Continuous production system and production method of 1-(4-chlorphenyl)-3-pyrazole alcohol

Abstract

The invention belongs to the technical field of synthesis of organic compounds, and particularly discloses a continuous production system and a production method of 1-(4-chlorphenyl)-3-pyrazole alcohol. The method is used for solving the problems of low production efficiency, high operation cost and danger and large wastewater discharge of a traditional intermittent hydrogen peroxide oxidation process. The production system comprises a raw material premixing tank, a conveying pump, an air source, an ejector, a reaction unit, a pH adjusting tank, a continuous filter, a temporary storage tank, a continuous dryer and an ion resin exchanger, the reaction unit comprises a plurality of static mixing tubular continuous flow reactors which are connected in series, static mixing elements are arranged in the static mixing tubular continuous flow reactors, and heat exchange jackets are arranged outside the static mixing tubular continuous flow reactors; heat exchange jackets or coil pipes are arranged on the outer side walls of the raw material premixing tank and the pH adjusting tank; and the ion resin exchanger is provided with a backwashing port. According to the invention, full-process continuous production is realized, green and safe preparation is realized, and the production efficiency, the product yield and the product purity are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of organic compound synthesis, and in particular relates to a continuous production system and a production method of 1-(4-chlorophenyl)-3-pyrazole alcohol. Background Art

[0002] 1-(4-chlorophenyl)-3-pyrazolol is an important intermediate for synthetic drugs in the fields of medicine, chemical industry and pesticides, and has a very high market share. The main preparation route of 1-(4-chlorophenyl)-3-pyrazolol is the oxidation synthesis of 1-(4-chlorophenyl)pyrazolidine-3-one. The traditional production method of 1-(4-chlorophenyl)-3-pyrazolol is mainly based on the process of synthesizing 1-(4-chlorophenyl)-3-pyrazolol by oxidizing 1-(4-chlorophenyl)pyrazolidine-3-one with hydrogen peroxide. This process is a dangerous process, the reaction process is difficult to control, the product is easily over-oxidized, and has the defects of low yield, poor quality, long reaction time, high production cost, great safety hazards, and large wastewater discharge.

[0003] The existing production equipment for 1-(4-chlorophenyl)-3-pyrazolol is mainly intermittent reactors, and the production processes involving reaction, filtration and drying are mainly intermittent operations. The equipment occupies a large area, has high operating costs and a low level of automation. Therefore, it is urgent to introduce a new continuous production method for 1-(4-chlorophenyl)-3-pyrazolol to achieve green and safe 1-(4-chlorophenyl)-3-pyrazolol preparation industry upgrade. Summary of the invention

[0004] One object of the present invention is to provide a continuous production system of 1-(4-chlorophenyl)-3-pyrazolol, which effectively solves the problems of low production efficiency, high operating cost and hazard, and large wastewater discharge of traditional intermittent hydrogen peroxide oxidation process.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a continuous production system of 1-(4-chlorophenyl)-3-pyrazolol, comprising a raw material premixing tank, a delivery pump, an air source, an ejector, a reaction unit, a pH adjustment tank, a continuous filter, a temporary storage tank, a continuous dryer and an ion resin exchanger, wherein the reaction unit comprises a plurality of static mixing tubular continuous flow reactors connected in series, and the ion resin exchanger comprises an exchanger inlet at the top, a backwashing port at the bottom, a wastewater discharge port at the bottom and a flushing liquid outlet at the top.

[0006] The outlet of the raw material premixing tank is connected to the inlet of the delivery pump, the outlet of the delivery pump is connected to the inlet of the continuous phase pipeline of the ejector, the outlet of the air source is connected to the inlet of the discrete phase pipeline of the ejector, the outlet of the ejector is connected to the inlet of the reaction unit, the outlet of the reaction unit is connected to the inlet of the pH adjustment tank, the outlet of the pH adjustment tank is connected to the inlet of the continuous filter, the liquid phase outlet of the continuous filter is connected to the inlet of the temporary storage tank, the solid phase outlet of the continuous filter is connected to the inlet of the continuous dryer, the outlet of the temporary storage tank is connected to the exchanger inlet of the ion resin exchanger, and the flushing liquid outlet of the ion resin exchanger is connected to the inlet of the raw material premixing tank.

[0007] Furthermore, there are multiple raw material premixing tanks, which are arranged in parallel. During the raw material premixing process, the continuous output of the premixed raw materials is achieved through switching and coordination between the raw material premixing tanks.

[0008] Furthermore, a heat exchange jacket or a coil is provided on the outer side wall of the raw material premixing tank, and the coil can also be provided inside the tank body of the raw material premixing tank.

