apparatus for the synthesis of phenylglycine precursor phenylhydantoin

Abstract

This invention provides a synthesis apparatus for phenylhydantoin, a precursor of phenylglycine, belonging to the field of chemical equipment technology. It includes an ammonium bicarbonate solution reaction tank, an intermediate tank, and a phenylhydantoin solution synthesis tank. The ammonium bicarbonate solution reaction tank is equipped with an ammonia inlet pipe and a carbon dioxide gas inlet pipe. The intermediate tank is connected to the ammonium bicarbonate solution outlet at the bottom of the reaction tank via a pipeline. The top of the phenylhydantoin solution synthesis tank is equipped with a sodium cyanide solution inlet pipe, a benzaldehyde solution inlet pipe, and an ammonium bicarbonate solution inlet pipe. The phenylhydantoin solution synthesis tank includes a jacketed synthesis tank body and is equipped with a heating pipe and a discharge pipe connected to the internal cavity of the jacket to provide a suitable temperature for the synthesis of phenylhydantoin. This application can reduce the frequent dumping operations of the batch reactor, realize the continuous reaction of the phenylhydantoin solution, and at the same time, use ammonia to absorb carbon dioxide instead of solid ammonium bicarbonate, reducing the safety hazards and environmental risks caused by leakage and improving production efficiency.

Description

Technical Field

[0001] This utility model belongs to the field of chemical equipment technology, and specifically relates to a synthesis apparatus for phenylglycine precursor benhyin. Background Technology

[0002] With the rapid development of biotechnology and the pharmaceutical industry, the demand for natural amino acids is constantly increasing. Phenylglycine, as an important amino acid derivative, has wide applications in medicine, pesticides, dyes, and other fields.

[0003] The existing phenylglycine precursor benzylhydantoin is produced in a batch reactor. There is a possibility of material leakage at the sealing surface during the material transfer process. In addition, the use of solid ammonium bicarbonate as feed generates dust and fugitive exhaust gas, which poses high safety hazards and environmental risks. Utility Model Content

[0004] This invention provides a synthesis apparatus for phenylglycine precursor phenylhydantoin, aiming to achieve continuous production of phenylglycine precursor phenylhydantoin, improve production efficiency, and reduce safety hazards and environmental risks.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is: to provide a synthesis apparatus for phenylglycine precursor phenylhydantoin, comprising: The ammonium bicarbonate solution reaction vessel is equipped with an ammonia water inlet pipe and a carbon dioxide gas inlet pipe for generating ammonium bicarbonate solution. An intermediate tank, connected via a pipeline to the ammonium bicarbonate solution outlet at the bottom of the reaction tank, is used to buffer the ammonium bicarbonate solution pumped in by the first pumping pump; and The benzyl-hydantoin solution synthesis tank is equipped with a sodium cyanide solution inlet pipe, a benzaldehyde solution inlet pipe and an ammonium bicarbonate solution inlet pipe at the top, and a benzyl-hydantoin solution outlet pipe at the bottom, for synthesizing benzyl-hydantoin solution. The benzyl-hydantoin solution synthesis tank includes a synthesis tank body with a jacket, and is provided with a heating pipe and a discharge pipe communicating with the internal cavity of the jacket to heat the benzyl-hydantoin solution synthesis tank.

[0006] In one possible implementation, a pipeline mixer is further included in front of the benzene-hydantoin solution synthesis tank, wherein the sodium cyanide solution inlet pipe, the benzaldehyde solution inlet pipe, and the ammonium bicarbonate solution inlet pipe are all connected to the pipeline mixer, so that the added sodium cyanide solution, benzaldehyde solution, and ammonium bicarbonate solution are mixed in the pipeline mixer and then enter the benzene-hydantoin solution synthesis tank.

[0007] In one possible implementation, a fourth flow meter and a fourth regulating valve are provided on the benzaldehyde solution feed pipe, and a fifth flow meter and a fifth regulating valve are provided on the sodium cyanide solution feed pipe; the ammonium bicarbonate solution feed pipe is connected between the bottom outlet of the intermediate tank and the pipeline mixer, and a third flow meter and a third regulating valve are provided on the ammonium bicarbonate solution feed pipe.

[0008] In one possible implementation, a third level gauge is provided on the intermediate tank, and the third regulating valve is interlocked with the third level gauge.

