Synthesis and Anticancer Activity of Novel Oxadiazole Functionalized Pyrazolo[3,4-b]pyridine Derivatives

Abstract

A series of novel oxadiazole functionalized pyrazolo[3,4-b]pyridine derivatives (6a-n)was synthesized using 6-thiophenyl-4-(trifluoromethyl)-1H-pyrazolo[3,4-b]pyridin-3-amine (1) through reaction with 2-bromoethyl acetate, followed by hydrazine hydrate to afford hydrazide derivatives (5). These compounds were further treated with aromatic acids in the presence of phosphoryl chloride and obtained oxadiazole functionalized pyrazolo[3,4-b]pyridine derivatives (6a-n). All the synthesized compounds 6a-n were screened for anticancer activity against four cancer cell lines such as HeLa - cervical cancer (CCL-2); COLO 205-colon cancer (CCL-222); HepG2-liver cancer (HB-8065); MCF7-breast cancer (HTB-22). Compounds 6i, 6m and 6n were found to have more prominent anticancer activity at micromolar concentration.