反应详情

Glycine tert-butyl ester (0.015 g, 0.112 mmol) and N-Methylmorpholine (0.028 g, 0.281 mmol) were added to a solution of [4-((2R,3R)-3-{[(5,5-dimethyl-2-phenyl-1,3-dioxan-2-yl)methyl]thio}-4-oxo-1-phenylazetidin-2-yl)phenoxy]acetic acid (0.050 g, 0.094 mmol) in CH2Cl2 (5 ml). After 10 minutes, TBTU (0.039 g, 0.122 mmol) was added. The reaction was stirred overnight. The resulting tert-butyl ester was purified on silica gel and eluted with EtOAc/CH2Cl2 (25/75). The pure fractions were collected and concentrated. CH2Cl2 (4 ml) and TFA (1 ml) were added. The solvent was evaporated after 2 h and the residue was purified by preparative HPLC using an eluent of 20-70% CH3CN in 0.1M NH4OAc buffer. Freeze-drying of the pure fractions gave the title product as a colourless solid. M/z: 503.5 (M-1). 1H NMR (CD3CN), 400 MHz] δ 3.84 (d, 2H), 4.18 (d, 1H), 4.24 (s, 2H), 4.50 (s, 2H), 5.04 (d, 1H), 6.99-7.12 (m, 3H), 7.25-7.66 (m, 9H), 7.94-7.96 (m, 2H).

1. customThe resulting tert-butyl ester was purified on silica gel
2. washeluted with EtOAc/CH2Cl2 (25/75)
3. customThe pure fractions were collected
4. concentrationconcentrated
5. additionCH2Cl2 (4 ml) and TFA (1 ml) were added
6. customThe solvent was evaporated after 2 h
7. customthe residue was purified by preparative HPLC
8. customFreeze-drying of the pure fractions