Method for using trichloroethylene to prepare trifluoro-acetic chloride

A technology of trifluoroacetyl chloride and trichloroethylene, which is applied in the preparation of acyl halides, halogenated hydrocarbons, chemical instruments and methods, etc., can solve the problems of poor selectivity, difficult separation, unsafety and the like, and achieves low cost and simple process. , the effect of less environmental pollution

Inactive Publication Date: 2018-09-11
JIANGSU BLUESTAR GREEN TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

US5241113 describes the preparation of TFAC by utilizing activated carbon to catalyze the oxidation of 1,1,1-trifluoro-2,2-dichloroethane, the higher reaction temperature causes the carbon-carbon bond in some raw materials to break, and the selectivity is poor
US5041647 describes the preparation of TFAC by oxidizing 1,1,1-trifluoro-2,2-dichloroethane, but water must be used as a catalyst, and the requirement for stirring to prevent local overheating in the reactor is also quite harsh, due to The presence of water to generate TFAC will be accompanied by the generation of trifluoroacetic acid (TFAA), and there are difficulties in the separation of TFAC, TFAA and water
US5259938 describes the preparation of TFAC by liquid-phase oxidation of 1,1,1-trifluoro-2,2-dichloroethane, which improves the selectivity of the reaction by filtering out the part with a wavelength of less than 280nm in the light source, while avoiding glass The corrosion problem of the reactor, the liquid phase material is required to fill the entire reactor during the reaction, and there is no buffer in the gas phase space in the reactor, which is unsafe in industrial production

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] A method for preparing trifluoroacetyl chloride from trichlorethylene, comprising the following steps:

[0020] (1) Preparation of 1,1,1-trifluoro-2,2-dichloroethane: Trichlorethylene is fluorinated and thermally chlorinated to obtain a mixed gas, and the mixed gas enters a reaction tank equipped with activated carbon for catalysis Chlorination reaction, the reaction temperature is 180-240 ° C, the speed ratio of chlorine gas and mixed gas is controlled to be 1:10-80 during the reaction catalytic process; the gas after the reaction is washed with water and alkali, and the product is obtained by fractional distillation; the activated carbon is honeycomb activated carbon, the shape Activated carbon is pre-soaked in hydrofluoric acid solution at room temperature for 24-48 hours, then cleaned with distilled water, dried in a drying oven after cleaning, and then used to further remove water or ash with nitrogen, and then activated with chlorine for 24-36 hours;

[0021] (2) ...

Embodiment 2

[0024] The difference of embodiment 2 reaction and experiment 1 is that no shading plate is added below the gas-liquid phase interface of embodiment 2, other conditions are the same as experiment 1, TFAC accounts for 90% in the gas phase product except raw material, oxygen, chlorine and hydrogen chloride gas, altogether 0.95 mol TFAC was produced. The content of 1,1,1-trifluoro-2,2-dichloroethane in the bottom liquid is 94.14%, and the by-product CFC-113a is 6.78%. Glass corrosion was found at the gas-liquid phase interface of the reactor, the gas phase part, and the condensation return pipe.

Embodiment 3

[0026] The difference between reaction and experiment 1 in embodiment 3 is that the mercury lamp power in embodiment 3 is 200w, and other conditions are the same as experiment 1, and TFAC accounts for 96% except raw material, oxygen, chlorine and hydrogen chloride gas in the gas phase product, co-generated 0.92mol TFAC. The content of 1,1,1-trifluoro-2,2-dichloroethane in the bottom liquid is 94.32%, and the by-product CFC-113a is 5.65%. No corrosion was found in the glass of the reactor, condenser, etc.

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PUM

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Abstract

The invention relates to a preparation method of compounds, in particular to a method for using trichloroethylene to prepare trifluoro-acetic chloride. The preparation method includes the following steps: (1) 1, 1, 1 three fluorine 2, 2 preparation of dichloroethane: mixed gas is obtained by the trichloroethylene through fluorination and thermal chlorination; the mixed gas enters a reaction tank filled with activated carbon for catalytic chlorination; the reaction temperature is 180-240 DEG C; the speed ratio of controlling chlorine and the mixed gas in a reaction catalysis process is 1:10-80;after reaction, the gas is washed by water alkali and fractionated to obtain products; (2) preparation of the trifluoro-acetic chloride. The preparation method of the method for using the trichloroethylene to prepare the trifluoro-acetic chloride has the advantages of being simple in process, low in cost, high in reaction conversion rate and little in environmental pollution. The method for usingthe trichloroethylene to prepare the trifluoro-acetic chloride requires gas phase space in a reactor and shading components is arranged below a gas-liquid interface. Mercury lamps are completely submerged under the shading components, thereby being capable of effectively preventing TFAC from being radiated and decomposed by the mercury lamps in the gas phase space and avoiding a corrosion problemof decomposition products to a glass reactor and lamp tubes.

Description

technical field [0001] The invention relates to a preparation method of a compound, in particular to a method for preparing trifluoroacetyl chloride from trichlorethylene. Background technique [0002] The acid chloride group in TFAC can easily react with amines and alcohols to form amides and esters respectively. It is an important raw material for the synthesis of pesticides and medicines. [0003] Several methods have been disclosed which can be used to prepare TFAC. US3883407 describes the preparation of TFAC by vapor phase oxidation of 1,1,1-trifluoro-2,2-dichloroethane with a water content of less than 0.1% by ultraviolet lamp radiation. This reaction needs to be carried out under certain temperature and pressure. And think that this reaction is not suitable for carrying out in the liquid phase, because the hydrofluoric acid generated by the side reaction will corrode the ultraviolet lamp tube. US5241113 describes the preparation of TFAC by using activated carbon to ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C53/48C07C51/58
CPCC07C17/00C07C51/58C07C53/48C07C19/12
Inventor 徐祥松尹国君张晓飞陈刚
Owner JIANGSU BLUESTAR GREEN TECH
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