2-Nitrophenol → Nalpha-Boc-Ndelta-Cbz-(R)-ornithine o-nitrophenyl ester

HRID 366029Notes

Reaction equation

HRID 366029 reaction equation
[C:1]([NH:8][C@@H:9]([C:24]([OH:26])=[O:25])[CH2:10][CH2:11][CH2:12][NH:13][C:14]([O:16][CH2:17][C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1)=[O:15])([O:3][C:4]([CH3:7])([CH3:6])[CH3:5])=[O:2].[N+:27]([C:30]1[CH:35]=[CH:34][CH:33]=[CH:32][C:31]=1O)([O-:29])=[O:28].C1(N=C=NC2CCCCC2)CCCCC1>N1C=CC=CC=1.CCOC(C)=O.C(O)(C)C>[N+:27]([C:30]1[CH:35]=[CH:34][CH:33]=[CH:32][C:31]=1[O:25][C:24](=[O:26])[C@@H:9]([CH2:10][CH2:11][CH2:12][NH:13][C:14]([O:16][CH2:17][C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1)=[O:15])[NH:8][C:1]([O:3][C:4]([CH3:7])([CH3:6])[CH3:5])=[O:2])([O-:29])=[O:28]

Participants

7

Reactant 3

HCID 69472-NitrophenolHCID 10868DicyclohexylcarbodiimideHCID 7272030N2-((1,1-Dimethylethoxy)carbonyl)-N5-((phenylmethoxy)carbonyl)-D-ornithine

Product 1

HCID 54461433Nalpha-Boc-Ndelta-Cbz-(R)-ornithine o-nitrophenyl ester

Reagents, catalysts & solvents 3

HCID 1049PyridineSolventHCID 3776IsopropanolSolventHCID 8857Ethyl AcetateSolvent2×

Conditions

Temperature
0 °C

Procedure

A solution Nα -Boc-Nδ -Cbz-(R)-ornithine (25.0 g; 68.2 mmol) and o-nitrophenol (19.0 g; 136.4 mmol) in pyridine (250 mL) was cooled to 0° C. Dicyclohexylcarbodiimide (13.4 g; 64.8 mmol) was added at 0° C. The solution was stirred at 0° C. for several hours, warmed to room temperature and stirred overnight. The resulting heterogeneous solution was diluted with EtOAc and filtered. The filtrate was concentrated under reduced pressure to afford a thick oil. The oil was dissolved in a minimal amount of warm isopropanol and stirred. The resultant precipitate was collected via vacuum filtration and washed with isopropanol, then diethyl ether. Concentration of the isopropanol/ether filtrate and crystallization from isopropanol provided a second crop. The combined product was dissolved in EtOAc at room temperature and filtered. Concentration of the EtOAc gave the sub-title compound as a solid.

Workup

  1. temperaturewarmed to room temperature
  2. stirringstirred overnight
  3. filtrationfiltered
  4. concentrationThe filtrate was concentrated under reduced pressure
  5. customto afford a thick oil
  6. stirringstirred
  7. filtrationThe resultant precipitate was collected via vacuum filtration
  8. washwashed with isopropanol
  9. customConcentration of the isopropanol/ether filtrate and crystallization from isopropanol
  10. customprovided a second crop
  11. filtrationfiltered

Sources & evidence

ORD record
ord-3e5502f7e0f84f19932ab48ef72f19fc
Source dataset
uspto-grants-2000_10
Patent number
US06127414

Reaction notes

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