U.S. patent application number 09/854594 was filed with the patent office on 2002-12-26 for semifluorinated alkanes and the use thereof.
Invention is credited to Meinert, Hasso.
Application Number | 20020198266 09/854594 |
Document ID | / |
Family ID | 7773697 |
Filed Date | 2002-12-26 |
United States Patent
Application |
20020198266 |
Kind Code |
A1 |
Meinert, Hasso |
December 26, 2002 |
Semifluorinated alkanes and the use thereof
Abstract
The invention concerns semi-fluorinated alkanes of the general
formulae R.sub.FR.sub.H or R.sub.FR.sub.HR.sub.F, R.sub.F being a
linear or branched perfluoroalkyl group and R.sub.H being a linear
or branched saturated (hydrocarbon)-alkyl group.
Inventors: |
Meinert, Hasso; (Ulm,
DE) |
Correspondence
Address: |
CROWELL & MORING, L.L.P.
1200 G Street, N.W., Suite 700
Washington
DC
20005
US
|
Family ID: |
7773697 |
Appl. No.: |
09/854594 |
Filed: |
May 15, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09854594 |
May 15, 2001 |
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09043489 |
Sep 30, 1998 |
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6262126 |
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09043489 |
Sep 30, 1998 |
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PCT/EP96/03542 |
Aug 9, 1996 |
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Current U.S.
Class: |
514/743 |
Current CPC
Class: |
A61L 27/00 20130101;
C10M 2213/02 20130101; C10M 105/52 20130101; A61P 17/16 20180101;
Y10S 514/887 20130101; C10M 147/02 20130101; C07C 17/23 20130101;
C10M 2211/06 20130101; A61P 17/00 20180101; Y10S 514/886 20130101;
C10M 131/04 20130101; Y10S 514/912 20130101; A61K 9/007 20130101;
A61P 41/00 20180101; C10M 107/38 20130101; C10M 2213/062 20130101;
A61P 27/04 20180101; C07C 17/275 20130101; A61K 9/0048 20130101;
C07C 19/08 20130101; C07C 17/269 20130101; A61K 9/0014 20130101;
C10M 2211/022 20130101; A61K 9/0026 20130101; A61K 47/06 20130101;
C10L 1/201 20130101; A61P 17/02 20180101; C10L 1/207 20130101; C07C
17/23 20130101; C07C 19/08 20130101; C07C 17/269 20130101; C07C
19/08 20130101; C07C 17/275 20130101; C07C 19/16 20130101 |
Class at
Publication: |
514/743 |
International
Class: |
A61K 031/02 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 29, 1995 |
DE |
195 36 504.6 |
Claims
What is claimed is:
21. A skin remedy according to claim 43, which allows gas
transportation therethrough.
22. A skin remedy according to claim 21, in the form of an aqueous
emulsion of at least one semiflurinated alkane with a biocompatible
emulsifier said emulsion having a high gas solubility.
43. A skin remedy comprising at least one adjuvant which comprises
a semifluorinated alkane of the general formula F.sub.fR.sub.Hor
R.sub.fR.sub.hR.sub.fwherein R.sub.F is a linear or branched
perfluoralkyl group and R.sub.H is a linear or branched, saturated
alkyl group, wherein the linear semifluorinated alkane has the
formula:F(CF.sub.2).sub.n(CH.sub.2).sub.mH or
F(CR.sub.2).sub.n(CH.sub.2)- .sub.m(CF.sub.2).sub.nF, the branched
semifluorinated alkane includes within the perfluoralkyl groups
-FCX- units where X=C.sub.2F.sub.5, C.sub.3F.sub.7or C.sub.4F.sub.9
and within the alkyl groups -HCY- units where Y=C.sub.2H.sub.5,
C.sub.3H.sub.7or C.sub.4H.sub.9, contained within a perfluoralkyl
chain is a -CY.sub.2- group, and wherein further the total number
of the carbon atoms in the perfluoralkyl part are between 1 and 20
, and in the alkyl part the number of carbon atoms is between 3 and
20.
44. A skin remedy according to claim 43, in the form of an aqueous
emulsion of at least one semifluorinated alkane with a
biocompatible emulsifier said emulsion having a high gas
solubility.
Description
BACKGROUND AND SUMMARY OF THE INVENTION
[0001] This invention relates to semifluorinated alkanes of the
general formulas
R.sub.FR.sub.H and R.sub.FR.sub.HR.sub.F
[0002] wherein R.sub.F is a linear or branched perfluoralkyl group
and R.sub.H is a linear or branched, saturated (hydrocarbon)-alkyl
group.
[0003] The unbranched semifluorinated alkanes have the
formulas:
F(CF.sub.2).sub.n(CH.sub.2).sub.mH
[0004] and
F(CF.sub.2).sub.n(CH.sub.2).sub.m(CF.sub.2).sub.nF
[0005] wherein n=1-20 and m=3-20.
[0006] The branched semifluorinated alkanes can also contain within
the perfluoralkyl groups FCX units wherein X=C.sub.2F.sub.5,
C.sub.3F.sub.7 or C.sub.4F.sub.9
[0007] as well as --HCY-- units within the alkyl groups
[0008] wherein Y=C.sub.2H.sub.5, C.sub.3H.sub.7 or
C.sub.4H.sub.9.
[0009] A --CX.sub.2-- group can be contained within a perfluoralkyl
chain, and a --CY.sub.2-- group within an alkyl chain.
[0010] Instead of the perfluoralkyl group F.sub.3C--, an
FCX.sub.2-- or F.sub.2CX-group, with X=C.sub.2F.sub.5,
C.sub.3F.sub.7 or C.sub.4F.sub.9, can be bound in the terminal
position in the molecule, and likewise an HCY.sub.2-- or
H.sub.2CY-- group wherein Y=C.sub.2H.sub.51 C.sub.3H.sub.7, or
C.sub.4H.sub.9
[0011] can be found in the terminal position in the molecule
instead of the alkyl group H.sub.3C--.
[0012] But in the case of all of the named isomers, that is to say
linear or branched semifluorinated alkanes, the total number of the
carbon atoms in the perfluoralkyl part remains, as stated, within
the limits of n=1-20, and also in the alkyl part the number of the
carbon atoms remains in the stated limits of m=3-20.
[0013] The invention furthermore relates to the use of these
semifluorinated alkanes in medicine, pharmacy, biology and
technology.
