Abstract
The problem of delamination of electro‐deposited polypyrrole (PPY) layers on several substrates can be avoided by using an adhesion promoting system. A new class of compounds–ω‐(pyrrol‐3‐yl)alkylphosphonic acids have been designed to link polypyrrole layers covalently to metal oxide surfaces. Synthetic routes, which lead to the formation of 3‐substituted pyrroles with surface active groups are described. The synthesis and characterization are shown in detail. 1‐Phenylsulfonyl pyrrole was utilized as a precursor in the synthesis of 3‐substituted pyrroles via Friedel‐Crafts acylation reaction. Subsequently, two methods were used to synthesize ω‐(pyrrol‐3‐yl)alkylpho‐ sphonic acid esters. One starts from the brominated oxoalkyl derivatives by removing the protecting group followed by reduction yielding ω‐(pyrrol‐3‐yl)alkylphosphonic acid esters. This method is suitable for hexyl or longer chain derivatives. The other is the reduction of carbonyl group followed by de‐protection, which is successful for short as well as long chain derivatives. Finally, ω‐(pyrrol‐3‐yl)alkylphosphonic acids were obtained by hydrolysis of the ester derivatives.