A preparation method of o-methylbenzoyl nitrile

Abstract

The invention discloses a method for preparing o-methylbenzoyl nitrile. The method for preparing o-methylbenzoyl nitrile is achieved by o-methylbenzoyl nitrile preparation equipment. The o-methylbenzoyl nitrile preparation equipment comprises a reaction chamber body, wherein a support platform is provided on the bottom wall of an inner cavity of the reaction chamber body, a pot body is provided on the upper end of the support platform, a stirring air intake mechanism is provided in the middle of the bottom wall of the pot body, a first trigger mechanism is provided on the upper part of the stirring air intake mechanism, a second trigger mechanism is provided in the middle of the inner cavity of the reaction chamber body, a positioning mechanism is provided on the upper part of the inner cavity of the reaction chamber body, and an external circulation mechanism is provided on the upper part of the positioning mechanism. By providing the internal circulation mechanism, the amount of HCN gas introduced is reduced, production raw materials are saved, a large amount of nitrogen resources are saved by providing the first trigger mechanism, the second trigger mechanism and the positioning mechanism, and the stirring air intake mechanism is provided to improve the efficiency of blowing out HCN and HCl gases.

Description

Technical Field

[0001] The invention relates to the field of o-methylbenzoyl nitrile production equipment, and in particular to a preparation method of o-methylbenzoyl nitrile. Background Art

[0002] Trifloxystrobin is a strobilurin fungicide first developed by Syngenta and later by Bayer AG of Germany. It has a broad-spectrum fungicidal effect and has a significant inhibitory effect on almost all fungal diseases (such as powdery mildew, rust, downy mildew, gray mold and rice blast). The emergence of trifloxystrobin is of great significance to improving my country's pesticide structure, reducing pesticide residues and alleviating adverse effects on the ecological environment.

[0003] The synthesis of trifloxystrobin has become a research focus for major pesticide companies. o-Toluocyanate is a key intermediate in the industrial synthesis of trifloxystrobin. The current synthesis process involves directly reacting o-Toluocyanate with hydrocyanic acid. The product is then filtered, distilled under reduced pressure, and then distilled under high vacuum to obtain o-Toluocyanate in a yield exceeding 95%.

[0004] In the production process, o-methylbenzoyl chloride is added to acetonitrile, followed by the addition of ethylene glycol as a catalyst. The temperature is then lowered to 10-15°C. HCN gas is then introduced into the liquid surface at a temperature between 10-15°C, with by-product HCl gas being expelled during the aeration process. The solution is then incubated for 5 hours. Excess HCN and remaining HCl are then blown out with nitrogen, leaving a toluene solution of o-methylbenzoyl nitrile. The acetonitrile is then removed by vacuum distillation, leaving a crude o-methylbenzoyl nitrile product. The resulting crude o-methylbenzoyl nitrile product is then subjected to high vacuum distillation to obtain the o-methylbenzoyl nitrile product. First, in the process of introducing HCN gas and discharging the by-product HCl gas, the commonly used means in this field is to introduce excessive HCN gas so that the HCN gas fills the entire reaction chamber and discharges the by-product HCl. A large amount of HCN needs to be consumed in the whole process. When an air pump is used to extract the by-product HCl, HCN that has not reacted in time will also be sucked out, and a toluene solution of excessive HCN and o-methylbenzoyl nitrile still needs to be introduced, which also wastes a large amount of HCN. Secondly, in the process of bubbling out the excessive HCN and the remaining HCl with nitrogen, when the HCN and HCl contained in the solution become less and less, we also need to constantly introduce an equal amount of nitrogen into the solution to maintain the solution bubbling, and bubbling out a small amount of HCN and HCl in the solution. In this process, a large amount of nitrogen needs to be consumed, and the purpose is to remove a small amount of HCN and HCl in the solution, which consumes a large amount of industrial materials. For this reason, we propose a preparation method for o-methylbenzoyl nitrile. Summary of the Invention

[0005] The main purpose of the present invention is to provide a method for preparing o-methylbenzoyl nitrile, which can effectively solve the problem of consuming a large amount of HCN and nitrogen in the background technology.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] A method for preparing o-methylbenzoyl nitrile is achieved by using o-methylbenzoyl nitrile preparation equipment. The o-methylbenzoyl nitrile preparation equipment comprises a reaction chamber body, wherein a support platform is provided on the bottom wall of an inner cavity of the reaction chamber body, a pot body is provided on the upper end of the support platform, a stirring air intake mechanism is provided in the middle of the bottom wall of the pot body, a first trigger mechanism is provided on the upper part of the stirring air intake mechanism, a second trigger mechanism is provided in the middle of the inner cavity of the reaction chamber body, a positioning mechanism is provided on the upper part of the inner cavity of the reaction chamber body, an external circulation mechanism is provided on the upper part of the positioning mechanism, two groups of air intake ports are provided in the middle of the outer wall of the reaction chamber body, a group of internal circulation mechanisms are provided at each of the two groups of air intake ports, and an HCN inlet is provided at the lower left side of the reaction chamber body.

