Piperidine → (R)-1-Benzyl 3-ethyl piperidine-1,3-dicarboxylate

Participants

Reaction Conditions

Reaction Steps

A 1.0 L round-bottom flask was charged with K2CO3 (29.2 g; 171 mmol), piperidine (50 g; 163 mmol), and a 1:1 mixture of THF/H2O (800 mL). A 150 mL addition funnel was placed on the flask and charged with CbzCl (29.2 g, 171 mmol). The flask was cooled to 0° C. and then CbzCl was added dropwise over 5 minutes. The reaction mixture was warmed to 20° C. and stirred for 1 h. The reaction mixture was extracted with EtOAc (500 mL) and the organic layer was washed with water (500 mL), saturated NaCl (500 mL), dried (MgSO4), filtered and concentrated in vacuo. The crude material was purified by flash chromatography (silica gel, hexanes/EtOAc 9:1 to 4:1) to give pure product (49.3 g, 100% yield). 1H-NMR (300 MHz) δ (ppm) 7.40 (m; 5H); 5.17 (s; 2H); 4.19 (q; 2H); 4.04 (m; 1H); 3.12 (m; 1H); 2.95 (m; 1H); 2.48 (m; 1H); 2.08 (m; 1H); 1.75 (m; 3H); 1.53 (m; 1H); 1.28 (t; 3H).

Provenance & Evidence