NMR signal assignment of a new quinolone antibiotic substance

Abstract

A new fluoroquinolone(DW-116) with a broad antibiotical spetrum was synthesized by introducing functional fluoropyridyl and methylpyrazine group on N1, C7 position of quinolone moiety, respectively. 1H and 13C NMRsignal assignments and structure were completely elucidated by 2D-NMR methods. Physicochamical properties of products were also investigated. DW-116 is decomposed at 306.9 C and the decomposition starts around 285 C. The free base form is melt at 280.7 C and started to be decomposed immediately. DW-116 has two kinds of polymorphism which is important in drug action but these two plate and rod types have the same solubility in water. However, the solubility is quite different in less or polar solvent. The plate type is more soluble in less polar solvent except in dichloromethane.