[0008] Preferably, the stirring air intake mechanism includes a driving motor, a transmission gear, a driven gear, a meshing gear, a support rod and a stirring blade, the output end of the driving motor is fixedly connected to the transmission gear, the left part of the transmission gear is meshed with the driven gear, the left part of the driven gear is meshed with the meshing gear, the middle part of the upper end of the meshing gear is fixedly plugged with a support rod, the support rod passes through the middle part of the bottom wall of the inner cavity of the pot body, and the support rod is movably connected to the pot body, a stirring blade is fixedly installed on the right side of the middle part of the outer surface of the support rod, and the lower part of the outer surface of the stirring blade is in contact with the inner wall of the pot body.

[0009] Preferably, a plurality of evenly distributed air outlets are provided on the lower portion of the outer surface of the stirring blade, and a first connecting pipe is buried inside the stirring blade and the support rod, and the first connecting pipe is connected to the air outlet.

[0010] Preferably, the first trigger mechanism includes a supporting chassis, a ball carrier, a placement groove, a placement block, a push rod, a first contact limiter and a trigger spring, the middle part of the upper end of the supporting chassis is fixedly connected to the ball carrier, a group of placement grooves are opened on the left and right sides of the upper end of the ball carrier, a group of placement blocks are fixedly installed on the bottom wall of the placement groove, a group of push rods are movably inserted in the inner cavity of the placement block, a group of trigger springs are fixedly connected to the middle part of the lower end of the push rod, a group of first contact limiters are fixedly installed in the middle part of the bottom wall of the inner cavity of the placement block, and the supporting chassis is movably sleeved on the upper part of the support rod to movably connect the first trigger mechanism with the stirring and air intake mechanism.

[0011] Preferably, the second trigger mechanism includes a limiting slide, a slide, a fitting block, a positioning slot and a sealing cover. There are two groups of limiting slides, and a slide is slidably connected between the two groups of limiting slides. A fitting block is fixedly connected to the middle of the lower end of the slide. A group of symmetrically distributed positioning slots are opened on the left and right sides of the lower end of the slide. A group of sealing covers are movably inserted at the lower notches of the positioning slots. The two groups of limiting slides are respectively fixedly installed on the left and right inner walls of the reaction chamber body to fix the second trigger mechanism to the reaction chamber body.

[0012] Preferably, a fitting cavity is opened in the middle of the upper end of the fitting block, a touch slider is slidably connected in the fitting cavity, a second contact limiter is fixedly installed in the middle of the upper end of the touch slider, a connecting spring is fixedly connected to the middle of the lower end of the touch slider, and a group of adsorption electromagnets are fixedly connected to the upper parts of the left and right sides of the fitting block, and the adsorption electromagnets are electrically connected to the second contact limiter.

[0013] Preferably, a group of positioning springs are fixedly connected to the upper end of the sealing cover, the upper part of the positioning springs is fixedly connected to the groove wall of the positioning slot, and the positioning springs are in a tensioned state.

[0014] Preferably, the internal circulation mechanism includes a first separation chamber, an internal circulation air pump, an HCl separation outlet, a first circulation pipe and an electromagnetic control valve. The right end of the first separation chamber is fixedly connected to the internal circulation air pump, the internal circulation air pump is electrically connected to the first contact limiter, and the right part of the internal circulation air pump is fixedly connected to the air intake port. The middle part of the lower end of the first separation chamber is connected to the first circulation pipe, and a group of electromagnetic control valves are installed at the right port of the air intake port and the right port of the first circulation pipe. The other end of the first circulation pipe passes through the outer wall of the reaction chamber body and communicates with the inner cavity of the pot.

[0015] Preferably, the positioning mechanism includes a positioning plate, a second connecting tube, a fitting slot, an adsorption iron block and a connecting hole. A group of second connecting tubes are fixedly plugged into the left and right sides of the upper end of the positioning plate. A fitting slot is provided in the middle of the lower end of the positioning plate. A group of adsorption iron blocks are fixedly installed on the left and right side walls of the fitting slot. A plurality of groups of evenly distributed connecting holes are provided on the outer surface of the lower end of the second connecting tube. The positioning mechanism is fixedly connected to the reaction chamber body through the positioning plate.

[0016] Preferably, the external circulation mechanism includes a second separation chamber, an external circulation air pump, a circulation air duct, a first outlet and a second outlet, the first outlet and the second outlet are fixedly installed on the upper and lower parts of the right end of the second separation chamber respectively, the middle part of the lower end of the second separation chamber is fixedly connected to the external circulation air pump, the upper part of the second separation chamber and the lower part of the external circulation air pump are both connected to the circulation air duct, and the circulation air duct is respectively connected to the first connecting pipe and the second connecting pipe.

[0017] Preferably, the preparation method of o-methylbenzoyl nitrile comprises the following steps:

[0018] S1. o-Toluoyl chloride and acetonitrile are added to a pot in a reaction chamber, ethylene glycol is added as a catalyst, a certain amount of HCN is introduced from the HCN inlet, the stirring and air inlet mechanism is started, the stirring blade rotates around the support rod, stirring the reaction solution, and HCN passes through a first connecting pipe and enters the pot from the air outlet on the stirring blade to react with o-Toluoyl chloride and acetonitrile to obtain o-Toluoyl nitrile and a by-product HCl.

[0019] S2. Start the internal circulation mechanism and open the electromagnetic control valve. The internal circulation pump sends the HCN and HCl gases on the reaction liquid surface into the first separation chamber for separation. The separated HCl gas is discharged and recovered from the HCl separation outlet. The HCN gas returns to the pot body through the first circulation pipe and continues to react with the reaction solution to generate o-methylbenzoyl nitrile and by-product HCl.

