Continuous synthesis system and method of ethyl 4-chloroacetoacetate

A technology for the synthesis of ethyl chloroacetoacetate, which is applied in the chemical industry, can solve problems such as difficulty in controlling the depth of chlorination, difficulty in industrial production, and difficulty in controlling the reaction, so as to reduce production raw material costs and energy costs, avoid by-products, Reduces the effect of polychlorinated products and other by-products

Inactive Publication Date: 2017-05-31
JIANGSU CHENGXIN PHARMA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Existing industrial production is mainly through batch tank chlorination production, which has problems such as long reaction time, difficult control of chlorination depth, many by-products, and low yield.
[0003] Patents CN201210257429.X and CN201310321570.6 disclose a production method that takes diketene as the starting material and synthesizes ethyl 4-chloroacetoacetate through two steps of chlorination and esterification. The raw materials are all cheap and easy to obtain and become the mainstream production method, but It also has its own inherent shortcoming that the product yield is on the low side, only 75%-88%, causing the cost to be on the high side, and the reason for the low yield is exactly that a certain amount of ethyl 2-chloroacetoacetate (5 %), and the boiling point of ethyl 2-chloroacetoacetate is very close to the boiling point of ethyl 4-chloroacetoacetate (about 2-3°C under reduced pressure), so repeated rectification is usually required for purification , resulting in a large amount of decomposition of the product, resulting in a low yield
[0004] Patents WO2012146604A1 and CN105693509A report the continuous synthesis of ethyl 4-chloroacetoacetate. Diketene and chlorine are used as raw materials to react in a falling film reactor. After the reaction, enter the esterification tank for esterification to synthesize 4-chloroacetoacetate Ethyl ester, the process reaction of this technical scheme is not easy to control, and it is not easy for industrial production

Method used

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  • Continuous synthesis system and method of ethyl 4-chloroacetoacetate
  • Continuous synthesis system and method of ethyl 4-chloroacetoacetate

Examples

Experimental program
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Effect test

Embodiment example 1

[0026] Such as figure 1 , figure 2 Shown, a kind of continuous synthesis system of ethyl chloroacetoacetate comprises the first solution tank 1, the second solution tank 2, pump 3, microchannel reactor 4; The upstream of this microchannel reactor 4 is provided with Feed pipe 5, downstream is provided with discharge pipe 6; Described first solution tank 1, the second solution tank 2 are respectively connected with the feed pipe 5 of described microchannel reactor 4 by pump 3; Also comprise the second reactor 7. The second reactor 7 includes a feed branch pipe 8 and a discharge main pipe 9. There are at least two feed branch pipes 8; a third solution tank 12 is also included, and the feed branch pipe 8 is connected to the third solution tank respectively. The solution tank 12 and the discharge pipe 6 are connected, and a pump 3 is arranged between the third solution tank 12 and the feed branch pipe 8; a collection tank 13 and an exhaust gas absorbing device 14 are also include...

Embodiment 2

[0029] A method for the continuous synthesis system of ethyl 4-chloroacetoacetate described in Example 1, mainly comprising the following steps:

[0030] 1) Diketene and chlorine gas are dissolved in organic solvent respectively to form a solution; the molar ratio of diketene to organic solvent is 0.05~50:1; the molar ratio of chlorine gas to organic solvent is 0.01~50:1;

[0031] 2) Input the prepared diketene and chlorine gas solution into the microchannel reactor 4 through pump 3 to carry out chlorination reaction; the reaction temperature range of diketene solution and chlorine gas solution is -50℃~0℃, and the reaction time is 0.1~50s The molar ratio to chlorine gas is 0.9~1.5:1;

[0032] 3) After the diketene chlorination reaction is completed, react with ethanol through the second reactor 7 to synthesize ethyl 4-chloroacetoacetate, and the product enters the collection tank 13 through the discharge main pipe 9, and the collection tank 13 is connected to the tail gas abso...

Embodiment example 3

[0037] The device used in this embodiment is the same as in Embodiment 1.

[0038] The molar ratio of diketene and methylene chloride is 0.2:1 to prepare a solution, and the molar ratio of chlorine to methylene chloride is 0.05:1 to prepare a solution;

[0039] The prepared diketene solution and chlorine gas solution were respectively input into the continuous flow microchannel reactor through metering pumps, the molar ratio of diketene to chlorine gas was 1.1:1, the reaction temperature was -5°C, and the reaction time was 30s;

[0040]After the diketene chlorination reaction is completed, the ethanol is input through the metering pump, and after the reaction is completed, it enters the product collection tank, and the collection tank is connected to the tail gas absorption device. According to GC analysis, the content of ethyl acetoacetate is 1%, the content of ethyl 4-chloroacetoacetate is 96%, the content of ethyl 2,4-dichloroacetoacetate is about 0.2%, and other impurities...

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PUM

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Abstract

The invention relates to a continuous synthesis system and method of ethyl 4-chloroacetoacetate. The method comprises the steps of adopting diketene, chlorine and ethyl alcohol as raw materials and inputting the raw materials into a micro-channel reactor through a metering pump; and carrying out chlorination and esterification and then synthesizing the ethyl 4-chloroacetoacetate. The reaction time is greatly shortened, and the produced product is high in content, low in cost, small in pollution and high in security and meets the requirements of industrial production.

Description

technical field [0001] The invention belongs to the technical field of chemical industry, and in particular relates to a continuous synthesis system and method of ethyl 4-chloroacetoacetate. Background technique [0002] Ethyl 4-chloroacetoacetate is a colorless to pale yellow transparent liquid. It is an important intermediate for the production of raw materials such as niclodipine, oxiracetam, and atorvastin calcium, and has a large market demand. Existing industrial production is mainly through batch tank chlorination, which has problems such as long reaction time, difficulty in controlling the depth of chlorination, many by-products, and low yield. [0003] Patents CN201210257429.X and CN201310321570.6 disclose a production method that takes diketene as the starting material and synthesizes ethyl 4-chloroacetoacetate through two steps of chlorination and esterification. The raw materials are all cheap and easy to obtain and become the mainstream production method, but I...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C67/14C07C69/72
CPCC07C67/14C07C51/58
Inventor 刘家生祝俊刘加根严生虎陈代祥张超张晨晨辜顺林沈介发马晓明
Owner JIANGSU CHENGXIN PHARMA
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