Production process of 2-amino-6-nitrobenzoic acid

Abstract

The present invention provides a 2-amino-6-nitrobenzoic acid production process, and relates to the technical field of 2-amino-6-nitrobenzoic acid production, and the 2-amino-6-nitrobenzoic acid production comprises the following steps: S1, acetic anhydride acylation protection: 3-chloro-2-methylaniline and anhydrous toluene are added into a container, stirring is performed to dissolve the solid, acetic anhydride is dropwise added, heat is released through a reaction, a large amount of white crystals are generated, and the white crystals are subjected to suction filtration; after dripping, quickly stirring, and then heating and refluxing; according to the scheme, potassium permanganate and water are finally added in multiple times, constant-temperature stirring is continued or potassium permanganate fades, the side reaction that a benzene ring of xylene is oxidized and damaged by potassium permanganate due to the fact that one-time complete adding is conducted is avoided, a large reactor does not need to be used, the reaction risk is reduced, and the production cost is reduced. The problem that the utilization rate of organic matters is reduced due to the fact that the concentration of potassium permanganate is gradually reduced along with the reaction when potassium permanganate and water are added at one time can be avoided.

Description

Technical Field

[0001] The invention relates to the technical field of 2-amino-6-nitrobenzoic acid production, in particular to a production process of 2-amino-6-nitrobenzoic acid. Background Art

[0002] 2-Amino-6-nitrobenzoic acid is an important intermediate in organic synthesis and is used to produce various organic compounds. It is also widely used in the pigment industry as a pigment intermediate.

[0003] In the relevant technology, 2-amino-6-nitrobenzoic acid is an important organic compound, mainly used as a pharmaceutical intermediate. It plays a key role in drug synthesis, especially in the production of antibiotics and other biologically active molecules. Although 2-amino-6-nitrobenzoic acid itself is not directly used to treat diseases, its importance in the synthesis of drugs and pesticides cannot be ignored. It provides the necessary chemical structure for the research and development and production of many drugs and pesticides, thereby indirectly affecting human health and agricultural production. There are several main production processes for 2-amino-6-nitrobenzoic acid, including 2,6-dinitrobenzoic acid method, 2-halogenated-6-nitrobenzoic acid ammonolysis method, 2-carbamoyl-6-nitrobenzoic acid method and 3-chloro-2-methylaniline preparation method.

[0004] At present, in the step of producing 2-amino-6-nitrobenzoic acid using 3-chloro-2-methylaniline as a raw material, the oxidant is added in one go during the oxidation reaction of the raw material. The reaction is too violent and may cause a side reaction in which the benzene ring is destroyed by the oxidant. In addition, a large amount of water is required for complete dissolution in one go, and the reactor will also be enlarged accordingly, which will increase the risk of the reaction.

[0005] Therefore, it is necessary to provide a production process of 2-amino-6-nitrobenzoic acid to solve the above-mentioned technical problems. Summary of the invention

[0006] The invention provides a production process of 2-amino-6-nitrobenzoic acid, which solves the technical problem in the related art that the one-time addition of an oxidant causes an overly violent reaction and may cause oxidation and destruction of the benzene ring.

[0007] In order to solve the above technical problems, the production process of 2-amino-6-nitrobenzoic acid provided by the present invention comprises the following steps:

[0008] Step S1: Acylation protection with acetic anhydride,

[0009] Add 3-chloro-2-methylaniline and anhydrous toluene into a container, stir to dissolve the solid, drop acetic anhydride, the reaction is exothermic, and a large amount of white crystals are generated. After the drop is complete, stir rapidly and heat to reflux;

[0010] Stop the reaction, cool and let stand, extract the solid, wash with toluene, concentrate the mother liquor and cool it to get some products, dry it, and use toluene to recrystallize the product into pure white needle-shaped crystals;

[0011] Step S2: Potassium permanganate oxidation,

[0012] Add 3-chloro-2-methylacetanilide, solvent xylene, and catalyst tetrabutylammonium bromide into a container, stir and heat, add water several times, stir quickly to form a brown-white milky mixture, maintain the internal temperature, add potassium permanganate several times, continue to stir at a constant temperature or until the potassium permanganate fades;

[0013] Filter while hot, wash the filter cake (manganese dioxide) with hot water, let the filtrate stand, separate the lower organic phase, and extract the upper aqueous phase with chloroform;

[0014] The obtained aqueous solution was allowed to stand, filtered to remove a small amount of solid, and hydrochloric acid was slowly added dropwise while cooling and stirring to adjust the pH, to generate a large amount of white solid, which was then cooled and filtered, and washed with a small amount of cold water. The obtained white solid was dried at a constant temperature, the mother liquor was concentrated, and cooled and allowed to stand to obtain needle-shaped crystals;

