U.S. patent application number 14/663418 was filed with the patent office on 2015-07-09 for method for producing 1,2-dichloro-3,3,3-trifluoropropene.
The applicant listed for this patent is CENTRAL GLASS COMPANY, LIMITED. Invention is credited to Yoshio NISHIGUCHI, Satoru OKAMOTO, Fuyuhiko SAKYU.
Application Number | 20150191406 14/663418 |
Document ID | / |
Family ID | 50341550 |
Filed Date | 2015-07-09 |
United States Patent
Application |
20150191406 |
Kind Code |
A1 |
NISHIGUCHI; Yoshio ; et
al. |
July 9, 2015 |
METHOD FOR PRODUCING 1,2-DICHLORO-3,3,3-TRIFLUOROPROPENE
Abstract
A method for producing 1,2-dichloro-3,3,3-trifluoropropene of
the present invention includes reacting
1,2-dichloro-1-halogeno-3,3,3-trifluoropropane with a base in a
liquid phase; and extracting generated
1,2-dichloro-3,3,3-trifluoropropene to the outside of a reaction
system to recover while the reaction is continued. According to the
present invention, 1,2-dichloro-3,3,3-trifluoropropene is obtained
at a high yield by a simple method. Thus,
1,2-dichloro-3,3,3-trifluoropropene is produced in an industrial
scale.
Inventors: |
NISHIGUCHI; Yoshio;
(Kawagoe-shi, JP) ; OKAMOTO; Satoru; (Kawagoe-shi,
JP) ; SAKYU; Fuyuhiko; (Kawagoe-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CENTRAL GLASS COMPANY, LIMITED |
Ube City |
|
JP |
|
|
Family ID: |
50341550 |
Appl. No.: |
14/663418 |
Filed: |
March 19, 2015 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
PCT/JP2013/075540 |
Sep 20, 2013 |
|
|
|
14663418 |
|
|
|
|
Current U.S.
Class: |
570/155 |
Current CPC
Class: |
C07C 17/23 20130101;
C07C 21/18 20130101; C07C 17/25 20130101; C07C 17/25 20130101 |
International
Class: |
C07C 17/25 20060101
C07C017/25 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 21, 2012 |
JP |
2012-207928 |
Claims
1. A method for producing 1,2-dichloro-3,3,3-trifluoropropene
comprising: reacting 1,2-dichloro-1-halogeno-3,3,3-trifluoropropane
represented by formula [1] as shown below with a base in a liquid
phase; and extracting the generated
1,2-dichloro-3,3,3-trifluoropropene to the outside of a reaction
system to recover while the reaction is continued: ##STR00003## (in
the formula, X represents fluorine, chlorine or bromine).
2. A method according to claim 1, wherein the reaction of the
1,2-dichloro-1-halogeno-3,3,3-trifluoropropane with the base is
caused with neither a phase transfer catalyst nor a compatibilizer
being present.
3. A method according to claim 1, wherein the base is at least one
inorganic base selected from the group consisting of alkaline metal
alkoxides, carbonates of alkaline metals, carbonates of alkaline
earth metals, hydroxides of alkaline metals, and hydroxides of
alkaline earth metals.
4. A method according to claim 1, wherein the
1,2-dichloro-1-halogeno-3,3,3-trifluoropropane is
1,1,2-trichloro-3,3,3-trifluoropropane.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is based upon and claims the benefit of
priority from Japanese Patent Applications No. 2012-207928 filed on
Sep. 21, 2012 and the prior PCT Application PCT/JP2013/075540 filed
on Sep. 20, 2013, the entire contents of which are incorporated
herein by reference.
FIELD
[0002] The present invention relates to a method for producing
1,2-dichloro-3,3,3-trifluoropropene.
BACKGROUND
[0003] 1,2-dichloro-3,3,3-trifluoropropene includes an unsaturated
bond, and is expected to provide a function of a cleaner or a
coolant as hydrochlorofluorocarbon (HCFC), which is relatively
easily decomposed in the atmosphere.
[0004] There are various known methods for producing
1,2-dichloro-3,3,3-trifluoropropene. For example, A. L. Henne et
al., J. Am. Chem. Soc., 1941, pp. 3478-3479 discloses a method of
reacting 1,2,3,3,3-pentachloropropene with antimony trifluoride in
a liquid phase.
[0005] A. M. Whaley et al., J. Am. Chem. Soc., 1948, pp. 1026-1027
discloses a method of reacting 1,1,2,3,3-pentachloropropene and
antimony trifluoride with adding antimony pentachloride in a liquid
phase. R. N. Haszeldine et al., J. Chem. Soc., 1951, pp 2495-2504
discloses a method of adding potassium hydroxide in a solid state
to 1,2,2-trichloro-3,3,3-trifluoropropane in a liquid state and
refluxing, while heating, the resultant substance to produce
1,2-dichloro-3,3,3-trifluoropropene.
