NL8105228A - O-ALKYL AND O-ARYL-S- (TERT.ALKYL) ALKYL PHOSPHONOTHIOATES, METHOD FOR THE PRODUCTION THEREOF, AND THEIR USE AS INSECTICIDES AND NEMATOCIDES. - Google Patents

Description

e, ♦ 3Γ.0. 30,572 O-Alkyl and O-aryl-S- (tert.alkyl) alkylphosphonothioates, process for their preparation * and their use as insecticides and namatocides.

The present invention relates to O-alkyl and O-aryl-S- (t-alkyl) alkylphosphonothioate compounds * their preparation and their use as active ingredients * namely in insecticidal and nematocidal preparations for the protection of plants * 5 as well as intermediates of these connections.

Certain alkylphosphonothiate insecticides have been described, such as in U.S. Pat. No. 3, 209,020. None of the compounds disclosed in this patent or other prior art contain the S-tert.alkyl group in their formula.

It has been found that the S-tert.alkyl compounds of the formula 1 * in which S is an alkyl group of 1 to 8 carbon atoms, a haloalkyl group of 1 to 8 carbon atoms, an alkenyl group of 2 to 8 carbon atoms, a haloalkenyl group of 2 to 8 carbon-15 atoms, an alkenyl group with 2 to 8 carbon atoms or a haloalkynyl group with 2 to 8 carbon atoms, an alkyl group with 1 to 8 carbon atoms or aryl and a tert.alkyl group with 4 to 8 carbon atoms, a broad insecticide and nematocidal activity spectrum and 20 are of particular importance for the fight against

Diabrotica sp because of their excellent activity against this evil and their long residual effect in the soil.

A preferred group of these compounds has the formula 1, wherein 25 H is an alkyl group of 1 to 4 carbon atoms, most preferably methyl or ethyl, an alkyl group of 1 to 4 carbon atoms or phenyl or phenyl substituted with at least (but preferably a ) group selected from the group consisting of alkyl of 1 to 4 carbon-30 atoms (preferably methyl), alkoxy of 1 to 4 carbon atoms (preferably methoxy), alkylthio of 1 to 4 carbon atoms, alkylsulfinyl of 1 to 4 carbon atoms, alkylsulfonyl of 1 to 4 carbon atoms or a chlorine, bromine or fluorine atom or a nitro, cyano or trifluoromethyl group, and is tert-butyl or tert-amyl.

8105228 "2 ί 5" ν

The compounds described here can be prepared by methods known per se. Preferably, the compounds of the present invention are prepared from a starting S-alkyl-alkyl-phosphonothioic acid halide, which is reacted with an alcohol in the presence of a base to obtain the compounds of the present invention.

The preferred reaction scheme is the scheme of FIG. 1, wherein B is an alkyl group of 1 to 8 carbon atoms, a haloalkyl group of 1 to 8 carbon atoms, an alkenyl group of 2 to 8 carbon atoms, a haloalkenyl group of 2 to 8 carbon atoms. 8 carbon atoms, an alkynyl group of 2 to 8 carbon atoms or a haloalkynyl group of 2 to 8 carbon atoms, an alkyl group of 1 to 8 carbon atoms or aryl, R 1 is a tert.alkyl group of k to 8 carbon atoms and 15 y X halogen, preferably Cl is *

The reaction is preferably carried out at a temperature of about 0 ° C to 100 ° C in an organic solvent in the presence of a tertiary amine or of an aqueous base, such as aqueous NaOH, or, when the alkali metal alcohol is used or -phenolate, to obtain alkali metal salts, such as sodium.

Suitable organic solvents are, for example, benzene, toluene, cyclohexane and 2-butanone or the alcohol itself.

Suitable tertiary amines include trimethylamine, triethylamine, dimethylaniline, diethylaniline and pyridine.

