Combating insects and acarids with O-alkyl-O-[2-substituted-6-alkoxy-pyrimidin(4)yl]-thionophosphonic acid esters
This is a division of application Ser. No. 829,553, filed Aug. 31, 1977, now U.S. Pat. No. 4,150,159. 
    
    
     The present invention relates to and has for its objects the provision of particular new O-alkyl-O-[2-substituted-6-alkoxy-pyrimidin(4)yl]-thionophosphonic acid esters which possess arthropodicidal properties, active compositions in the form of mixtures of such compounds with solid and liquid dispersible carrier vehicles, and methods for producing such compounds and for using such compounds in a new way especially for combating pests, e.g. arthropods, with other and further objects becoming apparent from a study of the within specification and accompanying examples. 
     It is already known from U.S. Pat. Nos. 2,754,243 and 3,862,188 that the alkyl-substituted and alkoxy-substituted pyrimidinylthionophosphoric acid esters, for example, O,O-diethyl-O-[2-isopropyl-4-methyl-pyrimidin(6)yl]-(Compound A) and O,O-dimethyl-O-[2-ethyl-4-ethoxy-pyrimidin(6)yl]-thionophosphoric acid ester (Compound B), possess insecticidal and acaricidal properties. 
     The present invention now provides, as new compounds, the alkoxy-substituted pyrimidinylthionophosphonic acid esters of the general formula ##STR2## in which R and R 3  each independently is alkyl, 
     R 1  is phenyl or alkyl, and 
     R 2  is alkyl, alkoxy, alkylthio or dialkylamino. 
     Preferably, R and R 3 , which may be identical or different, each is straight-chain or branched alkyl with 1 to 6 (especially 1 to 4) carbon atoms, R 1  is phenyl or straight-chain or branched alkyl with 1 to 4 (especially 1 to 3) carbon atoms and R 2  is straight-chain or branched alkyl with 1 to 6 (especially 1 to 4) carbon atoms or straight-chain or branched alkoxy or alkylthio or dialkylamino with 1 to 4 (especially 1 to 3) carbon atoms per alkyl radical. 
     Surprisingly, the alkoxy-substituted pyrimidinylthionophosphonic acid esters according to the invention exhibit a better insecticidal and acaricidal action than the previously known pyrimidinylthionophosphoric acid esters of analogous structure and of the same type of action. The compounds according to the invention thus represent a genuine enrichment of the art. 
     The present invention also provides a process for the preparation of an alkoxy-substituted pyrimidinylthionophosphonic acid ester of the formula (I), in which a thionophosphonic acid ester halide of the general formula ##STR3## in which R and R 1  have the above-mentioned meanings and 
     Hal is halogen, preferably chlorine, 
     is reacted, if appropriate in the presence of a solvent or diluent, with a 4-hydroxy-6-alkoxy-pyrimidine of the general formula ##STR4## in which 
     R 2  and R 3  have the above-mentioned meanings, 
     the latter being reacted as such in the presence of an acid acceptor or in the form of an alkali metal salt, alkaline earth metal salt or ammonium salt. 
     If, for example, 2-ethoxy-4-hydroxy-6-iso-propoxypyrimidine and O-n-propylthionoethanephosphoric acid ester chloride are used as starting materials, the course of the reaction can be represented by the following equation: ##STR5## 
     The thionophosphonic acid ester halides (II) to be used as starting materials are known and can easily be prepared in accordance with customary processes. 
     The following may be mentioned as individual examples thereof: O-methyl-, O-ethyl-, O-n-propyl-, O-iso-propyl-, O-n-butyl, O-iso-butyl- and O-sec.-butyl-methane, ethane-, n-propane-, iso-propane, n-butane, iso-butane, tert.-butane-, sec.-butane- and phenyl-thionophosphonic acid ester chloride. 
     4-Hydroxy-6-alkoxy-pyrimidines (III), also to be used as starting materials, are described in the literature and can be prepared in accordance with known processes, e.g. German Offenlegungsschriften DOS 2,412,854 and 2,412,903. 
     The following may be mentioned as individual examples thereof: 2-methyl-6-methoxy-, 2-methyl-6-ethoxy-, 2-methyl-6-n-propoxy, 2-methyl-6-iso-propoxy-, 2-methyl-6-n-butoxy-, 2-methyl-6-iso-butoxy-, 2-methyl-6-sec.-butoxy-, 2-methyl-6-tert.-butoxy-, 2-ethyl-6-methoxy-, 2-ethyl-6-ethoxy-, 2-ethyl-6-n-propoxy, 2-ethyl-6-iso-propoxy-, 2-ethyl-6-n-butoxy-, 2-ethyl-6-iso-butoxy-, 2-ethyl-6-sec.-butoxy-, 2-ethyl-6-tert.-butoxy-, 2-n-propyl-6-methoxy-, 2-n-propyl-6-ethoxy-, 2-n-propyl-6-n-propoxy, 2-n-propoxy-6-iso-propoxy-, 2-n-propyl-6-n-butoxy-, 2-n-propyl-6-iso-butoxy-, 2-n-propyl-6-sec.-butoxy-, 2-n-propyl-6-tert.-butoxy-, 2-iso-propyl-6-methoxy-, 2-iso-propyl-6-ethoxy-, 2-iso-propyl-6-n-propoxy-, 2-iso-propyl-6-iso-propoxy-, 2-iso-propyl-6-n-butoxy, 2-iso-propyl-6-iso-butoxy-, 2-iso-propyl-6-sec.-butoxy-, 2-iso-propyl-6-tert.-butoxy-, 2-n-butyl-6-methoxy-, 2-n-butyl-6-ethoxy-, 2-n-butyl-6-n-propoxy-, 2-n-butyl-6-iso-propoxy-, 2-n-butyl-6-n-butoxy-, 2-n-butyl-6 -iso-butoxy-, 2-n-butyl-6-sec.-butoxy-, 2-n-butyl-6-tert.-butoxy, 2-iso-butyl-6-methoxy-, 2-iso-butyl-6-ethoxy-, 2-iso-butyl-6-n-propoxy-, 2-iso-butyl-6-iso-propoxy-, 2-iso-butyl-6-n-butoxy-, 2-iso-butyl-6-iso-butoxy, 2-iso-butyl-6-sec.-butoxy-, 2-iso-butyl-6-tert.-butoxy-, 2-sec.-butyl-6-methoxy-, 2-sec.-butyl-6-ethoxy-, 2-sec.-butyl-6-n-propoxy-l, 2-sec.-butyl-6-iso-propoxy-, 2-sec.-butyl-6-n-butoxy-, 2-sec.-butyl-6-iso-butoxy-, 2-sec.-butyl-6-sec.-butoxy-, 2-sec.-butyl-6-tert.-butoxy-, 2-tert.-butyl-6-methoxy-, 2-tert.-butyl-6-ethoxy-, 2-tert.-butyl-6-n-propoxy-, 2-tert.-butyl-6-iso-propoxy-, 2-tert.-butyl-6-n-butoxy-, 2-tert.-butyl-6-iso-butoxy-, 2-tert.-butyl-6-sec.-butoxy-, 2-tert.-butyl-6-tert.-butoxy, 2,6-dimethoxy-, 2-methoxy-6-ethoxy-, 2-methoxy-6-n-propoxy-, 2-methoxy-6-iso-propoxy-, 2-methoxy-6-n-butoxy-, 2-methoxy-6-iso-butoxy-, 2-methoxy-6sec.-butoxy-, 2-methoxy-6-tert.-butoxy-, 2-ethoxy-6-methoxy-, 2,6-diethoxy-, 2-ethoxy-6-n-propoxy-, 2-ethoxy-6-iso-propoxy-, 2-ethoxy-6-n-butoxy-, 2-ethoxy-6-iso-butoxy-, 2-ethoxy-6-sec.-butoxy-, 2-ethoxy-6-tert.