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A kind of preparation method of 4,4-difluoroacetoacetate alkyl ester

A technology of alkyl difluoroacetoacetate and alkyl acetate, which is applied in the field of preparation of alkyl 4,4-difluoroacetoacetate, can solve the problems such as the complicated preparation process of intermediate ethyl difluoroacetate, and achieve Simplify the reaction process, improve the safety factor, and benefit the effect of environmental protection

Active Publication Date: 2017-05-17
KINGCHEM LIAONING CHEMICAL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] The first object of the present invention is to provide a preparation method of alkyl 4,4-difluoroacetoacetate, which has simple steps and safe operation, and solves the problem of complicated preparation process of the intermediate ethyl difluoroacetate
[0008] Another object of the present invention is to solve the problem that the reaction needs to be introduced outside the acid to continue the reaction

Method used

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  • A kind of preparation method of 4,4-difluoroacetoacetate alkyl ester
  • A kind of preparation method of 4,4-difluoroacetoacetate alkyl ester
  • A kind of preparation method of 4,4-difluoroacetoacetate alkyl ester

Examples

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Embodiment 1

[0039] In a 1000mL Teflon-lined reactor, add 243g (2.4mol) of 98% sulfuric acid, cool down in a water bath, control the temperature at 10-30°C, slowly add 57g (3.2mol) of water dropwise, and then slowly add 1,1, 438 g (3.0 mol) of 2,2-tetrafluoroethyl ethyl ether. After the dropwise addition, the temperature was raised to 54-56° C. for 1 hour. At this time, there is almost no gas overflow, and the temperature is slowly raised to 80° C., and hydrogen fluoride gas overflows (pass the overflow gas into the next reaction). Lower the temperature of the system to 10-20°C, control the temperature T<30°C, and separate the hydrogen fluoride by rectifying the system under reduced pressure (separate the hydrogen fluoride and pass it into the next step reaction). The crude ethyl difluoroacetate was evaporated, washed with water, washed with sodium bicarbonate solution, washed with water and rectified to obtain 316.0 g of ethyl difluoroacetate with a yield of 85%.

[0040] In a 1000mL gl...

Embodiment 2

[0042] In a 1000ml polytetrafluoroethylene-lined reactor, add 243g (2.4mol) of 98% sulfuric acid, cool down in a water bath, control the temperature at 10-30°C, slowly add 57g (3.2mol) of water dropwise, and then slowly add 1,1,2 , 438 g (3.0 mol) of 2-tetrafluoroethyl ethyl ether. After the dropwise addition, the temperature was raised to 54-56° C. for 1 hour. At this time, there is almost no gas overflow, and the temperature is slowly raised to 80° C., and hydrogen fluoride gas overflows (pass the overflow gas into the next reaction). Lower the temperature of the system to 10-20°C, control the temperature T<30°C, and separate the hydrogen fluoride by rectifying the system under reduced pressure (separate the hydrogen fluoride and pass it into the next step reaction). Evaporate the crude product of ethyl difluoroacetate, control the temperature of the crude product at T<10°C, pass through ammonia gas, adjust the pH=7, filter, rinse the filter cake with 200g of ethyl acetate,...

Embodiment 3

[0045] In a 1000ml polytetrafluoroethylene-lined reactor, add 243g (2.4mol) of 98% sulfuric acid, cool down in a water bath, control the temperature at 10-30°C, slowly add 57g (3.2mol) of water dropwise, and then slowly add 1,1,2 , 438 g (3.0 mol) of 2-tetrafluoroethyl ethyl ether. After the dropwise addition, the temperature was raised to 54-56° C. for 1 hour. At this time, there is almost no gas overflow, and the temperature is slowly raised to 80° C., and hydrogen fluoride gas overflows (pass the overflow gas into the next reaction). Lower the temperature of the system to 10-20°C, control the temperature T<30°C, and separate the hydrogen fluoride by rectifying the system under reduced pressure (separate the hydrogen fluoride and pass it into the next step reaction). Evaporate the crude product of ethyl difluoroacetate, control the temperature of the crude product at T<10°C, pass through ammonia gas, adjust the pH=7, filter, rinse the filter cake with 200g of ethyl acetate,...

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Abstract

The invention discloses a method for preparing alkyl 4,4-difluoroacetylacetate. The method has the advantages of easily available raw materials, simple process flow, safety in operation and high yield. The method comprises the following steps: (1) carrying out hydrolysis reaction on 1,1,2,2-tetrafluoroethyl ether used as a raw material and water in an acid and separating to obtain ethyl difluoroacetate and hydrogen fluoride; (2) reacting ethyl difluoroacetate obtained in the step (1) and alkyl acetate in the presence of an alkaline catalyst to obtain 1,1-difluoro-2-butenoic acid alkyl ester-2-hydroxy salt; and (3) neutralizing 1,1-difluoro-2-butenoic acid alkyl ester-2-hydroxy salt obtained in the step (2) and hydrogen fluoride to obtain alkyl 4,4-difluoroacetylacetate.

Description

technical field [0001] The invention relates to the field of preparation methods of alkyl 4,4-difluoroacetoacetate, in particular to a preparation method of alkyl 4,4-difluoroacetoacetate. Background technique [0002] Alkyl 4,4-difluoroacetoacetate is an intermediate in the synthesis of new pesticides and medicines, and has a wide range of applications in the chemical and pharmaceutical fields. The common method for the preparation of alkyl 4,4-difluoroacetoacetate is Claisen ester condensation reaction. The Claisen ester condensation reaction is a reaction in which esters containing α-active hydrogen undergo a condensation reaction to form β-keto ester compounds under the action of a catalyst such as sodium alkoxide, sodium trityl and other basic catalysts. In the preparation of alkyl 4,4-difluoroacetoacetate, ethyl difluoroacetate and alkyl acetate are usually reacted under the catalysis of a basic catalyst to obtain the product. [0003] Patent CN1968934A introduces th...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C69/716C07C67/313
CPCC07C67/00C07C67/313C07C67/343C07C69/716C07C69/732
Inventor 刘强贾铁成宋诚吴波唐小凤
Owner KINGCHEM LIAONING CHEMICAL CO LTD
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