A method for electrochemically synthesizing organophosphorus pesticides

Abstract

The present invention discloses a method for electrochemically synthesizing organophosphorus pesticides, and belongs to the technical field of electrolytic processes for producing compounds. In the present invention, white phosphorus is mixed with alcohol compounds, thiol compounds, additives, electrolytes, and organic solvents under an inert atmosphere to form an electrolytic reaction liquid; the electrolytic reaction liquid is electrolyzed under direct current, and the organophosphorus pesticides are collected. The method has the advantages of low cost and strong reaction selectivity, and overcomes the technical problem of low yield of target products caused by competitive reaction between thiol and hydroxyl groups; the present invention has high atomic utilization, low pollution, weak corrosion to equipment, meets the requirements of green and safe production, and has good prospects for industrial application.

Description

Technical Field

[0001] The invention relates to the technical field of electrolytic process for producing compounds, and in particular to a method for electrochemically synthesizing organophosphorus pesticides. Background Art

[0002] Organophosphorus pesticides are a widely used class of pesticides that work primarily by inhibiting the activity of acetylcholinesterase, leading to nerve conduction disorders and ultimately the death of pests.

[0003] The molecular structure of organophosphorus pesticides usually contains two phosphorus-oxygen bonds (PO) and one phosphorus-sulfur bond (PS). In the traditional synthesis method, phosphorus oxychloride is first subjected to a substitution reaction with alcohol or phenol, and then an oxidative coupling reaction is carried out with thiol to obtain the organophosphorus pesticide of the target structure. However, the reaction process will release a large amount of hydrogen chloride, which is very serious for environmental pollution and corrosion of the equipment. In addition, the synthesis route involves multiple reaction steps, the reaction system becomes more complicated, and the chance of side reactions increases accordingly. These side reactions may consume raw materials or be converted into by-products that are difficult to separate, thereby reducing the yield of the target product. The increase in reaction steps may also introduce additional losses during the separation, purification or conversion process. These losses may come from incomplete reactions, the generation of by-products, or from operational errors or inefficient equipment. Therefore, the traditional synthesis method of organophosphorus pesticides has the disadvantages of low yield and poor environmental protection.

[0004] The electrochemical synthesis route is a new method for preparing organophosphorus pesticides. For example, the Chinese invention patent with the publication number CN112921345A discloses a direct electrochemical synthesis method for thiophosphate compounds. The reaction adopts a three-electrode system, the cathode and the anode are platinum electrodes, and 0.1 mol / L silver nitrate acetonitrile solution is used as the reference electrode; in a certain concentration of tetrabutylammonium tetrafluoroborate (Bu4NBF4) acetonitrile solution, phosphite triester and thiol are added, and the electrolysis reaction is stirred for 2-6 h at a temperature of 25-55°C and a constant pressure of 0.6-1.4 V. After the reaction is completed, the thiophosphate compounds are obtained by separation. The synthesis method of the invention uses clean electric energy as an oxidant, which reduces environmental costs; the reaction substrate has good universality. However, its substrate uses phosphite triester compounds, which are toxic to organisms. They are usually volatile and have a strong odor. They can enter the organism through various routes such as inhalation, oral administration and skin contact. The procurement cost in industrial production and the harm to operators are high.

[0005] White phosphorus is a single substance of phosphorus, and its chemical formula is P4. White phosphorus is not volatile, can be stored in water for a long time, and has a wide source and low price. It is an ideal raw material for the industrial preparation of organophosphorus pesticides. In the invention patent with publication number CN115323406A, the inventor provides an electrochemical preparation method of phosphate triester compounds, wherein an organic solvent, white phosphorus, alcohol or phenol and an electrolyte are mixed, and an electrolysis reaction is carried out in a constant current mode to obtain phosphate triester compounds. The invention uses alcohol or phenol as a nucleophilic reagent, and reacts by electrooxidation of white phosphorus to obtain phosphate triester compounds with high Faraday efficiency. And the only by-product is hydrogen, which meets the requirements of green synthesis and has good industrial application prospects. Since thiol or thiophenol has similar functional group properties to alcohol or phenol, on the basis of the invention, if the reaction of hydroxyl, sulfhydryl and white phosphorus can be used to generate an organophosphorus pesticide molecule with two phosphorus oxygen bonds and one phosphorus sulfur bond in the structure, the synthesis of organophosphorus pesticides can be achieved in a safer way at a lower raw material cost.

[0006] However, the technical difficulty of using white phosphorus as a phosphorus source to react with hydroxyl and thiol groups through electrolysis to produce organophosphorus pesticide molecules is that there is obvious competition between hydroxyl and thiol groups during the synthesis. Under the premise of complete reaction, there are also four types of main products according to the arrangement and combination of group types, while in the case of incomplete reaction, there are more types of side reaction products. Therefore, the selectivity control of this strategy is extremely challenging. How to control the selectivity of this synthetic route is the key to achieving low-cost large-scale production. Summary of the invention

[0007] In view of the above-mentioned defects of the prior art, in the first aspect of the present invention, a method for electrochemically synthesizing organophosphorus pesticides with low cost, safety, environmental protection and strong reaction selectivity is provided, comprising the following steps:

[0008] In an inert atmosphere, white phosphorus is mixed with an alcohol compound of formula I, a thiol compound of formula II, an additive, an electrolyte, and an organic solvent to form an electrolytic reaction solution; the electrolytic reaction solution is electrolyzed under direct current to collect an organophosphorus pesticide of formula III;

[0009] The thiol compound is a thiol or thiophenol compound;

[0010] The additive includes at least one of acetic acid, sulfuric acid, trifluoroacetic acid, ferric chloride, zinc chloride, cupric chloride, scandium trifluoromethanesulfonate, lanthanum trifluoromethanesulfonate, lithium trifluoromethanesulfonate, ytterbium trifluoromethanesulfonate, samarium chloride, lithium chloride, lithium hexafluorophosphate, zinc hexafluorophosphate, calcium hexafluorophosphate, sodium hexafluorophosphate, lithium tetrafluoroborate, sodium tetrafluoroborate, and calcium tetrafluoroborate;

[0011] The reaction formula of the electrolysis is as follows:

[0012] ;

[0013] In the formula, R 1 Selected from C1-C 10 Alkyl, phenethyl;

[0014] When the thiol compound is a thiol compound, R 2 Selected from C1-C 19 Alkyl, benzyl and its halides, N-methylacetamide, methyl acetate, ethyl acetate, methyl propionate;

[0015] When the thiol compound is a thiophenol compound, R 2 Selected from substituted or unsubstituted phenyl groups; in the substituted phenyl group, the substituent includes at least one of C1-C4 alkyl, halogen, fluorine, methoxy and methylthio.

