Imidazole → (R)-3-(tert-butyldimethylsilyloxy)-1-(2-nitro-4-(trifluoromethyl)phenyl)piperidine

Participants

Reaction Steps

To a solution of (R)-1-(2-nitro-4-(trifluoromethyl)phenyl)piperidin-3-ol (3.35 g, 11.5 mmol) and imidazole (1.02 g, 15.0 mmol) in DMF at ambient temperature under nitrogen was added tert-butyldimethylsilylchloride (1.91 g, 12.7 mmol). The reaction was allowed to stir for 24 h, at which point additional 0.3 g tert-butyldimethylsilylchloride was added. The reaction was allowed to stir for an additional 14 h, and was then poured into Et2O/saturated aqueous NaHCO3. The organic layer was washed 2× H2O, 1× brine, dried over anhydrous MgSO4, filtered and concentrated to a yellow oil. The crude material was treated with hexanes and adsorbed onto silica gel and passed through a Redi-Sep® pre-packed silica gel column (80 g) eluting with 0-20% EtOAc/hexane. The product-containing fractions were concentrated to afford (R)-3-(tert-butyldimethylsilyloxy)-1-(2-nitro-4-(trifluoromethyl)phenyl)piperidine as a yellow oil. MS m/z=405 [M+H]+. Calc'd for C18H27F3N2O3Si: 404.

Provenance & Evidence