1-Hydroxybenzotriazole → 4-[6-chloro-3-[(E)-2-(4-chloro-phenyl)-vinyl]-1-(tetrahydro-pyran-2-yl)-1H-pyrazolo[3,4-b]pyridine-4-carbonyl]-piperazine-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

To a solution of 6-chloro-3-[(E)-2-(4-chloro-phenyl)-vinyl]-1-(tetrahydro-pyran-2-yl)-1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid (2 g, 4.79 mmol) in a mixture of anhydrous tetrahydrofuran (42 ml) and N,N-dimethylacetamide (10 ml) were added 1-boc-piperazine (0.98 g, 5.27 mmol), 1-hydroxybenzotriazole (0.06 g, 0.48 mmol), and N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (0.91 g, 4.79 mmol). The reaction mixture was stirred at room temperature for 4 hours, tetrahydrofuran was evaporated under reduced pressure, water and dichloromethane were then added. The organic phase was separated, dried over anhydrous sodium sulfate, filtered and concentrated in vacuum. The crude residue was purified on a silica gel column chromatography using a gradient of ethyl acetate (0-45%) in cyclohexane to yield the title compound as a yellow foam (1.51 g, 54%).

Provenance & Evidence