[0016] In chemical synthesis, those skilled in the art can add a chemical reaction amount of substrate based on the reaction formula, and considering the influence of reaction kinetics in actual synthesis, it is appropriate to add an excess amount of substrate to improve the yield. In addition, in the electrolysis of the present invention, controlling the ratio of alcohol compounds and thiol compounds within the following appropriate range also helps to optimize the competitive reaction of thiol and hydroxyl groups, and optimize the yield within an appropriate cost control range.

[0017] Preferably, the molar ratio of the white phosphorus to the alcohol compound is 1:2-50; the molar ratio of the white phosphorus to the thiol compound is 1:1-25; and the molar ratio of the white phosphorus to the additive is 0.2-5:1.

[0018] Preferably, the alcohol compound includes one of methanol, ethanol, isopropanol, n-butanol, n-hexanol and phenylethanol.

[0019] Preferably, the thiol compound includes one of benzyl mercaptan, 2-mercapto-N-methylacetamide, 2-methylpropanethiol, butyl mercaptan, phenylethyl mercaptan, 2-chlorobenzyl mercaptan, methyl thioglycolate, ethyl thioglycolate, and methyl mercaptopropionate.

[0020] Preferably, the thiophenol compound includes one of 4-methylthiophenol, 4-fluorothiophenol, 4-methoxythiophenol, 4-methylthiothiophenol, 2,4-dimethylthiophenol and 2,4-difluorothiophenol.

[0021] The electrolyte plays a role in improving the conductivity of the solution system, which helps to promote the normal progress of electrolysis and reduce energy consumption. Those skilled in the art can select common electrolyte types according to actual conditions, such as tetrabutylammonium iodide, potassium iodide, sodium iodide, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutyltetrafluoroboric acid, tetraethylammonium tetrafluoroborate, tetramethylammonium tetrafluoroborate, etc., all of which are suitable types for the present invention.

[0022] Preferably, the electrolyte includes at least one of tetrabutylammonium iodide, potassium iodide, sodium iodide, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutyltetrafluoroboric acid, tetraethylammonium tetrafluoroborate, and tetramethylammonium tetrafluoroborate.

[0023] Preferably, the concentration of the electrolyte in the electrolytic reaction solution is 0.1-0.4 mol / L.

[0024] The organic solvent is used to promote the dispersion of substances and create a suitable environment for the reaction. It is chemically inert to the raw materials, intermediates or products used in the synthesis and does not react with them. Similarly, those skilled in the art can select the appropriate solvent type and amount according to actual conditions. For example, 5-10 mL of organic solvent can be added to 1 mmol of white phosphorus.

[0025] Preferably, the organic solvent comprises at most four of acetonitrile, dimethyl sulfoxide, tetrahydrofuran, 1,4-dioxane, dichloromethane, N,N-dimethylformamide, N,N-dimethylacetamide, dichloroethane, chloroform, and N-methylpyrrolidone.

[0026] The electrolysis process can be implemented using a general electrolysis device without the need for specialized equipment or processing. For example, an integrated electrolytic cell equipped with a stirrer and an electrode can complete the synthesis of organophosphorus pesticides. In the electrolysis device, the types of cathode and anode are various. Anodes such as carbon sheets, graphite felt, carbon cloth, carbon paper, platinum sheets, carbon rods, etc., and cathodes such as platinum sheets, stainless steel, iron sheets, nickel sheets, copper sheets, carbon rods, magnesium sheets, zinc sheets, aluminum sheets, zinc sheets, etc. are all suitable electrode types. In addition, the electrolysis of the present invention can be carried out at a temperature in a relatively wide range. During the electrolysis process, the current density should be controlled within a suitable range, which is not only conducive to the efficient conversion of white phosphorus and reducing energy consumption, but also can avoid the serious heat release of the system caused by excessive current.

[0027] Preferably, the current density of the electrolysis is 5-500 mA / cm 2 .

[0028] Preferably, the electrolysis temperature is 0-60° C., and the electrolysis time is 20 min-4 h.

[0029] During the electrolysis process, high value-added hydrogen can be collected simultaneously. After the synthesis of the organophosphorus pesticide is completed, the product can be recovered by the process means commonly used in the art. For example, the reaction solution is organically extracted with an organic solvent, and then separated and purified to obtain the product; or the electrolyte is distilled and low-temperature condensed to collect the product.

[0030] Based on the above technical scheme, the inventive concept of the present invention is to use white phosphorus, which is widely available, cheap, low in toxicity and non-volatile, as a phosphorus source, and electrolyze it with alcohol, thiol or thiophenol compounds in an electrolyte environment, so that the functional groups of the target structure in the alcohol, thiol or thiophenol compounds are introduced into phosphorus to obtain an organophosphorus pesticide containing two PO bonds and one PS bond. The present invention adds additives to the electrolyte, activates white phosphorus during the electrolysis process, adjusts and improves the selectivity of the white phosphorus reaction, optimizes the competitive reaction between thiol and hydroxyl, and thus generates an organophosphorus pesticide with a target configuration.

[0031] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0032] The present invention provides a method for electrochemically synthesizing organophosphorus pesticides, which has the advantages of low cost and strong reaction selectivity, and overcomes the technical problem of low yield of target products caused by competitive reaction between thiol and hydroxyl groups; the present invention has high atomic utilization rate, low pollution, weak corrosion to equipment, meets the requirements of green and safe production, and has good prospects for industrial application. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is the nuclear magnetic resonance (NMR) hydrogen spectrum of the product of Example 8;

[0034] Figure 2 This is the carbon NMR spectrum of the product of Example 8. DETAILED DESCRIPTION

[0035] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. The experimental methods in the following examples without specifying specific conditions are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0036] In the following embodiments:

[0037] The anode and cathode are sheet electrodes with a size of 1.5 cm × 1.5 cm;

[0038] The sulfuric acid is commercially available concentrated sulfuric acid with a concentration of >98 wt.%.

[0039] Example 1

[0040] The method for electrochemical synthesis of organophosphorus pesticides comprises the following steps:

[0041]

[0042] In an argon atmosphere, 1 mmol of white phosphorus was added into a reaction tube and mixed with 5 mL of ethanol, 0.5 mL of benzyl mercaptan, 3 mmol of sulfuric acid, 3 mmol of tetrabutylammonium tetrafluoroborate (TBABF4), and 5 mL of 1,4-dioxane to obtain an electrolytic reaction solution;

[0043] The electrolytic reaction solution was placed in an integrated electrolytic cell equipped with a stirrer, with a carbon plate (CP) as the anode and a platinum plate (Pt) as the cathode, and electrolyzed at room temperature (rt) for 4 h under a constant direct current of 100 mA;

[0044] After the electrolysis, the crude product was purified by flash chromatography (the solvent was a mixture of petroleum and ethyl acetate in a volume ratio of 5:1) to recover the target product with a yield of 52%.

[0045] The NMR spectrum data of the product are as follows:

[0046] 1 H NMR (400 MHz, Chloroform-d) δ 7.48 – 7.19 (m, 5H), 4.37 – 3.68 (m,6H), 1.30 (t, J = 7.1 Hz, 6H).

