NO753096L - - Google Patents

Description

. Pyridazinyl(thiono)(thiol)phosphorus(phosphono)-

acid esters or -esteramides and their use as insecticides and acaricides.

The invention relates to new pyridazinyl(thiono)-(thiol).phosphorus (phosphonic) acid esters resp. -esteramides and their use as insecticides and acaricides.

It is already known that 0,0-dialkyl-O-pyridazinylthiophosphoric acid esters, e.g. O/_ -1-phenyl-1,6-dihydro-6-oxo-pyridazin(3)yl7- resp. 0-/_~ 1-hydroxymethyl-1,6-dihydro-."6-oxo-pyridazin(3)yl../~j0-V 1-(N,N-dimethylaminomethyl)-1,6-dihydro-6 -oxo-pyridazin(3)yl7 and 0-/~1-(p-methylphenyl)-1,6-dihydro-6-oxo-pyridazine (3 )yJL/-0,0-diethylthiophosphoric acid residues have insecticidal and acaricidal properties _/ compare US Patent No. 2,759-937, Published Application No. 20,025/72 and Journal of Organic Chemistry, Volume 26, No. 9 (1961), page 338233867.

It has now been found that the new pyridazinyl(thiono)

(thiol)-phosphorus (phosphonic) acid esters resp. -ester amides of formula

in which

R means alkyl with 1 to 6 carbon atoms,

R' means phenyl, alkyl with 1 to 4, alkoxy with

1 to 6, alkylthio with 1 to 6, mono- or dialkylamino with 1 to 4 carbon atoms per alkyl chain,

R" and

R"' can be the same or different and mean

1

hydrogen or methyl.and

IV

RIV means' hydrogen, halogen, nitro or haloalkyl with 1 to 3 carbon atoms, while

n means a hero. numbers from 1 to M and X means an oxygen or sulfur atom,

has strong insecticidal and acaricidal properties.

The new^. pyridazinyl (thiono) (thiol) phosphorus (phosphon) - acid esters resp. -ester amides with constitution (I) are obtained when (thiono)(thiol)-phosphorus (phosphonic)-acid ester halides resp.

-ester amide halides of formula

in which.

R, R' and X have the above meaning and

Hal means a halogen atom,

-"is reacted with 1-phenyl-3_hydroxy-1,6-dihydro-pyridazinone(6) derivatives of formula

in which

R and n have the above meaning,

optionally in the presence of a dissolving or diluting agent and optionally in the presence of acid-binding agents.

Surprisingly, pyridazinyl(thiono)(thiol)phosphorus (phosphonic) acid esters resp. -ester amides according to the invention have a better insecticidal and acaricidal effect than the previously known 0,O-diethyl-0-pyridazinyl-thionophosphoric acid ester derivatives of analogous constitution and the same direction of action.

The new substances are therefore effective not only against plant-damaging insects and mites, but also against hygiene and storage pests and in the veterinary medical sector against animal ectoparasites, e.g. parasitizing fly larvae. Thus, the new compounds lead to an enrichment of the technique.

If one uses, for example, 0-ethyl-O-sec.-butyl-thiono-phosphoric acid diester chloride and 1-(3 5 5-bis-trifluoromethyl-phenyl)-3-hydroxy-6-oxo-pyridazine as starting materials, then the course of the reaction can be reproduced by the following formula core:

The starting materials to be used are unambiguously generally defined with the formulas II and III.

Preferably means here, however

R straight or branched alkyl with 1 to 5, especially 1 to 4 carbon atoms,

R' phenyl, linear or branched alkyl with 1. to 3j especially 1 and 2, straight or branched alkoxy or alkylthio with each 1 to 5, especially 1 to 4, mono-'resp. dial-. chylamino with 1 to 3, especially 1 and 2 carbon atoms per alkyl chain,

R" and R"' hydrogen or .'methyl,

R"1""^ hydrogen, . halogen, especially chlorine, nitro or haloalkyl, especially trifluoromethyl,

n means 1 to 3S especially 1 and

X oxygen or sulphur.