[0009] In one possible implementation, two second feed pumps are connected in parallel on the ammonium bicarbonate solution feed pipe.

[0010] In one possible implementation, a gas distributor is provided at one end of the carbon dioxide gas inlet pipe that extends into the ammonium bicarbonate solution reaction vessel, and the gas distributor is located at the lower part of the ammonium bicarbonate solution reaction vessel.

[0011] In one possible implementation, the gas distributor includes distribution pipes arranged in concentric circles and connecting pipes connecting each distribution pipe, with a plurality of exhaust holes provided on the upward-facing side of each distribution pipe.

[0012] In one possible implementation, a first stirrer is provided inside the ammonium bicarbonate solution reaction vessel. The first stirrer includes a first motor, a first stirring shaft extending into the ammonium bicarbonate solution reaction vessel, and stirring blades fixed to the first stirring shaft.

[0013] In one possible embodiment, the ammonium bicarbonate solution reaction vessel is provided with a hemispherical bottom, the lower end of the first stirring shaft extends into the hemispherical bottom, and is provided with an arc-shaped stirring paddle.

[0014] In one possible implementation, a second flow meter and a second regulating valve are provided on the ammonia inlet pipe, and a first flow meter and a first regulating valve are provided on the carbon dioxide gas inlet pipe.

[0015] The apparatus for synthesizing phenylhydantoin, a precursor of phenylglycine, provided by this invention has the following advantages compared with the prior art: A certain amount of ammonia water is pumped into the ammonium bicarbonate solution reaction tank, and carbon dioxide gas is injected into the ammonium bicarbonate solution reactor for absorption reaction to obtain ammonium bicarbonate solution, which is then pumped into an intermediate tank for later use; Ammonium bicarbonate solution, benzaldehyde, and sodium cyanide are injected into the phenylhydantoin solution synthesis tank in a suitable ratio via a pump for reaction to obtain phenylhydantoin solution.

[0016] The synthesis apparatus provided in this application can realize the continuous production of benzyl-hydantoin solution, thereby improving production efficiency; it eliminates the need for a material transfer process, avoiding material leakage; and it uses ammonia water pumped in through pipelines and injected carbon dioxide gas to react in the reaction tank to generate ammonium bicarbonate solution, avoiding the generation of dust and waste gas from the feeding of solid ammonium bicarbonate, thus reducing safety hazards and environmental risks. Attached Figure Description

[0017] Figure 1 A schematic diagram of the apparatus for synthesizing phenylglycine precursor phenylhydantoin provided in an embodiment of this utility model; Figure 2 Schematic diagram of the gas distributor provided in the embodiment of this utility model Figure 1 ; Figure 3 Schematic diagram of the gas distributor provided in the embodiment of this utility model Figure 2 ; Explanation of reference numerals in the attached figures: 1. Ammonium bicarbonate solution reaction vessel; 2. Gas distributor; 201. Distribution pipe; 202. Connecting pipe; 203. Vent; 204. Through hole; 3. Arc-shaped stirring paddle; 4. First feed pump; 5. Intermediate tank; 6. Third level gauge; 7. Third regulating valve; 8. Second feed pump; 9. Discharge pipe; 10. Third feed pump; 11. Benzylhexane solution synthesis vessel; 12. Heating tube; 13. Second stirrer; 14. Online pH meter; 15. Second level gauge; 16. Second pressure gauge; 17. Pipeline mixer; 18. Fifth regulating valve; 19. Fifth flow meter; 20. Fourth regulating valve; 21. Fourth flow meter; 22. First level gauge; 23. First pressure gauge; 24. Motor; 25. Second regulating valve; 26. Second flow meter; 27. First flow meter; 28. First regulating valve; 29. ​​Third flow meter. Detailed Implementation

[0018] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model 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 merely illustrative of the present utility model and are not intended to limit the present utility model.

[0019] Please refer to sections 1 to 2. Figure 3 The present invention will now describe the apparatus for synthesizing phenylglycine precursor phenylhydantoin. The apparatus for synthesizing phenylglycine precursor phenylhydantoin includes an ammonium bicarbonate solution reaction vessel 1, an intermediate vessel 5, and a phenylhydantoin solution synthesis vessel 11.