The present invention also relates to the compounds of the formula II wherein R, R 1 and X have the meanings given above, which intermediates may be prepared by a simple process by direct addition of thiols to the alkylphosphonic acid dihalides *

The synthesis of S-alkyl-alkylphosphonothioic acid halides is usually carried out by methods other than the direct addition of thiols to alkylphosphonic acid dihalides, because the direct reaction is usually accompanied by an undesired side reaction, substituting both halogen atoms in the phosphonodihalide with the alkylthiol. The side reaction is a particular problem when using normal alkylthiols. Therefore, if the synthesis of normal S-alkyl-alkylphosphonothioic acid chlorides is desired, other routes are chosen.

40 It has now been found that tertiary alkylthiols react gently with alkyl phosphosonic acid dichloride to obtain the addition of a thiol with good yields according to the reaction equation of Figure 2, by reacting the compound of formula 3 with R 1 SH solvent * at a temperature of about 20 ° C to 100 ° C in the presence of a base, where R is an alkyl group of 1 to 8 carbon atoms, a haloalkyl group of 1 to 8 carbon atoms * an alkenyl group of 2 to 8 carbon atoms, a halo-alkenyl group having 2 to 8 carbon atoms, an alkynyl group having 2 to 8 carbon atoms or a haloalkenyl group having 2 to 8 carbon atoms, preferably R is an alkyl group having 1 to 4 carbon atoms, especially methyl or ethyl E is a tert-alkyl group having 4 to 8 carbon atoms, preferably tert-butyl or tert-amyl and X is halogen, especially chlorine.

Suitable reaction solvents include water and organic solvents. With water, the base is expediently an inorganic base, such as sodium hydroxide. With organic solvents, the base is expediently a tertiary amine such as trimethylamine, triethylamine, pyridine, dimethylaniline or diethylaniline.

Suitable organic solvents include benzene, toluene, cyclohexane, acetone and 2-butanone.

Generally, the reaction is carried out at a temperature between about 20 ° C and 10 ° C, however the temperature is not critical provided it is sufficient to allow the reaction to proceed at a reasonable rate and not to be excessive . It has been found effective to add the tertiary amine to the other reagents at a temperature of about 20 ° C to 30 ° C and then heating the entire reaction mixture to a temperature of about 70 ° C to 80 ° C to complete the reaction .

The reaction is usually carried out with a substantially equal molar ratio of the alkyl phosphonic acid dihalide, thiol and the base. An excess of about 10 to 20% of the alkyl phosphonic acid dihalide can be used with respect to the other reagents. In contrast, the use of a slight excess of thiol and base with respect to the alkylphosphonic acid dihalide (excess 5-10%) does not appreciably affect the yield.

The following examples illustrate the preparation of the intermediates of the compounds of the present invention, of the compounds themselves, as well as the pesticidal properties of the latter. It will be appreciated that all of the compounds described herein can be prepared by methods analogous to the methods described below.

Example I

S-tert-butyl-ethylphosphonothioic acid chloride 5 (Compound of formula ^).

To a solution of 32 * 0 g (0 * 22 mol) ethylphosphonic acid dichloride in 300 ml of toluene, 18 g (0 »2 mol) of 2-methyl-2-propanethiol was added * 22 g (0.22 mol) was added dropwise with stirring ) triethylamine was added and the reaction temperature was kept at 30-35 ° C during the addition of the amine. * After the complete addition of hefine, the mixture was stirred at ambient temperature overnight. * The amine hydrochloride was filtered off. and the toluene solution was concentrated under reduced pressure * 200 ml of hexane was added and the solution was filtered again at-13.

The solvents were stripped under reduced pressure and the residual liquid was distilled. The product (25 g, yield 72.5%) distilled at 72-73 ° C / 0.09 kPa. 1 H-NMR in chloroform-d- (CDCl 2) with Si (Me), as reference confirmed the 3 * 20 structure of the above compound.

Example II

Preparation of O-ethyl-S-tert-butyl-ethylphosphonothioate

To a solution of 8 * 0 g (0.01 $ mol) of S-tert.-butyl-ethyl-phosphonothioic acid chloride (Example I) in 50 ml of toluene was added a solution of Qt0k mol of sodium ethanolate in IfO ml of ethanol. The addition was carried out dropwise with stirring and the reaction was kept under nitrogen. The stirring was continued overnight at ambient temperature and then about 80% of the solvents were removed under reduced pressure. 100 ml of toluene were added and the sodium chloride formed by the reaction was filtered off. Toluene was stripped under reduced pressure and the residual liquid was distilled. The product (5 * 8 g, yield 69 * 6%) distilled at 69 - 72 ° C / 0.26 kPa.

