4-Methoxybenzyl bromide → tert-Butyl 6-fluoro-1-(4-methoxybenzyl)-1H-pyrazolo[3,4-b]pyridine-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of tert-butyl 6-fluoro-1H-pyrazolo[3,4-b]pyridine-3-carboxylate (29.55 g, 125 mmol) in THF (300 mL) cooled in an ice bath was added KOtBu (13.98 g, 125 mmol) at such a rate as to maintain the temperature between 5-10° C., and then 4-methoxybenzyl bromide (18.2 mL, 125 mmol) was added. The resulting mixture was stirred in an ice bath for 1 hour and then stirred at room temperature for 18 hours. The resulting suspension was quenched with saturated aqueous NH4Cl (200 mL) and then extracted with EtOAc (2×300 mL). The combined organic extracts were washed with brine, dried with MgSO4 and the solvent removed in vacuo. The resulting residue was purified on a silica gel (1000 g) column (0-11% EtOAc/hexanes) to give the title compound I-B. LRMS (M+1)=380.1

Provenance & Evidence