[0015] Step S3: hydrolysis with sodium hydroxide solution,

[0016] Add 2-chloro-6-acetylaminobenzoic acid, 96% sodium hydroxide and aqueous solution into a container and stir to dissolve the solid quickly to obtain a light yellow transparent solution;

[0017] Heat to an oil bath, react, cool slightly, add activated carbon, and continue heating;

[0018] Stop the reaction, cool the reaction solution in an ice-water bath, filter to remove the activated carbon, drop concentrated hydrochloric acid into the mixture while stirring to adjust the pH, leave at low temperature overnight, filter out the solid, and dry at a constant temperature to obtain a light yellow solid;

[0019] Step S4: Ammonolysis reaction,

[0020] In an organic solvent, under the action of a cuprous catalyst, 2-chloro-6-aminobenzoic acid and ammonia are subjected to a catalytic aminolysis reaction to obtain 2-amino-6-nitrobenzoic acid.

[0021] Preferably, in the step S2 of the 2-amino-6-nitrobenzoic acid production process, when adding potassium permanganate, a reaction kettle, a kettle cover, a material discharge mechanism and a water addition mechanism are required;

[0022] The unloading mechanism comprises a driving shaft vertically rotatably connected to the inner side of the kettle cover, the top of the kettle cover and the surface of the driving shaft are rotatably connected with a gear plate, the surface of the driving shaft and the top of the gear plate are provided with a gear, two sliding brackets are fixedly provided on the rear side of the top of the kettle cover, the inner sides of the two sliding brackets are slidably connected with a sliding plate, the top of the sliding plate is fixedly provided with a first bracket, the top of the kettle cover is fixedly provided with a rotating shaft, the surface of the rotating shaft is rotatably connected with a second bracket, the top of the sliding plate and the inner side of the second bracket are fixedly provided with a driving column, the right side of the top of the kettle cover is connected with a feeding hopper, the inner side of the feeding hopper is slidably connected with a unloading plate, the right side of the sliding plate is fixedly connected to the surface of the unloading plate, and two columns are fixedly provided on the top of the gear plate;

[0023] A protective shell is slidably connected to the surface of the sliding bracket, and the bottom of the protective shell is fixedly connected to the top of the kettle cover;

[0024] The water adding mechanism includes a water inlet pipe arranged on the inner side of the protective shell, the bottom end of the water inlet pipe passes through the top of the kettle cover and extends to the interior of the reactor, a valve is arranged on the surface of the water inlet pipe, a tension spring is arranged on the surface of the valve, the left side of the tension spring is fixedly connected to the back side of the inner wall of the protective shell, and a moving column is threadedly connected to the inner side of the top of the sliding plate.

[0025] Preferably, a gear groove for cooperating with the gear is provided on the inner side of the gear plate, and a protrusion for connecting with the gear keyway is provided on the surface of the drive shaft. After the gear is moved downward to form a keyway connection relationship with the drive shaft, the gear is located on the inner side of the gear plate.

[0026] Preferably, the surface of the sliding plate is provided with a groove for use with the sliding bracket, the inner side of the second bracket is provided with a U-shaped groove for use with the driving column, and the inner side of the blanking plate is provided with an annular groove for blanking.

[0027] Preferably, a pretreatment mechanism is fixedly provided on the right side of the reactor, and the pretreatment mechanism includes a treatment box fixedly provided on the right side of the reactor, a mixing rod is vertically rotatably connected to the inner side of the treatment box, a first pulley is fixedly provided on the top of the mixing rod, a second pulley is fixedly provided on the surface of the gear plate, belts are sleeved on the surfaces of the first pulley and the second pulley, and a mixing plate is fixedly provided on the surface of the mixing rod and located on the inner side of the treatment box.

[0028] Preferably, an exhaust mechanism is fixedly provided on the front of the processing box, and the exhaust mechanism includes a support base fixedly provided on the front of the processing box, a vacuum pump is provided on the top of the support base, the left side of the vacuum pump is connected to an exhaust pipe, the left end of the exhaust pipe is connected to the right side of the reactor, the top of the vacuum pump is connected to an outlet pipe, the bottom end of the outlet pipe passes through the top of the processing box and extends to the interior of the processing box, and the right side of the processing box is connected to an exhaust pipe.

