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

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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-carboxy late (Int-9h, 3.24 g, 4.44 mmol) in DMF (20 mL) was added N-bromosuccinimide (750 mg, 4.21 mmol). The mixture was allowed to stir at room temperature for one hour. More N-bromosuccinimide (75 mg) was added and the mixture was stirred for another half hour before being diluted with EtOAc (200 mL). The mixture was washed with water three times, brine and dried (MgSO4). After solvent was removed under reduced pressure, and the residue was purified on silica. Elution with EtOAc in hexanes (0-50%) gave the title compound (3 g, 83%). LC/MS: m/z=809 (M+H+).

Provenance & Evidence