Electronic study of receptor binding of analgesic aryl moiety II: Prodine analogs

Analogs of the prodine analgesics were prepared and tested for analgesic activity. A good correlation seems to exist between the energy level of the highest occupied molecular orbital and biological activity. The energy level of the highest occupied molecular orbital of the aryl moiety of these analogs may permit a charge transfer interaction between the aryl groups of the analgesic molecules and their receptors with the aryl groups acting as charge donors.