U.S. patent application number 10/291398 was filed with the patent office on 2004-05-13 for method for the preparation of 2, 2, 3, 4, 4, 4-hexafluoro-1-butanol.
This patent application is currently assigned to Chung-Shan Institute of Science & Technology. Invention is credited to Guu, Wang-Tsae, Jong, Shean-Jeng, Liang, Chung-Mou.
Application Number | 20040089531 10/291398 |
Document ID | / |
Family ID | 32229250 |
Filed Date | 2004-05-13 |
United States Patent
Application |
20040089531 |
Kind Code |
A1 |
Jong, Shean-Jeng ; et
al. |
May 13, 2004 |
METHOD FOR THE PREPARATION OF 2, 2, 3, 4, 4,
4-HEXAFLUORO-1-BUTANOL
Abstract
The method for preparing 2,2,3,4,4,4-hexafluoro-1-butanol
includes reacting methanol and hexafluoropropene in the presence of
a free radical initiator such as di-isopropyl peroxydicarbonate at
25-50.degree. C. and a pressure of 100-300 psi in an autoclave. An
inert gas such as nitrogen and argon is added to the autoclave when
the pressure is lower than 100 psi in the course of the
reaction.
Inventors: |
Jong, Shean-Jeng; (Tao-Yuan,
TW) ; Guu, Wang-Tsae; (Tao-Yuan, TW) ; Liang,
Chung-Mou; (Tao-Yuan, TW) |
Correspondence
Address: |
BACON & THOMAS, PLLC
625 SLATERS LANE
FOURTH FLOOR
ALEXANDRIA
VA
22314
|
Assignee: |
Chung-Shan Institute of Science
& Technology
Tao-Yuan
TW
|
Family ID: |
32229250 |
Appl. No.: |
10/291398 |
Filed: |
November 12, 2002 |
Current U.S.
Class: |
204/157.9 ;
568/842 |
Current CPC
Class: |
C07C 29/32 20130101;
C07C 29/32 20130101; C07C 31/38 20130101 |
Class at
Publication: |
204/157.9 ;
568/842 |
International
Class: |
C07C 031/38 |
Claims
1. A method for preparing 2,2,3,4,4,4-hexafluoro-1-butanol
comprising reacting methanol and hexafluoropropene in the presence
of a free radical initiator s at 25-50.degree. C., and a pressure
of 100-300 psi in an autoclave for a period of time, wherein an
inert gas is added to the autoclave when said pressure is lower
than 100 psi in the course of the reaction.
2. The method according to claim 1, wherein nitrogen is introduced
to the autoclave so that said pressure is maintained at 200-300
psi.
3. The method according to claim 1, wherein said free radical
initiator is di-isopropyl peroxydicarbonate.
4. The method according to claim 1, wherein methanol and
hexafluoropropene is reacted with a molar ratio of
hexafluoropropene to methanol of 0.2-1 at the beginning of the
reaction, and no hexafluoropropene being added in the course of the
reaction.
5. The method according to claim 4, wherein said molar ratio of
hexafluoropropene to methanol is of 0.3-0.4.
6. The method according to claim 4, wherein said period of time is
20-40 hours.
7. The method according to claim 3, wherein said reaction
temperature is 40-50.degree. C.
Description
FIELD OF THE INVENTION
[0001] The present invention is related to a preparation method of
2,2,3,4,4,4-hexafluoro-1-butanol, and in particular to a low
temperature and high pressure method for the preparation of
2,2,3,4,4,4-hexafluoro-1-- butanol.
BACKGROUND OF THE INVENTION
[0002] Japanese patent publication Nos. 200252823 (2002), 200253506
(2002), and 200253507 (2002) describe that a short-chain
fluoroalkanol having the following formula (I) can be used as a
solvent for an optical information recording dye of CD-R and
DVD-R:
H(CFR.sub.1CF.sub.2).sub.nCH.sub.2OH (I)
[0003] wherein the formula (I) represents
2,2,3,3-tetrafluoro-1-propanol, when R1=F, n=1;
2,2,3,3,4,4,5,5-octafluoro-1-pentanol, when R.sub.1=F, n=2; and
2,2,3,4,4,4-hexafluoro-1-butanol (hereinafter abbreviated as HFB),
when R.sub.1=CF.sub.3, n=1.