[0009] Furthermore, a static mixing element is provided inside the static mixing tubular continuous flow reactor, and a heat exchange jacket is provided outside the static mixing tubular continuous flow reactor.

[0010] Furthermore, there are multiple pH adjustment tanks, which are arranged in parallel, and the continuous output of the suspension is achieved by switching and cooperating between the pH adjustment tanks during the pH adjustment process. A heat exchange jacket or coil is provided on the outer wall of the pH adjustment tank, and the coil can also be arranged inside the tank body of the pH adjustment tank.

[0011] Furthermore, the raw material premixing tank is used to stir and mix the raw materials into uniform premixed raw materials; the delivery pump is used to deliver the premixed raw materials to the static mixing tube type continuous flow reactor of the reaction unit through the continuous phase pipeline of the ejector; the air source is used to provide air required for the reaction process; the ejector is used to inject air into the reaction pipeline to mix with the premixed raw materials in parallel; the static mixing tube type continuous flow reactor is used to catalyze the oxidation of 1-(4-chlorophenyl)pyrazolidine-3-one by oxygen in the air to synthesize 1-(4-chlorophenyl)-3-pyrazolol Oxidation reaction process; the pH adjustment tank is used to adjust the pH to make the liquid phase 1-(4-chlorophenyl)-3-pyrazolol after oxidation synthesis precipitate in the form of solid phase precipitation to form a suspension; the continuous filter is used for continuous solid-liquid separation of the suspension; the temporary storage tank is used for temporary storage of the mother liquor after filtration; the continuous dryer is used for continuous drying of the solid phase 1-(4-chlorophenyl)-3-pyrazolol; the ion resin exchanger is used to recover the transition metal ion catalyst, and the ion resin exchanger is used to return the liquid phase catalyst recovered after backwashing to the raw material premixing tank.

[0012] Another object of the present invention is to provide a continuous production method of 1-(4-chlorophenyl)-3-pyrazolol, which is applied to the continuous production system of 1-(4-chlorophenyl)-3-pyrazolol described in the above embodiment, comprising the following steps: S1, putting 1-(4-chlorophenyl)pyrazolidin-3-one, inorganic base, transition metal ion catalyst and water into a raw material premixing tank, stirring and mixing, and controlling the temperature at 20 to 50° C. to form a premixed raw material.

[0013] Among them, the molar ratio of 1-(4-chlorophenyl)pyrazolidine-3-one to the inorganic base is 1:1.1-1.8, the molar ratio of 1-(4-chlorophenyl)pyrazolidine-3-one to the transition metal ion catalyst is 1:0.001-0.02, and the mass fraction of 1-(4-chlorophenyl)pyrazolidine-3-one is 10%-40%.

[0014] S2. The premixed raw materials are transported to the static mixing tubular continuous flow reactor of the reaction unit through the continuous phase pipeline of the ejector by a delivery pump, and the air from the air source is ejected into the static mixing tubular continuous flow reactor of the reaction unit through the discrete phase pipeline by the ejector.

[0015] The 1-(4-chlorophenyl)pyrazolidine-3-one in the premixed raw materials and the oxygen in the air undergo an oxidation reaction in a static mixing tubular continuous flow reactor to obtain liquid-phase 1-(4-chlorophenyl)-3-pyrazolol.

[0016] The molar ratio of 1-(4-chlorophenyl)pyrazolidin-3-one to oxygen in the air is 1:0.55-0.85, the reaction temperature is 40-90°C, the reaction pressure is 0.1-1.6MPa, and the total residence time of the premixed raw materials in the reaction unit is 0.6-10min.

[0017] S3. The liquid phase 1-(4-chlorophenyl)-3-pyrazolol generated by the reaction enters a pH adjustment tank, hydrochloric acid is introduced into the pH adjustment tank to adjust the pH to 3-6, the temperature in the pH adjustment tank is controlled at 30-50° C., 1-(4-chlorophenyl)-3-pyrazolol is precipitated in the form of a solid phase, and the stirring time is 5-30 minutes; then the temperature is lowered to 20-30° C. to form a suspension.

[0018] S4. Pass the suspension through a continuous filter for continuous solid-liquid separation to separate the suspension into a solid phase 1-(4-chlorophenyl)-3-pyrazolol and a mother liquor.

[0019] S5. The separated solid phase 1-(4-chlorophenyl)-3-pyrazolol enters a continuous dryer at a drying temperature of 60 to 95° C. After drying, the 1-(4-chlorophenyl)-3-pyrazolol product is obtained.

