A preparation method, special equipment and application of 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione

Abstract

The application provides a preparation method, special equipment and application of 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, wherein the preparation method comprises the following steps: S1, continuously inputting dry inorganic acidic gas into a reactor; S2, mixing raw material N-[[(3,5-dichlorophenyl)amino] carbonyl] amino acetic acid and an auxiliary agent and then inputting the mixture into the reactor; S3, under the catalysis of the acidic gas, the raw material and the auxiliary agent perform cyclization reaction to obtain a mixture of 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, water and the auxiliary agent; and S4, cooling and separating the mixture obtained in the step S3 to obtain 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione solid and an aqueous auxiliary agent solution respectively. The preparation method of 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione has the advantages of continuous production, high efficiency, simplicity, near-zero emission and mild reaction conditions, can effectively shorten the reaction time, improve the production efficiency, reduce the safety risk, and the yield of the product can reach more than 93%, and the purity can reach more than 99%.

Description

Technical Field

[0001] This invention relates to the field of compound preparation, and more particularly to a method for preparing 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, the special equipment used, and its application. Background Technology

[0002] 3-(3,5-Dichlorophenyl)-2,4-imidazolidinedione is an important intermediate in the synthesis of the fungicide iprodione. Currently, the commonly used industrial preparation method involves using N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid as a raw material, and then dehydrating and cyclizing it at a certain temperature to obtain 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione.

[0003] Industrial production typically takes place in batch reactors, with complex post-processing steps and low production efficiency. During the cyclization process, the chlorine on the benzene ring is prone to hydrolysis side reactions, the acidic catalyst cannot be reused, the yield is generally no more than 92%, and the purity is no more than 99%.

[0004] For example, Chinese patent CN 107245055 discloses a method for preparing isopyrone, which involves mixing N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid with an organic solvent and preparing the intermediate 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione under the catalysis of a mixture of concentrated sulfuric acid, methanesulfonic acid and p-toluenesulfonic acid.

[0005] This preparation method uses organic solvents, which easily generate VOC emissions during production, polluting the environment and negatively impacting the health of production workers. The large-scale use of flammable and explosive organic solvents in chemical production also increases safety hazards. Furthermore, the large quantity of strongly acidic catalysts used results in a significant amount of acidic wastewater that cannot be reused, placing considerable pressure on environmental protection efforts.

[0006] Chinese patent CN109265401 discloses another experimental method for preparing the isourea intermediate 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, which involves mixing N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid with 20% hydrochloric acid, stirring, heating and refluxing to obtain the product.

[0007] Although this experimental method successfully obtained the target product, the preparation method involving heating with dilute hydrochloric acid has a slow reaction rate and is prone to producing the decomposition product 3,5-dichloroaniline. Furthermore, the feed concentration needs to be controlled at a low level; otherwise, the material is prone to expansion upon heating, posing a risk of material overflow, resulting in low preparation efficiency and poor safety. Moreover, using dilute hydrochloric acid as a catalytic system presents challenges such as a large volume of acidic wastewater requiring post-treatment and high recovery costs, making industrial-scale operation impractical. Summary of the Invention

[0008] In view of the deficiencies in the prior art, the purpose of this invention is to provide a method for preparing 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, a special equipment thereof, and its application.

[0009] A method for preparing 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione according to the present invention includes the following steps:

[0010] S1. Continuously input dry acidic gas into the reactor to control the jacket temperature and internal pressure of the reactor.

[0011] S2. The raw material N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid and the auxiliary agent are mixed and then fed into the reactor;

[0012] S3. Controlling the reactor rotation speed, the raw material N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid and the auxiliary agent undergo a cyclization reaction under the catalysis of acidic gas and at a preset reaction temperature to obtain a mixture of product 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, water and auxiliary agent.

[0013] S4. Cool and separate the mixture obtained in step S3 to obtain 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione solid and an aqueous solution of the auxiliaries, respectively.

[0014] In some embodiments, the reactor is a continuous tubular reactor with a dynamic stirring structure inside, where the raw material N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid and the auxiliary agent undergo a continuous cyclization reaction under the action of the dynamic stirring structure.

