Ammonia → tert-Butyl (S)-(1-amino-1-oxobutan-2-yl)carbamate

Participants

Reaction Conditions

Reaction Steps

To a solution of (S)-2-tertbutoxycarbonylamino butyric acid (1.2 g, 5.8 mmol) in anhydrous THF (20 mL) cooled to −15° C. was added N-methylmorpholine (0.64 mL, 5.8 mmol) and isobutylchloroformate (0.75 mL, 5.8 mmol) under an atmosphere of nitrogen. After 2 minutes, 33% aqueous ammonia (0.5 mL, 8.7 mmol) was added and the resulting mixture stirred at this −15° C. for 2 h. The reaction mixture was left to warm to RT then 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 (1.0 g, 85%). 1H NMR (CDCl3, 300 MHz): δ 6.15 (1H, br s), 5.63 (1H, br s), 5.08 (1H, br s), 4.05 (1H, br s), 1.95-1.80 (1H, m), 1.70-1.53 (1H, m), 1.40 (9H, s), 0.95 (3H, d, J=6.71 Hz). 327997

Provenance & Evidence