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A kind of preparation method of ethyl 4-chloroacetoacetate

A technology of ethyl chloroacetoacetate and esterification, applied in the directions of acid halide preparation, carboxylic acid halide preparation, organic chemistry, etc., can solve the problems of low yield and high production cost, and achieve the improvement of distillation yield and cost reduction. Effect

Active Publication Date: 2016-03-02
SHANDONG HUIHAI PHARMA & CHEM
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  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0010] The technical problem to be solved by the present invention is to provide a preparation method of ethyl 4-chloroacetoacetate, which overcomes the problems of low yield and high production cost caused by the by-product ethyl 2-chloroacetoacetate which are ubiquitous in the prior art

Method used

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  • A kind of preparation method of ethyl 4-chloroacetoacetate
  • A kind of preparation method of ethyl 4-chloroacetoacetate

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Effect test

Embodiment 1

[0022] Add 84g of diketene, 220g of dichloromethane, 0.4g of anhydrous copper sulfate (0.48%) into the reaction kettle, start stirring, cool down to -10°C, pass in 44g of chlorine gas, and dropwise add 55g of ethanol after the completion of the reaction. The dichloromethane was removed to obtain the crude product of ethyl 4-chloroacetoacetate (the content of ethyl 2-chloroacetoacetate was 0.42%). After rectification, 156.3 g of the product was obtained, with a yield of 95.04%.

Embodiment 2

[0024] Add 84g of diketene, 220g of dichloromethane, and 0.84g (1%) of anhydrous copper sulfate into the reaction kettle, start stirring, cool down to -10°C, and introduce 44g of chlorine gas. After the ventilation is completed, add 55g of ethanol dropwise. The dichloromethane was removed to obtain the crude product of ethyl 4-chloroacetoacetate (the content of ethyl 2-chloroacetoacetate was 0.49%). After rectification, 155.5 g of the product was obtained, with a yield of 94.55%.

Embodiment 3

[0026] Add 84g of diketene, 220g of dichloromethane, and 0.08g (0.1%) of anhydrous copper sulfate to the reaction kettle, start stirring, cool down to -10°C, and introduce 44g of chlorine gas. After the aeration is completed, add 55g of ethanol dropwise. The dichloromethane was removed to obtain the crude product of ethyl 4-chloroacetoacetate (the content of ethyl 2-chloroacetoacetate was 0.31%). After rectification, 158g of the product was obtained, with a yield of 96.08%.

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Abstract

The invention relates to a preparation method of 4-chloracetyl ethyl acetate. The preparation method comprises the following steps: by taking diketene as an initial raw material, synthesizing a 4-chloracetyl ethyl acetate coarse product in two steps: chlorination and esterification; then, rectifying to obtain a finished product, and adding a stabilizer anhydrous cupric sulfate into the chlorination step, wherein the addition is 0.02-1wt% of diketene. Compared with the prior art, the preparation method provided by the invention has the advantages that 1, by adding the stabilizer anhydrous cupric sulfate, the production of a byproduct 2-chloracetyl ethyl acetate is reduced and the production of the byproduct 2-chloracetyl ethyl acetate in the 4-chloracetyl ethyl acetate coarse product can be controlled below 0.5%, so that the distill yield is greatly improved; 2, the yield of 2-chloracetyl ethyl acetate is over 94.5%, and the cost is greatly lowered.

Description

technical field [0001] The present invention relates to a kind of preparation method of medicine intermediate, relate to a kind of preparation method of ethyl 4-chloroacetoacetate more specifically. Background technique [0002] Ethyl 4-chloroacetoacetate is a colorless to light yellow transparent liquid, mainly used in the field of medicine, especially the key intermediate of oxiracetam, which has broad market prospects. [0003] After searching relevant information and comparative analysis, there are mainly two processing routes for synthesizing ethyl 4-chloroacetoacetate both at home and abroad at present, as follows: [0004] 1: The ethyl chloroacetate method uses benzene as a solvent, and in the presence of mercuric chloride, two molecules of ethyl chloroacetate are condensed in one step to obtain ethyl 4-chloroacetoacetate, but it is only reported in foreign patent documents (Fr1438387). At the same time, although the conversion rate of this route is relatively high (...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C69/72C07C67/14
CPCC07C51/58C07C67/14C07C69/716C07C59/88
Inventor 牟应科姜福元侯绪会张世凤
Owner SHANDONG HUIHAI PHARMA & CHEM
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