Process for the production of hydrofluoroethers

• US 5,750,797 A
• Filed: 04/15/1996
• Issued: 05/12/1998
• Est. Priority Date: 04/15/1996
• Status: Expired due to Term

• Current Assignee: 3M Company
• Original Assignee: 3M Company
• Inventors: Vitcak, Daniel R., Flynn, Richard M.
• Primary Examiner(s): Geist, Gary
• Assistant Examiner(s): PUTTLITZ, KARL J
• Application Number:
  US08/632,697
• Time in Patent Office: 757 Days
• Field of Search: 568/681, 568/683, 568/414
• US Class Current: 568/683
• CPC Class Codes: C07C 41/01 Preparation of ethers
• CPC Class Codes: C07C 41/42 by distillation
• CPC Class Codes: C07C 43/12 containing halogen

Abstract

Briefly, in one aspect, this invention provides an improved alkylation process for the preparation of primary and secondary hydrofluoroether compounds, said process comprising:

(1) combining in a polar, aprotic solvent:

a) a fluorinated carbonyl-containing compound;

b) an anhydrous source of fluoride ion;

c) a tertiary or aromatic amine; and

d) optionally, an effective amount of a phase transfer catalyst;

(2) contacting the resulting mixture with an alkylating agent; and

(3) recovering hydrofluoroether from the resulting product mixture.

Claims

1. An alkylation process for the preparation of hydrofluoroether compounds, said process comprising:

(1) combining in a polar, aprotic solvent;

a) a fluorinated carbonyl-containing compound of the formula;

##STR8## wherein n is 1 to 3; and

when n is 1, R_f is a fluorinated alkyl group having from 1 to about 15 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms;

when n is 2, R_f is a fluorinated alkylene group having from 1 to about 15 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms;

when n is 3, R_f is a fluorinated alkylidene group having from 1 to about 15 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms; and

wherein each X is independently a halogen atom or is of the formula R'"'"'_f or OOCR'"'"'_f where R'"'"'_f is a fluorinated alkyl group having from 1 to about 10 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms;

where X is an R'"'"'_f group, that R'"'"'_f group may form a ring with said R_f group;

b) an anhydrous source of fluoride ion; and

c) an amount of a tertiary or aromatic amine sufficient to neutralize substantially all acid contaminants present in the reactant mixture;

(2) contacting the resulting mixture with an alkylating agent of the general formula;

space="preserve" listing-type="equation">Y--R

wherein;

R is a substituted or unsubstituted, cyclic or acyclic, linear or branched, non-fluorinated or partially fluorinated alkyl group having from 1 to about 10 carbon atoms that may contain one or more catenary heteroatoms; and

Y is a chlorine, bromine, or iodine atom or is a group of the formula R'"'"'--SO₂ --O-- where R'"'"' is a phenyl or toluyl group or is a non-fluorinated or fully fluorinated alkyl group or an alkoxy group either of which may contain from 1 to about 10 carbon atoms; and

(3) recovering hydrofluoroether from the resulting product mixture.

2. The process of claim 1 wherein the anhydrous source of fluoride ion is selected from the group consisting of metal fluorides, metal bifluorides, quaternary ammonium fluoride, and quaternary phosphonium fluoride and wherein the polar, aprotic solvent is selected from the group consisting of glycol ethers, tetrahydrofuran, acetonitrile, and dimethylformamide.

3. The process of claim 1 wherein the alkylating agent is selected from the group consisting of dialkyl sulfates, alkyl halides, alkyl-p-toluenesulfonates, partially fluorinated alkyl perfluoroalkanesulfonates and alkyl perfluoroalkanesulfonates.

4. The process of claim 1 wherein the tertiary or aromatic amine is selected from the group consisting of substituted and unsubstituted, cyclic and acyclic trialkyl amines, pyridine, 2,6-dimethyl pyridine, 3,4-dimethyl pyridine, 3,5-dimethyl pyridine, 2-picoline, 3-picoline, 4-picoline and quinoline.

