WO1989001929A2 - Fluorination of orthocarbonates and polyalkoxypropanes - Google Patents

Abstract

Perfluoroalkylorthocarbonates and perfluoropolyalkoxypropanes are disclosed. The perfluoro compounds are synthesized by direct fluorination procedures. The perfluoro compounds are useful lubricants, heat exchangers, vapor phase soldering fluids, solvents, and oxygen carriers.

Description

FLUORINATION OF ORTHOCARBONATES AND POLYALKOXYPROPANES

Background

The difficulty with the synthesis of perfluoro esters lies in instability of the ester linkage toward hydrogen fluoride and the facile dissociation of perfluoro esters by nucleophilic attack. The electrolytic fluorination of esters is precluded because they are spontaneously decomposed in the acidic solution. The direct fluorination of ethyl acetate (See Adcock, J.L. et al., J. Org. Chem. 40, 3271 (1975)) represents the first successful fluorination of an ester, giving CF₃COOCF₂CF₃ and CF₃COOCHFCF₃ in 5% and 20% yield respectively. Extension of this direct fluorination technigue has, previously led to the conversion of hydrocarbon polyesters to highly fluorinated polyesters, which are important precursors to perfluoropolyethers. Persico, D.F. et al., J. Am. Chem. Soc. 107, 1197 (1985).

There were few reports of the preparation of perfluoroesters by indirect methods. The first reported reactions were the dimerization and trimerization of COF₂ to yield FCO₂CF₃ and (CF₃O)₂CO respectively. Photolysis reaction of CF₃OF and

CF₃OOCF₃ in the presence of CO resulted in the same products as above reactions. Aymonino, P.J., Chem. Commun. 241 (1965); Varetti, E.L. and Aymonino, P.J., Chem. Commun. 91 (1971). A more general synthesis is the low temperature reaction of perfluoroacyl fluorides with perfluoro alkoxide salts. With the execption of the reaction of fluoroesters R_fCOOCH₃ with dimethyl sulfone to yield ortho esters R_fC(OCH₃)₃ (Holm, T., U.S. Patent No. 2,611,787 (1952)) and the isolation of CHFClC(OC₂H₅)₃ by Tarrant and Brown (Tarrant, P. and Brown, H.A., J. Am. Chem. Soc. 73, 1781 (1951)) little synthetic information on fluorinated ortho esters has appeared in the literature.

Summary of the Invention This invention pertains to perfluoroalkyl orthocarbonates and perfluoropolyalkoxypropanes and to methods of producing these perfluorinated compounds.

The perfluoroalkyoorthocarbonates are represented by the formula:

wherein R_f1, R_f2, R_f3 and R_f4 are the same or different short, straight or branched chain perfluoroalkyl radicals. In preferred embodiments, R_f1, R_f2, R_f3 and R_f4 are the same or different and are selected from -CF₃, -CF₂CF₃, -CF₂CF₂CF₃, -CF(CF₃)₂, -CF₂CF₂CF₂CF₃, -CF(CF₃) CF₂CF₃, -CF₂CF(CF₃)₂, and -C(CF₃)₃.

The perfluoroalkoxypropanes are represented by the formula:

f2 f4 wherein R_f1, R_f2, R_f3 and R_f4 are short, straight or branched chain perfluoroalkyl radicals. In preferred embodiments, R_fχ, R_f2, R_f3 and R_f4 are the same or different and are selected from -CF₃, -CF₂CF₃, -CF₂CF₂CF₃, -CF(CF₃)₂, -CF₂CF₂CF₂CF₃,

-CF(CF₃)CF₂CF₃, -CF₂CF(CF₃)₂, and -C(CF₃)₃.

The perfluoroalkylorthocarbonates and perfluoroalkoxypropanes of this invention are produced by direct fluorination with elemental fluorine. The perfluoro compounds are more volatile than perfluoropolyethers of the same molecular weight. They are unaffected by concentrated sulfuriσ acid and nitric acid, but decompose in hydrogen fluoride solution and concentrated hydrochloric acid. They are stable at 150°C and above. The perfluoro compounds of this invention are useful as lubricants, heat exchangers, solvents, vapor phase soldering fluids and oxygen carriers.

