Methods for synthesizing and purifying 1, 2, 3, 4-tetrafluorohexafluorobutane

Abstract

The invention relates to methods for synthesizing and purifying 1, 2, 3, 4-tetrafluorohexafluorobutane. The methods comprise the steps as follows: a 1, 2-difluoro-1, 2-dichloroethylene solution and fluorine gas react in a mole ratio of (0.2-0.5): 1 at the temperature ranging from subzero 20 DEG C to subzero 100 DEG C under the contion of lower than 0.1 Mpa, and an obtained solution contains 1, 2, 3, 4-tetrafluorohexafluorobutane; and the obtained solution is distilled, rectified and dried sequentially so as to obtain highly-purified 1, 2, 3, 4-tetrafluorohexafluorobutane. According to the invention, the preparation technology of 1, 2, 3, 4-tetrafluorohexafluorobutane has a short route and only requires one-step reaction and three-step purification; preparation of 1 mol of 1, 2, 3, 4-tetrafluorohexafluorobutane only requires to consume 1 mol of theoretical fluorine gas amount, and the raw material cost is reduced; the reaction temperature is low, the side reaction is reduced, and byproducts have higher economic values; the reaction is easy to control, and the operation is simple; and the raw material conversion rate is close to 100%. The methods have higher economical efficiency, and can be industrial mass production of 1, 2, 3, 4-tetrafluorohexafluorobutane.

Description

technical field [0001] The invention relates to the field of chemical industry, in particular to a method for synthesizing and purifying 1,2,3,4-tetrachlorohexafluorobutane. Background technique [0002] 1,2,3,4-Tetrachlorohexafluorobutane is the main raw material for the synthesis of hexafluoro-1,3-butadiene, and hexafluoro-1,3-butadiene is used as an etching gas for semiconductor processing. Attention, it can etch a width of 100nm or even narrower, and has high precision; at the same time, hexafluoro-1,3-butadiene has a global warming potential of 290 and a low lifetime in the atmosphere in 2 days. Therefore, the development of a synthetic method for 1,2,3,4-tetrachlorohexafluorobutane has good economic value and environmental protection significance. [0003] Currently, methods for synthesizing 1,2,3,4-tetrachlorohexafluorobutane include: [0004] 1. Synthesize 1,2,3,4-tetrachlorohexafluorobutane by using 1,2-difluoro-1,2-dichloroethylene as raw material through three-...

AI Technical Summary

Problems solved by technology

A large amount of chlorine and fluorine are consumed in the synthesis process of this method, and 2 mol of theoretical chlorine and 3 mol of theoretical fluorine are required to prepare 1 mol of 1,2,3,4-tetrachlorohexafluorobutane, so the cost is relatively high, and in the reaction process The gas HF and HCl are generated, which seriously corrodes the equipment and increases the difficulty of separation and purification; the properties of the two optical isomers of the intermediate 1,2,3,4-tetrachlorobutane in the synthesis process of this method are different Larger, increased its treatment steps; in the synthesis process of this method, due to the different degrees of chlorination and fluorination, a series of halogenated butanes will be produced, which will reduce the concentration of 1,2,3,4-tetrachlorohexafluorobutane The selectivity also makes the separation more difficult

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