[0015] In some embodiments, the acidic gas in step S1 is one of hydrogen chloride, hydrogen bromide, and hydrogen iodide.

[0016] In some embodiments, the temperature of the reactor jacket in step S1 is 80-150°C, and the pressure inside the cavity is 0.05-1.0 MPa.

[0017] In some embodiments, the additive in step S2 is one or a mixture of two of the following: glyceryl monostearate, polyethylene glycol, sodium lignosulfonate, sodium polyacrylate, polydimethylsiloxane, polyoxypropylene glycerol ether, glycerol random polyether, benzyl triethylamine chloride, and tetrabutylammonium chloride.

[0018] In some embodiments, the mass concentration of the additive is 0.1-5%.

[0019] In some embodiments, the reactor rotation speed is 50-300 rpm and the reaction temperature is 70-140°C during the cyclization reaction in step S3.

[0020] In some embodiments, the aqueous solution of the auxiliary agent obtained in step S4 is concentrated by membrane distillation and then sent to step S2 for reuse.

[0021] The present invention also provides a dedicated apparatus for preparing 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, including a mixer and a reactor;

[0022] The mixer (1) is equipped with inlet A and inlet B. The raw material N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid enters from inlet A, and the auxiliary agent enters from inlet B. The outlet of the mixer is connected to the inlet of the reactor.

[0023] The reactor (2) is equipped with an inlet C, an outlet D and a discharge outlet E. Acidic gas enters through the inlet C. The gas generated by the cyclization reaction of the raw material N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid and the auxiliary agent under the catalysis of acidic gas enters the tail gas removal system through the outlet D. The mixture of the product 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, water and auxiliary agent enters the separator through the discharge outlet E for separation.

[0024] The reactor is a continuous tubular reactor with a spiral stirring structure inside. The raw material N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid, the auxiliary agent, and the acidic gas enter from one end of the reactor and undergo a cyclization reaction. At the same time, the spiral stirring structure pushes them to the other end to achieve a continuous cyclization reaction.

[0025] The present invention also provides a method for preparing 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione and its application in the preparation of iprodione fungicide.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] (1) In the preparation method of 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione of the present invention, inorganic acidic gas is used as catalyst, so there is no VOC emission in the reaction system, which reduces the generation of pollutants in the production and reduces the treatment of subsequent pollutants.

[0028] (2) In the preparation method of 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione of the present invention, a dynamic tubular reactor is used to carry out a continuous dehydration cyclization reaction, thereby realizing the continuous cyclization reaction of raw materials and auxiliaries, achieving efficient and continuous production of 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, improving production efficiency. Compared with the existing technology using a batch reactor, the online liquid holding capacity is smaller, the reaction efficiency is higher, and it is safer and more reliable.

[0029] (3) In the preparation method of 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione of the present invention, the auxiliary agent used is a surfactant, which promotes uniform dispersion of solid particles, effectively avoids the expansion of the reaction system, inhibits the occurrence of side reactions, and has a high reaction conversion rate. After the mother liquor generated in the post-treatment is treated by membrane distillation, the recovered auxiliary agent can be directly recycled, saving energy and reducing energy waste.

[0030] (4) The preparation method of 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione of the present invention has the advantages of continuous operation, high efficiency and simplicity, near-zero emission and mild reaction conditions. It can effectively shorten the reaction time, improve production efficiency, reduce safety risks, and the product yield can reach more than 93% and the purity can reach more than 99%. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of the special equipment of this invention;