The (thiono) (thiol)-phosphorus (phosphonic)-acid ester halides that can be used as starting materials resp. -ester amide halides (II) are known and can be prepared according to methods known in the literature, as well as the 1-phenyl-3-hydroxy-1,6-dihydro-6-oxo-pyridazine derivatives (III), which can, for example, be prepared still from the correspondingly substituted phenylhydrazines, -dissolved in dilute hydrochloric acid by reaction with maleic anhydride according to the following scheme:

wherein R^<V>and n have the above-mentioned meanings.

1

As examples for (thiono)(thiol)phosphorus (phosphonic) acid ester^halides resp. -esteramide halides to be reacted must be mentioned in detail: 0,0-dimethyl-, 0,0-di.ethyl 1-, 0,O-di-n-propyl-, 0,O-di-isopropyl- , 0,0-di-n-butyl-, 0,0-di-iso-butyl-, 0,0-di-sec-butyl-, 0,0-di-tert-butyl-, 0-ethy1 -0-n-propyl-, 0-ethyl-O-iso-propyl-, O.-n-butyl-0-ethyl-,• 0-ethyl-O-sec-butyl- and O-ethyl-0-methyl phosphoric acid diester chloride and the corresponding thione analogs.

0-methyl-, 0-ethyl-, 0-n-propyl-, 0-iso-propyl-, 0-n-butyl-j 0-sec.-butyl-, 0-iso-butyl- and 0-tert. -butyl-mefean- resp. -ethane-, n-propane-, -iso-propane- and -phenylphosphonic acid ester chloride and the corresponding thione analogues.

0,S-dimethyl-, 0,S-diethyl-, 0,S-di-n-propyl-, 0,S-di-isopropyl-, 0 ,S-di-n-butyl-, 0,S-di -iso-butyl-, 0, S-di.-tert-butyl-, 0-ethyl-S-n-propyl-, 0-ethyl-S-iso-propyl-, 0-ethyl-S-n-butyl-, 0- ethyl-S-sec.-butyl-, 0-n-propyl-S-ethyl-, 0-n-propyl-S-iso-propyl-, 0-n-butyl-S-n-propyl- and 0-sec.- butyl-S-ethylthiol phosphoric acid diester chloride and the corresponding thio analogues.

0-methyl-N-methyl-, 0-ethyl-N-methyl-, 0-n-propyl-N-methyl-, 0-iso-propyl-N-methyl-, 0-n-butyl-N-methyl- , 0-sec-butyl-N-methyl-, 0-methyl-N-ethyl-, 0-ethyl-N-ethy 1-, 0-^n-propyl-N-ethyl-, 0-iso-propyl- N-ethyl-, 0-n-butyl-N-ethyl-, 0-sec-butyl-N-ethyl-, 0-methyl-N-n-propyl-, 0-ethyl-N-n-propyl-, 0-n- propyl-N-n-propyl-, O-iso-propyl-N-ethyl- and O-tert-butyl-N-ethyl-phosphoric acid ester amide chloride, the corresponding thiono analogues and the corresponding dialkylamides.

As examples of applicable 1-phenyl-3-hydroxy-1,6-dihydro-6-oxo-pyridazine derivatives (III) the following should be mentioned in detail: 1- (2- or 3-trifluoromethyl-, 3,5~bis- trifluoromethyl-, 2-trifluoromethyl-4-chloro-, 2-chloro-5~trifluoromethyl-, 2-nitro-4-trifluoromethyl-, 6-chloro-3~trifluoromethylphenyl)-3-hydroxy-1,6-dihydro-6 -oxo-pyridazine, further the corresponding 4- and/or ,5-methyl derivatives.

