Synthesis
General procedure for the synthesis of 5-hydroxy-2-piperidine from compound (CAS:179532-81-1): (5) 29 g of compound 5, 435 mL of methanol and 2.9 g of Pd/C catalyst were added to a 1 L autoclave at room temperature. After displacing the reaction system with hydrogen 5 times, the reduction reaction was carried out overnight under 0.5 MPa hydrogen pressure. Upon completion of the reaction, the reaction mixture was filtered directly through a diatomaceous earth bed and the filter cake was washed with 50 mL of methanol. The filtrates were combined and concentrated using a rotary evaporator at 45°C in a water bath to give a dark gray solid precipitate. To the concentrate was added 50 mL of dichloromethane followed by 150 mL of acetonitrile, and the solid was observed to be insoluble. The mixture was separated by filtration and the filter cake was washed with 50 mL of acetonitrile. Finally, the filter cake was dried in a rotary evaporator to give 9.2 g of white solid (compound 6).