[0020] The ammonium bicarbonate solution reaction tank 1 is equipped with an ammonia water inlet pipe and a carbon dioxide gas inlet pipe for generating ammonium bicarbonate solution. The intermediate tank 5 is connected to the ammonium bicarbonate solution outlet at the bottom of the reaction tank via a pipeline for buffering the ammonium bicarbonate solution pumped in by the first pump. The benzene-hydantoin solution synthesis tank 11 is equipped with a sodium cyanide solution inlet pipe, a benzaldehyde solution inlet pipe, and an ammonium bicarbonate solution inlet pipe at the top, and a benzene-hydantoin solution outlet pipe at the bottom for synthesizing benzene-hydantoin solution. The benzene-hydantoin solution synthesis tank 11 includes a jacketed synthesis tank body and is equipped with a heating pipe 12 and a discharge pipe 9 connected to the internal cavity of the jacket to heat the benzene-hydantoin solution synthesis tank 11 and provide a suitable temperature for the synthesis of benzene-hydantoin.

[0021] The apparatus for synthesizing phenylhydantoin, the precursor of phenylglycine, provided by this invention has the following advantages compared with the prior art: A certain amount of ammonia water is pumped into the ammonium bicarbonate solution reaction tank 1, and carbon dioxide gas is injected into the ammonium bicarbonate solution reactor to absorb and react to obtain an ammonium bicarbonate solution, which is then pumped into the intermediate tank 5 for later use; the ammonium bicarbonate solution, benzaldehyde, and sodium cyanide are injected into the phenylhydantoin solution synthesis tank 11 in a suitable proportion by pumping to carry out the reaction, thereby obtaining the phenylhydantoin solution.

[0022] The synthesis apparatus provided in this application can realize the continuous production of benzyl-hydantoin solution, thereby improving production efficiency; it eliminates the need for a material transfer process, avoiding material leakage; and it uses ammonia water pumped in through pipelines and injected carbon dioxide gas to react in the reaction tank to generate ammonium bicarbonate solution, avoiding the generation of dust and waste gas from the feeding of solid ammonium bicarbonate, thus reducing safety hazards and environmental risks.

[0023] A sixth flow meter and a sixth regulating valve are installed on the heating pipe 12, which is connected to the internal cavity of the jacket. High-temperature steam enters the jacket from the heating pipe 12 to maintain the temperature of the tank. After the steam is condensed through heat exchange, the condensate is discharged from the discharge pipe 9 at the bottom of the benzene-hydantoin solution synthesis tank 11. The condensate returns to the heater through the pipeline to form high-temperature steam, and then enters the jacket again to achieve recycling.

[0024] The generated ammonium bicarbonate solution is pumped into intermediate tank 5 for buffering. After the ammonium bicarbonate solution is stabilized, it is added to the benzene-hydantoin solution synthesis tank 11 as needed. This reduces the fluctuation of the mixed solution caused by direct addition to the benzene-hydantoin solution synthesis tank 11, ensuring a stable and uniform mixing reaction of the solution and improving the quality of the produced products.

[0025] In some embodiments, see Figure 1As shown, the synthesis apparatus provided in this application also includes a pipeline mixer 17 placed before the benzene-hydantoin solution synthesis tank 11. The sodium cyanide solution feed pipe, benzaldehyde solution feed pipe and ammonium bicarbonate solution feed pipe are all connected to the pipeline mixer 17 so that the added sodium cyanide solution, benzaldehyde solution and ammonium bicarbonate solution are mixed in the pipeline mixer 17 and then enter the benzene-hydantoin solution synthesis tank 11.

[0026] Ammonium bicarbonate solution, sodium cyanide solution, and benzaldehyde are mixed in a certain mass ratio through a pipe mixer 17 and then pumped into a benzene-hydantoin solution synthesis tank 11 preheated to 90°C for mixing and reaction to prepare the desired benzene-hydantoin solution. By mixing in the pipe mixer 17 beforehand, the uniformity of material mixing and the sufficiency of reaction are improved, thereby improving the completeness of the reaction and the quality of the benzene-hydantoin solution, and also avoiding the phenomenon of material waste caused by incomplete reaction.

[0027] In some embodiments, see Figure 1 As shown, a fourth flow meter 21 and a fourth regulating valve 20 are installed on the benzaldehyde solution feed pipe, and a fifth flow meter 19 and a fifth regulating valve 18 are installed on the sodium cyanide solution feed pipe; the ammonium bicarbonate solution feed pipe is connected between the bottom outlet of the intermediate tank 5 and the pipeline mixer 17, and a third flow meter 29 and a third regulating valve 7 are installed on the ammonium bicarbonate solution feed pipe.

