CS216540B2 - Ectoparazitocide means and method of making the active substances - Google Patents

Description

(84) Ectoparasiticidal agent and process for the manufacture of active substances

The present invention relates to an ectoparasiticidal composition comprising (+) - (α-cyano-3-phenoxy-4-fluorobenzyl) ester (+) -trans-3- [Z-2-chloro-2- (4-chlorophenyl) vinyl] as active ingredient -2,2-Dimethylcyclopropanecarboxylic acid as well as a process for the preparation of this Z-isomer.

It is already known that mixtures of (+) - cis - and (+) - trans-forms of (+) - (α-cyano-3-phenoxy-4-fluorobenzyl) ester of 3- [E, Z-2-chloro-2] (4-Chlorophenyl) vinyl] - N 2 -dimethylcycloipropane-1-carboxylic acids are insecticides and acaricidally active (see Example 17 of DOS No. 2,730,515).

The (+) - (α-cyano-3-phenoxy-4-fluorobenzyl ester (+) -trans-3- [2-chloro-2- (4-chlorophenyl) ynyl] -2,2-isomer has now been found -dimethylcyclopropane-1-carboxylic acid of formula 1b.

The novel compound of formula (1b) above can be obtained by reacting the Z-isomer of (+) - trans-3- (2-chloro-2- (4-chlorophenyl) vinyl) cyclopropane-1-carboxylic acid chloride of formula IIb

216310

reacted with 3-phenoxy-4-fluoro-benzaldehyde of formula III ...... ...... —---------------------— ... ...— -

in the presence of at least an equimolar amount of alkali metal cyanide, optionally in the presence of a catalyst and optionally using diluents, at a temperature between 0 and 100 ° C.

Our related Czechoslovak patent specification No. 2,16,539 discloses an ectoparasiticidal composition comprising; A mixture of the (+) - trans-3- (2-chloro-2) ester (+) - (.alpha.-cyano-3-phenoxy-4-fluorobenzyl) ester as active ingredient. H (4-EHL © rf'enyljvinyl] ^ · 2,21diinie- 'thylpyJ pT0pa ^ ^«i ^^ h 985y.kwé: << teýeeMny and method above« toy: © 4ET -S ^ drinkable that individual Z ¹ .tohoto isomer according to the invention can also be obtained by conventional digestion with the aforementioned mixtures of E, Z-isomers into the individual antipodes.

The novel compound of formula Ib is characterized by high insecticidal and acaricidal activity.

Surprisingly, the novel compound according to the invention exhibits considerably higher insecticidal and acaricidal, in particular ectoparasiticidal, activity than the known mixtures of the isomers of (3-cyano-3-phenoxy-4-fluorobenzyl) ester of 3- [2-chloro-2- ( tert-Phenylphenyl] -2,2-dimethylcyclopropane-1-carboxylic acid.

The acid chloride of the above formula IIb used as starting material is not yet described in the literature. This compound can be obtained by reacting the Z-isomer (+), -tp-ps-3t [4-phenylene-10-vinyl] _with

4-Methylcyclopropane-1-to-ariphenyls of the acid of formula IVh

It is reacted with a chlorinating agent, for example thionyl chloride, optionally in the presence of a diluent, for example, tetrabromomethane, at a temperature between 10 and 100 ° C.

The acid of formula IVb is not yet described in the literature. , ^k

This acid can be obtained by separating (+) -trans-3- [E, Z-2-chloro-2- (4-chlorophenyl) vinyl] -2,2-dimethylcyclopropane-1-carboxylic acid into individual E- and -2-isomers.

(i-trans-3- [E, Z-chloro-2- (4-chlorophenyl) vinyl] -2,2-dimethylcyclopropane-1-carbonyl) thyivaThese form of formula (IV). The corresponding alkyl ester of formula (V) is:

(V) 'in which

R is C 1 -C 4 alkyl, saponified in a conventional manner, for example by heating the above ester with an alkaline lye, for example an aqueous alcoholic liquor; sodium, at a temperature between 50 and 100 ° C.

To work up the reaction mixture, the alcohol is optionally distilled off, the product is extracted with a water-insoluble solvent, for example methylene chloride, and the extractant is distilled off under reduced pressure.

Examples of the esters of formula (V) are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutytesteax, ₍ se + butyedtOK and tert-butyl ester (+] - trans-3- [E ')). -cíjlorrÉ- _{^) t.}

- (4-chlorophenyl) vinyl] cyclopropane-1-carboxylic acid.

