Synthesis of furoquinolines by a multicomponent domino process

Five bonds form in one pot, from three well-designed yet readily accessible substrates. Simply mixing an o-alkynyl aniline, e.g., 2-H2NC6H4C==CCO2Me, an aldehyde, e.g., heptanal, and ammonium chloride in toluene at room temp., followed by addn. of an isocyanoacetamide, e.g., PhCH2CH(CN)COR (R = morpholino), and heating to reflux, provides the polysubstituted furo[2,3-c]quinoline, e.g. I (same R), in good to excellent yield. [on SciFinder (R)]