The method for producing the compound according to the invention is preferably carried out with the co-use of a suitable solvent and diluent. As such, practically all inert organic solvents come into question. This includes particularly aliphatic and aromatic, 1

optionally chlorinated hydrocarbons such as benzene, toluene, xylene, benzine, methylene chloride, chloroform, carbon tetrachloride, chlorobenzene or ethers, e.g. diethyl and dibutyl ether, dioxane, further ketones, e.g. acetone, methylethyl, methylisopro -pyl- and methyl isobutyl ketone, also nitriles such as aceto- and propionitrile.

As acid acceptors it can be used

all common acid binders. In particular, alkali carbonates and alcoholates, such as sodium and potassium carbonate, sodium and potassium methylate or -ethylate, further aliphatic, aromatic or heterocyclic amines, for example triethylamine, trimethylamine, dimethylaniline, dimethylbenzylamine and pyridine. '

The reaction temperature can be varied within a large range. Usually one works between 0 and 120°C, preferably at 40 to 60°C.

To carry out the method, the starting substances are generally used in equimolar proportions. An excess of one or the other component usually does not entail any significant advantages. The turnover is carried out preferably

in the presence of one of the above-mentioned solvents, optionally in the presence of an acid acceptor at the indicated temperatures. After one to several hours of reaction time, mostly at elevated temperatures

temperatures, the reaction mixture is cooled to room temperature, an organic solvent is added, e.g.

toluene and works up the organic phase according to usual methods, e.g. washing, drying and distillation.

The new compounds often appear in the form of oils which, for the most part, cannot be distilled unbroken, however, by so-called "over-distillation", i.e. by prolonged heating under reduced pressure at slightly elevated temperatures, the last volatiles can be freed parts and in this way cleaned. The refractive index serves for their characterization. In part, the products are also available in crystalline form; in this case they can be characterized by their melting point.

As has already been mentioned several times, pyridazinyl (thiono) (thiol) phosphorous (phosphori) acid esters resp. -esteramides according to the invention with an outstanding insecticidal and acaricidal effect. They not only work against plant, hygiene and storage pests, but also in the veterinary-medical sector against animal parasites (ectoparasites), such as parasitizing fly larvae. J)e has a low phytotoxicity as well as a good effect against sucking as well as biting insects such as mites.

For these reasons, the compound according to the invention is used with results in plant protection as well as in the hygiene, storage protection and veterinary sectors as pest control agent-1.

For the economically important agricultural and forestry sectors. storage, material and hygiene pests belong: From the order Isopoda, e.g. Oniscus asellus, Armadillidium vulgare, Porcellio scaber.

From the order Diploda e.g. Blaniulus guttulatus.

From the order Chilopoda e.g. Geophilus carpophagus, Scutigera spee.

From the order Symphyla e.g. Scutigerella immaculata.

.From the order Arachnida e.g. Scorpio maurus, Latrodectus mactans. From the order Acarina e.g. Acarus siro, Argas reflexus, Ornithodoros moubata, Dermanyssus ga.llinae, Eriophyes ribis, Phyllocoptruta oleivora, Boophilus microplus, Rhipicephalus evertsi, Sarcoptes scabiei, Tarsonemus spee. Bryobia praetiosa, Panonychus citri, Panonychus ulmi, Tetranychus telarius, Tetranychus tumidus, Tetranychus urticae. From the order Thysanura e.g. Lepisma saccharina.

From the order Collembola e.g. Onychiurus armatus..

From the order Orthoptera e.g. Blatta orientalis, Periplaneta americana, Leucophaea maderae, Blattella germanica, Acheta domesticus, Gryllotalpha spee., Loeusta migratoria migratorio-ides, Melanoplus differentialis, Schistocerca gregaria.

From the order of Dermaptera e.g. Forficula auricularia.

From the order of Isoptera e.g. Reticulitermes spee.

From the order of Anoplura e.g. Phylloxera vastatrix, Pemphigus spee., Pediculus humanus corporis.

