IL32650A - Thionophosphonic acid esters,their preparation and use for combatting insects - Google Patents

Description

TBIOIOPHOSPHOMIC ACID B3SBRS, THEIR PREPARATION AKD Ιίΰίϋ FOR COiSBAT'ilNG INSECTS F BBIPABHIEIST BAYER A TXM&ESELLSCIdUUFT 32650/2- The present invention relates to certain new thionophos-phonic acid esters, to a process for their production and to their use as insecticides and acaricides.

In U.S. Patent Specification 2,754,244 there are described among other things, 0,0-dialkyl-0-[3-methylpyrazolyl-(5)]- . phosphoric or -thionophosphoric acid esters* These "compounds can be prepared by reaction of equimolar amounts of the 0,0-dialkyl-(thiono)-phosphoric acid ester chlorides concerned and 3-methylpyrazolone-(5), that is, 3-methl-5-hydroxypyra-zole.

The present invention provides thionophosphonic acid ester of the general formula >. in which R^ and R2 independently, denote straight or branched alk l radicals having 1 to 4 carbon atoms.

The present invention also provides a process for the production of thionophosphonic acid esters of the formula (l) in which a thionophosphonic acid ester halide of the general formula (2) 32650/2 is reacted with 3-hydroxy-5-methylpyrazole.

In formula (?)., the symbols and E2 have the meaning stated' above and Hal stands for a halogen atom.

The compounds according to the invention are distinguished by outstanding insecticidal and acaricidal properties. They possess an excellent effectiveness against bitin as well as against sucking insects. Moreover, they exhibit a dis'tinct herbicidal and rodehticidal side-effect. The new compounds are clearly superior to the above-mentioned known products.

The course of the above-mentioned process is illustrated (3) In equation (3)» the symbols ¾, R2 and. Hal have the meaning stated above. ! and ^ denote lower alkyl radicals with, in each qase, 1 to 4 carbon atoms, such as the methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl and sec .-butyl radicals, and R^ possibly being the same as, or different from one another. Hal preferably denotes a chlorine atom.

When carrying out the reaction according to the invention,, preferably the free 3-hydroxy-5-methylpyrazole is used and the reaction is caused to proceed in the presence of an acid- binding agent. For this purpose, practically all customary acid acceptors may be used. Particularly suitable, however, are alkali metal alcoholates and carbonates, such as sodium or potassium methylate, eth late and carbonate, as well as ter triethylamine, dimethylaniline, dimethylbenzylaml ne or pyridine.

The process is preferably carried out with the use of a solvent (which term includes a mere diluent) 0 As such, practically all inert organic solvents or mixtures thereof are suitable, such as hydrocarbons, for example benzine, benzene, toluene, chlorobenzene, xylene; ethers, for example diethyl ether, di-n-butyl ether and dioxan; further, ketones, for example acetone, methylethyl ketone, methylisopropyl ketone and methylisobutyl ketone. For the said purpose, however, particularly good results have been obtained with low-boiling aliphatic alcohols, for example methanol and ethanol, and, above all, nitriles, for example acetonitrile and propionitrile, and dimethyl formamide.

When carrying out the reaction, the temperature of the mixture can be varied within a fairly wide range. In generals the reaction is carried out at from 30° to 70°C.

The starting materials, as well as any auxiliary materials to be used (acid-binding agents), are, in general, used in equimolar amounts.

After combining the starting materials, it is advantageous to continue stirring the mixture for a long period (say 3 to 10 hours) in order to complete the reaction. The products are then obtained with good yields and in high purity.

The thionophosphonic acid esters according to the present invention are obtained in most cases in the form of colourless to yellow-coloured, water-insoluble oils which, by so-called "slight distillation", that is heating to moderately elevated temperatures for long periods under reduced pressure, can be freed from the last volatile components and can in this way be purified. Their structure is indicated by infra-red and NMR spectra. (l) are distinguished by outstanding insecticidal and acari-cidal effectiveness. They possess at the same time only a slight phytotoxicity. The effect sets in rapidly and is long-lasting. For this reason, the compounds according to the invention can be used with success in crop protection for the control of noxious sucking and biting insects and Diptera, as well as against mites (Acarina).

To the sucking insects there belong, in the main, aphids (Aphidae) such as the green peach aphid (Myzus persicae), the bean aphid (Doralis fabae), the bird cherry aphid (Rhopalosiphum padi), the pea aphid (Macrosiphum pisi) and the potato aphid (Macrosiphum solanifolii) , the currant gall aphid (Crytomyzus korschelti), the mealy apple aphid (Sappaphis mali), the mealy plum aphid (Hyalopterus arundinis) and the cherry black-fly (I¾rzus cerasi); in addition, scales and mealybugs (Coccina), for example the oleander scale (Aspidiotus hederae) and the soft scale (Lecanium hesperidum) as well as the grape mealybug (Pseudococcus maritimus); thrips (Thysanoptera, such as Hercinothrips femoralis, and bugs, for example the beet bug (Piesma quadrata) , the cotton bug (Dysdercus intermedius) , the bed bug (Cimex lectularius) , the assassin bug (Ehodnius pro-lixus) and Chagas' bug (Triatoma infestans), and, further, cicadas, such as Euscelis bilobatus and Nephotettix bipunctatus.