[0029] Preferably, a stirring mechanism is fixedly provided on the surface of the drive shaft and located on the inner side of the reactor, the stirring mechanism includes stirring blades fixedly provided on the surface of the drive shaft, two connecting brackets are fixedly provided on the surface of the drive shaft and located on the inner side of the reactor, scrapers are fixedly provided on both sides of the two connecting brackets, and a driving motor for driving the drive shaft to rotate is provided on the top of the protective shell.

[0030] Preferably, a mounting frame is provided on the surface of the reactor, a feed pipe is connected to the left side of the reactor, and a discharge pipe is connected to the bottom of the reactor.

[0031] Compared with the related art, the production process of 2-amino-6-nitrobenzoic acid provided by the present invention has the following beneficial effects:

[0032] In the process of producing 2-amino-6-nitrobenzoic acid using 3-chloro-2-methylaniline as a raw material, potassium permanganate and water are added in multiple times, and constant temperature stirring is continued or the potassium permanganate is faded, so as to avoid a side reaction in which the benzene ring of xylene is oxidized and destroyed by potassium permanganate due to excessive reaction caused by adding all at once, and no larger reactor is needed, thereby reducing the risk of the reaction, and avoiding the problem that potassium permanganate and water are added at one time, and the concentration of potassium permanganate gradually decreases as the reaction proceeds, resulting in a reduced utilization rate of organic matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0034] Figure 1 The best structural diagram provided by the present invention;

[0035] Figure 2 A schematic diagram of the structure of the right side view of the reactor provided by the present invention;

[0036] Figure 3A schematic diagram of the structure of the material feeding mechanism and the water adding mechanism provided by the present invention;

[0037] Figure 4 for Figure 3 The structural schematic diagram of the feeding mechanism shown;

[0038] Figure 5 for Figure 4 The structural schematic diagram of the gear plate shown;

[0039] Figure 6 for Figure 5 A schematic diagram of the structure of the bottom view of the gear plate shown;

[0040] Figure 7 for Figure 4 The schematic diagram of the gear structure shown;

[0041] Figure 8 for Figure 4 The schematic diagram of the state in which the gear is moved downward, the rotating shaft drives the gear plate to rotate through the gear, and the sliding plate drives the blanking plate to move to the right under the action of the column and the first bracket;

[0042] Fig. 9 A schematic diagram of the structure of the water adding mechanism provided by the present invention;

[0043] Fig.10 A schematic diagram of the structure of the pretreatment mechanism and the air extraction mechanism provided by the present invention;

[0044] Fig.11 for Fig.10 A schematic structural diagram of a cross-sectional view of a processing box shown;

[0045] Fig.12 A schematic diagram of a state in which the gear provided by the present invention is moved downward, the rotating shaft drives the gear plate to rotate through the gear, and the second pulley drives the first pulley and the mixing rod to rotate using the belt;

[0046] Fig.13 This is a schematic structural diagram of the stirring mechanism provided by the present invention.

[0047] Description of Figure Numbers:

[0048] 1. Reactor; 2. Reactor cover;

[0049] 3. Feeding mechanism; 31. Driving shaft; 32. Gear plate; 33. Gear; 34. Sliding bracket; 35. Sliding plate; 36. First bracket; 37. Rotating shaft; 38. Second bracket; 39. Driving column; 310. Feed hopper; 311. Feeding plate; 312. Column;

[0050] 4. Water adding mechanism; 41. Water inlet pipe; 42. Valve; 43. Tension spring; 44. Moving column;

[0051] 5. Protective shell;

[0052] 6. Pretreatment mechanism; 61. Treatment box; 62. Mixing rod; 63. First pulley; 64. Second pulley; 65. Belt; 66. Mixing plate;

[0053] 7. Air extraction mechanism; 71. Support seat; 72. Air extraction pump; 73. Air extraction pipe; 74. Air outlet pipe; 75. Discharge pipe;

[0054] 8. stirring mechanism; 81. stirring blade; 82. connecting bracket; 83. scraper; 84. driving motor;

[0055] 9. Mounting frame; 10. Feed pipe; 11. Discharge pipe.

[0056] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0057] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] The invention provides a production process of 2-amino-6-nitrobenzoic acid.

