Method for preparing 2-chloro-1,1,1,4,4,4-hexafluoro-2-butene

Abstract

The invention discloses a method for preparing 2-chloro-1,1,1,4,4,4-hexafluoro-2-butene. The method comprises the steps: in the presence of a liquid phase composite catalyst, hydrogen fluoride and 1,1,1,3,3-pentachloro-4,4,4-trifluorobutane are subjected to liquid phase fluorination to prepare 2-chloro-1,1,1,4,4,4-hexafluoro-2-butene, wherein the molar ratio of HF to 1,1,1,3,3-pentachloro-4,4,4-trifluorobutane is (3 to 50):1, the molar ratio of 1,1,1,3,3-pentachloro-4,4,4-trifluorobutane to the liquid phase composite catalyst is (0.1 to 3):1, the reaction temperature is 50-150 DEG C, the reaction time is 0.5-10 h, the liquid phase composite catalyst consists of metal fluoride and a compounding agent, the metal fluoride is TaF5, NbF5, TiF4 or SnF4, the compounding agent is an organic amine or a quaternary ammonium salt, and the molar ratio of the compounding agent to the metal fluoride is (0-2):1. The invention is mainly used for preparing 2-chloro-1,1,1,4,4,4-hexafluoro-2-butene.

Description

technical field [0001] The present invention relates to a method for preparing 2-chloro-1,1,1,4,4,4-hexafluoro-2-butene, in particular to 1,1,1,3,3-pentachloro-4, A method for preparing 2-chloro-1,1,1,4,4,4-hexafluoro-2-butene by liquid-phase fluorination of 4,4-trifluorobutane as a raw material. Background technique [0002] cis-1,1,1,4,4,4-hexafluoro-2-butene (Z-HFO-1336mzz) has the same foaming, heat insulation and heat preservation properties as traditional foaming agents, and its ozone depletion potential (ODP ) is zero, the greenhouse effect potential value (GWP) is 9, has little impact on the environment, and is regarded as a new generation of green and environmentally friendly blowing agent. As an important intermediate in the synthesis of Z-HFO-1336mzz, the large-scale synthesis of 2-chloro-1,1,1,4,4,4-hexafluoro-2-butene is the key to the industrial preparation of Z-HFO-1336mzz One of the techniques. [0003] Chinese patent CN 104072333B reports the synthesis of...

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Problems solved by technology

[0003] Chinese patent CN 104072333B reports the synthesis of 2-chloro-1,1,1,4,4,4 by liquid-phase fluorination of hexachlorobutadiene and anhydrous hydrogen fluoride under the catalysis of antimony pentachloride at a reaction temperature of 100°C -hexafluoro-2-butene. Under this condition, antimony pentachloride has the disadvantages of reduced valence, inactivation, poor thermal stability, etc., and its life is extremely short, making it difficult to achieve large-scale synthesis; Synthesis of 2-chloro-1,1,1,4,4,4,4-hexafluoro-2-butene from dichloro-1,1,1,4,4,4-hexafluoro-2-butene by hydrodechlorination Butene, but because the hydrogenation reaction is difficult to control, the process has problems such as poor product selectivity

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