Sulfuric acid magnesium salt (1:1) → tert-Butyl 3-methyl-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate

HRID 1501756Notes

Reaction equation

HRID 1501756 reaction equation
O=[C:2]([CH3:21])[CH2:3][C:4]1([C:17](OC)=[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:28].[Na+].S([O-])([O-])(=O)=O.[Mg+2]>CO>[CH3:21][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:28]1

Participants

6

Reactant 4

HCID 24083Sulfuric acid magnesium salt (1:1)HCID 517165Ammonium AcetateHCID 5003444Sodium cyanoborohydrideHCID 867094441-Tert-butyl 4-methyl 4-(2-oxopropyl)piperidine-1,4-dicarboxylate

Product 1

HCID 86709445tert-Butyl 3-methyl-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
80 °C

Procedure

1-tert-Butyl 4-methyl 4-(2-oxopropyl)piperidine-1,4-dicarboxylate (1.15 g, 3.84 mmol) in methanol (25 mL) was treated with ammonium acetate (3.85 g, 49.9 mmol), sodium cyanoborohydride (0.681 g, 10.83 mmol) and magnesium sulfate (2.54 g, 21.1 mmol). The mixture was heated at 80° C. in a sealed tube for 12 hours. The reaction mixture was filtered through a pad of CELITE® and the filter cake was washed with methanol. The filtrates were then concentrated and the residue was purified by column chromatography eluting with 0-10% methanol/ethyl acetate to afford the title compound. LC-MS (IE, m/z): 291.27 (M+23)+

Workup

  1. filtrationThe reaction mixture was filtered through a pad of CELITE®
  2. washthe filter cake was washed with methanol
  3. concentrationThe filtrates were then concentrated
  4. customthe residue was purified by column chromatography
  5. washeluting with 0-10% methanol/ethyl acetate

Sources & evidence

ORD record
ord-8526817832b543d49fba645f767f5fdd
Source dataset
uspto-grants-2015_12
Patent number
US09206198B2

Reaction notes

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