Synthesis of Salicylic Acid-based 1,3,4-oxadiazole Derivatives Coupled with Chiral Oxazolidinones: Novel Hybrid Heterocycles as Antitumor Agents

A series of novel salicylic acid-based 1,3,4-oxadiazoles derivatives coupled with chiral oxazolidinones were synthesized to screen for their in vitro antitumor activity against five human cancer cell lines. Some of these compounds showed good antitumor activities with IC50alues ranging from 31.19-57.21 µM. Among the tested compounds 11, 15, 19, 23, 24, and 34 showed broad-spectrum antitumor activity against all the cell lines. In particular, compound 19 revealed remarkable antitumor activity with IC50 = 31.19-41.87 µM. A431 was the most sensitive cell line against all the compounds studied, followed by HeLa, MCF-7, A549 and HepG2. Structures of newly synthesized compounds were confirmed by IR, 1H NMR, 13C NMR and HRMS spectral data.