[0032] Figure 2 This is a schematic diagram of the process flow of the preparation method of the present invention. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0034] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0035] like Figure 1-2As shown, the method for preparing 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione provided by this invention uses specialized equipment to continuously prepare 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione. The specialized equipment mainly includes a mixer 1, a reactor 2, and a centrifuge. The feed inlet A of the mixer 1 is used to feed the raw material N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid, and the feed inlet B of the mixer 1 is used to feed the auxiliary agent. The raw material and auxiliary agent are simultaneously and continuously fed in, stirred and mixed in the mixer 1, and then enter the reactor 2. The gas inlet C of the reactor 2 is used to input inorganic acidic gas, which is used to catalyze the cyclization reaction of the raw material and auxiliary agent. The reactor 2 is a continuous tubular reactor with a spiral stirring structure 21 inside. Specifically, the continuous dehydration cyclization reaction is carried out using a dynamic tubular reactor 2, which has a smaller online liquid hold-up than the traditional batch reactor, resulting in higher reaction efficiency and greater safety and reliability. The continuous tubular reactor has a dynamic stirring structure in its internal channels, which is more conducive to gas-solid phase mixing, avoids local material accumulation, reduces the cyclization reaction temperature, effectively reduces the generation of decomposition by-products, and improves product content and yield. The tail gas outlet of reactor 2 is connected to the tail gas treatment system to purify the waste gas generated in the production process. The discharge port of reactor 2 is connected to a centrifuge to output a mixture of 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, water, and additives, which is then separated in the centrifuge. The separated solid 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione is used for the synthesis of the bactericide isopropionate. The mother liquor is an aqueous solution of additives, which is concentrated by membrane distillation and then sent to mixer 1 for reuse.

[0036] The present invention discloses a method for preparing 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, which adopts a continuous feeding method to achieve continuous cyclization reaction of raw materials and auxiliaries, thereby realizing the efficient and continuous production of 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione and improving production efficiency.

[0037] Specifically, it includes the following steps:

[0038] S1. Connect the tail gas outlet of reactor 2 to the tail gas treatment system, open the tail gas valve, and continuously input dry inorganic acidic gas into reactor 2 through the inlet of reactor 2. Control the jacket temperature inside reactor 2 to 80-150℃ and the internal pressure of reactor 2 to 0.05-1.0MPa. The inorganic acidic gas is one of hydrogen chloride, hydrogen bromide, or hydrogen iodide. Because of the catalysis by the inorganic acidic gas, the reaction system has no VOC emissions, reducing the generation of pollutants during production and minimizing subsequent pollutant treatment.

[0039] S2. The raw material N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid and the auxiliary agent are continuously fed into the mixer 1 from the feed port A and feed port B, respectively. After being mixed by the mixer 1, they are fed into the reactor 2. The mass concentration of the auxiliary agent is 0.1-5%.

[0040] The additives are one or a mixture of two of the following: glyceryl monostearate, polyethylene glycol, sodium lignosulfonate, sodium polyacrylate, polydimethylsiloxane, polyoxypropylene glycerol ether, glycerol random polyether, benzyl triethylamine chloride, and tetrabutylammonium chloride. In this embodiment, polydimethylsiloxane is preferred. Using this additive ensures uniform dispersion of solid particles, effectively preventing the reaction system from expanding and suppressing side reactions, resulting in a high reaction conversion rate. After membrane distillation, the mother liquor generated in the post-treatment process can be recycled directly, saving energy and reducing energy waste.

[0041] S3. Under the catalytic action of acidic gas, the raw materials and additives undergo a cyclization reaction in reactor 2 to obtain a mixture of 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, water, and additives; the rotation speed of reactor 2 during the cyclization reaction is 50-300 rpm, and the reaction temperature is 70-140℃.

[0042] S4. After cooling the mixture obtained in step S3, separate it by centrifugation to obtain 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione solid and an aqueous solution of the auxiliary agent. The aqueous solution of the auxiliary agent is sent to the mixer 1 in step S2 for reuse after passing through a membrane distillation system. The recovered auxiliary agent can be directly recycled, saving energy and reducing energy waste.

[0043] Specifically, the reaction formula in this embodiment is:

[0044]

[0045] The preparation method of this embodiment has the advantages of being continuous, efficient and simple, with near-zero emissions and mild reaction conditions. It can effectively shorten the reaction time, improve production efficiency, reduce safety risks, and achieve a product yield of over 93% and a purity of over 99%.