[0047] 13 C NMR (101 MHz, Chloroform-d) δ 137.53 (d, J = 5.2 Hz), 128.90,128.65, 127.62, 63.51 (d, J = 5.7 Hz), 34.97 (d, J = 3.9 Hz), 15.96 (d, J =7.3 Hz).

[0048] 31 P NMR (162 MHz, Chloroform-d) δ 26.69.

[0049] Example 2

[0050] The method for electrochemical synthesis of organophosphorus pesticides comprises the following steps:

[0051]

[0052] In an argon atmosphere, 1 mmol of white phosphorus, 5 mL of methanol, 0.5 mL of 2-mercapto-N-methylacetamide, 3 mmol of sulfuric acid, 3 mmol of tetrabutylammonium tetrafluoroborate, and 5 mL of acetonitrile (methyl cyanide, MeCN) were added to a reaction tube to obtain an electrolytic reaction solution;

[0053] The electrolytic reaction solution was placed in an integrated electrolytic cell equipped with a stirrer, with a carbon sheet as the anode and a platinum sheet as the cathode, and electrolyzed at room temperature for 4 h under a constant direct current of 100 mA;

[0054] After the electrolysis, the crude product was purified by flash chromatography (the solvent was a mixture of petroleum and ethyl acetate in a volume ratio of 5:1) to recover the target product with a yield of 54%.

[0055] The NMR spectrum data of the product are as follows:

[0056] 1 H NMR (400 MHz, Chloroform-d)δ 7.12 (s, 1H), 4.18-4.08 (m, 4H), 3.40 (d, J = 19.2 Hz, 2H), 2.77 (d, J = 4.8 Hz, 3H), 1.32 (t, J = 6.8 Hz, 6H).

[0057] 13 C NMR (101 MHz, Chloroform-d)δ 168.7, 64.2 (d, JC-P = 6.8 Hz), 32.7 (d, JC-P = 3.5 Hz), 26.5, 15.8 (d, JC-P = 7.0 Hz).

[0058] 31 P NMR (162 MHz, Chloroform-d)δ 26.9.

[0059] Example 3

[0060] The method for electrochemical synthesis of organophosphorus pesticides comprises the following steps:

[0061]

[0062] In an argon atmosphere, 1 mmol of white phosphorus, 5 mL of ethanol, 0.5 mL of 2-methylpropanethiol, 3 mmol of sulfuric acid, 3 mmol of tetrabutylammonium tetrafluoroborate, and 5 mL of tetrahydrofuran (THF) were added into a reaction tube to obtain an electrolytic reaction solution;

[0063] The electrolytic reaction solution was placed in an integrated electrolytic cell equipped with a stirrer, with a carbon sheet as the anode and a platinum sheet as the cathode, and electrolyzed at room temperature for 4 h under a constant direct current of 100 mA;

[0064] After the electrolysis, the crude product was purified by flash chromatography (the solvent was a mixture of petroleum and ethyl acetate in a volume ratio of 5:1) to recover the target product with a yield of 56%.

[0065] The NMR spectrum data of the product are as follows:

[0066] 1 H NMR (400 MHz, Chloroform-d) δ 4.26 – 4.07 (m, 4H), 2.78 – 2.69 (m,2H), 1.98 – 1.85 (m, 1H), 1.36 (t, J = 7.1 Hz, 6H), 1.02 (d, J = 6.7 Hz, 6H).

[0067] 13 C NMR (101 MHz, Chloroform-d) δ 63.37 (d, J = 5.9 Hz), 39.33 (d, J =3.9 Hz), 29.45 (d, J = 5.9 Hz), 21.56, 16.03 (d, J = 7.3 Hz).

[0068] 31 P NMR (162 MHz, Chloroform-d) δ 28.49.

[0069] Example 4

[0070] The method for electrochemical synthesis of organophosphorus pesticides comprises the following steps:

[0071]

[0072] In an argon atmosphere, 1 mmol of white phosphorus was mixed with 5 mL of ethanol, 0.5 mL of propylmercaptan, 3 mmol of sulfuric acid, 3 mmol of tetrabutylammonium tetrafluoroborate, and 5 mL of dimethyl sulfoxide (DMSO) in a reaction tube to obtain an electrolytic reaction solution;

[0073] The electrolytic reaction solution was placed in an integrated electrolytic cell equipped with a stirrer, with a carbon sheet as the anode and a platinum sheet as the cathode, and electrolyzed at room temperature for 4 h under a constant direct current of 100 mA;

[0074] After the electrolysis, the crude product was purified by flash chromatography (the solvent was a mixture of petroleum and ethyl acetate in a volume ratio of 5:1) to recover the target product with a yield of 71%.

[0075] The NMR spectrum data of the product are as follows:

[0076] 1 H NMR (400 MHz, Chloroform-d) δ 4.22 – 4.03 (m, 4H), 2.78 (dt, J =14.5, 7.3 Hz, 2H), 1.68 (h, J = 7.3 Hz, 2H), 1.33 (t, J = 7.1 Hz, 6H), 0.97(t, J = 7.3 Hz, 3H).

[0077] 13 C NMR (101 MHz, Chloroform-d) δ 63.35 (d, J = 6.1 Hz), 32.79 (d, J =4.0 Hz), 24.14 (d, J = 5.7 Hz), 16.01 (d, J = 7.3 Hz), 13.10.

[0078] 31 P NMR (162 MHz, Chloroform-d) δ 28.25.

[0079] Example 5

[0080] The method for electrochemical synthesis of organophosphorus pesticides comprises the following steps:

[0081]

[0082] In an argon atmosphere, 1 mmol of white phosphorus was mixed with 5 mL of ethanol, 0.5 mL of phenylethylmercaptan, 3 mmol of sulfuric acid, 3 mmol of tetrabutylammonium tetrafluoroborate, and 5 mL of dimethyl sulfoxide in a reaction tube to obtain an electrolytic reaction solution;

[0083] The electrolytic reaction solution was placed in an integrated electrolytic cell equipped with a stirrer, with carbon cloth (CC) used as the anode and platinum sheet used as the cathode, and electrolyzed at room temperature for 4 h under a constant direct current of 100 mA;

[0084] After the electrolysis, the crude product was purified by flash chromatography (the solvent was a mixture of petroleum and ethyl acetate in a volume ratio of 3:1) to recover the target product with a yield of 51%.

[0085] The NMR spectrum data of the product are as follows:

[0086] 1 H NMR (400 MHz, Chloroform-d) δ 7.36 – 7.20 (m, 5H), 4.26 – 4.05 (m,4H), 3.16 – 3.04 (m, 2H), 3.01 (dd, J = 8.5, 5.9 Hz, 2H), 1.37 (t, J = 7.1Hz, 6H).