[0059] First embodiment:

[0060] A production process of 2-amino-6-nitrobenzoic acid comprises the following steps:

[0061] Step S1: Acylation protection with acetic anhydride,

[0062] Add 3-chloro-2-methylaniline and anhydrous toluene into a container, stir to dissolve the solid, drop acetic anhydride, the reaction is exothermic, and a large amount of white crystals are generated. After the drop is complete, stir rapidly and heat to reflux;

[0063] Stop the reaction, cool and let stand, extract the solid, wash with toluene, concentrate the mother liquor and cool it to get some products, dry it, and use toluene to recrystallize the product into pure white needle-shaped crystals;

[0064] Step S2: Potassium permanganate oxidation,

[0065] Add 3-chloro-2-methylacetanilide, solvent xylene, and catalyst tetrabutylammonium bromide into a container, stir and heat, add water several times, stir quickly to form a brown-white milky mixture, maintain the internal temperature, add potassium permanganate several times, continue to stir at a constant temperature or until the potassium permanganate fades;

[0066] Filter while hot, wash the filter cake (manganese dioxide) with hot water, let the filtrate stand, separate the lower organic phase, and extract the upper aqueous phase with chloroform;

[0067] The obtained aqueous solution was allowed to stand, filtered to remove a small amount of solid, and hydrochloric acid was slowly added dropwise while cooling and stirring to adjust the pH, to generate a large amount of white solid, which was then cooled and filtered, and washed with a small amount of cold water. The obtained white solid was dried at a constant temperature, the mother liquor was concentrated, and cooled and allowed to stand to obtain needle-shaped crystals;

[0068] Step S3: hydrolysis with sodium hydroxide solution,

[0069] Add 2-chloro-6-acetylaminobenzoic acid, 96% sodium hydroxide and aqueous solution into a container and stir to dissolve the solid quickly to obtain a light yellow transparent solution;

[0070] Heat to an oil bath, react, cool slightly, add activated carbon, and continue heating;

[0071] Stop the reaction, cool the reaction solution in an ice-water bath, filter to remove the activated carbon, drop concentrated hydrochloric acid into the mixture while stirring to adjust the pH, leave at low temperature overnight, filter out the solid, and dry at a constant temperature to obtain a light yellow solid;

[0072] Step S4: Ammonolysis reaction,

[0073] In an organic solvent, under the action of a cuprous catalyst, 2-chloro-6-aminobenzoic acid and ammonia are subjected to a catalytic aminolysis reaction to obtain 2-amino-6-nitrobenzoic acid.

[0074] In the present embodiment, in the process of producing 2-amino-6-nitrobenzoic acid with 3-chloro-2-methylaniline as raw material, potassium permanganate and water are added several times, and constant temperature stirring is continued or potassium permanganate is faded, so that the reaction is too violent due to the one-time complete addition, which causes the side reaction of the benzene ring of xylene being oxidized and destroyed by potassium permanganate, and there is no need to use a larger reactor, which reduces the risk of the reaction, and it can be avoided that potassium permanganate and water are added once, and the potassium permanganate concentration gradually decreases as the reaction proceeds, resulting in a problem of reduced utilization rate of organic matter.

[0075] Second embodiment:

[0076] See also Figures 1 to 9 In the step S2 of the production process of 2-amino-6-nitrobenzoic acid, when adding potassium permanganate, a reaction kettle 1, a kettle cover 2, a material discharge mechanism 3 and a water adding mechanism 4 are required;

[0077] The unloading mechanism 3 includes a driving shaft 31 vertically rotatably connected to the inner side of the kettle cover 2, a gear plate 32 is rotatably connected to the top of the kettle cover 2 and located on the surface of the driving shaft 31, a gear 33 is provided on the surface of the driving shaft 31 and located on the top of the gear plate 32, two sliding brackets 34 are fixedly provided on the rear side of the top of the kettle cover 2, a sliding plate 35 is slidably connected to the inner side of the two sliding brackets 34, a first bracket 36 is fixedly provided on the top of the sliding plate 35, a rotating shaft 37 is fixedly provided on the top of the kettle cover 2, a second bracket 38 is rotatably connected to the surface of the rotating shaft 37, a driving column 39 is fixedly provided on the top of the sliding plate 35 and located on the inner side of the second bracket 38, a feed hopper 310 is connected to the right side of the top of the kettle cover 2, a unloading plate 311 is slidably connected to the inner side of the feed hopper 310, the right side of the sliding plate 35 is fixedly connected to the surface of the unloading plate 311, and two columns 312 are fixedly provided on the top of the gear plate 32;

[0078] Please combine Figures 3 to 8 : Move the gear 33 downward on the surface of the driving shaft 31, so that the gear 33 is key-connected with the driving shaft 31, and the rotation of the driving shaft 31 drives the gear 33 to rotate, and the rotation of the gear 33 drives the gear plate 32 to rotate, and the rotation of the gear plate 32 drives the two columns 312 to rotate, and the column 312 touches the first bracket 36 during the rotation, and pushes the first bracket 36 to the right, and the movement of the first bracket 36 drives the sliding plate 35 to slide to the right on the inner side of the sliding bracket 34, and the sliding plate 35 moves to the right and drives the blanking plate 311 to move to the right, so that the annular groove provided inside the blanking plate 311 is located inside the feed hopper 310, so that potassium permanganate falls into the reactor 1 through the annular groove provided in the blanking plate 311;

