Abstract: 3-Acyl-4-hydroxy-2(1H)-quinolones are obtained by hydrolytic ring opening and
subsequent decarboxylation from the corresponding pyrano[3,2-c]quinolin-2,5(6H)-diones, which
in turn are easily obtained from 1:2 condensation of anilines with diethyl malonate or 1:1
condensation of diethyl alkyl- or arylmalonates with 4-hydroxy-2(1H)-quinolones. Nitro-
pyranoquinolinediones furnish after ringopening 3-nitroacetyl-4-hydroxy-2(1)-quinolones.
Pyranoquinolines with acetyl- or aminosubstituents are hydrolyzed during basic ringopening
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