Synthesis method of ethyl 4-chloroacetoacetate

Abstract

The invention discloses a synthesis method of ethyl 4-chloroacetoacetate. The synthesis method is characterized by comprising the steps: (1) mixing diketene and dichloromethane at a volume ratio of 1:(1-2) so as to form a mixed solution, adding the mixed solution from the top of a glass suction tube at a speed of 5-15 mL / min, and adding diketene and chlorine gas at a molar ratio of 1:(0.95-1) froman inlet in the side surface of the glass suction tube at a speed of 2-6 g / min; (2) adding anhydrous ethanol from an inlet in the side surface of a straight vacuum receiving tube at a speed of 2-7 ml / min so as to make the molar ratio of diketene to anhydrous ethanol at 1:(1.2-1.3), cooling a serpentine condenser tube by using water, and controlling the temperature at 50-70 DEG C for a reaction for 2-5 h so as to obtain a crude product; and (3) performing reduced pressure rectification on the crude product at a pressure of 1-3 mmHg and a tower top temperature of 45-60 DEG C so as to obtain ethyl 4-chloroacetoacetate. The synthesis method has the advantages that the reaction is a continuous reaction, and has a high reaction speed, no accumulation of a large amount of hazardous materials andsmall danger, the equipment has low cost, are all conventional organic synthesis equipment, no expensive and special equipment is needed, easy duplication is achieved, and the production efficiency is improved.

Description

technical field [0001] The invention belongs to the technical field of chemical production, and relates to a method for synthesizing ethyl 4-chloroacetoacetate. Background technique [0002] Ethyl 4-chloroacetoacetate is an important raw material for the synthesis of ethyl aminothiaxate, but it has not been widely used because of the high cost of the raw material (ethyl 4-chloroacetoacetate); at present, ethyl 4-chloroacetoacetate The following two problems exist in the production of 4-chloroacetoacetate: one is that the activity of the reactants is too high (chlorine, diketene) and the reaction needs to be carried out at low temperature and low concentration, which is not conducive to expanding the output; the other is that the thermal stability of ethyl 4-chloroacetoacetate is poor And the high boiling point makes it easy to decompose in the process of product post-processing (rectification under reduced pressure). Contents of the invention [0003] The purpose of the p...

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Problems solved by technology

[0002] Ethyl 4-chloroacetoacetate is an important raw material for the synthesis of ethyl aminothiaxate, but it has not been widely used because of the high cost of the raw material (ethyl 4-chloroacetoacetate); at present, ethyl 4-chloroacetoacetate The following two problems exist in the production of 4-chloroacetoacetate: one is that the activity of the reactants is too high (chlorine, diketene) and the reaction needs to be carried out at low temperature and low concentration, which is not conducive to expanding the output; the other is that the thermal stability of ethyl 4-chloroacetoacetate is poor And the high boiling point makes it easy to decompose in the process of product post-processing (rectification under reduced pressure)

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