1,2-Dichloroethane → Tert-butyl 4-(cyclopropylamino)-3-hydroxy-4-oxo-1-phenylbutan-2-ylcarbamate

Participants

Reaction Steps

To 3-(tert-butoxycarbonylamino)-2-hydroxy-4-phenylbutanoic acid (3 g, 10.16 mmol), cyclopropanamine (780 μL, 11.26 mmol) in dichloromethane (70 ml) at 5° C. EDC (2.4 g, 12.52 mmol), HOBt (1.9 g, 12.41 mmol) and Et3N (3 ml, 21.52 mmol) were added and the mixture stirred at room temperature for 48 h. After completion of reaction dichloromethane (100 ml) was added, the solution washed with water and brine, dried, filtered off with suction and concentrated to give 3.9 g of a brown oil which was purified further via chromatography on silica gel (eluent: CH2Cl2+5-30% (v/v) methanol). After evaporation of the combined product fractions 0.82 g of a pale oil were obtained; ESI-MS [M-Boc+H]±: 235.1.

Provenance & Evidence