CS214852B2 - Insecticide means - Google Patents

Abstract

The present invention relates to a novel insecticidal composition. The essence of this means lies in that it contains a compound as an active ingredient from the group consisting of (S) -or-cyano-3 -phenoxybenzyl- [2,2-dimethyl-3R- (2,2-dichlorvinyl) cyclopropan-1R] carboxylate and (R) -α-cyano-3-phenoxybenzyl- [2,2-dimethyl- -3R- (2,2-dichlorvinyl) cyclopropan-1R] carboxylate.

Description

The invention relates to a novel insecticidal composition.

For several years, the esterification of chiral acids with α-cyano-3-phenoxybenzyl alcohol has produced insecticidally active compounds with outstanding biological activity.

It has now been found that esters of chiral acid 2,2-dimethyl-3R- (2,2-dichlorvinyl) cyclopropane-1R-carboxylic acid and optically active α-cyano-3-phenoxybenzyl alcohol of the formula

structures (Rj or · (Sj have useful insecticidal activity), which activity is significantly higher than the insecticidal activity of the aforementioned chiral acid ester form with optically inactive racemic α-cyano-3-phenoxybenzyl alcohol of structure [R, S].

SUMMARY OF THE INVENTION The present invention provides a novel insecticidal composition comprising, as an active ingredient, a compound selected from the group consisting of (S) -α-cyano-3-phenoxybenzyl- [2,2-dimethyl-3R- (2,2-dichlorviinyl)]. cyclopropane-1R-carboxylate; and (R) - N -cyanophenoxybenzyl [2,2-dimethyl-3R- (2,2-dichlorvinyl) cyclopropane-1R] carboxylate.

However ^{, the a-} cyano-3-phenoxybenzylalcohol has so far been prepared only in the form of a racemic compound. Due to the relative instability of the alcohol molecule, it was not possible to prepare its enantiomers in a stereoselective manner; for the same reason, it was also not possible to split said racemic alcohol into its optically active antipodes.

The only hitherto known method of obtaining chiral acid esters with alcohols is by separating the chiral acid ester and the alcohol of structure (RJ from the chiral acid ester and alcohol of structure (S) by selectively desolubilizing the other of said esters in a suitable solvent, to a relatively low yield well below 50% based on the weight of the racemic ester used.

However, it has now been found to economically prepare chiral acid esters of the formula

in which Hal represents a chlorine atom or a bromine atom, and an optically active alcohol of structure (SJ and / or (Rj) of the formula

This novel process, which can also be used to prepare the active ingredients of the insecticidal composition of the present invention (Hal in the above chiral acid formula, is chlorine and is the subject of U.S. Pat. No. 214,851), is to form a chiral acid ester of a racemic alcohol. or a non-equimolar mixture of a chiral acid ester and an optically active alcohol of said structure formula (RJ and a chiral acid ester of an optically active alcohol of the formula) structures (Sj acts with a basic agent selected from the group consisting of ammonia, primary amines, secondary amines, tertiary amines, quaternary ammonium salts, basic ion-exchange resins, high molecular weight liquid amines and strong bases, which strong bases are used in catalytic amounts, solvent n or in a solvent mixture in which, optionally, the chiral acid ester of the optically active alcohol of said structure (R) is soluble, whereupon such insoluble chiral acid ester of the active alcohol of structure (SJ) is isolated from the reaction mixture.

In this process, the base is preferably selected from ammonia, triethylamine, diethylamine, morpholine, piperidine and strong bases from sodium carbonate, potassium carbonate, alkali metal alcoholates and alkali metal hydrides, the strong bases being used in catalytic amounts. .

The basic agent may also preferably be selected from the group consisting of diisopropylamine, ephedrine, triethylenediamine, potassium tert-butylate and sodium isopropylate, the latter two being used in catalytic amounts.

The above solvent or solvent mixture is preferably selected from the group consisting of acetonitrile, alkanols and mixtures of alkanol and petroleum ether.

