DE4314037A1 - Nematicidal agents based on 2-dichloromethyl-1,3,4-oxadiazoles - Google Patents

Description

The invention relates to the use of partially known 2-dichloromethyl 1,3,4-oxadiazoles, new 2-dichloromethyl-1,3,4-oxadiazoles and process for their Manufacturing.

The synthesis of 2-dichloromethyl-1,3,4-oxadiazoles and their use as intermediate products are already known (see, for example, J. Heterocycl. Chem., 17 (4), 625-629, 1980; Bull. Soc. Chim. Fr., (3-4, Pt. 2), 333-336, 1977; Tetrahedron Lett., (23), 2333-2335, 1972; J. Org. Chem., 33 (5), 2076-2078, 1968). Your use However, it is not known as a pesticide.

It is also known that certain 2-dichloromethyl-1,3,4-oxadiazoles in herbicides Mixtures added as an antidote (cf. US 4,488,897) or 5 - [(4,5,6,7-tetrahydro- 2H-isoindol-1,3-dion-2-yl) phenyl] -1,3,4-oxadiazoles can be used as herbicides can (see JO 1139581), but nothing is known about their effectiveness as nematicides known.

It was found that the partially known 2-dichloromethyl-1,3,4-oxadiazoles of the general formula (I)

in which
X stands for a direct bond or for one of the following groupings

-O-, -S-, -S (O) -, -SO₂-, -NH- or -NR²-

R¹ represents alkyl, cycloalkyl, aryl, aralkyl, heteroaryl, which can optionally be substituted,
R² represents optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted aryl or optionally substituted hetaryl or
R¹ and R² together with the nitrogen atom to which they are attached form a cycle,
possess insecticidal, nematicidal and acaricidal properties.

Surprisingly, the 2-dichloro to be used according to the invention show methyl-1,3,4-oxadiazole an extraordinarily good nematicidal and acaricidal activity totality.

Unless otherwise defined, the following preferably means in the general formulas:
Alkyl - straight-chain or branched alkyl having preferably 1 to 20, particularly preferably 1 to 15 and very particularly preferably 1 to 12 carbon atoms. Examples of optionally substituted methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-butyl, i-butyl, t-butyl, n-pentyl, i-pentyl and undecyl may be mentioned.
Cycloalkyl - unsubstituted or substituted cycloalkyl with preferably 3 to 8, in particular 3.5 or 6 carbon atoms. Unsubstituted or substituted cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and cycloheptyl may be mentioned as examples.
Aryl - Unsubstituted or substituted aryl, preferably having 6 to 10 carbon atoms in the aryl part. Examples include unsubstituted or substituted phenyl or naphthyl, especially phenyl.
Heteroaryl - unsubstituted or substituted 5- to 9-membered ring, in particular 5- to 7-membered ring, which contains 1 to 4, preferably 1 to 3, identical or different heteroatoms. Oxygen, sulfur and nitrogen are preferred as heteroatoms. Exemplary and preferred are pyrimidinyl, pyrrolyl, isothiazolyl, oxazolyl, thienyl, furyl, pyridazinyl, pyrazinyl, isoxazolyl, thiazolyl, pyridyl, imidazolyl, benzimidazolyl.