5. The process of claim 1 wherein the tertiary or aromatic amine is added in amount equal to the molar concentration of the acid contaminants present in the reaction mixture.

6. The process of claim 1 wherein the tertiary or aromatic amine is present in the reactant mixture at a molar concentration of between 0.01 and 5.0 percent.

7. The process of claim 1 wherein the fluorinated carbonyl-containing compound is of the formula:

##STR9## wherein n is 1 to 3; and

when n is 1, R_f is a perfluorinated alkyl group having from 1 to about 15 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms;

when n is 2, R_f is a perfluorinated alkylene group having from 1 to about 15 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms;

when n is 3, R_f is a perfluorinated alkylidene group having from 1 to about 15 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms; and

wherein each X is independently a halogen atom or is of the formula R'"'"'_f or OOCR'"'"'_f where R'"'"'_f is a perfluorinated alkyl group having from 1 to about 10 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms;

where X is an R'"'"'_f group, that R'"'"'_f group may form a ring with said R_f group.

8. An alkylation process for the preparation of hydrofluoroether compounds, said process comprising:

(1) combining in a polar, aprotic solvent;

a) a fluorinated carbonyl-containing compound of the formula;

##STR10## wherein n is 1 to 3; and

when n is 1, R_f is a fluorinated alkyl group having from 1 to about 15 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms;

when n is 2, R_f is a fluorinated alkylene group having from 1 to about 15 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms;

when n is 3, R_f is a fluorinated alkylidene group having from 1 to about 15 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms; and

wherein each X is independently a halogen atom or is of the formula R'"'"'_f or OOCR'"'"'_f where R'"'"'_f is a fluorinated alkyl group having from 1 to about 10 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms;

where X is an R'"'"'_f group, that R'"'"'_f group may form a ring with said R_f group;

b) an anhydrous source of fluoride ion;

c) an amount of a tertiary or aromatic amine sufficient to neutralize substantially all acid contaminants present in the reaction mixture; and

d) an effective amount of a phase transfer catalyst selected from the group consisting of quaternary ammonium and phosphonium salts, crown ethers, and cryptands;

(2) contacting the resulting mixture with an alkylating agent of the general formula;

space="preserve" listing-type="equation">Y--R

wherein;

R is a substituted or unsubstituted, cyclic or acyclic, linear or branched, non-fluorinated or partially fluorinated alkyl group having from 1 to about 10 carbon atoms that may contain one or more catenary heteroatoms; and

Y is a chlorine, bromine, or iodine atom or is a group of the formula R'"'"'--SO₂ --O-- where R'"'"' is a phenyl or toluyl group or is a non-fluorinated or fully fluorinated alkyl group or an alkoxy group either of which may contain from 1 to about 10 carbon atoms; and

(3) recovering hydrofluoroether from the resulting product mixture.

9. The process of claim 8 wherein the anhydrous source of fluoride ion is selected from the group consisting of metal fluorides, metal bifluorides, quaternary ammonium fluorides, and quaternary phosphonium fluorides and wherein the polar, aprotic solvent is selected from the group consisting of glycol ethers, tetrahydrofuran, acetonitrile, and dimethylformamide.

10. The process of claim 8 wherein the alkylating agent is selected from the group consisting of dialkyl sulfates, alkyl halides, alkyl-p-toluenesulfonates, partially fluorinated alkyl perfluoroalkanesulfonates, and alkyl perfluoroalkanesulfonates.

11. The process of claim 8 wherein the tertiary or aromatic amine is selected from the group consisting of substituted and unsubstituted, cyclic and acyclic trialkyl amines, pyridine, 2,6-dimethyl pyridine, 3,4-dimethyl pyridine, 3,5-dimethyl pyridine, 2-picoline, 3-picoline, 4-picoline and quinoline.

12. The process of claim 8 wherein the tertiary or aromatic amine is added in amount equal to the molar concentration of the acid contaminants present in the reaction mixture.