[0006] Regarding a reaction of 1,2-dichloro-3,3,3-trifluoropropene,
U.S. Pat. No. 2,739,987 discloses that a reaction of
1,2-dichloro-3,3,3-trifluoropropene with methanol in the presence
of potassium hydroxide generates
1-chloro-2-methoxy-3,3,3-trifluoropropene.
[0007] WO2012/112827 discloses that a reaction of
1,2-dichloro-3,3,3-trifluoropropene with a base generates
1-chloro-3,3,3-trifluoropropyne.
[0008] According to the production method described in R. N.
Haszeldine et al., J. Chem. Soc., 1951, pp 2495-2504, powdery
potassium hydroxide is dispersed in
1,2,2-trichloro-3,3,3-trifluoropropane in a liquid state to cause a
reaction. However, the yield is low (48%) and the reaction is not
uniform. Therefore, this method is not considered to be efficient
as an industrial production method.
[0009] As can be seen from the above, it has been desired to
establish a method for producing
1,2-dichloro-3,3,3-trifluoropropene, which is a target compound of
the present invention, easily and in an industrial scale.
SUMMARY
[0010] As a result of accumulating active studies to solve the
above-described problem, the present inventors found that
1,2-dichloro-3,3,3-trifluoropropene is obtained at a high yield by
reacting 1,2-dichloro-1-halogeno-3,3,3-trifluoropropane with a base
in a liquid phase and extracting the generated
1,2-dichloro-3,3,3-trifluoropropene to the outside of the reaction
system to recover, and thus achieved the present invention.
[0011] Namely, the present invention is as follows.
[0012] [Invention 1]
[0013] A method for producing 1,2-dichloro-3,3,3-trifluoropropene,
including reacting 1,2-dichloro-1-halogeno-3,3,3-trifluoropropane
represented by formula [1] as shown below with a base in a liquid
phase; and extracting the generated
1,2-dichloro-3,3,3-trifluoropropene to the outside of a reaction
system to recover while the reaction is continued:
##STR00001##
(in the formula, X represents fluorine, chlorine or bromine).
[0014] According to the invention 1, the reaction of
1,2-dichloro-1-halogeno-3,3,3-trifluoropropane is suppressed from
being advanced to generate a propyne such as
1-chloro-3,3,3-trifluoropropyne or the like and the reaction can be
stopped in the state where an alkene compound is generated.
Therefore, generation of byproducts, which are not
1,2-dichloro-3,3,3-trifluoropropene, can be suppressed, and
1,2-dichloro-3,3,3-trifluoropropene can be obtained at a higher
yield.
[0015] [Invention 2]
[0016] A method according to invention 1, wherein the reaction of
the 1,2-dichloro-1-halogeno-3,3,3-trifluoropropane with the base is
caused with neither a phase transfer catalyst nor a compatibilizer
being present. The expression "neither a phase transfer catalyst
nor a compatibilizer being present" indicates that each of the
phase transfer catalyst and the compatibilizer is contained at a
content in the range lower than or equal to 0.01% by mass that
includes zero (0).
[0017] According to the invention 2, in the reaction of
1,2-dichloro-1-halogeno-3,3,3-trifluoropropane with the base,
generation of byproducts, which are not
1,2-dichloro-3,3,3-trifluoropropene, can be suppressed, and
1,2-dichloro-3,3,3-trifluoropropene can be obtained at a higher
yield.
[0018] [Invention 3]
[0019] A method according to invention 1 or 2, wherein the base is
at least one inorganic base selected from the group consisting of
alkaline metal alkoxides, carbonates of alkaline metals, carbonates
of alkaline earth metals, hydroxides of alkaline metals, and
hydroxides of alkaline earth metals.
[0020] [Invention 4]
[0021] A method according to any one of inventions 1 through 3,
wherein the 1,2-dichloro-1-halogeno-3,3,3-trifluoropropane is
1,1,2-trichloro-3,3,3-trifluoropropane.
DESCRIPTION OF EMBODIMENTS
[0022] Hereinafter, the present invention will be described in more
detail. The present invention is directed to a method for producing
1,2-dichloro-3,3,3-trifluoropropene, by which
1,2-dichloro-1-halogeno-3,3,3-trifluoropropane is reacted with a
base in a liquid phase, and 1,2-dichloro-3,3,3-trifluoropropene
generated by the reaction is extracted to the outside of the
reaction system to be recovered, while the reaction is
continued.
[0023] The present invention is not limited to the description of
this specification, and may be carried out in embodiments other
than the following embodiments. The following embodiments may be
optionally modified without departing from the gist of the present
invention. All the publications cited in this specification, for
example, prior art documents, laid-open publications, patent
publications and other patent documents are incorporated herein by
reference.
[0024] 1,2-dichloro-1-halogeno-3,3,3-trifluoropropane, which is a
starting material of the present invention, is represented by the
following formula [1].
