A series of pyrrolidines were synthesised using phenylalanine and isatin with dipolarophiles. Azomethine ylide was first formed from phenylalanine and isatin which undergoes 1,3-dipolar cycloaddition with dipolarophiles yielding pyrrolidines. The corrosion inhibition property of the pyrrolidines towards mild steel corrosion in 1M HCl has been investigated using electrochemical techniques. The results showed that the presence of pyrrolidines in the acid solution suppress the corrosion rate of mild steel. The inhibition efficiency was found to dependent on the substitutions in the ring and with the concentration of the particular species in acid solution. Potentiodynamic polarizations studies revealed the mixed type inhibition nature of the compounds. Electrochemical impedance spectroscopy suggested the charge transfer controlled mechanism of corrosion inhibition.