[0046] Example 1

[0047] The tail gas outlet of reactor 2 is connected to the tail gas treatment system. The tail gas valve is opened, and dry hydrogen bromide gas is continuously introduced into reactor 2 through the inlet. The jacket temperature of reactor 2 is controlled at 80℃, and the internal pressure of reactor 2 is controlled at 0.05MPa. The raw materials N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid and polyoxypropylene glycerol ether are continuously introduced into mixer 1, with the mass concentration of polyoxypropylene glycerol ether being 0.5%. The rotation speed of reactor 2 is controlled at 50 rpm, and the reaction temperature is controlled at 70℃ to carry out a cyclization and dehydration reaction, obtaining a mixture of product 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, water, and additives. After centrifugation, the separated aqueous phase is introduced into a membrane distillation system for concentration and recovery of polyoxypropylene glycerol ether, and returned to mixer 1 for batching. The obtained 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione solid is analyzed by liquid chromatography with external standard method. The product purity is 99.1%, and the yield is 93.5%.

[0048] Example 2

[0049] The tail gas outlet of reactor 2 is connected to the tail gas treatment system. The tail gas valve is opened, and dry hydrogen chloride gas is continuously introduced into reactor 2 through the inlet. The jacket temperature of reactor 2 is controlled at 90℃ and the internal pressure of reactor 2 chamber is controlled at 0.1MPa. The raw materials N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid and sodium lignosulfonate are continuously introduced into mixer 1, with the mass concentration of sodium lignosulfonate being 5%. The reactor speed is controlled at 100rpm and the reaction temperature is controlled at 80℃ to carry out a cyclization and dehydration reaction, obtaining a mixture of product 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, water, and auxiliaries. After centrifugation, the aqueous phase is introduced into a membrane distillation system for concentration and recovery of sodium lignosulfonate, and returned to mixer 1 for batching. The obtained 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione solid is analyzed by liquid chromatography with external standard method. The product purity is 99.2% and the yield is 94.7%.

[0050] Example 3

[0051] The tail gas outlet of reactor 2 is connected to the tail gas treatment system. The tail gas valve is opened, and dry hydrogen iodide gas is continuously introduced into reactor 2 through the inlet. The jacket temperature of reactor 2 is controlled at 80℃, and the internal pressure of reactor 2 is controlled at 0.2MPa. The raw materials N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid and tetrabutylammonium chloride are continuously introduced into mixer 1, with a mass concentration of 0.1% for tetrabutylammonium chloride. The rotation speed of reactor 2 is controlled at 300 rpm, and the reaction temperature is controlled at 90℃ to carry out a cyclization and dehydration reaction, yielding a mixture of product 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, water, and additives. After centrifugation, the aqueous phase is introduced into a membrane distillation system for concentration and recovery of tetrabutylammonium chloride, and then returned to mixer 1 for batching. The obtained 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione solid is analyzed by liquid chromatography with external standard method. The product purity is 99%, and the yield is 95%.

[0052] Example 4

[0053] The tail gas outlet of reactor 2 is connected to the tail gas treatment system. The tail gas valve is opened, and dry hydrogen chloride gas is continuously introduced into reactor 2 through the inlet. The jacket temperature of reactor 2 is controlled at 100℃ and the internal pressure of reactor 2 chamber is controlled at 0.4MPa. The raw materials N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid and polydimethylsiloxane are continuously introduced into mixer 1, respectively. The mass concentration of polydimethylsiloxane is 0.2%. The reactor speed is controlled at 200rpm and the reaction temperature is controlled at 90℃ to carry out cyclization and dehydration reaction, and a mixture of product 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, water and auxiliaries is obtained. After centrifugation, the aqueous phase is introduced into the membrane distillation system for concentration and recovery of polydimethylsiloxane, and returned to mixer 1 for batching. The obtained 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione solid is analyzed by liquid chromatography with external standard method. The product purity is 99.5% and the yield is 94.5%.

