Complete assignment of the 1H and 13C NMR spectra of 2-phenyl-3H-naphtho[2,1-b][1,4]oxazin-3-one, 2-p-methoxyphenylnaphtho[1,2-d] oxazole and 2-phenylnaphtho[1,2-d]oxazole. Concerted use of one-and two-dimensional NMR techniques

Abstract

The 1H and 13C NMR spectra of 2-phenyl-3H-naphtho[2,1-b][1,4]oxazin-3-one, 2-p-methoxyphenylnaphtho[1,2-d]oxazole and 2-phenylnaphtho[1,2-d]oxazole were totally assigned using a combination of one-and two-dimensional NMR techniques. In addition to correlation of the proton signals by a COSY spectrum and one-bond heteronuclear correlation, complete assignment of the 1H and 13C NMR spectra of these heterocyclic compounds required the application of long-range CH coupling information, particularly for quaternary resonance assignments and for orientations of individual spin systems relative to one another. © 1998 John Wiley & Sons, Ltd.