ITMI962660A1 - FUNGICIDE COMPOSITIONS BASED ON (N-PHENYLACETYL-N-2,6-XYLYL)- METHYL ALANINATE - Google Patents

Description

DESCRIPTION

The present invention relates to fungicidal compositions based on methyl (N-phenylacetyl-N-2,6-xylyl) -alaninate.

More particularly, the present invention relates to fungicidal compositions comprising the compound corresponding to methyl (N-phenylacetyl-N-2, 6-xylyl) alaninate in which more than 50% of said compound consists of the left-handed optical isomer and one or most known fungicides and their use in the agricultural field for the control of fungal diseases that cause serious damage to agricultural crops.

Some economically important crops such as, for example, vines, tobacco, potatoes and tomatoes, can be infected with fungal pathogens that cause economically harmful diseases.

It is therefore important to have remedies suitable for the control of these fungal infections that are able to act in full respect of the environment, the user and the final user of agricultural production.

In this regard, it is particularly advantageous that the products with fungicidal activity can be easily degraded by the host plant at the end of the period for which the fungicidal activity is required, in such a way as to guarantee the minimum quantity of residual active principle.

The reduction of residues of active ingredient in vegetables at the time of harvest is in fact linked to the potential risk for any consumer of the agricultural product: the lower the quantity of residual active ingredient, the lower the risk for the consumer.

The methyl compound (N-phenylacetyl-N-2,6-xylyl) -DL-alaninate, also known under the trade name of Benalaxyl, is particularly effective in controlling diseases caused by Oomycetes. Said fungicide is described in US patents Nos.

4,291,049 and 4,425,357.

Benalaxyl has a center of asymmetry and consists of an equimolecular mixture of the two optical isomers. When prepared according to the methods described in the two US patents reported above, Benalaxyl is obtained as a racemic mixture in which the optical isomers are present in equimolecular quantities.

In "Pesticide Science" (1985), Vol. 16, pp.

277-286 / the preparation of the left-handed optical isomer is also described, corresponding to methyl (N-phenylacetyl-N-2,6-xylyl) -D-alaninate and its greater activity is highlighted both with respect to dextrorotatory optical isomer, corresponding to methyl (N-phenylacetyl-N-2,6-xylyl) -L-alaninate, both with respect to the racemic, corresponding to (N-phenylacetyl-N-2,6-xylyl) -DL- methyl alaninate. This increased activity was found both by experimenting with the left-handed optical isomer in in vitro tests, and by applying it on infected plants or on infested plants after its application, as well as by applying it to the soil or to the seed of the plant, to control the pathogens present in the soil. .

The racemic Benalaxyl is degraded at a different rate depending on the type of vegetable and the portion of the same to which it is applied.

For example, the degradation rate of racemic Benalaxyl in hops makes it unsuitable to use this product as an antifungal, to the detriment of its undoubted fungicidal efficacy: in fact, two weeks after treatment, the residual levels of the active ingredient are still high. .

The Applicant has now found that fungicidal compositions comprising the levorotatory isomer of Benalaxyl, corresponding to methyl (N-phenylacetyl-N-2,6-xylyl) -D-alaninate and one or more known fungicides, in addition to having a high fungicidal activity, also thanks to the synergistic effects found between the fungicides used, also have a better environmental impact.

Therefore, the subject of the present invention is fungicidal compositions comprising:

(a) the compound corresponding to methyl (N-phenylacetyl-N-2,6-xylyl) alaninate having formula (I):

in which more than 50% of the compound having formula (I) consists of the left-handed optical isomer; (b) one or more fungicides chosen from:

(1) Cymoxanil corresponding to 1- (2-cyano-2-methoxyiminoacetyl) -3-ethyl-urea;

(2) Fosetil having formula:

(3) Metalaxyl corresponding to methyl-N- (2-methoxyacetyl) -N-2, 6-xylyl-DL-alaninate;

(4) Oxadixyl corresponding to 2-methoxy-N- (2-oxo-1/3-oxazolidin-3-yl) - acet-2 ', 6' - xylidine;

(5) Ofurace corresponding to DL-3- [N-chloroacetyl-N- {2,6-dimethylphenyl) -amino] -Y ~ butyrolactone;

(6) Fluazinam corresponding to 3-chloro-N- [3-chloro— 2,6— dinitro-4— (trifluoromethyl) -phenyl] -5-trifluoromethyl-2-pyridinamine;

(7) methyl (E) -2- [2- [6— (2-cyanophenoxy) - pyrimidine-4-yloxy] -phenyl-3-methoxyacrylate; (8) (E) -methos siimino -α-o-tolyloxy) -o-tolyl] - methyl acetate;

(9) N-methyl- (E) -methoxyimino- [2- (2,5-dimethylphenoxymethyl) -phenyl] acetamide;

(10) N-methyl- (E) -methoxy imino- [2-phenoxyphenyl] acetamide;

