Electrochemical synthesis process of iodobenzene diacetic acid

Abstract

The invention discloses an electrochemical synthesis process of iodobenzene diacetic acid, and belongs to the technical field of electrolysis processes for producing compounds. The method comprises the following steps: continuously electrolyzing iodobenzene and acetic acid in an electrolyte environment at a certain temperature, continuously discharging iodobenzene diacetic acid generated by reaction along with the electrolyte, and continuously supplementing iodobenzene, acetic acid and the electrolyte into an electrolytic cell in the electrolysis process. The process has the advantages of cleanness, high efficiency, safety and controllability, realizes continuous synthesis of iodobenzene diacetic acid with high yield and current efficiency, is suitable for large-scale production, and has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of electrolysis processes for producing compounds, and particularly to an electrochemical synthesis process for iodobenzene diacetic acid. Background Art

[0002] Iodobenzene diacetic acid is a mild and non-toxic oxidant with good selective oxidation characteristics and is widely used in industries such as synthesis and pharmaceuticals. Iodobenzene diacetic acid has a wide range of uses, is stable in nature, easy to store, and the by-products of the reaction are usually the relatively expensive organic raw material iodobenzene, which can be recycled or used to synthesize other compounds without polluting the environment, making it an ideal oxidizing reagent.

[0003] Iodobenzene diacetic acid can be synthesized through various routes. For example, using benzene and acetic acid as reaction substrates, it undergoes nitration, reduction, iodination, and acidification reactions to synthesize iodobenzene diacetic acid. First, in the nitration reaction, benzene reacts with concentrated nitric acid and concentrated sulfuric acid to form nitrobenzene and sulfuric acid; nitrobenzene undergoes a reduction reaction with reducing agents such as sodium sulfite to reduce the nitro group to an amino group, obtaining aniline; subsequently, aniline reacts with iodine and cuprous iodide to introduce an iodine group into the aromatic amine, generating iodoaniline; finally, iodoaniline and an acidic solution such as concentrated sulfuric acid undergo an acidification reaction to acidify the amino group to a carboxyl group, synthesizing iodobenzene diacetic acid. However, the order and conditions of the reaction steps in this method need to be strictly controlled to ensure the smooth progress of the synthesis reaction. The synthesis route involves many reaction steps and raw materials, with low yield and high production cost, which is not conducive to industrial scale production.

[0004] In the industrial production field, for example, the literature (Org. Synth. 1963, 43, 62. DOI: 10.15227 / orgsyn.043.0062) reports that the synthesis method of iodobenzene diacetic acid is usually the peracetic acid oxidation method. Another example is the Chinese patent with the publication number CN107814719A, which discloses a method for preparing iodobenzene diacetate with high efficiency and environmental protection and a method for recycling the mother liquor. Starting from iodobenzene as the raw material, acetic acid as the solvent, reacting with peracetic acid, and adding water to precipitate iodobenzene diacetate. The process of this invention is simple and easy to operate, with mild conditions, low production cost, and less wastewater discharge, suitable for industrial production. However, in the above synthesis process, high-concentration (30% - 40%) peracetic acid needs to be used as the oxidant, and high-concentration peracetic acid is explosive, posing a relatively high risk hazard during production, transportation, storage, and use.

[0005] The Chinese invention patent with the publication number CN101575293A provides a method for preparing iodobenzene diacetate. This method uses sodium perborate tetrahydrate as the raw material, and undergoes an acylation reaction with iodobenzene in the presence of a glacial acetic acid / acetic anhydride mixed solution. The molar ratio of sodium perborate tetrahydrate to iodobenzene is 3 - 10:1, the reaction temperature is 30 - 45 °C, the reaction time is 4 - 24 h. After the reaction, ice water is added to obtain the crude product of iodobenzene diacetate, and then recrystallization is carried out to obtain iodobenzene diacetate. The process of this invention has the advantages of simple operation, production safety, and being suitable for large-scale industrial production. However, the yield of this method is relatively low, only 40% - 70%, and a large amount of waste will be generated after the reaction of sodium perborate tetrahydrate, which is complex and costly to process, and it is difficult to meet the requirements of green production.

