Synthesis and Antimicrobial Activity of 5, 6-dihydro-3-arylnaphtho [1,2-b] [1,8] naphthyridine and their DerivativesAuthor(s): M. Ranadheer Kumar, E. Laxminarayana, D. Ramesh, B. Sreenivasulu and M. Thirumala Chary
2-Aminopyridine-3-carboxaldehyde (1) on condensation with 3,4-dihydro-6-methoxynaphthalen- 1(2H)-one (2) afforded 5,6-dihydro-3-methoxynaphtho[1,2-b][1,8] naphthyridine (3) in very good yields. It underwent demethylation with aqueous hydrobromic acid to furnish 5,6-dihydronaphtho[1,2- b][1,8]naphthyridin-3-ol (4), followed by treatment with trifluoromethane sulfonic anhydride yielded 5,6- dihydronaphtho[1,2-b][1,8]naphthyridin-3-yl trifluoromethane sulfonate (5). The compound (5) on further treatment with various aromatic boronic acids gave 5,6-dihydro-3-arylnaphtho[1,2-b][1,8]naphthyridine and their derivative (6a-f).The structures of these new compounds were established by spectral data. All the new compounds have been screened for their antimicrobial activity.