrier solution of hydrazone can be carried out.

As already mentioned, the N-formylphenylhydrazones according to the invention have a fungicidal action and the invention therefore also includes the use of these compounds as active ingredients in fungicides, generally with a carrier and / or a surface-active agent.

When these fungicides are used, the plant stands, the seeds of the plants or the soil in which they grow are themselves treated with an amount of the preparation or the N-formylphenylhydrazone which is effective as a fungicide.

The fungicides comprise a carrier, which is to be understood as a solid or liquid substance, which can be inorganic or organic and of synthetic or natural origin, with which the active ingredient is mixed or processed in order to apply it to the plant, the seed, the To facilitate the handling of soil or another object to be treated or its handling, storage or transport. The solid or liquid carrier is selected from the substances customary for the purpose in question.

Natural and synthetic clays and silicates, e.g. B. natural silica, such as diatomaceous earth, or magnesium silicates, e.g. Talke, or magnesium aluminum silicates, e.g. B. Attapulgite and Ver-miculite, and aluminum silicates, such as kaolinite, Mont-morillonite and mica. Calcium carbonates, calcium sulfate or synthetic hydrated silicon oxides and synthetic calcium or aluminum silicates are also suitable, as are elements such as carbon and sulfur, and natural and synthetic resins such as e.g. Coumarone resins, polyvinyl chloride and styrene polymers and copolymers; solid polychlorophenols, bitumen, waxes such as beeswax or paraffin and chlorinated mineral waxes can also serve as carriers, as can solid synthetic fertilizers, e.g. Superphosphates.

Examples of liquid carriers are: water; Alcohols such as 2-propanol; Glycols; Ketones, e.g. Acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohecanone; Ether; aromatic hydrocarbons, e.g. benzene. Toluene and xylene; Petroleum fractions, e.g. Kerosene or light oils; chlorinated hydrocarbons, e.g. Carbon tetrachloride, perchlorethylene or trichloroethane, including liquefied, usually gaseous compounds. Mixtures of different liquids often prove to be suitable.

The surfactant can be a nonionic or ionic emulsifying, dispersing or wetting agent customary for herbicides, fungicides or insecticides. Examples are the sodium or calcium salts of poly

637 920

acrylic 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; the fatty acid esters of glycerin, sorbitan, 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-octylcresol, with ethylene oxide and / or propylene oxide; Sulfates or sulfonates of these condensation products; Alkali or alkaline earth metal salts, preferably sodium salts of sulfuric acid or sulfonic acid esters with at least 10 carbon atoms in the molecule, e.g. B. sodium lauryl sulfate, secondary sodium alkyl sulfates, sodium salts of sulfonated castor oil and sodium alkylarylsulfonates such as sodium dodecylbenzenesulfonate; and finally polymers of ethylene oxide and copolymers of ethylene oxide and propylene oxide.

The fungicides can be present as wettable powders, dusts, granules, solutions, emulsifiable concentrates, emulsions, suspension concentrates and aerosols and usually contain 0.5 to 95, preferably 0.5 to 75% by weight of N-formylphenylhydrazones according to the invention. Wettable powders usually contain 25, 50 or 75% active compound and mostly, in addition to the solid carrier, 3-10% by weight of dispersant and, if necessary, up to 10% by weight of stabilizers or other additives, such as agents to facilitate penetration or adhesives . Dusts are usually present as concentrates, the composition of which corresponds to that of the wettable powders, but without a dispersant; when used, they are diluted with a further solid carrier, so that a preparation is obtained which usually contains 0.5 to 10% by weight of N-formylphenylhydrazones according to the invention.

