Borane → 2,2-Difluoro-2-phenylethylamine

Participants

Reaction Conditions

Reaction Steps

2,2-Difluoro-2-phenylacetamide (2.4 g, 14 mmol), as prepared in the preceding step, was dissolved in tetrahydrofuran (30 mL) and cooled to 0° C. To this stirred solution was added 1.0 M borane in tetrahydrofuran (35 mL, 35 mmol) dropwise in 30 minutes, and the reaction mixture was refluxed for 16 hours. After cooling to room temperature, a solution of potassium carbonate (5 g) in water (20 mL) was added to the reaction mixture. The mixture was concentrated in vacuo to about 50 mL and extracted with dichloromethane (3×50 mL). The dichloromethane layer was washed with brine, dried over Na2SO4, and concentrated in vacuo. The residue was then purified by flash column chromatography (1:1 ethyl acetate:hexane) to give the title compound as a pale yellow oil (900 mg, 41%). 1H NMR (400 MHz, CDCl3) δ 7.45 (m, 5 H), 3.18 (t, 2 H, J=14.5 Hz), 1.60 (s(br), 2 H).

Provenance & Evidence