##STR00002##
(in the formula, X represents fluorine, chlorine or bromine).
[0025] Specific compounds usable as
1,2-dichloro-1-halogeno-3,3,3-trifluoropropane include
1,1,2-trichloro-3,3,3-trifluoropropane,
1,2-dichloro-1,3,3,3-tetrafluoropropane, and
1-bromo-1,2-dichloro-3,3,3-trifluoropropane. Among these compounds,
1,1,2-trichloro-3,3,3-trifluoropropane is preferably usable for
easy availability thereof and usefulness of a resultant compound.
In the case where 1,1,2-trichloro-3,3,3-trifluoropropane is used as
the material, hydrogen chloride, which is generated together with
1,2-dichloro-3,3,3-trifluoropropene, can be industrially used.
[0026] According to the method for producing
1,2-dichloro-3,3,3-trifluoropropene of the present invention, the
reaction is caused in a liquid phase.
1,2-dichloro-1-halogeno-3,3,3-trifluoropropane, which is a starting
material of the present invention, is in a liquid state at room
temperature and normal pressure, and therefore does not need to be
supplied with a solvent. Needless to say, the reaction may be
caused with a solvent.
[0027] Generally in a dehydrohalogenation reaction, a phase
transfer catalyst and/or a compatibilizer is occasionally used as
an additive in order to promote a reaction of a starting material
in an organic phase with a base in an aqueous phase. In the method
for producing 1,2-dichloro-3,3,3-trifluoropropene according to the
present invention, a phase transfer catalyst and/or a
compatibilizer may be used as an additive in addition to a solvent.
However, it is preferable that the method according to the present
invention is performed with neither a phase transfer catalyst nor a
compatibilizer being present, for the following reason. If the
method according to the present invention is performed in the
presence of a phase transfer catalyst and/or a compatibilizer, a
reaction byproduct is generated and thus the purity of the target
compound is decreased, and also the generated
1,2-dichloro-3,3,3-trifluoropropene is dissolved in the aqueous
phase and thus is made difficult to be recovered. When
1,2-dichloro-1-halogeno-3,3,3-trifluoropropane is reacted with a
base with neither a phase transfer catalyst nor a compatibilizer
being present in the present invention, generation of a reaction
byproduct such as 1-chloro-3,3,3-trifluoropropyne or the like can
be suppressed, and also the generated
1,2-dichloro-3,3,3-trifluoropropene can be recovered efficiently.
Therefore, 1,2-dichloro-3,3,3-trifluoropropene can be obtained at a
high selectivity and a high yield.
[0028] The term "phase transfer catalyst" refers to a "substance
having a function of, in a reaction system of an aqueous phase
containing nucleophilic anion and a non-polar organic phase
containing an organic substrate reactive with the aqueous phase,
exchanging the nucleophilic anion that is present in the aqueous
phase with anion of itself and moving between the aqueous phase and
the organic phase to transfer the nucleophilic anion to the organic
substrate that is present in the organic phase, thus to promote a
reaction". Substances usable as the "phase transfer catalyst"
include, for example, crown ether, cryptand, and onium salt, which
are generally known. The term "compatibilizer" refers to a
"substance that decreases the surface tension of substances that
are non-compatible with each other, thus to increase the
compatibility". Substances usable as the "compatibilizer" include,
for example, methanol, ethanol, and propanol, which are generally
known.
[0029] It is preferable to use, as the base for the reaction, a
hydroxide of an alkaline metal or a hydroxide of an alkaline earth
metal, which are both economical and easy to handle. The term
"alkaline metal" refers to lithium, sodium, potassium, rubidium or
cesium. The term "alkaline earth metal" refers to magnesium,
calcium or strontium.
[0030] Specific examples of the hydroxide of the alkaline metal and
the hydroxide of the alkaline earth metal include compounds such as
lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium
hydroxide, magnesium hydroxide, strontium hydroxide, and the like.
Among these compounds, potassium hydroxide, sodium hydroxide,
calcium hydroxide, and magnesium hydroxide are preferable.
Potassium hydroxide and sodium hydroxide, which are low-cost and
industrially available in a large amount, are especially
preferable. Also, it is preferable to use, as the base for the
reaction, a carbonate of an alkaline metal or a carbonate of an
alkaline earth metal. Additionally, it is preferable to use, as the
base for the reaction, an alkaline metal alkoxide. Specific
examples of the alkaline metal alkoxide include compounds such as
sodium methoxide, sodium ethoxide, and the like.
[0031] According to the present invention, one type of base may be
used or two or more types of bases may be combined.
[0032] According to the present invention, the base needs to be
used in an amount that is at least 1 mol with respect to 1 mol of
1,2-dichloro-1-halogeno-3,3,3-trifluoropropane. Usually, the amount
of the base may be optionally selected from the range higher than
or equal to 1 mol and smaller than or equal to 10 mol with respect
to 1 mol of the propane. The amount of the base is preferably
larger than or equal to 1 mol and smaller than or equal to 4 mol,
and more preferably larger than or equal to 1 mol and smaller than
or equal to 2 mol. It is possible to use the base in an amount
larger than 10 mol with respect to 1 mol of
1,2-dichloro-1-halogeno-3,3,3-trifluoropropane, but there is no
advantage of using the base in such a large amount.
