Trimesic Acid is a Suitable Building Block in Triple Four-Component Ugi Reaction: Access to Unique Trivalent Compounds

A triple four-component Ugi reaction of isocyanide, amine, aldehyde, and trimesic acid as the acid component with three acidic functional groups in MeOH at 65 °C has been disclosed. The process employs readily available and low-cost reagents, a convenient synthetic procedure, and mild reaction conditions for the synthesis of pharmacologically significant and structurally interesting compounds with several peptide groups, suitable for dendrimers and self-assembling. Substituents could be independently varied at three different positions. The structural assignments are supported by 1H and 13C NMR data.