NO149946B - PREPARATIONS FOR THE FIGHT AGAINST INSECTS (INSECTA) AND SPIDER ANIMALS (ARACHNIDA) CONTAINING CYCLOBUTANCHARAN BOXYLATES - Google Patents

Description

The present invention relates to preparations for combating insects (Insecta) and arachnids (Arachnida), and the peculiarity of the preparations according to the invention is that they contain as active ingredients 1-phenyl-cyclobutane-carboxylate compounds with the general formula (I)

wherein R<*> is hydrogen or methoxy, ethoxy, propoxy, butoxy, tetrafluoroethoxy, methylthio, ethylthio, propylthio, fluorine, chlorine, bromine, methyl, ethyl or nitro, and R 2 is 1 2 hydrogen or a methyl group, or R and R together form a methylenedioxy group, R^ is hydrogen or a lower alkyl group, or one of the following groups (a) to (f),

3

wherein Y<1>, Y<2>, Y<3>, Y<4>, Y<5> and Y<6> are the same or different and each represents hydrogen or fluorine, bromine or chlorine, with the proviso that when is hydrogen, fluorine, chlorine or

2 16

bromine and R is hydrogen, at least one of Y - Y has a meaning other than hydrogen.

These and other features of the invention appear in the patent claims.

The terms "Insecta" and "Arachnida" refer to each other

the systematic class designations for arthropods. The terms "insecticide" and "insecticide effect" used in the following refer to the effect on these classes of arthropods. It has been established by experiment that the compounds (I) are active against mites.

Known compounds which may be considered related to the compounds of formula I are those in which groups (a) to (f) are present as esterifying groups with chrysanthemic acid in commercial or experimental pyrethroids. DE-OS 2,653,189 describes a similar class of esters..

DE-OS 2,733,740 describes compounds of formula I

16 12

wherein all groups Y - Y are hydrogen, R and R are each hydrogen, or fluorine, chlorine, bromine or methyl and R<3>

is one of groups (a), (c) and (e) above. When used in insecticidal preparations, these compounds have an insecticidal effect which is less than for the preparations according to the present invention.

Preferably, R 1 is ethoxy or propoxy and R<2> is hydrogen.

1 2

Compounds in which R and R form the methylenedioxy group are also preferred.

Also preferred is R<3> one of the groups (a), (c) and (e) as defined above.

It is also preferred that from one to all six of the groups

Y1 to Y<6> is a fluorine group, any remaining groups being hydrogen. Tetrafluoro substitution (Y<1>, Y2, Y3, Y4 = F, Y<5>, Y<6> = H) is particularly preferred.

Particularly preferred compounds in accordance with the invention are the following: 3'-phenoxybenzyl-1-(3,4-methylenedioxyphenyl)-2,2,3,3-tetrafluorocyclobutanecarboxylate and its α-ethynyl derivatives;

3'-phenoxybenzyl-1-(4-ethoxyphenyl)-2,2,3,3-tetrafluorocyclobutanecarboxylate and its o-cyano and a-ethynyl derivatives.

The compounds of formula I in which R 3 is one of the groups (a) to (f) are extremely active as insecticides, with an insecticidal activity of an order of magnitude greater than most known insecticides. Certain compounds also have the property of contact repellency towards insects. The compounds according to the invention are generally more active against flies than the compounds according to the above-mentioned DE-OS 2,653,189.

The compounds of formula I are optically active and can be resolved into their optical isomers by conventional methods into the individual (+) and (-) optical isomers of the compounds as well as their racemic

(-) forms.

It is also noted that the insecticidal effects of optical isomers of the compound I with R 3 = (a) to (f) can be very different.

Compounds I in which R is one of the groups (a) to (f) can e.g. produced by esterification of the free acid

3 3

(formula I, R =H) with the appropriate alcohol R OH, wherein R 3 is one of the groups (a) to (f). This esterification can

carried out by any suitable known method, e.g. by direct reaction or by prior conversion of the acid and/or alcohol into a suitable reactive derivative, or by a transesterification reaction between the alcohol R 3 OH (R 3=(a) to (f)) and a lower alkyl ester of the acid.

The acid (formula I, R 3=H) is prepared, e.g. by

reaction between an appropriately substituted benzyl compound and an appropriately substituted 1,3-dihalopropane to form a 1-phenylcyclobutane compound which can be hydrolyzed to the acid.