[0079] Furthermore, through the continuous rotation of the gear plate 32, the column 312 will touch the second bracket 38, so that the second bracket 38 rotates on the surface of the rotating shaft 37. When the second bracket 38 rotates, the driving column 39 causes the sliding plate 35 to move to the left on the inner side of the sliding bracket 34, thereby resetting the position of the first bracket 36. The movement of the sliding plate 35 drives the unloading plate 311 to move to the left, so that the annular groove in the unloading plate 311 is separated from the inside of the feed hopper 310, and the position of the unloading plate 311 is reset, thereby stopping the unloading of potassium permanganate.

[0080] Furthermore, the gear plate 32 is continuously rotated to drive the two uprights 312 to continuously rotate, and under the action of the first bracket 36 and the second bracket 38, the sliding plate 35 is reciprocated on the inner side of the sliding bracket 34, and the reciprocating sliding of the sliding plate 35 drives the unloading plate 311 to reciprocate, thereby unloading potassium permanganate intermittently;

[0081] The surface of the sliding bracket 34 is slidably connected with a protective shell 5, and the bottom of the protective shell 5 is fixedly connected to the top of the kettle cover 2;

[0082] The water adding mechanism 4 includes a water inlet pipe 41 arranged inside the protective shell 5, the bottom end of the water inlet pipe 41 passes through the top of the kettle cover 2 and extends to the inside of the reactor 1, a valve 42 is arranged on the surface of the water inlet pipe 41, a tension spring 43 is arranged on the surface of the valve 42, the left side of the tension spring 43 is fixedly connected to the back side of the inner wall of the protective shell 5, and a moving column 44 is threadedly connected to the inner side of the top of the sliding plate 35;

[0083] Please combine Figure 3 , Figure 4 and Fig. 9 : When the sliding plate 35 slides to the right, the sliding plate 35 drives the moving column 44 to move to the right. The moving column 44 touches the valve 42 during the movement and pushes the valve 42 to the right. The tension spring 43 is stretched, so that water can enter the reactor 1;

[0084] Furthermore, when the sliding plate 35 slides to the left, the sliding plate 35 drives the moving column 44 to move to the left, and under the tension of the tension spring 43, the valve 42 is reset, thereby stopping the water supply to the reactor 1;

[0085] Furthermore, when the sliding plate 35 drives the unloading plate 311 to move back and forth left and right to unload potassium permanganate intermittently, the sliding plate 35 will simultaneously drive the moving column 44 to move back and forth left and right, and with the cooperation of the tension spring 43, intermittent water supply will be carried out into the reactor 1 through the control valve 42 at the same time.

[0086] The inner side of the gear plate 32 is provided with a gear groove for use with the gear 33, and the surface of the drive shaft 31 is provided with a protrusion for connection with the keyway of the gear 33. After the gear 33 is moved downward to form a keyway connection relationship with the drive shaft 31, the gear 33 is located on the inner side of the gear plate 32.

[0087] The surface of the sliding plate 35 is provided with a groove for use with the sliding bracket 34, the inner side of the second bracket 38 is provided with a U-shaped groove for use with the driving column 39, and the inner side of the blanking plate 311 is provided with an annular groove for blanking.

[0088] In this embodiment, compared with the existing device, when adding potassium permanganate, the gear 33 is moved downward to be key-connected with the drive shaft 31, and the gear plate 32 and the column 312 are driven to rotate by the rotation of the gear 33. With the cooperation of the first bracket 36 and the second bracket 38, the sliding plate 35 is made to slide back and forth in the sliding bracket 34, and then the unloading plate 311 is moved back and forth to unload potassium permanganate intermittently. During the unloading process, the sliding plate 35 will simultaneously drive the moving column 44 to move back and forth. With the cooperation of the tension spring 43, intermittent water supply is performed to the reactor 1 through the control valve 42, and potassium permanganate and water are added simultaneously in multiple times to avoid excessively violent reaction and the problem of a large amount of water required to completely dissolve potassium permanganate at one time.

