Reduction of 2-phenylindole gave the dihydro derivative which was hydrogenolysed to give bibenzyl-2-amine. The latter was best converted into 9,10-dihydrophenanthrene by decomposition of the derived azosulphone. Several methoxydihydrophenanthrenes, including orchinol methyl ether, were prepared by this route. ��� Conversion of dihydrophenanthrenes into phenanthrenes may be conveniently effected by benzylic bromination followed by dehydrobromination.
The synthesis of 2-nitrophenanthrene from 9,l0-dihydrophenanthrene is reported. Some 2-substituted phenanthrene and 9,l0-dihydrophenanthrene hydroxylamine derivatives have been prepared and the structure of the rearrangement products determined.