Para-benzihemiporphyrazine and its expanded [3 + 3]-type analogue

A novel para-benzihemiporphyrazine was synthesized from a stepwise reaction of 1,3-diiminoisoindoline and para-phenylenediamine via a linear [2 + 1]-type compound, whereas its ring-expanded [3 + 3]-type analogue was obtained from a onepot condensation reaction of the same starting materials.