[0014] These semifluorinated alkanes, also called diblock compounds
R.sub.FR.sub.H and triblock compounds R.sub.FR.sub.HR.sub.F, or
also "modified perfluorocarbons," can be linear or branched both in
the perfluoralkyl groups and in the alkyl groups, while in the case
of the isomers the total number of the carbon atoms in the
perfluoralkyl part remains in the stated limits of n=1 to 20 and in
the alkyl part the total number of carbon atoms remains in the
stated limits of m=3 to 20.
[0015] These semifluorinated alkanes can be used as medicinal
adjuvants, drugs for ophthalmology, as a glass body substitute, as
a dermal treatment for supporting oxygen transport in the skin, for
instillation and fluid artificial respiration in surgical
interventions and in emergency medical treatment, to facilitate
breathing in divers, and as friction-reducing additives in
lubricants and waxes.
[0016] These types of compounds proposed as patent-worthy are
similar to the perfluorocarbons (compounds which consist only of
carbon-fluorine bonds) are chemically, physically and
physiologically inert and thus nontoxic.
[0017] In comparison with the perf luorocarbons, the
semifluorinated diblock or triblock alkanes are of an entirely
different structure. They consist of closed hydrocarbon-alkane
groups, --(CH.sub.2).sub.n-- and --(CHR.sub.H).sub.n-- and
--(CH.sub.2).sub.nH, which are bound directly to ionic tensides,
with the aid of physical emulsification methods (ultrasound or
Gaulin homogenizers), to particle-stable emulsions with particle
sizes of about 100-300 nm.
[0018] In contradistinction to the perfluorocarbons, the
semifluorinated alkanes, regardless of their R.sub.F or R.sub.H
content, are soluble both in perfluorocarbons and derivatives of
perfluorocarbons (perfluorinated ethers of higher molecular weight,
Hostinert.RTM., Fomblin.RTM., etc.) [see H. Meinert, A. Knoblich,
Biomat. Art. Cells & Immob. Biotech., 21 (1993) 583; H.
Meinert, Fluorine in Medicine in the 21.sup.st Century, Manchester
(1994), paper 23; R. J. Twieg et al., Macromolecules 18 (1985)
1361; and J. Hopken et al., Macromol. Chem. 189 (1988) 911] and in
hydrocarbons and their derivatives and compounds with higher alkyl
group contents (e.g., liquid paraffins, silicone oils, fatty acid
esters, etc.). As the perfluoralkyl content increases the
solubility in the fluorocarbon systems increases, while with
increasing alkyl content the solubility in hydrocarbon systems
increases, and vice-versa. In solutions of semifluorinated alkanes,
especially semifluorinated linear alkanes, in hydrocarbon
substances, laminar double layers may be present, while under
certain circumstances, e.g. depending on the concentration ratio or
upon cooling, the previously homogeneous, optically clear solutions
turn into opaque gels. Upon subsequent cooling the homogeneous
solutions are recovered. The formation of the gel is due to the
fact that the solvent hydrocarbons are absorbed by the diblock
double layers of the R.sub.FR.sub.H [R. J. Twieg et al.,
Macromolecules 18 (1985) 1361; J. Hopken et al., Macromol. Chem.
189 (1988) 911].
[0019] In contrast to the perfluorocarbons (densities 1.8-2.0
g/cm.sup.3) the densities of the semifluorinated alkanes with
densities between 1.1 and 1.7 g/cm.sup.3 are substantially lower
due to the fact that these molecules have a high content of
hydrocarbon groupings.
[0020] On the other hand, the proposed compounds have the preferred
properties of the perfluorocarbons in regard to their boundary
surface tension against water (R.sub.FR.sub.H 50-58 nN/m at
20.degree. C.) and the extraordinarily low surface tension
(R.sub.FR.sub.H 25-22 mN/m at 20.degree. C., due to the fact that
perfluoralkyl groups are bonded to the end of the molecule.
[0021] If separation occurs in long-standing solutions of the
above-mentioned hydrocarbons and their derivatives with
semifluorinated diblock or triblock alkanes due to relatively great
differences in density (which occurs when semifluorinated alkanes
with a high perfluoralkyl content are used), the homogeneous,
optically clear solution can be restored by simple shaking.
[0022] The semifluorinated diblock or triblock alkanes are obtained
by the reaction of perfluoralkyl iodides with alkenes or .alpha.,
.omega.-dienes, after HI elimination followed by hydrogenation by
means of a platinum catalyst Organikum, Autorenkollektiv, Dtsch.
Verlag der Wissenschaften, Berlin (1977) 363 or by means of
tributyltin hydride [J. Hopken et al., Macromol. Chem. 189 (1988)
911] (see the Examples of syntheses of semifluorinated diblock and
triblock alkanes below).
[0023] The products thereby obtained for the proposed fields of
application can, in a preferred embodiment, also be highly
perfluoralkyl groups, --(CF.sub.2).sub.m-- and --(CFR.sub.F)-- and
--(CF.sub.2)F, respectively. The perf luoralkyl part can also begin
with a (CR.sub.FR.sub.FF)-- grouping and terminate in a
(CR.sub.HR.sub.HH) grouping. Within a perfluoralkyl chain an
--R.sub.FCR.sub.F-- group can be bound, and within an alkyl chain
an --R.sub.HCR.sub.H-- group can be bound.
[0024] In these types of compounds no intramolecular HF cleavage
with the formation of fluorolefinic double bonds can take place. On
the contrary, the closed hydrocarbon-alkane grouping has a bond
strengthening effect on the sometimes very strong C--F bonds in the
perfluoralkyl part of the compound in question.
[0025] The semifluorinated diblock or triblock alkanes are
colorless liquids or solids. They are not attacked by strong acids
or lyes or oxidants or nucleophiles, much less liable to metabolic
or catabolic attack.
[0026] Physically, the semifluorinated alkanes behave like modified
perfluorocarbons, and the boiling points and melting points
increase with increasing molecular mass (see FIGS. 1 and 2).
Semifluorinated alkanes, like the pure perfluorocarbons, have a
high solubility for gases, including O.sub.2 and CO.sub.2 (about
40-50 and 130-150 vol. %, respectively).
[0027] Like the perfluorocarbons and the hydrocarbons, the
semifluorinated alkanes are scarcely or not at all soluble.
[0028] However, they can be converted in a manner similar to H.
