Zur Reaktivität von C=N-Doppelbindungssystemen, VII. Synthesen von fluoreszierenden pyronokondensierten Heterocyclen / The Reactivity of the C=N-Double Bond Systems, VII. Syntheses of Condensed Pyronoheterocycles

Abstract

The combined action of orthoformate and aniline upon 4-hydroxy-coumarin yields anilinomethylene chromon-2,4-dione, which reacts with ethyl cyanoacetate in DMF in the presence of KOH to give the pyronocoumarine (6a). Pyronoquinolones are obtained in a similar way.