CS246097B2 - Fungicide for use in agriculture and method of efficient substances production - Google Patents

Description

(54) Fungicidal product for use in agriculture and process for the production of active substances

The invention relates to a process for the production of novel triazole derivatives which have antifungal activity and are useful in the treatment of fungal infections in animals, including humans, and as agricultural fungicides.

Accordingly, the invention provides a process for the preparation of compounds of formula (I) wherein:

R is phenyl optionally substituted with one to three substituents independently selected from fluoro, chloro, bromo and iodo and trifluoromethyl; n is 1 or 2; and

R ² represents an alkyl group having 1 to 4 carbon atoms, and their pharmaceutically and agriculturally acceptable salts.

The invention further provides a fungicidal composition for use in agriculture comprising a compound of formula I or an agriculturally acceptable salt thereof, together with an agriculturally useful diluent or carrier.

Further disclosed is a method of treating a fungus infested seed or plant, comprising contacting the seed or plant, or a locus thereof, with an antifungal effective amount of a compound of formula I or an agriculturally useful salt thereof.

R is preferably a phenyl group having 1 to 3 substituents, more preferably 1 or 2 substituents independently selected from the group consisting of fluoro, chloro, bromo, iodo and trifluoromethyl. Thus, R is especially 4-fluorophenyl, 4-chlorophenyl, 4-trifluoromethylphenyl, 2-fluorophenyl, 2,4-dichlorophenyl, 2,4-difluorophenyl, 2-fluoro-4-chlorophenyl, 2, 5-difluorophenyl, 2,4-trifluorophenyl or 4-bromo-2,5-difluorophenyl. Most preferably, R is 2,4-difluorophenyl, 2,4-dichlorophenyl, 4-chlorophenyl or 4-fluorophenyl.

246067

The symbol R preferably represents ^a methyl or ethyl radical.

Preferred is the compound of the above formula wherein R is 2,4-difluorophenyl, R ² is methyl and ⁿ is 1.

According to the invention, the diols of the above formula (I) are prepared by preparing a compound of formula (IA)

OH _O

in which

Ran is as defined above, reacted with a compound of formula

R ² .X in which

R ² has the abovementioned meaning and

X is MgBr or Mgi, or lithium.

The starting hydroxyketones of formula IA can be prepared by the general procedure of the following reaction scheme:

Y 2 -CH ³ C-COQ- ³ >

(«)

In the formulas shown in this scheme, Ran is as defined in formula (I) and Q is (C 1 -C 4) alkoxy.

The anion CF3 (CF2) _n ^_, is preferably obtained by using a Grignard reagent CF3 (CF2) MgI or CF3 (CF2) _n MgBr, typically as a mixture of both of these agents prepared from a compound of CF3 (CF2) _n I and methylmagnesium bromide. According to a typical embodiment of this reaction, the iodide of formula CF3 (CF2) _n I in a suitable solvent, for example dry ether, is reacted with methylmagnesium bromide at a temperature between about -65 and -70 ° C. The reaction mixture is stirred at this temperature for about 0.5 hours and then the compound of formula II, for example in dry ether, is slowly added while maintaining the temperature at -65 ° C or below. The mixture was stirred at the above temperature for about 1 hour, then allowed to slowly warm to about -25 ° C, an aqueous ammonium chloride solution was added, the ether layer was separated and washed with water. The aqueous layer was extracted with ether, the combined ether extracts were dried over magnesium sulphate, evaporated and the residue chromatographed on silica gel in conventional manner to give the desired product.

The starting materials of the formula II can be prepared in a conventional manner, for example according to the following reaction scheme:

RMg8r asbo 9, . -r Br-CMjCCOalk RLí - OH ------> 3r — C HnC ~ 000 & tK A | R · * ·

1,2,4-triazole potassium carbonate dimethylformamide up to 60 ° C

Oh 2 N-CH 2 C-COOalk

In the above formulas, alk is C 1 -C 4 alkyl.

Most preferably the ethyl ester is used in the above reaction.

