Trifluoroacetic acid → H-L-Ile-D,L-Pip-OBzl TFA

HRID 1725097Notes

Reaction equation

HRID 1725097 reaction equation
[NH:1](C(OC(C)(C)C)=O)[C@H:2]([C:7]([N:9]1[CH2:24][CH2:23][CH2:22][CH2:21][CH:10]1[C:11]([O:13][CH2:14][C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1)=[O:12])=[O:8])[C@H:3]([CH2:5][CH3:6])[CH3:4].[C:32]([OH:38])([C:34]([F:37])([F:36])[F:35])=[O:33]>>[NH2:1][C@H:2]([C:7]([N:9]1[CH2:24][CH2:23][CH2:22][CH2:21][CH:10]1[C:11]([O:13][CH2:14][C:15]1[CH:16]=[CH:17][CH:18]=[CH:19][CH:20]=1)=[O:12])=[O:8])[C@H:3]([CH2:5][CH3:6])[CH3:4].[F:35][C:34]([C:32]([OH:38])=[O:33])([F:37])[F:36]

Participants

3

Reactant 2

HCID 6422Trifluoroacetic acid2×HCID 131724669Boc-L-Ile-DL-Pip-OBzl

Product 1

HCID 131724670H-L-Ile-D,L-Pip-OBzl TFA

Procedure

Boc-L-Ile-DL-Pip-OBzl (3.33 g, 7.70 mmol) was dissolved in TFA (10 ml) and left with standing on ice for 30 minutes. On completion of the reaction, TFA was removed by evaporation, and the residue was vacuum-dried to obtain H-L-Ile-DL-Pip-OBzl.TFA. The compound was dissolved in DMF (16 ml), and Boc-D-Tyr(Me)-OH (3.41 g, 11.6 mmol) was then added. HBTU (4.38 g, 11.6 mmol), HOBt.H2O (1.18 g, 7.70 mmol), and triethylamine (7.01 ml, 50.1 mmol) were further added and stirred for 3 hours under ice-cooling. The reaction solution was concentrated, dissolved in ethyl acetate, and successively washed with an aqueous 10% citric acid solution, an aqueous 4% sodium bicarbonate solution, and saturated saline. The product was dried over MgSO4 and concentrated, and the resulting foam substance was purified by flash silica gel chromatography (4×30 cm, 1% methanol/chloroform) to obtain the foam title diastereomer mixture (3.46 g, 5.67 mmol, 74% yield). TLC: Rf=(CHCl3/MeOH=9/1).

Workup

  1. waitleft
  2. customwas removed by evaporation
  3. customthe residue was vacuum-dried

Sources & evidence

ORD record
ord-52f725c8f0cd46b7b76f0a59bc34cdfb
Source dataset
uspto-grants-2009_02
Patent number
US07488712B2

Reaction notes

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