[0020] S6. The mother liquor after separation continuously enters the temporary storage tank. When the mother liquor in the temporary storage tank reaches the upper volume limit of the temporary storage tank, the discharging operation is carried out. The mother liquor enters the ion resin exchanger and adsorbs the transition metal ion catalyst in the mother liquor through the ion resin in the ion resin exchanger. The mother liquor after adsorption is continuously discharged in the form of wastewater.

[0021] The discharge rate of the temporary storage tank is greater than the feed rate of the temporary storage tank. The mother liquor in the temporary storage tank gradually decreases and stops discharging after reaching the lower volume limit. The flushing liquid is introduced through the backwashing port of the ion resin exchanger to desorb the transition metal ion catalyst from the ion resin and return to the raw material premixing tank with the flushing liquid.

[0022] Furthermore, in step S1, there are two raw material premixing tanks, namely a first raw material premixing tank and a second raw material premixing tank. When the first raw material premixing tank outputs the premixed raw materials, the second raw material premixing tank performs a premixing operation on the raw materials. When the output of the premixed raw materials in the first raw material premixing tank is completed, the premixing operation on the raw materials is performed again, and the second raw material premixing tank is started to output the premixed raw materials. The continuous conveying process of the premixed raw materials is realized by switching and coordinating the first raw material premixing tank and the second raw material premixing tank.

[0023] Further, in step S3, there are two pH adjusting tanks, namely a first pH adjusting tank and a second pH adjusting tank. When the first pH adjusting tank performs pH adjustment to precipitate solid precipitation and discharge the suspension, the liquid phase 1-(4-chlorophenyl)-3-pyrazolol is transported into the second pH adjusting tank; after the suspension in the first pH adjusting tank is discharged, the liquid phase 1-(4-chlorophenyl)-3-pyrazolol is re-input into the first pH adjusting tank, and the liquid phase 1-(4-chlorophenyl)-3-pyrazolol stops entering the second pH adjusting tank, and the pH adjustment to precipitate solid precipitation and discharge the suspension are performed in the second pH adjusting tank; the continuous post-treatment process of the suspension is realized by switching and coordinating the first pH adjusting tank and the second pH adjusting tank.

[0024] Furthermore, in step S6, while the backwashing operation is being carried out, the separated mother liquor continuously enters the temporary storage tank, and when the volume upper limit in the temporary storage tank is reached again, step S6 is repeated to achieve continuous processing of the separated mother liquor.

[0025] Compared with the prior art, the beneficial technical effects of the present invention are: (1) The present invention relies on a static mixing tubular continuous flow reactor, a continuous filter and a continuous dryer to realize the full-process continuous production of the synthesis, filtration and drying of 1-(4-chlorophenyl)-3-pyrazolol, greatly improving the production efficiency, effectively reducing the equipment footprint, reducing the operating costs and operational risks, and realizing the green and safe 1-(4-chlorophenyl)-3-pyrazolol preparation industry upgrade.

[0026] (2) The present invention adopts a production method of 1-(4-chlorophenyl)pyrazolidine-3-one catalyzed by transition metal ions to replace the traditional hydrogen peroxide oxidation process, significantly reducing production costs and process risks, reducing the generation and discharge of wastewater, and achieving green and safe production.

[0027] (3) The present invention adopts a static mixing tubular continuous flow reactor to replace the traditional intermittent kettle reaction. By arranging a static mixing element with strong mixing effect and low resistance in the static mixing tubular continuous flow reactor, the gas-liquid two-phase mass transfer effect in the tube is effectively enhanced, the residence time in the reactor is accurately controlled, the reaction efficiency and process controllability are improved, the occurrence of excessive oxidation side reactions is avoided, and the output of 1-(4-chlorophenyl)-3-pyrazolol with high yield and high purity is achieved.

[0028] (4) The present invention realizes the recovery and reuse of liquid-phase transition metal ion catalysts through an ion resin exchanger, reduces the salt content in wastewater and the wastewater treatment pressure, and effectively reduces production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the connection structure of the continuous production system of 1-(4-chlorophenyl)-3-pyrazolol in Example 1.

[0030] Explanation of the reference numerals: first raw material premixing tank-1; second raw material premixing tank-2; first delivery pump-3; second delivery pump-4; air source-5; ejector-6; first pH adjustment tank-7; second pH adjustment tank-8; continuous filter-9; temporary storage tank-10; continuous dryer-11; ion resin exchanger-12; static mixing tubular continuous flow reactor-13; exchanger inlet-14; backwashing port-15; wastewater outlet-16; flushing liquid outlet-17; 1-(4-chlorophenyl)-3-pyrazolol product outlet-18. DETAILED DESCRIPTION

[0031] Example 1: Figure 1 As shown, the continuous production system of 1-(4-chlorophenyl)-3-pyrazolol includes a first raw material premixing tank 1, a second raw material premixing tank 2, a first delivery pump 3, a second delivery pump 4, an air source 5, an ejector 6, a reaction unit, a first pH adjustment tank 7, a second pH adjustment tank 8, a continuous filter 9, a temporary storage tank 10, a continuous dryer 11 and an ion resin exchanger 12.

