Trifluoroacetic acid → 2,2,2-Trifluoro-1-[3-(3-fluorophenyl)azetidin-1-yl]ethanone

Participants

Reaction Steps

A solution of tert-butyl 3-(3-fluorophenyl)azetidine-1-carboxylate (Intermediate 92, 2.51 g) in trifluoroacetic acid (15 mL) and DCM (15 mL) was left to stand at room temperature for 30 minutes. The mixture was concentrated in vacuo and the residue was azeotroped with toluene. The residue was dissolved in DCM (15 mL) and pyridine (5 mL) and trifluoroacetic anhydride (3.15 g) was added. The mixture was left to stand at room temperature for 30 minutes, then washed with 1M hydrochloric acid and filtered through a phase separator. The filtrate was concentrated in vacuo and the residue was purified by chromatography on silica, eluting with a mixture of ethyl acetate and cyclohexane with a gradient of 0-20% to give 2,2,2-trifluoro-1-[3-(3-fluorophenyl)azetidin-1-yl]ethanone (2.31 g) as a light brown oil.

Provenance & Evidence