The compounds of the invention contain two optical centers and the invention encompasses both the resolved and non-resolved forms of the individual diastereomers.

Pharmaceutically useful addition salts of the compounds of formula I are those with strong acids forming non-toxic addition salts such as hydrochlorides, hydrobromides, sulfates, oxalates and methanesulfonates.

These salts can be obtained by conventional methods, for example by mixing solutions containing equimolar amounts of the free base and the desired acid, and isolated by filtration if the salt is insoluble or by evaporation of the solvent.

The invention also includes alkali metal salts which are also prepared in conventional manner. ·

The compounds of formula I and their pharmaceutically acceptable salts are antifungal agents useful for combating fungal infections in animals, including humans. For example, the compounds may be used in human medicine to treat local fungal infections caused, inter alia, by Candida, Trichophyton, Microsporum or Epidermophyton, or to treat mucosal infections caused by Candida albicans (e.g., oral cavity and vaginal candidiasis). treating systemic fungal infections caused by, for example, Candida albicans, Cryptococcus neoformans, Aspergillus fumigatus, Coccidioides, Paracoccidioides, Histoplasma or Blasiomyces.

The in vitro evaluation of the antifungal activity of the disclosed compounds can be carried out by determining the minimum inhibitory concentrations of the test compounds in a suitable environment without growth of the respective microorganism. In practice, a series of agar plates, each containing the test compound at the appropriate concentration, are inoculated with a standard culture, such as Candida albicans, and all plates are then incubated at 37 ^° C for 48 hours. , respectively. in the absence of fungal growth and the appropriate value of the minimum inhibitory concentration is calculated. Other microorganisms useful for these assays include Cryptococcus neoformans, Aspergillus fumigatus, Trichophyton spp., Microsporum spp., Epidermophyton floccosum, Coccidioides immitis and Torulopsis glabrata.

The in vivo efficacy of the disclosed compounds can be assessed by administering a series of different doses of the test compound to mice inoculated with Candida albicans by intraperitoneal or intravenous injection. Efficacy is then calculated based on the number of surviving specimens of the test animals in the treated group after the death of the untreated mice. The observation period is 48 hours. The dose at which the test compound provides 50% protection against the lethal effect of IR & CJ (PD50) is determined.

After use in human medicine, the antifungal compounds of Formula I may be administered alone, but are generally administered in admixture with a pharmaceutical carrier selected taking into account the intended route of administration and standard pharmaceutical practice. For example, they may be administered orally in the form of tablets containing starch or lactose as carriers, or in the form of capsules or ovules containing either alone or in admixture with carriers, or in the form of elixirs or suspensions containing flavoring or coloring agents. . The disclosed compounds may be administered by parenteral injection, for example, intravenously, intramuscularly or subcutaneously. For parenteral administration, the disclosed compounds are best used in the form of a sterile aqueous solution which may contain other substances, such as salts or glucose, to render the solution isotonic.

When administered orally or parenterally in human medicine, the daily doses of the antifungal compounds of formula I will range from 0.1 to 5 mg / kg, the total dose being administered in divided doses. Thus, tablets or capsules will contain from 5 mg to 0.5 g of the active ingredient and will be administered once, twice or more daily as appropriate. The appropriate dose, which will be most suitable for a given patient and will vary depending on the patient's age, weight and response, will be determined by the attending physician. The above dosage range is merely an example of an average case, and of course there will be individual cases where higher or lower doses are required. These cases are also within the scope of the invention.

Alternatively, the antifungal compounds of the invention may be administered in the form of suppositories or pessaries, or administered topically in the form of a lotion, solution, cream, ointment or powder. For example, the compounds may be incorporated into a cream consisting of an aqueous emulsion of polyethylene glycols or liquid paraffin, or may be incorporated at a concentration of between 1 and 10% into an ointment consisting of white wax or white soft paraffin, optionally together with stabilizers and preservatives.

The compounds of formula I and their salts are also active against a number of phytopathogenic fungi, including, for example, various rusts, mildews and molds, and the compounds described herein can therefore be used to treat plants and seeds for the treatment or prevention of such diseases.