(11) O- (1-methylethyl) -N- [2-methyl-1- [[[1- (4-chlorophenyl) -ethyl] -animino] -carbonyl] -propyl] -carbamate;

(12) O- (1-methylethyl) -N- [2-methyl-1- [[[1- (4-methylphenyl) -ethyl) -amino] -carbonyl] -propll] -carbamate;

(13) 0- (1-methylethyl) -N- [2-methyl-1- [[[1- (4-ethylphenyl) -ethyl] -amino] -carbonyl} -propyl] -carbamate;

(14) O- (1-methylethyl) -N- [2-methyl-1- [[[1- (4-methoxyphenyl) -ethyl] -amino] -carbonyl] - propyl] - carbamate;

(15) 0- (phenyl) - N— [2-methyl-1 - [[[1- (4-methoxyphenyl) -ethyl] -amino] -carbonyl] - propyl] - carbamate;

(16) compounds belonging to the class of dithiocarbams having general formula (XIII):

where M represents manganese or zinc; (17) Thiram corresponding to bis- (dimethylthiocarbamoyl) -disulfide;

(18) Propineb having formula:

(19) Anilazine corresponding to N- (4, -dichloro-1,3, 5-triazin-1-2-yl) -aniline;

(20) Dichlof luanid having formula:

(21) Tolylf luanid having formula:

(22) Captan having formula:

(23) Folpet having the formula:

(24) Chlorothalonyl corresponding to 1,3-diciano-2, 4,5,6-tetrachlorobenzene;

(25) Dimethomorph having formula:

(26) Ν, Ν-diethylamide of 4-trifluoromethyl-6- (3,4-dimethoxyphenyl) -benzoic acid;

(27) Dlthianon corresponding to 5,10-dihydro-5,10-dioxonaftol- [2,3-b] -1,4-ditin-2,3-dicarbonyl;

(28) Tetraconazole corresponding to 1- (1H-1,2,4-triazol-1-yl) -2- (2,4-dichlorophenyl) -3- (1,1,2,2-tetrafluoroethoxy) -propane; (29) Propiconazole corresponding to 1- [2- (2,4-dichlorophenyl) -4-propyl-1,3-dioxolane-2-ylmethyl] -1H-1, 2,4-triazole;

(30) Triadimefon corresponding to 1- (4-chlorophenoxy) -3, 3-dimethyl-1- (1H-1, 2,4-triazol-lil) -butanone;

(31) Triadimenol corresponding to 1- (4-chlorophenoxy) -3, 3-dimethyl-1- (1H-1,2, 4-triazol-lil) -butan-2-ol;

(32) Bitertanol corresponding to 1- (diphenyl-4-yloxy) -3,3-dimethyl-1- (1H-1, 2,4-triazol-1 - yl) -butan-2-ol;

(33) Etridiazole corresponding to ethyl-3-trichloromethyl-1,2, 4-thiadiazolyl ether;

(34) Pencycuron corresponding to 1- {4-chlorobenzyl) -1-cyclopentyl-3-phenylurea;

(35) Hymexanol corresponding to 5-methylisoxazol-3-ol;

(36) Protiocarb corresponding to S-ethyl- (3-dimethylaminopropyl) -thiocarbamate;

(37) Propamocarb corresponding to propyl 3- (dimethylaminino) -propylcarbamate;

(38) copper (I) or copper (II) salts;

(39) Andoprim corresponding to 2-p-methoxyaniline-4, 6-dimethyl-pyrimidine;

(40) Famoxadone or DPX-JE874 corresponding to 5-methyl-5 - (4-phenoxyphenyl) -3- (phenylaminino) -oxazolidin-2 # 4-dione;

(41) 4-methyl-4 -phenyl-1- (phenylamino) -2-methylthioimidazolidin-5-one;

(42) pyrimidine compounds such as, for example, cyprodinil, mepanipyrim, pyrethanil. Preferably, in the compositions object of the present invention the compound having formula (I) contains at least 75% of the left-handed optical isomer and, more preferably, at least 90%. Even more preferred, for the purpose of the present invention, are the compositions in which the compound having formula (I) contains at least 99% of the left-handed optical isomer.

The left-handed optical isomer, corresponding to methyl (N-phenylacetyl-N-2,6-xylyl) -D-alaninate, has the following formula (II):

The asymmetric carbon present in the compound having formula (II) has the absolute configuration defined in said formula (II); this configuration can be described as having D form, according to the proper nomenclature of amino acids, or as having R form, according to the classification introduced by Cahn, Ingold and Prelog.

The better environmental impact of the fungicidal compositions object of the present invention is due to the fact that the compound having formula (I) in which more than 50% of said compound consists of the left-handed optical isomer, has a lower residual level of active principle in the crops treated at the completion of the fungicidal activity (as already mentioned above, the racemic Benalaxyl instead has residual levels of active principle still high after two weeks from treatment). The left-handed optical isomer is therefore degraded faster than racemic Benalaxyl.

