Ammonia → ((S)-1-Carbamoyl-2-methoxyethyl)carbamic acid tert-butyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a solution of (S)-2-tertbutoxycarbonylamino-3-methoxypropionic acid (1.13 g, 5.2 mmol) in anhydrous THF (20 mL) at −15° C. was added N-methylmorpholine (0.57 mL, 5.2 mmol) and isobutylchloroformate (0.67 mL, 5.2 mmol) under a nitrogen atmosphere. After 2 minutes, 33% aqueous ammonia (0.45 mL, 7.8 mmol) was added and the resulting mixture was 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, then dried (MgSO4) and concentrated in vacuo. The resulting pink oil was used without further purification (1.03 g, 91%). 1H NMR (CDCl3, 300 MHz): δ 6.42 (1H, br s), 5.48 (2H, br s), 4.25 (1H, br s), 3.83-3.74 (1H, m), 3.52-3.41 (1H, m), 3.40 (3H, s), 1.42 (9H, s).

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