The in vitro evaluation of the efficacy of the compounds of the invention against phytopathogenic fungi is carried out by detecting their minimal

at the same procedure as above except that plates are incubated at 30 ° C for 48 hours or longer before assessing fungal growth.

Microorganisms used in these tests include Cochliobolus carbonum, Ryricularia oryzae, Glomerella cingulata, Penicillium digitatum, Botrytis cinerea and Rhizoctonia solani.

Active substance Example No. H (I) 3.1 (Π) 1.6 (I) 6.2 (II) 3.1 (I) 0.4 (II) 0.8 (II) 0.2

For agricultural and horticultural applications, the compounds of the invention and their agriculturally useful salts are preferably used in the form of a composition adapted to the mode of application and the intended use. Thus, the compounds can be applied in the form of dusts, granules, seed dressings, aqueous solutions, dispersions or emulsions, baths, sprays, aerosols or fumes. The disclosed compounds can also be supplied in the form of dispersible powders, granules or grains, or concentrates to be diluted prior to application. Such compositions may also contain conventional carriers, diluents or excipients as known and used in agriculture and horticulture, and may be prepared by conventional techniques. The compositions described may also contain other active ingredients, for example compounds exhibiting herbicidal or antifungal activity

The following is the results of tests for the efficacy of the compounds of the invention against phytopathogenic fungi. The results are reported as the minimum inhibitory concentration (MIC) values for the following phytopathogenic organisms:

H ~ Helminthosporium

Pen - Penicillium

B - Botrytis

Py - Pyricularia

MIC (Atg / ml)

Pen B Py

12.5 6.2 50

3.1 1.6 3.1

6.2> 50

12.5 0.8 25

1.6 0.8 0.4

1.6 0.2 1.6

0.2 0.8 1.6 insecticidal activity or other fungicides. The compounds of the invention and compositions containing them can be applied directly to the leaves, stems, branches, seeds or roots of plants, or to soil or other growth media, and can be used not only to treat disease but also prophylactically to protect plants or seeds from fungal infestation. .

The following preparations describe the preparation of the starting ketones of formula IA.

Preparation 1.

(AND)

Preparation of 1- (ethoxycarbonyl) -1- (4-fluorophenyl) -2- (1H-1,2,4-triazol-1-yl) ethanol

BrC C OO C ^ H £ *

1,2,4-triazole k ₂ co ₃ r

(A)

g (0.29 mol) of p-fluorobromobenzene is reacted with 10 g (0.42 mol) of magnesium shavings in 200 ml of dry ether to form a Grignard reagent. The resulting Grignard reagent solution was added to a solution of 40.4 grams (0.24 mol) of ethyl bromopyruvate in 300 mL of dry ether, and the resulting solution was cooled to -70 to -65 degrees Celsius for about 2 hours. The reaction mixture was stirred at -70 ° C for 0.5 h, allowed to warm to -30 ° C over a further 0.5 h, while maintaining a temperature below 0 ^° C a solution of 100 g of ammonium chloride in 300 mL of water was added and the resulting mixture was allowed to warm to room temperature (20 ° C). The ether layer was separated and the aqueous layer was extracted twice with 500 ml of ether each time. The combined ether phases were dried over magnesium sulfate and evaporated. The obtained crude intermediate (A) was reacted for about 4 hours with 50 g (0.72 mol) of 1,2,4-triazole and 100 g (0.72 mol) of anhydrous potassium carbonate in 300 ml of dry dimethylformamide at 50-60 ° C. Deň: 32 ° C. The reaction mixture was allowed to cool to room temperature (20 ° C) and then 500 mL of ether was added. The ether layer was washed with 500 mL of water and the aqueous layer was extracted twice with 500 mL of ether each time. The combined ether fractions were washed with water (3.times.200 ml), dried (MgSO4) and evaporated. The crude product after chromatography on silica gel (230-400 mesh) eluting with ethyl acetate followed by trituration with petroleum ether (60-80 ° C) gave 20 g (yield 30%) of the title compound. A small sample of the product was converted for characterization by reaction with methanesulfonic acid in dry ether followed by recrystallization from ethyl acetate to methanesulfonate, m.p. 142-144 ° C.

