Synthesis of spiro[piperidine-4,3′-pyrrolo[3,4-c]quinolines via 1,3-dipolar cycloaddition of azomethine ylides and 3-Nitro-2(1H)-quinolones

The 1,3-dipolar cycloaddition of 3-nitro-2(1H)-quinolones and β-nitro-styrenes with azomethine ylides derived from sarcosine and benzyl 4-oxopiperidine-1-carboxylate have been investigated. The structure of the formed cycloadducts were studied in detail by X-ray diffraction and NMR spectroscopy methods. This process is a solid and versatile strategy for rapidly assembling quinoline fused pyrrolines scaffold with a spiropiperidine part containing orthogonal diversification points for further substitutions.