Borane → 2,2-Difluoro-2-phenylethylamine

Temperature

0 °C

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, 5H), 3.18 (t, 2H, J=14.5 Hz), 1.60 (s(br), 2H).

1. temperaturethe reaction mixture was refluxed for 16 hours
2. temperatureAfter cooling to room temperature
3. concentrationThe mixture was concentrated in vacuo to about 50 mL
4. extractionextracted with dichloromethane (3×50 mL)
5. washThe dichloromethane layer was washed with brine
6. dry with materialdried over Na2SO4
7. concentrationconcentrated in vacuo
8. customThe residue was then purified by flash column chromatography (1:1 ethyl acetate:hexane)

ORD record

ord-0a8dde71ef24498093945a0390d8ea30

Source dataset

uspto-grants-2002_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06476016B2