4-((S)-2-tert-Butoxycarbonylamino-pent-4-enoyl)-piperazine-1-carboxylic acid ethyl ester → 4-((S)-2-Benzyloxycarbonylamino-pent-4-enoyl)-piperazine-1-carboxylic acid ethyl ester

HRID 1970495Notes

Reaction equation

HRID 1970495 reaction equation
[CH2:1]([O:3][C:4]([N:6]1[CH2:11][CH2:10][N:9]([C:12](=[O:25])[C@@H:13]([NH:17][C:18]([O:20][C:21]([CH3:24])(C)C)=[O:19])[CH2:14][CH:15]=[CH2:16])[CH2:8][CH2:7]1)=[O:5])[CH3:2]>ClCCl.C(O)(C(F)(F)F)=O>[CH2:1]([O:3][C:4]([N:6]1[CH2:7][CH2:8][N:9]([C:12](=[O:25])[C@@H:13]([NH:17][C:18]([O:20][CH2:21][C:24]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)=[O:19])[CH2:14][CH:15]=[CH2:16])[CH2:10][CH2:11]1)=[O:5])[CH3:2]

Participants

4

Reactant 1

HCID 668550274-((S)-2-tert-Butoxycarbonylamino-pent-4-enoyl)-piperazine-1-carboxylic acid ethyl ester

Product 1

HCID 668557364-((S)-2-Benzyloxycarbonylamino-pent-4-enoyl)-piperazine-1-carboxylic acid ethyl ester

Reagents, catalysts & solvents 2

HCID 6344DichloromethaneSolventHCID 6422Trifluoroacetic acidSolvent

Procedure

A solution of 767 mg 4-((S)-2-tert-Butoxycarbonylamino-pent-4-enoyl)-piperazine-1-carboxylic acid ethyl ester in 5 ml dichloromethane and 1.6 ml TFA was stirred for 2 h. The reaction mixture was concentrated, the residue dissolved in 4 ml dioxane/water (1:1) and 661 mg NaHCO3 and 688 mg N-(Benzyloxycarbonyloxy)succinimide were added. After 12 h the reaction mixture was diluted with ethyl acetate and washed with water, 0.1 M HCl and half-saturated aqueous NaHCO3 solution. The crude product obtained after evaporation of the solvent was purified by chromatography on silica using ethyl acetate/heptane 1:2 to 2:1 as eluent. Yield: 640 mg.

Workup

  1. concentrationThe reaction mixture was concentrated
  2. dissolutionthe residue dissolved in 4 ml dioxane/water (1:1)
  3. addition661 mg NaHCO3 and 688 mg N-(Benzyloxycarbonyloxy)succinimide were added
  4. additionAfter 12 h the reaction mixture was diluted with ethyl acetate
  5. washwashed with water, 0.1 M HCl and half-saturated aqueous NaHCO3 solution

Sources & evidence

ORD record
ord-6690d6b80fed45038082f11d8de9f28c
Source dataset
uspto-grants-2013_04
Patent number
US08426420B2

Reaction notes

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