Esters of formula (V) are not yet described in the literature. These compounds are obtained by (1) - (trans) -3-trans-2,2-dimethyl-cyclopropane-1-carboxylic acid ester of formula (VI),

in which

R is C 1 -C 4 alkyl, reacted with a 4-chloro-α-chicrbenzylphosphonic acid ester of formula VII,

O p (OR ^ α

(Vil) in which.

R represents a C 1 -C 4 alkyl group in the presence of a base, for example sodium methoxide, optionally in the presence of a diluent, for example ethanol and / or tetrahydrofuran, at a temperature between -10 and + 5 ° C.

For work-up, the reaction mixture is diluted with water and extracted with a water immiscible solvent such as methylene chloride. The extracts were dried, filtered and the solvent was distilled off under reduced pressure.

Esters of the aforementioned general formula (VJ) are already known (see DOS No. 2,615,160). As ^one examples thereof include methyl, ethyléstar, n-propyl, isopropyl, n-butyl, isobutyl, sec. texc.butylester and (+) ^J of trans-3-fcirmyl-2,2-L-.dimethylcyklopropan -carboxylic acids.

The 4-chloro-.alpha.-chlorobenzylphosphonic acid esters of formula (VII) above are prepared from the known 4-chlorobenzaldehyde according to the following reaction scheme:

O

CHO hHP (OR) ->

or u. »u

ií

<v -CH-POR) _Z ř Vlil) OH -QH-P (OR) _Z Cl í Vil)

Reaction of 4-chlorobenzaldehyde with phosphorous acid esters such as diethyl phosphorous ester, optionally in the presence of a catalyst such as triethylamine at a temperature between 20 ° C and 10 ° C, yields 4-chloro-4-hydroxybenzylphosphonic acid esters of the above. of formula VIII. These esters can be converted to 4-chloro-α-chlorobenzylphosphonic acid esters of formula VII by reaction with chlorinating agents, for example thionyl chloride, at a temperature between 20 ° C and 100 ° C.

Examples of compounds of formula VII include dimethyl ester, diethyl ester, diisopropyl ester and 4-chloro-α-chlorobenzylphenoic acid di-sec-butyl ester.

The mixture of the ε, Ζ-isomers of (+ 1-trans-3- [2-chloro-2- (4'-chlorophenyl) -vinyl] -2,2-dimethylcyclopropane-1-carboxylic acid can be separated by dividing , Is-isomers of this acid are dissolved in a water-immiscible solvent such as methylene chloride by the addition of 0.001 to 1, preferably 0.1 to 1 equivalents of a base such as aqueous sodium hydroxide in X degrees, wherein X is a number between 1 and Whereby the continuous operation, preferably 2 to 100, is converted to a salt, after each addition of the base, the salt is extracted with water in X steps, the individual aqueous fractions are acidified with a mineral acid, for example hydrochloric acid, extracted with a solvent which is immiscible with sulfides, such as methylene chloride, each individual extract being treated in the usual manner, for example by drying, filtering and distilling off the solvent and the fraction in which one of the E neibo, Z isomers is predominant (according to. analysis by NiMR spectroscopy] are recrystallized from an organic solvent, preferably a hydrocarbon containing 5 to M carbon atoms.

The mixture of the ε, Ζ-isomers of (+ 1-trans-3- [2-chloro-2- (4-chlorophenyl) vinyl] -2,2-dimethylcyclopropane-1-carboxylic acid) can also be separated by: The E, Z-isomers of this acid are dissolved in an aqueous alkaline liquor, for example sodium hydroxide containing exactly one equivalent of base, by adding 0. 0011 to 1, preferably 0.1 to 1 equivalent of mineral acid in X degrees, wherein X is a number between 1 and &lt; &gt; &gt;, where &quot; o &quot; means a continuous process, preferably between 2 and 100 &apos;, acid is recovered, extraction is performed after each acid addition with a water-immiscible organic solvent such as methylene chloride; in a conventional manner, for example by drying, filtering and distilling off the solvent and the fractions in which one of the E or Z isomers predominates (according to NMR spectroscopy) are recrystallized from an organic solvent, preferably from a hydrocarbon containing containing 5 to 10 carbon atoms.

The 3-phenoxy-4-fluorobenzaldehyde of formula III, which is used as starting material in the preparation of the novel compound of formula 1b, is already known (see DOS No. 2 709 264).

The alkali metal cyanides used to prepare the novel compound of formula (1b) are preferably sodium cyanide and potassium cyanide.