-butoxy-, 2-n-propoxy-6-methoxy-, 2-n-propoxy-6-ethoxy-, 2,6-di-n-propoxy-, 2-n-propoxy-6-iso-propoxy-, 2-n-propoxy-6-n-butoxy-, 2-n-propoxy-6-iso-butoxy-, 2-n-propoxy-6-sec.-butoxy-, 2-n-propoxy-6-tert.-butoxy-, 2-iso-propoxy-6-methoxy-, 2-iso-propoxy-6-ethoxy-, 2-iso-propoxy-6-n-propoxy,-, 2,6-di-iso-propoxy-, 2-iso-propoxy-6-n-butoxy-, 2-iso-propoxy-6-iso-butoxy-, 2-iso-propoxy-6-sec.-butoxy-, 2-iso-propoxy-6-tert.-butoxy-, 2-methylthio-6-methoxy-, 2-methylthio-6-ethoxy-, 2-methylthio-6-n-propoxy-, 2-methylthio-6-iso-propoxy-, 2-methylthio-6-n-butoxy-, 2-methylthio-6-iso-butoxy-, 2-methylthio-6-sec.-butoxy-, 2-methylthio-6-tert.-butoxy-, 2-ethylthio-6-methoxy-, 2-ethylthio-6-ethoxy-, 2-ethylthio-6-n-propoxy-, 2-ethylthio-6-iso-propoxy-, 2-ethylthio-6-n-butoxy-, 2-ethylthio-6-iso-butoxy-, 2-ethylthio-6-sec.-butoxy-, 2-ethylthio-6-tert.-butoxy-, 2-n-propylthio-6-methoxy-, 2-n-propylthio-6-ethoxy-, 2-n-propylthio-6-n-propoxy-, 2-n-propylthio-6-iso-propoxy-, 2-n-propylthio-6-n-butoxy-, 2n-propylthio-6-iso-butoxy-, 2-n-propylthio-6-sec.-butoxy-, 2-n-propylthio-6-tert.-butoxy-, 2-iso-propylthio-6-methoxy-, 2-iso-propylthio-6-ethoxy-, 2-iso-propylthio-6-n-propoxy-, 2-iso-propylthio-6-iso-propoxy-, 2-iso-propylthio-6-n-butoxy-, 2-iso-propylthio-6-iso-butoxy-, 2-iso-propylthio-6-sec.-butoxy-, 2-iso-propylthio-6-tert.-butoxy-, 2-dimethylamino-6-methoxy-, 2-dimethylamino-6-ethoxy-, 2-dimethylamino-6-n-propoxy-, 2-dimethylamino-6-iso-propoxy-, 2-dimethylamino-6-n-butoxy-, 2-dimethylamino-6-iso-butoxy-, 2-dimethylamino-6-sec.-butoxy-, 2-dimethylamino-6-tert.-butoxy-, 2-diethylamino-6-methoxy-, 2-diethylamino-6-ethoxy-, 2-diethylamino-6-n-propoxy-, 2-diethylamino-6-iso-propoxy-, 2-diethylamino-6n-butoxy-, 2-diethylamino-6-iso-butoxy, 2-diethylamino-6-sec.-butoxy- and 2-diethylamino-6-tert.-butoxy-4-hydroxy-pyrimidine. 
     The process for the preparation of the compounds according to the invention is preferably carried out in the presence of a suitable solvent or diluent. Virtually all inert organic solvents can be used for this purpose, especially aliphatic and aromatic, optionally chlorinated, hydrocarbons, such as benzene, toluene, xylene, benzine, methylene chloride, chloroform, carbon tetrachloride and chlorobenzene; ethers, for example diethyl ether, dibutyl ether and dioxane; ketones, for example acetone, methyl ethyl ketone, methyl isopropyl ketone and methyl isobutyl ketone; and nitriles, such as acetonitrile and propionitrile. 
     All customary acid-binding agents can be used as acid acceptors. Alkali metal carbonates and alkali metal alcoholates, such as sodium carbonate and potassium carbonate, sodium methylate and ethylate and potassium methylate, ethylate and tert.-butylate, have proved particularly suitable, as have aliphatic, aromatic or heterocyclic amines, for example triethylamine, trimethylamine, dimethylaniline, dimethylbenzylamine and pyridine. 
     The reaction temperature can be varied within a fairly wide range. In general, the reaction is carried out at from 0° to 120° C., preferably at from 20° to 60° C. 
     In general, the reaction is allowed to take place under normal pressure. 
     To carry out the process, the starting materials are preferably employed in equimolar amounts. An excess of one or other reactant produces no significant advantages. 
     The reactants are in most cases combined in one of the above-mentioned solvents in the presence of an acid acceptor and are stirred for one or more hours at an elevated temperature to complete the reaction. The reaction solution is then cooled, an organic solvent, for example toluene, is added, the mixture is repeatedly extracted by shaking with water, the organic phase is separated off and dried and the solvent is distilled off under reduced pressure. 
     Some of the new compounds are obtained in the form of oils, which in most cases cannot be distilled without decomposition, but are freed from the last volatile constituents by so-called &#34;slight distillation&#34;, that is to say by prolonged heating under reduced pressure to moderately elevated temperatures, and are purified in this way. They are characterized by the refractive index. Some of the compounds are obtained in a crystalline form having a sharp melting point. 
     As already mentioned, the compounds according to the present invention are distinguished by an excellent insecticidal or acaricidal activity. They are therefore active against plant pests, pests harmful to health and pests of stored products and combine a low phytotoxicity with a good action against sucking and biting insects and against mites. 
     For this reason, the compounds according to the invention can be employed successfully as pesticides in plant protection and in the hygiene field and the field of protection of stored products. 
     The compounds according to the present invention can also be used in the field of veterinary medicine, since they are also active against animal parasites, in particular ectoparasites such as parasitic fly larvae and scab mites. 
     The active compounds are well tolerated by plants, have a favorable level of toxicity to warm-blooded animals, and can be used for combating arthropod pests, especially insects and arachnids which are encountered in agriculture, in forestry, in the protection of stored products and of materials, and in the hygiene field. They are active against normally sensitive and resistant species and against all or some stages of development. The abovementioned pests include: 
     from the class of the Isopoda, for example Oniscus asellus, Armadillidium vulgare and Porcellio scaber; 
     from the class of the Diplopoda, for example Blaniulus guttulatus; 
     from the class of the Chilopoda, for example Geophilus carpophagus and Scutigera spec.; 
     from the class of the Symphyla, for example Scuttigerella immaculata; 
     from the order of the Thysanura, for example Lepisma saccharina; 
     from the order of the Collembola, for example Onychiurus armatus; 
