CA2190116A1 - Omega-hydrofluoroalkyl ethers, precursor carboxylic acids and derivatives thereof, and their preparation and application - Google Patents

Abstract

Normally liquid, omega-hydrofluoroalkyl ether compounds (and selected mixtures thereof) have a saturated perfluoroaliphatic chain of carbon atoms interrupted by one or more ether oxygen atoms. The compounds can be prepared, e.g., by decarboxylation of the corresponding fluoroalkyl ether carboxylic acids and are useful, e.g., in cleaning and drying applications.

Description

2190~ 16 W0 9Sf32174 r~ r ' oMEGA-HYDRoFLuf)Rr~~TXVr, ETHERS, PRFCIIR~R r~RRo~vT TC
5 ACIDS AND DERIVATIVES THEREOF, AND THEIR
PREPARATION AND APPLICATION
This invention relates to omega-hydrof luoroalkyl ethers and their pI~aLation and application. In another aspect, this invention relates to perfluoro-(alkoxyalkanoic~ acids and derivatives thereof and their preparation. In another aspect, it relates to the preparation of perfluoro(alkoxyalkanoic) acids by direct f luorination of their hydrocarbon alkanoic acid or ester analogs and to the preparation of omega-hydrofluoroalkyl ethers, for example, by decarboxylation of said acids or their alkyl esters.
In another aspect, this invention relates to uses of perfluoro(alkoxyalkanoic) acids and derivatives thereof.
Because of a steady f low of bad news about the damaged stratospheric ozone layer, the dP~91 ;nPC for the end to industrialized countries ' production of chlorofluorocarbons ("CFCs") and other ozone-depleting chemicals were accelerated by countries who are parties to the Montreal Protocol on Substances That Deplete the 020ne Layer - see Zurer, P.S., "Looming Ban on Production of CFCs, Halons Spurs Switch to Substitutes," November 15, 1993, Chemical h Enqineerinq News, p. 12.
Work is under way to replace CFCs and halons, such as CC12F2, CC13F, CF3Br, and CCl2FCClF2, with substitute or alternative compounds and technologies. A number of hydrofluorocarbons ("HFCs"), e.g., CH2FCF3 ("HFC-134a"), are being used or have been proposed as CFC substitutes (and HFC-134a has been characterized as being more "ozone friendly" - see U. S . Patent No . 5 ,118, 494 21 ~q~llB

(Schultz et al. ) ) . Hydrochlorofluorocarbons ("HCFCs"), such as CH3CCl2F ("HCFC-141b), as the C&EN article, su~ra, points out, are CFC substitutes, but although they are not nearly as damaging, these substitutes do 5 carry ozone-depleting chlorine into the stratosphere.
Another ~IL~)OS~d substitute is the simple omega-hydrodifluoromethyl perfluoromethyl ether, CF30CF2H --See J.L Adcock et.al., "Fluorinated Ethers -- A new Family of Halons," l991 CFC Conference Pro~ in~c 10 (1991). Another hydro-fluoroalkyl ether (or ether hydride), F[CF(CF3)CF20]4CFHCF3, made by decarboxylation of the fluorinated 2-alkoxypropionic acid salt, has been tested as a blood emulsion -- see Chem. Pharm.
Bull. 33, 1221 (1985) .
U. S . Pat. No. 4 ,173, 654 (Scherer) states that fluorocarbons due to their inertness have found use as electronic coolant or leak testing fluids, and other ~ : having good solubility for oxygen have be~n investigated as artif icial blood substitutes . This 20 patent describes certain fluorocarbon "hybrid"
materials with metabolically active hydrocarbon moieties, such as, inter alia, -CH2-(CH2)m-H. U.S. Pat.
No. 4,686,024 (Scherer et al.), which describes certain perfluorocyclic ethers, states that various perfluoro 25 chemicals are disclosed in patents as being suitable as oxygen and carbon dioxide carriers. And International Application published as W0 93/11868 (~aufman et al.) describes certain chlorofluorochemicals and lci~nc thereof as useful in various oxygen transport 30 applications, e.g., as oxygen transfer agents or "artif icial bloods. "
There are a number of other patents describing various fluorocarbon ethers or polyethers. U.S. Patent No. 3, 342, 875 (Selman et al . ) describes certain 35 "hydrogen modified fluorocarbon ethers" (or "hydrogen capped polyethers" ) made, inter alia , by pyrolysis of a hydrogen-containing derivative of an ether, such as ~llgoll6 Wo 95/32174 r~
the fluorocarbon ether acid or the ammonium salt, which ether is obtained by the polymerization of fluorocarbon Pr~YitlP~ British Patent Specification 1,194,431 (Montecatini Edison S . P . A. ) describes certain 5 perf luorinated ethers and polyether derivatives having the general formula CF3-O- tC3F60) ~S- (CF2) N- (CF (CF3) -O) L--CF2X
10 where, inter ~, each subscript M, N, and L is zero or a whole number from 1 to 99, and X is a hydrogen atom or -COOMe wherein Me is an equivalent of an alkali or 7~lk~1 inP earth metal, an examples of which is pentafluorodimethyl ether, CF3-O-CF2H.
U. S . Patent No . 3, 597, 359 (Smith) describes certain perfluoroalkylene ether-containing compound represented by the f ormula R~--R--O~lF--~F--O3~ ~R
20 wherein, inter ~, R is alkylene, alkoxyalkylene, or perfluoroalkylene, Rl is fluorine or trifluoromethyl provided not more than one R1 is trif luoromethyl, R2 is fluorine or trifluoromethyl provided not more than one R2 is trifluoromethyl, R3 is fluorine or 25 trif luoromethyl, R4 is hydrogen or halogen provided that when R is alkylene or alkoxyalkylene R4 is hydrogen, Rs is perfluoroalkylene having at least 2 carbon atoms, R6 is, inter alia hydrogen, trifluoromethyl or perfluoroethyl, a is zero or l, n 30 and m are whole numbers of 0 to 50, and n + m is 1 to 50 .
U.S. Patent No. 3,962,460 (Croix et al.) describes aliphatic ethers, including those of the formulas 21~116

2 174 1 ~ .. , . 1 10 ~ ~ ~ cl~

5FC--O--CH, and CIC--O--CH3 ~F2Br CF2CI
International Patent Application WO 90/01901 (Long) describes certain perfluorocarbon hydrides, such as perfluorooctyl hydride, u6ed in emulsions for carrying oxygen to the tissues of an animal body. European Patent Application Publication No. 0 482 938 A1 15 (Chamber6 et al. ) describes fluorinated ethers of the f ormula R"-CF2-CF-O-CF2-R' R
wherein R is hydrogen, fluorine, or alkyl or fluoroalkyl of 1-6 carbon atoms, R' is hydrogen or alkyl or fluoroalkyl of 1 to 6 carbon atoms, and R" is fluorine or alkyl or fluoroalkyl of 1 to 6 carbon atoms .
Other patents describing one or more various fluoroalkoxyalkanoic acids and esters or other derivatives thereof and their preparation are U. S.
Patent Nos. 2,713,593 (Brice et al.), 3,214,478 (Mi l ian , Jr . ), 3 , 3 9 3 , 2 2 8 ( Braun), 4 , 1 18 , 4 2 1 (~lartini ), 4 , 3 57 , 2 8 2 (Anderson et al . ), 4 , 72 9 , 8 5 6 ( Bernonge), 4,847,427 (Nappa), 4,940,814 (Schwertfeger), 4,973,716 (Calini et al.), 5,053,536 (Bierschenk et 21.) 5,093,432 (Bierschenk et al.), and 5,118,494 (Schultz et al. ) and PCT International Applications Pub. Nos. WO
90/03357 (Iqoore et al. ) and Wo 90/06296 (Costello et al. ) . ~he aforementioned Brice et al. patent describes fluorocarbons acids made by electrochemical fluorination including an acid having a boiling point of 225~C and said to be n-C8F17OC2F4CO2H. The aforementioned Nappa, Bierschenk et al., ~qoore et al., ~aoll6 95/32174 r~ C 110 and Costello et al. publications describe the preparation of the f luorinated compounds by direct fluorination of hydrocarbon analog precursors.
In one aspect, this invention provides a normally 5 liquid (i.e., liquid under ambient conditions of temperature and ~L~6aUL~:) fluoroalkyl ether ~ _ ' or a normally liquid composition consisting or consisting essentially of a selected mixture of such _ _ '-, said ~ uu-,d having a saturated perfluoroaliphatic 10 chain of carbon atoms ~e.g., 4 to 30) interrupted by one or a plurality (e.g., 2 to 8) of ether (or catenary, i.e., in-chain) oxygen atoms. The chain carbon atom at one end (hereafter called the proximal end) of the chain is bonded to a hydrogen atom (i.e., 15 an omega-hydro substituent, or primary hydrogen atom) and two fluorine atoms, said proximal carbon atom being the carbon atom of a difluoromethyl group or moiety, -CF2E~, which is directly bonded to another chain carbon atom, such as that of perfluoroalkylene chain segment, 20 -CNF2N, or to a said ether-oxygen. The carbon atom at the other end of the chain (the distal end) is part of a distal group selected from the group consisting of a dif 1UUL~ L}~Y1~ a difluorochloromethyl, -CF2Cl, a perfluoroalkyl substituted with a saturated alicyclic 25 moiety, e.g., c-C6F1l-, a straight-chain perfluoroalkyl, and a branched chain perfluoroalkyl. In a said compound where said proximal end of the chain terminates in a dif luoromethyl group bonded to an ether-oxygen atom, then said straight-chain 30 perfluoroalkyl has at least 6 chain carbon atoms, e.g., 6 to 16 chain carbon atoms, and said branched-chain perfluoroalkyl has at least 4 carbon atoms, e.g., 4 to 16 carbon atoms. Examples of such omega-hydro fluoroalkyl ether compounds are:

