Sodium Carbonate → 4-Chloro-2-(2-chloro-6-fluorophenyl)-7-fluoro-2H-pyrazolo[4,3-c]pyridine

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Reaction Conditions

Reaction Steps

2-(2-Chloro-6-fluorophenyl)-7-fluoro-2H-pyrazolo[4,3-c]pyridine 5 oxide (7.2 g, 25.6 mmol) was suspended in DCE (130 mL) under an atmosphere of nitrogen and phosphorus oxychloride (7.2 mL, 77.0 mmol) was added. The reaction mixture was heated at 70° C. for 5 hours and then allowed to cool to room temperature. The resultant mixture was poured cautiously onto saturated aqueous sodium carbonate solution, with stirring, and the layers were separated. The organic layer was washed with brine, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The residue was purified by silica gel flash chromatography (20% ethyl acetate in cyclohexane) to afford the title compound as a white solid (3.08 g, 40% yield). 1H NMR (400 MHz, DMSO-d6): δ 9.54 (d, J=2.5 Hz, 1H), 8.22 (d, J=3.4 Hz, 1H), 7.86-7.78 (m, 1H), 7.76-7.66 (m, 2H).

Provenance & Evidence