Studies on the development of new efficient corrosion inhibitors for crude oil pipelines: Electrochemical impedance spectroscopy results for 1,8-naphthyridines

Abstract

Five 1,8-naphthyridines were tested as corrosion inhibitors, including three non-previously reported 3-alkyl-1,8-naphthyridines. All were produced via the extended Friedländer synthesis, that for 3-alkyl-1,8-naphthyridines involves the earliest use of aliphatic aldehydes. Fragmentation pattern in MS for 3-alkyl-1,8-naphthyridines shows a remarkable parallel with that exhibited by 3-alkylpyridines. Electrochemical Impedance Spectroscopy (EIS) was used to assess the inhibiting properties of these compounds on samples of API X52 carbon steel pipelines immersed in oilfield-related water. Except for one of the molecules tested, the inhibition efficiency (IE%) values were significantly higher than that calculated for a reference commercial inhibitor. © 2013, Sociedad Química de México.