Sodium hydride → HCID 131736296, compound

Participants

Reaction Steps

To a solution of trans-1-tert-butyl 4-ethyl 3-(5-bromopentanamido)piperidine-1,4-dicarboxylate 8 (3.0 g, 6.9 mmol, 1.0 equiv) in THF (20 mL), NaH (276 mg, 6.9 mmol, 1.0 equiv) was carefully added in small portions at 0° C. The reaction solution was stirred at reflux condition for 4 h. The mixture was quenched with H2O (20 mL), and extracted with EtOAc (30 mL×3). The organic layer was collected, dried (Na2SO4), filtered, and concentrated in vacuo. The residue was purified by column chromatography (silica, petroleum ether/EtOAc=1:2) to give (trans)-1′-tert-butyl 4′-ethyl 2-oxo-[1,3′-bipiperidine]-1′,4′-dicarboxylate 9 as a slight yellow oil (2.1 g, yield: 88%). ESI-MS (M+H-56)+: 299.1. 1H NMR (400 MHz, CDCl3) δ: 4.10 (q, 4H), 3.38-3.19 (m, 4H), 2.70-2.61 (m, 1H), 2.36-2.31 (m, 2H), 1.95-1.92 (m, 1H), 1.75-1.71 (m, 6H), 1.46 (s, 9H), 1.23 (t, 3H).

Provenance & Evidence