Hydrazine → 4-Iodo-1H-pyrazolo[3,4-b]pyridine

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Reaction Steps

A 1M solution of hydrazine in tetrahydrofuran (150 mL) was added slowly to 2-fluoro-4-iodopyridine-3-carboxaldehyde (10 g, 39.84 mmol) to give a clear solution. The reaction mixture was stirred at RT for 16 h. The mixture was concentrated in vacuo and the remaining solid was triturated with DCM to give the title compound as a pale yellow solid (8 g). The DCM filtrate was also washed with saturated sodium bicarbonate and brine. The organic layer was dried over sodium sulfate and concentrated under vacuum. The crude material was purified by trituration with DCM to give additional 4-iodo-1H-pyrazolo[3,4-b]pyridine as a yellow solid. MS (ESI, pos. ion) m/z: 245.9 (M+1).

Provenance & Evidence