cyclo-L-Ala-L-Glu(OBzl) → 3-((2S,5S)-5-Methyl-3,6-dioxopiperazin-2-yl)propanoic acid

HRID 474178Notes

Reaction equation

HRID 474178 reaction equation
[NH:1]1[C:20](=[O:21])[C@H:7]([CH2:8][CH2:9][C:10](=[O:19])[O:11]CC2C=CC=CC=2)[NH:6][C:4](=[O:5])[C@@H:2]1[CH3:3]>C(O)C(F)(F)F.[Pd]>[NH:1]1[C:20](=[O:21])[C@H:7]([CH2:8][CH2:9][C:10](=[O:11])[OH:19])[NH:6][C:4](=[O:5])[C@@H:2]1[CH3:3]

Participants

4

Reactant 1

HCID 131731166cyclo-L-Ala-L-Glu(OBzl)

Product 1

HCID 92095713-((2S,5S)-5-Methyl-3,6-dioxopiperazin-2-yl)propanoic acid

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 64092,2,2-TrifluoroethanolSolvent

Procedure

Cyclo-L-Ala-L-Glu(OBzl) (14.5 g, 0.05 mol) was dissolved in 200 ml of trifluorethanol and then 1.5 g of palladium black was added. Hydrogen was bubbled through the suspension and the mixture was stirred for 48 hours. The completion of the reaction was monitored by TLC. After the reaction was complete, the catalyst was filtered off and the solvent was evaporated in vacuum. The residual peptide was dissolved in 200 ml of distilled water and the impurities were extracted with 3×100 ml of EtOAc. The water phase was combined and evaporated in vacuum. The precipitate was washed with ether and hexane and then dried in air. The yield was 10.2 g (94%). Rf=0.2(CHCl3 EtOAc:MeOH:AcOH=6:3:1:0.1); Rf=0.5(CHCl3:EtOAc:MeOH: 32% Ac OH=6:3:1:0.1); HPLC data: retention time 6.7 min.

Workup

  1. customHydrogen was bubbled through the suspension
  2. filtrationthe catalyst was filtered off
  3. customthe solvent was evaporated in vacuum
  4. dissolutionThe residual peptide was dissolved in 200 ml of distilled water
  5. extractionthe impurities were extracted with 3×100 ml of EtOAc
  6. customevaporated in vacuum
  7. washThe precipitate was washed with ether and hexane
  8. customdried in air

Sources & evidence

ORD record
ord-ee70545168144bee868ee09750772dc8
Source dataset
uspto-grants-2014_01
Patent number
US08637521B2

Reaction notes

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