[0089] Third embodiment:

[0090] See also Figures 10 to 13 A pretreatment mechanism 6 is fixedly arranged on the right side of the reactor 1, and the pretreatment mechanism 6 includes a treatment box 61 fixedly arranged on the right side of the reactor 1, and a mixing rod 62 is vertically rotatably connected to the inner side of the treatment box 61, and a first pulley 63 is fixedly arranged on the top of the mixing rod 62, and a second pulley 64 is fixedly arranged on the surface of the gear plate 32, and a belt 65 is sleeved on the surfaces of the first pulley 63 and the second pulley 64, and a mixing plate 66 is fixedly arranged on the surface of the mixing rod 62 and located on the inner side of the treatment box 61;

[0091] Please combine Figures 10 to 12 : When the driving shaft 31 drives the gear plate 32 to rotate through the gear 33, the gear plate 32 will simultaneously drive the second pulley 64 to rotate, the second pulley 64 will further drive the first pulley 63 to rotate through the belt 65, and the first pulley 63 will further drive the mixing plate 66 to rotate through the mixing rod 62;

[0092] Preferably, the processing box 61 is provided with air treatment liquid or ion purification liquid or other liquids that can purify toxic and odorous gases, and the rotation of the mixing plate 66 can stir and mix the purified liquid and the toxic and odorous gases.

[0093] The front of the processing box 61 is fixedly provided with an exhaust mechanism 7, and the exhaust mechanism 7 includes a support base 71 fixedly provided on the front of the processing box 61, and an exhaust pump 72 is provided on the top of the support base 71, and the left side of the exhaust pump 72 is connected with an exhaust pipe 73, and the left end of the exhaust pipe 73 is connected with the right side of the reactor 1, and the top of the exhaust pump 72 is connected with an outlet pipe 74, and the bottom end of the outlet pipe 74 passes through the top of the processing box 61 and extends to the inside of the processing box 61, and the right side of the processing box 61 is connected with a discharge pipe 75;

[0094] Please combine Fig.10 : Start the vacuum pump 72, the vacuum pump 72 extracts the gas in the reaction kettle 1 through the vacuum pipe 73, and discharges it into the processing box 61 through the outlet pipe 74;

[0095] Preferably, the reactor 1 is externally connected to an air inlet pipe for gas exchange, and the exhaust pipe 75 is externally connected to a waste gas treatment device for secondary treatment of the extracted gas so that it meets the emission standards and then is discharged into the atmosphere.

[0096] A stirring mechanism 8 is fixedly arranged on the surface of the driving shaft 31 and located inside the reactor 1. The stirring mechanism 8 includes a stirring blade 81 fixedly arranged on the surface of the driving shaft 31. Two connecting brackets 82 are fixedly arranged on the surface of the driving shaft 31 and located inside the reactor 1. Scrapers 83 are fixedly arranged on both sides of the two connecting brackets 82. A driving motor 84 for driving the driving shaft 31 to rotate is arranged on the top of the protective shell 5.

[0097] Please combine Fig.13 : Start the drive motor 84, and the drive motor 84 rotates to drive the drive shaft 31 to rotate, and the drive shaft 31 rotates to drive the stirring blades 81, the connecting bracket 82 and the scraper 83 to rotate, so as to stir and mix the materials to quickly meet the production requirements;

[0098] Preferably, a heating structure is provided in the reactor 1 for heating the material.

[0099] A mounting frame 9 is provided on the surface of the reactor 1, a feed pipe 10 is connected to the left side of the reactor 1, and a discharge pipe 11 is connected to the bottom of the reactor 1;

[0100] Preferably, the processed raw materials can be discharged through the discharge pipe 11, and then the raw materials can be filtered and other processing steps. The surfaces of the feed pipe 10 and the discharge pipe 11 are both provided with control valves.

[0101] In the present embodiment, during the intermittent addition of raw materials, the toxic and odorous gases in the reactor 1 are sucked into the treatment box 61 by means of the vacuum pump 72, and the second pulley 64 is driven to rotate by the rotation of the gear plate 32. The second pulley 64 then drives the first pulley 63 to rotate through the belt 65, and the first pulley 63 then drives the mixing plate 66 to rotate through the mixing rod 62, thereby stirring and mixing the purified liquid and the toxic and odorous gases, avoiding damage to the body after the gas leaks, and improving the safety of the device when used.

