Phosphorus oxychloride → 6-chloro-1-(3,3,4,4,4-pentafluorobutyl)-1H-pyrazolo[3,4-b]pyridine-3-carbonitrile

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Reaction Conditions

Reaction Steps

To the intermediate from Step A above (225 mg, 0.735 mmol) was added POCl3 (2.8 g, 18.3 mmol) and the mixture was stirred at 75° C. for 9 hours. The reaction mixture was then concentrated in vacuo to remove POCl3. To the residue was added hexane/ethyl acetate (2/1, 50 mL) and the pH adjusted to 7.5˜8.0 with aqueous K2CO3 at 0° C. The water layer was extracted with the hexane/ethyl acetate (2/1, 2×20 mL). The combined organic layer was dried over Na2SO4 and evaporated under reduced pressure. The residue was purified by silica gel column chromatography using hexane/ethyl acetate eluent to give the product as a white solid. 1H NMR (500 MHz, CDCl3): δ 2.86 (m, 2H); 4.90 (t, J=8.4 Hz, 2H); 7.42 (d, J=8.4 Hz, 1H); 8.17 (d, J=8.4 Hz, 1H), m/z=325.04 (M+H).

Provenance & Evidence