[0004] The methods for the preparation of HFB published in the
literature include reacting hexafluoropropene and methanol under
irradiation of light, heating and in the presence of a free radical
initiator, wherein
[0005] J. Fluorine Chem., 291,28 (1985) and a patent application
with a publication number of CS268247 disclose a synthesis method
by using irradiation of light. This method requires special
lighting equipment, and suffers an abrupt change in temperature or
pressure during the reaction. Therefore, this method is not easy to
be put into mass production.
[0006] U.S. Pat. No. 3,927,129 (1975) discloses a high-temperature
synthesis method, wherein hexafluoropropene and methanol are
reacted at 280.degree. C. for four days, and the yield is 85%. The
yield drops to 31%, when the reaction temperature is 240.degree. C.
The high temperature and long reaction time are adverse factors for
a mass production based on this synthesis method.
[0007] PCT application WO 01/02329 (2001) discloses a process for
producing fluoroalkanol including heating methanol in an autoclave
at a temperature of 125.degree. C., separately and continuously
adding hexafluoropropene and a free radical initiator of di-t-butyl
peroxide in methanol to the autoclave. A high-pressure feeding
apparatus is required for the additions of hexafluoropropene and
the free radical initiator. Moreover, the rates of the additions
must be controlled accurately to avoid dangers caused by an abrupt
increase in temperature or pressure in the autoclave. For an
one-liter autoclave only 125 g of hexafluoropropene was reacted per
batch.
[0008] PCT application WO 01/62694 (2001) discloses a process for
preparation of HFB including heating methanol, a free radical
initiator and a small amount of hexafluoropropene in an autoclave,
and feeding hexafluoropropene during the reaction. This process
also requires high-pressure feeding apparatus, and suffers a
continuous increase in reaction temperature. In Example 1 of this
PCT application, the reaction temperature was increased from the
starting 48.degree. C. to 75.degree. C. after 7-hour of
hexafluoropropene feeding, wherein t-butylperoxy-2-ethyl hexanoate
was used as a free radical initiator and an 1-L autoclave was used.
A similar trend of reaction temperature increase was also observed
in the other examples. Therefore, the rates of the
hexafluoropropene feeding must be controlled accurately to avoid
dangers caused by an abrupt increase in temperature or pressure in
the autoclave. For the one-liter autoclave used in Example 1 of
this prior art 277 g of hexafluoropropene was reacted per batch,
and 5510 g of hexafluoropropene was reacted per batch for a 20-L
autoclave used in Example 2. The product yield after distillation
was about 75%.
SUMMARY OF THE INVENTION
[0009] The present invention provides a method for preparing
2,2,3,4,4,4-hexafluoro-1-butanol comprising reacting methanol and
hexafluoropropene in the presence of a free radical initiator such
as di-isopropyl peroxydicarbonate at 25-50.degree. C., preferably
40-50.degree. C., and a pressure of 100-300 psi in an autoclave for
a period of time. An inert gas such as nitrogen and argon is added
to the autoclave when the pressure is lower than 100 psi in the
course of the reaction.
[0010] In the method of the present invention, preferably nitrogen
is introduced to the autoclave so that the pressure is maintained
at 200-300 psi.
[0011] In the method of the present invention, preferably methanol
and hexafluoropropene is reacted with a molar ratio of
hexafluoropropene to methanol of 0.2-1 at the beginning of the
reaction, and no hexafluoropropene being added in the course of the
reaction. More preferably, molar ratio of hexafluoropropene to
methanol is of 0.3-0.4.