Analysis for:

C13H14FN3O3. CH3SO3H calculated:

44.8% C, 4.8% H, 11.2% N; found:

45.1% C, 4.9% H, 11.1% N.

(B)

Preparation of 2-hydroxy-2- (4-fluorophenyl) -4,4,5,5,5-pentafluoro-1- (1H-1,2,4-triazol-1-yl) pentan-3-one

A flask containing 40 ml of dry ether cooled to -70 ° C, equipped with a solid carbon dioxide-cooled condenser, was charged with 5 g (0.02 mol) of pentafluoroethyl iodide gas and then added over 5 minutes maintaining the temperature between -70 and -65 ° C was added 5.8 mL of 3M methylmagnesium bromide solution (0.017 mol). The resulting mixture was stirred at -70 ° C for 0.5 h and then 1.3 g (0.004 (7 mol) of 1-ethoxycarbonyl-1 - (-)) was added over 10 minutes while maintaining the temperature at -65 ° C or below. 4-Fluorophenyl) -2- (1H-1,2,4-triazol-1-yl) ethanol in 10 mL dry ether The reaction mixture was stirred at -70 ^° C for 1 h then allowed to stand for 1 h.

A solution of 5 g of ammonium chloride in 30 ml of water was added thereto for 1.5 hours. The ether layer was separated and the aqueous phase was extracted twice more with 40 ml of ether each time. The ether layers were combined, dried (MgSO4) and evaporated. The crude title compound was obtained as an oil which was purified by silica gel chromatography (230-400 mesh) eluting with ethyl acetate / petroleum ether (b.p. 60-80 ° C) 4: 1 (v / v) as eluent. . The product melts after recrystallization from cyclohexane at 128 to 132 degrees Celsius.

Analysis for:

C13H9F6N3O2 calculated:

44.2% C, 2.6% H, 11.9% N; found:

44.3% C, 2.6% H, 11.7% N.

Preparations 2 and 3

The following compounds were prepared from the corresponding starting materials in an analogous manner to that of Preparation 1 (A) and (B):

AND

-N

OH ¹

CHfC-R

R.

preparation R number

R ¹ melting point (° C) analysis (%) found (calculated)

C Η N o

II — CCF2CF3 147-150

42.0 2.2 11.1 (42.1 2.2 11.3) —CF2 CF3

100 - 101

42.0 2.5 11.4 (42.2 2.45 11.4)

WHOSE

The ester starting materials prepared in the first step (Part A) were characterized in the following forms.

OH

N, N-CH 2 COOC ₉ H

I I i

L = .N fe

R melting point (° C) Analysis (%} found (calculated) C Η N

117-119

- 52

42.45 4.3 10.6 (42.85 4.4 10.7)

I r

characterized as the methanesulfonic acid salt

53.8 5.2 14.0 (52.8 4.8 14.2)

Cl

The invention is illustrated by the following non-limiting examples.

Example 1

Preparation of 2- (2,4-difluorophenyl) -3-methyl-4,4,5,5,5-pentafluoro-1- (1H-1,2,4-triazol-1-yl) pentan-2, 3-diol

F

4 6 li 9 7

0.5 g (0.00135 mol) of 2- (2,4-difluorophenyl) -2-hydroxy-4,4,5,5,5-pentafluoro-1- (1H-1,2,4-triazole- 1-yl) pentan-3-one is dissolved in 50 ml of sodium-dried diethyl ether and 1.35 ml of a 3M solution of methylmagnesium bromide in ether (0.00405 mol) is added. After addition of 15 ml of dry tetrahydrofuran, the mixture was heated under reflux for 2 hours, then cooled and first treated with 50 ml of 5% aqueous ammonium chloride and then with 100 ml of ethyl acetate. The phases are separated, the organic phase is dried over magnesium sulphate and evaporated. The residue was purified by flash chromatography on silica gel (230-400 mesh), eluting with 500 mL of ethyl acetate / diethylamine (95: 5). Two diastereomers were isolated by collection and evaporation of the appropriate fractions, the first eluting diastereomer being referred to as diastereomer I.

