MULTINUCLEAR NMR-SPECTROSCOPY - STRUCTURAL-PROPERTIES OF OFLOXACIN

An accurate H-1, C-13 and N-15 NMR study on ofloxacin 1 is reported. T he conformational properties of the two mobile regions (the benzoxazin e and the piperazinyl ring) are studied and discussed. According to th e spectroscopic data, the condensed benzoxazine ring shows a conformat ion consistent with the C-2 atom below the mean molecular plane and th e 3-CH3 group in a pseudo-axial position and the piperazinyl group mai ntains a conformation favourable to N-1' conjugation with the aromatic ring. How multinuclear NMR spectroscopic studies may impact on biolog ical activity and SAR investigations is discussed.