Triethylamine → Benzyl (5-aminobicyclo[3.2.1]octan-1-yl)carbamate

Participants

Reaction Steps

A mixture of 5-(benzyloxycarbonylamino)bicyclo[3.2.1]octane-1-carboxylic acid (8.5 g, 28.0 mmol), diphenylphosphonic azide (9.3 g, 33.8 mmol) and triethylamine (5 mL, 68 mmol) in toluene (150 mL) was stirred at room temperature for one hour, and then refluxed for three hours. After cooled to 0° C., a solution of TMSOK (10.7 g, 83.6 mmol) in THF (85 mL) was added. The reaction mixture was warmed to room temperature and stirred for 1 h, and then quenched with 5% citric acid (20 mL) and concentrated under reduced pressure. The residue was treated with aq. HCl (2 N, 200 mL) at 0° C. The resulting mixture was extracted with ethyl acetate (3×100 mL). The aqueous phase was adjusted to pH 9˜10 with Na2CO3 and extracted with dichloromethane/methanol (10/1, 3×150 mL). The combined organic layer was washed with water and brine, dried over sodium sulfate and concentrated under reduced pressure to afford 5.13 g (42%) of benzyl 5-aminobicyclo[3.2.1]octan-1-ylcarbamate as a yellow solid. ESI-MS m/z: 275 (M++1).

Provenance & Evidence