169447-70-5

(S)-1-N-Boc-2-methylpiperazine is used in the preparation of pyrazolo[3,4-b]pyridine dual pharmacophores as PDE4-muscarinic antagonists.

A solution of (S)-2-methyl piperazine (2 g, 20 mmol) in THF (200 ml_) was mixed with nBuLi (25 ml, 1.6 M in hexanes, 40 mmol) at rt. The solution was stirred for 30 minutes before TBDMSCI (3.04 g, 20 mmol) was added. The mixture was stirred for 1 hour and then (Boc)2O (5.2 g, 24 mmol) was added to the solution. After 1 hour, the solution was diluted with H2O (50 ml). The organic layer was separated, washed with brine (50 mL), dried over Na2SO4, and concentrated EPO under vacuum. Finally, (S)-1-N-Boc-2-methylpiperazine was obtained after purification.