[0087] 13 C NMR (101 MHz, Chloroform-d) δ 139.42, 128.61 (d, J = 6.9 Hz), 126.70, 63.52 (d, J = 5.9 Hz), 37.20 (d, J = 5.5 Hz), 32.06 (d, J = 3.9 Hz), 16.09 (d, J = 7.3 Hz).

[0088] 31 P NMR (162 MHz, Chloroform-d) δ 27.78.

[0089] Example 6

[0090] The method for electrochemical synthesis of organophosphorus pesticides comprises the following steps:

[0091]

[0092] In an argon atmosphere, 1 mmol of white phosphorus, 5 mL of ethanol, 0.5 mL of 2-chlorobenzyl mercaptan, 3 mmol of sulfuric acid, 3 mmol of tetrabutylammonium tetrafluoroborate, and 5 mL of dimethyl sulfoxide were added into a reaction tube to obtain an electrolytic reaction solution;

[0093] The electrolytic reaction liquid was placed in an integrated electrolytic cell equipped with a stirrer, with graphite felt (CF) used as the anode and platinum sheet used as the cathode, and electrolyzed at room temperature for 4 h under a constant direct current of 100 mA;

[0094] After the electrolysis, the crude product was purified by flash chromatography (the solvent was a mixture of petroleum and ethyl acetate in a volume ratio of 3:1) to recover the target product with a yield of 55%.

[0095] The NMR spectrum data of the product are as follows:

[0096] 1H NMR (400 MHz, Chloroform-d) δ 7.46 (dd, J = 5.8, 3.5 Hz, 1H), 7.36 (dd, J = 5.8, 3.5 Hz, 1H), 7.22 (dd, J = 5.9, 3.5 Hz, 2H), 4.17 – 3.95 (m,6H), 1.28 (t, J = 7.1 Hz, 6H).

[0097] 13 C NMR (101 MHz, Chloroform-d) δ 135.26 (d, J = 4.7 Hz), 134.10,131.23, 129.68, 129.21, 126.99, 63.56 (d, J = 5.8 Hz), 32.85 (d, J = 3.8 Hz),15.93 (d, J = 7.4 Hz).

[0098] 31 P NMR (162 MHz, Chloroform-d) δ 26.58.

[0099] Example 7

[0100] The method for electrochemical synthesis of organophosphorus pesticides comprises the following steps:

[0101]

[0102] In an argon atmosphere, 1 mmol of white phosphorus was mixed with 1 mL of ethanol, 0.5 mL of 4-methylthiophenol, 1 mmol of sulfuric acid, 1 mmol of tetrabutylammonium tetrafluoroborate, 7 mL of acetonitrile, and 3 mL of dichloromethane (DCM) to obtain an electrolytic reaction solution;

[0103] The electrolytic reaction solution was placed in an integrated electrolytic cell equipped with a stirrer, with carbon cloth used as the anode and iron sheet (ferrum, Fe) used as the cathode, and electrolyzed at room temperature for 4 h under a constant direct current of 100 mA;

[0104] After the electrolysis, the crude product was purified by flash chromatography (the solvent was a mixture of petroleum and ethyl acetate in a volume ratio of 4:1) to recover the target product with a yield of 58%.

[0105] The NMR spectrum data of the product are as follows:

[0106] 1H NMR (400 MHz, Chloroform-d) δ 7.42 (dd, J = 8.3, 2.1 Hz, 2H), 7.12 (d, J = 7.9 Hz, 2H), 4.16 (tdd, J = 16.9, 8.6, 2.8 Hz, 4H), 2.31 (d, J = 2.1Hz, 3H), 1.28 (t, J = 7.1 Hz, 6H).

[0107] 13 C NMR (101 MHz, Chloroform-d) δ 139.23 (d, J = 3.1 Hz), 134.58 (d, J= 5.1 Hz), 130.13 (d, J = 2.4 Hz), 122.79 (d, J = 7.3 Hz), 63.93 (d, J = 6.2Hz), 21.14, 16.00 (d, J = 7.2 Hz).

[0108] 31 P NMR (162 MHz, Chloroform-d) δ 23.20.

[0109] Example 8

[0110] The method for electrochemical synthesis of organophosphorus pesticides comprises the following steps:

[0111]

[0112] In an argon atmosphere, 1 mmol of white phosphorus was mixed with 1 mL of ethanol, 0.5 mL of 4-fluorobenzenethiol, 1 mmol of lithium hexafluorophosphate (LiPF6), 1 mmol of tetrabutylammonium tetrafluoroborate, 7 mL of acetonitrile, and 3 mL of dichloromethane in a reaction tube to obtain an electrolytic reaction solution;

[0113] The electrolytic reaction solution was placed in an integrated electrolytic cell equipped with a stirrer, with carbon cloth used as the anode and iron sheet used as the cathode, and electrolyzed at room temperature for 4 h under a constant direct current of 100 mA;

[0114] After the electrolysis, the crude product was purified by flash chromatography (the solvent was a mixture of petroleum and ethyl acetate in a volume ratio of 3:1) to recover the target product with a yield of 73%.

[0115] The nuclear magnetic resonance spectrum data of the product are as follows, where the hydrogen spectrum and carbon spectrum of the nuclear magnetic resonance are as follows: Figure 1 , Figure 2 As shown:

[0116] 1 H NMR (400 MHz, Chloroform-d) δ 7.51 (ddd, J = 8.2, 5.5, 2.4 Hz, 2H), 7.01 (td, J = 8.7, 2.3 Hz, 2H), 4.14 (tdd, J = 16.7, 8.5, 2.7 Hz, 4H), 1.27 (td, J = 7.1, 2.0 Hz, 6H).

[0117] 13 C NMR (101 MHz, Chloroform-d) δ 163.28 (dd, J = 249.8, 3.3 Hz), 136.66 (dd, J = 8.5, 4.9 Hz), 121.70 (dd, J = 7.3, 3.4 Hz), 116.50 (dd, J =22.2, 2.4 Hz), 64.13 (d, J = 6.4 Hz), 15.97 (d, J = 7.0 Hz).

[0118] 31 P NMR (162 MHz, Chloroform-d) δ 22.50 (d, J = 6.0 Hz).

[0119] 19 F NMR (377 MHz, Chloroform-d) δ -111.68 (d, J = 5.3 Hz).

[0120] Example 9

[0121] The method for electrochemical synthesis of organophosphorus pesticides comprises the following steps:

[0122]

[0123] In an argon atmosphere, 1 mmol of white phosphorus, 1 mL of ethanol, 0.5 mL of 4-methoxythiophenol, 1 mmol of lithium chloride (LiCl), 3 mmol of tetrabutylammonium tetrafluoroborate, 9 mL of acetonitrile, and 1 mL of tetrahydrofuran were added into a reaction tube to obtain an electrolytic reaction solution;

[0124] The electrolytic reaction solution was placed in an integrated electrolytic cell equipped with a stirrer, with carbon cloth used as the anode and carbon rod (C rod) used as the cathode, and electrolyzed at room temperature for 4 h under a constant direct current of 100 mA;

[0125] After the electrolysis, the crude product was purified by flash chromatography (the solvent was a mixture of petroleum and ethyl acetate in a volume ratio of 1:1) to recover the target product with a yield of 60%.

