U.S. patent application number 11/123035 was filed with the patent office on 2005-09-08 for highly branched perfluoroolefins, super-stable perfluoroalkyl radicals and production methods thereof.
This patent application is currently assigned to NATIONAL INSTITUTE OF ADVANCED IND. SCIENCE AND TECH.. Invention is credited to Nishida, Masakazu, Okazaki, Masaharu, Ono, Taizo, Shimizu, Tetsuo, Toriyama, Kazumi.
Application Number | 20050197514 11/123035 |
Document ID | / |
Family ID | 19164643 |
Filed Date | 2005-09-08 |
United States Patent
Application |
20050197514 |
Kind Code |
A1 |
Ono, Taizo ; et al. |
September 8, 2005 |
Highly branched perfluoroolefins, super-stable perfluoroalkyl
radicals and production methods thereof
Abstract
The present invention is to provide a method for producing a
highly branched perfluoroolefin conveniently in a high yield, a
novel highly branched perfluoroolefin, a method for producing a
super-stable perfluoroalkyl radical and a novel super-stable
perfluoroalkyl radical. The present invention is a production
method of a perfluoroolefin which comprises reacting a
hexafluoropropene trimer with a trialkylperfluoroalkylsilane in an
aprotic polar solvent using a fluoride ion as a catalyst.
Inventors: |
Ono, Taizo; (Nagoya-shi,
JP) ; Nishida, Masakazu; (Nagoya, JP) ;
Okazaki, Masaharu; (Nagoya, JP) ; Toriyama,
Kazumi; (Nagoya, JP) ; Shimizu, Tetsuo;
(Settsu, JP) |
Correspondence
Address: |
SUGHRUE MION, PLLC
2100 PENNSYLVANIA AVENUE, N.W.
SUITE 800
WASHINGTON
DC
20037
US
|
Assignee: |
NATIONAL INSTITUTE OF ADVANCED IND.
SCIENCE AND TECH.
DAIKIN INDUSTRIES, LTD.
|
Family ID: |
19164643 |
Appl. No.: |
11/123035 |
Filed: |
May 6, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11123035 |
May 6, 2005 |
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10685447 |
Oct 16, 2003 |
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10685447 |
Oct 16, 2003 |
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10291699 |
Nov 12, 2002 |
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6710214 |
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Current U.S.
Class: |
570/153 |
Current CPC
Class: |
C07C 17/263 20130101;
C07C 19/08 20130101; C07C 17/04 20130101; C07C 17/04 20130101; C07C
17/263 20130101; C07C 21/18 20130101; C07C 21/18 20130101; C07C
19/08 20130101 |
Class at
Publication: |
570/153 |
International
Class: |
C07C 017/04 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 16, 2001 |
JP |
2001-352474 |
Claims
1. (canceled)
2. (canceled)
3. (canceled)
4. (canceled)
5. (canceled)
6. (canceled)
7. (canceled)
8. (canceled)
9. (canceled)
10. A production method of a super-stable perfluoroalkyl radical
which comprises producing a super-stable perfluoroalkyl radical
represented by the following general formula (1R):
[(CF.sub.3).sub.2CF][(CF.sub.3).sub.2- CY]Ra--CF(CF.sub.3)Z (1R) in
the formula, Ra represents a carbon atom having one unpaired
electron, Y and Z are the same or different and each represents F
or Rf, and Rf represents a straight or branched perfluoroalkyl
group having 1 to 16 carbon atoms, provided that Y and Z are not
simultaneously F, by fluorinating a highly branched perfluoroolefin
represented by the following general formula (1):
[(CF.sub.3).sub.2CF][(CF.sub.3).sub.2CY]C.dbd.C(CF.sub.3)Z (1) in
the formula, Y, and Z are the same or different and each represents
F or Rf, Rf represents a straight or branched perfluoroalkyl group
having 1 to 16 carbon atoms, provided that Y and Z are not
simultaneously F.
11. The production method of the super-stable perfluoroalkyl
radical according to claim 10, wherein the fluorination is
conducted using a fluorine gas.
12. The production method of the super-stable perfluoroalkyl
radical according to claim 11, wherein the fluorine gas is a pure
one.
13. The production method of the super-stable perfluoroalkyl
radical according to claim 10, wherein the highly branched
perfluoroolefin is one obtained by reacting a hexafluoropropene
trimer with a trialkylperfluoroalkylsilane represented by the
following general formula (2): 5in the formula, Rf represents a
straight or branched perfluoroalkyl group having 1 to 16 carbon
atoms, R.sup.1, R.sup.2 and R.sup.3 are the same or different and
each represents an alkyl group having 1 to 3 carbon atoms, in an
aprotic polar solvent using a fluoride ion as a catalyst.
14. The production method of the super-stable perfluoroalkyl
radical according to claim 10, wherein Y and Z are the same or
different and each represents F or a trifluoromethyl group,
provided that Y and Z are not simultaneously F.
15. The production method of the super-stable perfluoroalkyl
radical according to claim 10, wherein the highly branched
perfluoroolefin is perfluoro(2,4-dimethyl-3-isopropyl-2-pentene),
perfluoro(2,4,4-trimethyl-- 3-isopropyl-2-pentene) or
perfluoro(4,4-dimethyl-3-isopropyl-2-pentene).
16. A production method of a reduced-carbon super-stable
perfluoroalkyl radical which comprises producing a super-stable
perfluoroalkyl radical (AR) represented by the following general
formula (3R): [(CF.sub.3).sub.2CF].sub.2Ra--CF(CF.sub.3)Rf (3R) in
the formula, Ra represents a carbon atom having one unpaired
electron and Rf represents a straight or branched perfluoroalkyl
group having 1 to 16 carbon atoms, by fluorinating a highly
branched perfluoroolefin (B) represented by the following general
formula (4): [(CF.sub.3).sub.2CF][(CF.sub.3).sub.2CRf]C-
.dbd.C(CF.sub.3)Rf (4) in the formula, each Rf is the same or
different from 5 each other and is defined as described above.
17. The production method of the reduced-carbon super-stable
perfluoroalkyl radical according to claim 16, wherein Rf represents
a trifluoromethyl group.
18. A super-stable perfluoroalkyl radical (BR) represented by the
following general formula (4R):
[(CF.sub.3).sub.2CF][(CF.sub.3).sub.2CRf]- Ra--CF(CF.sub.3)Rf (4R)
in the formula, Ra represents a carbon atom having one unpaired
electron and each Rf is the same or different from each other and
represents a straight or branched perfluoroalkyl group having 1 to
16 carbon atoms.
19. The super-stable perfluoroalkyl radical according to claim 18,
which is perfluoro(2,4,4-trimethyl-3-isopropyl-3-pentyl).
20. A super-stable perfluoroalkyl radical (CR) represented by the
following general formula (5R):
[(CF.sub.3).sub.2CF][(CF.sub.3).sub.2CRf]- Ra--CF.sub.2(CF.sub.3)
(5R) in the formula, Ra represents a carbon atom having one
unpaired electron and Rf represents a straight or branched
perfluoroalkyl group having 1 to 16 carbon atoms.
