反应详情

温度

110 °C

To a manually stirred polyphosphoric acid (80 g, 800 mmol) in a 1000 mL beaker at room temperature was added 6-methyl-2-pyridinamine (15 g, 140 mmol), followed by methyl 4-bromo-3-oxohexanoate (37.3 g, 167 mmol). The mixture was heated with stirring at 110° C. for 5 h. After cooling, the dark slurry was transferred into 300 g of ice. The pH of the mixture was adjust to 6-7 with 10% sodium hydroxide. The precipitate was collected by filtration under reduced pressure, washed with water, and air dried to yield the desired product (25.4 g, 64.8%). LCMS calculated for C12H14BrN2O (M+H)+: m/z=281.0. Found: 281.2. 1H NMR (DMSO-d6, 300 MHz) δ 7.66 (1H, d, J=9.0 and 6.9 Hz), 7.39 (1H, d, J=9.0 Hz), 6.90 (1H, d, J=6.9 Hz), 6.33 (1H, s), 4.91 (1H, t, J=7.5 Hz), 2.91 (3H, s), 2.15 (2H, qd, J=7.5 and 7.5 Hz), 0.93 (3H, t, J=7.5 Hz) ppm.

1. temperatureThe mixture was heated
2. temperatureAfter cooling
3. filtrationThe precipitate was collected by filtration under reduced pressure
4. washwashed with water, and air
5. customdried