An alternative preparation method for the acid (formula I, R 3=H) in the form of its lower alkyl ester is by addition

1 2 3 4'

of the olefin Y Y C=CY Y to the substituted phenyl acrylic ester of formula II

1 2 1 2 3 4 in which R is a lower alkyl group and R''", R2, Y^, Y2, Y3, Y4, Y^ and Y^ have the above meaning.

Esters of formula I (R 3 = lower alkyl) in which

Y<3>=Y<4>=F and Y<1>=Y<2>=Y<5>=Y<6>=H can be prepared, by first

3 4 12

prepare the compounds in which Y = Y = F, Y = Y = Cl in accordance with the preceding method (using dichlorodifluoroethylene) and subsequent hydrogenation of the product to replace the chlorine groups with hydrogen.

The esters II in which Y^=Y^=H can be prepared by the following general methods: (1) A lower alkyl ester of the suitably substituted phenylacetic acid (V) is condensed with a dilower alkyl oxalate in the presence of a basic catalyst to to prepare the enolate salt (IV). (2) The solution of the enolate salt is acidified to give the corresponding phenyl oxaloacetate (III). (3) The compound III is reacted with formaldehyde under alkaline conditions to give the phenyl-hydroxymethylacetate which on dehydration (sometimes spontaneously) gives the phenylalkyl ester (II).

This reaction sequence is illustrated in the following total reaction nucleus. It will be understood that the specific acids and bases indicated may be replaced by other suitable compounds. Lower alkyl esters other than the ethyl esters shown can also be used. When Y^=Y^=F, the esters II can be prepared using the method described by D.G. Naae and D.J. Burton, Synthetic Communications, 3, 197-200 (1973). In this method, the appropriate phenyl-keto ester of formula VI is reacted with dibromodifluoromethane (CBr 2 F 2 ) in the presence of 2 mol of tris-(dimethylamino)phosphine and a suitable solvent such as e.g. diglyme or triglyme in which Ph has the above meaning and R is a lower alkyl group.

The most general method of forming the esters is as follows:

9

6,

where R , R , Y , Y , Y , Y , Y and Y have it

3

above meaning and R is one of groups (a) to (f) set forth above.

Alternatively, the ethyl ester can be converted directly as follows:

The compounds (I) described herein can be dissolved in a suitable organic solvent, or a mixture of solvents, to form solutions or brought into aqueous suspension by dispersing organic solvent solutions of the compounds in water, to

provide useful liquid mixtures, such as can be incorporated into dispersions of the aerosol type with the usual aerosol propellants.

The compounds may also be incorporated into solid preparations which may include inert solid diluents or carriers, to form useful solid preparations. Such mixtures can also include other substances such as e.g. wetting agents, dispersing agents or adhesives, and may be prepared in granular or other forms to provide slow release of the compounds over an extended period of time. The compounds can be used in such preparations either as the only active ingredient or in combination with other insecticides such as e.g. pyrethrum, rotenone, or with fungicidal or bactericidal agents, to provide preparations useful for household and agricultural spraying preparations and pesticides, textile coating and impregnating agents and the like.

In particular, the compounds (I) can advantageously be combined with other substances which have a synergistic or potentiating effect. In general, such substances are of the class of microsomal oxidase inhibitors, i.e. they prevent the detoxification of the insecticides in insects produced by the action of oxidative enzymes. Typical substances of this type are the pyrethrin synergists, of which the following are examples:

"Sesoxane" (manufactured by Shulton Inc., Clifton, N.J., USA) has been found to be particularly useful as a potentiator. The amount of "Sesoxane" used can vary from

1/1000 to the fivefold weight of compound (I)

the preferred range being from 1/100 to equal parts by weight. Piperonyl butoxide is also a useful potentiator in similar amounts.

The production and properties of the compounds (I) for use in the preparations are illustrated by means of the following specific examples, where Ex. 1 relates to the preparation of a compound used for comparison purposes.

