Leucine, N-carboxy-, N-benzyl ester, L- → Z-Leu-Leu methyl ester

HRID 610404Notes

Reaction equation

HRID 610404 reaction equation
[C:1]([NH:11][C@H:12]([C:17]([OH:19])=O)[CH2:13][CH:14]([CH3:16])[CH3:15])([O:3][CH2:4][C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1)=[O:2].Cl.[CH3:21][O:22][C:23](=[O:30])[C@H:24]([CH2:26][CH:27]([CH3:29])[CH3:28])[NH2:25].ON1C2C=CC=CC=2N=N1.Cl.CN(C)CCCN=C=NCC>CN(C=O)C.C(OCC)(=O)C>[CH3:21][O:22][C:23](=[O:30])[C@H:24]([CH2:26][CH:27]([CH3:29])[CH3:28])[NH:25][C:17](=[O:19])[C@H:12]([CH2:13][CH:14]([CH3:15])[CH3:16])[NH:11][C:1]([O:3][CH2:4][C:5]1[CH:6]=[CH:7][CH:8]=[CH:9][CH:10]=1)=[O:2]

Participants

7

Reactant 4

HCID 74840Leucine, N-carboxy-, N-benzyl ester, L-HCID 757711-HydroxybenzotriazoleHCID 2723695Leucine methyl ester hydrochlorideHCID 27239391,3-Propanediamine, N'-(ethylcarbonimidoyl)-N,N-dimethyl-, monohydrochloride

Product 1

HCID 7237624Z-Leu-Leu methyl esterYield 66%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolventHCID 8857Ethyl AcetateSolvent

Procedure

N-Cbz-L-leucine (Chemical Dynamics) (1.32 g, 4.97 mmol), L-leucine methyl ester hydrochloride (Aldrich) (0.99 g, 5.47 mmol), 1-hydroxybenzotriazol (0.14 g, 1.0 mmol) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (1.05 g, 5.47 mmol) were combined, dissolved in 25 mL of DMF and stirred at room temperature for 15 h. The solution was diluted with ethyl acetate (250 mL) and washed successively with water, 0.1 N HCl, saturated aqueous NaHCO3 and saturated brine, then dried MgSO4), filtered, and concentrated. The residue was purified by flash chromatography on 230-400 mesh silica gel, eluting with 1:3 ethyl acetate hexanes, to give the title compound as a white solid (1.28 g, 66%). 1H NMR (400 MHz, CDCl3) δ7.37-7.32 (m, 5H), 6.28 (d, 1H), 5.28 (m, 3H), 4.61-4.58 (m, 1H), 4.20 (m, 1H), 3.74 (s, 3H), 1.69-1.54 (m, 6H), 0.96-0.92 (m, 12H).

Workup

  1. washwashed successively with water, 0.1 N HCl, saturated aqueous NaHCO3 and saturated brine
  2. filtrationdried MgSO4), filtered
  3. concentrationconcentrated
  4. customThe residue was purified by flash chromatography on 230-400 mesh silica gel
  5. washeluting with 1:3 ethyl acetate hexanes

Sources & evidence

ORD record
ord-ca6d317ef9af49208f1e80e9c5b59e5a
Source dataset
uspto-grants-1999_12
Patent number
US05998470

Reaction notes

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