Design and synthesis of 4-amino-2-phenylquinazolines as novel topoisomerase I inhibitors with molecular modeling

4-Amino-2-phenylquinazolines were designed as bioisosteres of 3-arylisoquinolinamines that were energy minimized to provide stable conformers. The 2-phenyl ring of 4-amino-2-phenylquinazolines was parallel to the quinazoline ring and improved their DNA intercalation ability in the DNA-topo I complex.