2~901~
WO 95/32174 r_l~u.,,_; ~llO
CF3 ~CF2~ 4-O-CF2CF2H
CF3 (CF2 ) s-O-CF2H
CF3 ( CF2 ) 7 -O- ( CF2 ) sH
C~3 (CF2) s~O~ (CF2) 2- (CF2) 2H
H(CF2) 2-- (CF2) 2H
Cl (CF2) 4-O--(CF2) 4H
If a 6aid "selected mixture, " i . e., a predetermined mixture of selected omega-hydrof luoroalkyl ether r~mrollnfls, is desired for a particular use, a said composition of this invention can be made consisting or consisting essentially of a mixture of two or more of said compounds each having a desired discrete, non-random molecular weight, the selected ~ u--ds pre~erably being those having complementary properties, e.g., for imparting improved stability to ~m-ll cionC
where they are incorporated as oxygen carriers in medical applications.
The term "perfluoro, " such as in the case of "perfluoroaliphatic," "perfluoroalkylene," or "perf luoroalkyl, " means that except ~s may be otherwise indicated there are no carbon-bonded hydrogen atoms replaceable with f luorine nor any unsaturation .
Omega-hydrofluoroalkyl ethers of this invention are hydrophobic and less oleophobic than the perfluoroalkyl ether analogs, chemically inert, thermally stable, water insoluble, and normally liquid (e.g., at 20C), and they can be made in accordance with this invention in high yield, high purity, and with a wide range of molecular weights. The covalent bond between the omega-hydrogen and terminal carbon, i.e., the C-H bond, is generally degradable by atmospheric photo-oxidation, thus making the omega-hydrofluoroalkyl ethers environmentally acceptable or compatible. The omega-hydrofluoroalkyl ether c~,mrolln-ls, or the normally liquid composition 2~0tl~
~! W095/32174 P~ s~-11n consisting or consisting es6entially thereof, can be used in applications where the aforementioned CFCs, HCFCs or halons have been used, for example, as solvents for precision or metal cleaning of electronic 5 articles such as disks or circuit boards, heat transfer agents, coolants in refrigerator or freezer compressors or air conditioners, blowing agents or cell size regulators in making polyurethane foam insulation, or chemical fire extinguishing agents in streaming lO applications, total flooding,- explosion ~u~Les~ion and inertion, and as carrier solvents for highly fluorinated polyethers used as lubricants for magnetic recording media. Another field of utility for the omega-hydrofluoroalkyl ethers is in emulsions useful in 15 various medical and oxygen transport applications, for example, artificial or synthetic bloods.
The above-described omega-hydrof luoroalkyl ethers of this invention can be prepared by decarboxylation of the CULL~ n~1;n~ precursor fluoroalkyl ether 20 carboxylic acids and salts thereof or, preferably, the saponifiable alkyl esters thereof. Alternatively, the omega-hydrofluoroalkyl ethers can be prepared by reduction of the corresponding omega-chlorofluoroalkyl ethers (e.g., those described in W0 93/11868, su~ra).
25 The perfluoroalkyl ether carboxylic acids (and esters) themselves -- some of which are believed novel _ '. and they and their preparation are other aspects of this invention -- can be prepared by direct f luorination of their COL L c::,uunding hydrocarbon

3 0 analogs . The omega-hydrof luoroalkyl ethers are essentially pure fluorinated compounds and are useful as such or in the form of a normally liquid composition consisting or consisting essentially of a selected mixture of such compounds. The precursor 35 perfluoroalkyl ether carboxylic acid and ester compounds, like the above-described omega-hydrofluoroalkyl c uu-,~s of this invention, have a 21~01~6 W0 95/32174 r ~ o saturated perfluoroaliphatic chain of a plurality of carbon atoms, said, çhain' Iikewise being interrupted by one or a plurality of ether oxygen atoms, the proximal end of the chain being connected to a carboxyl group or alkyl ester thereof. This carboxyl group (or salts thereof or its saponif iable alkyl ester) can be decarboxylated, as mentioned above, and thereby replaced by the aforementioned omega-hydro substituent of the resulting omega-hydroalkyl ether of this invention.
The aforementioned novel perfluoroalkyl ether acids and esters can also be converted into various other derivatives, such as their ammonium salts, which have utility as surface active agents useful in modifying the surface tension or interfacial tension of liquids. These compounds are more soluble in aqueous media and other organic solvents than are the C:ULL ~ in~ perfluoroalkanoic acid derivatives, and this enhances their utility as surface-active agents.
The compounds can conveniently be prepared by direct fluorination of the corresponding hydrocarbon ether acids, or derivatives such as an ester, in high yields as single molecular species.
A class of the normally liquid, omega-hydrofluoroalkyl ether compounds of this invention can be represented by the general formula:
X-Rf-0- (Rf ' -0) n-Rf"-H
wherein:
is a primary hydrogen atom;
X is a fluorine atom, a primary hydrogen atom, or a primary chlorine atom bonded to a difluoromethylene (of Rf);
n is a integer of 0 to 7, preferably 0 to 3;
-a-21gOllB
09Sr32174 r~ J.. s -llo Rf, Rf', and Rf" are the same or different perfluoroalkylene (linear or branched~
groups , e . g ., -CF2CF2- , which are unsubstituted or substituted with a perf luoro organo group which can contain ether oxygen, for example, Rf can be -CF2CF(Rf"')CF2- or -Rf"'CF2- where Rf"' is a saturated perfluoroalicyclic group having 4 to 6 ring carbon atoms, such as perf luorocyclohexyl or perf luoro-cyclohexylene;
with the proviso that when X is H or Cl, Rf has 1 to 18, preferably 2 to 18, chain carbon atoms, Rf' has 1 to 12, preferably 2 to 12, chain carbon atoms, and Rf" has 2 to 12 chain carbon atoms;
and with the further proviso that when X is F, then Rf has at least 4, pref erably 4 to 18, chain carbon atoms, Rf ' has 1 or more, pref erably 1 to 12, more preferably 2 to 12, chain carbon atoms, and Rf" has 2 or more, preferably 2 to 12, chain carbon atoms.
A subclass of polyether compounds within the scope of general formula I is represented by the general formula:
X-Rf-O- (CF2CF2-O) m-r~f -H II
where m is an integer of 0 to 7, and H, X, Rf, and Rf"
are as defined for formula I.
Another subclass of ~_ _ul.ds within the scope of general formula I is represented by the general f ormula:
F-Rf-O- (Rf ' -O) p-Rf "-H III
where p is an integer of 0 to 2 and H, Rf, Rf ', and Rf"
are as defined for formula I, except Rf has 4 to 12 _g_ 219~
Wo 95~32174 . ~ o chain carbon atoms, Rf ' has 1 to 12 chain carbon atoms, and Rf" has 2 to 12 chain carbon atoms.
Another class of the normally liquid, omega-hydrof luoroalkyl ether compounds of the invention can be represented by the general formula:
X--Rf--OtRf '--OtnRf "--H
wherein:
H is a primary hydrogen atom;
X i8 a fluorine atom, a primary hydrogen atom, or a primary chlorine atom;
n is an integer of 0 to 7; and Rf, Rf', and Rf" are ;n~lprpn~lpntly selected from the group consisting of linear or branched, unsubstituted perf luoroalkylene groups;
linear or branched, perfluoroalkyl- or perf luorocycloalkyl-substituted perfluoroalkylene groups; and linear or branched perf luoroalkylene groups substituted with an ether oxygen-containing moiety;
with the proviso that when X is H or Cl, Rf has to 18 chain carbon atoms and each of Rf ' and Rf"
inrlPrPn-lP~tly has 1 to 12 chain carbon atoms;
and with the further proviso that when X is F, then Rf has at least 4 chain carbon atoms and each of Rf ' and Rf " ; n~lPrPnr1Pntly has 1 or more chain carbon atoms;
and with the still further proviso that when n is zero, then Rf is a perfluorocycloalkyl-substituted perfluoroalkylene group.
A list of representative examples of the omega-hydrof luoroalkyl ether compounds of this invention is as follows.

WO 95132174 , r ~ lo Table A
1. CF3 (CF2) s-O-CF2H
2 . CF3 (CF2) 3-0- (CF2) 2H
3 . c-C6Fl1CF2~0~ (CF2) 2H
. CF3 (CF2) 3--0-CF2C (CF3) 2CF2H
5 . (CF3) 2CFCF2-0-CF2H
6 . CF3 (CF2) 4-0--(CF2) sH
7 . CF3 (CF2) 6-0-CF2H
8 . CF3 (CF2) 5-0- (CF2) 2H
9 . CF3 (CF2) 5--o- (CF2) 3H
10. CF3 (CF2) 6-0--(CF2) 2H
11. CF3 (CF2) 7-0-CF2H
12 . CF3 ( CF2 ) 7-0- ( CF2 ) sH
13 . CF3 ( CF2 ) 7-0- ( CF2 ) 6H
14 . CF3 (CF2) 5-0- (CF2) 2-0-CF2H
15 . CF3 ( CF2 ) 5 -0- ( CF2 ) 2 ~ - ( CF2 ) 2H
16 . H- (CF2) 2-- (CF2) 2H
17 . H- (CF2) 4-0- (CF2) 4H
18. H-(CF2)2-0-(CF2)2-o-(cF2)2H
19. H-CF2-O-CF2C(CF3)2CF2-0-CF2H
20 . Cl (CF2) 4-0- (CF2) 4H
21. H ( CF2 ) 2 oCF2 C ( CF3 ) 2 CF2 ( CF2 ) 2H
22. C8Fl70CF20C3F6H
23 . (CF3) 3COC2F40CF20C2F40CF2H

As mentioned above, the omega-hydrofluoroalkyl ether _ _~,ds or compositions of this invention can be made by decarboxylation of their corrF~:pon-linq precursor perfluoroalkyl ether carboxylic acids, 30 hydrolyzable carboxylic acid derivatives, or hydrolyzable yl~-;UL~UL~ thereto (some of which are believed novel). A class of such precursor compounds can be represented by the general formula:
Rfp-O~R~ ' O~nR~'I~Z ' IV

~19011 WO 95132174 1 ~.lIU.. _. SllO
wherein Rfp is ROC(O) Rf or F-Rf, Rf being a perfluoroalkylene group as defined for formula I;
Rf ' and Rf " are also perf luc~3~oalkylene groups as def ined f or f ormu ~ca~ ~;
n is also as defined for formula I; and Z' is a C02H, C02R, COF, COCl, CONR1R2, or -CF20C(O~Rf, where R is selected from the group consisting of hydrogen, alkyl (such as a lower alkyl group of 1 to 6 carbon atoms), cycloalkyl, fluoroalkyl, and aryl, and where R1 and R2 are; na~Pr~nra~ntly selected from the group consisting of hydrogen, alkyl, cycloalkyl, and heteroatom-containing cycloalkyl .
In the decarboxylation of the ~ a_ of formula IV, the moiety Z ' is replaced by a hydrogen atom .
Subclasses of said ether acids and derivatives thereof, which have other utilities in addition to their use as precursors of the omega-hydro ether ~ ullds of this invention, for example, as surface active agents (or surfactants), as mentioned above, and which are believed novel, can be represented by the general formulas V, VI, VII, VIII and IX below, Rfo-O-Rfo'--Z V
3 0 wherein:
Rfo is a perfluoroalkyl group (linear or branched) having, for example, 1 to 18 carbon atoms, preferably 1 to 12 carbon atoms, Rfo~ is a perfluoroalkylene group (linear or branched) having, for example, 2 to 11 carbon atoms, at least one of Rfo and Rfo~ having at least 8 chain carbon atoms; and ~19~11

4 ~ r~ 0 Z is -COOH, -COOMl/V, -COONH4, -COOR, -CH2OH, -COF, --COCl, -CR, -CONRR, -CH2NH2, -CH2NCO, -CN, -CH20502R, -CH20COR, --CH20COCR=CH2 l -CONH(CH2)mSi(OR)3, or -CH2O(CH2)mSi(oR)3,

5 where ~q i6 an ammonium radical or a metal atom having a valence "v" of 1 to 4, such as Na, K, Ti, or Al, and each R is inflept~ntlt~ntly an alkyl (e.g., with 1 to 14 carbon atoms) or cycloalkyl, which groups can be partially or fully fluorinated, or an aryl (e.g., with 6 to 10 ring-carbon atoms), any of which groups can contain heteroatom(s), and m is an integer of 1 to about 11.
Rfgto-cF2cF2taocF2 Z VI
wherein:
Rfq is a perfluoroalkyl group (linear or branched) having from about 6 to about 18 carbon atoms, preferably 6 to 12 carbon atoms, subscript a is an integer of at least 2, preferably 3 to 7, but when a is 2, then Rfq has at least about 8 carbon atoms; and Z is as defined for formula V.
Rfr~O~cF2~O-Rfr Z VII
wherein:
Rfr is a perfluoroalkyl group (linear or branched) having, for example, 2 to 18 carbon atoms, pref erably 4 to 12 carbon atoms;
Rfr~ is a perfluoroalkylene group (linear or branched) having, for example, 1 to ll carbon atoms and preferably 1 to 5 carbon atoms; and Z is as defined for formula V; and the sum of the number of carbon atoms in the groups Rfr and Rfrt is at least about 7.
Rf~,-~CF2tb-Z VIII

