The reaction of anthracene (I) with refluxing vinylene carbonate (II) gives 9,10-dihydro-9,10-ethanoanthracene-11,12-diol cyclic carbonate (III), which is hydrolyzed with KOH in hot ethanol water affording 9,10-dihydro-9,10-ethanoanthracene-11,12-diol (IV). The oxidation of (IV) with lead tetraacetate in acetic acid yields 9,10-anthracenedicarboxaldehyde (V), which is finally condensed with 2-hydrazino-2-imidazoline (VI) by means of HCl in refluxing ethanol.