     from the order of the Orthoptera, for example Blatta orientalis, Periplaneta americana, Leucophaea maderae, Blattella germanica, Acheta domesticus, Gryllotalpa spp., Locusta migratoria migratorioides, Melanoplus differentialis and Schistocerca gregaria; 
     from the order of the Dermaptera, for example Forficula auricularia; 
     from the order of the Isoptera, for example Reticulitermes spp.; 
     from the order of the Anoplura, for example Phylloxera vastatrix, Phemphigus spp., Pediculus humanus corporis, Haematopinus spp. and Linognathus spp.; 
     from the order of the Mallophaga, for example Trichodectes spp. and Damalinea spp.; 
     from the order of the Thysanoptera, for example Hercinothrips femoralis and Thrips tabaci; 
     from the order of the Heteroptera, for example Eurygaster spp., Dysdercus intermedius, Piesma quadrata, Cimex lectularius, Rhodnius prolixus and Triatoma spp.; 
     from the order of the Homoptera, for example Aleurodes brassicae, Bemisia tabaci, Trialeurodes vaporariorum, Aphis gossypii, Brevicoryne brassicae, Cryptomyzus ribis, Doralis fabae, Doralis pomi, Eriosoma lanigerum, Hyalopterus arundinis, Macrosiphum avenae, Myzus spp., Phorodon humuli, Rhopalosiphum padi, Empoasca spp., Euscelis bilobatus, Nephotettix cincticeps, Lecanium corni, Saiessetia oleae, Laodelphax striatellus, Nilaparvata lugens, Aonidiella aurantii, Aspidiotus hederae, Pseudococcus spp. and Psylla spp.; 
     from the order of the Lepidoptera, for example Pectinophora gossypiella, Bupalus piniarius, Chemiatobia brumata, Lithocolletis blancardella, Hyponomeuta padella, Plutella maculipennis, Malacosoma neustria, Euproctis chrysorrhoea, Lymantria spp., Bucculatrix thurberiella, Phyllocnistis citrella, Agrotis spp., Euxoa spp., Feltia spp., Earias insulana, Heliothis spp., Laphygma exigua, Mamestra brassicae, Panolis flammea, Prodenia litura, Spodoptera spp., Trichloplusia ni, Carpocapsa pomonella, Pieris spp., Chilo spp., Pyrausta nubilalis, Ephestia kuehniella, Galleria mellonella, Cacoecia podana, Capua reticulana, Choristoneura fumiferana, Clysia ambiguella, Homona magnanima and Tortrix viridana; 
     from the order of the Coleoptera, for example Anobium punctatum, Rhizopertha dominica, Bruchidius obtectus, Acanthoscelides obtectus, Hylotrupes bajulus, Agelastica alni, Leptinotarsa decemlineata, Phaedon cochleariae, Diabrotica spp., Psylliodes chrysocephala, Epilachna varivestis, Atomaria spp., Oryzaephilus surinamensis, Anthonomus spp., Sitophilus spp., Otiorrhynchus sulcatus, Cosmopolites sordidus, Ceuthorrhynchus assimilis, Hypera postica, Dermestes spp., Trogoderma spp., Anthrenus spp., Attagenus spp., Lyctus spp., Meligethes aeneus, Ptinus spp., Niptus hololeucus, Gibbium psylloides, Tribolium spp., Tenebrio molitor, Agriotes spp., Conoderus spp., Melolontha melolontha, Amphimallon solstitialis and Costelytra zealandica; 
     from the order of the Hymenoptera, for example Diprion spp., Hoplocampa spp., Lasius spp., Monomorium pharaonis and Vespa spp.; 
     from the order of the Diptera, for example Aedes spp., Anopheles spp., Culex spp., Drosophila melanogaster, Musca spp., Fannia spp., Calliphora erythrocephala, Lucilia spp., Chrysomyia spp., Cuterebra spp., Gastrophilus spp., Hyppobosca spp., Stomoxys spp., Oestrus spp., Hypoderma spp., Tabanus spp., Tannia spp., Bibio hortulanus, Oscinella frit, Phorbia spp., Pegomyia hyoscyami, Ceratitis capitata, Dacus oleae and Tipula paludosa; 
     from the order of the Siphonaptera, for example Xenopsylla cheopis and Ceratophyllus spp.; 
     from the class of the Arachnida, for example Scorpio maurus and Latrodectus mactans; 
     from the order of the Acarina, for example Acarus siro, Argas spp., Ornithodoros spp., Dermanyssus gallinae, Eriophyes ribis, Phyllocoptruta oleivora, Boophilus spp., Rhipicephalus spp., Amblyomma spp., Hyalomma spp., Ixodes spp., Psoroptes spp., Chorioptes spp., Sarcoptes spp., Tarsonemus spp., Bryobia praetiosa, Panonychus spp. and Tetranychus spp.. 
     When used against hygiene pests and pests of stored products, the active compounds are distinguished by an excellent residual activity on wood and clay as well as a good stability to alkali on limed substrates. 
     The active compounds according to the instant invention can be utilized, if desired, in the form of the usual formulations or compositions with conventional inert (i.e. plant compatible or herbicidally inert) pesticide diluents or extenders, i.e. diluents, carriers or extenders of the type usable in conventional pesticide formulations or compositions, e.g. conventional pesticide dispersible carrier vehicles such as gases, solutions, emulsions, wettable powders, suspensions, powders, dusting agents, foams, pastes, soluble powders, granules, aerosols, suspension-emulsion concentrates, seed-treatment powders, natural and synthetic materials impregnated with active compound, very fine capsules in polymeric substances and in coating compositions, for use on seed, and formulations used with burning equipment, such as fumigating cartridges, fumigating cans, fumigating coils and the like, as well as ULV cold mist and warm mist formulations. 
     