Carbon Dioxide → 4,5,5-trifluoropent-4-enoic Acid

Participants

Reaction Conditions

Reaction Steps

To a stirred mixture of 2.4 grams (0.1 mole) of magnesium turnings in 100 ml of diethyl ether was added 18.9 grams (0.1 mole) of 4-bromo-1,1,2-trifluoro-1-butene. Upon completion of addition the reaction mixture was heated under reflux until the reaction was complete. The reaction mixture was cooled to 0° C. and 9.0 grams (0.2 mole) of carbon dioxide was bubbled in slowly. Upon completion of addition the reaction mixture was stirred for one hour, then 100 ml of aqueous 20% hydrochloric acid was added to destroy the excess magnesium. The reaction mixture was extracted with three 40 ml portions of diethyl ether. The combined extracts were cooled and 40 ml of aqueous 25% sodium hydroxide was added slowly. The organic layer was separated and extracted with one 40 ml portion of aqueous 25% sodium hydroxide. The combined base layers were cautiously acidified with aqueous 20% hydrochloric acid. The mixture was extracted with two 100 ml portions of diethyl ether. The combined extracts were dried with sodium sulfate and filtered. The filtrate was concentrated under reduced pressure to give 6.9 grams of 4,5,5-trifluoro-4-pentenoic acid as an oil. The nmr and ir spectra were consistent with the proposed structure.

Provenance & Evidence