Borane → tert-Butyl 4-aminomethyl-4-fluoropiperidine-1-carboxylate

Participants

Reaction Steps

To a 0° C. solution of 4-3 (8.83 g, 38.7 mmol) in 75 mL dry THF was added a solution of 1 M borane in THF (155 mL, 155 mmol) over 30 min. After 30 min more, the cold reaction was slowly quenched with EtOH (200 mL) and all solvent was removed in vacuo. The residue was taken up in saturated aq. NH4Cl/EtOAc (150 mL) and extracted with EtOAc (3×150 mL). The organic layers were washed with 1 N aq. NaOH, brine, dried over MgSO4, filtered, and concentrated in vacuo, giving crude 4-4 as a pale yellow oil. The crude amine 4-4 was carried forward. 1H NMR (CDCl3, 300 MHz): 3.94 (br, 2H), 3.08 (m, 2H), 1.85 (m, 2H), 1.51 (m, 4H), 1.44 (s, 9H); MS (Electrospray): m/z 218.2 (M−Me+H), 177.2 (M−t−Bu+H).

Provenance & Evidence