Imidazole → 3-O-(tert-Butyldimethylsilyl) Estrone

Participants

Reaction Steps

To a mixture of estrone (1, 29 g, 107.3 mmol) and tert-butyldimethylsilyl chloride (18 g, 118 mmol) in THF (350 mL) at room temperature under argon was added imidazole (18 g, 264 mmol) in DMF (350 mL). After stirring the reaction mixture overnight, the THF was evaporated and the reaction mixture was poured onto ice water. The resulting white precipitate was collected by filtration, dissolved in CH2Cl2, and the solution was dried (MgSO4). The desiccant was filtered and the solvent was evaporated under reduced pressure to afford 38.8 g of 2 as a white, crystalline solid (94% yield), m.p. 171-172° C.

Provenance & Evidence