synthesis of the novel 4,4?- and 6,6?- dihydroxamic - 2,2?-bipyridines and improved routes to 4,4?- and 6,6?- substituted 2,2?-bipyridines and mono-n-oxide-2,2?-bipyridine

The preparation of key precursors for many 2,2?-bipyridine derivatives such as 4,4?-dicarboxy- 2,2?-bipyridine (I), 6,6?-dicarboxy-2,2?-bipyridine- acid (II), 4,4?-dinitro-2,2?-bipyridine-N,N-dioxide (III), 6,6?-dicarbothioamide-2,2?-bipyridine (IV) and mono-N-oxide-2,2?-bipyridine (VII) through more efficient methods is described. The syntheses of the novel ligands 4,4?-dihydroxamic-2,2?-bipyridine (V) and 6,6?-dihydroxamic-2,2?-bipyridine (VI) are also reported.