Synthesis and biological studies of some novel furo naphthyridine compounds contain chalcone

Through a Vilsmeier–Haack condensation 2-chloro-3-formyl-1.8-nathyridine (I) was synthesized. When treated with aqueous hydrochloric acid converted to compound (II) was successfully obtained in high yield and then converted to Novel 1-(8-methyl) furo[2,3-b] -(1,8-naphthyridine-2-yl) ethenone (III) through Claisen –Schmidt condensation. The condensation between compound III (ketone) and benzaldehyde yield Novel (furo[2,3-b] (1,8-naphthyridine-2-yl)-2- acetyl called chalcone (4). The reaction between chalcone and bromine water yields dibromide (6), Iodo chalcone (5) produced by treatment of chalcone with one to two pieces of crystal iodine in dimethyl sulfoxide. Spectral analysis techniques such as 1H-NMR, FT-IR were employed to identify and confirm the structural formula of all products. The synthesized compounds (3-6) were evaluation for their anti- bacterial activity against both gram negative and gram-positive bacteria, demonstrating significant compared to standard drug. All these compounds showed moderate activity.