General procedure for the synthesis of methyl N-Cbz-4-piperidinecarboxylate from methanol and 1-(benzyloxycarbonyl)piperidine-4-carboxylic acid: concentrated sulfuric acid (two drops, using a Pasteur pipette) was slowly added dropwise (two drops) to a methanolic solution of 1-(benzyloxycarbonyl)piperidine-4-carboxylic acid (540 mg, 2.05 mmol), and the reaction mixture was heated and refluxed for 5 hours. Upon completion of the reaction, the solution was cooled to room temperature and subsequently concentrated under reduced pressure. To the concentrated residue was added saturated aqueous sodium bicarbonate solution and extracted with ethyl acetate. The organic layer was dried with magnesium sulfate, filtered and concentrated under reduced pressure to afford methyl N-Cbz-4-piperidinecarboxylate (532 mg, 1.92 mmol, 93% yield) as a colorless oil.1H-NMR (400 MHz, CDCl3) δ: 1.57-1.73 (2H, m), 1.82-1.96 (2H, m), 2.43-2.55 ( 1H, m), 2.85-2.97 (2H, m), 3.69 (3H, s), 4.02-4.17 (2H, m), 5.12 (2H, s), 7.29-7.40 (5H, m).IR (neat, cm-1): 1732, 1696, 1450, 1433, 1223, 1192, 1175, 1040.
![1-[(Benzyloxy)carbonyl]piperidine-4-carboxylic acid](/CAS/GIF/10314-98-4.gif)