[0006] In summary, developing a clean, efficient, safe and controllable synthesis process for iodobenzene diacetate to solve the problems existing in the above traditional synthesis methods is of great significance for expanding the application of iodobenzene diacetate. Summary of the Invention

[0007] In view of the above-mentioned defects of the prior art, the present invention provides an electrochemically synthetic process for iodobenzene diacetate that is clean, efficient, safe and controllable, including the following steps: Under the electrolyte environment and at a certain temperature, iodobenzene and acetic acid are continuously electrolyzed, and the generated iodobenzene diacetate is continuously discharged with the electrolyte. During the electrolysis process, iodobenzene, acetic acid and the electrolyte are continuously replenished into the electrolytic cell.

[0008] Preferably, the electrolyte includes an electrolyte and a solvent, and the concentration of the electrolyte in the electrolyte is 0.1 - 0.5 mol / L.

[0009] The electrolyte can play functions such as improving the conductivity of the system and ion balance in electrolysis, and it is a common additive form in the electrolysis industry. The electrolyte is chemically inert relative to the reaction substrates and will not interfere with the progress of the electrolysis reaction. The choice of its type is diverse, and those skilled in the art can select a suitable electrolyte type according to the actual situation.

[0010] More preferably, the electrolyte includes at least one of sodium chloride, ammonium chloride, potassium nitrate, sodium sulfate, sulfuric acid, lithium perchlorate, ammonium perchlorate, tetraethylammonium iodide, tetraethylammonium bromide, tetraethylammonium chloride, tetra-n-butylammonium chloride, tetra-n-butylammonium bromide, tetra-n-butylammonium hydrogen sulfate, tetra-n-butylammonium tetrafluoroborate, tetra-n-butylammonium acetate, tetra-n-butylammonium perchlorate.

[0011] The solvent has functions such as improving the dispersion of substances and creating a suitable reaction environment in electrolysis, and it is also chemically inert relative to the reaction substrates. Those skilled in the art can select a suitable solvent according to the actual conditions and the physical and chemical properties of the substrates and additives.

[0012] Further preferably, the solvent includes at least one of water, methanol, ethylene glycol dimethyl ether, ethyl acetate, dichloromethane, tetrahydrofuran, 1,4-dioxane, acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide, and N-methylpyrrolidone.

[0013] Further preferably, the volume ratio of the acetic acid to the solvent is 1:1 to 9.

[0014] Preferably, the concentration of iodobenzene in the electrolyte is 0.3 to 1.0 mol / L.

[0015] During the continuous production process, as the electrolysis proceeds, iodobenzene and acetic acid gain and lose electrons to react, generating the target product iodobenzene diacetic acid and being recycled, while the electrolyte continues to flow for cyclic electrolysis. Those skilled in the art can adopt a continuous feeding method to supplement the consumed iodobenzene and acetic acid in the reaction to maintain the ratio or concentration of the substrates at predetermined parameters.

[0016] The influence of temperature on the process is mainly reflected in the voltage fluctuation. For the smooth progress of electrolysis and improved efficiency, it is appropriate to control the temperature within a suitable range.

[0017] Preferably, the temperature of the electrolysis is 20 to 60 °C.

[0018] Preferably, the flow rate of the electrolyte continuously replenished into the electrolytic cell is 0.05 to 0.20 m / s.

[0019] Preferably, the electrolysis is constant current electrolysis, and the current density of the electrolysis is 5 to 20 A / dm 2 .

[0020] Preferably, the electrolysis is carried out in an electrolytic cell without a diaphragm or an electrolytic cell with a diaphragm.

[0021] Further preferably, when the electrolysis is carried out in an electrolytic cell with a diaphragm, the diaphragm is selected from one of a proton exchange membrane, a cation exchange membrane, or an anion exchange membrane.

[0022] Preferably, the anode used in the electrolysis is selected from a graphite plate or a dimensionally stable anode (DSA); the cathode used is selected from a nickel plate or a stainless steel plate.

[0023] Further preferably, the dimensionally stable anode is an iridium dioxide-ruthenium dioxide-titanium dioxide (IrO 2 -RuO 2 -TiO 2 ) mixed electrode.

[0024] Further preferably, the single electrode area of the anode or the cathode is 0.01 to 1.00 m 2 .

