Triethylamine → (R)-Tert-butyl 4-benzyl-2-methylpiperazine-1-carboxylate

HRID 2382202Notes

Reaction equation

HRID 2382202 reaction equation
[CH2:1]([N:8]1[CH2:13][CH2:12][NH:11][C@H:10]([CH3:14])[CH2:9]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C(N(CC)CC)C.[O:22](C(OC(C)(C)C)=O)[C:23]([O:25][C:26]([CH3:29])([CH3:28])[CH3:27])=O>ClCCl>[CH2:1]([N:8]1[CH2:13][CH2:12][N:11]([C:23]([O:25][C:26]([CH3:29])([CH3:28])[CH3:27])=[O:22])[C@H:10]([CH3:14])[CH2:9]1)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 90495Di-tert-butyl dicarbonateHCID 6923226(R)-1-Benzyl-3-methylpiperazine

Product 1

HCID 10085634(R)-Tert-butyl 4-benzyl-2-methylpiperazine-1-carboxylateYield 85.1%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of (R)-1-benzyl-3-methylpiperazine (10 g, 52.6 mmol) in dichloromethane (30 mL) at room temperature was added triethylamine (10.6 g, 106 mmol) and the reaction mixture was stirred for 1 h. To the reaction mixture was added (BOC)2O (13.7 g, 62.8 mmol) and the contents were stirred for further 4 h. The reaction mixture was quenched in water and extracted with dichloromethane. The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure to afford the crude product. The crude product was purified by silica gel (100-200 mesh) column chromatography eluting with 10% ethyl acetate in n-hexanes to afford 13.0 g of (R)-tert-butyl 4-benzyl-2-methylpiperazine-1-carboxylate.

Workup

  1. stirringthe contents were stirred for further 4 h
  2. customThe reaction mixture was quenched in water
  3. extractionextracted with dichloromethane
  4. dry with materialThe organic layer was dried over anhydrous sodium sulfate
  5. concentrationconcentrated under reduced pressure
  6. customto afford the crude product
  7. customThe crude product was purified by silica gel (100-200 mesh) column chromatography
  8. washeluting with 10% ethyl acetate in n-hexanes

Sources & evidence

ORD record
ord-cda46e477d794b1b897e262014fc7021
Source dataset
uspto-grants-2012_09
Patent number
US08258306B2

Reaction notes

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