Studies on quinoline derivatives and related compounds. 1. A new synthesis of 1??alkyl??1, 4??dihydro??4??oxo??3??quinolinecarboxylic acids

H Agui, T Mitani, M Nakashita…

Index: Agui,H. et al. Journal of Heterocyclic Chemistry, 1971 , vol. 8, p. 357 - 365

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Citation Number: 33

Abstract

Abstract A novel preparative method for 1-alkyl-1, 4-dihydro-4-oxo-3-quinolinecarboxylic acids was developed. The key process is the cyclization of N- alkylanilinomethylenemalonales, which was effected successfully in the presence of polyphosphoric acid, polyphosphate ester, boron tri-fluoride or a mixture of acetic anhydride and sulfuric acid. With phosphorus oxychloride, N-alkylanilinomethylenemalonates ...