In the preparation of the 2,2-dimethyl-3R- (2,2-dichlorinyl vinyl) cyclopropane-1R-carboxylic acid ester and the optically active α-cyano-3-phenoxybenzylalcohol of structure (Sj and structure (R)), the above process is carried out as follows: Preferably, the basic agent is selected from the group consisting of ammonia, triethylamine, diethylamine, morpholine, pyrrolidone, pi1.

2-52 Peridine and strong bases selected from the group consisting of sodium carbonate, potassium carbonate, alkali metal alcoholates, alkali metal amides and alkali metal hydrides, the latter strong bases being used in catalytic amounts and the solvent or solvent mixture used is selected from acetonitrile , alkanols and mixtures of alkanol and petroether.

Preferably, the basic agent is selected from the group consisting of diisopropylamine, ephedrine, triethylenediamine, potassium tert-butylate and sodium isopropyl, the latter two bases being used in catalytic amounts and the solvent or solvent mixture used is selected from acetonitrile, alkanols and a mixture of alkanol and petroleum ether.

The solution underlying the present invention is surprising since, to date, there has been no method for converting an optically active alcohol into an optically active alcohol ester that represents the optically active antipode thereof in virtually quantitative yield.

However, this process makes it possible, for example, to transform directly and in quantitative yield a .beta.-dimethyl-SR-.beta.-.beta.-dibromvinyl ester of cyclopropanecarboxylic acid or 2,2-dimethyl-3R- (2,2-dichloroyl) cyclopropane-1R-carboxylic acid, an active α-cyano-3-phenoxybenzyl alcohol of structure (Rj or esters of said chiral acids and racemic erkyan-3-phenoxybenzyl alcohol of structure (R.Sjj) or a mixture of an ester of said chiral acid and optically active α-cyano-3-phenoxybenzyl alcohol of structure (R) and ester said chiral acid and an optically active α-cyano-3-phenoxybenzyl alcohol of structure (S) having a rich ester content of said chiral acid and an optically active α-cyano-3-phenoxybenzyl alcohol of structure (R) to the ester of said chiral acid and optically active α-cyano -S-phthtoxybenzylalcohol of Structure j).

It goes without saying that the terms " non-volatile " in the case of chiral acid esters and optically active alcohols of the structure (S) and " " " o " in the case of chiral acid esters and optically active alcohol of Structures < In the solvents used in the process, the esters of the chiral acid and the optically active alcohol of structure (S) are nevertheless to some extent soluble; given the volume of solvent used, said solubility must be sufficiently low to achieve a good yield of the desired product. In practice, a volume of solvent or mixture of solvents is used which makes it possible to obtain the resulting chiral acid ester and the optically active? -Amylamino-3-phenoxybenzyl alcohol of structure (Sj ') in at least 80% yield.

With respect to the esters of said chiral acids and the optically active α-cyano-3-phenoxybenzyl alcohol of structure (R), these esters are very soluble in the solvents used in the above-described process, so that a limited volume of these solvents allows their complete dissolution.

The reaction temperature affects the reaction rate.

The reaction time depends on the temperature and also on the nature of the base used.

In the following description, the mechanism according to which the above-described method proceeds will be explained.

By the action of a base of a suitable force, which in the method described above is selected from the group comprising:

Ammonia, primary amines, secondary amines, tertiary amines, quaternary ammonium salts, basic ion-exchange resins, high molecular weight liquid amines and strong bases, used in catalytic amounts, to the chiral acid ester of the optically active alcohol structure (R) contained in the starting product forms an? -cyanecarbanion, which causes racemization of the corresponding carbon.

Thus, further retuning in the solvent or solvent mixture leads to a soluble fraction to form two diastereoisomers (a chiral acid ester and a sulfuric alcohol alcohol (a ester of a chiral acid and a strontium alcohol (alcohols)) in a small amount.

In a solvent or solvent mixture that is optionally used in the above process, the chiral acid ester of the structure (SJ is insoluble, while the chiral acid ester of the structure (RJ is soluble in this environment; therefore, the equilibrium is shifted in favor of formation of the chiral acid ester and the alcohol of structure (S), whereby in practice yields of the chiral acid ester and the optically active alcohol structure (SJ of about 80 to 90% based on the starting amount of the optically active ester taken into the reaction; an acid and an optically active alcohol structure (SJ) is thus excluded from the reaction mixture.

