5-Sulfosalicylic Acid Dihydrate-Catalyzed Multicomponent Synthesis of 3-(Arylamino)-Furan-2(5H)-ones

Abstract

This study explores an efficient one-pot, three-component synthesis of highly functionalized furan-2(5H)-one molecules using 5-sulfosalicylic acid dihydrate (5-SSA) as an organocatalyst. The reaction involves dimethyl acetylenedicarboxylate, amines, and arylaldehyde in ethanol under mild conditions achieving high yields (80%–96%) with short reaction times. 5-SSA in 10 mol% loading proved to be a superior catalyst compared to other tested organocatalysts offering a green and practical approach to synthesizing furan-2(5H)-one molecules. The catalyst activates arylaldehyde through protonation enhancing the nucleophilic attack of enamine. Additionally, it assists in the cyclization step by stabilizing intermediates leading to efficient product formation. The scope of the reaction was further investigated with various substituted amines and aldehydes, showing good functional group tolerance. We characterized the synthesized compounds using FTIR, NMR, and HRMS techniques. This methodology offers an environmentally friendly and efficient route for synthesizing furan-2(5H)-one heterocyclic compounds.