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Method for preparing 2-thiophenecarboxylic acid

A technology of thiophenecarboxylic acid and thiophene, which is applied in the field of preparation of 2-thiophenecarboxylic acid, can solve the problems that it is difficult to meet the needs of industrial production, hidden dangers of production and operation, and extremely high requirements for operators, and achieves the optimization of synthetic routes and less side reactions , The effect of production process optimization

Inactive Publication Date: 2018-04-27
王志训
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] In scheme A, it can be found that if this scheme is used, phosgene, a highly toxic and explosive dangerous raw material, must be used, which often causes safety hazards in production and operation, and has extremely high requirements for operators, and it is difficult to meet the requirements of the current industry. production needs
[0007] However, in scheme B, it can be found that if this scheme is used, a large amount of three wastes will be produced in the production process, which is not conducive to the requirements of contemporary green industry

Method used

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  • Method for preparing 2-thiophenecarboxylic acid
  • Method for preparing 2-thiophenecarboxylic acid
  • Method for preparing 2-thiophenecarboxylic acid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0047] After thiophene generates methyl 2-thiophenecarboxylate under the action of methyl chloroformate, it is hydrolyzed to obtain 2-thiophenecarboxylic acid. The specific equation is as follows:

[0048]

[0049] Add 2500ml of dichloromethane into the reaction kettle, add 10M thiophene and stir evenly, add 200g zinc chloride and stir for 10 minutes, then add dropwise 10M methyl chloroformate (or 5M, 9M, 12M, 15M methyl chloroformate), the dropwise addition was completed within 0.5 hours, warmed to 35°C, stirred the reaction, controlled the reaction through GC, stopped the reaction when GC showed that all thiophene was consumed (about 8-12 hours), Distill under reduced pressure to obtain 1390g of methyl 2-thiophenecarboxylate crude product; pour 1000g of ice water into it, slowly add 200g of 98% sulfuric acid dropwise while stirring, after the addition, the temperature is raised to 60°C, and after 2 hours of reaction (or 20°C, reaction 5 Hours, 100°C, reaction for 0.5 hour...

Embodiment 2

[0052] After thiophene generates ethyl 2-thiophenecarboxylate under the action of ethyl bromoformate, it is hydrolyzed to obtain 2-thiophenecarboxylic acid, and the specific equation is as follows:

[0053]

[0054] Add 2500ml of ethylene glycol dimethyl ether into the reaction kettle, add 10M thiophene and stir evenly, add 400g hydrochloric acid and stir for 10 minutes, then add 10M ethyl bromoformate dropwise at room temperature, and complete the dropwise addition within 0.5 hours , the reaction was stirred at room temperature, and the reaction was controlled by GC. When the GC showed that all thiophenes were consumed, the reaction was stopped (about 0.5-3 hours), the insoluble matter was removed by filtration, the solvent was removed by distillation under reduced pressure, and 500ml chloroform was added for multiple extractions. Remove chloroform, obtain 1410g ethyl 2-thiophene acetate crude product (or after the reaction finishes, carry out follow-up reaction after direc...

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Abstract

The invention provides a method for preparing 2-thiophenecarboxylic acid, which is characterized in that: thiophene is hydrolyzed to obtain 2-thiophenecarboxylic acid after generating 2-thiophene ester under the action of compound A. The production method provided by the invention is simple, and is different from complicated production methods and harsh production conditions in the prior art. The one-pot method of the invention can realize the synthesis of the target product. And the yield can be increased by at least 50% compared with the multi-step synthesis of the prior art. And because the present invention optimizes the production process and synthesis route, in the production process of the present invention, there are few side reactions, no need for selective reactions, few impurities, convenient post-treatment, mild production conditions, and are suitable for industrialized production models .

Description

technical field [0001] The invention relates to the field of organic synthesis, in particular to a preparation method of 2-thiophenecarboxylic acid. Background technique [0002] 2-Thienoic acid is an important intermediate of the anticancer drug raltitrexed, which is a thymus synthase inhibitor and belongs to quinazoline folate analogues. In vivo, after being actively taken up by cells, raltitrexed is quickly metabolized into a series of polyglutamic acids by folate-based polyglutamic acid synthase, and these metabolites have a stronger inhibitory effect on thymus synthase than raltitrexed, thereby Inhibits the synthesis of cellular DNA, and can be retained in cells to exert an inhibitory effect for a long time. In the treatment of colorectal cancer, the curative effect is similar to that of fluorouracil, but the incidence of side effects of raltitrexed is low, the method is simple, and the patient is easy to accept. [0003] In addition, 2-thiophenecarboxylic acid also h...

Claims

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Application Information

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IPC IPC(8): C07D333/40
CPCC07D333/40
Inventor 王志训
Owner 王志训