1-Benzyl-(3R)-methylpiperazine-2-one → 1-Benzyl-3-methylpiperazine
Reaction equation
[CH2:1]([N:8]1[CH2:13][CH2:12][NH:11][C@H:10]([CH3:14])[C:9]1=O)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[H-].[Al+3].[Li+].[H-].[H-].[H-]>C1COCC1>[CH2:1]([N:8]1[CH2:13][CH2:12][NH:11][CH:10]([CH3:14])[CH2:9]1)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
A mixture of 1-benzyl-3R-methylpiperazine-2-one (XX, 4.36 g), lithium aluminum hydride (LAH, 2.33 g) and THF (125 ml) is heated at reflux for 16 hr. After cooling to 20°-25°, the mixture is quenched slowly with water (2.3 ml), sodium hydroxide (10%, 3.5 ml) and water (5.7 ml). The residue is diluted with ether (100 ml) and is stirred for 1 hr. The solids are filtered and washed successively with ether, methylene chloride and ether. The combined filtrates are dried over potassium carbonate, filtered and concentrated to give 1-benzyl-(3R)-methylpiperazine (XXI), sufficiently pure to be carried on crude, NMR (CDCl3) 7.2-7.4, 3.49, 2.7-3.0, 1.95-2.1, 166, 1.3-1.7 and 1.01 δ.