From the order of Thysanoptera e.g. Hercinothrips femoralis, Thrips tabaci..

From the order of Heteroptera e.g. Eurygaster spee., Dysdercus intermedius, Piesma quadrata, Cimex lectularius, Rhodnius pro-lixus, Triatoma spee.

From the order of Homoptera e.g. Aleurodes brassicae, Bemisia tabaci, Trialeurodes vaporariorum, Aphis gossypii, Brevicoryne brassicae, Cryptomycus ribis, Doralis fabae, Doralis pomi, Erio-

soma lanigerum, Hyalopterus arundinis, Macrosiphum avenae,

Myzus cerasi, Myzus persicae, Phorodon humuli, Rhopalosiphum

padi, Empoasca spee. Eusc_elis bilobatus,' Nephotettix cincticeps, Lecanium corni, Saissetia oleae, Laodelphax striatellus, Nila-parvata lugens, Aonidiella' aurantii, Aspidiotus hederae, Pseu^-dococcus spee, Psylla spee.

From the order of Lepidoptera e.g. Pectinophora gossypiella, Bupalus piniarius, Cheimatobia brumata, Lithocolletis blancar-della, Hyponomeuta padella, Plutella maculipennis, Malacosoma neustria, Euproctis chrysorrhoea,. Lymantria spee., Bucculatrix thurberiella, Phyllocnistis citrella, Agrotis spee., Euxoa spee., Feltia spee., Earias insulana, Heliothis spee., Laphygma exigua, . Mamestra brassicae, Panolis flammea, Prodenia litura, Spodop-tera spee., Trichoplusia ni, Carpocapsa pomonella, Pieris spee., Chilo spee., Pyrausta nubilalis, Ephestia kiihniella, Galleria mellone.lla, Cacoecia podana, Capua reticulana, Choristoneura fumiferana, Clysia ambiguella, Homona magnanima, Tcrtrix viri-dana.

From the order of Coleoptera e.g. Anobium punctatum, Rhizopertha dominica, Bruchidius obtectus, Acanthoscelides obtectus, Hylo-trupes bajulus, Agelastica alni, Leptinotarsa decemlineata, Phaedon cochleariae, Diabrotica spee., Psylliodes. chrysocephala, Epilachna varivestis, Atomaria spee., Oryzaephilus surinamensis,

Anthonomus spee., Sitophilus spee., Otiorrhynchus sulcatus, C.smopolites sordidus, Ceuthorrhynchus assimilis, Hypera postica,

Dermestes spee., Trogoderma spee., Anthrenus spee., Attagenus spee., Lyctus spee., Meligethes aeneus, Ptinus spee., Niptus hololeucus, Gibbium psylloides, Tribolium spee., Tenebrio moli-•tor, Agriotes spee., Conoderus spee. , Melolonfeha melolontha, Amphimallus solstitialis, Costelytra zealandica.

From the order of Hymenoptera e.g. Diprion spee., Hoplocampa spee., Lasius spee., Monomorium pharaonis, Vespa spee.

From the order of Diptera e.g. Åedes spee., Anopheles spee.,

Culex spee., Drosophila melanogaster, Musea domestica, Fannia spee., Stomoxys calcitrans, Hypoderma spec., Bibio hortulans, Oscinella frit, Phormia spee., Pegomyia hyoscyami, Calliphora erythrocephala, Lucilia spee., Chrysomyia spee., Ceratitis capi-tata, Dacus oleae, Tipula paludosa.

From the order of Siphonaptera e.g. Xenopsylla cheopis.

1

The active substances can be transferred in the

formulations such as solutions, emulsions, spray powders, suspensions, powders, nebulizers, foams, pastes, soluble powders, granules, aerosols, suspension emulsion concentrates, seed powders, active substance-impregnated natural and synthetic substances, fine encapsulations in polymeric substances and in casing materials for seeds, further in the formulations of burning kits such as smoking cartridges, boxes, spirals and the like as well as ULV cold and hot fogging formulations.

