Synthesis and spectra of 7‐( o ‐ and p‐R ‐phenyl)‐10,10‐dimethyl‐8,9,10,11‐tetrahydrobenz[ c ]acridin‐8‐ones. Structure correction of 1,2,3,4‐tetrahydro‐2,2‐dimethyl‐5‐aryl‐6‐aza‐7,8‐benzophenanthren‐4‐ones

It has been reported that dimedone added to α‐arylidennaphthylamines in ethanol with formation of 1,4‐addition products derivatives of 5‐aryl‐5,6,7,8,9,10‐hexahydrobenzo[ c ]phenanthridin‐7‐ones, III , which are easily oxidized by chromic anhydride to the corresponding tetrahydro derivatives, IV . However, the attempted preparation of these compounds resulted instead of the formation of isomeric acridin‐8‐ones V and VI . Structures were confirmed by ir, 1 H nmr, ms and X‐ray spectroscopy.