反应详情

To a stirred 0° C. solution of 1-t-Butyloxycarbonyl-4-(2-hydroxyphenylamino)piperidine (5.2 g, 18 mmol) from Step 1 was added NaH (800 mg of a 60% suspension in mineral oil, 20 mmol). After 30 min, ethyl bromoacetate (2.2 mL, 20 mmol) was added and the reaction was warmed to ambient temperature and stirred for 2 h. The reaction was quenched by the addition of acetic acid (1 mL), and the solvents were removed under reduced pressure. The residue was purified by pressurized silica gel column chromatography using 20% EtOAc-hexanes as eluant. 1-t-Butyloxycarbonyl-4-((2-ethoxycarbonylmethoxyphenyl)amino)piperidine was obtained as an oil (90% yield).

1. customThe reaction was quenched by the addition of acetic acid (1 mL)
2. customthe solvents were removed under reduced pressure
3. customThe residue was purified by pressurized silica gel column chromatography