阅读说明：本技术 1,2-二溴-1-氯-1,2,2-三氟乙烷的制备方法 (Preparation method of 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane ) 是由 邹小毛 侯文萧 许辉 王如军 张振国 赵宝修 张枭 于 2019-10-24 设计创作，主要内容包括：本发明属于含氟精细化工领域,涉及一种1,2-二溴-1-氯-1,2,2-三氟乙烷的制备方法。本发明是将三氟氯乙烯经溴代加成反应制备1,2二溴-1-氯-1,2,2-三氟乙烷。具体技术方案是：本发明以1,2二溴-1-氯-1,2,2-三氟乙烷为溶剂,避免了使用其它有机溶剂时产物和溶剂需要分离的缺点。本发明采用的1,2-二溴-1-氯-1,2,2-三氟乙烷与液溴的质量比为1：1～1：3。反应温度优选-30～70℃,进一步优选20～60℃。本发明提供的方法具有环保、操作简便无需分离、无需溶剂回收、能耗低的优点。本发明主要用于1,2-二溴-1-氯-1,2,2-三氟乙烷的制备。(The invention belongs to the field of fluorine-containing fine chemical engineering, and relates to a preparation method of 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane. The invention prepares 1,2 dibromo-1-chloro-1, 2, 2-trifluoroethane by bromoaddition reaction of chlorotrifluoroethylene. The specific technical scheme is as follows: the invention takes 1,2 dibromo-1-chloro-1, 2, 2-trifluoroethane as a solvent, and avoids the defect that products and the solvent need to be separated when other organic solvents are used. The mass ratio of the 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane to the liquid bromine adopted by the invention is 1: 1-1: 3. the reaction temperature is preferably-30 to 70 ℃, and more preferably 20 to 60 ℃. The method provided by the invention has the advantages of environmental protection, simple and convenient operation, no need of separation, no need of solvent recovery and low energy consumption. The method is mainly used for preparing the 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane.)

1. A method for preparing 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane is characterized in that 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane is used as a solvent.

2. The process for producing 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane according to claim 1, wherein the reaction temperature is-30 to 70 ℃.

3. The process for producing 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane according to claim 2, wherein the reaction temperature is 20 to 60 ℃.

4. The process for producing 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane according to claim 1, wherein the 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane is subjected to suction filtration and nitrogen purging to obtain 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane having a purity of more than 99%.

The technical field is as follows:

the invention belongs to the field of fluorine-containing fine chemical engineering, and relates to a preparation method of 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane.

Background art:

1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane (1,2-dibromo-1-chloro-1,1,2-trifluoroethane, abbreviated as BCTFE) is an important fluorine-containing organic intermediate and can be used in the fields of pesticides, medicines, materials and the like.

In the prior art, the following reports are available for the preparation method of 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane: the 1, 2-bromo-1-chloro-1, 2, 2-trifluoroethane is prepared by the addition of chlorotrifluoroethylene and bromine.

US2003181615 discloses introducing chlorotrifluoroethylene at-80 ℃ and then heating to-40 ℃ for reaction. The industrialized low-temperature reaction at-40 ℃ has high energy consumption, and does not meet the requirements of energy conservation and emission reduction. European patent EP1418163 discloses passing chlorotrifluoroethylene gas through liquid bromine at room temperature to decolorization. Liquid bromine has a strong toxicity and corrosion. At normal temperature, the product can volatilize smoke with strong swimming irritation, irritate mucosa of eyes and respiratory tract, cause people to lacrimate and cough, burn skin, and cause severe stabbing pain, which is very unfavorable for operators. Meanwhile, the liquid bromine is used, which is not beneficial to environmental protection.

ZHAO, Jingwei in 2009 reported the use of 1,1, 2-trichlorotrifluoroethane (Freon 113) as the reaction solvent, with chlorotrifluoroethylene being slowly passed into solution at 0 ℃. After the reaction is completed, distillation operation and solvent recovery are required. Therefore, the above method is extremely disadvantageous in terms of cost, energy saving and environmental protection.

Therefore, there is a need to develop a novel process for preparing 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane.

The invention content is as follows:

the invention aims to provide a preparation method of 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane, which has the advantages of environmental protection, simple and convenient operation, no need of separation, no need of solvent recovery, low energy consumption and low cost.

The technical scheme adopted by the invention for achieving the purpose is as follows: 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane is used as a solvent, and chlorotrifluoroethylene is subjected to bromination addition reaction to prepare the 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane.

The mass ratio of the 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane to the liquid bromine adopted by the invention is as follows: 1: 1-1: 3.

the reaction temperature adopted by the method is preferably-30-70 ℃, and further preferably 20-60 ℃.

The invention adopts 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane as the solvent, avoids the defect that the product and the solvent need to be separated when an organic solvent is used, and the reaction product can be subjected to suction filtration and nitrogen purging to obtain the 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane with the purity of 100 percent, namely the 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane.

The method has simple operation and high yield, and is suitable for industrial production.

Detailed Description

The present invention is further illustrated by the following examples, which are not intended to limit the invention to these embodiments. :

example 1: synthesis of 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane

100g of 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane and 100g (0.626mol) of liquid bromine were charged into a 250ml three-necked round-bottomed flask, and the reaction system was magnetically stirred at 25 ℃. And (3) slowly introducing chlorotrifluoroethylene gas into the reaction system until the reddish brown of the reaction system fades. After the reaction, insoluble impurities were removed by suction filtration, and excess chlorotrifluoroethylene was removed by nitrogen purging the solution to obtain 266.21g of a colorless transparent liquid. The content of 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane was 99.53% by GC analysis, and the yield was 95.69%.

Example 2: synthesis of 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane

100g of 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane and 100g (0.626mol) of liquid bromine were charged into a 250ml three-necked round-bottomed flask, and the reaction system was magnetically stirred at 40 ℃. And (3) slowly introducing chlorotrifluoroethylene gas into the reaction system until the reddish brown of the reaction system fades. After the reaction, insoluble impurities were removed by suction filtration, and excess chlorotrifluoroethylene was removed by nitrogen purging the solution to obtain 265.63g of a colorless transparent liquid. The content of 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane was 99.65% by GC analysis, and the yield was 95.47%.

Example 3: synthesis of 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane

100g of 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane and 100g (0.626mol) of liquid bromine were charged into a 250ml three-necked round-bottomed flask, and the reaction system was magnetically stirred at 60 ℃. And (3) slowly introducing chlorotrifluoroethylene gas into the reaction system until the reddish brown of the reaction system fades. After the reaction, insoluble impurities were removed by suction filtration, and excess chlorotrifluoroethylene was removed by nitrogen purging the solution to obtain 266.47g of a colorless transparent liquid. The content of 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane was 99.26% by GC analysis, and the yield was 94.93%.

Comparative example 1: synthesis of 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane

100g of 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane and 100g (0.626mol) of liquid bromine were charged into a 250ml three-necked round-bottomed flask, and the reaction system was placed in a low-temperature reaction bath at-30 ℃ and mechanically stirred. And (3) slowly introducing chlorotrifluoroethylene gas into the reaction system until the reddish brown of the reaction system fades. After the reaction is finished, insoluble impurities are removed by suction filtration. The content of 1,2-dibromo-1-chloro-1, 2, 2-trifluoroethane was 95.10% by GC analysis, and the yield was 91.46%.