Benzaldehyde → (2S,5R)-1-allyl-4-benzyl-2,5-dimethylpiperazine

Participants

Reaction Steps

To a suspension of the camphoric acid salt of (+)-(2S,5R)-1-allyl-2,5-dimethylpiperazine from Preparation 1 (78.2 g) and benzaldehyde (26.5 g) in tetrahydrofuran (500 ml) containing glacial acetic acid (2 ml) was added sodium triacetoxyborohydride (93.3 g) portionwise over 10 minutes. The resulting mixture was stirred at room temperature for 4 hours. The reaction was partitioned between ethyl acetate (1500 ml) and aqueous sodium hydroxide (750 ml of 2N solution). The layers were separated and the organic phase was washed with 10% sodium metabisulphite solution (200 ml) and saturated brine solution. The organic layer was dried (MgSO4) and evaporated to dryness in vacuo to give the title compound, 52.1 g.

Provenance & Evidence