Metered addition device for anhydrous and anaerobic reactions and its usage method

Abstract

The present invention relates to a chemical reaction device, specifically to a metering dropping device for anhydrous and anaerobic reactions and its usage method, aiming to solve the deficiencies in the prior art, such as the difficulty in controlling the reagent addition rate in chemical reactions, ensuring that the reaction always occurs in an anhydrous and anaerobic environment, and the difficulty in sampling and analyzing during the reaction process. A metering dropping device for anhydrous and anaerobic reactions in the present invention includes an elastic airbag, as well as a reagent bottle, an intermediate bottle, and a reaction bottle arranged in sequence along the flow order of the reagent to be reacted. The reagent bottle, the intermediate bottle, and the reaction bottle are hermetically arranged, and the reagent bottle, the intermediate bottle, and the reaction bottle are connected in sequence. The elastic airbag is respectively connected to the intermediate bottle and the reaction bottle; the present invention also provides a usage method for the metering dropping device for anhydrous and anaerobic reactions. During the experiment, the gas in the device is replaced with an inert gas, and the reagent to be reacted is controlled to be dropped into the reaction bottle to achieve the effect of metering dropping.

Description

Technical Field

[0001] The present invention relates to a chemical reaction device, and particularly to a metering and dropping device for anhydrous and anaerobic reactions and its usage method. Background Art

[0002] In organic synthesis, organolithium reagents or other reagents that cannot contact water or oxygen media are often used, such as n-butyllithium, tert-butyllithium, lithium diisopropylamide, etc. These reagents are either highly flammable or extremely sensitive to air and water. The entire reaction process needs to be carried out in an anhydrous and anaerobic environment. In the laboratory, syringes are generally used to transfer such reagents. However, syringes are only suitable for experiments with small dosages, and it is difficult to effectively control the addition rate. It is also not easy to detect once the anhydrous and anaerobic sealed environment of the reaction system changes. During the reaction process, it is also difficult to collect samples for chemical analysis of the reaction. Therefore, how to solve the above problems and provide a stable anhydrous and anaerobic environment, a controllable metering and dropping device and method for the corresponding reaction has become a technical problem to be solved urgently in the field of organic synthesis. Summary of the Invention

[0003] The purpose of the present invention is to solve the deficiencies in the prior art, such as the difficulty in controlling the addition rate of reagents in chemical reactions, ensuring that the reaction is always carried out in an anhydrous and anaerobic environment, and the difficulty in sampling and analyzing during the reaction process, and to provide a metering and dropping device for anhydrous and anaerobic reactions and its usage method.

[0004] To achieve the above purpose, the technical solution provided by the present invention is as follows:

[0005] A metering and dropping device for anhydrous and anaerobic reactions, characterized in that: it includes an elastic airbag, and a reagent bottle, an intermediate bottle and a reaction bottle are sequentially arranged along the flow sequence of the reagent to be reacted, and the reagent bottle, the intermediate bottle and the reaction bottle are hermetically arranged; a weighing unit is arranged below the reagent bottle, and a first communication port is arranged on the reagent bottle; a second communication port, a first ventilation port and a third communication port are arranged on the intermediate bottle; a sealing device is arranged at the second communication port; an injection port, a sampling port and a second ventilation port are arranged on the reaction bottle, and a sampling device is arranged at the sampling port for sampling the reaction solution in the reaction bottle during the experiment;

[0006] Reagent suction heads are provided on both the first communication port and the third communication port. The inner end of the reagent suction head of the first communication port extends into the reagent to be reacted in the reagent bottle, and the inner end of the reagent suction head of the third communication port extends into the bottom of the intermediate bottle; Reagent input heads are provided on both the second communication port and the sample injection port; The first communication port is connected to the second communication port, and the third communication port is connected to the sample injection port through connecting pipes. The ends of the connecting pipes are connected to the rear ends of the corresponding reagent suction heads or reagent input heads respectively, and are used to transport the reagent in the reagent bottle to the intermediate bottle and transport the reagent in the intermediate bottle to the reaction bottle; The connecting pipes are made of corrosion-resistant pipes; The sealing device is an independently provided sealing plug that cooperates with the second communication port, or a stop valve provided on the connecting pipe, and is used to seal the second communication port before and after the transportation of the reagent to be reacted in the reagent bottle starts and ends;

[0007] The outlets of the elastic airbag are respectively connected to the first ventilation port and the second ventilation port. A first three-way valve is arranged between the elastic airbag and the second ventilation port. The first interface of the first three-way valve communicates with the second ventilation port, the second interface communicates with the elastic airbag, and the third interface communicates with the vacuum pump; A peristaltic pump is arranged between the elastic airbag and the first ventilation port, and is used to send the inert gas in the elastic airbag into the intermediate bottle and adjust the intake speed of the first ventilation port.

