Benzyl Bromide → Dimethyl 1-benzylpiperidine-3,5-dicarboxylate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To dimethyl piperidine-3,5-dicarboxylate (7.5 g, 37.3 mmol) in acetonitrile (100 mL) was added K2CO3 (20.6 g, 149.1) and benzylbromide (4.43 mL, 37.3 mmol). The reaction mixture was stirred at 23° C. for 4 hours. The K2CO3 was removed by filtration and the solvent evaporated in vacuo. A solution of NaHCO3 (1M, 150 mL) was added and the organic material extracted with ethyl acetate (3×50 mL), then dried (MgSO4) and concentrated in vacuo. The crude material was purified on a Silica gel column (Biotage flash chromatography system), eluting with a gradient of ethyl acetate/hexane (10:90) to (35:65) to afford the title compound as the cis diastereomer 1.6 g which eluted after the corresponding trans diastereomer. (based on the NMR reported in Synthetic Communications 1997, 27 (1), 69-71.). 1H NMR (400 MHz, CDCl3) δ ppm 7.26-7.36 (5 H, m), 3.68 (6 H, s), 3.59 (2 H, s), 3.15 (2 H, m), 2.66 (2 H, t, J=12.0 Hz), 2.36 (1 H, d, J=13.1 Hz), 2.05 (2 H, t, J=11.4 Hz), 1.56 (1 H, q, J=12.9 Hz). LCMS (+ESI, M+H+) m/z: 292.

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