Granules are usually in a grain size of 0.15-1.7 mm, which have been produced by agglomeration or impregnation. Granules usually contain 0.5-25% by weight of active ingredient and up to 10% by weight of additives such as stabilizers or retarders or binders. In addition to the solvent and optionally an auxiliary solvent, emulsifiable concentrates usually contain 10-50% weight / volume N-formylphenyl hydrazone, 2-20% weight / volume emulsifiers and up to 20% weight / volume suitable additives, such as stabilizers or agents for Facilitate penetration or to prevent corrosion. Suspension concentrates are prepared in such a way that a stable, non-settling, flowable product is obtained and usually contain 10-75% by weight of N-formylphenylhydrazone, 0.5-15% by weight of dispersant, up to 10% by weight. % Suspending agents, such as protective colloids or thixotropic agents and up to 10% by weight of additives, such as defoamers, corrosion inhibitors, stabilizers, agents to facilitate penetration and adhesives. Water or an organic liquid in which the N-formylphenylhydrazone is essentially insoluble is present as the carrier in the suspension concentrates; Certain organic salts may be dissolved in the carrier to prevent settling or, if water is present, freezing.

The use of aqueous dispersions and emulsions, e.g. B. those obtained by diluting a wettable powder or concentrate according to the invention also falls 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 fungicides obtainable with the compounds according to the invention can also contain other admixtures, e.g. B. other compounds with pesticide, especially insecticide, herbicide or acaricide properties.

3rd

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

637 920

The examples serve to illustrate the invention.

example 1

Preparation of 2-thienylmethylketone-N-formyl-4-fluorophenylhydrazone

A hot solution of 4-fluorophenylhydrazine hydrochloride (8.1 g, 0.05 mol) in aqueous ethanol (50 ml) containing anhydrous sodium acetate (5.0 g) was washed with a solution of 2-acetylthiophene ( 5.5 g, 0.05 mol) combined in aqueous ethanol (25 ml). The mixture was refluxed for 10 minutes, cooled and the excess solvent was removed. Then diethyl ether and water were added and the ether extracts separated and dried over anhydrous sodium sulfate. After the ether had been removed, the crude hydrazone derivative was recrystallized from 5% strength aqueous alcohol.

4.7 g (0.02 mol) of 2-thienylmethyl-ketone-4-fluorophenylhydrazone obtained as above were dissolved in 35 ml of dry 1,2-dimethoxyethane and mixed with excess mixed anhydride from formic and acetic acid (7.0 ml), whereupon the mixture was allowed to stand at room temperature for 48 hours.

After the excess solvent was stripped off under reduced pressure, 5% sodium bicarbonate solution was added to the viscous residue, and the mixture was extracted with methylene chloride and filtered through silica gel to remove colored, polar impurities. The pale yellow crude product was recrystallized from cyclohexane and then had an mp of 83-84 ° C.

Analysis: Ci3HnN2SOF:

calculated: C 59.5 H 4.2 N 10.7%

found: C 59.7 H 4.4 N 10.6%

Example 2

Preparation of 2-thienylmethylketone-N-formylphenylhydrazone 2-thienylmethylketone-phenylhydrazone (6.5 g, 0.03 mol) (prepared according to Example 1) was dissolved in dry diethyl ether (37.5 ml) and with an excess of mixed anhydride of formic and acetic acid (7.0 ml). After standing at room temperature for 48 hours, a crystalline product had formed, which was filtered off and washed with a little diethyl ether; it is the desired formylated product, which was in pale yellow leaves of mp 122-124 ° C.

Analysis: C13H12N2SO:

calculated: C 63.9 H 4.9 N 11.5%

found: C 63.5 H 5.0 N 11.2%

Example 3 Preparation of 2-furylmethylketone-N-formylphenylhydrazone 2-furylmethylketonephenylhydrazone (6 g, 0.03 mol) (prepared according to Example 1) was dissolved in diethyl ether and mixed with formic acid and acetic acid (7.0 ml) for 48 hours Leave room temperature. After the excess solvent had been stripped off under reduced pressure, the residue was recrystallized from cyclohexane; the desired product was obtained as a white solid of mp. 88-92 ° C.

