Allyl bromide → 2-(3,4-Dichlorophenyl)pent-4-enenitrile

Participants

Reaction Conditions

Reaction Steps

A solution of 3,4-dichlorophenyl acetonitrile (200 g, 1.075 mol) in dry tetrahydrofuran (400 ml) was added dropwise, over one hour to sodium hydride 60% w/w dispersion in oil (32.26 g, 1.075 mole) in dry tetrahydrofuran (400 ml) at 0° C. under nitrogen. After a further thirty minutes the solution was cooled to -20° C. and a solution of allyl bromide (92.9 ml, 1 mol equivalent) in tetrahydrofuran (200 ml) was added, the mixture allowed to warm to room temperature and stirred for fourteen hours. Saturated brine (600 ml) was added and the mixture extracted with dichloromethane (2×600 ml). The organic layers were combined, dried over magnesium sulphate, and the solvent removed under reduced pressure. The residue was chromatographed on silica gel, eluting with a solvent gradient of ethyl acetate/hexane to provide the title compound as an oil (71.3 g). TLC Rf=0.71 (silica, diethylether:hexane, 1:1 by volume). 1H-NMR (CDCl3): δ=2.6-2.75(m,2H), 3.85(t,1H), 5.1-5.25(m,2H), 5.7-5.9(m,1H), 7.2-7.25(m,1H), 7.5-7.55(m,2H) ppm.

Provenance & Evidence