A kind of method that phase transfer catalysis (PTC) prepares bromotrifluoroethylene
Technical field
The present invention relates to a kind of preparation method of bromotrifluoroethylene, more particularly to a kind of phase transfer catalysis (PTC) prepares trifluoro bromine
The method of ethene.
Background technology
Bromotrifluoroethylene has the property of Fluorine containing olefine, including halogenation, hydrogenation, necleophilic reaction, is mainly used in polymerization anti-
Should, it can also be used as chemical intermediate.Its metal organic intermediate is the reagent for synthesizing trifluoro-ethylene based compound, such as
The raw material trifluorostyrene of the sub- battery ions exchange membrane of synthetic fuel, or synthesis with superior etch performance, low GWP value it is green
Color etching gas hexachlorobutadiene etc..Bromotrifluoroethylene telomer can be used as high-precision navigation system liquid floated gyroscope and accelerometer
Supernatant liquid and damping fluid, these liquid are expensive, are widely used in aerospace industry.In addition, bromotrifluoroethylene is also to prepare
One of three kinds of monomers (tetrafluoroethene, perfluoro-methyl perfluoroalkyl vinyl ether, bromotrifluoroethylene) needed for solidification fluorubber.
The synthesis technique of bromotrifluoroethylene mainly has two lines, using trifluoro-ethylene as initiation material route and with trifluoro chlorine
Ethene is initiation material route.Late nineteenth century chemist is just by adding Br2To CF2=CFH first prepares CF2BrCHFBr
(K2CO3 and KOAc are in ethanol solution), then by product 1,2- bis- bromo- 1,1,2- HFC-143a is in alkali (sodium hydroxide, hydroxide
In the presence of potassium etc., removing hydrogen bromide obtains product bromotrifluoroethylene.Reaction equation is as follows:
Bromotrifluoroethylene is prepared using CTFE as raw material, it is necessary to by four steps, total recovery about 60%, reaction side
Formula is as follows:
CF2=CFCl+HBr → CF2BrCFClH (2)
CF2BrCFClH+Zn→CF2=CHF+ZnBrCl
CF2=CHF+Br2→CF2BrCHFBr
CF2BrCHFBr+KOH→CF2=CFBr+KBr+H2O
Above two lines intermediate product is 1,2- bis- bromo- 1,1,2- HFC-143a, subsequently by 1,2- bis- bromo- 1,1,2-
It is identical that HFC-143a dehydrobromination prepares bromotrifluoroethylene step, wherein 1,2- bis- bromo- 1,1,2- HFC-143a dehydrobromination step
Suddenly it is the committed step for restricting bromotrifluoroethylene combined coefficient.Traditional alkali lye dehydrobromination technique, due to raw material 1,2- bis- is bromo-
1,1,2- HFC-143a does not dissolve in alkali lye, there is poor mass transfer effect, reaction time length, the low problem of efficiency.
Therefore need exploitation is a kind of new to prepare bromotrifluoroethylene side by the bromo- 1,1,2- HFC-143as dehydrobrominations of 1,2- bis-
Method.
The content of the invention
It is an object of the invention to provide a kind of method that phase transfer catalysis (PTC) prepares bromotrifluoroethylene, with reaction speed
Hurry up, combined coefficient height, low cost, environmental protection the advantages of.
To reach that goal of the invention the technical solution adopted by the present invention is:
A kind of method for preparing bromotrifluoroethylene, in aqueous slkali, under phase transfer catalyst effect, 1,2- bis- bromo- 1,
Dehydrobromination reaction generation bromotrifluoroethylene occurs for 1,2- HFC-143a, wherein:
The aqueous slkali is the aqueous solution or alkali alcosol of alkali, and the alkali is selected from KOH and/or NaOH, and the alcohol is selected from
One kind, two or three of combination of the above in methanol, ethanol, normal propyl alcohol, isopropanol, n-butanol and cyclohexanol;
The phase transfer catalyst is selected from 4 bromide, tetraethylammonium bromide, TBAB, tetrabutyl chlorination
Ammonium, 4-butyl ammonium hydrogen sulfate, DTAC, DTAB, tetradecyltrimethylammonium chlorine
Change ammonium, TTAB and one kind, two or three of combination of the above in cetyl trimethylammonium bromide.
