SYNTHESIS OF SOME NEW NITROGEN HETEROCYCLIC COMPOUNDS OF ANTICIPATED ACTIVITY

Abstract

The availability and wide acceptance of several 1,8-naphthyridine derivatives as chemotherapeutic agents especially as antimicrobial agents, DNA-binding agents, and antiinflammatory agents, suggested to us to synthesize some• new series of this type of compounds incorporated into another different nitrogen, sulpher and/or oxygen heterocycles or ainino side chains, hoping that the resulting target products might possess an increased biological activity with less toxicity. This led to study the various variations in the structure of substituents of the target 1,8-naphthyridines on their biological activity. One of these variations is the introduction of different nitrogen heterocyclic systems like pyrrole, pyridine, pyrazoline and thiazole ring systems, or introduction of different nitrogen and oxygen heteroring systems such as oxadiazole and /or introduction of different nitrogen and sulphur heterocycles like thiadiazole through a para-phenylamino grouping at position 4 of the 1,8-naphthyridine moiety. The second variation is to incorporate the mentioned nitrogen, oxygen and sulphur heterocyclic ring systems into a para-phenoxy grouping instead of the p-anilino one to compare their biological activity. The third variation is the introduction of a basic Mannich side chain • to some of these products to increase both of the solubility and consequently the biological activity of the resulting new derivatives. The whole work including the synthesis and biological evaluation.of the new compounds is presented in the following parts.