Meinert, A. Knoblich, Biomat. Art. Cells & Immob. Biotech., 21
(1993) 583 by means of effective tensides (fluorotensides,
compounds with a fluorophilic head and a hydrophilic tail, ethylene
oxide-propylene oxide block polymers, Pluronics.RTM. or
phospholipids such as egg lecithin or soya lecithin, etc.) or
purified. For that purpose the semifluorinated alkanes are first
treated with acid permanganate solution in a manner similar to DE
42 05 341 (WO 93/16974), then they are refluxed or autoclaved for
about 72 hours at 150-180.degree. C. with a mixture of strong
aqueous caustic soda solution (4-8 n), CaO or BaO, and a
nucleophilic agent (e.g., secondary amine). The reaction product is
finally obtained by means of a separatory funnel from the aqueous
alkaline phase, which in a given case still contains alcohol, and
the amine phase is separated, treated repeatedly in succession with
dilute mineral acid, NaHCO.sub.3 solution, distilled water,
anhydrous Na.sub.2SO.sub.4 and anhydrous CaCl.sub.2 and
fractionally distilled through an efficient column.
[0029] The semifluorinated alkanes thus treated are found by
infrared, IH-NMR, .sup.19F-NMR, and GC-/MS spectroscopy to be free
of groupings which might lead by intramolecular HF elimination to
the formation of toxic olefinic byproducts.
[0030] A suitable quantitative method for the determination of
groupings that can lead to the intramolecular cleavage of HF or to
the exchange of a fluorine atom bound to the carbon by means of a
nucleophilic agent is, according to DE 42 05 341 (WO 93/16974), the
determination of ionizable fluoride in the reaction of the sample
material with hexamethylenediamine in nonane or decane by several
hours of heating at 120-150.degree. C., and detecting any freed
fluoride by means of an ion-sensitive electrode. After the
purification process, accordingly, no more fluoride ions were
detectable (detection limit for the fluoride concentration
.ltoreq.10.sup.-5 mol/l.sup.-1).
[0031] The highly purified semifluorinated alkanes show no
inhibition of proliferation in regard to DNS and protein synthesis
on HeLa or Molt4 or HEP.sub.2 cell cultures. Thus the
semifluorinated alkanes named in accord with the invention are
directly usable for medical, pharmaceutical and biological
purposes.
[0032] The semifluorinated alkanes according to the invention can
find many different uses, namely the use of linear or branched
semifluorinated alkanes as medical adjuvants, as drugs for
ophthalmology, as glass body substitute, as a dermal treatment
agent, for fluid artificial respiration by intubation, and as a
friction-reducing additive for lubricant oils and waxes.
[0033] It is known that liquid perf luorocarbons, on account of
their high density and low surface tension and boundary surface
tension are suitable as a fluid for the reattachment (unfolding) of
a detached retina to the choroid of the eye U.S. Pat. No. 4,490,351
(EP 0 112 658) U.S. Pat. No. 5,397,805 (EP 0 493 677, DE 41 00 059.
Certainly perfluorocarbons are not appropriate for permanent
tamponing on account of their high density and the resultant high
pressure on the choroid.
[0034] It is furthermore known that, by the use of modified
perfluorocarbons the disadvantageous effect of the excessive
density in comparison with pure perfluorocarbons can be obviated DE
42 11 958 (EP 0 563 446), although in this case only diblock and
triblock compounds with R.sub.F =CF.sub.3 and C.sub.2F.sub.5, and
R.sub.H =CH.sub.3(CH.sub.2).sub- .n where n=2-10 are used.
[0035] The diblock and triblock compounds of the semifluorinated
alkanes listed in claim 1 have broader applications, especially
those of the types F(CF.sub.2).sub.n(CH.sub.2).sub.mH and
F(CF.sub.2).sub.n(CH.sub.2).- sub.m(CF.sub.2).sub.nF where n=3-20
and m=3-20 as well as their branched isomers, because with the
lengthening of both the R.sub.F and R.sub.H content in the
molecule, the solubilities in perfluorocarbon and in hydrocarbon
systems are significantly broadened. The liquid representatives of
the semifluorinated alkanes (see FIGS. 1 and 2) can be used on
account of their outstanding physical properties directly for the
unfolding of the retina; they are suitable as very stable colorless
fluids for laser coagulation, because no degradation products are
formed by the laser beam.
[0036] The semifluorinated alkanes according to the invention are
suitable for retinal reattachment, the same as the pure
perfluorocarbons U.S. Pat. No. 4,490,351 (EP 0 112 658) U.S. Pat.
No. 5,397,805 (EP 0 493 677, DE 41 00 059 and the modified
perfluorocarbons claimed in DE 42 11 958 (EP 0 563 446).
Furthermore, the linear or branched semifluorinated alkanes are
especially appropriate for ophthalmic treatment, especially when
they have a relatively high alkyl content, --(CH.sub.2).sub.n,
--(CH.sub.2).sub.nH and their R.sub.H-substituted isomers, due to
their ability to dissolve medication as well as their ability to be
dyed.
[0037] The proposed semifluorinated diblock and triblock alkanes
with a high R.sub.F content are easily soluble in the
perfluorocarbons long used for retinal reattachment [S. Chang et
al., Am. J. Ophthalmol. 103 (1987) 29; S. Chang et al., Am. J.
Ophthalmol. 103 (1987) 38; S. Chang et al., Ophthalmology 96 (1989)
785; G. A. Peyman et al., Internal Tamponade in Vitreoretinal
Surgery, Ravenna (1994), paper 33], so that in retinal reattachment
variations are possible in regard to the densities and boundary
surface characteristics, if homogeneous mixtures of semifluorinated
alkanes with perfluorocarbons are applied.
[0038] Moreover, the semifluorinated alkanes according to the
invention, especially the diblock compounds of the R.sub.FR.sub.H
type with a high R.sub.H content are suitable as solvents for the
medications to be used in ophthalmology.
[0039] Thus, for example, medicaments such as 5-fluoruracil,
Retinol.RTM. or Daucomycin among others are moderately to easily
soluble.
[0040] In the case of retinol the solution is colored and therefore
easily visible. This is advantageous to surgeons in dealing with
the reattachment fluid in retinal reattachment.
[0041] It is known to use as a postoperative tamponade a
combination of perfluorophenanthrene, Vitreon.RTM. and silicone oil
[G. A. Peyman et al., Internal Tamponade in Vitreoretinal Surgery,
Ravenna (1994), paper 33]. Because, however, on account of the
insolubility of the perfluorocarbon in the silicone oil, such a
combination of two non-miscible fluids consists of different
densities, the result in the real system of a moving eye will be
difficulties in regard to transparency and "emulsification" at the
boundary surface of the two tamponade fluids.