[0008] Further, the reagent input head is a short needle, and the ends of the connecting pipes are respectively connected to the syringe barrels of the short needles;

[0009] The reagent suction head is a long needle, and the ends of the connecting pipes are respectively connected to the syringe barrels of the corresponding long needles; The tip of the long needle of the first communication port extends into the reagent to be reacted in the reagent bottle, and the tip of the long needle of the third communication port extends into the bottom of the intermediate bottle.

[0010] Further, the sampling device is a sampling needle, including a sampling needle tube and a sampling long needle. The sampling long needle is arranged in the sampling port, and the position of the tip can be adjusted; The sealing plug is a sealing needle tube, and the sealing needle tube is used to seal the short needle arranged at the second communication port.

[0011] Further, a temperature control device and a stirring device are further included. The temperature control device is arranged below the reaction bottle and is used to adjust the temperature of the reaction solution in the reaction bottle. The stirring device is arranged in the reaction bottle and is used to homogenize the reaction solution and improve the reaction rate.

[0012] Further, a second three-way valve is arranged at the outlet of the elastic airbag. The first interface of the second three-way valve communicates with the elastic airbag, the second interface communicates with the second interface of the first three-way valve, and the third interface communicates with the first ventilation port. The peristaltic pump is arranged between the second three-way valve and the first ventilation port.

[0013] Further, the connecting tubes between the elastic airbag and the first ventilation port, between the first communication port and the second communication port, between the third communication port and the sample injection port, and between the second ventilation port and the elastic airbag are all polytetrafluoroethylene hoses.

[0014] Meanwhile, a usage method for the metering dropping device for anhydrous and anaerobic reactions is also provided, which is characterized by including the following steps:

[0015] S1. Fill the elastic airbag with inert gas, add reaction reagents to the reaction flask and seal it, connect the intermediate flask, the reaction flask, the vacuum pump, the peristaltic pump, and the elastic airbag, and seal the second communication port; add the reagent to be reacted and inert gas to the reagent bottle and seal it.

[0016] S2. Replace the gas in the reaction flask and the intermediate flask with inert gas.

[0017] S3. Connect the second communication port and the first communication port to connect the intermediate flask and the reagent bottle; close the connection pipeline between the elastic airbag and the reaction flask, and record the reading of the weighing unit.

[0018] S4. Connect the vacuum pump and the reaction flask, turn on the vacuum pump to make the reagent to be reacted enter the intermediate flask from the reagent bottle, record the reading of the weighing unit, and determine the dosage of the reagent to be reacted through the difference between the reading in S3 and this reading.

[0019] S5. Fill the reaction flask and the intermediate flask with inert gas.

[0020] S6. Disconnect the first communication port and the second communication port, seal the second communication port, and at the same time make the reagent suction head provided at the third communication port extend to the bottom of the intermediate flask.

[0021] S7. Start the peristaltic pump, and the inert gas enters the intermediate flask, so that the reagent to be reacted in the intermediate flask is dropped into the reaction flask for reaction; after the reagent to be reacted is dropped, turn off the peristaltic pump to complete the reaction, and perform other experimental operations on the reaction solution.

[0022] Further, in S7, during the reaction process, the reaction solution in the reaction flask can be sampled and detected by a sampling device. Specifically: use a sampling needle for sampling, adjust the tip of the sampling needle below the liquid level of the reaction flask, suck a small amount of the reaction solution into the sampling needle tube, then adjust the tip position above the liquid level of the reaction flask, remove the sampling needle tube, add the sucked reaction solution to a volumetric flask or other containers for testing, and then install the sampling needle tube back to its original position.

[0023] Further, S2 is specifically:

[0024] S2.1. Adjust the first three-way valve to connect the vacuum pump, the reaction flask, and the intermediate flask, and adjust the second three-way valve to close the pipelines of the elastic airbag connecting to the reaction flask and the intermediate flask respectively; turn on the vacuum pump to evacuate the reaction flask and the intermediate flask;

[0025] S2.2. Adjust the first three-way valve and the second three-way valve to disconnect the connection of the vacuum pump, and make the elastic airbag communicate with the reaction flask and the intermediate flask to fill them with inert gas.

