Trifluoroacetic acid → 4-Benzyloxycarbonyl-3-(S)-(2-methylsulfanyl-ethyl)-piperazin-2-one

HRID 1433057Notes

Reaction equation

HRID 1433057 reaction equation
[CH2:1]([O:8][C:9]([N:11]1[CH:16]=[CH:15][NH:14][C:13](=[O:17])[C@@H:12]1[CH2:18][CH2:19][S:20][CH3:21])=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[SiH](CC)(CC)CC.C(C(O)=O)(F)(F)F>C(Cl)Cl>[CH2:1]([O:8][C:9]([N:11]1[CH2:16][CH2:15][NH:14][C:13](=[O:17])[C@@H:12]1[CH2:18][CH2:19][S:20][CH3:21])=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

5

Reactant 3

HCID 6422Trifluoroacetic acidHCID 12052TriethylsilaneHCID 690260114-benzyloxycarbonyl-3-(S)-(2-methylsulfanyl-ethyl)-3,4-dihydro-1H-pyrazine-2-one

Product 1

HCID 670141654-Benzyloxycarbonyl-3-(S)-(2-methylsulfanyl-ethyl)-piperazin-2-oneYield 46%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
0 °C

Procedure

To a solution of 4-benzyloxycarbonyl-3-(S)-(2-methylsulfanyl-ethyl)-3,4-dihydro-1H-pyrazine-2-one (0.3 g, 1 mmol) in CH2Cl2 is added Et3SiH (1.57 ml, 10 mmol). The resulting solution is cooled to 0° C. and CF3CO2H (2.2 ml, 30 mmol) is added dropwise. The mixture is stirred 16 hours at room temperature, washed with a saturated aqueous NaHCO3 solution, brine. The solution is dried over MgSO4, concentrated. The resulting crude product is purified by column chromatography on silica gel eluting with a gradient of 50% AcOEt:Hexane to 100% AcOEt. The title compound (0.138 g, 46% yield) is obtained as an oil.

Workup

  1. washwashed with a saturated aqueous NaHCO3 solution, brine
  2. dry with materialThe solution is dried over MgSO4
  3. concentrationconcentrated
  4. customThe resulting crude product is purified by column chromatography on silica gel eluting with a gradient of 50% AcOEt

Sources & evidence

ORD record
ord-9fa6259c2c104a1fb0455cd384b62185
Source dataset
uspto-grants-2009_11
Patent number
US07612075B2

Reaction notes

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