Brief Description of the Figures Figure 1 shows the reactions of elemental fluorine in the production of perfluoroalkylorthocarbonates and perfluoroalkyoxypropanes.

Detailed Description of the Invention

The perfluoroalkylorthocarbonate of this invention are represented by the formula:

wherein R_f1, R_f2, R_f3 and R_f4 are the same or different and are selected from short, straight or branched chain perfluoroalkyl radicals. In preferred embodiments, R_f1, R_f2, R_f3 and R_f4 are selected from -CF₃, -CF₂CF₃, -CF₂CF₂CF₃, -CF(CF₃)₂, -CF₂CF₂CF₂CF₃, -CF(CF₃)CF₂CF₃, -CF₂CF(CF₃)₂, and -C(CF₃)₃. Especially preferred perfluoroalkylorthocarbonates are represented by the formula:

C(OR_f)₄

wherein R_f is selected from -CF₃ , -CF₂CF₃ , CF₂CF₂CF₃ and CF(CF₃) ₂.

The perfluoroalkyoxypropanes of this invention are represented by the formula:

wherein R_f1, R_f2, R_f3 and R_f4 are shortr straight or branched chain perfluoroalkyl radicals. In preferred embodiments, R_f1, R_f2, R_f3 and R_f4 are selected from -CF₃, -CF₂CF₃, -CF₂CF₂CF₃, -CF(CF₃)₂, and -CF₂CF₂CF₂CF₃, -CF(CF₃)CF₂CF₃, -CF₂CF(CF₃) , -C(CF₃)₃. Especially preferred perfluoroalkyoxypropanes are represented by the formula:

(R_fO)₂CFCF₂CF(OR_f)₂

wherein R_f is selected from -CF₃, -CF CF₃, CF₂CF₂CF₃ and -CF(CF₃)₂.In addition, the fluorination procedures for production of perfluoroalkoxy propanes can yield novel compounds of the formula:

(R_fO)₂CFCF₂CF₂OR_f

wherein R_f is as defined above. The perfluoro compounds of this invention are produced by the direct fluorination technique of Lagow and Margrave, Prog, of Org. Chem. 26, 161: (1979). Appropriate orthocarbonate or polyalkoxy- propane starting materials are selected. For example, orthocarbonates can be selected from compounds of the formula:

3 wherein R₁, R₂, R₃ and R₄ can be the same or different and are selected from -CH₃, -CH₂CH₃, -CH₂CH₂CH₁, -CH(CH₃)₂, -CH₂CH₂CH₂CH₃, -CH(CH₃)CH₂CH₃, -CH₂CH(CH₃)₂, and -C(CH₃)₃.

Polyalkoxypropanes can be selected from compounds of the formula:

2 4 wherein R₁, R₂, R₃ can be the same different and are selected from -CH₃, -CH₂CH₃, -CH₂CH₂CH₃, -CH(CH₃)₂, -CH₂CH₂CH₂CH₃, -CH(CH₃) CH₂CH₃, -CH₂CH(CH₃)₂, and -C(CH₃)₃. The starting material is placed in a fluorine reactor such as the reactor described by Lagow and Margrave , supra. The reactor is cooled and flushed with an inert gas such as helium or nitrogen after which the fluorine is initiated under controlled conditions. Typically, low fluorine concentrations between about one and about ten percent are used initially. The dilute fluorine is passed over the material to be fluorinated. As the fluorination reaction proceeds the fluorine concentration and flow rate of the gas are gradually increased until pure fluorine conditions are achieved and the material is perfluorinated.

The best results are obtained when the fluorination is performed in the presence of a hydrogen fluoride scavenger such as sodium fluoride as described in United States Patent Application Serial Number 924,198, entitled "Perfluorination of Ethers in the Presence of Hydrogen Fluoride Scavengers", filed October 27, 1986, the teachings of which are incorporated herein. The presence of a hydrogen fluoride scavenger allows the use of more severe fluorination conditions in this direct fluorination procedure, that is, higher fluorine concentrations and faster rates of fluorine delivery can be used in the presence of a hydrogen fluoride scavenger than can be used in the absence of a scavenger. For example, initial fluorine levels of over 15% and up to 25% and fluorine flow rates of over 8cc/min/gram of starting material can be used.

