Ammonia → ((S)-2-Benzyloxy-1-carbamoylethyl)carbamic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

To a solution of (S)-3-benzyloxy-2-(tert butoxycarbonylamino)propionic acid (0.98 g, 3.3 mmol) in anhydrous THF (13 mL) at −15° C. was added N-methylmorpholine (0.4 mL, 3.3 mmol) and isobutylchloroformate (0.4 mL, 3.3 mmol) under a nitrogen atmosphere. After 2 minutes, 33% aqueous ammonia (0.3 mL, 5 mmol) was added and the resulting mixture stirred at −15° C. for 2 h. The reaction mixture was allowed to warm to RT and was partitioned between EtOAc and a saturated aqueous solution of NaHCO3. The combined organic fractions were washed with aqueous 5% NaHCO3, water, dried (MgSO4) and concentrated in vacuo. The resulting white solid was used without further purification (quant. yield). 1H NMR (CDCl3, 300 MHz): δ 7.41-7.25 (5H, m), 6.42 (1H, br s), 5.48 (2H, br s), 4.55 (2H, dd, J=22., 12 Hz), 4.30 (1H, br s), 3.95-3.85 (1H, dd, J=9.5, 3.9 Hz), 3.55 (1H, dd, J=9.5, 6.7 Hz), 1.42 (9H, s).

Provenance & Evidence