[0020] S3. As HCN reacts with the reaction solution and the generated HCl is separated, the HCN contained in the lower chamber formed by the entire reaction chamber body and the second trigger mechanism will become less and less, and the air pressure will become lower and lower, causing the slide in the second trigger mechanism to slide down along the limiting slide groove. When the fitting block is pressed down and contacts the push rod in the first trigger mechanism, the push rod is pressed down to touch the first contact limiter. The first contact limiter transmits a signal to the internal circulation pump. The internal circulation pump increases the working power, increases the pressure of the adsorption and delivery gas, and transports a small amount of HCN into the pot through the first circulation pipe to react with the reaction solution until the HCN and the reaction solution are completely reacted.

[0021] S4. Close the electromagnetic control valve and introduce nitrogen to blow out the HCN and HCl in the liquid surface. The nitrogen enters the first connecting pipe through the circulating air guide pipe in the external circulation mechanism and is then discharged from the air outlet. Nitrogen is blown into the liquid surface after the reaction in the pot. The stirring blade rotates so that the continuously input nitrogen can continuously generate bubbles with the bottom wall of the pot as the spherical surface, thereby blowing out the HCN and HCl gases dissolved in the liquid.

[0022] S5. Due to the continuous inflow of nitrogen, the pressure in the lower chamber formed by the entire reaction chamber body and the second trigger mechanism will become greater and greater, forcing the slide in the second trigger mechanism to slide upward along the direction of the limiting slide groove. When the touch slider on the fitting block is pressed to touch the second contact limiter, the second contact limiter controls the adsorption electromagnet to be in the open state, and the adsorption electromagnet is adsorbed together with the adsorption iron block in the positioning mechanism. At this time, the second connecting pipe in the positioning mechanism is inserted into the positioning slot in the second trigger mechanism, and the sealing cover is pushed out of the positioning slot by the end of the second connecting pipe. At this time, the mixed gas in the lower chamber formed by the reaction chamber body and the second trigger mechanism can enter the second connecting pipe through the connecting hole and then enter the external circulation mechanism.

[0023] S6. The mixed gas contains nitrogen, HCN and HCl. The mixed gas enters the second separation chamber and is separated and processed. HCl and HCN are discharged and collected from the first outlet and the second outlet respectively. Nitrogen is pumped out of the pot through the circulating air pipe and the first connecting pipe by the external circulating air pump to separate the reacted solution in the pot and remove HCN and HCl.

[0024] S7. After HCN and HCl in the reaction solution have been separated, the reaction solution is fed into a corresponding device and distilled under reduced pressure to remove acetonitrile, leaving a crude o-methylbenzoyl nitrile product. The obtained crude o-methylbenzoyl nitrile product is subjected to high vacuum distillation to obtain an o-methylbenzoyl nitrile product.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. In the present invention, a stirring and air-intake mechanism is provided, which can stir the mixed solution. An air outlet is provided at the lower part of the stirring blade. When the stirring blade rotates, the air outlet can lead out gas. When HCN is introduced, the mixed solution can be stirred so that HCN and the mixed solution fully react. When nitrogen is introduced, the reacted solution can be stirred. When nitrogen is led out from the air outlet, as the stirring blade rotates, the amount of bubbles generated is increased, the contact area between nitrogen and the reacted solution is also increased, and the efficiency of blasting HCN and HCl gas is improved.

[0027] 2. By setting up an internal circulation mechanism, the HCN introduced into the reaction pot can be repeatedly circulated and reacted, and the by-product HCl gas of the reaction can be filtered and discharged in time, thereby reducing the amount of HCN gas introduced and saving production raw materials.

[0028] 3. By providing a first trigger mechanism, a second trigger mechanism, and a positioning mechanism, the device can discharge HCl by-products and introduce nitrogen to blast out HCN and HCl in steps. When discharging HCl by-products, the internal circulation air pump is promptly increased in power by triggering or not triggering the first contact limiter in the first trigger mechanism, so that even when the amount of HCN is reduced, it can be circulated by the internal circulation mechanism into the pot body to contact the reaction solution and react again. When the second trigger mechanism and the positioning mechanism pass nitrogen, when the nitrogen continues to pass through and reaches a certain amount, the mixed gas in the reaction chamber body can be promptly sent to the external circulation mechanism to filter out and collect HCN and HCl, and the nitrogen is recycled to bubble the reacted solution to discharge HCN and HCl, thereby saving a large amount of nitrogen resources.