[0025] The process flow of the present invention can be simply implemented based on common electrolysis equipment in the art without the use of specialized devices, has wide applicability, and is conducive to industrial promotion. As presented in one or more embodiments of the present invention, in actual production, the following process can be referred to for synthesizing iodobenzenediacetic acid: (1) Prepare a reaction solution by formulating iodobenzene, acetic acid, an electrolyte, and a solvent according to the concentration and ratio requirements, and store it in a liquid storage device (liquid storage tank); (2) Heat the electrolyte to a predetermined temperature, turn on the circulating liquid delivery device (circulating pump), and start circulating electrolysis under a constant current (turn on the DC power supply and adjust it to a constant current). As the electrolysis progresses, continuously add the iodine benzene and acetic acid consumed by the reaction to the electrolyte to maintain the concentration of the reaction substrate at a predetermined parameter; (3) The iodobenzenediacetic acid generated by the reaction is continuously transported to the product separation device (such as a sedimentation separation device, a filtration separation device, a centrifugal separation device, etc. commonly used in industrial production) along with the electrolyte. The obtained solid is washed and dried to continuously recover the target product iodobenzenediacetic acid, and the electrolyte is transported back to the liquid storage device for continued electrolysis; (4) After the electrolysis is completed, the residual product in the electrolyte is obtained through evaporation concentration, washing, and drying, and the evaporation liquid is recovered.

[0026] The reaction formula of the electrolysis mechanism of the present invention is as follows: Overall reaction equation: PhI + 2 AcOH → PhI(OAc) 2 + H 2 ↑; Anodic reaction formula: PhI - 2 e - + 2 AcO - → PhI(OAc) 2 ; Cathodic reaction formula: 2 H + + 2 e - → H 2 ↑; At the anode of the electrolytic cell, iodobenzene is oxidized and then attacked by acetate ions to obtain the target product iodobenzenediacetic acid; at the cathode of the electrolytic cell, the protons ionized from acetic acid are reduced to obtain the valuable by-product hydrogen.

[0027] Based on the above technical solutions, the concept of the present invention is to utilize the electrical energy of an electric current to drive the reaction of iodobenzene and acetic acid to synthesize iodophenyl diacetic acid. Compared with existing methods, using an electrochemical method to prepare iodophenyl diacetic acid is undoubtedly a greener and safer choice. In the electrolytic cell, iodobenzene is oxidized at the anode and then attacked by acetate ions to form iodophenyl diacetic acid. During the entire reaction process, there is no need to add reaction equivalent or excessive oxidants, avoiding the potential hazards and large amounts of waste residues caused by the use of oxidants. In industrial production, the electrochemical method also has more advantages. The cost of electrochemical production equipment is lower, the floor space is smaller, and it can be started and stopped at any time, being safe and controllable. This process realizes the continuous synthesis of iodophenyl diacetic acid with high yield and current efficiency. Through the product separation device, the product and electrolyte can be separated, and the electrolyte can be recycled for electrolysis, further reducing the production cost and being suitable for large-scale production.

[0028] Compared with the prior art, the present invention has the following advantages and beneficial effects: The present invention provides an electrochemical synthesis process for iodophenyl diacetic acid, which has the advantages of being clean, efficient, safe and controllable. This process realizes the continuous synthesis of iodophenyl diacetic acid with high yield and current efficiency, is suitable for large-scale production, and has broad application prospects. Description of the Drawings

[0029] Figure 1 It is a schematic process flow diagram of the electrochemical synthesis of iodophenyl diacetic acid in the embodiment; Figure 2 It is a schematic diagram of the reaction principles of the cathode and anode in the electrochemical synthesis of iodophenyl diacetic acid. Detailed Embodiments

