Tetrahydrofuran → 1-Chloro-2-fluoro-4-vinylbenzene

Participants

Reaction Steps

Sodium hydride (8.549 g, 213.7 mmol, 60% suspension in mineral oil) was added portionwise to a cold (0° C.) solution of 4-chloro-3-fluorobenzaldehyde (26.07 g, 164.4 mmol) and methyltriphenylphosphonium bromide (70.48 g, 197.3 mmol) in THF (400 mL). The reaction mixture was allowed to warm up to room temperature overnight. The solids were removed by filtration, and the filter cake was washed with ether. The filtrate was concentrated (water bath about 20° C.), and the residue was suspended in hexanes and stirred for 30 minutes. The solids (mostly PPh3O) were removed by filtration, and the filter cake was washed with hexanes. The filtrate was concentrated, and the crude product was purified by column chromatography, eluting with hexanes/ethyl acetate (25:1) to give 1-chloro-2-fluoro-4-vinylbenzene (12.1 g, 47%) as an oil. 1H NMR (400 MHz, CDCl3) δ 7.33 (m, 1H), 7.18 (m, 1H), 7.10 (m, 1H), 6.63 (m, 1H), 5.74 (d, J=17.4 Hz, 1H), 5.32 (d, J=10.8 Hz, 1H).

Provenance & Evidence