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

HRID 25853Notes

Reaction equation

HRID 25853 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-bc3c826f7798473c9968d89d218e17b6
Source dataset
uspto-grants-2005_02
Patent number
US06858600B2

Reaction notes

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