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 record

ord-f38850dda08f4559b0c55ef2e39e8abe

Source dataset

uspto-grants-2013_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08552186B2