(3R,5R)-1-benzyl-3,5-dimethylpiperazine

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 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. then heated under reflux for a further 18 h The mixture was stirred for 1 h then filtered through a pad of kieselguhr washing with DCM The filtrate was concentrated in vacuo