Synthesis and Some Properties of Pentacene-2,3-dicarboxylic Acids and Metal Porphyrazines Based on Them

For the first time 6,13-dimethoxy-5,7,12,14-tetraoxo-5,7,12,14-tetrahydropentacene-2,3-dicarboxylic acid and its 1,4-dichloro derivative were synthesized. Heating these compounds with nickel or cobalt acetates in the presence of urea gave the corresponding nickel and cobalt porphyrazines. The spectral properties of new compounds are discussed.