The optionally substituted radicals of the general formulas can carry one or more, preferably 1 to 3, in particular 1 or 2 identical or different substituents. Examples of preferred substituents are:
Cyano; Halogen, preferably fluorine, chlorine and bromine, iodine, especially fluorine, chlorine and bromine; Haloalkoxy and haloalkylthio, and their oxides, with preferably 1 to 4, in particular 1 or 2, carbon atoms and preferably 1 to 9, in particular 1 to 5, halogen atoms, the halogen atoms being identical or different and preferably being fluorine, chlorine or bromine as halogen atoms, in particular fluorine, such as trifluoromethoxy, trifluoroethoxy, difluoromethoxy, pen tafluoroethoxy, tetrafluoroethoxy, trifluorochloroethoxy, trifluoromethylthio; Alkoxy preferably having 1 to 4, in particular 1 or 2, carbon atoms, such as methoxy, ethoxy, n- and i-propyloxy and n-, i-, sec.- and t-butyloxy; Alkylthio, and their oxides, preferably having 1 to 4, in particular 1 or 2 carbon atoms such as methylthio, ethylthio, n- and i-propylthio and n-, i-, sec.- and t-butylthio; unsubstituted or substituted alkenyl stands for straight-chain or branched alkenyl with preferably 2 to 10, particularly preferably 2 to 8 and in particular 2 to 6 carbon atoms, halogen, preferably fluorine, chlorine, bromine, iodine, in particular fluorine, chlorine and bromine, as the substituent comes; unsubstituted or substituted cycloalkyl having preferably 3 to 8, in particular 3, 5 or 6 carbon atoms, in particular cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and cycloheptyl, halogen, preferably fluorine, chlorine, bromine, iodine, in particular fluorine, chlorine and bromine being mentioned as the substituent be; in each case unsubstituted or substituted aryl, aryloxy or arylthio, where aryl as such or in connection with aryloxy or arylthio represents an aromatic radical having 6 to 10 carbon atoms, preferably phenyl or naphthyl, particularly preferably phenyl; unsubstituted or substituted hetaryl, which represents a 5- to 9-membered ring, in particular a 5- to 7-membered ring, which contains 1 to 4, preferably 1 to 3, identical or different heteroatoms. Oxygen, sulfur and nitrogen are preferred as heteroatoms. Examples include pyrimidinyl, pyrrolyl, isothiazolyl, oxazolyl, thienyl, pyridazinyl, pyrazinyl, isoxazolyl, thiazolyl, pyridyl and imidazolyl. Also suitable as substituents for alkyl are one of the following groups:

where R¹ has the meanings listed above.

Examples of substituents for cycloalkyl which may be mentioned are: optionally substituted alkyl, alkoxy, alkylthio, in each case unsubstituted or substituted aryl, aryloxy or arylthio.

These cycloalkyl substituents correspond in their respective meaning to the ent speaking definitions given above as substituents.

The substituents for aryl and hetaryl are exemplary and preferably those the above and additionally optionally substituted alkyl, if appropriate substituted aryl or hetaryl listed.

These aryl and hetaryl substituents correspond in their respective meaning to corresponding definitions given above as substituents for alkyl. Furthermore, one of the following comes as a substituent for aryl and hetaryl Groupings in question:

R¹-X-; -COOR¹; -COR¹

in which
R¹ and X have the meanings given above.

Formula (I) provides a general definition of the 2-dichloromethyl-1,3,4-oxadiazoles to be used according to the invention. Preferred compounds of the formula (I) are those
X stands for a direct bond or for one of the following groupings

-O-, -S-, -S (O) -, -SO₂-, -NH- or -NR²-

R¹ represents optionally substituted C₁-C₁₅-alkyl, optionally substituted C₃-C Cycl-cycloalkyl, optionally substituted phenyl or optionally substituted heteroaryl,
R² represents optionally substituted C₁-C₁₅ alkyl, optionally substituted C₃-C₈ cycloalkyl, optionally substituted phenyl or optionally substituted heteroaryl and
the substituents for alkyl, cycloalkyl, phenyl and hetaryl each have the meanings given above or
R¹ and R² together with the nitrogen atom to which they are attached form a 5- or 6-membered cycle.

Those compounds of formula (I) which are particularly preferred
X is a direct bond or represents oxygen, sulfur or a group -NH- or -NCH₃- and
R¹ is methyl, ethyl, n-propyl, i-propyl, n-butyl, sec.-butyl, i-butyl, t.-butyl, i-pentyl, hexyl, undecyl, methoxy, ethoxy, methylthiomethyl, trifluoromethyl, cyclopropyl , Cyclohexyl, 9-dodecenyl, undecenyl; furthermore for each unsubstituted or single, double or triple, identical or different phenoxymethyl, phen oxyethyl or 2-phenoxyethyl substituted by chlorine or methoxy; furthermore for phenyl, benzyl, phenyl, furyl, pyridyl, imidazolyl, benzimidazolyl or isoxazolyl substituted by methyl, ethyl, t-butyl, chlorine, trifluoromethyl, methoxy, ethoxy or phenyl, each unsubstituted or single, double or triple, identical or different; for one of the following heterocycle residues:

stands.

