Trifluoroacetic acid → tert-Butyl 4-hydroxy-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of 1-tert-butyl 4-methyl 4-(2-((tert-butoxycarbonyl)amino)-1-hydroxyethyl)piperidine-1,4-dicarboxylate (4000 mg, 9.94 mmol) in DCM (100 mL) was added TFA (23 mL, 298 mmol) at 0° C. and the resulting solution was stirred for 2 h. After removing the volatiles, it was put on high vacuum briefly to remove excess TFA, and the residue was dissolved in MeOH (100 mL), and potassium carbonate (13.7 g, 99 mmol) was added. The reaction mixture was heated at 60° C. for 2 h. After cooling to room temperature, aqueous NaHCO3 (50 mL) was added to the reaction mixture. (BOC)2O (6.51 g, 29.8 mmol) was added, and the reaction mixture was stirred overnight. The reaction mixture was extracted with DCM, dried with MgSO4, and concentrated to give the crude product, which was purified by column chromatography (0-20% MeOH/DCM, monitor at 210 nm) to afford the title compound. LC/MS: [(M+1)]+=271

Provenance & Evidence