C-13-NMR AND H-1-NMR SPECTRA OF 2-5-DIARYLOXAZOLES AND THEIR VINYLOGUES

The title NMR spectra are reported for nineteen 2,5-diaryl-oxazoles an d for two vinylogues, together with the corresponding assignments. The C-13-NMR spectral assignments were considerably assisted by substitut ion with fluorine in the 2-aryl group : five para-fluorophenyl and fiv e ortho-fluorophenyl derivatives are described ; the latter ones are d iscussed separately from the other ones, because of long-range couplin g between fluorine substituents and carbon atoms C - 2 and C - 5 in th e oxazole ring.