Method for synthesizing methyl 4-chloroacetoacetate or ethyl 4-chloroacetoacetate

A technology of ethyl chloroacetoacetate and methyl acetate, which is applied in the field of synthesizing methyl 4-chloroacetoacetate or ethyl 4-chloroacetoacetate, can solve the problems of large amount of waste water, achieve less chlorine-containing by-products, reduce Pollution, the effect of sufficient chlorine reaction

Active Publication Date: 2021-03-16
JIANGSU HENGAN CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method uses a three-stage HCL absorption system to treat tail gas, which solves the problem of large amount of waste water, but the product yield of this method is only 91-94%

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] Embodiment 1 synthetic 4-chloroacetoacetate methyl ester

[0038] (1) Chlorination: Add the first part of solvent 1500Kg dichloroethane into the chlorination kettle and cool down to -5°C, then mix the second part of solvent 750Kg dichloroethane and 320Kg diketene into the chlorination kettle to continue cooling to -20°C, then feed 272Kg of chlorine gas into the chlorination kettle, and control the temperature of the chlorination kettle at -18°C during the process of introducing chlorine gas; / h; when the quality of chlorine gas is 190.4-231.2Kg, the flow rate is 20kg / h; when the quality of chlorine gas is 321.2-258.4Kg, the flow rate is 12kg / h; When the mass is 258.4-272Kg, the flow rate is 10kg / h.

[0039] (2) Esterification: After the chlorine gas feeds in, add 123Kg of methanol dropwise to the chlorination kettle; stir evenly after the methanol dropwise addition, then the material is transported from the chlorination kettle to the warming still, and the temperature ...

Embodiment 2

[0043] Embodiment 2 synthetic 4-chloroacetoacetate methyl ester

[0044] (1) Chlorination: Add the first part of solvent 1500Kg dichloroethane into the chlorination kettle and cool down to -7°C, then mix the second part of solvent 750Kg dichloroethane and 321.7Kg diketene into the chlorination kettle to continue Cool down to -20°C, and then feed 270.56Kg of chlorine gas into the chlorination tank. During the process of introducing chlorine gas, the temperature of the chlorination tank is controlled at -20°C; when the mass of chlorine gas is 0-190.4Kg, the flow rate 25kg / h; when the quality of chlorine gas is 190.4-231.2Kg, the flow rate is 20kg / h; when the quality of chlorine gas is 321.2-258.4Kg, the flow rate is 12kg / h; When the incoming mass is 258.4-271Kg, the incoming flow rate is 10kg / h.

[0045] (2) Esterification: After the chlorine gas feeds in, add 123Kg of methanol dropwise to the chlorination kettle; stir evenly after the methanol dropwise addition, then the mater...

Embodiment 3

[0048] Embodiment 3 synthetic 4-chloroacetoacetate methyl esters

[0049] (1) Chlorination: Add the first part of solvent 1500Kg dichloroethane into the chlorination kettle and cool down to -10°C, then mix the second part of solvent 750Kg dichloroethane and 316.3Kg diketene into the chlorination kettle to continue Cool down to -20°C, and then feed 275.2Kg of chlorine gas into the chlorination kettle. During the process of introducing chlorine gas, the temperature of the chlorination kettle is controlled at -18°C; when the mass of chlorine gas is 0-190.4Kg, the flow rate 25kg / h; when the quality of chlorine gas is 190.4-231.2Kg, the flow rate is 20kg / h; when the quality of chlorine gas is 321.2-258.4Kg, the flow rate is 12kg / h; When the incoming mass is 258.4~276g, the incoming flow rate is 10kg / h;

[0050] (2) Esterification: After the chlorine gas feeds in, add 123Kg of methanol dropwise to the chlorination kettle; stir evenly after the methanol dropwise addition, then the m...

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PUM

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Abstract

The invention discloses a method for synthesizing methyl 4-chloroacetoacetate or ethyl 4-chloroacetoacetate. The synthesis steps are as following: adding a first part of a solvent into a chlorinationkettle, cooling, adding a second part of a solvent and diketene mixed solution, and cooling; introducing chlorine in sections, adjusting the introduction flow rate of chlorine in each section, and after introduction of chlorine is finished, dropwise adding methanol or ethanol, and carrying out esterification reaction; after the esterification reaction is finished, desolventizing and rectifying thereaction liquid to obtain a finished product of methyl 4-chloroacetoacetate or ethyl 4-chloroacetoacetate; in the chlorination reaction process, the traditional constant-flow chlorine introduction mode is changed and is replaced by a segmented introduction and variable-flow-rate mode; compared with the traditional process, multiple times of production experience groping verification confirms thatthe chlorine addition mode of segmented introduction and variable flow rate has the advantages that few chlorine-containing by-products are generated in the synthesis process, the environmental pollution is reduced, and the yield and content of the prepared product are higher.

Description

technical field [0001] The invention relates to the technical field of organic synthesis, in particular to a method for synthesizing methyl 4-chloroacetoacetate or ethyl 4-chloroacetoacetate. Background technique [0002] Methyl 4-chloroacetoacetate or ethyl 4-chloroacetoacetate is an important pharmaceutical intermediate, which is used to synthesize drugs such as oxiracetam and dolutegravir. Among them, oxiracetam belongs to the treatment of cerebrovascular diseases, and dolutegravir is a new anti-AIDS drug. Therefore, methyl 4-chloroacetoacetate has broad market prospects as a pharmaceutical intermediate. [0003] At present, the main conventional production method of methyl 4-chloroacetoacetate or ethyl 4-chloroacetoacetate in industrial production is: batch production, first dissolving diketene in a solvent, and cooling it to -30°C ~ -10°C , start stirring, feed a certain amount of chlorine gas into the reactor at a certain flow rate, keep it warm at -30°C to -10°C for...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C67/14C07C69/56C07C51/58C07C59/21
CPCC07C51/58C07C67/14C07C69/56C07C59/21
Inventor 华路生陈敏方王海根
Owner JIANGSU HENGAN CHEM
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