Process for the electrochemical fluorination of organic compounds

Patent metadata

Field	Value
Publication number	US-9340884-B2
Application number	US-201113316864-A
Country	US
Kind code	B2
Filing date	Dec 12, 2011
Priority date	Dec 15, 2010
Publication date	May 17, 2016
Grant date	May 17, 2016

Abstract

The present invention relates to a process for the electrochemical fluorination of an organic compound, wherein a reaction solution comprising the organic compound and a fluorinating agent is subjected to electric current in an electrochemical fluorination cell.

First claim

The invention claimed is:

1. A process of electrochemically fluorinating an organic compound, the process comprising:
electrolyzing a liquid reaction medium in a electrochemical cell,
wherein the liquid reaction medium comprises an organic compound comprising a hydrogen atom bound to a carbon atom;
the electrochemical cell comprises a cathode and an anode;
the liquid reaction medium further comprises a fluorinating agent selected from complexes of HF with amine bases;
the electrolyzing replaces the hydrogen atom of the organic compound with a fluorine atom; and
the anode comprises a gas diffusion layer,
wherein the gas diffusion layer comprises a fibre layer or substrate, and a microporous layer consisting of carbon particles attached to each other, and wherein the organic compound is a compound of formula (I):

wherein
X is O, N—R 3 or CR 4 R 5 ,
R 1 is C 1 -C 6 -alkyl, C 1 -C 6 -alkoxy-C 1 -C 6 -alkyl, formyl, C 1 -C 6 -alkylcarbonyl, or C 1 -C 6 -alkyloxycarbonyl, or, if X is a CR 4 R 5 group, R 1 is optionally C 1 -C 6 -alkoxy, or if X is N—R 3 or CR 4 R 5 , R 1 is optionally C 1 -C 6 -alkylcarbonyloxy,
R 2 is hydrogen, C 1 -C 6 -alkyl, C 1 -C 6 -alkoxy-C 1 -C 6 -alkyl, C 6 -C 10 -aryl-C 1 -C 6 -alkyl, C 3 -C 12 -cycloalkyl, or C 6 -C 10 -aryl,
R 3 is hydrogen, C 1 -C 6 -alkyl, C 1 -C 6 -alkoxy-C 1 -C 6 -alkyl, formyl, C 1 -C 6 alkylcarbonyl, or C 1 -C 6 -alkyloxycarbonyl,
R 4 and R 5 are each independently hydrogen, C 1 -C 6 -alkyl, C 1 -C 6 -alkoxy-C 1 -C 6 -alkyl, or C 1 -C 6 -alkoxy,
R 1 and R 2 and the X—(C═O)—O group to which they are bound optionally form a 5- to 7-membered heterocyclic ring optionally comprising O, S, NR a or C═O, wherein R a is hydrogen, alkyl, cycloalkyl, or aryl, and
if X is a CR 4 R 5 group, R 1 and R 4 and the carbon atom to which they are bound optionally form a carbocyclic ring of from 3 to 7 members.

2. The process according to claim 1 , wherein the fluorinating agent comprises a HF-complex which comprises a polyhydrofluoride complex of a trialkylamine or a tetraalkylammoniumfluoride.

3. The process according to claim 1 , wherein the fluorinating agent comprises a HF-complex which comprises (C 2 H 5 ) 3 N.3 HF.

4. The process according to claim 1 , wherein the cathode is a gas diffusion layer electrode, a Pt electrode, a Pb electrode, a steel electrode, or a Ni electrode.

5. The process according to claim 1 , wherein the liquid reaction medium does not comprise any additional solvents or additives.

6. The process according to claim 1 , wherein a current density of the electrolyzing is from 10 to 250 mA/cm 2 .

7. The process according to claim 1 , wherein selectivity, conversion rate, or both are greater than in an otherwise-identical process wherein the anode does not comprise the gas diffusion layer.

8. The process according to claim 7 , wherein the organic compound comprises ethylene carbonate and wherein a fluorination product of the electrolyzing comprises 4-fluoroethylene carbonate.

9. The process according to claim 7 , wherein the organic compound comprises propylene carbonate and wherein a fluorination product of the electrolyzing comprises 4-fluoropropylene carbonate.

10. The process according to claim 1 , wherein the gas diffusion layer does not comprise a catalyst.

11. The process according to claim 1 , wherein a molar ratio of the fluorinating agent to the organic compound is in a range from 1:1 to 99:1.

12. The process according to claim 1 , wherein a molar ratio of the fluorinating agent to the organic compound is in a range from 50:25 to 99:1.

Assignees

• Aust Nicola Christiane
• Malkowsky Itamar Michael
• Basf Se

Inventors

• Aust Nicola Christiane
• Malkowsky Itamar Michael

Classifications

• C25B3/08 Primary

  Chemistry & Metallurgy · mapped topic

• C25B3/28 Primary

  Fluorination · CPC title