219~1~ 6 WO 95132174 1 ~ 1l0 wherein:
Rfn i6 a perfluoT~i~yl group (linear or branched) having, for example, 1 to 18 carbon atoms, preferably 1 to 12 carbon atoms;
b is an integer of at least 3, pref erably 3 to 11;
and Z is as defined for formula V.
Rft- (O-Rft' ) ~~O- (CF2) d-Z IX
10 wherein:
Rft is a perfluoroalkyl group (linear or branched) having, for example, 1 to 18 carbon atoms, preferably 1 to 12 carbon atoms;
Rft' is a perfluoroalkylene group (linear or branched) having, for example, 1 to 11 carbon atoms, pre~erably 2 to 4 carbon atoms;
c is an integer of at least 1, preferably 1 to 4;
d is an integer of 3 or greater, preferably 3 to 9; and Z is as defined for formula V.
The carboxylic acids of f ormulas V to IX are useful intermediates for the preparation of many of the other derivatives of formulas V to IX. These 25 derivatives include nonfunctional or functional derivatives such as, for example, carboxylic acids, salts, esters, ~mides, nitriles, alcohols, acrylates, and vinyl ethers. Various patents describe processes for the preparation of a host of functional derivatives 30 of oxyperfluoroalkylene c /ou~lds, i.e., perfluoropolyethers, e.g., see U.S. Pat. Nos. 3,250,808 (Mitsch et al.) and 4,094,911 (Moore et al.). These derivatives have utility for various applications, such as surfactants, e1astomers, coatings, 1ubricants, 35 substances used in the preparation of liquid crystal materials such as those in U. S. 5, 262, 082 (Janulis et al. ), and in the treatment of fibrous substrates to 95/32174 P~ C'C I10 impart oil and water repellency thereto. The ammonium salts of the carboxylic acid derivatives are particularly useful as surfactants.
The carboxylic acid compounds of formula V are 5 normally solid. The carboxylic acid ~-, '- of formulas VI, VII, VIII and IX generally are normally liquid and normally liquid compositions can be made up which consist or consist essentially of selected mixtures of such compounds.
A list of representative examples of fluoroalkylether acids tor derivatives) which can be utilized to prepare omega-hydrof luoroalkyl ethers of this invention is as follows:
Table B
1. CF3 (CF2) ~--o-CF2c02H
2 . CF3 (CF2) 11-0-CF2C2H
3 . CF3 (CF2) 6--0-C2F4C2H
4 . CF3 (CF2) 4--o-C2F4c02H
5. CF3 (CF2) 5--o-C2F4c02H

6 . CF3 (CF2) 8--0-C2F4C2H

7 . CF3 (CF2) 7-o-C2F4c02H

8 . CF3 (CF2) g--o-C2F4c02H

9 . CF3 (CF2) ll-0-C2F4C2H

10. CF3 (CF2) s--OC2F40-C2F4C02H

11. C8Fl7-O- (CF2) 5C2H

12 . C1oF21~0~ (CF2 ) SC02H

13 . CF3--o- (CF2) 7C02H

14 . C2Fs--0--(CF2) ~C02H
3 0 15 . C3 F7 -o- ( CF2 ) 7 Co2H
16 . CF3--o- (CF2) sC02H
17 . CF3--0- (CF2) 1oC2H
18 . CF3 (CF2) 5-0-C2F4-0-C2F4-0-C2F4--0 19 . CF3 (CF2) 7-o-C2F4-o-C2F4-0-C2F4-0-2~ 9Qll~
W09~J32174 r~ J.. ,c.-'lll 20. CF3 (CF2) 9-0-C2F4-0-C2F4-0-C2F4-0 21. CF3 (CF2) ll-0-C2F4-0-C2F4-0-C2F4--CF2C2H ''' 22- CF3 (CF2) ll~.~0C2F4) l_s~O~CF2C02H from Br i j tm3 o acetate 23 . C6Fl30CF20 (CF2) 5C02H
24 . CF3 (CF2) 7-0-CF2-0-CF2C02H
25. CF3 (CF2) 7-0-CF2-o-c3F6c02H
26. (CF3) 3Coc2F40cF20c2F4co2H
27 . C4Fg~0~ (CF2) 3C2H
28 . CsFll-0- (CF2) 3C2H
29 . C6Fl3-0- (CF2) 3C2H
3 o . CsFll-0- (CF2) 4C2H
31. CF3-0- (CF2) sC02H
32- C4Fg-0- (CF2) sC02H
33, CsFll-0- (CF2) sC2H
34 . C4F9~0~C4Fg~0 (CF2) 3C2H
3 5 ~ C6 Fl 3 -0~ C4 F8 ~ ( CF2 ) 3 C2H
36. C4Fg-0-C2F40~C2F40(cF2)3co2H
37 . CF3-0- (C2F40) 3- (CF2) 3C2H
38. C8Fl70cF20csFloco2H
39 . (CF3) 3coc2F4ocF2oc2F4ocF2co2H
40. (CF3)2CFCF2CF20(cF2)sc02H
41. CF3 (CF2) 70C2F40C2F40CF2C02H
. cl`3~cF2)lloc~l q 2~ ~011~
Wo 95/32174 r . ~ o The following presents overall schemes of reactions that can be used in the preparation of omega-hydrofluoroalkyl ethers of this invention using general f ormulas def ined above . In these schemes, the 5 illustrated reaction results in the product whose formula is depicted on the su~!cPP~;n~ line Scheme I
a. R{)~ R'~R~ ~ C(O) OR F2 direct fl~ nnqtin.
hydrolysis or ~1 b. Rf~ Rf--O~ Rf'-C {o~ OR
c. Rff~t Rf~ Rf' -C {O~ O(H or CE~
Rf~ Rf~n Rf -H

21~0116 W0 95/32174 P~ 110 Scheme I1 a. R--~R'~)nR -CH~o--Coch3 direct fluorination b. Rf--O~Rf '~O)nRf --~F~O--COCF3 hydroly5is or methanolYsis c. Rf--OtRf'-O) Rf"-Co--O(H or CH3) }COH
Rf--otRf '--) -- R~_H
5 Scheme III
a. R~R--o)n~R -Cl direct fluorinatiOn b. Rf--OtRf ~)n--Rf ~-Cl Raney Ni Rf--~f '~ )n Rf -H
The ether alpha and omega dihydrides, that is, lO where X in formula I is H, may be prepared by analogous schemes. For example, the following Scheme IV i8 analogous to Scheme I

Wo 95/32174 2 1 ~ O 1 ~ 6 P~ lo Scheme IV
a. CH30--CO--R--otR ~O)r,~R -CO--OCH3 direct fluorirultior b. CF30--CO--Rf--~f ~)r' Rf -CO OCF3 hydrolYGig or methemolYsiS
c. (H or CH3) OCORfO(Rf ~--O¦~Rf "-CO--O (H or CH 3) doc~ bo~yl~tio H--Rf-O~Rf ~--O) Rf -H
Looking first at Scheme I above, in the direct fluorination, step "a", a fluorinatable precursor ether carboxylic acid ester, e.g., C4Hg-O-(CH2)5COOCH3, is directly fluorinated by contact with fluorine gas.
(The term "fluorinatable" means that the precursor lO contains carbon-bonded hydrogen atoms which are replaceable with f luorine and the precursor may contain unsaturation which can be saturated with f luorine . ) The resulting f luorinated ether acid ester _ _ ', depicted in step b, can be made with essentially the

15 same number and spatial arrangement of carbon and oxygen atoms as the precursor thereof. If a fluorinated ether acid composition which consists or consists essentially of a selected mixture of fluorinated ether, ~c is desired, a selected 20 mixture of the corresponding precursor _ ~c can be fluorinated or, alternatively, the selected precursor compounds can be separately f luorinated and then blended .
The direct fluorination of the fluorinatable ether 25 precursor can be carried out at temperatures typically used in direct f luorination , e . g ., at moderate or near ambient temperatures such as -20OC to +50C, using a stoichiometric excess of fluorine gas, which is preferably diluted with an inert gas, such as nitrogen, %L~
Wo 95/32174 r~ 110 to minimize or avoid the hazards of pure fluorine gas and to control the amount of heat generated upon contact of the precursor with f luorine . The fluorination is preferably carried~. out in an oxygen-and water-free environment and~ can be carried out in the presence of solid, parti~culate scavenger, e.g., sodium fluoride, for the hydrogen fluoride by-product generated. Liquid phase direct f luorination can be employed and involves using an inert liquid, such as a fluorocarbon or chlorofluorocarbon liquid, as a reaction medium. Both scavenger and an inert liquid reaction medium can be utilized, if desired. The fluorination is preferably carried out by liquid phase direct f luorination in the absence of hydrogen f luoride scavenger by using a temperature and inert gas f low rate sufficientto volatilize hydrogen fluoride by-product and enable its removal from the fluorination zone as it is generated.
In another aspect, this invention provides a fluorochemical composition containing the fluorinated ether acid or derivative thereof, hereinbef ore described, as the sole essential component of the f luorochemical composition .
Although direct f luorination is a substitution method involving the replacement of hydrogen atoms with f luorine, direct f luorination provides higher yields and purer products than do other substitution methods such as the electrorhPm;rAl fluorination and cobalt trifluoride methods -- see, for example, U.S. Pat. No.
5,093,432 (Bierschenk et al.). The purity of the perfluorinated ether acid (or ester) compositions of the invention is further Pnh~ncp~ by the use of single precursor compounds or selected (rather than random) mixtures thereo~.
The preferred method of fluorination is the "liquid phase direct fluorination technique, " which involves making a very dilute dispersion or, 2~301~6 o 95/32174 r ~ 1O
preferably, solution of the precursor(s) in a liquid reaction media, which is relatively inert to f luorine at the fluorination temperatures used, the ~;UI~c~:llLLCLtiOn of fluorinatable starting material thus 5 being relatively low so as to more easily control the reaction temperature. The reaction mixture can also contain or have dispersed therein a ~lyd~ oyerl f luoride s-;~v~ng~:L such as sodium fluoride, the 6cavenger:precursor weight ratio being, for example, from about 0.5:1 to 7:1. The reaction mixture can be vigorously agitated while the fluorine gas is bubbled through it, the fluorine preferably being used in admixture with an inert gas, such as nitrogen, at a concentration of about 5 to 50 volume %, more 15 preferably about 10 to 25 volume %, and being maintained in stoichiometric excess throughout the fluorination, e.g., up to 15 to 40%, or higher, dPron~l;ng on the particular starting material and the efficiency of the equipment used, such as the reactor 20 agitation. Yields generally in the range of about 30-77 mole %, and, with experience, as high as 65 to about 85 mole %, of the perf luorinated product may be achieved by this method.
Suitable liquids useful as reaction media for the 25 liquid phase direct fluorination technique are chlorof luorocarbons such as FreonTU 11 fluorotrichloromethane; chlorofluoroethers; Fluorinert~
electronic liquids FC-75, FC-72, and FC-40;
perfluoroAlkAno~ such as perfluoropentane and 30 perfluororl~rAl in; perfluoropolyethers; and perfluornAcetAl~. Mixtures of such liquids can be used, e.g., to get good dispersion of precursor and intC~ -~1 i Ate reaction products . The reaction media are conveniently used at atmospheric pressure. Lower 35 molecular weight members of the above classes of - reaction media can also be used, but elevated pressures are then required to provide a liquid phase.