EXAMPLE 1 (Comparison example)

(a) 1-(4-Chlorophenyl)cyclobutanenitrile

4-Chlorobenzyl cyanide (10 g) in dry DMSO (20 mL) was added over 5 min. to a stirred suspension of sodium hydride (4.4 g) in DMSO at 25°C under argon. The mixture was stirred for 30 min. and then a solution of 1,3-dibromopropane (27 g) in dry DMSO (50 ml) was added over 30 min. while the temperature of the reaction mixture was maintained at 25 - 30°C. After stirring for a further 40 min. at this temperature the reaction mixture was added to ice-water (500 ml) and extracted with dichloromethane (3 x 75 ml).

The extracts were evaporated and the residue extracted with diethyl ether (4 x 50 ml). The other extracts were washed with water, dried over anhydrous sodium sulfate and evaporated to give an oil (10.8 g) which on distillation gave the nitrile (boiling point 90°C/10~<6> Torr). Yield 5.4 g (43%).

Analysis: C 68.48%, H 5.49%, Cl 18.3%, C^H^Cl N

theoretically requires: C 68.93%, H 5.25%, Cl 18.5%.

(b) 1-(4-Chlorophenyl)cyclobutanecarboxylic acid

1-(4-Chlorophenyl)cyclobutanenitrile (5g) was mixed with ethylene glycol (60ml) and 40% w/w aqueous potassium hydroxide solution (80ml) and boiled under argon for 18h. The mixture was cooled, added to ice water and extracted with diethyl ether. The aqueous layer was acidified and the precipitate was filtered off, washed with water, dried and recrystallized from petroleum ether (boiling point 40-60°C) to give the acid as white needles of m.p. 88 - 89°C.

Yield 4.5 g (82%).

Analysis: C 62.70%, H 5.14%, Cl 16.5%, O 15.2%, C11H11<C>102

theoretically requires C 62.72%, H 5.26%, Cl 16.83%, O 15.2%.

(c) 3'-phenoxybenzyl-1-(4-chlorophenyl)cyclobutane carboxylate

1-(4-Chlorophenyl)cyclobutanecarboxylic acid (1 g) was dissolved in thionyl chloride (1 ml) and heated under reflux for 40 min. Excess thionyl chloride was removed under vacuum and the residue was taken up in petroleum ether 40 - 60°C (40 ml) and added over 15 min. to a stirred mixture of 3-phenoxybenzyl alcohol (1.1 g),

pyridine (1 ml), benzene (50 ml) and petroleum ether 40 - 60°C

(50 ml) maintained at 10°C. The mixture was stirred

at 20 - 25°C for 3 hours and then added to ice water, washed with 0.5M hydrochloric acid, water, dilute sodium bicarbonate solution and dried over anhydrous sodium sulfate. The solvent was evaporated to give an oil (2.3 g) which after chromatography on silica gel, eluting with benzene/petroleum ether, gave the ester 1.52 g

(82%).

Analysis: C 72.87%, H 5.30%, Cl 9.2%, O 12.1%.

C24H21C103 theoretically requires: C 73.37%, H 5.39%,

Cl 9.0%, O 12.2%.

EXAMPLE 2

(a) 1-(4- ethoxyphenyl) cyclobutane carboxylic acid

Ethyl 4-ethoxyphenyl acetate (14 g) in anhydrous diethyl ether

(20 mL) was added to a stirred suspension of sodium amide (5.3 g) in liquid ammonia (400 mL) over 3 min. and the mixture stirred for a further 20 min. 1,3-dibromopropane (14 g) in diethyl ether (10 ml)

was added within 20 min. and the mixture stirred in

17 hours. 50 ml of saturated ammonium chloride solution was added and the reaction mixture was extracted with diethyl ether. Evaporation of the solvent gave a residue (17.4 g) which, after chromatography on silica gel by elution with benzene/chloroform, gave an oil (7.2 g). The oil was dissolved in ethanol (50 ml) and 10% sodium hydroxide solution (50 ml) was added. The mixture was refluxed for 3 hours, cooled, added to ice water and extracted with diethyl ether. The aqueous layer was acidified and the precipitate was filtered off, washed with water, dried and recrystallized from petroleum ether 40-60°C to give the acid 5.2 g (35%) m.p. 90 - 91°C.

Analysis: C 71.04%, H 7.23%, O 22.0%

C13H16°3 theoretically required C 70.89%, H 7.32%, O 21.8%.

