Continuous synthesis device for 1-methyl-3-trifluoromethyl-5-hydroxypyrazole

Abstract

The utility model belongs to the technical field of chemical equipment, and discloses a continuous synthesis device for 1-methyl-3-trifluoromethyl-5-hydroxypyrazole, which comprises a head tank, an oximation reaction kettle, a pyridine reaction kettle, a crystallization kettle and a centrifugal machine which are sequentially communicated through pipelines, valves and pumps, the arrangement positions of the head tank, the oximation reaction kettle, the pyridine reaction kettle and the crystallization kettle are sequentially lowered; the oximation reaction kettle, the pyridine reaction kettle and the crystallization kettle are all provided with jackets, and the jackets are all communicated with cooling devices; the centrifugal machine is provided with a solid material outlet and a mother liquor outlet, and the solid material outlet of the centrifugal machine is communicated with the temporary storage tank through a pipeline. The device can be used for continuous production, and is simple to operate, uniform in reaction and high in production efficiency.

Description

Technical Field

[0001] The utility model belongs to the technical field of chemical equipment, and particularly relates to a continuous synthesis device for 1-methyl-3-trifluoromethyl-5-hydroxypyrazole. Background Art

[0002] Sulpirad, belonging to the isoxazole herbicide variety, is a new type, broad-spectrum, highly active, low-dose and safe pre-emergence soil treatment herbicide. Sulpirad can be safely used on a variety of major crops such as corn, cotton, peanut, wheat, sunflower, potato, etc., and can effectively control gramineous weeds such as Setaria, Digitaria, Echinochloa, etc., and can also better control broad-leaved weeds such as Amaranthus, Datura, Solanum, Abutilon, Chenopodium, etc. In the synthesis process of sulpirad, an important intermediate 1-methyl-3-trifluoromethyl-5-hydroxypyrazole is used. In the existing production process of 1-methyl-3-trifluoromethyl-5-hydroxypyrazole, methylhydrazine and hydrochloric acid are usually added to ethyl trifluoroacetoacetate to produce 1-methyl-3-trifluoromethyl-5-hydroxypyrazole. In the production process, the same reaction kettle is often used, which leads to multiple problems such as multiple feedings, multiple temperature adjustments, long service life and cleaning before feeding in the same reaction kettle, resulting in low production efficiency and high technical requirements for operators. Summary of the Invention

[0003] The technical problem to be solved by the utility model is to provide a continuous synthesis device for 1-methyl-3-trifluoromethyl-5-hydroxypyrazole, which overcomes the defects of the prior art, can carry out continuous production, and has simple operation, uniform reaction and high production efficiency.

[0004] To solve the above technical problem, the technical solution of the utility model is:

[0005] A continuous synthesis device for 1-methyl-3-trifluoromethyl-5-hydroxypyrazole, comprising a high-level tank, an oximation reaction kettle, a pyridine reaction kettle, a crystallization kettle and a centrifuge which are sequentially connected through pipelines, valves and pumps. The installation positions of the high-level tank, the oximation reaction kettle, the pyridine reaction kettle and the crystallization kettle decrease in sequence; the oximation reaction kettle, the pyridine reaction kettle and the crystallization kettle are all provided with jackets, and the jackets are all connected with a cooling device; the centrifuge is provided with a solid material outlet and a mother liquor outlet, and the solid material outlet of the centrifuge is connected to a temporary storage tank through a pipeline.

[0006] Preferably, the cooling device includes a cold source unit, a cold source inlet pipe and a cold source outlet pipe. The cold source unit is connected to the feed inlet of the jacket through a pump and the cold source inlet pipe, and the discharge outlet of the jacket is connected to the cold source unit through the cold source outlet pipe.

[0007] Preferably, the oximation reaction kettle, the pyridine reaction and the crystallization kettle are all provided with stirring devices.

[0008] Preferably, the mother liquor outlet of the centrifuge is connected to the mother liquor storage tank through a pipeline and a pump, and the mother liquor storage tank is connected to the crystallization kettle. Recycling the mother liquor for continuous crystallization can improve the yield.