[0033] In the case where the amount of the base is less than 1 mol
with respect to 1 mol of
1,2-dichloro-1-halogeno-3,3,3-trifluoropropane in the present
invention, the ratio of conversion realized by the reaction may be
decreased. In such a case, an unreacted
1,2-dichloro-1-halogeno-3,3,3-trifluoropropane may be recovered in
a purification step after the reaction and recycled for a
subsequent reaction.
[0034] According to the method for producing
1,2-dichloro-3,3,3-trifluoropropene of the present invention,
1,2-dichloro-1-halogeno-3,3,3-trifluoropropane is reacted with a
base in a liquid phase.
1,2-dichloro-1-halogeno-3,3,3-trifluoropropane, which is a starting
material of the present invention, is in a liquid state at room
temperature and normal pressure, and therefore does not need to be
supplied with a solvent.
[0035] According to the present invention, in the case where the
base is solid at room temperature and normal pressure, the base may
be supplied with water as a solvent and used in the form of an
aqueous solution in order to make the reaction operation easier.
The concentration of the aqueous solution may be optionally
adjusted by a person of ordinary skill in the art such that the
reaction advances sufficiently or such that the base is
sufficiently dissolved in the solvent. A specific concentration of
the aqueous solution varies in accordance with the type of compound
used as the base. In the case where, for example, an aqueous
solution of potassium hydroxide is used, the concentration of the
aqueous solution is usually higher than or equal to 5% by mass and
lower than or equal to 75% by mass, preferably higher than or equal
to 10% by mass and lower than or equal to 60% by mass, and more
preferably higher than or equal to 15% by mass and lower than or
equal to 50% by mass.
[0036] According to the method for producing
1,2-dichloro-3,3,3-trifluoropropene of the present invention,
generated 1,2-dichloro-3,3,3-trifluoropropene is extracted to the
outside of the reaction system. This suppresses generation of
1-chloro-3,3,3-trifluoropropyne, which would otherwise be caused by
a dehydrohalogenation reaction of
1,2-dichloro-3,3,3-trifluoropropene. The extraction of the
generated 1,2-dichloro-3,3,3-trifluoropropene to the outside of the
reaction system also decreases the concentration of
1,2-dichloro-3,3,3-trifluoropropene in the reaction system and thus
can suppress decrease in the reaction rate.
[0037] There is no limitation on the reaction pressure. In order to
extract 1,2-dichloro-3,3,3-trifluoropropene (standard boiling
point: 53.7.degree. C.), which is a product of the method, to the
outside of the reaction system as gas, the operation is preferably
performed at normal pressure or in a slightly pressurized state,
and more preferably at atmospheric pressure.
[0038] A preferable reaction temperature is as follows. In order to
extract 1,2-dichloro-3,3,3-trifluoropropene (standard boiling
point: 53.7.degree. C.), which is a product of the method, to the
outside of the reaction system as gas, a preferable reaction
temperature is higher than or equal to the boiling point of
1,2-dichloro-3,3,3-trifluoropropene at the above-described inner
pressure of the reactor. In the case where the reaction is caused
at atmospheric pressure, the reaction temperature is preferably
higher than or equal to 55.degree. C. and lower than or equal to
75.degree. C.
[0039] In the method for producing
1,2-dichloro-3,3,3-trifluoropropene of the present invention,
corrosive gas is not generated. Therefore, in the case where the
reaction is caused at normal pressure or in a pressurized state,
there is no specific limitation on the material of a reactor as
long as the material withstands the pressure. The material of the
reactor may be common stainless steel, glass, or fluorine resin.
Alternatively, the reactor may be formed of a material lined with
glass or fluorine resin.
[0040] A pressure-resistant reactor may be used. However, a
reaction caused in a liquid phase advances without the pressure in
the reaction system being much increased and may be caused at
normal pressure with no specific problem. Therefore, there is no
significant advantage of using a pressure-resistant reactor.
[0041] 1,2-dichloro-3,3,3-trifluoropropene produced by the method
according to the present invention exists in the form of a liquid
at room temperature and normal pressure. Therefore, the gas
obtained by the reaction of
1,2-dichloro-1-halogeno-3,3,3-trifluoropropane with a base, namely,
the generated 1,2-dichloro-3,3,3-trifluoropropene may be extracted
to the outside of the reaction system, caused to flow in a cooled
condenser to be condensed, and precision-distilled, so that highly
pure 1,2-dichloro-3,3,3-trifluoropropene is obtained.
1,2-dichloro-3,3,3-trifluoropropene generated by the reaction is a
mixture of geometric isomers such as cis and trans isomers.
