HCID 11128927, compound → HCID 10967168, compound

HRID 2270997Notes

Reaction equation

HRID 2270997 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][NH:11][CH:10]=[C:9]1[C:14]([O:16][CH2:17][CH3:18])=[O:15])=[O:7])([CH3:4])([CH3:3])[CH3:2]>C(O)(=O)C.[H][H].[Pt](=O)=O>[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][NH:11][CH2:10][CH:9]1[C:14]([O:16][CH2:17][CH3:18])=[O:15])=[O:7])([CH3:4])([CH3:3])[CH3:2]

Participants

5

Reactant 1

HCID 11128927HCID 11128927, compound

Product 1

HCID 10967168HCID 10967168, compoundYield 90.3%

Reagents, catalysts & solvents 3

HCID 345198Adams' catalystCatalystHCID 176Acetic AcidSolventHCID 178418361HCID 178418361, compoundSolvent

Procedure

A solution of ethyl 1-tert-butoxycarbonyl-1,4,5,6-tetrahydropyrazine-2-carboxylate (69.0 g) in acetic acid (AcOH, 500 ml) was subjected to catalytic reduction using platinum dioxide (4.0 g) at 40° C. in hydrogen at 3 atm for 4 hours. The catalyst was removed by filtration, and the filtrate was concentrated in vacuo. The residue was dissolved in H2O (800 ml) and the solution was washed with Et2O (500 ml×2). To the aqueous layer was added NaHCO3 to adjust the pH of the solution to 8 and the solution was extracted with AcOEt (800 ml×2). The combined organic layer was washed with saturated aqueous NaHCO3 solution and brine, dried over MgSO4 and concentrated in vacuo to give 62.8 g of ethyl 1-tert-butoxycarbonyl- piperazine-2-carboxylate as an oil.

Workup

  1. customat 40° C.
  2. customfor 4 hours
  3. customThe catalyst was removed by filtration
  4. concentrationthe filtrate was concentrated in vacuo
  5. dissolutionThe residue was dissolved in H2O (800 ml)
  6. washthe solution was washed with Et2O (500 ml×2)
  7. additionTo the aqueous layer was added NaHCO3
  8. extractionthe solution was extracted with AcOEt (800 ml×2)
  9. washThe combined organic layer was washed with saturated aqueous NaHCO3 solution and brine
  10. dry with materialdried over MgSO4
  11. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-8da586f7399748e0ba73f6af641a2963
Source dataset
uspto-grants-2001_12
Patent number
US06333324B1

Reaction notes

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