561314-57-6

169206-67-1

561314-57-6

Tert-butyl 3-oxo-2,8-diazaspiro[4,5]decane-8-carboxylate (920 mg, 3.62 mmol) was used as a raw material and dissolved in a solvent mixture (5 mL / 5 mL) of dichloromethane (DCM) and trifluoroacetic acid (TFA). The reaction mixture was stirred at 30 °C for 12 hours. The progress of the reaction was monitored by thin layer chromatography (TLC, unfolding agent ratio of petroleum ether: ethyl acetate = 1:1) to confirm that the reaction was complete. After completion of the reaction, the mixture was concentrated under reduced pressure to give the crude product. The crude product was dissolved in water (30 mL) and the pH was adjusted to 10 with 1N sodium hydroxide solution. subsequently, extraction was performed with dichloromethane (15 mL x 4). The organic layers were combined, dried with anhydrous sodium sulfate and concentrated under reduced pressure to afford the target compound 2,8-diazaspiro[4.5]decan-3-one (550 mg, 98% yield) as a yellow oil.