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

Temperatur

80 °C

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.

1. filtrationThe reaction mixture was filtered over CELITE®
2. customto remove MgSO4
3. concentrationthe filtrate was concentrated
4. dissolutionThe residue was re-dissolved in DCM (20 mL)
5. washwashed with saturated NaHCO3 (10 ml), water (10 mL) and brine (10 mL)
6. dry with materialThe organic layer was dried over anhydrous MgSO4
7. filtrationfiltered
8. concentrationconcentrated
9. custompurified by silica gel column chromatography (40 g RediSep Gold column)

ORD-Eintrag

ord-9147a3852bf74f01a14e48cedb440fe0

Quelldatensatz

uspto-grants-2015_12

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09206198B2