[0026] Further, in S7, adjust the gas pumping speed of the peristaltic pump to adjust the dropping speed of the reagent to be reacted; at the same time, control the reaction temperature through the temperature control device.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The present invention is provided with a reagent bottle, an intermediate flask, and a reaction flask, all of which are sealed structures. The reagent to be reacted is transported through a connecting pipe, and the intermediate flask and the reaction flask are connected to an elastic airbag for replacing inert gas; a vacuum pump is provided to evacuate the reaction flask and the intermediate flask to transfer the reagent to be reacted from the reagent bottle to the intermediate flask without manual transfer, saving time and effort and ensuring the anhydrous and anaerobic environmental requirements during the reaction process.

[0029] 2. The present invention is provided with a peristaltic pump between the elastic airbag and the intermediate flask, which communicates the intermediate flask, the elastic airbag, and the reaction flask to transport the inert gas in the elastic airbag and the reaction flask to the intermediate flask. The reagent to be reacted is dropped into the reaction flask by the extrusion of the inert gas, forming a closed loop to ensure the stability of the pressure in the device and continuously circulating like this; the peristaltic pump can control the gas pumping speed, thereby controlling the dropping speed of the reagent to be reacted into the reaction flask.

[0030] 3. The present invention is provided with a sampling device, which can directly penetrate into the reaction solution in the reaction flask to extract samples. Samples can be taken at any time during the use of the device without damaging the airtightness of the device.

[0031] 4. The present invention is provided with a long needle and a short needle, and the connecting pipe is connected through the long needle and the short needle. The long needle or the short needle has high hardness and corrosion resistance, is convenient for piercing through the stoppers of the sealed reagent bottle, intermediate flask, and reaction flask, and has a small aperture, and the position of the needle tip is easy to adjust, facilitating experimental operation.

[0032] 5. In the present invention, the sampling device uses a sampling needle. The sampling long needle is easy to penetrate through the seal of the reaction flask, and the position of the needle tip of the sampling needle is convenient to adjust. After sampling, remove the sampling needle tube, transfer the sample, and the sampling long needle remains on the reaction flask. The reaction solution remaining in the long needle can be used as a temporary water seal to ensure the airtightness of the device.

[0033] 6. The usage method of the metering and dropping device for anhydrous and anaerobic reactions of the present invention is based on the metering and dropping device for anhydrous and anaerobic reactions, and the experiment is controlled by a vacuum pump and an adjusting device, with a high degree of automation.

[0034] 7. The device in the present invention is convenient to connect, easy to maintain, and has a good sealing effect. Description of the Drawings

[0035] Figure 1 is a schematic structural principle diagram of an embodiment of the metering and dropping device for anhydrous and anaerobic reactions of the present invention;

[0036] Description of the Reference Numerals in the Drawings:

[0037] 1 - reaction flask, 2 - temperature control device, 3 - first three - way valve, 4 - reagent bottle, 5 - stirring device, 6 - short needle, 7 - second three - way valve, 8 - elastic airbag, 9 - peristaltic pump, 10 - intermediate bottle, 11 - long needle, 12 - sampling needle, 13 - electronic balance, 14 - sealed syringe. Detailed Embodiments

[0038] The following further describes the content of the present invention in detail with reference to the drawings and specific embodiments:

[0039] The metering and dropping device for anhydrous and anaerobic reactions of the present invention, as Figure 1 shown, includes an elastic airbag 8 and a reagent bottle 4, an intermediate bottle 10, and a reaction flask 1 arranged in sequence along the flow order of the reagent to be reacted. The mouths of the reagent bottle 4, the intermediate bottle 10, and the reaction flask 1 are sealed by rubber stoppers;

[0040] A weighing unit is arranged below the reagent bottle 4. In this embodiment, the weighing unit is an electronic balance 13; a first communication port is arranged on the reagent bottle 4; a second communication port, a first ventilation port, and a third communication port are arranged on the intermediate bottle 10; a sealing device is arranged at the second communication port for sealing the second communication port before and after the transportation of the reagent to be reacted in the reagent bottle 4 starts and ends; a sample injection port, a sampling port, and a second ventilation port are arranged on the reaction flask 1, and a sampling device is arranged at the sampling port for sampling the reaction solution in the reaction flask 1 during the experiment; the first communication port, the second communication port, the first ventilation port, the third communication port, the sample injection port, the sampling port, and the second ventilation port are all arranged on the rubber stoppers at the corresponding positions; a temperature control unit is arranged below the reaction flask 1, and a stirring device 5 is arranged in the reaction flask 1.