Analysis: Ci3H12N202:

calculated: C 68.4 H 5.3 found: C 68.8 H 5.3

io

20th

N 12.3% N 12.6%

Example 4

Preparation of tert-butylphenyl ketone N-formylphenylhydrazone t-butylphenyl ketone (8.1 g, 0.05 mol) and phenylhydra-25 tin (5.4 g, 0.05 mol) were mixed in dry xylene (50 ml) and heated under Dean and Stark conditions for 1/2 hour. After the xylene had been driven off under reduced pressure, a pale yellow solid was obtained which was recrystallized from petroleum ether. 7.5 g (0.03 mol) of the t-30 butylphenyl ketone phenyl hydrazone thus obtained were dissolved in diethyl ether and formic and acetic anhydride (7.0 ml) were added. After standing at room temperature for 48 hours, a crystallized product had formed which was filtered off and washed with diethyl ether; the desired product was obtained as pale yellow crystals of mp. 71-73 ° C.

Analysis: ClgH20N20:

calculated: C 77.1 H 7.1 N 10.0%

found: C 76.5 H 7.1 N 9.9%

40

Examples 5-11

Using the procedure described in Example 1-4, the further Verbin-45 fertilizers according to the invention listed in Table I with their physical data and analyzes were produced.

Table I

Example No.

connection

Mp ° C

analysis

C.

H

N

5

2-thienyl methyl ketone-N-formyl-4-chloro

phenylhydrazone

87-89

C ^ HnN.SOCl:

about:

56.0

4.0

10.0%

found:

56.4

4.3

9.9%

6

Acetophenone-N-formylphenylhydrazone

113-114

C1sH14N20;

calc .:

75.6

5.9

11.8%

found:

75.8

5.9

11.8%

7

Acetophenone-N-formyl-4-fluorophenyl-

hydrazone

69-71

C15H13N2OF:

calc .:

70.3

5.1

10.9%

found:

70.7

5.0

10.9%

8th

Benzophenone N-formylphenyl hydrazone

99-101

c20h16n2o calc .:

80.0

5.3

9.3%

found:

80.3

5.3

9.1%

9

4-chloroacetophenone-N-formylphenyl

hydrazone

59-61

c15h13n2oci ber .:

66.1

4.8

10.3%

found:

66.0

4.8

10.2%

10th

Propiophenone-N-formylphenylhydrazone

64-66

c16h16n2o calc .:

76.2

6.4

11.1%

found:

76.0

6.6

10.9%

11

4-fluorobenzophenone-N-formylphenyl

hydrazone

77-79

C1sH13N2FO

calc .:

70.3

5.1

10.9%

found:

70.4

5.4

11.0%

Example 12

The fungicide activity of the compounds according to the invention was determined as follows:

(1) Effect against the powdery barley melts (Erysiphe graminis)

The effect of the compounds applied by spraying the leaves on the fungal spores was measured. In each individual case, about 40 barley seedlings were left to rise to the single-leaf stage in a plastic pot with sterile compost. The plantlets were then inoculated by dusting the leaves with conidia from Erysiphe graminis. 24 hours after inoculation, the plantlets were sprayed with a solution of the compound to be tested in a mixture of acetone (50%), wetting agent (0.04%) and water. The amount applied would correspond to 1 kg of active ingredient per hectare when used in the open field. The effect of the treatment was first observed 5 days after the treatment, comparing the total spore formation on the treated plants with that on comparative plants.

(2) Effect against brown wheat rust (Puccinia recondita)

The procedure for measuring the immediate effect against spore formation was as follows: pots with about 25 wheat seedlings in which the first leaf was formed were inoculated by injecting the leaves with an aqueous compound 20-24 hours before treatment with the compound to be tested Sprayed suspension, which contained 105 spores and some wetting agent per milliliter. They inoculated

5 637 920

Plants were kept in a very humid atmosphere overnight, then dried at greenhouse temperature and sprayed with the active ingredient, the amount of which was selected so that it would have corresponded to 1 kg per hectare in the field test. After the treatment, the test plants were kept in the greenhouse at normal temperature and the efficacy was determined 11 days after the treatment. The effectiveness was determined on the basis of the relative density of the pustules caused by fungal spores per plant in comparison with control plants.

