反应详情

温度

140 °C

To a solution of 2-chloro-4-hydroxypyridine (12.9 g, 100 mmol) in n-BuOH (50 mL) was added t-butyl piperazine-1-carboxylate (46.5 g, 250 mmol). The mixture was heated at 140° C. for 3 days and then diluted with EtOAc (2 L) at ambient temperature. The organic phase was washed with saturated NH4Cl solution and then brine. The organic layer was separated, dried over MgSO4, and concentrated under reduced pressure. The residue was purified by column chromatography (5%-20% MeOH/CH2Cl2) to give 12.2 g (44%) of t-butyl 4-(4-hydroxypyridin-2-yl)piperazine-1-carboxylate as a white solid. MS m/z 280.2 [M+H]+; 1H NMR (500 MHz, CDCl3) δ (ppm) 7.72 (1H, d, J=6.62 Hz), 6.20 (1H, dd, J=6.31, 2.21 Hz), 6.02 (1H, d, J=1.89 Hz), 3.56 (4H, m), 3.42 (4H, m), 1.50 (9H, s).

1. washThe organic phase was washed with saturated NH4Cl solution
2. customThe organic layer was separated
3. dry with materialdried over MgSO4
4. concentrationconcentrated under reduced pressure
5. customThe residue was purified by column chromatography (5%-20% MeOH/CH2Cl2)