Synthesis and in Vitro Antiproliferative Screening of New 2,7-naphthyridine-3-carboxylic Acid Hydrazide Derivatives.

The new pyrrolo[3,4-c]pyridines and 2,7-naphthyridine derivatives have been synthesized. 4-Hydroxy-8-methyl-l-oxo-6-phenyl-1,2-dihydro-2,7-naphthyridine-3-carboxylic acid hydrazide (4) was the key intermediate for the synthesis of the novel derivatives of various chemical structures: Schiff bases, 1,3,4-oxadiazoles, pyrazoles, carbohydrazides, semi- and thiosemicarbazides. The structures of these new compounds were confirmed by elemental analysis and IR, NMR and MS spectra. The antitumor activities of the obtained derivatives were examined. Eight of the twenty one newly synthesized compounds were qualified by the NCI (Bethesda, MD, USA) for in vito screening against 60 different human tumor cell lines. The most active proved to be the Schiff bases.