DE1618416A1 - Process for the preparation of dithiolphosphoric acid triesters - Google Patents

Description

Process for the preparation of dithiolphosphoric acid triesters The present invention relates to dithiolphosphoric acid triesters of the general constitution which have fungicidal properties and a process for their preparation.

In the above formula, R stands for a lower alkyl, haloalkyl, Alkenyl, a cycloalkyl, phenyl or halophenyl radical, while R 'is a halogen atom, denotes a nitro, lower alkyl or alkoxy group and n denotes zero, 1, 2 or 3 has.

French Patent No. 1,378,035 already discloses (thino) dithiolphosphoric acid diester monoamides of the general structure known, where R5 and Rb can represent hydrogen atoms, alkyl or aryl radicals and Rc and Rd, inter alia, stand for aryl radicals, while X represents an oxygen or sulfur atom. According to the information in the aforementioned French patent, these compounds are suitable for controlling plant pests and plant diseases.

It has now been found that S, S-dibenzyldithiolphosphoric acid triesters of the structure (I) given above are obtained if phosphoric acid monoester dihalides of the general constitution with benzyl mercaptans of the formula in the presence of acid binders.

The S, S-diphenyldithiolphosphoric acid triesters obtainable according to the process are distinguished by excellent fungitoxic properties with only low toxicity to warm-blooded animals; In this respect, surprisingly, they are clearly superior to known, similarly built products that have already been proposed for the same purpose and thus represent a real enrichment of the technology. In the formulas (III) to (V) the symbols R, R 'and n have the meaning given above, while Hal stands for a halogen atom.

However, R preferably denotes a straight or branched one, optionally one or more halogen-substituted alkyl radical with 1 to 6 carbon atoms, e.g. the Methyl, ethyl, n- and isopropyl, n-, iso-, sec.- and tert-butyl, n-, sec.- and tert-amyl, n-hexyl, 2-chloroethyl, 2,2,2-trichloroethyl, and also an alkenyl group with a maximum of 4 carbon atoms, for example, the allyl or crotonyl radical. Farther R is preferably a cyclohexyl, also mono-, di- and trialkylcyclohexyl- such as 2- or 3- or 4-methylcyclohexyl, 1,1-, 1,2-, 1,3- and 1,4-dimethylcyclohexyl, 2-, 3- and 4-ethyl, propyl and tert-butyl-cyclohexyl radical.

Finally, R preferably also represents a phenyl, mono-, di- and trichlorophenyl radical represent.

R 'preferably denotes chlorine, bromine or fluorine, the nitro, methyl or methoxy group, Hal is a chlorine or bromine atom and n preferably has the value zero or 1. As examples of phosphoric acid monoester dihalides to be reacted according to the process of structure (III) may be mentioned: O-methyl-, -ethyl-, -n-propyl-, -iso-propyl-, -n-butyl-, -iso-butyl-, -sec-butyl-, -tert-butyl-, -2-chlorothyl-, -Cyclohexyl-, -2-, -3- and -4-methylcyclohexyl-, -4-tert-butylcyclohexyl, -phenyl-, -2-, -3- and -4-chlorophenyl-, -2,4- and 3,4-dichlorophenyl-, -2,4,5-, -3,4,5- and -2,4,6-trichlorophenylphosphoric acid monoester dichloride.

Benzyl mercaptans to be reacted according to the invention are of the general Constitution (IV) may be mentioned, for example: Benzyl-, 2-, 7- and 4-chlorobenzyl-, 2-, 3- and 4-methylbenzyl, 4-isopropylbenzyl, 4-methoxybenzyl, 2-, 3- and 4-nitrobenzyl, 2- and 4-bromobenzyl mercaptan.

Those to be used as starting materials according to the present invention Phosphoric acid monoester dihalides are for the most part already in the literature described. You can by known methods from the phosphorus oxyhalides Reaction with the corresponding alcohols or phenols often without use are produced by acid acceptors. The raw products obtainable in this way you can usually immediately without prior distillative purification in the gutter of the present Implementing the invention.

