Nuclear Bromination of Toluene Catalyzed by Rose Bengal

Abstract

Rose Bengal has a catalytic activity for the nuclear bromination of toluene. Thus, 10 ml of toluene containing 100 mg of Rose Bengal was treated with 0.98 ml of bromine at 30°C for 5 hr to give p- and o-bromotoluenes (p-/o-=1.5) in ca.90% yield. Without Rose Benga4l p- and o-bromotoluenes (p-/o-=1.6) and benzyl bromide were produced in yields of 17% and 74%, respectively.