In the case of the biting insects, above all there should be mentioned butterfly caterpillars (lepidoptera) , such as the diamond-back moth (Plutella maculipennis) , the gipsy moth (Lymantria dispar), the brown-tail moth (Euproctis chrysorrhoea) and tent caterpillar ( alacosoma neustria) ; further, the cabbage moth (Mamestra brassicae) and the cutworm (Agrotis segetum), the large white butterfly (Pieris brassicae), the small winter moth (Cheimatobia brumata) , the green oak tortrix moth (Tor- cotton worm (Prodenia litura), the ermine moth (Hyponomeuta padella), the Mediterranean flour moth (Ephestia uhniella) and greater wax moth (Galleria mellonella).

Also to be classed with the biting insects are beetles (Coleoptera) , for example the granary weevil (Sitophilus gran-arius = Calandra granaria), the Colorado beetle (Leptinotarsa decemlineata) , the dock beetle (Gastrophysa viridula) , the mustard beetle (Phaedon cochleariae), the blossom beetle (Meligethes aeneus), the raspberry beetle (By urus tomentosus), the bean weevil (Bruchidius = Acanthoscelides obtectus), the leather beetle (Dermestes frischi), the khapra beetle (Trogoderma granarium), the flour beetle (Tribolium castaneum), the northern corn billbug (Calandra or Sitophilus zeamais), the drugstore beetle (Stegobium paniceum), the yellow mealworm (Tenebrio molitor) and the saw-toothed grain beetle (Oryzaephilus surina-mensis), but also species living in the soil, for example wireworms (Agriotes spec.) and larvae of the cockchafer (Melolontha melolontha), cockroaches, such as the German cockroach (Blattslla germanica), American cockroach (Periplaneta americana), Madeira cockroach (Laucophaea or Rhyparobia madeirae), Oriental cockroach (Blatta orientalis), the giant cockroach (Blaberus giganteus) and the black giant cockroach (Blaberus fuacus) as well as Henschoutedenia flexivitta; further, Orthop- tera, for example the house cricket (Gryllus domesticus); termites such as the eastern subterranean termite (Reticulitermes flavipes) and Hymenoptera such as ants, for example the garden ant (lasius niger).

The Diptera comprise essentially the flies, such as the vinegar fly (Drosophila melanogaster) , the Mediterranean fruit fly (Ceratitis capitata), the house fly (musca domestica), the little house fly (Fannia canicularis) , the black blow fly as well as the stable fly (Stomoxys calcitrans); further, gnats, for example mosquitoes such as the yellow fever mosquito (Aedes aegypti), the northern house mosquito (Culex pipiens) and the malaria mosquito (Anopheles stephensi).

With the mites (Acari) there are classed, in particular, the spider mites (Tetranychidae) such as the two-spotted spider mite (Tetranychus telarius = Tetranychus althaeae or Tetrany-chus urticae) and the European red mite (Paratetranychus pilosus - Panonychus ulmi), blister mites, for example the currant blister mite (Eriophyes ribis) and tarsonemids, for example the broad mite (Hemitarsonemus latus) and the cyclamen mite (Tar-sonemus pallidus); finally, ticks, such as the relapsing fever tick (Ortnithodorus moubata) .

The active compounds according to the present invention can be converted into the usual formulations, such as solutions, emulsions, suspensions, powders, pastes and granulates. These may be produced in known manner, for example by mixing the active compounds with extenders, that is, liquid or solid diluents or carriers, optionally with the use of surface-active agents, that is, emulsifying agents and/or dispersing agents. In the case of the use of water as an extender, organic solvents can, for example, also be used as auxiliary solvents.

As liquid diluents or carriers, there are preferably used aromatic hydrocarbons, such as xylenes or benzene, chlorinated aromatic hydrocarbons, such as chlorobenzenes, paraffins, such as mineral oil fractions, alcohols, such as methanol or butanol, or strongly polar solvents, such as dimethyl formamide or dimethyl sulphoxide, as well as water.

