Synthesis and total assignment of ¹H and ¹³C NMR spectra of new oxoisoaporphines by long-range heteronuclear correlations

The new oxoisoaporphines 7H-dibenzo[de,h]quinolin-7-one, 5-methoxy-7H-dibenzo[de,h]quinolin-7-one, 5-methoxy-6-hydroxy-7H-dibenzo[de,h] quinolin-7-one, 5-hydroxy-7H-dibenzo[de,h]quinolin-7-one and 5-methoxy-6H-dibenzo[de,h]quinolin-6-one were prepared either by oxidation of their 2,3-dihydro derivatives or by heating (2′-(3,4-dihydro-6,7- dimethoxyisoquinolin-1′-yl)phenyl)methylbenzoate with an acetic acid/sulfuric acid mixture at 100°C. The structures were confirmed and ¹H and ¹³C NMR spectra were completely assigned using two-dimensional NMR techniques.