The compound having formula (I) can be conveniently prepared by various processes.

A process for the preparation of the compound having formula (I) comprises:

(a) reacting the methyl ester having general formula (III):

having an asymmetric carbon of type s and wherein X represents a halogen atom such as chlorine, fluorine, bromine or iodine; or X represents an activated ester such as a paratoluenesulfonate, a mesylate or a triflate, with a xylidine having formula (IV):

in the presence or absence of an inert organic solvent or of a mixture of inert organic solvents, at a temperature between 60 ° C and the boiling temperature of the selected solvent system, in the presence or absence of an organic or inorganic base, thus obtaining 1 'N-xylyl-D-alaninate of methyl having formula (V):

(b) acylating the methyl N-xylyl-D-alaninate having formula (V) obtained in step (a), with a phenylacetic acid derivative such as, for example, an acyl chloride; or with a mixed anhydride obtained by reaction of the salt of phenylacetic acid with an acyl chloride such as, for example, pivaloyl chloride; or with an alkyl chloroformate such as, for example, isobutyl chloroformate; in the presence of an inert organic solvent or a mixture of inert organic solvents, at a temperature between - 30 ° C and 120 ° C, in the presence or absence of an organic or inorganic base, obtaining the compound having formula (THE).

Examples of inert organic solvents useful in step (a) of the above process are: aromatic solvents such as, for example, toluene, xylene; protic solvents such as, for example, ethanol, propanol, butanol, octanol; dipolar aprotic solvents such as, for example, N, N-dimethylformamide, N-methylpyrrolidone, dimethylsulfoxide; or their mixtures.

Examples of organic bases useful in step (a) of the above process are tertiary amines such as, for example, triethylamine.

Examples of inorganic bases useful in step (a) of the above process are alkaline carbonates or hydrogen carbonates such as, for example, sodium hydrogen carbonate and potassium carbonate.

The use of the above bases must, however, be carried out with caution, in order to avoid racemizations of the asymmetric carbon.

Examples of inert organic solvents useful in step (b) of the above process are: esters such as, for example, ethyl acetate; chlorinated solvents such as, for example, methylene chloride, dichloroethane; aromatic solvents such as, for example, toluene, xylene; hydrocarbons such as, for example, hexane, petroleum ether; or their mixtures.

Examples of organic bases useful in step (b) of the above process are tertiary amines such as, for example, triethylamine, N-methylmorpholine; or heterocyclic amines such as, for example, pyridine.

Examples of inorganic bases useful in step (b) of the above process are alkaline carbonates such as, for example, sodium carbonate.

The methyl ester having general formula (III), can be conveniently prepared starting from the amino acid alanine, by diazotization of the anunine group in the presence of a halide ion as described, for example in "Methoden der Organischen Chemie - Band V / 4 - Halogen Verbindungen "(1960), p. 458, obtaining the corresponding halogenated acid having general formula (VI):

wherein X has the same meaning described above, which is subsequently esterified to obtain the methyl ester having general formula (III) according to one of the usual methods known in organic practice.

When X, in the methyl ester having general formula (III), represents an activated ester, said methyl ester having general formula (III), it is conveniently obtained from methyl lactate, a compound available commercially at low cost, by reaction with a suitable derivative methanesulfonic, paratoluenesulfonic, trifluoromethanesulfonic acids such as, for example, a chloride or an anhydride, in the presence or absence of an organic base such as, for example, triethylamine, N-methylmorpholine, pyridine, or an inorganic base such as, for example, sodium bicarbonate.

The xylidine having formula (IV) is a commercially available compound.

Alternatively, the process described above can be modified by carrying out the condensation of xylidine having formula (IV), described above, with an acid such as, for example, S-bromine propionic acid having formula (VII):

to obtain the N-arylamino acid having formula (VIII):

which is subsequently esterified with methanol (CH3OH) in an acidic environment by addition, for example, of hydrochloric acid or sulfuric acid, operating at a temperature between 20 'C and the boiling temperature of the solution, obtaining the N- methyl xylyl-D-alaninate having formula (V) described above. Alternatively, the N-arylamino acid having formula (VIII), can be acylated with the chloride of the phenylacetic acid, operating under the same conditions described in step (b) of the above procedure for the acylation of N-xylyl-D- methyl alaninate having formula (V), or by operating in an aqueous environment made basic with inorganic bases such as, for example, sodium bicarbonate or sodium hydroxide, optionally in the presence of an organic cosolvent such as, for example, methylene chloride, acetate of ethyl, or tetrahydrofuran, operating at a temperature between 0 ° C and 20 ° C, obtaining the acid having formula (IX):

which is subsequently transformed into methyl (N-phenylacetyl-N-2, 6-xylyl) -alaninate having formula (I), by esterification with methanol, in the presence of acids such as, for example, hydrochloric acid or sulfuric acid, operating at a temperature between 20 ° C and the boiling temperature of the solution.

