Method for preparing difluoroethanol

A technology of difluoroethanol and difluoroacetate, applied in the preparation of organic compounds, chemical instruments and methods, preparation of hydroxyl compounds, etc., can solve the problems of low reaction yield and long reaction time

Active Publication Date: 2012-11-07
XIAN MODERN CHEM RES INST
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  • Abstract
  • Description
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  • Method for preparing difluoroethanol

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Embodiment 1

[0015] Add 3.2g of the catalyst prepared above, 40g of methyl difluoroacetate and 40g of absolute ethanol into a stainless steel autoclave, close the autoclave, and feed 1MPa H 2 Replace the air in the reactor, then feed hydrogen gas to a pressure of 5 MPa, heat to 250°C with stirring, and react for 10 hours. After the reaction is over, cool down, and when the temperature drops to 25°C, release the pressure, open the reaction kettle, remove the reaction liquid, filter the reaction liquid, separate the catalyst from the reaction liquid, and rectify the resulting filtrate at atmospheric pressure to collect fractions at 97-99°C , to obtain 26.9 g of difluoroethanol with a yield of 90.3% and a purity of 99%.

Embodiment 2

[0017] Add 3.2g of the catalyst prepared above, 20g of ethyl difluoroacetate and 60g of absolute ethanol into a stainless steel autoclave, close the autoclave, and feed 1MPa H 2 The air in the reactor was replaced, and then the pressure of hydrogen was 10MPa, heated to 180°C under stirring, and reacted for 8h. After the reaction, cool down, and when the temperature drops to 25°C, release the pressure, open the reaction kettle, take out the reaction liquid, filter, separate the catalyst from the reaction liquid, rectify the filtrate at atmospheric pressure, collect the fraction at 97-99°C, and obtain the product Difluoroethanol 12.1g, yield 91.6%, purity 99%.

Embodiment 3

[0019] Add 3.2g of the catalyst prepared above, 30g of propyl difluoroacetate and 50g of absolute ethanol into a stainless steel autoclave, close the autoclave, and feed 1MPa H 2 The air in the reactor was replaced, and then the pressure of hydrogen gas was introduced to 8 MPa, and the temperature was raised to 200° C. under stirring, and the reaction was carried out for 6 hours. Cool and lower the temperature. After the temperature drops to 25°C, release the pressure, open the reaction kettle, take out the reaction solution, filter, separate the catalyst from the reaction solution, rectify the filtrate at atmospheric pressure, collect fractions at 97-99°C, and obtain 16.22 g of difluoroethanol , yield 91.0%, purity 99%.

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Abstract

The invention discloses a method for preparing difluoroethanol and aims at solving problems of long reaction time and low yield. Difluoro-acetic acid ester serves as the raw material, and the method includes the following steps: adding catalysts, difluoro-acetic acid ester and ethanol into a reaction kettle, leading hydrogen pressure to be 5-10MPa, stirring to lead temperature to rise to 180-250 DEG C, and reacting for 6-10h to obtain difluoroethanol, wherein mass ratio of catalysts: difluoro-acetic acid ester: ethanol is 1: (6.25-12.5):(12.5-18.75). According to mass percent, the catalysts are composed of 40-70% of copper oxide, 10-50% of aluminum oxide, 5-30% of manganese oxide and 5-30% of barium monoxide. The method is mainly used for preparing difluoroethanol.

Description

technical field [0001] The invention relates to a preparation method of a fluorine-containing compound. In particular, it relates to a preparation method of difluoroethanol. Background technique [0002] Due to the special structure of difluoroethanol containing difluoromethyl group, it has many incomparable characteristics of ordinary alcohols, and can participate in various organic synthesis reactions. As one of the important intermediates of fluorine-containing fine chemicals, difluoroethanol is mainly used in the synthesis of fluorine-containing medicines, pesticides and dyes. [0003] European patent EP2298723A1 discloses a preparation method of difluoroethanol. The method uses ethyl difluoroacetate as a raw material, a ruthenium complex as a catalyst, and tetrahydrofuran as a solvent to prepare difluoroethanol through raw material pretreatment and reaction. Specifically The steps are as follows: firstly add ethyl difluoroacetate, ruthenium complex catalyst, sodium me...

Claims

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Application Information

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IPC IPC(8): C07C31/38C07C29/149
Inventor 孙道安吕剑李春迎杜咏梅张伟王博亢建平张建伟马洋博
Owner XIAN MODERN CHEM RES INST
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