2-nitro-3-methylbenzoic acid chloride reaction apparatus

Abstract

The utility model provides a kind of 2-nitro-3-methylbenzoic acid acyl chloride reaction device, belong to chemical synthesis technical field, including: the reation kettle being equipped with feed inlet and suction port in top, vacuum pump is connected in suction port;First feed branch connected with feed inlet is connected with solvent tank by feed pump, second feed branch is connected with high tank by metering pump, third feed branch is connected with batching kettle by pipe chain conveyor;The reation kettle bottom is equipped with discharge port, discharge port is connected with product tank by discharge pump;The reation kettle inside is equipped with temperature sensor;The reation kettle outside is provided with double-layer heat exchange structure, and double-layer heat exchange structure is provided with heating control component, heat preservation control component and heat recovery control component.The reaction device can more accurately and timely control and adjust reaction temperature and heat preservation temperature by the double-layer heat exchange structure outside the reation kettle, reduce byproduct production capacity, reaction heat and residual heat can also be recycled in time, energy consumption is saved and energy utilization is improved.

Description

Technical Field

[0001] This utility model relates to the field of chemical synthesis technology, and in particular to a 2-nitro-3-methylbenzoic acid chlorination reaction apparatus. Background Technology

[0002] 2-Nitro-3-methylbenzoyl chloride, CAS number 50424-93-6, molecular formula C8H6ClNO3, molecular weight 199.59, also known as niraparib impurity 4 or niraparib impurity 16, is an organic synthesis intermediate and pharmaceutical intermediate, such as an intermediate for the highly effective and slightly toxic insecticide chlorantraniliprole. It can also be used in laboratory research and development processes and chemical production processes.

[0003] The existing synthesis of 2-nitro-3-methylbenzoyl chloride involves reacting 2-nitro-3-methylbenzoic acid with a chlorinating agent (such as phosphorus trichloride or thionyl chloride). This reaction often requires strict control of reaction conditions (such as reaction temperature) and typically releases a large amount of heat. To address the challenges of controlling the reaction temperature and preventing exothermic reactions, the main technical approaches currently employed include: 1. Control the rate of reactant addition to slow down the rate of exothermic reaction; 2. Install a stirring device to accelerate the dissipation of reaction heat.

[0004] The above-mentioned technologies have a certain effect on controlling the reaction, but there are still problems such as the reaction temperature being difficult to control and adjust in a timely manner, and high temperature easily leading to more reaction by-products.

[0005] Furthermore, most commonly used reactors currently achieve long-term constant temperature maintenance through steam heating. However, steam temperature often fluctuates significantly, making temperature control unstable and easily affecting the reaction conversion rate. Moreover, after the reactor's heat preservation process ends, a high temperature remains inside the reactor and its jacket. Current methods generally involve allowing this temperature to cool naturally without utilizing it, resulting in the loss and waste of residual heat energy, which does not meet the requirements of sustainable development.

[0006] Therefore, it is essential to develop an efficient, fast, environmentally friendly, and low-cost production system for 2-nitro-3-methylbenzoyl chloride. Utility Model Content

[0007] This invention provides a 2-nitro-3-methylbenzoic acid acyl chloride reaction apparatus to solve the problems in the prior art where the reaction temperature and holding temperature of the acyl chloride reaction are difficult to control and adjust, there are many reaction by-products, and the reaction heat and residual heat are not recovered and are lost in large quantities.

[0008] Specifically, this utility model provides a 2-nitro-3-methylbenzoic acid chlorination reaction apparatus, comprising: a reaction vessel, the top of which is provided with a feed inlet and a vacuum outlet, the vacuum outlet being connected to the inlet of a vacuum pump; the feed inlet is connected to three feed branches, wherein the first feed branch is connected to a solvent tank via a feed pump, the second feed branch is connected to a high-level tank via a metering pump, and the third feed branch is connected to the outlet of a batching vessel via a tubular chain conveyor; the high-level tank is used to store thionyl chloride; the solvent tank is used to store dichloroethane; the bottom of the reaction vessel is provided with a discharge outlet, which is connected to a product tank via a discharge pump; a temperature sensor is provided inside the reaction vessel; a double-layer heat exchange structure is provided on the outside of the reaction vessel, the double-layer heat exchange structure being provided with a heating control component, a heat preservation control component, and a heat recovery control component.

