ChemicalBook CAS DataBase List (S)-1-N-Boc-2-methylpiperazine

(S)-1-N-Boc-2-methylpiperazine synthesis

8synthesis methods

Product Name:(S)-1-N-Boc-2-methylpiperazine
CAS Number:169447-70-5
Molecular formula:C10H20N2O2
Molecular Weight:200.28

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.

24424-99-5 Synthesis

24424-99-5
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$13.50/25G

169447-70-5
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$5.00/250mg

Yield:169447-70-5 93%

Reaction Conditions:

Stage #1:(S)-2-methylpiperazine with n-butyllithium in tetrahydrofuran at 20; for 0.5 h;
Stage #2: with tert-butyldimethylsilyl chloride in tetrahydrofuran for 1 h;
Stage #3:di-tert-butyl dicarbonate in tetrahydrofuran for 1 h;

Steps:

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 min before TBDMSCI (3.04 g, 20 mmol) was added. The mixture was stirred for an additional hour and (Boc)₂O (5.2 g, 24 mmol) was added to the solution. The resulting mixture was stirred for another hour and diluted with H₂O (50 ml_). The organic layer was separated, washed with brine (50 mL), dried over Na₂SO₄ and concentrated EPO under vacuum. Flash chromatography on silica (5% MeOH / 2% NH₄OH / 93% CH₂CI₂) then provided the title compound as a yellow oil (3.7 g, 93%). LC/MS: m/z, 201 (M+H); ¹HNMR (CDCI₃) δ 1.26 (3H, d), 1.49 (9H, s), 2.1 (1 H, s), 2.7 (1 H, m), 2.85 (1 H, m), 3.0 (3H, m), 3.8 (1 H, m), 4.2 (1 H, m).

References:

GLAXO GROUP LIMITED WO2006/55553, 2006, A2 Location in patent:Page/Page column 36; 37

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