Abstract: | The condensation of 1-aminoanthraquinone to 1,1′-diamino-2,2′-dianthraquinonyl in a melt of anhydrous aluminium chloride and moist pyridine has been reinvestigated. By a similar procedure under anhydrous conditions the sodium salt of 1-aminoanthraquinone-2-sulfonic acid yielded the sodium salt of 4,4′-diamino-1,1′-dianthraquinonyl-3,3′-disulfonic acid. |