[0028] Flow meters are installed on each pipeline to detect the real-time feed flow rate. The opening of the regulating valve is adjusted accordingly through interlocking regulating valves to ensure that the ammonium bicarbonate solution, sodium cyanide solution and benzaldehyde solution are mixed and reacted in proportion, thus ensuring the quality of the synthesized benzene-hydantoin solution.

[0029] In some embodiments, see Figure 1 As shown, a third level gauge 6 is installed on the intermediate tank 5, and a third regulating valve 7 is interlocked with the third level gauge 6. Through the interlock between the third regulating valve 7 and the third level gauge 6 on the intermediate tank 5, the opening of the third regulating valve 7 can be adjusted according to the liquid level in the intermediate tank 5. When the liquid level in the intermediate tank 5 is lower than the minimum liquid level, the third regulating valve 7 can be closed.

[0030] Each regulating valve can be electrically controlled to achieve automatic control switching.

[0031] In some embodiments, see Figure 1 As shown, two second feeding pumps 8 are connected in parallel on the ammonium bicarbonate solution feed pipe, that is, two second feeding pumps 8 are connected in parallel on the pipeline between the intermediate tank 5 and the pipeline mixer 17. One of the two second feeding pumps 8 can be used as a standby pump. When one second feeding pump 8 fails, the other second feeding pump 8 can be turned on to achieve continuous production.

[0032] Similarly, two first feed pumps 4 are installed on the pipeline between the ammonium bicarbonate solution reaction tank 1 and the intermediate tank 5, and two third feed pumps 10 are connected in parallel on the benzene solution discharge pipe 9.

[0033] In some embodiments, see Figure 1 As shown, a gas distributor 2 is installed at one end of the carbon dioxide gas inlet pipe that extends into the ammonium bicarbonate solution reaction tank 1. The gas distributor 2 is located at the lower part of the ammonium bicarbonate solution reaction tank 1. The carbon dioxide gas inlet pipe is connected to an external compressed gas source, which is introduced into the gas distributor 2 to purge and mix the liquid in the tank, thereby improving the reaction efficiency.

[0034] In some embodiments, see Figure 2 As shown, the gas distributor 2 includes distribution pipes 201 arranged in concentric circles and connecting pipes 202 connecting each distribution pipe 201. Each distribution pipe 201 has several exhaust holes 203 on its upward-facing side. One end of the connecting pipe 202 can be installed on a support block or support ring provided on the inner wall of the ammonium bicarbonate solution reaction tank 1. A carbon dioxide gas inlet pipe is connected from the lower or upper side of the connecting pipe 202 or the distribution pipe 201 to introduce compressed gas into the distribution pipe 201.

[0035] See Figure 3 As shown, optionally, the gas distributor 2 can also be two distribution pipes 201 arranged in an I-shape and a connecting pipe 202 connecting the two parallel distribution pipes 201.

[0036] In some embodiments, see Figure 1 As shown, a first stirrer is installed inside the ammonium bicarbonate solution reaction tank 1. The first stirrer includes a first motor 24, a first stirring shaft extending into the ammonium bicarbonate solution reaction tank 1, and stirring blades fixed to the first stirring shaft. The first stirrer mixes the materials in the tank, improving the efficiency and effect of the reaction and enhancing the completeness of the reaction.

[0037] Meanwhile, a through hole 204 is provided in the center of the gas distributor 2 for the first stirring shaft to pass through, so as to ensure the rotation of the first stirring shaft. The first stirring shaft is connected to the first motor 24 via a coupling, and the first motor 24 is mounted on the top of the tank body.

[0038] In some embodiments, see Figure 1 As shown, the ammonium bicarbonate solution reaction vessel 1 has a hemispherical bottom. The lower end of the first stirring shaft extends into the hemispherical bottom, and an arc-shaped stirring paddle 3 is installed. The arc-shaped stirring paddle 3 stirs the material at the bottom of the vessel, avoiding incomplete reaction and material waste due to insufficient stirring of the material at the bottom.