S-bromine propionic acid having formula (VII) is a commercially available product.

A further process useful for the preparation of the compound of formula (I) consists in partially hydrolyzing, in the presence of enzymes, the compound (N-phenyl-acetyl-N-2,6-xylyl) -DL-methyl alaninate (in racemic form). Depending on the type of enzyme used, the compound of formula (1) can be obtained in its acid form which can be subsequently transformed into the expected compound having formula (I) by operating according to one of the usual methods described in the literature. Or, the compound having the left-handed formula (I) contained in the racemic is preserved, while the compound having the right-handed formula (I) is hydrolyzed to acid.

The aforesaid hydrolysis reactions can be carried out both in the presence of inert organic solvents such as, for example, chloroform, ethyl acetate, dioxane, and in water maintained at constant pH by adding suitable quantities of inorganic salts to obtain buffer systems. The temperature is kept between -10 ° C and 40'C, taking care not to choose temperatures that give rise to denaturation of the enzymes used. The above enzymatic type reaction can also be carried out on methyl N-xylyl-DL-alaninate to obtain methyl N-xylyl-D-alaninate having formula (V), which is subsequently transformed into the compound having formula (I) operating as described in step (b) of the above procedure.

The acid or the dextrorotatory ester / obtained with the method described above / can be subsequently racemized in basic environments and then be subjected to a further enzymatic reaction.

A further process useful for the preparation of the compound of formula (I) consists in salifying methyl N-xylyl-DL-alaninate with an enantiomerically pure acid such as, for example, tartaric acid or camphorsulfonic acid. The salt thus obtained can give, by fractional crystallization, the corresponding salt of methyl N-xylyl-D-alaninate in enantiomerically pure or enriched form. The salification reaction takes place in the presence of solvents such as, for example, halogenated solvents (methylene chloride, etc.), aliphatic esters (ethyl acetate, etc.), aromatic solvents (toluene, etc.), or their mixtures. Further possible recrystallizations, followed by the treatment of the salified form with basic aqueous solutions, allow to obtain methyl N-xylyl-D-alaninate having formula (V), which is then transformed into the compound having formula (I) operating as described in step (b) of the above procedure.

Alternatively methyl (N-phenylacetyl-N-2, 6-xylyl) -alaninate having formula (I), can be obtained by condensation of methyl pyruvate having formula (X):

with xylidine having formula (IV) described above, in the presence or absence of solvents such as, for example, toluene, ethyl acetate, ethyl alcohol, in the presence or absence of dehydrating agents such as, for example, anhydrous sodium sulphate and the molecular sieves, operating at a temperature between 20 ° C and the boiling temperature of the solution, to obtain the methyl N-xylylpropenoate ester having formula (XI):

which is condensed with the chloride of phenylacetic acid, in the presence or absence of an organic base such as, for example, triethylamine, N-methylmorpholine, pyridine, or of an inorganic base such as, for example, sodium bicarbonate, in the presence of an organic solvent such as, for example, methylene chloride, ethyl acetate, toluene, xylene, and in the presence or absence of a catalyst such as, for example, N, N-dimethylformamide, operating at a temperature between - 20 ° and the boiling temperature of the solution, obtaining the methyl ester (N-phenylacetyl-N-2, 6-xylyl) propenoate having formula (XII):

The methyl ester (N-phenylacetyl-N-2, 6-xylyl) propenoate having formula (XII), is then reduced by catalytic hydrogenation in the presence of a metal such as, for example, ruthenium, palladium, rhodium, platinum, and of a chiral inducer such as, for example, a phosphorated derivative such as, for example, 2,2 '-bis- (diphenylphosphino) -1,1'-dinaphthyl (known by the trade name of BINAP) or of chiral amine chelators, and in the presence of an alcoholic solvent such as, for example, methanol, ethanol, or of an organic solvent such as, for example, hexane, cyclohexane, ethyl acetate, toluene, dioxane, or of a dipolar aprotic solvent such as, for example, Ν , Ν-dimethylformamide, N-methylpyrrolidone, operating at a temperature between 20 ° C and 150 ° C and at a hydrogen pressure between 1 atm and 30 atm, obtaining the N-phenylacetyl-N-xylyl) -alaninate of methyl having formula (I)

Compound (1) is described in "The Pesticide Manual" (1983), VII3 edition, The Britlsh Crop Protection Council Ed., P. 148.

Compound (2) is described in "The Pesticide Manual" (1983), VII3 edition, The British Crop Protection Council Ed., P. 294.

Compound (3) is described in the British patent GB 1,500,581.

Compound (4) is described in the British patent GB 2,058,059.

Compound (5) is described in "Phytopatological News 12" (1978), Vol. 9, p. 142.

The compound (6) is described in the European patent application EP 31,257.