[0032] The reaction unit includes three static mixing tubular continuous flow reactors 13 connected in series, wherein the interior of the static mixing tubular continuous flow reactor 13 is provided with a static mixing element, and the exterior of the static mixing tubular continuous flow reactor 13 is provided with a heat exchange jacket. The outer walls of the first raw material premixing tank 1, the second raw material premixing tank 2, the first pH adjustment tank 7, and the second pH adjustment tank 8 are all provided with heat exchange jackets or coils, and the coils can also be provided inside the tank bodies of the first raw material premixing tank 1, the second raw material premixing tank 2, the first pH adjustment tank 7, and the second pH adjustment tank 8. The ion resin exchanger 12 includes an exchanger inlet 14 at the top, a backwash port 15 at the bottom, a wastewater outlet 16 at the bottom, and a flushing liquid outlet 17 at the top.

[0033] The outlet of the first raw material premixing tank 1 is connected to the inlet of the first delivery pump 3, the outlet of the second raw material premixing tank 2 is connected to the inlet of the second delivery pump 4, the outlet of the first delivery pump 3 and the outlet of the second delivery pump 4 are both connected to the inlet of the continuous phase pipeline of the ejector 6, the outlet of the air source 5 is connected to the inlet of the discrete phase pipeline of the ejector 6, and the outlet of the ejector 6 is connected to the inlet of the reaction unit.

[0034] The outlet of the reaction unit is connected to the inlet of the first pH adjusting tank 7 and the inlet of the second pH adjusting tank 8, the outlet of the first pH adjusting tank 7 and the outlet of the second pH adjusting tank 8 are both connected to the inlet of the continuous filter 9, the liquid phase outlet of the continuous filter 9 is connected to the inlet of the temporary storage tank 10, the solid phase outlet of the continuous filter 9 is connected to the inlet of the continuous dryer 11, the outlet of the temporary storage tank 10 is connected to the exchanger inlet 14 of the ion resin exchanger 12, and the flushing liquid outlet 17 of the ion resin exchanger 12 is connected to the inlet of the first raw material premixing tank 1.

[0035] The first raw material premixing tank 1 and the second raw material premixing tank 2 are both used to stir and mix the raw materials into uniform premixed raw materials; the first delivery pump 3 and the second delivery pump 4 are both used to deliver the premixed raw materials through the continuous phase pipeline of the ejector 6 to the static mixing tube type continuous flow reactor 13 of the reaction unit; the air source 5 is used to provide the air required for the reaction process; the ejector 6 is used to inject air into the reaction pipeline to mix with the premixed raw materials in parallel; the static mixing tube type continuous flow reactor 13 is used to catalyze the oxidation of 1-(4-chlorophenyl)pyrazolidine-3-one by oxygen in the air to synthesize 1-(4-chlorophenyl)-3-pyrazole The oxidation reaction process of alcohol; the first pH adjustment tank 7 and the second pH adjustment tank 8 are used to adjust the pH to make the liquid phase 1-(4-chlorophenyl)-3-pyrazolol after oxidation synthesis precipitate in the form of solid phase precipitation to form a suspension; the continuous filter 9 is used for continuous solid-liquid separation of the suspension; the temporary storage tank 10 is used for temporary storage of the mother liquor after filtration; the continuous dryer 11 is used for continuous drying of the solid phase 1-(4-chlorophenyl)-3-pyrazolol; the ion resin exchanger 12 is used to recover the transition metal ion catalyst, and the ion resin exchanger 12 is used to return the liquid phase catalyst recovered after backwashing to the first raw material premixing tank 1.

[0036] Example 2: A continuous production method for 1-(4-chlorophenyl)-3-pyrazolol, applied to the continuous production system of 1-(4-chlorophenyl)-3-pyrazolol described in Example 1, comprising the following steps: (1) adding 24 L of water to the first raw material premixing tank 1 and the second raw material premixing tank 2 respectively, and then slowly adding 852.8 g of sodium hydroxide, 4136.8 g of 1-(4-chlorophenyl)pyrazolidine-3-one and 40 g of ferric chloride under stirring, and stirring evenly at 35°C to form a premixed raw material.