Compounds of the formula (I) in which
X is a direct bond or represents oxygen and sulfur and
R¹ represents optionally substituted alkyl having 1 to 6 carbon atoms, the following being suitable as substituents: halogen, in particular fluorine and / or chlorine; optionally substituted alkenyl with 1 to 6 carbon atoms, the substituents being alkyl or halogen, in particular fluorine or chlorine; optionally substituted cycloalkyl having 3 to 6 carbon atoms, the substituents being in particular alkyl substituents and alkoxy substituents and haloalkyl and haloalkoxy substituents having 1 to 4 carbon atoms; optionally substituted aryl, in particular optionally substituted phenyl with 1 to 2 substituents defined in aryl; optionally substituted phenoxy, phenylthio with in particular 1 to 2 substituents defined in aryl; by optionally with alkyl, alkoxy and alkylthio with 1 to 6 carbon atoms, haloalkyl, haloalkoxy, haloalkylthio with 1 to 4 carbon atoms such as. As trifluoromethyl, trifluoromethoxy or trifluoromethylthio and 1,2-oxazole, thiazole, pyridyl and furyl substituted by halogen, in particular chlorine and fluorine;
furthermore stands for optionally substituted phenyl, where halogen, in particular chlorine, fluorine; Alkyl with 1 to 6 carbon atoms such. B. methyl, ethyl, propyl, isopropyl, butyl, t-butyl; Alkoxy and alkylthio with 1 to 6 carbon atoms such as. B. methoxy, ethoxy, i-propoxy, methylmercapto; Haloalkyl with 1 to 4 carbon atoms such as. B. dichloromethyl, trifluoromethyl; Halogenalkoxy with 1 to 4 carbon atoms such. B. trifluoromethoxy; Haloalkylthio with 1 to 4 carbon atoms such. B. trifluoromethylthio and their oxides such. B. trifluoromethylsulfonyl, phenyl and phenoxy with the above-mentioned substituents;
furthermore stands for optionally substituted pyridyl, furyl, 1,2-oxazolyl, thiazolyl or pyrimidinyl, the substituents here being halogen, alkyl, alkoxy, alkylthio, haloalkyl, haloalkoxy, haloalkylthio and their oxides and optionally 1 to 2 times substituted substituents Phenyl and phenoxy come into question.

In particular, in addition to the Ver mentioned in the production examples bonds the following 2-dichloromethyl-1,3,4-oxadiazoles of the general formula (I) called:

Table 1

The 2-dichloromethyl-1,3,4-oxadiazoles of For mel (I) are known in some cases (see: J. Heterocycl. Chem. 17 (4), 625-629, 1980; Bull. Soc. Chim. Fr., (3-4, Pt. 2), 333-336, 1977; Tetrahedron Lett., (23), 2333-2335, 1972; J. Org. Chem., 33 (5), 2076-2078, 1968; US 4,488,897 and JO 1139581).

2-dichloromethyl-1,3,4-oxadiazoles of the formula (I ′) are not yet known

in which
X and R¹ have the meaning given above,
except the following connections:
2- (dichloromethyl) -5- (3,5-dichlorophenyl) -1,3,4-oxadiazole,
2- (dichloromethyl) -5- (3-nitrophenyl) -1,3,4-oxadiazole,
2- (dichloromethyl) -5- (4-nitrophenyl) -1,3,4-oxadiazole,
2- (dichloromethyl) -5- (2,4-dichlorophenyl) -1,3,4-oxadiazole,
2- [5- (dichloromethyl) -1,3,4-oxadiazol-2-yl] phenol,
2- (dichloromethyl) -5-phenyl-1,3,4-oxadiazole,
2- (dichloromethyl) -5- (1H-pyrrol-2-yl) -1,3,4-oxadiazole,
2- [5- (dichloromethyl) -1,3,4-oxadiazol-2-yl] -1H-indole and
2,5-bis (dichloromethyl) -1,3,4-oxadiazole.

The compounds of formula (I ') thus defined are new and the subject of Invention.

The as yet unknown 2-dichloromethyl-1,3,4-oxadiazoles are obtained after a of the procedures described below when one

• A) compounds of the formula (II) in which
  R¹ and X have the meaning given above, optionally cyclized in the presence of a diluent and in the presence of a water-releasing agent
  or if you
• B) hydrazides of the formula (III) in which
  R¹ and X have the meaning given above,
  with 2,2-dichloro-N- (1-methylethyl) ethanimidoyl chloride of the formula (IV) optionally cyclized in the presence of a solvent.

