Sandmeyer reaction device

Abstract

The utility model relates to a Sandmeyer reaction device which comprises a raw material storage tank, a rolling type mixer, a micro-channel reactor, a fixed bed reactor and a feed liquid receiving kettle which are sequentially connected through pipelines. According to the utility model, aromatic amine is prepared into corresponding diazonium salt through the micro-channel reactor, and then a corresponding halogenated compound is prepared through a substitution reaction of the fixed bed reactor, so that the reaction device has the characteristics of short reaction time, few impurities, safe and controllable reaction process and the like.

Description

Technical Field

[0001] The utility model belongs to the field of chemical production devices, and particularly relates to a Sandmeyer reaction device. Background Art

[0002] The Sandmeyer reaction is a reaction in which a diazo functional group is replaced by a halogen or a cyano group under the catalysis of a cuprous salt. Compared with a simple halogenation reaction, the advantage of this reaction is that only one isomer is formed, avoiding the generation of other configurational impurities.

[0003] The mechanism of this reaction is through an electron transfer process. The specific process is as follows:

[0004]

[0005] Adopting the traditional batch reaction method, there are problems such as a large heat release during the reaction process, high danger, and instability and easy decomposition of diazonium salts, resulting in low product yield and content.

[0006] The prior art CN114907181B discloses a device for the Sandmeyer reaction. The device includes a premixing unit, a storage unit, a reverse bromination unit, and a water washing unit, which does not cause the accumulation of high-risk diazonium salts during the production process and solves the problem of high viscosity in the kettle system. However, the amount of copper salt used is relatively large, resulting in waste of heavy metals and difficult wastewater treatment; the present invention uses a microchannel reactor to accurately control the feed rate and feed ratio, with less backmixing and low impurity content during the reaction process, and can prepare a high-purity diazonium salt solution. Through the supported catalyst scheme, the consumption of copper salt is reduced, the wastewater and the difficulty of wastewater treatment are reduced, and it is more environmentally friendly. Therefore, optimizing the Sandmeyer reaction conditions, developing a safe and efficient synthesis device, and reducing the reaction energy consumption are the key points of concern in chemical synthesis. Summary of the Invention

[0007] The purpose of the utility model is to provide a Sandmeyer reaction device with a fast reaction speed, a safe reaction process, a high product yield, effectively avoiding the generation of impurities such as the decomposition of aromatic diazonium salts, low production risk, and continuous production.

[0008] In order to achieve the above technical purpose, the utility model adopts the following technical scheme: a Sandmeyer reaction device, including a raw material storage tank, a rolling mixer, a microchannel reactor, a fixed-bed reactor, and a liquid receiving kettle, and each device is connected in sequence through pipelines;

[0009] The described raw material storage tanks include an aromatic amine salt storage tank and a sodium nitrite solution storage tank. The two ends of the rolling mixer are respectively provided with a first feed inlet and a second feed inlet, and a discharge outlet is provided at the bottom. The aromatic amine salt storage tank is connected to the first feed inlet through a pipeline, and the sodium nitrite solution storage tank is connected to the second feed inlet through a pipeline. Control valves and metering pumps are respectively arranged on the material pipelines between the aromatic amine salt storage tank, the sodium nitrite solution storage tank and the rolling mixer.

[0010] The described microchannel reactor includes a microchannel feed inlet, a microchannel reactor temperature control system, and a microchannel partition. An electric star-shaped control valve is arranged on the pipeline connecting the microchannel reactor and the fixed bed reactor.

[0011] An outlet control valve is arranged on the pipeline connecting the fixed bed reactor and the liquid receiving kettle. A reflux control valve is arranged on the reflux pipeline of the fixed bed reactor, and the reflux pipeline is connected to the electric star-shaped control valve. A liquid downcomer and a stirrer are arranged inside the liquid receiving kettle. The outlet control valve of the fixed bed reactor is connected to the liquid downcomer through a pipeline.

[0012] Furthermore, a heat preservation jacket is arranged outside the raw material storage tank.

[0013] Furthermore, a check valve is arranged at the front end of the discharge outlet.

[0014] Furthermore, quality inspection ports are respectively arranged on the feed pipeline and the discharge pipeline of the fixed bed reactor.

[0015] Furthermore, the microchannel reactor temperature control system is provided with a constant temperature medium feed inlet and a constant temperature medium discharge outlet.

