Magnesium porphyrazinates substituted with eight (p-tolyl) and (o-tolyl) units on the peripheral positions have been synthesized for the first time by cyclotetramerization of 1,2-bis(p-tolyl)maleonitrile and 1,2-bis(o-tolyl)maleonitrile in the presence of magnesium butanolate. Their demetalation by the treatment with trifluoroacetic acid resulted in partially oxidized products, namely, octakis(p-tolyl)-2-seco-porphyrazine-2,3-dione and octakis(o-tolyl)-2-seco-porphyrazine-2,3-dione. Further reactions of these products with copper(II) acetate, zinc(II) acetate and cobalt(II) acetate have led to the metallo derivatives, [octakis(p-tolyl)-2-seco-2-,3-dioxoporphyrazinato]M(II) and [octakis(o-tolyl)-2-seco-2,3-dioxoporphyrazinato]M(II) (M = Cu, Zn, Co). These novel compounds have been characterized by elemental analysis, together with FT-IR, H-1 NMR, UV-vis and mass spectral data. Copyright (C) 2008 Society of Porphyrins & Phthalocyanines.