N-Iodosuccinimide → 2-(4-Fluorophenyl)-7-iodo-3-pyridin-4-ylpyrazolo[1,5-a]pyridine

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Reaction Conditions

Reaction Steps

To a stirred solution of 2-(4-fluorophenyl)-3-(4-pyridyl)-pyrazolo[1,5-α]pyridine (100 mg, 0.346 mmol) in 4 mL of tetrahydrofuran at −78° C. under N2 was added 2.5 M n-butyllithium in hexanes (2 eq.). The mixture was stirred at −78° C. for 30 min and N-iodosuccinimide (2.2 eq.) was then added. The mixture was allowed to warm to room temperature after 30 min and was stirred at room temperature for 1 hour. The mixture was diluted with ether and washed with 1N hydrochloric acid solution. The aqueous layer was basified with 1 N sodium hydroxide solution and extracted thoroughly with ether. The combined organic layers were dried on anhydrous magnesium sulfate, filtered and evaporated. Purification by chromatography yielded 2-(4-fluorophenyl)-7-iodo-3-pyridin-4-ylpyrazolo[1,5-α]pyridine as a yellow solid. 1H NMR (CDCl3): δ 8.54 (d, 2H, J=5.8 Hz), 7.50–7.57 (m, 3H), 7.37 (d, 1H, J=7.1 Hz), 7.20 (d, 2H, J=5.8 Hz), 7.00 (t, 2H, J=8.6 Hz), 6.90 (t, 1H, J=7.8 Hz); MS m/z 416 (M+1).

Provenance & Evidence