8-aMino-2-Azaspiro[4.5]decan-3-one synthesis

Yield:-

Reaction Conditions:

with hydrogen;palladium 10% on activated carbon in methanol at 20;

Steps:

9.3

Part 3: 8-Amino-2-azaspiro[4.5]decan-3-one (12): Nitro compound methyl (4-benzyloxycarbonylamino-1-nitromethylcyclohexyl)acetate (130 mg, 0.36 mmol) was dissolved in EtOH (5 mL) and Raney Ni (50% slurry in water, 3 mL) was added under N₂ atmosphere. The resulting suspension was stirred at rt for 72 h. The mixture was filtered through a Celite pad and solvent was removed in vacuo yield benzyl (3-oxo-2-azaspiro[4.5]dec-8-yl)carbamate (11) as an oil. Crude benzyl (3-oxo-2-azaspiro[4.5]dec-8-yl)carbamate was then dissolved in methanol (10 mL) and 10% Pd/C (100 mg) was added. The solution was then deoxygenated and back filled with N₂ atmosphere (repeated 2×). The solution was then degassed and back filled with H₂ atmosphere (repeated 2×). The mixture was then stirred under H₂ atmosphere at rt overnight. The mixture was filtered through a Celite pad and solvent was removed in vacuo yield crude 8-amino-2-azaspiro[4.5]decan-3-one, which was used directly in the coupling reaction without purification.

References:

US2006/63791,2006,A1 Location in patent:Page/Page column 14