The claimed process is preferred in the presence of solvents or thinners carried out. As such, practically all inert ones come organic solvents in retrospect. However, they may have proven particularly useful chlorinated aliphatic and aromatic hydrocarbons, such as methylene chloride, Di-, tri- and tetrachlorethylene, chloroform, carbon tetrachloride7 gasoline, benzene, Chlorobenzene, toluene and Xylene; Ethers, e.g. diethyl and di-n-butyl ethers, Dioxane, tetrahydrofuran; low molecular weight aliphatic ketones and nitriles, for example Acetone, methyl ethyl, methyl isopropyl and methyl isobutyl ketone, aceto and propionitrile, also low-boiling aliphatic alcohols such as methanol, ethanol and isopropanol.

As already mentioned above, the implementation is carried out in accordance with the procedure in the presence of acid binders. All common ones can be used for this purpose Acid acceptors, such as alkali hydroxides, carbonates and alcoholates, but also tertiary ones organic bases, e.g. triethylamine, dimethylaniline, benzyldimethylamine and pyridine be used. Instead of working in the presence of acid binders, it is the same It is quite possible to start with the salts, preferably alkali metal or ammonium salts, of the relevant To produce benzyl mercaptans in substance and then with the corresponding Implement phosphoric acid monoester dihalides.

The method according to the invention can be carried out within a relatively wide temperature range be carried out with success. Generally one works between -20 0C and the boiling point of the mixture, preferably from 0 to 1000C.

The reaction is preferably carried out under normal pressure, however can also be used with positive or negative pressure.

When carrying out the process according to the invention, one generally uses per mole of the phosphoric acid monoester dihalide in question two Moles of benzyl mercaptan; however, the latter can also be used in excess.

Furthermore, the phosphoric acid monoester dihalide is useful the above temperatures with stirring to the solution or suspension of the relevant benzyl mercaptan (or the corresponding mercaptide) was added dropwise. Included is - because the implementation usually has a more or less positive warmth runs - sometimes an external cooling of the mixture is necessary.

Finally, it has been found to be useful to add the reaction mixture after the initial components have been combined to complete the implementation extended time (1 to 5 hours or overnight), if necessary with heating stir. In this case, the process products are obtained in particularly good yields as well as in excellent purity.

The reaction mixture is worked up according to principles known in principle Methods by pouring the batch in water, separating the layers, washing and drying the organic phase, distilling off the solvent - as far as possible Fractional distillation of the residue under reduced pressure.

The dithiolphosphoric acid triesters obtainable according to the process fall either in the form of crystalline compounds with a sharp melting point, which are easily further purify by recrystallization from the common solvents leave or they represent colorless to yellow water-insoluble oils, which only partly under greatly reduced pressure without decomposition distilled can be. If this is not possible, one can use those obtainable according to the invention For the purpose of cleaning, "distill" compounds, i.e. by brushing them for a long time reduced pressure to slightly to moderately elevated temperatures from the last volatile Free impurities.

According to the process of the present invention, the following compounds, among others obtained: 0-ethyl-, -n-propyl- and -n-butyl-S, S-dibenzyl-, 0-ethyl-, n-propyl- and n-butyl-S, S-di (2- or 4-methyl-benzyl) -, 0-ethereal and isopropyl-S, S-di (4-chlorobenzyl -) -, O-ethyl-S, S-di (4-methoxybenzyl) -, 0-allyl-S, S-dibenzyl-, O-ethyl-S, S-di (2,4-dichlorobenzyl) -, O-Ethyl-S, S-di (4-nitrobenzyl) - O-IsOpropyl-S, S-dibenzyl- and O-isopropyl-S, S-di- (2-methylbenzyl) -dithiolphosphoric acid ester, 0-phenyl- and O-cyclohexyl-S, S-dibenzyl-, -S, S-bis- (2- or 4-methylbenzyl) -, -S, S-bis- (4-chlorobenzyl) -, -S, S-bis- (2,4- or 3,4-dichlorobenzyl) -, -S, S- (2,4,5- or

3,4,5- or 2,4,6-trichlorobenzyl) -, -S, S-bis- (2- or 3- or

4-methoxybenzyl) -, -S, S-bis- (2- or 3- or 4-nitrobenzyl) -dithiolphosphoric acid ester and the corresponding 0-trimethylcyclohexyl-S, S-dibenzyl-dithiolphosphoric acid esters.

