Triphenylphosphine → Tert-butyl 3-(pyridin-4-yloxy)azetidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

tert-Butyl 3-hydroxyazetidine-1-carboxylate (4.0 g) and pyridin-4-ol (1.8 g) were mixed with THF (50 ml), and triphenylphosphine (6.23 g) was added thereto. A 1.9 M DIAD/toluene solution (12.5 ml) was added dropwise, followed by stirring at 55° C. overnight. Triphenylphosphine (5 g) and a 1.9 M DIAD/toluene solution (10 ml) were added to the reaction mixture, followed by stirring at 55° C. overnight. The reaction mixture was concentrated under reduced pressure, and a liquid separation operation was carried out by the addition of EtOAc and 0.5 M hydrochloric acid. The aqueous layer was adjusted to a pH of around 10 by the addition of a 4 M aqueous NaOH solution, and extracted with CHCl3. The organic layer was dried over Na2SO4 and concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (CHCl3/MeOH) to obtain tert-butyl 3-(pyridin-4-yloxy)azetidine-1-carboxylate (4.2 g).

Provenance & Evidence