Nitro-1,8-naphthyridines review

Tire purpose of this chapter is to review the chemistry of the nitro-1,5-, -1,6-, -1,7-, and -1,8-naphthyridines (1) [nitro-2,6- and nitro-2,7-naph-thyridines (2) are unknown], with special attention to the results obtained in the laboratories of both authors. Tliis article mainly refers to the synthesis and reactivity of the nitronaphthyridines their physical and spectroscopic properties and biological activity are only covered briefly. For the convenience of the reader a table listing melting points of (di-)nitronaph-thyridines and some derivatives is included (Table III). Tire literature to about 1998 has been covered. 

Covalent hydration in the naphthyridines has been considered in comprehensive reviews.l60 161 Although no evidence could be obtained for covalent hydration in the neutral species or cations of 1,5-, 1,6-, 1,7-, and 1,8-naphthyridine, the 3-nitro- and 8-nitro-l,6-naph-thyridine cations readily undergo hydration. 3-Nitro-l,5-naph-thyridine, on the other hand, is not hydrated. 

Most nitro-1,6-naphthyridines have been used for reduction to 1,6-naphthyridi-namines. A comprehensive review of all nitronaphthyridines appeared in 2000.1273 It includes information on those within the 1,6-series. The mass spectra of nitro derivatives in the 1,5-, 1,6-, and 1,8-naphthyridines have been reviewed.492... 

---