These are prepared in known manner, for instance by extending the active compounds with conventional pesticide dispersible liquid diluent carriers and/or dispersible solid carriers optionally with the use of carrier vehicle assistants, e.g. conventional pesticide surface-active agents, including emulsifying agents and/or dispersing agents, whereby, for example, in the case where water is used as diluent, organic solvents may be added as auxiliary solvents. The following may be chiefly considered for use as conventional carrier vehicles for this purpose: aerosol propellants which are gaseous at normal temperatures and pressures, such as halogenated hydrocarbons, e.g. dichlorodifluoromethane and trichlorofluoromethane, as well as butane, propane, nitrogen and carbon dioxide; inert dispersible liquid diluent carriers, including inert organic solvents, such as aromatic hydrocarbons (e.g. benzene, toluene, xylene, alkyl naphthalenes, etc.), halogenated, especially chlorinated, aromatic hydrocarbons (e.g. chlorobenzenes, etc.), cycloalkanes (e.g. cyclohexane, etc.), paraffins (e.g. petroleum or mineral oil fractions), chlorinated aliphatic hydrocarbons (e.g. methylene chloride, chloroethylenes, etc.), alcohols (e.g. methanol, ethanol, propanol, butanol, glycol, etc.) as well as ethers and esters thereof (e.g. glycol monomethyl ether, etc.), amines (e.g. ethanolamine, etc.), amides (e.g. dimethyl formamide, etc.), sulfoxides (e.g. dimethyl sulfoxide, etc.), acetonitrile, ketones (e.g. acetone, methyl ethyl ketone) methyl isobutyl ketone, cyclohexanone, etc.), and/or water; as solid carriers, ground natural minerals, such as kaolins, clays, talc, chalk, quartz, attapulgite, montmorillonite or diatomaceous earth, and ground synthetic minerals, such as highly-dispersed silica acid, alumina and silicates; as solid carriers for granules; crushed and fractionated natural rocks such as calcite, marble, pumice, sepiolite and dolomite, as well as synthetic granules of inorganic and organic meals, and granules of organic material such as sawdust, coconut shells, maize cobs and tobacco stalks; whereas the following may be chiefly considered for use as conventional carrier vehicle assistants, e.g. surface-active agents, for this purpose: emulsifying agents, such as non-ionic and/or anionic emulsifying agents (e.g. polyethylene oxide esters of fatty acids, polyethylene oxide ethers of fatty alcohols, alkyl sulfates, alkyl sulfonates, aryl sulfonates, albumin hydrolyzates, etc., and especially alkyl arylpolyglycol ethers, magnesium stearate, sodium oleate, etc.); and/or dispersing agents, such as lignin-sulfite waste liquors, methyl cellulose, etc. 
     Adhesives such as carboxymethylcellulose and natural and synthetic polymers in the form of powders, granules or latices, such as gum arabic, polyvinyl alcohol and polyvinyl acetate, can be used in the formulations. 
     It is possible to use colorants such as inorganic pigments, for example iron oxide, titanium oxide and Prussian Blue, and organic dyestuffs, such as alizarin dyestuffs, azo dyestuffs and metal phthalocyanine dyestuffs, and trace nutrients such as salts of iron, manganese, boron, copper, cobalt, molybdenum and zinc. 
     Such active compounds may be employed alone or in the form of mixtures with one another and/or with such solid and/or liquid dispersible carrier vehicles and/or with other known compatible active agents, especially plant protection agents, such as other insecticides and acaricides, or fungicides, bactericides, rodenticides, herbicides, fertilizers, growth-regulating agents, etc., if desired, or in the form of particular dosage preparations for specific application made therefrom, such as solutions, emulsions, suspensions, powders, pastes, and granules which are thus ready for use. 
     As concerns commercially marketed preparations, these generally contemplate carrier composition mixtures in which the active compound is present in an amount substantially between about 0.1-95% by weight, and preferably 0.5-90% by weight, of the mixture, whereas carrier composition mixtures suitable for direct application or field application generally contemplate those in which the active compound is present in an amount substantially between about 0.0000001-100, preferably 0.01-10%, by weight of the mixture. Thus, the present invention contemplates overall compositions which comprise mixtures of a conventional dispersible carrier such as (1) a dispersible inert finely divided carrier solid, and/or (2) a dispersible carrier liquid such as an inert organic solvent and/or water, preferably including a surface-active effective amount of a carrier vehicle assistant, e.g. a surface-active agent, such as an emulsifying agent and/or a dispersing agent, and an amount of the active compound which is effective for the purpose in question and which is generally between about 0.0001-95%, and preferably 0.01-95%, by weight of the mixture. 
     The active compounds can also be used in accordance with the well known ultra-low-volume process with good success, i.e. by applying such compound if normally a liquid, or by applying a liquid composition containing the same, via very effective atomizing equipment, in finely divided form, e.g. average particle diameter of from 50-100 microns, or even less, i.e. mist form, for example by airplane crop spraying techniques. Only up to at most about a few liters/hectare are needed, and often amounts only up to about 15 to 1000 g/hectare, preferably 40 to 600 g/hectare, are sufficient. In this process it is possible to use highly concentrated liquid compositions with said liquid carrier vehicles containing from about 20 to about 95% by weight of the active compound or even the 100% active substance alone, e.g. about 20-100% by weight of the active compound. 
     Furthermore, the present invention contemplates methods of selectively killing, combating or controlling pests, e.g. insects and acarids, which comprises applying to at least one of correspondingly (a) such insects, (b) such acarids, and (c) the corresponding habitat thereof, i.e. the locus to be protected, e.g. to a growing crop, to an area where a crop is to be grown or to a domestic animal, a correspondingly combative or toxic amount, i.e. an insecticidally or acaricidally effective amount, of the particular active compound of the invention alone or together with a carrier vehicle as noted above. The instant formulations or compositions are applied in the usual manner, for instance by spraying, atomizing, vaporizing, scattering, dusting, watering, squirting, sprinkling, pouring, fumigating, and the like. 
     It will be realized, of course, that the concentration of the particular active compound utilized in admixture with the carrier vehicle will depend upon the intended application. Therefore, in special cases it is possible to go above or below the aforementioned concentration ranges. 
    
