Synthesis and antitumor activity evaluation of some novel pyrazolotriazine derivatives

6-Aminopyrazolo[1,2-<i>a</i>][1,2,4]triazine-4,8-dione derivative <b>3</b> was obtained upon the reaction of the acid hydrazide derivative <b>2a</b> with ethyl cyanoacetate. The reactions of <b>3</b> with several electrophiles such as aldehydes, isatin, acetic anhydride, phenyl isocyanate, benzoyl isothiocyanate, and <i>p</i>-toluenesulfonyl chloride were studied. The structures of the newly synthesized compounds were established on the basis of IR, ¹H NMR, mass spectra, and elemental analyses. The antitumor activities of some selective compounds were examined against two cell lines as liver carcinoma cell line (HEPG-2) and human breast cancer cell line (MCF7).