2-Benzyl-2-azaspiro[4.4]nonane-1,4-dione → 2-Benzyl-2-azaspiro[4.4]nonan-4-ol

Temperature

85 °C

To a solution of 2-benzyl-2-azaspiro[4.4]nonane-1,4-dione (10.00 g, 41.10 mmol) in THF (240 mL) was added LiAlH4 (3.12 g, 80.20 mmol) portionwise at 0° C. After addition, the reaction mixture was stirred at 85° C. for 1 hour, then cooled down to 0° C. and quenched carefully with water (3.12 mL) and 15% KOH aqueous solution (3.12 mL) followed by another water (9.36 mL). After that, anhydrous MgSO4 (20 g) was added to the above mixture and stirred at rt for 15 min, then filtered through a pad of Celite. The filtrate was extracted with DCM (100 mL×3) and then the separated organic layer was concentrated in vacuo. The residue was purified by silica gel column chromatography (DCM/MeOH (v/v)=100/1 to 5/1) to give the title compound as yellow oil (8.89 g, 93.5%).

1. additionAfter addition
2. temperaturecooled down to 0° C.
3. customquenched carefully with water (3.12 mL) and 15% KOH aqueous solution (3.12 mL)
4. additionAfter that, anhydrous MgSO4 (20 g) was added to the above mixture
5. stirringstirred at rt for 15 min
6. filtrationfiltered through a pad of Celite
7. extractionThe filtrate was extracted with DCM (100 mL×3)
8. concentrationthe separated organic layer was concentrated in vacuo
9. customThe residue was purified by silica gel column chromatography (DCM/MeOH (v/v)=100/1 to 5/1)

ORD record

ord-71bc2fea0f56401e8aab46fe15f3a80f

Source dataset

uspto-grants-2016_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09403801B2