反应详情

A mixture of (L)-proline methyl ester hydrochloride (0.28 g), 2-(R)-ethoxycarbonylamino-3-isopropylsulfanyl-3-methyl-butyric acid (0.44 g), N-methyl morpholine (0.73 mL) and 0.54 g of 2-(1H-benzotriazole-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate (TBTU) in 10 mL of dry N,N-dimethylformamide was stirred for 16 h at ambient temperature. The volatiles were pumped off and water was added followed by extraction with ethyl acetate and concentration of the organic layer. The remaining residue was purified by silica chromatography (ethyl acetate/isohexane=1/1) to give 0.45 g (72%) of the title compound as a colorless oil. (+)-APCI-MS: 375 (MH+).

1. extractionfollowed by extraction with ethyl acetate and concentration of the organic layer
2. customThe remaining residue was purified by silica chromatography (ethyl acetate/isohexane=1/1)