These formulations are prepared in a known manner, e.g. by mixing the active substances with emulsifiers, i.e. liquid solvents, pressurized liquefied gases and/or solid carriers, optionally1 using surface-active agents, i.e. emulsifiers and/or dispersants and/or foam-producing needles. In the case of using water as a suspending agent, it can e.g. organic solvents are also used as auxiliary solvents. As a liquid solvent, these are essentially: Aromatics such as xylene, toluene, benzene or alkylnaphthalenes, chlorinated aromatics or chlorinated aliphatic hydrocarbons such as chlorobenzenes, chloroethylenes or methylene chloride, aliphatic hydrocarbons such as cyclohexane or paraffins, e.g. petroleum fractions, alcohols such as butanol. or glycol as well as their ethers and esters, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone or cyclohexane.one, strongly polar solvents such as dimethylformamide and dimethyl sulfoxide as well as water; by liquefied gaseous suspending agents or carriers are meant such liquids which are gaseous at normal temperature and under normal pressure, e.g. aerosol propellants, such as halogenated hydrocarbons; as solid carriers: natural rock flour such as kaolin, clay, talc, chalk, quartz, attapulgite, montmorillonite or diatomaceous earth and synthetic rock flour such as highly dispersed silicic acid, alumina and silicates; as emulsifying and/or foaming agents: non-ionic and anionic emulsifiers such as polyoxyethylene fatty acid esters, polyoxyethylene fatty alcohol ethers, e.g. alkyl aryl polyglycol ethers, alkyl sulphonates, alkyl sulphates, aryl sulphonates and egg white hydrolysates; as dispersants: e.g. lignin,

■sulphite lye and methyl cellulose. The active substances according to the invention can be present in the formulation in admixture with others

known active substances.

The formulations usually contain between 0.1

and 95% by weight of active substance, preferably between 0.5% and 90%.

The active substances can be used as such

in the form of their formulations or the application forms prepared therefrom. The application takes place in the usual way, e.g.

by showering, spraying, fogging, atomizing, scattering, smoking, gassing, pouring, pickling or encrusting.

The active substance concentrations in the ready-to-use preparations can be varied within large areas. Usually it is between 0.0001 and 10% } preferably between 0.01 and 1%.

The active substances can also be used with good results in the Ultra-Low-Volume method (ULV), where it is possible to deliver formulations up to 95% or even the active ingredient alone.

When used against hygiene and storage pests, the active substances are distinguished by an outstanding residual effect on wood and clay as well as good alkali stability on limed substrates.

Example A.

Plutella sample.

Solvent: 3 parts by weight of acetone.

Emulsifier: 1 part by weight alkylaryl polyglycol ether.

To prepare a suitable active substance preparation, 1 part by weight of active substance is mixed with the indicated amount of solvent and the indicated amount of emulsifier and the concentrate is diluted with water to the desired concentration.

With the effective substance preparation, cabbage leaves (Brassica oleracea) are sprayed with dew and infested with larvae of the cabbage moth (Plutella maculipennis).

After the specified times, the extinction is determined in

%. Here - 100$ means that all larvae were eradicated, 0% means that no larvae were eradicated.

Active substances, active substance concentrations, assessment times and results appear in the following table 1.

T

Example B. Laphygma sample.

Solvent: 3 parts by weight of acetone.

Emulsifier: 1.weight part alkylaryl polyglycol ether.

To prepare a suitable active substance preparation, 1 part by weight of active substance is mixed with the specified amount of solvent and the specified amount of emulsifier. and dilutes the concentrate with water to the desired concentration. ' '

With the effective substance preparation, cotton leaves (Gossypium hirsutum) are sprayed with dew and infested with larvae of Laphygma exigua.

After the specified times, the extinction is determined in %. Here, $100 means that all larvae are eradicated, 0% means that no larvae were eradicated.

