WO1994007864A1

WO1994007864A1 - Cyanophenylpyrazolines as pesticides

Info

Publication number: WO1994007864A1
Application number: PCT/EP1993/002714
Authority: WO
Inventors: Andreas Van Almsick; Holger Hoffmann; Annegrit Bosum-Dybus; Thomas Wegmann; Hartmut Joppien; Harald Von Keyserlingk
Original assignee: Schering Aktiengesellschaft
Priority date: 1992-10-05
Filing date: 1993-10-04
Publication date: 1994-04-14
Also published as: CN1085549A; IL107168A0; AU5149093A; DE4233835A1; ZA937381B; AP9300577A0

Abstract

Pyrazoline derivatives of general formula (I), in which R?1 and R2¿ are phenyl, optionally substituted by one or more of the same or different groups selected from cyano, halogen, nitro, C¿1-6?-alkyl, C1-6-alkoxy, halo-C1-6-alkyl or halo-C1-6-alkoxy, in which at least one of the phenyl groups is substituted by cyano; R?3¿ is phenyl or cyclohexyl, each of which is optionally substituted by one or more of the same or different groups selected from halogen, nitro, cyano, C¿1-6?-alkyl, C1-6-alkoxy, halo-C1-6-alkyl, halo-C1-6-alkoxy, C1-6-alkylsulfonyl, halo-C1-6-alkylsulfonyl or C1-6-alkoxycarbonyl; and R?4¿ is hydrogen, C¿1-6?-alkyl, halo-C1-6-alkyl, C1-6-acyl, C1-6-alkoxycarbonyl or halo-C1-6-alkoxycarbonyl, have insecticidal and acaricidal activity.

Description

CYANOPHENYLPYRAZOLINES AS PESTICIDES

Field of the invention

This invention relates to new pyrazoline derivatives, processes for their preparation, as well as their use as pesticides. Prior Art

1-Phenylcarbamoylpyrazolines with insecticidal activity are already well known. There are a number of patents describing such compounds, for example GB 1,514,285, EP 58 424, EP 113 213, EP 227 055 and EP 300 692. In all these patents, there are disclosed compounds in which there is a substituted phenyl group in the 3 and 4 positions of the pyrazoline ring. In GB 1,514,285, for instance, these phenyl groups may be substituted by a wide range of substituents including cyano. However no specific compounds are disclosed in which either phenyl carries a cyano group. In EP 300 692, a few compounds are disclosed in which the phenyl in the 3 position is substituted by 4-cyano. However in EP 300 692, the phenyl in the 4 position must be substituted by a carbonyl-, thiocarbonyl- or sulfonyl- containing group.

The disadvantage of many of the prior art compounds is the insufficient activity and/or high mammalian toxicity and we have now found that the novel group of compounds of the present invention overcome these disadvantages.

Description of the Invention

According to the invention there is provided a pyrazoline derivative of general formula I ,

in which

R¹ and R² are phenyl, optionally substituted by one or more of the same or different groups selected from cyano, halogen, nitro, C_1-6-alkyl, C_1-6-alkoxy, halo-C_1-6-alkyl or halo-C_1-6 alkoxy, in which at least one of the phenyl groups is substituted by cyano;

R³ is phenyl or cyclohexyl, each of which is optionally substituted by one or more of the same or different groups selected from halogen, nitro, cyano,

C_1-6-alkyl, C_1-6-alkoxy, halo-C_1-6-alkyl, halo- C_1-6-alkoxy, C_1-6-alkylsulfonyl, halo-C_1-6-alkylsulfonyl or C_1-6-alkoxycarbonyl; and

R⁴ is hydrogen, C_1-6-alkyl, halo-C_1-6-alkyl, C_1-6-acyl,

C_1-6-alkoxycarbonyl or halo-C_1-6-alkoxycarbonyl.

By the term "halogen" it is preferably understood to mean fluorine, chlorine or bromine.

By the term "acyl" are to be understood groups which are derived from acids with up to 6 carbon atoms, especially lower and intermediate aliphatic carboxylic acids. These acids may be unsaturated and/or branched and/or polybasic and/or substituted e.g. by hydroxy, amino or halo.

Examples are such acids are acetic acid, propionic acid, valeric acid, caproic acid, trimethylacetic acid,

haloacetic acid, dialkylaminoacetic acid and succinic acid.

