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

HRID 1501809Notes

Reaction equation

HRID 1501809 reaction equation
O=[C:2]([CH2:22][CH3:23])[CH2:3][C:4]1([C:17](OCC)=[O:18])[CH2:9][CH2:8][N:7]([C:10]([O:12][C:13]([CH3:16])([CH3:15])[CH3:14])=[O:11])[CH2:6][CH2:5]1.C([O-])(=O)C.[NH4+].C([BH3-])#[N:30].[Na+].S([O-])([O-])(=O)=O.[Mg+2]>C(O)C>[CH2:22]([CH:2]1[CH2:3][C:4]2([CH2:9][CH2:8][N:7]([C:10]([O:12][C:13]([CH3:16])([CH3:15])[CH3:14])=[O:11])[CH2:6][CH2:5]2)[C:17](=[O:18])[NH:30]1)[CH3:23]

Participants

6

Conditions

Temperature
80 °C

Procedure

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.

Workup

  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)

Sources & evidence

ORD record
ord-9147a3852bf74f01a14e48cedb440fe0
Source dataset
uspto-grants-2015_12
Patent number
US09206198B2

Reaction notes

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