[0009] Furthermore, the inlet of the batching vessel is connected to a raw material acid tank and a catalyst tank, respectively; the raw material acid tank is used to store 2-nitro-3-methylbenzoic acid, and the catalyst tank is used to store N,N-dimethylformamide.

[0010] Furthermore, a motor is installed at the top of the reactor, and the output end of the motor is connected to one end of a stirring shaft extending into the reactor. A stirring component is connected to the stirring shaft.

[0011] Furthermore, the double-layer heat exchange structure includes an insulation jacket that is sealed to the outer wall of the reactor; a heat exchange coil is provided between the insulation jacket and the outer wall of the reactor, and a gap is provided between the heat exchange coils so that the outer wall of the reactor can directly contact the medium in the insulation jacket.

[0012] Furthermore, a steam inlet pipe is connected to the upper port of the heat exchange coil, and a steam outlet pipe is connected to the lower port of the heat exchange coil; an inlet control valve is provided on the steam inlet pipe, and an outlet control valve is provided on the steam outlet pipe; the steam inlet pipe, the steam outlet pipe, the inlet control valve, and the outlet control valve constitute the heating control assembly.

[0013] Furthermore, the lower end of the insulation jacket is connected to an oil inlet pipe, and the upper end of the insulation jacket is connected to an oil outlet pipe. An oil inlet control valve is provided on the oil inlet pipe, and an oil outlet control valve is provided on the oil outlet pipe. The oil inlet pipe, the oil outlet pipe, the oil inlet control valve, and the oil outlet control valve constitute the insulation control assembly. The insulation jacket is used to fill the heat-conducting oil.

[0014] Furthermore, the lower end of the heat exchange coil is connected to a water inlet pipe, and the upper end of the heat exchange coil is connected to a water outlet pipe. The water inlet pipe is equipped with a water inlet control valve, and the water outlet pipe is equipped with a water outlet control valve. The water inlet pipe, the water outlet pipe, the water inlet control valve, and the water outlet control valve constitute a heat recovery control component.

[0015] Furthermore, the temperature sensor is also electrically connected to the controller, and the steam inlet control valve, steam outlet control valve, oil inlet control valve, oil outlet control valve, water inlet control valve, and water outlet control valve are all electrically connected to the controller.

[0016] The 2-nitro-3-methylbenzoic acid acyl chloride reaction apparatus provided by this invention prepares acyl chloride through the reaction of 2-nitro-3-methylbenzoic acid and thionyl chloride. The addition of thionyl chloride to the reaction vessel via a metering pump allows for control of the reactant addition rate, slowing down the exothermic reaction and preventing temperature runaway. It also facilitates precise control of the reaction rate. Furthermore, the internal temperature sensor, combined with a double-layer heat exchange structure, enables more accurate and timely control and adjustment of the reaction and holding temperatures, making the reaction process more controllable and thus improving the production efficiency of acyl chloride. Moreover, the product exhibits high purity and high yield.

[0017] The double-layer heat exchange structure in this reaction apparatus requires no modification to the internal structure of the reactor, making modification and maintenance convenient. This double-layer heat exchange structure maintains the reaction temperature through an insulation jacket and heats or cools the reaction through heat exchange coils, perfectly matching the reaction process requirements. It not only enables rapid heating of the reactor but also rapid cooling when necessary. Furthermore, it can promptly recover residual heat from the reactor and insulation jacket during and after the reaction, resulting in high heat recovery efficiency and avoiding energy waste. In addition, with the assistance of a controller, automated control can be achieved for further precise control of reaction and production conditions. The simple and automated operation makes it suitable for industrial applications. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of the 2-nitro-3-methylbenzoic acid chlorination reaction apparatus provided in one embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a reaction vessel provided in one embodiment of the present invention; Figure 3 This is a schematic diagram of the control relationship of a double-layer heat exchange structure provided in one embodiment of the present invention.