21. The super-stable perfluoroalkyl radical according to claim 20,
which is perfluoro(4,4-dimethyl-3-isopropyl-3-pentyl).
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a divisional of application Ser. No. 10/685,447
filed Oct. 16, 2003, which is a divisional of application Ser. No.
10/291,699 filed Nov. 12, 2002, now issued as U.S. Pat. No.
6,710,214, the above-noted applications incorporated herein by
reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a highly branched
perfluoroolefin, a production method of the highly branched
perfluoroolefin comprising reacting a hexafluoropropene trimer with
a trialkylperfluoroalkylsilane, a super-stable perfluoroalkyl
radical and a method for producing a super-stable perfluoroalkyl
radical by fluorinating the highly branched perfluoroolefin.
PRIOR ART
[0003] As a super-stable perfluoroalkyl radical which is highly
stable, Japanese Kokoku Publication Hei-1-29175, for example,
discloses perfluoro(2,4-dimethyl-3-isopropyl-3-pentyl) and the
like.
[0004] In this gazette, it is described that
perfluoro(2,4-dimethyl-3-isop- ropyl-3-pentyl) generates a free
trifluoromethyl radical by, for example, heating, and this free
trifluoromethyl radical can be employed, for example, as a
polymerization catalyst.
[0005] A super-stable perfluoroalkyl radical is known to be
obtained, for example, by fluorinating a corresponding
perfluoroolefin. In this case, the perfluoroolefin acts as a
precursor for the super-stable perfluoroalkyl radical.
[0006] As a method for synthesizing a perfluoroolefin, a method for
oligomerizing a hexafluoropropene using an amine-based catalyst is
known.
[0007] As this oligomerization method, for example, the method for
producing a mixture of three kinds of hexafluoropropene trimers in
the presence of tris[2(2H-hexafluoropropoxy)ethyl]amine and
1,4-diazabicyclo[2.2.2]octane using dimethyl sulfoxide as a solvent
is reported (T. Martini and S. P. v. Halasz, Tetrahedron Lett.,
2129-2132 (1974)).
[0008] As three kinds of hexafluoropropene trimers, there may be
mentioned perfluoro(3-ethyl-2,4-dimethyl-2-pentene),
perfluoro(4-methyl-3-isopropyl- -2-pentene) and
perfluoro(2,4-dimethyl-3-heptene).
[0009] Among those listed above,
perfluoro(4-methyl-3-isopropyl-2-pentene) was reported, when being
fluorinated directly, to give
perfluoro(2,4-dimethyl-3-ethyl-3-pentyl) (hereinafter referred to
as "super-stable perfluoroalkyl radical (dR)") which is a
super-stable perfluoroalkyl radical at a yield of about 90% by
weight (K. V. Scherer, T. Ono, K. Yamanouchi, R. Fernandez, P.
Henderson, J.Am.Chem.Soc., 107, 718-719 (1985), U.S. Pat. No.
4,626,608).
[0010] Perfluoro(2,4-dimethyl-3-ethyl-3-pentyl) is known to be
obtained also by fluorinating
perfluoro(3-ethyl-2,4-dimethyl-2-pentene) directly.
[0011] It is known that perfluoro(2,4-dimethyl-3-ethyl-3-pentyl)
and perfluoro(4-methyl-3-isopropyl-2-pentene) are heated and
reacted together to give
perfluoro(2,4-dimethyl-3-isopropyl-3-pentyl). In this reaction,
perfluoro(2,4-dimethyl-3-ethyl-3-pentyl) is considered to act as a
trifluoromethylating reagent.
[0012] However, perfluoro(2,4-dimethyl-3-isopropyl-3-pentyl) is
obtained only in a trace amount by the synthesis method employing
perfluoro(2,4-dimethyl-3-ethyl-3-pentyl), therefore this synthesis
method is not practical. No other methods for synthesizing
perfluoro(2,4-dimethyl-3-isopropyl-3-pentyl) has hitherto been
known.
[0013] For synthesizing
perfluoro(2,4-dimethyl-3-isopropyl-3-pentyl) at a high yield, it is
considered to be desirable to use a precursor
perfluoro(2,4-dimethyl-3-isopropyl-2-pentene).
[0014] Nevertheless, such a highly branched and sterically
complicated perfluoroolefin is regarded to be very difficult to be
synthesized, and no methods for synthesizing the same has hitherto
been known. The synthesis should be conducted conveniently in a
high yield for an industrial application.
[0015] Highly branched perfluoroolefins having many branched chains
are considered to generate radicals as a result of fluorination,
and the resultant radicals are very stable due to the steric
hindrance, and thus are expected to be utilized as polymerization
catalysts similar to
perfluoro(2,4-dimethyl-3-isopropyl-3-pentyl).
SUMMARY OF THE INVENTION
[0016] In view of the above-mentioned state of the art, it is an
objective of the present invention to provide a method for
producing a highly branched perfluoroolefin conveniently in a high
yield, a novel highly branched perfluoroolefin, a method for
producing a super-stable perfluoroalkyl radical and a novel
super-stable perfluoroalkyl radical.
[0017] The present invention is a highly branched perfluoroolefin
represented by the following general formula (1):
[(CF.sub.3).sub.2CF][(CF.sub.3).sub.2CY]C.dbd.C(CF.sub.3)Z (1)
[0018] in the formula, Y and Z are the same or different and each
represents F or Rf, Rf represents a straight or branched
perfluoroalkyl group having 1 to 16 carbon atoms, provided that Y
and Z are not simultaneously F.
[0019] The present invention is a production method of a
perfluoroolefin for producing the above highly branched
perfluoroolefin which comprises reacting a hexafluoropropene trimer
with a trialkylperfluoroalkylsilane represented by the following
general formula (2): 1
[0020] in the formula, Rf represents a straight or branched
perfluoroalkyl group having 1 to 16 carbon atoms, R.sup.1, R.sup.2
and R.sup.3 are the same or different and each represents an alkyl
group having 1 to 3 carbon atoms, in an aprotic polar solvent using
a fluoride ion as a catalyst.
[0021] The present invention is a production method of a
super-stable perfluoroalkyl radical which comprises producing a
super-stable perfluoroalkyl radical represented by the following
general formula (1R):
[(CF.sub.3).sub.2CF][(CF.sub.3).sub.2CY]Ra--CF(CF.sub.3)Z (1R)
[0022] in the formula, Ra represents a carbon atom having one
unpaired electron, Y and Z are the same or different and each
represents F or Rf, and Rf represents a straight or branched
perfluoroalkyl group having 1 to 16 carbon atoms, provided that Y
and Z are not simultaneously F, by fluorinating the above highly
branched perfluoroolefin.