The compound (7), also known by the experimental code ICIA5504, is described in the European patent application EP 382,375, and its agronomic properties are reported in "Proceedings of the Brighton Crop Conference" (1992), pp. 435-442.

The compound (8), also known by the experimental code BASF490S, is described in the European patent application EP 253,213.

Compound (9), also known with the experimental code SSF129 and the compound (10), also known with the experimental code SSF126, are described in US patent 5,185,242.

The compounds (11) - (15) are described in European patent applications EP 610.764 and EP 550.788.

Specific examples of compounds (16), having general formula (VII), useful for the purpose of the present invention are:

manganese ethylene bis (dithiocarbamate) complexed with zinc salts, known as Mancozeb, described in "The Pesticide Manual" (1983), VII® edition, The British Crop Protection Council Ed., p. 339;

manganese ethylene bis (dithiocarbamate), known as Maneb, described in "The Pesticide Manual" (1983), 7th edition, The British Crop Protection Council Ed., p. 340;

zinc ethylene bis (dithiocarbamate), known as Zineb, described in "The Pesticide Manual" (1983), 7th edition, The British Crop Protection Council Ed., p. 564.

The compound (17) is described in "The Pesticide Manual" (1983), 7th edition, The British Crop Protection Council Ed., P. 534.

The compound (18) is described in "The Pesticide Manual" (1983), 7th edition, The British Crop Protection Council Ed., P. 469.

The compound (19) is described in "The Pesticide Manual" (1983), 7th edition, The British Crop Protection Council Ed., P. 17.

The compound (20) is described in "The Pesticide Manual" (1983), 7th edition, The British Crop Protection Council Ed., P. 175.

The compound (21) is described in "The Pesticide Manual" (1983), 7th edition, The British Crop Protection Council Ed., P. 537.

The compound (22) is described in "The Pesticide Manual" (1983), 7th edition, The British Crop Protection Council Ed., P. 87.

The compound (23) is described in "The Pesticide Manual" (1983), 7th edition, The British Crop Protection Council Ed., P. 599.

The compound (24) is described in "The Pesticide Manual" (1983), 7th edition, The British Crop Protection Council Ed., P. 120.

The compound (25) is described in the European patent application EP 219,756.

The compound (26) is described in European patent applications EP 360.701 and EP 611.232.

The compound (27) is described in "The Pesticide Manual" (1983), 7th edition, The British Crop Protection Council Ed., P. 225.

The compound (28) is described in the European patent application EP 234,242.

The compound (29) is described in the British patent GB 1,522,657.

Compound (30) is described in US patent 3,912,752.

The compound (31) is described in the German patent DE 2,324,010.

The compound (32) is described in the German patent DE 2,324,010.

The compound (33) is described in "The Pesticide Manual" (1983), 7th edition, The British Crop Protection Council Ed., P. 252.

The compound (34) is described in "The Pesticide Manual" (1983), 7th edition, The British Crop Protection Council Ed., P. 422.

The compound (35) is described in "The Pesticide Manual" (1983), 7th edition, The British Crop Protection Council Ed., P. 314.

The compound (36) is described in "The Pesticide Manual" (1983), 7th edition, The British Crop Protection Council Ed., P. 473.

The compound (37) is described in "The Pesticide Manual" (1983), 7th edition, The British Crop Protection Council Ed., P. 461.

Compounds (38) such as, for example, copper oxychloride, copper oxide (I) or (II), copper chloride hydroxide, copper sulphate, are readily available on the market.

The compound (39) is described in "7th International Congress of Pesticide Chemistry" (1990), Abstract, Hamburg, pg. 227.

The compound (40) is described in "Brighton Crop Protection Conference - Pests and Diseases (1996), Proceedings of Congress.

The compound (41) is described in the European patent application EP 629,616.

The compounds (42) are described in "Pesticide Science" (1996), Vol. 47, pp. 191-197.

Preferred fungicidal compositions for the purpose of the present invention are those comprising, in addition to the compound having formula (I):

Mancozeb alone or mixed with Fosetil or Cymoxanil;

the Fosetil;

Propamocarb corresponding to propyl 3- (dimethylaminino) propylcarbamate;

the Chlorothalonil;

copper (I) or copper (II) salts alone or mixed with Fosetil or Cymoxanil.

The fungicidal compositions object of the present invention are endowed with a high fungicidal activity towards Oomycetes. Examples of other pathogens controlled by the above compositions, as well as examples of application cultures, are given below:

Plasmopora viticola (vine);

Phvtophthora infestans (tomato, potato);

Phvtophthora nicotianae (tobacco, ornamental plants, etc.);

Phvtophthora palmivora (cocoa, etc.); fhytophthora cinnamoni (pineapple, cedar, lemon, tomato, eco);

Phytophthora chaosici (pepper, tomato, cucurbit, eco);

Phvtophthora crvptocrea (tomato, plum, ornamental, etc.);

Phvtophthora mecrasperma (ornamental, etc.);

Downy mildew tabacina (tobacco);

Pseudoperonospora cubensis (cabbage, cucurbits); Pseudoperonospora humuli (hops);

Phvthium ultimum (various crops); etc.