In addition, the yield and quality of the perfluoropolyether product is improved when fluorination is conducted in the presence of a hydrogen fluoride scavenger. The scavenger is believed to prevent the formation of ether-HF acid base complexes during the fluorination reaction.

Fluorination in the presence of a hydrogen fluoride scavenger can be performed in several ways. In the preferred mode, the hydrogen fluoride scavenger (in powdered or pellet form) is mixed with the orthocarbonate or polyalkoxypropane. The blend is placed in a suitable fluorination reactor and fluorinated by exposure to gradually increasing concentrations of fluorine gas. Alternatively, the orthocarbonate or polyalkoxypropane may be coated onto the scavenger and fluorinated in this form.

The perfluoroalkyorthocarbonates and perfluoroalkoxypropanes of this invention are useful as lubricants, heat exchangers, vapor phase soldering fluids, solvents and oxygen carriers. For example, the oils are useful as vacuum pump oils and oils for diffusion pumps. The more volatile orthocarbonates and alkoxypropanes are used to cool electronic devices such as computers. The perfluoro compounds are also useful as perfluorocarbon solvents, as oxygen carriers in biomedical applications and as oxygen carriers for organic oxidation reactions. This invention is illustrated further by the following examples.

EXAMPLES Tetramethyl orthocarbonate, tetraethyl orthocarbonate, tetra-i-propyl orthocarbonate, 1,1,3,3- tetramethoxypropane, and 1,1,3,3-tetraethoxypropane were used as received from Aldrich Chemicals. Fluorine was research grade and obtained from air Products and Chemicals, Inc. Elemental analyses were performed by E+R Mecroanalytical Laboratory, Inc., Corona, New York. 19F nmr spectra were recorded on a Varian EM 390 spectrometer operating at 84.67 MHz. Chemical shifts were reported relative to CFCl₃. Negative shifts refer to high field of the reference. Mass spectra were measured in a gas phase on a Bell & Howell Model 21-490 mass spectrometer. A Bendix 2300-gas chromatograph equipped with a cryogenic controller and a thermalconductivity detector was used for separation. Infrared spectra were recorded on a Beckman Acculab 8 spectrometer utilizing a gas cell with KBr windows.

In a typical reaction, a mixture of measured amounts of starting material with approximately 10 grams of powdered NaF was packed in a 5 in. x 1 in. copper tube, which was then placed in the first zone of the four-zone cryogenic reactor described previously. Lagow, R.J. and Margrave, J.L., Prog. Org. Chem. 26, 161 (1979). The last three zones were packed with fluorinated copper turnings. After all zones were cooled to - 100 ºC for two hours the system was flushed with helium for ten hours. The fluorination was then initiated under controlled conditions. As reactions was cpmpleted, the products were fractionated into -78, -131, and -196 ºC on a vacuum line. Final purification was done by gas chromatography using a fluorosilicone column.

Fluo rination of 1 ,1 ,3,3-tetram eth oxypropane

A 1.49 g of 1,1,3,3-tetramethoxypropane was fluorinated using the conditions as shown in Table 1. The crude product weighing 2.53 g was obtained in the -78 °C trap. Gas chromatographic separation of this portion (0 °C for 10 min., 5 °C/min. to 10 °C for 15 min., 10 °C/min. to 90 °C for 10 min.) gave perfluoro 1,1,3,3-tetramethoxy propane (1.92 g, 46.8%), and perfluoro 1,1,3-trimethoxy propane (0.48 g, 13.7%).

Perfluoro 1,1,3,3-tetramethoxypropane, bp. 93 °C. Anal. Calcd. for C₇F₁₆O₄: C, 18.60; F, 69.24. Found: C, 18.50; F, 66.97. MS, m/e(fragment ion): 433 (C₇F₁₅O₄, P-F), 367 (C₆F₁₃O₃, P-OCF₃), 279 (C₅F₉O₃), 213 (C₄F₇O₂), 201 (C₃F₇O₂), 191 (C₄F₅O₃), 185 (C₃F₇O), 163 (C₃F₅O₂), 135 (C₂F₅O), 125 (C₃F₃O₂), 97 (C₂F₃O), 78 (C₂F₂O), 69 (CF₃, base peak), 50 (CF₂), 47 (CFO). IR: 1300 (vs, br), 1240 (vs, br), 1130 (vs, br), 1020 (w), 892 (m), 865 (m), 795 (m), 725 (m) cm^-1. The FNMR data were reported in Table 5. Perfluoro 1,1,3-trimethoxypropane, bp. 75 °C. Anal. Calcd. for

