Aluminium lithium hydride → N-methyl-1-(propan-2-yl)piperidin-4-amine

100 ml absolute diethyl ether were placed in a dry three-necked flask equipped with a condenser. 4.35 g LiAlH4 (6 equiv.) were added and the mixture was stirred at room temperature under an argon atmosphere. Carefully, 4.10 g (19.13 mmol) (1-isopropyl-piperidin-4-yl)-carbamic acid ethyl ester were added portionwise and the resulting mixture was refluxed for 7 h. Since the conversion was not complete, 1.00 g (≈1.4 equiv.) LiAlH4 was added and the mixture was refluxed for further 2 h. The reaction mixture was cooled and, carefully, 14 ml water were added dropwise over a 20-minute period. The mixture was diluted with 40 ml water and 50 ml diethyl ether. The phases were separated. The aqueous phase (suspension) was treated with a 10% NaOH-solution and washed twice with 100 ml diethyl ether. The organic phases were combined, dried over anhydrous Na2SO4 and concentrated under reduced pressure. The crude product was obtained as a colorless oil. Yield: 2.91 g MS (ES+): m/e=157.

1. customequipped with a condenser
2. temperaturethe resulting mixture was refluxed for 7 h
3. temperaturethe mixture was refluxed for further 2 h
4. temperatureThe reaction mixture was cooled
5. customThe phases were separated
6. additionThe aqueous phase (suspension) was treated with a 10% NaOH-solution
7. washwashed twice with 100 ml diethyl ether
8. dry with materialdried over anhydrous Na2SO4
9. concentrationconcentrated under reduced pressure

ORD record

ord-a779b7a1ac3d4048b547656418135e34

Source dataset

uspto-grants-2012_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08088925B2