Abstract
Reactions of 4-aminoacridine-3-carbaldehyde with benzo[b]cycloalkanones and 3,4-dihydro-1(2H)-anthracenone afforded a series of corresponding 3,2'-polymethylene-2-phenylbenzo[b]-1,10-phenanthrolines and 3,3'-dimethylene-2-(naphth-2'-yl)benzo[b]-1,10-phenanthroline, respectively, as new N,N,C-terdentates. Dehydrogenation of dimethylene-bridged systems afforded the corresponding fully aromatized systems. Flexibility of annulated bridges is highly dependent on the length of the carbon chain, where tetramethylene-bridge is rigid enough to differentiate eight bridge protons in H-1 NMR time scale at room temperature.