Hydrochloric Acid → 6-Bromo-1H-pyrazolo[4,3-b]pyridine

Participants

Reaction Steps

To a solution of 1-(6-bromo-1H-pyrazolo[4,3-b]pyridin-1-yl)ethanone (1.4 g, 5.9 mmol) in tetrahydrofuran (20 mL) and methanol (15 mL) was added a solution of sodium hydroxide (0.71 g, 18 mmol) in water (5 mL) at 27° C. After 5 h, the reaction was neutralized with hydrogen chloride acid (2 mol/L, 10 mL), and the resulting mixture was extracted with ethyl acetate (3×50 mL). The collected organic extracts were concentrated in vacuo. Purification by flash column chromatography (15→30% ethyl acetate in petroleum ether) afforded 6-bromo-1H-pyrazolo[4,3-b]pyridine (1.0 g, 86% yield). 1H NMR (400 MHz, Chloroform-d) δ 10.46 (brs, 1 H), 8.58 (s, 1 H), 8.25 (s, 1 H), 7.98 (s, 1 H).

Provenance & Evidence