Method for preparing 6-chloro-3-pyridinecarboxylic acid

A technology of pyridine carboxylate and its manufacturing method, which is applied in the direction of organic chemistry, etc., can solve the problems of difficulty in improving the purity, difficulty in separation, and high cost of 6-chloro-3-pyridine carboxylate, and achieve the depth of application, high product purity, and low cost. low effect

Inactive Publication Date: 2006-07-19
KANGPENG AGRO CHEM JIANGYAN
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Because the physical and chemical properties of these two substances are very close, the subsequent separation is very difficult, so the purity of pyridine 6-chloro-3-carboxylate is difficult to improve, and it is greatly restricted as a medicinal raw material, and the cost is high

Method used

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  • Method for preparing 6-chloro-3-pyridinecarboxylic acid
  • Method for preparing 6-chloro-3-pyridinecarboxylic acid

Examples

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Embodiment 1

[0012] Example 1: Put 600 grams of concentrated sulfuric acid into a 1000ml four-necked flask with a stirrer, thermometer and tail gas outlet pipe, turn on the stirring, and slowly flow 100 grams of 2-chloro-5-trichloromethylpyridine into the flask. Then, the temperature is slowly raised to 120°C. When the temperature reaches 80°C, hydrogen chloride gas begins to be released, and the lye is introduced through the tail gas outlet pipe for absorption. When the temperature reaches 110°C, start to keep the temperature, keep the temperature between 110-120°C for 2 hours to end the reaction, and lower the temperature to 30°C. Then, the reaction solution was slowly added to ice water composed of 1000 grams of ice and 2000 grams of water, and the reaction solution was added while stirring, and a white precipitate was precipitated. After the addition, continue to stir, then filter, and dry to obtain 87.8 g of 6-chloro-3-carboxylic acid pyridine. The purity of the liquid spectrum analysis i...

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Abstract

The disclosed preparation method with 2-chlorine-5-trichloromethylpyridine and inorganic acid as material for 6-chlorine-3-pyridine carboxylate comprises: 1. reacting the material for 1-4h at 50-140Deg; 2. mixing the former reaction liquor with water for reaction at 0-60Deg. This invention has purity up to 99.5% with low cost and no side reaction.

Description

Technical field [0001] The invention relates to a method for preparing 6-chloro-3-carboxylic acid pyridine. Background technique [0002] The existing production of 6-chloro-3-carboxylic acid pyridine is based on carboxylic acid pyridine as raw material, and 6-chloro-3-carboxylic acid pyridine is obtained through chlorination reaction. In the chlorination process, 2-chloropyridine is inevitably produced -3-carboxylic acid pyridine and other by-products. Since the physicochemical properties of these two substances are very close, the subsequent separation is very difficult, so the purity of 6-chloro-3-carboxylic acid pyridine is difficult to improve, which is greatly restricted as a medicinal raw material, and the cost is high. Summary of the invention [0003] The manufacturing method of 6-chloro-3-carboxylic acid pyridine of the present invention uses 2-chloro-5-trichloromethylpyridine and inorganic acid as raw materials to react to produce 6-chloro-3-carboxylic acid pyridine w...

Claims

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Application Information

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IPC IPC(8): C07D213/62
Inventor 张京董富金童连才于永年
Owner KANGPENG AGRO CHEM JIANGYAN
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