(3) Efficacy against broad bean rust (Uromyces fabae)

Pots with one bean plant each were inoculated by spraying an aqueous solution on the underside of each leaf 20-24 hours before treatment with the test compound, each containing 5 × 104 spores and some wetting agent. The inoculated plants were kept in a very humid atmosphere overnight, dried at room temperature and then sprayed on the surface of the leaves, using the agent in a dosage which would have corresponded to 1 kg per hectare in the field test. The plants treated in this way were kept in the greenhouse for 11 days, after which the infestation or the fungicide-25 effect was determined on the basis of the relative density of the spore pustules per plant, compared to control plants.

In Table II below, the fungicide activity is evaluated as follows:

0 = suppression of the infestation of less than 50% 3o 1 = suppression of the infestation of 50-80% 2 = suppression of the infestation of more than 80%.

Table!!

Compound according to formula I R

R1

Fungicidal effects in the different types of fungus *

E.g. P.r. U.f.

CH3

4-F

1

0

ch3

ch3

4-C1 H

ch3

h ch3

o ch3

4-F

H

H

2 1 0

1 0 0

0 2

CH,

H

! Evaluation according to 0.1 and 2 as above

Claims (16)

637 920 .1 CX) (I) wherein R, R1, X and n have the meaning given above, and then reacted with a formylating agent. 17. The method according to claim 16, characterized in that a mixed anhydride of formic and acetic acid is used as the formylating agent. 18. Use of the compounds of formula I as active ingredients in fungicides. 2. N-Formylphenylhydrazone according to claim 1, characterized in that R represents a phenyl, thienyl or furyl group optionally substituted by an alkyl group or a halogen atom. 2nd PATENT CLAIMS 1. N-formylphenyl hydrazones of the general formula: H-OO C = Ï1 - 3. N-formylphenyl hydrazone according to claim 2, characterized in that R represents a phenyl, thienyl or furyl group optionally substituted by an alkyl group having 1 to 4 carbon atoms or a chlorine, fluorine or bromine atom. 4. N-formylphenyl hydrazone according to claim 3, characterized in that R represents a phenyl, thienyl or furyl group optionally substituted by a methyl group. 5. N-Formylphenylhydrazone according to any one of claims 1 to 4, characterized in that R1 represents an alkyl group with 1 to 4 carbon atoms or a cyclopropyl group. 6. N-formylphenyl hydrazone according to one of claims 1 to 5, characterized in that X represents a chlorine or fluorine atom. 7. N-formylphenyl hydrazone according to one of claims 1 to 6, characterized in that n is 0 or 1. 8. 2-thienylmethyl ketone-N-formyl-4-fluorophenylhy-drazon according to claim 1. 9. 2-thienylmethyl ketone-N-formyl-4-chlorophenylhydra-zone according to claim 1. 10. 2-thienylmethylketone-N-formylphenylhydrazone according to claim 1. 10th wherein R is an optionally substituted phenyl, thienyl, furyl or pyridyl group; R1 is an alkyl, phenyl or cycloalkyl group; and X represents a hydrogen or halogen atom or an alkyl or alkoxy group and n represents 0.1 or 2. 11. acetophenone-N-formylphenylhydrazone according to claim 1. 12. acetophenone-N-formyl-4-fluorophenylhydrazone according to claim 1. 13. Benzophenone-N-formylphenylhydrazone according to claim 1. 14.2-Furylmethylketone-N-formylphenylhydrazone according to claim 1. 15.4-chloroacetophenone-N-formylphenylhydrazone according to claim 1. 16. A process for the preparation of the N-formylphenylhydrazone of the formula I, characterized in that a ketone of the general formula: C-0 R1- ^ with a phenylhydrazone of the general formula: h0n • - ^