[0126] The NMR spectrum data of the product are as follows:

[0127] 1 H NMR (400 MHz, Chloroform-d) δ 7.51 – 7.44 (m, 2H), 6.92 – 6.84 (m,2H), 4.30 – 4.09 (m, 4H), 3.81 (s, 3H), 1.36 – 1.28 (m, 6H).

[0128] 13 C NMR (101 MHz, Chloroform-d) δ 160.50 (d, J = 2.9 Hz), 136.34 (d, J = 4.8 Hz), 116.64 (d, J = 7.4 Hz), 114.98 (d, J = 2.4 Hz), 63.95 (d, J = 6.2Hz), 55.36, 16.05 (d, J = 7.2 Hz).

[0129] 31 P NMR (162 MHz, Chloroform-d) δ 23.51.

[0130] Example 10

[0131] The method for electrochemical synthesis of organophosphorus pesticides comprises the following steps:

[0132]

[0133] In an argon atmosphere, 1 mmol of white phosphorus was mixed with 1 mL of ethanol, 0.5 mL of 4-methylthiobenzenethiol, 1 mmol of lithium chloride, 3 mmol of tetrabutylammonium tetrafluoroborate, 9 mL of acetonitrile, and 1 mL of dichloroethane (DCE) in a reaction tube to obtain an electrolytic reaction solution;

[0134] The electrolytic reaction solution was placed in an integrated electrolytic cell equipped with a stirrer, with carbon cloth used as the anode and carbon rod used as the cathode, and electrolyzed at room temperature for 4 h under a constant direct current of 100 mA;

[0135] After the electrolysis, the crude product was purified by flash chromatography (the solvent was a mixture of petroleum and ethyl acetate in a volume ratio of 3:1) to recover the target product with a yield of 52%.

[0136] The NMR spectrum data of the product are as follows:

[0137] 1 H NMR (400 MHz, Chloroform-d) 1H NMR (400 MHz, Chloroform-d) δ 7.52– 7.41 (m, 2H), 7.23 – 7.16 (m, 2H), 4.28 – 4.08 (m, 4H), 2.46 (s, 3H), 1.31(t, J = 7.1 Hz, 6H).

[0138] 13 C NMR (101 MHz, Chloroform-d) δ 140.68 (d, J = 3.4 Hz), 134.93 (d, J = 5.1 Hz), 126.65 (d, J = 2.3 Hz), 122.05 (d, J = 7.4 Hz), 64.07 (d, J = 6.2Hz), 16.03 (d, J = 7.1 Hz), 15.25.

[0139] 31 P NMR (162 MHz, Chloroform-d) δ 22.78.

[0140] Embodiment 11

[0141] The method for electrochemical synthesis of organophosphorus pesticides comprises the following steps:

[0142]

[0143] In an argon atmosphere, 1 mmol of white phosphorus was added into a reaction tube and mixed with 1 mL of ethanol, 0.5 mL of ethyl thioglycolate, 1 mmol of lithium chloride, 3 mmol of tetrabutylammonium tetrafluoroborate, 9 mL of acetonitrile, and 1 mL of N,N-dimethylformamide (DMF) to obtain an electrolytic reaction solution;

[0144] The electrolytic reaction solution was placed in an integrated electrolytic cell equipped with a stirrer, with carbon cloth used as the anode and carbon rod used as the cathode, and electrolyzed at room temperature for 4 h under a constant direct current of 100 mA;

[0145] After the electrolysis, the crude product was purified by flash chromatography (the solvent was a mixture of petroleum and ethyl acetate in a volume ratio of 3:1) to recover the target product with a yield of 77%.

[0146] The NMR spectrum data of the product are as follows:

[0147] 1 H NMR (400 MHz, Chloroform-d) δ 4.27 – 4.08 (m, 6H), 3.57 (d, J =15.3 Hz, 2H), 1.34 (t, J = 7.1 Hz, 6H), 1.26 (t, J = 7.1 Hz, 3H).

[0148] 13 C NMR (101 MHz, Chloroform-d) δ 168.69 (d, J = 4.8 Hz), 63.89 (d, J = 5.8 Hz), 61.94, 32.40 (d, J = 3.9 Hz), 15.94 (d, J = 7.4 Hz), 14.05.

[0149] 31 P NMR (162 MHz, Chloroform-d) δ 25.39.

[0150] Example 12

[0151] The method for electrochemical synthesis of organophosphorus pesticides comprises the following steps:

[0152]

[0153] In an argon atmosphere, 1 mmol of white phosphorus, 1 mL of ethanol, 0.5 mL of methyl thioglycolate, 1 mmol of lithium chloride, 3 mmol of tetrabutylammonium tetrafluoroborate, 9 mL of acetonitrile, and 1 mL of dimethyl sulfoxide were added into a reaction tube to obtain an electrolytic reaction solution;

[0154] The electrolytic reaction solution was placed in an integrated electrolytic cell equipped with a stirrer, with carbon cloth used as the anode and carbon rod used as the cathode, and electrolyzed at room temperature for 4 h under a constant direct current of 100 mA;

[0155] After the electrolysis, the crude product was purified by flash chromatography (the solvent was a mixture of petroleum and ethyl acetate in a volume ratio of 3:1) to recover the target product with a yield of 38%.

[0156] The NMR spectrum data of the product are as follows:

[0157] 1H NMR (400 MHz, Chloroform-d) δ 4.25 – 4.10 (m, 4H), 3.73 (s, 3H), 3.58 (d, J = 15.6 Hz, 2H), 1.34 (t, J = 7.1 Hz, 6H).

[0158] 13 C NMR (101 MHz, Chloroform-d) δ 63.94 (d, J = 5.8 Hz), 52.80, 32.13 (d, J = 3.9 Hz), 15.94 (d, J = 7.3 Hz).

[0159] 31 P NMR (162 MHz, Chloroform-d) δ 25.21.

[0160] Embodiment 13

[0161] The method for electrochemical synthesis of organophosphorus pesticides comprises the following steps:

[0162]

[0163] In an argon atmosphere, 1 mmol of white phosphorus was mixed with 1 mL of ethanol, 0.5 mL of methyl mercaptopropionate, 1 mmol of lithium chloride, 3 mmol of tetrabutylammonium tetrafluoroborate, 9 mL of acetonitrile, and 1 mL of N-methylpyrrolidone (NMP) to obtain an electrolytic reaction solution;

[0164] The electrolytic reaction solution was placed in an integrated electrolytic cell equipped with a stirrer, with carbon cloth used as the anode and carbon rod used as the cathode, and electrolyzed at room temperature for 4 h under a constant direct current of 100 mA;

[0165] After the electrolysis, the crude product was purified by flash chromatography (the solvent was a mixture of petroleum and ethyl acetate in a volume ratio of 3:1) to recover the target product with a yield of 58%.

