Reaktion #717752

Reaktionsgleichung

4-bromostyrene

magnesium

bis(2-phenylethyl)oxalate

NH4Cl

→

desired compound

Ausbeute 68.1%

2-phenylethyl 2-oxo-2-(4-vinylphenyl)acetate

Ausbeute 68.1%

Lösungsmittel

heptane ethyl acetate

THF

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.WAITThe mixture was left
2. 2
   ExtraktionExtraction with diethyl ether (500 mL)
3. 3
   Waschenwashing with a saturated solution of NaCl (300 mL, 3×), re-extraction of the aqueous phase with ether
4. 4
   Trocknendrying of the combined organic phases (Na2SO4)
5. 5
   workup.ADDITIONadding of tert-butyl hydroquinone (TBHQ, ca. 0.3 mg)
6. 6
   Einengenconcentrating
7. 7
   Sonstigedrying under vacuum (0.5 mbar, 0.5 h)
8. 8
   Sonstigeafforded 19.40 g of the crude compound
9. 9
   Einengenconcentrating
10. 10
    Sonstigedrying under vacuum

Vorschrift

A Grignard reagent prepared from freshly distilled 4-bromostyrene (9.45 g, 51.6 mmol) and magnesium (1.31 g, 54.0 mmol) in THF (70 mL) was added dropwise to a stirred solution of bis(2-phenylethyl)oxalate (14.0 g, 46.9 mmol) in THF (120 mL) at −60° C. The mixture was left warming to room temperature, and then poured onto a mixture of ice (200 g) and a saturated solution of NH4Cl (200 mL). Extraction with diethyl ether (500 mL), washing with a saturated solution of NaCl (300 mL, 3×), re-extraction of the aqueous phase with ether, drying of the combined organic phases (Na2SO4), adding of tert-butyl hydroquinone (TBHQ, ca. 0.3 mg), concentrating and drying under vacuum (0.5 mbar, 0.5 h) afforded 19.40 g of the crude compound. Column chromatography (SiO2, heptane/ethyl acetate 98:2), adding of TBHQ (0.2 mg) to the product fractions, concentrating and drying under vacuum gave 8.95 g (68%) of the desired compound.

Quelle