Diastereomer I:

Yield 123 mg.

M.p. 148-150 ° C.

Analysis for:

C14H12F7N3O2 calculated:

C 43.4%, H 3.1%, N 10.8%;

found:

% C, 43.7;% H, 3.15;

Diastereomer II:

Yield 60 mg.

127 DEG-129 DEG.

Analysis for:

C14H12F7N3O2 calculated:

% C, 43.4;% H, 3.1;% N, 10.8;

found:

43.5% C, 3.1% H, 10.8 θ / ο N.

The overall yield was 183 mg (35%).

Examples 2 to 4

In analogy to Example 1, the following compounds were prepared from the corresponding ketone and either methylmagnesium bromide or ethylmagnesium bromide:

CjH

CH ₂ CC 'C9F5

-N

R R 'example R number

R ² melting point (° C) analysis (° / o) found (calculated)

diastereomer I 207-209

CH3 diastereomer II 173-174 diastereomer I 184-185

CH3 diastereomer II 174-176

45.5 3.65 11.4 (45.5 3.55 11,4) 45.7 3.55 11.4 (45.5 3.55 11,4) 43.6 3.4 10.9 11.0) (43.8 3.5 43.5 3.4 10.9 (43.8 3.5 11.0)

45.35 3.6 10.2 (44.9 3.5 10,5) 43.1 3.3 9.9 (42.9 3.3 10.0)

diastereomer I 110-112

C2H5 diastereomer II

175 - 176 (as monohydrate)

4 6 17

In the above test, the following PD50 values (oral administration, 48 hours) were found for the individual compounds of the Examples in Candida albicans infected mice.

Claims (7)

SUBJECT Fungicidal composition for use in agriculture, characterized in that it contains a compound of the formula I as active substance QH OH in which R is phenyl optionally substituted with one to three substituents independently selected from fluoro, chloro, bromo, iodo and trifluoromethyl; n is 1 or 2; and R ² represents a C 1 -C 4 alkyl group, or a salt thereof, and an agriculturally acceptable diluent or carrier. 2. A process for the preparation of the compounds of the formula I according to claim 1 and their salts, characterized in that the compounds of the formula IA are used OH O ^ N-Cnyc-č-fa ^ CF, I ^of I 1 — N _R in which Ran is as defined above, reacted with a compound of formula R ² . X In which R ² has the abovementioned meaning and X is MgBr or Mg1, or lithium, and the resulting product of formula I is optionally converted to its salt. 3. Method according to claim 2, characterized in that starting materials are used of the general formula R ^2nd X, wherein R ² is methyl or ethyl and X represents MgBr. 4. A process according to claim 2 or 3, wherein the corresponding starting materials are used to form a compound of formula I wherein R is phenyl substituted by one or two substituents independently selected from fluoro, chloro, bromo. , iodo and trifluoromethyl, and R2 and ⁿ are as defined above. 5. A process according to claim 4, wherein the corresponding starting materials are used to form a compound of formula I wherein R is 4-fluorophenyl, 4-chlorophenyl, 4-trifluoromethylphenyl, 2-fluorophenyl, , 4-dichlorophenyl, 2,4-difluorophenyl, 2-fluoro-4-chlorophenyl, 2,5-difluorophenyl, 2,4,6-trifluorophenyl or 4-bromo-2,5-difluorophenyl, and R2 and ⁿ are as defined above. 6. The process of claim 5, wherein the corresponding starting materials are used to form a compound of formula I wherein R is 4-chlorophenyl, 4-fluorophenyl, 2,4-dichlorophenyl, or 2,4- difluorophenyl, and R ^z and n are as defined above. 7. Method according to claim 2, characterized in that starting materials are used of the general formula R ^2nd X, wherein R ² is methyl and X is MgBr or MgI.