New modified pyrrole derivatives, namely tetrahydroindol-4-ones and pyrrolo2,3-dpyrimidines, functionalized at position 3, were synthesized through a one-pot multicomponent condensation. Stabilized dimedone enaminones derived from α-amino acids and their esters (or 6-amino-1,3-dimethyluracil), arylglyoxals, and methylene-active compounds (malononitrile, Meldrum's acid) were selected as key reagents for the reaction. Functionalization of 3-cyanoacetamides within the 4,5,6,7-tetrahydroindol-4-one framework was performed, involving transformations of the cyanoamide fragment, carbonyl group, and acetate residue at position 1 of the bicyclic system. The reactions proceeded under mild conditions, without the use of hazardous organic solvents or catalysts. Multicomponent condensation approach is particularly attractive for such syntheses, as it offers high atom economy, operational efficiency, and enables the rapid construction of structurally diverse and complex molecules in a single synthetic operation, thereby affording good yields with straightforward purification.
Marchenko et al. (Thu,) studied this question.