The invention includes isomeric forms and as well as mixtures of isomers. Particularly preferred are compounds of formula I in which R¹ is 4-cyanophenyl, 4-fluorophenyl or

4-(2,2,2-trifluoroethoxy),

R² is phenyl, 4-cyanophenyl, 4-fluorophenyl- or

4-difluoromethoxy,

R³ is 4-difluoromethoxyphenyl, 4-trifluoromethylphenyl-,

4-trifluoromethoxyphenyl-,

4-(2,2,2-trifluoroethoxy)phenyl-, 4-chlorophenyl-,

4-cyanophenyl- or 4-trifluoromethylcyclohexyl, and R⁴ is hydrogen or methyl, especially hydrogen.

The compounds of the invention of general formula I, where R is hydrogen, can be prepared by reacting a pyrazoline of general formula II

with an isocyanate of general formula III

OCN - R³ (III)

in a solvent and optionally in the presence of a base, and if desired treating the resulting carbamoylpyrazoline in which R⁴ is hydrogen, with a compound of general formula

IV

R⁴-X (IV)

in which R⁴ is other than hydrogen and X is leaving group, such as halogen, especially chlorine, bromine or iodine, in the presence of an acid-binding agent and a solvent.

The solvent is one which is inert to the reactants, e.g aliphatic, alicyclic or aromatic hydrocarbons, which are optionally chlorinated, e.g. pentane, hexane, cyclohexane, petroleum ether, benzene, toluene, xylene,

dichloromethane, chloroform, carbon tetrachloride,

ethylene dichloride, trichloroethylene or chlorobenzene; ethers, such as diethyl ether, methyl ethyl ether,

diisopropyl ether, dibutyl ether, methyl tert. -butyl ether, dioxane or tetrahydrofuran; nitriles, such as acetonitrile, propionitrile or benzonitrile; esters, such as ethyl acetate or amyl acetate; amides, such as

dimethylformamide, N-methylpyrrolidone or

hexamethylphosphoric triamide, as well as sulfones, such as dimethyl sulfoxide or sulfolane.

Acid binding agents that can be used include aliphatic, aromatic and heterocyclic amine, e.g. triethylamine, dimethylaniline or pyridine, inorganic bases such as sodium or potassium carbonate, magnesium oxide, sodium hydroxide, sodium hydrogen carbonate or sodium hydride.

Both reactions can be carried out over a wide temperature range. In general, the reaction temperature lies between -20 and +100°C, preferably at however at room temperature,

The compounds of the invention prepared by these processes can be isolated from the reaction mixtures in conventional manner, for example by distillation of the solvent at normal or reduced pressure, by precipitation with water or by extraction. A higher level of purity can be achieved as a rule by column chromatography or recrystallisation.

The pyrazoline derivatives of the invention are colourless and odourless and in most cases are crystalline compounds. They have a low solubility in water and toluene, are more soluble in ethyl acetate and highly soluble in dimethylformamide

The preparation of the 3,4-dihydro-1H-pyrazoline of general formula II can be carried out in known manner for example as described in J. Agric. Food Chem. Vol. 25, No. 5, (1977) 987, J. Agric. Food Chem. Vol. 27, No. 2,

(1979), 406, J. Agric. Food Chem. Vol. 26, No. 4, (1978), 915; USP 4,439,440; EP-A 113 213; EP-A 058 424; USP

4,663,341; DE-A 3 628 647 and EP-A 286 346.

The compounds of the invention have insecticidal and acaricidal activity and are suitable for combating

parasites of humans and domestic animals as well as plant pests. Examples are Lepidoptera, such as Plutella

xylostella , Spodoptera littoralis, Heliothis armigera , Heliothis virescens and Pieris brassicae ; Diptera, such as Gaεterophiluε, Cochliomyia , Musca domestica , Ceratitis capitata , Erioischia brassicae , Lucilia sericata and Aedes aegypti ; Hemiptera, including aphids such as Megoura viciae and leafhoppers, such as Nilaparvata lugens and Nephotettix cincticeps ; Coleoptera, such as Phaedon cochleariae, Anthonomuε grandis and corn rootworms

(Diabrotica spp., e.g. Diabrotica undecimpunctata);

Orthoptera, such as Blattella germanica ; tioks, such as Boophiluε microplus and lice, such as Damalinia bovis and Linognathus vituli as well as mites such as Tetranychus urticae and Panonychuε ulmi . The compounds of the invention can be used either alone or in mixture with each other or another insecticide.

Optionally other plant protection or pesticidal

compositions, such as for example insecticides, acaricides or fungicides can be added depending on the desired result.

An improvement in the intensity and speed of action can be obtained, for example, by addition of suitable adjuvants, such as organic solvents, wetting agents and oils. Such additives may allow a decrease in the dose.

