Field of the invention

This invention relates to new substituted

1-(4-isopropoxyphenylcarbamoyl)pyrazolines, to a process for their preparation and to their use as a pesticide, in particular as insecticides and acaricides.

Substituted pyrazolines with good activity against animal pests are known (e.g. EP 227 055) . Also certain l-(4-isopropoxyphenylcarbamoyl)pyrazcline derivatives have been known for a long time (DE 2 529 689) .

The known pyrazolines do, however, have the disadvantage that they have an activity spectrum which does not meet all the requirements for use as a pesticide or their environmental behaviour, such as soil persistence is not acceptable.

It has now been found that l-(4-isopropoxyphenyl- carbamoyl)pyrazolines of general formula I,

in which

X is C _j -Cg-alkoxy or C -Cg-haloalkoxγ, have improved activity compared with known pyrazolines.

It is very surprising and unpredictable that the new pyrazolines possess a considerable activity spectrum combined with increased environmental tolerance. Thus one finds a clearly increased target activity compared with the known l-(4-isopropoxyphenylcarbamoyl)pyrazolines and a clearly better environmental tolerance, eg in relation to degradation in the soil, in comparison with known pyrazolines of similar activity levels.

Under general formula I are all isomeric forms and as well as mixtures of isomers.

The pyrazoline derivatives of the invention of general formula I, can be prepared either by reacting a pyrazoline of general formula II

in which X has the meaning given above, with 4-isopropoxyphenyl isocyanate, optionally in the presence of a base, or by reacting a pyrazoline of general formula III

in which X has the meaning given above, with

4-isopropoxyaniline optionally in the presence of a base.

The reaction of compounds of formula II with 4-isopropoxyphenyl isocyanate, or the reaction of the compounds of formula III with 4-isopropoxyaniline are preferably carried out in an organic solvent or solvent mixture at a temperature from -20 to 150°C, preferably 20 to 90°C.

Suitable solvents are those which are 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.

Aliphatic, aromatic and heterocyclic amines such as e.g. triethylamine, dimethylaniline and pyridine may be cited as bases.

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 compounds of general formula II and III are known in

the literature or can be obtained by known processes.

The new compounds have a markedly pronounced effectiveness against animal pests, in particular against insects and spider mites. They show a considerably better insecticidal effectiveness against plant-damaging and mammal- parasitizing insects and spider mites compared with known compounds which are chemically and biologically closely related.

Based on their insecticidal and acaricidal activity they are thus suitable for combating parasites of humans, domestic animals and plants. Examples of such parasites are Lepidoptera, such as Plutella xylostella , Spodoptera littoralis , Heliothis armigera , Heliothis virescens and Pieris brasεicae ; Diptera, such as Gasterophilus, Cochlio yia, Musca domestica , Ceratitis capitata , Erioischia brassicae , Lucilia sericata and Aedes aegypti ; Hemiptera, including aphids such as Megoura viciae and leaf oppers, such as Nilaparvata lugens and Nephotettix cincticeps; Coleoptera, such as Phaedon cochleariae, Anthonomus grandis and corn rootworms (Diabrotica spp., e.g. Diabrotica undecimpunctata) ; Orthoptera, such as Blattella germanicaj ticks, such as Boophilus microplus and lice, such as Damalinia bovis and Linognathus vituli as well as mites such as Tetranychus urticae and Panonychus ulmi .

The compounds of the invention can be used either alone or in mixture with other insecticides. 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 active ingredient is suitably in the form of a preparation such as a powder, dust, granule, solution, emulsion or suspension, 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 composition can be applied in customary fashion, for example with water as the carrier in spray mixture volumes of approximately 100 to 3,000 1/ha. The agents can be applied using low-volume or ultra-low-volume techniques or in the form of so-called microgranules.

The compound of the invention can be used in active ingredient concentrations of from 0.005 to 5% by weight, preferably from 0.01 to 0.5% by weight.

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.

Al 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 of the invention.