[0042] On the other hand, the semifluorinated alkanes of the
invention, especially the linear representatives of the
R.sub.FR.sub.H, have good solubility in silicone oils. The
semifluorinated alkanes are more soluble in silicone oils the
higher the R.sub.H content is. For example, in the silicone oils
most used for the silicone oil tamponade and having 5000 mPa/s or
1000 mPa/s, the fluid semifluorinated diblock compounds
C.sub.6F.sub.13C.sub.8H.sub.17 or C.sub.4F.sub.9C.sub.5H.sub.11 or
C.sub.2F.sub.5C.sub.8H17 are uniformly soluble. For example, these
R.sub.FR.sub.H's dissolve in silicone oil of 1000 mPa/s in ratios
of 2:1 to 1:2. The solubilities decrease as the viscosity of the
silicone oil increases.
[0043] Thus there is a completely new application for such
homogeneous solutions of R.sub.FR.sub.H's in silicone oils, on
account of the resultant adjustable low densities (1.0-1.3) and the
selectable boundary surface and surface tensions (see Table 1), for
the long-term tamponade.
1TABLE 1 Boundary surface Surface tension tension against water in
in mN/m (24.degree. C.) mN/m (24.degree. C.) Silicone oil 1000 mPas
23.3 22.2 C.sub.6F.sub.13--C.sub.8H.sub.17 49.0 21.2 1:1 mixture
26.6 20.9 (silicone oil l000/C.sub.6F.sub.13--C.sub.8H.sub.17)
[0044] Since the semifluorinated alkanes are solvents for
perfluorocarbons it is also possible to transform solutions of
perfluorocarbons to semifluorinated alkanes, especially of the
R.sub.FR.sub.H type, with the corresponding silicone oils, to
homogeneous, optically clear systems and then use them for the
tamponade.
[0045] Moreover, with these semifluorinated alkanes, especially the
linear R.sub.FR.sub.H's with a relatively high R.sub.H content, an
outstanding diluent and wash fluid for silicone oils after a
silicone oil retinal tamponade. Heretofore, the only way to remove
silicone oils thoroughly from the eye has been to extract them with
a cannula and syringe.
[0046] It is known to affect the oxygen status of the skin by
making oxygen available for metabolic processes in the skin by
means of biologically inert, oxygen-dissolving perfluorocarbons, in
addition to and independently of the vascular system of the living
organism. In U.S. Pat. No. 4,366,169 the use of perfluorocarbons is
claimed for the treatment of skin injuries and wounds, especially
burns, wherein the oxygen-containing perfluorocarbon is placed
either directly or in the form of an emulsion on the skin, on
bandages, or other such means.
[0047] In J. Hopken et al., Macromol. Chem. 189 (1988) 911 the
preparation is described of gel with gas transporting properties
for application to the skin, wherein, for example, a
perfluorocarbon is first converted to a gel by means of a tenside
and an emulsification, and finally a difficult separation is made
between the gel phase and the aqueous phase. This gel is applied to
the skin in appropriate formulations, and it operates there, but
without penetrating the stratum corneum.
[0048] In EP 29 66 61 a single-phase system containing
perfluorocarbon is described, which can act in the cosmetic field
and as a lotion to promote oxygen transportation. Perfluorocarbons
with a maximum concentration of 50% are emulsified in water with
perfluorinated emulsifiers of the alkanesulfonic acid amide type in
the presence of an aliphatic alcohol as an emulsifying aid.
[0049] In DE 41 27 442 and DE 42 21 255 a skin remedy is described
which, for the purpose of enhancing oxygen transport in the skin,
consists of asymmetrical lamellar aggregates built up from
phospholipids with a content of phosphatidyl choline ranging from
30 to 99 wt.-% which, unlike the well-known aqueous liposomes,
contain perfluorocarbons or mixtures ranging from 1 to 100% k w/v
in a vehicle suitable for dermatological application. In the known
systems, aliphatic, straight-chain and branched perfluoralkanes,
mono- or bicyclic, fluoralkyl-substituted perfluorocyclo alkanes,
perfluorinated aliphatic or bicyclic amines,
bis-(perfluoralkyl)-ethenes or mixtures thereof are described as
perfluorocarbons, and of this group perfluorodecalin,
perfluoroobutyltetrahydrofuran, perfluorotributylamine,
perfluoroctyl bromide, bis-fluoro(butyl)ethene or C.sub.6-C.sub.9
perfluoralkanes are preferred. Penetration into the skin is said to
be controlled by the carrier structure of the phospholipid
aggregates, but especially by the perfluorocarbons according to
their critical temperature of solubility in nhexane, the so-called
CST temperature. The lower the CST temperature is, the better is
the penetration. The CST temperatures of the perf luorocarbons
named preferentially in this claim are all above +22.degree. C.
[0050] Accordingly, a skin medication on the basis of
semifluorinated diblock or triblock alkanes, especially the fluid,
unbranched compounds of the R.sub.FR.sub.H type are proposed, which
represent outstanding system solutions. As stated earlier, the
semifluorinated alkanes according to the invention are easily to
moderately soluble in hydrocarbons and derivatives thereof, the
solubility increasing as the R.sub.H content increases and the
R.sub.F content decreasing in the semifluorinated alkane. For
example, the compounds C.sub.2F.sub.5--C.sub.8H.sub.17 and
C.sub.4F.sub.9--C.sub.10H.sub.21 dissolve in thin to thick liquid
paraffins which find use as pharmaceutical oils and adjuvants
(60-230 mPa/s), pump oils or motor oils. As the paraffin oil
viscosity increases the solubility decreases, but even in Vaseline,
R.sub.FR.sub.H's with a long R.sub.H content are still dissolved.
In some cases dissolving can be accelerated or facilitated with the
aid of physical emulsifying methods (ultrasound or Gaulin
homogenizer or Ultraturrax dispersing machine).
[0051] These R.sub.FR.sub.H's are also soluble in silicone oils, as
already explained.
[0052] Thus, without the aid of emulsifiers or tensides it is
possible to prepare a gas-transporting skin remedy or salve, in
which the oxygen or carbon dioxide transport is based on their very
good solubility in semifluorinated alkane. Also, as already
mentioned [R. J. Twieg et al., Macromolecules 18 (1985) 1361],
solutions of semifluorinated alkanes of the R.sub.FR.sub.H type can
be made in hydrocarbons which pass into a viscous gel state below a
characteristic transition temperature. Such gels are formed, for
example, of F(CF.sub.2).sub.n(CH.sub.2).sub.mH with n=12 and m=8-20
in decane as solvent, or with n=10 and m=12 in octane, decane,
dodecane, tetradecane, hexadecane or cyclodecane as solvents. The
transition temperatures of homogeneous, fluid solution and viscous
gel are given for these systems in FIG. 3; for the claimed
application purpose they are within an optimum range of skin and
room temperature.