~190116 Wo 95/32174 r~ IO ~1 The liquid phase direct fluorination reaction is generally carried out at a temperature between about -10C to +50C, preferably between about -10C to 0C
if a 1IYdL~Y~:n fluoride 8~CV~lly~:L is used, snd, if 6uch 5 a scavenger is not used, betw~h about 0C to 150C, preferably about 0C to 50~~:, most preferably about 10C to 30C, the temperàture being sufficient to volatilize the hydrogen fluoride by-product and, with the aid of the inert gas, flowing at a sufficient rate, 10 cause the purging of the by-product from the f luorination reactor as it is generated . At these t~ ~_L~LuLes, the liquids utilized as reaction media do not react appreciably with the diluted f luorine and are essentially inert. The reaction medium and other 15 organic substances may to some extent be present in the gaseous reactor effluent, and a rnnfl~n~Pr may be used to cnnl1~nc~ the gaseous reaction medium and such substances in the effluent and permit the cnnrlPn~ate to return to the reactor. The r!nn~l~ncF~r can be operated 20 so as to minimize or prevent the return to the reactor of ~IydL o~ f luoride by-product (which could have an adverse ei~fect on yield of product if allowed to remain in the reactor during f luorination) . The return of the hydrogen fluoride can be m;nim;7~d or prevented by 25 selective cnn~lpncation of the organic materials while allowing the hydrogen f luoride to pass through the con~lPnc~r, or by total condensation of both hydrogen fluoride and the organic materials into a separate vessel and followed, if desired, by separation of the 30 llydL-~y~ll fluoride as the upper liquid phase and the return of the lower liquid phase.
The liquid phase fluorination reaction may be carried out in a batch mode, in which all of the precursor is added to the liquid prior to fluorination 35 to provide a precursor concentration of up to about 109 by weight, and the fluorine-containing gas is then bubbled through the precursor-containing liquid. The 2 ~ ~0116 W0 95132174 ~ O
reaction can also be carried out in a semi-continuous mode, in which the precursor is continuously pumped or otherwise fed neat, or as a diluted solution or dispersion, in a suitable liquid of the type used as a 5 reaction medium, into the reactor, e.g., at a rate of about 1 to 3 g/hr into 400 mL of liquid reaction mixture, as fluorine is bubbled through, e.g., at a fluorine flow rate of about 40 to 120 mL/min and an inert gas flow rate of about 150 to 600 mL/min. The 10 fluorination can also be carried out in a continuous manner, in which the precursor (either neat or dissolved or dispersed in a suitable liquid of the type used as a reaction medium) is continuously pumped or otherwise fed into the reactor containing the reaction 15 medium as the fluorine-containing gas is introduced, as described above, and the stream of unreacted fluorine, hydrogen f luoride gas, and inert carrier gas is continuou61y removed from the reactor, as is a stream of liquid comprising perfluorinated product, 20 incompletely fluorinated precursor, and inert liquid reaction medium, and the n~c~c~ry separations are made to recover the fluoroalkyl ether composition. If desired, the unreacted ~luorine and the incompletely f luorinated precursor can be recycled . The amount of 25 inert liquid medium in the reactor can be maintained at a constant level by addition of recycled or fresh liquid .
Due to the extremely high exothermicity of the fluorination reaction, a cooled liquid or ice bath is 30 generally employed in order that acceptable rates of reaction may be achieved. When the reaction is complete, the reactor is purged of f luorine and the reactor contents are removed . Where the f luorination is carried out by the liquid phase fluorination 35 technique in the presence of a hydrogen fluoride scavenger, the spent scavenger can be separated by filtration or decantation from the liquid reactor WO95~32174 P~ A-~ln contents and the latter then distilled to separate the reaction medium from the crude product. Where the fluorination is carried out by the liquid phase fluorination technique without using the scavenger, the 5 reaction product mixture can be~distilled to recover the product.
Useful representative precursor f luorinatable ether acid e6ters which can be used to prepare the omega-hydrof luoroalkyl ethers of this invention are the lO hydrocarbon counterparts of the structures listed in Table A above, except that instead of the terminal hydrogen atom the structures of the esters terminate with -Z' (where Z' is as defined for formula IV) or -CH2OC(O)R (as shown in Scheme II SuPra) and that the 15 precursors can contain unsaturation.
Representative examples of the f luoroether acids of or used in this invention include the perfluorinated (i.e., having essentially all hydrogens replaced with fluorine) counterparts of the precursor fluorinatable 20 acid esters fleerr; hP~l above. When the precursors have Ull2~cltUL~tiOn, the ~uLL~:a~uullding fluorinated ether acids are saturated.
As pointed out above, the fluoroether acids and derivatives can be used as precursors in the 25 preparation of the omega-hydrofluoroalkyl ethers and they are also useful, for example, as surfactants.
The above-described f luoroether acids or the esters thereof, e . g., alkyl esters such as the methyl ester, can be converted by a decarboxylation process to 30 ~ the omega-hydrofluoroalkyl ethers of this invention.
In one such process, a solution of l~ûH in ethylene glycol is prepared and the f luoroether acid or ester precursor is added thereto (neat or as a solution in an inert solvent liquid such as a perfluorinated liquid), 3 5 pref erably dropwise with stirring at ambient or room temperature. The resulting mixture can then be heated 610wly, for example, to 190C, during which time the methanol (from the saponification of a methyl ester), water (from neutralization of an acid), and decarboxylated product are distilled. The omega-hydrofluoroalkyl ethers of the invention are surprisingly stable under such harsh basic conditions.
An inert solvent liquid, if used, can be removed, for example, at low temperature under vacuum after neutralization. The resulting distillate, comprising the omega-hydrofluoroalkyl ether product, can be washed with water, dried with silica gel or magnesium sulfate, and then distilled to purify the product. If desired, the hydrofluoroalkyl ether product can be refluxed with a solution of potassium permanganate in acetone to remove easily-oxidized impurities. The yields of the ether product are generally high and the product generally will be quite pure and consist or consist essentially of the desired omega-hydrofluoroalkyl ether .
The omega-hydrofluoroalkyl ether compositions are non-toxic and capable of dissolving and transporting oxygen and are therefore potentially useful as blood substitutes which can be employed invasively in the treatment of trauma, vascular obstructions, as adjuvants to cancer radiation treatment or chemotherapy, and as imaging contrast agents. Por such uses, emulsions of the compositions can be prepared by methods such as those described, for example, in U.S.
Pat. Nos. 3,911,138 (Clark) and 5,077,036 (Long) and the PCT International Application published as Wo 93/11868 (Kaufman et al.). The omega-hydrofluoroalkyl ether compositions are also useful as solvents for cleaning and drying applications such as those described in U. S. Patent Nos. 5 ,125, 089 (Flynn et al . ), 3 , 9 0 3 , 0 12 ( Brandreth), and 4 , 1 6 9 , 8 07 ( Zuber ) . Minor amounts of optional components, e.g., surfactants, may be added to the fluoroether compositions to impart particular desired properties for particular uses. The 21~116 W0 95132174 ~ n ether compositions are also useful as heat transfer agents or coolants in refrigerator or freezer eSSUL ~ or air conditioners, blowing agents or cell size regulators in making polyurethane foam insulation, 5 or chemical firê extinguishing agents in streaming applications, total flooding, exp~osion ~u~.L~ssion and inertion, and as carrier solven'cs for highly fluorinated polyethers used as lubricants for magnetic recording media.
In using the omega-hydrof luoroalkyl ether compositions of this invention for the drying of or displacing water from the surface of articles, such as circuit boards, the processes of drying or water displacement described in U.S. Patent No. 5,125,978 15 (Flynn et al. ) can be used. Broadly, such process comprises contacting the surface of an article with a liquid composition comprising the ether composition of this invention, preferably in admixture with a non-ionic fluoroaliphatic surface active agent. The wet 20 article is immersed in the liquid composition and agitated therein, the displaced water is separated from the liquid composition, and the resulting water-free article is removed from the liquid composition.
Further description o~ the process and the articles 25 which can be treated are found in said U.S. Patent No.
5, 125, 978 .
In using the ether composition of this invention as a heat transfer liquid in vapor phase soldering, the process described in U.S. Patent No. 5,104,034 (Hansen) 30 can be used. Briefly, such process comprises immersing the component to be soldered in a body of vapor comprising the ether composition of this invention to melt the solder. In carrying out such a process, a liquid pool of the ether composition of this invention 35 can be heated to boiling in a tank to form a saturated vapor in the space between the boiling liquid and a condensing means, a workpiece to be soldered is ' ~g'~11'6 W0 9~/32174 P~
immersed in the vapor whereby the vapor is condensed on the surface of the workpiece so as to melt and reflow the solder, and the soldered workpiece is then removed from the space containing the vapor.
In using the ether composition of this invention as a blowing agent in making plastic foam, such as foamed polyurethane, the process reactants, and reaction conditions described in U. S . Patent No .
5,210,106 (Dams et al.) can be used. In carrying out such process, organic polyisocyanate and high molecular weight ~_ wu~-d with at least 2 reactive hydrogen atoms, such as a polyol, are admixed in the presence of a blowing agent mixture comprising an ether composition of this invention, catalyst, and a surfactant.
This invention is further illustrated by the following examples, but the particular materials and amounts thereof recited in these examples, as well as other conditions and details, should not be construed to unduly limit this invention.
Example 1. Preparation of CaF 7-0-C2F4H from C8F17-o-C2F4c02cH3 The organic starting material, C8H17-0-C2H4C02CH3, was prepared by base-catalyzed Michael addition of n-octanol to acrylonitrile, followed by acid-catalyzed methanolysis. The methyl ester was directly f luorinated with F2 to produce the f luorinated ester, C8F17-0-C2F2C02CF3 . This f luorination was carried out in a 2-liter, jacketed reactor vessel of ~onel metal equipped with a magnetic drive agitator, gas feed line, organic reactant feed line, and a reflux condenser.
The gas feed line was 0 . 3 cm diameter tube reaching to a point below the bottom impeller of the agitator. The feed line was a 0.15 cm diameter tube connected to a syringe pump. The reflux condenser consisted of about 6-meters of two coiled concentric tubes, the inner tube having a 1. 27 cm diameter and the outer tube having a ~ ~ 9 ~
WO 95/32174 ~ C ~
2 . 54 cm diameter. Gases from the reactor were cooled in the inner tube by refrigerant, ethylene glycol-water, flowing in the annulus between the two tubes.
The reactor was charged with about 1. 8 liters of Freon 113 chlorofluorocarbon and purged with 650 mL/min of nitrogen f or 2 0 minutes . The gas stream was then changed to a mixture of 310 mL/min fluorine and 1100 mL/min nitrogen. After about 12 minutes, 100 g of C8~17-0-C2H4-C02CH3, diluted to 260 mL with Freon'U 113 chlorofluorocarbon, was fed to the reactor at a rate of 13 mL/hr (5 g/hr feed rate). The reactor contents were maintained at about 16-18 C throughout the f luorination . The condenser temperature was about -22C. The fluorine flow was continued for ten minutes after complete addition of the organic feed. The reactor was then purged with nitrogen for one hour.
The Freon~ 113 solution of the crude perfluorinated ester was treated with 150mL of 14% BF3 in methanol and agitated vigorously for 24 hrs. The mixture was washed with water, dried over MgSO4 and distilled ~b.p.
40CI0.2 torr) to yield C8Fl7-O-C2F4-CO2CH3 (47% yield).
For purposes of decarboxylation, 39 g of 85% KOH was dissolved in approximately 300 mL of ethylene glycol and the above-described f luorinated methyl ester was added dropwise with stirring to the KOH solution at room temperature. Upon complete addition, the reaction mixture had a pH of 8 to 9. The mixture was heated slowly with stirring and the product of decarboxylation, C8Fl7-O-C2F4H, was distilled along with methanol from saponification of the methyl ester, water from the KOH and a small amount of ethylene glycol.
When the reaction mixture temperature reached 170C, the heating was 6topped . The lower f luorochemical phase of the distillate was separated, washed with water, dried and distilled through a three-plate Snyder column. The main fraction, boiling at 146-150C, yielded 122 g of product. Gas chromatography and mass 2~L90~ ~6:
WO 95/32174 3 ~~
spe~:LL ~, ~ (GC/MS~ of a sample of the product showed the sample to be 94% pure and confirmed the structure as C8Fl7-o-c2F2H-Example 2. Preparation of C8Fl7-O-C2F4H from C8F17--o-C2F4C02H
C8H17-O-C2H4CO2CH3 was prepared by base-catalyzed Michael addition of n-octanol to acrylonitrile, followed by acid-catalyzed methanolysis. This carboxylic acid ester was directly fluorinated by essentially the same fluorination procedure described in Example 1 to produce the corre5ponding ether acid, C8F17-0-C2F4COOH upon hydrolysis. Differential sc~nrl;n~
calorimetry revealed multiple tran5ition5, which is characteristic of polymorphism.
A solution of 116 g of 85% KOH in 800 mL of ethylene glycol was prepared in a 3 L round-bottom flask. 1000 g of the C8F170C2F4-CO2H was added dropwise to the stirred KOH solution. Upon complete addition, an additional 10 g of KOH was added and the mixture heated . The f luorochemical product of decarboxylation was distilled together with a small amount of water from the neutralization of the acid. The lower fluorochemical phase of the distillate was separated, washed with salt water, dried over Na2SO4 and distilled as in Example 1 to yield 817 g of C8Fl7-O-C2F4H.
Example 3. Preparation of C7Fls-O-C2F4H from 3 o C7Fls - o-c2F4co2cH3 C7H1s-O-C2H4CO2CH3 was prepared by base-catalyzed Michael addition of n-heptanol to acrylonitrile, followed by acid-catalyzed methanolysis. 550 g of the corresponding methyl ester, C7F1s-O-C2F4COOCH3, (prepared by essentially the same fluorination and methanolysis procedures of Example 1), was added dropwise to a solution of 166. 6 g of KOH in approximately 880 mL of ethylene glycol. The 219~1~6 WO95/32174 P~ C 110 fluorochemical product was recovered essentially as in Example 1 to yield 440 g which was distilled through a six-plate Snyder column and the fraction boiling from 130 to 131C was collected (340 g). This fraction was combined with 8.5 g of KMnO4 and approximately 350 g of acetone and heated to reflux. ~fter four hours, an additional 5 g of KMnO4 was added and the resulting mixture was heated for an additional 3 hours. The mixture was filtered, the filter cake washed with 10 aeetone, and water was added to the filtrate causing a lower fluorochemical phase to form whieh was then washed with water, followed by conc. H2S04, again with water, and then filtered through silica. 1H NMR
and 19F NMR conf irmed the reaction product to have the 15 desired structure, C7Fls-O-C2F2H. Gas-liquid chromatography of a sample showed it to be 98 . 7% pure.
Example 4. Preparation of C F -O-C F -O-CF H from C6F13-O-C2F4-0cF2cO2cH3 6 13 2 4 2 The starting material, C6H13-O-C2H4-O-C2H4-O-COCH3, wac~ prepared by acetylation of hexyloxyethoxy ethanol with acetyl chloride. The acetate was then converted to C6F13-O-C2F4-OCF2CO2CH3 by essentially the same fluorination and methanolysis procedures of Example 1.
548 g of this fluorochemical was combined with 144 . 2 g of KOH in 600 g of ethylene glycol. The resulting mixture was heated, distilled and the product, C6F13-O-C2F4-OCF2H, was L~ )v~t:d as in Example 1. Total yield was 433 g. The product was again distilled (b.p 131C) through a 12-inch (30 . 5 cm) perforated-plate column at atmospheric ~JL li:~-t~UL.::. The structure of the product was conf irmed by lH and 19F NMR as C6F13-0-C2F4-OCF2H. GC/MS
revealed a sample of it to be 99 . 6% pure.
Bxample 5. Preparation of C8F17-O-CF2H from ~19~
WO9~132174 ~ C l10 C8Hl7-O-C2H4-O- (CO) CF3 was prepared by acetylation of octyloxyethanol with trifluoroacetic anhydride. 100 g of the trif luoroacetate was directly f luorinated by essentially the same fluorination procedures of Example 5 1 and the f luorination product was quenched with a solution of BF3 in methanol to yield crude C8Fl7-O-CF2-C02CH3, which was further purified by distillation, b.
92-97C Q20 torr.
A 58 g sample of the latter methyl ester was 10 decarboxylated using 10 . 8 grams of KOH in ethylene glycol and the product, C8F17-O-CF2H, was recovered as in Example 1. The structure of the product was conf irmed by 19F NMR . GLC revealed the product to be 99.6% pure, b. 134-136C.

