Abstract: The present invention relates to a method of preparing a porphyrin derivative from a meso-acrylonitrile-substituted porphyrin compound. According to the invention a Vilsmeier reagent carrying an aromatic ring is used, wherein said Vilsmeier reagent is a soft electrophile. The use of this Vilsmeier reagent results in a porphyrin derivative having the ring system of the Vilsmeier reagent condensed to its porphyrin macrocycle via two new 6 membered rings. Thus a new class of porphyrin derivatives is provided, wherein said derivatives are photodynamically more active than the starting compound. The invention also relates to a porphyrin derivative, use of said porphyrin derivative and a pharmaceutical composition containing said porphyrin derivative.

Abstract: Method of preparing a porphyrin derivative starting from a meso-substituted porphyrin compound. According to the invention, the meso-substituted porphyrin compound used is a meso-(2?-cyanovinyl)-substituted porphyrin compound, wherein said meso-(2?-cyanovinyl)-substituted porphyrin compound, in a form in which its porphyrin ring is complexed with a bivalent metal ion is converted, in the present of an acid for which 0<pKa<5 and an oxidizing agent; or in the presence of a Vilsmeier reagent, into a porphyrin derivative having a quinoline-ring system ring peri-condensed to the porphyrin ring.