Synthesis of polycyclic 3,3′-spirooxindoles and some new 2-arylquinoxalines from (E/Z)- 1-(2-oxo-2-arylethylidene)-5,6-dihydro-4H-pyrrolo[3,2,1-ij]quinolin-2(1H)-ones

p-Toluenesulfonic acid-promoted organic transformations for the generation of molecular complexity

“…Baradarani and co-workers reported the synthesis of a series of polycyclic 3,3′-spirooxindoles via cyclocondensation of 1-(2-oxo-2-arylethylidene)-5,6-dihydro-4 H -pyrrolo[3,2,1- ij ]quinolin-2(1 H )-ones with aliphatic-1,2-diamines (Scheme 76). 123 Reactions performed in the presence of p -TSA under reflux conditions in ethanol as solvent afforded the corresponding polycyclic spirooxindoles in good yields without column chromatographic purification.…”