H-NMR spectrum analysis of this product confirmed the structure of the above compound.

Examples III-VI

In an analogous manner as described in Example II, the following compounds of formula 1 were prepared. ifO

8105228 5

Example R R «j Kpt. C / kPa III c2H5 CH3 tert.butyl 64-67 / 0.09 IV C2H ^ tert.butyl 61-63 / 0.0065 V C2H ^ (0H3) 2CH tert.butyl 42-43 / 0.0065 5 vi C „ H_ C_H_ tert.amyl 56-58 / 0.009 2 5

Example VII

Preparation of O-phenyl-S-tert-butyl-ethylphosphonothioate (Compound of formula ^) *

To a solution of 5 g (0.025 mol) of S-tert-butyl-ethylphos-10-phonothioic acid chloride and 2.35 g (0.025 mol) of phenol in 20 ml of acetone was added 2.5 g (0.025 mol) of triethylamine at once, after which the mixture was stirred under nitrogen at ambient temperature overnight. The reaction mixture was diluted with 100 ml of toluene and washed once with a 5% solution of NaOH and twice with water. The solution was dried over anhydrous sodium sulfate and the solvent was stripped under reduced pressure. The residual liquid was subjected to a high vacuum (0.026 kPa) at 60 ° C for 15 minutes to obtain the desired product, which was confirmed by 20 1 H-NMR spectrum in chloroform-d- (CDCl 4) with tetramethylsilane as reference .

Examples VIII-XV

Described analogously ai.a in Example VII, the following compounds of formula 1 were prepared.

Example RR ^ R2 VIII o-methyl-phenyl tert-butyl IX C_H_ p-chloro-phenyl tert-butyl 2 3 X C2H3 phenyl tert.amyl XI C-m-trifluoromethylphenyl tert.amyl 2 3 30 XII C2H3 p-fluoro-phenyl tert.amyl XIII C2H3 p-chloro-phenyl tert.amyl XIV o-chloro-phenyl tert.amyl XV phenyl tert.amyl

Example XVI

4.6 g of meta-cresol were dissolved in 100 ml of acetone and potassium carbonate was added. The mixture was stirred at ambient temperature for 30 minutes, after which 7.5 g of S-tert-butyl-methylphosphonothioic acid chloride was added. Stirring was continued overnight, then filtered and the solvent 8105228 6 was evaporated. 100 ml of water were added and the mixture was extracted with 100 ml of ether. The ether extract was washed once with 5% potassium hydroxide, then with water, and finally dried and evaporated, yielding 0 g of 0-3-tolyl-S-tert.hutyl-methyl-5-phosphonothioate. The product was identified by its NMR spectrum. * The purity is greater than 90 #.

Example XVII

Experiment concerning the intrinsic activity on Diabrotica (• "corn rootworm") and "Southern ArmywormM.

10 A. Intrinsic activity on corn rootworm (CRw)

The compound to be tested is prepared in a 1% solution with acetone or ethanol. The stock solution is then diluted with an aqueous solution of Tween-20 and. water to the desired concentration (ie »500» 100, 1, 0.1, or 0.05 ppm). 2 ml of this solution are pipetted into a 9 cm * Petri dish containing two layers of filter paper.

Second stage larvae are introduced into the shell and the shell is closed. Observations regarding mortality and dying larvae are made after 2 days (if 8 hours) of treatment. The insecticidal activity is primarily a contact and a vapor effect with minimal absorption by the stomach. The results are summarized in Table A.

B * Intrinsic activity on Southern Armyworm (SAw)

A 1% stock solution of the material to be tested was prepared in acetone and diluted to the desired concentration with a 500 ppm aqueous Tween-20 solution.

Leaves of the Lima bean are dipped in the solution and transferred to Petri dishes (100 x 15 mm) containing two filter papers moistened with 2 ml of water. Each Petri dish contained one tray and was held open until the solution dried on the tray. Five larvae of Stage 3 Southern Armyworm (Spodoptera eridania) were added to the leaf and the shell was finally covered

The insects were kept at 25 ° C for 72 hours and the percent kill was recorded. The results are summarized in Table A.