Example 6. Preparation of C4Fg-O-C2F4H from C4Fg-O-The methyl ester, C4Hg-O-C2H4-CO2CH3, was prepared 20 by base-catalyzed Michael addition of n-butanol to acrylonitrile, followed by acid-catalyzed methanolysis.
The methyl ester was then converted to the corresponding fluorinated methyl ester, C4Fg-O-CF2CF2-CO2CH3, by essentially the same fluorination and 25 methanolysis procedures described in Example 1.
1160 g of the latter methyl ester was added dropwise with stirring to 3103 g of ethylene glycol and 129.5 g of NaOH. The product was distilled (b.p. 83OC) and treated with ~MnO4/acetone, and worked up as in 3 0 Example 3 . The structure of the purif ied , ', C4Fg-O-CF2CF2H, was confirmed by lH and l9F NMR and GC/MS .
A sample of this compound was evaluated for use in precision cleaning applications by measuring the 35 solubilities of selected hydrocarbon solvents in the sample. High solubility would indicate; . ve.l performance as a cleaning agent relative to perfluorocarbon solvents The following hydrocarbon 21~01:~6~, WO 95132174 r~l,. ll0 solvents were found to be soluble in amounts up to 50%
by weight with the ether hydride: hexane, heptane, toluene, acetone, 2-butanone, 4-methyl-2-pentanone, ethyl acetate, methanol, ethanol, isopropanol, dimethyl 5 formamide, trans-1,2-dichloroethylene and isopropyl ether. o-Xylene was found to be soluble to 19% by weight. Chloroform was found to be soluble to 45~6 by weight. Ethylene glycol was found to be soluble to les6 than 15% by weight and a light hydrocarbon oil was 10 found to be soluble to less than 0 . 05% by weight.
A sample of the - ._ .1 was also evaluated for use in spot-free drying applications such as taught in U.S. Patent No. 5,125,978 (Flynn et al.). A water displacement composition was prepared by dissolving 0 . 2% by weight of C4FgOC2F4OCF2CONHC2H4OH in C4Fg-O-C2F4H. The solution was heated to 45C in an ultrasonic bath. Using the procedure described in U. S . Patent No.
5,125,978, test~coupons of glass and stainless steel were wetted with water and subsequently immersed into 20 this solution with ultrasonic agitation. All water was displace~ within 60 seconds.
A sample of this rr--rolln-l was also evaluated for use as a rinse agent in co-solvent cleaning applications. tSuch rlP~n;n~ applications are taught, 25 for example, in International Patent Publication No. WO
92/22678 (Petroferm Inc. ) . Organic esters such as methyl decanoate have found utility as solvating agents in two-phase cleaning applications using perfluorohexane as the carrier liquid and rinse agent. ) 30 Iqethyl decanoate and C4FgOC2F4H were placed in separate containers and heated to 50C in an ultrasonic bath. A
50 mm X 25 mm X 1. 5 mm aluminum coupon was contaminated with 0.0831 g of a light hydrocarbon oil. The contaminated coupon was first immersed in the methyl 35 decanoate for about 60 seconds and then immersed in the C4FgOC2F4H for about 60 seconds. The C4FgOC2F4H rinsed 100 percent (as determined by weight difference) of the ~0116 W095/32174 r~l~u._C 110 oil and the methyl decanoate from the coupon. Under the same conditions, perfluorohexane removed only 98.5 percent of the oil and methyl decanoate, indicating that C4FgOC2F4H can be more effective as a carrier 5 liquid and rinse agent than perf luorohexane .
Example 7. Preparation of HCF2CF2-0-CF2CF2-0-CF2CF2H
f rom CH30C (O ) C2F4-0-C2F4-0-C2F4C (O ) OCH3 The starting material, CH30C (O) C2H4-0-C2H4-0-C2H4C (O) OCH3, was prepared by ba5e-catalyzed Michael addition of ethylene glycol to acrylonitrile, followed by acid-catalyzed methanolysis. The starting material was then f luorinated and methanolysed by essentially 15 the same procedures described in Example 1 to give CH30C (O) C2F4-0-C2F4-0-C2F4C (O) OCH3 .
1136 grams of the fluorinated ester was added to a mixture of 305. 6 g of ROH in 2665 g of ethylene glycol.
The decarboxylation was carried out essentially as 20 described in Example 1, and the crude product distilled after phase separation but without water washing. The distillate still contained methanol which was removed by a wash with concentrated sulfuric acid followed by two water washes to give 695 g of the desired ether 25 hydride product, with a boiling range of 93-94C.
Example 8 . Preparation of C4Fg-O- (CF2) sH from C4Fg-O-(CF2) s--C02H
118.2 g (1.0 mol) hexane-1,6-diol, 4.4 g Adogenn' 464 quaternary ammonium salt, 80.0 g (2.0 mol) NaOH, and 250 mL tetrahydrofuran was stirred at reflux. 80 mL H20 was added to get better mixing. After 20 min more, 137 g (1.0 mol) butyl bromide was added over 0.5 hr, and stirred overnight at reflux. The reaction mixture was quenched in 1 L H20, and the upper layer was combined with an ether extract of the lower layer, dried over MgSO4, and stripped on a rotary evaporator.
Treating the resulting stripped layer (151 g) in 100 mL
CHC13 with 150 mL acetyl chloride added dropwise and 2~ ~bl~ 6 Wo 95132174 . ~~ 110 subsequently heating at ref lux 4 hr and solvent removal gave 225 . 4 g of liquid. Distillation of the liquid gave 176.0 g (b. 100-104C/0.9 torr) of distillate.
GLC indicated 56% of it to be the desired 6-butoxyhexyl 5 acetate, ~: nied by h~Yi~n~.rliol diacetate and dibutoxyhexane. 100 g of this m~5xture was fluorinated essentially as in Example 1. ~eatment of the resulting fluorinated product with 30 mL of a 10 weight percent solution of H25O4 in H2O and shaking at room 10 temperature for 2 hours, filtration of solid fluorinated adiplc acid, separation of the F-113 layer, drying over MgSO4, and distillation produced a main cut of 73.4 g, b. 116C/20 torr, 96% pure C4Fg-O-(CF2~sCOOH.
The latter was ~dded to a solution of 10.0 g (0.25 mol) 15 NaOH and 100 mL ethylene glycol and the mixture was heated to 120C, with C4Fg-O(CF2)6-O-C4F9 impurity from fluorination collecting in the Dean-Stark trap. On continued heating, gas evolution began and a liquid, C4Fg-O(CF2)5H, (44.6 g) collected in the trap, ending by 20 170C. The collected liquid was dried over silica gel and distilled on a 4-inch (10.2 cm) Vigreux column to 38.8 g, b.p 131C. F-nmr confirmed structure, in high purity, to be C4Fg-O-(CF2)sH.
25 Example 9 . Preparation of C F -o- (CF ) H from CsFll-O- (CF2) sCOOH 5 11 2 5 .
In a similar fashion to Example 8, hf~Y:~n~ l was alkylated with n-pentyl bromide, the product was 30 acetylated, and the crude acetate, CsH11-O-(CH2)6OC(O)CH3, was distilled (b. 125C/3 torr) and the distillate was f luorinated essentially by the fluorination procedure of Example 1. The fluorinated ester was hydrolyzed to the corresponding acid.
35 Decarboxylation of the fluorinated acid, CsF11O (CF2) sCOOH, with NaOH gave 829 g of product . The product was washed with water, dried over MgSO4, and WO 95132174 1 ~ 5.'/~
distilled to yield 555 g of C5F11-O-(CF2)5H, b. 145-149C.
Example 10. Preparation of C F -O- (CF ) H from C8Fl7 - o- (CF2) sCH 8 17 2 5 In a fashion similar to Example 8, h~Y~nerliol was alkylated with n-octyl bromide, the product was acetylated, and the resulting C8Hl7-O- (CH2) 6-O-COCH3 was directly fluorinated and hydrolyzed as in Example 8 to C8Fl7-O- (CF2) sCOOH, which was recrystallized from perfluorohexane. The recrystallized acid (37.5 g) was mixed with 4 . 0 g NaOH and 100 mL ethylene glycol and heated to 185C. The product was washed with water, and the residual 27 . 9 g was distilled to give pure C8Fl7-O-(CF2)5H, micro b.p. 195C.
Example 11. Preparation of C4Fg-O-CF2C(CF3)2CF2H from C4Fg--O-CF2C ( CF3 ) The alkylation of 2, 2-dimethyl-1, 3-propanediol with n-butyl bromide carried out essentially as in Example 8 gave the crude mono-alkylated product, which was treated with SOCl2 to give C4Hg-O-CH2C(CH3)2CH2Cl, 2 5 b . 8 0 -9 0 C / 2 0 - 3 0 torr . Thi s c ompound wa s then fluorinated as in Example l to give C4Fg-O-CF2C(CF3)2CF2Cl. 20.0 g of the latter chloride was mixed with 5 . 3 g water-wet Raney Ni and 50 mL of NH3-saturated methanol. The mixture was left shaking on a Parr hydrogenation apparatus for 3 days at about 25 C, with most of the 21 kPa (3 psig) hydrogen pressure drop occurring in the f irst day . The product was recovered by filtration and quenched in water, yielding 7.9 g with some mechanical loss . l9F-nmr conf irmed the product to be C4Fg-O-CF2C(CF3)2CF2H. A scaleup to 100 g gave 47 g, distilled to b.p 135C.

