not really new, just not often in use; derivatives of diphenylpyridine are used to identify impurities connected with the illegal metoxyamphetamine sources
tbh, i think i have something now and it seems legit, but without the electrophilic substitutions. im providing the decription below, although i think it might be a bit chaotic, sorry for that!
I protonated the ketone group, then nitrogen electron pair attacked the carbonyl carbon in order to remove the positive charge on oxygen. nucleophilic addition of water helped to remove positive charge on nitrogen. then i had some hydrogen migration in order to make amide and to protonate the 2nd ketone group and then the other positive charge was removed via cyclisation (water took one hydrogen). in the end i had simply 2x dehydratations under acidic conditions to form double bonds.