Water → (3R,5R)-3,5-Dimethyl-1-(phenylmethyl)piperazine

Temperature

0 °C

a solution of (R,R) 1-benzyl-3,5-dimethylpiperazine-2-one (1.3 g) in THF (10 ml) was added dropwise to a stirred suspension of lithium aluminium hydride (0.68 g) in THF (30 ml) at 0° C. under Ar. The mixture was stirred for 30 min then heated under reflux for a further 18 h. The mixture was cooled to 0° C. and diluted with ether (50 ml). To the stirred mixture were added water (2 ml) sodium hydroxide solution (2 ml) and water (2 ml). The mixture was stirred for 1 h then filtered through a pad of kieselguhr, washing with DCM. The filtrate was concentrated in vacuo to give the product as a clear oil (0.99 g); δH (400 MHz, CDCl3) 7.35–7.20 (5H, m), 3.48 (1H, d, J 13 Hz), 3.38 (1H, d, J 13 Hz), 3.19 (1H, m), 2.49 (2H, dd, J 10.5, 3 Hz), 2.09 (2H, dd, J 10, 6.5 Hz) and 1.14 (6H, d, J 6.5 Hz); LC 93%, 1.91 min.

1. temperaturethen heated
2. temperatureunder reflux for a further 18 h
3. stirringThe mixture was stirred for 1 h
4. filtrationthen filtered through a pad of kieselguhr
5. washwashing with DCM
6. concentrationThe filtrate was concentrated in vacuo

ORD record

ord-1b7e1c4ea3d64c2ba3a4dd71afa48896

Source dataset

uspto-grants-2006_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07022707B2