The present invention relates to cyclopropanecarboxylic acid esters, processes for their manufacture and their use in pest control.

The cyclopropanecarboxylic acid esters have the formula ##STR2## wherein X₁ represents chlorine or bromine, R₁ represents hydrogen, methyl, vinyl, ethynyl or cyano, Y₁ represents hydrogen, fluorine, chlorine or bromine, and n is 2.

On account of its activity, the preferred compound is that of the formula I, wherein X₁ represents chlorine, R₁ represents cyano, Y₁ represents hydrogen and n is 2.

The compounds of the formula I are obtained by methods which are known per se, for example as follows: ##STR3##

In the formulae II to VII, X₁, Y₁, R₁ and n are as defined for formula I.

In the formulae III and IV, X represents a halogen atom, especially a chlorine or bromine atom, and in formula VI R represents C₁ -C₄ alkyl, especially methyl or ethyl.

Suitable acid acceptors for processes 1 and 2 are in particular tertiary amines, such as trialkylamine and pyridine, and also hydroxides, oxides, carbonates and bicarbonates of alkali metals and alkaline earth metals, and in addition alkali metal alcoholates, for example potassium tert-butylate and sodium methylate. As hydrophilic agent for process 3, dicyclohexylcarbodiimide can be used for example. Processes 1 to 4 are carried out at a reaction temperature between -10° and 120° C., usually between 20° and 80° C., under normal or elevated pressure and preferably in an inert solvent or diluent. Examples of suitable solvents or diluents are: ether and ethereal compounds, for example diethyl ether, dipropyl ether, dioxane, dimethoxyethane and tetrahydrofurane; amides, such as N,N-dialkylated carboxamides; aliphatic, aromatic and halogenated hydrocarbons, especially benzene, toluene, xylenes, chloroform and chlorobenzene; nitriles, such as acetonitrile; dimethyl sulphoxide; and ketones, such as acetone and methyl ethyl ketone.

The starting materials of the formulae II to VII are known or they can be prepared by methods analogous to known ones.

The compounds of the formula I are in the form of a mixture of different optically active isomers if individual optically active starting materials are not used in the reaction. The different isomer mixtures can be separated into the individual isomers by known methods. The compound of the formula I is to be understood as comprising both the individual isomers and the mixtures thereof. The compounds of the formula I are suitable for controlling a variety of animal and plant pests. In particular, the compounds of the formula I are suitable for controlling insects, phytopathogenic mites and ticks, for example of the orders: Lepidoptera, Coleoptera, Homoptera, Heteroptera, Diptera, Acarina, Thysanoptera, Orthoptera, Anoplura, Siphonaptera, Mallophaga, Thysanura, Isoptera, Psocoptera and Hymenoptera.

In particular, the compounds of the formula I are suitable for controlling insects which are harmful to plants, especially insects which damage plants by eating, in ornamentals and crops of useful plants, especially in cotton plantations (e.g. Spodoptera littoralis and Heliothis virescens) and in vegetable crops (for example Leptinotarsa decemlineata and Myzus persicae).

The active compounds of the formula I also have a very good action against flies, for example Musca domestica and mosquito larvae.

The insecticidal and/or acaricidal action can be substantially broadened and adapted to prevailing circumstances by addition of other insecticides and/or acaricides. Examples of suitable additives include: organic phosphorus compounds, nitrophenols and derivatives thereof, formamidines, ureas, pyethroids, carbamates, and chlorinated hydrocarbons.

Compounds of the formula I are also combined with particular advantage with substances which exert a synergistic or potentiating effect on pyrethroids. Examples of such compounds include: piperonyl butoxide, propynyl ether, propynyl oximes, propynyl carbamates and propynyl phosphates, 2-(3,4-methylenedioxyphenoxy)-3,6,9-trioxaundecane (Sesamex or Sesoxane), S,S,S-tributylphosphorotrithioate, 1,2-methylenedioxy-4(2-(octylsulfinyl)-propyl)-benzene.

The compounds of the formula I may be used as pure active substance or together with suitable carriers and/or additives. Suitable carriers and additives can be solid or liquid and correspond to the substances conventionally used in the art of formulation, for example natural or regenerated substances, solvents, dispersants, wetting agents, tackifiers, thickeners, binders and/or fertilisers.

The compositions of the present invention are manufactured in known manner by homogeneously mixing and/or grinding active substances of the formula I with the suitable carriers, with or without the addition of dispersants or solvents which are inert to the active substances.

The compounds of the formula I may be processed to the following formulations:

Solid formulations:

Dusts, tracking powders and granules (coated granules, impregnated granules and homogeneous granules).

Liquid formulations:

(a) active substances which are dispersable in water: wettable powders, pastes and emulsions;

(b) solutions.

The content of active substance in the above described compositions is generally between 0.1% and 95%, though concentrations of up to 99.5% or even pure active substance can also be used if the compositions are applied from an aircraft or other appropriate application devices.

The compounds (active substances) of the formula I can, for example, be formulated as follows (throughout the present specification all parts and percentages are by weight):

Dusts

The following substances are used to formulate

(a)

a 5% and (b) a 2% dust:

(a)

5 parts of active substance,

95 parts of talc;

(b)

2 parts of active substance,

1 part of highly disperse silicic acid,

97 parts of talc.

The active substance is mixed with the carriers and ground.

Granules

The following substances are used to formulate 5% granules:

5 parts of active substance

0.25 parts of epichlorohydrin,

0.25 parts of cetyl polyglycol ether,

3.50 parts of polyethylene glycol,

91 parts of kaolin (particle size 0.3-0.8 mm).