[0053] The tissue penetration is due to the lipophilia of the
oxygen carrier. Perfluorocarbons are far less lipophilic than the
semifluorinated alkanes according to the invention, and their
lipophilia is based on the R.sub.H part of the molecule. In harmony
with this, the CST temperature in the semifluorinated alkanes of
the R.sub.F R.sub.H type is entirely below -22.degree. C., while
for most perfluorocarbons it is above +20.degree. C.
[0054] Thus, for very quick absorption into the corneal region of
the skin and in adjacent tissue, the use of the R.sub.FR.sub.H's
claimed according to the invention offers a significant advantage
over all of the perfluorocarbon compounds described in U.S. Pat.
No. 4,366,169, GB 2087882, EP 29 66 61, DE 41 27 442, and DE 42 21
255.
[0055] Saturation with the oxygen of atmospheric air offers a
higher oxygen capacity than any of the comparable known systems.
The yielding of oxygen to neglected tissue takes place through a
topical application.
[0056] As described in the beginning, the semifluorinated alkanes
according to the invention can be made very easily into stable,
aqueous emulsions of the o/w and w/o types with asymmetrical
lamellar aggregates, by means of biocompatible emulsifiers (natural
phospholipids, such as soya or egg lecithin or synthetically
prepared lecithins, or phospholipid mixtures with a content of
60-98% of phosphatidylcholine or ethylene oxidepropylene oxide
block polymers, Pluronic.RTM., etc.) with the aid of physical
emulsification methods (ultrasound or Gaulin homogenizer,
Ultraturrax dispersion machine). Thus the systems thus prepared
constitute the effective, gas-transporting substance in salves,
cremes, pastes, lotions and other aqueous or alcoholic
dermatological formulations as well as in powders. The skin remedy
according to the invention can be applied to bandages, plasters,
wound coverings and other means coming in contact with the
skin.
[0057] There is a useful application for oxygen-starved fatty
tissue (cellulitis) and for deficiencies due to arteriosclerosis
("smoker's leg," etc.) and for the treatment of burns wherein the
damaged tissue remains covered over a long period with the ointment
bases according to the invention, and at the same time is supplied
with oxygen. By supplying oxygen through the coating, anoxia of the
underlying tissue is prevented. Besides, the body's own production
of collagen is stimulated, which is an oxygen consuming process due
to the oxidation of proline to hydroxyproline. The in vivo
production of collagen is directly connected with the healing of
skin injuries. The paste bases and salve bases named according to
the invention also serve for bedsore prophylaxis and treatment in
bedridden patients, e.g., in cases of leg fracture, long-term
assisted breathing after poisoning, polytrauma or organic
insufficiency.
[0058] The salve bases according to the invention furthermore serve
for protection against contact dermatitis.
[0059] It is known that oxygen-saturated liquid perfluorocarbons,
such as perfluordecalin, are used in certain surgical interventions
such that this perfluorocarbon is directly fed into the lungs
through a tube introduced into the trachea and thus enters the
alveolar system. Respiration is then assured through the
oxygen-saturated perfluorocarbon and collapse of the lungs is at
the same time prevented.
[0060] The use of artificial respiration via fluid intubation with
the aid of the semifluorinated diblock or triblock alkanes to ease
respiration is also possible for the opening of lungs with
atelectasis. in lung obstructions for the opening of collapsed
lungs, and in the artificial respiration of astronauts, which has
not yet been mentioned and is similar to that of divers.
[0061] This liquid respiration is possible even in divers with the
aid of the semifluorinated alkanes according to the invention. The
medium carrying O.sub.2 or CO.sub.2 put into the lungs through the
tube can be constantly enriched with O.sub.2 by means of an
oxygenator through a circulatory system and freed of CO.sub.2 by
means of a corresponding CO.sub.2 trapping system. A diver thus
supplied no longer needs to breathe air or oxygen from
compressed-air bottles and exhale through a system of valves. The
valve noises and the issuing gas and air bubbles enable the diver
to be found by means of sensitive sonar systems.
[0062] In the known liquid artificial respiration there are
difficulties both in surgical interventions and in the case of
divers because, due to the high density of perfluorocarbon (approx.
1.8-2.0 g/cm.sup.3) the breathing or transport of the oxygen and
carbon dioxide carrying medium is made difficult by a weakened or
stressed body.
[0063] The advantage of the invention consists in the use of the
fluid, liquid semifluorinated alkanes, especially
C.sub.6F.sub.13C.sub.8H.sub.17 (b.p. 22.degree. C.),
C.sub.4F.sub.9C.sub.5H.sub.11 (b.p. 131.degree. C.),
C.sub.2F.sub.5C.sub.8H.sub.17 (b.p. 159.degree. C.),
C.sub.2F.sub.5C.sub.4H.sub.8C.sub.2F.sub.5 (b.p. 138.degree. C.),
C.sub.2F.sub.5C.sub.6H.sub.12C.sub.2F.sub.5 (b.p. 200.degree. C.),
C.sub.3F.sub.7C.sub.2H.sub.4C.sub.3F.sub.7 (b.p. 115.degree. C.),
C.sub.3F.sub.7C.sub.4H.sub.8C.sub.3F.sub.7 (b.p. 180.degree. C.).
In the case of gas solubility similar to the perfluorocarbons
(R.sub.FR.sub.H approx. 45-52 vol. %, R.sub.FR.sub.HR.sub.F approx.
145-150 vol. % CO.sub.2), the density of the proposed liquid
semifluorinated alkanes amounts to only 1.1-1.5 g/cm.sup.3
(25.degree. C.).
[0064] The advantages which the use of the proposed semifluorinated
alkanes in the described and still scarcely known methods of
instillation and fluid artificial respiration offers over the
perfluorocarbons, which anyway are no more than conceivable for
this purpose, are thus definitely to be found in easier
respiration.
[0065] It is known to add perfluorocarbons and perfluorocarbon
derivates to lubricant oils and waxes as friction reducing agents.
It is also known to cover heavily stressed wall materials with thin
coatings of fluoropolymers to reduce friction.
[0066] In DD 207310 friction reducing additives are described for
motor oils, pump oils and silicone oils, consisting of 0.1 to 10
wt. % of perfluoroalkylethers or -thioethers of the formula
R--X--R.sub.1where R=C.sub.4-10-perfluoralkyl or CnF.sub.2n.sub.1,
n=8-10), X=S or O, and R.sub.1=C.sub.8H.sub.17, C.sub.12-25,
CH.sub.2CH.sub.2OH, or CH.sub.2CH.sub.2OEt).