~9~116 . . !
WO 95f32174 PCT/US95/06110 Example 12. Preparation of H(CF ) -0-(CF ) H from Cl(CF2)4-O-(cF2)4cl 2 4 2 4 Cl-(CH2)4-O-(CH2)4-Cl was fluorinated as in Example 1 to provide Cl(CF2)4-O-(CF2)4Cl. A mixture of 30.3 g Cl(CF2)4-O-(CF2)4Cl, 11.3 g fresh water-wet Raney Ni, and 200 mL methanol was purged for several minutes with NH3 and pressurized with 310 kPa (45 psig) hydrogen on a Parr hydrogenation apparatus at about 25 C. After 17 hr, pLes,.uLa had dropped to 255 kPa (37 psig) and the mixture had become acidic, with glass etching noted.
More ammonia was added and the reduction was continued, dropping another 62 kPa (9 psig). The reaction product was filtered and quenched in water to give 15 . 4 g of lower phase, 689~ pure product confirmed by GLC to be H(CF2)4-O-(CF2)4H. Distillation yielded 27.0 g, b. 121-124C, 87% pure.
Example 13. Preparation of H(CF2)4-O-(CF2)4H and Cl (CF2) 4-O- (CF2) 4H from Cl (CF2) 4-O- (CF2) 4C1 A mixture of 50 . 0 g Cl (CF2) 4-O- (CF2) 4Cl and 30 g Zn in butanol was stirred at 110C for 2 days. GLC of a sample of the resulting reaction product indicated 25 partial conversion. 21 g more Zn was added and the mixture was heated one more day. Filtration and ql~pnr~h;n~ of the resulting material in water gave 27.0 g of a colorless li~uid. The product was 35% of H(CF2)4-O-(CF2)4H, 42% mono hydride, and 16% unreduced 30 dichloride.
Example 14. Preparation of C6Fl3-O-CF2CF2H from C6F13 The starting material, C6H13-O-C2H4-C02CH3, was 35 prepared by the Michael addi~ion of hexanol to acrylonitrile foIlowed by acid-catalyzed esterification with methanol. The resulting ester was then f luorinated and hydrolyzed to give the C6Fl3-O-C2F4C02H .

~93~
WO 95132174 1 ~ IIU.,,~ 0 500 g of the acid C6F13-O-C2F4CO2H, was added slowly to a solution of 68 . 7 g KOH in 700 g ethylene glycol. At the end of the addition, an additional 5 g of KOH was added to the homogeneous solution to bring the pH to 9. The decarboxylation was carried out as in Example 1 and subse~uently distilled, producing 327 g of product, b. 104-107 C. The product was treated with potassium permanganate essentially as in Example 3 . GC/MS, 19F nmr, lH nmr and IR conf irmed structure of the product as C6F73-O-CF2CF2H.
Example 15. Preparation of C6F13-O-CF2H from C6F13-o-CF2C02cH3 The starting material, C6H13-O-C2H4OC(O) CH3, 15 prepared by acetylation of ethylene glycol monohexyl ether, was fluorinated and decarboxylated by essentially the procedures of Example 1 to give 146 g of C6F13 -O- CF2H ( b . 9 2--9 6 C ) .
Example 16. Preparation of CF3CF(CF3)CF2-O-CF2H from CF3CF ( CF3 ) CF2-O-CF2CO2CH3 The starting material, CH3CH(CH3)CH2-O-CH2CH2-oC (O) CH3, was prepared by acetylation of ethylene glycol monoisobutyl ether and conversion by essentially the fluorination and methanolysis procedures of Example 1 to give the methyl ester, CF3CF(CF3)CF2-O-CF2CO2CH3, b. 118-120C.
149 g of the methyl ester was added to 28. 6 g of KOH in 700 g of ethylene glycol rapidly dropwise. The decarboxylation was carried out to afford, after distillation, the product cut, 70 g, b. 45-47C, of 99%
purity by GLC . The structure was conf irmed by GC/MS, 1H nmr, and 19F nmr analysis as CF3-CF (CF3 ) CF2-O-CF2H -Example 17. Preparation of C4Fg-O-(CF2)4-O-(CF2)3H
from C4Fg-O- (CF2) 4-O- (CF2) 3COOCH3 6 j l~3~
Wo 95/32174 } ~ 110 The starting material, C4Hg-O-C4H8-O-(CH2)3CH2OCOCH3, was directly fluorinated and methanolysed essentially by the procedures of Example 1 to produce C4Fg-O-C4F8-O-(CF2)3CO2CH3. 56 g of the latter wa6 added rapidly to a solution of 5 . 6 g KOH in 250 ml of ethylene glycol. The decarboxylation was carried out and the product phase separated, washed once with brine, and distilled to yield 36.6 g of product (b.p. 155-158C) of GLC purity 100%. GC/MS, lH, and 19F nmr analysis confirmed the product to be C4Fg-O- (CF2) 4-O- (CF2) 3H-Example 18 . Preparation of (C2Fs) 2CFCF2-O-C2F4H from ( C2 Fs ) 2CFCF2 -O -CF2 CF2 - C ( O ) OCH3 Starting material, (C2H5)2CHCH2-O-CH2CH2C(O)OCH3, prepared by the Michael addition of 2-ethylbutanol to acrylonitrile followed by acid-catalyzed esterification with methanol, was f luorinated and methanolysed essentially by the procedures of Example 1 to give (C2F5)2CFCF2-O-CF2CF2-C(o)OCH3, b.p. 159C, the direct fluorination yield, based on the methyl ester starting material being 88%.
The decarboxylation was carried out essentially as in Example 1 and the product distilled at 108-110C
to yield 145 g, the IR analysis o~ which was consistent with the structure (C2Fs) 2CFCF2-O-CF2CF2H.
Example 19. Preparation of c-C6F11CF2-O-C2F4H from c-C6F11CF2-O-C2F4C (O) OCH3 The starting material, c-C6H11CH2-O-C2H4C(O)OCH3, prepared by the reaction of cyclohexylmethanol with acrylonitrile followed by acid-catalyzed esterification with methanol, was then fluorinated and methanolysed with BF3 in methanol by essentially the procedures of Example 1 to give a 65% yield (based on the fluorination) of c-C6F11CF2-0-C2F4C(O)OCH3.