[0029] 4. By setting up an external circulation mechanism, during the process of blowing out excess HCN and remaining HCl with nitrogen, nitrogen can be circulated into the solution after the reaction, continuously blowing out HCN and HCl in the solution after the reaction, thereby improving the blowing efficiency and saving a large amount of nitrogen resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the overall structure of a method for preparing o-methylbenzoyl nitrile of the present invention;

[0031] Figure 2 This is a structural schematic diagram of a stirring and air-intake mechanism for a method for preparing o-methylbenzoyl nitrile according to the present invention;

[0032] Figure 3 This is a schematic structural diagram of a first trigger mechanism of a method for preparing o-methylbenzoyl nitrile according to the present invention;

[0033] Figure 4 This is a schematic structural diagram of a second trigger mechanism in a method for preparing o-methylbenzoyl nitrile according to the present invention;

[0034] Figure 5 This is an enlarged view of point A of a method for preparing o-methylbenzoyl nitrile of the present invention;

[0035] Figure 6 This is a schematic structural diagram of an internal circulation mechanism of a method for preparing o-methylbenzoyl nitrile of the present invention;

[0036] Figure 7 This is a schematic structural diagram of a positioning mechanism in a method for preparing o-methylbenzoyl nitrile of the present invention;

[0037] Figure 8 This is a schematic structural diagram of an external circulation mechanism of a method for preparing o-methylbenzoyl nitrile of the present invention;

[0038] Figure 9This is a schematic diagram of the second trigger mechanism structure and the positioning mechanism of the preparation method of o-methylbenzoyl nitrile of the present invention being fitted together.

[0039] In the figure: 1. Reaction chamber body; 2. Support platform; 3. Pot body; 4. Stirring air inlet mechanism; 41. Driving motor; 42. Transmission gear; 43. Driven gear; 44. Engaging gear; 45. Support rod; 46. Stirring blade; 461. Air outlet; 462. First connecting pipe; 5. First trigger mechanism; 51. Support chassis; 52. Ball carrier; 53. Placement groove; 54. Placement block; 55. Push rod; 56. First contact limiter; 57. Trigger spring; 6. Second trigger mechanism; 61. Limiting slide groove; 62. Slide plate; 63. Fitting block; 631. Fitting cavity; 632. Touch slider; 633. Second contact Limiter; 634, connecting spring; 635, adsorption electromagnet; 64, positioning slot; 65, sealing cover; 651, positioning spring; 7, internal circulation mechanism; 71, first separation chamber; 72, internal circulation air pump; 73, HCl separation outlet; 74, first circulation pipe; 75, electromagnetic control valve; 8, positioning mechanism; 81, positioning plate; 82, second connecting pipe; 83, fitting slot; 84, adsorption iron block; 85, connecting hole; 9, external circulation mechanism; 91, second separation chamber; 92, external circulation air pump; 93, circulation air duct; 94, first outlet; 95, second outlet; 10, air intake; 11, HCN inlet. DETAILED DESCRIPTION

[0040] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific implementation methods.

[0041] In the description of the present invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," "the other end," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0042] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "provided with," "connected," etc., should be understood in a broad sense. For example, "connected" may refer to a fixed connection, a detachable connection, or an integral connection; it may refer to a mechanical connection or an electrical connection; it may refer to a direct connection or an indirect connection through an intermediate medium; it may refer to internal communication between two components. Those skilled in the art will be able to understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0043] like Figure 1-9 As shown, a method for preparing o-methylbenzoyl nitrile is implemented by an o-methylbenzoyl nitrile preparation device, and the o-methylbenzoyl nitrile preparation device includes a reaction chamber body 1, a support platform 2 is provided on the bottom wall of the inner cavity of the reaction chamber body 1, a pot body 3 is provided on the upper end of the support platform 2, a stirring air intake mechanism 4 is provided in the middle of the bottom wall of the pot body 3, a first trigger mechanism 5 is provided on the upper part of the stirring air intake mechanism 4, a second trigger mechanism 6 is provided in the middle of the inner cavity of the reaction chamber body 1, a positioning mechanism 8 is provided on the upper part of the inner cavity of the reaction chamber body 1, an external circulation mechanism 9 is provided on the upper part of the positioning mechanism 8, two groups of air intake ports 10 are provided in the middle of the outer wall of the reaction chamber body 1, and a group of internal circulation mechanisms 7 are provided at each of the two groups of air intake ports 10. An HCN inlet 11 is provided at the lower left part of the reaction chamber body 1.

[0044] The stirring air intake mechanism 4 includes a driving motor 41, a transmission gear 42, a driven gear 43, a meshing gear 44, a support rod 45 and a stirring blade 46. The output end of the driving motor 41 is fixedly connected to the transmission gear 42, the left part of the transmission gear 42 is meshed with the driven gear 43, the left part of the driven gear 43 is meshed with the meshing gear 44, and the middle part of the upper end of the meshing gear 44 is fixedly plugged with a support rod 45. The support rod 45 passes through the middle of the bottom wall of the inner cavity of the pot body 3, and the support rod 45 is movably connected to the pot body 3. A stirring blade 46 is fixedly installed on the right side of the middle of the outer surface of the support rod 45, and the lower part of the outer surface of the stirring blade 46 is in contact with the inner wall of the pot body 3. The lower part of the outer surface of the stirring blade 46 is provided with multiple A uniformly distributed gas outlet port 461 is provided. A first connecting pipe 462 is embedded in the interior of the stirring blade 46 and the support rod 45. The first connecting pipe 462 is connected to the gas outlet port 461. The gas outlet port 461 is provided at the lower part of the stirring blade 46. When the stirring blade 46 rotates, the gas outlet port 461 can discharge gas. When HCN is introduced, the mixed solution can be stirred to allow HCN and the mixed solution to fully react. When nitrogen is introduced, the reacted solution can be stirred. When nitrogen is discharged from the gas outlet port 461, as the stirring blade 46 rotates, the amount of bubbles generated is increased, the contact area between nitrogen and the reacted solution is increased, and the efficiency of blasting HCN and HCl gas is improved.