    
     The process of the present invention is illustrated by the following preparative examples. 
     EXAMPLE 1 ##STR6## 
     A mixture of 16.8 g (0.1 mol) of 2-iso-propyl-4-hydroxy-6-methoxy-pyrimidine, 20.7 g (0.15 mol) of potassium carbonate, 17.2 g (0.1 mol) of O-ethyl-ethanethionophosphonic acid ester chloride and 300 ml of acetonitrile was stirred for 4 hours at 50° C. The batch was then cooled to room temperature and after adding 400 ml of toluene it was extracted twice by shaking with 300 ml of water at a time. The organic phase was separated off, dried over sodium sulphate and freed from the solvent in vacuo, and the residue was subjected to slight distillation. 27 g (86% of theory) of O-ethyl-O-[2-iso-propyl-6-methoxy-pyrimidin(4)yl]-ethanethionophosphonic acid ester were thus obtained in the form of a yellow oil having a refractive index n D   22  of 1.5088. 
     The following compounds of the formula ##STR7## could be prepared analogously: 
     
                                           TABLE 1                                 
__________________________________________________________________________
                                 Refractive                               
Compound                   Yield (%                                       
                                 index:                                   
No.   R    R.sup.1                                                        
                R.sup.2                                                   
                      R.sup.3                                             
                           of theory)                                     
                                 melting point °C.                 
__________________________________________________________________________
2     C.sub.2 H.sub.5                                                     
            ##STR8##                                                      
                C.sub.3 H.sub.7 -iso                                      
                      C.sub.2 H.sub.5                                     
                           81    n.sub.D.sup.20 :1,5537                   
3     C.sub.2 H.sub.5                                                     
           C.sub.2 H.sub.5                                                
                C.sub.3 H.sub.7 -iso                                      
                      C.sub.3 H.sub.7 -iso                                
                           68    n.sub.D.sup.21 :1,5028                   
4     CH.sub.3                                                            
           CH.sub.3                                                       
                C.sub.3 H.sub.7 -iso                                      
                      CH.sub.3                                            
                           77    n.sub.D.sup.27 :1,5152                   
5     C.sub.2 H.sub.5                                                     
           CH.sub.3                                                       
                N(CH.sub.3).sub.2                                         
                      CH.sub.3                                            
                           74    n.sub.D.sup.25 :1,5436                   
6     C.sub.2 H.sub.5                                                     
           C.sub.2 H.sub.5                                                
                SCH.sub.3                                                 
                      C.sub.2 H.sub.5                                     
                           96    n.sub.D.sup.20 :1,5481                   
7     C.sub.3 H.sub.7 -iso                                                
           CH.sub.3                                                       
                C.sub.3 H.sub.7 -iso                                      
                      CH.sub.3                                            
                           85    n.sub.D.sup.21 :1,5058                   
8     C.sub.2 H.sub.5                                                     
           CH.sub.3                                                       
                C.sub.3 H.sub.7 -iso                                      
                      CH.sub.3                                            
                           72    n.sub.D.sup.21 :1,5128                   
9     C.sub.3 H.sub.7 -iso                                                
           CH.sub.3                                                       
                C.sub.3 H.sub.7 -iso                                      
                      C.sub.2 H.sub.5                                     
                           85    n.sub.D.sup.21 :1,5000                   
10    CH.sub.3                                                            
           C.sub.2 H.sub.5                                                
                C.sub. 3 H.sub.7 -iso                                     
                      C.sub.2 H.sub.5                                     
                           85    n.sub.D.sup.21 :1,5108                   
11    C.sub.2 H.sub.5                                                     
           CH.sub.3                                                       
                C.sub.3 H.sub.7 -iso                                      
                      C.sub.2 H.sub.5                                     
                           77    n.sub.D.sup.19 :1,5082                   
12    CH.sub.3                                                            
           C.sub.2 H.sub.5                                                
                C.sub.3 H.sub.7 -iso                                      
                      CH.sub.3                                            
                           77    n.sub.D.sup.24 :1,5120                   
13    CH.sub.3                                                            
           C.sub.2 H.sub.5                                                
                C.sub.2 H.sub.5                                           
                      C.sub.2 H.sub.5                                     
                           57    n.sub.D.sup.24 :1,5130                   
14    C.sub.2 H.sub.5                                                     
           CH.sub.3                                                       
                C.sub.2 H.sub.5                                           
                      C.sub.2 H.sub.5                                     
                           61    n.sub.D.sup.24 :1,5090                   
15    CH.sub.3                                                            
           CH.sub.3                                                       
                C.sub.2 H.sub.5                                           
                      C.sub.2 H.sub.5                                     
                           68    n.sub.D.sup.24 :1,5168                   
16    CH.sub.3                                                            
           C.sub.2 H.sub.5                                                
                N(CH.sub.3).sub.2                                         
                      CH.sub.3                                            
                           60    n.sub.D.sup.26 :1,5488                   
17    CH.sub.3                                                            
           CH.sub.3                                                       
                N(CH.sub.3).sub.2                                         
                      CH.sub.3                                            
                           72    n.sub.D.sup.26 :1,5540                   
18    CH.sub.3                                                            
           C.sub.2 H.sub.5                                                
                CH.sub.3                                                  
                      CH.sub.3                                            
                           23    n.sub.D.sup.26 :1,5235                   
19    C.sub.2 H.sub.5                                                     
           CH.sub.3                                                       
                CH.sub.3                                                  
                      CH.sub.3                                            
20    CH.sub.3                                                            
           CH.sub.3                                                       
                CH.sub.3                                                  
                      CH.sub.3                                            
21    CH.sub.3                                                            
           C.sub.2 H.sub.5                                                
                OCH.sub.3                                                 
                      CH.sub.3                                            
22    C.sub.2 H.sub.5                                                     
           CH.sub.3                                                       
                OCH.sub.3                                                 
                      CH.sub.3                                            
23    CH.sub.3                                                            
           CH.sub.3                                                       
                OCH.sub.3                                                 
                      CH.sub.3                                            
24    C.sub.3 H.sub.7 -n                                                  
           CH.sub.3                                                       
                C.sub.3 H.sub.7 -iso                                      
                      CH.sub.3                                            
25    CH.sub.3                                                            
           CH.sub.3                                                       
                C.sub.4 H.sub.9 -tert.                                    
                      CH.sub.3                                            
                           83    n.sub.D.sup.23 :1,5121                   
26    CH.sub.3                                                            
           CH.sub.3                                                       
                C.sub.3 H.sub.7 -n                                        
                      CH.sub.3                                            
                           76    54                                       
27    C.sub.3 H.sub.7 -iso                                                
           CH.sub.3                                                       
                N(CH.sub.3).sub.2                                         
                      CH.sub.3                                            
                           75    n.sub.D.sup.22 :1,5349                   
28    CH.sub.3                                                            
           C.sub.2 H.sub.5                                                
                C.sub.3 H.sub.7 -n                                        
                      CH.sub.3                                            
29    CH.sub.3                                                            
           CH.sub.3                                                       
                C.sub.4 H.sub.9 -n                                        
                      CH.sub.3                                            
30    CH.sub.3                                                            
           CH.sub.3                                                       
                C.sub.4 H.sub.9 -iso                                      
                      CH.sub.3                                            
31    CH.sub.3                                                            
           CH.sub.3                                                       
                C.sub.4 H.sub.9 -sec                                      
                      CH.sub.3                                            
32    C.sub.2 H.sub.5                                                     
           C.sub.2 H.sub.5                                                
                C.sub.3 H.sub.7 -n                                        
                      CH.sub.3                                            
33    C.sub.3 H.sub.7 -iso                                                
           CH.sub.3                                                       
                C.sub.3 H.sub.7 -n                                        
                      CH.sub.3                                            
34    C.sub.2 H.sub.5                                                     
           CH.sub.3                                                       
                C.sub.3 H.sub.7 -n                                        
                      CH.sub.3                                            
35    CH.sub.3                                                            
           CH.sub.3                                                       
                C.sub.3 H.sub.7 -n                                        
                      C.sub.2 H.sub.5                                     
36    C.sub.2 H.sub.5                                                     
           CH.sub.3                                                       
                C.sub.3 H.sub.7 -n                                        
                      C.sub.2 H.sub.5                                     
37    C.sub.2 H.sub.5                                                     
           CH.sub.3                                                       
                C.sub.4 H.sub.9 -sec                                      
                      CH.sub.3                                            
38    C.sub.5 H.sub.11 -n                                                 
           CH.sub.3                                                       
                N(C.sub.2 H.sub.5).sub.2                                  
                      CH.sub.3                                            
39    CH.sub.3                                                            
           C.sub.4 H.sub.9 -n                                             
                OC.sub.3 H.sub.7 -iso                                     
                      CH.sub.3                                            
40    CH.sub.3                                                            
           CH.sub.3                                                       
                C.sub.5 H.sub.11 -n                                       
                      CH.sub.3                                            
41    CH.sub.3                                                            
           CH.sub.3                                                       
                SC.sub.4 H.sub.9 -sec                                     
                      CH.sub.3                                            
42    CH.sub.3                                                            
           CH.sub.3                                                       
                CH.sub.3                                                  
                      C.sub.6 H.sub.13 -n                                 
__________________________________________________________________________
 
