Phosphorus tribromide → 3-(2-Phenyl-vinyl)-benzyl bromide

Participants

Reaction Steps

21 g (0.1 mol) of 3-(2-phenyl-vinyl)-benzyl alcohol were dissolved in 200 ml of anhydrous toluene, and 10 g of phosphorus tribromide were added dropwise at 0°-10° C., whilst stirring. The mixture was then stirred at 10° C. for 2 hours and at room temperature for a further 2 hours. The reaction mixture was then extracted by shaking twice with 500 ml of water each time, the organic phase was separated off and dried over magnesium sulphate and the solvent was distilled off under a waterpump vacuum. Last residues of solvent were removed by subjecting the product to brief incipient distillation at a bath temperature of 60° C./2 mm Hg. 23 g (84.2% of theory) of 3-(2-phenyl-vinyl)-benzyl bromide were obtained as a yellow oil with the refractive index nD22 : 1.6376 (isomer mixture with a cis proportion of about 90%). ##STR63##

Provenance & Evidence