The process for preparing the novel compound of formula 1b is preferably carried out using diluents. Suitable diluents are practically all inert organic solvents, including in particular aliphatic and aromatic or chlorinated hydrocarbons, such as pentane, hexane, heptane, cyclohexane, benzene, toluene, xylene, methylene chloride, chloroform ¹ , carbon tetrachloride, chlorobenzene and o-. dichlorobenzene, ethers such as diethyl ether, dibutyl ether, tetrahydrofuran and dioxane, ketones such as acetone, methylethylketone, methylisopiropylketone and methylisohutylketone, as well as nitriles such as acetonitrile and propionitrile.

Preferably, of the above-mentioned solvents, water-immiscible solvents are used in combination with water as the second component of the solvent system, i.e. the process is carried out in a two-phase system.

In the present case, the catalysts which are usually used in phase-to-phase reactions as auxiliary agents for the phase transfer of the reactants can be used as catalysts. In particular, tetraalkyl- and thirialkylaralkylammonium salts such as tetrabutylammonium bromide, methyltrioctylammonium chloride and trimethylbenzylammonium hydrogen sulphate may be mentioned.

The reaction temperature is generally maintained between 0 and 100 ° C. preferably between 10 ° and 50 ° C. The reaction is usually carried out at normal pressure.

To work according to the process of the invention, the starting materials are usually employed in equimolar amounts. The excess of some of the reaction components does not bring any significant advantages. The reaction is generally carried out in suitable solvents, optionally in the presence of a catalyst. The reaction mixture is stirred for several hours at the desired temperature, then an organic solvent, for example toluene, is added thereto, and the organic phase is worked up by washing, drying and distilling off the solvent in the usual manner.

The novel compound of the present invention results in an oily form and cannot be distilled without decomposition, but is purified by so-called "distillation", i.e., a long glow under reduced pressure to a moderately elevated temperature to remove the last residual volatiles. The 1 H-NMR spectrum was used to characterize this compound.

The active ingredient according to the invention exhibits, at low toxicity, a warm-blooded and rapidly emerging ectoparasifticidal (insefcticidal and acaricidal effect), in particular against mites which, as animal ectoparasites, attack domestic animals such as cattle, sheep and rabbits. combating animal ectoparasites from the order of the mites (Acarinaj.

The active ingredient according to the invention can be converted into the customary formulations such as solutions, emulsions, wettable powders, suspensions, powders, spirits, foams, pastes, soluble powders, granules, aerosols, concentrates based on suspensions and emulsions, powdered seed dressings, natural and synthetic substances impregnated with active substances and encapsulated forms in polymeric substances.

These compositions are prepared in a manner known per se, for example by mixing the active ingredient with fillers, i.e. liquid solvents, with liquefied gases present under the traction or with solid carriers, optionally using surfactants, i.e. an emulsifier and / or dispersants and / or foaming agents. reagents. If water is used as a filler, it is also possible to use, for example, organic solvents as co-solvents. Basically suitable liquid solvents are: aromatics, such as xylene, toluene or alkylnaphthalenes, chlorinated aromatics or chlorinated aliphatic hydrocarbons, such as chlorobenzenes, chlorethylenes or methylene chloride, aliphatic hydrocarbons, such as cyclohexane or ¹ paraffins, for example petroleum fractions, alcohols such as butanol or glycol, as well as their ethers and esters, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketoin or cyclohexanone, strongly polar solvents such as dimethylformamide and dimethyl sulfoxide, and water. By liquefied gaseous fillers or carriers is meant those liquids which are gaseous at normal temperature and pressure, for example aerosol propellants such as halogenated hydrocarbons, as well as butane, propane, nitrogen and carbon dioxide. Suitable solid carriers are natural stone meal, such as kaolins, alumina, talc, chalk, quartz, aittaipulgite, montmorillonite or diatomaceous earth, and synthetic stone meal, such as highly disperse silica, alumina and silicates. Suitable solid carriers for the preparation of granulates are the gritty and refined natural stone mortars, such as limestone, marble, pumice, sepiollt and dolomite, as well as synthetic; granules of inorganic and organic flours and granules of organic material such as sawdust, coconut shells, corn sticks and tobacco stems such as emulsifiers and / or foaming agents are suitable, nonionic and anionic emulsifiers such as polyoxyothylene esters of fatty acids, fatty alcohol polyoxyethylene ethers. for example alkylaryl polyglycoletber, alkylsulphonates, alkylsulphates, arylsulphonates and protein hydrolysates, and as dispersants, for example, lignin, sulphite waste liquors and methyleehilose.