Preparation example 1 (Process B)

4-(4-fluoropheny1)-N-(4-isopropoxyphen l) - 3-[4-(2,2,2-trifluoroethoxy)phenyl]-4,5-dihydropyrazole- 1-carboxamide

2.81 g (7 mmol) 4-(4-Fluorophenyl) -3-[4-(2,2,2-trifluoro¬ ethoxy)phenyl]-4,5-dihydropyrazole-l-carbonyl chloride was added to a solution of 2.11 g (14 mmol) 4-isopropoxy- aniline in 14 ml absolute pyridine which had been cooled to 0°C. The mixture was stirred at this temperature for 30 minutes, allowed to warm to room temperature, added to water and extracted with ethyl acetate. The organic phase was washed with 2M hydrochloric acid, water and aqueous sodium hydrogen carbonate, dried with magnesium sulfate and concentrated in a rotary evaporator. The crude product was chromatographically purified on silica gel using ethyl acetate/hexane (1:1) as eluent.

Yield: 2.53 g (70% of theory) as colourless crystals, m.p. : 175°C; Rf : 0.70 (silica gel/ethyl acetate)

Preparation example 2 (Process A)

4-(4-fluorophenyl)-N-(4-isopropoxyphenyl) -

3-[4-(2 , 2,2-trifluoroethoxy)phenyl]-4,5-dihydropyrazole-

1-carboxamide

4.42 g (13.06 mmol) 4-(4-Fluorophenyl) -

3-[4-(2, 2,2-trifluoroethoxy)phenyl]-4, 5-dihydropyrazole was dissolved in 20 ml absolute methylene dichloride and treated with a solution of 2.31 g (13.06 mmol) 4-isopropoxyphenyl isocyanate in 10 ml absolute methylene dichloride. The mixture was stirred for 30 minutes, concentrated in a rotary evaporator and the crude product

was chromatographically purified on silica gel using ethyl acetate/hexane (1:1) as eluent.

Yield: 3.64 g (54% of theory) as colourless crystals. m.p.: 175°C;

Rf : 0.70 (silica gel/ethyl acetate)

In a similar manner the following compounds of Formula I were obtained:

Example No X m.p. (°C)

3 -OCH ₃ 170

4 ^-0C 2 ^H 5 ¹²² 5 ^_0C 3 ^H 7 ¹²⁷

6 -OC ₄ H ₉ 141

7 -OC ₅ H _π 125

8 -OCH(CH ₃₎₂ 162

Test Example B

Activity aσainst adult cotton boll-weevil (Anthonomus σrandis)

Test Example A

Activity aσainst larvae CLll of the cotton bollworm (Heliothis virescens)

The compounds of the invention were made up as aqueous preparations at various concentrations. 0.2 ml of this preparation was pipetted onto feed material, in 5 polystyrene petri dishes. After drying, 10 LI cotton bollworms (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 weevils at the end of the test indicated the level of activity.

The compounds of Examples 1-8 showed 80 - 100% activity.

Test Example B

Activity aσainst adult cotton boll-weevil (Anthonomus σrandis)

The compounds of the invention were introduced as described above but with the addition that the bottom of the petri dish was also treated with 0.2 ml of the active ingredient preparation. After drying, 5 adult (2 day old) cotton boll-weevils (Anthonomus grandis) were counted into the dishes. The closed dishes were left as described above. The % mortality of the weevils at the end of the test indicated the level of activity.

The compounds of Examples 1-8 showed 80 - 100% activity.

Comparison test

Activity aσainst larvae fLl) of the cotton bollworm (Heliothis virescens)

Emulsifiable concentrates of the compounds were diluted with water to the desired concentration. In these active ingredient preparations, discs of feed material were dipped for 2 seconds and allowed to drip for 1 second. The so treated discs were each put in 5 polystyrene petri dishes and allowed to dry for 1 to 1.5 hours. In each dish 10 larvae (LI, 1 day old, unfed) of the cotton bollworm were placed on the feed material, the dishes were closed with lids and left for up under extended daylight conditions at a temperature of 25-30°C and 50-60% relative humidity.

After two and five days, the dead, injured and normal pests were counted and the % activity calculated according to the following equation:

2a+b

% Activity = x 100

2(a+b+c)

in which a = number of dead larvae b = number of injured larvae and c = number of normal larvae.

Compound ppm ai % activity % activity after after 2 days 5 days

Example 1

DE 25 29 689 Al page 12

Control

ai = active ingredient