1. 1,6- and 1,7-naphthyridines. I. Rearrangement of quinolinimidoacetic acid derivatives
2. Rf: ratio front in tlc experiments on Silica gel using chloroform-methanol (9:1) as the solvent.
3. 1,6- and 1,7-naphthyridines.II. Synthesis from acyclic precursors
4. The presence of an intramolecular hydrogen bonding between the enol hydrogen and ester carbonyl, as is evident in 1,7-naphthyridines [3] would avoid this correlation. However, it is well accepted the breaking of such bonds in DMSO-d6 solutions as well as the presence of inter-molecular hydrogen bond between the hydroxyl and the solvent [5,6] (structure B, Scheme V).
5. Inter- and intra-molecular hydrogen bonding effects on geminal15N,1H spin coupling and15N chemical shifts in pyridine derivatives