[0012] Preferably, said period of time for said reaction is 20-40
hours.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0013] The present invention discloses a novel method for preparing
2,2,3,4,4,4-hexafluoro-1-butanol (HFB) by reacting methanol and
hexafluoropropene in the presence of a free radical initiator at
25-50.degree. C. in an autoclave, wherein an insert gas including
(but not limited to) nitrogen and argon may be added to the
autoclave to maintain a pressure in the autoclave not lower than a
predetermined value. The advantages of the present invention
include: no addition of reactants during the reaction, no abrupt
change in temperature, and increase in the amount of reactants
reacted per volume of the autoclave per batch.
[0014] An example of the free radical initiator used in the method
of the present invention is di-isopropyl peroxydicarbonate. The
amount of the free radical initiator used ranges from 0.001 to 10,
and preferably from 0.01 to 0.06, times of the weight of methanol
used.
[0015] The present invention can be better understood by the
following examples which are illustrative only, not for limiting
the scope of the present invention.
EXAMPLE 1
[0016] To a mixture of 240 g of methanol and 3 g of a free radical
initiator, Luperox IPP, sold by ELF Atochem, Inc. (containing
27-28% of di-isopropyl peroxydicarbonate) in a 600-ml autoclave,
370 g of hexafluoropropene was added after degas thereof. Nitrogen
was then introduced to the autoclave until the pressure therein
reached 263 psi. The mixture in the autoclave was heated to
50.degree. C. in 10 minutes, and the pressure was increased slowly
to 287 psi right after the heating. The temperature was maintained
at 50.degree. C. for reaction for 24 hours by heating. During the
reaction nitrogen was supplied to the autoclave when the pressure
therein dropped below 250 psi, and the nitrogen supply was cut off
when it was back up to 300 psi. The reaction mixture was removed
from the autoclave after the reaction, and distilled. The distilled
product collected at 114-118.degree. C. is 90 g.
EXAMPLE 2
[0017] To a mixture of 240 g of methanol and 4 g of Luperox IPP in
a 600-ml autoclave, 370 g of hexafluoropropene was added after
degas thereof. Nitrogen was then introduced to the autoclave until
the pressure therein reached 290 psi. The mixture in the autoclave
was heated to 5.degree. C. in 10 minutes, and the pressure was
decreased to 285 psi right after the heating. The temperature was
maintained at 50.degree. C. for reaction for 24 hours by heating.
During the reaction nitrogen was supplied to the autoclave when the
pressure therein dropped below 250 psi, and the nitrogen supply was
cut off when it was back up to 300 psi. The reaction mixture was
removed from the autoclave after the reaction, and distilled. The
distilled product collected at 114-118.degree. C. is 100 g.
EXAMPLE 3
[0018] To a mixture of 240 g of methanol and 10 g of Luperox IPP in
a 600-ml autoclave, 368 g of hexafluoropropene was added after
degas thereof. Nitrogen was then introduced to the autoclave until
the pressure therein reached 290 psi. The mixture in the autoclave
was heated to 40.degree. C. in 4 minutes, and the pressure was
decreased to 229 psi right after the heating. The temperature was
maintained at 40.degree. C. for reaction for 8 hours by heating;
then increased to 45.degree. C. by heating in 20 minutes, and
maintained at 45.degree. C. for reaction for 18 hours by heating;
and finally increased to 50.degree. C. by heating in 20 minutes,
and maintained at 50.degree. C. for reaction for 10 hours by
heating. During the reaction nitrogen was supplied to the autoclave
when the pressure therein dropped below 220 psi, and the nitrogen
supply was cut off when it was back up to 300 psi. The reaction
mixture was removed from the autoclave after the reaction, and
distilled. The distilled product collected at 114-118.degree. C. is
300 g. Yield 67%.
EXAMPLE 4
[0019] To a mixture of 240 g of methanol and 10 g of Luperox IPP in
a 600-ml autoclave, 360 g of hexafluoropropene was added after
degas thereof. The pressure in the autoclave at room temperature
(25.degree. C.) was 123 psi. The mixture in the autoclave was
heated to 50.degree. C. in 40 minutes, and the pressure was
increased to 203 psi right after the heating. The temperature was
maintained at 50.degree. C. for reaction for 36 hours by heating.