[0020] Explanation of reference numerals in the attached figures: 1-Reaction vessel, 2-Vacuum pump, 3-Discharge pump, 4-Product tank, 11-Inlet, 12-Ejector port, 13-Discharge port, 14-Motor, 15-Stirring shaft, 16-Temperature sensor, 17-Double-layer heat exchange structure, 18-Controller, 51-Inlet pump, 52-Solvent tank, 53-Metering pump, 54-High-level tank, 55-Tube chain conveyor, 56-Battery mixing vessel, 57-Raw material acid tank, 58- Catalyst tank, 171-Insulation jacket, 172-Heat exchange coil, 173-Steam inlet pipe, 174-Steam outlet pipe, 175-Oil inlet pipe, 176-Oil outlet pipe, 177-Water inlet pipe, 178-Water outlet pipe, 1731-Steam inlet control valve, 1741-Steam outlet control valve, 1751-Oil inlet control valve, 1761-Oil outlet control valve, 1771-Water inlet control valve, 1781-Water outlet control valve. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions in the embodiments of this utility model are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are also within the protection scope of this utility model.

[0022] like Figure 1 and Figure 2 This invention relates to a 2-nitro-3-methylbenzoic acid chlorination reaction apparatus, comprising: a reaction vessel 1, the top of which is provided with a feed inlet 11 and a vacuum outlet 12, the vacuum outlet 12 being connected to the inlet of a vacuum pump 2; the feed inlet 11 is connected to three feed branches, wherein the first feed branch is connected to a solvent tank 52 via a feed pump 51, the second feed branch is connected to a high-level tank 54 via a metering pump 53, and the third feed branch is connected to the outlet of a batching vessel 56 via a tubular chain conveyor 55; the high-level tank 54 is used to store thionyl chloride; the solvent tank 52 is used to store dichloroethane; the bottom of the reaction vessel 1 is provided with a discharge outlet 13, which is connected to a product tank 4 via a discharge pump 3; a temperature sensor 16 is provided inside the reaction vessel 1; a double-layer heat exchange structure 17 is provided outside the reaction vessel 1, the double-layer heat exchange structure 17 being provided with a heating control component, a heat preservation control component, and a heat recovery control component.

[0023] The feeding sequence of reactor 1 during production is as follows: first, the solvent is fed through the first feed branch; then, the mixture of raw material acid and catalyst is fed through the third feed branch; and finally, thionyl chloride is added dropwise through the second feed branch. This feeding sequence facilitates uniform mixing of the raw materials within the system, improving reaction efficiency. The high-level tank 54 adds thionyl chloride dropwise to reactor 1 via metering pump 53, which controls the rate of reactant addition, slows down the exothermic reaction rate, avoids side reactions caused by localized overheating, prevents temperature runaway, and also facilitates precise control of the reaction rate, improving reaction selectivity and conversion rate.

[0024] The evacuation port 12 of reactor 1 facilitates vacuuming via vacuum pump 2 before the reaction feed, and simultaneously removes gaseous products such as sulfur dioxide and hydrogen chloride from the reaction products during the reaction process, preventing reversible reactions and promoting product separation. The outlet of vacuum pump 2 can be connected to a waste gas treatment system for the recovery or purification of the extracted waste gas. The discharge port 13 of reactor 1 is connected to product tank 4. The reaction product is 2-nitro-3-methylbenzoyl chloride, which can undergo further methylation reactions to produce K-amine (2-amino-3-methyl-5-chlorobenzoic acid), an important raw material for chlorantraniliprole. Product tank 4 can also be connected to solvent and catalyst recovery equipment to recover and reuse solvents and catalysts, thereby saving production costs.

[0025] The temperature sensor 16 inside the reactor 1 can promptly reflect the internal temperature of the materials. Combined with the double-layer heat exchange structure 17, it enables more precise and timely control and adjustment of the reaction and holding temperatures, making the reaction process more controllable and thus improving the production efficiency of acyl chloride. Furthermore, the product has high purity and high yield. Specifically, before the reaction begins, the heating control component raises the temperature. After the addition of thionyl chloride and the start of the reaction, the heat recovery control component promptly recovers the heat of reaction, reducing the production of by-products and controlling the reaction temperature. During the holding stage after the addition of thionyl chloride, the holding control component maintains the temperature, which helps control the reaction state within the system. After the holding stage, the residual heat is recovered again using the recovery control component, saving energy and improving energy utilization.