The compositions of the invention may include adhesives such as carboxymethylcellulose, natural and synthetic powdered, granular or latex polymers such as gum arabic, polyvinyl alcohol and polyvinyl acetate.

In addition, these compositions may contain colorants such as inorganic pigments, for example iron oxide, titanium dioxide and ferrocyanide. blue, and organic dyes, such as alizarin dyes and metallic azo-phthalicylamine dyes, as well as trace elements such as salts of iron, manganese, boron, copper, cobalt, molybdenum and zinc.

The concentrates generally contain between 0.1 and 95% by weight, preferably between 0.5 and 9.0% by weight of active ingredient.

The active compound according to the invention can be used in the form of commercial preparations and / or in dosage forms prepared from these preparations.

The content of active ingredient in dosage forms prepared from commercial preparations can vary within wide limits. The active compound concentration of the use ^forms: movable cd · 0, 0000.0101 up to 100 percent by weight, preferably from 0.0001 to 10% by weight.

The application is carried out in a conventional manner adapted to the application form used.

The compositions according to the invention are prepared in a manner known per se by mixing the individual components in the necessary weight ratios, the order of addition of active and auxiliary substances generally not playing any. significant corner ..

In Veterinary Reported. The active compound according to the invention is applied in a manner known per se, such as orally in the form of, for example, tablets, capsules, drinks or granules, dermally in the form of, for example, immersion. sprays, pouring agents (pour-oin and spci-co) and powders, as well as parenterally in the form of, for example, injections.

Example 1 I d

Tick test (Boophilus microplus - resistant strain Biarra j / in vitro solvent test:

parts by weight of ethylene glycotanonomethyl ether

- + - 3 (5 parts by weight of nonylphenol polyglycol ether)

To prepare a suitable active ingredient, 3 parts by weight of the active compound are mixed with 7 parts by weight of the above solvent, and the concentrate thus obtained is diluted with water to the desired concentration.

10 adults of Boophilus microplus (resistant strain) are immersed in the test drug for 1 minute. The treated specimens were transferred to a plastic beaker and stored at room temperature for mortality.

In this test, the compound of the invention has a better effect than the prior art.

The results obtained are shown in Table I below.

Table I

Tick test (Boophilus microplus - resistant Biarra strain j / in vitro test active substance concentration effective mortality in% of the substance in ppm known active substance 8 100 of Example 17 4 SO

DOS No. 2 730 515 * 2 8 ©

20 May

0,5 10,

0,25 0

100 ALIGN!

100 ALIGN!

10.0

0.3 10O

0.1 100 active ingredient of Example 1

Legend:

*) The product in Example 17 of DOS No. 2,730,515 is a mixture of (+) - cis - ^and (+) - trans forms (+) - α-cyano-3-phenoxy-4-fluorobenzyl ester of 3- [Ε, Ζ- 2-chloro-2- (4-chlorophenyl) vinyl] -2,2-dimethylcyclopropain-1-carboxylic acid

Example II

Test with parasitic adult Stomoxys calcitrans

parts by weight of ethylene glycol monomethyl ether + 35 parts by weight of nonylphenol polyglycol ether

To prepare a suitable active ingredient, 3 parts by weight of the active compound are mixed with 7 parts by weight of the above solvent, and the concentrate thus obtained is diluted with water to the desired concentration.

adult Stomoxys calcitrans specimens are placed in Petri dishes containing sandwiches, which were soaked with 1 ml of the active ingredient tested the day before starting the test. After 3 hours the percent mortality was found. 100% means that all test thistles were killed. 0 ° / o means that no thistle has been killed.

The active substances, active substance concentrations and results obtained are given in Table II below.

Table II

Test with parasitic adult Stomoxys calcitrans active substance concentration effective mortality in% of the substance in ppm known active substance of Example 17

DOS No. 2,730,515 the active ingredient of Example 1

Example III

Rabbit (Psoroptes cuniculi) solvent test:

parts by weight of ethylene glycol monomethyl ether + 35 parts by weight of nonylphenol polyglycol ether

3 parts by weight of active compound are mixed to prepare a suitable active ingredient

3 | 00

100 ALIGN!

300

100 ALIGN!

100 o

100 with 7 parts by weight of the above solvent and the concentrate thus obtained is diluted with water to the desired concentration.