After the reaction the pressure in the autoclave dropped to 94 psi.
The reaction mixture was removed from the autoclave after the
reaction, and distilled. The distilled product collected at
114-118.degree. C. is 255 g.
EXAMPLE 5
[0020] To a mixture of 240 g of methanol and 10 g of Luperox IPP in
a 600-ml autoclave, 290 g of hexafluoropropene was added after
degas thereof. Nitrogen was then introduced to the autoclave until
the pressure therein reached 296 psi. The mixture in the autoclave
was heated to 40.degree. C. in 18 minutes, and the pressure was
decreased slowly to 259 psi right after the heating. The
temperature was maintained at 40.degree. C. for reaction for 22
hours by heating. During the reaction nitrogen was supplied to the
autoclave when the pressure therein dropped below 230 psi, and the
nitrogen supply was cut off when it was back up to 300 psi. The
reaction mixture was removed from the autoclave after the reaction,
and distilled. The distilled product collected at 114-118.degree.
C. is 30 g.
CONTROL EXAMPLE 1
[0021] To a mixture of 240 g of methanol and 15 g of Luperox IPP in
a 600-ml autoclave, 366 g of hexafluoropropene was added after
degas thereof. Nitrogen was then introduced to the autoclave until
the pressure therein reached 275 psi. The mixture in the autoclave
was heated to 40.degree. C. in 10 minutes, and the pressure was
decreased to 243 psi right after the heating. The temperature was
maintained at 40.degree. C. for reaction for 4 hours by heating,
then was increased to 60.degree. C. in 10 minutes (pressure ramped
from 250 psi to 630 psi), and maintained at 60.degree. C. for 17
hours (pressure dropped finally to 271 psi). The reaction mixture
was removed from the autoclave after the reaction, and distilled.
The distilled product collected at 114-118.degree. C. is 264 g.
CONTROL EXAMPLE 2
[0022] To a mixture of 240 g of methanol and 3 g of Luperox IPP in
a 600-ml autoclave, 364 g of hexafluoropropene was added after
degas thereof. Nitrogen was then introduced to the autoclave until
the pressure therein reached 297 psi. The mixture in the autoclave
was heated slowly to 100.degree. C. in 10 minutes, wherein the
pressure was increased to 990 psi when the temperature reached
75.degree. C., and was 886 psi when the temperature reached
100.degree. C. The temperature was maintained at 100.degree. C. for
reaction for 26 hours by heating (pressure decreased from 886 psi
to 481 psi). The reaction mixture was removed from the autoclave
after the reaction, and distilled. The distilled product collected
at 114-118.degree. C. is 106 g.
[0023] The results are listed in Table 1. It can be from the
results of Example 1 and Control Example 2 that the yield is not
enhanced by increasing the reaction temperature high than
50.degree. C., instead the pressure in the autoclave is abruptly
increased. Control Example 2 shows that the pressure in the
autoclave ramps as the reaction temperature is raised to higher
than 50.degree. C. during the reaction, even though the initial
reaction temperature is lower than 50.degree. C. The results of
Examples 3 and 4 indicate that the nitrogen supply for maintaining
the reaction pressure can enhance the yield. It is believed that
the low yield of Example 3 is due to a low reaction
temperature.
1 TABLE 1 Reaction Weight of IPP, CH.sub.3OH, g
CF.sub.3CF.dbd.CF.sub.2 time product, g g (mole) (mole) (hour)
(yeidl, %) Example 1 3 240 370 24 90 (7.5) (2.47) Example 2 4 240
370 24 100 (7.5) (2.47) Example 3 10 240 368 36 300 (7.5) (2.45)
(67%) Example 4 10 240 360 36 255 (7.5) (2.40) Example 5 10 240 290
22 30 (7.5) (1.93) Control Ex. 15 240 366 21 264 1 (7.5) (2.44)
Control Ex. 3 240 364 26 106 2 (7.5) (2.43)
* * * * *