PREPARATION OF PERFLUOROVINYL ETHER SULFINIC ACIDS AND

THEIR SALTS

The present invention relates to methods of making monomeric perfluorovinyl ether sulfmic acids and salts thereof.

BACKGROUND

Perfluorovinyl ether sulfmic acids and salts thereof have utility as initiators in free radical polymerization reactions.

Methods for the synthesis of fluorochemical sulfmates have been reported in the literature. For example, perfluoroalkane sulfmates can be prepared from the corresponding perfluoroalkanehalides via a dehalogenation and sulfmation reaction using a sulfite plus an oxidant, hydroxymethane sulfmate, thiourea dioxide or sodium dithionite in water and such cosolvents as acetonitrile, glycol, diethylene glycol and alcohols.

Fluorocarbon sulfmates can also be prepared by reduction of the corresponding perfluoroalkane sulfonyl halides using sulfites, hydrazine, dithionites, and zinc in solvents such as dioxane, dimethoxyethane, di-n-butyl ether, tetrahydrofuran (THF), and diethylene glycol diethyl ether. These methods are reported in U.S. Patent No. 3,420,877; U.S. Patent No. 5,285,002 (Grootaert); U.S. Patent No.5,639,837 (Farnham et al); U.S. Patent No. 6,462,228 (Dams); Japanese Laid Open Patent Publication No. 2006131588 (Aoki); WO 03/10647 (Moll); C. M. Hu, F. L. Quing and W. Y. Huang, J Org Chem, 1991, 2801-2804; W. Y. Huang, Journal of Fluorine Chemistry, 58, 1992, 1-8; W. Y. Huang, B. N. Huang and W. Wang in Acta Chim. Sinica (Engl. Ed.), 1986, 178-184, and Acta Chim. Sinica (Engl. Ed.), 1986, 68-72; F. H. Wu and B. N. Huang, Journal of Fluorine Chemistry, 67, 1994, 233-234; C. M. Hu, F. L. Quing and W. Y. Huang, Journal of Fluorine Chemistry, 42, 1989, 145-148.

For some functionalized starting materials, these methods present several disadvantages, including slow reaction times, large amounts of by-products which typically must be removed from the sulfmate and required use of a cosolvent that may have a negative impact on processes in which the sulfmate is ultimately employed, e.g., free-radical polymerization reactions.

Polymeric f uorosulfinates have also been synthesized by utilizing methods such as reduction of fluorosulfonyl halide polymer side chains and dehalogenation and sulfmation of alkyl halide polymer side chains, as reported in U.S. Patent No. 4,544,458 (Grot et al.) and Japanese Patent No. 52-24176 (Seko et al.).

Although some functionalized polymeric sulfinates have been synthesized with conventional methods, conventional methods of synthesizing the corresponding monomeric functionalized perfluoroalkyl sulfinates have resulted in poor yields and numerous by-products that require additional separation and purification steps. See, for example, U.S. Patent No. 5,639,837 (Farnham et al.).

Accordingly, there continues to be a need for an improved process for preparing fluorinated sulfinates, particularly functionalized fluorinated sulfinates, that does not require further processing or purification of the resulting reaction mixture. It is further desirable to improve the yield of the fluorinated sulfmate.

SUMMARY

In one aspect, the description herein provides a process comprising:

a) providing a perfluorovinylether sulfonyl halide represented by the following formula (I):

CF ₂ =CF-0-R-CFX-S0 ₂ -Y

wherein Y is CI or F, X is F or a linear or branched perfluorinated alkyl group, and R is a linear or branched perfluorinated linking group, which may be saturated or unsaturated, substituted or unsubstituted; and

b) reducing the perfluorovinylether sulfonyl halide with a reducing agent in an organic protic solvent, wherein the reducing agent is represented by one of formula (II) and formula (III), wherein

formula (II) is:

MBH _n (R) ₄ _ _n

wherein n is 1, 2, 3, or 4, M is an alkali metal, and R is R", OR", OH, or OC(0)R", wherein R" is a CI to C6 linear or branched alkyl group; and

or

formula (III) is:

Al _x (B _y H _z ) w wherein x is 0 or 1, y is 1 or 2, z is 3, 4, 5, or 6, and w is 1,

2, or 3.

In some embodiments, the process further comprises the step of adding an acid to produce a perfluorovinylether sulfmic acid. In some embodiments, the process further comprises the step of adding a base to the perfluorovinylether sulfmic acid to produce a perfluorovinylether sulfmic acid salt.

