Sodium ethoxide → Z-Leu-Phe-COOEt

HRID 1757133Notes

Reaction equation

HRID 1757133 reaction equation
[NH:1]([C:21]([O:23][CH2:24][C:25]1[CH:30]=[CH:29][CH:28]=[CH:27][CH:26]=1)=[O:22])[C@H:2]([C:7]([NH:9][C@H:10]([C:18]([OH:20])=[O:19])[CH2:11][C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)=[O:8])[CH2:3][CH:4]([CH3:6])[CH3:5].[O-][CH2:32][CH3:33].[Na+]>C(O)C>[NH:1]([C:21]([O:23][CH2:24][C:25]1[CH:26]=[CH:27][CH:28]=[CH:29][CH:30]=1)=[O:22])[C@H:2]([C:7]([NH:9][C@H:10]([C:18]([O:20][CH2:32][CH3:33])=[O:19])[CH2:11][C:12]1[CH:13]=[CH:14][CH:15]=[CH:16][CH:17]=1)=[O:8])[CH2:3][CH:4]([CH3:6])[CH3:5]

Participants

4

Reactant 2

HCID 2723922Sodium ethoxideHCID 7408339Z-Leu-phe-OH

Product 1

HCID 14562839Z-Leu-Phe-COOEtYield 308.7%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent2×

Procedure

Single Aminoacid, Di- and Tripeptide-ketoesters (General Procedure). To a stirred solution of 8.53 g (15.0 mmol) of Z-Leu-Phe-EE in 40 ml anhydrous ethanol at room temperature was added dropwise a solution of sodium ethoxide (0.204 g; 3.0 mmol) in 20.0 ml anhydrous ethanol. The color of the reaction mixture change from colorless or pall yellow to deep yellow or orange dependent on enol-ester. Then the reaction mixture was stirred at room temperature for 4-5 hours, the ethanol was then evaporated in vacuo (rotavaporator) and the residue treated with 200 ml ethyl ether (or 200 ml ethyl acetate in the case of the tripeptide). The ether (ethyl acetate) solution was washed with 2×75 ml H2O, 2×75 ml satd. NaCl, decolorized with carbon and dried over MgSO4. After evaporation of solvent, the crude product 6.09 g (89.7%) was flash chromatographed on silica gel using CHCl3 : MeOH=50:1 v/v. Evaporation of solvent give pure Z-Leu-Phe-COOEt (4.08 g; 58.0%) as a thick oil. Single spot on TLC, Rf =0.60, A; 0.47, M. Mass spectrum, FB-MS [(M+1)/Z]=469.

Workup

  1. customthe ethanol was then evaporated in vacuo (rotavaporator)
  2. additionthe residue treated with 200 ml ethyl ether (or 200 ml ethyl acetate in the case of the tripeptide)
  3. washThe ether (ethyl acetate) solution was washed with 2×75 ml H2O, 2×75 ml
  4. dry with materialdried over MgSO4
  5. customAfter evaporation of solvent
  6. customchromatographed on silica gel
  7. customEvaporation of solvent

Sources & evidence

ORD record
ord-63a6606828e542858f92058510c87ff5
Source dataset
uspto-grants-1995_08
Patent number
US05444042

Reaction notes

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