(b) '3'-phenoxybenzyl-1-(4-ethoxyphenyl)cyclobutanecarboxylate

1-(4-Ethoxyphenyl)cyclobutanecarboxylic acid (1 g) was refluxed in thionyl chloride (1 ml) for 30 min. and excess thionyl chloride removed under vacuum. The residue was taken up in petroleum ether 40 - 60°C (25 ml) and added over 5 min. to a stirred mixture of 3-phenoxybenzyl alcohol (1.1 g) pyridine (1 ml) benzene

(25 ml) and petroleum ether 40 - 60°c' (25 ml) at 15°C. The mixture was stirred at 15°C for 3 hours and then added to ice-water and extracted with diethyl ether. The extract was washed with water, 0.5M hydrochloric acid and sodium bicarbonate solution and then dried over anhydrous sodium sulfate and the solvent removed to give an oil (2.1 g). Chromatography on silica gel, eluting with benzene gave the ester (1.5 g) (82%).

Analysis: C 77.55%, H 6.65%, O 16.0%

C 2 , H 2 O . theoretically requires C 77.59%, H 6.51%, 0 15.9%.

EXAMPLE 3

(a) 2-(4-Ethoxyphenyl)propenoic acid ethyl ester

This part of the example shows the general method for preparing the 2-aryl acrylic acid esters. (Formula II).

Alcohol-free sodium ethoxide freshly prepared from sodium (13.9 g) and excess ethanol was slurried in dry benzene (200 mL). To this suspension, diethyl oxalate (88.5 g) was added over 15 min. Ethyl p-ethoxyphenyl acetate (V) (114.2 g) was added to the resulting clear yellow solution over 30 min. at room temperature. After a further 1 hour, the reaction mixture solidified. The solid sodium diethyl 2-p-ethoxyphenyl-3-ethoxy-3-oxido-oxaloacetate (IV) was triturated and washed well with ether. The combined ether extracts were evaporated to a small volume to give an additional amount of salt.

The total yield was 227.4 g.

The sodium salt was acidified by adding it in portions to a well-stirred emulsion of equal parts of diethyl ether and dilute acetic acid (about 10%). After separation, the ether layer was washed with water and dilute sodium bicarbonate solution and dried with anhydrous sodium sulfate. After evaporation of ether, the remaining oil was crystallized from petroleum ether (boiling point 60 - 80°C) to give diethyl 2-ethoxyphenyl oxaloacetate (III)

(143.8 g) (85%), m.p. 59 - 60°C.

The keto ester III (143.8 g) was stirred in dilute formaldehyde solution (62 ml 37% formaldehyde + water 220 ml) and potassium carbonate solution (54.5 g in water 280 ml) was added dropwise to the suspension. At the end of the addition, ether was added to the stirred suspension to dissolve the gummy precipitate that had formed and after a further 15 min. gas development began. When this gas evolution ceased (after about 2 hours) the reaction mixture was extracted with additional ether and the combined ether extracts were washed with water and evaporated after drying over Na 2 SO 4 . The yield of ethyl 2-(4-ethoxyphenyl)propenoate (ii) (isolated as a yellow oil) was 97.8 g (79.8%).

(b) ethyl- 1-(4- ethoxyphenyl)- 2, 2, 3, 3- tetrafluorocyclo-butane- carboxylate

2-(4-Ethoxyphenyl)propenoic acid ethyl ester (13.2 g) was mixed with benzene (7.5 ml), α-pinene (2 drops) N-ethyldiisopropylamine (2 drops) and tetrafluoroethylene

(15.5 ml) and heated to 150 - 155°C for 24 hours and then at 155 - 160°C for 17 hours. After evaporation of volatiles, the residue (16.6 g) was dissolved in dichloromethane and chromatographed on a column of silica gel to give the ester as a colorless oil 14.5 g (75%).

Analysis: C 56.47%, H 5.24%, F 23.4%.

<C>15<H>16<F>4°3 theoretically requires C 56.25%, H 5.04%, F 23.7%.

(c) 1-(4-ethoxyphenyl)-2,2,3,3-tetrafluorocyclobutanecarboxylic acid

Ethyl 1-(4-ethoxyphenyl)-2,2,3,3-tetrafluorocyclobutane carboxylate (14.5 g) was dissolved in ethanol (100 mL) and 10% w/w sodium hydroxide solution in water (100 mL) was added and the mixture refluxed for 2.5 hours. The mixture was cooled, added to ice water and extracted with diethyl ether. The aqueous layer was acidified and the precipitate was filtered off, washed with water, dried and crystallized from 50-80°C petroleum ether to give the acid with m.p. 112 - 113°C. Yield 11.2 g (85%).