The fungicidal compositions object of the present invention can be prepared by mixing each compound in order to use the following doses per hectare:

5-500 g of compound having formula (I);

5-3500 g of each fungicide from (1) to (42). The fungicidal compositions object of the present invention are capable of carrying out a fungicidal action of both curative and preventive character and, moreover, exhibit little or no phytotoxicity.

The application of the aforementioned compositions can take place on any part of the plant, both on the aerial parts (leaves, stems, shoots, branches), and on the underground parts for the control of pathogens typical of the roots, or on the seeds themselves before sowing, or even on the soil where the plant grows.

It is possible to use compositions in the form of dry powders, wettable powders, emulsifiable concentrates, microemulsions, pastes, granulates, solutions, suspensions, etc: the choice of the type of composition will depend on the specific use.

The compositions are prepared in a known manner, for example by diluting or dissolving the active substances with a solvent medium and / or a solid diluent, optionally in the presence of surfactants.

As solid diluents, or supports, the following can be used: silica, kaolin, bentonite, talc, diatomaceous earth, dolomite, calcium carbonate, magnesia, gypsum, clays, synthetic silicates, attapulgite, sepiolite.

As liquid diluents, in addition of course to water, various solvents can be used, for example aromatics (xylols or mixtures of alkylbenzols), chloroaromatics (chlorobenzol), paraffins (petroleum fractions), alcohols (methanol, propanol, butanol, octanol, glycerin ), amines, amides (Ν, Ν-dimethylformamide, N-methylpyrrolidone), ketones (cyclohexanone, acetone, acetophenone, isophorone, ethylamyl ketone), esters (isobutyl acetate).

As surfactants, sodium, calcium, triethanolamine or triethylamine salts of alkylsulfonates, alkylaryl sulphonates, polyethoxylated alkylphenols, fatty alcohols condensed with ethylene oxide, polyoxyethylated fatty acids, polyoxyethylated sorbitol esters, lignosulfonates can be used.

The compositions can also contain special additives for particular purposes such as, for example, tackifying agents, such as gum arabic, polyvinyl alcohol, polyvinylpyrrolidone.

If desired, it is possible to add to the compositions object of the present invention also other compatible substances such as, for example, plant growth regulators, antibiotics, herbicides, insecticides, fertilizers.

The concentrations of the active substances in the above compositions can vary within a wide range, depending on the crop, the pathogen, the environmental conditions and the type of formulation adopted.

In general, the concentration of the active substances varies between 0.1% and 95%, preferably between 0.5% and 90%.

In the event that the aforementioned fungicidal compositions are applied to the leaves, a dose equal to 5-350 g / hl of each active ingredient for the treatment of fruiting crops is used, while a dose equal to 80- 3500 g / ha of each active ingredient for the treatment of extensive crops (potato, hops, etc.),

In the event that the aforementioned fungicidal compositions are applied to the seed, total doses of active ingredients equal to 0.0001-30 g per kilogram of seeds are used.

The examples reported below are for illustrative and not limitative purposes of the present invention.

EXAMPLE 1

(A) Preparation of methyl N-xylyl-D-alaninate.

13.5 g of 2,6-xylidine (Aldrich) are added to 16.7 g of methyl S-bromopropionate (Aldrich) and the mixture is heated for 3 hours at a temperature of 110'C. The crude obtained is purified directly on silica gel, using a mixture of hexane and ethyl acetate in the ratio 7/3 v / v, as eluent.

16.3 g of methyl N-xylyl-D-alaninate are obtained (yield 79%).

(B) Preparation of methyl (N-phenylacetyl-N-2,6-xylyl-D-alaninate having formula (II).

A solution of 20.7 g of methyl N-xylyl-D-alaninate, obtained as described above, in 100 cm3 of toluene, is added with 15.5 g of phenylacetic acid chloride. After 4 hours under reflux, the reaction is cooled, evaporated under reduced pressure and the crude obtained is purified on silica gel, using a mixture of hexane and ethyl acetate in a ratio of 7/3 v / v, as eluent.

28.9 g of methyl (N-phenylacetyl-N-2,6-xylyl-D-alaninate are obtained having formula (II), having an optical rotational power ([α] D) of - 27.3 "(c = 1, acetone) (yield 89%).

EXAMPLE 2

Similarly to the glove described in Example 1, but starting from methyl R-bromopropionate, (methyl N-phenylacetyl-N-2,6-xylyl-D-alaninate having formula (II), having a rotational optical power ([α] D) of 27.4 ° (c = 1, acetone) (yield 89%).

EXAMPLE 3

"In vitro" activity on Phvthium ult-jmum.