Active substances, active substance concentrates. tions, assessment times and results appear, from the following,

.table 2.

1 yr..,..

Example C. Myzus test (contact effect)

Solvent: 3 parts by weight of acetone.

Emulsifier: 1 part by weight of alkyl aryl polyglycol ether.

To prepare a suitable active substance preparation, you mix 1 part by weight of active substance with the indicated amount of solvent, which contains the indicated amount of emulsifier and dilute the concentrate with water to the desired concentration.

With the effective substance preparation, drop-moist cabbage leaves (Brassica oleracea), which are heavily infested by peach aphids (Myzus persicae), are sprayed.

After the indicated times, the degree of extinction is determined in %. Here, $100 means that all aphids were eradicated,

0$. means that no aphids were eradicated.

Active substances, active substance concentrations, assessment times and results appear in the following table 3. Example D. Tetranychus sample (resistant) • Solvent: 3 parts by weight of acetone.

Emulsifier: 1 part by weight of alkyl aryl polyglycol ether.

For the preparation of a suitable active ingredient preparation, one part by weight of active ingredient is mixed with the indicated amount of solvent and the indicated amount of emulsifier and the concentrate is diluted with water to the desired concentration.

With the effective substance preparation, bean plants (Phaseolus vulgar.is), which are approximately 10 to 30 cm high, are sprayed with droplet moisture. These bean plants are heavily attacked with all stages of development by the common spider mite or bean spider mite (Tetranychus urticae).

After the specified times, the extinction is determined in

%. Here 100$ means;;atlall'.:spider mite] was '.eradicated; 0% means that no spider mites were eradicated.

Active substances, active substance concentrations, assessment times and results appear in the following table 4.

Example E. LD100 sample.

Test animal: Sitophilus granarius...

Solvent:- Acetone..

2 parts by weight of active substance are taken up in 1000 parts by volume of solvent. The solution thus formed is diluted with additional solvent to the desired concentrations.

2.5 ml of active substance solution is pipetted into a Petri dish. At the bottom of the Petri dish there is a filter paper with a diameter of approx. 9.5 cm. The Petri dish remains open until the solvent has completely evaporated. Depending on the concentration of the active substance solution, the amount of active substance is different per m pfilter paper.Then you add about 25 test animals to the Petri dish and cover them with a glass lid.

The condition of the animals is checked 3 days after the start of the experiment. The extinction is determined in %. Here means. 100$ that all test animals were exterminated, 0% means that no test animals were exterminated.

Active substances, active substance concentrations, test animals and results are shown in the following table-5-

1

Example F. • LT-^q sample, for. dipter.

Test animal: Åedes aegypti .••. •

Solvent: A.ce't'on. '•.

2 parts by weight of active substance are taken up in 1000 parts by volume of solvent. The solution thus formed is diluted with further solvent to the desired smaller concentrations.

2.5 ml active substance solution is pipetted into a Petri dish.- At the bottom of the Petri dish is a filter paper with a diameter of approx. 9.5 cm. The Petri dish- remains open until the solvent has completely evaporated. Depending on the concentration of the active substance solution, the amount of active substance is different. per m 2 filter paper. Then you put approx. 25 test animals in the Petri dish and cover them with a glass lid.

The condition of the test animals is continuously checked.

The time required for a $100 eradication is determined.

Test animals, active substances, active substance concentrations and times when there is a 100# extinction appear in the following table 6.

1 Example LT-^QQ-<p>^practice for dipt.ers.

Test animals: Musea domest^ca.

Solvent: Acetone. ■

2 parts by weight of active substance are taken up in 1000 parts by volume of solvent. The solution thus formed is diluted with additional solvent to the desired smaller concentrations. 2.5 ml of active substance solution is pipetted into a Petri dish. At the bottom of the Petri dish is a filter paper with a diameter of approx. 9.5 cm. The petri dish remains open until the solvent has completely evaporated. Based on the concentration of the active substance solution, the amount of active substance per m 2 filter paper of different heights.. •Then you place approx. 25 test animals in the Petri dish and cover them with a glass lid. The condition of the test animals is constantly checked. ,The

the time required for 100% eradication is determined.