[0023] The present invention is a production method of a
reduced-carbon super-stable perfluoroalkyl radical which comprises
producing a super-stable perfluoroalkyl radical (AR) represented by
the following general formula (3R):
[(CF.sub.3).sub.2CF].sub.2Ra--CF(CF.sub.3)Rf (3R)
[0024] in the formula, Ra represents a carbon atom having one
unpaired electron and Rf represents a straight or branched
perfluoroalkyl group having 1 to 16 carbon atoms, by fluorinating a
highly branched perfluoroolefin (B) represented by the following
general formula (4):
[(CF.sub.3).sub.2CF][(CF.sub.3).sub.2CRf]C.dbd.C(CF.sub.3)Rf
(4)
[0025] in the formula, each Rf is the same or different from each
other and is defined as described above.
[0026] The present invention is a super-stable perfluoroalkyl
radical (BR) represented by the following general formula (4R):
[(CF.sub.3).sub.2CF][(CF.sub.3).sub.2CRf]Ra--CF(CF.sub.3)Rf
(4R)
[0027] in the formula, Ra represents a carbon atom having one
unpaired electron and each Rf is the same or different from each
other and represents a straight or branched perfluoroalkyl group
having 1 to 16 carbon atoms.
[0028] The present invention is a super-stable perfluoroalkyl
radical (CR) represented by the following general formula (5R):
[(CF.sub.3).sub.2CF][(CF.sub.3).sub.2CRf]Ra--CF.sub.2(CF.sub.3)
(5R)
[0029] in the formula, Ra represents a carbon atom having one
unpaired electron and Rf represents a straight or branched
perfluoroalkyl group having 1 to 16 carbon atoms.
DETAILED DISCLOSURE OF THE INVENTION
[0030] In the following, the present invention is described in
detail.
[0031] The highly branched perfluoroolefin of the invention is
represented by the above general formula (1).
[0032] Accordingly, the highly branched perfluoroolefin of the
invention is a highly branched perfluoroolefin (A) represented by
the following general formula (3):
[(CF.sub.3).sub.2CF].sub.2C.dbd.C(CF.sub.3)Rf (3)
[0033] in the formula, Rf represents a straight or branched
perfluoroalkyl group having 1 to 16 carbon atoms, a highly branched
perfluoroolefin (B) represented by the following general formula
(4):
[(CF.sub.3).sub.2CF][(CF.sub.3).sub.2CRf]C.dbd.C(CF.sub.3)Rf
(4)
[0034] in the formula, each Rf is the same to or different from
each other and represents a straight or branched perfluoroalkyl
group having 1 to 16 carbon atoms, or, a highly branched
perfluoroolefin (C) represented by the following general formula
(5):
[(CF.sub.3).sub.2CF][(CF.sub.3).sub.2CRf]C.dbd.CF(CF.sub.3) (5)
[0035] in the formula, Rf represents a straight or branched
perfluoroalkyl group having 1 to 16 carbon atoms.
[0036] While the above Rf is not particularly limited provided that
it is a perfluoroalkyl group having 1 to 16 carbon atoms and may be
straight or branched, it is preferably a perfluoroalkyl group
having 1 to 3 carbon atoms since these are easily, purified and
analyzed, with trifluoromethyl group being more preferred.
[0037] In the above general formula (1), Y is preferably Rf. In
such case, the highly branched perfluoroolefin of the invention is
the above highly branched perfluoroolefin (B) or the above highly
branched perfluoroolefin (C). While the above highly branched
perfluoroolefin (C) may be any of two kinds of geometric isomers, Z
form is more preferred than E form because of a less steric
hindrance and a sufficient stability.
[0038] The above highly branched perfluoroolefin (A) is preferably
perfluoro(2,4-dimethyl-3-isopropyl-2-pentene) (hereinafter referred
to as "highly branched perfluoroolefin (a)"). The above highly
branched perfluoroolefin (B) is preferably
perfluoro(2,4,4-trimethyl-3-isopropyl-2- -pentene) (hereinafter
referred to as "highly branched perfluoroolefin (b)"). The above
highly branched perfluoroolefin (C) is preferably
perfluoro(4,4-dimethyl-3-isopropyl-2-pentene) (hereinafter referred
to as "highly branched perfluoroolefin (c)").
[0039] The highly branched perfluoroolefin of the invention is
utilized not only as an intermediate for synthesizing surfactants,
pharmaceuticals and pesticides, but also as a precursor for a
super-stable perfluoroalkyl radical in the production method of the
super-stable perfluoroalkyl radical of the invention described
below.
[0040] The production method of the perfluoroolefin of the
invention is a method for producing the above highly branched
perfluoroolefin, and comprises reacting a hexafluoropropene trimer
with a trialkylperfluoroalkylsilane represented by the above
general formula (2) in an aprotic polar solvent using a fluoride
ion as a catalyst.
[0041] The above hexafluoropropene trimer may for example be
perfluoro(2,4-dimethyl-3-ethyl-2-pentene) (hereinafter referred to
as "trimer A"), perfluoro(4-methyl-3-isopropyl-2-pentene)
(hereinafter referred to as "trimer B") and
perfluoro(2,4-dimethyl-3-heptene) (hereinafter referred to as
"trimer C"). Among those listed above, the above trimer A and the
above trimer B are preferred since the yield is preferable.
[0042] As the above hexafluoropropene trimer, one or two or more
species can be used, thus, for example, only the above trimer A,
only the above trimer B, a combination of the above trimer A and
the above trimer B, or the mixture of these with the above trimer C
may be employed. When the above trimer C is mixed, the above trimer
C is preferably employed in a small amount for the purpose of
raising the purity in the reaction solution.
[0043] While the above trialkylperfluoroalkylsilane is not
particularly limited provided that it is represented by the above
general formula (2), Rf in the above general formula (2) is
preferably a straight or branched perfluoroalkyl group having 1 to
3 carbon atoms, with a trifluoromethyl group being more
preferred.
[0044] In the production method of the perfluoroolefin of the
invention, Rf in the above general formula (2) serves as a
perfluoroalkyl group to be introduced into the above
hexafluoropropene trimer. Thus, Rf in the above general formula (1)
in the resultant highly branched perfluoroolefin is derived from Rf
in the above general formula (2) of the above
trialkylperfluoroalkylsilane molecule.
[0045] R.sup.1, R.sup.2 or R.sup.3 in the above general formula (2)
is preferably a methyl group. R.sup.1, R.sup.2 and R.sup.3 are
preferably the same to one another, and it is more preferable that
all are methyl groups.
[0046] The trialkylperfluoroalkylsilane described above is
preferably trifluoromethyltrimethylsilane in view of the cost of
the raw material.
[0047] The aprotic polar solvent employed in the production method
of the perfluoroolefin of the invention is not particularly
limited, and may for example be a Glyme-based solvent, dimethyl
sulfoxide (DMSO), dimethyl acetamide (DMA), dimethyl formamide
(DMF), 1-methyl-2-pyrrolidone (NMP), and
1,3-dimethyl-2-imidazolidinone (DMI) and the like. The Glyme-based
solvent mentioned above may for example be diethylene glycol
dimethyl ether, triethylene glycol dimethyl ether, tetraethylene
glycol dimethyl ether, triethylene glycol diethyl ether,
tetraethylene glycol diethyl ether and the like, as well as higher
homologues thereof.
