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116. Synthesis and Reactions of 4-Hydroxy-8,9,10,11-tetrahydro-pyrido[3,2,1-jk]carbazol-6-ones
Stadlbauer W., Dang H. V., Berger B. S. J.Heterocycl.Chem., 47 (2010) 807-824.

Tetrahydrocarbazoles 4 obtained from phenylhydrazines and cyclohexanones gave by cyclocondensation with 2-substituted malonates 5 in all cases 4-hydroxy-8,9,10,11- tetrahydropyrido[3,2,1-jk]carbazol-6-ones 6 by attack at the nitrogen and the aromatic ring of tetrahydrocarbazoles 4; the direction of the cyclization was not dependent from substituents either in the aromatic or the saturated ring; isomer pyridocarbazoles could not be isolated. Electrophilic substitutions of pyridocarbazoles 6 under mild conditions took place exclusively at the 5-position and gave pyridocarbazolediones 9-11 with 5-nitro-, 5-hydroxy or 5-chloro-substituents. Exchange of the chloro substituent in 11 gave 5-azido- and 5-amino products 12, 14 or 16. Reactions at the aromatic ring were not observed. Chlorination of 4-hydroxypyridocarbazoles 6 with phosphorylchloride by nucleophilic substitution took place exclusively at the 4-position and gave 4- chloropyridocarbazolones 17, which were further reacted to azides and amines 18, 19.

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