tert-Butanol → tert-butyl {(3S)-1-[5-[(tert-butoxycarbonyl)amino]-1-(4-methoxybenzyl)-1H-pyrazolo[3,4-b]pyridin-4-yl]piperidin-3-yl}carbamate

Participants

Reaction Steps

A mixture of 4-{(3S)-3-[(tert-butoxycarbonyl)amino]piperidin-1-yl}-1-(4-methoxybenzyl)-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid (1.0 g, 2.1 mmol), diphenylphosphonic azide (0.58 mL, 2.7 mmol) and DIPEA (0.72 mL, 4.2 mmol) in tert-butyl alcohol (20 mL) heated under reflux overnight. The solution was then evaporated under reduced pressure. The resulting residue was dissolved in DCM, washed with 1 M aq. NaOH and brine, then dried over Na2SO4 and evaporated under reduced pressure. The residue was purified by column chromatography on silica gel using CombiFlash® apparatus, eluting with 0 to 50% EtOAc/hexanes, to give the sub-title compound as a brown oil (0.50 g, 44%). LCMS calc. for C29H41N6O5 (M+H)+: m/z=553.3. Found: 553.2.

Provenance & Evidence