The formation of an intermediate non-equimolar mixture of the chiral acid ester and the alcohol structure (SJ and the chiral acid ester and the alcohol structure (RJ) can be demonstrated by evaporation of the soluble fraction. Racemization is practically in quantitative yield. solvent mixtures in which, optionally, in which esters are praised of acid and alcohol of structure (S), ester of chiral acid and alcohol of structure (R) and ester of chiral acid and racemic alcohol of structure (R, SJ) are soluble.

(SJ - N -cyain-3-phenoxybenzyl [2,2-dimethyl-3R- (2,2-dichlorvinyl) cyclopropane-1R] carboxylate and (R) -α-cyano-3-phenoxybenzyl [2,2 -dimethyl-3R- (2,2-dichlorvinyl) cyclopropane-1R-carboxylate are novel compounds since they have not been described in the literature yet.

The first of these compounds, the ester of chiral acid and alcohol structure (SJ), is particularly suitable for controlling insects in agriculture.

For example, the compound can be used to control butterfly larvae. It can also be used as an insecticidal composition for domestic insects such as mosquitoes or flies.

The insecticidal efficacy tests are given. in the exemplary part of the description, they demonstrate the high insecticidal activity of the compounds of the invention in controlling domestic flies and larvae of Spodoptera Littoralis and Epilachna Varivestris.

(R) -α-cyano-3-phenoxybenzyl [2,2-dimethyl-3R- (2,2-dichlorvinyl) cyclopropane-1R] carboxylate shows lower insecticidal activity than the corresponding alcohol ester of structure (I).

(S) -α-cyano-3-phenoxybenzyl [2,2-dimethyl-3R- (2,2-dichlorvinyl) cyclopropam-1R] carboxylate; and (R) -α-cyano-3-phenoxybenzyl- [. Therefore, 2,2-dimethyl-3R- (2,2-dichlorvinyl) cyclopropain-1R] carboxylate can be used for the preparation of insecticidal compositions containing one or the other of the compounds as active ingredient.

In these compositions, the active ingredient may consist of one or more pesticidal agents. These compositions can be formulated as dusts, granules, suspensions, emulsions, solutions, aerosol solutions, and other formulations known in the art for such applications.

Said insecticidal compositions may contain, in addition to the active ingredient, a carrier and / or a non-ionic surfactant, ensuring, inter alia, uniform dispersion of the constituents forming the mixture. As the carrier, liquid carriers such as water, alcohol, hydrocarbons or other organic solvents, mineral oil, animal oil or vegetable oil, powdered carriers such as talc, clays, silicates or sillkagel, or solid flammable carriers can be used.

In order to enhance the insecticidal activity of the compounds, conventional synergistic compounds such as 1- (2,5,8-trixadodecyl-2-propyl-4,5-methylenedioxy) benzene, N- (2-ethylheptyl) may be added thereto. bicyclo [2.2.1] -5-heptene-2,3-dicarboximide and piperonyl-b: s-2- (2'-n-butoxy) ethyl acetate.

Said insecticidal compositions preferably contain from 0.005 to 10% by weight of active ingredient.

In order to further elucidate the invention, several examples are set forth below.

Example 1

Transformation of (R) -α-cyano-3-phenoxybenzyl- [2,2-diniethyl-3R- (2,2-dichlorvinyl) cyclopropane-1R] carboxylate to (S) -α-cyano-3-phenoxybenzyl- [2, 2-Dimethyl-3R- (2,2-dichlorvinyl) cyclopropane-1R] carboxylate a) Preparation of alcohol ester of structure (R):

g of the racemic alcohol ester (R, S) having [α] _D ²⁰ = + 16.5 ° (10%, benzene) is chromatographed on silica gel, eluting with a mixture of petroleum ether (b.p. 40-70 ° C) and isopropyl ether (85:15); 3 g of (R) - N -cyano-3-phenoxybenzyl [2,2-dimethyl-3R- (2,2-dichlorvinyl) cyclopropane-1R] carboxylate having [α] _D ²⁰ = - 31 ° (1) are obtained %, benzene) or [α] _D ²⁰ = - 21.5 ° (1%, chloroform).

