Design, synthesis and antitumor activity of valproic acid salicylanilide esters

A series of valproic acid salicylanilide esters were designed and synthesized based on the principle of prodrug.  The structures of the target compounds were confirmed by MS, ¹H NMR and ¹³C NMR.  Anti-tumor activities of these compounds against K562, A549, A431cells in vitro were investigated by MTT assay and SRB assay.  The results indicated that the compounds 6h−6j were found to have stronger cell growth inhibitory action than gefitinib, and comparable to niclosamide, which are worth to be intensively studied further.