If, for example, N- (4-chlorobenzoyl) -N '- (dichlor acetyl) hydrazine and inorganic acid chlorides, such as phosphorus oxychloride as a water-releasing agent, the course of the reaction of Represent manufacturing process (A) by the following formula:

Variant: (A-1)

For example, N'-dichloroacetyl-6-chlorine is used as the starting material nicotinic acid hydrazide and polyphosphoric acid (PPA) as water-releasing agent, so can the course of the reaction of the production process (A) by represent the following formula:

Variant: (A-2)  

For example, if N-benzoyl-N ′ - (dichloroacetyl) - hydrazine and p-toluenesulfonic acid as water-releasing agent, so the Reaction course of the production process (A) by the following formula represent:

Variant: (A-3)

For example, if N- (4-chlorobenzoyl) -N'- is used as the starting material (dichloroacetyl) hydrazine and organic acid chlorides as water-releasing agents, such as dichloroacetyl chloride, the course of the reaction of Her represent position procedure (A) by the following formula:

Variant: (A-4)  

If one uses, for example, as a starting material (3-methylaminosulfonyl) - benzoyl hydrazide and 2,2-dichloro-N- (1-methylethyl) ethanimidoyl chloride, so lets the course of the reaction of the production process (B) is shown by the following For show melschema:

The required to carry out the manufacturing process (A) as starting materials Formula (II) generally defines compounds. In this formula (II) R¹ and X are preferably those meanings which are already in the Description of the substances of formula (I) to be used according to the invention as were preferred for these radicals.

Most of the compounds of the formula (II) are known or can be modified according to known processes can be produced in a simple, analogous manner (cf. e.g. Tetrahedron Lett., (23), 2333-2335, 1972; Bull. Soc. Chim. Fr., (3-4, Pt. 2), 333-336, 1977; J. Heterocycl. Chem., 17 (4), 625-629, 1980; Justus Liebigs Ann. Chem., (3), 504-522, 1974).

To carry out the manufacturing process (B) as starting materials required hydrazides are generally defined by the formula (III). In this Formula (III) R¹ and X and n preferably represent those meanings that already in the description of the substances to be used according to the invention Formula (I) were mentioned as preferred for these radicals.

The compounds of formula (III) are generally known compounds of organic chemistry.  

The to carry out the method (B) according to the invention as The required starting material is 2,2-dichloro-N- (1-methylethyl) ethanimidoyl chloride also known (US 4,781,752).

The processes (A) and (B) according to the invention for the preparation of the new 2-dichloromethyl-1,3,4-oxadiazoles of the formula (I) can be prepared in the usual manner generally known methods are carried out in which the compounds of formula (II) or (III) in an inert organic solvent, such as for example toluene, 1,2-dichlorobenzene, xylene or dimethylacetamide Temperatures between 20 ° C and 170 ° C, preferably 30 ° C and 140 ° C, optionally on the water separator, with a water-releasing agent, such as for example phosphorus oxychloride, polyphosphoric acid, p-toluenesulfonic acid, 2,2-dichloro-N- (1-methylethyl) ethanimidoyl chloride or dichloroacetyl chloride heated (see manufacturing examples).

The active ingredients are suitable for controlling animal pests, preferably nematodes and acarids, which are used in agriculture, in forests as well occur in the hygiene sector. They are normally sensitive and resistant Species as well as against all or individual stages of development. To the above The pests mentioned include in particular:

From the order of Acarina z. B. Acarus siro, Argas spp., Ornithodoros spp., Dermanyssus gallinae, Eriophyes ribis, Phyllocorptruta oleivora, Boophilus spp., Rhipicephalus spp., Amblyomma spp., Hyalomma spp., Ixodes spp., Psoroptes spp., Chorioptes spp., Sarcoptes spp., Tarsonemus spp., Bryobia praetiosa, Panonychus spp., Tetranychus spp.

The active compounds according to the invention act not only against plant, hygiene and Pests, but also against the veterinary sector animal parasites (ectoparasites and endoparasites) such as tick ticks, Leather ticks, room mites, running mites, flies (stinging and licking), parasitic fly larvae, lice, hair lice, featherlings, fleas and endoparasitic worms. For example, they show excellent Efficacy against ticks, such as Boophilus microphus.  

The active compounds according to the invention are notable for high nematicidal and acaricidal effectiveness.

They can be used with particularly good success to control soil insects, such as for example, use Diabrotica balteata larvae. They are also suitable excellent for combating nematodes, such as Meloidogyne incognita.

