Fluoronation of alpha-haloalkyl ketones

1. A method for producing an α-fluoroalkyl ketone of the formula:

said method consisting essentially of contacting a non-fluoro α-haloalkyl ketone of the formula:

with a fluorohydrogenate salt under reaction conditions sufficient to produce an α-fluoroalkyl ketone of the Formula I, wherein the fluoride anion of said fluorohydrogenate salt is solvated with >1 and ≦3 equivalent of hydrogen fluoride, and wherein

Ar is aryl or heteroaryl, each of which is optionally substituted;

X is a non-fluoro halide;

each of R a and R b is independently hydrogen, alkyl or halide;

provided when R a , R b or both of the non-fluoro α-haloalkyl ketone of Formula II is a non-fluoro halide, then the corresponding R a , R b or both of α-halofluoroalkyl ketone of Formula I that is produced can also be fluoride.

2. The method of claim 1 , wherein Ar is optionally substituted aryl.

3. The method of claim 2 , wherein Ar is substituted with one or more substituents, each of which is independently selected from the group consisting of C 1-12 alkyl, C 1-12 alkoxy, aryloxy, halide, cyano, and nitro.

4. The method of claim 1 , wherein said fluorohydrogenate salt is of the formula: Q + [F.(HF) n ], wherein Q is an onium cation and 1<n≦3.

5. The method of claim 4 , wherein Q + is a quaternary ammonium cation, a quaternary phosphonium cation or a quaternary thiazolium cation.

6. The method of claim 5 , wherein Q + is a quaternary ammonium cation.

7. The method of claim 6 , wherein Q + is selected from the group consisting of N-ethyl-N-methylimidazolium, N-methyl-N-propylpyrrolidinium or N-methyl-N-butylpyrrolidinium, and a combination thereof.

8. The method of claim 1 , wherein said fluorohydrogenate salt is an ionic liquid.

9. The method of claim 1 , wherein R a and R b are hydrogen.

10. The method of claim 1 , wherein the reaction is carried out in the presence of an organic solvent.

11. The method of claim 10 , wherein the organic solvent comprises dichloromethane, chloroform, tetrahydrofuran, ether, toluene, mono-, di- or triglyme, or a combination thereof.

12. The method of claim 1 , wherein the amount of said fluorohydrogenate salt used is from about 1 to about 3 equivalents relative to the amount of said non-fluoro α-halomethyl aryl ketones.

13. The method of claim 1 further comprising the steps of contacting the reaction mixture with an acidic aqueous solution.

14. The method of claim 13 , wherein said acidic aqueous solution comprises hydrochloric acid, aqueous HF, sulfuric acid, nitric acid, or any water soluble Lewis acid.

15. The method of claim 1 , wherein said α-fluoromethyl aryl ketone is an α-perfluoromethyl aryl ketone.

16. A method for producing an α-fluoroalkyl aryl ketone, said method consisting essentially of contacting a non-fluoro α-haloalkyl aryl ketone with a fluorohydrogenate ionic liquid optionally in the presence of a solvent under reaction conditions sufficient to produce an α-fluoroalkyl aryl ketone.

17. The method of claim 16 , wherein said α-fluoroalkyl aryl ketone is α-fluoromethyl aryl ketone.

18. The method of claim 16 , wherein said fluorohydrogenate ionic liquid comprises N-methyl-N-propylpyrrolidinium fluorohydrogenate, N-methyl-N-butylpyrrolidinium fluorohydrogenate, N-methyl-N-ethylimidazolium fluorohydrogenate or a mixture thereof.

19. A method for producing an α-perfluoroalkyl ketone of the formula:

said method comprising contacting a non-fluoro α-haloalkyl ketone of the formula:

with a fluorohydrogenate salt under reaction conditions sufficient to produce an α-fluoroalkyl ketone of the Formula I,

wherein

Ar is aryl or heteroaryl, each of which is optionally substituted;

X is a non-fluoro halide; and

each of R a and R b is independently a halide.