2~ 90~.16 WO 9~/32174 r ~ l,u~ -l ln 224 g of the latter fluorinated e6ter was added to a solution of 28.2 g of 85% KOH and 466 g ethylene glycol held at 60C. The resulting mixture wa5 then heated to 100C and its pH adjusted to a pH greater than 7 by the addition of 5 g of 45 wt% aqueous KOH.
Decarboxylation was carried out by distillation of the re6ulting mixture. The lower fluorochemical phase of the refiulting distillate was separated therefrom, washed with an equal volume of water, and distilled at 123-126C to give 155 g of a product (99.7% purity).
The product was treated with K~lnO4 in acetone to give c-c6FllcF2-o - c2F4H ' Example 20. Preparation of C4Fg-O-C2F4-O-C3F6H from C4Fg~O~C2F4~O-c3F6c (O) OCH3 C4Hg-O-C2H4-O-C4H8OC(O)CH3 was fluorinated and methanolysed by essentially the procedure of Example 1.
The resulting product, C4Fg-O-C2F4-O-C3F6C(O)OCH3, in the amount of 419 g was rapidly added dropwise to a mixture of 49 . 4 g KOH in 800 g ethylene glycol . The resulting mixture was then heated slowly to a f inal flask temperature of 190C. During such heating, methanol from the saponification of the ester, water, and C4Fg-O-C2F4-O-C3F6H distilled from the reaction mixture. Water was added to the distillate and the lower, fluorochemical phase (355 g) was separated and distilled (b. 120-122C) to provide 308 g C4Fg-O-C2F4-OC3F6H (82% yield).
Example 21. Preparation of C6F13-O-C4F8-H from The starting material, C6H13-O-C5H1o~OC(O)CH3, was prepared by monoalkylation of 1, 5-pentanediol with 35 hexyl bromide, followed by acetylation with acetyl chloride. This compound was f luorinated and methanolysed by essentially the procedure of Example I, WO 95132174 2 1 ~ 6 P~ ll0 to give C6Fl3-O-C4F8-C02CH3, b.p 100C @ 13 torr. This eGter was decarboxylated by heating a solution of 200 grams of ester in 250 mL of ethylene glycol with 30 g of KOH until the hydride produc;~ distilled. This 5 lisluid was washed with water~ dried over ~gs04 to give 128 g of C6F13-O-C4F8-H of 82% purity. This was further purified by distillation using a 12 plate packed glass column, b.p. 146C. The ~Llu-:~uLe was confirmed by 19F
NMR.
Example 22. Preparation of C6F13-O-C3F6-H from The starting material, C6Hl3-O-C4H8-OC(O)CH3, was prepared by monoalkylation of 1,4-butanediol with hexyl 15 bromide, followed by acetylation with acetic anhydride. This compound was f luorinated and methanolysed by essentially the procedure of Example 1, to give C6F13-O-C3F6-C02CH3. The methyl ester was saponified using excess KOH, and then dried in a vacuum 20 oven to yield the potassium salt. 575 g of the salt was heated with stirring in 250 mL of ethylene glycol and the product hydride recovered from the distillate, b.p. 129C. The structure was confirmed by 19F NMR.
Example 23. Preparation of C5Fll-O-C4F8-H from CsFll~~C4Fs~C2 Na The starting material, CsHll-O-C5Hlo~O~C(O)CH3 was prepared by monoalkylation of 1, 5-pentanediol with pentyl bromide, followed by acetylation with acetyl 3 0 chloride . This compound was f luorinated and methanolysed by essentially the ~LUC~dULe of Example 1, to give CsFll-O-C4F8-CO2CH3. The methyl ester was saponified using excess NaOH, and decarboxylated and distilled essentially as in Example 22. Distillation through a twelve-plate packed glass column gave pure C5Fll-O-C4F8-H, b.p. 125C. The structure was conf irmed by 19F NMR.

~lgOt lB
W0 95132174 r~l~u. ~ n Example 24. Preparation of C4Fg-O-C3F6-H from C4Fg -0-C3F6-C02~Na+
The starting material, C4H9-o-C4H8-OC(O)cH3, was pL~paled by monoalkylation of 1,4-butanediol with butyl 5 bromide, followed by acetylation with acetyl chloride.
This ~ ' was f luorinated and methanoly6ed by essentially the procedure of Example 1, to give C4Fg-O-C3F6-C02CH3. This methyl ester was saponified, decarboxylated and the crude hydride I eCO\/I:L ~d as in 10 Example 23, and then further distilled to yield pure C4Fg-O-C3F6-H, b.p. 90C. The structure was confirmed by 19F NMR.
Example 25. Evaluation of surfactant activity of 15 perfluoroether carboxylic acids.
The surf actant activity of novel perf luoroether carboxylic acids of this invention was measured with a DeNuoy tensiometer after conversion of the acids to the cuLL~,,uol~ding ammonium salts. The acids were 20 prepared by direct fluorination of their hydrocarbon precursors, followed by hydrolysis. The ammonium salts were prepared by treatment of the acid with excess aqueous ammonia followed by freeze drying. The results are reported in dynes/cm in the following Table C which 25 lists the parent acid (from Table B) of the ammonium salt .
TABLE C
Parent Acid Melting Surface Tension (dynes/cm) from Table B Point(s) of Acid (C) Cunu~ LLcltion of Ammonium Salt 50 100 500 lOoO
ppm ppm ppm ppm 7l9 37 26 l9 17 219~1~6 WO 95132174 I ~ 0 Parent Acid ~qelting Surface Tension (dynes/cm) from Table B Point(s~ of Acid ( C) Concentration of A~amonium Salt ppm ppm ppm ppm 6 3~ 23 18 17 8 7 ~3`3 31 26 24 1149, 59 18 15 15 1516,-27 30 17 17

16 24 19 18 17 Example 26. Evaluation of ethers as fire extinguishing agents .
Omega-hydrofluoroalkyl ether compounds of this invention were evaluated as f ire extinguishing agents 25 using the National Fire Protection Association 2001 Fire Protection Standard, with a cup burner modified to handle liquid lc. The results, shown below in Table D, indicate that the compounds could be ef f ective agents for fire extinguishing, explosion suppression, 30 and as flammable atmosphere inerting agents.

~ WO 9S/32174 ~ ~ 9 0 ~l 1 6 P~ r ~
TA~LE D
Agent Extingl~; ! ' L
concentration, vol. ~6 C4FgOC2F4H 5 . 6 Example 27. Preparation of foamed polyurethane.
omega-hydrof luoralkyl ether compounds of this invention were evaluated as blowing agents for foams using the procedures taught in U. S . Patent No.
5,210,106 (Dams et al.). Component A contained 15.0 parts by weight of PAPITU27, a methylene diphenyldiisocyanate having an isocyanate equivalent of 134 . 0, available from Dow Chemical . Component B of the foam contained 10.5 parts by weight ~pbw) of Voranoln' 360, a polyether polyol with a hydroxyl number of 360 available from Dow ('hP~ l; 0.26 pbw of water; 0.26 pbw of an oligomeric fluorochemical surfactant as described in Example 1 of U.S. Patent No. 3,787,351;
0.13 pbw of Polycatn' 8, a N,N-dimethylcyclohexylamine catalyst available from Air Products; and 1.87 pbw of C4FgOCF2CF2H as the blowing agent.
The ingredients of Component B were mixed to obtain an emulsion which was then admixed with Component A and stirred at 2500 rpm for 10 seconds.
The cream time of the foam was approximately 10 seconds. Rise time and tack-free time was approximately 2 and 3 minutes respectively. The WO9~/3ZI74 r~ Si; 'lO
resulting polyurethane foam was rigid and had a uniform distribution of very fine, closed cells.
Example 28 . Preparation of (CF3) 3COC2F40CF20CF2C02CH3 .
The ~ UL~Or, (t-C4HgOC2H40) 2CH2, prepared by alkylation of methylene chloride~-with t-butoxy ethanol, was fluorinated and methanolysed essentially as in Example 1 to yield (CF3)3COC2F40CF20CF2C02CH3, having a boiling range 80-82C at 18 torr, and whose structure was conf irmed by 19F NMR.
Example 29. Preparation of C8F170CF20C3F6H from C8F170CF20C3F6C02cH3 -The precursor, C8H170CH20C4H80H was prepared by monoalkylation of butane diol with octyl chloromethyl ether. The precursor was f irst acetylated with acetyl chloride in methylene chloride containing triethylamine and then f luorinated, and a portion of the crude perf luorinated product was hydrolyzed by treatment with aqueous sulfuric acid and then distilled to yield the carboxylic acid C8F170CF20C3F6C02H, having a boiling range 100-106C at 1.1 torr. Differential scanning calorimetry revealed the acid had a Tg of -97.0C and several crystalline exotherms of -77.4, -61.5 and -37.7C and a broad melting point at -9.0C.
Another portion of the crude perfluorinated products was methanolysed essentially as in Example 1 to yield C8F170CF20C3F6C02CH3, having a boiling range 124-130C at 25 torr. The latter methyl ester was then decarboxylated using the procedure of Example 1 to yield C8F170CF20C3F6H, having a boiling range of 178-183C; the structures of this hydride and the precursor fluorinated ester were confirmed by 19F NMR.
Example 30 . Preparation of C8F170- (C2F40) 2CF2C02H.
The precursor was prepared by monoalkylation of triethylene glycol with octyl bromide, followed by 2~116 WO 95/32174 Y~ o acetylation . The precursor was f luorinated as in Example 1, hydrolyzed by treatment with aqueous sulfuric acid, and distilled, the product, C8F17O-(C2F4O) 2CF2CO2H, having a boiling range of 105-110C at 5 1. 4 torr, and a melting point of 24 ~C.
Example 31. Preparation of HC3F6OC3F6H from CH30 (CO) C3F6OC3F6COOCH3 The starting diacetate, CH3C ( O ) OC4H8O- ( C4H8O ) nC4H8OC ( O ) CH3, was prepared by acetylation of polytetramethylene glycol (average molecular weight of 250) with acetyl chloride. The diacetate was then converted to CH3OC(O)C3F6O-(C4F8O)nC3F6COOCH3 by essentially the same fluorination and methanolysis procedures described in Example 1. 1400 g of the resulting mixture of diesters was distilled on a ten-plate glass-packed column to isolate CH30C (O) C3F6OC3F6COOCH3 .
278 g of the isolated fluorochemical was combined with 72 g of KOH in 250 mL of ethylene glycol. The resulting mixture was heated, distilled, and the product, HC3F6OC3F6H, was recovered essentially as in Example 1 (b.p. 84 C). The structure of the product was conf irmed by 19F NMR.
Example 32. Preparation of n-Cl2F2sOC2F4OC2F4OCF2CO2H.
The precursor, n-C12H2sO(C2H4O)3H, was prepared by monoalkylation of triethylene glycol with n-dodecyl bromide. After acetylation, the resulting product was fluorinated essentially as in Example 1, and the f luorinated product was concentrated and treated with 55 . 0 g NaOH in 300 mL water. After heating for 5 hours on a steam bath, the product was acidified with an excess of a 50 weight percent solution of HzSO4 in water and then extracted with FluorinertT~ FC-75 21~
WO 9~/32174 P~ O
perfluorinated liquid (a mixture of C8 perfluorochemicals, b.p. 103C) which had been heated to about 60C on a steam bath. Distillation yielded pure n-C12F2sOC2F40C2F40CF2c02H (Tss= -62 7 C and Tm =
69.2C by DSC) .
Example 33. Preparation of CF,4 CH3t~
CF,O~} from ~CH2Co~

The starting material, methyl 2-(3,4-dimethoxyphenyl) acetate was fluorinated essentially as in Example 1 to yield perfluoro-2-(3,4-15 d;-- h~ycyclohexyl) acetic acid after hydrolysis. This was then decarboxylated essentially as described in Example 1 to the perf luorinated ether hydride .
Example 34. Preparation of C,F~S)~CF2CF,H~ rom ~~CO~CH, The starting material, methyl 3-(4-ethoxyphenyl)-trans-2-propenoate was prepared by condensation of 4-25 ethoxyb~n~s~ld~hyde with malonic acid, followed byesterification. This methyl ester was fluorinated, methanolized, and decarboxylated essentially as in Example 1 to produce the perf luorinated ether hydride .