Nonetheless, the mixture can be precision-distilled to provide
highly pure cis-1,2-dichloro-3,3,3-trifluoropropene and
trans-1,2-dichloro-3,3,3-trifluoropropene. The present inventors
found that in the case where 1,2-dichloro-3,3,3-trifluoropropene
generated by the reaction of
1,2-dichloro-1-halogeno-3,3,3-trifluoropropane with a base is
extracted to the outside of the reaction system and recovered,
generation of 1-chloro-3,3,3-trifluoropropyne, which is a
byproduct, is significantly suppressed, and
1,2-dichloro-3,3,3-trifluoropropene, which is the target compound,
is obtained at a high yield.
[0042] According to the present invention, extraction of the
generated 1,2-dichloro-3,3,3-trifluoropropene to the outside of the
reaction system is preferably performed continuously or
semi-continuously, as can be optionally adjusted by a person of
ordinary skill in the art.
EXAMPLES
[0043] Hereinafter, the present invention will be described in more
detail by way of examples. The present invention is not limited to
the following examples. Herein, "%" used for a composition analysis
value represents the "surface area %" of each of components of a
reaction mixture measured by direct use of gas chromatography
(unless otherwise specified, the detector is FID).
[0044] In the examples, the expression "composition containing
1,1,2-trichloro-3,3,3-trifluoropropane" refers to a mixture of a
reaction product containing 1,1,2-trichloro-3,3,3-trifluoropropane
as a main component, an unreacted material, and a reaction
byproduct. The expression "composition containing
1,2-dichloro-3,3,3-trifluoropropene" refers to a mixture of a
reaction product containing 1,2-dichloro-3,3,3-trifluoropropene as
a main component, an unreacted material, and a reaction
byproduct.
[0045] In each of examples 1 through 5 described below,
1,2-dichloro-3,3,3-trifluoropropene was produced by use of, as a
material compound, a compound represented by formula [1] identified
above in which X was Cl
(1,1,2-trichloro-3,3,3-trifluoropropane).
Example 1
Example in which Neither a Compatibilizer Nor a Phase Transfer
Catalyst was Used
[0046] A 1000 ml glass reactor equipped with a gas introduction
inlet was cooled in an iced water bath of 0.degree. C., and was
supplied with 554.1 g (4.24 mol) of
trans-1-chloro-3,3,3-trifluoropropene. While the reactor was cooled
in the iced water bath of 0.degree. C., chlorine was introduced
into the reactor at 0.8 g/min., and the reactor was irradiated with
light by use of a high-pressure mercury lamp provided outside the
reactor. The organic substance supplied as the material compound
and chlorine in the reactor were stirred by a magnetic stirrer.
After chlorine was introduced for six hours, the light irradiation
by use of the high-pressure mercury lamp was stopped to finish the
reaction. After the reaction was finished, the organic substance in
the reactor was washed with water, a weakly alkaline aqueous
solution and a saturated saline solution. As a result, 836.3 g of
composition containing 1,1,2-trichloro-3,3,3-trifluoropropane was
obtained.
[0047] The obtained composition was analyzed by gas chromatography
to find the following composition ratio. The composition contained
1,1,2-trichloro-3,3,3-trifluoropropane at a content of 96.2%. The
yield of 1,1,2-trichloro-3,3,3-trifluoropropane was 94.1%.
[0048] A 1000 ml round-bottom three-neck glass flask equipped with
a dropping funnel, a glass protective tube for receiving a
thermocouple, and a gas discharge tube was supplied with 893.2 g of
25% by weight of aqueous solution of potassium hydroxide (potassium
hydroxide: 3.98 mol). This reactor was heated in an oil bath set at
75.degree. C. 400 g of the above-obtained composition containing
1,1,2-trichloro-3,3,3-trifluoropropane was dropped into the reactor
while being stirred by a magnetic stirrer (introduction rate: 2.2
g/min.). Highly concentrated 1,2-dichloro-3,3,3-trifluoropropene
gas generated by the reaction was guided out of the reactor
continuously through the gas discharge tube, condensed by a glass
cooling device in which a coolant of 0.degree. C. was circulated,
and collected in a flask cooled in a dry ice-acetone bath. Three
hours later, the composition containing
1,1,2-trichloro-3,3,3-trifluoropropane was entirely supplied to the
reactor. After the supply of the material was finished, the reactor
was heated for 30 minutes, and the collection of the composition
containing 1,2-dichloro-3,3,3-trifluoropropene was finished. After
the reaction was finished, the product collected in the flask
provided at an exit of the cooling device was washed with water and
then with a saturated saline solution. As a result, 314.7 g of
composition containing 1,2-dichloro-3,3,3-trifluoropropene was
obtained.
