Fused fluoroquinolones: synthesis and H-1 and F-19 NMR studies

New derivatives of fused fluoroquinolones bearing five aromatic rings have been obtained. The F-19 NMR spectra of these pentacyclic fluoroquinolones d emonstrate unusual through space H-1-F-19 and F-19-F-19 spin-spin interacti ons with coupling constants (6)J(F, H) = 2.0-3.0 Hz, (7)J(F, F) = 3.5-4.0 H z and (9)J(F, H) = 3.0-3.5 Hz. Relative reactivities of fluorine atoms in p entacyclic fluoroquinolones in the amino-defluorination reactions are also different relative to bi- and tricyclic fluoroquinolones. (C) 2001 Elsevier Science B.V. All rights reserved.