[0048] The above aprotic polar solvent is preferably dimethyl
formamide (DMF), 1-methyl-2-pyrrolidone (NMP) and
1,3-dimethyl-2-imidazolidinone (DMI) because of generally higher
reaction rates, with 1,3-dimethyl-2-imidazolidinone (DMI) being
more preferred because of higher reaction rate and higher
selectivity.
[0049] The production method of the perfluoroolefin of the
invention uses a fluoride ion as a catalyst. The above fluoride ion
is enabled to act as a catalyst by using a compound which generates
the fluoride ion.
[0050] Such a compound is not particularly limited provided that it
can generate a fluoride ion, and may for example be sodium
fluoride, potassium fluoride, acidic potassium fluoride, cesium
fluoride, tetrabutylammonium fluoride, tetramethylammonium
fluoride, tris(dimethylamino)sulfonium trimethylsilyl difluoride,
tetrabutylammonium difluorotriphenyl stannate, pyridinium (hydrogen
polyfluoride), triethylamine (hydrogen trifluoride) and the like.
Among those listed above, pyridinium (hydrogen polyfluoride) is
referred to also as Olah reagent.
[0051] While the highly branched perfluoroolefin obtained by the
production method of the perfluoroolefin of the invention is not
particularly limited provided that it is represented by the above
general formula (1), it is preferably the above highly branched
perfluoroolefin (A), more preferably the above highly branched
perfluoroolefin (a). The above highly branched perfluoroolefin may
preferably be the above highly branched perfluoroolefin (b) and the
above highly branched perfluoroolefin (c).
[0052] The above highly branched perfluoroolefin is generally
obtained as a mixture of at least two species selected from the
group consisting of the above highly branched perfluoroolefin (A),
the above highly branched perfluoroolefin (B) and the above highly
branched perfluoroolefin (C), although it may vary depending on the
species and the amount of addition of the hexafluoropropene trimer
and the aprotic polar solvent as well as the reaction conditions.
The following scheme shows the example in case that Rf is a
trifluoromethyl group. 2
[0053] As the above highly branched perfluoroolefin, when the
trimer A is employed as a hexafluoropropene trimer, the tendency is
such that an yield of the highly branched perfluoroolefin (B) is
high, for example 15 to 80% by weight, an yield of the highly
branched perfluoroolefin (C) is significantly lower than the yield
of the highly branched perfluoroolefin (B), for example 10 to 50%
by weight, and, an yield of the highly branched perfluoroolefin (A)
is 5% by weight or less and may substantially be zero in some
cases.
[0054] As the above highly branched perfluoroolefin, when the
trimer B is employed as a hexafluoropropene trimer, the tendency is
such that an yield of the highly branched perfluoroolefin (A) is
high, for example 30 to 95% by weight, an yield of the highly
branched perfluoroolefin (B) is significantly lower than the yield
of the highly branched perfluoroolefin (A), for example 45% by
weight or less, and an yield of the highly branched perfluoroolefin
(C) is 5% by weight or less and may substantially be zero in some
cases.
[0055] For the purpose of obtaining the highly branched
perfluoroolefin (A) selectively in the production method of the
perfluoroolefin of the invention, 1,3-dimethyl-2-imidazolidinone is
preferably employed as the aprotic polar solvent. By using
1,3-dimethyl-2-imidazolidinone as the aprotic polar solvent,
by-products, which are generally produced, are not produced
substantially. The above highly branched perfluoroolefin (A) is
preferably employed since the selectivity is high when the highly
branched perfluoroolefin (a) is to be obtained.
[0056] The term "selectively" employed in this specification
describing the reaction for obtaining the above highly branched
perfluoroolefin (A) selectively means that the intended product is
obtained in a high yield. The above term "high yield" means a yield
of 60% by weight or higher.
[0057] The reaction for obtaining the above highly branched
perfluoroolefin (A) selectively may be one where the starting
material hexafluoropropene trimer is remained unreacted, and the
amount of the unreacted material is usually 25% by weight or less
of the starting material. For the purpose of obtaining the reaction
product of the above highly branched perfluoroolefin (A) at a
purity as high as possible, the amount of the unreacted material
may be reduced, in some cases, by increasing the amount of addition
of the trialkylperfluoroalkylsilane.
[0058] In the production method of the perfluoroolefin of the
invention, the lower and upper limits of the reaction temperature
are generally 0.degree. C. and 70.degree. C., respectively, and the
upper limit is preferably 30.degree. C., and the reaction may
generally be conducted at room temperature without any particular
need of heating, thus the method can be employed easily and enables
an energy-saving operation.
[0059] The production method of the super-stable perfluoroalkyl
radical of the invention comprises producing the super-stable
perfluoroalkyl radical represented by the above general formula
(1R) by fluorinating the above highly branched perfluoroolefin.
[0060] Such a highly branched perfluoroolefin may be any of the
highly branched perfluoroolefins of the invention listed above, and
these can be obtained by the production method of the
perfluoroolefin of the invention as described above.
[0061] The highly branched perfluoroolefin employed in the
production method of the super-stable perfluoroalkyl radical of the
invention is preferably the highly branched perfluoroolefin (a),
highly branched perfluoroolefin (b) or highly branched
perfluoroolefin (c) described above, with the highly branched
perfluoroolefin (a) being more preferred since the super-stable
perfluoroalkyl radical can be synthesized in a high yield. While
two or more species may be employed as the above highly branched
perfluoroolefins, it is preferable to use one species for the
purpose of increasing the purity of the resultant super-stable
perfluoroalkyl radical.
[0062] The fluorination in the production method of the
super-stable perfluoroalkyl radical of the invention is preferably
conducted using a fluorine gas. The above fluorine gas may be a
diluted one or a neat one without dilution. The dilution of the
above fluorine gas may be conducted with an inert gas such as
nitrogen or argon. The fluorine gas described above is preferably a
pure one.
[0063] The fluorination in the production method of the
super-stable perfluoroalkyl radical of the invention can generally
be conducted by introducing a diluted fluorine gas or neat pure
fluorine gas into the bottom of the reaction vessel, or also by
effecting the reaction under pressure with a fluorine gas in the
sealed vessel. The pressure of the fluorine gas may be 10 atoms
(absolute pressure), preferably 1 to 10 atoms (absolute
pressure).
[0064] Such a fluorination results in the addition of a fluorine
atom to one of the double bond-forming carbon atoms of the highly
branched perfluoroolefin, whereby obtaining a super-stable
perfluoroalkyl radical having an unpaired electron on the other
carbon atom of said double bond-forming carbon atoms. In this
specification, the above fluorination may be referred to as a
"direct fluorination".