The aqueous slkali that the present invention is used both can be the aqueous solution or alkali alcosol of alkali;The quality of aqueous slkali
Percentage concentration is preferably 5.0~40.0%, and more preferably 15.0~30.0%.Suitable alcohol is preferably selected from methanol, second
One kind, two or three of combination of the above in alcohol, normal propyl alcohol, isopropanol, n-butanol and cyclohexanol, more preferably selected from second
One kind in alcohol, normal propyl alcohol and isopropanol, two or three.
The present invention improves alkali and 1 using phase transfer catalyst, and 2- bis- bromo- 1, effective contact of 1,2- HFC-143a changes
Kind mass transfer effect, greatly speeds up reaction rate, shortens the reaction time.Suitable phase transfer catalyst be selected from 4 bromide,
Tetraethylammonium bromide, TBAB, tetrabutylammonium chloride, 4-butyl ammonium hydrogen sulfate, DTAC, ten
Dialkyl group trimethylammonium bromide, tetradecyl trimethyl ammonium chloride, TTAB and cetyl trimethyl
One kind, two or three of combination of the above in ammonium bromide;It is preferably selected from 4 bromide, tetraethylammonium bromide, dodecane
One kind, two or three of combination of the above in base trimethylammonium bromide and cetyl trimethylammonium bromide.
The addition for the phase transfer catalyst that the present invention is used is preferably the bromo- 1,1,2- HFC-143as quality of 1,2- bis-
0.1~5.0%, more preferably the addition of phase transfer catalyst be 1,2- bis- bromo- 1,1,2- HFC-143a amount 0.5~
2.0%.The addition for the alkali that the present invention is used is preferably 1,2- bis- bromo- 1,0.5~4.0 times of 1,2- HFC-143a mole,
More preferably the addition of alkali is 1.5~2.0 times of the bromo- 1,1,2- HFC-143as moles of 1,2- bis-.
In the method for the present invention for preparing bromotrifluoroethylene, the aqueous solution or alkali of used phase transfer catalyst and alkali
Alcoholic solution can recycled, the yield of bromotrifluoroethylene is not influenceed.
The raw material 1 that the present invention is used, 2- bis- bromo- 1,1,2- HFC-143a can be by trifluoro-ethylene or CTFE system
It is standby.
Present invention also offers a kind of processing step for preparing bromotrifluoroethylene, including:
(1) a certain amount of aqueous slkali input reactor is configured, the mass percentage concentration of aqueous slkali is 5.0~40.0%;
(2) a certain proportion of phase transfer catalyst is added into reactor, addition phase transfer catalysis (PTC) dosage is that 1,2- bis- is bromo-
The 0.1~5.0% of 1,1,2- HFC-143a quality;
(3) stirring and condensation reflux unit are opened, 40~120 DEG C of reaction temperature is risen to;
(4) raw material 1 is added dropwise into reactor, 2- bis- bromo- 1,1,2- HFC-143a controls the addition of alkali for 1,2- bis-
0.5~4.0 times of bromo- 1,1,2- HFC-143a mole, product is collected using low temperature cold hydrazine;
(5) 1~8h is incubated after the bromo- 1,1,2- HFC-143as completion of dropwise addition of 1,2- bis-;
(6) room temperature is down to, is filtered, point liquid obtains organic phase and aqueous phase, and wherein organic phase is bromotrifluoroethylene.
For the aqueous phase obtained in reaction, by that toward a certain amount of alkali is added in aqueous phase, Bromide solid can be separated out, carried out
Filtering, liquid can be used as the alkali lye of next secondary response, realize the recycled of spent lye, substantially reduce three-protection design amount.
Compared with prior art, the present invention has advantages below:Do not changing the feelings of original reaction system and reaction condition
Under condition, by adding phase transfer catalyst, promote effective contact of reaction mass, improve mass transfer effect, reaction speed can be accelerated
Rate, shortens the reaction time, improves production efficiency;The recycled of phase transfer catalyst and alkali lye can be realized simultaneously, reduce the three wastes,
Reduce production cost.
Embodiment
The present invention is further described with reference to specific embodiment, but does not limit the invention to these tools
Body embodiment.One skilled in the art would recognize that present invention encompasses potentially included in Claims scope
All alternatives, improvement project and equivalents.