In one aspect, R is selected from: -(CF ₂ ) _a -, -(CF ₂ ) _a -0-(CF ₂ )b-, and -(CF ₂ ) _a -[0- (CF ₂ )b] _c -, -[(CF ₂ ) _a -0-]b-[(CF ₂ ) _c -0-]d, and combinations thereof, wherein a, b, c, and d are independently at least 1. In another aspect, the perfluorovinylether sulfonyl halide used in the process of the present invention comprises CF ₂ =CF-0-C ₄ F ₈ -S0 ₂ F and the

perfluorovinylether sulfmate formed by the process of the present invention comprises CF ₂ =CF-0-C ₄ F ₈ -S0 ₂ M', wherein M' is hydrogen or an organic or inorganic cation. In another aspect the perfluorovinylether sulfonyl halide used in the process of the present invention comprises CF ₂ =CF-0-CF ₂ CF(CF ₃ )-0-CF ₂ CF ₂ -S0 ₂ F and the perfluorovinylether sulfmate formed by the process of the present invention comprises CF ₂ =CF-0-

CF ₂ CF(CF ₃ )-0-CF ₂ CF ₂ -S0 ₂ M', wherein M' is hydrogen or an organic or inorganic cation. In still another aspect, the perfluorovinylether sulfonyl halide used in the process of the present invention comprises CF ₂ =CF-0-CF ₂ CF ₂ -S0 ₂ F and the perfluorovinylether sulfmate formed by the process of the present invention comprises CF ₂ =CF-0-CF ₂ CF2- S0 ₂ M', wherein M' is hydrogen or an organic or inorganic cation.

In some embodiments of the present invention, the hydride reducing agent is selected from the group comprising NaBH ₄ and KBH ₄ .

In still another aspect, the step of reducing the perfluorovinylether sulfonyl halide with a reducing agent in an organic protic solvent is performed such that the reducing agent is added to a mixture of the perfluorovinylether sulfonyl halide and the organic protic solvent.

In some embodiments, the solvent is selected from the group comprising a Ci-C ₄ alcohol and a Ci-C ₄ alcohol comprising an ether. In some embodiments, the solvent further comprises at least one cosolvent.

The above summary is not intended to describe each embodiment. The details of one or more embodiments of the invention are also set forth in the description below. Other features, objects, and advantages will be apparent from the description and from the claims.

DETAILED DESCRIPTION

As used herein, the term:

"a", "an", and "the" are used interchangeably and mean one or more; and "and/or" is used to indicate one or both stated cases may occur, for example A and/or B includes, (A and B) and (A or B). Also herein, recitation of ranges by endpoints includes all numbers subsumed within that range (e.g., 1 to 10 includes 1.4, 1.9, 2.33, 5.75, 9.98, etc.). Also herein, recitation of "at least one" includes all numbers of one and greater (e.g., at least 2, at least 4, at least 6, at least 8, at least 10, at least 25, at least 50, at least 100, etc.).

"Sulfmate" is used to indicate both sulfinic acids and sulfinic acid salts. Also herein, "fluoro sulfmate" and "fluorinated sulfmate" are used interchangeably to indicate sulfinic acids and sulfinic acid salts which contain at least one fluorine atom.

Perfluorovinyl ether sulfonyl halides useful in the present invention may be represented by formula (I). The perfluorovinyl ether sulfonyl halides may comprise a single perfluorovinyl ether sulfonyl halide compound or a mixture of perfluorovinyl ether sulfonyl halides. In some embodiments, the perfluorinated linking group, R, is a saturated or unsaturated, linear or branched moiety. R can be substituted, for example, one or more substituent groups, or R can be unsubstituted. The perfluorinated linking group can optionally comprise catenary heteroatoms, for example, nitrogen, oxygen, or sulfur atoms that replace one or more carbon atoms of the perfluorinated linking group, R, in a manner such that the heteroatom is bonded to at least two carbon atoms of the perfluorinated linking group. In some embodiments R is selected from: -(CF ₂ ) _a -, -(CF ₂ ) _a -0-(CF ₂ ) _b -, and - (CF ₂ ) _a -[0-(CF ₂ )b]c-, -[(CF ₂ )a-0-]b-[(CF ₂ ) _c -0-]d, and combinations thereof, wherein a, b, c, and d are independently at least 1. In some embodiments, R will have from about 1, 2, 5, or even 7 to about 10, 12, 15, 18, or even 20 carbon atoms.

Exemplary perfluorovinyl ether sulfonyl halides useful in the present invention include:

