Method for preparing trifluoroacetyl chloride from 2,2-dichloro-1,1,1-trifluoroethane

A technology of trifluoroacetyl chloride and trifluoroethane, which is applied in the field of compound preparation and can solve problems such as corrosion of ultraviolet lamps

Inactive Publication Date: 2010-06-16
杭州原正工程技术装备有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

US3883407, has described and is less than 0.1% HCFC-123 preparation TFAC by ultraviolet lamp radiation vapor phase oxidation, this reaction needs just can carry out under certain temperature and pressure, and thinks that this reaction is not suitable for carrying out in liquid phase, because The hydrofluoric acid generated by the side reaction will corrode the UV lamp

Method used

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  • Method for preparing trifluoroacetyl chloride from 2,2-dichloro-1,1,1-trifluoroethane
  • Method for preparing trifluoroacetyl chloride from 2,2-dichloro-1,1,1-trifluoroethane
  • Method for preparing trifluoroacetyl chloride from 2,2-dichloro-1,1,1-trifluoroethane

Examples

Experimental program
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Effect test

Embodiment 1

[0029] Add 1L of HCFC-123 into a 1L special glass flask. The middle interface on the top of the flask is a mercury lamp installation port. Place a 500w mercury lamp, quartz cold hydrazine, and quartz sleeve in sequence from the inside to the outside. The sleeve and the interface are sealed. Continuously feed oxygen and chlorine under stirring, flow rate is respectively 75ml / min and 15ml / min, open mercury lamp after 15 minutes, carry out photochemical oxidation reaction by mercury lamp radiation, react at normal pressure, material bubble point temperature (about 28°C). The reactant is continuously discharged from the gas phase outlet on the upper part of the reactor in the form of gas phase, and the liquid level in the reactor is kept constant by continuously adding HCFC-123 through the dropping funnel, and the supplementary speed is determined by the reaction rate; the continuously discharged reactant includes HCFC vaporized during the reaction -123, product TFAC, by-product h...

Embodiment 2

[0033]The difference between the reaction of Example 2 and Example 1 is that an ice water bath is added outside the flask in Example 2 to control the reaction temperature in the flask to be 10°C, and other conditions are the same as in Experiment 1, except for HCFC-123, oxygen, and chlorine in the gas phase products TFAC accounts for 94% with hydrogen chloride gas, and generates 0.78mol TFAC in total. The content of HCFC-123 in the bottom liquid is 95.21%, and the by-product CFC-113a is 4.74%. After several batches of continuous reaction, corrosion was found in the glass of the reactor, quartz tube, and reflux condenser.

Embodiment 3

[0035] Reaction in embodiment 3 is different from experiment 1 in that the reaction pressure of embodiment 3 is 0.05MPa, and reaction temperature is the bubble point temperature (about 10 ℃) of material in the reactor, and other conditions are identical with experiment 1, except that HCFC-123, oxygen, chlorine and hydrogen chloride gas accounted for 98% of TFAC, and a total of 0.80mol TFAC was generated. The content of HCFC-123 in the bottom liquid is 95.11%, and the by-product CFC-113a is 4.77%. After several batches of continuous reaction, no corrosion phenomenon was found in glass such as reactor, quartz tube and reflux condenser tube.

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Abstract

The invention discloses a method for preparing trifluoroacetyl chloride (TFAC) from 2,2-dichloro-1,1,1-trifluoroethane (HCFC-123), comprising the following steps: 1) HCFC-123 is added into a reactor, oxygen and chlorine are continuously introduced while stirring, photochemical oxidation reaction is carried out through mercury lamp radiation, the reactant is continuously exhausted from the upper part of the reactor in the form of gas phase, and the liquid level in the reactor keeps constant by continuously supplementing HCFC-123; and 2) the vaporized HCFC-123 in the reaction is condensed by a condenser or a condensation and separation tower and flows back into the reactor to continue participating in the reaction, the product TFAC is exhausted from the top of the condenser or the condensation and separation tower and is collected after compression and condensation, the by-product hydrogen chloride is absorbed by water washing and the unreacted chlorine is absorbed by alkali washing. In the invention, reaction is required to be carried out at or above the bubble point temperature of the materials in the reactor, thus being beneficial to ensuring the product TFAC to rapidly escape from the materials in the reactor and preventing TFAC from radiation decomposition by the mercury lamp; meanwhile, plentiful reaction heat can be transferred through phase change of the materials in the reactor, thus solving the problem of safely transferring the reaction heat.

Description

technical field [0001] The present invention relates to a compound preparation method, in particular to a method for preparing trifluoroacetyl chloride from 2,2-dichloro-1,1,1-trifluoroethane. 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, has described and is less than 0.1% HCFC-123 preparation TFAC by ultraviolet lamp radiation vapor phase oxidation, this reaction needs just can carry out under certain temperature and pressure, and thinks that this reaction is not suitable for carrying out in liquid phase, because The hydrofluoric acid produced by the side reaction will corrode the UV lamp. US5259938 describes the preparation of TFAC by liquid-phase oxidation of HCFC-123. By filtering out the part with a wave...

Claims

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Application Information

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IPC IPC(8): C07C53/48C07C51/58
Inventor 赵建明韩箴贤崔觉剑
Owner 杭州原正工程技术装备有限公司
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