[0065] During the fluorination described above, when it is
conducted under the condition of 1 atom (absolute pressure), the
reaction temperature is preferably 40.degree. C. or lower, more
preferably 30.degree. C. or lower, for the purpose of raising the
yield of the super-stable perfluoroalkyl radical; preferably
-10.degree. C. or higher, more preferably 0.degree. C. or higher,
for the purpose of promoting the reaction; and when the yield and
the promotion of the reaction are taken into account, the upper
limit is preferably 10.degree. C., more, preferably 5.degree. C.,
and the lower limit is preferably -10.degree. C., more preferably
-5.degree. C.
[0066] During the fluorination described above, when it is
conducted under the condition of 1 atom (absolute pressure), the
aeration time period is generally preferably 500 hours or longer,
more preferably 720 hours or longer, for the purpose of raising the
yield of the super-stable perfluoroalkyl radical.
[0067] The fluorination described above is conducted preferably
under pressure and/or at a low temperature such as -5 to 5.degree.
C., for instance, for the purpose of reducing the reaction time,
preferably under pressure and at a low temperature such as -5 to
5.degree. C. especially for the purpose of industrial
application.
[0068] The super-stable perfluoroalkyl radical to be obtained by
the production method of the super-stable perfluoroalkyl radical of
the invention is not particularly limited provided that it is
represented by the above general formula (1R).
[0069] While Rf in the above general formula (1R) is not
particularly limited provided that it is a perfluoroalkyl group
having 1 to 16 carbon atoms and may be straight or branched, it is
preferably a perfluoroalkyl group having 1 to 3 carbon atoms since
it is easily purified and analyzed, with a trifluoromethyl group
being more preferred. The above Rf is derived from Rf in the above
general formula (1) representing the highly branched
perfluoroolefin employed in the production method of the
super-stable perfluoroalkyl radical of the invention.
[0070] In the above general formula (1R), Ra is a carbon atom
having one unpaired electron. The term "carbon atom having one
unpaired electron" employed herein means a carbon having, on the
atom, an unpaired electron possessed by a free radical.
[0071] The super-stable perfluoroalkyl radical represented by the
above general formula (1R) is a super-stable perfluoroalkyl radical
(AR) represented by the following general formula (3R):
(CF.sub.3).sub.2CF].sub.2Ra--CF(CF.sub.3)Rf (3R)
[0072] in the formula, Ra represents a carbon atom having one
unpaired electron and Rf represents a straight or branched
perfluoroalkyl group having 1 to 16 carbon atoms;
[0073] a super-stable perfluoroalkyl radical (BR) represented by
the following general formula (4R):
[(CF.sub.3).sub.2CF][(CF.sub.3).sub.2CRf]Ra--CF(CF.sub.3)Rf
(4R)
[0074] in the formula, Ra represents a carbon atom having one
unpaired electron and each Rf is the same or different from each
other and represents a straight or branched perfluoroalkyl group
having 1 to 16 carbon atoms, or, a super-stable perfluoroalkyl
radical (CR) represented by the following general formula (5R):
[(CF.sub.3).sub.2CF][(CF.sub.3).sub.2CRf]Ra--CF.sub.2(CF.sub.3)
(5R)
[0075] in the formula, Ra represents a carbon atom having one
unpaired electron and Rf represents a straight or branched
perfluoroalkyl group having 1 to 16 carbon atoms.
[0076] The above super-stable perfluoroalkyl radical (AR) is
preferably perfluoro(2,4-dimethyl-3-isopropyl-3-pentyl)
(hereinafter referred to as "super-stable perfluoroalkyl radical
(aR)"). The above super-stable perfluoroalkyl radical (BR) is
preferably perfluoro(2,4,4-trimethyl-3-iso- propyl-3-pentyl)
(hereinafter referred to as "super-stable perfluoroalkyl radical
(bR)"). The above super-stable perfluoroalkyl radical (CR) is
preferably perfluoro(4,4-dimethyl-3-isopropyl-3-pentyl)
(hereinafter referred to as "super-stable perfluoroalkyl radical
(cR)").
[0077] As a super-stable perfluoroalkyl radical to be obtained by
the production method of the super-stable perfluoroalkyl radical of
the invention, the above super-stable perfluoroalkyl radical (AR)
is obtained as a main product from the above highly branched
perfluoroolefin (A), the above super-stable perfluoroalkyl radical
(BR) is obtained as a main product from the above highly branched
perfluoroolefin (B), and the above super-stable perfluoroalkyl
radical (CR) is obtained as a main product from the above highly
branched perfluoroolefin (C), depending on the species of the
highly branched perfluoroolefin employed and the reaction
conditions.
[0078] Accordingly, as shown in the following scheme, as the main
product by the production method of the super-stable perfluoroalkyl
radical of the invention, the above super-stable perfluoroalkyl
radical (aR) is obtained from the above highly branched
perfluoroolefin (a), the above super-stable perfluoroalkyl radical
(bR) is obtained from the above highly branched perfluoroolefin (b)
and the above super-stable perfluoroalkyl radical (cR) is obtained
from the above highly branched perfluoroolefin (c). 3
[0079] The above super-stable perfluoroalkyl radical is, usually,
sufficiently stable at a temperature below 90.degree. C., depending
on the chemical structure, however. While the above super-stable
perfluoroalkyl radical is decomposed by heating, for example, to
undergo P-cleavage to generate a free trifluoromethyl radical, it
usually has a half life of 6 hours or longer at a temperature below
90.degree. C.
[0080] Especially, the above super-stable perfluoroalkyl radical
(aR) is highly stable such that it does not react even with a pure
fluorine gas at 0.degree. C., and undergoes no chemical change at
room temperature over a period longer than one year. The above
super-stable perfluoroalkyl radical (aR) is decomposed at a
half-life of about 6 hours when heated at 90.degree. C. to generate
a free trifluoromethyl radical.
[0081] Since the super-stable perfluoroalkyl radical is extremely
and sufficiently stable as discussed above, a perfluoroalkyl
radical with low molecular weight such as trifluoromethyl released
upon heating at, for example, 90.degree. C. or higher can be
employed not only as an initiator in a polymer synthesis, but also
as a standard substance for electron spin resonance (ESR), surface
treatment reagent, leak checking reagent for a container with a
complicated shape, emulsion as a contrast agent for biological
imaging.
[0082] Among them, the above super-stable perfluoroalkyl radical
(aR) and the above super-stable perfluoroalkyl radical (bR),
especially the above super-stable perfluoroalkyl radical (aR), can
be employed preferably as standard substrates for ESR, since they
are highly symmetric.
[0083] The production method of the reduced-carbon super-stable
perfluoroalkyl radical of the invention comprises producing the
super-stable perfluoroalkyl radical (AR) by fluorinating the highly
branched perfluoroolefin (B).
[0084] The above highly branched perfluoroolefin (B) and the above
super-stable perfluoroalkyl radical (AR) are similar to those
described above, and the fluorination mentioned above is conducted
by the method similar to the fluorination as described above with
regard to the production method of the super-stable perfluoroalkyl
radical of the invention.
[0085] The production method of the reduced-carbon super-stable
perfluoroalkyl radical of the invention comprises fluorinating the
above highly branched perfluoroolefin (B) to produce the above
super-stable perfluoroalkyl radical (AR) having a number of carbon
atom lower than that of the above highly branched perfluoroolefin
(B).
