反应详情

HATU (1.72 g, 4.5 mmol) was added to a solution of 2,2-bis(tert-butoxycarbonylamino)-5-(1-ethoxycarbonyl-ethylamino)-pentanoic acid (1.31 g, 3.0 mmol) and 4-methylmorpholine in dimethylformamide (50 mL). After 30 minutes the solvent was removed under reduced pressure and the residue was subjected to flash chromatography with eluent of ethyl acetate and hexane. The product-containing fractions were combined and the solvent was removed under reduced pressure to provide 2-[3,3-bis(tert-butoxycarbonylamino)-2-oxo-piperidin-1-yl]-propionic acid ethyl ester (1.11 g, 2.6 mmol, 86%). C20H34N2O7 calculated 414.2 observed [M+1]+ 415.2; rt=2.77 min.

1. customAfter 30 minutes the solvent was removed under reduced pressure
2. customthe solvent was removed under reduced pressure