Sulfuric acid magnesium salt (1:1) → Tert-butyl 3-ethyl-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 1-tert-butyl 4-ethyl 4-(2-oxobutyl)piperidine-1,4-dicarboxylate (0.78 g, 2.38 mmol) in ethanol (24 mL) in a sealed tube was added ammonium acetate (2.39 g, 31.0 mmol), sodium cyanoborohydride (0.422 g, 6.72 mmol) and magnesium sulfate (1.577 g, 13.10 mmol) and the resulting mixture was heated for 16 hours at 80° C. The reaction mixture was filtered over CELITE® to remove MgSO4 and the filtrate was concentrated. The residue was re-dissolved in DCM (20 mL) and washed with saturated NaHCO3 (10 ml), water (10 mL) and brine (10 mL). The organic layer was dried over anhydrous MgSO4, filtered, concentrated, then purified by silica gel column chromatography (40 g RediSep Gold column) using (0-10) % MeOH/EtOAc to give the title compound.

Provenance & Evidence