[0049] The obtained composition containing
1,2-dichloro-3,3,3-trifluoropropene was analyzed by gas
chromatography to find the following composition ratio. The
composition contained cis-1,2-dichloro-3,3,3-trifluoropropene at a
content of 84.5% and trans-1,2-dichloro-3,3,3-trifluoropropene at a
content of 7.7%. The yield of 1,2-dichloro-3,3,3-trifluoropropene
(total yield of the cis isomer and the trans isomer) was 91.1%.
[0050] The obtained composition containing
1,2-dichloro-3,3,3-trifluoropropene was distilled and purified to
obtain cis-1,2-dichloro-3,3,3-trifluoropropene and
trans-1,2-dichloro-3,3,3-trifluoropropene.
Example 2
Example in which Neither a Compatibilizer Nor a Phase Transfer
Catalyst was Used
[0051] A reaction was caused in substantially the same manner as in
example 1 except that 640.1 g of 25% by weight of aqueous solution
of sodium hydroxide (sodium hydroxide: 4.00 mol) was used and that
400 g of composition containing
1,1,2-trichloro-3,3,3-trifluoropropane was dropped for 5 hours
(introduction rate: 1.3 g/min.). As a result, 318.2 g of
composition containing 1,2-dichloro-3,3,3-trifluoropropene was
obtained.
[0052] The obtained composition containing
1,2-dichloro-3,3,3-trifluoropropene was analyzed by gas
chromatography to find the following composition ratio. The
composition contained cis-1,2-dichloro-3,3,3-trifluoropropene at a
content of 84.7% and trans-1,2-dichloro-3,3,3-trifluoropropene at a
content of 7.8%. The yield of 1,2-dichloro-3,3,3-trifluoropropene
(total yield of the cis isomer and the trans isomer) was 93.4%.
Example 3
Example in which a Phase Transfer Catalyst was Used
[0053] A reaction was caused in substantially the same manner as in
example 1 except that 4.7 g of tetrabutylammonium bromide was
supplied as a phase transfer catalyst to a reactor accommodating
the composition containing 1,1,2-trichloro-3,3,3-trifluoropropane.
As a result, 224.7 g of composition containing
1,2-dichloro-3,3,3-trifluoropropene was obtained.
[0054] The obtained composition containing
1,2-dichloro-3,3,3-trifluoropropene was analyzed by gas
chromatography to find the following compound ratio. The compound
contained cis-1,2-dichloro-3,3,3-trifluoropropene at a content of
67.5%, trans-1,2-dichloro-3,3,3-trifluoropropene at a content of
9.8%, and 1-chloro-3,3,3-trifluoropropyne at a content of 12.5%.
The yield of 1,2-dichloro-3,3,3-trifluoropropene (total yield of
the cis isomer and the trans isomer) was 54.1%.
Example 4
Example in which a Compatibilizer was Used
[0055] A reaction was caused in substantially the same manner as in
example 1 except that 167.5 g of methanol was supplied as a
compatibilizer for 1,1,2-trichloro-3,3,3-trifluoropropane and an
aqueous solution of the base to a reactor accommodating the
composition containing 1,1,2-trichloro-3,3,3-trifluoropropane. As a
result, 301.9 g of composition containing
1,2-dichloro-3,3,3-trifluoropropene was obtained.
[0056] The obtained composition containing
1,2-dichloro-3,3,3-trifluoropropene was analyzed by gas
chromatography to find the following composition ratio. The
composition contained cis-1,2-dichloro-3,3,3-trifluoropropene at a
content of 81.8%, trans-1,2-dichloro-3,3,3-trifluoropropene at a
content of 7.1%, 1-chloro-3,3,3-trifluoropropyne at a content of
0.1%, and 1-chloro-2-methoxy-3,3,3-trifluoropropene at a content of
0.3%. The yield of 1,2-dichloro-3,3,3-trifluoropropene (total yield
of the cis isomer and the trans isomer) was 83.0%.
Example 5
Example in which a Compatibilizer and a Phase Transfer Catalyst
were Both Used
[0057] A reaction was caused in substantially the same manner as in
example 1 except that 167.5 g of methanol was supplied as a
compatibilizer for 1,1,2-trichloro-3,3,3-trifluoropropane and an
aqueous solution of the base, and 4.7 g of tetrabutylammonium
bromide was supplied as a phase transfer catalyst, to a reactor
accommodating the composition containing
1,1,2-trichloro-3,3,3-trifluoropropane. As a result, 260.4 g of
composition containing 1,2-dichloro-3,3,3-trifluoropropene was
obtained.
[0058] The obtained composition containing
1,2-dichloro-3,3,3-trifluoropropene was analyzed by gas
chromatography to find the following composition ratio. The
composition contained cis-1,2-dichloro-3,3,3-trifluoropropene at a
content of 78.5%, trans-1,2-dichloro-3,3,3-trifluoropropene at a
content of 9.0%, 1-chloro-3,3,3-trifluoropropyne at a content of
2.9%, and 1-chloro-2-methoxy-3,3,3-trifluoropropene at a content of
1.4%. The yield of 1,2-dichloro-3,3,3-trifluoropropene (total yield
of the cis isomer and the trans isomer) was 70.9%.