The active substance is mixed with epichlorohydrin and the mixture is dissolved in 6 parts of acetone; the polyethylene glycol and cetyl polyglycol ether are then added. The resultant solution is sprayed on kaolin, and the acetone is subsequently evaporated in vacuo.

Wettable powders

The following constituents are used to formulate

(a)

a 40%, (b) and (c) a 25%, and (d) a 10% wettable powder:

(a)

40 parts of active substance,

5 parts of sodium dibutylnaphthalenesulfonate,

54 parts of silicic acid.

(b)

25 parts of active substance,

4.5 parts of calcium ligninsulfonate,

1.9 parts of Champagne chalk/hydroxyethyl cellulose mixture (1:1),

1.5 parts of sodium dibutylnaphthalenesulfonate,

19.1 parts of silicic acid,

19.5 parts of Champagne chalk,

28.1 parts of kaolin,

(c)

25 parts of active substance,

2.5 parts of isooctylphenoxy-polyoxyethyleneethanol,

1.7 parts of Champagne chalk/hydroxyethyl cellulose mixture (1:1),

8.3 parts of sodium aluminium silicate,

16.5 parts of kieselguhr,

46 parts of kaolin;

(d)

10 parts of active substance,

3 parts of a mixture of the sodium salts of saturated fatty alcohol sulfates,

5 parts of naphthalenesulphonic acid/formaldehyde condensate,

82 parts of kaolin.

The active substances are homogeneously mixed with the additives in suitable mixers and the mixture is then ground is appropriate mills and rollers. Wettable powders are obtained which can be diluted with water to give suspensions of the desired concentration.

Emulsifiable concentrates

The following substances are used to formulate (a) a 10%, (b) a 25% and (c) a 50% emulsifiable concentrate:

(a)

10 parts of active substance,

3.4 parts of epoxidised vegetable oil,

3.4 parts of a combination emulsifier consisting of fatty alcohol polyglycol ether and alkylarylsulfonates calcium salt,

40 parts of dimethyl formamide,

43.2 parts of xylene;

(b)

25 parts of active substance,

2.5 parts of epoxidised vegetable oil,

10 parts of alkylarylsulfonate/fatty alcohol polyglycol ether mixture,

5 parts of dimethyl formamide,

57.5 parts of xylene;

(c)

50 parts of active substance,

4.2 parts of tributylphenol-polyglycol ether,

5.8 parts of cylcium dodecylbenzenesulfonate,

20 parts of cyclohexanene,

20 parts of xylene.

By diluting these concentrates with water it is possible to obtain emulsions of the required concentration.

Sprays

The following ingredients are used to formulate (a) a 5% spray, and (b) a 95% spray:

(a)

5 parts of active substance,

1 part of epichlorohydrin,

94 parts of ligroin (boiling range 160°-190° C.);

(b)

95 parts of active substance,

5 parts of epichlorohydrin.

The invention is further illustrated by the following Examples.

EXAMPLE 1

Manufacture of 2-(1',2'-dibromo-2',2'-dichloroethyl)-spiro-[2,2]-pentanecarboxylic acid m-phenoxy-α-cyanobenzyl ester.

0.48 g of bromine is added at 0° to 5° C. to a solution of 1.2 g of the 2-dichlorovinyl-spiro-[2,2]-pentanecarboxylic acid ester of α-cyano-2-phenoxybenzyl alcohol in 25 ml of carbon tetrachloride. The mixture is stirred for 30 minutes at 0° C. and then for 10 hours at room temperature. The solvent is distilled off and the crude product is chromatographed on silica gel (eluant: hexane/diethyl ether 3:1), affording the compound of the formula ##STR4## in the form of viscous oil with a refractive index of n_D ⁴⁰ : 1.5751.

The following compounds are also prepared in analogous manner: ##STR5##

EXAMPLE 2

Insecticidal stomach poison action

Cotton plants were sprayed with a 0.05% aqueous emulsion of active substance (obtained from a 10% emulsifiable concentrate). After the spray coating had dried, the cotton plants were populated with Spodoptera littoralis and Heliothis virescens in the L₃ -stage. The test was carried out at 24° C. and 60% relative humidity. In this test, the compounds of Example 1 exhibited a good insecticidal stomach poison action against Spodoptera and Heliothis larvae.

EXAMPLE 3

Acaricidal action

Twelve hours before the test for acaricidal action, Phaseolus vulgaris plants were populated with an infested piece of leaf from a mass culture of Tetranychus urticae. The mobile stages which had migrated to the plants were sprayed with the emulsified test preparations from a chromatography atomiser in such a way that the spray broth did not run off. The number of living and dead larvae, adults and eggs was evaluated under a stereoscopic microscope after 2 and 7 days and the result expressed in percentage values. During the test run, the plants stood in greenhouse compartments at 25° C. In this test, the compounds of Example 1 acted against adults, larvae and eggs of Tetranychus urticae.

EXAMPLE 4

Action against ticks

(A) Rhipicephalus bursa

Five adult ticks and 50 tick larvae were counted into each of a number of test tubes and immersed for 1 to 2 minutes in 2 ml of an aqueous emulsion containing a concentration of 100, 10, 1 or 0.1 ppm of test substance. Each test tube was then sealed with a cotton-wool plug and placed on its head to enable the cotton wool to absorb the active substance emulsion. Evaluation of the action against adults was made after 2 weeks and of that against larvae after 2 days. Each test was repeated twice.

(B) Boophilus microplus (larvae)

Test were carried out with 20 OP-sensitive and 20 OP-resistant larvae using aqueous emulsions similar to those used in Test A. (The resistance refers to the tolerance towards diazinone). The compounds of Example 1 acted in these tests against adults and larvae of Rhipicephalus bursa and OP-sensitive and OP-resistant larvae of Boophilus microplus.