    
     The insecticidal and acaricidal activity of the compounds of this invention is illustrated by the following examples in which the compounds according to the present invention are each identified by the number given in brackets and the known comparison compounds have the following structures: ##STR9## 
     EXAMPLE 2 
     Laphygma test 
     Solvent: 3 parts by weight of acetone 
     Emulsifier: 1 part by weight of alkylaryl polyglycol ether 
     To produce a suitable preparation of active compound, 1 part by weight of the active compound was mixed with the stated amount of solvent and the stated amount of emulsifier and the concentrate was diluted with water to the desired concentration. 
     Cotton leaves (Gossypium hirsutum) were sprayed with the preparation of the active compound until dew-moist and were then infested with caterpillars of the owlet moth (Laphygma exigua). 
     After the specified periods of time, the destruction in % was determined. 100% meant that all of the caterpillars had been killed whereas 0% indicated that none of the caterpillars had been killed. 
     The active compounds, the concentrations of the active compounds, the evaluation times and the results can be seen from the following table: 
     
                       TABLE 2                                                     
______________________________________                                    
(Laphygma test)                                                           
              Active com-                                                 
                         Degree of                                        
              pound con- destruction                                      
              centration in % after                                       
Active compound                                                           
              in %       3 days                                           
______________________________________                                    
(A)           0.01       100                                              
              0.001      0                                                
(6)           0.01       100                                              
              0.001      80                                               
(5)           0.01       100                                              
              0.001      80                                               
(8)           0.01       100                                              
              0.001      100                                              
(1)           0.01       100                                              
              0.001      100                                              
(7)           0.01       100                                              
              0.001      100                                              
(10)          0.01       100                                              
              0.001      100                                              
(11)          0.01       100                                              
              0.001      100                                              
(9)           0.01       100                                              
              0.001      100                                              
(17)          0.01       100                                              
              0.001      100                                              
(13)          0.01       100                                              
              0.001      100                                              
(14)          0.01       100                                              
              0.001      100                                              
(12)          0.01       100                                              
              0.001      100                                              
______________________________________                                    
 