CF ₂ =CF-0-CF ₂ CF ₂ -S0 ₂ F

CF ₂ =CF-0-CF ₂ CF ₂ -S0 ₂ Cl CF ₂ = =CF-0-CF ₂ CF ₂ CF ₂ -S0 ₂ F

CF ₂ = =CF-0-CF ₂ CF ₂ CF ₂ -S0 ₂ Cl

CF ₂ = =CF-0-CF ₂ CF ₂ CF-S0 ₂ F

CF ₃

CF ₂ = =CF-0-CF ₂ CF ₂ CF-S0 ₂ Cl

CF ₃

CF ₂ = =CF-0-CF ₂ CF ₂ CF ₂ CF ₂ -S0 ₂ F

CF ₂ = =CF-0-CF ₂ CF ₂ CF ₂ CF ₂ -S0 ₂ Cl

CF ₂ = =CF-0-CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ -S0 ₂ F

CF ₂ = =CF-0-CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ -S0 ₂ Cl

CF ₂ = =CF-0-CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ -S0 ₂ F

CF ₂ = =CF-0-CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ -S0 ₂ Cl

CF ₂ = =CF-0-CF ₂ CF ₂ -0-CF-S0 ₂ F

CF ₃

CF ₂ = =CF-0-CF ₂ CF ₂ -0-CF-S0 ₂ Cl

CF ₃

CF ₂ = =CF-0-[CF ₂ CF(CF ₃ )-0]-CF ₂ CF ₂ -S0 ₂ F

CF ₂ = =CF-0-[CF ₂ CF(CF ₃ )-0]-CF ₂ CF ₂ -S0 ₂ Cl

CF ₂ = =CF-0-[CF ₂ CF(CF ₃ )-0]-CF ₂ CF-S0 ₂ F

CF ₃

CF ₂ = =CF-0-[CF ₂ CF(CF ₃ )-0]-CF ₂ CF-S0 ₂ Cl

CF ₃

CF ₂ = =CF-0-[CF ₂ CF(CF ₃ )-0] ₂ -CF ₂ CF ₂ -S0 ₂ F

CF ₂ = =CF-0-[CF ₂ CF(CF ₃ )-0] ₂ -CF ₂ CF ₂ -S0 ₂ Cl

CF ₂ = =CF-0-[CF ₂ CF(CF ₃ )-0] ₃ -CF ₂ CF ₂ -S0 ₂ F

CF ₂ = =CF-0-[CF ₂ CF(CF ₃ )-0] ₃ -CF ₂ CF ₂ -S0 ₂ Cl

CF ₂ = =CF-0-[CF ₂ CF(CF ₃ )-0] ₄ -CF ₂ CF ₂ -S0 ₂ F

CF ₂ = =CF-0-[CF ₂ CF(CF ₃ )-0] ₄ -CF ₂ CF ₂ -S0 ₂ Cl

CF ₂ = =CF-0-[CF ₂ CF(CF ₃ )-0]-CF ₂ CF ₂ CF ₂ -S0 ₂ F CF ₂ = =CF- -0- ^■ [CF ₂ CF(CF ₃ ^■ 0]-CF ₂ CF ₂ CF ₂ -S0 ₂ Cl

CF ₂ = =CF- -0- ■[CF ₂ CF(CF ₃ ■0] ₂ -CF ₂ CF ₂ CF ₂ -S0 ₂ F

CF ₂ = =CF- -0- ■[CF ₂ CF(CF ₃ ^■ 0] ₂ -CF ₂ CF ₂ CF ₂ -S0 ₂ Cl

CF ₂ = =CF- -0- ■[CF ₂ CF(CF ₃ ■0]-CF ₂ CF ₂ CF ₂ CF ₂ -S0 ₂ F

CF ₂ = =CF- -0- ■[CF ₂ CF(CF ₃ -0]-CF ₂ CF ₂ CF ₂ CF ₂ -S0 ₂ Cl

CF ₂ = =CF- -0- ■[CF ₂ CF(CF ₃ ■0] ₂ -CF ₂ CF ₂ CF ₂ CF ₂ -S0 ₂ F

CF ₂ = =CF- -0- ■[CF ₂ CF(CF ₃ ^■ 0] ₂ -CF ₂ CF ₂ CF ₂ CF ₂ -S0 ₂ Cl

The solvent comprises at least one organic protic solvent. In some embodiments, the solvent may comprise one or more alcohols having a boiling point of 110° C or less at 760 torr. Exemplary useful organic protic solvents include formic acid, acetic acid, and alcohols. In some embodiments, the solvent will not contain water. Lower alkanols, particularly those having from 1 to 4 carbon atoms, are preferred for use in the process as solvents. In some embodiments the lower alkanols may contain additional oxygen groups, such as a methoxy group. Exemplary useful alcohols include methanol, ethanol, isopropanol, n-butanol, tertiary butanol, isobutanol, methoxyethanol and glycol. In some embodiments, the solvent is ethanol. In some embodiments, the solvent is isopropanol.

In some embodiments, a cosolvent may be present in addition to the at least one organic protic solvent. In some embodiments, the cosolvent may be an additional organic protic solvent. In some embodiments, the cosolvent may be an aprotic solvent. In some embodiments, the cosolvent may include tetrahydrofuran (THF), glyme,

dimethylformamide (DMF), diethyl ether, or water.

The solvent should be present in an amount sufficient to allow adequate stirring and heat transfer during the reaction. In some embodiments, the solvent can be removed after completion of the reaction to achieve the desired level of fluorosulfinate product purity. In some embodiments, a cosolvent may be present in an amount up to 90 wt.% of the total combined solvent and cosolvent amount.

Any conventional method may be used to remove the solvent, such as extraction, distillation under reduced pressure, recrystallization, column chromatography, and other known methods of separation.

Reducing agents useful in some embodiments of the present invention include those represented by formula (II): MBH _n (R') ₄ _ _n , wherein n is 1, 2, 3, or 4, M is an alkali metal, and R' is R", OR", OH, or OC(0)R", wherein R" is a CI to C6 linear or branched alkyl group. In some embodiments, useful hydride reducing agents include sodium borohydride, potassium borohydride, and lithium borohydride. In some embodiments of the present invention, useful reducing agents include those represented by formula (III): Al _x (B _y H _z ) _w , wherein x is 0 or 1, y is 1 or 2, z is 3, 4, 5, or 6, and w is 1, 2, or 3. Exemplary reducing agents for use in some embodiments of the present invention include NaBH ₄ ,

KBH ₄ , NaBH(OCH ₃ ) ₃ , LiBH ₄ , A1(BH ₄ ) ₃ , NaBH CN, LiBH(CH ₃ ) ₃ , LiBH(CH ₂ CH ₃ ) ₃ , BH , and B ₂ H ₆ .

