反应详情

Dry DMF (30 mL) was added to zinc dust (2.78 g, 42.6 mmol) in a flame dried bottom flask under N2. (R)-Methyl 2-(tert-butoxycarbonylamino)-3-iodopropanoate (3.85 g, 11.7 mmol) was added followed by a catalytic amount of iodine (1.06 g, 0.10 mmol). The mixture was stirred at ambient temperature for 0.5 h. Pd2(dba)3 (487 mg, 0.050 mmol), S—Phos (437 g, 0.100 mmol) and 4-bromo-2-methoxypyridine (2.00 g, 10.6 mmol) were added. The reaction mixture was heated at 60° C. for 6 h and then cooled to ambient temperature. EtOAc (200 mL) and water (200 mL) were added. The organic phase was separated, washed with water (300 mL×3) and brine (300 mL×1), dried over anhydrous sodium sulfate, and concentrated. The residue was purified by flash column chromatography on silica gel (hexane/EtOAc=2:1) to afford (S)-methyl 2-(tert-butoxycarbonylamino)-3-(2-methoxypyridin-4-yl)propanoate (2.4 g, 73% yield).

1. customdried bottom flask under N2
2. temperatureThe reaction mixture was heated at 60° C. for 6 h
3. temperaturecooled to ambient temperature
4. customThe organic phase was separated
5. washwashed with water (300 mL×3) and brine (300 mL×1)
6. dry with materialdried over anhydrous sodium sulfate
7. concentrationconcentrated
8. customThe residue was purified by flash column chromatography on silica gel (hexane/EtOAc=2:1)