反应详情

To a cold (0° C.) solution of phosphorus oxychloride (8.0 mL 86 mmol) in N,N-dimethylformamide (160 mL) was added 2-(4-fluorophenyl)-6-(trifluoromethyl)pyrazolo[1,5-α]pyridine (11.0 g, 39.3 mmol). The reaction mixture was stirred at room temperature for 72 hours, then quenched with ice water. The solid precipitate was collected on a filter to provide 2-(4-fluorophenyl)-6-(trifluoromethyl)pyrazolo[1,5-α]pyridine-3-carbaldehyde (11.4 g, 94%) as a white solid. Rf 0.45 (4:1 hexanes:ethyl acetate); 1H NMR (400 MHz, CDCl3): δ 10.15 (s, 1H), 8.92 (s, 1H), 8.53 (d, 1H), 7.80 (m, 2H), 7.70 (d, 1H), 7.27 (t, 2H); 19F NMR (CDCl3) δ −62.62, −110.62; MS m/z 307 (M−1).

1. customquenched with ice water
2. customThe solid precipitate was collected on
3. filtrationa filter