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Synthetic method of 2-thiopheneacetic acid

A technology of thiopheneacetic acid and synthesis method, which is applied in the direction of organic chemistry, can solve the problems of low final yield, difficulty in product purification, and poor selectivity, and achieve good oxidation selectivity, high product yield, and less impurities.

Inactive Publication Date: 2019-07-12
QINGDAO FRONTIERCHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, this process will produce a large amount of sulfur-containing and amine-containing wastewater, and the yield is only 20.9%
[0005] 2. British patent 1122658 reported that thiophene reacted with N,N-dimethylformamide in the presence of phosphorus oxychloride to obtain 2-thiophene carboxaldehyde, and then reacted with sodium cyanide and chloroform, and hydrogenated the resulting product to obtain 2- Thiophene acetonitrile is then hydrolyzed to obtain 2-thiophene acetic acid. This method requires the use of the highly toxic substance sodium cyanide and the use of a high-concentration platinum catalyst. Considering safety and economy, it is not suitable for industrial production
The intermediate product 2-chloromethylthiophene obtained by this method is a kind of tear gas substance, which is unstable and cannot be stored for a long time, and there is a danger of explosion when it is airtight
[0007] 4. Chinese patent 103467441A reports that thiophene reacts with methyl chloroacetate Friedel-Crafts to generate methyl thiophene acetate, which is then hydrolyzed to produce 2-thiophene acetic acid. Although this process has a short route, the selectivity is poor, making it difficult to purify the product. The final yield not tall

Method used

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  • Synthetic method of 2-thiopheneacetic acid

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Effect test

Embodiment 1

[0028] The present embodiment provides a kind of synthetic method of 2-thiopheneacetic acid, comprises the following steps:

[0029] (1) The three-necked flask is equipped with a mechanical stirrer, a thermometer, and a dropping funnel. Under nitrogen protection, 10.8g (0.2mol) of sodium methoxide and 135mL of methanol are added to the flask, cooled to -10°C, and 22.43g of 2-thiophenecarbaldehyde ( 0.2mol) and 26.05g (0.24mol) of methyl chloroacetate, the temperature was controlled at -10°C to 0°C, after the dropwise addition was completed, the mixture was kept stirring for 2 hours. Control the temperature at -10°C to 0°C, add 42.7g of sodium hydroxide solution (30%, 0.32mol) dropwise and let it stand still. After the dropwise addition is complete, keep stirring for 1 hour and set aside.

[0030] (2) Separately prepare a three-necked flask equipped with mechanical stirring, a thermometer, and a dropping funnel. Prepare 10% hydrochloric acid (0.6mol) in the flask, cool down to ...

Embodiment 2

[0032] The present embodiment provides a kind of synthetic method of 2-thiopheneacetic acid, comprises the following steps:

[0033] (1) The three-necked flask is equipped with a mechanical stirrer, a thermometer, and a dropping funnel. Under nitrogen protection, 19.05 g (0.28 mol) of sodium ethoxide and 135 mL of dichloromethane are added to the flask, cooled to -10°C, and 22.43 g of 2-thiophenecarbaldehyde is added dropwise. g (0.2 mol) and 21.60 g (0.20 mol) of methyl chloroacetate, the temperature is controlled at -20°C to -10°C, after the dropwise addition is complete, keep stirring for 2 hours. Control the temperature at -10°C to 0°C, add dropwise 42.7g of sodium hydroxide solution (30%, 0.10mol) and let it stand, after the dropwise addition is complete, keep stirring for 1 hour and set aside.

[0034] (2) Separately prepare a three-necked flask equipped with a mechanical stirrer, a thermometer, and a dropping funnel. Prepare 10% sulfuric acid (0.8mol) in the flask, cool...

Embodiment 3

[0036] The present embodiment provides a kind of synthetic method of 2-thiopheneacetic acid, comprises the following steps:

[0037] (1) The three-necked flask is equipped with a mechanical stirrer, a thermometer, and a dropping funnel. Under nitrogen protection, 26.9 g (0.28 mol) of sodium tert-butoxide and 135 mL of ethanol are added to the flask, cooled to -10°C, and 22.43 g of 2-thiophenecarbaldehyde is added dropwise. g (0.2mol) and 29.41g (0.24mol) of ethyl chloroacetate, the temperature is controlled at 0°C to 10°C, after the dropwise addition is complete, keep stirring for 1 hour. Control the temperature at -10°C to 0°C, add 42.7g of sodium hydroxide solution (30%, 0.40mol) dropwise and let it stand, after the dropwise addition is complete, keep stirring for 1 hour.

[0038] (2) Control the temperature at 0°C to 10°C, directly add 219g of 10% hydrochloric acid dropwise, keep stirring for 1 hour after dropping, add hydrogen peroxide (30%, 0.52mol), adjust the pH to 3, c...

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Abstract

The invention discloses a synthetic method of 2-thiopheneacetic acid and belongs to the technical field of synthesis of intermediates. The synthetic method comprises the following steps: synthesis of3-(2-thiophene)-2,3-epoxy sodium propionate: taking 2-thiophenecarboxaldehyde and chloracetate as raw materials, carrying out Darzen reaction to synthesize epoxy acid ester and then hydrolyzing to obtain the 3-(2-thiophene)-2,3-epoxy sodium propionate; synthesis of 2-thiopheneacetic acid: acidizing the 3-(2-thiophene)-2,3-epoxy sodium propionate, carrying out decarboxylation rearrangement to obtain 2-thiophene acetaldehyde and then carrying out Pinnick oxidation reaction to obtain the 2-thiopheneacetic acid. In the synthesis method of the 2-thiopheneacetic acid provided by the invention, Darzen reaction and Pinnick oxidation reaction are adopted; due to high conversion rate of the Darzen reaction and good selectivity of Pinnick oxidation, the product has the advantages of high yield, fewercontained impurities, significant advantages and practical value.

Description

technical field [0001] The invention relates to the technical field of intermediate synthesis, in particular to a synthesis method of 2-thiopheneacetic acid. Background technique [0002] 2-thiopheneacetic acid is currently the most widely used thiophene series derivative, which is widely used in the field of medicine, especially for the synthesis of cephalosporins, such as cephalothin, cefotaxime, and cefoxitin. [0003] At present, the synthetic method of 2-thiopheneacetic acid has many reports, mainly contains the following: [0004] 1. German patent 832755 discloses that thiophene is acetylated and then undergoes Willgerodt reaction to generate 2-thiopheneacetamide, which is then hydrolyzed to obtain 2-thiopheneacetic acid. However, this process will produce a large amount of sulfur-containing and amine-containing wastewater, and the yield is only 20.9%. [0005] 2. British patent 1122658 reported that thiophene reacted with N,N-dimethylformamide in the presence of pho...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D333/24
CPCC07D333/24
Inventor 梅浩高晓飞李小英王铁巍刘国超
Owner QINGDAO FRONTIERCHEM