Embodiment 1
250ml three-necked flasks are placed in oil bath pan, 1# cold hydrazines are filled on three-necked flask is used for flow back unreacted raw material, 1#
Cold hydrazine temperature is -2 DEG C, and 2# cold hydrazines are refilled after 1# cold hydrazines is used for the collection of product, and 2# cold hydrazines temperature is -20 DEG C.In three-necked flask
It is 30%KOH and 0.9g DTACs to add 69g concentration, and by 60g raw materials 1,2- bis- bromo- 1,1,2- trifluoro
Ethane loads constant pressure funnel (NaOH:CF2BrCHFBr=1.5:1 mol ratio).When oil bath pan is warming up to 70 DEG C, while stirring
Raw material CF is added dropwise into three-necked flask2BrCHFBr, is added dropwise to complete follow-up continuation of insurance temperature 5h.Reaction result is shown in Table 1.
Embodiment 2
250ml three-necked flasks are placed in oil bath pan, 1# cold hydrazines are filled on three-necked flask is used for flow back unreacted raw material, 1#
Cold hydrazine temperature is -2 DEG C, and 2# cold hydrazines are refilled after 1# cold hydrazines is used for the collection of product, and 2# cold hydrazines temperature is -20 DEG C.In three-necked flask
It is 30%KOH and 0.9g DTACs to add 69g concentration, and by 60g raw materials 1,2- bis- bromo- 1,1,2- trifluoro
Ethane loads constant pressure funnel (NaOH:CF2BrCHFBr=1.5:1 mol ratio).When oil bath pan is warming up to 70 DEG C, while stirring
Raw material CF is added dropwise into three-necked flask2BrCHFBr, is added dropwise to complete follow-up continuation of insurance temperature 4h.Reaction result is shown in Table 1.
Embodiment 3
250ml three-necked flasks are placed in oil bath pan, 1# cold hydrazines are filled on three-necked flask is used for flow back unreacted raw material, 1#
Cold hydrazine temperature is -2 DEG C, and 2# cold hydrazines are refilled after 1# cold hydrazines is used for the collection of product, and 2# cold hydrazines temperature is -20 DEG C.In three-necked flask
It is 30%KOH and 0.9g DTACs to add 69g concentration, and by 60g raw materials 1,2- bis- bromo- 1,1,2- trifluoro
Ethane loads constant pressure funnel (NaOH:CF2BrCHFBr=1.5:1 mol ratio).When oil bath pan is warming up to 70 DEG C, while stirring
Raw material CF is added dropwise into three-necked flask2BrCHFBr, is added dropwise to complete follow-up continuation of insurance temperature 3h.Reaction result is shown in Table 1.
Embodiment 4
250ml three-necked flasks are placed in oil bath pan, 1# cold hydrazines are filled on three-necked flask is used for flow back unreacted raw material, 1#
Cold hydrazine temperature is -2 DEG C, and 2# cold hydrazines are refilled after 1# cold hydrazines is used for the collection of product, and 2# cold hydrazines temperature is -20 DEG C.In three-necked flask
It is 30%KOH and 0.9g TBABs to add 69g concentration, and by 60g raw materials 1,2- bis- bromo- 1,1,2- HFC-143a loads
Constant pressure funnel (NaOH:CF2BrCHFBr=1.5:1 mol ratio).When oil bath pan is warming up to 70 DEG C, burnt while stirring to three mouthfuls
Raw material CF is added dropwise in bottle2BrCHFBr, is added dropwise to complete follow-up continuation of insurance temperature 3h.Reaction result is shown in Table 1.
Embodiment 5
250ml three-necked flasks are placed in oil bath pan, 1# cold hydrazines are filled on three-necked flask is used for flow back unreacted raw material, 1#
Cold hydrazine temperature is -2 DEG C, and 2# cold hydrazines are refilled after 1# cold hydrazines is used for the collection of product, and 2# cold hydrazines temperature is -20 DEG C.In three-necked flask
It is 30%KOH and 0.9g 4 bromides to add 69g concentration, and by 60g raw materials 1,2- bis- bromo- 1,1,2- HFC-143a loads
Constant pressure funnel (NaOH:CF2BrCHFBr=1.5:1 mol ratio).When oil bath pan is warming up to 70 DEG C, burnt while stirring to three mouthfuls
Raw material CF is added dropwise in bottle2BrCHFBr, is added dropwise to complete follow-up continuation of insurance temperature 3h.Reaction result is shown in Table 1.
