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Preparation method of 6-chloronicotinic acid

A technology of chloronicotinic acid and cobalt acetate, which is applied in the field of catalytic oxidation to prepare 6-chloronicotinic acid, can solve the problems of three wastes treatment, and achieve the effects of low cost, good product quality and yield, and mild reaction conditions

Active Publication Date: 2014-02-12
常熟市联创化学有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0012] This method will produce a large amount of manganese dioxide solid residue, and in the process of industrialization, there will also be three wastes treatment problems

Method used

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  • Preparation method of 6-chloronicotinic acid
  • Preparation method of 6-chloronicotinic acid
  • Preparation method of 6-chloronicotinic acid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0036] In a 1000mL flask, add 450g of chlorobenzene, 100g of 2-chloro-5-methylpyridine, and 3g of cobalt acetate catalyst under stirring, heat the system up to 80°C, and feed oxygen, the oxygen flow rate is controlled at 0.4L / min, React under these conditions for 4 hours. After the reaction, the system was cooled to room temperature, filtered, and dried to obtain 119 g of a mixture of 6-chloronicotinic acid and cobalt acetate.

[0037] Put the above-mentioned mixed crude product in a 1000mL flask, add 600g of recrystallization solvent methanol, stir and raise the temperature to reflux, wait until the crude product of 6-chloronicotinic acid is completely dissolved, and keep it warm for 5min, the system is slowly cooled to 5°C, white crystals are precipitated, and the temperature is maintained at this After continuing to stir at internal temperature for 1 hour, filter, wash the filter cake once with a small amount of cooled methanol, and dry the obtained tidal product at 80°C fo...

Embodiment 2

[0040] In a 1000mL flask, add 600g of chlorobenzene, 100g of 2-chloro-5-picoline, and 1g of catalyst cobalt acetate under stirring, heat the system up to 70°C, and feed oxygen. The oxygen flow rate is controlled at 1.0L / min. Under these conditions, the reaction was carried out for 5 hours. After the reaction, the system was cooled to room temperature, filtered, and dried to obtain 107 g of a mixture of 6-chloronicotinic acid and cobalt acetate.

[0041] Put the above-mentioned mixed crude product in a 1000mL flask, add 550g of recrystallization solvent methanol, stir and raise the temperature to reflux, wait until the crude product of 6-chloronicotinic acid is completely dissolved, keep warm for 3min, the system cools down to 7°C, white crystals are precipitated, and the temperature is maintained at this temperature. Continue to stir at high temperature for 70 minutes, then filter off the crystallization mother liquor, and dry the obtained tidal product in an oven at 75° C. fo...

Embodiment 3

[0044] In a 1000mL flask, add 400g of chlorobenzene, 100g of 2-chloro-5-picoline, and 10g of catalyst cobalt acetate under stirring, heat the system up to 100°C, and feed in oxygen. The oxygen flow rate is controlled at 0.4L / min. Under these conditions, the reaction was carried out for 7 hours. After the reaction, the system was cooled to room temperature and filtered, and dried to obtain a mixture of 114g 6-chloronicotinic acid and cobalt acetate

[0045] Put the above-mentioned mixed crude product in a 1000mL flask, add 570g of recrystallization solvent methanol, stir and raise the temperature to reflux, wait until the crude 6-chloronicotinic acid is completely dissolved, keep warm for 7min, cool the system to 3°C, white crystals are precipitated, keep Continue to stir at high temperature for 90 minutes, then filter off the crystallization mother liquor, and dry the obtained tidal product in an oven at 90°C for 3 hours to obtain 95.2 g of genuine 6-chloronicotinic acid, with...

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PUM

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Abstract

The invention discloses a preparation method of 6-chloronicotinic acid. The method comprises the following steps: directly oxidizing 2-choro-5-methylpyridine used as an initial material by virtue of oxygen under the catalysis of cobalt acetate by taking chlorobenzene as a solvent, so as to prepare a 6-chloronicotinic acid crude product; recrystallizing to obtain a 6-chloronicotinic acid product. By adopting the method, a lot of acid or potassium permanganate and the like with large environmental pollution are avoided; the reaction condition is mild; the product quality and the yield achieve a higher level.

Description

technical field [0001] The invention relates to the field of synthesis of fine organic intermediates, in particular to a method for preparing 6-chloronicotinic acid by catalytic oxidation. Background technique [0002] 6-chloronicotinic acid is a key intermediate of drugs such as tazarotene, and can also be used in the field of synthesis of emerging pesticide products; the preparation methods of 6-chloronicotinic acid currently reported mainly include the following three methods: [0003] (1) Take 2-chloro-5-trichloromethylpyridine as raw material [0004] The method disclosed in patent CN1803772A and EP0092117B1 is to use 2-chloro-5-trichloromethylpyridine as a raw material, react with a large amount of inorganic acid, and then perform hydrolysis to obtain the product 6-chloronicotinic acid. [0005] [0006] This method needs to consume a large amount of acid, and in the industrialization process, there will be three wastes treatment problems. [0007] (2) Literature ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D213/803C07D213/80
CPCC07D213/80C07D213/803
Inventor 陈华
Owner 常熟市联创化学有限公司
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