Method for producing difluoroacetic acid ester

A technology of difluoroacetate and manufacturing method, which is applied in the direction of carboxylic acid ester preparation, carboxylic acid halide preparation, chemical instruments and methods, etc., can solve the problems of increasing solubility and reducing recovery rate, and achieve the improvement of comprehensive yield, The effect of low environmental load and high reaction yield

Inactive Publication Date: 2012-11-07
CENT GLASS CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, in the methods described in these documents, in order to remove or detoxify the inert hydrogen fluoride that becomes the salt, washing with an aqueous solution is performed, but the fluorine-containing carboxylic acid ester has high hydrolyzabi

Method used

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  • Method for producing difluoroacetic acid ester
  • Method for producing difluoroacetic acid ester
  • Method for producing difluoroacetic acid ester

Examples

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Embodiment

[0069] The present invention will be described below using examples, but the embodiments of the present invention are not limited thereto. In the examples, ethyl difluoroacetate (CHF 2 COOEt), ethanol (EtOH), difluoroacetic acid (CHF 2 COOH) and other organic components are measured by FID gas chromatography (GC), and the content of inorganic acids such as hydrogen fluoride is measured by ion chromatography (IC).

Synthetic example 1

[0071] Aluminum phosphate manufactured by Aldrich was pelletized into pellets of 5 mmφ×5 mmL, and fired at 700° C. for 5 hours in a nitrogen stream to prepare an aluminum phosphate catalyst. 2200 cc of this was filled in a large gas phase reaction tube (made of stainless steel, inner diameter 43 mmφ×1800 mmL) equipped with a vaporizer. While flowing nitrogen gas at a rate of 1000 cc / min, the reaction tube was heated by an external electric furnace. After the temperature of the catalyst reached 50° C., hydrogen fluoride (HF) was introduced at a maximum rate of 6 g / min through the vaporizer while monitoring so as not to generate sudden heat generation. In the state of circulating HF, slowly raise the temperature to 300°C, slowly increase the HF supply rate to 12g / min, and keep it at 300°C for 72 hours, after that, lower the set temperature of the heater, and the internal temperature reaches 250°C , stop the flow of HF, increase the nitrogen flow rate to 2000cc / min, keep it for ...

Synthetic example 2

[0073] Aluminum phosphate manufactured by Aldrich was pelletized into pellets of 5 mmφ×5 mmL, and fired at 700° C. for 5 hours in a nitrogen stream to prepare an aluminum phosphate catalyst. 200 cc of this was filled in a small gas phase reaction tube (made of stainless steel, inner diameter 37 mmφ×500 mmL) equipped with a vaporizer. While flowing nitrogen gas at a rate of 100 cc / min, the reaction tube was heated by an external electric furnace. After the temperature of the catalyst reached 50° C., hydrogen fluoride (HF) was introduced through the vaporizer at a maximum rate of 0.6 g / min while monitoring so as not to generate sudden heat generation. In the state of circulating HF, slowly raise the temperature to 300°C, slowly increase the HF supply rate to 1.2g / min, and keep it at 300°C for 72 hours, after that, lower the set temperature of the heater, and the internal temperature reaches 250 At ℃, stop the flow of HF, increase the nitrogen flow to 200cc / min, keep it for 8 ho...

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Abstract

Disclosed is a method for producing a difluoroacetic acid ester which involves at least: a reaction step in which a reaction solution is obtained by bring an alcohol represented by ROH into contact with a difluoroacetic acid fluoride (CHF2COF) in the presence of a hydrogen fluoride scavenger comprising an amide compound represented by formula (1) or a sulfone compound represented by formula (2); and a distillation step (A) in which a difluoroacetic acid ester represented by CHF2COOR is obtained as a distillate from the reaction solution obtained in the reaction step. As a consequence, said production method does not cause a drop in product yield attributable to hydrogen fluoride, which is a by-product of the mechanism of esterification reaction using difluoroacetic acid fluoride.

Description

technical field [0001] The present invention relates to a method for producing difluoroacetate used as a medicine and pesticide intermediate and a reaction reagent, and more particularly to a method for effectively removing by-product hydrogen fluoride (HF) in the reaction between difluoroacetyl fluoride and alcohol. Background technique [0002] As methods for producing difluoroacetic acid esters, the following methods have been proposed: (1) a method of reacting difluoroacetic acid with an alcohol, (2) a method of making 1-alkoxy-1,1,2,2-tetrafluoroethane , the method of reacting sulfuric acid and silicon dioxide (non-patent literature 1), (3) bubbling the reaction crude gas containing difluoroacetyl fluoride into a mixture of ethanol and triethylamine, followed by washing with water and extracting with dichloromethane, A method of obtaining ethyl difluoroacetate (Patent Document 1) and the like. [0003] In the esterification reaction between carboxylic acid fluoride and...

Claims

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Application Information

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IPC IPC(8): C07C67/14C07C67/54C07C67/62C07C69/63
CPCC07C67/14C07C67/54C07C69/63
Inventor 冈本正宗高田直门井村英明
Owner CENT GLASS CO LTD
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