[0041] In this embodiment, the sampling device is a sampling needle 12, which includes a sampling needle tube and a sampling long needle. The sampling long needle is arranged in the sampling port, and the position of the needle tip is adjustable. In other embodiments of the present invention, other sampling devices can also be used, including a sampling tube arranged in the sampling port and a power device adapted thereto. During the reaction process, an appropriate amount of reaction solution is extracted through the sampling tube.

[0042] Reagent suction heads are arranged at the first communication port and the third communication port, and reagent input heads are arranged at the second communication port and the sample injection port. In this embodiment, the reagent suction head is set as a long needle 11, and the reagent input head is set as a short needle 6. The sealing device is a sealing needle tube 14 that cooperates with the short needle 6 at the second communication port. The long needle 11, the short needle 6, and the sampling long needle can move conveniently on the rubber stopper and have little impact on the airtightness of the sealing device.

[0043] The reagent bottle 4 and the intermediate bottle 10 are connected through a connecting pipe, and the intermediate bottle 10 and the reaction bottle 1 are connected through a connecting pipe. The connecting pipe is selected as a corrosion-resistant pipeline. The two ends of the connecting pipe between the reagent bottle 4 and the intermediate bottle 10 are respectively connected to the long needle 11 at the first communication port and the short needle 6 at the second communication port. The two ends of the connecting pipe between the intermediate bottle 10 and the reaction bottle 1 are respectively connected to the long needle 11 at the third communication port and the short needle 6 at the sample injection port. The tip of the long needle 11 at the third communication port can be adjusted to contact the bottom of the intermediate bottle 10, and the tip of the long needle 11 at the first communication port can be adjusted to contact the bottom of the reagent bottle 4.

[0044] In other embodiments of the present invention, the sealing device can also be selected as a sealing plug adapted to the syringe barrel of the short needle 6 or a reagent input head with the same effect, or a stop valve arranged on the connecting pipe. The valve is adjusted to be closed to achieve the sealing of the second communication port.

[0045] A first three-way valve 3 is arranged at the second ventilation port. The first interface of the first three-way valve 3 is connected to the second ventilation port, the second interface is connected to the elastic airbag 8, and the third interface is connected to the vacuum pump. A second three-way valve 7 is arranged at the outlet of the elastic airbag 8. The other two interfaces of the second three-way valve 7 are respectively connected to the second interface of the first three-way valve 3 and the first ventilation port. A peristaltic pump 9 is arranged between the elastic airbag 8 and the first ventilation port. By adjusting the rotation speed of the peristaltic pump 9, the speed of pumping inert gas can be adjusted, thereby adjusting the speed of the reagent to be reacted entering the reaction bottle 1. The connecting pipes between the elastic airbag 8 and the peristaltic pump 9, between the peristaltic pump 9 and the first ventilation port, between the reagent bottle 4 and the intermediate bottle 10, between the third communication port and the sample injection port, and between the second ventilation port and the elastic airbag 8 are polytetrafluoroethylene hoses that are corrosion-resistant and acid-alkali-resistant.

[0046] The working principle of the present invention is as follows: After replacing the entire reaction system with an inert gas, the reagent to be reacted is added to the intermediate bottle 10 through the second communication port by a vacuum pump, and the second communication port is sealed. The inert gas enters the intermediate bottle 10 from the first ventilation port, pushing the reagent to be reacted in the intermediate bottle 10 to be added dropwise into the reaction bottle 1 through the short needle 6 of the reaction bottle 1. The inert gas in the reaction bottle 1 enters the peristaltic pump 9 through the second ventilation port, and so on continuously. Because the pressure in the entire reaction system is consistent, the reagent can be added dropwise at a uniform and stable speed; by adjusting the rotation speed of the peristaltic pump 9, the dropping speed can be accurately controlled. During the reaction process, the temperature control device 2 regulates the temperature in the reaction bottle 1; the volume change of the elastic airbag 8 will intuitively reflect the airtightness of the entire device. If there is a leakage, inert gas can also be filled into the elastic airbag 8 for supplementation; during the reaction process, the reaction solution can be collected from the reaction bottle 1 through the sampling device for detection and analysis. When collecting samples, there will be some reaction solution left in the sampling long needle 11 or the sampling tube to prevent the change of the airtightness of the device.