[0054] Example 5

[0055] The tail gas outlet of reactor 2 is connected to the tail gas treatment system. The tail gas valve is opened, and dry hydrogen bromide gas is continuously introduced into reactor 2 through the inlet. The jacket temperature of reactor 2 is controlled at 110℃ and the internal pressure of reactor 2 chamber is controlled at 0.1MPa. The raw materials N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid and polydimethylsiloxane are continuously introduced into mixer 1, with the mass concentration of polydimethylsiloxane being 1%. The rotation speed of reactor 2 is controlled at 300rpm and the reaction temperature at 100℃ to carry out the cyclization and dehydration reaction, obtaining a mixture of product 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, water, and additives. After centrifugation, the aqueous phase is introduced into a membrane distillation system for concentration and recovery of polydimethylsiloxane, and returned to mixer 1 for batching. The obtained 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione solid is analyzed by liquid chromatography with external standard method. The product purity is 99.5% and the yield is 95.4%.

[0056] Example 6

[0057] The tail gas outlet of reactor 2 is connected to the tail gas treatment system. The tail gas valve is opened, and dry hydrogen iodide gas is continuously introduced into reactor 2 through the inlet. The jacket temperature of reactor 2 is controlled at 110℃ and the internal pressure of reactor 2 chamber is controlled at 0.6MPa. The raw materials N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid and glycerol random polyether are continuously introduced into mixer 1, with the mass concentration of glycerol random polyether being 2%. The rotation speed of reactor 2 is controlled at 300rpm and the reaction temperature at 100℃ to carry out the cyclization and dehydration reaction, obtaining a mixture of product 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, water, and additives. After centrifugation, the aqueous phase is introduced into a membrane distillation system for concentration and recovery of glycerol random polyether, and returned to mixer 1 for batching. The obtained 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione solid is analyzed by liquid chromatography with external standard method. The product purity is 99.6% and the yield is 95.2%.

[0058] Example 7

[0059] The tail gas outlet of reactor 2 is connected to the tail gas treatment system. The tail gas valve is opened, and dry hydrogen chloride gas is continuously introduced into reactor 2 through the inlet. The jacket temperature of reactor 2 is controlled at 80℃, and the internal pressure of reactor 2 chamber is controlled at 1.0MPa. The raw materials N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid and sodium polyacrylate are continuously introduced into mixer 1, respectively. The mass concentration of sodium polyacrylate is 1.5%. The rotation speed of reactor 2 is controlled at 220rpm, and the reaction temperature is controlled at 140℃ to carry out cyclization and dehydration reaction, to obtain a mixture of product 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, water, and auxiliaries. After centrifugation, the aqueous phase is introduced into a membrane distillation system for concentration and recovery of sodium polyacrylate, and returned to mixer 1 for batching. The obtained 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione solid is analyzed by liquid chromatography with external standard method. The product purity is 99.1%, and the yield is 93.8%.

[0060] Example 8

[0061] The tail gas outlet of reactor 2 is connected to the tail gas treatment system. The tail gas valve is opened, and dry hydrogen bromide gas is continuously introduced into reactor 2 through the inlet. The jacket temperature of reactor 2 is controlled at 90℃, and the internal pressure of reactor 2 is controlled at 0.7MPa. The raw materials N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid and sodium polyacrylate are continuously introduced into mixer 1, respectively. The mass concentration of sodium polyacrylate is 4%. The reactor speed is controlled at 180rpm, and the reaction temperature is controlled at 80℃ to carry out the cyclization and dehydration reaction, and a mixture of product 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, water, and additives is obtained. After centrifugation, the aqueous phase is introduced into the membrane distillation system for concentration and recovery of sodium polyacrylate, and returned to mixer 1 for batching. The obtained 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione solid is analyzed by liquid chromatography with external standard method. The product purity is 99.4%, and the yield is 95.5%.

[0062] Example 9

[0063] The tail gas outlet of reactor 2 is connected to the tail gas treatment system. The tail gas valve is opened, and dry hydrogen bromide gas is continuously introduced into reactor 2 through the inlet. The jacket temperature of reactor 2 is controlled at 110℃ and the internal pressure of reactor 2 chamber is controlled at 0.5MPa. The raw materials N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid and benzyl triethylamine chloride are continuously introduced into mixer 1, respectively. The mass concentration of benzyl triethylamine chloride is 3%. The reactor speed is controlled at 110 rpm and the reaction temperature is controlled at 100℃ to carry out the cyclization and dehydration reaction, and a mixture of product 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, water and auxiliaries is obtained. After centrifugation, the aqueous phase is introduced into the membrane distillation system for concentration and recovery of benzyl triethylamine chloride, and returned to mixer 1 for batching. The obtained 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione solid is analyzed by liquid chromatography with external standard method. The product purity is 99.2% and the yield is 93%.

