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

HRID 2417161Notes

Reaction equation

HRID 2417161 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 acidHCID 131724669Boc-L-Ile-DL-Pip-OBzl

Product 1

HCID 131724670H-L-Ile-D,L-Pip-OBzl TFAYield 144%

Procedure

Boc-L-Ile-D,L-Pip-OBzl (432 mg, 1 mmol) was dissolved in TFA (3 ml) and allowed to stand for 30 minutes under ice cooling. The reaction solution was distilled and dried under reduced pressure to yield H-L-Ile-D,L-Pip-OBzl TFA (638 mg; yield 144%), which was then dissolved in DMF (5 ml). The solution was mixed with Boc-D-Cha-OH (326 mg, 1.2 mmol) and subsequently mixed with HOBt H2O (230 mg, 1.5 mmol, 1.5 equivalents), Et3N (0.52 ml, 3.7 mmol, 3.7 equivalents) and BOP (663 mg, 1.5 mmol, 1.5 equivalents) under ice cooling, followed by stirring at room temperature for 15 hours. The reaction mixture was concentrated, extracted with ethyl acetate (100 ml), and washed twice with 10% citric acid, 4% NaHCO3 and brine, respectively. After drying over magnesium sulfate, ethyl acetate was distilled off. The residue was vacuum dried and purified by flash chromatography (2.4×14 cm) with CHCl3/MeOH (99:1) to yield Boc-D-Cha-L-Ile-D,L-Pip-OBzl (565 mg, 0.96 mmol; yield 96%) as a foam.

Workup

  1. distillationThe reaction solution was distilled
  2. customdried under reduced pressure

Sources & evidence

ORD record
ord-06fff12623214950b04808705cf6f4fa
Source dataset
uspto-grants-2004_11
Patent number
US06825317B2

Reaction notes

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