反应详情

温度

110 °C

To 2-tert-butyl-5-cyclobutyl-2H-pyrazol-3-ylamine (5.0 g, 25.9 mmol) in acetic acid (25 mL) was added methyl dimethoxypropionate (7.4 mL, 51.8 mmol), and then the reaction was heated to 110° C. After 24 hr, the reaction mixture was cooled to room temperature, and concentrated to a viscous oil that was diluted with EtOAc. The organic layer was washed with aqueous NaHCO3 and then the organic layer was dried over MgSO4, filtered, and concentrated under reduced pressure. Purification of this material was accomplished by MPLC using a 45 L Biotage® column eluting with 20% EtOAc/hexanes. The product-containing fractions were collected and concentrated under reduced pressure, and the resulting solid was washed with hexanes and dried to afford the title compound (2.0 g, 32% yield) as a colorless solid. Rf=0.33 (10% MeOH/CH2Cl2). 400 MHz 1H NMR (CDCl3) d 7.72 (d, J=9.1 Hz, 1H), 6.26 (d, J=9.1 Hz, 1H), 3.68 (dddd, J=8.7, 8.7, 8.7, 8.7 Hz, 1H), 2.46-2.32 (m, 4H), 2.14-1.89 (m, 2H), 1.71 (s, 9H). LRMS m/z (APCI+) 246 (M+1).

1. temperaturethe reaction mixture was cooled to room temperature
2. concentrationconcentrated to a viscous oil that
3. additionwas diluted with EtOAc
4. washThe organic layer was washed with aqueous NaHCO3
5. dry with materialthe organic layer was dried over MgSO4
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure
8. customPurification of this material
9. washeluting with 20% EtOAc/hexanes
10. customThe product-containing fractions were collected
11. concentrationconcentrated under reduced pressure
12. washthe resulting solid was washed with hexanes
13. customdried