Synthesis of the First Azomethine Derivatives of Pd(II) Coproporphyrins I and II

The effective synthesis of Pd(II) monofunctional azomethine derivatives of coproporphyrin isomers I and II is reported. The proposed method is based on the interaction of a “phosphorus complex”, generated in situ by Vilsmeier-Haack reaction, with various amines. The reaction with palladium complex of coproporphyrin II gave Schiff bases as a mixture of two structural isomers in 4:1 ratio. The structure of the obtained compounds was determined using 1H, 13C, 1H-1H NOESY and UV-vis spectroscopy and mass spectrometry data.