Amination of pyrido[3,2,1‐ jk ]carbazol‐6‐ones

Amination of 4‐hydroxypyridocarbazolones 1 with aniline or benzylamine gave in good yields 4‐amines 3 . With piperidine in a sealed tube from 4‐hydroxy‐ or 4‐chloro‐5‐alkylpyridocarbazolones 1 or 4 ring opened 1‐acylcarbazoles 5 were obtained. Only 4‐hydroxy‐5‐phenyl‐pyridocarbazolone 1d gave 4‐amines 6 . Reduction of 4‐azidopyridocarbazolones 7 either by catalytic hydrogenation or in a 2‐step synthesis via phosphazenes 8 gave 4‐aminopyridocarbazolones 9 . Amines 9 were also obtained from benzylamines 3 by catalytic debenzylation. A one step amination of 4‐hydroxy‐5‐phenylpyridocarbazolone 1d via debenzylation to 9d was observed by reaction with benzylammonium chloride. At elevated temperatures the highly fused 6,13b‐diazaindeno[1,2,3‐ hi ]chrysenone 10 was formed from 1d .