As already mentioned, the products of the process are highly fungitoxic Effective against a number of fungal pathogens. Based on these In fact, as well as in view of their low toxicity to warm blooded animals, they are therefore used Combating unwanted fungal growth particularly suitable, with dS being good compatibility for higher plants their use against fungal diseases is particularly favored. the Compounds obtainable according to the invention can be used as fungitoxic agents in crop protection against fungi of various classes, e.g. Archimycetes, Phycomycetes, Ascomycetes, Basidiomycetes and Fungi imperfecti.

However, the process products have proven particularly useful in Combating rice diseases, as it is an excellent protective and curative Have an effect against Piricularia oryzae on rice.

In addition, they can also be used to combat further fungus-proof Find pathogens on ice plants and other cultivated plants. A special They are effective against the following types of fungi: Cochliobolus miyabeanus Mycosphaerella species Corticium species Cerospora species Alternaria species Botrytis species aside from that show the active ingredients to be used according to the invention a very good effect on Fungi that attack the plant from the ground and sometimes cause tracheomycoses, such as Fusarium cubense, Fusarium dianthi, Verticillium alboatrum and Phialophora cinereecens.

When used as fungitoxic agents, one can use those according to the invention active ingredients that can be produced either individually or in combination with one another Bring commitment. It is also a mixture with other pesticides, such as Fungicides, herbicides, insecticides and bactericides possible.

Depending on their intended use, the new active ingredients can be converted into the usual ones Formulations such as solutions, emulsions, suspensions, powders, Pastes and granulates. These are made in a known manner, e.g. B. by stretching of the active ingredients with solvents and / or carriers, if appropriate with use of emulsifiers and / or dispersants, where z. B. in the case of use of water as the diluent, optionally organic solvents as auxiliary solvents can be used (cf.

Agricultural Chemicals, March 1960, pages 35-38). As auxiliaries are essentially: solvents such as aromatics (e.g. xylene, benzene), chlorinated aromatics (e.g.

Chlorobenzenes), paraffins (e.g. 3rd petroleum fractions), alcohols (e.g. methanol, Butanol), amines and amine derivatives (e.g. ethanol- "amine, dimethylformamide) and water; Carriers, such as natural ones Rock flour (e.g. kaolins, clays, Talc, chalk) and synthetic stone powder (e.g. highly dispersed silica, silicates); Emulsifiers, such as non-ionic and anionic emulsifiers (e.g. polyoxyethylene fatty acid esters, Polyoxyethylene fatty alcohol ethers, alkyl sulfonates and aryl sulfonates) and dispersants, such as lignin, sulphite waste liquors and methyl cellulose.

As already mentioned above, the active ingredients according to the invention can openly present in the formulations as a mixture with other known active ingredients.

The formulations generally contain between 0.1 and 95 percent by weight Active ingredient, preferably between 0.5 and 90%.

The use of the process products or their preparations as fungitoxic agents happen in the usual way, e.g. by spraying, scattering, Spraying, misting. The active ingredient comes depending on the intended use in a concentration of 5 to 0.0005% for use. This area of concentration however, it can also be exceeded or not reached in special cases.

The excellent fungitoxic effect of those producible according to the invention S, S-diphenyldithiophosphoric acid triesters and their clear superiority in comparison The following test results show that products of the state of the art constructed in a similar manner are based on the results emerged: Example A Piricularia test / liquid active ingredient preparation Solvent: 1 part by weight of acetone. Dispersant: 0.05 part by weight of sodium oleate Other additives: 0.2 parts by weight gelatin, water 98.75 parts by weight H20 the amount of active substance required for the desired concentration of active substance in the spray liquid with the specified amount of solvent and dilute the concentrate with the specified amount of water containing the additives mentioned.

30 rice plants about 14 days old are sprayed with the spray liquid until dripping wet. The plants remain in a greenhouse until they are dried at temperatures of 22 to 24 0C and a relative humidity of about 70,.

After that, they are treated with an aqueous suspension of 100,000 to 200 000 spores / ml of Piricularia oryza and inoculated in a room at 24 - 26 ° C and 100% relative humidity.

5 days after the inoculation, the infestation is in all at the time of Inoculation of leaves present as a percentage of the untreated, cancer also inoculated Control plants determined. 0% means no infestation, 100% means that the infestation is exactly 80 as high as the control plants.

