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Synthesis of benzo‐halogenated 4‐hydroxy‐2(1 H )‐quinolones
Author(s) -
Kappe Thomas,
Karem Abdel S.,
Stadlbauer Wolfgang
Publication year - 1988
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570250330
Subject(s) - chemistry , yield (engineering) , phosphorus pentoxide , catalysis , medicinal chemistry , sulfonic acid , organic chemistry , metallurgy , materials science
Malondianilides 3 derived from dichloro substituted anilines 2 undergo cyclization to afford 4‐hydroxy‐2(1 H )‐quinolones 4 in very good yields using methane sulfonic acid‐phosphorus pentoxide as catalyst. 3,4‐Dichloro anilines 5 can be shown to yield two isomers, 7 and 8 , whereas 3‐substituted anilines 9 afford merely 7‐substituted 4‐hydroxy‐2(1 H )‐quinolones 11.