C A ..........- 8105228 7 j

Table A% Mortality

• n. Dosage C Η I SAW

\ 4n dpm__

Example.

No. 1 0.1 0.05 500 100 II 100 95 75 100 100 III 100 100 100 100 90 IV 100 70 - 100 15 V 80 2 {5 80 15 VI 100 95 100 100 50 VII 100 100 90 100 95 VIII 100 100 15 100 100 IX 100 35 40 100 95 X 100 100 70 100 8o XI 100 100 85 100 80 XII 100 100 90 100 6o XIII 100 85 55 100- '75 XIV 95 95 15 100 80 XVI 100 100 100

These results demonstrate the excellent insecticidal activity of the compounds of the invention, which can be used to control numerous insects that damage crops, such as coleoptera (namely Diabrotica sp) or corn 5 rootworm and lepidoptera (in particular Spodoptera eridania) .

Moreover, no phytotoxicity has been observed on the treated plants in these tests.

For practical use, the compounds according to the invention are usually used in the form of preparations, which also form part of the invention and which generally contain one or more solid or liquid carriers in addition to the active ingredient according to the invention, which are common in agriculture and / or one or more surfactants, which are also common in agriculture.

In general, the preparations usually contain 0.001 to 95% by weight of active ingredient. Their surfactant content is generally between 0.1 and 20% by weight.

The term "" carrier "" within the meaning of the present specification refers to an organic or inorganic, natural 20 * 8105228 * * "8 or synthetic material * with which the active material is combined to facilitate application * transportation or handling · The carrier must therefore be inert and acceptable for agriculture. The carrier may be solid (eg clay products, natural or synthetic silicates, calcium or magnesium bicarbonate, calcium sulfate * or liquid (eg water, alcohols, ketones, ethers, esters, aromatic or aliphatic hydrocarbons, halogenated hydrocarbons, petroleum fractions, liquefied gas, etc.). When the carrier is water or a conventional organic solvent, the preparation preferably contains in addition to the active ingredient another compound such as, for example, a surfactant, a pesticide (for example, an insecticide or fungicide The surfactant which is suitable in the compositions of the invention may be a wetting, dispersing or emulsifying agent, either ionic or nonionic. Examples of nonionic products are condensation products of epoxyethane with fatty alcohols or with fatty acids or with fatty amides or amines, alkylphenols, esters of fatty acids and sorbitol, sucrose derivatives, and examples of anionic compounds are lignosulfonic acid salts, alkyl aryl sulfonic acids, alkyl sulfosuccinates and sulfosuccinamates, amino acid derivatives, cationic compounds such as the acetates of alkyl amines or imidazoline, amphoteric products such as the alkyl betaines or sulfobetaines.

In addition to the active ingredient, the carrier and the surfactant, the compositions of the invention may contain other additives such as non-surfactant dispersants, peptizers, protective colloids, thickeners, rain-resistant adhesives, stabilizers, preservatives , corrosion inhibitors, dyes, sequestering agents, anti-foaming agents, anti-lump agents, anti-gels, thixotropic agents and further known active ingredients with pesticidal properties (in particular herbicide, fungicide and insecticidal properties) or properties for promoting plant growth (in particular fertilizers) or plant growth control properties.

The preparations according to the invention can be prepared in the form of spray powders, dusts, granules, solutions, emulsifiable concentrates, emulsions, suspension concentrates and aerosols.

The spray powders usually contain 10 to 95% by weight of active ingredient and generally contain, in addition to a solid carrier, 0 to 5% by weight of wetting agent and 3 to 10% by weight of one or more stabilizers and / or other additives such as penetration. agents, adhesives or anti-caking agents, dyes and the like.

They are prepared by mixing the ingredients in mixers and grinding them in mills or other suitable crushers, eg airmills, to obtain the desired particle size.