[0067] In DD 289424 lubricant additives on the basis of
monofluorinated or oligomeric fluorinated hydrocarbons are
described, which contain in addition to CF bonds, bonds with weakly
bonded moieties such as Cl, OH, OR, SH and SR, R representing an
amine and/or NH.sub.4.sup.+--, Ba.sup.2+--, or Zn.sup.2+-- salt of
monofluorophosphates or fluorophosphonates. Such a lubricant may
also contain a nonionic fluorine tenside,
C.sub.nF.sub.2n-1(CH.sub.2CH.sub.2O)mH, where n=8-11 and m=1-4, as
emulsifier. The additives are described as usable for
metal-to-metal surfaces in machines.
[0068] In R. C. Bowers et al, Lubric. Engng. 12 (1956) 245 there is
described the use of fluoresters, synthesized from aliphatic
dibasic acids and fluorinated alcohols, as additives for
heatresistant oily and waxy lubricants for reducing wear on steel
surfaces.
[0069] According to V. S. Isakovich et al, Trenie Iznos 13 (1992)
306 the presence of chemosorbed, hydrophobic coatings of fluorine
tensides or perfluoresters leads to a reduction of friction of
steel against steel.
[0070] In W. R. Jones et al., NASA Report TM-87284 (1986) perf
luoralkyl ethers of low molecular weight are described as
lubricants for extremely low temperatures, in outer space, for
example.
[0071] In S. Mori, W. Morales, Wear 132 (1989) 111 the tribological
reaction of perfluoralkyl polyether oils with steel under high
vacuum conditions at room temperature is studied and it is found
that, due to tribological reactions, metal fluorides are formed
which in turn have a catalytic action on the decomposition of
perfluorether. Furthermore, the fluorides formed on the friction
path act as boundary layers with simultaneous reduction of the
coefficient of friction.
[0072] According to K. von Werner, EP 0 545 174 A1 (1993) oligomers
of fluorinated olefins of the type X(CF.sub.2).sub.2-16--O.sub.0 o
r .sub.1--CH.dbd.CH.sub.2, where X=H or F are described as
adjuvants for the application of fluoralkane waxes and as
lubricants for the shaping and extrusion of polyethylene.
[0073] A series of publications on the application of thin coatings
of fluorinated polymers to steel, ceramic or other inorganic
materials and the friction-reducing effect on surfaces prepared in
this manner are described by way of example in D.L. Cho, H. Yasuda,
J. Appl. Polymer Sci.: Appl. Polymer Symp. 42 (1988) 139. The
application of plasma-polymer films significantly reduces the
friction of sliding parts, e.g., in combustion chambers.
[0074] On the other hand, in comparison with the known compounds,
the semifluorinated alkanes according to the invention have
outstanding properties as friction-reducing additives for highly
stressed lubricant oils, waxes, hydraulic fluids and compressor
fluids.
[0075] As initially described, semifluorinated alkanes are
physically, chemically and physiologically inert. Due to the closed
hydrocarbon-alkane groups, --(CH.sub.2).sub.m--,
--(CHR.sub.H).sub.M--, --(R.sub.HCR.sub.H)--, --(CH.sub.2).sub.mH,
--(CHR.sub.H).sub.mH, --(--(R.sub.HCR.sub.H)H), the CF bonds in the
perfluoralkyl groups directly bonded thereto, --(CF.sub.2)--,
--(CFR.sub.F)--, --(R.sub.FCR.sub.F)--, --(CF.sub.2)F,
--(CFR.sub.F)F, and --(R.sub.FCR.sub.F)F, (in comparison with the
CF bonds in the pure perfluorocarbons) are further strengthened.
Intramolecular HF cleavage with the formation of fluorolefinic
double bonds does not occur. Thus, for the application according to
the invention as friction-reducing additives in greatly stressed
oils, corrosion phenomena are also excluded.
[0076] The synthesis of this class of compounds on the technical
scale is simple (see the Examples of syntheses of semifluorinated
diblock and triblock alkanes below). Use as additives in lubricants
ranges from 0.1-10 wt. %, preferably in closed systems. Thus,
problems of ecological damage are minor or irrelevant.
[0077] The semifluorinated alkanes according to the invention are
of an amphiphilic character. Especially compounds of the
F(CF.sub.2).sub.n(CH.sub.2).sub.mH type are characterized by low
boundary surface tensions (50-58 mN/m at 20.degree. C.), and
extraordinarily low surface tensions (15-22 mN/m at 20.degree. C.),
due to the fact that the oleophobic and lipophobic R.sub.F groups
are bound to the one end of the molecule and the oleophilic and
lipophilic R.sub.H groups are bound to the other end.
[0078] Due to this amphiphilic, boundary surface active behavior in
the case of solutions in paraffins or hydrocarbon waxes or also
silicone oils, the R.sub.FR.sub.H's at the boundary surfaces of
these systems arrange themselves such that their R.sub.H part
reaches into the solvent containing hydrocarbons, while the
oleophobic R.sub.F part reaches outward. But such an arrangement
also exists in the case of the diblock compounds
F(CF.sub.2).sub.n(CH.sub.2).sub.m(CF.sub.2).sub.nF, since in the
longer-chain molecules, due to the steric arrangement of the
molecule, the R.sub.F groups of both ends arrange themselves
unilaterally against the long-chain alkane bonding link. The result
is the reduction of friction on metal surfaces or ceramic surfaces
or polymeric carbon fibers or structures, etc. Furthermore, the
result is also a barrier effect against the escape of volatile
solvent molecules through these boundary layers.
[0079] As mentioned in the beginning, solubility in hydrocarbons
and their derivatives increases with a high percentage of alkyl
groups, and therefore also in silicone oils, in the case of the
R.sub.FR.sub.H with increasing R.sub.H content and decreasing
R.sub.F content.
[0080] For example, the compounds C.sub.2F.sub.5C.sub.8H.sub.17
(b.p. 160.degree. C.), C.sub.4F.sub.9C.sub.5H.sub.11 (b.p.
131.degree. C.), C.sub.6F.sub.13C.sub.8H.sub.17 (b.p..sub.20
104.degree. C.), C.sub.10F.sub.21C.sub.12H.sub.25 (b.p. 64.degree.
C.) and C.sub.12F.sub.25C.sub.20H.sub.41 (b.p. 98.degree. C.) are
easily soluble for the stated use and at the given concentrations
(0.1-10 wt. %).
[0081] Thus, in principle, the addition of these friction-reducing
additives in gasoline and Diesel engines is possible, assuming that
R.sub.FR.sub.H's of corresponding low boiling point are used.
