Benzyl chloroformate → Benzyl [(2S,3S)-2-phenylpiperidin-3-yl]carbamate

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Reaction Steps

To a solution of (2S,3S)-(−)-3-amino-2-phenylpiperidine (152 mg, 0.86 mmole) (L-tartaric acid salt, [a]D=−57.1 (EtOH, c=0.1138)) in methylene chloride (10 mL) at room temperature was added benzyl chloroformate (0.123 mL, 0.86 mmole) and diisopropylethylamine (0.45 mL, 2.58 mmole). The reaction was stirred for 16 hours and was then diluted with methylene chloride and quenched by addition of water. The mixture was separated and the aqueous was reextracted with 2 additional aliquots of methylene chloride. The organic layers were successively washed with a portion of brine, dried over sodium sulfate, combined and evaporated. The residue was purified by flash chromatography (5% methanol in methylene chloride) to afford 214 mg (80%) of the title compound. NMR (CDCl3): δ 1.55 (br, d, J=9 Hz, 1 H), 1.6-1.9 (m, 2 H), 2.02 (br. d, J=9 Hz, 1 H), 2.79 (dd, J=9 and 10 Hz, 1 H), 3.22 (dd, J=1 and 10 Hz, 1 H), 3.91 (br. s, 1 H), 4.01 (dd, J=1 and 8 Hz, 1 H), 4.89 (s, 2 H), 5.65 and 5.88 (2 br. s, 1 H), 7.1-7.4 (m, 10 H).

Provenance & Evidence