Other useful reducing agents include hydrogen, hydrazine, diisobutyl aluminum hydride, sodium hydride, lithium hydride, potassium hydride, aluminum hydride, calcium hydride, lithium aluminum hydride, mono-, di-, or tri(lower alkoxy) alkali metal aluminum hydrides, mono-, di-, or tri(lower alkoxy lower alkoxy) alkali metal aluminum hydrides, di(lower alkyl) aluminum hydrides, alkalimetalcyanoborohydrides, tri(loweralkyl) tin hydrides, tri(aryl) tin hydrides, and the like.

In some embodiments, the process of the invention is carried out by adding the reducing agent to a perfluorovinyl ether sulfonyl halide-solvent mixture. Alternatively, the process may also be carried out by adding the perfluorovinyl ether sulfonyl halide to a reducing agent-solvent mixture.

In some embodiments, the process of the reducing step is performed in an oxygen- free environment. In some embodiments, the oxygen-free environment can be achieved through the use of nitrogen gas.

In some embodiments the process of the reducing step is carried out using dry, no- moisture solvents that do not contain water.

The reducing agent may be added in an amount such that the ratio of moles of reducing agent to moles of perfluorovinyl ether sulfonyl halide is in the range of at least 0.25, 0.5, 0.75, 1.0, 1.25, 1.5, or even 1.7 to at most 1.8, 1.9, 2.0, or even 3.0. In some embodiments the ratio of moles of reducing agent to moles of perfluorovinyl ether sulfonyl halide is from 1.7 to 1.8. In some embodiments, the ratio of moles of reducing agent to moles of perfluorovinyl ether sulfonyl halide is 1.8.

The temperature of the sulfmic acid, including mixtures of solvent and sulfmic acid, should be maintained under 120°C to prevent decomposition of the sulfmic group.

In some embodiments, the addition of the reducing agent is performed at a temperature between about -20°C to about 100°C. For example, the reducing agent can be added while the reaction solution is kept at a temperature of from about -20°C, -10°C, 0°C, or even 10°C to about 20°C, 40°C, 60°C, 80°C, or even 100°C. In some embodiments, the temperature range for addition of the reducing agent is between 0°C and 30°C. In some embodiments, the reduction reaction mixture is allowed to warm to room temperature following addition of the reducing agent. In some embodiments, the temperature of the reaction mixture may be maintained at a temperature of from about -20°C, -10°C, 0°C, or even 10°C to about 20°C, 40°C, 60°C, 80°C, or even 100°C for the duration of the reaction time.

The addition time of the reducing step may last, in some embodiments, for up to 2 hours, up to 4 hours, or up to 10 hours. In some embodiments the addition time may last longer, for up to 15 hours, up to 20 hours, or even up to 24 hours.

To generate the free perfluorovinyl ether sulfmic acid, an acid may be added immediately following the reduction reaction. In some embodiments, a strong acid, such as hydrochloric acid, nitric acid, or sulfuric acid may be added. In some embodiments, the acid is added when the reaction mixture reaches room temperature, e.g. 23°C. The acid may be added in some embodiments at the end of the desired addition time for the reducing step, such as at 2 hours, 4 hours, 10 hours, 15 hours, 20 hours, or 24 hours after addition of the reducing agent. In some embodiments, the acid is added in an amount sufficient to decrease the pH of the reaction mixture to pH 5, pH 3, or even pH 1.

If desired, the free perfluorovinyl ether sulfmic acid can be converted to the acid salt through the additional step of adding a base. In some embodiments, the base can be an alkali metal hydroxide, for example, sodium hydroxide and potassium hydroxide, or an alkaline earth hydroxide. In some embodiments, the base can be ammonium hydroxide.

In some embodiments, the base is added in an amount sufficient to neutralize the solution. In some embodiments, no excess base is added. The base may be added, in some embodiments, to an aqueous solution of perfluorovinyl ether sulfmic acid to ensure complete titration. Following addition of the base, vacuum stripping may be used to remove water and isolate the neat salt. In some embodiments, the final salt can be diluted with water to make an aqueous solution of the perfluorovinyl ether sulfmic acid salt.

The fluorosulfinate product largely comprises the fluorosulfinate derivatives of the fluoroaliphatic sulfonyl halide(s) used in the reaction mixture. Typically, the

fluorosulfinate product will comprise at least about 20, 40, 50, 60, 70, 80, or even 90 weight percent fluorosulfmate compounds, based on the total weight of the fluorosulfmate product.