[0039] The gas distributor 2 is positioned above the arc-shaped stirring paddle 3, and the first stirring shaft extends into the bottom of the hemispherical tank through the through hole 204 on the gas distributor 2.

[0040] See Figure 1 As shown, a second stirrer 13 is installed on the benzylhexane solution synthesis tank 11 to stir and mix the solution in the tank, thereby improving the uniformity of material mixing, the completeness of the reaction, and the reaction efficiency. The structure of the second stirrer 13 is the same as or similar to that of the first stirrer, and will not be described in detail.

[0041] In some embodiments, see Figure 1 As shown, a second flow meter 26 and a second regulating valve 25 are installed on the ammonia water inlet pipe, and a first flow meter 27 and a first regulating valve 28 are installed on the carbon dioxide gas inlet pipe. The proportion of materials added is controlled by the flow meters and regulating valves to ensure that the added ammonia water and carbon dioxide gas are added in proportion, avoiding the phenomenon of waste caused by excess of one material.

[0042] The ammonium bicarbonate solution reaction tank 1 is equipped with a first pressure gauge 23 and a first level gauge 22, while the benzene-hydantoin solution synthesis tank 11 is equipped with a second pressure gauge 16, a second level gauge 15, and an online pH meter 14. Automatic control of the device can be achieved through the configured detection elements and electric regulating valves. Since automatic control is a conventional technical means in chemical processes, and it is not the inventive point of this application, this paper will not elaborate on automatic control.

[0043] The working process of this application is as follows (see...) Figure 1 (As indicated by the middle arrow): A certain amount of ammonia water is pumped into the ammonium bicarbonate solution reaction tank 1. Carbon dioxide is injected into the ammonium bicarbonate solution reaction tank 1 through the gas distributor 2 below the ammonium bicarbonate solution reaction tank. The absorption reaction yields ammonium bicarbonate solution, which is then pumped into the intermediate tank 5 for later use. The ammonium bicarbonate solution, benzaldehyde, and sodium cyanide are premixed in a suitable ratio by pumping into the pipeline mixer 17. After that, they flow naturally into the benzene-hydantoin solution synthesis tank 11 for reaction.

[0044] In this reactor, a gas distributor 2 is installed at the bottom of the ammonium bicarbonate solution reaction tank 1 to ensure sufficient contact between carbon dioxide gas and the material. A flow meter and regulating valve control the feed rate to ensure stable feed. A pipeline mixer 17 controls the feed flow rates of the ammonium bicarbonate solution, benzaldehyde, and sodium cyanide solutions via a flow meter and regulating valve. All three are equipped with flow meters and regulating valves to control the feed ratio and ensure stable feed. During the reaction in the benzene-hydantoin solution synthesis tank 11, the tank pressure should be approximately 0.3 MPa, and the temperature should be maintained at approximately 90°C through jacket heating. An online pH meter 14 monitors and regulates the pH value of the solution reaction within the tank to ensure pH stability. The ammonia gas produced in the reaction is separated in a subsequent gas-liquid separator and then absorbed and recovered in a falling film absorption tower to obtain ammonia water for recycling.

[0045] Specifically, a gas-liquid separator (not shown in the figure) is installed on the benzyl hydantoin solution discharge pipe 9 to separate the ammonia gas in the benzyl hydantoin solution and connect it to the ammonium bicarbonate solution reaction tank 1 through a circulation pipeline, so as to realize the recycling of resources and reduce resource waste.

[0046] In summary, the synthesis apparatus provided in this application has the following advantages: (1) It reduces the frequent feeding operations of the batch reactor, realizes the continuous reaction of benzene-hydantoin solution, reduces the safety hazards and environmental risks caused by leakage, and improves production efficiency.

[0047] (2) Adding instruments such as pressure gauges, flow meters, level gauges and electric regulating valves can achieve automatic control.

[0048] (3) Ammonia water was used to absorb carbon dioxide instead of solid ammonium bicarbonate, which successfully avoided the dust and fugitive exhaust gas generated when solid ammonium bicarbonate was fed, thus reducing air pollution.

[0049] (4) The generated ammonia gas is separated by a gas-liquid separator and then absorbed by water to obtain ammonia water that can be recycled, reducing production costs.

[0050] (5) By controlling the material ratio through regulating valves, flow meters, etc., and by controlling the mixing and temperature of the agitator, production fluctuations are minimized and product quality is stabilized.

