Dimethyl Sulfoxide → (2S)-1-tert-butoxycarbonyl-2-phenylpiperidin-3-one

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Reaction Conditions

Reaction Steps

Alternatively, dimethyl sulfoxide (20.80 mL, 22.90 g, 29.3 mmol) in dichloromethane (75 mL) is added dropwise to a cooled (0° C.) solution of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (160 mmol) in dichloromethane (350 mL). The mixture is stirred at 0° C. for 15 min., then (2S,3S)-1-tert-butoxycarbonyl-3-hydroxy-2-phenylpiperidine (36.91 g. 133 mmol) in dichloromethane (150 mL) is added dropwise. The mixture was stirred at 0° C. for 20 min and pyridine (400 mmol) is added slowly followed by trifluroacetic acid (400 mmol). The mixture is allowed to warm to 0° C. and diluted with ice-cooled dichloromethane (250 mL). The mixture is washed with ice cold aqueous citric acid solution (5%, 2×300 mL) and water (300 mL), dried (MgSO4), and the solvent is evaporated under reduced pressure to give (2S)-1-tert-butoxycarbonyl-2-phenylpiperidi n-3-one.

Provenance & Evidence