Two routes by which 4bromophenanthrene (1) has been synthesized are described in detail. In one 4 phenanthrenecarboxylic acid (2) is treated with mercuric acetate in N- methylpyrrolidone at 100". The re-sulting solution is treated with pyridinium hydrobromide perbromide (or with bromine) to give 1 in 55% yield. The second route involves conversion of diphenic acid (3) in seven steps to 1 in 11% over-all yield.