[0047] A method for using a metering dropping device for anhydrous and anaerobic reactions, and the specific steps are as follows:

[0048] S1. Fill the elastic airbag 8 with inert gas, add the reaction reagent to the reaction bottle 1 and seal it. Connect the intermediate bottle 10, the reaction bottle 1, the vacuum pump, the peristaltic pump 9 and the elastic airbag 8. The intermediate bottle 10 and the reaction bottle 1 are connected. Connect the sealing syringe 14 to the short needle 6 of the second communication port to seal the second communication port; add the reagent to be reacted and inert gas to the reagent bottle 4 and seal it.

[0049] S2. Adjust the first three-way valve 3 to connect the vacuum pump, the reaction bottle 1 and the intermediate bottle 10, and adjust the second three-way valve 7 to close the pipelines of the elastic airbag 8 respectively with the reaction bottle 1 and the intermediate bottle 10; turn on the vacuum pump to evacuate the reaction bottle 1 and the intermediate bottle 10.

[0050] S3. Adjust the first three-way valve 3 and the second three-way valve 7 to disconnect the connection of the vacuum pump, and make the elastic airbag 8 communicate with the reaction bottle 1 and the intermediate bottle 10, and fill them with inert gas.

[0051] S4. Remove the sealing syringe 14 connected to the short needle 6 of the second communication port, connect the second communication port and the first communication port to make the intermediate bottle 10 communicate with the reagent bottle 4, adjust the long needle 11 of the third communication port to make the tip close to the third communication port; adjust the first three-way valve 3 and the second three-way valve 7 to close the pipeline of the elastic airbag 8 and the reaction bottle 1, and record the reading of the electronic balance 13.

[0052] S5. Adjust the first three-way valve 3 to connect to the vacuum pump. Turn on the vacuum pump to allow the reagent to be reacted to enter the intermediate bottle 10 from the reagent bottle 4. Turn off the vacuum pump and record the reading of the electronic balance 13. Determine the amount of the reagent to be reacted based on the difference between the reading in S4 and this reading.

[0053] S6. Adjust the first three-way valve 3 and the second three-way valve 7 to connect the elastic airbag 8 to the reaction bottle 1, the intermediate bottle 10, and the reagent bottle 4, and fill them with inert gas.

[0054] S7. Disconnect the first connection port and the second connection port, and connect the sealed syringe 14 to the short needle 6 of the second connection port to seal the second connection port. Adjust the long needle 11 of the third connection port so that its tip extends to the bottom of the intermediate bottle 10.

[0055] S8. Start the peristaltic pump 9 so that the inert gas enters the intermediate bottle 10 along the first ventilation port, causing the reagent to be reacted in the intermediate bottle 10 to be dropped into the reaction bottle 1 for reaction. At the same time, start the stirring device 5 and the temperature control device 2, and adjust the temperature in the reaction bottle 1 through the temperature control device 2.

[0056] During the reaction, adjust the gas pumping speed to adjust the dropping speed of the reagent to be reacted.

[0057] During the reaction, sample with the sampling needle 12 for testing and analysis.

[0058] After all the reagent to be reacted in the intermediate bottle 10 has been dropped, turn off the peristaltic pump 9.

[0059] S9. After the reaction is completed, adjust the first three-way valve 3 and the second three-way valve 7 to disconnect the connection between the elastic airbag 8 and the reaction bottle 1 and the intermediate bottle 10, and disconnect the connection between the intermediate bottle 10 and the reaction bottle 1. Seal the reaction bottle 1 to maintain an anhydrous and anaerobic environment, and perform subsequent experimental operations on the reaction solution in the reaction bottle 1. If no further operations are required, disassemble the device and clean it.

[0060] In S8, the specific operation of sampling with the sampling needle 12 for testing and analysis is as follows: Adjust the tip of the sampling needle 12 below the liquid level of the reaction bottle 1. After sucking a small amount of the reaction solution into the sampling needle tube, adjust the position of the tip above the liquid level of the reaction bottle 1, quickly remove the sampling needle tube, add the sucked reaction solution to a volumetric flask or other container for testing, and then install the sampling needle tube back to its original position. During this process, a small amount of the reaction solution in the sampling long needle at the sampling port will have a similar liquid sealing effect and will not affect the airtightness of the device system in a short time.

