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Method for preparing 4-chloroacetoacetic acid ethyl ester

A technology of ethyl chloroacetoacetate and chlorine gas is applied in the chemical field, and can solve the problems of difficult industrialization, complicated process and high cost, and achieve the effects of low cost, simple equipment requirements and safe feeding method.

Inactive Publication Date: 2012-10-24
JIANGSU CHENGXIN PHARMA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

And the technology of existing industrialized production (R, S)-4-chloro-3-hydroxybutyrate ethyl is to obtain 4-chloro-3-hydroxybutyronitrile with sodium cyanide and epichlorohydrin reaction, then with hydrochloric acid Ethanol solution reacts to obtain the target product. In this process, highly toxic sodium cyanide, hydrochloric acid ethanol solution and expensive palladium carbon catalyst are used. The process is complicated, the cost is high, the yield is low, the cost is high, and it is not easy to realize industrialization

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  • Method for preparing 4-chloroacetoacetic acid ethyl ester

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Embodiment 1

[0023] Add 100g of dichloromethane into a 250ml three-neck flask, add 15g of diketene at one time, under stirring, the temperature of the reaction solution drops to -5°C, feed 13g of chlorine gas, complete in 1 hour, control the reaction temperature at -5~0°C, pass After that, continue stirring at the same temperature for half an hour. Add 8.6g of ethanol dropwise to the reaction solution, and keep the temperature of the reaction solution at 0°C. After dropping, raise the temperature of the reaction solution to 25°C and stir for 1 small test; fractionate the reaction solution, and recover dichloromethane until there is no fraction Flow out, then residual reaction solution is carried out rectification, collects 22g of colorless transparent liquid, is target product ethyl 4-chloroacetoacetate. The yield of ethyl 4-chloroacetoacetate in this example was 75%.

Embodiment 2

[0025] Add 200g of dichloromethane into a 500ml three-necked flask, add 50g of diketene at one time, under stirring, the temperature of the reaction solution drops to -5°C, feed 44g of chlorine gas, and complete in 1 hour, control the reaction temperature at -5~0°C, pass After that, continue stirring at the same temperature for half an hour. Add 28.7g of ethanol dropwise to the reaction solution and keep the temperature of the reaction solution at 0°C. After dropping, raise the temperature of the reaction solution to 25°C and stir for 1 small test; fractionate the reaction solution and recover dichloromethane until there is no fraction Until it flows out, then the remaining reaction solution is rectified, and 78.4 g of a colorless transparent liquid is collected, which is the target product ethyl 4-chloroacetoacetate. The yield of ethyl 4-chloroacetoacetate in this example was 80%.

Embodiment 3

[0027] Add 200g of dichloromethane into a 500ml three-necked flask, add 50g of diketene at one time, and under stirring, the temperature of the reaction solution drops to -30°C, inject 44g of chlorine gas, and complete in 1.5 hours. Control the reaction temperature at -10~-5°C, After passing through, continue to stir at the same temperature for half an hour. Add 28.7g of ethanol dropwise to the reaction solution, and keep the temperature of the reaction solution at 0°C. After dropping, raise the temperature of the reaction solution to 25°C and stir for 1 hour; carry out fractional distillation of the reaction solution, and recover dichloromethane until no fraction flows out Till then, remaining reaction liquid is carried out rectification, collects 83.3g of colorless transparent liquid, is the target product ethyl 4-chloroacetoacetate. The yield of ethyl 4-chloroacetoacetate in this example was 85%.

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Abstract

The invention relates to a method for preparing 4-chloroacetoacetic acid ethyl ester. The method comprises the following steps of: (1), putting an organic solvent into a container, cooling to 30 DEG C below zero-0 DEG C; (2) adding diketene, uniformly stirring, and controlling the reaction temperature at 30 DEG C below zero-0 DEG C; (3) controlling the temperature of a reaction liquid at 30 DEG C below zero-10 DEG C while stirring, and introducing chlorine gas; (4) keeping the temperature of the reaction liquid at 30 DEG C below zero-10 DEG C while stirring, and dropwise adding ethanol; (5) heating the reaction liquid to 0-30 DEG C while stirring; (6) distilling the reaction liquid, and recovering the organic solvent till no fraction flows out; and (7) refining oily matters, and collecting a colorless or slightly-yellow transparent liquid to obtain a target product, i.e., 4-chloroacetoacetic acid ethyl ester. The yield of the 4-chloroacetoacetic acid ethyl ester prepared with a process method is 75-88 percent.

Description

technical field [0001] The invention belongs to the technical field of chemical industry, in particular to a preparation method of ethyl 4-chloroacetoacetate. Background technique [0002] Ethyl 4-chloroacetoacetate (also known as ethyl 4-chloro-3-hydroxybutyrate), the molecular formula is: [0003] [0004] It is the main intermediate for the production of azlodipine, oxiracetam, atorvastatin calcium and other raw materials, so it is especially special to synthesize ethyl 4-chloro-3-hydroxybutyrate with a low-cost, simple and safe production process important. And the technology of existing industrialized production (R, S)-4-chloro-3-hydroxybutyrate ethyl is to obtain 4-chloro-3-hydroxybutyronitrile with sodium cyanide and epichlorohydrin reaction, then with hydrochloric acid The ethanol solution reacts to obtain the target product. In this process, highly toxic sodium cyanide, hydrochloric acid ethanol solution and expensive palladium carbon catalyst are used. The pro...

Claims

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Application Information

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IPC IPC(8): C07C69/72C07C67/08
Inventor 许刘华刘加根
Owner JIANGSU CHENGXIN PHARMA
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