New class of Metal Pyridino‐porphyrazine pigments

Cobalt, Nickel and Copper hexaazabiphthalocyanine were prepared by the reaction of pyridine 2,3‐dicarboxylic acid anhydride, pyromillitic acid dianhydride, with urea and metal salt in presence of ammonium molybdate catalyst. The reaction is carried out in an inert solvent [nitrobenzene]. The structure of the prepared compound was confirmed by microanalytical and pectrophotometric methods. Evaluation of the highly coloured products according to international standard methods showed their suitability as excellent pigments for coating applications.