Citric Acid → 8-[(Tert-butoxy)carbonyl]-8-azabicyclo[3.2.1]octane-3-carboxylic acid

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Reaction Steps

To 3-cyano-8-aza-bicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (Intermediate 104, 190 mg, 0.81 mmol) was added potassium hydroxide (270 mg, 4.83 mmol), EtOH (3 mL) and water (1 mL). The mixture was heated at 95 C for 4 h, allowed to cool and acidified to pH=2 with a 1 M aq. solution of citric acid. The mixture was then extracted with EtOAc (2×5 mL) and the combined extracts washed with saturated brine (10 mL), and dried over anhydrous sodium sulfate. Evaporation gave the crude title compound which was used directly without further purification (190 mg, 94%). Method B HPLC-MS: MH+ requires m/z=255. Found: m/z=200 (MH-tBu), Rt=1.68 min (76%).

Provenance & Evidence