Diazanaphthalene

Diazanaphthalenes are a class of aromatic heterocyclic chemical compounds that have the formula C₈H₆N₂. They consist of a naphthalene double ring in which two of the carbon atoms have been replaced with nitrogen atoms. There are ten positional isomers, which differ by the locations of the nitrogen atoms.

The group consist of two subgroups:

• four benzodiazines with both N atoms in one ring: cinnoline, quinazoline, quinoxaline, and phthalazine
• six naphthyridines with one N atom per ring[1][2]

Isomers

Names	Structure	Subgroup	CAS RN
1,2-diazanaphthalene cinnoline		benzodiazine	253-66-7
2,3-diazanaphthalene phthalazine		benzodiazine	253-52-1
1,3-diazanaphthalene quinazoline		benzodiazine	253-82-7
1,4-diazanaphthalene quinoxaline		benzodiazine	91-19-0
1,8-naphthyridine 1,8-diazanaphthalene		naphthyridine	254-60-4
1,7-naphthyridine 1,7-diazanaphthalene		naphthyridine	253-69-0
2,7-naphthyridine 2,7-diazanaphthalene		naphthyridine	253-45-2
1,6-naphthyridine 1,6-diazanaphthalene		naphthyridine	253-72-5
1,5-naphthyridine 1,5-diazanaphthalene		naphthyridine	254-79-5
2,6-naphthyridine 2,6-diazanaphthalene		naphthyridine	254 79 5

References

1. Desmond J. Brown, Jonathan A. Ellman, Edward C. Taylor: The Chemistry of Heterocyclic Compounds, The Naphthyridines, John Wiley & Sons, 2007.
2. Paudler, William W.; Kress, Thomas J. (1968). "Naphthyridine chemistry. IX. Bromination and animation of the 1,X-naphthyridines". The Journal of Organic Chemistry. 33 (4): 1384–1387. doi:10.1021/jo01268a018.