About 10-25 specimens of Psoroptes cuniculi are placed in 1 ml of the tested 'active agent, pipetted' into the wells in deep-drawing containers for packaging tablets. After 24 hours, mortality was found in%.

In this test, for example, the following compounds of the Examples exhibit a better effect than the prior art compounds:

Table lil

Rabbit (Psoroptes cuniculiJ) test active substance concentration of the active substance mortality in% in ppm

known active substance 1000 ' 100 ALIGN! from Example 17 300 0 DOS No. 2,730 ´515 the active ingredient of Example 1 100 ALIGN! 100 ALIGN! 30 0

The preparation of the active compounds according to the invention is illustrated by the following examples, but the scope of the invention is not limited in any way.

Example 1

Example AI

1.08 g (0.005 mol) of 3-phenoxy-4-fluorobenzaldehyde and 1.52 g (0.005 mol) of (+) -trans-3- [Z-2-chloro-2- (4-chlorophenyl) vinyl chloride ] -2,2: ^{-d'ime! l} thylcyklopropank arboxylové acid with stirring at 20 to 25 ° C along ^ dropwise to a mixture of 0.4 g of sodium cyanide, 0.6 ml of water, 210 ml of n-hexane and 0 ,, g of tetrabutylammonium bromide. the reaction mixture was stirred for 4 hours at 20 ¹ to 25 ° C., then was added 100 ml of toluene and the resulting mixture was extracted twice with 60 mL water. the organic phase was separated, dried over sodium sulfate and the solvent is distilled off under a water pump vacuum and the last solvent residues are removed by brief distillation at 60 ° C at 1 mmHg.

1.8 g (70.6% of theory) of (+) - (α-cyano-3-phenoxy-4-fluorobenzyl) ester (+) -trans-3- [Z-2-chloro-2- ( 4-chlorophenyl) vinyl] -2,2-diimethylcyclopropanecarboxylic acid as a viscous oil. The structure of the product was confirmed by 1 H-NMR spectrum.

¹ H-NMR spectrum (deuterochloroform / tetramethylsilane, τ values in ppm):

aromatic protons:

2.3-3.1 (multiplet, 12H), benzyl residue proton:

3.60: (singlet, 1/2 H) a

3.62 (singlet, 1/2 H), proton of vinyl residue:

4.14 (dulblet, 1H), cyclopropane or proton protons:

7.26-7.57 (multiplet, 1H);

8.26 (doublet, 1H), dimethyl group protons:

8.50'-8.80; (multiplet, 6H).

The following examples describe the preparation of starting materials.

Dissolve 1.0 g (0.0035 mol) of (+) -trans-3- [Z-2-chloro-2- (4-chlorophenyl) vinyl] -2,2-dimethylcyclopropanecarboxylic acid in 20 ml of carbon tetrachloride and of the solution 5 ml of thionyl chloride are slowly added dropwise with stirring at 25 ° C. The reaction mixture was refluxed for 4 hours, then excess thionyl chloride and carbon tetrachloride were distilled off in a water-jet vacuum. The last residual solvent was removed by brief distillation at a pressure of 267 Pa at a bath temperature of 60 ° C. 1.03 g (96.9% of theory) of (+ j-trains-3- [Z-2-chloro-2- (4-chlorophenyl) vinyl] -2,2-dimethylcyclopropanecarboxylic acid chloride) are obtained in the form of an oily liquid. .

Example A 2

22.2 g (0.071 mol) of (+) -trans-3- [E, Z-2-chloro-2- (4-chlorophenyl) vinyl] -2,2-dimethylcyclopropanecarboxylic acid ethyl ester is dissolved in 100 ml of ethanol A solution of 5.7 g of sodium hydroxide in 100 ml of water was added to the solution, and the mixture was heated under reflux for 4 hours with stirring. The ethanol was distilled off under a water pump vacuum, the residue was taken up in 300 ml of warm water and extracted once with 300 ml of methylene chloride. The aqueous phase is separated, acidified with concentrated hydrochloric acid and extracted twice with 300 ml of methylene chloride each time. The organic phase is separated, dried over magnesium sulphate and the solvent is distilled off under a water pump vacuum. The last residual solvent was removed by brief distillation at a pressure of 267 Pa at a bath temperature of 60 ° C. 15.5 g (76.6% of theory) of (+) - trans-3- [E, Z-2-chloro-2- (4-chlorophenyl) vinyl] -ZZ-dimethylmethylcyclopropanecarboxylic acid are obtained in the form of a viscous oil, which crystallizes after some time and melts at 120 to 132 ° C after recrystallization from acetonitrile. Example A 3