[0009] Preferably, the temporary storage tank is sequentially connected to a washing tank and a dryer. The solid material after centrifugation is washed and then dried to obtain the finished product.

[0010] Preferably, the centrifuge is a belt centrifuge, with the model of PLD1600NF and the manufacturer of Jiangsu Saidel Pharmaceutical Machinery Manufacturing Co., Ltd.

[0011] Due to the adoption of the above technical solutions, the beneficial effects of the present utility model are as follows:

[0012] In the present utility model, methyl hydrazine is dropped from the elevated tank into the oximation reaction kettle to react with ethyl trifluoroacetoacetate to obtain an oximation intermediate; the oximation intermediate is then dropped into the pyridine reaction kettle to react with hydrochloric acid to obtain 1-methyl-3-trifluoromethyl-5-hydroxypyrazole; the obtained 1-methyl-3-trifluoromethyl-5-hydroxypyrazole is transported to the crystallization kettle for crystallization, and the crystallized liquid is centrifuged by a centrifuge to obtain 1-methyl-3-trifluoromethyl-5-hydroxypyrazole and mother liquor, and the mother liquor is pumped into the storage tank for biochemical treatment through a water pump; the oximation reaction temperature is maintained at 10°C to 15°C, the pyridine synthesis temperature is maintained at 20°C to 30°C, and the crystallization temperature is maintained below 5°C. Since three kettles are used for continuous reaction, the corresponding reaction kettle only needs to maintain the corresponding temperature, avoiding temperature adjustment. Moreover, the oximation intermediate is added to hydrochloric acid, and the feeding order is also adjusted compared with the prior art. In the prior art, hydrochloric acid is added to the oximation intermediate, and a large amount of salt will precipitate due to the rapid reaction of the oximation intermediate, resulting in the turbidity of the reaction solution, thus making the reaction uneven and the reaction slow. However, in the present utility model, the oximation intermediate is added to hydrochloric acid, and the oximation intermediate will quickly react with hydrochloric acid to form 1-methyl-3-trifluoromethyl-5-hydroxypyrazole, and the precipitated salt will be dispersed in water, without affecting stirring and fluidity, and promoting the reaction. Therefore, the present utility model can solve the problems of cumbersome operation, repeated temperature adjustment, and slow reaction in the same reaction kettle. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic structural diagram of an embodiment of the present utility model;

[0014] In the figure, 1, elevated tank; 2, oximation reaction kettle; 3, pyridine reaction kettle; 4, crystallization kettle; 5, centrifuge; 6, jacket; 7, cold source unit; 8, cold source inlet pipe; 9, cold source outlet pipe; 10, temporary storage tank. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0015] The present utility model will be further described below in conjunction with the drawings and embodiments.

[0016] Example 1:

[0017] As shown Figure 1 in the figure, a continuous synthesis device for 1-methyl-3-trifluoromethyl-5-hydroxypyrazole includes a high-level tank 1, an oximation reaction kettle 2, a pyridine reaction kettle 3, a crystallization kettle 4, and a centrifuge 5 that are sequentially connected through pipes (not marked), valves (not marked), and pumps (not marked). The installation positions of the high-level tank 1, the oximation reaction kettle 2, the pyridine reaction kettle 3, and the crystallization kettle 4 decrease in sequence; the oximation reaction kettle 2, the pyridine reaction kettle 3, and the crystallization kettle 4 are all provided with jackets 6, and the jackets 6 are all connected to a cooling device (not marked). The cooling device includes a cold source unit 7, a cold source inlet pipe 8, and a cold source outlet pipe 9; the centrifuge 5 is provided with a solid material outlet (not marked) and a mother liquor outlet (not marked), and the solid material outlet of the centrifuge 5 is connected to a temporary storage tank 10 through a pipe.

