反应详情

6.26 g (18.83 mmol) of 3-[(3,4-dichloro-phenyl)-(2-oxo-ethyl)-amino]-propionic acid tert-butyl ester and 4.89 g (18.83 mmol) of (S)-2-amino-4-benzyloxy-butyric acid methyl ester; hydrochloride (intermediate 5) were dissolved in DCE:EtOH (1:1, 134 ml) and treated slowly with 3.15 ml (18.83 mmol) of triethylamine, 4.94 ml of AcOH and 4.94 ml (39.55 mmol, 8 M in pyridine) of pyridine-borane complex (cooling with a water bath to RT). The reaction was stirred at RT over 1 h, then partitioned between aq. NaHCO3 solution and EtOAc (3×). The organic phases were washed with aq. sat. NaHCO3 solution, aq. 10% NaCl solution, dried over Na2SO4 evaporated and purified by flash silica gel column (CH2Cl2:MeOH 99:1) to yield 9.35 g (92%) of the title compound as yellow oil. MS: 539.5 (MH+, 2Cl).

1. custompartitioned between aq. NaHCO3 solution and EtOAc (3×)
2. washThe organic phases were washed with aq. sat. NaHCO3 solution, aq. 10% NaCl solution
3. dry with materialdried over Na2SO4
4. customevaporated
5. custompurified by flash silica gel column (CH2Cl2:MeOH 99:1)