Synthesis and electropolymerization of N-(4′-carboxyphenyl)-2,5-di(2″-thienyl)pyrrole

N-(4′-carboxyphenyl)-2,5-di(2″-thienyl)pyrrole has been efficiently prepared by the Knorr–Paal condensation of 1,4-di(2′-thienyl)butane-1,4-dione with benzocaine(ethyl-4-aminobenzoate), giving N-(ethyl-4′-benzoate)-2,5-di(2″-thienyl)pyrrole, followed by saponification to give the desired acid. Both new compounds are electropolymerizable, and the polymer films stable to repetitive cycling up to +1.2 V Vs Ag/AgCl.