Embodiment 6
250ml three-necked flasks are placed in oil bath pan, 1# cold hydrazines are filled on three-necked flask is used for flow back unreacted raw material, 1#
Cold hydrazine temperature is -2 DEG C, and 2# cold hydrazines are refilled after 1# cold hydrazines is used for the collection of product, and 2# cold hydrazines temperature is -20 DEG C.In three-necked flask
It is 30%KOH and 0.9g cetyl trimethylammonium bromides to add 69g concentration, and by 60g raw materials 1,2- bis- bromo- 1,1,2- trifluoro
Ethane loads constant pressure funnel (NaOH:CF2BrCHFBr=1.5:1 mol ratio).When oil bath pan is warming up to 70 DEG C, while stirring
Raw material CF is added dropwise into three-necked flask2BrCHFBr, is added dropwise to complete follow-up continuation of insurance temperature 3h.Reaction result is shown in Table 1.
Embodiment 7
250ml three-necked flasks are placed in oil bath pan, 1# cold hydrazines are filled on three-necked flask is used for flow back unreacted raw material, 1#
Cold hydrazine temperature is -2 DEG C, and 2# cold hydrazines are refilled after 1# cold hydrazines is used for the collection of product, and 2# cold hydrazines temperature is -20 DEG C.In three-necked flask
It is 30%KOH and 1.2g DTACs to add 69g concentration, and by 60g raw materials 1,2- bis- bromo- 1,1,2- trifluoro
Ethane loads constant pressure funnel (NaOH:CF2BrCHFBr=1.5:1 mol ratio).When oil bath pan is warming up to 70 DEG C, while stirring
Raw material CF is added dropwise into three-necked flask2BrCHFBr, is added dropwise to complete follow-up continuation of insurance temperature 3h.Reaction result is shown in Table 1.
Embodiment 8
250ml three-necked flasks are placed in oil bath pan, 1# cold hydrazines are filled on three-necked flask is used for flow back unreacted raw material, 1#
Cold hydrazine temperature is -2 DEG C, and 2# cold hydrazines are refilled after 1# cold hydrazines is used for the collection of product, and 2# cold hydrazines temperature is -20 DEG C.In three-necked flask
It is 30%KOH and 0.6g DTACs to add 69g concentration, and by 60g raw materials 1,2- bis- bromo- 1,1,2- trifluoro
Ethane loads constant pressure funnel (NaOH:CF2BrCHFBr=1.5:1 mol ratio).When oil bath pan is warming up to 70 DEG C, while stirring
Raw material CF is added dropwise into three-necked flask2BrCHFBr, is added dropwise to complete follow-up continuation of insurance temperature 3h.Reaction result is shown in Table 1.
Embodiment 9
250ml three-necked flasks are placed in oil bath pan, 1# cold hydrazines are filled on three-necked flask is used for flow back unreacted raw material, 1#
Cold hydrazine temperature is -2 DEG C, and 2# cold hydrazines are refilled after 1# cold hydrazines is used for the collection of product, and 2# cold hydrazines temperature is -20 DEG C.In three-necked flask
It is 30%KOH and 0.3g DTACs to add 69g concentration, and by 60g raw materials 1,2- bis- bromo- 1,1,2- trifluoro
Ethane loads constant pressure funnel (NaOH:CF2BrCHFBr=1.5:1 mol ratio).When oil bath pan is warming up to 70 DEG C, while stirring
Raw material CF is added dropwise into three-necked flask2BrCHFBr, is added dropwise to complete follow-up continuation of insurance temperature 3h.Reaction result is shown in Table 1.
Comparative example 1
250ml three-necked flasks are placed in oil bath pan, 1# cold hydrazines are filled on three-necked flask is used for flow back unreacted raw material, 1#
Cold hydrazine temperature is -2 DEG C, and 2# cold hydrazines are refilled after 1# cold hydrazines is used for the collection of product, and 2# cold hydrazines temperature is -20 DEG C.In three-necked flask
It is 20%NaOH to add 69g concentration, and by 60g raw materials 1,2- bis- bromo- 1,1,2- HFC-143a loads constant pressure funnel (NaOH:
CF2BrCHFBr=1.5:1 mol ratio).When oil bath pan is warming up to 70 DEG C, raw material is added dropwise into three-necked flask while stirring
CF2BrCHFBr, is added dropwise to complete follow-up continuation of insurance temperature 5h.Reaction result is shown in Table 1.
