Trifluoroacetic acid → 1-(3-(2-Fluoropyridin-3-yl)pyrrolidin-1-yl)ethanone

Participants

Reaction Steps

To tert-butyl 3-(2-fluoropyridin-3-yl)pyrrolidine-1-carboxylate (0.25 g, 0.939 mmol) dissolved in DCM (3.1 mL) was added trifluoroacetic acid (1.05 mL, 14.1 mmol). The reaction mixture was stirred at RT for 1 h. The solvent was evaporated in vacuo and to the residue dissolved in DCM (1 mL) was added acetic anhydride (0.44 mL, 4.7 mmol) and sodium bicarbonate (0.4 g, 4.7 mmol). The reaction mixture was stirred at RT under N2 for 3 h. The reaction mixture was partitioned between 1N NaOH and DCM. The aqueous layer was back extracted with DCM (3×) and the combined DCM layer was dried (Na2SO4) and concentrated. The crude material was purified by chromatography through a Redi-Sep pre-packed silica gel column (40 g), eluting with a gradient of 0% to 100% EtOAc in hexane, then 10% MeOH in EtOAc, to provide 1-(3-(2-fluoropyridin-3-yl)pyrrolidin-1-yl)ethanone as tan oil. [M+H]=209.2.

Provenance & Evidence