Phenarithrene condensed under drastic conditions with two molecules of phthalic anhydride. Ring closure of the resulting dicarboxylic acid gave heptaphene diquinone which was reduced to heptaphene, the structure of which was proved by the absorption spectrum. Pyrolysis of a mixture of di-0-toluoylphenanthrenes yielded mostly 2, 3, 8, 9-dibenzopicene, which was also obtained as a by-product in the above synthesis. An orange hydrocarbon, ...
![Dibenzo[b,n]picene Structure](https://image.chemsrc.com/caspic/141/213-44-5.png)