[0030] The present invention will be further described below by way of examples, but the present invention is not limited to the scope of the described examples. The experimental methods without specific conditions in the following examples are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0031] Example 1 The electrochemical synthesis process of iodophenyl diacetic acid is as Figure 1 shown, and the steps are as follows: The device structure of this example is an electrolytic cell in series of five stages without a diaphragm in the cell. The anode is made of a graphite plate and the cathode is made of a nickel plate, and the single electrode area is 0.01 m 2The concentration of iodobenzene in the electrolyte is 0.3 mol / L. Sodium chloride and tetraethylammonium chloride are used as the electrolyte, with a molar ratio of 1:1 and a total electrolyte concentration of 0.1 mol / L. Water and ethylene glycol dimethyl ether are used as the solvent, with a volume ratio of 2:1. The volume ratio of acetic acid to the mixed solvent is 1:9, where acetic acid is 0.2 L and the total volume of the mixed solvent is 1.8 L. After the electrolyte is mixed evenly, it is heated to 30 °C. After the pump circulation is normal, the DC power supply is turned on and adjusted to the constant current electrolysis mode. The current is adjusted to 25 A, and the current density is 5 A / dm 2 , and the flow rate of the electrolyte continuously replenished into the electrolytic cell is 0.05 m / s. At the same time, iodobenzene and acetic acid are continuously added to the electrolyte at speeds of 95 g / h and 50 mL / h respectively. At the start of electrolysis, the circulation pump is turned on simultaneously to continuously pump the electrolyte into the product separation device to continuously separate the product. After 10 h of electrolysis, the DC power supply is turned off to stop electrolysis. After all the electrolyte is refluxed to the storage tank, the circulation pump is turned off. The solid continuously separated in the product separation device is washed and dried to obtain a part of iodobenzene diacetic acid. The residual product in the storage tank is evaporated, concentrated, washed, and dried to obtain another part of iodobenzene diacetic acid, and the evaporation liquid is recycled. The total output of iodobenzene diacetic acid in this example is 1.42 kg, the total yield is 96%, and the Faraday current efficiency is 95%.

[0032] The nuclear magnetic resonance spectroscopic data of the obtained product iodobenzene diacetic acid are as follows: 1 H NMR (400 MHz, CDCl 3 ) δ 8.12 – 8.07 (m, 2H), 7.63 – 7.57 (m, 1H),7.54 – 7.47 (m, 2H), 2.01 (s, 6H). 13 C NMR (101 MHz, CDCl 3 ) δ 176.4, 134.9, 131.7, 130.9, 121.6, 20.3. It shows that using iodobenzene and acetic acid as substrates, the target product iodobenzene diacetic acid is successfully obtained through electrochemical synthesis.

[0033] Example 2 The electrochemical synthesis process of iodobenzene diacetic acid is as follows: The device structure in this example is an electrolytic cell with three - stage series connection, equipped with a proton - exchange membrane in the cell. The anode is made of a graphite plate and the cathode is made of a stainless steel plate, and the single - electrode area is 0.1 m 2。The concentration of iodobenzene in the anolyte is 0.5 mol / L. The electrolyte used is tetrabutylammonium hydrogensulfate with a concentration of 0.2 mol / L. The solvent used is dimethyl sulfoxide. The volume ratio of acetic acid to dimethyl sulfoxide is 1:5, with 2 L of acetic acid and 10 L of dimethyl sulfoxide. In the catholyte, the electrolyte used is sulfuric acid with a concentration of 0.2 mol / L. The solvent used is dimethyl sulfoxide. The volume ratio of acetic acid to dimethyl sulfoxide is 1:5, with 2 L of acetic acid and 10 L of dimethyl sulfoxide. After the electrolytes are mixed evenly respectively, the temperature is raised to 40 °C. After the pump circulation is normal, the DC power supply is turned on, adjusted to the constant current electrolysis mode, the current is adjusted to 300 A, and the current density is 10 A / dm 2 . The flow rate of the electrolyte continuously replenished into the electrolytic cell is 0.1 m / s. High-current electrolysis is carried out. At the same time, iodobenzene and acetic acid are continuously added to the electrolyte at speeds of 1140 g / h and 600 mL / h respectively. When the electrolysis starts, the circulation pump is turned on simultaneously to continuously pump the electrolyte into the product separation device to continuously separate the product. After 10 h of electrolysis, the DC power supply is turned off to stop the electrolysis. After all the electrolyte is refluxed to the storage tank, the circulation pump is turned off. The solid continuously separated in the product separation device is washed and dried to obtain a part of iodobenzene diacetic acid. The residual product in the storage tank is evaporated, concentrated, washed, and dried to obtain another part of iodobenzene diacetic acid, and the evaporation liquid is recovered. The total output of iodobenzene diacetic acid in this example is 16.6 kg, the total yield is 95%, and the Faraday current efficiency is 92%. Calculated according to this efficiency and output, the annual output of this device can reach 11.9 tons / year (calculated according to 300 days).

