Production method for carrying out low boiler recycling on methyl acetoacetate

A technology for the production of methyl acetoacetate, which is applied in the chemical industry, can solve problems such as combustion, and achieve the effects of reducing losses, reducing costs, and improving total yield

Active Publication Date: 2017-05-31
NANTONG ACETIC ACID CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Combustible, there is a danger of burning when expos

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0021] Example 1 (Reaction part):

[0022] Add 1.8kg of methanol 500kg catalyst triethylenediamine into the reaction kettle, raise the temperature to reflux, add 1312.5kg of diketene dropwise, raise the temperature to 115°C and keep it warm. After the reaction is completed, lower the temperature of the reaction solution to 30°C, add 0.79kg of concentrated sulfuric acid and keep it warm for 30 minutes , Filtration, and continuous distillation of the filtrate to obtain methyl acetoacetate and low boilers.

Example Embodiment

[0023] Example 2 (Reaction part)

[0024] Add methanol 500kg catalyst triethylenediamine 0.15kg to the reaction kettle, raise the temperature to reflux, add 1009.6kg diketene dropwise, raise the temperature to 130℃ and keep it warm. After the reaction is completed, cool the reaction solution to 30℃, add 0.06kg of concentrated sulfuric acid and keep it for 30 minutes , Filtration, and continuous distillation of the filtrate to obtain methyl acetoacetate and low boilers.

Example Embodiment

[0025] Example 3

[0026] Add 4000 kg of low boilers obtained in reference example 1 into the reactor (the content of methyl acetoacetate is 46.5%, acetic acid is 12.1%, methanol is 25.6%), the temperature is raised to 60°C and refluxed, 900g of concentrated sulfuric acid is added, and esterification reaction 1 After hours, the low boiling point was distilled out under normal pressure, the temperature of the kettle was raised to 120℃, the rectification was finished, and 188g of solid sodium hydroxide was added to neutralize after cooling to 44℃. After neutralization, it was rectified by a conventional negative pressure rectification tower. Methyl acetoacetate is 1781.9 kg, the content of methyl acetoacetate is 99.5%, the acidity is 0.045%, and the product recovery rate is 95.8%.

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PUM

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Abstract

The invention discloses a production method for carrying out low boiler recycling on methyl acetoacetate. The production method comprises the following steps: adding methanol and a catalyst triethylene diamine in a reaction kettle; carrying out heating reflux; dropwise adding diketene; keeping warm; cooling a reaction solution after a reaction is completed; adding concentrated sulfuric acid; keeping warm; filtering; carrying out continuous rectification on filtrate; rectifying a low boiler; adding acid in the low boiler for esterifying; rectifying the low boiler at normal pressure after carrying out the heating reflux for 1 to 2 hours; stopping rectifying after rising the kettle temperature to be 115 to 125 DEG C; cooling to 40 to 50 DEG C; neutralizing by using solid base; enabling a neutralized material to enter a conventional negative pressure rectifying system, and rectifying a methyl acetoacetate finished product, wherein the content of the methyl acetoacetate finished product is greater than 99.0 percent, the acidity is smaller than 0.05 percent, and the product recovery rate is 95 percent or above. According to the production method disclosed by the invention, loss of the methyl acetoacetate is reduced, the total yield of the methyl acetoacetate is increased, a resource can be recycled and reutilized, and the cost is reduced.

Description

technical field [0001] The invention relates to the field of chemical industry, in particular to a method for recovering methyl acetoacetate. Background technique [0002] Methyl acetoacetate, English name: Methyl acetoacetate, alias: methyl acetoacetate, molecular formula and molecular weight: C 6 h 8 o 3 = 116.12. Physical and chemical properties: slightly soluble in water, easily soluble in organic solvents. When it encounters ferric chloride, it turns dark red, and boils with water to decompose into acetone, methanol, and carbon dioxide. Appearance: Colorless liquid with aromatic odor. Melting point / °C: -80, boiling point / °C: 171.7, relative density: 1.0747, refractive index (20°C): 1.4186, flash point (closed cup) / °C: 82, viscosity (20°C) / mPa.s: 1.704. Slightly soluble in water, miscible with organic solvents such as ethanol and ether. Combustible, there is a danger of burning when exposed to open flame, high heat or contact with oxidants. Low toxicity, rat oral...

Claims

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Application Information

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IPC IPC(8): C07C69/72C07C67/46C07C67/54
CPCC07C67/46C07C67/54C07C69/72
Inventor 丁彩峰庆九朱小刚刘芳孙赵姚俊生
Owner NANTONG ACETIC ACID CHEM
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