The active compounds according to the invention also show leaf-insecticidal activity.

The active ingredients can be converted into the usual formulations, such as Solutions, emulsions, wettable powders, suspensions, powders, dusts, pastes, soluble powders, granules, suspension emulsion concentrates, active ingredient impregnated natural and synthetic materials as well as very fine encapsulation in polymeric fabrics.

These formulations are prepared in a known manner, e.g. B. by Mixing the active ingredients with extenders, i.e. liquid solvents and / or solid carriers, optionally using surface-active agents, ie emulsifiers and / or foam-generating agents Means.

In the case of the use of water as an extender, e.g. B. also organic Solvents are used as auxiliary solvents. As a liquid solvent essentially come into question: aromatics, such as xylene, toluene or Alkylnaphthalenes, chlorinated aromatics and chlorinated aliphatic Hydrocarbons, such as chlorobenzenes, chlorethylenes or methylene chloride, aliphatic hydrocarbons, such as cyclohexane or paraffins, e.g. B. Petroleum fractions, mineral and vegetable oils, alcohols such as butanol or Glycol and their ethers and esters, ketones such as acetone, methyl ethyl ketone, Methyl isobutyl ketone or cyclohexanone, strongly polar solvents, such as Dimethylformamide and dimethyl sulfoxide, as well as water.  

The following are suitable as solid carriers: e.g. B. ammonium salts and natural rock powders such as kaolins, clays, Talc, chalk, quartz, attapulgite, montmorillonite or diatomaceous earth and synthetic stone powder, such as highly disperse silica, aluminum oxide and Silicates, as solid carriers for granules come into question: z. B. broken and fractionated natural rocks such as calcite, marble, pumice, sepiolite, dolomite as well as synthetic granules from inorganic and organic flours and Granules made of organic material such as sawdust, coconut shells, corn cobs and tobacco stems; come as emulsifying and / or foam-generating agents in question: e.g. B. non-ionic and anionic emulsifiers, such as polyoxyethylene Fatty acid esters, polyoxyethylene fatty alcohol ethers, e.g. B. alkylaryl polyglycol ether, Alkyl sulfonates, alkyl sulfates, aryl sulfonates and protein hydrolyzates; when Dispersants come into question: z. B. Lingnin sulfite and methyl cellulose.

In the formulations, adhesives such as carboxymethyl cellulose, natural and synthetic powdery, granular or latex-shaped polymers are used such as gum arabic, polyvinyl alcohol, polyvinyl acetate, and natural Phospholipids such as cephalins and lecithins and synthetic phospholipids. Other additives can be mineral and vegetable oils.

Dyes such as inorganic pigments, e.g. B. iron oxide, titanium oxide, Ferrocyan blue and organic dyes such as alizarin, azo and Metal phthalocyanine dyes and trace nutrients such as salts of iron, manganese, Boron, copper, cobalt, molybdenum and zinc can be used.

The formulations generally contain between 0.1 and 95% by weight Active ingredient, preferably between 0.5 and 90%.

The active compounds according to the invention can be used as such or in their formulations also used in a mixture with known herbicides for weed control find, where ready formulations or tank mixes are possible.  

A mixture with other known active ingredients, such as fungicides, Insecticides, acaricides, nematicides, bird repellants, Plant nutrients and soil structure improvers are possible.

The active substances can be used as such, in the form of their formulations or in the form thereof application forms prepared by further dilution, such as ready-to-use Solutions, suspensions, emulsions, powders, pastes and granules are used become. The application is done in the usual way, e.g. B. by pouring, spraying, Spray, sprinkle.

The active compounds according to the invention can be used both before and after emergence of the plants are applied.

They can also be worked into the soil before sowing.

The amount of active ingredient used can vary over a wide range. they depends essentially on the type of effect desired. In general the application rates are between 0.01 and 10 kg of active ingredient per hectare Soil area, preferably between 0.05 and 5 kg per ha.

The preparation and use of the active compounds according to the invention is based on following examples.

Manufacturing examples example 1

Variant (A-1)

To a suspension of 0.7 g (0.0025 mol) of N- (4-chlorobenzoyl) -N ′ - (dichloroacetyl) - hydrazine in 20 ml of xylene, 1.53 g (0.01 mol) of phosphorus oxychloride are added dropwise and the batch heated at 130 ° C for 8 hours. Then allowed to room temperature cool, wash with 20 ml water and dry over sodium sulfate. After this Distilling off the solvent gives 0.5 g (75% of theory) 2-dichloromethyl-5- (4-chlorophenyl) -1,3,4-oxadiazole, melting point mp 128 ° C.