[0051] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0052] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A device for the synthesis of the phenylglycine precursor methenamine, characterized by, include: The ammonium bicarbonate solution reaction vessel (1) is equipped with an ammonia water inlet pipe and a carbon dioxide gas inlet pipe for generating ammonium bicarbonate solution; An intermediate tank (5) is connected via a pipeline to the ammonium bicarbonate solution outlet at the bottom of the reaction tank, and is used to buffer the ammonium bicarbonate solution pumped in by the first pumping pump; and The benzene-hydantoin solution synthesis tank (11) is equipped with a sodium cyanide solution feed pipe, a benzaldehyde solution feed pipe and an ammonium bicarbonate solution feed pipe at the top, and a benzene-hydantoin solution discharge pipe at the bottom, for synthesizing benzene-hydantoin solution. The benzyl hydantoin solution synthesis tank (11) includes a synthesis tank body with a jacket, and is provided with a heating pipe (12) and a discharge pipe (9) communicating with the internal cavity of the jacket to heat the benzyl hydantoin solution synthesis tank (11).

2. The apparatus for synthesizing phenylglycine precursor phenylhydantoin according to claim 1, wherein, It also includes a pipe mixer (17) placed before the benzyl cyanide solution synthesis tank (11), wherein the sodium cyanide solution inlet pipe, the benzaldehyde solution inlet pipe and the ammonium bicarbonate solution inlet pipe are all connected to the pipe mixer (17) so that the added sodium cyanide solution, benzaldehyde solution and ammonium bicarbonate solution are mixed in the pipe mixer (17) and then enter the benzyl cyanide solution synthesis tank (11).

3. The apparatus for synthesizing phenylglycine precursor phenylhydantoin according to claim 2, characterized by, The benzaldehyde solution feed pipe is equipped with a fourth flow meter (21) and a fourth regulating valve (20), and the sodium cyanide solution feed pipe is equipped with a fifth flow meter (19) and a fifth regulating valve (18); the ammonium bicarbonate solution feed pipe is connected between the bottom outlet of the intermediate tank (5) and the pipeline mixer (17), and the ammonium bicarbonate solution feed pipe is equipped with a third flow meter (29) and a third regulating valve (7).

4. The apparatus for synthesizing phenylglycine precursor phenylhydantoin according to claim 3, characterized by, The intermediate tank (5) is equipped with a third level gauge (6), and the third regulating valve (7) is interlocked with the third level gauge (6).

5. The apparatus for synthesizing phenylglycine precursor phenylhydantoin as claimed in claim 1, wherein, Two second feeding pumps (8) are connected in parallel on the ammonium bicarbonate solution feed pipe.

6. The apparatus for synthesizing phenylglycine precursor phenylhydantoin as claimed in claim 1, wherein, A gas distributor (2) is provided at one end of the carbon dioxide gas inlet pipe that extends into the ammonium bicarbonate solution reaction tank (1), and the gas distributor (2) is located at the lower part of the ammonium bicarbonate solution reaction tank (1).

7. The apparatus for synthesizing phenylglycine precursor phenylhydantoin as claimed in claim 6, wherein, The gas distributor (2) includes distribution pipes (201) arranged in concentric circles, a connecting pipe (202) connecting each distribution pipe (201), and a number of exhaust holes (203) provided on the upward side of each distribution pipe (201).

8. The apparatus for synthesizing phenylglycine precursor phenylhydantoin as claimed in claim 1, wherein, The ammonium bicarbonate solution reaction tank (1) is equipped with a first stirrer, which includes a first motor (24), a first stirring shaft extending into the ammonium bicarbonate solution reaction tank (1), and stirring blades fixed on the first stirring shaft.

9. The apparatus for synthesizing phenylglycine precursor phenylhydantoin as claimed in claim 8, wherein, The ammonium bicarbonate solution reaction vessel (1) is provided with a hemispherical bottom, the lower end of the first stirring shaft extends into the hemispherical bottom, and is provided with an arc-shaped stirring paddle (3).

10. The apparatus for synthesizing phenylglycine precursor phenylhydantoin as claimed in claim 1, wherein, The ammonia inlet pipe is equipped with a second flow meter (26) and a second regulating valve (25), and the carbon dioxide gas inlet pipe is equipped with a first flow meter (27) and a first regulating valve (28).

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