Methyl (N-phenylacetyl-N-2, 6-xylyl-D-alaninate having formula (li) obtained as described above, methyl (N-phenylacetyl-N-2, 6-xylyl-L-alaninate and methyl N-phenylacetyl-N-2, 6-xylyl-DL-alaninate (Benalaxyl), are incorporated into a culture medium agarl, at a temperature of 50 ° C, which is dispensed in petri dishes with a diameter of 55 mm After solidification of the agar medium, the capsules are inoculated by placing in the center a disk with a diameter of 6 mm of agar supporting the mycelium of the fungus under examination (Phvthium ultimuml.

After 5 days of storage at 28 ° C, the diameter of the colony that has developed is measured which is compared to the diameter of a colony grown on untreated soil.

On the basis of these measures, the percentage of growth inhibition is calculated according to the formula:

I = (1 - d1 / d0) * 100 where d1 is the diameter of the treated colony and d0 that of the untreated colony.

The aforementioned left-handed (D), dextrorotary (L) and racemic (DL) compounds are tested at different concentrations to establish the minimum amount capable of inhibiting 50% mycelial growth (MIC). The data obtained are reported in Table 1.

EXAMPLE 4

Determination of active ingredient residues in hops.

Hop seedlings are treated with six foliar applications of methyl (N-phenylacetyl-N-2,6-xylyl-D-alaninate having formula (II) obtained as described above, or of N-phenylacetyl-N-2,6- methyl xylyl-DL-alaninate (Benalaxyl), at a dose of 450 g / ha, at intervals of 10-15 days.

Hop samples, equal to about 1 kg of wet vegetable, are taken after having carried out the last treatment (T0) and, subsequently, after 1 day (T3) and after three days (T3) from the same. Each sample is homogenized and macerated with acetone. The suspension obtained is then filtered on glass fiber (GF / C W Whatman) under vacuum suction. The liquid phase is evaporated and the aqueous residue obtained is extracted with methylene chloride.

The organic phase is concentrated and the organic extract thus obtained is purified on alumina, eluting with hexane / acetone in a 90/10 ratio. The fractions containing the active principle are collected, which are subsequently evaporated and taken up with ethyl acetate up to a known volume. The active ingredient content is then determined through a gas-chromatographic analysis (GLC / FID; "alkaline flame ionization detector) with respect to an external standard and returned to the original sample.

The inedies of the data obtained are reported in Table 2 in which (D) indicates the left-handed compound and e (DL) indicates the racemic.

Claims (14)

