Pyrazole‐promoted synthesis of pyrrolo[3,4‐c] quinoline-1,3‐diones in a novel diketene-based reaction

We describe the first classic example of green synthesis pyrrolo[3,4-c]quinolones scaffolds by catalyst-free unusual reaction diketene, isatin, and primary amines in ethanol presence pyrazole as a promoter for 4 h. The whole structure new product was confirmed X-ray analysis. overall transformation involves cleavage generation multiple carbon-nitrogen carbon-carbon bonds. This report represents simple straightforward approach pyrrolo[3,4-c]quinoline-1,3-diones, which has significant advantages like readily available precursors, non-use toxic solvent, operational simplicity, mild conditions, good atom economy, excellent yields; therefore it provides sustainable strategy access to range interesting N -containing heterocyclic compounds medicinal organic chemistry.