Phenanthrene → Barium 2-phenanthrenesulfonate

Participants

Reaction Steps

Phenanthrene is sulfonated with concentrated sulfuric acid and then treated with barium chloride to obtain barium 2-phenanthrenesulfonate. The resulting barium salt is subjected to alkali fusion in an electric oven and then treated with hydrochloric acid to obtain 2-phenanthrol. 2-Phenanthrol is subjected to oxidative coupling in the presence of a copper-amine complex to synthesize racemic 1,1'-biphenanthryl-2,2'-diol (I). The resulting diol is reacted with optically active phenylethylamine and thiophosphoryl chloride to afford (±)-N((S)-1-phenylethyl)-1,1'-biphenanthryl-2,2'-diylthiophosphorylamide. Recrystallization of the racemate gives an optically active compound, which is then hydrogenolyzed with a reducing agent, such as lithium aluminum hydride, to give optically active 1,1'-biphenanthryl-2,2'-diol with an optical purity reaching nearly 100%.

Provenance & Evidence