Benzyl chloroformate → 1-Boc-4-Cbz-amino-piperidine

Participants

Reaction Steps

To a solution of 1.2 g (6.0 mmol) 4-amino-1-(tert-butoxycarbonyl)piperidine from Step B in 40 mL of dichloromethane was added 3.15 mL (18 mmol) of N,N-diisopropylethylamine and 1.03 mL (7.2 mmol) of benzyl chloroformate while cooled in an ice bath. After 0.5 h the reaction was quenched with aqueous sodium carbonate and extracted three times with dichloromethane. The organic layers were each washed with a portion of brine, dried over sodium sulfate, combined and concentrated. The residue was purified by flash column chromatography, eluting with 25% ethyl acetate in hexane, to afford 1.94 g of title compound. 1H NMR (400 MHz, CDCl3): δ 7.33 (m, 5H), 5.09 (s, 2H), 4.42 (bs, 1H), 4.08 (m, 2H), 3.58 (m, 1H), 2.90 (bt, 2H), 1.90 (bd, 2H, J=12 Hz), 1.42 (s, 9H), 1.26 (m, 2H).

Provenance & Evidence