One-Pot Site-Selective Sonogashira Cross-Coupling–Heteroannulation of the 2-Aryl-6,8-Dibromoquinolin-4(1H)-Ones: Synthesis of Novel 6-H-Pyrrolo[3,2,1-ij]Quinolin-6-Ones

Crystal structure of 8-bromo-6-oxo-2-phenyl-6H-pyrrolo[3,2,1-ij]quinoline-5-carbaldehyde, C18H11BrNO2

C18H11BrNO2, orthorhombic, Pbcn (no. 60), a = 20.745(2) Å, b = 6.7956(8) Å, c = 20.470(3) Å, V = 2885.8(6) Å3, Z = 8, R gt(F) = 0.034, wR ref(F 2) = 0.0846, T = 173(2) K.

Vilsmeier-Haack reaction of 7-acetyl-2-arylindoles: a convenient method for the synthesis of 6-oxo-6H-pyrrolo[3,2,1-ij]quinoline-1,5-dicarbaldehydes

A simple and efficient method for the one-pot synthesis of novel 6-oxo-6H-pyrrolo[3,2,1-ij]quinoline-1,5-dicarbaldehydes via the Vilsmeier-Haack reaction of the corresponding 7-acetyl-2-arylindoles has been developed. The mechanism of this reaction is envisaged to involve initial C-3 formylation and subsequent diformylation at the acetyl group with the excess Vilsmeier-Haack reagent followed by heteroannulation of the six-membered ring with concomitant extrusion of dimethylamine to afford the 1,2,5,8-tetrasubstituted pyrroloquinolinones. The highlight of this method is the construction of carbon-carbon and carbon-nitrogen bonds in a single-pot operation to afford polycarbo-substituted pyrroloquinolinones.