52065-78-8

19365-07-2

52065-78-8

(6) 6 g of 5-hydroxy-2-piperidine (compound 6) was dispersed in dichloromethane (DCM) at room temperature, Dess-Martin oxidizer (Dess-Martin periodinane) was added to the system and the reaction was carried out at room temperature overnight under nitrogen protection. After completion of the reaction, the reaction mixture was filtered directly, the filter cake was washed with 50 mL of methanol and the filtrate was concentrated by rotary evaporation. The concentrate was mixed with 30 g silica gel and purified by column chromatography to collect the purer fractions. After concentration, the solid was precipitated and washed by adding 20 mL of dichloromethane (DCM), and the filter cake was dried to give 1 g of 2,5-dipiperidone (target product).