b) Transformation to alcohol ester of structure (S):

To 60 g of (R) -α-cyano-3-phenoxybenzyl [2,2-dimethyl-3R- (2,2-dichlorvinyl) cyclopropane-1R] carboxylate having [α] _D ²⁰ = - 31 ° (1 °) [α] _D ²⁰ = - 21.5 ° (1%, chloroform) obtained in (a) above is added 120 ml of isopropanol and then 9 ml of aqueous ammonia solution (22 ° Be); the mixture thus obtained was cooled to 0 ° C and then stirred for 40 hours at 0 ° C. The precipitate was collected by centrifugation, washed with isopropanoil (30 mL) at -20 ° C and dried to give 48.5 g of (S) -α-cyano-3-phenoxybenzyl- [2,2-dimethyl-3R- 2-dichlorvinyl] cyclopropane-1R] carboxylate having a melting point of 60 ° C;

[.alpha.] D @ ²⁰ = + 66 DEG (1%, benzene) or [.alpha.] D @ ²⁰ = + 34 DEG (1%, chloroform).

Example 1 a d 2

Transformation of (R, S) -α-cyano-3-phenoxybenzyl [2,2-dimethyl-3R- (2,2-dichlorvinyl) cyclopropane-1 H] carboxylate to (SJ-α-cyano-3-phenoxybenzyl- [2,2- dimethyl 3R- (2,2-di-Chlorvinyl) cyclopropane-1R] carboxylate

To 600 g of the racemic alcohol ester (R, S) having [α] D ²⁰ = + 16.5 ° (10%, benzene) is added 1200 ml of isopropanol, and 90 ml of aqueous ammonia solution ( 22 ° Bé). The resulting mixture was cooled to 0 ° C and stirred at this temperature for forty-eight hours. The precipitate formed is collected by centrifugation, washed with 300 ml of isiopropanol at -20 DEG C., dried and weighed to give 485 g of (S) -? - cyano-3-phenoxybenzyl- [2,2-dimethyl-3R- (2)]; 2-dichlorvinyl cyclopropane-1R] carboxylate having a melting point of 60 ° C;

[.Alpha.] D @ ²⁰ = -186 DEG (1%, benzene) or (.alpha. @ ²⁰ = + -34 DEG (1%, chloroform)).

Analysis: C22H19O3NCl2 (416.28)

Calculated:

63.48% C, 4.60. % H, 3.36% N, 17.03% Cl,

Found:

63.7% C, 4.60% H, 3.4% N,

17.1% Cl.

14113 2

Example 3

Example 4

(S) -R-Cyano-S-phenoxybenzyl- [2,2-dimethyl-3R- (2,2-dichloro-vinyl) -cyclopropane-3R] -carbonylate Compound

It is mixed:

(S) - N -cyano-5-phenoxybenzyl [2,2-dimethyl-3R- (2,2-dichlorotinyl) cyclopropane-1R] carboxylate 25 g / l

2,6-di-tert-butyl cresol 10 g / l surfactant consisting of a mixture of calcium salts of alkylbenzene sulphonate (anlonate part) and polyoxyethylene ethers (non-ionic part) 70 g / l

Aromatic solvent mixture 785 g / l

Study of insecticidal activity (S) - «- cyano-3-phenoxy benzyl- {e ^i, 2-dimethyl-3R - C2, S-Ůichlorvinyl) Cyclo-IR jkárboxylátu propane (compound A)

a) Study of insecticidal activity on housefly

Testing insects are the mixed-sex home hills. The active ingredient is administered by the physical application of 1 µl of acetone solution to the dorsal thorax of the insect test. The dough oven is made up of insect individuals. Insect mortality was determined 24 hours after drug administration to determine the lethal dose (LD 50) of the test compound. The results are summarized in the following table:

