Synthesis of Novel Ethyl (substituted)phenyl‐4‐oxothiazolidin‐3‐yl)‐1‐ethyl‐4‐oxo‐1,4‐dihydroquinoline‐3‐Carboxylates as Potential Anticancer Agents

Abstract

A series of ethyl (substituted)phenyl‐4‐oxothiazolidin‐3‐yl)‐1‐ethyl‐4‐oxo‐1,4‐dihydroquinoline‐3‐carboxylates (7a, 7b, 7c, 7d, 7e, 7f, 7g) has been prepared from reactions between aminoquinolones 6 with arenealdehydes and mercaptoacetic acid. The critical intermediates, 6a and 6b, were obtained from appropriate amines by a sequence of steps involving (i) reaction with diethylethoxymethylenemalonate, (ii) thermal cyclization in diphenyl ether, (iii) ethylation and (iv) Pd/C catalyzed reduction. New compounds 7a, 7b, 7c, 7d, 7e, 7f, 7g were fully identified and characterized by NMR (1H and 13C) and specifically for 7d by X‐ray crystallography. Compounds 7b, 7c, 7d, 7e, 7f were found not to exhibit activity at 10 uM concentrations against gastric ascitis (AGP‐01), gastric adenocarcinoma kind intestinal (ACP‐02), colon (HCT‐116) and murine melanome (B16F10) cancer cells. However, none exhibited cytotoxicity against normal cells human fibroblast (MRC‐5), murine fibroblast (NIH3T3) and normal human melanocyte (Melan‐A).