N-Benzyloxycarbonyl-phenylalanine glycine-methylester → Cyclo(-Gly-Phe)

HRID 971366Notes

Reaction equation

HRID 971366 reaction equation
C([O:8][C:9]([NH:11][C@H:12]([C:20]([OH:22])=O)[CH2:13][C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1)=O)C1C=CC=CC=1.COC(=O)[CH2:26][NH2:27]>CO.[Pd]>[CH2:13]([C@@H:12]1[NH:11][C:9](=[O:8])[CH2:26][NH:27][C:20]1=[O:22])[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1

Participants

4

Reactant 1

HCID 69129857N-Benzyloxycarbonyl-phenylalanine glycine-methylester

Product 1

HCID 7076549Cyclo(-Gly-Phe)Yield 83.4%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 887MethanolSolvent

Procedure

A solution of 23.30 g (62.91 mmol) N-Benzyloxycarbonyl-phenylalanine-glycine-methylester (obtained above) in 650 ml dry methanol was hydrogenated by adding Pd/C-catalyst and stirring the resulting mixture under H2 at r.t. for 3 h. After that, the mixture was filtered through celite and then half of the solvent was evaporated. The remaining solution was refluxed for 17 h. Filtration of the white precipitate and washing it twice with methanol yielded 10.71 g (52.45 mmol, 83.37%) 6-(S)-Benzyl-piperazine-2,5-dione as a white solid.

Workup

  1. filtrationAfter that, the mixture was filtered through celite
  2. customhalf of the solvent was evaporated
  3. temperatureThe remaining solution was refluxed for 17 h
  4. filtrationFiltration of the white precipitate
  5. washwashing it twice with methanol

Sources & evidence

ORD record
ord-0f446ddd01c141479e561b6fb66dc0a6
Source dataset
uspto-grants-2007_12
Patent number
US07312246B2

Reaction notes

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