[0018] During actual production: First, use the cold source unit 7 and the cold source inlet pipe 8 to input coolant into the jackets 6 of the oximation reaction kettle 2 and the pyridine reaction kettle 3, and circulate the coolant through the cold source outlet pipe 9 to reduce the temperature in the oximation reaction kettle 2 to 10°C and the temperature in the pyridine reaction kettle 3 to 20°C; then, drop 500 kg of methylhydrazine aqueous solution into the oximation reaction kettle 2 containing 800 kg of ethyl trichloroacetoacetate added in advance through the high-level tank 1 for mixing. The dropping time of 500 kg of methylhydrazine aqueous solution is 1 hour. Then, under the conditions of 10°C to 15°C and a stirring speed of 45 r / min, carry out oximation reaction for 1 hour to obtain 1000 kg of oximation intermediate; drop the obtained oximation intermediate into the pyridine reaction kettle 3 containing 610 kg of dilute hydrochloric acid added in advance through a pipe for mixing. The dropping time is 1 hour. Then, under the conditions of 20°C to 30°C and a stirring speed of 45 r / min, react for 1 hour to obtain the crude product of 1-methyl-3-trifluoromethyl-5-hydroxypyrazole; the 1-methyl-3-trifluoromethyl-5-hydroxypyrazole synthesized in the pyridine reaction kettle 3 is transported to the crystallization kettle 4 through a pipe for crystallization, and stirred for 1 hour under the conditions of below 5°C and a stirring speed of 45 r / min; then, transport the crystallized material to the centrifuge 5 for filtration. The solid material obtained by filtration is first transported to the temporary storage tank 10 for temporary storage, and when a certain amount is stored, it is transported to a washing tank (not marked), washed and then dried to obtain 1-methyl-3-trifluoromethyl-5-hydroxypyrazole; the mother liquor obtained by centrifugation is transported to the mother liquor storage tank for temporary storage.

[0019] Through the above settings, after the reaction in the oximation reaction kettle 2 is completed, emptied, and cleaned, it can be refilled to carry out the next oximation reaction, and continue production downward in sequence, thus realizing continuous production.

[0020] It should be understood that these embodiments are only used to illustrate the present utility model and not to limit the scope of the present utility model. In addition, it should be understood that after reading the content taught by the present utility model, those skilled in the art can make various changes or modifications to the present utility model, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

Claims

1. A 1-methyl-3-trifluoromethyl-5-hydroxypyrazole continuous synthesis device, characterized in that: The invention comprises an elevated tank, an oximation reactor, a pyridine reactor, a crystallization reactor and a centrifuge which are sequentially connected through pipelines, valves and pumps, wherein the elevated tank, the oximation reactor, the pyridine reactor and the crystallization reactor are arranged at successively lower positions; the oximation reactor, the pyridine reactor and the crystallization reactor are all provided with jackets, and the jackets are all connected with a cooling device; the centrifuge is provided with a solid material outlet and a mother liquor outlet, and the solid material outlet of the centrifuge is connected to a temporary storage tank through a pipeline.

2. The 1-methyl-3-trifluoromethyl-5-hydroxypyrazole continuous synthesis device according to claim 1, characterized in that: The cooling device comprises a cold source unit, a cold source inlet pipe and a cold source outlet pipe. The cold source unit is connected to the feed port of the jacket through a pump and the cold source inlet pipe, and the outlet of the jacket is connected to the cold source unit through the cold source outlet pipe.

3. The 1-methyl-3-trifluoromethyl-5-hydroxypyrazole continuous synthesis device according to claim 1, characterized in that: The oximation reaction kettle, pyridine reaction kettle and crystallization kettle are all provided with stirring devices.

4. The 1-methyl-3-trifluoromethyl-5-hydroxypyrazole continuous synthesis device according to claim 1, characterized in that: The mother liquor outlet of the centrifuge is connected to the mother liquor storage tank through a pipeline and a pump, and the mother liquor storage tank is connected to the crystallization kettle.

5. The 1-methyl-3-trifluoromethyl-5-hydroxypyrazole continuous synthesis device according to claim 1, characterized in that: The temporary storage tank is sequentially connected with a washing tank and a drying machine.

6. The 1-methyl-3-trifluoromethyl-5-hydroxypyrazole continuous synthesis device according to claim 1, characterized in that: The centrifuge is a belt centrifuge.

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