Preparation method of ethyl 4,4,4-trifluoroacetoacetate

Abstract

The invention discloses a preparation method of ethyl 4,4,4-trifluoroacetoacetate. With an ethanol solution of sodium ethoxide as a catalyst and in the presence of an organic solvent, ethyl trifluoroacetate and ethyl acetate are subjected to a Claisen condensation reaction, and ethyl 4,4,4-trifluoroacetoacetate is synthesized. The method provided by the invention has the advantages of mild conditions, simple operation, relatively high conversion rate of raw materials, relatively high product selectivity, easy separation of the product, low energy consumption and the like, and is suitable for industrialized production. The prepared ethyl 4,4,4-trifluoroacetoacetate is an important pesticide and medicine intermediate, can be used for preparation of thifluzamide, fluacrypyrim, thiazopyr and other pesticides, and also can be used for preparation of befloxatone and other medicines.

Description

technical field [0001] The invention relates to a preparation method of ethyl 4,4,4-trifluoroacetoacetate. Background technique [0002] 4,4,4-Ethyl trifluoroacetoacetate (hereinafter referred to as ethyl trifluoroacetoacetate), the English name is ethyl 4,4,4-trifluoroacetoacetate, and the CAS number is 372-31-6. Molecular formula is C 6 h 7 f 3 o 3 , the molecular weight is 184.11, the density is 1.259, the melting point is -39 ℃, the boiling point is 129.5 ℃ (760 mmHg), the refractive index is 1.375-1.378, the flash point is 28 ℃, and the solubility in water is 10 g / L (20 ℃). Ethyl trifluoroacetoacetate has two configurations, enol and ketone, which can be converted freely under normal circumstances. The specific structure is as follows: Ethyl trifluoroacetoacetate is an important pesticide and pharmaceutical intermediate, which can be used to prepare pesticides such as flufenam, pyrimidin, and thiazopyr, and can also be used to prepare medicines such as beflux...

AI Technical Summary

Problems solved by technology

In this production process: solid sodium alkali releases heat violently during the feeding process, the feeding process is difficult to control, and it is easy to cause dust pollution; using metal sodium and ethanol to prepare sodium ethoxide will generate a large amount of hydrogen, which has potential safety hazards in industrial production; Boiling dealcoholization, high energy consumption, difficult to control the end point of the dealcoholization process, resulting in unstable process; dealcoholization uses a large amount of cyclohexane, resulting in increased energy consumption and reaction time for solvent recovery

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