Suitable mixture partners may also include phospholipids, e.g. such as from the group phosphatidylcholine, hydrated phosphatidylcholine, phosphatidylethanolamine,

N-acyl-phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, lysolecithin or phosphatidylglycerol.

The designated active ingredients or their mixtures can suitably be used, for example, as powders, dusts,

granules, solutions, emulsions or suspensions, with the addition of liquid and/or solid carriers and/or diluents and, optionally, binding, wetting, emulsifying and/or dispersing adjuvants.

Suitable liquid carriers are, for example aliphatic and aromatic hydrocarbons such as benzene, toluene, xylene, cyclohexanone, isophorone, dimethyl sulfoxide,

dimethylformamide, other mineral-oil fractions and plant oils.

Suitable solid carriers include mineral earths, e.g.

tonsil, silica gel, talcum, kaolin, attapulgite,

limestone, silicic acid and plant products, e.g. flours. As surface-active agents there can be used for example calcium lignosulfonate, polyoxyethylenealkylphenyl ether, naphthalenesulfonic acids and their salts, phenolsulfonic acids and their salts, formaldehyde condensates, fatty alcohol sulfates, as well as substituted benzenesulfonic acids and their salts.

The percentage of the active ingredient(s) in the various preparations can vary within wide limits. For example, the compositions can contain about 10 to 90 percent by weight active ingredients, and about 90 to 10 percent by weight liquid or solid carriers, as well as, optionally up to 20 percent by weight of surfactant. The agents can be applied in customary fashion, for example with water as the carrier in spray mixture volumes of approximately 100 to 1,000 l/ha. The agents can be applied using low-volume or ultra-low-volume techniques or in the form of so-called microgranules.

The preparation of these formulations can be carried out in known manner, for example by milling or mixing

processes. Optionally, individual components can be mixed just before use for example by the commonly used so-called tank-mixing method.

Formulations can be prepared, for example, from the following ingredients.

A1 WETTABLE POWDER

80 percent by weight active ingredient

15 percent by weight kaolin

5 percent by weight of surfactant based on

of the sodium salt of N-methyl-N-oleyltaurine and calcium lignosulfonate

A2 WETTABLE POWDER

20 percent by weight active ingredient

35 percent by weight fuller's earth

8 percent by weight calcium lignosulfonate 2 percent by weight sodium salt of

N-methyl-N-oleyltaurine

35 percent by weight silicic acid

B PASTE

45 percent by weight active ingredient

5 percent by weight sodium aluminium silicate 15 percent by weight cetylpolyglycol ether with 8 moles ethylene oxide

2 percent by weight spindle oil

10 percent by weight polyethylene glycol

23 parts water

C EMULSIFIABLE CONCENTRATE

20 percent by weight active ingredient

75 percent by weight isophorone

5 percent by weight of a mixture of

ionic and nonionic surfactants The following examples illustrate the preparation of compounds according to the invention.

Preparation Example 1

4-(4-Cyanophenyl)-N-[4-(1,1-difluoromethoxy)phenyl]- 3-[4-(2,2,2-trifluoroethoxy)phenyl]-4,5-dihydropyrazole- 1-carboxamide

3.45 g (10 mmol) 4-(4-Cyanophenyl)-3-[4-(2,2,2-trifluoroethoxy)phenyl]-4,5-dihydropyrazole was dissolved in 35 ml methylene chloride and under anhydrous conditions, treated with stirring with 1.85 g (10 mmol) 4-(1,1-difluoromethoxy)phenyl isocyanate. The mixture was diluted with methylene chloride, washed twice with water and dried over magnesium sulfate. After removal of the solvent in a rotary evaporator, the residue was purified by silica gel column chromatography (ethyl acetate/hexane, 1:1).

Yield: 1.67 g, 32% of theory

colourless crystals, m.p. : 90-93°C

R_f = 0.80 (ethyl acetate)

Preparation Example 2

N,3-bis-(4-cyanophenyl)-4-(4-fluorophenyl)-N-methyl-4,5-dihydropyrazole-1-carboxamide

0.78 g (1.9 mmol) of N, 3-bis-(4-cyanophenyl)- 4-(4-fluorophenyl)-4,5-dihydropyrazole-1-carboxamide

(compound 10, prepared in a similar manner to Example 1) was dissolved in 16 ml absolute tetrahydrofuran and treated with with 0.07 g (2.33 mmol) 80% sodium hydride under anhydrous conditions. The mixture was stirred for about one hour at room temperature, then 0.15 ml (2.4 mmol) iodomethane added and the mixture heated under reflux for about one hour. It was then cooled, 10 ml water added and extracted with ethyl acetate. The crude product, obtained by concentration of the organic phases, The organic phase was dried over magnesium sulfate and

concentrated in a rotary evaporator. The product was separated from by-products by silica gel column

chromatography (diethyl ether/hexane, 3:1).