[0102] Please refer to Figures 1 to 13 The working principle of the production process of 2-amino-6-nitrobenzoic acid provided by the present invention is as follows:

[0103] Step S1, the operator wears protective equipment, then 3-chloro-2-methylacetanilide, solvent xylene, catalyst tetrabutylammonium bromide and water are added into the reactor 1 in sequence, and the drive motor 84 is started, and the drive motor 84 rotates to drive the drive shaft 31 to rotate, and the drive shaft 31 rotates to drive the stirring blade 81, the connecting bracket 82 and the scraper 83 to rotate, so that the materials are stirred and mixed to form a brown-white milky mixture;

[0104] Step S2, maintaining the temperature inside the reactor 1, and then moving the gear 33 downward on the surface of the driving shaft 31, so that the gear 33 and the driving shaft 31 are key-connected, and the rotation of the driving shaft 31 drives the gear 33 to rotate, and the rotation of the gear 33 drives the gear plate 32 to rotate, and the rotation of the gear plate 32 drives the two columns 312 to rotate, and under the action of the first bracket 36 and the second bracket 38, the sliding plate 35 is made to slide back and forth on the inner side of the sliding bracket 34, and the sliding plate 35 is driven to slide back and forth to drive the unloading plate 311 to slide back and forth, so as to unload potassium permanganate intermittently;

[0105] When the sliding plate 35 drives the unloading plate 311 to move back and forth to unload potassium permanganate intermittently, the sliding plate 35 will simultaneously drive the moving column 44 to move back and forth, and with the cooperation of the tension spring 43, water will be intermittently supplied to the reactor 1 through the control valve 42;

[0106] Step S3, when the driving shaft 31 drives the gear plate 32 to rotate through the gear 33, the gear plate 32 will simultaneously drive the second pulley 64 to rotate, the second pulley 64 will further drive the first pulley 63 to rotate through the belt 65, and the first pulley 63 will further drive the mixing plate 66 to rotate through the mixing rod 62;

[0107] The vacuum pump 72 is started, and the vacuum pump 72 extracts the gas in the reactor 1 through the vacuum pipe 73, and discharges it into the processing box 61 through the gas outlet pipe 74. The purified liquid and the toxic and odorous gas are mixed and stirred by the rotation of the mixing plate 66, so that the toxic and odorous gas is initially treated, and then discharged to the exhaust gas treatment equipment through the discharge pipe 75 after treatment. The extracted gas is subjected to secondary treatment to meet the emission standards, and then discharged into the atmosphere;

[0108] Step S4, after the potassium permanganate is stirred at a constant temperature until it fades, the drive motor 84 and the vacuum pump 72 are turned off, and it is discharged through the discharge pipe 11, and then the raw materials are filtered and other processing steps are performed.

[0109] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A production process for 2-amino-6-nitrobenzoic acid, characterized in that: The following steps are involved: Step S1: Acylation protection with acetic anhydride, Add 3-chloro-2-methylaniline and anhydrous toluene into a container, stir to dissolve the solid, drop acetic anhydride, the reaction is exothermic, and a large amount of white crystals are generated. After the drop is complete, stir rapidly and heat to reflux; Stop the reaction, cool and let stand, extract the solid, wash with toluene, concentrate the mother liquor and cool it to get some products, dry it, and recrystallize it with toluene to get pure white needle-shaped crystals; Step S2: Potassium permanganate oxidation, Add 3-chloro-2-methylacetanilide, solvent xylene, and catalyst tetrabutylammonium bromide into a container, stir and heat, add water several times, stir quickly to form a brown-white milky mixture, maintain the internal temperature, add potassium permanganate several times, continue to stir at a constant temperature or until the potassium permanganate fades; Filter while hot, wash the filter cake (manganese dioxide) with hot water, let the filtrate stand, separate the lower organic phase, and extract the upper aqueous phase with chloroform; The obtained aqueous solution was allowed to stand, filtered to remove a small amount of solid, and hydrochloric acid was slowly added dropwise while cooling and stirring to adjust the pH, to generate a large amount of white solid, which was then cooled and filtered, and washed with a small amount of cold water. The obtained white solid was dried at a constant temperature, the mother liquor was concentrated, and cooled and allowed to stand to obtain needle-shaped crystals; Step S3: hydrolysis with sodium hydroxide solution, Add 2-chloro-6-acetylaminobenzoic acid, 96% sodium hydroxide and aqueous solution into a container and stir to dissolve the solid quickly to obtain a light yellow transparent solution; Heat to an oil bath, react, cool slightly, add activated carbon, and continue heating; Stop the reaction, cool the reaction solution with an ice-water bath, filter to remove the activated carbon, drop concentrated hydrochloric acid into the mixture while stirring to adjust the pH, leave at low temperature overnight, filter out the solid, and dry at a constant temperature to obtain a light yellow solid; Step S4: Ammonolysis reaction, In an organic solvent, under the action of a cuprous catalyst, 2-chloro-6-aminobenzoic acid and ammonia are subjected to a catalytic aminolysis reaction to obtain 2-amino-6-nitrobenzoic acid.

