10-Sila-2-azaanthracenes hydrogenated in the pyridine fragment

The corresponding 1,2,3,4,4a, 9,9a, 10-octahydro derivatives were obtained in the catalytic hydrogenation of 10,10-dimethyl- and 10-methyl-10-phenyl-9,10-dihydro-10-sila-2-azaanthracenes. The hydrogenation of 10,10-dimethyl-10-sila-2-azaanthrone also leads to a substituted octahydrosilaazaanthracene. Isomeric (with respect to the position of the double bond in the nitrogen-containing ring) hexahydrosilaaza-9-anthrols were isolated as a result of the reduction of the methiodide of this silaazaanthrone with sodium borohydride.