As solid diluents or carriers, there are preferably used ground natural minerals, such as kaolins, clays, talc or chalk, or ground synthetic minerals, such as highly-dispersed silicic Preferred examples of emulsifying agents include non-ionic and anionic emulsifiers, such as polyoxyethylene-fatty acid esters, polyoxyethylene-fatty alcohol ethers, for example alkylarylpoly lycol ethers, alkyl sulphonates and aryl sul-phonates; and preferred examples of dispersing agents include · lignin, sulphite waste liquors and methyl cellulose.

The active compounds according to the invention may be present in the formulations in admixture with other active compounds· The formulations contain, in general, from 0.1 to 95, preferably from 0.5 to 90, per cent by weight of active compound.

The active compounds may be used as such or in the form of their formulations or of the application forms prepared therefrom, such as ready-to-use solutions, emulsifiable concentrates, emulsions, suspensions, spray powders, pastes, soluble powders, dusting agents and granulates. Application may take place in the usual manner, for example by watering, spraying, atomising, vaporisation, fumigation, scattering and dusting.

The concentrations of active compounds can be varied within a fairly wide range for actual application. In general, concentrations by weight of 0.00001$ to 20 , preferably of 0.01 to 5f°t are used.

The new compounds can also be used with good results in the ultra-low-volume (ULV) process, where it is possible to apply formulations up to $ of active compound. It is also possible, in some cases, to use the active compound alone.

Surprisingly, the products according to the invention, compared with the active compounds (known from the literature cited above) of analogous constitution and the same direction effectiveness with, in part, considerably lower toxicity to warm-blooded animals. They therefore represent a genuine enrichment of the art.

The present invention also provides an insecticidal or acaricidal composition containing as active ingredient a thionophosphonlc acid ester according to the present invention in admixture with a solid diluent or carrier or in admixture with a liquid diluent or carrier containing a surface active agent.

The present invention also provides a method of combating s insects and acarids which comprises applying to the insects, acarids or a habitat thereof a thionophosphonlc acid ester according to the present invention alone or in the form of a composition containing as active ingredient a thionophosphonlc acid ester according to the present invention in admixture with a solid or liquid diluent or carrier, The present invention further provides crops protected from damage by insects or acarids by being grown in areas in which immediately prior to and/or during the time of growing a thionophosphonlc acid ester according to the present invention was applied alone or in admixture with a solid or liquid diluent or carrier.

The unexpected superiority, as well as the outstanding activity of the compounds of the present invention when used against a variety of pests, can be seen from the following experimental results: Example A Plutella test Solvent: 3 parts by weight acetone Emulsifier: 1 part by weight alkylaryl polyglycol ether To produce a suitable preparation of active compound, 1 part by weight of the active compound is mixed with the stated amount of solvent containing the stated amount of emulsifier and the concentrate is diluted with water to the desired concentration.

Cabbage leaves (Brassica oleracea) are sprayed with the preparation of the active compound until dew moist and are then infested with caterpillars of the diamond-back moth (Plutella maculipennis) .

After the specified periods of time, the degree of destruction is determined as a percentage: 100$ means that all the caterpillars are killed whereas Ofo means that none of the caterpillars are killed.

The active compounds, the concentrations of the active compounds, the evaluation times and the results can be seen from the following Table A: We A Plutella test Active compound Concentration of Degree of (constitution) active compound destruction in <fo in $ after davs (known comparative compound) Le A 11 647 11 ■ Example B Myzus test (contact action) Solvent: 3 parts by weight acetone Emulsifier: 1 part by weight alk laryl pol gl col ether To produce a suitable preparation of active compound, 1 part by weight of the active compound is mixed with the stated amount of solvent containing the stated amount of emulsifier and the concentrate is diluted with water to the desired concentration.

Cabbage plants (Brassica oleracea) which have been heavily infested with peach aphids (Myzus persicae) are sprayed with the preparation of the active compound until dripping wet.

After the specified periods of time, the degree of destruction is determined as a percentage: 100^ means that all the aphids are killed whereas 0/° means that none of the aphids are killed.

The active compounds, the concentrations of the active compounds, the evaluation times and the results can be seen from the following Table B; Table B Concentration Degree of des of active truction in o compound in after 24 ' hours (known comparative compound) (known comparative compound) (5) Example C Tetranychus test Solvent: 3 parts by weight acetone Emulsifier: 1 part by weight alkylaryl polyglycol ether To produce a suitable preparation of active compound, 1 part by weight of the active compound is mixed with the stated amount of solvent containing the stated amount of emulsifier and the concentrate so obtained is diluted with water to the desired concentration.

Bean plants (Phaseolus vulgaris), which have a height of approximately 10-30 cm. , are sprayed with the preparation of the active compound until dripping wet. These bean plants are heavily infested with spider mites (Tetranychus telarius) in all stages of development.

After the specified periods of time, the effectiveness of the preparation of active compound is determined by counting the dead mites. The degree of destruction thus obtained is expressed as a percentage: 100$ means that all the spider mites are killed whereas 0$ means that none of the spider mites are killed.

