1,2-Dichloroethane → Di-tert-butyl [(3R,6S)-6-(2,3-difluorophenyl)-1-(2-hydroxy-2-methylpropyl)-2-oxoazepan-3-yl]imidodicarbonate

참여 물질

반응 조건

반응 단계

A mixture of (5S) —N2,N2-bis(tert-butoxycarbonyl)-5-(2,3-difluorophenyl)-D-lysine (0.569 g, 1.24 mmol, described in Intermediate 4), 1-chloro-2-methyl-2-propanol (0.202 g, 1.86 mmol) and N,N-diisopropylethylamine (0.713 mL, 4.10 mmol) in EtOH (5 mL) was heated at 75° C. for 18 h. The reaction mixture was concentrated to dryness under reduced pressure and the residue was dissolved in CH2Cl2 (20 mL), then EDC (0.358 g, 1.87 mmol), HOAT (0.252 g, 1.87 mmol) and N,N-diisopropylethylamine (0.650 mL, 3.73 mmol) were added. The resulting mixture was stirred at ambient temperature for 18 h, then aqueous NaHCO3 was added. The layers were separated and the aqueous phase was extracted with CH2Cl2. The combined organic extracts were dried over MgSO4, filtered, and concentrated in vacuo. The residue was purified by silica gel chromatography, eluting with a gradient of hexane:EtOAc—90:10 to 65:35, to give the title compound. MS: m/z=513 (M+1).

출처 및 근거