Bromine → Ethyl 3-bromo-1-(1-methylethyl)-6-phenyl-1H-pyrazolo[3,4-b]pyridine-4-carboxylate

Participants

Reaction Conditions

Reaction Steps

Ethyl 1-(1-methylethyl)-6-phenyl-1H-pyrazolo[3,4-b]pyridine-4-carboxylate (120 mg, 0.388 mmol), was suspended in acetic acid (2 mL) followed by addition of bromine (26 μl, 0.504 mmol). The reaction mixture was stirred with heating at 80° C. After 1 h, a second portion of bromine was added (26 μl, 0.504 mmol) and the reaction mixture heated at 80° C. for an additional 2 h. After cooling to room temperature, the solution was added to a saturated aqueous solution of sodium bicarbonate (6 mL) and extracted with dichloromethane (2×10 mL) The combined organic layers were concentrated in vacuo. The crude product was purified by silica gel chromatography (eluent: EtOAc/Hexanes, 0-50% gradient). The product was collected as a white powder (112 mg, 74%). LCMS E-S (M+H)=388.0/390.2. 1H NMR (400 MHz, CHLOROFORM-d) δ 8.18 (dd, J=1.52, 8.08 Hz, 2H), 8.00 (s, 1H), 7.48-7.58 (m, 3H), 5.47 (quin, J=6.76 Hz, 1H), 4.58 (q, J=7.16 Hz, 2H), 1.65 (d, J=6.82 Hz, 6H), 1.52 (t, J=7.20 Hz, 3H).

Provenance & Evidence