CS211398B2 - Fungicide means for supressing the weeds - Google Patents

Description

The disclosed compounds are useful in an effective amount for controlling the growth of powdery mildew. The compounds of the invention are prepared by conventional reactions using appropriately selected starting materials and can be applied in conventional manner.

For compounds of formula II, X is preferably bromine and R is preferably methyl.

The compounds of the invention are useful in an effective amount as anti-powdery mildew. As used herein, the term " anti-powdery mildew " refers to compounds useful for controlling fungal growth, referred to as mildew. Suppressing powdery mildew growth with said compounds can be accomplished by applying an effective amount of the compound in an environment where powdery mildew growth is promoted. The compounds can be applied to any area where the growth and development of a fungus causing mildew is promoted. 'Suppression' means preventing the growth of a fungus.

The novel compounds of the invention can generally be prepared as follows:

1. Preparation of (3,4,5-trisubstituted phenoxy-alkanoic acid)

The 3,4,5-trisubstituted phenol is reacted with a halogen-substituted aliphatic acid of the formula

X is bromo or methyl and R is hydrogen or methyl.

II

X-C — C-OH,

C2H5 where

X is chlorine or bromine, in the presence of sodium hydroxide at a temperature of about 40 ° C to 110 ° C to give the corresponding 2- (3,4,5-trisubstituted) phenoxyalkanoic acid.

2. Preparation of (3,4,5-trisubstituted phenoxy) alkanoic acid chloride

The acid prepared in Step 1 is reacted with phosgene at a temperature of about 40 to about 70 ° C in the presence of dimethylformamide as a catalyst to give the corresponding chloride (3,4,5-substituted phenoxy-alkanic acid).

3. Preparation of the (3,4,5-substituted phenoxy) alkanoic acid amides of the invention

The acid chloride prepared in step 2 is reacted with an amine of formula

CH3

AND

HzN — C — C = CR

CH3 where

R is hydrogen or methyl, in the presence of sodium hydroxide or, an organic base such as triethylamine in a solvent such as methylene chloride at a temperature of about -15 to about 35 ° C to provide the desired amide.

An alternative method of preparation consists in reacting an α-halo-substituted aliphatic acid of formula

O

XCHC — OH,

CzHs kde

X is chlorine or bromine, with foisgen and dimethylformamide as a catalyst to give the corresponding acyl chloride of formula

O

II

XCHCC1,

C2H5 where

X is chlorine or bromine, which is then reacted with an amine of formula

CH3

I-IzNC — C-CR

CH3 where

R is hydrogen or methyl, in the presence of an organic base such as triethylamine, to give the corresponding α-haloalkyl amide.

This amide is reacted with phenol sodium salt ³

where

X is hydrogen, chloro, bromo, thiocyanoisio or methyl, prepared by the reaction of this phenol and sodium hydride in tetrahydrofuran to form the amides of the invention.

The following examples demonstrate the preparation of novel compounds and their utility in the control of powdery mildew.

Example 1

N- (1,1-dimethyl-2'-butynyl) -2- (4-bromo-3,5-dimethylphenoxy) butyramide and 18 g (0.09 mol) of 4-bromo-3,5-dimethylphenol were mixed together. with 18 g (0.11 mol) of 2-bromobutyric acid in a 500 ml flask equipped with a stirrer and maintained at 15 DEG C. 18.4 g (0.23 mol) of 500% aqueous sodium hydroxide are added with rapid stirring. , which was raised to 45 [deg.] C. during the addition, was kept below 45 [deg.] C. with cooling bath. After addition of all sodium hydroxide, cooling was terminated and the mixture was heated to 110 [deg.] C. for 15 min. perchlorethylene and 20 ml of concentrated hydrochloric acid, the mixture is heated to 85 DEG C., the phases are separated, and the organic layer is cooled, and the product identified by the nuclear magnetic resonance spectrum as acid 2 (4-broim-3,5-). dimethylphenoxy) butane separated as a solid which was isolated by filtration and air dried to give

21.3 g (yield 82%) of the product, m.p. 78-85 ° C.

