SYNTHESIS OF 2,3-FUSED QUINOLINES FROM 3-SUBSTITUTED QUINOLINE 1-OXIDES .3. INTRAMOLECULAR CYCLIZATION OF QUINOLINE 1-OXIDES BEARING ACTIVEMETHYLENE GROUPS AT THE 3-POSITION IN THE PRESENCE OF ACETIC-ANHYDRIDE
Y. Miura et al., SYNTHESIS OF 2,3-FUSED QUINOLINES FROM 3-SUBSTITUTED QUINOLINE 1-OXIDES .3. INTRAMOLECULAR CYCLIZATION OF QUINOLINE 1-OXIDES BEARING ACTIVEMETHYLENE GROUPS AT THE 3-POSITION IN THE PRESENCE OF ACETIC-ANHYDRIDE, Heterocycles, 35(2), 1993, pp. 693-699
3-N-Alkylcyanoacetamidoquinoline 1-oxides (3a and 3c) react with Ac2O
at room temperature in chloroform to afford 1-alkyl-3-cyano-4H-pyrrolo
[3,2-b]quinolin-2-ones (4a and 4c). The cyclization of 3-N-alkylethoxy
carbonylacetamidoquinoline 1-oxides (3b and 3d) occurs upon heating wi
th Ac2O at 60-degrees-C. 3-(3,3-Dicyanopropoxy) quinoline 1-oxide (5)
also cyclizes to the pyranoquinoline (6) when treated with Ac2O at roo
m temperature in chloroform-DMF.