The active compounds, the concentrations of the active compounds, the evaluation times and the results can be seen from the following Table C: Table C Tetranychus Active compound Concentration Degree of des(constitution) of active truction in e compound in after 8 days (7) (known comparative compound) (known comparative compound) (6) (7) The process of the invention is illustrated by the following Examples, Example 1 (4) (Known) g (0.3 mole) triethylamine are added to a solution of 30 g (0.3 mole) 3-hydroxy-5-methylpyrazole in 150 ml aceto-nitrile. 67 g (0.3 mole) phenylthionophosphonic acid 0-ethyl ester chloride are then added dropwise to the reaction mixture at 40°C, and the latter is further heated to 50°C for 3 hours. Thereafter, the mixture is further stirred overnight at room temperature, then taken up in chloroform and diluted with water. Finally, the chloroform solution is concentrated and the reaction product is slightly distilled under greatly reduced pressure. 51 g (60.7$ of the theory) phenylthionophosphonic acid 0-ethyl-0-[5-methylpyrazolyl-(3)]-ester with the refractive index n^ = 1.5216 are obtained.

Analysis for ¾2¾5ir2025S (molecular weigkt 281) N Calculated: 9.98$; Pound: 9.66$.

In analogous manner, the following compounds can be prepared: Yield: 79* of the theory; refractive index η50> = 1.5298 Analysis for (molecular weight 220) N P S Yield: 81.5# of the theory; refractive index: n^ Analysis: for (molecular weight 234) P Calculated: 13.31$; Pound: 13·83$. 32650/2

Claims (2)

1. CLAIMS 1, Thionophosphonic acid esters of the general formula in which R^ and' independently denote straight or branched alkyl radicals having 1 to 4 carbon atoms*
2. 2. Thionophosphonic acid esters according to Claim 1 in which R^ and Rg independently denote methyl, ethyl, n-propyl, isopropyl, n-biityl, isob tyl or sec. -butyl. The thionophosphonic acid ester of the formula 4... The thionophosphonic acid ester of the formula le A 11 647 - 18 - . A process for the production of thionophosphonic acid esters according to claim 1 in which a thionophosphonic acid ester halide of the formula II P-Hal (2) R20 ' in which and R2 have the meaning stated in claim 1, and Hal denotes a halogen atom is reacted with 3~hydroxy-5-methylpyrazole. 5 6 ll A process according to claim v in which Hal denotes a chlorine atom. 5 6 7 S$. A process according to claim jE> or ή in which the reaction is effected in an inert organic solvent. 5 7 8 · A process according to any of claims # to # in which the reaction is effected in the presence of an acid- binding agent. 9 ¾0. A process according to claim 4 in which the acid-binding agent is an alkali metal alcoholate, an alkali metal carbonate or a tertiary amine. Q . 5 y 10 jOji. A process according to any of claims to £j0 in which the reaction is effected at a temperature of from 30° to 70°C. 5 10 113J2. A process according to any of claims to to &Ϊ. in which the thionophosphonic acid ester halide and the 3-hydroxy-5-meth l- pyrazole, as well as the acid-binding agent if employed, are used in substantially equimolar quantities. 12 /ifa/. A process for the production of thionophosphonic acid esters according to claim 1 substantially as hereinbefore described in Example 1. 5 12 'prepared by a process according to -any of claims έ to ί^. An insecticidal or acaricidal composition containing as active ingredient a thionophosphonic acid ester according % 13 to any of claims 1 to ¾f or i admixture with a solid diluent or carrier or in admixture with a liquid diluent or carrier containing a surface active agent. 14 X6C A composition according to claim ¾J5 containing from 0.1 to 95$ of the active compound, by weight, 15 Μ· A composition according to claim f> containing from 0.5 to 90 of the active compound, by weight. W. A method of combating insects and acarids which comprises applying to the insects, acarids or habitats thereof a thionophosphonic acid ester according to any of claims 1 to 13 or3" alone or in the form of a composition containing as active ingredient a thionophosphonic acid ester according to any of claims 1 to 5 or 14 in admixture with a solid or liquid diluent or carrier. flfef, A method according to claim in which a composition is used containing from 0.00001 to 20$ of the active compound by weight. 18 A method according to claim in which a composition is used containing from 0.01 to $ of the active compound. 17 19 #y. A method according to any of claims ¾fi to 2)0 in which the thionophosphonic acid ester is one of those mentioned in any of Examples A to C. Grops protected from damage by insects or acarids by being grown in areas in which immediately prior to and/or during the time of growing a thionophosphonic acid ester according to any of claims 1 to 6 or was applied alone or in admixture with a solid or liquid diluent or carrier. Le A 11 647 - 20 -