Interesting method for the synthesis of monofunctionalized phthalocyanines via subphthalocyanines for photodynamic therapy of cancer

摘要

The photodynamic therapy (PDT) of cancer is based on the reaction of dyes, light and oxygen in tumorous tissue. Currently, mainly two different photosensitizers $LB@Photofrin II and Hematoporphyrine derivatives (HPD)$RB are used in clinical investigations. They are far from being ideal for this purpose as they do not have the required specificity and the absorption maxima do not lie in the ideal region of 760 nm (maximum transmission for human tissue). These properties could potentially be improved by monofunctionalization of the photosensitizers which would allow them to be coupled with tumor specific antibodies. Also, variation of the peripheric substituents would lead to a shift in the absorption maxima to a point nearer to 760 nm. By modification of the methods found in the literature it has been possible to synthesize two new subphthalocyanines and one new subnaphthalocyanine. Starting by reacting 3,6-Dihydroxyphthalicaciddinitrile, 3,6-Dibutyloxyphthalodi-nitrile or 2,3-Dicyanonaphthalene with boron trichloride in a solvent with a high boiling point, it has been possible to form the subphthalocyanines (I) and subnaphthalocyanine (II).