NO117670B - - Google Patents

Description

Insecticide preparation.

The present invention relates to an insecticidal preparation. Dutch patent no. 6410 413 describes substituted benz-iraidazoles with the general formula:

where. X is chlorine, bromine, nitro, cyan, amino, monoalkylamino and dialkylamino groups, R1 is hydrogen, alkyl, aryl or aralkyl, substituted or unsubstituted, and R is a mono- or polyhaloalkyl group, and it is indicated that such compounds have herbicidal and biocide own-Kfr. at 12p-9 and ;45 1-9/12

creates. However, the defined compounds are not suitable for insecticidal use. According to the present invention, it has been found that the compounds defined below, which have the group -CO(Z) R^ in the 1-position, are very active insecticides and are suitable for commercial use use as insecticides.

The present invention relates to an insecticidal preparation, characterized in that it consists of or contains as an active ingredient a substituted benzimidazole with the following formula:

where R 1 , R 2 , ' R-? > and Ir å. are the same or different and are chlorine, bromine, Ky/roj*», or nitro, where at least one of these substituents is different from hydrogen, and at most one of them is nitro, Z is oxygen or sulphur, n is 0 or 1, R^ is lower alkyl, lower alkenyl, phenyl or phenyl-lower alkyl, with R-* not being lower alkyl when Z is oxygen and n=1, as well as salts thereof.

The insecticidal preparation may also contain carriers, wetting compounds, inert and solid diluents, solvents, edible compounds to attract insects, colors and varnishes. The types of material that can be treated using preparation etch include any type that can be expected to be attacked by harmful organisms, and examples include woven fabrics, paper and wood.

The substituted benzimidazoles can be prepared using the general method where the benzimidazole of formula I, but where the lj position is unsubstituted, is reacted with a halide of the general formula:

where Hal represents a halogen such as e.g. chlorine, | ; in the presence of an acid acceptor. Usually, the reaction is carried out with the benzimidazole starting material in the form of an alkali metal salt or in the presence of an organic base.

In the case where Z is oxygen and n is 1, the reaction can e.g. produced as follows:

where R 1 , R 2 , R T , å. and r *S have the same meaning as stated above, and where the reaction is suitably carried out in the presence of a base such as potassium carbonate and a solvent such as e.g. acetone.

In the cases where n is 1 and Z is sulphur, the reaction can be prepared in a similar way as follows:

and suitable, is carried out in the presence of a base such as e.g. triethylamine.

In cases where n is zero, the reaction can be similarly represented as follows:

and suitable for use in the presence of a base such as e.g. triethylamine, as well as a solvent such as e.g. acetone.

The substituted benzimidazole can be incorporated into insecticidally active preparations in the usual way with or without wetting compounds and inert diluents.

If desired, they may be substituted benzimidazoles

dissolved in a solvent that is not miscible with water, such as e.g. a high-boiling hydrocarbon in which an emulsifying compound has been suitably dissolved, so that the hydrocarbon acts as a self-emulsifying oil when added to water.

The substituted benzimidazoles can further be mixed with a wetting compound with or without an inert diluent, so that a wettable powder is formed which is soluble or dispersible in water, or they can be mixed with an inert solvent so that a solid or powdery product is formed.

The substituted benzimidazoles and salts thereof can be incorporated into solid inert diluents in powdered or divided form, such as e.g. clay, sand, talc, mica*, fertilizers etc., regardless of whether such products are in powder form or consist of larger particles.

The wetting compounds that can be used include anionic compounds such as saps, fatty sulfate esters such as didecyl sodium sulfate, aromatic fatty sulfonates such as alkylbenzene sulfonates or butyl naphthalene sulfonate, more complex fatty sulfonates such as the amide condensation product of oleic acid and N-methyltaurine or dioctyl sodium sulfate -succinate.

The moisturizing compounds can further.; include non-ionic compounds such as the condensation products of fatty acids, fatty alcohols or fat-substituted phenols with ethylene oxide, • or fatty esters of sugars or polyalcohols, or the products obtained by condensing the latter compounds with ethylene oxide, or the products called block copolymers of ethylene oxide and propylene The wetting compounds may further include cationic compounds such as cetyl trimethylammonium bromide and the like.

The insecticidally active preparation according to the present invention can further, in addition to the substituted benzimidazoles or salts thereof, contain other physiologically active compounds such as herbicides (e.g. MCPA), insecticides (e.g. DDT), fungicides (e.g. copper derivatives) and slug killers. The preparation may also contain edible substances that attract insects, such as e.g. sugar, molasses and protein hydrolysates, preferably together with specific insect attractants.

The following examples are given to illustrate the invention.

Example 1

Slices (7 cm diameter) of cabbage leaves were brushed with 1 ml of an aqueous acetone solution of ethyl 4,5,6(5,6,7)trichloro-2-trifluoromethylbenzimidazol-1-thiolcarboxylate at concentrations corresponding to the use of 5 ,6, 1.12, 0.56, 0.28, 0.14, and 0.07 kg of active ingredient per hectare. After drying, each leaf disc was placed in a 9 cm diameter Petri dish, infested with ten larvae of the white cabbage moth Pieris brassicae, after which the dishes were covered with a glass lid. Three parallel experiments were carried out at each concentration level. After 48 hours, the leaves were examined and it was found that all the larvae at all concentration levels were dead. Corresponding larvae on untreated leaves were completely unaffected.

Example 2

An aqueous suspension containing 1 part of 1-acetyl-4,5,6-tri-chloro-2-trifluoromethylbenzimidazole in 1000 parts of water was prepared by diluting a 20% solution in acetone with a 0.05% solution of octyl-cresol polyethylene oxide condensate in water. This solution was in one

amount corresponding to 5^5 1-per hectare sprayed on young bonne plants

(Vicia fabae) which was attacked by mature aphids (Megoura viciae). After treatment, the plants were placed for 24 hours in glass cages with gas on top for ventilation, and an examination showed that all aphids had been killed

The compounds used in the present preparation are much more active than corresponding compounds where the nitrogen atom is unsubstituted. LD^q for 4,5i6-.trichloro-2-trifluoromethylbenzimidazole used on aphids (Megoura viciae) is thus e.g. 900 parts of connecting-. sen per 1 million parts of preparation, while on the other hand for l-ethylthiocarlonyl-

~4>5>6-trichloro-2-trifluoromethylbenzimidazole is 50 parts of compound

sen per 1 million parts of preparation. This means that the insecticidal activity of 1-ethylthiocarbonyl-4,5,6-trichloro-2-trifluoromethylbenzimidazole is more than 10 times greater than that of the corresponding compound which is unsubstituted in the 1-position.

The following further comparative experiments also show such superior activity for the compounds used in the present preparation:

Experiment 1 - Activity against mosquitoes (Åedes aegyptii)

Experiment 2 - Activity against larvae of the white cabbage butterfly (Pieris brassicae) Experiment 3 - activity against larvae of the white cabbage butterfly (Pieris brassicae) Experiment 4 - Activity against mosquitoes (Åedes aegyptii)

Claims (1)

Insecticidal preparation, characterized in that it consists of or contains as an active ingredient a substituted benzimidazole with the following formula: 12?A where R , R , RJ and R 4" are the same or different and are hydrogen, chlorine, bromine or nitro, where at least one of these substituents is different from hydrogen, and at least one of them is nitro, Z is oxygen or sulphur, n is 0 or 1, R^ is lower alkyl, lower alkenyl, phenyl or phenyl-lower alkyl, with R^ not being lower alkyl when Z is oxygen and n = 1, as well as salts thereof.