ON THE SYNTHESIS OF OMEGA-APPENDED HYPERICIN DERIVATIVES

A method for the preparation of bis-omega-appended hypericin derivatives bearing n-octyl n-hexadecyl, and 2-(2-(2-hydroxyethoxy)-ethoxy)-ethoxymethyl substituents was developed. The key step - the synthesis of appropriately omega-substituted emodin derivatives - was achieved by solvolyzing 3-bromomethyl-1,6,8-triacetyloxy-anthracene-9,10-dione (omega-bromo triacetylemodin) in an appropriate alcohol in the presence of silver perchlorate. The corresponding bis-omega-substituted hypericins were then prepared conventionally by dimerizing the omega-substituted emodin anthrones. The latter were prepared by reduction of the omega-appended emodins.