Triphenylphosphine → (R)-1-(5-acetoxyhexyl)-8-bromo-7-(2-(N-tert-butoxycarbonylamino)ethyl)-3-methylxanthine

Participants

Reaction Steps

To a stirring suspension of (R)-1-(5-acetoxyhexyl)-8-bromo-3-methylxanthine (5.10 g, 13.2 mmol), triphenylphosphine (5.24 g, 20.0 mmol) and 3-(tert-butoxycarbonylamino)-1-propanol (3.2 g, 20.0 mmol) in anhydrous 1,2-dichloroethane (100 ml) at room temperature was added diethylazodicarboxylate (3.48 g, 20.0 mmol) dropwise. The mixture was stirred at room temperature overnight and concentrated under reduced pressure. The residue was purified by column chromatography on silica gel eluting with ethyl acetate-hexane (1:1) to provide (R)-1-(5-acetoxyhexyl)-8-bromo-7-(2-(N-tert-butoxycarbonylamino)ethyl)-3-methylxanthine (6.10 g, 85% yield) as a beige oil.

Provenance & Evidence