[0086] While the reaction temperature of the production method of
the reduced-carbon super-stable perfluoroalkyl radical of the
invention is not particularly limited, the preferable lower limit
and upper limit are -78.degree. C. and 45.degree. C., more
preferably -10.degree. C. and 15.degree. C., respectively.
[0087] The mechanism of this reaction has not been elucidated
clearly, but it is considered such that, by the above fluorination,
a fluorine atom is added to a double bond to form an unpaired
electron and then the unpaired electron dissociates one Rf in the
general formula (4) representing the above highly branched
perfluoroolefin (B) to release as a free radical. This reaction
tends to occur easily especially when the fluorination is carried
out using a pure fluorine gas at a reaction temperature of
0.degree. C. to room temperature. The above Rf is preferably a
trifluoromethyl group.
[0088] In the production method of the super-stable perfluoroalkyl
radical of the invention, the above super-stable perfluoroalkyl
radical (AR), as described above, can be obtained from the highly
branched perfluoroolefin (A) whose number of carbon atom is the
same as that of the above super-stable perfluoroalkyl radical (AR).
This reaction is proceeded quantitatively when performing the
fluorination using a pure fluorine gas at a reaction temperature
especially about 0.degree. C.
[0089] Therefore, by adjusting the reaction temperature, the
intended super-stable perfluoroalkyl radical can be obtained. Such
an adjustment of the reaction temperature is considered to be
useful especially when the highly branched perfluoroolefin employed
is a mixture comprising the above highly branched perfluoroolefin
(A) and the above highly branched perfluoroolefin (B).
[0090] As the example of the reaction for obtaining the above
super-stable perfluoroalkyl radical (AR) by the production method
of the reduced-carbon super-stable perfluoroalkyl radical of the
invention and the reaction for obtaining the same by the above
production method of the super-stable perfluoroalkyl radical,
reactions for obtaining the super-stable perfluoroalkyl radical
(aR) from a highly branched perfluoroolefin (b) and from a highly
branched perfluoroolefin (a) are described in the following scheme.
4
[0091] The reaction for formation of the super-stable
perfluoroalkyl radical (AR) by the production method of the
reduced-carbon super-stable perfluoroalkyl radical of the invention
may be accompanied with the reaction for formation of the
super-stable perfluoroalkyl radical (BR) by the production method
of the super-stable perfluoroalkyl radical described above,
simultaneously.
[0092] The highly branched-perfluoroolefin of the invention, which
has a chemical structure described above, is a novel compound and
can be used as a precursor for the super-stable perfluoroalkyl
radical as described above.
[0093] The production method of the perfluoroolefin of the
invention allows the above highly branched perfluoroolefin to be
obtained in a high yield by a convenient method as described
above.
[0094] Since the production method of the super-stable
perfluoroalkyl radical of the invention allows the super-stable
perfluoroalkyl radical to be obtained in a high yield with high
purity by an inexpensive and convenient method and the reaction
scale can be enlarged easily, it is suitable to an industrial
application which requires a large scale synthesis.
[0095] The production method of the reduced-carbon super-stable
perfluoroalkyl radical of the invention allows the super-stable
perfluoroalkyl radical (AR) to be obtained in a high yield by a
convenient method and can give a wider option in selecting the
method for producing the above highly stable perfluoroalkyl radical
(AR).
[0096] The above-mentioned super-stable perfluoroalkyl radical (BR)
is also encompassed within the present invention. As the above
super-stable perfluoroalkyl radical (BR), the super-stable
perfluoroalkyl radical (bR) described above is preferred.
[0097] The super-stable perfluoroalkyl radical (CR) described above
is also encompassed within the present invention. As the above
super-stable perfluoroalkyl radical (CR), the super-stable
perfluoroalkyl radical (cR) described above is preferred.
[0098] Since the above super-stable perfluoroalkyl radical (BR) and
the super-stable perfluoroalkyl radical (CR) are sufficiently
stable, as described above, each of them is heated to 90.degree. C.
or higher to liberate a perfluoroalkyl radical having a low
molecular weight such as trifluoromethyl, whereby being utilized as
a polymerization initiator.
[0099] The production method of the perfluoroolefin of the
invention allows the highly branched perfluoroolefin to be obtained
by a convenient method in a high yield. The production method of
the super-stable perfluoroalkyl radical of the invention enables a
simple and efficient production of the super-stable perfluoroalkyl
radical which was obtained only in a small amount by conventional
methods. The super-stable perfluoroalkyl radical of the invention
is sufficiently stable, and its ability of generating a radical
upon heating makes it applicable to various applications. The
highly branched perfluoroolefin of the invention can be a precursor
for the above super-stable perfluoroalkyl radical.
EXAMPLES
[0100] The following examples illustrate the present invention in
further detail. These examples are, however, by no means limitative
of the scope of the present invention. .sup.19F-NMR (282.24 MHz)
described in examples were measured using deuterated chloroform as
a solvent and fluoroform (CFCl.sub.3) as an internal standard. Each
chemical shift value in .sup.19F-NMR was represented as .delta. ppm
with an absorption at a magnetic field higher than fluoroform being
regarded as negative. For gas chromatography measurement, a
capillary column (NB-1, 0.25 .mu.m, 1.5 mm ID.times.60 m) was used
and an FID was used as a detector. For preparative gas
chromatography, a packed column whose mobile phase was Fomblin was
used. Mass spectroscopy (MS) was measured using a gas
chromatograph-quadrupole mass spectrometer (GC-MS), with the
ionization voltage of 70 eV. Paramagnetic nuclear magnetic
resonance absorption spectrum (ESR) was measured using FC-72
(perfluorocarbon containing. perfluorohexane as a main component)
as a solvent.
Example 1
Synthesis of perfluoro(2,4-dimethyl-3-isopropyl-2-pentene)
[0101] 1 mmol (450 mg) of a hexafluoropropene trimer mixture
(containing 10% by weight of
perfluoro(3-ethyl-2,4-dimethyl-2-pentene)) whose main component was
perfluoro(4-methyl-3-isopropyl-2-pentene) and 1.1 mmol (23.4 mg) of
trifluoromethyltrimethylsilane were weighed into a 10-ml
fluororesin-made reaction container, and 1 ml of dimethyl formamide
and 0.3 mmol of acidic potassium fluoride (KHF.sub.2) were added. A
fluororesin-made magnetic stirrer was placed therein, and the
mixture was stirred vigorously for 1 hour at room temperature. The
transparent lower perfluorocarbon layer was separated into each
component by preparative gas chromatography (using a column whose
mobile phase was Fomblin), and the structure was identified by
.sup.19F-NMR. The yield of a main product
perfluoro(2,4-dimethyl-3-isopropyl-2-pentene) calculated on the
basis of the ratio of the peak areas in the gas chromatography
using a capillary column (NB-1, 0.25 .mu.m, 1.5 mm ID.times.60 m)
was 62.7% by weight.
