A remarkable side-product from the synthesis of an octaalkylphthalocyanine: formation of a tetrabenzotriazaporphyrin. 
1,4,8,11,15,18,22,25-Octahexyl-29H,31H-tetrabenzo[b,g,l,q][5,10,15]triazaporphyrin has been isolated as the main side product in the preparation of 1,4,8,11,15,18,22,25-octahexylphthalocyanine via a lithium pentyloxide induced cyclotetramerisation of 3,6-dihexylphthalonitrile.