13. The process of claim 8 wherein the tertiary or aromatic amine is present in the reactant mixture at a molar concentration of between 0.01 and 5.0 percent.

14. The process of claim 8 wherein the phase transfer catalyst is present in the reaction mixture at a molar concentration of between 0.001 and 5.0 percent.

15. The process of claim 8 wherein the fluorinated carbonyl-containing compound is of the formula:

##STR11## wherein n is 1 to 3; and

when n is 1, R_f is a perfluorinated alkyl group having from 1 to about 15 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms;

when n is 2, R_f is a perfluorinated alkylene group having from 1 to about 15 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms;

when n is 3, R_f is a perfluorinated alkylidene group having from 1 to about 15 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms; and

wherein each X is independently a halogen atom or is of the formula R'"'"'_f or OOCR'"'"'_f where R'"'"'_f is a perfluorinated alkyl group having from 1 to about 10 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms;

where X is an R'"'"'_f group, that R'"'"'_f group may form a ring with said R_f group.

16. A process for the production of a secondary hydrofluoroether comprising:

(1) combining in a polar, aprotic solvent;

a) a fluorinated carbonyl-containing compound of the formula;

##STR12## wherein;

R_f is a fluorinated alkyl group having from 1 to about 15 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may optionally contain one or more catenary heteroatoms; and

X is a halogen atom or is OOCR'"'"'_f where R'"'"'_f is a fluorinated alkyl group having from 1 to about 10 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may optionally contain one or more catenary heteroatoms;

b) a perfluorinated olefin having from 2 to 6 carbon atoms;

c) an anhydrous source of fluoride ion; and

d) an amount of a tertiary or aromatic amine sufficient to neutralize substantially all acid contaminants present in the reaction mixture;

(2) contacting the resulting mixture with an alkylating agent of the general formula;

space="preserve" listing-type="equation">Y--R

wherein;

R is a substituted or unsubstituted, cyclic or acyclic, linear or branched, non-fluorinated or partially fluorinated alkyl group having from 1 to about 10 carbon atoms that may contain one or more catenary heteroatoms; and

Y is a chlorine, bromine, or iodine atom or is a group of the formula R'"'"'--SO₂ --O-- where R'"'"' is a phenyl or toluyl group or is a non-fluorinated or fully fluorinated alkyl group or an alkoxy group either of which may contain from 1 to about 10 carbon atoms; and

(3) recovering hydrofluoroether from the resulting product mixture.

17. The process of claim 16 wherein the anhydrous source of fluoride ion is selected from the group consisting of metal fluorides, metal bifluorides, quaternary ammonium fluorides, and quaternary phosphonium fluorides and wherein the polar, aprotic solvent is selected from the group consisting of glycol ethers, tetrahydrofuran, acetonitrile, and dimethylformamide.

18. The process of claim 16 wherein the alkylating agent is selected from the group consisting of dialkyl sulfates, alkyl halides, alkyl-p-toluenesulfonates, partially fluorinated alkyl perfluoroalkanesulfonates, and alkyl perfluoroalkanesulfonates.

19. The process of claim 16 wherein the tertiary or aromatic amine is selected from the group consisting of substituted and unsubstituted, cyclic and acyclic trialkyl amines, pyridine, 2,6-dimethyl pyridine, 3,4-dimethyl pyridine, 3,5-dimethyl pyridine, 2-picoline, 3-picoline, 4-picoline and quinoline.

20. The process of claim 16 wherein the tertiary or aromatic amine is added in amount equal to the molar concentration of the acid contaminants present in the reaction mixture.

21. The process of claim 16 wherein the tertiary or aromatic amine is present in the reactant mixture at a molar concentration of between 0.01 and 5.0 percent.

