Preparation method for difluoro acetate

A technology of difluoroacetate and difluoroacetonitrile, which is applied in the field of preparation of difluoroacetate, can solve the problems of difficult acquisition of raw materials, high price of raw materials, and difficulty in scaling up, and achieve less waste, simple operation, and high yield Effect

Inactive Publication Date: 2008-09-24
JUHUA GROUP TECH CENT +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The route using R132a as raw material adopts photocatalytic oxidation method, which has the disadvantage that it is not easy to scale up in production
The production of difluoroacetate by reductive dechlorination of chlorofluoroalkanoate in the presence of alcohol and zinc

Method used

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Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0015] The preparation method of difluoroacetate is to use difluoroacetonitrile as a raw material, and in the presence of a catalyst, synthesize difluoroacetate in one step with alcohol and water. The synthesis temperature is from 0°C to the reflux temperature of the reaction solution. , alcohol, and water in a molar ratio of 1:0.5-10.0:0.5-10.0:0.5-5.0, the reaction solution is rectified to obtain difluoroacetic acid ester, or the reaction solution is extracted, layered, and rectified to obtain difluoroacetic acid ester.

[0016] The difluoroacetonitrile, water and alcohol are added once or continuously. The catalyst is added at one time or continuously. The catalyst is sulfuric acid or p-toluenesulfonic acid. The molar ratio of difluoroacetonitrile to catalyst is preferably 1:1.0-3.0. The molar ratio of difluoroacetonitrile to alcohol is preferably 1:1.0-4.0. The molar ratio of difluoroacetonitrile to water is preferably 1:1.0-2.0. The alcohol is methanol, ethanol, prop...

Embodiment 1

[0019] Add 46.0g (1.0mol) of absolute ethanol to a 250ml reaction flask, stir, cool, slowly add 172.0g (1.0mol) p-toluenesulfonic acid, the temperature does not exceed 40 ° C, after adding p-toluenesulfonic acid, cool to Below 0°C, slowly add 7.7g (0.1mol) of difluoroacetonitrile, raise the temperature to reflux, and add 9.0g (0.5mol) of water within half an hour. After the addition, the reflux reaction was continued for 8 hours, the reaction solution was cooled, extracted with ether, and the organic layer was rectified to obtain 7.0 g of ethyl difluoroacetate, with a yield of 56.4% (calculated as difluoroacetonitrile).

Embodiment 2

[0021] Add 4.6g (0.1mol) butanol to a 250ml reaction flask, stir, cool, slowly add 10.0g (0.1mol) concentrated sulfuric acid, the temperature does not exceed 40°C, after adding the concentrated sulfuric acid, cool to below 0°C, slowly Slowly add 15.4 g (0.2 mol) of difluoroacetonitrile, raise the temperature to reflux, and add 1.8 g (0.1 mol) of water within half an hour. After the addition, the reflux reaction was continued for 8 hours, the reaction solution was cooled, extracted with benzene, and the organic layer was rectified to obtain 5.7 g of ethyl difluoroacetate, with a yield of 46.0%.

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Abstract

The present invention discloses a preparation method of difluoro acetate. In the method, difluoro acetonitrile is used as raw material and reacts with alcohol and water to further synthesize the difluoro acetate with a catalyst; the temperature of the synthesis is between 0 DEG C and the reflux temperature of the reaction solution; the molar ratio of the difluoro acetonitrile, the catalyst, the alcohol and the water is equal to 1 : 0.5 to 10.0 : 0.5 to 10.0 : 0.5 to 5.0; the reaction solution can be refined to prepare the difluoro acetate, or extracted, delaminated and refined to prepare the difluoro acetate. The method can be used for preparing the difluoro acetate with high yield rate and high purity. With an appropriate ratio, the transformation ratios of the raw materials exceed 99.0 percent; the selectivity of various esters can exceed 95.0 percent; the yield rate is more than 85 percent. The purity of the synthesized product is more than or equal to 99.5 percent and is suitable for the needs in various aspects. The method has the advantages of short technical process, simple operation, high yield, less three-waste, high purity of the product and so on.

Description

technical field [0001] The invention relates to a preparation method of difluoroacetate. Background technique [0002] JP6228043 patent discloses a production method for synthesizing difluoroacetic acid from dichloroacetic acid derivatives through fluorination of fluoride salts. For example: the reaction of dichloroacetyl chloride and diethylamine in toluene solvent at 10°C gives 89% of N,N-diethyldichloroacetamide, and N,N-diethyldichloroacetamide reacts at 150°C with Potassium fluoride in diethylene glycol is heated and reacted to obtain 75% N, N-diethyl difluoroacetamide, and then hydrolyzed with potassium hydroxide to obtain difluoroacetic acid. [0003] EP0694523 discloses a preparation method of difluoroacetyl fluoride and its difluoroacetate. The method uses tetrafluoroethylene as a raw material, and tetrafluoroethylene is added with methanol in the presence of a catalyst to obtain methoxytetrafluoroethane (CH 3 OCF 2 CF 2 H), methoxytetrafluoroethane is catalyti...

Claims

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Application Information

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IPC IPC(8): C07C69/63C07C67/22
Inventor 叶立峰周强姜永清应赢理
Owner JUHUA GROUP TECH CENT
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