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5-chloro-3-thiophenecarboxylic acid preparation method

A technology of thiophenecarboxylic acid and sulfuryl chloride, which is applied in the direction of organic chemistry, can solve the problem of low purity of 5-chloro-3-thiophenecarboxylic acid, and achieve the effects of improving purity and quality, reducing production cost, and being easy to obtain

Inactive Publication Date: 2016-04-13
CHONGQING TIANYI HENGHUA TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] In view of the above-mentioned problems in the prior art, the present invention proposes a preparation method of 5-chloro-3-thiophenecarboxylic acid, and the present invention solves the technical problem that the purity of 5-chloro-3-thiophenecarboxylic acid prepared by the prior art is not high

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  • 5-chloro-3-thiophenecarboxylic acid preparation method

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Embodiment 1

[0019] A preparation method of 5-chloro-3-thiophenecarboxylic acid, comprising the steps of: adding 128g of 3-thiophenecarboxylic acid and 600g of dichloromethane into a 1000ml three-necked flask, lowering the temperature to about -10°C, and adding dropwise 135g of sulfur into the three-necked flask Acyl chloride, after the dropwise addition, slowly raise the temperature to above 5°C to react for 1.5 hours; after the reaction, pour the reaction solution into about 1000ml of ice water, separate the reaction solution, separate the organic layer, dry the organic layer, filter and concentrate Obtain 135g of crude 5-chloro-3-thiophenecarboxylic acid; recrystallize the crude 5-chloro-3-thiophenecarboxylic acid obtained with 800ml of methyl tert-butyl ether, filter to obtain a crystalline solid, and then dry the crystalline solid to obtain 73g with a purity of 93.1 % pure 5-chloro-3-thiophenecarboxylic acid.

Embodiment 2

[0021] A preparation method of 5-chloro-3-thiophenecarboxylic acid, comprising the steps of: adding 128g of 3-thiophenecarboxylic acid and 600g of dichloromethane into a 1000ml three-necked flask, lowering the temperature to about -15°C, and adding dropwise 140g of sulfur into the three-necked flask Acyl chloride, after the dropwise addition, slowly raise the temperature to above 10°C to react for 2 hours; after the reaction, pour the reaction solution into about 1000ml of ice water, separate the reaction solution, separate the organic layer, dry the organic layer, filter and concentrate Obtain 165g of 5-chloro-3-thiophenecarboxylic acid crude product; The obtained 5-chloro-3-thiophenecarboxylic acid crude product is recrystallized with 800ml of methyl tert-butyl ether, filtered to obtain a crystalline solid, and then the crystalline solid is dried to obtain 100g with a purity of 97 % pure 5-chloro-3-thiophenecarboxylic acid.

Embodiment 3

[0023] A preparation method of 5-chloro-3-thiophenecarboxylic acid, comprising the steps of: adding 128g of 3-thiophenecarboxylic acid and 600g of dichloromethane into a 1000ml three-necked flask, lowering the temperature to about -20°C, and dripping 148g of sulfur into the three-necked flask Acyl chloride, after the dropwise addition, slowly raise the temperature to above 15°C to react for 3 hours; after the reaction, pour the reaction solution into about 1000ml of ice water, separate the reaction solution, separate the organic layer, dry the organic layer, filter and concentrate Obtain 170g of 5-chloro-3-thiophenecarboxylic acid crude product; The obtained 5-chloro-3-thiophenecarboxylic acid crude product is recrystallized with 800ml of methyl tert-butyl ether, filtered to obtain a crystalline solid, and then the crystalline solid is dried to obtain 101g with a purity of 97 % pure 5-chloro-3-thiophenecarboxylic acid.

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Abstract

The present invention discloses a 5-chloro-3-thiophenecarboxylic acid preparation method comprising the following steps: (1) adding 3-thiophenecarboxylic acid and an organic solvent into a reaction vessel, reducing the temperature to 0 DEG C to -30 DEG C, adding dropwise sulfuryl chloride into the reaction vessel, and after the addition is complete, heating slowly to 0 DEG C-20 DEG C for reaction for 1 to 3 hours; (2) after completion of the reaction, pouring the reaction solution into ice water, layering the reaction solution, separating an organic layer, drying the organic layer, filtering and concentrating to obtain a crude 5-chloro-3-thiophenecarboxylic acid product; (3) using methyl tert-butyl ether for recrystallizing the crude 5-chloro-3-thiophenecarboxylic acid product obtained in the step (2), filtering to obtain a crystal solid, and drying the crystal solid to obtain a pure 5-chloro-3-thiophenecarboxylic acid product. The novel 5-chloro-3-thiophenecarboxylic acid preparation method is provided, and a 5-chloro-3-thiophenecarboxylic acid product with a purity of 97% can be obtained.

Description

technical field [0001] The invention relates to a preparation method of 5-chloro-3-thiophenecarboxylic acid. Background technique [0002] 5-Chloro-3-thiophenecarboxylic acid is an important intermediate in chemical synthesis and new medicine synthesis. At present, the main method for preparing 5-chloro-3-thiophenecarboxylic acid is to use 3-thiophenecarboxylic acid as raw material, through N-chloro The chlorination of succinimide, the product 5-chloro-3-thiophenecarboxylic acid that obtains is not high in purity, and can't be refined and obtains the 5-chloro-3-thiophenecarboxylic acid of high purity. Contents of the invention [0003] In view of the above-mentioned problems in the prior art, the present invention proposes a preparation method of 5-chloro-3-thiophenecarboxylic acid, and the present invention solves the technical problem that the purity of 5-chloro-3-thiophenecarboxylic acid prepared by the prior art is not high . [0004] The chemical reaction formula of...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D333/38
CPCC07D333/38
Inventor 郑伟唐勇
Owner CHONGQING TIANYI HENGHUA TECH CO LTD