[0016] Furthermore, the fixed bed reactor temperature control system includes a heat medium feed inlet and a heat medium discharge outlet.

[0017] Furthermore, a heat preservation jacket for the liquid receiving kettle is arranged outside the liquid receiving kettle.

[0018] Furthermore, the heat preservation jacket for the liquid receiving kettle is provided with a cold water inlet and a cold water outlet.

[0019] Furthermore, a temperature analyzer is arranged at the upper part of the liquid receiving kettle.

[0020] Furthermore, a rupture disc is arranged at the upper part of the liquid receiving kettle.

[0021] Beneficial effects:

[0022] 1) By carrying out the diazotization reaction through a microchannel reactor, the reaction safety is improved, the safety risk is reduced, and the reaction time is shortened.

[0023] 2) The microchannel reactor is connected in series with the fixed-bed reactor, and the aromatic amine diazonium salt directly undergoes a substitution reaction, avoiding the decomposition of the diazonium salt and improving the product yield;

[0024] 3) It can achieve continuous production, significantly improve production efficiency, and reduce the consumption of reaction raw materials;

[0025] 4) Reduce the generation of reaction impurities, and high-yield and high-content products can be obtained. Description of the Drawings

[0026] Figure 1 It is a schematic structural diagram of the Sandmeyer reaction device of the present utility model;

[0027] In the figure: 1 - Aromatic amine salt storage tank, 11 - Control valve a, 12 - Metering pump a, 13 - Heat preservation jacket a, 131 - Inlet of heat preservation jacket a; 132 - Outlet of heat preservation jacket a;

[0028] 2 - Sodium nitrite solution storage tank, 21 - Control valve b, 22 - Metering pump b, 23 - Heat preservation jacket b, 231 - Inlet of heat preservation jacket b; 232 - Outlet of heat preservation jacket b;

[0029] 3 - Rotary mixer, 31 - First feed inlet, 32 - Second feed inlet, 33 - Discharge outlet, 34 - Check valve;

[0030] 4 - Microchannel reactor, 41 - Microchannel feed inlet, 42 - Temperature control system of the microchannel reactor, 421 - Constant temperature medium feed inlet, 422 - Constant temperature medium discharge outlet, 43 - Quality detection port a, 44 - Microchannel partition;

[0031] 5 - Fixed-bed reactor, 51 - Electric star-shaped control valve, 52 - Temperature control system of the fixed-bed reactor, 521 - Heat medium feed inlet, 522 - Heat medium discharge outlet, 53 - Quality detection port b, 54 - Discharge control valve, 55 - Return control valve;

[0032] 6 - Liquid receiving kettle, 61 - Downcomer, 62 - Stirrer, 63 - Temperature analyzer, 64 - Rupture disc, 65 - Heat preservation jacket of the liquid receiving kettle, 651 - Cold water inlet, 652 - Cold water outlet. Detailed Embodiment

[0033] In order to make the technical solutions and advantages of the present utility model clearer and more understandable, the following describes the technical solutions in the embodiments of the present utility model clearly and completely with reference to the specific drawings. The described embodiments are only a part of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts belong to the scope of protection of the present utility model. The following further describes the present utility model with reference to the drawings of the specification:

[0034] As shown Figure 1 is a Sandmeyer reaction device, including a raw material storage tank, a rolling mixer 3, a microchannel reactor 4, a fixed-bed reactor 5 and a liquid receiving kettle 6. Each device is connected in sequence through pipelines;

[0035] The raw material storage tank includes an aromatic amine salt storage tank 1 and a sodium nitrite solution storage tank 2. The two ends of the rolling mixer 3 are respectively provided with a first feed inlet 31 and a second feed inlet 32, and the bottom is provided with a discharge outlet 33. The aromatic amine salt storage tank 1 is connected to the first feed inlet 31 through a pipeline, and the sodium nitrite solution storage tank 2 is connected to the second feed inlet 32 through a pipeline. A check valve 34 is arranged at the front end of the discharge outlet 33, and the check valve 34 can effectively block the backflow of materials.