[0037] (2) Start the first delivery pump 3 to deliver the premixed raw material in the first raw material premixing tank 1 to the static mixing tubular continuous flow reactor 13 of the reaction unit through the continuous phase pipeline of the ejector 6; while starting the first delivery pump 3, start the air source 5 to eject air through the discrete phase pipeline of the ejector 6 into the static mixing tubular continuous flow reactor 13 of the reaction unit.

[0038] When the premixed raw materials in the first raw material premixing tank 1 are transported, the first delivery pump 3 is turned off, and the second delivery pump 4 is started to continue to transport the premixed raw materials in the second raw material premixing tank 2. The first raw material premixing tank 1 repeats the loading and stirring process to ensure continuous transportation of the premixed raw materials.

[0039] The 1-(4-chlorophenyl)pyrazolidin-3-one in the premixed raw material and the oxygen in the air undergo an oxidation reaction in the static mixing tubular continuous flow reactor 13, and the molar ratio of 1-(4-chlorophenyl)pyrazolidin-3-one to the oxygen in the air in the static mixing tubular continuous flow reactor 13 is controlled to be 1:0.65, and the reaction pressure is 0.6 MPa; the total residence time of the premixed raw material in the reaction unit is 1.2 min, and the reaction temperature is controlled to be 50° C. by using the heat exchange jacket of the static mixing tubular continuous flow reactor 13.

[0040] (3) The liquid 1-(4-chlorophenyl)-3-pyrazolol obtained by the oxidation reaction is continuously discharged from the outlet of the static mixing tubular continuous flow reactor 13 and first input into the first pH adjustment tank 7. After reaching the target liquid level, the input is stopped. Hydrochloric acid is introduced into the first pH adjustment tank 7 to adjust the pH to 5, and the temperature in the tank is controlled at 50°C. After stirring for 10 minutes, the liquid 1-(4-chlorophenyl)-3-pyrazolol is completely precipitated in the form of solid phase precipitation. The heat exchange jacket of the first pH adjustment tank 7 is used to cool down to 20-30°C to form a suspension.

[0041] (4) The suspension in the first pH adjustment tank 7 is transported to the continuous filter 9 for continuous solid-liquid separation to separate the solid phase 1-(4-chlorophenyl)-3-pyrazolol and the mother liquor.

[0042] In step (3), when the liquid phase 1-(4-chlorophenyl)-3-pyrazolol stops being input into the first pH adjustment tank 7, the liquid phase 1-(4-chlorophenyl)-3-pyrazolol starts to be input into the second pH adjustment tank 8; in step (4), after the suspension in the first pH adjustment tank 7 is emptied, the second pH adjustment tank 8 repeats the pH adjustment and continuous filtration operations in steps (3) and (4); the pH adjustment and continuous filtration operation time in the first pH adjustment tank 7 matches the input time of the liquid phase 1-(4-chlorophenyl)-3-pyrazolol in the second pH adjustment tank 8; the switching and coordination between the first pH adjustment tank 7 and the second pH adjustment tank 8 ensures the continuous post-treatment of the liquid phase 1-(4-chlorophenyl)-3-pyrazolol.

[0043] (5) The solid phase outlet of the continuous filter 9 is connected to the inlet of the continuous dryer 11. The separated solid phase 1-(4-chlorophenyl)-3-pyrazolol enters the continuous dryer 11 at a drying temperature of 70°C. After drying, the solid phase 1-(4-chlorophenyl)-3-pyrazolol is continuously discharged through the 1-(4-chlorophenyl)-3-pyrazolol product outlet 18. The HPLC detection shows that the 1-(4-chlorophenyl)-3-pyrazolol content is 95.6%, and the product yield is 92%.

[0044] (6) The liquid phase outlet of the continuous filter 9 is connected to the inlet of the temporary storage tank 10, and the mother liquid filtered and separated in step (4) continuously enters the temporary storage tank 10.

[0045] (7) When the mother liquor in the temporary storage tank 10 reaches the upper limit of volume, the discharge operation is carried out, and the mother liquor enters the ion resin exchanger 12 and the Fe in the mother liquor is adsorbed by the ion resin 3+ The discharge rate of the temporary storage tank 10 is greater than the feed rate. The mother liquid in the temporary storage tank 10 gradually decreases and stops discharging after reaching the lower limit of volume. The flushing liquid is introduced through the backwashing port 15 at the side end of the ion resin exchanger 12 to make Fe 3+ Desorbed from the ion resin and returned to the first raw material premixing tank 1 with the flushing liquid from the flushing liquid outlet 17. The Fe 3+ The mother liquor after adsorption is discharged from the wastewater outlet 16.

