Cyclic amidines. Part XXII. Novel isomerism of disubstituted tricycloquinazolines and molecular orientations in carcinogenesis

Certain disubstituted tricycloquinazolines exhibit an unusual structural isomerism originating from the modification of the symmetry of tricycloquinazoline by substitution. Molecular orientations specific for carcinogenesis, consistent with differences in the carcinogenic activities of such isomers and other 2-substituted tricycloquinazolines, have been deduced.