The starting material used for the ester of formula V can be prepared as follows:

2.53 g (0.1.1 mol) of sodium are dissolved in portions in 50 ml of ethanol. After all of the sodium has dissolved, 150 ml of anhydrous tetrahydrofuran are added and 29.7 g (0.1 mol) of 4-chloro-chlorobenzylphosphonic acid diethyl ester stearate dissolved in 30 ml of anhydrous tetrahydrofuran are added dropwise at 0 ° C. The mixture was stirred at 0-5 ° C for 2 hours. 17 g (0.1 mol) of ethyl ester (+ 1-trans-2,2-dimethyl-) were added dropwise with stirring at 0 ° C. The reaction mixture was stirred at 20-25 ° C for 121 hours, then 500 ml of water was added and the resulting mixture was extracted twice with 300 ml of methylene chloride each time. The organic phase is separated, dried over magnesium sulphate, the solvent is distilled off under a water pump vacuum and the residue is distilled under vacuum.

23.2 g (74.1% of theory) of (+) - trans-3- [E, Z-2-chloro-2- (4-chlorophenyl) vinyl] -2,2,2-dimethylcyclopropanecarboxylic acid ethyl ester in ethyl ester are obtained. · Yellow oil: boiling point 155-1.65 ° C / 133 Pa.

IC

EXAMPLE A 4.

130.2 g (0.4508 mol) of (+ 1-trans- [E, Z-2-chloro-2- (4-chlorophenyl) vinyl] -2,2-dimethylcyclopropanecarboxylic acid with an E / Z = 00) isomer ratio 40 is suspended in 500 ml of water and converted with stirring to 18.27 g (0.4508 mot) of sodium hydroxide dissolved in 10 ml of water, converted to ¹ by seeding salt, and the aqueous salt solution overlaps with 10 ml of methylene chloride. To this was added 0.04568 mL of water in an aqueous solution, the mixture was stirred vigorously for 5 minutes, then the methylene chloride phase was separated, acidified and separated. In the same manner, the remaining 10 phases are dried in magnesium sulphate and evaporated in vacuo to give 110 acids of the above-mentioned acid with a different isometric ratio E and Z. determined by: ⁴ H-NMR spectrum,

Fraction I (first separated by acid) has an E / Z ratio of 85/15;

Fraction IX. has ratio: E / Z = 40/00.

Fraction IX (10.4 g) was dissolved in cyclohexane at 30 ° C and 40 degrees Celsius. Standing at room temperature: crystals of salicylic acid ('+) - trans-3- [Z.-2; -chloro-2- (4'-ehlt (Mif erayyl) ethyl) -2,2-dimethylcyclopropanecarboxylic acid 1411-142 ° C. The structure of the product is confirmed by ¹ H-NMR spectrum.

1 H-NMR spectrum (deutero-chloOformithetramethylsilane, τ values in ppns j:

arooiatic protons: ·

2.37-2.81 (multiplet, 4 H), vinyl residue proton:

4.10 '(doublet, 1H), cyclopropane residue protons:

7.26—7.56 (multiplet, 1 lij and

8.216 (doublet, 1H, protons of the dlmethyl group:

8.55 (singlet, 3H), a

8.7 (0 (singlet, 3H))

Claims (2)

SUBJECT Ectoparasiticidal composition, characterized in that it contains (+) - (α-cyano-3-phenoxy-4-fluorobenzyl) ester as the active ingredient OF THE INVENTION (+ 1-trans-3- [Z-2-chloro-2- (4-chlorophenyl) vinyl] -2,2-dimethylcyclopropanecarboxylic acid of formula 1b). CN 2 :. (+) - (α-Cyano-3-phenoxy-4-fluorobenzyl ester) (+) - trans- [3- [Z-2-chloro-2- (4-chlorophenyl) vinyl] -2,2 -dimethylcyclopropanecarboxylic acid of the above formula 1b, characterized in that (+ 1 -trans-3- [Z-2-chloro-2- (4-chlorophenyl) vinyl) cyclopropane-1-carboxylic acid chloride of formula IIb is reacted with 3-phenoxy-4-fluorobenzaldehyde in the presence of at least an equimolar amount of alkali metal cyanide, optionally in the presence of a catalyst and optionally using diluents, at a temperature between 0 and 100 ° C.