Diisopropylethylamine → (S)-tert-butyl 2-(4-chlorophenyl)-3-(4-(3-(2-hydroxyethoxy)-1H-pyrazolo[3,4-b]pyridin-4-yl)piperazin-1-yl)-3-oxopropyl(isopropyl)carbamate

Participants

Reaction Steps

DIEA (0.0815 mL, 0.468 mmol) was added to 2-(4-(piperazin-1-yl)-1H-pyrazolo[3,4-b]pyridin-3-yloxy)ethanol dihydrochloride (0.0472 g, 0.140 mmol), (S)-3-(tert-butoxycarbonyl(isopropyl)amino)-2-(4-chlorophenyl)propanoic acid (0.234 mL, 0.117 mmol, see Example B) and TBTU (0.0451 g, 0.140 mmol) in DCM (1 mL) and stirred at room temperature for 1 hour. The reaction was concentrated to dryness. The resulting residue was dissolved in THF/MeOH (2 mL, 1:1). A LiOH solution (1 mL, 2M) was added and stirred for 10 minutes. Ether (20 mL) was added. The organic layer was separated, washed with brine (5 mL), and dried over sodium sulfate. After removal of the solvent, the resulting residue was purified by chromatography (ethyl acetate) to give (S)-tert-butyl 2-(4-chlorophenyl)-3-(4-(3-(2-hydroxyethoxy)-1H-pyrazolo[3,4-b]pyridin-4-yl)piperazin-1-yl)-3-oxopropyl(isopropyl)carbamate as a solid. The solid was then dissolved in DCM (1 mL), and TFA (0.4 mL) was added. The mixture was stirred at room temperature for 1 hour and then concentrated to dryness. The resulting residue was dissolved in DCM (0.5 mL), and HCl in ether (1 mL, 2N) was added. The solvent was removed, and the resulting solid was dissolved in MeOH (2 mL). A LiOH solution (2 mL, 2M) was added and stirred for 10 minutes. DCM (20 mL) and water (10 mL) were added. The organic layer was separated, dried over sodium sulfate and concentrated to give (S)-2-(4-chlorophenyl)-1-(4-(3-(2-hydroxyethoxy)-1H-pyrazolo[3,4-b]pyridin-4-yl)piperazin-1-yl)-3-(isopropylamino)propan-1-one (0.018 g, 32%) as a solid. MS APCI (+) m/z 487.3 detected.

Provenance & Evidence