CLAIMS 1. Fungicidal compositions comprising: (a) the compound corresponding to methyl (N-phenylacetyl-N-2, 6-xylyl) alaninate having formula (I): in which more than 50% of the compound having formula (I) consists of the left-handed optical isomer; (b) one or more fungicides chosen from: (1) Cymoxanil corresponding to 1- (2-cyano-2-methoxyiminoacetyl) -3-ethyl-urea; (2) Fosetil having formula: (3) Metalaxyl corresponding to methyl-N- (2-methoxyacetyl) -N-2,6-xylyl-DL-alaninate; (4) Oxadixyl corresponding to 2-methoxyN- {2-oxo- 1,3-oxazolidin-3-yl) - acet - 2 ', 6'-xylidine; (5) Ofurace corresponding to DL-3- [N-chloroacetyl-N- (2,6-dimethylfenyl) -araraino] - γ-butyrolactone; (6) Fluazinam corresponding to 3-chloro-N- [3-chloro-2, 6-dinitro-4- (trifluorome - thyl) -phenyl] -5-trifluoromethyl-2-pyrides - namine; (7) methyl (E) —2— [2— [6— (2-cyanophenoxy) -pyrimidine-4-yloxl] -phenyl-3-methoxyacrylate; (8) methyl (E) -methoxyimino-a-o-tolyloxy) -o-tolyl] -acetate; (9) N-methyl- (E) -methoxyimino- [2- (2,5-dimethylphenoxymethyl) -phenyl] acetamide; (10) N-methyl- (E) -methoxyimino- [2-phenoxy phenyl] acetamide; {11) 0- (1-methylethyl) -N- [2-methyl - 1— [[[1— {4— chlorophenyl) -ethyl] - amino] - carbonyl] - propyl] -carbamate; (12) 0- (1-methylethyl) -N- [2-methyl— 1— [{[1- (4-methylphenyl) -ethyl] - amino] -carbonyl] - propyl] -carbamate; (13) 0- (1-methylethyl) -N- [2-methyl - 1— [[[1- (4ethylphenyl) - ethyl] - amino] - carbons1] - propyl] -carbamate; (14) O- (1-methylethyl) -N- [2-methyl— 1— [[[1- (4-methoxyphenyl) -ethyl] -amino] -carbonyl - propyl] -carbamate; (15) 0- (phenyl) -N- [2-methyl- 1 - [[[1- (4-methoxyphenyl) -ethyl] -amino] -carbonyl] -propyl] -carbamate; (16) compounds belonging to the class of dithiocarbamates having general formula (XIII): where M represents manganese or zinc; (17) Thiram corresponding to bis- (dimethylthiocarbamoyl) -disulfide; (18) Propineb having formula: (19) Anilazine corresponding to N- (4,6-dichloro-1,2-yl) -aniline; (20) Dichlofluanid having formula: (21) Tolylfluanid having formula: (22) Captan having formula: (23) Folpet having the formula: (24) Chlorothalonyl corresponding to 1,3-dicyano-2,4,5,6-tetrachlorobenzene; (25) Dimethomorph having formula: (26) Ν, Ν-diethylamide of 4-trifluoromethyl— 6— (3,4-dimethoxyphenyl) -benzoic acid; (27) Dithianon corresponding to 5,10-dihydro-5,10-dioxonaftol- [2/3-b] -1,4-di-tin-2,3-di-carbonyl; (28) Tetraconazole corresponding to 1- (1H-1,2,4-triazol-1-yl) - 2— (2,4-dichlorophenyl) -3- (1,1,2,2-tetrafluoroethoxy) -propane ; (29) Propiconazole corresponding to 1- [2- (2,4-dichlorophenyl) -4-propyl-1,3-dioxolane-2-yl-methyl] -1H-1,2,4-triazole; (30) Triadimefon corresponding to 1- (4-chlorophenoxy) -3,3-dimethyl-1- (1H-1,2,4 - triazol-1-yl) -butanone; (31) Triadimenol corresponding to 1- (4-chlorophenoxy) -3,3-dimethyl-1- (1H-1,2,4 - triazol-1-yl) -butan-2-ol; (32) Bitertanol corresponding to 1- (diphenyl-4-yloxy) -3 # 3-dimethyl-1- (1H-1 # 2/4-triazol-1-yl) -butan-2-ol; (33) Etridiazole corresponding to ethyl-3-trichloromethyl-1, 2/4-thiadiazolyl ether; (34) Pencycuron corresponding to 1- (4-chlorobenzyl) -1-cyclopentyl-3-phenylurea; (35) Hymexanol corresponding to 5-methylisoxazol-3-ol; (36) Protiocarb corresponding to S-ethyl- (3-dimethylaminopropyl) -thiocarbamate; (37) Propamocarb corresponding to propyl 3- (dimethylamino) -propylcarbamate; (38) copper (I) or copper (II) salts; (39) Andoprim corresponding to 2-p-methoxyaniline-4, 6-dimethyl-pyrimidine; (40) Famoxadone or DPX-JE874 corresponding to 5-methyl-5- (4-phenoxyphenyl) -3- (phenylamino) -oxazolidin-2,4-dione; (41) 4-methyl-4-phenyl-1- (phenylamino) - 2-methylthioimidazolidin-5-one; (42) pyrimidine compounds such as cyprodinil, raepanipyrim, pyrethanil. 2. Fungicidal compositions according to claim 1, wherein the compound having formula (I) contains at least 75% of the left-handed optical isomer. 3. Fungicidal compositions according to claim 1, in which the compound having formula (I) contains at least 90% of the left-handed optical isomer. 4. Fungicidal compositions according to claim 1, wherein the compound having formula (I) contains at least 99% of the left-handed optical isomer. 5. Fungicidal compositions according to claim 1, wherein the fungicide (b) is Mancozeb alone or in mixture with Fosetil or Cymoxanil. 6. Fungicidal compositions according to claim 1, wherein the fungicide (b) is Fosetil. 7. Fungicidal compositions according to claim 1, wherein the fungicide (b) is Propamocarb corresponding to 3- (dlmethylaminino) propylcarbamate. 8. Fungicidal compositions according to claim 1, wherein the fungicide (b) is Chlorothalonil. 9. Fungicidal compositions according to claim 1, wherein the fungicide (b) is selected from the copper (I) or copper (II) salts alone or in mixture with Fosetil or Cymoxanil. 10. Fungicidal compositions according to any one of the preceding claims, wherein the compounds are present at the following doses per hectare: 5-500 g of compound having formula (I); 5-3500 g of each fungicide from (1) to (42). 11. Fungicidal compositions according to any one of the preceding claims, comprising solid supports, liquid diluents, surfactants or other special additives. 12. Fungicidal compositions according to any one of the preceding claims, in which plant growth regulators, antibiotics, herbicides, insecticides, fertilizers are present. 13. Fungicidal compositions according to any one of the preceding claims having a better environmental impact in which, said better environmental impact, is due to the fact that the compound having formula (I) is used in which more than 50% of said compound consists of left-handed optical isomer. 14. Method to combat fungal infections consisting in applying to every part of the plant, both on the aerial parts (leaves, stems, shoots, branches), and on the underground parts for the control of the typical pathogens of the roots, or on the seeds themselves before of sowing, or on the soil in which the plant grows, fungicidal compositions according to any one of the preceding claims.