The synthesis, structural characterization and in vitro anti-cancer activity of novel N-{6-(ferrocenyl) ethynyl-2-naphthoyl} amino acid and dipeptide ethyl esters

N-{6-(Ferrocenyl) ethynyl-2-naphthoyl} amino acid and dipeptide ethyl esters 2–8 were prepared by coupling 6-(ferrocenyl) ethynyl-2-naphthoic acid 1 to the amino acid ethyl ester GABA(OEt) and the dipeptide ethyl esters GlyGly(OEt), GlyAla(OEt), SarGly(OEt), SarAla(OEt), ProGly(OEt) and ProAla(OEt) using the standard N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC), 1-hydroxybenzotriazole (HOBt) protocol. All the compounds were fully characterized using a combination of 1H NMR, 13C NMR, DEPT-135 and 1H–13C COSY (HMQC) spectroscopy, electrospray ionization mass spectrometry (ESI-MS) and cyclic voltammetry (CV). Compounds, 2–8 showed micromolar activity in the H1299 NSCLC cell line, with IC50 values in the range of 3.2–7.2 μM.