反应详情

N-Boc-Cys(StBu)-OH 9 (1.00 g, 3.23 mmol) was dissolved in dry dichloromethane (25 mL) followed by the addition of EDC (0.75 g, 3.87 mmol), HOBt (0.53 g, 3.87 mmol), NMM (1.77 mL, 16.15 mmol) and glycine methyl ester hydrochloride (0.61 g, 4.84 mmol) at 0° C. under argon. The reaction mixture was then allowed to warm to room temperature and stirred overnight. After evaporation of solvent, the residue obtained was taken in EtOAc (35 mL), washed with 20% citric acid solution (2 30 mL), sat. NaHCO3 (20 mL), brine and dried over MgSO4. The EtOAc layer was evaporated in vacuo and resulting crude product was purified by flash silica gel column chromatography to get the dipeptide product 12 as white foam (1.09 g, 89% yield). 1H NMR (300 MHz, CDCl3) δ7.35, 5.81 (2H), 4.44 (1H), 3.82 (2H), 3.61 (3H), 3.02-2.83 (2H), 1.43, 1.28 (18H); 13C NMR (75 MHz, CDCl3) δ171.2, 169.9, 155.5, 80.0, 53.5, 52.3, 48.0, 41.4, 37.9, 30.0, 28.5; ESI-LRMS m/z 380.5 (M+H)+.

1. customAfter evaporation of solvent
2. customthe residue obtained
3. washwashed with 20% citric acid solution (2 30 mL), sat. NaHCO3 (20 mL), brine
4. dry with materialdried over MgSO4
5. customThe EtOAc layer was evaporated in vacuo
6. customresulting crude product
7. customwas purified by flash silica gel column chromatography