[0166] The NMR spectrum data of the product are as follows:

[0167] 1H NMR (400 MHz, Chloroform-d) δ 4.23 – 4.05 (m, 4H), 3.67 (d, J =2.1 Hz, 3H), 3.04 (dtd, J = 16.4, 7.1, 1.9 Hz, 2H), 2.73 (td, J = 7.1, 2.0Hz, 2H), 1.33 (td, J = 7.1, 2.0 Hz, 6H).

[0168] 3 C NMR (101 MHz, Chloroform-d) δ 171.56, 63.65 (d, J = 6.1 Hz), 51.83, 35.36 (d, J = 3.9 Hz), 25.60 (d, J = 4.1 Hz), 15.99 (d, J = 7.3 Hz).

[0169] 31 P NMR (162 MHz, Chloroform-d) δ 27.02.

[0170] Embodiment 14

[0171] The method for electrochemical synthesis of organophosphorus pesticides comprises the following steps:

[0172]

[0173] In an argon atmosphere, 1 mmol of white phosphorus, 1 mL of ethanol, 0.5 mL of 2,4-dimethylthiophenol, 1 mmol of acetic acid (AcOH), 3 mmol of tetrabutylammonium tetrafluoroborate, 5 mL of acetonitrile, and 5 mL of tetrahydrofuran were added into a reaction tube to obtain an electrolytic reaction solution;

[0174] The electrolytic reaction solution was placed in an integrated electrolytic cell equipped with a stirrer, with carbon cloth used as the anode and stainless steel (SS) used as the cathode, and electrolyzed at room temperature for 4 h under a constant direct current of 100 mA;

[0175] After the electrolysis, the crude product was purified by flash chromatography (the solvent was a mixture of petroleum and ethyl acetate in a volume ratio of 5:1) to recover the target product with a yield of 60%.

[0176] The NMR spectrum data of the product are as follows:

[0177] 1H NMR (400 MHz, Chloroform-d) δ 7.48 (dd, J = 7.9, 2.2 Hz, 1H), 7.08(s, 1H), 6.99 (dd, J = 7.8, 1.9 Hz, 1H), 4.25 – 4.06 (m, 4H), 2.49 (s, 3H), 2.31 (d, J = 2.3 Hz, 3H), 1.30 (t, J = 7.1 Hz, 6H).

[0178] 13 C NMR (101 MHz, Chloroform-d) δ 142.07 (d, J = 5.4 Hz), 139.63 (d, J= 3.5 Hz), 136.25 (d, J = 4.1 Hz), 131.72 (d, J = 2.9 Hz), 127.60 (d, J = 2.8Hz), 122.02 (d, J = 7.4 Hz), 64.02 (d, J = 6.8 Hz), 21.28, 21.08 (d, J = 1.2Hz), 16.06 (d, J = 7.1 Hz).

[0179] 31 P NMR (162 MHz, Chloroform-d) δ 23.39.

[0180] Embodiment 15

[0181] The method for electrochemical synthesis of organophosphorus pesticides comprises the following steps:

[0182]

[0183] In an argon atmosphere, 1 mmol of white phosphorus, 1 mL of ethanol, 0.5 mL of 2,4-difluorobenzenethiol, 1 mmol of trifluoroacetic acid (TFA), 3 mmol of tetrabutylammonium tetrafluoroborate, 5 mL of acetonitrile, and 5 mL of tetrahydrofuran were added into a reaction tube to obtain an electrolytic reaction solution;

[0184] The electrolytic reaction solution was placed in an integrated electrolytic cell equipped with a stirrer, with carbon cloth as the anode and stainless steel as the cathode, and electrolyzed at room temperature for 4 h under a constant direct current of 100 mA;

[0185] After the electrolysis, the crude product was purified by flash chromatography (the solvent was a mixture of petroleum and ethyl acetate in a volume ratio of 5:1) to recover the target product with a yield of 59%.

[0186] The NMR spectrum data of the product are as follows:

[0187] 1 H NMR (400 MHz, Chloroform-d) δ 7.58 (tdd, J = 8.4, 6.2, 2.3 Hz, 1H), 6.88 (ddt, J = 11.3, 8.8, 3.1 Hz, 2H), 4.20 (dq, J = 16.1, 7.3 Hz, 4H),1.39 – 1.21 (m, 6H).

[0188] 13 C NMR (101 MHz, Chloroform-d) δ 166.85 – 163.79 (m), 163.27 – 160.83(m), 138.57 (ddd, J = 9.7, 4.1, 1.4 Hz), 113.50 – 111.37 (m), 109.36 (ddd, J= 18.9, 7.4, 4.1 Hz), 104.85 (td, J = 26.4, 2.6 Hz), 64.29 (d, J = 6.2 Hz), 15.90 (d, J = 7.4 Hz).

[0189] 31 P NMR (162 MHz, Chloroform-d) δ 21.02 (t, J = 4.8 Hz).

[0190] 19 F NMR (377 MHz, Chloroform-d) δ -101.16 (dd, J = 9.8, 3.7 Hz), -106.26 (dd, J = 9.6, 5.5 Hz).

[0191] Example 16

[0192] The method for electrochemical synthesis of organophosphorus pesticides comprises the following steps:

[0193]

[0194] In an argon atmosphere, 1 mmol of white phosphorus was mixed with 4 mL of methanol, 0.5 mL of 4-fluorobenzenethiol, 1 mmol of trifluoroacetic acid, 3 mmol of tetrabutylammonium tetrafluoroborate, and 6 mL of acetonitrile to obtain an electrolytic reaction solution;

[0195] The electrolytic reaction solution was placed in an integrated electrolytic cell equipped with a stirrer, with carbon cloth as the anode and stainless steel as the cathode, and electrolyzed at room temperature for 4 h under a constant direct current of 100 mA;

[0196] After the electrolysis, the crude product was purified by flash chromatography (the solvent was a mixture of petroleum and ethyl acetate in a volume ratio of 1:1) to recover the target product with a yield of 58%.

[0197] The NMR spectrum data of the product are as follows:

[0198] 1 H NMR (400 MHz, Chloroform-d) δ 7.53 (dtd, J = 10.5, 5.2, 2.7 Hz, 2H), 7.05 (t, J = 8.5 Hz, 2H), 3.80 (d, J = 12.6 Hz, 6H).

[0199] 13 C NMR (101 MHz, Chloroform-d) δ 163.41 (dd, J = 250.1, 3.3 Hz), 136.76 (dd, J = 8.5, 4.9 Hz), 121.12 (dd, J = 7.4, 3.5 Hz), 116.69 (dd, J =22.3, 2.5 Hz), 54.32 (d, J = 6.3 Hz).,

[0200] 31 P NMR (162 MHz, Chloroform-d) δ 25.86 (d, J = 7.1 Hz).

