Summary 3-Bromo-lI2-phenanthrenequinone and 2-bromo-3, 4-phenanthrenequinone add dienes readily and the addition products can be converted in good yield into 3, 4- benzphenanthrenequinones and chrysenequinones, respectively. From a preliminary study of the chlorination of 3-phenanthrol it appears that the substance not only is attacked in the hydroxylated ring but adds chlorine at the 9, lO-position.