Triphenylphosphine → tert-butyl 4-({(2S)-2-[(2,5-dichloropyridin-3-yl)oxy]propanoyl}amino)piperidine-1-carboxylate

Participants

Reaction Steps

To a tetrahydrofuran solution (148 ml) of tert-butyl 4-{[(2R)-2-hydroxypropanoyl]amino}piperidine-1-carboxylate (5.13 g), 2,5-dichloropyridin-3-ol (3.40 g) and triphenylphosphine (6.41 g) was added dropwise at room temperature a tetrahydrofuran solution (40 ml) of di-tert-butyl azodicarboxylate (5.63 g) over 10 minutes. The reaction solution was stirred at room temperature for 1 hour, then poured into water, and extracted with ethyl acetate. The organic layer was washed sequentially with water and saturated sodium chloride solution, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to afford tert-butyl 4-({(2S)-2-[(2,5-dichloropyridin-3-yl)oxy]propanoyl}amino)piperidine-1-carboxylate (6.40 g).

Provenance & Evidence