General procedure for the synthesis of ethyl 3-pyrrolidinecarboxylate from ethyl 1-benzylpyrrolidine-3-carboxylate: ethyl 1-benzylpyrrolidine-3-carboxylate (10.00 g, 42.9 mmol) was dissolved in ethanol (200 mL) and 10% Pd/C catalyst (2.0 g) was added. The reaction was hydrogenated for 6 hours at room temperature under 60 psi hydrogen pressure. Upon completion of the reaction, the reaction mixture was filtered through a diatomaceous earth pad to remove the catalyst and the filter cake was washed with dichloromethane (CH2Cl2). The filtrate and washings were combined and concentrated under reduced pressure to give the crude product ethyl 3-pyrrolidinecarboxylate (7.12 g, 100% yield). The product was characterized by 1H NMR (CDCl3): δ 4.16 (q, 2H), 3.02-3.17 (m, 3H), 2.82-2.94 (m, 2H), 1.91-2.07 (m, 2H), 1.26 (t, 3H).LC-MS (APCI+) analysis showed the molecular ion peak m/z 144 (100%, [MH]+).
