DE2110532A1 - O-(1-phenyl-4(1h)-oxo-6-pyridazinyl) (thio) phosphates - with insecticidal activity - Google Patents

Abstract

Cpds. of formula (I): (where X is halogen or alkoxy Y = O or S; R2 and R3 are 1 - 6C alkyl opt. substd. by halogen, or R2 + R3 is ethylene) are insecticides esp. active against adult and larval forms of diptera. Preferred are (I) where X = MeO, R2 = R3 = Et and Y = O or S. (I; Y = O) may be prepd. by reacting (II) with (III): (where W = halogen; R4 = alkyl). Cpds. (I) can also be prepd. by reacting an enol or alkali metal enolate of 1-Ph-5-X-pyridazine-4(5H), 6(1H)-dione with Cl(Y)P(OR2)OR3 in an inert solvent in the presence of an acid binder.

Description

Substituted Phosphoric Acid Esters The present invention relates to valuable new phosphoric acid esters, processes for their production, pesticides, which contain these active ingredients and methods for combating pests with these connections.

It is known to use 0,0-dimethyl-0 - () - chloro-4-nitrophenyl) phosphorothioate (Chlorothione) and O, O-diethyl-O- (, 4-tetramethylene-coumarinyl) -phosphorothioate (coumithoate) to use as a pest control agent. However, their effects are satisfactory not in all skins.

It has been found that new substituted phosphoric acid esters of the general formula wherein R1 is a phenyl radical, X is halogen (chlorine), alkoxy (methoxy), Y is oxygen or sulfur, Z is hydrogen and R2 and R5 are linear or branched alkyl radicals with 1 to 6 carbon atoms which can be substituted by halogen atoms (ethyl), or R2 and R5 together mean the ethylene residue, have a good effect against pests. The effect is particularly evident against adults and larvae of Diptera. They are therefore suitable for controlling pests, in particular house flies, fruit flies, vegetable flies of the genera Musca, Fannia, Ceratitis, Dacus, Drosophila, Mylemia, Psila or Calliphora.

The new phosphoric acid esters (with Y = 0) can be obtained by reacting an oxopyridazinone of the general formula 4 where R1, X and Z have the meanings given above and W is a halogenate Qm, with a trialkyl phosphite of the general formula: in which R2 and R3 have the meanings given above and R4 is an alkyl radical, are prepared.

The phosphoric esters can also be prepared by using the metal salt of a hydroxyl compound of the general formula as the pyridazinone component where R1, Z and X have the meanings given above and M is an alkali metal or alkaline earth metal, with a dialkylphosphoric acid chloride of the general formula in which Y, R2 and R5 have the meanings given above.

The sulfur-containing phosphoric acid esters are most conveniently prepared in such a way that a hydroxyl compound of the general formula is used in which R1, Z and X have the meanings given above, with a dialkylthiophosphoric acid chloride of the general formula in which R2 and R have the meanings given above, is reacted in the presence of an acid acceptor in an inert solvent.

For example in dimethylformamide, acetonitrile, dimethyl sulfoxide, Water; Benzene, toluene, xylene; Ketones such as acetone, methyl ethyl ketone, cyclohexanone; aliphatic esters such as ethyl acetate, methyl propionate, ethyl butyrate; Ether how Dioxane, tetrahydrofuran, di-n-butyl ether.

In this case, the reaction is carried out in the presence of a hydrogen chloride acceptor, for example an alkali carbonate.

The following examples illustrate the preparation of the new substituted Phosphoric acid ester.

Example 1 15 parts (parts by weight) 1-phenyl-6-oxo-5,5-dichloro-pyridazinone (4) are dissolved in 50 parts of benzene. For this purpose, 20 parts of triethyl phosphite are included added slowly with vigorous stirring. The mixture is wound under reflux boiled, then the solvent is removed in vacuo. The The residue is crystallized from absolute alcohol and 11.5 parts of the are obtained 1-Phenyl-5-chloro-6- (diethoxy-phosphonyloxy) -pyridazinons (a) as yellow crystalline Substance with a melting point of 5 to 56 ° C.