[0026] In one embodiment, the inlet of the mixing vessel 56 is connected to a raw acid tank 57 and a catalyst tank 58, respectively. The raw acid tank 57 is used to store 2-nitro-3-methylbenzoic acid, and the catalyst tank 58 is used to store N,N-dimethylformamide. To ensure more uniform mixing of the raw acid and catalyst, the mixing vessel 56 may be equipped with stirring components commonly used in the art; the specific structure and quantity are not limited herein. The catalyst in the catalyst tank 58 is preferably an amide catalyst, and more preferably, N,N-dimethylformamide (DMF). However, when using N,N-dimethylformamide as a catalyst, it is crucial to carefully control the reaction temperature to avoid an increase in byproducts due to high temperatures.

[0027] like Figure 2 In one embodiment, a motor 14 is provided at the top of the reactor 1. The output end of the motor 14 is connected to one end of a stirring shaft 15 extending into the reactor 1. A stirring component is connected to the stirring shaft 15. The function of the stirring component is to disperse and mix the reactants, so that the reaction proceeds quickly and fully, and also to accelerate the heat conduction between the reactants, facilitating the control of the reaction temperature. The stirring component is a conventional feature in the art, and its specific structure and quantity can be selected by those skilled in the art; no restrictions are imposed here.

[0028] In one embodiment, the double-layer heat exchange structure 17 includes a heat-insulating jacket 171 that is sealed to the outer wall of the reactor 1; a heat exchange coil 172 is provided between the heat-insulating jacket 171 and the outer wall of the reactor 1, and a gap is provided between the heat exchange coils 172 for direct contact between the outer wall of the reactor 1 and the medium in the heat-insulating jacket 171.

[0029] The aforementioned double-layer heat exchange structure 17 requires no modification to the interior of the reactor 1, making it easy to modify and maintain. The double-layer heat exchange structure 17 insulates the reaction through the insulation jacket 171 and heats or cools the reaction through the heat exchange coil 172, perfectly matching the requirements of the reaction process. It can not only rapidly heat the reactor 1, but also rapidly cool it when necessary. In addition, it can promptly recover the residual heat in the reactor 1 and the insulation jacket 171 during and after the reaction, resulting in high heat recovery and utilization efficiency and avoiding energy waste.

[0030] In one embodiment, a steam inlet pipe 173 is connected to the upper port of the heat exchange coil 172, and a steam outlet pipe 174 is connected to the lower port of the heat exchange coil 172. An inlet control valve 1731 is provided on the steam inlet pipe 173, and an outlet control valve 1741 is provided on the steam outlet pipe 174. The steam inlet pipe 173, the steam outlet pipe 174, the inlet control valve 1731, and the outlet control valve 1741 constitute a heating control assembly. Steam enters the heat exchange coil 172 from the steam inlet pipe 173 and exits from the steam outlet pipe 174. The heating control assembly controls the opening and closing of the steam heating channel by controlling the inlet control valve 1731 and the outlet control valve 1741, thereby controlling the heating of the reactor 1.

[0031] In one embodiment, the lower end of the insulation jacket 171 is connected to an oil inlet pipe 175, and the upper end of the insulation jacket 171 is connected to an oil outlet pipe 176. An oil inlet control valve 1751 is provided on the oil inlet pipe 175, and an oil outlet control valve 1761 is provided on the oil outlet pipe 176. The oil inlet pipe 175, the oil outlet pipe 176, the oil inlet control valve 1751, and the oil outlet control valve 1761 constitute an insulation control assembly. The insulation jacket 171 is used to fill the heat-conducting oil.

[0032] The heat transfer oil enters the insulation jacket 171 through the oil inlet pipe 175 and exits through the oil outlet pipe 176. The insulation control assembly controls the opening and closing of the insulation channel through the oil inlet control valve 1751 and the oil outlet control valve 1761, thereby controlling the insulation of the reactor 1. The temperature of the heat transfer oil is usually more stable than that of steam, making it more suitable as a heat source during the insulation stage, thus avoiding excessive temperature fluctuations during the insulation stage that could affect the reaction.

[0033] In one embodiment, the lower end of the heat exchange coil 172 is connected to a water inlet pipe 177, and the upper end of the heat exchange coil 172 is connected to a water outlet pipe 178. The water inlet pipe 177 is provided with a water inlet control valve 1771, and the water outlet pipe 178 is provided with a water outlet control valve 1781. The water inlet pipe 177, the water outlet pipe 178, the water inlet control valve 1771, and the water outlet control valve 1781 constitute a heat recovery control component.

