Fluorination of acrylate esters and derivatives
The present invention generally relates to processes for converting acrylate esters or a derivative thereof to difluoropropionic acid or a derivative thereof. This process is generally performed using fluorine gas in a hydrofluorocarbon solvent.
1. A process for fluorinating a double bond comprising:
forming a reaction mixture comprising a fluorocarbon or hydrofluorocarbon solvent, fluorine gas, and a compound of formula 1
wherein R 1 is hydroxy, alkoxy, chloro, or —OC(O)CH═CH 2 to form a compound of formula 2
wherein R 2 is hydroxy, alkoxy, chloro, —OC(O)CHFCH 2 F; and to form fluoromethyl 2,3-difluoropropanoate, methyl 2,3,3-trifluoropropanoate, fluoromethyl 2,3,3-trifluoropropanoate, or a combination thereof.
2. The process of claim 1 wherein R 1 is methoxy.
3. The process of claim 1 wherein R 1 is hydroxy.
4. The process of claim 1 wherein R 1 is chloro.
5. The process of claim 2 , wherein R 2 is methoxy.
6. The process of claim 1 , wherein the hydrofluorocarbon solvent has a melting point less than about −20° C.
7. The process of claim 1 , wherein the reaction mixture is a liquid at a temperature less than about −40° C.
8. The process of claim 1 , wherein the hydrofluorocarbon solvent has a boiling point greater than about 30° C.
9. The process of claim 1 , wherein the hydrofluorocarbon solvent is 2H,3H-decafluoropentane, eicosafluorononane, tetradecafluorohexane, tetradecafluoro-2-methylpentane, hexafluorobenzene, octadecafluorodecahydronaphthalene, octadecafluorooctane, octafluorocyclopentene, octafluorotoluene, perfluoro(1,3-dimethylcyclohexane), perfluoroheptane, perfluoro(2-butyltetrahydrofuran), perfluorotriethylamine, heptacosafluorotributylamine, tetradecafluoromethylcyclohexane, 1,1,1,3,3-pentafluorobutane, or a combination thereof.
10. The process of claim 9 , wherein the hydrofluorocarbon solvent is 2H,3H-decafluoropentane.
11. The process of claim 9 , wherein the reaction mixture has a temperature from about −80° C. to about −20° C.
12. The process of claim 11 , wherein the reaction mixture has a temperature from about −80° C. to about −60° C.
13. The process of claim 1 , wherein the reaction mixture further comprises a fluorination additive and the fluorination additive is an alcohol, an acid, or a combination thereof.
14. The process of claim 13 , wherein the fluorination additive is the alcohol, and the alcohol comprises ethanol, methanol, trifluoroethanol, or a combination thereof.
15. The process of claim 13 , wherein the fluorination additive is the acid, and the acid comprises triflic acid, trifluoroacetic acid, sulfuric acid, formic acid, acetic acid, or a combination thereof.
16. The process of claim 1 , wherein the process is a continuous process and has an infusion rate of the compound of formula 1 or 5 from about 0.2 to about 2 mL/minute.
17. The process of claim 9 , further comprising contacting the compound of formula 2 with an alcohol and a catalyst, wherein the catalyst is a Brønsted acid or a Lewis acid.
18. The process of claim 1 , wherein methyl 2,3,3-trifluoropropanoate, fluoromethyl 2,3,3-trifluoropropanoate, or a combination thereof is formed.
19. The process of claim 1 , wherein methyl 2,3,3-trifluoropropanoate is formed.