反应详情

To a solution of [3-(2-methyl-2H-pyrazol-3-yl)-4-trifluoromethoxy-phenyl]-carbamic acid tart-butyl ester (65 mg, 0.18 mmol) in DMF (1.5 mL) N-bromosuccinimide (35.6 mg, 0.2 mmol) was added at 0° C. then reaction mixture stirred at room temperature overnight. The resulting mixture was diluted with ethyl acetate, washed with brine and water. The organic layer was separated, dried over anhydrous sodium sulfate, filtered and concentrated to give a yellow oily residue that was subjected to a purification by flash chromatography (SiO2, Hexanes/EtOAc gradient elution) to afford [3-(2-methyl-2H-pyrazol-3-yl)-4-trifluoromethoxy-phenyl]-carbamic acid tert-butyl ester as a white solid in 89.2% yield. LCMS m/z (%)=436 (M+H 79Br, 100), 438 (M+H 81Br, 98). 1H NMR (400 MHz, CD3OD) δ: 7.79 (d, J=8.90 Hz, 1H), 7.61 (s, 1H), 7.55 (s, 1H), 7.43 (d, J=8.94 Hz, 1H), 3.73 (s, 3H), 1.55 (s, 9H).

1. customreaction mixture
2. washwashed with brine and water
3. customThe organic layer was separated
4. dry with materialdried over anhydrous sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated
7. customto give a yellow oily residue that
8. customwas subjected to a purification by flash chromatography (SiO2, Hexanes/EtOAc gradient elution)