Synthesis of Some Novel 1,8-Naphthyridine Chalcones as Antibacterial Agents

Nanomaterials are interesting candidates as heterogeneous catalysts for different organic reactions. In this research SiO2 nanoparticles was applied for synthesis of some new 2-chloro-1,8-naphthyridine-3-carbaaldehyde (1) through vilsmeier – haack cyclization of N-(pyridine-2-yl)acetamide has been reported and transformation to new chalcones containing morpholine ring from reaction of 2-morpholine-3-formyl-1,8-naphthyridine (2) and 2-aminoacetophenone to produce E-3-(2-morpholino-1,8-naphthyridine-3-yl)-1-(4-aminophenyl) prop-2-en-1-one (3) through Claisen-Schmidt reaction by used (Nano silicon dioxide imidazolidin sulfite propyl silyl trifloroacetate) as catalyst . which on treatment with N-chloroacetyl-4,6-diphenyl pyrimidinyl amine (4) gave compound (5). Compound (3) treated chloro acetyl arylamine (4) in presence of small amount of carbonate in DMF gave compound (6). The structures of the final compounds were confirmed by IR and 1HNMR. These compounds were evaluated for their antibacterial activity against gram positive and gram-negative bacteria using dilution procedure showed activity against the bacteria under study; 1,8-naphthyridine derivatives boost the fluoroquinolone antibiotics’ efficiency against multi-resistant bacteria, and therefore appealing prospects for development of treatments against bacterial infections caused by multidrug-resistant strains.