Test animals, active substances, active substance concentrations and times, where there is 100% eradication can be seen from the following table 7. Example H. Sample with parasitizing fly larvae.

Solvent: 35 parts by weight of ethylene polyglycol monomethyl ether.

35 parts by weight nonylphenol polyglycol ether.

For the preparation of a suitable active substance preparation, 30 parts by weight of the active substance in question are mixed with the amount of solvent indicated therein, which contains the above-mentioned amount of emulsifier, and the concentrate thus formed is diluted with water to the desired concentration.

Approx. 20 fly larvae (Lucilia cuprina) are brought in

a test tube containing approx. 2 cm^ horse muscle. On

0.5 ml of the active substance preparation is brought to this horsemeat. After 24 hours, the degree of eradication is determined in %. Thereby, 100$ means that all and 0% that no larvae have been eradicated.

Researched active substances, tested active

"substance concentrations, and the results obtained are shown in the following" table 8. 1 Mainly in 1 ling's examples: Example_ l 1.

A mixture of 25.6 g (0.1 mol) 1-(3-trifluoromethylphenyl)-3-hydroxy-1,6-dihydropyridazinone (6), 20.7 g (0.15 mol) potassium carbonate, 18 .8 g (0.1 mol) of 0.0-diethylthiophosphoric acid diester chloride and 300 ml of acetonitrile are stirred for 4 hours at 50°C. It is then cooled to room temperature and shaken after adding 400 ml of toluene twice with 300 ml of water each time. The organic phase is separated, dried over sodium sulphate and freed of solvent in vacuo. The residue is distilled. One thus obtains 33.4 g (82% of the theoretical) 0,0-diethyl-0-_/~1-(3-trifluoromethylphenyl)-1,6-dihydropyridaz(6)one(3)yl7- thionophosphoric acid ester in the form of a yellow oil of refractive index nQ 22: 1.5240.

Analogously, the following compound of formula can be prepared

1 ....

They' as output products. required 1-phenyl-3-hydroxy-6-oxo-pyridazine derivatives (III) can, for example, be prepared as follows:

176 g (1 mol) of 3-trifluoromethylphenylhydrazine (preparation see DAS 1.116.53<*>0 is dissolved in a mixture of 1000 ml of water and 250 ml of concentrated hydrochloric acid and mixed at approx. 90°C with 98 g (1 mol ) maleic anhydride. You then stir for • 1 hour at 95 - 100°C and, after the reaction mixture has cooled, the crystallized product is filtered off with suction. For purification,

it is dissolved in dilute caustic soda and again precipitated with 'hydrochloric acid. One thus obtains 210 g (82% of the theoretical) 1-(3-trifluoromethylphenyl)-3-hydroxy-16-dihydropyridazinone (6) in the form of a faint yellow powder of melting point 176°C.

Analogously, the following compounds can be prepared

Claims (3)

1. „ Pyridazinyl(thiono)(thiol)-phosphorus(phosphonic)-acid esters resp. -esteramides with insecticidal and acaricidal action and with formula in which R means alkyl with 1 to 6 carbon atoms, R' means phenyl, alkyl with 1 to 4, alkoxy with 1 to 6, alkylthio with 1 to 6, mono- or dialkylamino with " 1 to 4 carbon atoms per alkyl chain, R" and R"' which may be the same or different mean hydrogen or methyl and R means hydrogen, halogen, nitro or haloalkyl with 1 to 3 carbon atoms, but n means an integer from 1 to 4 and X means an oxygen or sulfur atom. 2. Insecticidal and acaricidal agents, characterized by a content of compounds according to claim 1. 3. Use of compounds according to claims. 1 more. insect and mite control.