N-Hydroxyphthalimide → N-[4-(tert-butyldimethylsilyloxy)benzyloxy]phthalimide

Participants

Reaction Steps

Diethyl azodicarboxylate (40% toluene solution, 54.0 g) was added dropwise to a solution of 4-(tert-butyldimethylsilyloxy)benzylalcohol (27.5 g), N-hydroxyphthalimide (16.8 g) and triphenylphosphine (31.1 g) in tetrahydrofuran (450 ml) at room temperature and stirred for 18 hours. After the reaction mixture was concentrated, diisopropyl ether (200 ml) was added and the residual crystals were removed by filtration. The filtrate was concentrated, and the residue was subjected to silica gel chromatography to obtain N-[4-(tert-butyldimethylsilyloxy)benzyloxy]phthalimide (17.4 g, yield 43%) as crystals from an ethyl acetate-hexane-toluene (1:10:10, v/v)-eluted fraction. The crystals were recrystallized from ethyl acetate-hexane to obtain colorless crystals. m.p. 76-77° C.

Provenance & Evidence