Practical and Efficient Synthesis of Tris(4-formylphenyl)amine, a Key Building Block in Materials Chemistry

Abstract

A short, practical and efficient preparation of tris(4-formylphenyl)amine, a key building block in materials chemistry, is described. It involves a two-flask synthesis from triphenylamine, which requires shorter overall time than the direct one-flask threefold Vilsmeier-Haack formylation, while giving higher yields. The reaction levels off at the disubstitution stage, due to the deactivation of the bis-iminium intermediate, but hydrolysis of the latter into a less deactivated dialdehyde allows the third formylation to occur. The simple experimental protocol makes this method more convenient than the previously reported procedures.