Active ingredients, active ingredient concentrations and results are based on the following Table shows: Test for curative effect In the case of the above described test with liquid active ingredient preparation is in addition to the protective the curative effect of the process products is also determined. The exam for curative The effect deviates in some points from the test procedure described above; the only provides a statement about the protective effect, insofar as the active ingredients not before, but only 16 hours after the inoculation. Substances, the b this type of implementation shows an effect, are able to kill the fungus after infection and thereby have a curative effect.

Table Pircularia test / liquid active ingredient preparation Infestation in% of the infestation of the untreated control at an active ingredient concentration (in%) of active ingredient (constitution) 0.05 0.025 (Comparative preparation known from French patent specification 1,378,035) It means: pr. = protective effect cur. = curative effect The following examples provide an overview of the claimed method: Example 1: 0.5 molar batch: 124 g of benzyl mercaptan are dissolved in 600 com benzene. 102 g of triethylamine are added to this solution while stirring, then 82 g of 0-ethylphosphoric acid ester dich10rid are added dropwise with further stirring and the mixture is then stirred for a further 2 hours at room temperature. The reaction mixture is then washed with water until the reaction is neutral, the aqueous layer is separated off, the benzene solution is dried over sodium sulfate and finally the solvent is distilled off under reduced pressure. 130 g (77% of theory) of the O-ethyl-S, S-dibenzyl-dithiolphosphoric acid ester are obtained as a colorless, water-insoluble oil.

Analysis: P S calculated for a molecular weight of 338: 9.2%; 18.9%; Found: 9.3%; 18.8.

Example 2: 0.25 molar batch: 51 g of triethylamine are added to a solution of 80 g of 4-chlorobenzyl mercaptan in 300 cc of benzene, 4.1 g of O-ethylphosphoric acid ester dichloride are then added dropwise while stirring at 200 ° C. The mixture is then stirred for another hour and worked then as described in Example 1. 90 g (89% of theory) of the O-ethyl-S, S bis (4-chlorobenzyl) dithiolphosphoric acid ester are obtained in the form of a water-insoluble colorless oil.

Analysis: P S cl calculated for a molecular weight of 407: 7.6%; 15.7 %; 17.4%; Found: 7.5%; 15.2%, 18.0%.

Example 3: 0.6 molar batch: 147 g of benzyl mercaptan are dissolved in 600 cc of benzene, 123 g of triethylamine are added to this solution, then 108 g of on-propylphosphoric acid ester dichloride are added dropwise with stirring at 15 to 20 ° C., the reaction mixture is then stirred for a further 4 hours and worked it then up as in the previous examples. 168 g (80% of theory) of the on-propyl-S, S-dibenzyl-dithioiphosphoric acid ester are thus obtained as a colorless, water-insoluble oil.

Analysis: P S calculated for a molecular weight of 352: 8.8%; 18.2%; Found: 8.1%; 18.0%.

Example 4: 0.75 molar batch: A solution of 186 g of benzyl mercaptan in 800 cc of benzene is first admixed with 153 g of triethylamine and then with 147 g of 0-sec.-butylphosphoric acid ester dichloride dropwise with stirring at 20 to 30 ° C. The reaction mixture is then stirred for a further 4 hours and then worked up as described in Example 1. 228 g (83% of theory) of the O-sec-butyl-S, S-dibenzyl-dithiolphosphoric acid ester are thus obtained as water-insoluble oil.

Analysis: Calculated for a molecular weight of 366: 8.5%; 17.5%; Found: 8.4%; 17.0.

Example 5: 0.6 molar batch: 147 g of benzyl mercaptan are dissolved in 600 cc of benzene. First 123 g of triethylamine are added to this solution, followed by 165 g of 0- (4-tert-butylcyclohexyl) phosphoric acid ester dichloride, dissolved in 150 cc of benzene, then dropwise at 20 to 30 ° C. The mixture is then stirred for a further 2 hours at 30 to 4 ° C. and then works it up in the manner described above. 185 g (69% of theory) of the O- (4-tert-butylcyclohexyl) - S, S-dibenzyldithiolphosphoric acid ester are thus obtained in the form of a water-insoluble oil.

Analysis: P S calculated for a molecular weight of 448: 6.9%; 14.3%; Found: 6.9%; 14.1%.

Example 6: X, molar approach: 147 g are dissolved in 600 com benzene, this solution is first treated with 123 g of triethvlamin, then dropwise at 25 to 300 ° C. with 127 g of 0-phenylphosphoric acid ester dichloride, then stirred for a further 2 hours at room temperature and it works Reaction mixture as described in Example 1. 205 g (88% of theory) of the O-phenyl-S, S-dibenzyl-dithiolphosphoric acid ester are thus obtained as a colorless, water-insoluble oil.