[0045] The first trigger mechanism 5 includes a supporting chassis 51, a ball carrier 52, a placement groove 53, a placement block 54, a push rod 55, a first contact limiter 56 and a trigger spring 57. The supporting chassis 51 is fixedly connected to the middle part of the upper end of the ball carrier 52. A group of placement grooves 53 are opened on the left and right sides of the upper end of the ball carrier 52. A group of placement blocks 54 are fixedly installed on the bottom wall of the placement groove 53. A group of push rods 55 are movably inserted into the inner cavity of the placement block 54. A group of trigger springs 57 are fixedly connected to the middle part of the lower end of the push rod 55. A group of first contact limiters 56 are fixedly installed in the middle part of the bottom wall of the inner cavity of the placement block 54. The supporting chassis 51 is movably sleeved on the upper part of the support rod 45 to movably connect the first trigger mechanism 5 with the stirring and air intake mechanism 4, so that the internal circulation air pump 72 can increase the working power in time, so that when the amount of HCN is reduced, it can be circulated by the internal circulation mechanism 7 into the pot body 3 to contact the reaction solution and react again;

[0046] The second trigger mechanism 6 includes a limiting slide 61, a slide 62, a fitting block 63, a positioning slot 64 and a sealing cover 65. There are two groups of limiting slides 61, and a slide 62 is slidably connected between the two groups of limiting slides 61. The middle part of the lower end of the slide 62 is fixedly connected with a fitting block 63. A group of symmetrically distributed positioning slots 64 are opened on both sides of the lower end of the slide 62. A group of sealing covers 65 are movably inserted at the lower notch of the positioning slot 64. The two groups of limiting slides 61 are respectively fixedly installed on the inner walls of the left and right sides of the reaction chamber body 1 to fix the second trigger mechanism 6 and the reaction chamber body 1 together. A fitting cavity 631 is opened in the middle of the upper end of the fitting block 63, and a touch slider 632 is slidably connected in the fitting cavity 631. The middle part of the upper end of the touch slider 632 is fixedly installed with a second contact The stopper 633 and the touch slider 632 are fixedly connected to a connecting spring 634 at the middle of the lower end. A group of adsorption electromagnets 635 are fixedly connected to the upper parts of the left and right sides of the fitting block 63. The adsorption electromagnets 635 are electrically connected to the second contact stopper 633. A group of positioning springs 651 are fixedly connected to the upper end of the sealing cover 65. The upper part of the positioning spring 651 is fixedly connected to the groove wall of the positioning slot 64, and the positioning spring 651 is in a taut state. When nitrogen passes through the second trigger mechanism 6 and the positioning mechanism 8, when the nitrogen continues to pass through and reaches a certain amount, the mixed gas in the reaction chamber body 1 can be promptly sent to the external circulation mechanism 9 to filter out and collect HCN and HCl, and the nitrogen is recycled to bubble the reacted solution to discharge HCN and HCl.

[0047] The internal circulation mechanism 7 includes a first separation chamber 71, an internal circulation air pump 72, an HCl separation outlet 73, a first circulation pipe 74 and an electromagnetic control valve 75. The right end of the first separation chamber 71 is fixedly connected to the internal circulation air pump 72, the internal circulation air pump 72 is electrically connected to the first contact limiter 56, and the right part of the internal circulation air pump 72 is fixedly connected to the air intake port 10. The middle part of the lower end of the first separation chamber 71 is connected to the first circulation pipe 74. A group of electromagnetic control valves 75 are installed at the right port of the air intake port 10 and the right port of the first circulation pipe 74. The other end of the first circulation pipe 74 passes through the outer wall of the reaction chamber body 1 and communicates with the inner cavity of the pot body 3. It can repeatedly circulate the HCN introduced into the pot body 3 and filter and discharge the by-product HCl gas of the reaction in time to reduce the amount of HCN gas introduced;

[0048] The positioning mechanism 8 includes a positioning plate 81, a second connecting pipe 82, a fitting slot 83, an adsorption iron block 84, and a connecting hole 85. A set of second connecting pipes 82 are fixedly inserted on both sides of the upper end of the positioning plate 81. A fitting slot 83 is provided in the middle of the lower end of the positioning plate 81. A set of adsorption iron blocks 84 are fixedly installed on the left and right side walls of the fitting slot 83. A plurality of evenly distributed connecting holes 85 are provided on the outer surface of the lower end of the second connecting pipe 82. The positioning mechanism 8 is fixedly connected to the reaction chamber body 1 through the positioning plate 81 to facilitate nitrogen circulation.

[0049] The external circulation mechanism 9 includes a second separation chamber 91, an external circulation air pump 92, a circulation air guide pipe 93, a first outlet 94, and a second outlet 95. The first outlet 94 and the second outlet 95 are fixedly installed at the upper and lower parts of the right end of the second separation chamber 91, respectively. The middle part of the lower end of the second separation chamber 91 is fixedly connected to the external circulation air pump 92. The upper part of the second separation chamber 91 and the lower part of the external circulation air pump 92 are both connected to the circulation air guide pipe 93. The circulation air guide pipe 93 is respectively connected to the first connecting pipe 462 and the second connecting pipe 82, so as to facilitate the separation of the bulged HCN and HCl and the recycling of the nitrogen.