[0034] Example 3 The electrochemical synthesis process of iodobenzene diacetic acid is as follows: The device structure of this example is a single-stage electrolytic cell. The anode is made of a dimensionally stable anode, and the cathode is made of a nickel plate. The single electrode area is 0.6 m 2 . The concentration of iodobenzene in the anolyte is 0.7 mol / L. The electrolytes used are lithium perchlorate and tetrabutylammonium tetrafluoroborate, and the molar ratio is 2:1. The total electrolyte concentration is 0.3 mol / L. The solvent used is a mixed solvent of water and acetonitrile with a volume ratio of 1:1. The volume ratio of acetic acid to the mixed solvent is 1:3, with 9 L of acetic acid and 27 L of the mixed solvent. In the catholyte, the electrolyte used is tetrabutylammonium acetate with a concentration of 0.3 mol / L. The solvent used is acetonitrile. The volume ratio of acetic acid to acetonitrile is 1:3, with 9 L of acetic acid and 27 L of acetonitrile. After the electrolytes are mixed evenly respectively, the temperature is raised to 50 °C. After the pump circulation is normal, the DC power supply is turned on, adjusted to the constant current electrolysis mode, the current is adjusted to 900 A, and the current density is 15 A / dm 2, the flow rate of the electrolyte continuously replenished into the electrolytic cell is 0.15 m / s, electrolysis is carried out at a large current, and iodobenzene and acetic acid are continuously added to the electrolyte at speeds of 3.42 kg / h and 1.8 L / h respectively. At the beginning of electrolysis, the circulation pump is turned on to continuously pump the electrolyte into the product separation device to continuously separate the products. After 10 h of electrolysis, the DC power supply is turned off to stop electrolysis. After all the electrolyte is refluxed to the storage tank, the circulation pump is turned off. The solid continuously separated in the product separation device is washed and dried to obtain a part of iodophenyl diacetic acid. The residual product in the storage tank is evaporated, concentrated, washed and dried to obtain another part of iodophenyl diacetic acid, and the evaporation liquid is recovered. The total output of iodophenyl diacetic acid in this example is 47 kg, the total yield is 93%, and the Faraday current efficiency is 87%. Calculated according to this efficiency and output, the annual output of this device can reach 33.8 tons / year (calculated according to 300 days).

[0035] Example 4 The electrochemical synthesis process of iodophenyl diacetic acid is as follows: The device structure of this example is an electrolytic cell with two stages in series. The cell is equipped with an anion exchange membrane. The anode uses a dimensionally stable electrode, and the cathode uses a stainless steel plate. The single electrode area is 1 m 2 . The concentration of iodobenzene in the anolyte is 1 mol / L, the electrolyte used is tetraethylammonium iodide with a concentration of 0.5 mol / L, the solvent used is N,N-dimethylformamide, and the volume ratio of acetic acid to N,N-dimethylformamide is 1:1, where acetic acid is 50 L and N,N-dimethylformamide is 50 L; in the catholyte, the electrolyte used is sulfuric acid with a concentration of 0.5 mol / L, the solvent used is N,N-dimethylformamide, and the volume ratio of acetic acid to N,N-dimethylformamide is 1:1, where acetic acid is 50 L and N,N-dimethylformamide is 50 L; after the electrolytes are respectively mixed evenly and heated to 60 °C, after the pump circulation is normal, the DC power supply is turned on and adjusted to the constant current electrolysis mode, the current is adjusted to 4000 A, and the current density is 20 A / dm 2 . The flow rate of the electrolyte continuously replenished into the electrolytic cell is 0.2 m / s, electrolysis is carried out at a large current, and iodobenzene and acetic acid are continuously added to the electrolyte at speeds of 15.2 kg / h and 8 L / h respectively. At the beginning of electrolysis, the circulation pump is turned on to continuously pump the electrolyte into the product separation device to continuously separate the products. After 24 h of electrolysis, the DC power supply is turned off to stop electrolysis. After all the electrolyte is refluxed to the storage tank, the circulation pump is turned off. The solid continuously separated in the product separation device is washed and dried to obtain a part of iodophenyl diacetic acid. The residual product in the storage tank is evaporated, concentrated, washed and dried to obtain another part of iodophenyl diacetic acid, and the evaporation liquid is recovered. The total output of iodophenyl diacetic acid in this example is 484.4 kg, the total yield is 90%, and the Faraday current efficiency is 84%. Calculated according to this efficiency and output, the annual output of this device can reach 145 tons / year (calculated according to 300 days).