C₆F₁₄O₂: C, 18.67; F, 68.90. Found: C, 18.21; F,68.29. MS, m/e(fragment ion): 367 (C₆F₁₃O₂, P-F), 301 (C₅F₁₁O₂, P-OCF₃), 213 (C₄F₇O₂, base peak), 201 (C₃F₇O₂), 185 (C₃F₇O), 163 (C₃F₅O₂), 147 (C₃F₅O), 135 (C₂F₅O), 125 (C₃F₃O), 119 (C₂F₅), 113 (C₂F₃O₂), 100 (C₂F₄), 97 (C₂F₃O), 78 (C₂F₂O), 69 (CF₃), 50 (CF₂), 47 (CFO). IR: 1320 (vs), 1250 (vs, br), 1150 (vs, br), 1020 (m, sh), 1004 (m, sh), 918 (w), 822 (m), 800 (m), 720 (m) cm^{- 1}. The FNMR data were reported in Table 5. Fluorination of 1 , 1 ,3,3-tetra ethoxy propan e

A 1.82 g of 1,1,3,3-tetraethoxypropane was fluorinated using the same conditions as those for 1 , 1,3 ,3-tetramethoxypropane. After fractionation 2.72 grams of crude products were collected. From GC separation at 25 °C were isolated perfluoro 1 ,1,3,3-tetraethoxypropane (a), perfluoro-1 ,1,3-triethoxypropane (b), perfIuoro-1 ,3-diethoxypropane (c), and perfluoro-1 ,1-diethoxypropane (d). The yields were 13.0%, 23.4%, 20.0%, and 9.3% respectively, based on the starting 1, 1,3,3-tetraethoxy propane. GC retention time increased in the order: d < c < b < a.

Perfluoro-1,1,3,3-tetraethoxypropane, bp. 143 °C. Anal. Calcd. for C₁₁F₂₄O₄: C, 20.26; F, 69.92. Found: C, 20.04; F, 69.63. MS, m/e(fragment ion): 517 (C₉F₁₉O₃, P-OC₂F₅), 301 (C₅F_{1 1}O₂), 263 (C₅F₉O₂), 235 (C₄F₉O), 119. (C₂F₅, base peak), 100 (C₂F₄), 97 (C₂F₃O), 69 (CF₃), 50 (CF₂). IR: 1284 (s), 1230 (vs, br), 1150 (vs, br), 1090 (vs), 974 (m, sh), 835 (m), 746 (s, sh), 728 (s, sh), 704 (s, sh) cm^-1. The FNMR data were reported in Table 5.

Perfluoro-1 , 1 ,3-triethoxypropane, bp. 115 °C. Anal. Calcd. for C₉F₂₀O₃: C, 20.17; F, 70.88. Found: C, 19.86; F, 70.55. MS, m/e(fragment ion): 401 (C₇F₁₅O₂, P-OC₂F₅), 301 (C₅F_{1 1}O₂), 263 (C₅F₉O₂), 235 (C₄F₉O), 185 (C₃F₇O), 147 (C₃F₅O), 119 (C₂F₅, base peak), 100 (C₂F₄), 97 (C₂F₃O), 69 (CF₃), 50 (CF₂), 47 (CFO). IR: 1300 (s), 1220 (vs, sh), 1135 (vs, br), 1090 (vs), 980 (m, sh), 724 (s, sh), 705 (s, sh) cm^{- 1}. The FNMR data were reproted in Table 5.

Perfluoro-1,3-diethoxypropane, bp. 77 °C. Anal. Calcd. for C₇F₁₆O₂: C, 20.02; F, 72.37. Found: C, 19.65; F, 72.17. MS, m/e(fragment ion): 401 (C₇F₁₅O₂, P-F), 285 (C₅F₁₁O), 263 (C₅F₉O₂), 235 (C₄F₉O), 185 (C₃F₇O), 169 (C₃F₇), 147 (C₃F₅O), 119 (C₂F₅, base peak), 100 (C₂F₄), 97 (C₂F₃O), 69 (CF₃), 50 (CF₂), 47 (CFO). IR: 1330 (s, sh), 1230 (vs, sh), 1150 (vs, br), 1100 (vs, sh), 994 (s, sh), 730 (s, sh), 718 (s, sh) cm^{- 1}. The FNMR data were reported in Table 5.