[0064] Example 10

[0065] Connect the tail gas outlet of reactor 2 to the tail gas treatment system, open the tail gas valve, and continuously input dry hydrogen bromide gas into reactor 2 through the inlet. Control the jacket temperature of reactor 2 to 120℃ and the internal pressure of reactor 2 chamber to 0.2MPa. Continuously input the raw materials N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid, glyceryl stearate, and sodium polyacrylate into mixer 1. The mass concentration of glyceryl stearate is 0.8%, and the mass concentration of sodium polyacrylate is 2%. The reactor 2 was rotated at 250 rpm and the reaction temperature was set at 120 °C to carry out a cyclization and dehydration reaction, yielding a mixture of product 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, water, and auxiliaries. After centrifugation, the aqueous phase was fed into a membrane distillation system for concentration to recover glyceryl monostearate, and then returned to mixer 1 for batching. The obtained 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione solid was analyzed by external standard liquid chromatography, and the product purity was 99.5% with a yield of 94.8%.

[0066] Example 11

[0067] Connect the tail gas outlet of reactor 2 to the tail gas treatment system, open the tail gas valve, and continuously input dry hydrogen chloride gas into reactor 2 through the inlet. Control the jacket temperature of reactor 2 to 120℃ and the internal pressure of reactor 2 chamber to 0.08MPa. Continuously input the raw materials N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid, polyethylene glycol, and glycerol random polyether into mixer 1, respectively. The mass concentration of polyethylene glycol is 1.5%, and the mass concentration of glycerol is 0.6%. Control... Reactor 2 operates at 80 rpm and a reaction temperature of 130°C to carry out a cyclization and dehydration reaction, yielding a mixture of product 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, water, and additives. The aqueous phase is separated by centrifugation and fed into a membrane distillation system for concentration to recover polyethylene glycol and glycerol random polyether, which is then returned to mixer 1 for batching. The resulting 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione solid is analyzed by external standard liquid chromatography, showing a purity of 99.3% and a yield of 93.6%.

[0068] Example 12

[0069] Connect the tail gas outlet of reactor 2 to the tail gas treatment system, open the tail gas valve, and continuously input dry hydrogen bromide gas into reactor 2 through the inlet. Control the jacket temperature of reactor 2 to 120℃ and the internal pressure of reactor 2 chamber to 0.3MPa. Continuously input the raw materials N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid, tetrabutylammonium chloride, and benzyltriethylamine chloride into mixer 1, respectively. The mass concentration of tetrabutylammonium chloride is 2%, and the mass concentration of benzyltriethylamine chloride is 2.5%. Control... Reactor 2 was operated at 150 rpm and the reaction temperature was 120 °C to carry out a cyclization and dehydration reaction, yielding a mixture of product 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, water, and auxiliaries. After centrifugation, the aqueous phase was fed into a membrane distillation system for concentration to recover tetrabutylammonium chloride and benzyltriethylamine chloride, and then returned to mixer 1 for batching. The obtained 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione solid was analyzed by liquid chromatography with external standard method, and the product purity was 99.4% and the yield was 96.2%.

[0070] Comparative Example 1

[0071] N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid was mixed with a 20% aqueous hydrochloric acid solution to obtain a homogeneous suspension of N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid with a mass concentration of 5%.

[0072] After the resulting mixture flows out of the mixer, it is fed into the front end of a continuous dynamic tubular reactor. The rotation speed of the tubular reactor is set to 300 rpm and the jacket temperature is 80℃. Sampling and testing at the outlet of the dynamic tubular reactor revealed that the material expanded and the raw material could not be completely converted. The content of the product 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione was only 42%, and the content of the decomposition product 3,5-dichloroaniline was 4.5%.

