Dibenzo naphthyridines

A series of 6-substituted 8,9-dimethoxy-2,3-methylenedioxy-6ff-dibenzo[c,h] [2,6] naphthyridin-5-ones (IX) was synthesized and evaluated for topo I-targeting activity as well as for cytotoxicity against different cell lines by Zhu et al. [53]. From the topo I-mediated DNA cleavage data of these compounds (IX), we developed Eq. 7 (Table 5) ... 

The alkaloids of perennial rye grass, perloline (438) and perlolidine (302), have been shown to be benzo[/][2,7]naphthyridine derivatives <66JCS(B)454), whilst degradation of calycanthine (439) affords calycanine or dibenzo[c,fc][2,6]naphthyridine (356), the structure of which was proven by an unequivocal synthesis from leucoisoindigo (60MI21100). A number... 

The electron-impact-induced fragmentations of two dibenzo[6,/]-1,6-naphthyridines,50 several benzo[/]l,7-naphthyridines,45 and some perhydro tricyclic homologs of 1,6- and 2,7-naphthyridine51 follow expected breakdown pathways. 

Ethyl 7-chloro-1 -ethyl-4-oxo-1,4-dihydro-1,5-naphthyridine-3-carboxylate (45) gave 1 -ethyl-7-methoxy-4-oxo-1,4-dihydro-1,5-naphthyridine-3-carboxylic acid (46) (KOH, MeOH, dibenzo-l,8-crown-6 MeCNJ, reflux, 7h 67% it would seem that the crown ether was required to assist alcoholysis of the unactivated chloro substituent note incidental saponification of the ester group).1398... 

Naphthyridine (1.5) Br2 in aqueous H2S04 (135°) 3. Dibenzo Derivatives 3-Bromo 3,7-Dibromo 56... 

Substituted 6-methyl-l-oxo-l,2-dihydrobenzo[Z>][l,6]naphthyridine-4-carboxylic acids (2003JMC1049), 5I/-dibenzo[c,/ ][l,6]naphthyridine derivatives (2003MI9) and 5,6,7,8-tetrahydro-l,6-naphthyridin-2(l//)-one derivatives (2003USP2003199542) were prepared as potential anticancer agents. 

Depending on the ring fusion, pyridoacridines can be classified into the following main classes pyrido[a]acridines (benzo[ ]phenanthrolines), pyrido[b]acridines, pyrido[c]acridines (benzo[h]phenanthrolines), and pyr-ido[k/]acridines (dibenzo[/,i/][2,7]naphthyridines). 

H-benzo[d,f] [l,3]diazepines dibenzo[b,g]-l,8-naphthyridines imidazoles (glyoxalines) imidazo [1,2-a] pyridines indolopyridines 12H-indolo[2,3-a]pyridocoli-nium rings... 

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