    
     EXAMPLE 3 
     Tetranychus test (resistant) 
     Solvent: 3 parts by weight of acetone 
     Emulsifier: 1 part by weight of alkylaryl polyglycol ether 
     To produce a suitable preparation of active compound, 1 part by weight of the active compound was mixed with the stated amount of solvent and the stated amount of emulsifier and the concentrate was diluted with water to the desired concentration. 
     Bean plants (Phaseolus vulgaris) which were heavily infested with the two-spotted spider mite (Tetranychus urticae) in all stages of development were sprayed with the preparation of the active compound until dripping wet. 
     After the specified periods of time, the degree of destruction was determined as a percentage: 100% meant that all of the spider mites were killed whereas 0% meant that none of the spider mites were killed. 
     The active compounds, the concentrations of the active compounds, the evaluation times and the results can be seen from the following table: 
     
                       TABLE 3                                                     
______________________________________                                    
(Tetranychus test)                                                        
              Active com-                                                 
                         Degree of                                        
              pound con- destruction                                      
              centration in % after                                       
Active compound                                                           
              in %       2 days                                           
______________________________________                                    
(A)           0.1        95                                               
              0.01       0                                                
(B)           0.01       98                                               
              0.01       0                                                
(6)           0.1        98                                               
              0.01       60                                               
(5)           0.1        100                                              
              0.01       100                                              
(8)           0.1        100                                              
              0.01       100                                              
(7)           0.1        100                                              
              0.01       100                                              
(11)          0.1        100                                              
              0.01       100                                              
(9)           0.1        100                                              
              0.01       100                                              
(18)          0.1        100                                              
              0.01       98                                               
(15)          0.1        100                                              
              0.01       80                                               
(13)          0.1        100                                              
              0.01       98                                               
(14)          0.1        99                                               
              0.01       98                                               
(12)          0.1        100                                              
              0.01       80                                               
______________________________________                                    
 
    
     EXAMPLE 4 
     Test insect: Tenebrio molitor larvae in the soil 
     Solvent: 3 parts by weight of acetone 
     Emulsifier: 1 part by weight of alkylaryl polyglycol ether 
     To produce a suitable preparation of active compound, 1 part by weight of active compound was mixed with the stated amount of solvent, the stated amount of emulsifier was added and the concentrate was diluted with water to the desired concentration. 
     The amount of active compound was intimately mixed with the soil. The concentration of the active compound in the preparation was practically immaterial, the only decisive factor being the amount by weight of active compound per unit volume of soil, which is quoted hereinafter in ppm (=mg/l). The treated soil was filled into pots and the pots were left to stand at room temperature. 
     After 24 hours the test insects were introduced into the treated soil and after a further 2 to 7 days the degree of effectiveness of the active compound was determined in % by counting the dead and the live test insects. The degree of effectiveness was 100% if all of the test insects had been killed and was 0% if exactly as many test insects were still alive as in the case of the untreated control. 
     The active compounds, the amounts used and the results can be seen from the table which follows: 
     
                       TABLE 4                                                     
______________________________________                                    
(Tenebrio molitor larvae in the soil)                                     
                  Degree of destruction                                   
                  at an active compound                                   
                  concentration of                                        
Active compound   1.25 ppm                                                
______________________________________                                    
(B)               0                                                       
(3)               100                                                     
(7)               100                                                     
(9)               100                                                     
(10)              100                                                     
______________________________________                                    
 
    
     EXAMPLE 5 
     LT 100  test for Diptera 
     Test insects: Musca domestica 
     Solvent: Acetone 
     The active compound was dissolved in the solvent at a rate of 2 g per liter. The solution so obtained was diluted with further solvent to the desired lower concentrations. 
     2.5 ml of the solution of active compound were pipetted into a Petri dish. On the bottom of the Petri dish there was a filter paper with a diameter of about 9.5 cm. The Petri dish remained uncovered until the solvent had completely evaporated. The amount of active compound per square meter of filter paper varied with the concentration of the solution of active compound. About 25 test insects were then placed in the Petri dish and it was covered with a glass lid. 
     The condition of the test insects was continuously observed. The time which was necessary for 100% destruction was determined. 
     The active compounds, the concentrations of the active compounds and the times at which there was 100% destruction can be seen from the following table: 
     
                       TABLE 5                                                     
______________________________________                                    
(LT.sub.100 test for Diptera/Musca domestica)                             
              Active com-                                                 
              pound con-                                                  
              centration   LT.sub.100 in                                  
              of the       minutes (&#39;)                                    
Active compound                                                           
              solution in %                                               
                           or hours (h)                                   
______________________________________                                    
(B)           0.02         6.sup.h = 90%                                  
(4)           0.002        120&#39;                                           
(3)           0.02         210&#39;                                           
(1)           0.002        6.sup.h                                        
(7)           0.02         90&#39;                                            
(8)           0.02         120&#39;                                           
(9)           0.02         150&#39;                                           
(10)          0.02         150&#39;                                           
______________________________________                                    
 
