Reaction of phenylhydrazo ethylacetoacetate with cyano acetyl hydrazine: Novel synthesis of pyridazine and pyrazole derivatives and their anti-tumor evaluations.

The reaction of phenylhydrazoethyl acetoacetate (1) with cyanoacetyl hydrazine (2) in an oil bath in the presence of ammonium acetate gave the pyridazine derivative 4. However, carrying the same reaction but in ethanolic/Et3N gave the pyrazole derivative 5. Compounds 4 and 5 were used in a series of heterocyclization reactions to afford products that showed anti-tumor activities towards three cell lines namely, breast adenocarcinoma (MCF-7), non-small cell lung cancer (NCI-H460) and CNS cancer (SF- 268).