[0034] Cooling water enters the heat exchange coil 172 through the inlet pipe 177 and exits through the outlet pipe 178. The heat recovery control component controls the opening and closing of the heat exchange coil 172 through the inlet control valve 1771 and the outlet control valve 1781, realizing the recovery of reaction heat and residual heat after the reaction in the reactor 1, effectively improving reaction conditions, reducing heat loss during and after the reaction, and the hot water generated after heat recovery can be used in other water-using units, saving energy consumption and meeting the requirements of sustainable development. Three-way valves can be installed at the upper and lower ports of the heat exchange coil 172 to connect to the steam inlet pipe 173, the steam outlet pipe 174, the inlet pipe 177, and the outlet pipe 178, respectively.

[0035] like Figure 3 In one embodiment, the temperature sensor 16 is also electrically connected to the controller 18, and the steam inlet control valve 1731, the steam outlet control valve 1741, the oil inlet control valve 1751, the oil outlet control valve 1761, the water inlet control valve 1771, and the water outlet control valve 1781 are all electrically connected to the controller 18.

[0036] The signal from temperature sensor 16 can be transmitted to controller 18. Controller 18 compares and analyzes the received signal with a preset control program, and then controls the corresponding heating control components, insulation control components, and heat recovery control components in the double-layer heat exchange structure 17 separately. This includes timely adjustment of the opening degree of each control valve, enabling the start / stop, switching, and adjustment of the working state of different control components. This makes the entire device simple and automated to operate, suitable for industrial applications. Controller 18 and its control system are existing technologies and will not be described in detail here.

[0037] It should be noted that arrows without reference numerals indicate the flow direction of gas-liquid mixtures, gas phases, or liquid phases.

[0038] In the aforementioned 2-nitro-3-methylbenzoic acid acylation reaction apparatus, during operation, 2-nitro-3-methylbenzoic acid and N,N-dimethylformamide are fed into the mixing tank 56 from the raw material acid tank 57 and catalyst tank 58, respectively, and mixed evenly for later use. Dichloroethane solvent is pumped into the reaction vessel 1 via the feed pump 51, and the vacuum pump 2 is activated to promptly remove gaseous products such as sulfur dioxide and hydrogen chloride from the reaction products. Simultaneously, the motor 14 on the reaction vessel 1 is activated, driving the stirring shaft 15 and its stirring components to rotate. The mixture from the mixing tank 56 is fed into the reaction vessel 1 via the tubular chain conveyor 55. Then, the steam inlet control valve 1731 and steam outlet control valve 1741 are opened via the controller 18, allowing steam to flow through the heat exchange coil 172 to heat the materials in the reaction vessel 1. Once the temperature sensor 16 detects that the temperature has reached 55°C, the metering pump 53 is activated to add thionyl chloride dropwise into the reaction vessel 1. Simultaneously, controller 18 closes the steam inlet control valve 1731 and the steam outlet control valve 1741, and opens the water inlet control valve 1771 and the water outlet control valve 1781, allowing cooling water to flow through the heat exchange coil 172 to recover the heat of reaction and maintain the reaction temperature at 55-65℃. After the dripping is completed, controller 18 closes the water inlet control valve 1771 and the water outlet control valve 1781, and opens the oil inlet control valve 1751 and the oil outlet control valve 1761, allowing the heat transfer oil to flow through the insulation jacket 171 to maintain the reaction temperature. After maintaining the temperature for 2 hours, samples are taken for analysis. If the samples pass the analysis, the temperature is maintained for another 4 hours. After the temperature maintenance is completed, the reaction system is transferred to the product tank 4 via the discharge pump 3 to facilitate the methylation reaction. The controller 18 can close the oil inlet control valve 1751 and the oil outlet control valve 1761, and open the water inlet control valve 1771 and the water outlet control valve 1781, so that cooling water flows through the heat exchange coil 172 to recover the residual heat after the reaction, reduce heat loss, and the hot water generated after heat recovery can be used in other water-using units, saving energy consumption and meeting the requirements of sustainable development.

[0039] It should be noted that the detailed structure of some devices in this utility model is not described in detail, but belongs to the prior art known to those skilled in the art, and therefore will not be described again here. In addition, the parts of this device not described are the same as or can be implemented using existing technology.

