Dm. Drew et Cc. Leznoff, THE SYNTHESIS OF PURE 1,11,15,25-TETRASUBSTITUTED PHTHALOCYANINES AS SINGLE ISOMERS USING BISPHTHALONITRILES, Synlett, (8), 1994, pp. 623-624
Bisphthalonitriles linked by 2,2-disubstitutedpropan-1,3-diol precurso
rs gave pure 1,11,15,25-substituted isomers of mononuclear phthalocyan
ine derivatives upon homocyclization. Reasonable yields of these phtha
locyanines could be obtained with limited polymeric side-products util
izing modified cyclization methods. The H-1 NMR spectrum of these phth
alocyanines exhibited the discrete doublet-triplet-doublet proton sign
als expected of a pure isomer.