Novel ring contraction of 3-hydroxy-2,4(1H,3H)-quinolinediones in aqueous alkali. The first convenient route to 2-hydroxyindoxyls

Citation
S. Kafka et al., Novel ring contraction of 3-hydroxy-2,4(1H,3H)-quinolinediones in aqueous alkali. The first convenient route to 2-hydroxyindoxyls, J ORG CHEM, 66(19), 2001, pp. 6394-6399
Citations number
64
Categorie Soggetti
Chemistry & Analysis","Organic Chemistry/Polymer Science
Journal title
JOURNAL OF ORGANIC CHEMISTRY
ISSN journal
00223263 → ACNP
Volume
66
Issue
19
Year of publication
2001
Pages
6394 - 6399
Database
ISI
SICI code
0022-3263(20010921)66:19<6394:NRCO3I>2.0.ZU;2-7
Abstract
Ring contraction of 3-hydroxy-2,4(1H,3H)-quinolinediones (1) in aqueous pot assium hydroxide resulted in the formation of 2-hydroxyindoxyls and/or diox indoles. The choice of N-substituent and the reaction conditions govern the chemoselectivity of the reaction. N-Phenyl-substituted derivatives 1 give 2-hydroxyindoxyls, while N-alkyl- and N-benzyl-substituted derivatives affo rd the corresponding dioxindols. On the basis of byproduct analysis, as wel l as independent experiments, the most plausible reaction mechanism is prop osed.