[0073] Comparative Example 2

[0074] N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid was mixed with a 20% aqueous hydrochloric acid solution to obtain a homogeneous suspension of N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid with a mass concentration of 20%, and 4% polydimethylsiloxane was added as an auxiliary agent.

[0075] After the resulting mixture flows out of the mixer, it is fed into the front end of a continuous dynamic tubular reactor. The rotation speed of the tubular reactor is set to 300 rpm and the jacket temperature is 80℃. Sampling and testing at the outlet of the dynamic tubular reactor revealed that the material expanded and the raw material could not be completely converted. The content of the product 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione was only 23%, and the content of the decomposition product 3,5-dichloroaniline was 6%.

[0076] In summary, the product prepared according to the present invention, 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, its preparation method and special equipment, has a yield of over 93% and a purity of over 99%, which is far superior to the purity and yield of Comparative Example 1 and Comparative Example 2.

[0077] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for preparing 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, characterized in that, Includes the following steps: S1. Continuously input dry acidic gas into reactor (2) and control the jacket temperature and internal pressure of reactor (2); the acidic gas is one of hydrogen chloride, hydrogen bromide and hydrogen iodide. S2. The raw material N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid and the auxiliary agent are mixed and then fed into the reactor (2); the auxiliary agent is one or a mixture of two of the following: glyceryl monostearate, polyethylene glycol, sodium lignosulfonate, sodium polyacrylate, polydimethylsiloxane, polyoxypropylene glycerol ether, glycerol random polyether, benzyl triethylamine chloride, and tetrabutylammonium chloride; S3. Control the rotation speed of the reactor (2). The raw material N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid and the auxiliary agent undergo a cyclization reaction under the catalysis of the acidic gas and at a preset reaction temperature to obtain a mixture of product 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, water and auxiliary agent. S4. Cool and separate the mixture obtained in step S3 to obtain 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione solid and an aqueous solution of the auxiliaries, respectively.

2. The method for preparing 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione according to claim 1, characterized in that, The reactor (2) is a continuous tubular reactor. The reactor (2) is equipped with a spiral stirring structure (21). The raw material N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid and the auxiliary agent undergo a continuous cyclization reaction under the action of the spiral stirring structure (21).

3. The method for preparing 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione according to claim 1, characterized in that, The temperature of the inner jacket of the reactor (2) in step S1 is 80-150℃, and the pressure inside the cavity is 0.05-1.0MPa.

4. The method for preparing 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione according to claim 1, characterized in that, The mass concentration of the auxiliary agent is 0.1-5%.

5. The method for preparing 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione according to claim 1, characterized in that, In step S3, the reactor (2) rotates at 50-300 rpm and the reaction temperature is 70-140℃ during the cyclization reaction.

6. The method for preparing 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione according to claim 1, characterized in that, The aqueous solution of the auxiliary agent obtained in step S4 is concentrated by membrane distillation and then sent to step S2 for reuse.

7. An apparatus for preparing the 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione of claim 1, characterized in that, Includes a mixer (1) and a reactor (2); The mixer (1) is provided with inlet A and inlet B. The raw material N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid enters from inlet A, and the auxiliary agent enters from inlet B. The outlet of the mixer (1) is connected to the inlet of the reactor (2). The reactor (2) is provided with an inlet C, an outlet D and a discharge port E. The acidic gas enters through the inlet C. The gas generated by the cyclization reaction of the raw material N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid and the auxiliary agent under the catalysis of the acidic gas enters the tail gas removal system through the outlet D. The mixture of the product 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione, water and auxiliary agent enters the separator through the discharge port E for separation. The reactor (2) is a continuous tubular reactor. The reactor (2) is equipped with a spiral stirring structure (21). The raw material N-[[(3,5-dichlorophenyl)amino]carbonyl]aminoacetic acid, the auxiliary agent and the acidic gas enter from one end of the reactor (2) and are pushed to the other end by the spiral stirring structure (21) while carrying out the cyclization reaction, thus realizing the continuous cyclization reaction.

8. The application of the preparation method of 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione as described in any one of claims 1-6 in the preparation of iprodione fungicide.

Images