Facile Synthesis of Pyrazolo[3,4‐<i>c</i>]pyrazoles Bearing Coumarine Ring as Anticancer Agents

Abstract

In the present study, 2‐(2‐oxo‐2 H ‐chromene‐3‐carbonyl)‐5‐phenyl‐2,4‐dihydro‐3 H ‐pyrazol‐3‐one was prepared and reacted with various hydrazonoyl halides to give a series of 2‐(2‐oxo‐2 H ‐chromene‐3‐carbonyl)‐5‐phenyl‐4‐((2‐phenylhydrazono)methyl)‐2,4‐dihydro‐3 H ‐pyrazol‐3‐one in good yield. Cyclization of the latter hydrazone with POCl 3 yielded the respective 3‐(3‐phenyl‐ 4,6‐disubstituted‐1,6‐dihydropyrazolo[3,4‐c]pyrazole‐1‐carbonyl)‐2 H ‐chromen‐2‐ones. The structures of the newly synthesized compounds were established on the basis of spectroscopic evidences and their alternative syntheses. The newly synthesized compounds were evaluated for their antitumor activities against hepatocellular carcinoma (HepG2) cell line and the results revealed promising activities of compounds 4e , 4c , and 4d with IC 50 equal 0.92 ± 0.22, 1.43 ± 0.19, and 2.17 ± 0.21 μM, respectively.