Exemplary perfluorovinyl ether sulfmates that can be obtained through the process of the present invention include:

CF ₂ = =CF- ■0- -CF ₂ CF ₂ -S0 ₂ H

CF ₂ = =CF- -0- -CF ₂ CF ₂ -S0 ₂ Na

CF ₂ = =CF- ■0- -CF ₂ CF ₂ -S0 ₂ K

CF ₂ = =CF- ■0- -CF ₂ CF ₂ -S0 ₂ NH ₄

CF ₂ = =CF- ■0- ■CF ₂ CF ₂ CF ₂ -S0 ₂ H

CF ₂ = =CF- ■0- -CF ₂ CF ₂ CF-S0 ₂ H

CF ₃

CF ₂ = =CF- -0- ■CF ₂ CF ₂ CF ₂ CF ₂ -S0 ₂ H

CF ₂ = =CF- ■0- ■CF ₂ CF ₂ CF ₂ CF ₂ -S0 ₂ Na

CF ₂ = =CF- ■0- ■CF ₂ CF ₂ CF ₂ CF ₂ -S0 ₂ K

CF ₂ = =CF- ■0- -CF ₂ CF ₂ CF ₂ CF ₂ -S0 ₂ NH ₄

CF ₂ = =CF- ■0- ■CF ₂ CF ₂ -0-CF-S0 ₂ H

CF ₃

CF ₂ = =CF- ■0- ■CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ -S0 ₂ H

CF ₂ = =CF- -0- ■CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ -S0 ₂ H

CF ₂ = =CF- ■0- [CF ₂ CF(CF ₃ )-0]-CF ₂ CF ₂ -S0 ₂ H

CF ₂ = =CF- ■0- -[CF ₂ CF(CF ₃ )-0]-CF ₂ CF ₂ -S0 ₂ Na

CF ₂ = =CF- ■0- -[CF ₂ CF(CF ₃ )-0]-CF ₂ CF ₂ -S0 ₂ K

CF ₂ = =CF- ■0- -[CF ₂ CF(CF ₃ )-0]-CF ₂ CF ₂ -S0 ₂ NH ₄

CF ₂ = =CF- -0- [CF ₂ CF(CF ₃ )-0]-CF ₂ CF-S0 ₂ H

CF ₃

CF ₂ = =CF- ■0- -[CF ₂ CF(CF ₃ )-0] ₂ -CF ₂ CF ₂ -S0 ₂ H

CF ₂ = =CF- ■0- [CF ₂ CF(CF ₃ )-0] ₃ -CF ₂ CF ₂ -S0 ₂ H

CF ₂ = =CF- ■0- -[CF ₂ CF(CF ₃ )-0] ₄ -CF ₂ CF ₂ -S0 ₂ H

CF ₂ = =CF- ■0- [CF ₂ CF(CF ₃ )-0]-CF ₂ CF ₂ CF ₂ -S0 ₂ H

CF ₂ = =CF- -0- [CF ₂ CF(CF ₃ )-0] ₂ -CF ₂ CF ₂ CF ₂ -S0 ₂ H

CF ₂ = =CF- ■0- [CF ₂ CF(CF ₃ )-0]-CF ₂ CF ₂ CF ₂ CF ₂ -S0 ₂ H CF ₂ =CF-0-[CF ₂ CF(CF ₃ )-0] ₂ -CF ₂ CF ₂ CF ₂ CF ₂ -S0 ₂ H

Fluoroolefins are useful as comonomers for making fluoropolymers. The fluorinated sulfinate products prepared in accordance with the process of this invention are particularly suitable for initiating a free radical polymerization of ethylenically unsaturated monomers. The fluorinated sulfinate products can be used to initiate the homo- or copolymerization of polymerizable mixtures comprising fluorine-containing ethylenically unsaturated monomer, and optionally, fluorine free, terminally unsaturated monoolefm comonomers (e.g., ethylene or propylene), or iodine- or bromine-containing cure-site comonomers. The polymerization techniques in which the fluorosulfmates of the present invention can be useful typically include emulsion or suspension polymerization in an aqueous medium.

Fluorosulfmates prepared in accordance with the process of the present invention are particularly useful for producing fluoropolymers without ionic ends that benefit the processing of the polymers. Fluorosulfmates produced by the process of the present invention can be used as a surfactant, initiator, reactive intermediate, and reactive monomer to generate unique branched fluoropolymers.

The following embodiments are representatives of the subject matter of the present application:

1. A process for preparing a perfluorovinylether sulfinate comprising:

a) providing a perfluorovinylether sulfonyl halide represented by the following formula (I):

CF ₂ =CF-0-R-CFX-S0 ₂ -Y

wherein Y is CI or F, X is F or a linear or branched perfluorinated alkyl group, and R is a linear or branched perfluorinated linking group, which may be saturated or unsaturated, substituted or unsubstituted, and optionally comprises catenary heteroatoms; and

b) reducing the perfluorovinylether sulfonyl halide with a reducing agent in an organic protic solvent, wherein the reducing agent is represented by one of

formula (II):

MBH _n (R') ₄ _ _n wherein n is 1, 2, 3, or 4, M is an alkali metal, and R' is R", OR", OH, or OC(0)R", wherein R" is a CI to C6 linear or branched alkyl group;

or

formula (III):

Al _x (B _y H _z ) w

wherein x is 0 or 1, y is 1 or 2, z is 3, 4, 5, or 6, and w is 1,

2, or 3.

2. The process according to embodiment 1, wherein the process further comprises the step of adding an acid to produce a perfluorovinylether sulfmic acid.

3. The process according to embodiment 2, wherein the process further comprises the step of adding a base to the perfluorovinylether sulfmic acid to produce a perfluorovinylether sulfmic acid salt.