Perfluoro-1,1-diethoxyethane, bp. 53 °C Anal. Calcd. for C₆F₁₄O ₂: C, 19.48; F, 71.88. Found: C, 19.20; F, 71.44. MS, m/e(fragment ion): 301 (C₅F₁₁O₂, P-CF₃), 235 (C₄F₉O), 185 (C₃F₇O), 169 (C₃F₇), 131 (C₃F₅), 119 (C₂F₅, base peak), 100 (C₂F₄), 97 (C₂F₃O), 69 (CF₃), 50 (CF₂), 47 (CFO). IR: 1230 (vs), 1195 (vs), 1158 (vs), 1100 (vs, br), 746 (s, sh), 720 (s, sh), 694 (s, sh) cm^-1. The FNMR data were reported in Table 5. Fluorinnton of tetramethyl orthocarbonate

Tetramethyl orthocarbonate was introduced into the reactor in different manner. Inside the cryogenic reactor the first two zones were packed with a mixture of NaF and copper turnings, and the last two zones were packed with fluorinated copper turnings. Tetramethyl orthocarbonate (2.04 g) was slowly injected into the evaporator and condensed in the first zone by the passage of 60 cc/min of helium flow, while zones 2, 3, 4 were cooled to -100 °C. The reactor was then cooled to

-120 °C and the fluorinaton was started using the conditions listed in Table

2. The majority of products stopped in the -78 °C trap on the vacuum-line separation. Final purification on a fluorosilicone column at 0 °C produced

2.63 g of perfluoro tetramethyl orthocarbonate, corresponding to a 49.5% yield.

Perfluoro tetramethyl orthocarbonate, bp. 20.8 °C. The FNMR spectrum gave a singlet peak at -59.0 ppm upfield from CFCI₃. MS, m/e(fragment ion): 267 (C(OCF₃)₃), 201 (CF(OCF₃)₂, base peak), 113

(OCOCF₃), 85 (OCF₃), 47 (OCF). IR: 1170 (vs, br), 1050 (vs, br), 1010 (vs, br), 750 (m), 710 (m) cm^-1.

Fluorination of tetraethyl orthocarbonate

Tetraethyl orthocarbonate (1.6 g) was handled in an usual way and fluorinated from -100 °C to room temperature (see Table 3). A 2.6 g of perfluoro tetraethyl orthocarbonate was isolated from 2.86 g of crude products. The yield was 56.5% based on the starting tetraethyl orthocarbonate.

Perfluoro tetraethyl orthocarbonate, bp. 80 °C. Anal. Calcd. for C₉F₂₀O₄: C, 19.58; F, 68.33. Found: C, 19.33; F, 69.05. MS, m/e(fragment ion): 301 (CF(OC₂F₅)₂), 163 (OCOC₂F₅), 119 (C₂F₅, base peak), 100 (C₂F₄), 97 (OC₂F₃), 69 (CF₃), 50 (CF₂). IR: 1240 (vs, br), 1100 (vs, br), 850 (m), 750 (s, sh), 725 (s), 675 (m) cm^-1. The FNMR spectrum consisted of two peaks at -88.3 ppm (-CF₃) and -91.0 ppm (-CF₂-). The relative ratio was 2 : 1. Fluorination of tetra-i-propyl orthocarbonate Tetra-i-propyl orthocarbonate (1.4 g) was fluorinated using the similar conditions as those for tetraethyl orthocarbonate, except the reaction was initiated at -120 °C (see Table 4). Large amounts of lowboiling products passed to -131 °C on a vacuum-line separation. The GC assay indicated the presence of a number of components, which were inseparable. The -78 °C fraction contained the desired products, from which a mixture of perfluoro tetra-n-propyl orthocarbonate and perfluoro tetra-i-propyl orthocarbonate was isolated in an amount of 0.55 grams. The total yield was 12.8%.