Dose% mortality after 24 hours

ELSO

3.75

2.5

1,25

0.625

93.3

83.2

68.0

34.5

10.0 iisnograniu for individuals

It is apparent from the above table that Compound A shows high insecticidal activity against house flies,

b) Study of insecticidal activity against larvae of Spodoptera Littoralis

Tests were performed using the Tpl application. A 1 μΐ acetone solution of the test compound is placed on the dorsal thorax of each individual. Use 15 Spodoptera Littoralis caterpillars in the fourth larval stage for each dose administered. After administration, the individuals used were placed in artificial culture medium (Poltot), and 24 hours and 48 hours were applied to control the efficacy of the test product (percent mortality relative to the control group of individuals), and the lethal count was determined. dose (LD 50) in natnograms for caterpillar.

The results are summarized in the following table.

Dose% mortality LD 50 at 48 hours after 24 hours at 48 hours

125 85 6 97.8 0.625 80.0 82.2 0.3 nanograms per 0.3125 48.9 62.2 caterpillar 0.1562 20.5 27.3

Example 5

Comparison of the insecticidal activity of the active compounds according to the invention with the insecticidal activity Similar known compounds The compounds tested are:

- (S) - N -cyano-3-phenoxybenzyl- [2,2-dimethyl-1-3R- (2,2-dichlorvinyl) cyclopropane-1R] -carboxylate (Compound A; according to the invention);

- (R, S) -α-cyano-3-phenoxybenzyl- [2,2-dimethyl-3R- (2,2-dichlorvinyl) cyclopropane-1H) carboxylate (Compound B; prior art);

- (R) - > 4-methyl-3-methyl-6-methyl-{2,2-dimethyl-3R- (2,2-dichlorvinyl) cyclopropane-1R] -carboxylate (compound C; according to the invention);

1. Study of insecticidal activity against house fly

The test insects are female flies of a domestic strain resistant to pyrethrinoid compounds; the test insects were kept at 22-23 ° C at 60-65% relative humidity; the insects are 4 to 5 days old. Topical application of a 1 µl acetone solution of the test compound to the dorsal thorax of insects using an Ar214852 nold micromanipulator is used. 50 subjects are used for each dose of test compound. Insect mortality is evaluated 24 hours after application. Lethal dose LD50 in nano · grams per insect is determined.

Compound LD 50 without synergy

Compound A 2.07

Compound B 4.06

Compound C -

2. Study of shocking effect on housefly

The test insects are female 4-5 days old. Direct spraying in a Kearns-March cylinder is used; A mixture of acetone (5%) and kerosene is used as solvent (amount of solvent used: 2 ml per second. 50 individuals are used per dose. Up to 10 minutes every minute and then, after 15 minutes, determined by conventional KT 50 methods. The results obtained are shown in the following table:

Compound KT 50 Compound A 4.03 Compound B 4.6 Compound C 7.4

-.......

The test is carried out without addition of a synergistic agent and in the presence of a synergistically active piperonyl butoxide.

The results are summarized in the following table:

in nanograms per insect with synergy ...... -

1,22

35.3

3. Effectiveness study on Epilachna Varivestris larvae

The test is performed using a topical application similar to that used in the Housefly and Spodoptera LittoraPs larvae tests. Use larvae at the penultimate stage of the larvae; after application, the larvae are fed with bean plants. 72 hours after application, mortality assessment is performed. Results are expressed as the lethal LD 50 dose in nanograms per insect. The results are shown in the following table:

Compound LD 50 in nanograms per subject

Compound A 1.98

Compound B -

Compound C 49.1

Claims (1)

An insecticidal composition comprising, as active ingredient, a compound selected from the group consisting of (S-α-cyano-3-phenoxybenzyl- [2,2-dimethylmethyl-3R- (2,2-dichlorvinyl) -cyclopropane-1R] carboxylate, and (R 1 -α-Cyano-3-phenoxybenzyl- [2,2-dimethyl-3R- (2,2-dichlorvinyl) cyclopropane-1R] carboxylate.