[0046] While the backwashing operation is being carried out, the mother liquor filtered and separated in step (4) continuously enters the temporary storage tank 10. When the upper limit of the mother liquor volume in the temporary storage tank 10 is reached again, step (7) is repeated to achieve continuous treatment of the separated mother liquor.

[0047] Example 3: A continuous production method of 1-(4-chlorophenyl)-3-pyrazolol is applied to the continuous production system of 1-(4-chlorophenyl)-3-pyrazolol described in Example 1.

[0048] The difference between this embodiment and embodiment 2 is that: in step (1), cuprous chloride is used as the transition metal ion catalyst instead of ferric chloride, and the added mass of cuprous chloride is 23.76 g; in step (2), the total residence time of the premixed raw materials in the reaction unit is 1.5 min, and the reaction temperature is controlled at 63° C. by the heat exchange jacket of the static mixing tubular continuous flow reactor 13.

[0049] In this embodiment, the content of 1-(4-chlorophenyl)-3-pyrazolol was 95.1% by HPLC, and the product yield was 97%.

[0050] Example 4: A continuous production method of 1-(4-chlorophenyl)-3-pyrazolol is applied to the continuous production system of 1-(4-chlorophenyl)-3-pyrazolol described in Example 1.

[0051] The difference between this embodiment and embodiment 2 is that: in step (1), the transition metal ion catalyst is potassium ferrocyanide instead of ferric chloride, and the added mass of potassium ferrocyanide is 13.17 g; in step (1), the inorganic base is potassium hydroxide instead of sodium hydroxide, and the added mass of potassium hydroxide is 1178.31 g; in step (2), the total residence time of the premixed raw materials in the reaction unit is 0.9 min, and the reaction temperature is controlled at 80° C. by the heat exchange jacket of the static mixing tubular continuous flow reactor 13; in step (3), hydrochloric acid is introduced to adjust the pH to 3.5, and the stirring time is 15 min.

[0052] In this embodiment, the content of 1-(4-chlorophenyl)-3-pyrazolol was 97% by HPLC, and the product yield was 95.4%.

[0053] Comparative Example 1: This comparative example adopts the conventional intermittent hydrogen peroxide oxidation process to produce 1-(4-chlorophenyl)-3-pyrazolol. The molar ratio of 1-(4-chlorophenyl)pyrazolidine-3-one to hydrogen peroxide in the reactor is 1.0:1.2-1.8, the temperature in the reactor is controlled to be 75°C-90°C, the hydrogen peroxide dripping time is 2-3h, and the temperature needs to be kept for 0.5h after the dripping is completed; after the reaction is completed, the temperature is lowered to 35°C-40°C, 30% hydrochloric acid is dripped, the pH is adjusted to 5, and after stirring for 1h, centrifugal filtration and drying are performed. The maximum content of 1-(4-chlorophenyl)-3-pyrazolol in the obtained product is 90% by HPLC, and the product yield is 75%-82%.

[0054] Based on the experimental results of Examples 2-4 and Comparative Example 1, it can be seen that compared with Comparative Example 1, the continuous production method of 1-(4-chlorophenyl)-3-pyrazole alcohol provided by Example 2-4 achieves the output of 1-(4-chlorophenyl)-3-pyrazole alcohol with high yield and high purity.

[0055] The present invention adopts transition metal ions (Fe 3+ and Cu + )The production method of 1-(4-chlorophenyl)pyrazolidine-3-one by catalytic air oxidation has replaced the traditional hydrogen peroxide oxidation process, significantly reducing production costs and process risks, reducing the generation and discharge of wastewater, and achieving green and safe production.

[0056] The present invention adopts a static mixing tubular continuous flow reactor 13 to replace the traditional intermittent kettle reaction. By arranging a static mixing element with strong mixing effect and low resistance in the static mixing tubular continuous flow reactor 13, the gas-liquid two-phase mass transfer effect in the tube is effectively enhanced, the residence time in the reactor is accurately controlled, the reaction efficiency and process controllability are improved, the occurrence of excessive oxidation side reactions is avoided, and the output of 1-(4-chlorophenyl)-3-pyrazolol with high yield and high purity is achieved.

[0057] The present invention realizes the recovery and reuse of the liquid-phase transition metal ion catalyst through the ion resin exchanger 12, reduces the salt content in the wastewater and the wastewater treatment pressure, and effectively reduces the production cost.

