Environmentally friendly domino multicomponent strategy for the synthesis of pyrroloquinolinone hybrid heterocycles.

An efficient and elegant assembly of pyrene/aryl fused pyrrolo[2,3- b ]quinolinone and pyrrolizino[3,2- b ]quinolinone hybrid heterocycles was achieved via a domino multicomponent reaction strategy using a solid state melt reaction (SSMR) condition. The 1,3-dipole component was generated in situ from N -methylgylcine/l-proline and isatin, while the Baylis-Hillman adduct prepared from pyrene-1-carbaldehyde and various benzaldehydes is used as the dipolarophile. The domino protocol comprises 1,3-dipolar cycloaddition and a consequent double annulation reaction process. The advantages of this cascade protocol include environmentally friendly conditions, the avoidance of toxic organic solvents, simple work-up and good to excellent product yields.