Tributylphosphine → t-Butyl 3-[3-(benzenesulphonylmethyl)-6-(furan-3-yl)-2-(methoxycarbonyl)phenoxy]azetidine-1-carboxylate

Participants

Reaction Steps

Tri-n-butylphosphine (0.087 g) was added dropwise to a solution of di-isopropyl azodicarboxylate (0.099 g) in dry THF (2 ml) at 0° C. The mixture was warmed to room temperature for 10 minutes then re-cooled to 0° C. A mixture of methyl 6-(benzenesulphonylmethyl)-3-(furan-3-yl)-2-hydroxybenzoate (Intermediate 114, 0.05 g) and N-Boc-azetidin-3-ol (0.045 g) in THF (1 ml) was added dropwise and then the reaction mixture was warmed to room temperature for 10 minutes then heated to 55° C. for 6 hours. After cooling, ethyl acetate and water were added and the organic layer was separated, dried (Na2SO4) and filtered. The filtrate was evaporated to dryness and the residue was purified by chromatography on silica, eluting with a mixture of ethyl acetate and cyclohexane (1:3) to give t-butyl 3-[3-(benzenesulphonylmethyl)-6-(furan-3-yl)-2-(methoxycarbonyl)phenoxy]azetidine-1-carboxylate (0.316 g) as a gum.

Provenance & Evidence