Sodium Hydroxide → HCID 178526791, compound

Participants

Reaction Steps

4N NaOH (5.12 mL, 20.5 mmol) was added to a cold (0° C.) solution of 5-nitro-1H-pyrazolo[3,4-b]pyridine (0.84 g, 5.12 mmol) in dioxane (30 mL), followed by bromine (1.05 mL, 20.5 mmol). The cold bath was removed, and the reaction mixture was left at room temperature for 30 minutes. The reaction mixture was diluted with ethyl acetate (100 mL) and quenched with saturated Na2S2O3 (50 mL) The aqueous layer was extracted with ethyl acetate (100 mL). The combined organic layers were dried, filtered and concentrated. The crude product was purified by column chromatography, eluting with hexanes/ethyl acetate (9:1) to give 3-bromo-5-nitro-1H-pyrazolo[3,4-b]pyridine (1.10 g, 88%) as a solid.

Provenance & Evidence