Sodium hydride → Styrene

Methanesulfonic acid 2-[2-(2-hydroxy-ethyl)-phenyl]-ethyl ester (2.2 g/9.0 mmol) was dissolved in tetrahydrofuran (400 mL). Sodium hydride (540 mg/14.5 mmol) was added (hydrogen evolution) and the reaction allowed to stir at room temperature overnight. The reaction was quenched by the addition of water (10 mL) and the reaction concentrated to a volume of ca. 50 mL by rotary evaporation. The residue was partitioned between water (50 mL) and ethyl ether (50 mL). The aqueous layer was extracted with an additional portion of ethyl ether (50 mL) and the combined organics were washed with brine (100 mL), dried over magnesium sulfate, filtered and concentrated onto silica gel. Column chromatography on silica gel (eluting with 0→50% ethyl acetate/hexanes) afforded 5,6,8,9-Tetrahydro-7-oxa-benzocycloheptene as a colorless oil (240 mg/18%) along with a styrene by-product formed by mesylate elimination (600 mg/45%). Oxapene: 1H NMR (400 MHz, CDCl3) δ 7.11 (m, 4H), 3.80 (m, 4H), 3.00 (m, 4H).

1. customThe reaction was quenched by the addition of water (10 mL)
2. concentrationthe reaction concentrated to a volume of ca. 50 mL by rotary evaporation
3. customThe residue was partitioned between water (50 mL) and ethyl ether (50 mL)
4. extractionThe aqueous layer was extracted with an additional portion of ethyl ether (50 mL)
5. washthe combined organics were washed with brine (100 mL)
6. dry with materialdried over magnesium sulfate
7. filtrationfiltered
8. concentrationconcentrated onto silica gel

ORD-Eintrag

ord-17d8a16e27164d3a8d3e0b37439ed573

Quelldatensatz

uspto-grants-2012_04

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08148391B2