Synthesis of New Pyrano[2′,3′: 5,6]chromeno[4,3‐<i>b</i>]quinolin‐4‐ones <i>via</i> Aza‐<i>DielsAlder</i> Reaction

Abstract

Abstract New pyrano[2′,3′: 5,6]chromeno[4,3‐ b ]quinolin‐4‐ones have been synthesized by intramolecular aza‐ DielsAlder reaction of the azadienes generated in situ from aryl amines and 8‐formyl‐7‐(prop‐2‐ynyl)2,3‐disubstituted chromones using CuFe 2 O 4 nanoparticles as a catalyst in DMSO at 80–90° in good‐to‐excellent yields. Particularly valuable features of this methodology include simple implementation, inexpensive and reusable catalyst, and good yields. The structures were established by spectroscopic data and further confirmed by X‐ray diffraction analysis of one of the products.