[0059] The results of examples 1 through 5 are summarized in Table
1. 1,1,2-trichloro-3,3,3-trifluoropropane and potassium hydroxide,
and 1,1,2-trichloro-3,3,3-trifluoropropane and sodium hydroxide,
are separated from each other to form two layers and are not
essentially compatible with each other. However, in examples 1 and
2 in which neither a phase transfer catalyst nor a compatibilizer
was added, 1,2-dichloro-3,3,3-trifluoropropene as the target
compound was obtained at a higher yield than in examples 3 through
5 in which a phase transfer catalyst and/or a compatibilizer was
added.
TABLE-US-00001 TABLE 1 Phase transfer Yield [mol %] catalyst
Compatibilizer 1223xd CI-TFPy Example 1 Not used Not used 91.1
<0.1 Example 2 Not used Not used 93.4 <0.1 Example 3 Used Not
used 54.1 11.2 Example 4 Not used Used 83.0 0.1 Example 5 Used Used
70.9 3.0 1223xd: 1,2-dichloro-3,3,3-trifluoropropene CI-TFPy:
1-chloro-3,3,3-trifluoropropyne
[0060] Next, in example 6,1,2-dichloro-3,3,3-trifluoropropene was
produced by use of, as a material compound, a compound represented
by formula [1] identified above in which X was F
(2,3-dichloro-1,1,1,3-tetrafluoropropane).
Example 6
[0061] A 1000 ml glass reactor equipped with a gas introduction
inlet was cooled in a dry ice-acetone bath of -78.degree. C., and
was supplied with 901.86 g (7.90 mol) of
trans-1,3,3,3-tetrafluoropropene. While the reactor was cooled at
-78.degree. C., chlorine was introduced into the reactor at an
average rate of 1.70 g/min., and the reactor was irradiated with
light by use of a high-pressure mercury lamp provided outside the
reactor. The organic substance supplied as the material compound
and chlorine in the reactor were stirred by a magnetic stirrer.
Five hours and 30 minutes after the start of the reaction, the
introduction of chlorine and the light irradiation by use of the
high-pressure mercury lamp were stopped to finish the reaction.
Chlorine was introduced in an amount of 560.5 g (7.90 mol). After
the reaction was finished, the organic substance in the reactor was
washed with water, an aqueous solution of saturated sodium hydrogen
carbonate and a saturated saline solution. As a result, 1427.0 g of
composition containing 2,3-dichloro-1,1,1,3-tetrafluoropropane
(HCFC-234da) was obtained. The obtained composition was analyzed by
gas chromatography to find the following composition ratio. The
composition contained 2,3-dichloro-1,1,1,3-tetrafluoropropane at a
content of 98.7% (total of diastereomer). The yield of
2,3-dichloro-1,1,1,3-tetrafluoropropane was 96.3%.
[0062] A 2000 ml round-bottom three-neck glass flask equipped with
a dropping funnel, a glass protective tube for receiving a
thermocouple, and a gas discharge tube was supplied with 1464.4 g
of 25% by weight of aqueous solution of potassium hydroxide
(potassium hydroxide: 6.52 mol) and 164.7 g of methanol. This
reactor was cooled in an iced water bath set at 0.degree. C. 600 g
of the above-obtained composition containing
2,3-dichloro-1,1,1,3-tetrafluoropropane was dropped into the
reactor while being stirred by a magnetic stirrer (introduction
rate: 3.3 g/min.).
[0063] After 2,3-dichloro-1,1,1,3-tetrafluoropropane was entirely
dropped, the temperature of the water bath was raised to 50.degree.
C. The reaction product was guided out of the reactor, condensed by
a glass cooling device in which a coolant of 0.degree. C. was
circulated, and collected in a flask cooled in a dry ice-acetone
bath. 1.5 hours later, the collection of composition A containing
1,2-dichloro-3,3,3-trifluoropropene was finished. The product
collected in the flask provided at an exit of the cooling device
was washed with water and then with a saturated saline solution. As
a result, 107.3 g of composition A containing
1,2-dichloro-3,3,3-trifluoropropene was obtained.
[0064] The temperature of the water bath was raised to 75.degree.
C., and the reaction product was guided out of the reactor,
condensed by a glass cooling device in which a coolant of 0.degree.
C. was circulated, and collected in a flask cooled in a dry
ice-acetone bath. 1.5 hours later, the collection of composition B
containing 1,2-dichloro-3,3,3-trifluoropropene was finished. The
product collected in the flask provided at an exit of the cooling
device was washed with water and then with a saturated saline
solution. As a result, 109.3 g of composition B containing
1,2-dichloro-3,3,3-trifluoropropene was obtained.