22. A process for the production of a secondary hydrofluoroether comprising:

(1) combining in a polar, aprotic solvent;

a) a fluorinated carbonyl-containing compound of the formula;

##STR13## wherein;

R_f is a fluorinated alkyl group having from 1 to about 15 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may optionally contain one or more catenary heteroatoms; and

X is a halogen atom or is OOCR'"'"'_f where R'"'"'_f is a fluorinated alkyl group having from 1 to about 10 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may optionally contain one or more catenary heteroatoms;

b) a perfluorinated olefin having from 2 to 6 carbon atoms;

c) an anhydrous source of fluoride ion;

d) an amount of a tertiary or aromatic amine sufficient to neutralize substantially all acid contaminants present in the reaction mixture; and

e) an effective amount of a phase transfer catalyst selected from the group consisting of quaternary ammonium and phosphonium salts, crown ethers, and cryptands;

(2) contacting the resulting mixture with an alkylating agent of the general formula;

space="preserve" listing-type="equation">Y--R

wherein;

R is a substituted or unsubstituted, cyclic or acyclic, linear or branched, non-fluorinated or partially fluorinated alkyl group having from 1 to about 10 carbon atoms that may contain one or more catenary heteroatoms; and

Y is a chlorine, bromine, or iodine atom or is a group of the formula R'"'"'--SO₂ --O-- where R'"'"' is a phenyl or toluyl group or is a non-fluorinated or fully fluorinated alkyl group or an alkoxy group either of which may contain from 1 to about 10 carbon atoms; and

(3) recovering hydrofluoroether from the resulting product mixture.

23. The process of claim 22 wherein the anhydrous source of fluoride ion is selected from the group consisting of metal fluorides, metal bifluorides, quaternary ammonium fluorides, and quaternary phosphonium fluorides and wherein the polar, aprotic solvent is selected from the group consisting of glycol ethers, tetrahydrofuran, acetonitrile, and dimethylformamide.

24. The process of claim 22 wherein the alkylating agent is selected from the group consisting of dialkyl sulfates, alkyl halides, alkyl-p-toluenesulfonates, partially fluorinated alkyl perfluoroalkanesulfonates, and alkyl perfluoroalkanesulfonates.

25. The process of claim 22 wherein the tertiary or aromatic amine is selected from the group consisting of substituted and unsubstituted, cyclic and acyclic trialkyl amines, pyridine, 2,6-dimethyl pyridine, 3,4-dimethyl pyridine, 3,5-dimethyl pyridine, 2-picoline, 3-picoline, 4-picoline and quinoline.

26. The process of claim 22 wherein the tertiary or aromatic amine is added in amount equal to the molar concentration of the acid contaminants present in the reaction mixture.

27. The process of claim 22 wherein the tertiary or aromatic amine is present in the reactant mixture at a molar concentration of between 0.01 and 5.0 percent.

28. The process of claim 22 wherein the phase transfer catalyst is present in the reaction mixture at a molar concentration of between 0.001 and 5.0 percent.

29. A method for recovering solvent from an alkylation process for the preparation of hydrofluoroether compounds comprising:

(1) combining in a glycol ether solvent;

a) a fluorinated carbonyl-containing compound of the formula;

##STR14## wherein n is 1 to 3; and

when n is 1, R_f is a fluorinated alkyl group having from 1 to about 15 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms;

when n is 2, R_f is a fluorinated alkylene group having from 1 to about 15 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms;

when n is 3, R_f is a fluorinated alkylidene group having from 1 to about 15 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms; and

wherein each X is independently a halogen atom or is of the formula R'"'"'_f or OOCR'"'"'_f where R'"'"'_f is a fluorinated alkyl group having from 1 to about 10 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms;

where X is an R'"'"'_f group, that R'"'"'_f group may form a ring with said R_f group;

b) an anhydrous source of fluoride ion;

c) an amount of a tertiary or aromatic amine sufficient to neutralize substantially all acid contaminants present in the reaction mixture;

(2) contacting the mixture with a sulfate group-containing alkylating agent of the general formula;

space="preserve" listing-type="equation">Y--R

wherein;

