Aluminium lithium hydride → 1-Benzyl-4,4-dimethylpiperidin-3-amine

To a solution of (Z)-1-benzyl-4,4-dimethylpiperidine-2,3,6-trione 3-oxime (490 mg, 1.88 mmol) in THF (5 mL) at 0° C. was slowly added LiAlH4 (1.0M in THF, 9.4 mL, 9.4 mmol). After the addition, the reaction mixture was warmed to room temperature and stirred for 2 h then heated at 60° C. overnight. The reaction mixture was cooled to 0° C. and carefully quenched by portionwise addition of solid Na2SO4.10H2O until gas evolution had ceased. The mixture was diluted with EtOAc and stirred vigorously at room temperature for 1 h then filtered, rinsing with EtOAc and MeOH. The filtrate was concentrated and the residue was purified by SiO2 chromatography (0% to 10% MeOH/CH2Cl2 (0.5% NH4OH)) to afford 210 mg (51%) of 1-benzyl-4,4-dimethylpiperidin-3-amine as a red oil.

1. customat 0° C.
2. additionAfter the addition
3. temperaturethen heated at 60° C. overnight
4. temperatureThe reaction mixture was cooled to 0° C.
5. customcarefully quenched by portionwise addition of solid Na2SO4.10H2O until gas evolution
6. additionThe mixture was diluted with EtOAc
7. stirringstirred vigorously at room temperature for 1 h
8. filtrationthen filtered
9. washrinsing with EtOAc and MeOH
10. concentrationThe filtrate was concentrated
11. customthe residue was purified by SiO2 chromatography (0% to 10% MeOH/CH2Cl2 (0.5% NH4OH))

ORD record

ord-920de1811ce04932bc7b243098fb8f80

Source dataset

uspto-grants-2012_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08329699B2