Perfluoro tetra-n-propyl orthocarbonate and Perfluoro tetra-i-propyl orthocarbonate were inseparable under the experminental GC conditions. Both compounds were thus characterized in a mixture state. The boiling point is around 130 ºC. Anal. Calcd. for C₁₃F₂₈O₄: C, 20.76; F, 70.73. Found: C, 20.97; F, 70.80. MS, m/e(fragment ion): 567 (C(OC₃F₇)₃), 401 (CF(OC₃F₇)₂, base peak), 213 (OCOC₃F₇), 169 (C₃F₇), 147 (OC₃F₅), 119 (C₂F₅), 100 (C₂F₄), 69 (CF₃), 47 (CFO). The nmr chemical shifts for C(OCF(CF₃)₂)₄ are -80.6 ppm (-CF₃) and -146.5 ppm (-OCF=). The assignments for C(OCF₂CF₂CF₃)₄ are -81.8 ppm (-CF₃), -85.3 ppm (-OCF₂-) and -130.3 ppm (-CF₂-). The relative intensities were consistent with the theoretical value.

Equivalents

Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims.

INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT)

(51) International Patent Classification ⁴ (11) International Publication Number: WO 89/ 019

C07C 43/32, 43/313, 41/60 A3 C07C 41/48 (43) International Publication Date: 9 March 1989 (09.03.

(21) International Application Number : PCT/US88/02966 (81) Designated States: AT (European patent), AU, BE ( ropean patent), BR, CH (European patent), DE (E

(22) International Filing Date : 26 August 1988 (26.08.88) ropean patent), FR (European patent), GB (Eu pean patent), IT (European patent), JP, KR, LU (E ropean patent), NL (European patent), SE (Europe

(31) Priority Application Number: 090,658 patent).

(32) Priority Date: 28 August 1987 (28.08.87)

Published

(33) Priority Country: US With international search report

Before the expiration of the time limit for amending t claims and to be repiώlisked in the event of the receipt

(71) Applicant: EXFLUOR RESEARCH CORPORATION amendments.

[US/US]; 8868 Research Boulevard, Suite 206, Austin, TX 78758 (US). (88) Date of publication of the international search report:

1 June 1989 (01.06.8

(72) Inventor: LAGOW, Richard, J. 100 Navajo Trail, Georgetown, TX 78628 (US).

(74) Agents: DeCONTI, Giulio, A., Jr. et al. ; Hamilton, Brook, Smith & Reynolds, Two Militia Drive, Lexington, MA 02173 (US).

(54) Title: FLUORINATION OF ORTHOCARBONATES AND POLYALKOXYPROPANES

ft

? _F

CH₃-0-C-0-CH₃ J

0 0 CH, ft

TETRAETHYL WTHOCARBONATE

(57) Abstract

Perfluoroalkylorthocarbonates and perfluoropolyalkoxypropanes are disclosed. The perfluoro compounds are syn thesized by direct fluorination procedures. The perfluoro compounds are useful lubricants, heat exchangers, vapor phas soldering fluids, solvents, and oxygen carriers.

FOR HIE PURPOSES OF MFORMAHON ONLY

Codes used to identify States party to the PCT on the front pages of pamphlets publishing international applications under the PCT.

Claims

1. Perfluorotetra alkylorthocarbontes of the formula:

wherein R_f1, R_f2, R_f3 and R_f4 represent the same of different, short, straight or branched chain perfluoroalkyl groups.

2. A perfluorotetraalkylorthocarbonate of Claim 1, wherein R_f1, R_f2, R_f3 and R_f4 are the same or different and are selected from the group consisting of -CF₃, -CF₂CF₃, -CF₂CF₂CF₃, -CF(CF₃)₂, -CF₂CF₂CF₂CF₃, -CF(CF₃)CF₂CF₃, -CF₂CF(CF₃)₂, and -C(CF₃)₃.

3. Perfluorotetraalkylorthocarbonates of the formula:

C(OR_f)₄

wherein R_f is selected from the group consisting of -CF₃, -CF₂CF₃, -CF₂CF₂CF₃, and -CF(CF₃)₂.

4. C(OCF₃)₄.

5. C(OCF₂CF₃)₄.

6. C(OCF₂CF₂CF₃)₄.

7. C(OCF(CF₃)₂)₄.

8. Perfluoroalkyoxypropanes of the formula:

wherein R_f1, R_f2, R_f3 and R_f4 are the same or different, short, straight or branched chain perfluoroalkyl groups .

