Water → Bromo-PEG4-t-butyl ester

HRID 2083889Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 2083889
[C:1]([O:5][C:6](=[O:22])[CH2:7][CH2:8][O:9][CH2:10][CH2:11][O:12][CH2:13][CH2:14][O:15][CH2:16][CH2:17][O:18][CH2:19][CH2:20]O)([CH3:4])([CH3:3])[CH3:2].P(Br)(Br)[Br:24].O>N1C=CC=CC=1>[C:1]([O:5][C:6](=[O:22])[CH2:7][CH2:8][O:9][CH2:10][CH2:11][O:12][CH2:13][CH2:14][O:15][CH2:16][CH2:17][O:18][CH2:19][CH2:20][Br:24])([CH3:4])([CH3:3])[CH3:2]

Komponenten

5

Edukt 3

HCID 962WaterHCID 24614Phosphorus tribromideHCID 11174684Hydroxy-PEG4-t-butyl ester

Produkt 1

HCID 12082266Bromo-PEG4-t-butyl esterAusbeute 85,1 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 1049PyridineLösungsmittel

Versuchsvorschrift

To a stirred solution of 9a (1.0 g, 3.11 mmol) in 1 mL of pyridine at 0° C. was slowly added phosphorus tribromide (0.116 mL, 1.22 mmol) via syringe (Bradshaw et al., J. Het. Chem., 27:347-349 (1990)). The solution was allowed to stir overnight, at which time TLC analysis indicated that the reaction was complete. Water (25 mL) was poured into the reaction vessel and the organics were extracted into methylene chloride (3×25 mL). The combined organic layers were washed with sodium bicarbonate (25 mL), followed by brine (25 mL), dried over magnesium sulfate, and the solvent was removed in vacuo. The residue was purified on silica gel using neat ethyl acetate as the eluant to give 400 mg (35% yield) of pure product 10a (FIG. 7). 1H NMR: 1.37 (s, 9H), 2.43 (t, 2H, J=6.4 Hz), 3.40 (t, 2H, J=6.4 Hz), 3.53-3.61 (m, 12H), 3.64 (t, 2H, J=6.4 Hz), 3.74 (t, 2H, J=6.4 Hz). 13C NMR: 27.90, 30.13, 36.06, 66.68, 70.17, 70.31, 70.32, 70.39, 70.46, 70.99, 80.22, 170.65.

Aufarbeitung

  1. customat 0° C.
  2. extractionthe organics were extracted into methylene chloride (3×25 mL)
  3. washThe combined organic layers were washed with sodium bicarbonate (25 mL)
  4. dry with materialdried over magnesium sulfate
  5. customthe solvent was removed in vacuo
  6. customThe residue was purified on silica gel using neat ethyl acetate as the eluant

Quellen und Nachweise

ORD-Eintrag
ord-838cf3f93d9249f39285c20d1d324d4a
Quelldatensatz
uspto-grants-2004_04
Patentnummer
US06716821B2

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