4. The composition according to any one of the previous embodiments, wherein R is selected from: -(CF ₂ ) _a -, -(CF ₂ ) _a -0-(CF ₂ ) _b -, and -(CF ₂ ) _a -[0-(CF ₂ ) _b ] _c -, -[(CF ₂ ) _a - 0-]b-[(CF ₂ ) _c -0-]d, and combinations thereof, wherein a, b, c, and d are independently at least 1.

5. The process according to any one of the preceding embodiments wherein the perfluorovinylether sulfonyl halide comprises CF ₂ =CF-0-C4F ₈ -S0 ₂ F and the perfluorovinylether sulfmate comprises CF ₂ =CF-0-C4F ₈ -S0 ₂ M', wherein M' is hydrogen or an organic or inorganic cation.

6. The process according to any one of the preceding embodiments wherein the perfluorovinylether sulfonyl halide comprises CF ₂ =CF-0-CF ₂ CF(CF ₃ )-0-CF ₂ CF ₂ - S0 ₂ F and the perfluorovinylether sulfmate comprises CF ₂ =CF-0-CF ₂ CF(CF ₃ )-0-CF ₂ CF ₂ - S0 ₂ M', wherein M' is hydrogen or an organic or inorganic cation. 7. The process according to any one of the preceding embodiments wherein the perfluorovinylether sulfonyl halide comprises CF ₂ =CF-0-CF ₂ CF ₂ -S0 ₂ F and the perfluorovinylether sulfonate comprises CF ₂ =CF-0-CF ₂ CF ₂ -S0 ₂ M', wherein M' is hydrogen or an organic or inorganic cation.

8. The process according to any one of the preceding embodiments wherein the hydride reducing agent is selected from the group comprising NaBH ₄ and KBH ₄ .

9. The process according to any one of the preceding embodiments wherein the step of reducing the perfluorovinylether sulfonyl halide with a reducing agent in an organic protic solvent is performed such that the reducing agent is added to a mixture of the perfluorovinylether sulfonyl halide and the organic protic solvent.

10. The process according to any one of the preceding embodiments wherein the step of reducing the perfluorovinylether sulfonyl halide with a reducing agent in an organic protic solvent is performed such that the perfluorovinylether sulfonyl halide is added to a mixture of the reducing agent and the organic protic solvent.

11. The process according to any one of the preceding embodiments wherein the solvent is selected from the group comprising a Ci-C ₄ alcohol and a Ci-C ₄ alcohol comprising an ether.

12. The process according to any one of the preceding embodiments wherein the solvent further comprises at least one cosolvent.

EXAMPLES

Advantages and embodiments of this disclosure are 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. In these examples, all parts, percentages, proportions, ratios, and the like are by weight unless otherwise indicated. Unless otherwise noted, all reagents were obtained or are available from Aldrich Chemical Co., Milwaukee, Wis., or may be synthesized by known methods.

These abbreviations are used in the following examples: g = gram, min = minutes, cm= centimeter, mm = millimeter, ml = milliliter, and mmHg = millimeters of mercury.

The following examples are merely for illustrative purposes and are not meant to limit in any way the scope of the appended claims.

Materials

Comparative Example 1

250g (0.66mol) MV4S and 500g tetrahydrofuran (THF) was added to a 3-neck round bottom flask and the solution was stirred and cooled to 0°C. 47g (1.2mol) NaBH ₄ was added in portions through a solids addition funnel over one hour. No exotherm was observed. The reaction was kept under 10°C throughout the addition of NaBH ₄ . The bath was removed and the slurry was allowed to warm to 20°C. A very exothermic reaction followed that rose to 71°C. After the reaction was allowed to return to 20°C 130g of concentrated sulfuric acid in 650g water was slowly added to give two phases. The lower fluorochemical phase was vacuum stripped overnight to give 116g of a slight yellow oil after removing solids by filtration. Nuclear magnetic resonance spectroscopy (NMR) gave the desired MV4S0 ₂ H in 23 % yield. Comparative Example 2

50g (0.13mol) MV4S and 120g of dimethylformamide (DMF) were added to a 1L 3 -neck round bottom flask with stirring and the solution was nitrogen purged and cooled to 0°C. 8.9g (0.23mol) NaBH ₄ was added in portions over one hour with a 5°C exotherm per portion. The reaction was kept under 13°C throughout the addition of NaBH ₄ . The flask was allowed to warm to 20°C and the slurry was stirred for 30 minutes. 50g concentrated sulfuric acid in 25 Og water was added slowly. A one phase solution formed and 150g methyl t-butyl ether (MTBE) was used to extract a top phase. The top phase was vacuum stripped to remove solvent yielding 48.5g of reaction mixture. NMR gave very little desired MV4S0 ₂ H product.