Analysis: C 53.20%, H 4.22%, F 25.9%.

C13H12F4°3 theoretically requires C 53.43%, H 4.14%, F 26.0%.

(d) 3'-phenoxybenzyl-1-(4-ethoxyphenyl)-2,2,3,3-tetrafluoro-cyclobutane-carboxylate

1-(4-Ethoxyphenyl)-2,2,3,3-tetrafluorocyclobutanecarboxylic acid (0.9 g) was refluxed with thionyl chloride (1 mL) for 45 min. and excess thionyl chloride was removed under vacuum. The residue was dissolved in petroleum ether 40 - 60°C (40 ml) and added over 5 min. to a mixture of 3-phenoxybenzyl alcohol (1 g), pyridine (1 ml), benzene (25 ml), and petroleum ether 40 - 60°C (25 ml kept at 20°C). The mixture was stirred for 3 hours and then added to ice-water and extracted with diethyl ether. The extract was washed with water, 0.5M hydrochloric acid and sodium bicarbonate solution,

dried over anhydrous sodium sulfate and the solvent evaporated to give an oil (2 g). Chromatography on silica gel eluting with benzene gave the ester 1.2 g (82%).

Analysis: C 65.45%, H 4.84%, F 16.0%:

Co,Ho_F.0. theoretically requires C 65.82%, H 4.67%, F 16.0%.

26 22 4 4

EXAMPLE 4

(a) (-) enantiomer of 1-( 4- ethoxyphenyl)- 2, 2, 3, 3-tetrafluoro- cyclobutane- carboxylic acid

α(+)-(1-Naphthyl)ethylamine was added to a solution of the racemic acid (2 g) (prepared as in Example 3 (C)) in ethyl acetate (75 ml) and n-hexane. The salt formed was crystallized four times from ethyl acetate at room temperature. The (+) (-) salt was cleaved with hydrochloric acid (1M) and the residue recrystallized twice from ethanol. The (-) acid had a = -118.2 and m.p. 194°C

and was achieved in 15% yield.

(b) (-) 3'-phenoxybenzyl-1-(4-ethoxyphenyl)-2,2,3,3-tetrafluorocyclobutanecarboxylate

The isolated (-) acid, 0.2 g, was refluxed

in thionyl chloride (1 ml) for 1 hour. After evaporation of excess thionyl chloride, the residue was dissolved in petroleum ether (boiling point 60 - 80°C) and added to 3-phenoxybenzyl alcohol (0.139 g) and pyridine (0.238 g) 1 benzene (3 ml) and petroleum ether (3 ml). The reaction mixture was stirred overnight, quenched with ice water, washed with water and the solvent layer separated and dried over a molecular sieve. After evaporation of the solvent, the pure ester was obtained as a viscous liquid by chromatography on silica gel using methylene chloride as eluent.

Yield 99.1%, a® = -58.2.

EXAMPLE 5

(a) 1-(3.,4-methylenedioxyphenyl)-2,2,3,3-tetrafluoro-cyclobutane-carboxylic acid

A mixture of ethyl 2-(3,4-methylenedioxyphenyl)propenoate (2.2 g), tetrafluoroethylene (5 ml), α-pinene (1 drop), N-ethyldiisopropylamine (1 drop) and benzene (10 ml) was heated at 150 - 155°C for 24 hours and then at 160 - 165°C for 16 hours and then cooled. The solvent was evaporated leaving an oil (3.0 g).

This oil was purified by chromatography on silica gel using benzene as eluent to give 1.4 g (44%) of ethyl 1-(3,4-methylenedioxyphenyl)-2,2,3,3-tetrafluorocyclobutanecarboxylate.

The ethyl ester was hydrolysed by refluxing for 2 hours with a mixture of potassium hydroxide (5 g), water (50 ml) and ethanol (50 ml). Ethanol was removed by evaporation and the aqueous residue extracted with diethyl ether. The aqueous layer was acidified and the precipitate, dried and recrystallized from petroleum ether (b.p. 60 - 80°)/diethyl ether to give 0.9 g of the acid as white crystals of m.p. 168 - 169°C.

