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

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Reaction Conditions

Reaction Steps

A mixture of tert-butyl [(3S,5R)-1-(3-nitro-1-oxido-6,7-dihydro-5H-cyclopenta[b]pyridin-4-yl)-5-(trifluoromethyl)piperidin-3-yl]carbamate (0.100 g, 0.224 mmol) in Ac2O (1.5 mL, 16 mmol) was stirred at 90° C. for 1 h. The solution was allowed to cool to room temperature, then concentrated under reduced pressure at 60° C. The residue was diluted with EtOAc (5 mL), washed quickly with 1N NaOH. The aqueous phase was extracted with EtOAc twice. The combined organic phases were condensed and columned on 20 g silica gel, eluting with 0-50% EtOAc in hexanes to give the sub-title compound as a brown solid (0.085 g, 78%). LCMS calc. for C21H28F3N4O6 (M+H)+ m/z=489.2. found: 489.0.

Provenance & Evidence