ASSIGNMENTS OF H-1 AND C-13 NMR OF 6(9)-METHYL-BENZO[B]NAPHTHYRIDINES(5-METHYLDIAZAANTHRACENES)

A complete assignment of the H-1 and C-13 NMR spectra of four 6(9)-met hyl-benzo[b]naphthyridines in CDCl3 is presented. The proton signals h ave been assigned from (H-1-H-1) coupling patterns and by the comparis ons of chemical shifts with those of related heterocycles. Complete C- 13 assignments have been made using proton detected one bond C-13-H-1) 2D heteronuclear single quantum correlation, the INEPT technique, and chemical shift comparisons with related heterocycles. The proton dete cted long range (C-13-H-1) 2D heteronuclear multiple quantum correlati on experiment leads to an unambiguous assignment of the two quaternary carbons in 6-methyl-benzo[b][1,5]naphthyridine.