[0058] The present invention relies on a static mixing tubular continuous flow reactor 13, a continuous filter 9 and a continuous dryer 11 to realize the full-process continuous production of synthesis, filtration and drying of 1-(4-chlorophenyl)-3-pyrazolol, greatly improves production efficiency, effectively reduces the floor space occupied by equipment, reduces operating costs and operational risks, and realizes green and safe 1-(4-chlorophenyl)-3-pyrazolol preparation industry upgrading.

[0059] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A continuous production system of 1-(4-chlorophenyl)-3-pyrazolol, characterized in that: It includes a raw material premixing tank, a delivery pump, an air source, an ejector, a reaction unit, a pH adjustment tank, a continuous filter, a temporary storage tank, a continuous dryer and an ion resin exchanger, wherein the reaction unit includes a plurality of static mixing tubular continuous flow reactors connected in series, and the ion resin exchanger includes an exchanger inlet at the top, a backwashing port at the bottom, a wastewater outlet at the bottom and a flushing liquid outlet at the top; The outlet of the raw material premixing tank is connected to the inlet of the delivery pump, the outlet of the delivery pump is connected to the inlet of the continuous phase pipeline of the ejector, the outlet of the air source is connected to the inlet of the discrete phase pipeline of the ejector, the outlet of the ejector is connected to the inlet of the reaction unit, the outlet of the reaction unit is connected to the inlet of the pH adjustment tank, the outlet of the pH adjustment tank is connected to the inlet of the continuous filter, the liquid phase outlet of the continuous filter is connected to the inlet of the temporary storage tank, the solid phase outlet of the continuous filter is connected to the inlet of the continuous dryer, the outlet of the temporary storage tank is connected to the exchanger inlet of the ion resin exchanger, and the flushing liquid outlet of the ion resin exchanger is connected to the inlet of the raw material premixing tank; The raw material premixing tank is used to stir and mix the raw materials into uniform premixed raw materials, the delivery pump is used to deliver the premixed raw materials to the static mixing tube type continuous flow reactor of the reaction unit through the continuous phase pipeline of the ejector, the air source is used to provide air required for the reaction process, the ejector is used to inject air into the reaction pipeline to mix with the premixed raw materials in parallel, and the static mixing tube type continuous flow reactor is used to carry out an oxidation reaction process of catalytically oxidizing 1-(4-chlorophenyl)pyrazolidine-3-one through oxygen in the air to synthesize 1-(4-chlorophenyl)-3-pyrazolol; The pH adjustment tank is used to adjust the pH so that the liquid phase 1-(4-chlorophenyl)-3-pyrazolol synthesized by oxidation is precipitated in the form of solid phase precipitation to form a suspension; The continuous filter is used for continuous solid-liquid separation of the suspension, the temporary storage tank is used for temporary storage of the mother liquor after filtration, and the continuous dryer is used for continuous drying of solid-phase 1-(4-chlorophenyl)-3-pyrazolol; The ion resin exchanger is used to recover the transition metal ion catalyst, and the ion resin exchanger is also used to return the liquid phase catalyst recovered after backwashing to the raw material premixing tank.

2. The continuous production system of 1-(4-chlorophenyl)-3-pyrazolol according to claim 1, characterized in that: There are multiple raw material premixing tanks, which are arranged in parallel. During the raw material premixing process, the continuous output of the premixed raw materials is achieved through switching and coordination between the raw material premixing tanks.

3. The continuous production system of 1-(4-chlorophenyl)-3-pyrazolol according to claim 2, characterized in that: A heat exchange jacket or coil is provided on the outer side wall of the raw material premixing tank.

4. The continuous production system of 1-(4-chlorophenyl)-3-pyrazolol according to claim 3, characterized in that: A static mixing element is arranged inside the static mixing tubular continuous flow reactor, and a heat exchange jacket is arranged outside the static mixing tubular continuous flow reactor.

5. The continuous production system of 1-(4-chlorophenyl)-3-pyrazolol according to claim 4, characterized in that: There are multiple pH adjustment tanks, which are arranged in parallel. During the pH adjustment process, the continuous output of the suspension is achieved by switching between the pH adjustment tanks. The outer side wall of the pH adjustment tank is provided with a heat exchange jacket or a coil.