R is a substituted or unsubstituted, cyclic or acyclic, linear or branched, non-fluorinated or partially fluorinated alkyl group having from 1 to about 10 carbon atoms that may contain one or more catenary heteroatoms; and

Y is a group of the formula R'"'"'--SO₂ --O-- where R'"'"' is a phenyl or toluyl group or is a non-fluorinated or fully fluorinated alkyl group or an alkoxy group either of which may contain from 1 to about 10 carbon atoms;

(3) contacting the resulting product mixture with an amount of potassium hydroxide sufficient to neutralize any unreacted sulfate group-containing alkylating agent while maintaining the mixture at or below a temperature of 35°

C. until said neutralization is substantially complete;

(4) contacting the neutralized product mixture with an amount of hydrogen fluoride sufficient to bring the mixture to a substantially neutral pH; and

(5) recovering hydrofluoroether product from the product mixture.

30. The process of claim 29 wherein the anhydrous source of fluoride ion is selected from the group consisting of metal fluorides, metal bifluorides, quaternary ammonium fluorides, and quaternary phosphonium fluorides.

31. The process of claim 29 wherein the alkylating agent is selected from the group consisting of dialkyl sulfates, alkyl-p-toluenesulfonates, and alkyl perfluoroalkanesulfonates.

32. The process of claim 29 wherein the tertiary or aromatic amine is selected from the group consisting of substituted and unsubstituted, cyclic and acyclic trialkyl amines, pyridine, 2,6-dimethyl pyridine, 3,4-dimethyl pyridine, 3,5-dimethyl pyridine, 2-picoline, 3-picoline, 4-picoline and quinoline.

33. The process of claim 29 wherein the tertiary or aromatic amine is added in amount equal to the molar concentration of the acid contaminants present in the reaction mixture.

34. The process of claim 29 wherein the tertiary or aromatic amine is present in the reactant mixture at a molar concentration of between 0.01 and 5.0 percent.

35. The process of claim 29 wherein the fluorinated carbonyl-containing compound is of the formula:

##STR15## wherein n is 1 to 3; and

when n is 1, R_f is a perfluorinated alkyl group having from 1 to about 15 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms;

when n is 2, R_f is a perfluorinated alkylene group having from 1 to about 15 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms;

when n is 3, R_f is a perfluorinated alkylidene group having from 1 to about 15 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms; and

wherein each X is independently a halogen atom or is of the formula R'"'"'_f or OOCR'"'"'_f where R'"'"'_f is a perfluorinated alkyl group having from 1 to about 10 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms;

where X is an R'"'"'_f group, that R'"'"'_f group may form a ring with said R_f group.

36. A method for recovering solvent from an alkylation process for the preparation of hydrofluoroether compounds comprising:

(1) combining in a glycol ether solvent;

a) a fluorinated carbonyl-containing compound of the formula;

##STR16## wherein n is 1 to 3; and

when n is 1, R_f is a fluorinated alkyl group having from 1 to about 15 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms;

when n is 2, R_f is a fluorinated alkylene group having from 1 to about 15 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms;

when n is 3, R_f is a fluorinated alkylidene group having from 1 to about 15 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms; and

wherein each X is independently a halogen atom or is of the formula R'"'"'_f or OOCR'"'"'_f where R'"'"'_f is a fluorinated alkyl group having from 1 to about 10 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms;

where X is an R'"'"'_f group, that R'"'"'_f group may form a ring with said R_f group;

b) an anhydrous source of fluoride ion;

c) an amount of a tertiary or aromatic amine sufficient to neutralize substantially all acid contaminants present in the reaction mixture; and

d) an effective amount of a phase transfer catalyst selected from the group consisting of quaternary ammonium and phosphonium salts, crown ethers, and cryptands;

(2) contacting the mixture with a sulfate group-containing alkylating agent of the general formula;

space="preserve" listing-type="equation">Y--R

wherein;

