2-(trifluoromethyl) benzamide production device and method

Abstract

The invention relates to a 2-(trifluoromethyl) benzamide production device and a 2-(trifluoromethyl) benzamide production method. The production device comprises a horizontally arranged spiral conveyor, a tubular reactor and a thickener, wherein a perforated spiral stirring blade is arranged in the tubular reactor. By optimizing the arrangement of gas, liquid and solid feeding and discharging structures, the defects of non-uniform gas phase distribution, solid phase material sinking to the bottom, insufficient material reaction and the like in the traditional multi-phase continuous reaction technology are overcome, and the multi-phase continuous reaction device has the advantages of high reaction efficiency, continuous operation, energy conservation, environment friendliness and the like.

Description

Technical Field

[0001] The present invention generally relates to the synthesis of 2-(trifluoromethyl)benzamide. Background Art

[0002] 2-(Trifluoromethyl)benzamide has a wide application in the synthesis technology of fungicides and can be used to prepare fluxapyroxad. This type of fungicide has good applications, especially for controlling crop pathogenic bacteria and fungal infections.

[0003] The synthesis reaction of 2-(trifluoromethyl)benzamide is one of the common gas-liquid-solid multiphase reaction types in the chemical industry, involving the three-transfer and one-reaction process between substances in different phases. There are many factors affecting the synthesis quality and production safety of 2-(trifluoromethyl)benzamide, which has become one of the difficulties in the field of fine chemical preparation of 2-(trifluoromethyl)benzamide in organic synthesis.

[0004] The traditional method of synthesizing 2-(trifluoromethyl)benzamide in a stirred reaction kettle has many problems: the reaction kettle equipment is huge; the reaction raw material is ammonia water, and the amount of reaction wastewater is large; solid materials sink to the bottom during the production process; the reaction of 2-(trifluoromethyl)benzoyl chloride, water, sodium carbonate, and ammonia is not sufficient; it is necessary to manually proportion 2-(trifluoromethyl)benzoyl chloride, sodium carbonate, and ammonia gas for a long time and transfer the mother liquor of 2-(trifluoromethyl)benzamide, which takes a lot of manual auxiliary operation time, resulting in a reduction in the production efficiency of 2-(trifluoromethyl)benzamide; it is difficult to meet the requirement of sufficient reaction of the multiphase mixture of 2-(trifluoromethyl)benzoyl chloride, water, sodium carbonate, ammonia gas, etc., resulting in slow preparation of 2-(trifluoromethyl)benzamide, a long production cycle, and a reduction in production efficiency. Summary of the Invention

[0005] The object of the present invention is to provide an improved production device and method for 2-(trifluoromethyl)benzamide.

[0006] According to a first aspect of the present invention, there is provided a production device for 2-(trifluoromethyl)benzamide, comprising:

[0007] A horizontally arranged screw conveyor having a feed inlet for receiving solid ammonium carbonate, a liquid inlet for receiving 2-(trifluoromethyl)benzoyl chloride and / or water, and a discharge port, wherein the feed inlet and the liquid inlet are respectively located at the upstream end of the screw conveyor, and the discharge port is located at the downstream end of the screw conveyor;

[0008] A reactor, having a receiving port, an ammonia inlet, and a reaction product outlet, wherein a horizontal rotating shaft and spiral stirring blades mounted on the horizontal rotating shaft are arranged inside the reactor, an internal cavity communicating with the ammonia inlet is formed in the horizontal rotating shaft, and a plurality of exhaust holes communicating with the internal cavity of the horizontal rotating shaft are formed in the spiral stirring blades. The receiving port and the ammonia inlet are respectively located at the upstream end of the reactor, and the reaction product outlet is located at the downstream end of the reactor. The receiving port of the reactor is connected to the discharge port of a screw conveyor; and

[0009] A thickener, having a reaction product inlet, an exhaust port, a mother liquor overflow port, and a slurry product outlet, wherein the reaction product inlet is connected to the reaction product outlet of the reactor.

[0010] According to the present invention, the material of the reactor can be carbon steel or stainless steel, the length-diameter ratio can be (20 - 100:1), and thermometers can be respectively arranged at both ends of the reactor for monitoring the temperature of the reaction materials inside it.

[0011] According to the present invention, a gap of 20 - 30 mm can exist between the spiral stirring blades and the inner wall of the reactor.

[0012] According to the present invention, the spiral stirring blades can be spirally distributed around the rotating shaft at a pitch of, for example, 200 mm, and the exhaust holes thereon can be arranged staggeredly along the blade wall surface.