[0102] .sup.19F-NMR: 56.07 (3F, doublet quartet, J=58.6,12.0 Hz),
59.35(3F, septet quartet, J=15.5,12.0 Hz), 70.11(6F,multiplet),
70.56(6F,broad doublet, J=36.4 Hz), 153.6(1F,septet doublet,
J=35.7,12.7 Hz), 157.5(1F,quartet doublet,J=58.6,12.0 Hz)
[0103] MS(m/z, %): 481(M-F,1.3), 393(C.sub.9F.sub.15,1.9),
343(C.sub.8F.sub.13,2.2), 293(C.sub.7F.sub.11,2.5),
243(C.sub.6F.sub.9,1.7), 205(C.sub.5F.sub.4CF.sub.3,1.7),
181(C.sub.4F.sub.7,1.2), 155(C.sub.5F.sub.5,1.7),
124(C.sub.4F.sub.4,1.0)- , 119(C.sub.2F.sub.5, 1.3),
100(C.sub.2F.sub.4,1.3), 93 (C.sub.3F.sub.3,1.3),
69(CF.sub.3,100)
[0104] As the by-products,
perfluoro(4,4-dimethyl-3-isopropyl-2-pentene) and
perfluoro(2,4,4-trimethyl-3-isopropyl-2-pentene) were obtained at
the yields of 2.6% by weight and 13.3% by weight, respectively.
Starting materials perfluoro(4-methyl-3-isopropyl-2-pentene) and
perfluoro(3-ethyl-2,4-dimethyl-2-pentene) were contained at the
levels of 7.1% by weight and 14.2% by weight, respectively.
[0105] .sup.19F-NMR of
perfluoro(4,4-dimethyl-3-isopropyl-2-pentene): 60.05(9F,doublet
quartet,J=26.7,13.2 Hz), 66.29(3F,decaplet doublet,J=11.7,4.3 Hz),
67.03(1F,septet doublet quartet,39.7,15.5,4.2 Hz), 72.38
(6F,doublet,J=39.5 Hz), 166.3(1F,decaplet doublet,J=26.7,15.5
Hz).
[0106] MS (m/z, %) of
perfluoro(4,4-dimethyl-3-isopropyl-2-pentene):
393(C.sub.9F.sub.15,3.6), 343(C.sub.8F.sub.13,2.1),
293(C.sub.7F.sub.11,1.7), 255(C.sub.5F.sub.3(CF.sub.3).sub.2,0.7),
243(C.sub.6F.sub.9,1.4), 205(C.sub.5F.sub.4CF.sub.3,1.2),
200(C.sub.4F.sub.8,0.9), 181(C.sub.4F.sub.7,1.0),
155(C.sub.5F.sub.5,1.0)- , 150(C.sub.3F.sub.6,0.6),
143(C.sub.4F.sub.5,1.3), 131(C.sub.3F.sub.5,1.1),
124(C.sub.4F.sub.4,1.2), 119(C.sub.2F.sub.5,2.3)- ,
117(C.sub.5F.sub.3,0.7), 100(C.sub.2F.sub.4,1.1),
93(C.sub.3F.sub.3,1.8), 69(CF.sub.3,100), 50(CF.sub.2,0.8)
[0107] .sup.19F-NMR of
perfluoro(2,4,4-trimethyl-3-isopropyl-2-pentene):
55.09(3F,septet,J=12.9 Hz), 56.83(3F,decaplet,J=15.5 Hz),
57.98(9F,broad singlet), 70.40(6F,broad singlet),
146.99(1F,decaplet,J=31.7 Hz)
[0108] MS(m/z, %) of
perfluoro(2,4,4-trimethyl-3-isopropyl-2-pentene):
443(C.sub.10F.sub.17,1.1), 393(C.sub.9F.sub.15,0.9),
355(C.sub.5F.sub.2(CF.sub.3).sub.2(C.sub.2F.sub.5),0.7),
293(C.sub.7F.sub.11,1.0), 243(C.sub.6F.sub.9,0.6),
205(C.sub.5F.sub.4CF.sub.3,1.7), 200(C.sub.4F.sub.8,0.7),
181(C.sub.4F.sub.7,1.8), 155(C.sub.5F.sub.5,1.0),
131(C.sub.3F.sub.5,0.9)- , 124(C.sub.4F.sub.4,0.7),
117(C.sub.5F.sub.3,0.7), 100(C.sub.2F.sub.4,0.7),
93(C.sub.3F.sub.3,1.1), 69(CF.sub.3,100), 50(CF.sub.2,0.7).
Example 2
Synthesis of perfluoro(2,4-dimethyl-3-isopropyl-2-pentene)
[0109] 1 mmol (450 mg) of a hexafluoropropene trimer mixture
(containing 10% by weight of
perfluoro(3-ethyl-2,4-dimethyl-2-pentene)) whose main component was
perfluoro(4-methyl-3-isopropyl-2-pentene) and 4.0 mmol (568.8 mg)
of trifluoromethyltrimethylsilane were weighed into a 10-ml
fluororesin-made reaction container, and 1 ml of dimethyl formamide
and 0.1 mmol of acidic potassium fluoride (KHF.sub.2, 7.8 mg) were
added. A fluororesin-made magnetic stirrer was placed therein, and
the mixture was stirred vigorously for 1 hour at room temperature.
The transparent lower perfluorocarbon layer was analyzed by gas
chromatography using a capillary column (NB-1, 0.25 .mu.m, 1.5 mm
ID.times.60 m). The yields of the main product
perfluoro(2,4-dimethyl-3-isopropyl-2-pentene) and perfluoro
(2,4,4-trimethyl-3-isopropyl-2-pentene) were 63.5% by weight and
36.5% by weight, respectively.
[0110] Accordingly, it was revealed that the reaction conditions
described above allowed only the by-product
perfluoro(2,4,4-trimethyl-3-isopropyl-2- -pentene) to be contained
but did not allow perfluoro(4,4-dimethyl-3-isopr- opyl-2-pentene)
to be contained.
Example 3
Selective synthesis of
perfluoro(2,4-dimethyl-3-isopropyl-2-pentene)
[0111] 1 mmol (450 mg) of a hexafluoropropene trimer mixture
(containing 10% by weight of
perfluoro(3-ethyl-2,4-dimethyl-2-pentene)) whose main component was
perfluoro(4-methyl-3-isopropyl-2-pentene) and 2.0 mmol (284.4 mg)
of trifluoromethyltrimethylsilane were weighed into a 10-ml
fluororesin-made reaction container, then 1 ml of
1,3-dimethyl-2-imidazol- idinone and 0.1 mmol of acidic potassium
fluoride (KHF.sub.2, 7.8 mg) were added therein. A fluororesin-made
magnetic stirrer was placed and the mixture was stirred vigorously
for 1 hour at room temperature, and then 1.0 mmol of
trifluoromethyltrimethylsilane (142.2 mg) and 0.1 mmol of acidic
potassium fluoride (KHF.sub.2, 7.8 mg) were added and the mixture
was further stirred vigorously for 1 hour at room temperature.
