Synthesis
3 -bromophenanthreneTo a 250 mL vessel equipped with a pyrex inner water-cooled jacket was added l-bromo-4-[2- phenylvinyl] benzene (520 mg, 2.0 mmol) from Step 1 above, in cyclohexane (230 mL) and THF (5 mL). To this solution was added iodine (770 mg, 3.0 mmol). The stirred solution was first degassed by bubbling nitrogen and was then exposed to UV light for 16 hours by inserting a 450 W medium pressure mercury lamp in the inner insert. The reaction was quenched with 10% Na2S2?3 and the aqueous layer was extracted with ethyl acetate. The combined organic layers were washed with brine, dried over Na2SO4 and the volatiles were removed under reduced pressure. The crude material was purified by flash chromatography on silica (100 % hexanes) to afford 3-bromophenanthrene (486 mg, 94%) as a white solid.