[0050] A preparation method of o-methylbenzoyl nitrile comprises the following steps:

[0051] S1. o-Toluoyl chloride and acetonitrile are added to the pot 3 in the reaction chamber body 1, ethylene glycol catalyst is added, a certain amount of HCN is introduced from the HCN inlet 11, the stirring and air inlet mechanism 4 is started, the stirring blade 46 rotates around the support rod 45 to stir the reaction solution, and the HCN passes through the first connecting pipe 462 and the air outlet port 461 on the stirring blade 46 into the pot 3 to react with the o-Toluoyl chloride and acetonitrile to obtain o-Toluoyl nitrile and HCl as a by-product.

[0052] S2. Start the internal circulation mechanism 7, open the electromagnetic control valve 75, and the internal circulation pump 72 sends the HCN and HCl gases on the reaction liquid surface into the first separation chamber 71 for separation. The separated HCl gas is discharged and recovered from the HCl separation outlet 73, and the HCN gas returns to the pot body 3 through the first circulation pipe 74 to continue to react with the reaction solution to generate o-methylbenzoyl nitrile and by-product HCl.

[0053] S3. As HCN reacts with the reaction solution and the generated HCl is separated, the HCN contained in the lower chamber formed by the entire reaction chamber body 1 and the second trigger mechanism 6 will become less and less, and the air pressure will become lower and lower, causing the slide 62 in the second trigger mechanism 6 to slide downward along the limiting slide groove 61. When the fitting block 63 is pressed down and contacts the push rod 55 in the first trigger mechanism 5, the push rod 55 is pressed down to touch the first contact limiter 56. The first contact limiter 56 transmits a signal to the internal circulation pump 72. The internal circulation pump 72 increases the working power, increases the pressure of the adsorption and delivery gas, and transports a small amount of HCN through the first circulation pipe 74 to the pot body 3 to react with the reaction solution until the HCN and the reaction solution are completely reacted.

[0054] S4. Close the electromagnetic control valve 75 and introduce nitrogen to blow out the HCN and HCl in the liquid surface. The nitrogen enters the first connecting pipe 462 through the circulating air guide pipe 93 in the external circulation mechanism 9 and is then discharged from the gas outlet 461. Nitrogen is blown into the liquid surface after the reaction in the pot body 3. The stirring blade 46 rotates so that the continuously input nitrogen can continuously generate bubbles with the bottom wall of the pot body 3 as the spherical surface, thereby blowing out the HCN and HCl gases dissolved in the liquid.

[0055] S5. As nitrogen continues to flow in, the pressure in the lower chamber formed by the entire reaction chamber body 1 and the second trigger mechanism 6 will become increasingly greater, forcing the slide 62 in the second trigger mechanism 6 to slide upward along the direction of the limiting slide groove 61. When the touch slider 632 on the fitting block 63 is pressed to touch the second contact limiter 633, the second contact limiter 633 controls the adsorption electromagnet 635 to be in the open state, and the adsorption electromagnet 635 is adsorbed together with the adsorption iron block 84 in the positioning mechanism 8. At this time, the second connecting pipe 82 in the positioning mechanism 8 is inserted into the positioning slot 64 in the second trigger mechanism 6, and the sealing cover 65 is pushed out of the positioning slot 64 by the end of the second connecting pipe 82. At this time, the mixed gas in the lower chamber formed by the reaction chamber body 1 and the second trigger mechanism 6 can enter the second connecting pipe 82 through the connecting hole 85 and then enter the external circulation mechanism 9.

[0056] S6. The mixed gas contains nitrogen, HCN and HCl. The mixed gas enters the second separation chamber 91 and is separated. HCl and HCN are discharged and collected through the first outlet 94 and the second outlet 95 respectively. The nitrogen is driven by the external circulation air pump 92 and continues to enter the pot body 3 through the circulation air pipe 93 through the first connecting pipe 462. The reacted solution in the pot body 3 is again bulged out to separate and remove HCN and HCl.

[0057] S7. After HCN and HCl in the reaction solution have been separated, the reaction solution is fed into a corresponding device and distilled under reduced pressure to remove acetonitrile, leaving a crude o-methylbenzoyl nitrile product. The obtained crude o-methylbenzoyl nitrile product is subjected to high vacuum distillation to obtain an o-methylbenzoyl nitrile product.

