Hydrochloric Acid → 1-Allyl-3-chloro-4-fluorobenzene

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Reaction Steps

The corresponding arylmagnesium bromide was prepared from 406 g (1.94 mol) of 4-bromo-2-chlorofluorobenzene and 48.6 g (2.00 mol) of magnesium turnings in 1,300 ml of anhydrous tetrahydrofuran by the customary process. The solution thus obtained was added dropwise to a solution of 278.3 g (2.3 mol) of allyl bromide in 200 ml of anhydrous tetrahydrofuran at 30°-45° C. The mixture was then heated under reflux for 0.5 h, allowed to stand at room temperature for 16 h and poured onto 1.5 liters of ice-water. After acidification using a little 2N hydrochloric acid, the mixture was extracted twice using 1 liter of hexane each time. The extracts were washed three times with water, dried over Na2SO4 and evaporated. The residue yielded 235 g (71%) of 3-(3-chloro-4-fluorophenyl)propene of b.p.10 =72° C. with a purity of 98.7% (determined by gas chromatography) on subsequent distillation.

Provenance & Evidence