R is a substituted or unsubstituted, cyclic or acyclic, linear or branched, non-fluorinated or partially fluorinated alkyl group having from 1 to about 10 carbon atoms that may contain one or more catenary heteroatoms; and

Y is a group of the formula R'"'"'--SO₂ --O-- where R'"'"' is a phenyl or toluyl group or is a non-fluorinated or fully fluorinated alkyl group or an alkoxy group either of which may contain from 1 to about 10 carbon atoms;

(3) contacting the resulting product mixture with an amount of potassium hydroxide sufficient to neutralize any unreacted sulfate group-containing alkylating agent while maintaining the mixture at or below a temperature of 35°

C. until said neutralization is substantially complete;

(4) contacting the neutralized product mixture with an amount of hydrogen fluoride sufficient to bring the mixture to a substantially neutral pH; and

(5) recovering hydrofluoroether product from the product mixture.

37. The process of claim 36 wherein the anhydrous source of fluoride ion is selected from the group consisting of metal fluorides, metal bifluorides, quaternary ammonium fluorides, and quaternary phosphonium fluorides.

38. The process of claim 36 wherein the alkylating agent is selected from the group consisting of dialkyl sulfates, alkyl-p-toluenesulfonates, and alkyl perfluoroalkanesulfonates.

39. The process of claim 36 wherein the tertiary or aromatic amine is selected from the group consisting of substituted and unsubstituted, cyclic and acyclic trialkyl amines, pyridine, 2,6-dimethyl pyridine, 3,4-dimethyl pyridine, 3,5-dimethyl pyridine, 2-picoline, 3-picoline, 4-picoline and quinoline.

40. The process of claim 36 wherein the tertiary or aromatic amine is added in amount equal to the molar concentration of the acid contaminants present in the reaction mixture.

41. The process of claim 36 wherein the tertiary or aromatic amine is present in the reactant mixture at a molar concentration of between 0.01 and 5.0 percent.

42. The process of claim 36 wherein the phase transfer catalyst is present in the reaction mixture at a molar concentration of between 0.001 and 5.0 percent.

43. The process of claim 36 wherein the fluorinated carbonyl-containing compound is of the formula:

##STR17## wherein n is 1 to 3; and

when n is 1, R_f is a perfluorinated alkyl group having from 1 to about 15 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms;

when n is 2, R_f is a perfluorinated alkylene group having from 1 to about 15 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms;

when n is 3, R_f is a perfluorinated alkylidene group having from 1 to about 15 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms; and

wherein each X is independently a halogen atom or is of the formula R'"'"'_f or OOCR'"'"'_f where R'"'"'_f is a perfluorinated alkyl group having from 1 to about 10 carbon atoms that may be substituted or unsubstituted, cyclic or acyclic, linear or branched and may contain one or more catenary heteroatoms;

where X is an R'"'"'_f group, that R'"'"'_f group may form a ring with said R_f group.

44. An alkylation process for the preparation of hydrofluoroether compounds, said process comprising:

(1) combining in a polar, aprotic solvent;

a) perfluorinated carboxylic acid ester;

b) an anhydrous source of fluoride ion; and

c) an amount of a tertiary or aromatic amine sufficient to neutralize substantially all acid contaminants present in the reactant mixture;

(2) contacting the resulting mixture with an alkylating agent of the general formula;

space="preserve" listing-type="equation">Y--R

wherein;

R is a substituted or unsubstituted, cyclic or acyclic, linear or branched, non-fluorinated or partially fluorinated alkyl group having from 1 to about 10 carbon atoms that may contain one or more catenary heteroatoms; and

Y is a chlorine, bromine, or iodine atom or is a group of the formula R'"'"'--SO₂ --O-- where R'"'"' is a phenyl or toluyl group or is a non-fluorinated or fully fluorinated alkyl group or an alkoxy group either of which may contain from 1 to about 10 carbon atoms; and

(3) recovering hydrofluoroether from the resulting product mixture.