Comparative Example 3

50g (0.13mol) MV4S and 120g of reagent grade 1 ,2-dimethoxyethane (glyme) were placed in a 1L 3 -neck round bottom flask with stirring, nitrogen purged and cooled to 0°C. 8.9g (0.23mol) NaBH ₄ was added in portions over one hour with a 5°C exotherm per portion. The reaction was kept under 19°C throughout the addition of NaBH ₄ . The flask was allowed to warm to 20°C and an exothermic reaction occurred that raised the temperature to 80°C. After the reaction temperature cooled to 20°C, 50g concentrated sulfuric acid in 25 Og water was added slowly. A one phase solution formed and 150g methyl t-butyl ether (MTBE) was used to extract a top phase. The top phase was vacuum stripped to remove solvent yielding 37.8g of reaction mixture. NMR gave very little vinyl ether product.

Example 1

50g (0.13mol) MV4S and 150ml of reagent grade ethanol was added to a 1 liter 3- neck round bottom flask. The solution was stirred and cooled to 0°C. 3.4g (0.09mol) NaBH ₄ was added in portions over 30 minutes with a 5°C exothermic temperature rise per portion. The reaction was kept under 10°C throughout the addition of NaBH ₄ . The flask was allowed to warm to 20°C and the slurry was stirred for 30 minutes. 26g concentrated H ₂ S0 ₄ in 200g water was added slowly resulting in a temperature rise to 32°C. A lower fluorochemical phase of 31g of unreacted MV4S was recovered. The clear top solution was extracted with 1 lOg methyl-t-butyl ether (MTBE) and vacuum stripped to recover 28g of a semi-solid material. The semi-solid material still contained some water, ethanol, and salts. NMR gave the desired MV4S0 ₂ H in an 86% yield based on reacted MV4S.

Example 2

Example 2 was run identically to example 1 except that used 180g ethanol, 8.8 g NaBH ₄ , 50g concentrated H ₂ S0 ₄ in 250 mL water and 150g MTBE. Vacuum stripping of the top phase removed solvent and yielded 88.6g of concentrated product which was then diluted with water to 156g. NMR gave the desired MV4S0 ₂ H in a 91% yield.

Example 3

Example 3 was run identically to example 2 except on a larger scale. In place of the amounts used in example 2, example 3 used 25 lg (0.66mol) MV4S, 600g of ethanol, 44.2g (1.16mol) NaBH ₄ , 250g concentrated H ₂ S0 ₄ in 1250mL water and 500g MTBE. Vacuum stripping of the top phase removed solvent and yielded 380g of concentrated product after filtration of solids which was then diluted with water to 786g. NMR gave the desired MV4S0 ₂ H in an 89% yield.

Example 4

Example 4 was run identically to example 3 except in place of the amounts used in example 3, example 4 used 255g (0.67mol) MV4S and 44g (1.15mol) NaBH ₄ . This example demonstrates the salt formation. Vacuum stripping of the top phase removed solvent and yielded 212g of concentrated product after filtration of solids. NMR gave the desired MV4S0 ₂ H in an 81% yield.

Addition of 20g (0.32mol) ammonia (as 27% ammonium hydroxide) to 1 lOg of MV4S0 ₂ H gave a quantitative yield of MV4S0 ₂ NH ₄ as a waxy solid. A melting point of 74°C was measured for MV4S0 ₂ NH ₄ .

Example 5

lOOg (0.26mol) CF ₂ =CFOC ₄ F ₈ S0 ₂ F, MV4S and 220g of absolute ethanol was added to a 1L 3 -neck round bottom flask with stirring and nitrogen purged at 20°C. A charge of 17.7g (0.46mol) NaBH ₄ was added in portions over one hour with the exotherm kept at 50°C. The reaction mixture was foamy with a slight reflux. The reaction was allowed to return to 20°C and lOOg concentrated H ₂ SO ₄ in 400g water was added. A slight opaque one phase solution formed and 182g MTBE was used to extract a top phase.

Vacuum stripping of the top phase removed solvent and gave 118g of concentrated product after filtration of solids. NMR gave the desired MV4S0 ₂ H in a 72% yield.

Example 6

54g (0.14mol) MV4S and 1 lOg of 2-propanol was added to a 1L 3-neck round bottom flask with stirring, nitrogen purged and cooled to 0°C. 9.6g (0.25mol) NaBH ₄ was added in portions over one hour with the reaction temperature allowing to reach 36°C. The flask was allowed to return to 20°C and the slurry was stirred for 30 minutes. Addition of 50g concentrated H ₂ S0 ₄ in 200g water was added slowly. A slight opaque one phase solution formed and lOOg MTBE was used to extract a top phase. Vacuum stripping of the top phase removed solvent and gave 36g of concentrated product after filtration of solids. NMR gave the desired MV4S0 ₂ H in a 57% yield.

Example 7

51.5g (0.14mol) MV4S and 1 lOg of anhydrous methanol was added to a 1L 3-neck round bottom flask with stirring, nitrogen purged and cooled to 0°C. Addition of 9.2g (0.24mol) NaBH ₄ was added in portions over one hour with a 5°C exothermic temperature rise per portion. The reaction was kept under 10°C throughout the addition of NaBH ₄ . The flask was allowed to warm to room temperature and the slurry was stirred for 30 minutes. Addition of 50g concentrated H ₂ S0 ₄ in 200g water was added slowly. A slight opaque one phase solution formed and lOOg MTBE was used to extract a top phase. Vacuum stripped of the top phase removed solvent and gave 36g of concentrated product after filtration of solids. NMR gave the desired MV4S0 ₂ H in a 66% yield.

