Synthesis of 1,8-naphthyridinyl substituted formazans and their antibacterial activity

2-(p-Aminophenyl)-1,8-naphthyridine 1 on condensation with 3,4-methylenedio xybenzaldehyde 2 affords 2-[4-(3,4-methylenedioxybenzylideneimino) phenyl]- 1,8-naphthyridine 3. The latter on treatment with aryldiazonium chloride at 0-5 degrees furnishes respective 2-[4-[arylazo (3,4-methylenedioxyphenyl) methyleneimino] phenyl]-1,8-naphthyridines 4. The antibacterial activity of these compounds have been assayed against various Gram -ve and Gram +ve ba cteria. The constitution of the products have been elucidated by IR, H-1 NM R and mass spectral data and elemental analyses.