    
     EXAMPLE 6 
     Test insects: Sitophilus granarius 
     Solvent: Acetone 
     The active compound was taken up in the solvent at a rate of 2 g per liter. The solution so obtained was diluted with further solvent to the desired concentrations. 
     2.5 ml of the solution of the active compound were pipetted into a Petri dish. On the bottom of the Petri dish there was a filter paper with a diameter of about 9.5 cm. The Petri dish remained uncovered until the solvent had completely evaporated. The amount of active compound per square meter of filter paper varied with the concentration of the solution of active compound. About 25 test insects were then placed in the Petri dish and it was covered with a glass lid. 
     The condition of the test insects was observed 3 days after the commencement of the experiments. The destruction, in %, was determined. 100% denoted that all of the test insects had been killed; 0% denoted that none of the test insects had been killed. 
     The active compounds, the concentrations of the active compounds, and the results can be seen from the following 
     
                       TABLE 6                                                     
______________________________________                                    
(Sitophilus granarius)                                                    
              Active com-                                                 
              pound concen- Degree of                                     
              tration of the                                              
                            destruction                                   
Active compound                                                           
              solution in % in %                                          
______________________________________                                    
(B)           0.002         0                                             
(4)           0.0002        100                                           
(1)           0.002         100                                           
(7)           0.002         100                                           
(8)           0.002         100                                           
(10)          0.002         100                                           
______________________________________                                    
 
    
     EXAMPLE 7 
     Test with parasitic fly larvae 
     Solvent: 35 parts by weight of ethylene polyglycol monomethyl ether 
     Emulsifier: 35 parts by weight of nonylphenol polyglycol ether 
     To produce a suitable preparation of active compound, 30 parts by weight of the active substance in question were mixed with the stated amount of solvent which contained the above-mentioned proportion of emulsifier and the concentrate thus obtained was diluted with water to the desired concentration. 
     About 20 fly larvae (Lucilia cuprina) were introduced into a test tube which contained about 2 ml of horse muscle. 0.5 ml of the preparation of active compound was applied to this horse meat. After 24 hours the degree of destruction in % was determined. 100% meant that all of the larvae had been killed and 0% meant that none of the larvae had been killed. 
     The active compounds, the concentrations of the active compounds and the results can be seen from the table which follows: 
     
                       TABLE 7                                                     
______________________________________                                    
(Test with parasitic fly larvae/Lucilia                                   
cuprina res.)                                                             
              Active com-                                                 
              pound con-    Degree of                                     
              centration    destruction                                   
Active compound                                                           
              in ppm        in %                                          
______________________________________                                    
(10)          100           100                                           
              30            100                                           
              10            100                                           
              3             100                                           
              1             100                                           
(11)          100           100                                           
              10            100                                           
              1             100                                           
______________________________________                                    
 
    
     EXAMPLE 8 
     Test with parasitic, adult stable flies (Stomoxys calcitrans) 
     Solvent: Cremophor 
     To produce a suitable preparation of active compound, the active substance in question was mixed with the stated solvent in the ratio of 1:2 and the concentrate thus obtained was diluted with water to the desired concentration. 
     10 Adult stable flies (Stomoxys calcitrans) were placed in Petri dishes which contained sandwiches which had been impregnated, one day before the start of the experiment, with 1 ml of the active compound preparation to be tested. After 3 hours the degree of destruction in percent was determined; 100% meant that all of the flies had been killed and 0% that none of the flies had been killed. 
     Active compounds, active compound concentrations and results can be seen from the table which follows: 
     
                       TABLE 8                                                     
______________________________________                                    
 (Test with parasitic, adult stable flies/                                
Stomoxys calcitrans)                                                      
             Active compound Degree of                                    
             concentration   destruction                                  
Active compound                                                           
             in ppm          in %                                         
______________________________________                                    
(10)         1,000           100                                          
             300             100                                          
             100             &gt;50                                          
             30              &lt;50                                          
(11)         1,000           100                                          
             300             100                                          
             100             100                                          
             30              100                                          
             10              &gt;50                                          
______________________________________                                    
 
    
     EXAMPLE 9 
     Test with parasitic scab mites (Psoroptes cuniculi) 
     Solvent: Cremophor 
     To produce a suitable preparation of active compound, the active substance in question was mixed with the stated solvent in the ratio of 1:2 and the concentrate thus obtained was diluted with water to the desired concentration. 
     About 10-25 scab mites (Psoroptes cuniculi) were introduced into 1 ml portions of the active compound preparation to be tested, which had been pipetted into the tablet nests of a blister pack. After 24 hours the degree of destruction in percent was determined. 100% meant that all of the mites had been killed and 0% meant that none of the mites had been killed. 
     Active compounds, active compound concentrations and results can be seen from the table which follows: 
     
                       TABLE 9                                                     
______________________________________                                    
(Test with parasitic scab mites/Psoroptes                                 
cuniculi)                                                                 
             Active compound Degree of                                    
             concentration   destruction                                  
Active compound                                                           
             in ppm          in %                                         
______________________________________                                    
(11)         1,000           100                                          
             100             100                                          
______________________________________                                    
 
    
     EXAMPLE 10 
     Test with parasitic, adult faceflies (Musca autumnalis) 
     Solvent: Cremophor 
     To produce a suitable preparation of active compound, the active substance in question was mixed with the stated solvent in the ratio of 1:2 and the concentrate thus obtained was diluted with water to the desired concentration. 
     10 Adult faceflies (Musca autumnalis) were placed in Petri dishes which contained sandwiches which had been impregnated, one day before the start of the experiment, with 1 ml of the active compound preparation to be tested. After 3 hours, the degree of destruction in percent was determined; 100% meant that all of the flies had been killed and 0% that none of the flies had been killed. 
     Active compounds, active compound concentrations and results can be seen from the table which follows: 
     
                       TABLE 10                                                    
______________________________________                                    
(Test with parasitic, adult faceflies/                                    
Musca autumnalis)                                                         
             Active compound Degree of                                    
             concentration   destruction                                  
Active compound                                                           
             in ppm          in %                                         
______________________________________                                    
(10)         1,000           100                                          
             300             100                                          
             100             100                                          
             30              &gt;50                                          
             10              &lt;50                                          
(11)         1,000           100                                          
             300             100                                          
             100             &gt;50                                          
             30              &lt;50                                          
______________________________________                                    
 
    
     It will be appreciated that the instant specification and examples are set forth by way of illustration and not limitation, and that various modifications and changes may be made without departing from the spirit and scope of the present invention.