Analysis: P Calculated for a molecular weight of 386: 8.0%; 16.6%; Found: 7.9%; 16.7%.

Example 7: 0.6 molar batch: To a solution of 147 g of benzyl mercaptan in 600 cc of benzene, 123 g of triethylamine and then 138 g of O (4-chlorophenyl) phosphoric acid ester dichloride are added dropwise with stirring at 25 to 30 ° C. The mixture is then stirred for a further two hours, then worked up in the manner described above and 177 g (70% of theory) of the 0- (4-chlorophenyl) -S, S-dibenzyl-dithiolphosphoric acid ester are obtained in the form of colorless crystals Melting point 660C.

Analysis: r S C1 Calculated for a molecular weight of 420: 7.4%; 15.2 %; 8.4%; Found: 7.8%; 15.2 2%; 8.5.

Example 8: 0.6 molar batch: 123 g of triethylamine are added to a solution of 147 g of benzyl mercaptan in 600 cc of benzene. 140 g of 0- (3-methylcyclohexyl) phosphoric acid ester dichloride are then added dropwise to the reaction mixture at 200.degree. C. while stirring, the latter is stirred for a further 3 hours at 30.degree. To 400.degree. C. and then worked up as described in Example 1. 160 g (66% of theory) of the 0- (3-methylcyclohexyl) -S, S-dibenzyl-dithiolphosphoric acid ester are thus obtained as a colorless, water-insoluble oil.

Analysis: P S calculated for a molecular weight of 406: 7.6%; 15.8%; Found: 7.6%; 15.2%.

Example 9: 0.6 molar batch: 147 g of benzyl mercaptan are dissolved in 600 cc of benzene. This solution is first mixed with 123 g of triethylamine, then at 15 to 200C dropwise with stirring with 140 g of 0- (4-methylcyclohexyl) phosphoric acid ester dichloride, the mixture is then stirred for a few hours and then worked up in the manner described above. 195 g (79 * of theory) of the O- (4-methyl-cyclohexyl) - S, S-dibenzyl-dithiolphosphoric acid ester are thus obtained in the form of a colorless, water-insoluble oil.

Analysis: P S calculated for a molecular weight of 406: 7.6%; 15.7%; Found: 7.1%; 15.0%.

Example 10 0.6 molar batch: 147 g of benzyl mercaptan are dissolved in 6-00 com benzene, 123 g of triethylamine are added to this solution and 140 g of O- (2-methylcyclohexyl) phosphoric acid ester dichloride are then added dropwise with stirring at 20 to 35 ° C. After the addition is complete, the reaction mixture is heated to 40 to 50 ° C. for a further 3 hours and then worked up as in Example 1. In this way, 105 g (43% of theory) of the O- (2-methylcyclohexyl) -S, S-dibenzyldithiolphosphoric acid ester are obtained in the form of a pale yellow, water-insoluble oil.

Analysis: P S calculated for a molecular weight of 406: 7.6%; 15.8%; Found: 7.6%; 16.1%.

Claims (5)

Claims: 1) Process for the preparation of dithiolphosphoric acid triesters, characterized in that phosphoric acid monoester dihalides of the general formula in which R represents a lower alkyl, haloalkyl, alkenyl, cycloalkyl, phenyl or halophenyl radical and Hal represents a halogen atom, with benzyl mercaptans of the general formula wherein R 'denotes a halogen atom, a nitro, lower alkyl or alkoxy group and n has the value zero, 1, 2 or 3, in the presence of acid binders. 2) S, S-dibenzyldithiolphosphoric acid triester of the general formula in which R, R 'and n have the meaning given in claim 1. 3) Fungitoxic agents characterized by a content of S, S-dibenzyldithiolphosphoric acid triestrem according to claim 2. 4) Method of combating fungi, characterized in that one S, S-Dibenzyl-dithiolphosphorsäuretriester according to claim 2 on the mushrooms or lets their living space work on. 5) Process for the production of fungitoxic agents, characterized in that that S, S-Dibenzyi-dithiolphosphorsäuretriester according to claim 2 with extenders and / or mixes surfactants.