2. The production process of 2-amino-6-nitrobenzoic acid according to claim 1, characterized in that: The 2-amino-6-nitrobenzoic acid production process step S2 requires the use of a reaction kettle, a kettle cover, a material discharge mechanism and a water addition mechanism when adding potassium permanganate; The unloading mechanism comprises a driving shaft vertically rotatably connected to the inner side of the kettle cover, the top of the kettle cover and the surface of the driving shaft are rotatably connected with a gear plate, the surface of the driving shaft and the top of the gear plate are provided with a gear, two sliding brackets are fixedly provided on the rear side of the top of the kettle cover, the inner sides of the two sliding brackets are slidably connected with a sliding plate, the top of the sliding plate is fixedly provided with a first bracket, the top of the kettle cover is fixedly provided with a rotating shaft, the surface of the rotating shaft is rotatably connected with a second bracket, the top of the sliding plate and the inner side of the second bracket are fixedly provided with a driving column, the right side of the top of the kettle cover is connected with a feeding hopper, the inner side of the feeding hopper is slidably connected with a unloading plate, the right side of the sliding plate is fixedly connected to the surface of the unloading plate, and two columns are fixedly provided on the top of the gear plate; A protective shell is slidably connected to the surface of the sliding bracket, and the bottom of the protective shell is fixedly connected to the top of the kettle cover; The water adding mechanism includes a water inlet pipe arranged on the inner side of the protective shell, the bottom end of the water inlet pipe passes through the top of the kettle cover and extends to the interior of the reactor, a valve is arranged on the surface of the water inlet pipe, a tension spring is arranged on the surface of the valve, the left side of the tension spring is fixedly connected to the back side of the inner wall of the protective shell, and a moving column is threadedly connected to the inner side of the top of the sliding plate.

3. The production process of 2-amino-6-nitrobenzoic acid according to claim 2, characterized in that, The inner side of the gear plate is provided with a gear groove for use with the gear, and the surface of the drive shaft is provided with a protrusion for connection with the gear keyway. After the gear is moved downward to form a keyway connection relationship with the drive shaft, the gear is located on the inner side of the gear plate.

4. The production process of 2-amino-6-nitrobenzoic acid according to claim 2, characterized in that: The surface of the sliding plate is provided with a groove used in conjunction with the sliding bracket, the inner side of the second bracket is provided with a U-shaped groove used in conjunction with the driving column, and the inner side of the blanking plate is provided with an annular groove for blanking.

5. The production process of 2-amino-6-nitrobenzoic acid according to claim 2, characterized in that, A pretreatment mechanism is fixedly provided on the right side of the reactor, and the pretreatment mechanism includes a treatment box fixedly provided on the right side of the reactor, a mixing rod is vertically rotatably connected to the inner side of the treatment box, a first pulley is fixedly provided on the top of the mixing rod, a second pulley is fixedly provided on the surface of the gear plate, belts are sleeved on the surfaces of the first pulley and the second pulley, and a mixing plate is fixedly provided on the surface of the mixing rod and located on the inner side of the treatment box.

6. The production process of 2-amino-6-nitrobenzoic acid according to claim 5, characterized in that: An exhaust mechanism is fixedly provided on the front of the processing box, and the exhaust mechanism includes a support base fixedly provided on the front of the processing box, a vacuum pump is provided on the top of the support base, the left side of the vacuum pump is connected to an exhaust pipe, the left end of the exhaust pipe is connected to the right side of the reactor, the top of the vacuum pump is connected to an outlet pipe, the bottom end of the outlet pipe passes through the top of the processing box and extends to the interior of the processing box, and the right side of the processing box is connected to a discharge pipe.

7. The production process of 2-amino-6-nitrobenzoic acid according to claim 2, characterized in that: A stirring mechanism is fixedly arranged on the surface of the driving shaft and located on the inner side of the reactor, and the stirring mechanism includes stirring blades fixedly arranged on the surface of the driving shaft, and two connecting brackets are fixedly arranged on the surface of the driving shaft and located on the inner side of the reactor, and scrapers are fixedly arranged on both sides of the two connecting brackets, and a driving motor for driving the driving shaft to rotate is arranged on the top of the protective shell.

8. The production process of 2-amino-6-nitrobenzoic acid according to claim 2, characterized in that: A mounting frame is arranged on the surface of the reactor, a feed pipe is connected to the left side of the reactor, and a discharge pipe is connected to the bottom of the reactor.

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