Catalytic hydrogenation of 1,2-benzanthracene and of its 10-methyl and 10-acetoxy derivatives in the presence of Adams catalyst (usually with a promoter) results in the saturation of the terminal ring of the anthracene system, giving 5,6,7,8tetrahydrides. With the acetoxy compound, which is more susceptible to attack than the other two substances, further hydrogenation results in the reduction of the other terminal ring. There is no indication that the hydrogenation of the benzanthracene derivatives proceeds through the intermediate fixation of hydrogen to the mesopositions, and indeed in one case a 9,10-dihydride was found to yield on hydrogenation a product quite different from the 5,6,7,8-tetrahydride obtained directly from the aromatic hydrocarbon.On reduction with sodium and amyl alcohol, 1,2-benzanthracene and 10-methyl-1,2-benzanthracene are converted into 1',2',3',4',9,10-hexahydro derivatives. New derivatives of the careinogenically active 10-methyl-l,2-benzanthracene which have been submitted to biological tests include the 9,10dihydride, the l',2 ',3',4'-and 5,6,7,8-tetrahydrides, and the 1',2',3',4',9,10-hexahydride.