Comparative example 2
250ml three-necked flasks are placed in oil bath pan, 1# cold hydrazines are filled on three-necked flask is used for flow back unreacted raw material, 1#
Cold hydrazine temperature is -2 DEG C, and 2# cold hydrazines are refilled after 1# cold hydrazines is used for the collection of product, and 2# cold hydrazines temperature is -20 DEG C.In three-necked flask
It is 20%NaOH to add 69g concentration, and by 60g raw materials 1,2- bis- bromo- 1,1,2- HFC-143a loads constant pressure funnel (NaOH:
CF2BrCHFBr=1.5:1 mol ratio).When oil bath pan is warming up to 120 DEG C, raw material is added dropwise into three-necked flask while stirring
CF2BrCHFBr, is added dropwise to complete follow-up continuation of insurance temperature 5h.Reaction result is shown in Table 1.
Comparative example 3
250ml three-necked flasks are placed in oil bath pan, 1# cold hydrazines are filled on three-necked flask is used for flow back unreacted raw material, 1#
Cold hydrazine temperature is -2 DEG C, and 2# cold hydrazines are refilled after 1# cold hydrazines is used for the collection of product, and 2# cold hydrazines temperature is -20 DEG C.In three-necked flask
It is 20%NaOH to add 33g concentration, and by 60g raw materials 1,2- bis- bromo- 1,1,2- HFC-143a loads constant pressure funnel (NaOH:
CF2BrCHFBr=0.7:1 mol ratio).When oil bath pan is warming up to 70 DEG C, raw material is added dropwise into three-necked flask while stirring
CF2BrCHFBr, is added dropwise to complete follow-up continuation of insurance temperature 5h.Reaction result is shown in Table 1.
Comparative example 4
250ml three-necked flasks are placed in oil bath pan, 1# cold hydrazines are filled on three-necked flask is used for flow back unreacted raw material, 1#
Cold hydrazine temperature is -2 DEG C, and 2# cold hydrazines are refilled after 1# cold hydrazines is used for the collection of product, and 2# cold hydrazines temperature is -20 DEG C.In three-necked flask
It is 20%NaOH to add 115g concentration, and by 60g raw materials 1,2- bis- bromo- 1,1,2- HFC-143a loads constant pressure funnel (NaOH:
CF2BrCHFBr=2.5:1 mol ratio).When oil bath pan is warming up to 70 DEG C, raw material is added dropwise into three-necked flask while stirring
CF2BrCHFBr, is added dropwise to complete follow-up continuation of insurance temperature 5h.Reaction result is shown in Table 1.
Comparative example 5
250ml three-necked flasks are placed in oil bath pan, 1# cold hydrazines are filled on three-necked flask is used for flow back unreacted raw material, 1#
Cold hydrazine temperature is -2 DEG C, and 2# cold hydrazines are refilled after 1# cold hydrazines is used for the collection of product, and 2# cold hydrazines temperature is -20 DEG C.In three-necked flask
It is 20%NaOH to add 161g concentration, and by 60g raw materials 1,2- bis- bromo- 1,1,2- HFC-143a loads constant pressure funnel (NaOH:
CF2BrCHFBr=3.5:1 mol ratio).When oil bath pan is warming up to 70 DEG C, raw material is added dropwise into three-necked flask while stirring
CF2BrCHFBr, is added dropwise to complete follow-up continuation of insurance temperature 5h.Reaction result is shown in Table 1.
The reaction result carried out under the different condition of table 1.
As can be known from Table 1, added in reaction system after phase transfer catalyst, because phase transfer catalyst is promoted instead
Effective contact of material is answered, improves mass transfer effect, accelerate reaction rate, not only under identical soaking time, the conversion ratio of reaction is equal
Have obvious rise, even and if shorten soaking time, the conversion ratio of reaction is also apparently higher than the reactant for being not added with catalyst
System.
Embodiment 10
Present embodiment describes the recycled technique that the present invention realizes phase transfer catalyst and alkali lye:First set reaction is protected
Temperature is down to room temperature after terminating, and filters out Bromide, and carry out a point liquid to organic phase and aqueous phase;A certain amount of alkali is added in aqueous phase
It is 30% to concentration of lye, filters the Bromide solid now separated out, due to filtering and dividing in liquid operating process, phase transfer is urged
Agent has a certain amount of loss, applies mechanically be both needed to add a certain amount of catalyst every time, other specific operations are implemented with contrast
Example 1 is identical, and reaction temperature is 70 DEG C, and alkali lye is 30%KOH solution, and soaking time 3h, reaction result is as shown in table 2.
Reaction result under the conditions of the phase transfer catalyst of table 2. and alkali lye recycled