Variant (A-4)

To a solution of 0.7 g (0.0025 mol) of N- (4-chlorobenzoyl) -N ′ - (dichloroacetyl) - hydrazine in 20 ml of dimethylacetamide become 0.3 ml (0.003 mol) Dichloroacetyl chloride was added dropwise and the mixture was stirred at 40 ° C. for 12 hours. The approach 200 ml of water are added dropwise at 5 ° C. Then with 100 ml Extracted dichloromethane, the organic phase dried over sodium sulfate and the solvent removed in vacuo.

330 mg (50% of theory) of 2-dichloromethyl-5- (4-chlorophenyl) -1,3,4- oxadiazole, melting point mp 128 ° C.  

Example 2

Variant (A-2)

In 50 g of polyphosphoric acid at 70 ° C to 80 ° C within 30 minutes 14.1 g (0.05 mol) of N'-dichloroacetyl-6-chloronicotinic acid hydrazide in portions worn and stirred for 7 hours at 80 ° C. To the reaction mixture at 0 ° C ice and then 150 ml of dichloromethane. The fancy Precipitate is filtered off, the organic phase is washed with water and then dried over sodium sulfate. After evaporating off the solvent, one obtains a crystalline residue, which is triturated in ether. The so obtained Crystal mash is suctioned off and dried.

10.9 g (82% of theory) of 2-dichloromethyl-5- (2-chloropyridin-5-yl) -1,3,4- are obtained. oxadiazole, melting point mp 170 ° C.  

Example 3

Variant (A-3)

3.8 g (0.02 mol) of p-toluenesulfonic acid monohydrate are dissolved in 100 ml of absolute Toluene is heated on the water boiler until the water it contains is completely removed. 4.94 g (0.02 mol) of N-benzoyl are added to this suspension. N '- (dichloroacetyl) hydrazine given. The reaction mixture is at 3 hours Heated at 110 ° C on a water separator, at room temperature with 100 ml of water washed and the organic phase dried over sodium sulfate. After this Distilling off the solvent in vacuo gives 1.3 g (28.3% of theory) 2-dichloromethyl-5-phenyl-1,3,4-oxadiazole, melting point mp 84 ° C.  

Example 4

Variant (B)

6.9 g (0.03 mol) of (3-methylaminosulfonyl) benzoyl hydrazine are dissolved in 100 ml Toluene suspended. 7.5 g (0.0398 mol) of 2,2-dichloro-N- (1-methylethyl) - ethane-imidoyl chloride and the reaction mixture at 110 ° C for 15 hours Water separator heated. It is then filtered and the filtrate with 100 ml Washed water, dried over sodium sulfate and the solvent in Vacuum removed. The residue obtained is stirred with ether and suction filtered.

1.4 g (14.7% of theory) of 2-dichloromethyl-5- (3-methylaminosulfonyl) are obtained phenyl) -1,3,4-oxadiazole, melting point mp 164 ° C.  

Analogous to preparation examples 1 to 4 and according to the general information The processes listed in Table 2 are obtained for the processes according to the invention Compounds of the general formula (I)

Table 2

Examples of use Example A Limit concentration test / soil insects

Test insect: Diabrotica balteata - larvae in the soil
Solvent: 4 parts by weight of acetone
Emulsifier: 1 part by weight of alkylaryl polyglycol ether

To produce a suitable preparation of active compound, mix 1 Part by weight of active ingredient with the specified amount of solvent gives the specified amount of emulsifier and dilute the concentrate with water to the desired concentration. The concentration of the active ingredient plays in the Preparation practically does not matter, the decisive factor is the active ingredient alone amount of weight per unit volume of soil, which is in ppm. (mg / l) is given. The bottom is filled into 0.5 l pots and left at 20 ° C.

Immediately after the preparation, 5 pre-germinated corn kernels are laid out per pot. To The appropriate test insects are placed in the treated soil for 1 day. After a further 7 days, the effectiveness of the active ingredient is determined by counting the dead and live test insects determined in%. The efficiency is 100% if all test insects are killed, it is 0%, if exactly as many test insects live like the untreated control.