[0065] The organic substance remaining in a pot in the reactor was
washed with water and then with a saturated saline solution. As a
result, 215.5 g of composition C containing
1,2-dichloro-3,3,3-trifluoropropene was obtained.
[0066] The obtained compositions A, B and C containing
1,2-dichloro-3,3,3-trifluoropropene were analyzed by gas
chromatography. Compositions A, B and C contained
cis-1,2-dichloro-3,3,3-trifluoropropene at contents of 11.4%, 54.0%
and 6.6%, respectively. The yield of
1,2-dichloro-3,3,3-trifluoropropene (total yield of the cis isomer
and the trans isomer) was 16.1%.
Comparative Example
[0067] A 500 ml round-bottom three-neck glass flask equipped with a
glass cooling device in which a coolant of 0.degree. C. was
circulated, a glass trap cooled in a dry ice-acetone bath adjusted
to -78.degree. C., and a glass protective tube for receiving a
thermocouple was supplied with 40.30 g (0.20 mol) of
1,1,2-trichloro-3,3,3-trifluoropropane, 32.00 g (0.57 mol) of
potassium hydroxide, 0.68 g of tetrabutylammonium bromide, and
96.01 g of water. These compounds were stirred by a magnetic
stirrer while being cooled to be dissolved. After the dissolution,
the inner temperature of the flask was raised to 30.degree. C. in a
water bath, the flask was kept at this temperature for 2 hours and
then the flask was cooled. The reaction was finished without the
reaction product being extracted. The reaction product was cooled
in the recovery grass trap cooled in the dry ice-acetone bath
provided at an exit of the condenser, and 30.84 g of liquefied
reaction product was collected.
[0068] The collected liquid was analyzed by gas chromatography. The
reaction product was not 1,2-dichloro-3,3,3-trifluoropropene, but
was 1-chloro-3,3,3-trifluoropropyne. The purity of the obtained
1-chloro-3,3,3-trifluoropropyne was 97.6%, and the yield of
1-chloro-3,3,3-trifluoropropyne was 74.0%.
[0069] The following is understood from a comparison of examples 1
through 5 against the comparative example. According to the method
of the present invention, by which
1,2-dichloro-1-halogeno-3,3,3-trifluoropropane is reacted with a
base in a liquid phase, and 1,2-dichloro-3,3,3-trifluoropropene
generated by the reaction is extracted to the outside of the
reaction system to be recovered while the reaction is continued,
1,2-dichloro-3,3,3-trifluoropropene as the target compound is
obtained at a high yield. By contrast, in the comparative example,
in which 1,2-dichloro-3,3,3-trifluoropropene is not extracted to
the outside of the reaction system, the reaction is excessively
advanced to even generate a propyne, and thus
1,2-dichloro-3,3,3-trifluoropropene is not recovered. As can be
seen from a comparison of examples 1 and 2 against examples 3
through 5, the yield of 1,2-dichloro-3,3,3-trifluoropropene is
higher in the case where neither a phase transfer catalyst nor a
compatibilizer is used than in the case where a phase transfer
catalyst and/or a compatibilizer is used. A conceivable reason for
this is that in the case where neither a phase transfer catalyst
nor a compatibilizer is used, generation of a reaction byproduct
such as 1-chloro-3,3,3-trifluoropropyne or the like is suppressed,
and also dissolution of 1,2-dichloro-3,3,3-trifluoropropene in the
aqueous phase is suppressed. Thus,
1,2-dichloro-3,3,3-trifluoropropene is obtained at a higher
selectivity and a higher yield in the case where neither a phase
transfer catalyst nor a compatibilizer is used than in the case
where a phase transfer catalyst and/or a compatibilizer is
used.
[0070] As can be seen from a comparison of examples 1 through 5
against example 6,1,2-dichloro-3,3,3-trifluoropropene as the target
compound is obtained at a higher yield in the case where a compound
represented by formula [1] in which X is Cl
(1,1,2-trichloro-3,3,3-trifluoropropane) is used as the material
compound than in the case where a compound represented by formula
[1] in which X is F (2,3-dichloro-1,1,1,3-tetrafluoropropane) is
uses as the material compound. Therefore, it is understood that in
the method for producing 1,2-dichloro-3,3,3-trifluoropropene of the
present invention, a compound represented by formula [1] in which X
is Cl (1,1,2-trichloro-3,3,3-trifluoropropane) is preferable as the
material compound.
[0071] According to the present invention,
1,2-dichloro-3,3,3-trifluoropropene is obtained at a high yield by
a simple method. Thus, the present invention provides a method for
producing 1,2-dichloro-3,3,3-trifluoropropene easily and in an
industrial scale.
[0072] 1,2-dichloro-3,3,3-trifluoropropene, which is a target
compound of the present invention, is usable as a heat transfer
medium usable for a heat pump cycle or a rankine cycle, a
functional material such as a cleaner or the like, a
physiologically active substance, an intermediate of a functional
material, or a monomer of a polymer compound.
* * * * *