[0036] Control valves a11 and metering pumps a12 are arranged on the material pipeline between the aromatic amine salt storage tank 1 and the rolling mixer 3; control valves b21 and metering pumps b22 are respectively arranged on the material pipeline between the sodium nitrite solution storage tank 2 and the rolling mixer 3; heat preservation jackets a13 and b23 are respectively arranged outside the aromatic amine salt storage tank 1 and the sodium nitrite solution storage tank 2; the heat preservation jacket a13 is provided with a heat preservation jacket a liquid inlet 131 and a heat preservation jacket a liquid outlet 132; the heat preservation jacket a13 controls the temperature of the aromatic amine salt storage tank 1 at 0°C to 5°C; the heat preservation jacket b23 is provided with a heat preservation jacket b liquid inlet 231 and a heat preservation jacket b liquid outlet 232; the sodium nitrite solution heat preservation jacket b23 controls the temperature of the sodium nitrite solution storage tank 2 at 0°C to 5°C;

[0037] The microchannel reactor 4 includes a microchannel feed inlet 41, a microchannel reactor temperature control system 42, and a microchannel partition 44. An electric star-shaped control valve 51 is arranged on the connecting pipeline between the microchannel reactor 4 and the fixed-bed reactor 5. The microchannel reactor temperature control system 42 is provided with a constant temperature medium feed inlet 421 and a constant temperature medium discharge outlet 422, and controls the temperature of the microchannel reactor 4 at 0 - 5°C.

[0038] An outlet control valve 54 is arranged on the connecting pipeline between the fixed-bed reactor 5 and the liquid receiving kettle 6. A reflux control valve 55 is arranged on the reflux pipeline of the fixed-bed reactor 5, and the reflux pipeline is connected to the electric star-shaped control valve 51. The fixed-bed reactor temperature control system 52 includes a heat medium feed inlet 521 and a heat medium discharge outlet 522, and controls the temperature of the fixed-bed reactor 5 at 60 - 80°C.

[0039] Inside the liquid receiving kettle 6, a liquid discharge pipe 61 and a stirrer 62 are provided; the discharge control valve 54 of the fixed bed reactor 5 is connected to the liquid discharge pipe 61 through a pipeline; outside the liquid receiving kettle 6, a heat preservation jacket 65 for the liquid receiving kettle is provided, and the heat preservation jacket 65 for the liquid receiving kettle is provided with a cold water inlet 651 and a cold water outlet 652 to control the temperature of the liquid receiving kettle 6 at 10 - 20 °C.

[0040] On the feed pipeline and the discharge pipeline of the fixed bed reactor 5, quality detection ports are respectively provided, specifically a quality detection port a 43 and a quality detection port b 53; on the upper part of the liquid receiving kettle 6, a temperature analyzer 63 and a rupture disc 64 are also provided.

[0041] For the microchannel reactor 4, the feed inlet is connected to the check valve 34 through a material pipeline, and the discharge outlet is connected to the control valve 42 through a material pipeline; the microchannel reactor is equipped with a temperature control system 41 to control the temperature of the microchannel reactor 4 at 0 - 5 °C;

[0042] For the fixed bed reactor 5, the feed inlet is connected to the control valve 42 through a material pipeline, and the discharge outlet is connected to the control valve 52 through a material pipeline; the fixed bed reactor is equipped with a temperature control system 51 to control the temperature of the fixed bed reactor 5 at 60 - 80 °C;

[0043] The feed inlet of the liquid receiving kettle 6 is connected to the control valve 52 through a material pipeline, and the discharge outlet is connected to the post - treatment system through a material pipeline, and a control valve 62 is provided therebetween; outside the liquid receiving kettle 6, there is a temperature control system 61 to control the temperature of the liquid receiving kettle 6 at 10 - 20 °C.

[0044] o - Bromonitrobenzene is prepared using o - nitroaniline hydrobromide:

[0045] Add o - nitroaniline hydrobromide to the aromatic amine salt storage tank 1, and add the sodium nitrite solution to the sodium nitrite solution storage tank 2, and control the temperature at 0 - 5 °C.

[0046] Open the control valves a 11, control valve b 21, metering pump a 12, and metering pump b 22; the metering pump a 12 controls the o - nitroaniline hydrochloride to enter the rolling mixer 3 from the first feed port 31 at a certain flow rate, and the metering pump b 22 controls the sodium nitrite solution to enter the rolling mixer 3 from the second feed port 32 at a certain flow rate. The materials are fully mixed in the rolling mixer 3, and the materials pass through the discharge port 33 at the bottom of the rolling mixer 3 and enter the microchannel reactor 4. A check valve 34 is provided on the material pipeline between the rolling mixer 3 and the microchannel reactor 4 to prevent the reverse flow of materials.