Yield: 0.22 g, 27% of theory

colourless crystals, m.p. : >200°C

R_f = 0.52 (ethyl acetate)

The following examples illustrate the possibilities for use of the compounds of the invention.

Test Example A

Activity against adult cotton boll-weevil (Anthonomus grandis)

The compounds of the invention were made up as aqueous preparations at a concentration of 0.1%. 0.2 ml of this preparation was pipetted onto feed material, in a

polystyrene petri dish and 0.2 ml onto the bottom of the petri dish. After drying, 5 adult (2 day old) cotton boll-weevils (Anthonomus grandis) were counted into the dishes . The closed dishes were left for up to 7 days at 25°C under extended daylight conditions. The % mortality of the weevils at the end of the test indicated the level of activity.

The compounds of Examples 1, 3-9, 11-15, 17-21 and 23-27 showed 80 - 100% activity.

Test Example B

Activity against larvae (L1) of the cotton bollworm

(Heliothis virescens)

polystyrene petri dish and 0.2 ml onto the bottom of the petri dish. After drying, 10 L1 of the cotton bollworm (Heliothis virescens) were counted into the dishes. The closed dishes were left for up to 7 days at 25°C under extended daylight conditions. The % mortality of the larvae at the end of the test indicated the level of activity. The compounds of Examples 1, 3-9, 11-15 and 17-27 showed 80 - 100% activity.

Use Example C

Activity in the prophylactic treatment of feed against the against black bean aphids (Aphis fabae Scop. )

From the primary leaf of field beans (Phaseolus vulgaris nanus Aschers.), 24 mm diameter discs were cut. Some of these were treated with a 0.1% aqueous preparations of the active ingredient and these alongside untreated discs were placed on wet filter papers with the underside of the leaves turned upwards. After drying the test pieces, they were each infested with wingless stages of Aphiε fabae (approx 30 per leaf piece) . The leaves were kept on wet filter papers for 6 days at 25°C and 16 hours light per day. The number of living insects at the end of the test was measured. The activity was calculated using Abbott's method in comparison with the untreated controls.

The compound of Example 14 showed 80 - 100% activity.

Use Example D

Activity in prophylactic treatment of leaves against brown rice-hoppers (Nilapairvata luαens Stå)

In a heated greenhouse, rice seedlings (about 15 per pot) were grown until formation of the third leaf and then sprayed until dripping wet with an aqueous preparation containing 0.1% of active material. After drying the spray coating, a transparent cylinder was placed over each pot. 30 Adult brown rice-hoppers (Nilaparvata lugens) were introduced into each pot. After 6 days at 25-26°C in the greenhouse and 16 hours light per day, the amount of dead hoppers was determined. The activity was calculated according to Abbott in comparison with several untreated control pots.

The compounds of Example 3, 5, 6, 7, 13, 14, 20 and 23 showed 80 - 100% activity.

Claims

1. Pyrazolines of general formula I

,

in which

R¹ and R² are phenyl, optionally substituted by one or more of the same or different groups selected from cyano, halogen, nitro, C_1-6-alkyl, C_1-6-alkoxy, halo-C_1-6-alkyl or halo-C_1-6-alkoxy, in which at least one of the phenyl groups is substituted by cyano;

R⁴ is hydrogen, C_1-6-alkyl, halo-C_1-6-alkyl, C_1-6-acyl,

C_1-6-alkoxycarbonyl or halo-C_1-6-alkoxycarbonyl.

2. Pyrazolines according to claim 1, in which

R¹ is 4-cyanophenyl, 4-fluorophenyl or

4-(2,2,2-trifluoroethoxy), R² is phenyl, 4-cyanophenyl, 4-fluorophenyl- or

4-difluoromethoxy,

R³ is 4-difluoromethoxyphenyl, 4-trifluoromethylphenyl-,

4-trifluoromethoxyphenyl-,

4-(2,2,2-trifluoroethoxy)phenyl-, 4-chlorophenyl-,

4-cyanophenyl- or 4-trifluoromethylcyclohexyl, and R⁴ is hydrogen or methyl.

3. An insecticidal and acaricidal composition which comprises a compound claimed in claim 1 or 2 in admixture with an agriculturally acceptable diluent or carrier.

4. Use of a compound claimed in claim 1 or 2 any one of the preceding claims, for combating insects or acarids.

5. A method of combating insects and acarids which comprises applying to the insect or acarid or their locus, an effective amount of a compound claimed in claim 1 or 2.