反应详情

To a suspension of 3-tert-butyl-1-methyl-1H-pyrazol-5-amine (0.75 g, 9.8 mmol) and potassium carbonate (1.76 g, 12.7 mmol) in THF (20 mL) at 0° C. was added dropwise phenyl chloroformate (0.7 mL, 10.8 mmol). The mixture was stirred at rt for 16 h. The mixture was then filtered through celite and solvent was removed under reduced pressure. The crude residue was purified by silica gel flash chromatography, eluting with 0% to 100% EtOAc in hexanes, to afford phenyl 3-tert-butyl-1-methyl-1H-pyrazol-5-ylcarbamate (1.05 g, 39% yield). LCMS (ESI) m/z 348 (M+H)+; 1H NMR (300 MHz, DMSO-d6) δ 10.11 (br s, 1H), 7.45-7.40 (m, 2H), 7.29-7.21 (m, 3H), 6.04 (s, 1H), 3.58 (s, 3H), 1.20 (s, 9H).

1. filtrationThe mixture was then filtered through celite and solvent
2. customwas removed under reduced pressure
3. customThe crude residue was purified by silica gel flash chromatography
4. washeluting with 0% to 100% EtOAc in hexanes