After completion of the reaction, the transparent lower
perfluorocarbon layer was analyzed by gas chromatography using a
capillary column (NB-1, 0.25 .mu.m. 1.5 mm ID.times.60 m). The
yield of the main product
perfluoro(2,4-dimethyl-3-isopropyl-2-pentene) was 89.6% by weight.
The remainders were the starting materials
perfluoro(4-methyl-3-isopropyl-2-p- entene) and
perfluoro(3-ethyl-2,4-dimethyl-2-pentene), which were present at
4.2% by weight and 2.6% by weight, respectively.
Example 4
Synthesis of perfluoro(2,4,4-trimethyl-3-isopropyl-2-pentene)
[0112] 1 mmol (450 mg) of perfluoro(3-ethyl-2,4-dimethyl-2-pentene)
and 4.0 mmol (568.8 mg) of trifluoromethyltrimethylsilane were
weighed into a 10-ml fluororesin-made reaction container, then 1 ml
of dimethyl formamide and 0.1 mmol of acidic potassium fluoride
(KHF.sub.2, 7.8 mg) were added therein. A fluororesin-made magnetic
stirrer was placed and the mixture was stirred vigorously for 1
hour at room temperature, and then 1.0 mmol of
trifluoromethyltrimethylsilane (142.2 mg) and 0.1 mmol of acidic
potassium fluoride (KHF.sub.2, 7.8 mg) were added and the mixture
was further stirred vigorously for 1 hour at room temperature.
After completion of the reaction, the transparent lower
perfluorocarbon layer was analyzed by gas chromatography using a
capillary column (NB-1, 0.25 .mu.m, 1.5 mm ID.times.60 m). The
yield of the main product
perfluoro(2,4,4-trimethyl-3-isopropyl-2-pentene) was 74.5% by
weight. As the by-product, perfluoro
4,4-dimethyl-3-isopropyl-2-pentene was obtained at the yield of
25.5% by weight. The starting material
perfluoro(3-ethyl-2,4-dimethyl-2-pentene) was consumed completely
by the reaction.
Example 5
Direct fluorination of
perfluoro(2,4-dimethyl-3-isopropyl-2-pentene) (Room
Temperature)
[0113] A 20-ml Hauk cylinder was charged with
perfluoro(2,4-dimethyl-3-iso- propyl-2-pentene) (12 g, 24 mmol)
obtained in Example 3, then a fluororesin-made magnetic stirrer was
placed therein and connected with the fluorine line. The cylinder
was cooled with liquid nitrogen, and the inside pressure was
reduced by a vacuum pump. After three freeze-and-thaw cycles
followed by purging the container with nitrogen, a pure fluorine
gas was introduced via the line, and the reaction was conducted at
room temperature under the condition of 1 atom (absolute pressure)
with stirring. After reaction for 10 days, the reaction solution
was taken out and analyzed by gas chromatograph-quadrupole mass
spectrometer (GC-MS) and ESR. The yield of
perfluoro(2,4-dimethyl-3-isopropyl-3-pentyl) on the basis of the
ratio of the peak areas in the gas chromatography was 51% by
weight. The remainder 49% by weight corresponded to the saturated
form of perfluoro(2,4-dimethyl-3-isopropylpentane). Perfluoro
(2,4-dimethyl-3-isopropyl-3-pentyl) was fractionated and purified
by gas chromatography using a packed column whose mobile phase was
Fomblin, and dissolved in FC-72 (perfluoroalkane containing
perfluorohexane as a main component) to prepare an ESR sample. The
structure was identified by MS and ESR.
[0114] MSm/z (%): 481 (C.sub.10F.sub.19,0.3),
431(C.sub.9F.sub.17,0.6), 393(C.sub.9F.sub.15,0.6),
381(C.sub.8F.sub.15,0.6), 362(C8F.sub.14,1.2),
355(C.sub.9F.sub.13,1.3), 343(C.sub.8F.sub.13,2.8),
293(C.sub.7F.sub.11,3.7), 281(C.sub.6F.sub.11,5.9),
267(C.sub.8F.sub.9,1.4), 255(C.sub.7F.sub.9,0.3),
243(C.sub.6F.sub.9,2.2)- , 231(C.sub.5F.sub.9,0.2),
205(C.sub.6F.sub.7,1.0), 193(C.sub.5F.sub.7,1.2),
181(C.sub.4F.sub.7,0.8), 169(C.sub.3F.sub.7,0.3)- ,
155(C.sub.5F.sub.5,1.0), 150(C.sub.3F.sub.6,1.3),
143(C.sub.4F.sub.5,1.2), 131(C.sub.3F.sub.5,0.8),
124(C.sub.4F.sub.4,1.1)- , 119(C.sub.2F.sub.5,5.7),
117(C.sub.5F.sub.3,0.6), 105(C.sub.4F.sub.3,0.4),
100(C.sub.3F.sub.4,1.7), 93(C.sub.3F.sub.3,1.6),
74(C.sub.3F.sub.2,1.0), 69(CF.sub.3,100), 50(CF.sub.2,1.3).
Example 6
Direct fluorination of
perfluoro(2,4-dimethyl-3-isopropyl-2-pentene) (0.degree. C.)
[0115] Perfluoro (2,4-dimethyl-3-isopropyl-2-pentene) (3.1 g, 6.2
mmol) obtained in Example 3 was placed in a 10-ml fluororesin-made
reaction tube, and dissolved in 5 ml of FC-72. A fluororesin-made
magnetic stirrer was placed, then a fluorine gas inlet tube was
placed at the bottom of the test tube, and the reaction container
was cooled in ice-water bath. A pure fluorine gas was introduced
and the mixture was stirred vigorously. After reaction for 30 days,
the starting material was entirely converted into
perfluoro(2,4-dimethyl-3-isopropyl-3-pentyl). Gas chromatography
revealed that the reaction proceeded quantitatively. The structure
was identified by ESR as similar to Example 1.
Example 7
Direct fluorination of
perfluoro(2,4,4-trimethyl-3-isopropyl-2-pentene) (0.degree. C.)
[0116] Perfluoro(2,4,4-trimethyl-3-isopropyl-2-pentene) (80 mg,
0.145 mmol) obtained in Example 4 was placed in a 10-ml
fluororesin-made reaction tube and dissolved in 5 ml of FC-72. A
fluororesin-made magnetic stirrer was placed, then a fluorine gas
inlet tube was placed at the bottom of the test tube, and the
reaction-.container was cooled in ice-water bath. A pure fluorine
gas was introduced and the mixture was stirred vigorously for 4
hours. The gas chromatography analysis of the reaction solution
revealed that 30.7% by weight of the raw material was consumed and
converted into perfluoro(2,4-dimethyl-3-isopropyl-3-pentyl) which
is a super-stable perfluoroalkyl radical and
perfluoro(2,4-dimethyl-3-isopropyl-2-pentene). The yields based on
the consumed raw material were 35.2% by weight and 64.8% by weight,
respectively.
* * * * *