[0013] According to the second aspect of the present invention, a method for continuously producing 2-(trifluoromethyl)benzamide by using the above production device is provided, including:

[0014] Continuously feeding solid ammonium carbonate through the feed port and continuously feeding 2-(trifluoromethyl)benzoyl chloride and water through the liquid inlet into the screw conveyor in a working state, wherein the water flow rate is 15 - 35 l / min; the flow rate of 2-(trifluoromethyl)benzoyl chloride is 5 - 25 l / min; the feeding amount of sodium carbonate is 5 - 10 kg / min;

[0015] Continuously feeding ammonia into the reactor through the ammonia inlet, simultaneously starting the spiral stirring blades to carry out the reaction and pushing the reaction product towards the reaction product outlet, wherein the ammonia flow rate is 10 - 25 l / min, and the reaction temperature is 65°C - 90°C;

[0016] The slurry product flowing out of the thickener from the slurry product outlet is washed and dried to obtain the final product 2-(trifluoromethyl)benzamide.

[0017] According to the method of the present invention, the continuous residence time of the reaction materials in the reactor is preferably 5 - 15 min.

[0018] Due to the adoption of a gas-liquid-solid continuous tubular reactor with a helical stirring impeller having uniformly distributed openings inside, the present invention has extremely high mass transfer and heat transfer efficiency, avoiding problems such as solid material settling at the bottom and uneven gas distribution in a kettle reactor, significantly improving the reaction selectivity, and the product yield is as high as 95%.

[0019] The production device of the present invention can feed materials continuously and precisely, and can continuously separate the reaction slurry, significantly reducing the auxiliary production time and greatly improving the production efficiency.

[0020] Compared with the traditional process of using ammonia water as a raw material, the present invention is safer and more environmentally friendly, avoiding the problem of ammonia water storage tank volatilization, reducing the amount of acid used for tail gas absorption; effectively avoiding the waste water in the traditional process; having low energy consumption and improving the economic benefits.

[0021] In summary, by optimizing the gas, liquid, and solid feeding and discharging structure layout, the present invention solves the defects such as uneven gas phase distribution, solid phase material settling at the bottom, and insufficient material reaction in the traditional multiphase continuous reaction technology, and has the advantages of high reaction efficiency, continuous operation, energy conservation and environmental protection, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic structural diagram of the production device of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] The present invention will be further described below with reference to the drawings.

[0024] Figure 1 It is a schematic overall structure diagram of the production device of 2-(trifluoromethyl)benzamide of the present invention, which generally includes a screw conveyor 10, a reactor 20 and a thickener 30.

[0025] The screw conveyor 10 is horizontally arranged and has a feed inlet 11, a liquid inlet 12 and a discharge port 13. The feed inlet 11 is located at the upstream end of the screw conveyor (the left end shown with a motor M), and is connected to a weighing and reducing device 14 to receive solid ammonium carbonate from it. The liquid inlet 12 is also located at the upstream end of the screw conveyor 10, and can be one or two, for receiving 2-(trifluoromethyl)benzoyl chloride and / or water. The discharge port 13 is located at the downstream end of the screw conveyor 10 (the right end shown).

[0026] (Tube-type) reactor 20 has an ammonia inlet 21, a receiving port 22 and a reaction product outlet 23. The receiving port 22 is located at the upstream end of the reactor 20 (the left end shown), and is hermetically connected to the discharge port 13 of the screw conveyor 10 to receive the corresponding materials therefrom by gravity. The ammonia inlet 21 is also located at the upstream end of the reactor 20, for receiving ammonia from an external ammonia supply source. The reaction product outlet 23 is located at the downstream end of the reactor 20 (the right end shown with a motor M).

[0027] Inside the reactor 20, a horizontal rotating shaft 24 and a spiral stirring blade 25 mounted on the horizontal rotating shaft 24 are arranged. The spiral stirring blade 25 is formed with a plurality of exhaust holes 250. The horizontal rotating shaft 24 is formed with an internal cavity communicating with the ammonia inlet 21, and it also communicates with the exhaust holes 250.

[0028] The thickener 30 has a reaction product inlet 31, an exhaust port 32, a mother liquor overflow port 33, and a slurry product outlet 34. The reaction product inlet 31 is hermetically connected to the reaction product outlet 23 of the reactor 20 to receive the reaction product therefrom by gravity.

[0029] Through the above production device, the following process can be used to continuously produce 2-(trifluoromethyl)benzamide.

