Acetic Anhydride → 4-[(3S,5R)-3-[(tert-butoxycarbonyl)amino]-5-(trifluoromethyl)piperidin-1-yl]-3-nitro-6,7-dihydro-5H-cyclopenta[b]pyridin-7-yl acetate

Participants

Reaction Conditions

Reaction Steps

To tert-butyl [(3S,5R)-1-(3-nitro-1-oxido-6,7-dihydro-5H-cyclopenta[b]pyridin-4-yl)-5-(trifluoromethyl)piperidin-3-yl]carbamate (114.7 mg, 0.2569 mmol) was added Ac2O (2.0 mL, 21 mmol). The reaction mixture was heated at 90° C. for 1 h. After cooling to room temperature, the reaction mixture was concentrated under reduced pressure. The residue was diluted with DCM, and poured into a saturated aqueous solution of Na2CO3 at 0° C. The separated aqueous layer was further extracted with DCM (3 times). The combined organic layers were washed with brine, dried over Na2SO4, and concentrated under reduced pressure. The resulting residue was purified by chromatography on silica gel (0-100% EtOAc in hexanes) to give the sub-title compound as a brown foamy solid (92.3 mg, 74%). LCMS calc. for C21H28F3N4O6 (M+H)+: m/z=489.2. found 489.2.

Provenance & Evidence