N-bromobutanimide → Tert-butyl 4-(7-(bis((2-(trimethylsilyl)ethoxy)methyl)amino)-6-bromo-3-(6-phenylpyridin-3-yl)pyrazolo[1,5-a]pyrimidin-5-yl)piperidine-1-carboxylate

Participants

Reaction Steps

To a solution of tert-butyl 4-(7-(bis((2-(trimethylsilyl)ethoxy)methyl)amino)-3-(6-phenylpyridin-3-yl)pyrazolo[1,5-a]pyrimidin-5-yl)piperidine-1-carboxylate (3.24 g, 4.44 mmol) in DMF (20 mL) was added NBS (750 mg, 4.21 mmol). After stirring at rt for one hour, NBS (75 mg 0.42 mmol) was added and the resulting mixture was stirred for another 40 minutes to complete the reaction. The reaction mixture was diluted with EtOAc (200 mL), washed with water (2×50 mL), brine (20 mL) and dried (MgSO4). After concentration in vacuo the residue was purified on silica gel. Elution with EtOAc/Hexanes (0-40%) gave tert-butyl 4-(7-(bis((2-(trimethylsilyl)ethoxy)methyl)amino)-6-bromo-3-(6-phenylpyridin-3-yl)pyrazolo[1,5-a]pyrimidin-5-yl)piperidine-1-carboxylate (3 g, 83%).

Provenance & Evidence