Production method of aryl pyrazole nitrile

An arylpyrazole nitrile technology and a production method, which are applied in directions such as organic chemistry, can solve problems such as low yield, potential safety hazards, and difficulty in handling the three wastes, and achieve high yield, reduced side reactions, and shortened residence time. Effect

Pending Publication Date: 2020-04-17
江苏优普生物化学科技股份有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The patent reaction produces a large amount of waste acid, the "three wastes" are difficult to deal with, and the yield is low; patent CN1137090C discloses a 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoroform The preparation method of phenyl) pyrazole, sodium cyanide, ethyl cyanoacetate, paraformaldehyde react in ethanol hydrochloride to obtain ethyl 2,3-dicyanopropionate, then add ethanol hydrochloride, 2,6- Dichloro-4-trifluoromethylaniline, sodium nitrite, to obtain 2,3-dicyano-2-[2,6-dichloro-4-trifluoromethylphenyl)azo]propionic acid ethyl ester, and then cyclized with ammonia gas at 0°C, after extraction and crystallization, 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole was obtained , yield 78%
The patent uses highly toxic sodium cyanide, which poses a great safety hazard in production
Patent literature CN103396366B discloses a production method of 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole, 2,6-dichloro-4- Mix trifluoromethylaniline with acid, add ethyl 2,3-dicyanopropionate, add sodium nitrite or potassium nitrite at 5-15°C, add water phase after the reaction, and adjust the oil phase with concentrated ammonia water pH ≥ 11, after washing, suction filtration and drying, the target product is obtained with a yield of 83%. Although the process shows that sulfuric acid is not used, a large amount of hydrochloric acid or acetic acid solution is still used, and a large amount of waste water is generated after the synthesis

Method used

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  • Production method of aryl pyrazole nitrile
  • Production method of aryl pyrazole nitrile
  • Production method of aryl pyrazole nitrile

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0033] Reactor I is a horizontal tubular reactor made of DN32 glass-lined seamless steel pipe. The straight pipe part is equipped with a sleeve pipe that can be connected to frozen brine or circulating water for cooling. It has a built-in PTFE SK type static mixer. The rooms are connected by elbows, with an effective length of 60 meters and an effective volume of 40 liters. There are three thermocouples and a pH meter, and nitrite electrodes are installed in the middle of the reactor and before the outlet. The reactor can be divided into three sections and cooled with cooling media of different temperatures, so as to control different temperatures. The front end of each section is equipped with a feeding interface, and sodium nitrite or acid ethanol can be replenished when sodium nitrite or acid value is insufficient.

[0034]Add about 30% of commercially available acid ethanol (hydrogen chloride ethanol) into anhydrous ethanol to prepare 7-12% acid ethanol; add 98% 2,6-dichlo...

example 2

[0038] Frozen brine below 0°C was passed into the reactor jacket of the above example 1, and the flow rate of the chilled brine was reduced after normal circulation. The feed solution was then pumped into the reactor described in Example 1 at a flow rate of 1.00 liters / minute, while the suspension described in Example 1 was pumped into the reactor described in Example 1 at a flow rate of 0.20 liters / minute. The flow rate of frozen brine was adjusted to keep the temperature of the material in the reactor between 10 and 15°C. Monitor pH value and nitrous acid concentration, fine-tune the flow rate of the suspension, and control the nitrite concentration at the outlet of the reactor to be 0.1-0.5% and the pH value to be 1-5. The 2,6-dichloro-4-trifluoromethylaniline content was detected by sampling at the outlet of the reactor every 15 minutes, and the reaction was continued for 2 hours. The outlet of the reactor was 2,6-dichloro-4-trifluoromethylaniline. The average content was...

example 2～9

[0040] The experimental process of Example 2 is repeated with different flow rates, and the content of the 2,6-dichloro-4-trifluoromethylaniline material at the outlet of the reactor is as shown in Table 1:

[0041] Table 1 Diazo-coupling reaction at different flow rates at 10~15℃

[0042]

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Abstract

The invention discloses a production method of aryl pyrazole nitrile, which comprises the following steps: dissolving 2, 6-dichloro-4-trifluoromethylaniline and ethyl 2, 3-dicyanopropionate in an acidic solvent to form a solution, adding the solution and sodium nitrite or a suspension composed of sodium nitrite and an alcohol into a reactor at the same time, and reacting to obtain a synthetic solution 1; adding a reducing agent into the synthetic liquid 1 to terminate the reaction to obtain a synthetic liquid 2; adding an alkaline material into the synthetic liquid 2 to carry out alcoholysis and cyclization under an alkaline condition to obtain a synthetic liquid 3; and adding the synthetic liquid 3 into an acidic solvent for neutralization, desolventizing and refining to obtain a target product.

Description

technical field [0001] The present invention proposes a continuous process for synthesizing arylpyrazole nitriles. Background technique [0002] The arylpyrazole nitrile chemical name of the present invention is 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl) pyrazole, also known as pyrazole ring, which The structural formula is as follows: [0003] [0004] Arylpyrazoles are important intermediates of N-phenylpyrazole pesticides such as fipronil, ethiprole, butene-fipronil. The action principle of N-phenylpyrazole pesticides such as fipronil and ethiprole is to interfere with the chloride ion channel through the chloride channel regulated by γ-aminobutyric acid, destroy the activity of the normal central nervous system, and cause the death of insects. Due to this unique mechanism of action, this type of pesticide has significant characteristics different from conventional insecticides: this series of insecticides are effective against pests including Hemiptera...

Claims

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Application Information

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IPC IPC(8): C07D231/38
CPCC07D231/38
Inventor 张继钱施云云马成龙江飞顾佳林
Owner 江苏优普生物化学科技股份有限公司
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