Triphenylphosphine → [2-(4-Bromo-pyrazol-1-yl)-ethyl]-methyl-carbamic acid tert-butyl ester

Participants

Reaction Steps

Diethylazodicarboxylate (0.48 mL, 3.1 mmol) was added to a 0° C. solution of triphenylphosphine (0.80 g, 3.1 mmol) in THF (20 mL). After stirring for 5 minutes, 4-bromopyrazole (0.30 mg, 2.0 mmol) was added. After another 5 minutes of stirring, (2-hydroxyethyl)-methyl-carbamic acid tert-butyl ester (0.45 g, 2.6 mmol) was added. The reaction was allowed to warm to room temperature and stir overnight. The reaction was cooled to 0° C. and filtered. The filtrate was concentrated by rotary evaporation. The residue was purified by silica gel chromatography using gradient elution of dichloromethane, ethyl acetate to afford [2-(4-bromo-pyrazol-1-yl)-ethyl]-methyl-carbamic acid tert-butyl ester (541 mg, 87%).

Provenance & Evidence