Example 8

52.4g (0.14mol) MV4S and 1 lOg of reagent grade 1-butanol was added to a 1L 3- neck round bottom flask with stirring and nitrogen purged. 9.3g (0.24mol) NaBH ₄ was added in portions over one hour with the reaction temperature allowing to go to 50°C. The flask was allowed to reach room temperature and the slurry was stirred for 30 minutes. Addition of 50g concentrated H ₂ S0 ₄ in 200g water was added slowly. Two phases were obtained with the product and solvent in the top phase. Vacuum stripped of the top phase removed solvent and gave 49.6g of concentrated product after filtration of solids. NMR gave the desired MV4S0 ₂ H in a 60% yield.

Example 9

45g (O. lOmol) MV3b2S and 180g of reagent grade ethanol was added to a 1L 3- neck round bottom flask with stirring, nitrogen purged and cooled to 0°C. Addition of 6.9g (0.18mol) NaBH ₄ was added in portions over 30 minutes with a 5°C exothermic temperature rise per portion. The reaction was kept under 10°C throughout the addition of NaBH ₄ . The flask was allowed to warm to 20°C and the slurry was stirred for 30 minutes. 50g concentrated H ₂ S0 ₄ in 250g water was added slowly. A slight opaque one phase solution formed and 150g MTBE was used to extract a top phase. Vacuum stripping of the top phase removed solvent and gave 20g of concentrated product after filtration of solids for a 51% crude yield. NMR gave the desired MV3b2S0 ₂ H.

Example 10

Addition of 2.2g (0.03 mol) ammonia (as 27% ammonium hydroxide) to lOg of MV3b2S0 ₂ H from example 9 gave a quantitative yield of MV3b2S0 ₂ NH ₄ as a waxy solid. No melting point for MV3b2S0 ₂ NH ₄ was observed and onset of decomposition occurred at 208°C.

Example 11

17.7g (0.46mol) NaBH ₄ and 218g of reagent grade ethanol was placed in a 1L 3- neck round bottom flask with stirring, nitrogen purged and cooled to 0°C. lOOg (0.26mol) MV4S was added over two hours with the reaction temperature kept under 10°C. The reaction was warmed to 20°C and stirred for one-half an hour followed by addition of lOOg concentrated sulfuric acid in 400g water. A one phase solution formed and 200g MTBE was used to extract a top phase. The top phase was vacuum stripped to remove solvent yielding 75 g of concentrated product after filtration of solids. NMR gave the desired MV4S0 ₂ H in a 43% yield. Example 12

lOg MV4S (26.3mmol), 20g dried THF (distilled from CaH ₂ ) and 5g absolute ethanol were charged into a 250ml 3 -neck round bottom flask fitted with a thermometer, reflux condenser, nitrogen flow and a solid-addition funnel. The solution was cooled to 0°C under nitrogen and 1.32g NaBH ₄ (34.9mmol) was added in portions with stirring over 30 minutes keeping the temperature below 10°C. After addition the solution was allowed to slowly warm up to 20°C under nitrogen. ¹⁹ F NMR analysis of the reaction mixture indicated 92% conversion of-S0 ₂ F after reaction at 20°C for 15 minutes and 100% conversion after 30 minutes. The chemical shift of -S0 ₂ F at +42ppm disappeared and the signal of-CF ₂ S0 ₂ F at -11 lppm was shifted to -135ppm for the corresponding -CF ₂ S0 ₂ Na product. Based on the signal of -CF ₂ S0 ₂ Na at -135ppm and the signal of CF ₂ =CFO-, an NMR yield of >95% of the desired product, CF ₂ =CF-0-C ₄ F ₈ -S0 ₂ Na, was identified. No hydride by-product was observed. Example 13

lOg MV4S (26.3mmol), 24g dried THF (distilled from CaH ₂ ) and 4.0g acetic acid (obtained from EM Science, Gibbstown, NJ, >99.5%>) were charged into a 250ml 3-neck round bottom flask fitted with a thermometer, reflux condenser, nitrogen flow and a solid- addition funnel. The solution was cooled below 10°C under nitrogen and 0.85g NaBH ₄ (34.9mmol) was added in portions with stirring over 30 minutes keeping the temperature below 10°C. After addition the solution was allowed to slowly warm up to 20°C under nitrogen and stirring was continued for 30 minutes. ¹⁹ F NMR analysis showed 36% conversion of-S0 ₂ F to -S0 ₂ Na with high selectivity. Another 0.5g NaBH ₄ (13.2mmol) was added and reacted at 20°C for another 1 hour and the conversion increased to 50%. The conversion was further increased to 94% when another 0.42g NaBH4 was added at 20°C and reacted for an additional one hour. The final ratio of

and hydride by-product was 96 to 4.

The complete disclosures of the patents, patent documents, and publications cited herein are incorporated by reference in their entirety as if each were individually incorporated. Various modifications and alterations to this invention will become apparent to those skilled in the art without departing from the scope and spirit of this invention. It should be understood that this invention is not intended to be unduly limited by the illustrative embodiments and examples set forth herein and that such examples and embodiments are presented by way of example only with the scope of the invention intended to be limited only by the claims set forth herein as follows.