反应详情

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.

1. waitThe mixture was left
2. extractionExtraction with diethyl ether (500 mL)
3. washwashing with a saturated solution of NaCl (300 mL, 3×), re-extraction of the aqueous phase with ether
4. dry with materialdrying of the combined organic phases (Na2SO4)
5. additionadding of tert-butyl hydroquinone (TBHQ, ca. 0.3 mg)
6. concentrationconcentrating
7. customdrying under vacuum (0.5 mbar, 0.5 h)
8. customafforded 19.40 g of the crude compound
9. concentrationconcentrating
10. customdrying under vacuum