9. A perfluoroalkyoxypropane of Claim 9, wherein R_f1, R_f2, R_f3 and R_f4 are the same or different and are selected from the group consisting of -CF₃, -CF₂CF₃, -CF₂CF₂CF₃, -CF(CF₃)₂, -CF₂CF₂CF₂CF₃, -CF(CF₃)CF₂CF₃, -CF₂CF(CF₃)₂, and -C(CF₃)₃.

10. A compound of the formula:

(R_fO)₂CFCF₂CF(OR_f)₂

wherein R_f is selected from the group consisting of -CF₃, -CF₂CF₃, and -CF₂CF₂CF₃.

11. A compound of the formula: (R_fO)₂CFCF₂CF₂OR_f

wherein R_f is selected from the group consisting of -CF₃, -CF₂CF₃ and CF₂CF₂CF₃.

12. Perfluoro-1,1,3,5,-tetraalkyoxypropane.

13. Perfluoro 1,1,3,3,-tetramethoxypropane.

14. A method of fluorinating an alkyl orthocarbonate, comprising the steps of: a. placing the alkyl orthocarbonate and a hydrogen fluoride scavenger into a fluorine reactor, the amount of hydrogen fluoride scavenger in relation to the amount of orthocarbonate being sufficient to react with the hydrogen fluoride formed during fluorination; and b. fluorinating the orthocarbonate by:

(i) establishing a flow of gas mixture of fluorine gas and an inert gas into the reactor under conditions which allow fluorination of the orthocarbonate, the fluorine concentration of the gas mixture being, for example, about 0.5% to about 25%;

(ii) maintaining or gradually increasing the concentration of fluorine gas in the gas mixture to fluorinate the orthocarbonate; and c. after the fluorination reaction is completed to desired degree, removing the fluorinated orthocarbonate and the hydrogen fluoride scavenger from the reactor.

15. A method of Claim 14, wherein the alkyl orthocarbonate has the formula:

wherein R₁, R₂, R₃ and R₄ are the same or different and are selected from the group consisting of -CH₃, -CH₂CH₃, - CH₂CH₂CH₃, -CH(CH₃)₃, -CH₂CH₂CH₂CH₃, -CH(CH₃)CH₂CH₃, -CH₂CH(CH₃)₂, and -C(CH₃)₃.

16. The method of Claim 14, wherein the orthocarbonate is perfluorinated.

17. The method of Claim 14, wherein the hydrogen fluoride scavenger is in the form of a powder or pellet.

18. The method of Claim 14, wherein the hydrogen fluoride scavenger is sodium fluoride or potassium fluoride.

19. A method of fluorinating a polyalkoxypropane, comprising the steps of: a. placing the polyalkoxypropane and a hydrogen fluoride scavenger into a fluorine reactor, the amount of hydrogen fluoride scavenger in relation to the amount of polyalkoxypropane being sufficient to react with the hydrogen fluoride formed during fluorination; and b. fluorinating the polyalkoxypropane by:

(i) establishing a flow of gas mixture of fluorine gas and an inert gas into the reactor under conditions which allow fluorination of the polyalkoxypropane, the fluorine concentration of the gas mixture being, for example, about 0.5% to about 25%; (ii) maintaining or gradually increasing the concentration of fluorine gas in the gas mixture to fluorinate the polyalkoxypropane; and c. after the fluorination reaction is completed to desired degree, removing the fluorinated polyalkoxypropane and the hydrogen fluoride scavenger from the reactor.

20. The method of Claim 19, wherein the polyalkoxypropane has the formula:

wherein R₁, R₂, R₃ and R₄ are the same or different and are selected from the group consisting of -CH₃, -CH₂CH₃, -CH₂CH₂CH₃, -CH(CH₃)₂, -CH₂CH₂CH₂CH₃, -CH(CH₃)CH₂CH₃, -CH₂CH(CH₃)₂, and -C(CH₃)₃.

21. The method of Claim 19, wherein the polyalkoxypropane is perfluorinated.

22. The method of Claim 19, wherein the hydrogen fluoride scavenger is in the form of a powder or pellet.

23. The method of Claim 19, wherein the hydrogen fluoride scavenger is sodium fluoride or potassium fluoride.