Example 2 24 parts of the sodium salt of 1-phenyl-6-hydroxy-5-methoxypyridazinone (4) are dissolved in 350 parts of dimethylformamide. There are 17.3 parts of diethylphosphoric acid chloride added slowly. The reaction mixture warms up to 5500. Thereafter is stirred for a further 22 hours at room temperature. Then it is filtered, -das The solvent was evaporated off in vacuo and the residue was dissolved in toluene. This solution is successively with 200 parts of 10% (wt.%) aqueous Na2CO3 solution and 200 parts of saturated aqueous saline solution. The organic phase is dried over CaC12, then the solvent is evaporated off in vacuo. When the viscous residue obtained in this way cools down, crystals form which after Washing with cold toluene and recrystallization from methanol 14 parts of l-phenyl-5-methoxy-6- (diethoxyphosphony1ccy) yridazinone (4), from melting point 85 to 8600.

Example 3 21.8 parts of 1-phenyl-6-hydroxy-5-methoxypyridazinone (4) are together with 10.6 parts of anhydrous sodium carbonate in 150 parts of dimethylformamide suspended. 18.9 parts of diethylthiophosphoric acid chloride are added to the mixture with stirring dripped in. A slight increase in temperature to around 300C occurs here. Afterward the reaction mixture is stirred for 22 hours at room temperature.

The solvent is then evaporated off in vacuo, the residue Dissolved in toluene, this solution successively with 200 parts of lOfiiger soda solution and Washed 200 parts of concentrated sodium chloride solution and finally the organic Phase concentrated to dryness.

The residue is recrystallized from methanol and 16.5 parts of 1-phenyl-5-methoxy-6- (diSthoxy-thiophosphonyloxy) -pyridazinone (4) with a melting point of 105 to 1070 ° C. are obtained. The following compounds can be prepared in a corresponding manner: -Phenyl-6-oxo-5,5-dichloropyridazinone (4) + trimethyl phosphite 1-Phenyl-5-chloro-6- (dimethoxyphosphonyloxy) -pyridazinone (4) M.p .: 75 to 760C 1-Phenyl-6-oxo-5,5-dichloro-pyridazinone (4) + 2-ethoxy-1,3 , 2-dioxaphospholane 1-Phenyl-5-chloro-6- (ß- ¢ chloroethoxy-ethoxyphosphonyl-oxy) -pyridazinone (4) M.p .: 73 to 740C 1-phenyl-6-hydroxypyridazinone (4) + diethylthiophosphoric acid chloride 1-phenyl-6- (diethoxy-thiophosphonyloxy) -pyridazinone (4) nD20 = 1.5036 1-phenyl-6-hydroxypyridazinone (4) + diethylphosphoric acid chloride 1-phenyl-6- (diethoxyphosphonyloxy) -pyridazinone (4) nD20 = 1.5129.

The agents according to the invention can be used as solutions, emulsions, suspensions or dusts are used. The forms of application depend entirely on the purposes of use; they should in each case a fine distribution of the effective Ensure substance.

Hydrocarbons can be used to produce solutions that can be sprayed directly with boiling points higher than 1500C, e.g. B. tetrahydronaphthalene or alkylated naphthalenes or organic liquids with boiling points higher than 1500C and one or more functional groups, e.g. B. the keto group, the Xthergruppe, the ester group or the amide group, this group being a substituent on a hydrocarbon chain stand or be part of a heterocyclic ring, as spray liquids 4 Aqueous application forms can be used from emulsion concentrates and pastes or wettable powders (wettable powders) can be prepared by adding water. To produce emulsions, the substances can be used as such or in a solvent dissolved, by means of wetting or dispersing agents, e.g. B. Polyethylene oxide addition products be homogenized in water or organic solvents. But it can also from active substance, Emulsifiers or dispersants and possibly Solvent-based concentrates are made for dilution with Water are suitable.

Dusts can be created by mixing or grinding together the effective Substances with a solid carrier, e.g. B. kieselguhr, talc, clay or fertilizers getting produced.

The active ingredients are used in such a way that the pests or the plants, animals or rooms to be protected from attack by pests be treated with the active ingredient.

The following active ingredients were used for the biological tests: (Example 2) (Example)) A comparison was made with. the known active ingredients: (Chlorothione) (Coumithoate) Effect on larvae of the vinegar fly (Drosophila melanogaster) The active ingredients are added to the nutrient medium, the development of the larvae at 240C is determined.

Result: Active substance content of the medium in active substance I 2.5 ppm inhibition over 90% II 2.5 ppm inhibition over 90 ffi III 7.5 ppm inhibition over 90% 2.5 ppm no inhibition of toxic effects on houseflies (Musca domestica) The active ingredients are incorporated into 100 mg milk sugar tablets that last 24 hours for 4 days old flies are offered as the only food.