Analysis: C 49.62%, H 2.72%, F 25.8%.

C12HgF4O4 theoretically requires C 49.33%, H 2.76%, F 26.0%.

(b) 3'-phenoxybenzyl-1-(3,4-methylenedioxyphenyl)-

2, 2, 3, 3- tetrafluorocyclobutane carboxylate

The acid prepared under Example 5 (a) (0.5 g) was mixed with thionyl chloride (1 ml) and refluxed for 45 min. Excess thionyl chloride was removed under vacuum. The residue was dissolved in petroleum ether (boiling point 40 - 60°C) (5 ml) and added over 5 min. to a stirred mixture of 3-phenoxybenzyl alcohol (0.4 g), pyridine (0.5 ml), benzene (15 ml) and petroleum ether (boiling point 40 - 60°C) (15 ml). After stirring overnight at room temperature, the mixture was added to ice-water and extracted with diethyl ether. The ether extract was washed with dilute hydrochloric acid, water, sodium bicarbonate solution and dried over anhydrous sodium sulfate. Evaporation of ether left an oily residue (0.78 g) which was purified by chromatography on silica gel eluting with benzene to give 0.7 g of the 3-phenoxy-benzyl ester as a clear yellow oil.

Analysis: C 63.54%, H 4.01%, F 15.9%.

C25H18F4°5 theoretically requires C 63.30%, H 3.82%, F 16.0%.

EXAMPLES 6 to 20

By applying the general method indicated in Example 3, the following compounds reproduced in Table 1 were obtained from the corresponding starting materials.

Elemental analysis, spectra and other characteristics

data were consistent with the specified structures.

Table 1 includes the compounds from examples 1, 2, 3, 4 and 5 for an easier overview.

EXAMPLE 21

The biological activity of the new cyclobutane esters was investigated in a series of tests with results collected in the subsequent table 2.

Insecticidal activity was investigated against the common housefly, Musea domestica, and the goldfly, Lucilia cuprina. The methods used were as follows:

(i) Houseflies

(a) The compound alone

Experiments were conducted using a standard DDT-proficient strain (WHO/IN/1) of M. domestica. The compound was added in acetone solution using

a micro-needle to the dorsum of the thorax of 2-day-old female flies propagated from the pupal stage with an average weight of 2.2 - 2.5 g/100 pupae. The adult flies were fed water and a diet of sugar alone and maintained at 26°C and 70% relative humidity. Mortality was determined 48 hours after treatment and compared with acetone-treated control animals. Flies that were unable to move or stand normally were considered dead. LD,-Q value was obtained from a calculator program based on three groups of 10 flies at each dosage level. The LD^Q value for DDT determined under the same conditions was 0.26 ug/fly.

(b) Potentiation

The compound was also tested on insects described above in connection with the potentiator "Sesoxane" by pre-treating the insect with 1 µg of the potentiator in acetone.

Mortality was determined 48 hours after treatment and compared to acetone, and acetone/potentiator controls.

LD,-Q value was determined as described above.

For DDT, with the same potentiator, the LD^^ value was 0.24 pg/fly.

Approximately the same levels of potentiation were obtained when "Sesoxane" was replaced by an equal amount of piperonyl butoxide.

(c) Insect repellent

Repulsion tests were carried out with the same strain of houseflies as in the mortality tests. Female flies that were at least 2 days old, which had not previously been fed protein, were anesthetized with C0 2 the day before the test and counted in containers each containing 20 flies. These were supplied with water and solid sucrose. On the test day, food and water were removed in the morning (09:00). When the tests were carried out only between 12.00 and At 17.30 the flies were therefore kept fasting for at least 3 hours before the testing.

The test involves the use of attractants to which the test compound was applied. These were exposed to the flies and the number of flies that landed on each lure was noted. The decoys consisted of aluminum bowls with an area of 5.94 cm 2 filled with common baker's yeast mixed with water and heated to form a firm surface film.

Each group of 20 flies was used in an experiment where

7 dishes were treated with a graded dilution series of the test compound using acetone as a solvent, along with one dish treated with acetone as a control. The concentration of the compound ranged from 0.0 to 31 ug/ul which was doubled at each level up to 2.0 µg/µl 100 microliters of each solution was pipetted evenly over the surface of each dish and left until the acetone evaporated.