[0082] The barrier effect described above, which is due to the
orientation of the semifluorinated alkanes in the boundary surface,
also reduces the flammability of lubricants and fuels.
[0083] The additives according to the invention find use primarily
in lubricating oils and waxes for closed systems.
[0084] Consequently the use of the additives in motor oils,
transmission oils, and hydraulic and compressor oils is
possible.
[0085] With improved lubrication the working life and intervals of
maintenance of equipment, systems and units that have it will be
lengthened, and there will be savings of lubricants and fuels.
[0086] As lubricants which are effective even at very low
temperatures, semifluorinated alkanes of corresponding low boiling
point (FIGS. 1 and 2) are used directly, i.e., without additional
lubricant, or also as additives.
BRIEF DESCRIPTION OF THE DRAWINGS
[0087] FIG. 1 is a graph showing the boiling points of diblock
compounds of the R.sub.FR.sub.H type, wherein R.sub.H has x=2-10
(measured and calculated);
[0088] FIG. 2 is a graph showing the boiling points of triblock
comounds of the R.sub.FR.sub.HR.sub.F type, wherein R.sub.H has
x=2, 4, 6, 8, (10) (measured and calculated); and
[0089] FIG. 3 is phase diagrams of C.sub.10F.sub.21C.sub.12H.sub.25
(abbreviated: F.sub.10H.sub.12) in octane, decane, hexadecane and
cyclodecane according to R. J. Twieg et al., Macromolecules 18
(1985) 1361.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0090] Examples of Syntheses of Semifluorinated Diblock and
Triblock Alkanes
EXAMPLE 1
[0091] In accordance with K. von Werner, DE 39 25 525 A1 (1989), in
a four-necked flask of 250 cm.sup.3 capacity, which is equipped
with a dropping funnel (with bypass for pressure equalization),
vane stirrer, thermometer and ref lux condenser with superimposed
check valve, 1.82 g (0.075 mol) magnesium chips are placed under
argon in 10 cm.sup.3 of anhydrous di-n-propyl ether and activated
with a few drops of methyl iodide with gentle heating. The
temperature is raised to 80.degree. C. while a mixture of 23.7 g
(0.05 mol) of C.sub.6F.sub.13CH.sub.2CH.sub.21 and 60 cm.sup.3 of
anhydrous di-n-propyl ether is added drop by drop within one hour
with vigorous stirring. Then the mixture is stirred with ref luxing
for 9 hours and then cooled to 10.degree. C., hydrolyzed with 100
cm.sup.3 of 5 wt. % aqueous hydrochloric acid until the excess
magnesium has dissolved. Then the ether phase is separated and
concentrated with a rotary evaporator. The oily residue thus
obtained is treated with 30 cm.sup.3 of chloroform and let stand
for 1 hour at 0.degree. C. The solid product precipitated from the
mixture is suction filtered and dried in the desiccator. 11.0 g of
C.sub.6F.sub.13(CH.sub.2)- .sub.4C.sub.6F.sub.13 is obtained as
nearly colorless crystals which have a melting point of 48.degree.
C. The yield is 63.2% of the theoretical.
[0092] By means of nuclear resonance spectral analysis the
following values were obtained (in CDC13 solution with
tetramethysilane as internal standard):
[0093] .sup.1H-NMR: 2.11 PPM (CF.sub.2CH.sub.2), 1.72 PPM
(CH.sub.2H.sub.2)
EXAMPLE 2
[0094] The procedure is as given in Example 1, the following
substances being used:
[0095] 1.82 g (0.075 mol) of magnesium chips
[0096] 28.7 g (0.05 mol) C.sub.8F.sub.17CH.sub.2CH.sub.2I
[0097] 70 cm.sup.3 of anhydrous di-n-propyl ether
[0098] After hydrolysis with dilute hydrochloric acid the mixture
is filtered, the raw product is washed with water and dried in the
desiccator; then it is recrystallized from chloroform and vacuum
dried. 14.9 g of colorless chips are obtained of the compound
C.sub.8F.sub.17(CH.sub.2).sub.4C.sub.8F.sub.17 which have a melting
point of 92 to 93.degree. C. The yield is 66.8% of the
theoretical.
[0099] In the nuclear resonance spectral analysis the following
values were obtained:
[0100] .sup.1H-NMR: 2.12 ppm [CF.sub.2CH.sub.2, .sup.3(HF)=18.2
Hz], 1.73 ppm (CH.sub.2CH.sub.2)
[0101] .sup.13C--NMR: 31.17 ppm [CF.sub.2CH.sub.2, .sup.2I(CF)=22.6
Hz] 20.37 ppm (CH.sub.2CH.sub.2)
EXAMPLE 3
[0102] The procedure is as described in Example 2, but after the
magnesium chips are activated with methyl iodide, 93.6 mg (0.143
mmol) of the compound [(C.sub.6H.sub.5).sub.3P].sub.2CoCl.sub.2 is
added as catalyst. After recrystallization of the reaction product
from chloroform and drying it in vacuo, as described in Example 2,
16.6 g of the compound
C.sub.8F.sub.17(CH.sub.2).sub.4C.sub.8F.sub.17 is obtained, which
has a melting point of 92 to 93.degree. C. The amount obtained)
corresponds to 74.1% of the theoretical.
[0103] Nuclear resonance spectral analysis gives the same values as
given in Example 2.
EXAMPLE 4
[0104] The operation is performed again as given in Example 2, but
after the magnesium chips are activated, 2.2 g [0.005 mol=10 mol-%
with respect to the compound of the formula
(C.sub.8F.sub.17CH.sub.2CH.sub.2I) of the compound
C.sub.8F.sub.17CH.dbd.CH.sub.2 is added together with the mixture
of anhydrous di-n-propyl ether and the compound
C.sub.8F.sub.17CH.sub.2CH.sub.2I. After the reaction product is
recrystallized out of chloroform and vacuum-dried, 17.5 g of the
compound C.sub.8F.sub.17(CH.sub.2).sub.4C.sub.8F.sub.17 is
obtained, which has a melting point of 92 to 93.degree. C. The
amount produced corresponds to 78.1% of the theoretical.
[0105] Nuclear resonance spectral analysis gives the same values as
given in Example 2.
[0106] After filtration of the crude product, the phase containing
di-n-propyl ether is separated from the filtrate and dried with
sodium sulfate. Gas chromatography of the ether solution thus
obtained gives a content of 2.31 g of the compound
C.sub.8F.sub.17CH.dbd.CH.sub.2. The 2.2 g of this compound
originally put in evidently remains unchanged, so it acts as a
catalyst; moreover a small amount of the same compound forms during
the reaction with magnesium out of the perfluoroctylethyl
iodide.
