Synthesis and Characterization of Some Novel Hydrazones of N-{11H-pyrido[2,1-b]quinazolin-11-one-9-yl} hydrazine


The 2-[(6-chloro-2-pyridyl) amino]benzoic acid (I) was synthesized viaUllmann-Goldberg coupling by reaction of anthranilic acid with2,6-dichloropyridine. The compound (I) was cyclized by using poly phosphoric acid (PPA) to give 9-chloro-11H-pyrido[2,1-b]quinazolin-11-one (II). The compound (II) reacted with hydrazine hydrate to give N-{11H-pyrido[2,1-b]quinazolin-11-one-9-yl} hydrazine (III). The compound (III) reacted with various aromatic aldehydes to yield the hydrazones (IVa-p). The reaction progress was followed by thin layer of chromatography (TLC). The physical constants and Rf values were recorded. The synthesized compounds were confirmed via the spectral data (UV,I.R,1H-NMR, 13C-NMR, mass spectra). The possible fragmentation pattrene of GC/MS for the compounds (IVa) were investigated (IVh).