Result: Active ingredient Content of active ingredient I 0.25 mg toxic in one tablet II 0.25 mg toxic IV 1.0 mg toxic 0.25 mg no effect The sample I was found also against other insects as a strong food poison.

In the case of the bedbugs Dysdercus intermedius, which are harmful to cotton crops In the experiment, the single treatment of cotton seeds with a 0.01% strength was sufficient aqueous emulsion of active ingredient I to kill all bedbugs.

Example 4 80 parts by weight of compound I are mixed with 20 Parts by weight of N-methyl - pyrrolidone and receives a solution that can be used in Form of the smallest drops is suitable.

Example 5 20 parts by weight of compound II are in a mixture dissolved that of 80 parts by weight of xylene, 10 parts by weight of the adduct from 8 to 10 moles of ethylene oxide to 1 mole of oleic acid-N-monoethanolamide, 5 parts by weight Calcium salt of dodecylbenzenesulfonic acid and 5 parts by weight of the adduct consists of 40 moles of ethylene oxide to 1 mole of castor oil. By pouring it in and distributing it finely the solution in 100,000 parts by weight of water gives an aqueous dispersion, which contains 0.02 percent by weight of the active ingredient.

Example 6 20 parts by weight of compound I are in a mixture dissolved, the 40 parts by weight of cyclohexanone, 30 parts by weight of isobutanol, 20 Parts by weight of the adduct of 7 moles of ethylene oxide and 1 mole of isooctylphenol and 10 parts by weight of the adduct of 40 moles of ethylene oxide and 1 mole of castor oil consists. By pouring the solution into 100,000 parts by weight and finely distributing it Water gives an aqueous dispersion containing 0.02 percent by weight of the active ingredient contains.

Example 7 20 parts by weight of compound II are in a mixture dissolved that of 25 parts by weight of cyclohexanol, 65 parts by weight of a mineral oil fraction from the boiling point 210 to 280 0C and 10 parts by weight of the adduct of 40 moles of ethylene oxide to 1 mole of castor oil. By pouring it in and distributing it finely the solution in 100,000 parts by weight of water gives an aqueous dispersion, which contains 0.02 percent by weight of the active ingredient.

Example 8 20 parts by weight of the active ingredient I are mixed with 3 parts by weight of the sodium salt of diisobutylnaphthalene-sirsulfonic acid, 17 parts by weight of the Sodium salt of a lignosulfonic acid from a Sulphite waste liquor and 60 parts by weight of powdered silica gel mixed well and placed in a hammer mill grind. By finely distributing the mixture in 20,000 parts by weight of water a spray mixture is obtained which contains 0.1 percent by weight of the active ingredient.

Example 9 5 parts by weight of compound II become 97 parts by weight finely divided kaolin intimately mixed. In this way a dust is obtained the) contains percent by weight of the active ingredient.

Example 10 30 parts by weight of compound I are mixed with a mixture from 92 parts by weight of powdered silica gel and 8 parts by weight of paraffin oil, which was sprayed onto the surface of this silica gel, intimately mixed. Man In this way, the active ingredient is prepared with good adhesion.

Claims (7)

Claims O Substituted phosphoric acid esters of the general formula wherein R1- is a phenyl radical, X is halogen or alkoxy, Z is hydrogen, Y is oxygen or sulfur and R2 and R) are linear or branched alkyl radicals with 1 to 6 carbon atoms which can be substituted by halogen atoms, or R2 and R3 together represent the ethylene radical mean. 2. Pesticides containing a solid or liquid Carrier and a compound according to claim 1. 3. Use of a compound according to claim 1 as a pesticide. 4. 1-Phenyl-5-methoxy-6- (diethoxyphosphonyloxy) pyridazinone (4). 5. i-Phenyl-5-methoxy-6- (diethoxythiophosphonyloxy) pyridazinone (4). 6. Process for the preparation of substituted phosphoric esters according to claim 1, characterized in that an oxopyridazinone of the general formula in which Z, X and R1 have the abovementioned meanings and W is halogen, with a trialkyl phosphite of the general formula in which R2 and R3 have the meanings given above and R4 is an alkyl radical. 7. A process for the preparation of substituted phosphoric esters according to claim 1, characterized in that a dialkyl phosphoric acid chloride of the general formula is used in which Y, R2, R3 have the meanings given above, with a compound of the general formula in which R1, Z and X have the meanings given above and M is hydrogen or an alkali metal or alkaline earth metal, is reacted in the presence of an acid acceptor in an inert solvent.