3-Bromo derivatives of 1,5- and 1,7-azulenequinones easily react with various nucleophiles to give 3-methoxy, phenoxy, p-nitrophenoxy, butylthio, butylamino, p-tolylamino, dimethylamino, 2-hydroxyethylamino, azulenyl, and guaiazulenyl derivatives of the respective azulenequinones almost quantitatively. 3-Bromo-1,5- and -1,7-azulenequinones afford the 2,3-bisbutylthio derivatives under basic conditions
3-Methoxy-1,5-azulenequinone gave dimers when irradiated with a high-pressure mercury lamp. The product distribution was dependent on the polarity of the solvent. In a polar solvent, a head-to-head dimer was predominant whereas a head-to-tail dimer was mainly formed in a nonpolar solvent.