The composition of an 80 percent spray powder is given by way of example (percentages by weight): 15 active ingredient 80% sodium alkylnaphthalene sulfonate 2% sodium lignosulfonate 2% anti-caking silica 3% kaolinite 13% 20 Another example of a spray powder is; active ingredient 50% sodium alkylnaphthalene sulfonate 2% low viscosity methyl cellulose 2% diatomaceous earth if6% 25 Yet another example of a spray powder isf active ingredient 90 # sodium dioctyl sulfosuccinate 0.2% synthetic silica 9 * 8%

A further example of a wettable powder according to the invention is: active material (compound no * 1) 30% calcium lignosulfonate (anti-flocculant) 5 # sodium isopropylnaphthalene sulfonate (humectant) 1% silicon oxide, anti-caking agent 30% 35 kaolin 34%

The powdered powders can be prepared as the wettable powders, but without the surfactants, dispersants, protective colloids, which are useless in these formulations. In that case, the solid support 40 is selected in particular to facilitate the grinding, 8 1 0 5 22 8. "· ΊΟ for absorbing when the active material is liquid and for ensuring the flow *

The granules and micro-granules, generally with a low active ingredient content, can be prepared in advance and then impregnated or incorporated in the mass, for example by spraying or by extrusion. In the latter case, the addition of binders and hygroscopic products is necessary to ensure their rapid disintegration into the soil. They generally have dimensions between 0.1 and 2 mm. The granules generally contain 0.5 to 25% by weight of active ingredient and 0 to 10% by weight of additives, such as stabilizers, slow release modifiers, and solvents.

The emulsifiable concentrates contain the active ingredient dissolved in a solvent (generally an aromatic hydrocarbon) and additionally, if necessary, an auxiliary solvent or a co-solvent, such as a ketone, an ester, an ether, etc.

Generally, the concentrates contain 5 to 60 wt / vol% active ingredients, 2 to 20 wt / vol% of the emulsifying agent and can be prepared, for example, by dissolving the active ingredient in the solvent or in a mixture of solvents and emulsifying agent, in a reservoir, which is provided with a good stirrer and a liquid circulation for heating and cooling. In addition to the active ingredient and the solvent, surfactants, stabilizers, penetrants, corrosion inhibitors, dyes and adhesives may be present.

An example of an emulsifiable concentrate is as follows: active ingredient (compound no. 1) 400 g / l alkali metal dodecylbenzene sulfonate 24 g / l nonylphenol treated with 10 mol epoxyethane 16 g / l cyelohexanone 200 g / l aromatic hydrocarbons q.s.p. 1 litre

The concentrated suspensions, which can also be used by spraying, are prepared to obtain a stable, flowable product which does not form deposits and these suspensions usually contain 10 to 75% by weight of active ingredient, 0.5 to 15% by weight. surfactants, 0.1 to 10 wt. thixotropic agents, 0 to 10 wt.% of suitable additives, such as anti-foaming agents, corrosion inhibitors, stabilizers, penetrants and adhesives, and as carrier water or an organic liquid 40 in which the active ingredient is substantially insoluble. Certain organic solids or inorganic salts can be dissolved in the carrier to assist in the prevention of sedimentation or to act as anti-freeze agents for the water. · These concentrated suspensions can be prepared, for example, by pre-crushing dispersing the active ingredient in a liquid carrier »containing water» a vegetable or mineral oil or the emulsified mixture thereof, containing the auxiliary ingredients such as the viscosity agent, the preservative agent and the antifreeze agent, followed by grinding the dispersion in a ball mill ·

The aqueous dispersions and emulsions obtained by diluting the aforementioned preparations with water, in particular the wettable powders and the emulsifiable concentrates according to the invention, also fall within the general scope of the present invention. -in-oil 'type or of the oil-in-water type and they can have a thick capacity, such as that of mayonnaise · For a so-called "low volume1 * application with spraying to very fine drops 20, solutions in organic solvents are prepared , which contain 70 to 99% active ingredient

All of these aqueous dispersions and emulsions or spray mixtures can be applied by any suitable method to crops in which weeds are to be destroyed, mainly by spraying, at dosages generally in the order of 900 to 1000 liters spray mixture per hectare. In addition to the compounds of the formula I, the preparation of these compounds and insecticidal and / or nematocidal preparations containing these compounds, the present invention relates to a method of controlling insects, characterized in that it consists of contacting the insects with an effective amount of a compound of the formula 1. This insecticidal treatment can, if desired, be carried out preventively, that is, before insects are present, by applying the compound 35 according to the invention to the overhead protect plant parts or on the ground, or by absorbing the product in the ground.