[0047] The temperature control system 42 of the microchannel reactor controls the reaction temperature of the microchannel reactor 4 between 0 and 20 °C. After the materials fully react in the microchannel reactor 4, they enter the fixed-bed reactor 5 through the material pipeline.

[0048] The fixed-bed reactor 5 is filled with a copper bromide supported catalyst. The temperature control system 52 of the fixed-bed reactor controls the reaction temperature between 60 and 80 °C. After the materials fully react in the fixed-bed reactor 5, the materials are sampled through the quality inspection port b. If the quality is unqualified, the material control valve 54 is closed, the reflux control valve 55 and the electric star-shaped control valve 51 are opened, and the reaction is cycled; if the quality is qualified, the reflux control valve 55 is closed, the discharge control valve 54 is opened, and the materials enter the liquid receiving kettle 6 through the material pipeline; a circulating cooling system is equipped on the liquid receiving kettle 6. After the liquid enters the receiving kettle 6, it is gradually cooled to 20 °C and then enters the post-treatment system for centrifugal drying to obtain o-bromonitrobenzene. The reaction conversion rate reaches more than 98%, and the molar yield is 95%.

[0049] The above embodiments are only the preferred technical solutions of the present invention and should not be regarded as limitations on the present invention. The protection scope of the present invention should be the technical solutions recorded in the claims, including the equivalent replacement solutions of the technical features in the technical solutions recorded in the claims, that is, the equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A Sandmeyer reaction device, characterized in that: It includes a raw material storage tank, a rolling mixer, a microchannel reactor, a fixed bed reactor and a liquid receiving kettle, and each device is connected in sequence through pipelines; The raw material storage tanks include an aromatic amine salt storage tank and a sodium nitrite solution storage tank. The two ends of the rolling mixer are respectively provided with a first feed port and a second feed port, and a discharge port is provided at the bottom; the aromatic amine salt storage tank is connected to the first feed port through a pipeline, and the sodium nitrite solution storage tank is connected to the second feed port through a pipeline; the material pipelines between the aromatic amine salt storage tank, the sodium nitrite solution storage tank and the rolling mixer are respectively provided with control valves and metering pumps; The microchannel reactor comprises a microchannel feed port, a microchannel reactor temperature control system, and a microchannel baffle; an electric star-shaped control valve is arranged on the pipeline connecting the microchannel reactor and the fixed bed reactor; a discharge control valve is arranged on the pipeline connecting the fixed bed reactor and the liquid receiving kettle, a reflux control valve is arranged on the reflux pipeline of the fixed bed reactor, and the reflux pipeline is connected to the electric star-shaped control valve; a liquid down pipe and an agitator are arranged inside the liquid receiving kettle; and the discharge control valve of the fixed bed reactor is connected to the liquid down pipe through a pipeline.

2. The Sandmeyer reaction device according to claim 1, characterized in that: The raw material storage tank is provided with a heat-insulating jacket outside.

3. The Sandmeyer reaction device according to claim 1, characterized in that: A check valve is arranged at the front end of the discharge port.

4. The Sandmeyer reaction device according to claim 1, characterized in that: The feed pipeline and the discharge pipeline of the fixed bed reactor are respectively provided with quality detection ports.

5. The Sandmeyer reaction device according to claim 1, characterized in that: The microchannel reactor temperature control system is provided with a constant temperature medium feed port and a constant temperature medium discharge port.

6. The Sandmeyer reaction device according to claim 1, characterized in that: The fixed bed reactor temperature control system includes a heat medium feed port and a heat medium discharge port.

7. The Sandmeyer reaction device according to claim 1, characterized in that: The outside of the liquid receiving kettle is provided with a liquid receiving kettle insulation jacket.

8. The Sandmeyer reaction device according to claim 7, characterized in that: The liquid receiving kettle insulation jacket is provided with a cold water inlet and a cold water outlet.

9. The Sandmeyer reaction device according to claim 1, characterized in that: A temperature analyzer is arranged on the upper part of the liquid receiving kettle.

10. The Sandmeyer reaction device according to claim 1, characterized in that: An explosion relief piece is arranged on the upper part of the liquid receiving kettle.

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