Solid-phase synthesis of imidazoquinazolinone derivatives with three-point diversity

A novel imidazoquinazolinone-based tricyclic structure with three-point diversity has been synthesized using solid-phase methodology. The compounds were obtained by treating the amino group of polymer-linked amino acids with 2-nitrobenzaldehyde followed by reduction of the nitro group to an amine. Derivatization of amine with isothiocyanates and cyclization of the resulting thioureas with DIC followed by acidolytic cleavage yielded the desired imidazoquinazolinone based compounds in high purity and moderate to high yield.