[0040] It should be noted that those skilled in the art, under the guidance of this utility model, can also make some modifications to the design of the above system. For example, the equipment in the system is also equipped with level gauges, overflow / nitrogen pipelines, etc.; pumps, pressure sensors, flow meters or temperature sensors are installed on the conveying pipelines inside the system in different units or devices, and different valves, such as pressure relief valves, pressure regulating valves, safety valves, pneumatic valves, etc., are also installed to regulate and stabilize the pressure of the entire system, and the opening degree of the valves can also be adjusted to regulate the flow rate of materials in the pipeline, etc.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A 2-nitro-3-methylbenzoic acid chlorination reaction apparatus, characterized in that, include: The reactor has a feed inlet and an exhaust port at its top, with the exhaust port connected to the inlet of a vacuum pump. The feed inlet has three feed branches: a first feed branch connected to a solvent tank via a feed pump, a second feed branch connected to a high-level tank via a metering pump, and a third feed branch connected to the outlet of a batching vessel via a tubular chain conveyor. The high-level tank stores thionyl chloride; the solvent tank stores dichloroethane; the reactor has an outlet at its bottom, connected to a product tank via an outlet pump; a temperature sensor is installed inside the reactor; and a double-layer heat exchange structure is installed on the outside of the reactor, including a heating control component, a heat preservation control component, and a heat recovery control component.

2. The 2-nitro-3-methylbenzoic acid chlorination reaction apparatus according to claim 1, characterized in that, The inlet of the batching vessel is connected to a raw material acid tank and a catalyst tank respectively; the raw material acid tank is used to store 2-nitro-3-methylbenzoic acid, and the catalyst tank is used to store N,N-dimethylformamide.

3. The 2-nitro-3-methylbenzoic acid chlorination reaction apparatus according to claim 1, characterized in that, The reactor is equipped with a motor at the top, and the output end of the motor is connected to one end of a stirring shaft that extends into the reactor. A stirring component is connected to the stirring shaft.

4. The 2-nitro-3-methylbenzoic acid chlorination reaction apparatus according to claim 1, characterized in that, The double-layer heat exchange structure includes an insulation jacket that is sealed to the outer wall of the reactor; a heat exchange coil is provided between the insulation jacket and the outer wall of the reactor, and a gap is provided between the heat exchange coils so that the outer wall of the reactor can directly contact the medium in the insulation jacket.

5. The 2-nitro-3-methylbenzoic acid chlorination reaction apparatus according to claim 4, characterized in that, The upper port of the heat exchange coil is connected to a steam inlet pipe, and the lower port of the heat exchange coil is connected to a steam outlet pipe; the steam inlet pipe is equipped with a steam inlet control valve, and the steam outlet pipe is equipped with a steam outlet control valve; the steam inlet pipe, the steam outlet pipe, the steam inlet control valve, and the steam outlet control valve constitute the heating control assembly.

6. The 2-nitro-3-methylbenzoic acid chlorination reaction apparatus according to claim 5, characterized in that, The lower port of the insulation jacket is connected to an oil inlet pipe, and the upper port of the insulation jacket is connected to an oil outlet pipe. An oil inlet control valve is provided on the oil inlet pipe, and an oil outlet control valve is provided on the oil outlet pipe. The oil inlet pipe, the oil outlet pipe, the oil inlet control valve, and the oil outlet control valve constitute the insulation control assembly. The insulation jacket is used to fill the heat-conducting oil.

7. The 2-nitro-3-methylbenzoic acid chlorination reaction apparatus according to claim 6, characterized in that, The lower end of the heat exchange coil is connected to a water inlet pipe, and the upper end of the heat exchange coil is connected to a water outlet pipe. The water inlet pipe is equipped with a water inlet control valve, and the water outlet pipe is equipped with a water outlet control valve. The water inlet pipe, the water outlet pipe, the water inlet control valve, and the water outlet control valve constitute the heat recovery control component.

8. The 2-nitro-3-methylbenzoic acid chlorination apparatus according to claim 7, characterized in that, The temperature sensor is also electrically connected to the controller, and the steam inlet control valve, the steam outlet control valve, the oil inlet control valve, the oil outlet control valve, the water inlet control valve, and the water outlet control valve are all electrically connected to the controller.

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