Synthesis of novel norsufentanil analogs via a four-component Ugi reaction and in vivo, docking, and QSAR studies of their analgesic activity.

Novel substituted amino acid tethered norsufentanil derivatives were synthesized by the four-component Ugi reaction. Norsufentanil was reacted with succinic anhydride to produce the corresponding carboxylic acid. The resulting carboxylic acid has undergone a multicomponent reaction with different aldehydes, amines, and isocyanides to produce a library of the desired compounds.