In this test, for example, compound 15 according to the invention showed one excellent effectiveness.  

Example B Limit concentration test

Test nematode: Meloidogyne incognita
Solvent: 4 parts by weight of acetone
Emulsifier: 1 part by weight of alkylaryl polyglycol ether

To produce a suitable preparation of active compound, mix 1 Part by weight of active ingredient with the specified amount of solvent gives the specified amount of emulsifier and dilute the concentrate with water to the desired concentration.

The active ingredient preparation is intimately mixed with the soil, which with the Test nematodes is heavily contaminated. The concentration of the active ingredient plays in the preparation is practically irrelevant, the decisive factor is the amount of active ingredient per unit volume of soil, which is given in ppm (= mg / l). You fill it treated soil in pots, seeds lettuce and keeps the pots at one Greenhouse temperature of 25 ° C.

After four weeks, the lettuce roots are attacked by nematodes (root galls) examined and the efficiency of the active ingredient determined in%. The efficiency is 100% if the infestation is as high as that of the control plants in untreated but contaminated soil in the same way.

In this test, for example, the active ingredients 1, 2, 3, 7, 8, 10 and 15 excellent effectiveness.  

Example C Test with Boophilus microplus resistant / SP-resistant Parkhurst strain

Solvent: 35 parts by weight of ethylene glycol monomethyl ether
35 parts by weight of nonylphenol polyglycol ether

Three are mixed to produce a suitable preparation of active compound Parts by weight of active ingredient with seven parts by weight of the above Solvent mixture and dilute the concentrate thus obtained with water the desired concentration.

10 adult Boophilus microplus become resistant in the one to be tested Active ingredient preparation immersed for 1 minute. After checking in plastic cups and Storage in an air-conditioned room determines the degree of killing.

100% means that all ticks have been killed; 0% means that none Ticks were killed.

In this test, for example, compound 15 according to the invention showed a very good effect.

Claims (9)

