Boron tribromide → Lasofoxifene

Participants

Reaction Steps

To a solution of 400 mg (0.94 mmol) of cis-1-{2-[4-(6-methoxy-2-phenyl 1,2,3,4-tetrahydronaphthalen-1-yl)phenoxy]ethyl}pyrrolidine in 25 mL of methylene chloride at 0° C. was added, dropwise with stirring, 4.7 ml (4.7 mmol) of a 1.0 M solution of boron tribromide in methylene chloride. After 3 hours at room temperature, the reaction was poured into 100 mL of rapidly stirring saturated aqueous sodium bicarbonate. The organic layer was separated, dried over sodium sulfate, filtered, and concentrated to afford 287 mg (74% yield) of lasofoxifene as the free base.

Provenance & Evidence