[0201] 19 F NMR (377 MHz, Chloroform-d) δ -111.31 (d, J = 5.3 Hz).

[0202] Embodiment 17

[0203] The method for electrochemical synthesis of organophosphorus pesticides comprises the following steps:

[0204]

[0205] In an argon atmosphere, 1 mmol of white phosphorus, 4 mL of n-butanol, 0.5 mL of 4-fluorobenzenethiol, 1 mmol of trifluoroacetic acid, 3 mmol of tetrabutylammonium tetrafluoroborate, and 6 mL of acetonitrile were added into a reaction tube to obtain an electrolytic reaction solution;

[0206] The electrolytic reaction solution was placed in an integrated electrolytic cell equipped with a stirrer, with carbon cloth as the anode and stainless steel as the cathode, and electrolyzed at room temperature for 4 h under a constant direct current of 100 mA;

[0207] After the electrolysis, the crude product was purified by flash chromatography (the solvent was a mixture of petroleum and ethyl acetate in a volume ratio of 5:1) to recover the target product with a yield of 76%.

[0208] The NMR spectrum data of the product are as follows:

[0209] 1 H NMR (400 MHz, Chloroform-d) δ 7.53 (ddt, J = 9.0, 4.0, 1.9 Hz,2H), 7.02 (td, J = 8.5, 1.8 Hz, 2H), 4.18 – 4.00 (m, 4H), 1.61 (p, J = 6.8Hz, 4H), 1.34 (hd, J = 7.4, 1.6 Hz, 4H), 0.89 (td, J = 7.4, 1.7 Hz, 6H).

[0210] 13 C NMR (101 MHz, Chloroform-d) δ 163.28 (dd, J = 249.9, 3.2 Hz), 136.62 (dd, J = 8.5, 5.1 Hz), 121.79 (dd, J = 7.2, 3.5 Hz), 116.45 (dd, J =22.1, 2.3 Hz), 67.83 (d, J = 6.9 Hz), 32.11 (d, J = 7.0 Hz), 18.61, 13.47.

[0211] 31 P NMR (162 MHz, Chloroform-d) δ 22.63 (q, J = 7.6 Hz).

[0212] 19 F NMR (377 MHz, Chloroform-d) δ -111.82 (dt, J = 8.4, 4.4 Hz).

[0213] Embodiment 18

[0214] The method for electrochemical synthesis of organophosphorus pesticides comprises the following steps:

[0215]

[0216] In an argon atmosphere, 1 mmol of white phosphorus, 4 mL of n-hexanol, 0.5 mL of 4-fluorobenzenethiol, 1 mmol of trifluoroacetic acid, 3 mmol of tetrabutylammonium tetrafluoroborate, and 6 mL of acetonitrile were added into a reaction tube to obtain an electrolytic reaction solution;

[0217] The electrolytic reaction solution was placed in an integrated electrolytic cell equipped with a stirrer, with carbon cloth as the anode and stainless steel as the cathode, and electrolyzed at room temperature for 4 h under a constant direct current of 100 mA;

[0218] After the electrolysis, the crude product was purified by flash chromatography (the solvent was a mixture of petroleum and ethyl acetate in a volume ratio of 5:1) to recover the target product with a yield of 52%.

[0219] The NMR spectrum data of the product are as follows:

[0220] 1 H NMR (400 MHz, Chloroform-d) δ 7.55 (ddd, J = 8.2, 5.1, 2.1 Hz,2H), 7.04 (t, J = 8.5 Hz, 2H), 4.20 – 4.01 (m, 4H), 1.65 (p, J = 6.7 Hz, 4H),1.40 – 1.20 (m, 12H), 0.89 (t, J = 6.7 Hz, 6H).

[0221] 13 C NMR (101 MHz, Chloroform-d) δ 163.31 (dd, J = 249.8, 3.3 Hz), 136.62 (dd, J = 8.5, 5.1 Hz), 121.80 (dd, J = 7.1, 3.4 Hz), 116.48 (dd, J =22.1, 2.5 Hz), 68.19 (d, J = 6.9 Hz), 31.25, 30.11 (d, J = 7.0 Hz), 25.09, 22.48, 13.93.

[0222] 31 P NMR (162 MHz, Chloroform-d) δ 22.68 (d, J = 5.1 Hz).

[0223] 19 F NMR (377 MHz, Chloroform-d) δ -111.78 (d, J = 4.9 Hz).

[0224] Embodiment 19

[0225] The method for electrochemical synthesis of organophosphorus pesticides comprises the following steps:

[0226]

[0227] In an argon atmosphere, 1 mmol of white phosphorus, 4 mL of phenylethanol, 0.5 mL of 4-fluorobenzenethiol, 1 mmol of trifluoroacetic acid, 3 mmol of tetrabutylammonium tetrafluoroborate, and 6 mL of acetonitrile were added into a reaction tube to obtain an electrolytic reaction solution;

[0228] The electrolytic reaction solution was placed in an integrated electrolytic cell equipped with a stirrer, with carbon cloth as the anode and stainless steel as the cathode, and electrolyzed at room temperature for 4 h under a constant direct current of 100 mA;

[0229] After the electrolysis, the crude product was purified by flash chromatography (the solvent was a mixture of petroleum and ethyl acetate in a volume ratio of 5:1) to recover the target product with a yield of 64%.

[0230] The NMR spectrum data of the product are as follows:

[0231] 1 H NMR (400 MHz, Chloroform-d) δ 7.42 – 7.26 (m, 8H), 6.96 (t, J =8.6 Hz, 2H), 4.39 – 4.20 (m, 4H), 2.97 (t, J = 6.9 Hz, 4H).

[0232] 13 C NMR (101 MHz, Chloroform-d) δ 163.29 (dd, J = 249.9, 3.2 Hz), 136.93, 136.70 (dd, J = 8.5, 5.0 Hz), 129.06, 128.60, 126.82, 121.22 (dd, J =7.3, 3.4 Hz), 116.57 (dd, J = 22.1, 2.5 Hz), 68.32 (d, J = 7.0 Hz), 36.60 (d,J = 7.2 Hz).

[0233] 31 P NMR (162 MHz, Chloroform-d) δ 22.85 (d, J = 5.6 Hz).

[0234] 19F NMR (377 MHz, Chloroform-d) δ -111.49 (d, J = 5.4 Hz).