1. Use of 2-dichloromethyl-1,3,4-oxadiazoles of the general formula (I) in which
X represents a direct bond or one of the following groupings -O-, -S-, -S (O) -, -SO₂-, -NH- or -NR²-R¹ represents alkyl, cycloalkyl, aryl, aralkyl, heteroaryl, which may be substituted,
R² is optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted aryl or optionally substituted hetaryl or
R¹ and R² together with the nitrogen atom to which they are attached,
form a cycle as insecticides, nematicides and acaricides. 2. Use according to claim 1, characterized in that compounds of formula (I), in which
X stands for a direct bond or for one of the following groupings -O-, -S-, -S (O) -, -SO₂-, -NH- or -NR²-R¹ for optionally substituted C₁-C₁₅ alkyl, optionally substituted ized C₃-C₈ cycloalkyl, optionally substituted phenyl or optionally substituted heteroaryl,
R² stands for optionally substituted C₁-C₁₅-alkyl, optionally substituted ₃-C₈-cycloalkyl, optionally substituted phenyl or optionally substituted heteroaryl or
R¹ and R² together with the nitrogen atom to which they are attached form a 5- or 6-membered cycle can be used. 3. Use according to claim 1, characterized in that compounds of formula (I), in which
X is a direct bond or represents oxygen, sulfur or a group -NH- or -NCH₃- and
R¹ for methyl, ethyl, n-propyl, i-propyl, n-butyl, sec.-butyl, i-butyl, t.-butyl, i-pentyl, hexyl, undecyl, methoxy, ethoxy, methylthiomethyl, trifluoromethyl, cyclopropyl, Cyclohexyl, 9-dodecenyl, undecenyl; furthermore for each unsubstituted or single, double or triple, identically or differently substituted by chlorine or methoxy, phenoxymethyl, phenoxyethyl or 2-phenoxyethyl; furthermore for phenyl, benzyl, phenyl, furyl, pyridyl, imidazolyl, benzimidazolyl or isoxazolyl substituted by methyl, ethyl, t-butyl, chlorine, trifluoromethyl, methoxy, ethoxy or phenyl, each unsubstituted or single, double or triple, identical or different; for one of the following heterocycle residues: stands, are used. 4. Use according to claim 1, characterized in that compounds of formula (I), in which
X represents a direct bond or oxygen and sulfur and
R¹ represents optionally substituted alkyl having 1 to 6 carbon atoms, the following being suitable as substituents: halogen, in particular fluorine and / or chlorine; optionally substituted alkenyl having 1 to 6 carbon atoms, the substituents being alkyl or halogen, in particular fluorine or chlorine; optionally substituted cycloalkyl having 3 to 6 carbon atoms, the substituents being in particular alkyl substituents and alkoxy substituents and haloalkyl and haloalkoxy substituents having 1 to 4 carbon atoms; optionally substituted aryl, in particular special optionally substituted phenyl with 1 to 2 substituents defined in aryl; optionally substituted phenoxy, phenylthio with in particular 1 to 2 substituents defined in aryl; by optionally with alkyl, alkoxy and alkylthio with 1 to 6 carbon atoms, haloalkyl, haloalkoxy, haloalkylthio with 1 to 4 carbon atoms such as. As trifluoromethyl, trifluoromethoxy or trifluoromethylthio and 1,2-oxazole, thiazole, pyridyl and furyl substituted by halogen, in particular chlorine and fluorine;
furthermore stands for optionally substituted phenyl, with halogen, in particular chlorine, fluorine; Alkyl with 1 to 6 carbon atoms such. B. methyl, ethyl, propyl, isopropyl, butyl, t-butyl; Alkoxy and alkylthio with 1 to 6 carbon atoms such as. B. methoxy, ethoxy, i-propoxy, methylmercapto; Haloalkyl with 1 to 4 carbon atoms such as. B. dichloromethyl, trifluoromethyl; Halogen alkoxy with 1 to 4 carbon atoms such as. B. trifluoromethoxy; Halo genalkylthio with 1 to 4 carbon atoms such. B. trifluoromethylthio and their oxides such. B. trifluoromethylsulfonyl, phenyl and phenoxy with the above-mentioned substituents come into question;
furthermore stands for optionally substituted pyridyl, furyl, 1,2-oxazolyl, thiazolyl or pyrimidinyl, the substituents here being the halogen, alkyl, alkoxy, alkylthio, haloalkyl, haloalkoxy, haloalkylthio and their oxides and optionally 1 to 2 times substituted phenyl Phenyl and phenoxy come into question
be used. 5. Insecticides, nematicides, acaricides characterized by a content of 2-dichloromethyl-1,3,4-oxadiazoles of the formula (I) according to Claims 1 to 4. 6. methods of controlling harmful insects, nematodes or acarinae, characterized in that 2-dichloromethyl-1,3,4-oxadiazoles according to Claims 1 to 4 on insects, nematodes or acarinae or their Living space. 7. Process for the production of insecticides, nematicides or acaricides Agents, characterized in that 2-dichloromethyl-1,3,4-oxadiazoles according to claims 1 to 4 with surfactants and stretch or Diluents mixed. 8. 2-dichloromethyl-1,3,4-oxadiazoles of the formula (I ') in which
X and R¹ have the meaning given above,
except the following connections:
2- (dichloromethyl) -5- (3,5-dichlorophenyl) -1,3,4-oxadiazole,
2- (dichloromethyl) -5- (3-nitrophenyl) -1,3,4-oxadiazole,
2- (dichloromethyl) -5- (4-nitrophenyl) -1,3,4-oxadiazole,
2- (dichloromethyl) -5- (2,4-dichlorophenyl) -1,3,4-oxadiazole,
2- [5- (dichloromethyl) -1,3,4-oxadiazol-2-yl] phenol,
2- (dichloromethyl) -5-phenyl-1,3,4-oxadiazole,
2- (dichloromethyl) -5- (1H-pyrrol-2-yl) -1,3,4-oxadiazole,
2- [5- (dichloromethyl) -1,3,4-oxadiazol-2-yl] -1H-indole and
2,5-bis (dichloromethyl) -1,3,4-oxadiazole. 9. A process for the preparation of the new 2-dichloromethyl-1,3,4-oxadiazoles of the formula (I ') according to claim 8, characterized in that

• A) compounds of the formula (II) in which
  R¹ and X have the meaning given in claim 8,
  optionally cyclized in the presence of a diluent and in the presence of a water-releasing agent
  or that one
• B) hydrazides of the formula (III) in which
  R¹ and X have the meaning given in claim 8,
  with 2,2-dichloro-N- (1-methylethyl) ethanimidoyl chloride of the formula (IV) optionally cyclized in the presence of a solvent.