(b) 21.3 g (0.07 mol) of the acid produced in step (a) are suspended in 50 ml of toluene in a 500 ml flask equipped with a gas supply tube, stirrer, thermometer and cooler with dry ice and isopropyl alcohol, with 0.2 ml dimethylformamide and heated to 60 ° C. 10.0 g (0.10 mol) of phosgene are slowly added to the mixture. Upon completion of the foegen addition, the dry ice cooler is removed and replaced with a water cooler. Excess phosgene and hydrogen chloride are removed by blowing argon at 60 ° C. Cooling the solution and removing the solvent in vacuo gave 21.3 g (yield 99.6%) of the product as an oil which was identified as 2- (4-bromo-3,5-di-methylphenoxy) butyryl chloride by nuclear magnetic resonance spectrum. .

c) 8 g (0.03 mol) of the acyl chloride produced in step b) are added dropwise to a 300 ml flask containing a stirred solution of 3.9 g (0.04 mol) of 4-amino-4-methyl-2- butinium and 4.0 g (0.04 mol) of triethylamine in 100 ml of methylene chloride, at 10-15 ^° C. Cooling is required to maintain the temperature. After all the acyl chloride has been added, the mixture is allowed to reach room temperature and the product is isolated by successive washing with 100 ml of water, dilute hydrochloric acid, 5% sodium carbonate solution and water. The organic phase is dried over magnesium sulphate and the solvent is removed in vacuo to give 6.8 g (62% yield) of a solid, mp 81.5-82.5 ° C. The product was identified as the title compound by nuclear magnetic resonance spectrum.

The following tables show the results of the Example, along with two other examples, which were carried out in an analogous manner, using the appropriate starting materials. The compounds listed in the table are typical examples of the compounds of the invention. Each compound is identified by a number and is referred to hereinafter.

TABLE I

Compound number

CH, χ-Λ

O

II

OL

3

-O- CHCNHC-C = CP ch ₃

X

Physical properties, melting point (PC) —Br —Br —CH3

Efficacy tests as foliar fungicide

Preventive effectiveness against powdery mildew on bean

Dissolve the test substance in a suitable solvent and dilute with water containing a few drops of Tween 20 ^R (polyoxyethylene sorbitan monolaurate based wetting agent). Test solutions at a concentration of 1000 ppm downwards are sprayed until they run down to the primary bean leaves (Phaseolus vulgaris L.). When the plants are dry, the leaves are dusted with spores of powdery mildew (Erysiphe pclygoni De Candolle) and kept in the greenhouse until the fungus grows on the leaf surface. The efficacy is recorded as the lowest concentration in ppm, which causes a 50% reduction in mycelial formation over untreated inoculated plants. The values obtained are shown in Table II.

—H 104 to 106 — CHs 81.5 to 82.5 —H 100 to 102

TABLE II

Preventive action

Compound number Powdery mildew on bean

100 ALIGN!

25

500

The compounds of the invention are usually incorporated into a suitable delivery photon. For example, they may be included in pesticidal compositions that are supplied in the form of emulsions, suspensions, solutions, powders, and aerosol mixtures. These compositions generally contain, in addition to the active compound, excipients which are conventional in pesticide formulations. The active compounds of the invention may be present in the compositions as a single pesticide component or may be used in admixture with other compounds having similar uses. The pesticidal compositions of the invention may contain, as excipients, organic solvents such as sesame oil, xylenes, naphtha, water, emulsifiers, surfactants, talc, pyrophyllite, diatomite, gypsum, clays, propellants, for example dichlorodiifluoirmeithane and the like. However, if desired, the active compounds can be applied directly to feed, seed or the like on which the pests are present. In this mode of application, it is preferable to use non-volatile compounds. With respect to the activity of the disclosed pesticidal compounds, it is noted that they do not need to be effective as such. The purpose of the invention will be fully achieved if the compound becomes active by external influences, such as light or certain physiological functions, occurring during the processing of the compound in the body of the pest.

The particular use of the pesticidal compositions of the invention will be readily apparent to those skilled in the art. The active pesticidal compound is conveniently incorporated into a liquid composition, for example an emulsion, suspension or aerosol. The concentration of active substance in the composition may vary within wide limits but generally does not exceed about 15.0 ^l0 / o by weight. However, the pesticidal compositions of the present invention are preferably in the form of a solution or suspension containing from about 0.1 to about 1.0% by weight of the active pesticide.

Claims (1)

A fungicidal mildew suppressant composition comprising, as an active ingredient, a compound of formula (II) wherein: X is selected from the group consisting of bromine and methyl, and R is selected from the group consisting of hydrogen and methyl. ^CH > O CH, X - (-) - O-CHCNHC-C = CR CH, Vs CH, an