Method for preparing difluoroethanol by gas phase catalytic hydrogenation

A difluoroethanol, catalytic hydrogenation technology, applied in chemical instruments and methods, preparation of hydroxyl compounds, preparation of organic compounds, etc., can solve the problem of low conversion rate of difluorocarboxylate, unsuitable for industrial production, unfavorable industrial production The problem is to overcome the harsh reaction conditions, low cost and low equipment requirements.

Active Publication Date: 2014-01-22
ZHEJIANG JUHUA HANZHENG NEW MATERIAL +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantage is that the use of a large number of catalysts containing precious metal components leads to a substantial increase in cost, which is not conducive to industrial production
The disadvantage is that the catalyst containing expensive noble metals is used, and the conversion rate of difluorocarb

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] CuO / ZnO / Al 2 o 3 / La (the molar ratio of Cu, Zn, Al, and La is Cu:Zn:Al:La=1:0.5:0.5:0.1) catalyst 3g is placed in a stainless steel gas phase reaction tube with a diameter of 10mm and 316L, and heated to 150°C Introduce 10ml / min of hydrogen gas to activate the catalyst for 0.5h, and then inject methyl difluoroacetate and hydrogen gas with a molar ratio of 1:10. The reaction temperature is 150°C, the reaction pressure is normal pressure, and the space velocity is 5s. -1 The reaction is carried out under the conditions, and the reaction product is collected and rectified to obtain the product. After reacting for 1 hour, sampling and analysis were carried out at the outlet of the gas phase reaction tube. The conversion rate of methyl difluoroacetate was 90%, and the selectivity of difluoroethanol was 85%.

Embodiment 2

[0032] CuO / ZnO / Al 2 o 3 / Y (the molar ratio of Cu, Zn:, Al, Y is Cu:Zn:Al:Y=1:0.1:0.1:0.01) catalyst 3g is placed in a gas phase reaction tube with a diameter of 10mm and 316L, and heated to 270°C Introduce 10ml / min of hydrogen gas to activate the catalyst for 0.5h, and then inject ethyl difluoroacetate and hydrogen gas with a molar ratio of 1:8. The reaction temperature is 270°C, the reaction pressure is normal pressure, and the space velocity is 15s. -1 The reaction is carried out under the conditions, and the reaction product is collected and rectified to obtain the product. After reacting for 1 hour, sample analysis was carried out at the outlet of the gas phase reaction tube, the conversion rate was 89%, and the selectivity was 84.5%.

Embodiment 3

[0034] CuO / ZnO / Al 2 o 3 / Lu (the molar ratio of Cu, Zn:, Al, Lu is Cu:Zn:Al:Lu=1:1:0.3:0.05) the catalyst is placed in a gas phase reaction tube with a diameter of 10mm and 316L, heated to 290°C and passed through 10ml / min of hydrogen, after activating the catalyst for 0.5h, feed difluoropropyl acetate and hydrogen with a molar ratio of 1:6, the reaction temperature is 290°C, the reaction pressure is normal pressure, and the space velocity is 30s -1 The reaction is carried out under the conditions, and the reaction product is collected and rectified to obtain the product. After reacting for 1 hour, sample analysis was carried out at the outlet of the gas phase reaction tube, the conversion rate was 92%, and the selectivity was 90%.

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Abstract

The invention discloses a method for preparing difluoroethanol by gas phase catalytic hydrogenation. The method comprises the following steps: in the presence of a catalyst, mixing difluoroacetate and hydrogen in a molar ratio of 1:(1-10); carrying out a reaction under conditions that the reaction temperature is 100-400 DEG C, the reaction pressure is ordinary pressure and the reaction idling speed is 1-100/s<-1>; and collecting a reaction product and rectifying to obtain the difluoroethanol. The method disclosed by the invention has the advantages of mild reaction temperature, high raw material conversion ratio, good product selectivity and low cost.

Description

technical field [0001] The invention relates to a method for preparing fluoroalcohol, in particular to a method for preparing difluoroethanol by gas-phase catalytic hydrogenation. Background technique [0002] Difluoroethanol contains a special structure of difluoromethyl, so its properties are different from other alcohols, and it can participate in a variety of organic synthesis reactions, especially for the synthesis of fluorine-containing medicines, pesticides and dyes, and is an excellent choice for fluorine-containing fine chemicals One of the important intermediates. [0003] Difluoroethanol is usually prepared from difluoroacetic acid, difluoroacetyl chloride or difluoroacetic acid ester through reduction reaction. Among them, the process of preparing difluoroethanol by hydrogenation and reduction of difluoroacetate has a small discharge of three wastes and simple operation compared with other synthetic processes. However, in the prior art, high temperature and hig...

Claims

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Application Information

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IPC IPC(8): C07C31/38C07C29/149
CPCC07C29/149C07C31/38
Inventor 王宗令周强李宏峰
Owner ZHEJIANG JUHUA HANZHENG NEW MATERIAL
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