[0061] During the experiment, the airtightness of the device can be detected by the volume change of the elastic airbag 8; if the volume of the elastic airbag 8 decreases significantly, it indicates that there is a gas leak in the device. Check the connections of the device for troubleshooting. If no obvious leak point is found, turn off the peristaltic pump 9, adjust the second three-way valve 7, close the connection between the elastic airbag 8 and the reaction flask 1, remove the elastic airbag 8, refill it with inert gas, reconnect it, and adjust the second three-way valve 7, then start the peristaltic pump 9; under the action of the inert gas in the elastic airbag 8, the pressure in the device is slightly higher than the external pressure. Even if there is a problem with the airtightness of the device, by promptly filling the elastic airbag 8 with inert gas, an anhydrous and anaerobic environment required for the reaction can be ensured.

Claims

1. A metering dropping device for anhydrous and anaerobic reactions, characterized in that: it includes an elastic airbag (8) and reagent bottles (4), an intermediate bottle (10) and a reaction bottle (1) arranged in sequence along the flow order of the reagent to be reacted, and the reagent bottles (4), the intermediate bottle (10) and the reaction bottle (1) are hermetically arranged; a weighing unit is arranged below the reagent bottle (4), and a first communication port is arranged on the reagent bottle (4); a second communication port, a first ventilation port and a third communication port are arranged on the intermediate bottle (10); a sealing device is arranged at the second communication port; a sample inlet, a sampling port and a second ventilation port are arranged on the reaction bottle (1), and a sampling device is arranged at the sampling port for sampling the reaction solution in the reaction bottle (1) during the experiment; reagent suction heads are arranged on both the first communication port and the third communication port. The inner end of the reagent suction head of the first communication port extends into the reagent to be reacted in the reagent bottle (4), and the inner end of the reagent suction head of the third communication port extends into the bottom of the intermediate bottle (10); reagent input heads are arranged at both the second communication port and the sample inlet; the first communication port is communicated with the second communication port, and the third communication port is communicated with the sample inlet through connecting pipes. The ends of the connecting pipes are connected to the rear ends of the corresponding reagent suction heads or reagent input heads respectively, and are used to transport the reagent in the reagent bottle (4) to the intermediate bottle (10) and transport the reagent in the intermediate bottle (10) to the reaction bottle (1); the connecting pipes are made of corrosion-resistant pipes; the sealing device is an independently arranged sealing plug that cooperates with the second communication port, or a stop valve arranged on the connecting pipe, and is used to seal the second communication port before and after the transportation of the reagent to be reacted in the reagent bottle (4) starts; the outlet of the elastic airbag (8) is respectively connected to the first ventilation port and the second ventilation port. A first three-way valve (3) is arranged between the elastic airbag (8) and the second ventilation port. The first interface of the first three-way valve (3) is communicated with the second ventilation port, the second interface is communicated with the elastic airbag (8), and the third interface is communicated with a vacuum pump; a peristaltic pump (9) is arranged between the elastic airbag (8) and the first ventilation port, and is used to send the inert gas in the elastic airbag (8) into the intermediate bottle (10) and adjust the intake speed of the first ventilation port.

2. The metering dropping device for anhydrous and anaerobic reactions according to claim 1, characterized in that: the reagent input head is a short needle (6), and the ends of the connecting pipes are respectively communicated with the syringe barrel of the short needle (6); the reagent suction head is a long needle (11), and the ends of the connecting pipes are respectively communicated with the syringe barrel of the corresponding long needle (11); the tip of the long needle (11) of the first communication port extends into the reagent to be reacted in the reagent bottle (4), and the tip of the long needle (11) of the third communication port extends into the bottom of the intermediate bottle (10).

3. The metering dropping device for anhydrous and anaerobic reactions according to claim 2, characterized in that: the sampling device is a sampling needle (12), including a sampling needle tube and a sampling long needle, and the sampling long needle is arranged in the sampling port; the sealing plug is a sealing needle tube (14), and the sealing needle tube (14) is used to seal the short needle (6) arranged at the second communication port.

4. The metering and dropping device for anhydrous and anaerobic reactions according to any one of claims 1-3, characterized in that: it further includes a temperature control device (2) and a stirring device (5), the temperature control device (2) is arranged below the reaction flask (1); the stirring device (5) is arranged in the reaction flask (1).