[0030] Ammonium carbonate (solid powder) is continuously passed through the feed port 11 by the weighing device with reduced weight, and 2-(trifluoromethyl)benzoyl chloride and water are continuously fed into the working screw conveyor 10 through the liquid inlet 12;

[0031] Ammonia is continuously fed into the reactor 20 through the ammonia inlet 21, and at the same time, the spiral stirring blade 25 is started to carry out the reaction and push the reaction product towards the reaction product outlet 23;

[0032] Next, the slurry product flowing out of the thickener 30 from the slurry product outlet 34 is washed and dried to obtain the final product 2-(trifluoromethyl)benzamide.

[0033] In addition, the gas discharged through the exhaust port 32 and the mother liquor flowing out through the mother liquor overflow port 33 can be discharged after post-treatment or recycled for reuse.

[0034] Example 1

[0035] The flow rate of 2-(trifluoromethyl)benzoyl chloride (liquid) is 1000 L / h, the flow rate of water is 1500 L / h, and the continuous addition amount of ammonium carbonate is 500 kg / h. The three are mixed and conveyed to the reactor 20 (diameter 25 m) through the screw conveyor 10; the ammonia flow rate is 1000 L / h; the internal reaction temperature of the reactor is 70 °C, and the total residence time of the reaction materials is 10 min; the slurry product at the bottom of the thickener 30 is first filtered and washed to obtain a wet product, and then dried to obtain the final product 2-(trifluoromethyl)benzamide: the gas-phase internal standard content is 96.1%, and the yield based on the pure product is 95.3%.

[0036] Example 2

[0037] The flow rate of 2-(trifluoromethyl)benzoyl chloride is 1000 L / h, the flow rate of water is 1500 L / h, and the continuous addition amount of ammonium carbonate is 400 kg / h. The three are mixed and conveyed to the reactor 20 (with a diameter of 25 m) through the screw conveyor 10; the flow rate of ammonia gas is 1200 L / h; the internal reaction temperature of the reactor is 85 °C, and the total residence time of the reaction materials is 10 min; the slurry product at the bottom of the thickener 30 is first filtered and washed to obtain the wet product, and then dried to obtain the final product 2-(trifluoromethyl)benzamide: the content of the gas-phase internal standard is 95.3%, and the yield based on the pure product is 92.7%.

[0038] In summary, the present invention provides a method and device for efficiently and continuously producing 2-(trifluoromethyl)benzamide, which also has many advantages such as a short production cycle, high yield, low energy consumption, safety, and environmental protection, and is very suitable for industrial production.

Claims

1. A 2-(trifluoromethyl)benzamide production device, comprising: A horizontally arranged screw conveyor having a feed port for receiving solid ammonium carbonate, a liquid inlet and a discharge port for receiving 2-(trifluoromethyl)benzoyl chloride and / or water, wherein the feed port and the liquid inlet are respectively located at the upstream end of the screw conveyor, and the discharge port is located at the downstream end of the screw conveyor; A reactor having a receiving port, an ammonia inlet and a reaction product outlet, wherein a horizontal rotating shaft and a spiral stirring blade installed on the horizontal rotating shaft are arranged inside the reactor, the horizontal rotating shaft forms an internal cavity connected to the ammonia inlet, and the spiral stirring blade forms a plurality of exhaust holes connected to the internal cavity of the horizontal rotating shaft, the receiving port and the ammonia inlet are respectively located at the upstream end of the reactor, the reaction product outlet is located at the downstream end of the reactor, and the receiving port of the reactor is connected to the discharge port of the screw conveyor; as well as The thickener is provided with a reaction product inlet, a vent, a mother liquor overflow port and a slurry product outlet, wherein the reaction product inlet is connected to the reaction product outlet of the reactor.

2. A method for continuously producing 2-(trifluoromethyl)benzamide using the production device of claim 1, comprising: Solid ammonium carbonate is continuously fed through the feed port, and 2-(trifluoromethyl)benzoyl chloride and water are continuously fed through the liquid inlet into the screw conveyor in the working state, wherein the water flow rate is 15-35 l / min; the 2-(trifluoromethyl)benzoyl chloride flow rate is 5-25 l / min; and the sodium carbonate feeding amount is 5-10 kg / min; Ammonia is continuously fed into the reactor through the ammonia inlet, and the spiral stirring blade is started to react and push the reaction product to the reaction product outlet, wherein the ammonia flow rate is 10-25 l / min, and the reaction temperature is 65°C-90°C; The slurry product flowing out of the thickener from the slurry product outlet is washed and dried to obtain the final product 2-(trifluoromethyl)benzamide.

3. The method according to claim 2, wherein the continuous residence time of the reaction materials in the reactor is 5 to 15 minutes.

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