[0058] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing o-methylbenzoyl nitrile, characterized in that: The preparation method of o-methylbenzoyl nitrile is realized by an o-methylbenzoyl nitrile preparation device, which comprises a reaction chamber body (1), a support platform (2) is provided on the bottom wall of the inner cavity of the reaction chamber body (1), a pot body (3) is provided on the upper end of the support platform (2), a stirring air intake mechanism (4) is provided in the middle of the bottom wall of the pot body (3), a first trigger mechanism (5) is provided on the upper part of the stirring air intake mechanism (4), a second trigger mechanism (6) is provided in the middle of the inner cavity of the reaction chamber body (1), a positioning mechanism (8) is provided on the upper part of the inner cavity of the reaction chamber body (1), an external circulation mechanism (9) is provided on the upper part of the positioning mechanism (8), two groups of air intake ports (10) are provided in the middle of the outer wall of the reaction chamber body (1), and a group of internal circulation mechanisms (7) are provided at each of the two groups of air intake ports (10), and an HCN inlet (11) is provided at the lower left part of the reaction chamber body (1). ); the first trigger mechanism (5) comprises a supporting chassis (51), a ball carrier (52), a placement groove (53), a placement block (54), a push rod (55), a first contact limiter (56) and a trigger spring (57); the middle part of the upper end of the supporting chassis (51) is fixedly connected to the ball carrier (52); a group of placement grooves (53) are provided on both sides of the upper end of the ball carrier (52); a group of placement blocks (54) are fixedly installed on the bottom wall of the placement groove (53); a group of push rods (55) are movably inserted into the inner cavity of the placement block (54); a group of trigger springs (57) are fixedly connected to the middle part of the lower end of the push rod (55); a group of first contact limiters (56) are fixedly installed on the middle part of the inner bottom wall of the placement block (54); the supporting chassis (51) is movably sleeved on the upper part of the support rod (45) to movably connect the first trigger mechanism (5) and the stirring air intake mechanism (4); The second trigger mechanism (6) comprises a limiting slide (61), a slide plate (62), a fitting block (63), a positioning slot (64) and a sealing cover (65). The limiting slide (61) has two groups, and a slide plate (62) is slidably connected between the two groups of limiting slides (61). The middle part of the lower end of the slide plate (62) is fixedly connected with a fitting block (63). A group of symmetrically distributed positioning slots (64) are opened on both sides of the lower end of the slide plate (62). A group of sealing covers (65) are movably inserted at the notch of the lower part of the positioning slot (64). The two groups of limiting slides (61) are respectively fixedly installed on the inner walls of the left and right sides of the reaction chamber body (1) to fix the second trigger mechanism (6) and the reaction chamber body (1) together; the internal circulation mechanism (7) comprises a first separation chamber (71), an internal circulation air pump (72), an HCl separation outlet (73), a first A circulation pipe (74) and an electromagnetic control valve (75); the right end of the first separation chamber (71) is fixedly connected to an internal circulation air pump (72); the internal circulation air pump (72) is electrically connected to the first contact limiter (56); and the right part of the internal circulation air pump (72) is fixedly connected to the air intake port (10); the middle part of the lower end of the first separation chamber (71) is connected to a first circulation pipe (74); a group of electromagnetic control valves (75) are installed at the right end of the air intake port (10) and the right end of the first circulation pipe (74); the other end of the first circulation pipe (74) passes through the outer wall of the reaction chamber body (1) and communicates with the inner cavity of the pot body (3); o-methylbenzoyl chloride and acetonitrile are put into the pot body (3) in the reaction chamber body (1), catalyst ethylene glycol is added, a certain amount of HCN is introduced from the HCN inlet (11), the stirring air intake mechanism (4) is started, and the reaction solution is stirred.

2. A method for preparing o-methylbenzoyl nitrile according to claim 1, wherein: The stirring air intake mechanism (4) comprises a driving motor (41), a transmission gear (42), a driven gear (43), a meshing gear (44), a support rod (45) and a stirring blade (46); the output end of the driving motor (41) is fixedly connected to the transmission gear (42); the left portion of the transmission gear (42) is meshed with the driven gear (43); the left portion of the driven gear (43) is meshed with the meshing gear (44); the middle portion of the upper end of the meshing gear (44) is fixedly plugged with a support rod (45); the support rod (45) passes through the middle portion of the bottom wall of the inner cavity of the pot body (3), and the support rod (45) is movably connected to the pot body (3); a stirring blade (46) is fixedly installed on the right side of the middle portion of the outer surface of the support rod (45), and the lower portion of the outer surface of the stirring blade (46) is in contact with the inner wall of the pot body (3).

3. A method for preparing o-methylbenzoyl nitrile according to claim 2, wherein: The lower portion of the outer surface of the stirring blade (46) is provided with a plurality of evenly distributed air outlets (461). The stirring blade (46) and the support rod (45) are both embedded with a first connecting pipe (462), and the first connecting pipe (462) is connected to the air outlet (461).

4. A method for preparing o-methylbenzoyl nitrile according to claim 3, wherein: A fitting cavity (631) is provided in the middle of the upper end of the fitting block (63), a touch slider (632) is slidably connected in the fitting cavity (631), a second contact limiter (633) is fixedly installed in the middle of the upper end of the touch slider (632), a connecting spring (634) is fixedly connected to the middle of the lower end of the touch slider (632), and a group of adsorption electromagnets (635) are fixedly connected to the upper parts of the left and right sides of the fitting block (63), and the adsorption electromagnets (635) are electrically connected to the second contact limiter (633).

5. A method for preparing o-methylbenzoyl nitrile according to claim 4, wherein: A group of positioning springs (651) are fixedly connected to the upper ends of the sealing covers (65), the upper parts of the positioning springs (651) are fixedly connected to the slot walls of the positioning slots (64), and the positioning springs (651) are in a tensioned state.

6. A method for preparing o-methylbenzoyl nitrile according to claim 5, wherein: The positioning mechanism (8) comprises a positioning plate (81), a second communicating tube (82), a fitting slot (83), an adsorption iron block (84) and a communicating hole (85); a group of second communicating tubes (82) are fixedly plugged into the left and right sides of the upper end of the positioning plate (81); a fitting slot (83) is provided in the middle of the lower end of the positioning plate (81); a group of adsorption iron blocks (84) are fixedly installed on the left and right side walls of the fitting slot (83); a plurality of groups of evenly distributed communicating holes (85) are provided on the outer surface of the lower end of the second communicating tube (82); the positioning mechanism (8) is fixedly connected to the reaction chamber body (1) through the positioning plate (81).

