Synthesis of a novel category of Ugi adducts using succinic acid, succinic anhydride and maleic anhydride and their application in post-Ugi reactions for synthesis of functionalized piperazine 2,5-diones

A new category of bis- and tris-amides was synthesized using succinic acid, succinic anhydride and maleic anhydride in the Ugi reaction. It provides a simple approach for the synthesis of novel Ugi adducts with additional functional groups such as carboxylic acid, carboxamide and alpha,beta-unsaturated amide. In addition, post-condensation cyclization of Ugi adducts with maleic anhydride was performed in the presence of NaH to form functionalized piperazine 2,5-diones via intramolecular Michael addition reaction. (C) 2017 Elsevier Ltd. All rights reserved.