EXAMPLE 5
[0107] Work is performed as described in Example 1, the following
substances being used:
[0108] 1.82 g (0.075 mol) of magnesium chips
[0109] 30.1 g (0.05 mol) C.sub.8F.sub.17(CH.sub.2).sub.4I
[0110] 70 cm.sup.3 of anhydrous di-n-propyl ether
[0111] After hydrolysis with dilute hydrochloric acid the mixture
is filtered, and the filtered crude product is washed with water
and dried in the desiccator. After recrystallization out of
chloroform and vacuum drying 14.3 g is obtained of the compound
C.sub.8F.sub.17(CH.sub.2).sub.8- C.sub.8F.sub.17 as colorless
leaves which have a melting point of 84.5.degree. C. The amount
produced corresponds to 60.1% of the theoretical.
[0112] In the nuclear resonance spectral analysis the following
values are obtained:
[0113] Classification:
C.sub.8F.sub.17--CH.sub.2--CH.sub.2--CH.sub.2--CH.s-
ub.2--CH.sub.2--CH.sub.2--CH.sub.2--CH.sub.2-C.sub.8F.sub.17
[0114] .sup.1H-NMR: (1)/(8) 2.01 ppm, (2)/(7) 1.62 ppm, (3)/(4)/(5)
and (6) 1.38 ppm
[0115] .sup.13C--NMR: (1)/(8) 31.21 ppm, [.sup.2I(CF)=22.1 Hz],
(2)/(7) 20.34 ppm, (3)/(4)/(5) and (6) 29.17 ppm.
EXAMPLE 6
[0116] The operation is performed according to K. von Werner, DE 39
25 525 A1 (1989), but instead of the compound
C.sub.8F.sub.17CH.dbd.CH.sub.2 after activation of the magnesium
chips, 1.2 g [0.002S mol=5 mol-%, with respect to the amount of
compound C.sub.8F.sub.17(CH.sub.2).sub.4] of the compound
C.sub.8F.sub.17(CH.sub.2).sub.2CH.dbd.CH.sub.2 is added as
catalyst. After work-up 16.2 g of the compound
C.sub.8F.sub.17(CH.sub.2).- sub.8C.sub.8F.sub.17 is obtained which
has a melting point of 84.5.degree. C. The amount produced
corresponds to 68.2% of the theoretical yield.
EXAMPLE 7
[0117] Preparation of semifluorinated diblock alkanes according to
H. Meinert, A. Knoblich, Biomat. Art. Cells & Immob. Biotech.,
21 (1993) 583.
[0118] 2 mmol of perfluoralkyl halide and 4 mmol of alkene(1) were
dissolved in 15 ml of octane, degassed with argon and heated to
90.degree. C. Then 150 mg of azo-isobutyryl nitrile was added
within 30 min, divided among several portions. A slight yellowing
of the solution occurred. Then the mixture was distilled. The
desired compounds of the type R.sub.F--CHI--CH.sub.2--R.sub.F were
able to be distilled at a reduced pressure of <0.5 mbar. The
yield amounted to 85 to 90% with respect to the input amount of
perfluoralkyl halide in the iodides and 22% in the bromides.
[0119] Reduction of the perfluoralkyl alkylhalides:
[0120] 6.6 mmol of perfluoralkyl alkylhalide was dissolved in 15 ml
of diethyl ether and 5 ml of acetic acid was added. The mixture was
heated to 50.degree. C. and 4 mmol of zinc was added. After
cooling, water was added and the phases were separated. The organic
phase was dried and distilled. Up to 68% of a mixture of
semifluorinated alkanes and alkenes (5.1) and about 10% of
dimerization product were isolated.
EXAMPLE 8
[0121] Preparation of semifluorinated triblock alkanes according to
H. Meinert, A. Knoblich, Biomat. Art. Cells & Immob. Biotech.,
21 (1993) 583.
[0122] To 30 ml n-dibutyl ether and 4 g of magnesium, 4 g of
C.sub.6F.sub.13C.sub.2H.sub.3 was added, and the temperature raised
to 120.degree. C. Then 40 g C.sub.6F.sub.13C.sub.2H.sub.4I
dissolved in n-dibutyl ether was added. After about 90 minutes the
solution had a dark black color, which after a while vanished
again. Then the mixture was filtered and water was carefully added;
the separated organic phase was dried and distilled. The
highest-boiling fractions were placed overnight in the ice box at
-20.degree. C. C.sub.6F.sub.13C.sub.4H.sub.8C.sub.6F.su- b.13
settled out as a white precipitate. This was filtered out and
vacuum dried. Preparation with butyl lithium:
[0123] 3 g of C.sub.6F.sub.13C.sub.2H.sub.4 and 4 ml of 1.6 m of
butyl lithium in hexane were added to 5 ml of hexane and heated to
60.degree. C. After about 10 minutes a white precipitate began to
settle out. The temperature was maintained for another 50 minutes.
Then water was cautiously added and the phases were separated. The
organic phase was dried and distilled. The next operation was
similar to the reaction with magnesium. The ratio of production of
R.sub.FR.sub.HR.sub.HR.sub.F to R.sub.FR.sub.H--Bu was determined
by gas chromatography. Perfluorodecalin was used as the standard.
The total yield was 3.1 g (85%).
[0124] The compounds were identified by comparison with the known
substances by gas chromatography, MS and .sup.1H-NMR.
EXAMPLE 9
[0125] As in J. Hopken et al., Macromol. Chem. 189 (1988) 911 the
synthesis is performed of F(CF.sub.2).sub.12(CH.sub.2).sub.nH (n=4,
6, 8, 10, 12, 14, 16, 18, 20),
F(CF.sub.2).sub.10(CH.sub.2).sub.8(CF.sub.2).sub- .10F and
F(CF.sub.2).sub.12(CH.sub.2).sub.10(CF.sub.2).sub.12F by reacting
perfluorodecyl iodide or perfluorododecyl iodide by radical
addition with the corresponding alkenes or dialkenes and then
reducing the corresponding perfluoralkyl iodide with tributyltin
hydride and AIBN in toluene.
EXAMPLE 10
[0126] As in Organikum, Autorenkollektiv, Dtsch. Verlag der
Wissenschaften, Berlin (1977) 363, first the perf luoralkyl iodide
is formed as in Example 9, but then follows reduction to the
semifluorinated alkane, R.sub.FR.sub.H and R.sub.FR.sub.HR.sub.F,
with palladium charcoal or platinum oxide as catalyst, with
hydrogen at 4 bar in the autoclave.
* * * * *