The amount of active ingredient to be used may vary depending on the particular compound and the bO insect to be controlled. In general, amounts of 10 to 10 g / cm 8105228-12 are suitable. When the compounds are used as nematocides, the amounts are 0.5 to 5 kg / ha. Obviously, larger quantities can be used in difficult cases.

8105228

Claims (9)

Rg is a tertiary alkyl group of 4 to 8 carbon atoms. Compounds according to claim 1, characterized in that R is an alkyl group of 1 to 4 carbon atoms. Compounds according to claims 1 and 2, characterized in that R 1 is an alkyl group of 1 to 4 carbon atoms. Compounds according to claim 1, wherein phenyl or phenyl substituted with one or more substituents selected from the group consisting of alkyl of 1 to 4 carbon atoms, alkoxy of 1 to 4 carbon atoms, alkyltio of 1 to 4 carbon atoms, alkylsulfinyl of 1 to 4 carbon atoms alkylsulfonyl of 1 to 4 carbon atoms, chlorine, bromine, fluorine, nitro, cyano and trifluoromethyl. Compounds according to claims 1 to 4, characterized in that R 1 is tert-butyl or tert-amyl. Compounds according to claim 1, characterized in. that R is alkyl, R 1 is alkyl of 1 to 3 carbon atoms, and 25 is R-tert-butyl or tert-amyl. 7. A mph or mole of claims 1,2 and 4 *, characterized in that R is methyl or ethyl, R 1 is phenyl or phenyl substituted with an atom of chlorine or fluorine or with methyl, metboxy or trifluoromethyl and R 1 is tert.butyl or tert. amyl. 8. Process for preparing the compounds according to claims 1 to 7, characterized in that an alkylphosphonotbioic acid balogenide is reacted with an alcobol or a phenol according to the reaction equation of fig. 1, wherein R, R 1 and R 2 are the above have the meanings stated and X represents a balogen atom. 9. Process according to claim 8, characterized in that the reaction is carried out with an alkylphosphonotbioic acid chloride. 10. Process according to either of Claims 8 or 9, characterized in that the reaction is carried out at a temperature of about 0 ° C to 100 ° C in an organic solvent in the presence of a tertiary amine or an inorganic base. Insecticide or nematocidal preparation, characterized in that the preparation as active ingredient contains at least 5 a compound according to claims 1 to 7. 12 * Method for protecting plants against insects, characterized in that a preparation according to claim 11 is used * 13 * Compounds of formula 2, wherein 10 B is an alkyl group with 1 to 8 carbon atoms, a haloalkyl group with 1 to 8 carbon atoms, an alkenyl group of 2 to 8 carbon atoms, a haloalkenyl group of 2 to 8 carbon atoms, an alkynyl group of 2 to 8 carbon atoms or a haloalkynyl group of 2 to 8 carbon atoms, B_ is a tertiary alkyl group having 4 to 8 carbon atoms and X X is halogen. * 14 * Compounds according to claim 13, characterized in that X is a chlorine atom. Compounds according to any one of claims 13 and 14, characterized in that B is tert-butyl or tert-amyl. Compounds according to claims 13 to 15, characterized in that E is an alkyl group with 1 to 4 carbon atoms. 17 * Process for the preparation of compounds according to claims 13 to 16, characterized in that a compound of formula 3 with BgSH is converted into a solvent in the presence of a base at a temperature of about 20 ° C to 100 ° C. . 18 * Process according to claim 17, characterized in that the solvent used is benzene, toluene, cyclohexane, acetone or 2-butanone. 19 * Process according to claim 17, characterized in that the base is trimethylamine, triethylamine, pyridine, dimethylaniline or diethylaniline * 20. Process according to claim 17, characterized in that as a solvent a solution of an inorganic base in water is used. ********* 8105228