Triethylamine → 1,1-Dimethylethyl (2S)-4-[(4-aminophenyl)methyl]-2-methyl-1-piperazinecarboxylate

HRID 883781Notes

Reaction equation

HRID 883781 reaction equation
[CH3:1][C@H:2]1[CH2:7][N:6]([CH2:8][C:9]2[CH:14]=[CH:13][C:12]([N+:15]([O-])=O)=[CH:11][CH:10]=2)[CH2:5][CH2:4][N:3]1[C:18]([O:20][C:21]([CH3:24])([CH3:23])[CH3:22])=[O:19].C(N(CC)CC)C>[Pt].CO>[NH2:15][C:12]1[CH:13]=[CH:14][C:9]([CH2:8][N:6]2[CH2:5][CH2:4][N:3]([C:18]([O:20][C:21]([CH3:24])([CH3:23])[CH3:22])=[O:19])[C@@H:2]([CH3:1])[CH2:7]2)=[CH:10][CH:11]=1

Participants

5

Reactant 2

HCID 8471TriethylamineHCID 592622041,1-Dimethylethyl (2S)-2-methyl-4-[(4-nitrophenyl)methyl]-1-piperazinecarboxylate

Product 1

HCID 592622171,1-Dimethylethyl (2S)-4-[(4-aminophenyl)methyl]-2-methyl-1-piperazinecarboxylateYield 99.3%

Reagents, catalysts & solvents 2

HCID 23939PlatinumCatalystHCID 887MethanolSolvent

Procedure

A mixture of 1,1-dimethylethyl (2S)-2-methyl-4-[(4-nitrophenyl)methyl]-1-piperazinecarboxylate (D21) (21.62 g, 0.0644 mol), triethylamine (40 mL) and 5% Pt/C catalyst (21 g, 56% w/w water) in MeOH (400 mL) was hydrogenated at room temperature and atmospheric pressure overnight. The catalyst was removed by filtration and washed with further MeOH. The filtrate was concentrated in vacuo, re-dissolved in DCM (200 mL) and washed with 2M NaOH solution. The aqueous wash was re-extracted with DCM (×2, 100 mL) and all organic phases were combined, washed with brine, dried and concentrated to give the title compound (19.53 g) which was used in the next step without further purification.

Workup

  1. customwas hydrogenated at room temperature
  2. customatmospheric pressure overnight
  3. customThe catalyst was removed by filtration
  4. washwashed with further MeOH
  5. concentrationThe filtrate was concentrated in vacuo
  6. dissolutionre-dissolved in DCM (200 mL)
  7. washwashed with 2M NaOH solution
  8. washThe aqueous wash
  9. extractionwas re-extracted with DCM (×2, 100 mL)
  10. washwashed with brine
  11. customdried
  12. concentrationconcentrated

Sources & evidence

ORD record
ord-5ca0bf849424497fa8d9dc03e65fbcd3
Source dataset
uspto-grants-2012_08
Patent number
US08236953B2

Reaction notes

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