6. A continuous production method of 1-(4-chlorophenyl)-3-pyrazolol, characterized in that: The continuous production system of 1-(4-chlorophenyl)-3-pyrazolol used in any one of claims 1 to 5 comprises the following steps: S1. Put 1-(4-chlorophenyl)pyrazolidin-3-one, inorganic base, transition metal ion catalyst and water into a raw material premixing tank, stir and mix, and control the temperature at 20-50° C. to form a premixed raw material; The molar ratio of 1-(4-chlorophenyl)pyrazolidin-3-one to the inorganic base is 1:1.1-1.8, the molar ratio of 1-(4-chlorophenyl)pyrazolidin-3-one to the transition metal ion catalyst is 1:0.001-0.02, and the mass fraction of 1-(4-chlorophenyl)pyrazolidin-3-one is 10%-40%; S2, delivering the premixed raw materials to the static mixing tubular continuous flow reactor of the reaction unit through the continuous phase pipeline of the ejector by a delivery pump, and injecting air from the air source into the static mixing tubular continuous flow reactor of the reaction unit through the discrete phase pipeline by the ejector; The 1-(4-chlorophenyl)pyrazolidin-3-one in the premixed raw material and the oxygen in the air undergo an oxidation reaction in a static mixing tubular continuous flow reactor to obtain liquid 1-(4-chlorophenyl)-3-pyrazolol; The molar ratio of 1-(4-chlorophenyl)pyrazolidin-3-one to oxygen in the air is 1:0.55-0.85, the reaction temperature is 40-90° C., the reaction pressure is 0.1-1.6 MPa, and the total residence time of the premixed raw materials in the reaction unit is 0.6-10 min; S3, the liquid phase 1-(4-chlorophenyl)-3-pyrazolol generated by the reaction enters a pH adjustment tank, hydrochloric acid is introduced into the pH adjustment tank to adjust the pH to 3-6, the temperature in the pH adjustment tank is controlled at 30-50° C., 1-(4-chlorophenyl)-3-pyrazolol is precipitated in the form of a solid phase, and the stirring time is 5-30 minutes; then the temperature is lowered to 20-30° C. to form a suspension; S4, passing the suspension into a continuous filter for continuous solid-liquid separation to separate the suspension into a solid phase 1-(4-chlorophenyl)-3-pyrazolol and a mother liquor; S5, the separated solid phase 1-(4-chlorophenyl)-3-pyrazolol enters a continuous dryer at a drying temperature of 60 to 95° C., and after drying, a 1-(4-chlorophenyl)-3-pyrazolol product is obtained; S6, the mother liquor after separation continuously enters the temporary storage tank, and when the mother liquor in the temporary storage tank reaches the upper limit of the volume of the temporary storage tank, the discharging operation is performed, and the mother liquor enters the ion resin exchanger and adsorbs the transition metal ion catalyst in the mother liquor through the ion resin in the ion resin exchanger, and the mother liquor after adsorption is continuously discharged in the form of wastewater; The discharge rate of the temporary storage tank is greater than the feed rate of the temporary storage tank. The mother liquor in the temporary storage tank gradually decreases and stops discharging after reaching the lower volume limit. The flushing liquid is introduced through the backwashing port of the ion resin exchanger to desorb the transition metal ion catalyst from the ion resin and return to the raw material premixing tank with the flushing liquid.

7. The continuous production method of 1-(4-chlorophenyl)-3-pyrazolol according to claim 6, characterized in that: In step S1, there are two raw material premixing tanks, namely a first raw material premixing tank and a second raw material premixing tank. When the first raw material premixing tank outputs the premixed raw materials, the second raw material premixing tank performs the premixing operation of the raw materials. When the premixed raw materials in the first raw material premixing tank are output, the premixing operation of the raw materials is performed again, and the second raw material premixing tank is started to output the premixed raw materials. The continuous conveying process of the premixed raw materials is realized by switching and coordinating the first raw material premixing tank and the second raw material premixing tank.

8. The continuous production method of 1-(4-chlorophenyl)-3-pyrazolol according to claim 7, characterized in that: In step S3, there are two pH adjustment tanks, namely a first pH adjustment tank and a second pH adjustment tank. When the first pH adjustment tank performs pH adjustment to precipitate solids and discharge the suspension, the liquid phase 1-(4-chlorophenyl)-3-pyrazolol is transported into the second pH adjustment tank. When the suspension in the first pH adjustment tank is discharged, the liquid phase 1-(4-chlorophenyl)-3-pyrazolol is re-input into the first pH adjustment tank, and the liquid phase 1-(4-chlorophenyl)-3-pyrazolol stops entering the second pH adjustment tank, and the pH is adjusted in the second pH adjustment tank to precipitate solid precipitation and discharge the suspension; the continuous post-treatment process of the suspension is realized by switching and coordinating the first pH adjustment tank and the second pH adjustment tank.

9. The continuous production method of 1-(4-chlorophenyl)-3-pyrazolol according to claim 8, characterized in that: In step S6, while the backwashing operation is being carried out, the separated mother liquor continuously enters the temporary storage tank. When the volume upper limit in the temporary storage tank is reached again, step S6 is repeated to achieve continuous processing of the separated mother liquor.

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