Synthesis
To a 25 mL three-necked round-bottomed flask was added piperidine-2-carboxylic acid (975 mg, 7.56 mmol), aqueous formaldehyde (37 wt%, 2.0 mL) and formic acid (2.6 mL). The reaction mixture was heated to reflux with stirring and the reaction temperature was maintained for 5 hours. The reaction process was monitored by liquid chromatography-mass spectrometry (LCMS). After completion of the reaction, the reaction mixture was concentrated under reduced pressure using a rotary evaporator. The concentrated residue was co-milled with 30 mL of ether (Et2O) to afford 1-methylpiperidine-2-carboxylic acid as a white solid (0.5 g, 41% yield).