[0235] Embodiment 20

[0236] The method for electrochemical synthesis of organophosphorus pesticides comprises the following steps:

[0237]

[0238] In an argon atmosphere, 1 mmol of white phosphorus, 4 mL of isopropanol, 0.5 mL of benzyl mercaptan, 1 mmol of trifluoroacetic acid, 3 mmol of tetrabutylammonium tetrafluoroborate, and 6 mL of acetonitrile were added into a reaction tube to obtain an electrolytic reaction solution;

[0239] The electrolytic reaction solution was placed in an integrated electrolytic cell equipped with a stirrer, with carbon cloth as the anode and stainless steel as the cathode, and electrolyzed at room temperature for 4 h under a constant direct current of 100 mA;

[0240] After the electrolysis, the crude product was purified by flash chromatography (the solvent was a mixture of petroleum and ethyl acetate in a volume ratio of 5:1) to recover the target product with a yield of 50%.

[0241] The NMR spectrum data of the product are as follows:

[0242] 1 H NMR (400 MHz, Chloroform-d) δ 7.37-7.26 (m, 5H), 4.72-4.66 (m,2H), 4.06 (d, J = 3.3 Hz, 2H), 1.33 (d, J = 6.0 Hz, 6H), 1.28 (d, J = 6.4 Hz,6H).

[0243] 13 C NMR (101 MHz, Chloroform-d) δ 137.4 (d, JC-P = 6.0 Hz), 128.9,128.6, 127.5, 72.6 (d, JC-P = 7.0 Hz), 35.1 (d, JC-P = 3.4 Hz), 23.7 (d, JC-P= 3.5 Hz), 23.4 (d, JC-P = 5.3 Hz).

[0244] 31 P NMR (162 MHz, Chloroform-d)δ 24.1

[0245] Comparative Example 1

[0246] This comparative example studies the effect of electrochemically synthesizing organophosphorus pesticides without adding additives under the conditions of Example 1, and the steps are as follows:

[0247]

[0248] In an argon atmosphere, 1 mmol of white phosphorus, 5 mL of ethanol, 0.5 mL of benzyl mercaptan, 3 mmol of tetrabutylammonium tetrafluoroborate, and 5 mL of 1,4-dioxane were added into a reaction tube to obtain an electrolytic reaction solution;

[0249] The electrolytic reaction solution was placed in an integrated electrolytic cell equipped with a stirrer, with a carbon sheet as the anode and a platinum sheet as the cathode, and electrolyzed at room temperature for 4 h under a constant direct current of 100 mA;

[0250] After the electrolysis was completed, the crude product was purified by flash chromatography (the solvent was a mixture of petroleum and ethyl acetate in a volume ratio of 5:1) to recover the product of Example 1 with a yield of 16%.

[0251] In the absence of additives, the competitive reaction between thiol and hydroxyl groups is fierce and the selectivity is poor, resulting in a significant reduction in the yield of the target product; at the same time, a large amount of white phosphorus polymerization occurs in the electrolysis system, which is not conducive to the conversion of white phosphorus and its participation in the reaction.

[0252] In summary, the present invention uses white phosphorus, which is widely available, cheap, low in toxicity and non-volatile, as a phosphorus source, and electrolyzes it with alcohols, thiols or thiophenol compounds in an electrolyte environment, successfully introducing functional groups of target structures in alcohols, thiols or thiophenol compounds into phosphorus, and obtaining multiple types of organophosphorus pesticides containing two PO bonds and one PS bond. The electrolyte contains additives, which can activate white phosphorus during the electrolysis process and adjust and improve the selectivity of the white phosphorus reaction, optimize the competitive reaction between thiol and hydroxyl, and generate organophosphorus pesticides of target configuration. The present invention has high atomic utilization, low pollution, weak corrosion to the device, meets the requirements of green and safe production, and has good prospects for industrial application.

[0253] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A method for electrochemically synthesizing organophosphorus pesticides, characterized in that: The steps include: In an inert atmosphere, white phosphorus is mixed with an alcohol compound of formula I, a thiol compound of formula II, an additive, an electrolyte, and an organic solvent to form an electrolytic reaction solution; the electrolytic reaction solution is electrolyzed under direct current to collect an organophosphorus pesticide of formula III; The thiol compound is a thiol or thiophenol compound; The additive is one of acetic acid, sulfuric acid, trifluoroacetic acid, lithium chloride, and lithium hexafluorophosphate; The molar ratio of the white phosphorus to the alcohol compound is 1:2-50; the molar ratio of the white phosphorus to the thiol compound is 1:1-25; the molar ratio of the white phosphorus to the additive is 0.2-5:1; The reaction formula of the electrolysis is as follows: ； In the formula, R 1 Selected from C1-C 10 Alkyl, phenethyl; When the thiol compound is a thiol compound, R 2 Selected from C1-C 19 Alkyl, benzyl and its halides, N-methylacetamide, methyl acetate, ethyl acetate, methyl propionate; When the thiol compound is a thiophenol compound, R 2 Selected from substituted or unsubstituted phenyl groups; in the substituted phenyl group, the substituent includes at least one of C1-C4 alkyl, halogen, fluorine, methoxy and methylthio.

2. The method for electrochemical synthesis of organophosphorus pesticides according to claim 1, characterized in that: The alcohol compound includes one of methanol, ethanol, isopropanol, n-butanol, n-hexanol and phenylethanol.

3. The method for electrochemical synthesis of organophosphorus pesticides according to claim 1, characterized in that: The thiol compound includes one of benzyl mercaptan, 2-mercapto-N-methylacetamide, 2-methylpropanethiol, butyl mercaptan, phenylethyl mercaptan, 2-chlorobenzyl mercaptan, methyl thioglycolate, ethyl thioglycolate, and methyl mercaptopropionate.

4. The method for electrochemical synthesis of organophosphorus pesticides according to claim 1, characterized in that: The thiophenol compound includes one of 4-methylthiophenol, 4-fluorothiophenol, 4-methoxythiophenol, 4-methylthiothiophenol, 2,4-dimethylthiophenol and 2,4-difluorothiophenol.

5. The method for electrochemical synthesis of organophosphorus pesticides according to claim 1, characterized in that: The electrolyte includes at least one of tetrabutylammonium iodide, potassium iodide, sodium iodide, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutyltetrafluoroboric acid, tetraethylammonium tetrafluoroborate, and tetramethylammonium tetrafluoroborate.

6. The method for electrochemical synthesis of organophosphorus pesticides according to claim 1, characterized in that: The concentration of the electrolyte in the electrolytic reaction solution is 0.1-0.4 mol / L.

7. The method for electrochemical synthesis of organophosphorus pesticides according to claim 1, characterized in that: The organic solvent includes at most four of acetonitrile, dimethyl sulfoxide, tetrahydrofuran, 1,4-dioxane, dichloromethane, N,N-dimethylformamide, N,N-dimethylacetamide, dichloroethane, chloroform, and N-methylpyrrolidone.

8. The method for electrochemical synthesis of organophosphorus pesticides according to claim 1, characterized in that: The current density of the electrolysis is 5-500 mA / cm 2 .

9. The method for electrochemical synthesis of organophosphorus pesticides according to claim 1, characterized in that: The electrolysis temperature is room temperature, and the electrolysis time is 20 min-4 h.

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