5. The metering and dropping device for anhydrous and anaerobic reactions according to claim 4, characterized in that: a second three-way valve (7) is arranged at the outlet of the elastic airbag (8), the first interface of the second three-way valve (7) is communicated with the elastic airbag (8), the second interface is communicated with the second interface of the first three-way valve (3), the third interface is communicated with the first ventilation port, and the peristaltic pump (9) is arranged between the second three-way valve (7) and the first ventilation port.

6. The metering and dropping device for anhydrous and anaerobic reactions according to claim 5, characterized in that: the connecting pipes between the elastic airbag (8) and the first ventilation port, between the first communication port and the second communication port, between the third communication port and the sample injection port, and between the second ventilation port and the elastic airbag (8) are polytetrafluoroethylene hoses.

7. A method for using the metering and dropping device for anhydrous and anaerobic reactions, based on the metering and dropping device for anhydrous and anaerobic reactions according to any one of claims 1-6, characterized in that, it includes the following steps: S1. Fill the elastic airbag (8) with inert gas, add reaction reagents into the reaction flask (1) and seal it, connect the intermediate flask (10), the reaction flask (1), the vacuum pump, the peristaltic pump (9) and the elastic airbag (8), and seal the second communication port; add the reagent to be reacted and inert gas into the reagent bottle (4) and seal it; S2. Replace the gas in the reaction flask (1) and the intermediate flask (10) with inert gas; S3. Connect the second communication port and the first communication port to make the intermediate flask (10) and the reagent bottle (4) communicate; close the connecting pipeline between the elastic airbag (8) and the reaction flask (1), and record the reading of the weighing unit; S4. Connect the vacuum pump and the reaction flask (1), turn on the vacuum pump to make the reagent to be reacted enter the intermediate flask (10) from the reagent bottle (4), record the reading of the weighing unit, and determine the dosage of the reagent to be reacted through the difference between the reading in S3 and this reading; S5. Fill the reaction flask (1) and the intermediate flask (10) with inert gas; S6. Disconnect the first communication port and the second communication port, and seal the second communication port. At the same time, make the reagent suction head arranged at the third communication port extend to the bottom of the intermediate flask (10); S7. Start the peristaltic pump (9), inert gas enters the intermediate flask (10), so that the reagent to be reacted in the intermediate flask (10) is dropped into the reaction flask (1) for reaction; after the reagent to be reacted is dropped, turn off the peristaltic pump (9) to complete the reaction, and perform other experimental operations on the reaction solution.

8. The method for using the metering and dropping device for anhydrous and anaerobic reactions according to claim 7, characterized in that: In S7, during the reaction process, the reaction solution in the reaction flask (1) can be sampled and tested by a sampling device. Specifically: A sampling needle (12) is used for sampling. The tip of the sampling needle (12) is adjusted to below the liquid level of the reaction flask (1). After sucking a small amount of the reaction solution into the sampling needle tube, the tip position is adjusted to above the liquid level of the reaction flask (1). The sampling needle tube is removed, and the sucked reaction solution is added to a volumetric flask or other containers for testing. Then, the sampling needle tube is reinstalled in place.

9. The method for using the metering and dropping device for anhydrous and anaerobic reactions according to claim 8, characterized in that, S2 is specifically: S2.

1. A second three-way valve (7) is provided at the outlet of the elastic airbag (8). The first interface of the second three-way valve (7) is connected to the elastic airbag (8), the second interface is connected to the second interface of the first three-way valve (3), and the third interface is connected to the first ventilation port. The first three-way valve (3) is adjusted to connect the vacuum pump, the reaction flask (1) and the intermediate flask (10). The second three-way valve (7) is adjusted to close the pipelines between the elastic airbag (8) and the reaction flask (1) and the intermediate flask (10) respectively. The vacuum pump is turned on to evacuate the reaction flask (1) and the intermediate flask (10). S2.

2. The first three-way valve (3) and the second three-way valve (7) are adjusted to disconnect the connection to the vacuum pump, so that the elastic airbag (8) is connected to the reaction flask (1) and the intermediate flask (10), and an inert gas is filled into them.

10. The method for using the metering and dropping device for anhydrous and anaerobic reactions according to claim 9, characterized in that: In S7, the gas pumping speed of the peristaltic pump (9) is adjusted to thereby adjust the dropping speed of the reagent to be reacted; meanwhile, the reaction temperature is controlled by the temperature control device (2) provided below the reaction flask (1).

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