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Preparation method of diethyl methylmalonate by taking heteropolyacid as catalyst

A technology of diethyl methylmalonate and heteropolyacids, which is applied in the preparation of carboxylate esters, organic compounds, carboxylates, etc., and can solve complex post-processing of products, many side reactions, and environmental pollution. problems, to achieve the effect of low equipment corrosion, high esterification yield and high catalytic activity

Inactive Publication Date: 2020-04-17
JIANGXI WANLI PHARMA CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Due to the dehydration, esterification and oxidation of concentrated sulfuric acid and hydrochloric acid, by-products such as ether, sulfuric acid ester, unsaturated compounds and carbonyl compounds are easily contained in the esterification mixture, resulting in many side reactions in the production process and complicated product post-treatment. Moreover, the concentrated sulfuric acid and hydrochloric acid used corrode equipment and pollute the environment

Method used

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Examples

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Effect test

preparation example Construction

[0010] A kind of preparation method using heteropolyacid as the diethyl methylmalonate of catalyzer, the steps are as follows:

[0011] Step 1: neutralize with 2-chloropropionic acid and potassium carbonate to generate potassium 2-chloropropionic acid, then carry out continuous cyanation with potassium cyanide, and obtain 2-cyanopropionic acid after acidifying with hydrochloric acid;

[0012] Step 2: Add 2-cyanopropionic acid to ethanol to dissolve, control the molar ratio of 2-cyanopropionic acid to ethanol to be 1:3~4, transfer to the reaction kettle after dissolving; stir at room temperature, and add Heteropolyacid catalyst, control the mass ratio of 2-cyanopropionic acid to heteropolyacid catalyst to 2:1~2, control the temperature at 65~80°C, react for 3-4h, and then end the reaction; distill and separate ethanol, add ammonia water to carry out Neutralize, adjust the pH to neutral, distill the crude diethyl methylmalonate; put the crude diethyl methylmalonate into the rect...

Embodiment 1

[0014] Add 108kg of 2-chloropropionic acid and 138kg of potassium carbonate to the reaction kettle to neutralize to generate potassium 2-chloropropionate, then gradually add potassium cyanide dropwise for cyanation until complete cyanation, and then acidify with hydrochloric acid to obtain 2-cyanopropane acid;

[0015] Add 2-cyanopropionic acid to ethanol to dissolve, control the molar ratio of 2-cyanopropionic acid to ethanol to be 1:4, transfer to the reaction kettle after dissolving; stir at room temperature, and add heteropolyacid catalyst, Control the mass ratio of 2-cyanopropionic acid to heteropolyacid catalyst to 2:1, control the temperature at 65°C, react for 3 hours, and then end the reaction; distill and separate ethanol, add ammonia water for neutralization, adjust the pH to neutral, and fractionally distill The crude product of diethyl methylmalonate; the crude product of diethyl methylmalonate is put into a rectification column for vacuum distillation to obtain d...

Embodiment 2

[0017] Add 108kg of 2-chloropropionic acid and 138kg of potassium carbonate to the reaction kettle to neutralize to generate potassium 2-chloropropionate, then gradually add potassium cyanide dropwise for cyanation until complete cyanation, and then acidify with hydrochloric acid to obtain 2-cyanopropane acid;

[0018] Add 2-cyanopropionic acid to ethanol to dissolve, control the molar ratio of 2-cyanopropionic acid to ethanol to be 1:3, transfer to the reaction kettle after dissolving; stir at room temperature, and add heteropolyacid catalyst, Control the mass ratio of 2-cyanopropionic acid to heteropolyacid catalyst to 2:2, control the temperature at 70°C, react for 4 hours, and then end the reaction; distill and separate ethanol, add ammonia water for neutralization, adjust the pH to neutral, and fractionally distill The crude product of diethyl methylmalonate; the crude product of diethyl methylmalonate is put into a rectification column for vacuum distillation to obtain d...

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PUM

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Abstract

The invention relates to a preparation method of diethyl methylmalonate by taking heteropolyacid as a catalyst. The method comprises the following steps: adding 2-cyanopropionic acid into ethanol fordissolving, controlling the molar ratio of 2-cyanopropionic acid to ethanol to be 1:(3-4), and transferring the obtained solution into a reaction kettle after dissolving; stirring at room temperature,adding the heteropolyacid catalyst, controlling the mass ratio of 2-cyanopropionic acid to the heteropolyacid catalyst to be 2:(1-2), controlling the temperature to be 65-80 DEG C, reacting for 3-4 h, and then ending the reaction; distilling to separate ethanol, adding ammonia water to neutralize, regulating the pH value to be neutral, and fractionating to obtain crude diethyl methylmalonate; andputting the crude diethyl methylmalonate into a rectifying tower, and carrying out reduced pressure rectification to obtain diethyl methylmalonate. Sulfuric acid is replaced with the heteropolyacid catalyst for an esterification reaction, so the method has the advantages of good selectivity, high catalytic activity, high regeneration speed and small corrosion to equipment.

Description

technical field [0001] The invention relates to the technical field of pharmacy, in particular to a method for preparing diethyl methylmalonate using a heteropolyacid as a catalyst. Background technique [0002] Diethyl methylmalonate is a colorless liquid, insoluble in water, used as an organic intermediate; it can be used to synthesize dipropylmalonic acid, and further synthesize antiepileptic drugs such as antiepileptics. The route of synthesizing diethyl methylmalonate mainly contains two kinds: 1) take diethyl malonate as raw material, under the presence of organic bases such as sodium acetate, with methylating reagent (as: methyl iodide, methyl bromide and dimethyl sulfate, etc.) a methylation substitution reaction occurs. 2) Using 2-chloropropionic acid as raw material to obtain diethyl methylmalonate through neutralization, cyanation, alkali hydrolysis, acidification and esterification. At present, concentrated sulfuric acid and hydrochloric acid are mostly used as...

Claims

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Application Information

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IPC IPC(8): C07C67/22C07C69/38
CPCC07C51/412C07C67/22C07C253/14C07C253/30C07C69/38C07C255/19C07C53/19
Inventor 王金鹏李晓瑜刘来龙赵虹江罗刚刘志峰
Owner JIANGXI WANLI PHARMA CO LTD
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