Trifluoroacetic acid → Trifluoroacetic acid

Participants

Reaction Conditions

Reaction Steps

TFA and TFM were obtained from Mallinckrodt and Halocarbon Products, acetic acid and anhydride from J. T. Baker and diketene from Aldrich Chemical. Ketene was prepared by two methods: Method A: Diketene was passed through a heated tube at a temperature between 500-600° C. The formed gas was condensed in a dry ice bath at −78° C., redistilled into a calibrated cold finger, measured based on a density of 0.65 g/ml and transferred under reduced pressure to a reaction vessel also chilled to −78° C. Method B: Acetic acid was passed through a heated tube with quartz packing at a temperature between 500-600° C. The formed gas was trapped in a series of scrubbers through which TFA was circulated at a rate approximately 4.5 ml per minute. The TFA solution of Ac-TFA obtained from the scrubbers was characterized by 13C NMR to determine the relative amounts of acetic acid, acetic anhydride, acetyl trifluoroacetate and trifluoroacetic anhydride.

Provenance & Evidence