[0036] The above embodiments successfully achieved the electrochemical synthesis of iodobenzene diacetic acid using iodobenzene and acetic acid with high efficiency and yield. During the electrolysis process, as Figure 2 shown, at the anode of the electrolytic cell, iodobenzene is oxidized and then attacked by acetate ions to obtain the target product iodobenzene diacetic acid; at the cathode of the electrolytic cell, the protons ionized from acetic acid are reduced to obtain the valuable by-product hydrogen. No equivalent or excessive oxidant is required during the whole reaction process. In the synthesis of this process, the electrolyte continuously flows for cyclic electrolysis, and the product iodobenzene diacetic acid can be continuously harvested, which is suitable for large-scale production.

[0037] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations based on the concept of the present invention without creative efforts. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field of the present invention based on the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the prior art should be within the protection scope determined by the claims.

Claims

1. An electrochemical synthesis process for iodophenyldiacetic acid, characterized in that, The steps include: In an electrolyte environment and at a certain temperature, iodobenzene and acetic acid are continuously electrolyzed, and iodobenzene diacetic acid generated by the reaction is continuously discharged along with the electrolyte. During the electrolysis process, iodobenzene, acetic acid and the electrolyte are continuously added to the electrolytic cell.

2. The electrochemical synthesis process of iodophenyldiacetic acid according to claim 1, characterized in that: The electrolyte includes an electrolyte and a solvent, wherein the concentration of the electrolyte in the electrolyte is 0.1-0.5 mol / L; the concentration of the iodobenzene in the electrolyte is 0.3-1.0 mol / L; and the volume ratio of the acetic acid to the solvent is 1:1-9.

3. The electrochemical synthesis process of iodophenyldiacetic acid according to claim 2, characterized in that: The electrolyte includes at least one of sodium chloride, ammonium chloride, potassium nitrate, sodium sulfate, sulfuric acid, lithium perchlorate, ammonium perchlorate, tetraethylammonium iodide, tetraethylammonium bromide, tetraethylammonium chloride, tetra-n-butylammonium chloride, tetra-n-butylammonium bromide, tetra-n-butylammonium hydrogen sulfate, tetra-n-butylammonium tetrafluoroborate, tetra-n-butylammonium acetate, and tetra-n-butylammonium perchlorate.

4. The electrochemical synthesis process of iodophenyldiacetic acid according to claim 2, characterized in that: The solvent includes at least one of water, methanol, ethylene glycol dimethyl ether, ethyl acetate, dichloromethane, tetrahydrofuran, 1,4-dioxane, acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide, and N-methylpyrrolidone.

5. The electrochemical synthesis process of iodophenyldiacetic acid according to claim 1, characterized in that: The electrolysis temperature is 20-60°C, and the flow rate of the electrolyte continuously added into the electrolytic cell is 0.05-0.20 m / s.

6. The electrochemical synthesis process of iodophenyldiacetic acid according to claim 1, characterized in that: The electrolysis is constant current electrolysis, and the current density of the electrolysis is 5-20 A / dm 2 .

7. The electrochemical synthesis process of iodophenyldiacetic acid according to claim 1, characterized in that: The electrolysis is carried out in an electrolytic cell without a diaphragm or in an electrolytic cell with a diaphragm.

8. The electrochemical synthesis process of iodophenyldiacetic acid according to claim 7, characterized in that: When the electrolysis is carried out in an electrolytic cell with a diaphragm, the diaphragm is selected from one of a proton exchange membrane, a cation exchange membrane or an anion exchange membrane.

9. The electrochemical synthesis process of iodophenyldiacetic acid according to claim 1, characterized in that: The anode used in the electrolysis is selected from a graphite plate or a dimensionally stable electrode; the cathode used is selected from a nickel plate or a stainless steel plate.

10. The electrochemical synthesis process of iodophenyldiacetic acid according to claim 9, characterized in that: The single electrode area of ​​the anode or cathode is 0.01-1.00 m 2 .

Images