A kind of synthetic method of chloro-2,2-bis(perfluoro substituent)-1,3-dioxolane compounds

Abstract

The invention discloses a method for synthesizing chloro-2, 2-di (perfluoroalkyl)-1, 3-dioxolane. The method comprises the following steps: mixing 2, 2-di (perfluoroalkyl)-1, 3-dioxolane liquid with acatalyst, introducing chlorine gas, heating to the temperature of 100-200 DEG C, and carrying out chlorination reaction to obtain 4, 4, 5, 5-tetrachloro-2, 2-di (perfluoro substituent)-1, 3-dioxolane. The perfluoroalkyl is independently selected from C1-4 perfluoroalkyls or fluorine atoms. According to the method, liquid-phase chlorination reaction is adopted, the reaction temperature is effectively reduced, the activity of the catalyst in the reaction is high, the side reaction is relieved, the requirements on equipment are reduced, the method is safe and simple to operate, the quality stability of the obtained product is high, and the industrial application feasibility is high.

Description

technical field [0001] The invention relates to the synthesis of fluorine-containing organic compounds, in particular to a synthesis method of chloro-2,2-bis(perfluoro substituent)-1,3-dioxolane compounds. Background technique [0002] Halogenated 2,2-bis(perfluorosubstituent)-1,3-dioxolane compounds are an important class of intermediates, which can be used to synthesize a variety of monomers for preparing high-end polymers. Such as 4,5-dichloro-4,5-difluoro-2,2-bis(trifluoromethyl)-1,3-dioxolane, the 4,5-difluoro -2,2-bis(trifluoromethyl)-1,3-dioxole ("PDD" for short), can be used as a monomer to prepare high-end, transparent and amorphous fluoropolymers. Therefore, it is necessary to develop a method suitable for large-scale industrial production of halogenated 2,2-bis(perfluorosubstituent)-1,3-dioxolane compounds. [0003] The synthesis method of chloro-2,2-bis(perfluoro substituent)-1,3-dioxolane compounds is disclosed in the prior art, specifically: [0004] (1) U.S...

AI Technical Summary

Problems solved by technology

[0007] The reaction selectivity of the above-mentioned photochlorination method is poor, and multi-step reactions are required to obtain 4,4,5,5,-tetrachloro-2,2-bis(perfluorosubstituent)-1,3-dioxolane , so the limitation of this method is prominent, and the industrial application is difficult

[0008] In addition, the Chinese patent application document with the publication number CN201684601U discloses the problems existing in the existing photochlorination reaction devices: the material can only exist in a single-phase form; all of them are batch reactions, and continuous production cannot be realized; the product quality cannot be online control

The Chinese patent application document with the publication number CN107417490A discloses the defects in the prior art of photochlorination reaction: free radical chain reaction, many side reactions, relatively difficult control of chlorination site and chlorination depth; in order to enhance reaction selection nature, it is often necessary to introduce a variety of auxiliary components, which is not suitable for the preparation of high-purity products; the reaction needs to add a free radical initiator to start the reaction; the reaction is highly exothermic, the heat of reaction is difficult to control, and it is prone to excessive chlorination and other side reactions. Tar substances, when these substances appear, can only be treated as waste, which has a considerable adverse effect on product quality

[0010] The reaction temperature of the above method is as high as 250-300°C, the conditions are harsh, the requirements for the reaction device are high, and the heat release of the perchlorination reaction is serious. During the enlarged production process, the axial temperature difference of the reactor will be large, and the local temperature will be too high, which will make the catalyst Easy to deactivate and coke

At the same time, due to the unique structure of 1,3-dioxolane, the raw materials are prone to side reactions such as over-chlorination and decomposition during the high-temperature chlorination process, which affects the stability of product quality

This method puts forward higher requirements for reactor design and high requirements for operating conditions, which further increases production costs and is not suitable for large-scale production applications.

Images