The flies that were used were released into the standard

205 mm x 205 mm x 255 mm wire mesh cage and allowed to acclimatize in the test room which was maintained at a temperature of 26°C - 1°C and humidity approximately 60% for 10 min. before the treated bowls were introduced into each cage. Before use, the bowls were marked on the back and then randomly mixed to avoid certain tendencies in the assessment. At the 30 min. test, the number of flies on the surface of each dish was noted in the first and second minutes after the introduction of the baits and then every other minute. In this way, sixteen counts were made for each concentration, the sum of these being used for a regression analysis of the concentration effect. A total count of the landings for each concentration was also obtained and used to calculate the repellency index (IR). All relevant tests were carried out with fresh flies and baits, and the compounds were tested in three replicate groups.

The total number of flies recorded for each dish

0

the seven concentration levels were summarized and averaged. In the following formula, this designation is indicated by (N), where (C) indicates the number of flies noted on the control:

(ii) Goldflies

(a) Insecticidal action

The compounds were tested for activity against a dieldrin-sensitive strain (LBB) that had been collected prior to dieldrin use in the field.

The test compound was applied in acetone solution, 0.5 µl distributed with a Drummond micropipette to the dorsum of the thorax of 2-3 day old female flies. Adult flies were supplied with water and the sugarcane kept at 25°C and 60 - 70% RH. Mortality was determined after 24 hours. Immobile flies were considered dead. The LD^Q values, on a concentration basis, were interpolated from a graphical representation using a computer program.

Comparative LD^Q figures for DDT and dieldring are

0.17 respectively 0.025 ug/insect.

(b) Potentiation

Potentiation with "Sesoxane" was examined as described above in the housefly tests.

(c) Repudiation

Repulsion was determined as described above in the housefly tests, with the exception that the baits consisted of an agar gel containing fresh bovine blood. The test methods are described in DE-OS No. 2,653,189 published on 8 June 1977, see e.g. 38 i (c) (houseflies) and 38 iii (c) (goldflies).

EXAMPLE 22

The following are examples of insecticidal preparations in which all proportions are by weight.

(a) Syringe preparation

The following mixture is suitable for application by spraying

(b) Aerosol

The following materials are supplied in a suitable pressure vessel which is sealed and fitted with a valve in the usual manner.

(c) Water dispersible powder

The following powder mixture is suitable for dispersion in water for application by spraying.

Claims (6)

1. Preparations for combating insects (Insecta) and spiders (Arachnida), characterized in that they contain as active ingredients 1-phenyl-cyclobutane-carboxylate compounds with the general formula (I) wherein R<*> is hydrogen or methoxy, ethoxy, propoxy, butoxy, tetrafluoroethoxy, methylthio, ethylthio, propylthio, fluorine, chlorine, bromine, methyl, ethyl or nitro and R 2 is hydrogen or a methyl group, or R 1 and R 2 together form a methylenedioxy group, R 3 is hydrogen or a lower alkyl group, or one of the following groups (a) to (f) wherein y\ Y2, Y<3>, Y<4>, Y^ and Y^ are the same or different and each represents hydrogen or fluorine, bromine or chlorine, with the proviso that when R is hydrogen, fluorine, chlorine 2 16 or bromine and R is hydrogen, has at least one of Y - Y a meaning other than hydrogen.; 2. Preparations as stated in claim 1, characterized in that R* in the cyclobutane compounds is methoxy, ethoxy or propoxy and R 2 is hydrogen, or R 1 and R 2 together form a methylenedioxy^ group. 3. Preparations as stated in claim 1, characterized in that R 3 in the cyclobutane compounds is one of the groups (a), (c) and (e). 4. Preparations as stated in claims 1-3, characterized in that they further contain at least one synergistic or potentiating component of the class of microsomal oxidase inhibitors. 5. Preparations as stated in claim 4, characterized in that the synergistic or potentiating component is a pyrethrin synergist. 6. Preparations as stated in claim 5, characterized in that the synergistic component is α[2-(2-butoxyethoxy)ethoxy]-4,5-methylenedioxy-2-propyltoluene or 2-(3,4-methylenedioxy-phenoxy)-3,6,9-trioxaundecane, used in an amount of 0.001 to 5 and preferably 0.01 to 1 part (weight/weight) in relation to the cyclobutane compounds.