tert-Butanol → Tert-butyl 3-bromopyrazolo[1,5-a]pyrimidin-2-ylcarbamate

Participants

Reaction Steps

3-Bromopyrazolo[1,5-a]pyrimidine-2-carboxylic acid (1.95 g, 8.06 mmol; Art-Chem) was suspended in tert-butyl alcohol (75 mL). Triethylamine (1.35 mL, 9.67 mmol) and diphenylphosphoryl azide (2.09 mL, 9.67 mmol) was added and the mixture was stirred under refluxing condition for 4 hours. The reaction mixture was cooled to ambient temperature and concentrated under vacuum. The resulting residue was purified by reverse-phase HPLC [Waters XBridge™ RP18 column, 5 μm, 50×100 mm, flow rate 100 mL/minute, 20-75% gradient of methanol in buffer (0.1 M aqueous ammonium bicarbonate, adjusted to pH 10 with ammonium hydroxide)] to afford the title compound. MS (ESI) m/z 310/313 (M−H)−.

Provenance & Evidence