~90~1~
W0 95/32174 P~ 110 Example 35. Preparation of f rom CzH~ 0 CH2C02CH3 c~r~cxcFi~ C2H~ CH2CO2CH3 The 6tarting material was prepared by co~ ncation of 2, 2-diethyl propane diol with dimethyl 3-oxoglutarate. This dimethyl ester was fluorinated, methanolyzed to the diester, and decarboxylated e6sentially a6 in Example 1 to produce the 10 perfluorinated ether dihydride.
Example 36. Preparation of F, ~
(~OCF,H from (~2~2H~oAc CF, The starting material was prepared by reaction of 2, 6-dimethylphenol with ethylene carbonate and 6ubsequent acetylation with acetyl chloride. This acetate was f luorinated, methanolyzed, and 20 decarboxylated essentially as in Example 1 to produce the perfluorinated ether hydride (b.p. 132C).
Example 37. Preparation of CF, _~
F2cF2H ~OCH2C~CI
2 5 CF, 2~ 6 WO 95/32174 r~ 5 -110 The starting material was prepared by the treatment of 2-(2,6-dimethylphenyloxy)ethanol (from Example 36) with thionyl chloride. This was fluorinated essentially as in Exam~ple 1, followed by Raney Ni reduction of the chl~ride ~Ccl~nt; i l l 1 y as described in Example 12 to produce the perf luorinated ether hydride.
Example 38. Preparation of ~c f rom I~H2CH20AC
The starting material was prepared from the addition of ~-napthol to ethylene carbonate, followed by acetylation with acetyl chloride. This acetate was fluorinated, methanolyzed, and decarboxylated essentially as in Example 1 to produce the perfluorinated ether hydride (b.p. 171C).
Example 39. Preparation of C5FllOCF2C(CF3)2CF2H from CsHllocH2c (CH3) 2CH2Cl The starting material was prepared essentially a_ described above in Example 11. The ether chloride was fluorinated essentially as in Example 1, followed by Raney Ni reduction of the chloride essentially as described in Example lI to produce the perfluorinated ether hydride (b.p. 148C).
Example 40. Preparation of (C4FgO) 2CFCF2H from (C4HgO) 2CHCH2Cl The starting material was prepared by the addition of n-butanol to 2-chloroacetaldehyde and was fluorinated essentially as in Example 1, followed by 35 Raney Ni reduction of the chloride essentially as ~3 ~
Wo 95/32174 r~ t~llO
described in Example 11 to produce the perfluorinated ether hydride.
Example 41. Preparation of CF3O(CF2)9H from CH3 O ( CH2 ) 1oOAc The starting material was prep~red by monoalkylation of l,10-clerAn~liol with dimethyl 6ulfate, followed by acetylation with acetyl chloride.
10 This acetate was fluorinated, hydrolyzed, and decarboxylated essentially as in Example 1 to produce the perf luorinated ether hydride.
Example 42. Preparation of CgFlgOCF2H from CgH1gOC2H4OAc The starting material was prepared by monoalkylation of ethylene glycol with n-nonyl bromide, f ollowed by acetylation with acetyl chloride . This acetate was fluorinated, hydrolyzed, and decarboxylated 20 essentially as in Example 1 to produce the perfluorinated ether hydride (b.p. 155C).
Example 43. Preparation of (iso-C3F7)2CFOC2F4H from ( iso-c3H7 ) 2CHoC2H4C02CH3 The starting material was prepared by Michael addition of 2, 4-dimethyl-3-pentanol to acrylonitrile, followed by methanolysis to the methyl ester. This ester was fluorinated, hydrolyzed, and decarboxylated 30 essentially as in Example 1 to produce the perfluorinated ether hydride.
Example 44. Preparation of C,F,~ f rom ~O~H2CO, ~19~1~6 W0 95/32174 ~ n The ~tarting material was prepared by the alkylation of 4-ethylphenol with methyl chloroacetate.
This ester was f luorinated, hydrolyzed, and decarboxylated essentially as in Example 1 to produce 5 the perfluorinated ether hydride ~p. 131C).
.

Example 45. Comparative At - r~^ric Lifetimes and Boiling Points The ~, , h~ric lifetime of variou6 sample c~ ,_ 'q was calculated by the techni~ue described in Y. Tang, AtmosPheric Fate of Various Fluorocarbons, M. S. Thesis, MAqqr~r hllqetts Institute of Technology (1993~. As shown in the table below, the atmospheric 20 lifetime of an ether hydride compound having two or more carbon atoms between the ether oxygen atom and the terminal IIY~LVYt:~I atom is considerably shorter than the ai -~ ric lifetimes of ether hydride c, '- having only one carbon atom between the ether oxygen atom and 25 the terminal hydrogen atom. Because of the shorter ai ~, '-ric lifetimes of the ~: ~q of the present invention, these compounds are more environmentally acceptable .
Compound Atmospheric Lifetime (yrs) C6F130C2F40CF2H >1~0 C4F90C2F40cF2H >170 C9Fl70CF2cF2H 80 In addition, as shown in the table below, ether hydride compounds having two or more carbon atoms W095/32174 2 1 9 ~ 1 1 6 P IIL 'A'110 between the ether oxygen atom and the tP~m;nAl 1IYI1LO~
atom have lower boiling points than analogous non-ether ~ c, and significantly lower boiling points than analogous ether hydride ~u~Luu~,~c having only one 5 carbon atom between the ether oxygen atom and the terminal llydr uy~ atom. The unexpectedly low boiling points of _ '~ of the present invention render the __I.d6 useful in processes involving temperature-sensitive substrates such as plastics. (For example, lO in vapor-phase cleaning, a substrate is rinsed in the condensing vapor of a boiling fluid, and in con~Pn~ation heating, a substrate is heated by immersion in a boiling fluid. ) In such applications, a lower-boiling fluid is preferred so as to avoid damage 15 to the substrate. While it is known that boiling points can be reduced by selection of a compound having fewer carbon atoms, this may result in a boiling point reduction of 25C or more, in addition to adversely affecting other properties such as solvency.

WO95/32174 P~l/l 'C '10 C~ _ ' Boiling Point ~~
(C) C7Fl50C2F4H 131 / \ 126 ~C3F6H

C~}C2F4CF2H

C2F5{~}0CF2H

~}CF20C2F4H
CgFlgCF2H 154 CgF1gOCF2H 155 C8Fl70C2F4H 148 C5FllOcsFloH 150 .... .

Various modif ications and alterations of this invention will ~ecome apparent to those skilled in the art without departing from the scope and spirit of this invention .

Claims (10)

WHAT IS CLAIMED IS:

1. A normally liquid, omega-hydrofluoroalkyl ether compound represented by the general formula:
F-Rf-O-(-Rf'-O-)-nRf"-H
wherein:
H is a primary hydrogen atom;
n is an integer of 0 to 7; and Rf, Rf' and Rf" are independently selected from the group consisting of linear or branched, unsubstituted perfluoroalkylene groups; linear or branched, perfluoroalkyl- or perfluorocycloalkyl-substituted perfluoroalkylene groups; and linear or branched perfluoroalkylene groups substituted with an ether oxygen-containing moiety;
and Rf has at least 4 chain carbon atoms, Rf' has 1 or more chain carbon atoms and Rf" has 2 or more chain carbon atoms.

2. A normally liquid, omega-hydrofluoroalkyl ether compound represented by the general formula:
F-RfO-(-Rf'-O-)-nRf'"-H
wherein:
H is a primary hydrogen atom;
n is an integer of 0 to 7; and Rf, Rf' and Rf"' are independently selected from the group consisting of linear or branched, unsubstituted perfluoroalkylene groups; linear or branched, perfluoroalkyl- or perfluorocycloalkyl-substituted perfluoroalkylene groups; and linear or branched perfluoroalkylene groups substituted with an ether oxygen-containing moiety;
and Rf has at least 4 chain carbon atoms, and each of Rf' and Rf"' independently has 1 or more chain carbon atoms;
and with the proviso that when n is zero, then Rf is a perfluorocycloalkyl-substituted perfluoroalkylene group.

3. A process for preparing an omega-hydrofluoroalkyl ether compound of claim 1, which comprises decarboxylating the corresponding precursor fluoroalkylether carboxylic acid, hydrolyzable derivative of said carboxylic acid, or hydrolyzable precursor to said carboxylic acid or said derivative, said decarboxylating being carried out by contacting said precursor carboxylic acid or ester with a solution of inorganic base in protic solvent and heating the resulting reaction mixture.

4. A method of displacing water from a surface which comprises contacting the surface with a liquid composition comprising a normally liquid omega-hydrofluoroalkyl ether compound having a saturated perfluoroaliphatic chain of carbon atoms interrupted by one or more ether oxygen atoms, the chain carbon atom at one end, the proximal end, of the chain being that of a difluoromethyl group which is bonded to another chain carbon atom or to said ether-oxygen atom, the carbon atom at the other end, the distal end, of the chain being part of a distal group selected from the group consisting of difluoromethyl, difluorochloromethyl, a straight-chain perfluoroalkyl, a branched-chain perfluoroalkyl, and a perfluoroalkyl substituted with a saturated perfluoroalicyclic moiety, with the proviso that where said difluoromethyl group at the proximal end is bonded to a said ether-oxygen atom, then said straight-chain perfluoroalkyl has at least 6 chain carbon atoms and said branched-chain perfluoroalkyl has at least 4 carbon atoms.

-54a-

5. In a method of vapor phase soldering wherein a component to be soldered is immersed in or enveloped by a body of fluorinated liquid vapor to melt the solder, and the component is then withdrawn from the body of vapor, the improvement comprising using as the fluorinated liquid a composition comprising at least one omega-hydrofluoroalkyl ether compound as defined in claim 4.

6. A process for preparing a foamed plastic comprising the steps of:
admixing organic polyisocyanate and high molecular weight compound with at least 2 reactive hydrogen atoms in the presence of:
1) blowing agent mixture comprising at least one omega-hydrofluoroalkyl ether compound as defined in claim 4.
2) a catalyst; and 3) a surfactant.

7. A method of removing a contaminant from an article comprising contacting said article with a composition at least one omega-hydrofluoroalkylether compound as defined in claim 4.

8. A method for the extinction of fires comprising applying to a fire a composition comprising at least one omega-hydrofluoroalkyl ether compound as defined in claim 4.

9. A method for converting -CF2Cl groups to -CF2H groups comprising the step of contacting at least one compound containing at least one -CF2Cl group with hydrogen gas, said contacting being carried out at a temperature below about 200°C in the presence of both a solution of base and a catalytic amount of at least one metal or supported metal, said metal being selected from the group consisting of nickel, palladium and platinum as defined in claim 4.

10. A compound represented by the formula:
Rft-(O-Rft')c-O-(CF2)d-Z
wherein:
Rft, is a linear or branched perfluoroalkyl group having from 1 to 18 carbon atoms;
Rtf' is a linear or branched perfluoroalkylene group having from 1 to 11 carbon atoms;

c is an integer of at least 1;
d is an integer of at least 3; and Z is selected from the group consisting of -COOH, -COOM1/v, -COONH4, -COOR, -CH2OH, -COF, -COCl, -COR, -CONRR, -CH2NH2, -CH2NCO, -CN, -CH2OSO2R, -CH2OCOR, -CH2OCOCR=CH2, -CONH(CH2)mSi(OR)3, and -CH2O(CH2)mSi(OR)3, where M is an ammonium radical or a metal atom having a valence "v" of 1 to 4, each R is independently selected from the group consisting of alkyl groups having from 1 to 14 carbon atoms, fluoroalkyl groups having from 1 to 14 carbon atoms, aryl groups having from 6 to 10 ring-carbon atoms and heteroatom-containing alkyl groups having from 1 to 14 carbon atoms, fluoroalkyl groups having from 1 to 14 carbon atoms, and aryl groups having from 6 to 10 ring-carbon atoms and m is an integer of 1 to 11.