HCID 11415922, compound → 3-Benzyl-1-(tert-butoxycarbonyl)piperidine-3-carboxylic acid

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Reaction Steps

3-Benzylpiperidine-1,3-dicarboxylic acid 1-tert-butyl ester (76 g, 238 mmol) was dissolved in EtOAc (3,0 L) in a one neck flask (5 L) equipped with magnetic stirring. Then H2O (30 ml), R(+)-1-phenethylamine (18,2 ml, 143 mmol) and Et3N (13,2 ml, 95 mmol) were added and the mixture was stirred overnight at room temperature resulting in precipitation of white crystals (41,9 g), which were removed by filtration, washed with EtOAc and dried in vacuo. The precipitate was dissolved in a mixture of aqueous NaHSO4 (300 ml, 10%) and EtOAc (600 ml), layers were separated and the aqueous layer re-extracted with EtOAc (100 ml). The combined organic layers were washed with brine (100 ml), dried over MgSO4 and filtered. The solvent was removed in vacuo to afford a colorless oil, which was dissolved in EtOAc(1):heptane(10) and aged overnight. The crystals that had been formed were removed by filtration, washed with heptane and dried in vacuo to give one compound which is either (3R)-3-benzylpiperidine-1,3-dicarboxylic acid 1-tert-butyl ester or (3S)-3-benzylpiperidine-1,3-dicarboxylic acid 1-tert-butyl ester (27,8 g).

Provenance & Evidence