Method for preparing methyl acetoacetate by using novel composite catalyst

A technology of methyl acetoacetate and composite catalyst is applied in chemical instruments and methods, preparation of organic compounds, organic compounds/hydrides/coordination complex catalysts, etc., and can solve the problem of low product yield, crude methyl acetoacetate, etc. problems such as low content, to achieve the effects of improving distillation yield, complete esterification reaction, and reducing energy consumption
CN101337890BActive Publication Date: 2012-02-29安徽天成新材料有限公司
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
安徽天成新材料有限公司
Publication Date
2012-02-29

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Abstract

The invention discloses a method for preparing methyl acetoacetate by using complex catalyst, which comprises the following steps: carrying out esterification reaction of methanol and diketene to generate crude methyl acetoacetate, wherein two different catalysts are added in the different stages of the esterification reaction; triethylenediamine catalyst is added before the esterification reaction; and diketene can be added directly dropwise without being heated by vapor, thereby overcoming the disadvantage that diketene is added dropwise after heating methanol to the boiling point in the conventional process and reducing the energy consumption; and cooling the generated liquid to 40 DEG C after the reaction, adding concentrated sulfur acid catalyst, keeping the temperature for half an hour, filtering, continuously rectifying the filtrate, and separating to obtain fine methyl acetoacetate with the content larger than 99%. Compared with the conventional intermittent rectification method, the continuous rectification method has greatly improved throughput and more convenient operation.
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Description

technical field

[0001] The invention relates to a method for preparing methyl acetoacetate using a novel composite catalyst, which belongs to the technical field of chemical industry. Background technique

[0002] According to "Fine Organic Chemical Materials and Intermediates Handbook" (Chemical Industry Press, edited by Xu Kexun, March 1999), the reaction generation principle of methyl acetoacetate is: That is, use concentrated sulfuric acid as a catalyst, raise the temperature of methanol to boiling, add diketene dropwise, remove the low boilers in the reaction kettle, then stop the reception of the previous fraction, and start to receive the main fraction, refined methyl acetoacetate, until it is removed. . The content of crude methyl acetoacetate produced by the method is low (only 97.42%), and the product yield is low (only 96.84%). Contents of the invention

[0003] In order to overcome the deficiencies in the prior art, the object of the present invention is to ...

Claims

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