A new and efficient procedure has been described for the synthesis of 2- chloro-1,5-Naphthyridine-3-carbaldehyde(1) from the condensation of N-(pyridine-3-yl) acetamide in presence of dimethylformamide and phosphorous oxychloride through Vilsmeir – Haack cyclization. The condensation of compound (1) with acetophenone, p-hydroxy acetophenone, pyridine-3-acetyl, furan-2-acetyl, and indole-2-acetyl in the presence of ethanolic sodium hydroxide through Claisen- Schmidt condensation give quinolinyl chalcones (2a-e) and it's further treated with dimethyl sulfoxide in the presence of iodine to obtained iodo chalcone compounds (3a-e). The smooth and selective bromination of chalcones (2a-e) affords dibromide compounds (4a-e). The structure of prepared compounds was identification by spectral and physical methods. Synthesized compounds (4a, 3e, 3b and 4e) give good biological activity from against Staphylococcus aureus and Staphylococcus epidermidis and moderate activity against Escherichia Coli and Proteus Vulgaris. تفاصيل المقالة