Phosphorus tribromide → 1-(Bromomethyl)-2,3,5-triiodobenzene

A solution of phosphorous tribromide (3.8 ml, 40 mmol) was added dropwise to a solution of 2,3,5-triiodobenzyl alcohol 1 (9.72 g, 20 mmol) in dry tetrahydrofuran (50 ml) at 0° C. under dry nitrogen gas flow. The reaction mixture was stirred 5 minutes at 0° C., then 20 minutes at room temperature (18° C.), then cold H2O/DCM (60160 ml) was added. The resulting aqueous phase was extracted with dichloromethane (2×10 ml). The combined organic extracts were washed with NaHCO3 aq (20 ml) and H2O (20 ml) then dried (Na2SO4), filtered and concentrated. The white solid was also washed with cold methanol (45 ml). 9.35 g of 2,3,5-triiodobenzyl bromide in the form of a white clean solid was obtained in 85% yield.