7. A method for preparing o-methylbenzoyl nitrile according to claim 6, wherein: The external circulation mechanism (9) comprises a second separation chamber (91), an external circulation air pump (92), a circulation air guide pipe (93), a first outlet (94) and a second outlet (95); the first outlet (94) and the second outlet (95) are fixedly installed at the upper and lower parts of the right end of the second separation chamber (91), respectively; the middle part of the lower end of the second separation chamber (91) is fixedly connected to the external circulation air pump (92); the upper part of the second separation chamber (91) and the lower part of the external circulation air pump (92) are both connected to the circulation air guide pipe (93); the circulation air guide pipe (93) is respectively connected to the first connecting pipe (462) and the second connecting pipe (82).

8. A method for preparing o-methylbenzoyl nitrile according to claim 7, wherein: The preparation method of the o-methylbenzoyl nitrile comprises the following steps: S1, o-methylbenzoyl chloride and acetonitrile are put into the pot body (3) in the reaction chamber body (1), ethylene glycol as a catalyst is added, a certain amount of HCN is introduced from the HCN inlet (11), the stirring air inlet mechanism (4) is started, the stirring blade (46) rotates around the support rod (45) to stir the reaction solution, and HCN passes through the first connecting pipe (462) and the air outlet (461) on the stirring blade (46) into the pot body (3) to react with o-methylbenzoyl chloride and acetonitrile to obtain o-methylbenzoyl nitrile and by-product HCl; S2, start the internal circulation mechanism (7), open the electromagnetic control valve (75), and the internal circulation pump (72) sends the HCN and HCl gases on the reaction liquid surface into the first separation chamber (71) for separation. The separated HCl gas is discharged and recovered from the HCl separation outlet (73). The HCN gas returns to the pot body (3) through the first circulation pipe (74) and continues to react with the reaction solution to generate o-methylbenzoyl nitrile and by-product HCl; S3. As HCN reacts with the reaction solution and the generated HCl is separated, the HCN contained in the lower chamber formed by the entire reaction chamber body (1) and the second trigger mechanism (6) will become less and less, and the air pressure will become lower and lower, so that the slide plate (62) in the second trigger mechanism (6) will slide down along the limiting slide groove (61). When the fitting block (63) is pressed down and contacts the top rod (55) in the first trigger mechanism (5), the top rod (55) is pressed down to touch the first contact limiter (56). The first contact limiter (56) transmits a signal to the internal circulation pump (72). The internal circulation pump (72) increases the working power, increases the pressure of the adsorption and delivery gas, and transports a small amount of HCN to the pot body (3) through the first circulation pipe (74) to react with the reaction solution until the HCN and the reaction solution are completely reacted. S4, close the electromagnetic control valve (75), introduce nitrogen to blow out the HCN and HCl in the liquid surface, the nitrogen enters the first connecting pipe (462) from the circulation air guide pipe (93) in the external circulation mechanism (9), and then is discharged from the outlet pipe (461), which has an impact on the reaction in the pot body (3). Nitrogen is blown into the liquid surface, and the stirring blade (46) rotates so that the continuously input nitrogen can continuously generate bubbles with the bottom wall of the pot body (3) as the spherical surface, thereby bulging out the HCN and HCl gases dissolved in the liquid; S5. As nitrogen continues to flow in, the pressure in the lower chamber formed by the entire reaction chamber body (1) and the second trigger mechanism (6) becomes increasingly greater, forcing the slide (62) in the second trigger mechanism (6) to slide upward along the direction of the limiting slide groove (61). When the touch slider (632) on the fitting block (63) is pressed to touch the second contact limiter (633), the second contact limiter (633) controls the adsorption electromagnet (635) to be in the open state, and the adsorption electromagnet (635) The second connecting pipe (82) in the positioning mechanism (8) is inserted into the positioning slot (64) in the second trigger mechanism (6), and the sealing cover (65) is pushed out of the positioning slot (64) by the end of the second connecting pipe (82). At this time, the mixed gas in the lower chamber formed by the reaction chamber body (1) and the second trigger mechanism (6) can enter the second connecting pipe (82) through the connecting hole (85) and then enter the external circulation mechanism (9); S6, the mixed gas contains nitrogen, HCN and HCl, and the mixed gas enters the second separation chamber (91). After separation, HCl and HCN are discharged and collected from the first outlet (94) and the second outlet (95) respectively, while nitrogen is continuously pumped by the external circulation air pump (92) through the circulation air guide pipe (93) and the first connecting pipe (462) into the pot body (3), and the reacted solution in the pot body (3) is again bulged out to separate HCN and HCl; S7. After HCN and HCl in the reaction solution have been separated, the reaction solution is fed into a corresponding device and distilled under reduced pressure to remove acetonitrile, leaving a crude o-methylbenzoyl nitrile product. The obtained crude o-methylbenzoyl nitrile product is subjected to high vacuum distillation to obtain an o-methylbenzoyl nitrile product.

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