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2-chloro-3-cyanopyridine preparation process

A cyanopyridine and preparation technology, which is applied in the field of the preparation of intermediates in the chemical industry, can solve the problems of increasing the difficulty of enterprise wastewater treatment, environmental hazards, etc., and achieve the effect of good yield and increased yield

Inactive Publication Date: 2019-03-08
老河口市天和科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] At present, the common route for synthesizing 2-chloro-3-cyanopyridine is that 3-cyanopyridine is oxidized with hydrogen peroxide to obtain N-oxonicotinamide, and N-oxonicotinamide is chlorinated to obtain 2-chloro-3-cyanopyridine , a large amount of organic base needs to be used as a catalyst in the reaction process. Currently, the commonly used organic base is triethylamine. Therefore, this method is prone to produce a large amount of nitrogen-containing wastewater, which is harmful to the environment and increases the difficulty of wastewater treatment in enterprises.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] Weigh 50g of chloroform and add it to a 250ml three-necked flask, weigh 10g of N-oxonicotinic acid amide and add it to the three-necked flask, cool down to 15±5°C, weigh 20g of phosphorus oxychloride and add it dropwise to the three-necked flask with a controlled dropping time of 1.5h In the flask, after the dropwise addition is completed, then cool down to 10±5°C, weigh 10g of triethylamine and 1g of tri-n-propylamine and mix them evenly, and drop them into the three-necked flask at a controlled dropping time of 0.5h. After the dropwise addition, keep the temperature at Continue to stir at 5°C for 20 minutes, heat up to 25°C, keep stirring for 30 minutes, then raise the temperature to 50°C, keep stirring for 30 minutes, then raise the temperature to 95°C, keep stirring for 3 hours, and obtain the chloride reaction solution after the heat preservation, transfer the chloride reaction solution In the rotary evaporator, control the temperature at 50°C and the pressure at 2K...

Embodiment 2

[0019] Weigh 80g of dichloromethane and add it to a 250ml three-necked flask, weigh 10g of N-oxonicotinamide and add it to the three-necked flask, cool down to 15±5°C, weigh 30g of phosphorus oxychloride and add it dropwise to In the three-necked flask, after the dropwise addition is completed, cool down to 10±5°C, weigh 8g of diethylamine and 5g of di-n-propylamine and mix them evenly, and drop them into the three-necked flask for 1 hour. After the dropwise addition, keep the temperature at Continue to stir at 10°C for 30min, heat up to 35°C, keep stirring for 1h, then raise the temperature to 55°C, keep stirring for 1h, then raise the temperature to 97°C, keep stirring for 4h, after the heat preservation is completed, the chloride reaction solution is obtained, and the chloride reaction solution is transferred In the rotary evaporator, control the temperature at 60°C and the pressure at 5Kpa for rotary evaporation, until no obvious liquid flows out, measure 40ml of water into...

Embodiment 3

[0021] Weigh 100g of dichloroethane and add it to a 250ml three-necked flask, weigh 10g of N-oxonicotinamide and add it to the three-necked flask, cool down to 15±5°C, weigh 40g of phosphorus oxychloride and control the dropping time to 2.5h. Add it into the three-necked flask, after the dropwise addition is completed, then lower the temperature to 10±5°C, weigh 7g of triethylamine and 8g of n-butylamine and mix them evenly, control the dropping time for 1.5h and drop them into the three-necked flask, after the dropwise addition is completed, Keep the temperature at 15°C and continue to stir for 40min, then raise the temperature to 45°C, keep stirring for 1.5h, then raise the temperature to 60°C, keep stirring for 1.5h, then raise the temperature to 100°C, keep stirring for 5h, and obtain the chloride reaction solution after the heat preservation is completed. Transfer the chloride reaction liquid to a rotary evaporator, control the temperature at 70°C, and carry out rotary eva...

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PUM

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Abstract

The invention provides a 2-chloro-3-cyanopyridine preparation process which includes the steps: dissolving N-oxynicotinamide in an organic solvent; dripping phosphorus oxychloride at the temperature of 15+ / -5 DEG C; dripping organic alkali at the temperature of 10+ / -5 DEG C after dripping; keeping the temperature of 10+ / -5 DEG C to stir mixture for 30+ / -10 minutes after dripping; heating the mixture to reach the temperature of 35+ / -10 DEG C, and keeping the temperature for 1+ / -0.5 hour; heating the mixture to reach the temperature of 55+ / -5 DEG C, and keeping the temperature for 1+ / -0.5 hour;heating the mixture to reach the temperature of 95-100 DEG C, and keeping the temperature for 4+ / -1 hours to obtain chloride reaction solution after temperature keeping; performing reduced pressure distillation on the chloride reaction solution until flow out of visible liquid is omitted; adding water, controlling the temperature to reach 65+ / -5 DEG C, and stirring mixture for 2+ / -0.5 hour; cooling the mixture to reach the temperature of 20+ / -5 DEG C, stirring the mixture for 30+ / -10 minutes, and filtering the mixture to obtain a wet 2-chlorine-3-cyanopyridine product. According to the process, two mixed organic alkali substances serve as catalysts, and the yield of 2-chlorine-3-cyanopyridine is improved to some extent.

Description

technical field [0001] The invention relates to the technical field of preparation of kinetic chemical intermediates, in particular to a preparation process of 2-chloro-3-cyanopyridine. Background technique [0002] 2-chloronicotinic acid is an important fine chemical intermediate, which is used as an intermediate raw material for various drugs, insecticides, fungicides and herbicides, and 2-chloro-3-cyanopyridine is used to prepare 2-chloronicotinic acid key intermediates. [0003] At present, the common route for synthesizing 2-chloro-3-cyanopyridine is that 3-cyanopyridine is oxidized with hydrogen peroxide to obtain N-oxonicotinamide, and N-oxonicotinamide is chlorinated to obtain 2-chloro-3-cyanopyridine , need to use a large amount of organic bases as catalysts in the reaction process, currently commonly used organic bases are triethylamine, so this method is easy to produce a large amount of nitrogen-containing wastewater, which is harmful to the environment and incr...

Claims

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Application Information

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IPC IPC(8): C07D213/85B01J31/02
CPCC07D213/85B01J31/0237B01J31/0238B01J35/19
Inventor 齐鲲鹏
Owner 老河口市天和科技有限公司